inital

2024-05-22 14:55:29 +08:00 · 2024-05-22 14:55:29 +08:00 · 5037405615
commit 5037405615
349 changed files with 33724 additions and 0 deletions
--- a/llvm/10/clang/compiler-rt-baremetal.patch
+++ b/llvm/10/clang/compiler-rt-baremetal.patch
@ -0,0 +1,53 @@
+Index: lib/Driver/ToolChains/BareMetal.cpp
+===================================================================
+--- a/lib/Driver/ToolChains/BareMetal.cpp
+++ b/lib/Driver/ToolChains/BareMetal.cpp
+@@ -157,7 +157,7 @@
+ void BareMetal::AddLinkRuntimeLib(const ArgList &Args,
+                                   ArgStringList &CmdArgs) const {
+   CmdArgs.push_back(Args.MakeArgString("-lclang_rt.builtins-" +
+-                                       getTriple().getArchName() + ".a"));
+                                       getTriple().getArchName()));
+ }
+ 
+ void baremetal::Linker::ConstructJob(Compilation &C, const JobAction &JA,
+Index: test/Driver/baremetal.cpp
+===================================================================
+--- a/test/Driver/baremetal.cpp
+++ b/test/Driver/baremetal.cpp
+@@ -13,7 +13,7 @@
+ // CHECK-V6M-C-NEXT: "{{[^"]*}}ld{{(\.(lld|bfd|gold))?}}{{(\.exe)?}}" "{{.*}}.o" "-Bstatic"
+ // CHECK-V6M-C-SAME: "-L[[RESOURCE_DIR:[^"]+]]{{[/\\]+}}lib{{[/\\]+}}baremetal"
+ // CHECK-V6M-C-SAME: "-T" "semihosted.lds" "-Lsome{{[/\\]+}}directory{{[/\\]+}}user{{[/\\]+}}asked{{[/\\]+}}for"
+-// CHECK-V6M-C-SAME: "-lc" "-lm" "-lclang_rt.builtins-armv6m.a"
+// CHECK-V6M-C-SAME: "-lc" "-lm" "-lclang_rt.builtins-armv6m"
+ // CHECK-V6M-C-SAME: "-o" "{{.*}}.o"
+ 
+ // RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+@@ -35,7 +35,7 @@
+ // CHECK-V6M-DEFAULTCXX: "{{[^"]*}}ld{{(\.(lld|bfd|gold))?}}{{(\.exe)?}}" "{{.*}}.o" "-Bstatic"
+ // CHECK-V6M-DEFAULTCXX-SAME: "-L{{[^"]*}}{{[/\\]+}}lib{{(64)?}}{{[/\\]+}}clang{{[/\\]+}}{{.*}}{{[/\\]+}}lib{{[/\\]+}}baremetal"
+ // CHECK-V6M-DEFAULTCXX-SAME: "-lc++" "-lc++abi" "-lunwind"
+-// CHECK-V6M-DEFAULTCXX-SAME: "-lc" "-lm" "-lclang_rt.builtins-armv6m.a"
+// CHECK-V6M-DEFAULTCXX-SAME: "-lc" "-lm" "-lclang_rt.builtins-armv6m"
+ // CHECK-V6M-DEFAULTCXX-SAME: "-o" "{{.*}}.o"
+ 
+ // RUN: %clangxx -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+@@ -48,7 +48,7 @@
+ // CHECK-V6M-LIBCXX: "{{[^"]*}}ld{{(\.(lld|bfd|gold))?}}{{(\.exe)?}}" "{{.*}}.o" "-Bstatic"
+ // CHECK-V6M-LIBCXX-SAME: "-L{{[^"]*}}{{[/\\]+}}lib{{(64)?}}{{[/\\]+}}clang{{[/\\]+}}{{.*}}{{[/\\]+}}lib{{[/\\]+}}baremetal"
+ // CHECK-V6M-LIBCXX-SAME: "-lc++" "-lc++abi" "-lunwind"
+-// CHECK-V6M-LIBCXX-SAME: "-lc" "-lm" "-lclang_rt.builtins-armv6m.a"
+// CHECK-V6M-LIBCXX-SAME: "-lc" "-lm" "-lclang_rt.builtins-armv6m"
+ // CHECK-V6M-LIBCXX-SAME: "-o" "{{.*}}.o"
+ 
+ // RUN: %clangxx -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+@@ -61,7 +61,7 @@
+ // CHECK-V6M-LIBSTDCXX: "{{[^"]*}}ld{{(\.(lld|bfd|gold))?}}{{(\.exe)?}}" "{{.*}}.o" "-Bstatic"
+ // CHECK-V6M-LIBSTDCXX-SAME: "-L{{[^"]*}}{{[/\\]+}}lib{{(64)?}}{{[/\\]+}}clang{{[/\\]+}}{{.*}}{{[/\\]+}}lib{{[/\\]+}}baremetal"
+ // CHECK-V6M-LIBSTDCXX-SAME: "-lstdc++" "-lsupc++" "-lunwind"
+-// CHECK-V6M-LIBSTDCXX-SAME: "-lc" "-lm" "-lclang_rt.builtins-armv6m.a"
+// CHECK-V6M-LIBSTDCXX-SAME: "-lc" "-lm" "-lclang_rt.builtins-armv6m"
+ // CHECK-V6M-LIBSTDCXX-SAME: "-o" "{{.*}}.o"
+ 
+ // RUN: %clangxx -no-canonical-prefixes %s -### -o %t.o 2>&1 \
--- a/llvm/10/clang/default.nix
+++ b/llvm/10/clang/default.nix
@ -0,0 +1,133 @@
+{ lib, stdenv, llvm_meta, fetch, substituteAll, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
+, buildLlvmTools
+, fixDarwinDylibNames
+, enableManpages ? false
+}:
+
+let
+  self = stdenv.mkDerivation ({
+    pname = "clang";
+    inherit version;
+
+    src = fetch "clang" "091bvcny2lh32zy8f3m9viayyhb2zannrndni7325rl85cwgr6pr";
+
+    unpackPhase = ''
+      unpackFile $src
+      mv clang-${version}* clang
+      sourceRoot=$PWD/clang
+      unpackFile ${clang-tools-extra_src}
+      mv clang-tools-extra-* $sourceRoot/tools/extra
+    '';
+
+    nativeBuildInputs = [ cmake python3 ]
+      ++ lib.optional enableManpages python3.pkgs.sphinx
+      ++ lib.optional stdenv.hostPlatform.isDarwin fixDarwinDylibNames;
+
+    buildInputs = [ libxml2 libllvm ];
+
+    cmakeFlags = [
+      "-DCLANGD_BUILD_XPC=OFF"
+      "-DLLVM_ENABLE_RTTI=ON"
+    ] ++ lib.optionals enableManpages [
+      "-DCLANG_INCLUDE_DOCS=ON"
+      "-DLLVM_ENABLE_SPHINX=ON"
+      "-DSPHINX_OUTPUT_MAN=ON"
+      "-DSPHINX_OUTPUT_HTML=OFF"
+      "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
+    ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+      "-DLLVM_TABLEGEN_EXE=${buildLlvmTools.llvm}/bin/llvm-tblgen"
+      "-DCLANG_TABLEGEN=${buildLlvmTools.libclang.dev}/bin/clang-tblgen"
+    ];
+
+    patches = [
+      ./purity.patch
+      # https://reviews.llvm.org/D51899
+      ./compiler-rt-baremetal.patch
+      ./gnu-install-dirs.patch
+      (substituteAll {
+        src = ../../clang-6-10-LLVMgold-path.patch;
+        libllvmLibdir = "${libllvm.lib}/lib";
+      })
+    ];
+
+    postPatch = ''
+      sed -i -e 's/DriverArgs.hasArg(options::OPT_nostdlibinc)/true/' \
+             -e 's/Args.hasArg(options::OPT_nostdlibinc)/true/' \
+             lib/Driver/ToolChains/*.cpp
+    '' + lib.optionalString stdenv.hostPlatform.isMusl ''
+      sed -i -e 's/lgcc_s/lgcc_eh/' lib/Driver/ToolChains/*.cpp
+    '' + lib.optionalString stdenv.hostPlatform.isDarwin ''
+      substituteInPlace tools/extra/clangd/CMakeLists.txt \
+        --replace "NOT HAVE_CXX_ATOMICS64_WITHOUT_LIB" FALSE
+    '';
+
+    outputs = [ "out" "lib" "dev" "python" ];
+
+    postInstall = ''
+      ln -sv $out/bin/clang $out/bin/cpp
+
+      # Move libclang to 'lib' output
+      moveToOutput "lib/libclang.*" "$lib"
+      moveToOutput "lib/libclang-cpp.*" "$lib"
+      substituteInPlace $out/lib/cmake/clang/ClangTargets-release.cmake \
+          --replace "\''${_IMPORT_PREFIX}/lib/libclang." "$lib/lib/libclang." \
+          --replace "\''${_IMPORT_PREFIX}/lib/libclang-cpp." "$lib/lib/libclang-cpp."
+
+      mkdir -p $python/bin $python/share/{clang,scan-view}
+      mv $out/bin/{git-clang-format,scan-view} $python/bin
+      if [ -e $out/bin/set-xcode-analyzer ]; then
+        mv $out/bin/set-xcode-analyzer $python/bin
+      fi
+      mv $out/share/clang/*.py $python/share/clang
+      mv $out/share/scan-view/*.py $python/share/scan-view
+      rm $out/bin/c-index-test
+      patchShebangs $python/bin
+
+      mkdir -p $dev/bin
+      cp bin/clang-tblgen $dev/bin
+    '';
+
+    passthru = {
+      inherit libllvm;
+      isClang = true;
+      hardeningUnsupportedFlags = [ "fortify3" ];
+    };
+
+    meta = llvm_meta // {
+      homepage = "https://clang.llvm.org/";
+      description = "A C language family frontend for LLVM";
+      longDescription = ''
+        The Clang project provides a language front-end and tooling
+        infrastructure for languages in the C language family (C, C++, Objective
+        C/C++, OpenCL, CUDA, and RenderScript) for the LLVM project.
+        It aims to deliver amazingly fast compiles, extremely useful error and
+        warning messages and to provide a platform for building great source
+        level tools. The Clang Static Analyzer and clang-tidy are tools that
+        automatically find bugs in your code, and are great examples of the sort
+        of tools that can be built using the Clang frontend as a library to
+        parse C/C++ code.
+      '';
+      mainProgram = "clang";
+    };
+  } // lib.optionalAttrs enableManpages {
+    pname = "clang-manpages";
+
+    buildPhase = ''
+      make docs-clang-man
+    '';
+
+    installPhase = ''
+      mkdir -p $out/share/man/man1
+      # Manually install clang manpage
+      cp docs/man/*.1 $out/share/man/man1/
+    '';
+
+    outputs = [ "out" ];
+
+    doCheck = false;
+
+    meta = llvm_meta // {
+      description = "man page for Clang ${version}";
+    };
+  });
+in self
--- a/llvm/10/clang/gnu-install-dirs.patch
+++ b/llvm/10/clang/gnu-install-dirs.patch
@ -0,0 +1,248 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index dc1413f4b597..c173531e624f 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -9,6 +9,8 @@ endif()
+ if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
+   project(Clang)
+ 
+  include(GNUInstallDirs)
+
+   # Rely on llvm-config.
+   set(CONFIG_OUTPUT)
+   if(LLVM_CONFIG)
+@@ -417,7 +419,7 @@ include_directories(BEFORE
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/clang include/clang-c
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT clang-headers
+     FILES_MATCHING
+     PATTERN "*.def"
+@@ -427,7 +429,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+     )
+ 
+   install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/clang
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT clang-headers
+     FILES_MATCHING
+     PATTERN "CMakeFiles" EXCLUDE
+@@ -447,7 +449,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+ 
+   add_custom_target(bash-autocomplete DEPENDS utils/bash-autocomplete.sh)
+   install(PROGRAMS utils/bash-autocomplete.sh
+-          DESTINATION share/clang
+          DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+           COMPONENT bash-autocomplete)
+   if(NOT LLVM_ENABLE_IDE)
+     add_llvm_install_targets(install-bash-autocomplete
+diff --git a/cmake/modules/AddClang.cmake b/cmake/modules/AddClang.cmake
+index 577cc11ab015..a4f4481d8442 100644
+--- a/cmake/modules/AddClang.cmake
+++ b/cmake/modules/AddClang.cmake
+@@ -114,9 +114,9 @@ macro(add_clang_library name)
+       install(TARGETS ${name}
+         COMPONENT ${name}
+         ${export_to_clangtargets}
+-        LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-        ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-        RUNTIME DESTINATION bin)
+        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+        RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+ 
+       if (NOT LLVM_ENABLE_IDE)
+         add_llvm_install_targets(install-${name}
+@@ -160,7 +160,7 @@ macro(add_clang_tool name)
+ 
+     install(TARGETS ${name}
+       ${export_to_clangtargets}
+-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+       COMPONENT ${name})
+ 
+     if(NOT LLVM_ENABLE_IDE)
+@@ -175,7 +175,7 @@ endmacro()
+ macro(add_clang_symlink name dest)
+   add_llvm_tool_symlink(${name} ${dest} ALWAYS_GENERATE)
+   # Always generate install targets
+-  llvm_install_symlink(${name} ${dest} ALWAYS_GENERATE)
+  llvm_install_symlink(${name} ${dest} ${CMAKE_INSTALL_FULL_BINDIR} ALWAYS_GENERATE)
+ endmacro()
+ 
+ function(clang_target_link_libraries target type)
+diff --git a/lib/Headers/CMakeLists.txt b/lib/Headers/CMakeLists.txt
+index 85c3124234ad..64c48235d914 100644
+--- a/lib/Headers/CMakeLists.txt
+++ b/lib/Headers/CMakeLists.txt
+@@ -191,7 +191,7 @@ set_target_properties(clang-resource-headers PROPERTIES
+   FOLDER "Misc"
+   RUNTIME_OUTPUT_DIRECTORY "${output_dir}")
+ 
+-set(header_install_dir lib${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION}/include)
+set(header_install_dir ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION}/include)
+ 
+ install(
+   FILES ${files} ${generated_files}
+diff --git a/tools/c-index-test/CMakeLists.txt b/tools/c-index-test/CMakeLists.txt
+index ceef4b08637c..8efad5520ca4 100644
+--- a/tools/c-index-test/CMakeLists.txt
+++ b/tools/c-index-test/CMakeLists.txt
+@@ -54,7 +54,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+     set_property(TARGET c-index-test APPEND PROPERTY INSTALL_RPATH
+        "@executable_path/../../lib")
+   else()
+-    set(INSTALL_DESTINATION bin)
+    set(INSTALL_DESTINATION ${CMAKE_INSTALL_BINDIR})
+   endif()
+ 
+   install(TARGETS c-index-test
+diff --git a/tools/clang-format/CMakeLists.txt b/tools/clang-format/CMakeLists.txt
+index 35ecdb11253c..d77d75de0094 100644
+--- a/tools/clang-format/CMakeLists.txt
+++ b/tools/clang-format/CMakeLists.txt
+@@ -21,20 +21,20 @@ if( LLVM_LIB_FUZZING_ENGINE OR LLVM_USE_SANITIZE_COVERAGE )
+ endif()
+ 
+ install(PROGRAMS clang-format-bbedit.applescript
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format-diff.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format-sublime.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format.el
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS git-clang-format
+-  DESTINATION bin
+  DESTINATION ${CMAKE_INSTALL_BINDIR}
+   COMPONENT clang-format)
+diff --git a/tools/clang-rename/CMakeLists.txt b/tools/clang-rename/CMakeLists.txt
+index cda8e29ec5b1..0134d8ccd70b 100644
+--- a/tools/clang-rename/CMakeLists.txt
+++ b/tools/clang-rename/CMakeLists.txt
+@@ -19,8 +19,8 @@ clang_target_link_libraries(clang-rename
+   )
+ 
+ install(PROGRAMS clang-rename.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-rename)
+ install(PROGRAMS clang-rename.el
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-rename)
+diff --git a/tools/diagtool/CMakeLists.txt b/tools/diagtool/CMakeLists.txt
+index a95444be40ee..136d96d9bf5b 100644
+--- a/tools/diagtool/CMakeLists.txt
+++ b/tools/diagtool/CMakeLists.txt
+@@ -21,7 +21,7 @@ clang_target_link_libraries(diagtool
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(TARGETS diagtool
+     COMPONENT diagtool
+-    RUNTIME DESTINATION bin)
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+ 
+   if (NOT LLVM_ENABLE_IDE)
+     add_llvm_install_targets(install-diagtool
+diff --git a/tools/libclang/CMakeLists.txt b/tools/libclang/CMakeLists.txt
+index 973655361f71..0181002e4e3b 100644
+--- a/tools/libclang/CMakeLists.txt
+++ b/tools/libclang/CMakeLists.txt
+@@ -141,7 +141,7 @@ endif()
+ if(INTERNAL_INSTALL_PREFIX)
+   set(LIBCLANG_HEADERS_INSTALL_DESTINATION "${INTERNAL_INSTALL_PREFIX}/include")
+ else()
+-  set(LIBCLANG_HEADERS_INSTALL_DESTINATION include)
+  set(LIBCLANG_HEADERS_INSTALL_DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+ endif()
+ 
+ install(DIRECTORY ../../include/clang-c
+@@ -172,7 +172,7 @@ foreach(PythonVersion ${CLANG_PYTHON_BINDINGS_VERSIONS})
+           COMPONENT
+             libclang-python-bindings
+           DESTINATION
+-            "lib${LLVM_LIBDIR_SUFFIX}/python${PythonVersion}/site-packages")
+            "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/python${PythonVersion}/site-packages")
+ endforeach()
+ if(NOT LLVM_ENABLE_IDE)
+   add_custom_target(libclang-python-bindings)
+diff --git a/tools/scan-build/CMakeLists.txt b/tools/scan-build/CMakeLists.txt
+index 28241245fcb7..d6b59f02fc2a 100644
+--- a/tools/scan-build/CMakeLists.txt
+++ b/tools/scan-build/CMakeLists.txt
+@@ -42,7 +42,7 @@ if(CLANG_INSTALL_SCANBUILD)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bin/${BinFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/bin/${BinFile})
+     install(PROGRAMS bin/${BinFile}
+-            DESTINATION bin
+            DESTINATION ${CMAKE_INSTALL_BINDIR}
+             COMPONENT scan-build)
+   endforeach()
+ 
+@@ -56,7 +56,7 @@ if(CLANG_INSTALL_SCANBUILD)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/libexec/${LibexecFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/libexec/${LibexecFile})
+     install(PROGRAMS libexec/${LibexecFile}
+-            DESTINATION libexec
+            DESTINATION ${CMAKE_INSTALL_LIBEXECDIR}
+             COMPONENT scan-build)
+   endforeach()
+ 
+@@ -84,7 +84,7 @@ if(CLANG_INSTALL_SCANBUILD)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/share/scan-build/${ShareFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/share/scan-build/${ShareFile})
+     install(FILES share/scan-build/${ShareFile}
+-            DESTINATION share/scan-build
+            DESTINATION ${CMAKE_INSTALL_DATADIR}/scan-build
+             COMPONENT scan-build)
+   endforeach()
+ 
+diff --git a/tools/scan-view/CMakeLists.txt b/tools/scan-view/CMakeLists.txt
+index 22edb974bac7..9f140a9a4538 100644
+--- a/tools/scan-view/CMakeLists.txt
+++ b/tools/scan-view/CMakeLists.txt
+@@ -22,7 +22,7 @@ if(CLANG_INSTALL_SCANVIEW)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bin/${BinFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/bin/${BinFile})
+     install(PROGRAMS bin/${BinFile}
+-            DESTINATION bin
+            DESTINATION ${CMAKE_INSTALL_BINDIR}
+             COMPONENT scan-view)
+   endforeach()
+ 
+@@ -36,7 +36,7 @@ if(CLANG_INSTALL_SCANVIEW)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/share/${ShareFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/share/scan-view/${ShareFile})
+     install(FILES share/${ShareFile}
+-            DESTINATION share/scan-view
+            DESTINATION ${CMAKE_INSTALL_DATADIR}/scan-view
+             COMPONENT scan-view)
+   endforeach()
+ 
+diff --git a/utils/hmaptool/CMakeLists.txt b/utils/hmaptool/CMakeLists.txt
+index 62f2de0cb15c..6aa66825b6ec 100644
+--- a/utils/hmaptool/CMakeLists.txt
+++ b/utils/hmaptool/CMakeLists.txt
+@@ -10,7 +10,7 @@ add_custom_command(OUTPUT ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin/${CLANG_HM
+ 
+ list(APPEND Depends ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin/${CLANG_HMAPTOOL})
+ install(PROGRAMS ${CLANG_HMAPTOOL}
+-        DESTINATION bin
+        DESTINATION ${CMAKE_INSTALL_BINDIR}
+         COMPONENT hmaptool)
+ 
+ add_custom_target(hmaptool ALL DEPENDS ${Depends})
--- a/llvm/10/clang/purity.patch
+++ b/llvm/10/clang/purity.patch
@ -0,0 +1,30 @@
+From 4add81bba40dcec62c4ea4481be8e35ac53e89d8 Mon Sep 17 00:00:00 2001
+From: Will Dietz <w@wdtz.org>
+Date: Thu, 18 May 2017 11:56:12 -0500
+Subject: [PATCH] "purity" patch for 5.0
+
+---
+ lib/Driver/ToolChains/Gnu.cpp | 7 -------
+ 1 file changed, 7 deletions(-)
+
+diff --git a/lib/Driver/ToolChains/Gnu.cpp b/lib/Driver/ToolChains/Gnu.cpp
+index fe3c0191bb..c6a482bece 100644
+--- a/lib/Driver/ToolChains/Gnu.cpp
+++ b/lib/Driver/ToolChains/Gnu.cpp
+@@ -494,13 +494,6 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
+   if (!IsStatic) {
+     if (Args.hasArg(options::OPT_rdynamic))
+       CmdArgs.push_back("-export-dynamic");
+-
+-    if (!Args.hasArg(options::OPT_shared) && !IsStaticPIE) {
+-      const std::string Loader =
+-          D.DyldPrefix + ToolChain.getDynamicLinker(Args);
+-      CmdArgs.push_back("-dynamic-linker");
+-      CmdArgs.push_back(Args.MakeArgString(Loader));
+-    }
+   }
+ 
+   CmdArgs.push_back("-o");
+-- 
+2.11.0
+
--- a/llvm/10/compiler-rt/X86-support-extension.patch
+++ b/llvm/10/compiler-rt/X86-support-extension.patch
@ -0,0 +1,23 @@
+diff --git a/lib/builtins/CMakeLists.txt b/lib/builtins/CMakeLists.txt
+index 3a66dd9c3fb..7efc85d9f9f 100644
+--- a/lib/builtins/CMakeLists.txt
+++ b/lib/builtins/CMakeLists.txt
+@@ -301,6 +301,10 @@ if (NOT MSVC)
+     i386/umoddi3.S
+   )
+ 
+  set(i486_SOURCES ${i386_SOURCES})
+  set(i586_SOURCES ${i386_SOURCES})
+  set(i686_SOURCES ${i386_SOURCES})
+
+   if (WIN32)
+     set(i386_SOURCES
+       ${i386_SOURCES}
+@@ -608,6 +612,7 @@ else ()
+   endif()
+ 
+   foreach (arch ${BUILTIN_SUPPORTED_ARCH})
+      message("arch: ${arch}")
+     if (CAN_TARGET_${arch})
+       # For ARM archs, exclude any VFP builtins if VFP is not supported
+       if (${arch} MATCHES "^(arm|armhf|armv7|armv7s|armv7k|armv7m|armv7em)$")
--- a/llvm/10/compiler-rt/armv7l.patch
+++ b/llvm/10/compiler-rt/armv7l.patch
@ -0,0 +1,32 @@
+diff -ur compiler-rt-10.0.0.src/cmake/builtin-config-ix.cmake compiler-rt-10.0.0.src-patched/cmake/builtin-config-ix.cmake
+--- compiler-rt-10.0.0.src/cmake/builtin-config-ix.cmake	2020-03-24 00:01:02.000000000 +0900
+++ compiler-rt-10.0.0.src-patched/cmake/builtin-config-ix.cmake	2020-05-10 03:42:00.883450706 +0900
+@@ -24,7 +24,7 @@
+ 
+ 
+ set(ARM64 aarch64)
+-set(ARM32 arm armhf armv6m armv7m armv7em armv7 armv7s armv7k)
+set(ARM32 arm armhf armv6m armv7m armv7em armv7 armv7s armv7k armv7l)
+ set(HEXAGON hexagon)
+ set(X86 i386)
+ set(X86_64 x86_64)
+diff -ur compiler-rt-10.0.0.src/lib/builtins/CMakeLists.txt compiler-rt-10.0.0.src-patched/lib/builtins/CMakeLists.txt
+--- compiler-rt-10.0.0.src/lib/builtins/CMakeLists.txt	2020-03-24 00:01:02.000000000 +0900
+++ compiler-rt-10.0.0.src-patched/lib/builtins/CMakeLists.txt	2020-05-10 03:44:49.468579650 +0900
+@@ -474,6 +474,7 @@
+ set(armv7_SOURCES ${arm_SOURCES})
+ set(armv7s_SOURCES ${arm_SOURCES})
+ set(armv7k_SOURCES ${arm_SOURCES})
+set(armv7l_SOURCES ${arm_SOURCES})
+ set(arm64_SOURCES ${aarch64_SOURCES})
+ 
+ # macho_embedded archs
+@@ -595,7 +596,7 @@
+   foreach (arch ${BUILTIN_SUPPORTED_ARCH})
+     if (CAN_TARGET_${arch})
+       # For ARM archs, exclude any VFP builtins if VFP is not supported
+-      if (${arch} MATCHES "^(arm|armhf|armv7|armv7s|armv7k|armv7m|armv7em)$")
+      if (${arch} MATCHES "^(arm|armhf|armv7|armv7s|armv7k|armv7l|armv7m|armv7em)$")
+         string(REPLACE ";" " " _TARGET_${arch}_CFLAGS "${TARGET_${arch}_CFLAGS}")
+         check_compile_definition(__VFP_FP__ "${CMAKE_C_FLAGS} ${_TARGET_${arch}_CFLAGS}" COMPILER_RT_HAS_${arch}_VFP)
+         if(NOT COMPILER_RT_HAS_${arch}_VFP)
--- a/llvm/10/compiler-rt/default.nix
+++ b/llvm/10/compiler-rt/default.nix
@ -0,0 +1,131 @@
+{ lib, stdenv, llvm_meta, version, fetch, cmake, python3, libllvm, libcxxabi, libxcrypt
+, doFakeLibgcc ? stdenv.hostPlatform.isFreeBSD
+}:
+
+let
+
+  useLLVM = stdenv.hostPlatform.useLLVM or false;
+  bareMetal = stdenv.hostPlatform.parsed.kernel.name == "none";
+  haveLibc = stdenv.cc.libc != null;
+  inherit (stdenv.hostPlatform) isMusl;
+
+in
+
+stdenv.mkDerivation {
+  pname = "compiler-rt" + lib.optionalString (haveLibc) "-libc";
+  inherit version;
+  src = fetch "compiler-rt" "1yjqjri753w0fzmxcyz687nvd97sbc9rsqrxzpq720na47hwh3fr";
+
+  nativeBuildInputs = [ cmake python3 libllvm.dev ];
+  buildInputs = lib.optional stdenv.hostPlatform.isDarwin libcxxabi;
+
+  env.NIX_CFLAGS_COMPILE = toString [
+    "-DSCUDO_DEFAULT_OPTIONS=DeleteSizeMismatch=0:DeallocationTypeMismatch=0"
+  ];
+
+  cmakeFlags = [
+    "-DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON"
+    "-DCMAKE_C_COMPILER_TARGET=${stdenv.hostPlatform.config}"
+    "-DCMAKE_ASM_COMPILER_TARGET=${stdenv.hostPlatform.config}"
+  ] ++ lib.optionals (haveLibc && stdenv.hostPlatform.isGnu) [
+    "-DSANITIZER_COMMON_CFLAGS=-I${libxcrypt}/include"
+  ] ++ lib.optionals (useLLVM || bareMetal || isMusl) [
+    "-DCOMPILER_RT_BUILD_SANITIZERS=OFF"
+    "-DCOMPILER_RT_BUILD_XRAY=OFF"
+    "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
+  ] ++ lib.optionals (useLLVM || bareMetal) [
+    "-DCOMPILER_RT_BUILD_PROFILE=OFF"
+  ] ++ lib.optionals ((useLLVM || bareMetal) && !haveLibc) [
+    "-DCMAKE_C_COMPILER_WORKS=ON"
+    "-DCMAKE_CXX_COMPILER_WORKS=ON"
+    "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
+    "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
+  ] ++ lib.optionals (useLLVM) [
+    "-DCOMPILER_RT_BUILD_BUILTINS=ON"
+    #https://stackoverflow.com/questions/53633705/cmake-the-c-compiler-is-not-able-to-compile-a-simple-test-program
+    "-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY"
+  ] ++ lib.optionals (bareMetal) [
+    "-DCOMPILER_RT_OS_DIR=baremetal"
+  ] ++ lib.optionals (stdenv.hostPlatform.isDarwin) [
+    "-DDARWIN_macosx_OVERRIDE_SDK_VERSION=ON"
+    "-DDARWIN_osx_ARCHS=${stdenv.hostPlatform.darwinArch}"
+    "-DDARWIN_osx_BUILTIN_ARCHS=${stdenv.hostPlatform.darwinArch}"
+  ];
+
+  outputs = [ "out" "dev" ];
+
+  patches = [
+    ../../common/compiler-rt/7-12-codesign.patch # Revert compiler-rt commit that makes codesign mandatory
+    ./find-darwin-sdk-version.patch # don't test for macOS being >= 10.15
+    ./gnu-install-dirs.patch
+    ../../common/compiler-rt/libsanitizer-no-cyclades-11.patch
+    ./X86-support-extension.patch # backported from LLVM 11
+    # Fix build on armv6l
+    ../../common/compiler-rt/armv6-mcr-dmb.patch
+    ../../common/compiler-rt/armv6-sync-ops-no-thumb.patch
+    ../../common/compiler-rt/armv6-no-ldrexd-strexd.patch
+  ] ++ lib.optional stdenv.hostPlatform.isAarch32 ./armv7l.patch;
+
+  # TSAN requires XPC on Darwin, which we have no public/free source files for. We can depend on the Apple frameworks
+  # to get it, but they're unfree. Since LLVM is rather central to the stdenv, we patch out TSAN support so that Hydra
+  # can build this. If we didn't do it, basically the entire nixpkgs on Darwin would have an unfree dependency and we'd
+  # get no binary cache for the entire platform. If you really find yourself wanting the TSAN, make this controllable by
+  # a flag and turn the flag off during the stdenv build.
+  postPatch = lib.optionalString (!stdenv.isDarwin) ''
+    substituteInPlace cmake/builtin-config-ix.cmake \
+      --replace 'set(X86 i386)' 'set(X86 i386 i486 i586 i686)'
+    substituteInPlace cmake/config-ix.cmake \
+      --replace 'set(X86 i386)' 'set(X86 i386 i486 i586 i686)'
+  '' + lib.optionalString stdenv.isDarwin ''
+    substituteInPlace cmake/config-ix.cmake \
+      --replace 'set(COMPILER_RT_HAS_TSAN TRUE)' 'set(COMPILER_RT_HAS_TSAN FALSE)'
+  '' + lib.optionalString (useLLVM) ''
+    substituteInPlace lib/builtins/int_util.c \
+      --replace "#include <stdlib.h>" ""
+    substituteInPlace lib/builtins/clear_cache.c \
+      --replace "#include <assert.h>" ""
+    substituteInPlace lib/builtins/cpu_model.c \
+      --replace "#include <assert.h>" ""
+  '';
+
+  preConfigure = lib.optionalString (useLLVM && !haveLibc) ''
+    cmakeFlagsArray+=(-DCMAKE_C_FLAGS="-nodefaultlibs -ffreestanding")
+  '';
+
+  # Hack around weird upsream RPATH bug
+  postInstall = lib.optionalString (stdenv.hostPlatform.isDarwin || stdenv.hostPlatform.isWasm) ''
+    ln -s "$out/lib"/*/* "$out/lib"
+  '' + lib.optionalString (useLLVM) ''
+    ln -s $out/lib/*/clang_rt.crtbegin-*.o $out/lib/crtbegin.o
+    ln -s $out/lib/*/clang_rt.crtend-*.o $out/lib/crtend.o
+    ln -s $out/lib/*/clang_rt.crtbegin-*.o $out/lib/crtbeginS.o
+    ln -s $out/lib/*/clang_rt.crtend-*.o $out/lib/crtendS.o
+    ln -s $out/lib/*/clang_rt.crtbegin_shared-*.o $out/lib/crtbeginS.o
+    ln -s $out/lib/*/clang_rt.crtend_shared-*.o $out/lib/crtendS.o
+  ''
+  # See https://reviews.llvm.org/D37278 for why android exception
+  + lib.optionalString (stdenv.hostPlatform.isx86_32 && !stdenv.hostPlatform.isAndroid) ''
+    for f in $out/lib/*/*builtins-i?86*; do
+      ln -s "$f" $(echo "$f" | sed -e 's/builtins-i.86/builtins-i386/')
+    done
+  '' + lib.optionalString doFakeLibgcc ''
+    ln -s $out/lib/freebsd/libclang_rt.builtins-*.a $out/lib/libgcc.a
+  '';
+
+  meta = llvm_meta // {
+    homepage = "https://compiler-rt.llvm.org/";
+    description = "Compiler runtime libraries";
+    longDescription = ''
+      The compiler-rt project provides highly tuned implementations of the
+      low-level code generator support routines like "__fixunsdfdi" and other
+      calls generated when a target doesn't have a short sequence of native
+      instructions to implement a core IR operation. It also provides
+      implementations of run-time libraries for dynamic testing tools such as
+      AddressSanitizer, ThreadSanitizer, MemorySanitizer, and DataFlowSanitizer.
+    '';
+    # "All of the code in the compiler-rt project is dual licensed under the MIT
+    # license and the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+    broken = stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isAarch64;
+  };
+}
--- a/llvm/10/compiler-rt/find-darwin-sdk-version.patch
+++ b/llvm/10/compiler-rt/find-darwin-sdk-version.patch
@ -0,0 +1,62 @@
+--- a/cmake/Modules/CompilerRTDarwinUtils.cmake	2020-01-25 23:13:55.000000000 +0100
+++ b/cmake/Modules/CompilerRTDarwinUtils.cmake	2020-01-25 23:19:37.000000000 +0100
+@@ -43,41 +43,6 @@
+   set(DARWIN_${sdk_name}_CACHED_SYSROOT ${var_internal} CACHE STRING "Darwin SDK path for SDK ${sdk_name}." FORCE)
+ endfunction()
+ 
+-function(find_darwin_sdk_version var sdk_name)
+-  # We deliberately don't cache the result here because
+-  # CMake's caching causes too many problems.
+-  set(result_process 1)
+-  if(NOT DARWIN_PREFER_PUBLIC_SDK)
+-    # Let's first try the internal SDK, otherwise use the public SDK.
+-    execute_process(
+-      COMMAND xcrun --sdk ${sdk_name}.internal --show-sdk-version
+-      RESULT_VARIABLE result_process
+-      OUTPUT_VARIABLE var_internal
+-      OUTPUT_STRIP_TRAILING_WHITESPACE
+-      ERROR_FILE /dev/null
+-    )
+-  endif()
+-  if((NOT ${result_process} EQUAL 0) OR "" STREQUAL "${var_internal}")
+-    execute_process(
+-      COMMAND xcrun --sdk ${sdk_name} --show-sdk-version
+-      RESULT_VARIABLE result_process
+-      OUTPUT_VARIABLE var_internal
+-      OUTPUT_STRIP_TRAILING_WHITESPACE
+-      ERROR_FILE /dev/null
+-    )
+-  endif()
+-  if(NOT result_process EQUAL 0)
+-    message(FATAL_ERROR
+-      "Failed to determine SDK version for \"${sdk_name}\" SDK")
+-  endif()
+-  # Check reported version looks sane.
+-  if (NOT "${var_internal}" MATCHES "^[0-9]+\\.[0-9]+(\\.[0-9]+)?$")
+-    message(FATAL_ERROR
+-      "Reported SDK version \"${var_internal}\" does not look like a version")
+-  endif()
+-  set(${var} ${var_internal} PARENT_SCOPE)
+-endfunction()
+-
+ # There isn't a clear mapping of what architectures are supported with a given
+ # target platform, but ld's version output does list the architectures it can
+ # link for.
+@@ -119,17 +84,6 @@
+     foreach(flag ${DARWIN_${os}_LINK_FLAGS})
+       set(os_linker_flags "${os_linker_flags} ${flag}")
+     endforeach()
+-
+-    # Disable building for i386 for macOS SDK >= 10.15. The SDK doesn't support
+-    # linking for i386 and the corresponding OS doesn't allow running macOS i386
+-    # binaries.
+-    if ("${os}" STREQUAL "osx")
+-      find_darwin_sdk_version(macosx_sdk_version "macosx")
+-      if ("${macosx_sdk_version}" VERSION_GREATER 10.15 OR "${macosx_sdk_version}" VERSION_EQUAL 10.15)
+-        message(STATUS "Disabling i386 slice for ${valid_archs}")
+-        list(REMOVE_ITEM archs "i386")
+-      endif()
+-    endif()
+   endif()
+ 
+   # The simple program will build for x86_64h on the simulator because it is 
--- a/llvm/10/compiler-rt/gnu-install-dirs.patch
+++ b/llvm/10/compiler-rt/gnu-install-dirs.patch
@ -0,0 +1,129 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 8d768a404f21..74551dc5a004 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -12,6 +12,7 @@ endif()
+ # Check if compiler-rt is built as a standalone project.
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR COMPILER_RT_STANDALONE_BUILD)
+   project(CompilerRT C CXX ASM)
+  include(GNUInstallDirs)
+   set(COMPILER_RT_STANDALONE_BUILD TRUE)
+   set_property(GLOBAL PROPERTY USE_FOLDERS ON)
+ endif()
+diff --git a/cmake/Modules/AddCompilerRT.cmake b/cmake/Modules/AddCompilerRT.cmake
+index 35a48c6af29c..e4300f256091 100644
+--- a/cmake/Modules/AddCompilerRT.cmake
+++ b/cmake/Modules/AddCompilerRT.cmake
+@@ -493,7 +493,7 @@ macro(add_compiler_rt_resource_file target_name file_name component)
+   add_custom_target(${target_name} DEPENDS ${dst_file})
+   # Install in Clang resource directory.
+   install(FILES ${file_name}
+-    DESTINATION ${COMPILER_RT_INSTALL_PATH}/share
+    DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_DATADIR}
+     COMPONENT ${component})
+   add_dependencies(${component} ${target_name})
+ 
+@@ -510,7 +510,7 @@ macro(add_compiler_rt_script name)
+   add_custom_target(${name} DEPENDS ${dst})
+   install(FILES ${dst}
+     PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE
+-    DESTINATION ${COMPILER_RT_INSTALL_PATH}/bin)
+    DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_BINDIR})
+ endmacro(add_compiler_rt_script src name)
+ 
+ # Builds custom version of libc++ and installs it in <prefix>.
+diff --git a/cmake/Modules/CompilerRTDarwinUtils.cmake b/cmake/Modules/CompilerRTDarwinUtils.cmake
+index 9f501a61c4b6..f9a0d92dbca0 100644
+--- a/cmake/Modules/CompilerRTDarwinUtils.cmake
+++ b/cmake/Modules/CompilerRTDarwinUtils.cmake
+@@ -440,7 +440,7 @@ macro(darwin_add_embedded_builtin_libraries)
+     set(DARWIN_macho_embedded_LIBRARY_OUTPUT_DIR
+       ${COMPILER_RT_OUTPUT_DIR}/lib/macho_embedded)
+     set(DARWIN_macho_embedded_LIBRARY_INSTALL_DIR
+-      ${COMPILER_RT_INSTALL_PATH}/lib/macho_embedded)
+      ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_LIBDIR}/macho_embedded)
+       
+     set(CFLAGS_armv7 "-target thumbv7-apple-darwin-eabi")
+     set(CFLAGS_i386 "-march=pentium")
+diff --git a/cmake/Modules/CompilerRTUtils.cmake b/cmake/Modules/CompilerRTUtils.cmake
+index 6e672b1e1818..64999709958e 100644
+--- a/cmake/Modules/CompilerRTUtils.cmake
+++ b/cmake/Modules/CompilerRTUtils.cmake
+@@ -371,7 +371,7 @@ endfunction()
+ function(get_compiler_rt_install_dir arch install_dir)
+   if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+     get_compiler_rt_target(${arch} target)
+-    set(${install_dir} ${COMPILER_RT_INSTALL_PATH}/lib/${target} PARENT_SCOPE)
+    set(${install_dir} ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_LIBDIR}/${target} PARENT_SCOPE)
+   else()
+     set(${install_dir} ${COMPILER_RT_LIBRARY_INSTALL_DIR} PARENT_SCOPE)
+   endif()
+diff --git a/cmake/base-config-ix.cmake b/cmake/base-config-ix.cmake
+index b4b87aa53073..f1ae8668837c 100644
+--- a/cmake/base-config-ix.cmake
+++ b/cmake/base-config-ix.cmake
+@@ -65,11 +65,11 @@ if (LLVM_TREE_AVAILABLE)
+ else()
+     # Take output dir and install path from the user.
+   set(COMPILER_RT_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR} CACHE PATH
+-    "Path where built compiler-rt libraries should be stored.")
+    "Path where built compiler-rt build artifacts should be stored.")
+   set(COMPILER_RT_EXEC_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/bin CACHE PATH
+     "Path where built compiler-rt executables should be stored.")
+-  set(COMPILER_RT_INSTALL_PATH ${CMAKE_INSTALL_PREFIX} CACHE PATH
+-    "Path where built compiler-rt libraries should be installed.")
+  set(COMPILER_RT_INSTALL_PATH "" CACHE PATH
+    "Prefix where built compiler-rt artifacts should be installed, comes before CMAKE_INSTALL_PREFIX.")
+   option(COMPILER_RT_INCLUDE_TESTS "Generate and build compiler-rt unit tests." OFF)
+   option(COMPILER_RT_ENABLE_WERROR "Fail and stop if warning is triggered" OFF)
+   # Use a host compiler to compile/link tests.
+@@ -97,7 +97,7 @@ else(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR)
+   set(COMPILER_RT_LIBRARY_OUTPUT_DIR
+     ${COMPILER_RT_OUTPUT_DIR}/lib/${COMPILER_RT_OS_DIR})
+   set(COMPILER_RT_LIBRARY_INSTALL_DIR
+-    ${COMPILER_RT_INSTALL_PATH}/lib/${COMPILER_RT_OS_DIR})
+    ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_LIBDIR}/${COMPILER_RT_OS_DIR})
+ endif()
+ 
+ if(APPLE)
+diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
+index d47d7baeb118..507c8e5c713e 100644
+--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
+@@ -62,22 +62,22 @@ set_target_properties(compiler-rt-headers PROPERTIES FOLDER "Compiler-RT Misc")
+ install(FILES ${SANITIZER_HEADERS}
+   COMPONENT compiler-rt-headers
+   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/sanitizer)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/sanitizer)
+ # Install fuzzer headers.
+ install(FILES ${FUZZER_HEADERS}
+   COMPONENT compiler-rt-headers
+   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/fuzzer)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/fuzzer)
+ # Install xray headers.
+ install(FILES ${XRAY_HEADERS}
+   COMPONENT compiler-rt-headers
+   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/xray)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/xray)
+ # Install profile headers.
+ install(FILES ${PROFILE_HEADERS}
+   COMPONENT compiler-rt-headers
+   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/profile)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/profile)
+ 
+ if (NOT CMAKE_CONFIGURATION_TYPES) # don't add this for IDEs.
+   add_custom_target(install-compiler-rt-headers
+diff --git a/lib/dfsan/CMakeLists.txt b/lib/dfsan/CMakeLists.txt
+index 051215edbeb7..ecce1f52efb0 100644
+--- a/lib/dfsan/CMakeLists.txt
+++ b/lib/dfsan/CMakeLists.txt
+@@ -56,4 +56,4 @@ add_custom_command(OUTPUT ${dfsan_abilist_filename}
+                    DEPENDS done_abilist.txt libc_ubuntu1404_abilist.txt)
+ add_dependencies(dfsan dfsan_abilist)
+ install(FILES ${dfsan_abilist_filename}
+-        DESTINATION ${COMPILER_RT_INSTALL_PATH}/share)
+        DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_DATADIR})
--- a/llvm/10/default.nix
+++ b/llvm/10/default.nix
@ -0,0 +1,284 @@
+{ lowPrio, newScope, pkgs, lib, stdenv, cmake
+, gccForLibs, preLibcCrossHeaders
+, libxml2, python3, isl, fetchurl, overrideCC, wrapCCWith, wrapBintoolsWith
+, buildLlvmTools # tools, but from the previous stage, for cross
+, targetLlvmLibraries # libraries, but from the next stage, for cross
+, targetLlvm
+# This is the default binutils, but with *this* version of LLD rather
+# than the default LLVM version's, if LLD is the choice. We use these for
+# the `useLLVM` bootstrapping below.
+, bootBintoolsNoLibc ?
+    if stdenv.targetPlatform.linker == "lld"
+    then null
+    else pkgs.bintoolsNoLibc
+, bootBintools ?
+    if stdenv.targetPlatform.linker == "lld"
+    then null
+    else pkgs.bintools
+}:
+
+let
+  release_version = "10.0.1";
+  version = release_version; # differentiating these (variables) is important for RCs
+  targetConfig = stdenv.targetPlatform.config;
+
+  fetch = name: sha256: fetchurl {
+    url = "https://github.com/llvm/llvm-project/releases/download/llvmorg-${release_version}/${name}-${version}.src.tar.xz";
+    inherit sha256;
+  };
+
+  clang-tools-extra_src = fetch "clang-tools-extra" "06n1yp638rh24xdxv9v2df0qajxbjz4w59b7dd4ky36drwmpi4yh";
+
+  llvm_meta = {
+    license     = lib.licenses.ncsa;
+    maintainers = lib.teams.llvm.members;
+
+    # See llvm/cmake/config-ix.cmake.
+    platforms   =
+      lib.platforms.aarch64 ++
+      lib.platforms.arm ++
+      lib.platforms.mips ++
+      lib.platforms.power ++
+      lib.platforms.riscv ++
+      lib.platforms.s390x ++
+      lib.platforms.wasi ++
+      lib.platforms.x86;
+  };
+
+  tools = lib.makeExtensible (tools: let
+    callPackage = newScope (tools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch buildLlvmTools; });
+    mkExtraBuildCommands0 = cc: ''
+      rsrc="$out/resource-root"
+      mkdir "$rsrc"
+      ln -s "${cc.lib}/lib/clang/${release_version}/include" "$rsrc"
+      echo "-resource-dir=$rsrc" >> $out/nix-support/cc-cflags
+    '';
+    mkExtraBuildCommands = cc: mkExtraBuildCommands0 cc + ''
+      ln -s "${targetLlvmLibraries.compiler-rt.out}/lib" "$rsrc/lib"
+      ln -s "${targetLlvmLibraries.compiler-rt.out}/share" "$rsrc/share"
+    '';
+
+  bintoolsNoLibc' =
+    if bootBintoolsNoLibc == null
+    then tools.bintoolsNoLibc
+    else bootBintoolsNoLibc;
+  bintools' =
+    if bootBintools == null
+    then tools.bintools
+    else bootBintools;
+
+  in {
+
+    libllvm = callPackage ./llvm {
+      inherit llvm_meta;
+    };
+
+    # `llvm` historically had the binaries.  When choosing an output explicitly,
+    # we need to reintroduce `outputSpecified` to get the expected behavior e.g. of lib.get*
+    llvm = tools.libllvm;
+
+    libclang = callPackage ./clang {
+      inherit clang-tools-extra_src llvm_meta;
+    };
+
+    clang-unwrapped = tools.libclang;
+
+    # disabled until recommonmark supports sphinx 3
+    #Llvm-manpages = lowPrio (tools.libllvm.override {
+    #  enableManpages = true;
+    #  python3 = pkgs.python3;  # don't use python-boot
+    #});
+
+    clang-manpages = lowPrio (tools.libclang.override {
+      enableManpages = true;
+      python3 = pkgs.python3;  # don't use python-boot
+    });
+
+    # disabled until recommonmark supports sphinx 3
+    # lldb-manpages = lowPrio (tools.lldb.override {
+    #   enableManpages = true;
+    #   python3 = pkgs.python3;  # don't use python-boot
+    # });
+
+    # pick clang appropriate for package set we are targeting
+    clang =
+      /**/ if stdenv.targetPlatform.libc == null then tools.clangNoLibc
+      else if stdenv.targetPlatform.useLLVM or false then tools.clangUseLLVM
+      else if (pkgs.targetPackages.stdenv or stdenv).cc.isGNU then tools.libstdcxxClang
+      else tools.libcxxClang;
+
+    libstdcxxClang = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      # libstdcxx is taken from gcc in an ad-hoc way in cc-wrapper.
+      libcxx = null;
+      extraPackages = [
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = mkExtraBuildCommands cc;
+    };
+
+    libcxxClang = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = targetLlvmLibraries.libcxx;
+      extraPackages = [
+        libcxx.cxxabi
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = mkExtraBuildCommands cc;
+    };
+
+    lld = callPackage ./lld {
+      inherit llvm_meta;
+    };
+
+    lldb = callPackage ../common/lldb.nix {
+      src = fetch "lldb" "051p5b04y6z3g730rmc2n2v71lipbw7k69riww3a6sl74myfiaq7";
+      patches = [
+        ./lldb/procfs.patch
+        ./lldb/gnu-install-dirs.patch
+      ];
+      inherit llvm_meta;
+    };
+
+    # Below, is the LLVM bootstrapping logic. It handles building a
+    # fully LLVM toolchain from scratch. No GCC toolchain should be
+    # pulled in. As a consequence, it is very quick to build different
+    # targets provided by LLVM and we can also build for what GCC
+    # doesn’t support like LLVM. Probably we should move to some other
+    # file.
+
+    bintools-unwrapped = callPackage ../common/bintools.nix { };
+
+    bintoolsNoLibc = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+      libc = preLibcCrossHeaders;
+    };
+
+    bintools = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+    };
+
+    clangUseLLVM = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = targetLlvmLibraries.libcxx;
+      bintools = bintools';
+      extraPackages = [
+        libcxx.cxxabi
+        targetLlvmLibraries.compiler-rt
+      ] ++ lib.optionals (!stdenv.targetPlatform.isWasm) [
+        targetLlvmLibraries.libunwind
+      ];
+      extraBuildCommands = ''
+        echo "-rtlib=compiler-rt -Wno-unused-command-line-argument" >> $out/nix-support/cc-cflags
+        echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
+      '' + lib.optionalString (!stdenv.targetPlatform.isWasm) ''
+        echo "--unwindlib=libunwind" >> $out/nix-support/cc-cflags
+      '' + lib.optionalString (!stdenv.targetPlatform.isWasm && stdenv.targetPlatform.useLLVM or false) ''
+        echo "-lunwind" >> $out/nix-support/cc-ldflags
+      '' + lib.optionalString stdenv.targetPlatform.isWasm ''
+        echo "-fno-exceptions" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands cc;
+    };
+
+    clangNoLibcxx = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintools';
+      extraPackages = [
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = ''
+        echo "-rtlib=compiler-rt" >> $out/nix-support/cc-cflags
+        echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
+        echo "-nostdlib++" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands cc;
+    };
+
+    clangNoLibc = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintoolsNoLibc';
+      extraPackages = [
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = ''
+        echo "-rtlib=compiler-rt" >> $out/nix-support/cc-cflags
+        echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands cc;
+    };
+
+    clangNoCompilerRt = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintoolsNoLibc';
+      extraPackages = [ ];
+      extraBuildCommands = ''
+        echo "-nostartfiles" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands0 cc;
+    };
+
+    clangNoCompilerRtWithLibc = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintools';
+      extraPackages = [ ];
+      extraBuildCommands = mkExtraBuildCommands0 cc;
+    };
+
+  });
+
+  libraries = lib.makeExtensible (libraries: let
+    callPackage = newScope (libraries // buildLlvmTools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch; });
+  in {
+
+    compiler-rt-libc = callPackage ./compiler-rt {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.clangNoCompilerRtWithLibc
+               else stdenv;
+    };
+
+    compiler-rt-no-libc = callPackage ./compiler-rt {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.clangNoCompilerRt
+               else stdenv;
+    };
+
+    # N.B. condition is safe because without useLLVM both are the same.
+    compiler-rt = if stdenv.hostPlatform.isAndroid
+      then libraries.compiler-rt-libc
+      else libraries.compiler-rt-no-libc;
+
+    stdenv = overrideCC stdenv buildLlvmTools.clang;
+
+    libcxxStdenv = overrideCC stdenv buildLlvmTools.libcxxClang;
+
+    libcxx = callPackage ./libcxx {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.clangNoLibcxx
+               else stdenv;
+    };
+
+    libcxxabi = callPackage ./libcxxabi {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.clangNoLibcxx
+               else stdenv;
+    };
+
+    libunwind = callPackage ./libunwind {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.clangNoLibcxx
+               else stdenv;
+    };
+
+    openmp = callPackage ./openmp {
+      inherit llvm_meta targetLlvm;
+    };
+  });
+  noExtend = extensible: lib.attrsets.removeAttrs extensible [ "extend" ];
+
+in { inherit tools libraries release_version; } // (noExtend libraries) // (noExtend tools)
--- a/llvm/10/libcxx/default.nix
+++ b/llvm/10/libcxx/default.nix
@ -0,0 +1,88 @@
+{ lib, stdenv, llvm_meta, fetch, cmake, python3, fixDarwinDylibNames, version
+, cxxabi ? if stdenv.hostPlatform.isFreeBSD then libcxxrt else libcxxabi
+, libcxxabi, libcxxrt
+, enableShared ? !stdenv.hostPlatform.isStatic
+}:
+
+assert stdenv.isDarwin -> cxxabi.pname == "libcxxabi";
+
+stdenv.mkDerivation {
+  pname = "libcxx";
+  inherit version;
+
+  src = fetch "libcxx" "0v78bfr6h2zifvdqnj2wlfk4pvxzrqn3hg1v6lqk3y12bx9p9xny";
+
+  postUnpack = ''
+    unpackFile ${libcxxabi.src}
+    export LIBCXXABI_INCLUDE_DIR="$PWD/$(ls -d libcxxabi-${version}*)/include"
+  '';
+
+  outputs = [ "out" "dev" ];
+
+  patches = [
+    ./gnu-install-dirs.patch
+  ] ++ lib.optionals stdenv.hostPlatform.isMusl [
+    ../../libcxx-0001-musl-hacks.patch
+  ];
+
+  # Prevent errors like "error: 'foo' is unavailable: introduced in macOS yy.zz"
+  postPatch = ''
+    substituteInPlace include/__config \
+      --replace "#    define _LIBCPP_USE_AVAILABILITY_APPLE" ""
+  '';
+
+  preConfigure = ''
+    # Get headers from the cxxabi source so we can see private headers not installed by the cxxabi package
+    cmakeFlagsArray=($cmakeFlagsArray -DLIBCXX_CXX_ABI_INCLUDE_PATHS="$LIBCXXABI_INCLUDE_DIR")
+  '' + lib.optionalString stdenv.hostPlatform.isMusl ''
+    patchShebangs utils/cat_files.py
+  '';
+  nativeBuildInputs = [ cmake ]
+    ++ lib.optional (stdenv.hostPlatform.isMusl || stdenv.hostPlatform.isWasi) python3
+    ++ lib.optional stdenv.hostPlatform.isDarwin fixDarwinDylibNames;
+
+  buildInputs = [ cxxabi ];
+
+  cmakeFlags = [
+    "-DLIBCXX_LIBCPPABI_VERSION=2"
+    "-DLIBCXX_CXX_ABI=${cxxabi.pname}"
+  ] ++ lib.optional (stdenv.hostPlatform.isMusl || stdenv.hostPlatform.isWasi) "-DLIBCXX_HAS_MUSL_LIBC=1"
+    ++ lib.optional (cxxabi.pname == "libcxxabi") "-DLIBCXX_LIBCXXABI_LIB_PATH=${cxxabi}/lib"
+    ++ lib.optional (stdenv.hostPlatform.useLLVM or false) "-DLIBCXX_USE_COMPILER_RT=ON"
+    ++ lib.optionals stdenv.hostPlatform.isWasm [
+      "-DLIBCXX_ENABLE_THREADS=OFF"
+      "-DLIBCXX_ENABLE_FILESYSTEM=OFF"
+      "-DLIBCXX_ENABLE_EXCEPTIONS=OFF"
+    ] ++ lib.optional (!enableShared) "-DLIBCXX_ENABLE_SHARED=OFF";
+
+  preInstall = lib.optionalString (stdenv.isDarwin) ''
+    for file in lib/*.dylib; do
+      if [ -L "$file" ]; then continue; fi
+
+      baseName=$(basename $(${stdenv.cc.targetPrefix}otool -D $file | tail -n 1))
+      installName="$out/lib/$baseName"
+      abiName=$(echo "$baseName" | sed -e 's/libc++/libc++abi/')
+
+      for other in $(${stdenv.cc.targetPrefix}otool -L $file | awk '$1 ~ "/libc\\+\\+abi" { print $1 }'); do
+        ${stdenv.cc.targetPrefix}install_name_tool -change $other ${cxxabi}/lib/$abiName $file
+      done
+    done
+  '';
+
+  passthru = {
+    isLLVM = true;
+    inherit cxxabi;
+  };
+
+  meta = llvm_meta // {
+    homepage = "https://libcxx.llvm.org/";
+    description = "C++ standard library";
+    longDescription = ''
+      libc++ is an implementation of the C++ standard library, targeting C++11,
+      C++14 and above.
+    '';
+    # "All of the code in libc++ is dual licensed under the MIT license and the
+    # UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}
--- a/llvm/10/libcxx/gnu-install-dirs.patch
+++ b/llvm/10/libcxx/gnu-install-dirs.patch
@ -0,0 +1,99 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 60564dc96c7b..77d832ad5a44 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -26,6 +26,8 @@ set(CMAKE_MODULE_PATH
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXX_STANDALONE_BUILD)
+   project(libcxx CXX C)
+ 
+  include(GNUInstallDirs)
+
+   set(PACKAGE_NAME libcxx)
+   set(PACKAGE_VERSION 10.0.1)
+   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+@@ -415,7 +417,7 @@ string(REGEX MATCH "[0-9]+\\.[0-9]+(\\.[0-9]+)?" CLANG_VERSION
+ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   set(LIBCXX_HEADER_DIR ${LLVM_BINARY_DIR})
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   if(LIBCXX_LIBDIR_SUBDIR)
+     string(APPEND LIBCXX_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
+     string(APPEND LIBCXX_INSTALL_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
+@@ -423,10 +425,10 @@ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+ elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+   set(LIBCXX_HEADER_DIR  ${LLVM_BINARY_DIR})
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX})
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXX_LIBDIR_SUFFIX})
+ else()
+   set(LIBCXX_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX})
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXX_LIBDIR_SUFFIX})
+ endif()
+ 
+ file(MAKE_DIRECTORY "${LIBCXX_BINARY_INCLUDE_DIR}")
+diff --git a/cmake/Modules/HandleLibCXXABI.cmake b/cmake/Modules/HandleLibCXXABI.cmake
+index 10f100f7f0fb..95ed3978ab73 100644
+--- a/cmake/Modules/HandleLibCXXABI.cmake
+++ b/cmake/Modules/HandleLibCXXABI.cmake
+@@ -61,7 +61,7 @@ macro(setup_abi_lib abidefines abishared abistatic abifiles abidirs)
+ 
+         if (LIBCXX_INSTALL_HEADERS)
+           install(FILES "${LIBCXX_BINARY_INCLUDE_DIR}/${fpath}"
+-            DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1/${dstdir}
+            DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${CMAKE_INSTALL_INCLUDEDIR}/c++/v1/${dstdir}
+             COMPONENT cxx-headers
+             PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+             )
+diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
+index 302da8a131b4..4c6ab463f564 100644
+--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
+@@ -244,7 +244,7 @@ if (LIBCXX_INSTALL_HEADERS)
+   foreach(file ${files})
+     get_filename_component(dir ${file} DIRECTORY)
+     install(FILES ${file}
+-      DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1/${dir}
+      DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${CMAKE_INSTALL_INCLUDEDIR}/c++/v1/${dir}
+       COMPONENT ${CXX_HEADER_TARGET}
+       PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+     )
+@@ -253,7 +253,7 @@ if (LIBCXX_INSTALL_HEADERS)
+   if (LIBCXX_NEEDS_SITE_CONFIG)
+     # Install the generated header as __config.
+     install(FILES ${LIBCXX_BINARY_DIR}/__generated_config
+-      DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1
+      DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${CMAKE_INSTALL_INCLUDEDIR}/c++/v1
+       PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+       RENAME __config
+       COMPONENT ${CXX_HEADER_TARGET})
+diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
+index 120505fe18da..9b8456d8405a 100644
+--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
+@@ -341,21 +341,21 @@ if (LIBCXX_INSTALL_LIBRARY)
+     install(TARGETS cxx_shared
+       ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+       LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-      RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
+      RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+   endif()
+ 
+   if (LIBCXX_INSTALL_STATIC_LIBRARY)
+     install(TARGETS cxx_static
+       ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+       LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-      RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
+      RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+   endif()
+ 
+   if(LIBCXX_INSTALL_EXPERIMENTAL_LIBRARY)
+     install(TARGETS ${LIBCXX_INSTALL_TARGETS} ${experimental_lib}
+       LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+       ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-      RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
+      RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+   endif()
+ 
+   # NOTE: This install command must go after the cxx install command otherwise
--- a/llvm/10/libcxxabi/default.nix
+++ b/llvm/10/libcxxabi/default.nix
@ -0,0 +1,85 @@
+{ lib, stdenv, llvm_meta, cmake, fetch, libcxx, libunwind, llvm, version
+, enableShared ? !stdenv.hostPlatform.isStatic
+}:
+
+stdenv.mkDerivation {
+  pname = "libcxxabi";
+  inherit version;
+
+  src = fetch "libcxxabi" "0yqs722y76cwvmfsq0lb917r9m3fci7bf5z3yzl71yz9n88ghzm9";
+
+  outputs = [ "out" "dev" ];
+
+  postUnpack = ''
+    unpackFile ${libcxx.src}
+    unpackFile ${llvm.src}
+    cmakeFlags+=" -DLLVM_PATH=$PWD/$(ls -d llvm-*) -DLIBCXXABI_LIBCXX_PATH=$PWD/$(ls -d libcxx-*)"
+  '' + lib.optionalString stdenv.isDarwin ''
+    export TRIPLE=x86_64-apple-darwin
+  '' + lib.optionalString stdenv.hostPlatform.isMusl ''
+    patch -p1 -d $(ls -d libcxx-*) -i ${../../libcxx-0001-musl-hacks.patch}
+  '' + lib.optionalString stdenv.hostPlatform.isWasm ''
+    patch -p1 -d $(ls -d llvm-*) -i ${../../common/libcxxabi/wasm.patch}
+  '';
+
+  patches = [
+    ../../common/libcxxabi/no-threads.patch
+    ./gnu-install-dirs.patch
+  ];
+
+  nativeBuildInputs = [ cmake ];
+  buildInputs = lib.optional (!stdenv.isDarwin && !stdenv.hostPlatform.isWasm) libunwind;
+
+  cmakeFlags = lib.optionals (stdenv.hostPlatform.useLLVM or false) [
+    "-DLLVM_ENABLE_LIBCXX=ON"
+    "-DLIBCXXABI_USE_LLVM_UNWINDER=ON"
+  ] ++ lib.optionals stdenv.hostPlatform.isWasm [
+    "-DLIBCXXABI_ENABLE_THREADS=OFF"
+    "-DLIBCXXABI_ENABLE_EXCEPTIONS=OFF"
+  ] ++ lib.optionals (!enableShared) [
+    "-DLIBCXXABI_ENABLE_SHARED=OFF"
+  ];
+
+  preInstall = lib.optionalString stdenv.isDarwin ''
+    for file in lib/*.dylib; do
+      if [ -L "$file" ]; then continue; fi
+
+      # Fix up the install name. Preserve the basename, just replace the path.
+      installName="$out/lib/$(basename $(${stdenv.cc.targetPrefix}otool -D $file | tail -n 1))"
+
+      # this should be done in CMake, but having trouble figuring out
+      # the magic combination of necessary CMake variables
+      # if you fancy a try, take a look at
+      # https://gitlab.kitware.com/cmake/community/-/wikis/doc/cmake/RPATH-handling
+      ${stdenv.cc.targetPrefix}install_name_tool -id $installName $file
+
+      # cc-wrapper passes '-lc++abi' to all c++ link steps, but that causes
+      # libcxxabi to sometimes link against a different version of itself.
+      # Here we simply make that second reference point to ourselves.
+      for other in $(${stdenv.cc.targetPrefix}otool -L $file | awk '$1 ~ "/libc\\+\\+abi" { print $1 }'); do
+        ${stdenv.cc.targetPrefix}install_name_tool -change $other $installName $file
+      done
+    done
+  '';
+
+  postInstall = ''
+    mkdir -p "$dev/include"
+    install -m 644 ../include/${if stdenv.isDarwin then "*" else "cxxabi.h"} "$dev/include"
+  '';
+
+  passthru = {
+    libName = "c++abi";
+  };
+
+  meta = llvm_meta // {
+    homepage = "https://libcxxabi.llvm.org/";
+    description = "Provides C++ standard library support";
+    longDescription = ''
+      libc++abi is a new implementation of low level support for a standard C++ library.
+    '';
+    # "All of the code in libc++abi is dual licensed under the MIT license and
+    # the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+    maintainers = llvm_meta.maintainers ++ [ lib.maintainers.vlstill ];
+  };
+}
--- a/llvm/10/libcxxabi/gnu-install-dirs.patch
+++ b/llvm/10/libcxxabi/gnu-install-dirs.patch
@ -0,0 +1,34 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 8f9572586b4a..bf0e41dfc751 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -20,6 +20,8 @@ set(CMAKE_MODULE_PATH
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXXABI_STANDALONE_BUILD)
+   project(libcxxabi CXX C)
+ 
+  include(GNUInstallDirs)
+
+   set(PACKAGE_NAME libcxxabi)
+   set(PACKAGE_VERSION 10.0.1)
+   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+@@ -214,17 +216,17 @@ string(REGEX MATCH "[0-9]+\\.[0-9]+(\\.[0-9]+)?" CLANG_VERSION
+ 
+ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   if(LIBCXX_LIBDIR_SUBDIR)
+     string(APPEND LIBCXXABI_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
+     string(APPEND LIBCXXABI_INSTALL_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
+   endif()
+ elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX})
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXXABI_LIBDIR_SUFFIX})
+ else()
+   set(LIBCXXABI_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXXABI_LIBDIR_SUFFIX})
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX})
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXXABI_LIBDIR_SUFFIX})
+ endif()
+ 
+ set(LIBCXXABI_INSTALL_PREFIX "" CACHE STRING "Define libc++abi destination prefix.")
--- a/llvm/10/libunwind/default.nix
+++ b/llvm/10/libunwind/default.nix
@ -0,0 +1,32 @@
+{ lib, stdenv, llvm_meta, version, fetch, cmake, fetchpatch
+, enableShared ? !stdenv.hostPlatform.isStatic
+}:
+
+stdenv.mkDerivation rec {
+  pname = "libunwind";
+  inherit version;
+
+  src = fetch pname "09syx66idnm2pr46x2vmk0jn3iwdv0lkd04xy4zjbwmz3vn066bl";
+
+  patches = [
+    ./gnu-install-dirs.patch
+  ];
+
+  outputs = [ "out" "dev" ];
+
+  nativeBuildInputs = [ cmake ];
+
+  cmakeFlags = lib.optional (!enableShared) "-DLIBUNWIND_ENABLE_SHARED=OFF";
+
+  meta = llvm_meta // {
+    # Details: https://github.com/llvm/llvm-project/blob/main/libunwind/docs/index.rst
+    homepage = "https://clang.llvm.org/docs/Toolchain.html#unwind-library";
+    description = "LLVM's unwinder library";
+    longDescription = ''
+      The unwind library provides a family of _Unwind_* functions implementing
+      the language-neutral stack unwinding portion of the Itanium C++ ABI (Level
+      I). It is a dependency of the C++ ABI library, and sometimes is a
+      dependency of other runtimes.
+    '';
+  };
+}
--- a/llvm/10/libunwind/gnu-install-dirs.patch
+++ b/llvm/10/libunwind/gnu-install-dirs.patch
@ -0,0 +1,34 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index c033069ef1d0..e2846896eece 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -18,6 +18,8 @@ set(CMAKE_MODULE_PATH
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBUNWIND_STANDALONE_BUILD)
+   project(libunwind)
+ 
+  include(GNUInstallDirs)
+
+   # Rely on llvm-config.
+   set(CONFIG_OUTPUT)
+   if(NOT LLVM_CONFIG_PATH)
+@@ -189,17 +191,17 @@ string(REGEX MATCH "[0-9]+\\.[0-9]+(\\.[0-9]+)?" CLANG_VERSION
+ 
+ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   if(LIBCXX_LIBDIR_SUBDIR)
+     string(APPEND LIBUNWIND_LIBRARY_DIR /${LIBUNWIND_LIBDIR_SUBDIR})
+     string(APPEND LIBUNWIND_INSTALL_LIBRARY_DIR /${LIBUNWIND_LIBDIR_SUBDIR})
+   endif()
+ elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+   set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LIBUNWIND_LIBDIR_SUFFIX})
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBUNWIND_LIBDIR_SUFFIX})
+ else()
+   set(LIBUNWIND_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBUNWIND_LIBDIR_SUFFIX})
+-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LIBUNWIND_LIBDIR_SUFFIX})
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBUNWIND_LIBDIR_SUFFIX})
+ endif()
+ 
+ set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${LIBUNWIND_LIBRARY_DIR})
--- a/llvm/10/lld/default.nix
+++ b/llvm/10/lld/default.nix
@ -0,0 +1,46 @@
+{ lib, stdenv, llvm_meta
+, buildLlvmTools
+, fetch
+, cmake
+, libxml2
+, libllvm
+, version
+}:
+
+stdenv.mkDerivation rec {
+  pname = "lld";
+  inherit version;
+
+  src = fetch pname "0ynzi35r4fckvp6842alpd43qr810j3728yfslc66fk2mbh4j52r";
+
+  patches = [
+    ./gnu-install-dirs.patch
+  ];
+
+  nativeBuildInputs = [ cmake ];
+  buildInputs = [ libllvm libxml2 ];
+
+  cmakeFlags = [
+    "-DLLVM_CONFIG_PATH=${libllvm.dev}/bin/llvm-config${lib.optionalString (stdenv.hostPlatform != stdenv.buildPlatform) "-native"}"
+  ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+    "-DLLVM_TABLEGEN_EXE=${buildLlvmTools.llvm}/bin/llvm-tblgen"
+  ];
+
+  # Musl's default stack size is too small for lld to be able to link Firefox.
+  LDFLAGS = lib.optionalString stdenv.hostPlatform.isMusl "-Wl,-z,stack-size=2097152";
+
+  outputs = [ "out" "lib" "dev" ];
+
+  meta = llvm_meta // {
+    homepage = "https://lld.llvm.org/";
+    description = "The LLVM linker (unwrapped)";
+    longDescription = ''
+      LLD is a linker from the LLVM project that is a drop-in replacement for
+      system linkers and runs much faster than them. It also provides features
+      that are useful for toolchain developers.
+      The linker supports ELF (Unix), PE/COFF (Windows), Mach-O (macOS), and
+      WebAssembly in descending order of completeness. Internally, LLD consists
+      of several different linkers.
+    '';
+  };
+}
--- a/llvm/10/lld/gnu-install-dirs.patch
+++ b/llvm/10/lld/gnu-install-dirs.patch
@ -0,0 +1,68 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 641f71c114ae..9d44c1463aff 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -6,6 +6,8 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+   set(CMAKE_INCLUDE_CURRENT_DIR ON)
+   set(LLD_BUILT_STANDALONE TRUE)
+ 
+  include(GNUInstallDirs)
+
+   find_program(LLVM_CONFIG_PATH "llvm-config" DOC "Path to llvm-config binary")
+   if(NOT LLVM_CONFIG_PATH)
+     message(FATAL_ERROR "llvm-config not found: specify LLVM_CONFIG_PATH")
+@@ -202,7 +204,7 @@ include_directories(BEFORE
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN ".svn" EXCLUDE
+diff --git a/cmake/modules/AddLLD.cmake b/cmake/modules/AddLLD.cmake
+index fa48b428d26b..e7967aad3ceb 100644
+--- a/cmake/modules/AddLLD.cmake
+++ b/cmake/modules/AddLLD.cmake
+@@ -20,9 +20,9 @@ macro(add_lld_library name)
+     install(TARGETS ${name}
+       COMPONENT ${name}
+       ${export_to_lldtargets}
+-      LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-      ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-      RUNTIME DESTINATION bin)
+      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+ 
+     if (${ARG_SHARED} AND NOT CMAKE_CONFIGURATION_TYPES)
+       add_llvm_install_targets(install-${name}
+@@ -54,7 +54,7 @@ macro(add_lld_tool name)
+ 
+     install(TARGETS ${name}
+       ${export_to_lldtargets}
+-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+       COMPONENT ${name})
+ 
+     if(NOT CMAKE_CONFIGURATION_TYPES)
+@@ -69,5 +69,5 @@ endmacro()
+ macro(add_lld_symlink name dest)
+   add_llvm_tool_symlink(${name} ${dest} ALWAYS_GENERATE)
+   # Always generate install targets
+-  llvm_install_symlink(${name} ${dest} ALWAYS_GENERATE)
+  llvm_install_symlink(${name} ${dest} ${CMAKE_INSTALL_FULL_BINDIR} ALWAYS_GENERATE)
+ endmacro()
+diff --git a/tools/lld/CMakeLists.txt b/tools/lld/CMakeLists.txt
+index a15e296e31df..654c2cfdb9c0 100644
+--- a/tools/lld/CMakeLists.txt
+++ b/tools/lld/CMakeLists.txt
+@@ -17,7 +17,7 @@ target_link_libraries(lld
+   )
+ 
+ install(TARGETS lld
+-  RUNTIME DESTINATION bin)
+  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+ 
+ if(NOT LLD_SYMLINKS_TO_CREATE)
+   set(LLD_SYMLINKS_TO_CREATE lld-link ld.lld ld64.lld wasm-ld)
--- a/llvm/10/lldb/gnu-install-dirs.patch
+++ b/llvm/10/lldb/gnu-install-dirs.patch
@ -0,0 +1,91 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 573b8556989e..a12cc6f6ba77 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -17,6 +17,8 @@ set(CMAKE_MODULE_PATH
+ # If we are not building as part of LLVM, build LLDB as a standalone project,
+ # using LLVM as an external library.
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+  include(GNUInstallDirs)
+
+   project(lldb)
+   include(LLDBStandalone)
+ 
+diff --git a/cmake/modules/AddLLDB.cmake b/cmake/modules/AddLLDB.cmake
+index ecf0b66a41a3..6f2d97af7a11 100644
+--- a/cmake/modules/AddLLDB.cmake
+++ b/cmake/modules/AddLLDB.cmake
+@@ -107,13 +107,13 @@ function(add_lldb_library name)
+   endif()
+ 
+   if(PARAM_SHARED)
+-    set(install_dest lib${LLVM_LIBDIR_SUFFIX})
+    set(install_dest ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+     if(PARAM_INSTALL_PREFIX)
+       set(install_dest ${PARAM_INSTALL_PREFIX})
+     endif()
+     # RUNTIME is relevant for DLL platforms, FRAMEWORK for macOS
+     install(TARGETS ${name} COMPONENT ${name}
+-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+       LIBRARY DESTINATION ${install_dest}
+       ARCHIVE DESTINATION ${install_dest}
+       FRAMEWORK DESTINATION ${install_dest})
+diff --git a/cmake/modules/LLDBConfig.cmake b/cmake/modules/LLDBConfig.cmake
+index 4a15a343ee1d..c74bbb6878d7 100644
+--- a/cmake/modules/LLDBConfig.cmake
+++ b/cmake/modules/LLDBConfig.cmake
+@@ -238,7 +238,7 @@ include_directories(BEFORE
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/
+     COMPONENT lldb-headers
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN ".svn" EXCLUDE
+@@ -247,7 +247,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+ 
+   install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/
+     COMPONENT lldb-headers
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN ".svn" EXCLUDE
+diff --git a/tools/intel-features/CMakeLists.txt b/tools/intel-features/CMakeLists.txt
+index aff75d7db334..98a527c5e761 100644
+--- a/tools/intel-features/CMakeLists.txt
+++ b/tools/intel-features/CMakeLists.txt
+@@ -64,4 +64,4 @@ if (LLDB_ENABLE_PYTHON AND LLDB_BUILD_INTEL_PT)
+ endif()
+ 
+ install(TARGETS lldbIntelFeatures
+-  LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX})
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+diff --git a/cmake/modules/LLDBStandalone.cmake b/cmake/modules/LLDBStandalone.cmake
+index 752113b..010f187 100644
+--- a/cmake/modules/LLDBStandalone.cmake
+++ b/cmake/modules/LLDBStandalone.cmake
+@@ -62,7 +62,7 @@ endif()
+
+ # They are used as destination of target generators.
+ set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin)
+-set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
+set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+ if(WIN32 OR CYGWIN)
+   # DLL platform -- put DLLs into bin.
+   set(LLVM_SHLIB_OUTPUT_INTDIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index bf74802..1c98cae 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -222,7 +222,7 @@ if (LLDB_ENABLE_PYTHON)
+   if(LLDB_BUILD_FRAMEWORK)
+     set(LLDB_PYTHON_INSTALL_PATH ${LLDB_FRAMEWORK_INSTALL_DIR}/LLDB.framework/Resources/Python)
+   else()
+-    set(LLDB_PYTHON_INSTALL_PATH ${LLDB_PYTHON_RELATIVE_PATH})
+    set(LLDB_PYTHON_INSTALL_PATH ${CMAKE_INSTALL_LIBDIR}/../${LLDB_PYTHON_RELATIVE_PATH})
+   endif()
+   if (NOT CMAKE_CFG_INTDIR STREQUAL  ".")
+     string(REPLACE ${CMAKE_CFG_INTDIR} "\$\{CMAKE_INSTALL_CONFIG_NAME\}" LLDB_PYTHON_INSTALL_PATH ${LLDB_PYTHON_INSTALL_PATH})
--- a/llvm/10/lldb/procfs.patch
+++ b/llvm/10/lldb/procfs.patch
@ -0,0 +1,31 @@
+--- a/source/Plugins/Process/Linux/Procfs.h
+++ b/source/Plugins/Process/Linux/Procfs.h
+@@ -11,21 +11,12 @@
+ // sys/procfs.h on Android/Linux for all supported architectures.
+ 
+ #include <sys/ptrace.h>
+#include <asm/ptrace.h>
+ 
+-#ifdef __ANDROID__
+-#if defined(__arm64__) || defined(__aarch64__)
+-typedef unsigned long elf_greg_t;
+-typedef elf_greg_t
+-    elf_gregset_t[(sizeof(struct user_pt_regs) / sizeof(elf_greg_t))];
+-typedef struct user_fpsimd_state elf_fpregset_t;
+-#ifndef NT_FPREGSET
+-#define NT_FPREGSET NT_PRFPREG
+-#endif // NT_FPREGSET
+-#elif defined(__mips__)
+-#ifndef NT_FPREGSET
+-#define NT_FPREGSET NT_PRFPREG
+-#endif // NT_FPREGSET
+-#endif
+-#else // __ANDROID__
+#if !defined(__GLIBC__) && defined(__powerpc__)
+#define pt_regs musl_pt_regs
+#include <sys/procfs.h>
+#undef pt_regs
+#else
+ #include <sys/procfs.h>
+-#endif // __ANDROID__
+#endif
--- a/llvm/10/llvm/default.nix
+++ b/llvm/10/llvm/default.nix
@ -0,0 +1,355 @@
+{ lib, stdenv, llvm_meta
+, pkgsBuildBuild
+, fetch
+, fetchpatch
+, cmake
+, python3
+, libffi
+, enableGoldPlugin ? libbfd.hasPluginAPI
+, libbfd
+, libpfm
+, libxml2
+, ncurses
+, version
+, release_version
+, zlib
+, buildLlvmTools
+, debugVersion ? false
+, doCheck ? stdenv.isLinux && (!stdenv.isx86_32)
+  && (stdenv.hostPlatform == stdenv.buildPlatform)
+, enableManpages ? false
+, enableSharedLibraries ? !stdenv.hostPlatform.isStatic
+# broken for Ampere eMAG 8180 (c2.large.arm on Packet) #56245
+# broken for the armv7l builder
+, enablePFM ? stdenv.isLinux && !stdenv.hostPlatform.isAarch
+, enablePolly ? true
+}:
+
+let
+  inherit (lib) optional optionals optionalString;
+
+  # Used when creating a version-suffixed symlink of libLLVM.dylib
+  shortVersion = with lib;
+    concatStringsSep "." (take 1 (splitString "." release_version));
+
+  # Ordinarily we would just the `doCheck` and `checkDeps` functionality
+  # `mkDerivation` gives us to manage our test dependencies (instead of breaking
+  # out `doCheck` as a package level attribute).
+  #
+  # Unfortunately `lit` does not forward `$PYTHONPATH` to children processes, in
+  # particular the children it uses to do feature detection.
+  #
+  # This means that python deps we add to `checkDeps` (which the python
+  # interpreter is made aware of via `$PYTHONPATH` – populated by the python
+  # setup hook) are not picked up by `lit` which causes it to skip tests.
+  #
+  # Adding `python3.withPackages (ps: [ ... ])` to `checkDeps` also doesn't work
+  # because this package is shadowed in `$PATH` by the regular `python3`
+  # package.
+  #
+  # So, we "manually" assemble one python derivation for the package to depend
+  # on, taking into account whether checks are enabled or not:
+  python = if doCheck then
+    let
+      checkDeps = ps: with ps; [ psutil ];
+    in python3.withPackages checkDeps
+  else python3;
+
+in stdenv.mkDerivation (rec {
+  pname = "llvm";
+  inherit version;
+
+  src = fetch pname "1wydhbp9kyjp5y0rc627imxgkgqiv3dfirbqil9dgpnbaw5y7n65";
+  polly_src = fetch "polly" "0nm2d8niz47yjsa3r17v3p13b70igkd338ib8191znr1dfw0pyyj";
+
+  unpackPhase = ''
+    unpackFile $src
+    mv llvm-${version}* llvm
+    sourceRoot=$PWD/llvm
+  '' + optionalString enablePolly ''
+    unpackFile $polly_src
+    mv polly-* $sourceRoot/tools/polly
+  '';
+
+  outputs = [ "out" "lib" "dev" "python" ];
+
+  nativeBuildInputs = [ cmake python ]
+    ++ optionals enableManpages [ python3.pkgs.sphinx python3.pkgs.recommonmark ];
+
+  buildInputs = [ libxml2 libffi ]
+    ++ optional enablePFM libpfm; # exegesis
+
+  propagatedBuildInputs = [ ncurses zlib ];
+
+  patches = [
+    # When cross-compiling we configure llvm-config-native with an approximation
+    # of the flags used for the normal LLVM build. To avoid the need for building
+    # a native libLLVM.so (which would fail) we force llvm-config to be linked
+    # statically against the necessary LLVM components always.
+    ../../llvm-config-link-static.patch
+
+    ./gnu-install-dirs.patch
+    # On older CPUs (e.g. Hydra/wendy) we'd be getting an error in this test.
+    (fetchpatch {
+      name = "uops-CMOV16rm-noreg.diff";
+      url = "https://github.com/llvm/llvm-project/commit/9e9f991ac033.diff";
+      sha256 = "sha256:12s8vr6ibri8b48h2z38f3afhwam10arfiqfy4yg37bmc054p5hi";
+      stripLen = 1;
+    })
+
+    # Fix missing includes for GCC 11
+    (fetchpatch {
+      name = "headers-gcc-11.patch";
+      url = "https://github.com/llvm/llvm-project/commit/b498303066a63a203d24f739b2d2e0e56dca70d1.patch";
+      sha256 = "0nh123kld0dgz2h941lng331dkj3wbm5lfxm375k1f569gv83hlk";
+      stripLen = 1;
+    })
+
+    # Fix invalid std::string(nullptr) for GCC 12
+    (fetchpatch {
+      name = "nvptx-gcc-12.patch";
+      url = "https://github.com/llvm/llvm-project/commit/99e64623ec9b31def9375753491cc6093c831809.patch";
+      sha256 = "0zjfjgavqzi2ypqwqnlvy6flyvdz8hi1anwv0ybwnm2zqixg7za3";
+      stripLen = 1;
+    })
+    (fetchpatch {
+      name = "dfaemitter-gcc-12.patch";
+      url = "https://github.com/llvm/llvm-project/commit/0841916e87a39e3c223c986e8da31e4a9a1432e3.patch";
+      sha256 = "1kckghvsngs51mqm82asy0s9vr19h8aqbw43a0w44mccqw6bzrwf";
+      stripLen = 1;
+    })
+
+    # Fix musl build.
+    (fetchpatch {
+      url = "https://github.com/llvm/llvm-project/commit/5cd554303ead0f8891eee3cd6d25cb07f5a7bf67.patch";
+      relative = "llvm";
+      hash = "sha256-XPbvNJ45SzjMGlNUgt/IgEvM2dHQpDOe6woUJY+nUYA=";
+    })
+
+    # Backport gcc-13 fixes with missing includes.
+    (fetchpatch {
+      name = "signals-gcc-13.patch";
+      url = "https://github.com/llvm/llvm-project/commit/ff1681ddb303223973653f7f5f3f3435b48a1983.patch";
+      hash = "sha256-CXwYxQezTq5vdmc8Yn88BUAEly6YZ5VEIA6X3y5NNOs=";
+      stripLen = 1;
+    })
+  ] ++ lib.optionals enablePolly [
+    ./gnu-install-dirs-polly.patch
+    # Add missing isl header includess required to build LLVM 10 + Polly with clang 16.
+    (fetchpatch {
+      name = "polly-ppcg-isl-headers.patch";
+      url = "https://repo.or.cz/ppcg.git/patch/098ba285306114dc71497f7b51c357f69c9b4472";
+      hash = "sha256-c9L30rDROYAMbUSuaK9U/ixyFMlH/Sa1n+VgLODzSCQ=";
+      extraPrefix = "tools/polly/lib/External/ppcg/";
+      stripLen = 1;
+    })
+  ];
+
+  postPatch = optionalString stdenv.isDarwin ''
+    substituteInPlace cmake/modules/AddLLVM.cmake \
+      --replace 'set(_install_name_dir INSTALL_NAME_DIR "@rpath")' "set(_install_name_dir)" \
+      --replace 'set(_install_rpath "@loader_path/../''${CMAKE_INSTALL_LIBDIR}''${LLVM_LIBDIR_SUFFIX}" ''${extra_libdir})' ""
+  '' + ''
+    # FileSystem permissions tests fail with various special bits
+    substituteInPlace unittests/Support/CMakeLists.txt \
+      --replace "Path.cpp" ""
+    rm unittests/Support/Path.cpp
+  '' + optionalString stdenv.hostPlatform.isMusl ''
+    patch -p1 -i ${../../TLI-musl.patch}
+    substituteInPlace unittests/Support/CMakeLists.txt \
+      --replace "add_subdirectory(DynamicLibrary)" ""
+    rm unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
+    # valgrind unhappy with musl or glibc, but fails w/musl only
+    rm test/CodeGen/AArch64/wineh4.mir
+  '' + optionalString stdenv.hostPlatform.isAarch32 ''
+    # skip failing X86 test cases on 32-bit ARM
+    rm test/DebugInfo/X86/convert-debugloc.ll
+    rm test/DebugInfo/X86/convert-inlined.ll
+    rm test/DebugInfo/X86/convert-linked.ll
+    rm test/DebugInfo/X86/debug_addr.ll
+    rm test/tools/dsymutil/X86/op-convert.test
+  '' + optionalString (stdenv.hostPlatform.system == "armv6l-linux") ''
+    # Seems to require certain floating point hardware (NEON?)
+    rm test/ExecutionEngine/frem.ll
+  '' + ''
+    patchShebangs test/BugPoint/compile-custom.ll.py
+  '' + ''
+    # Tweak tests to ignore namespace part of type to support
+    # gcc-12: https://gcc.gnu.org/PR103598.
+    # The change below mangles strings like:
+    #    CHECK-NEXT: Starting llvm::Function pass manager run.
+    # to:
+    #    CHECK-NEXT: Starting {{.*}}Function pass manager run.
+    for f in \
+      test/Other/new-pass-manager.ll \
+      test/Other/new-pm-defaults.ll \
+      test/Other/new-pm-lto-defaults.ll \
+      test/Other/new-pm-thinlto-defaults.ll \
+      test/Other/pass-pipeline-parsing.ll \
+      test/Transforms/Inline/cgscc-incremental-invalidate.ll \
+      test/Transforms/Inline/clear-analyses.ll \
+      test/Transforms/LoopUnroll/unroll-loop-invalidation.ll \
+      test/Transforms/SCCP/ipsccp-preserve-analysis.ll \
+      test/Transforms/SCCP/preserve-analysis.ll \
+      test/Transforms/SROA/dead-inst.ll \
+      test/tools/gold/X86/new-pm.ll \
+      ; do
+      echo "PATCH: $f"
+      substituteInPlace $f \
+        --replace 'Starting llvm::' 'Starting {{.*}}' \
+        --replace 'Finished llvm::' 'Finished {{.*}}'
+    done
+  '';
+
+  preConfigure = ''
+    # Workaround for configure flags that need to have spaces
+    cmakeFlagsArray+=(
+      -DLLVM_LIT_ARGS='-svj''${NIX_BUILD_CORES} --no-progress-bar'
+    )
+  '';
+
+  # hacky fix: created binaries need to be run before installation
+  preBuild = ''
+    mkdir -p $out/
+    ln -sv $PWD/lib $out
+  '';
+
+  cmakeBuildType = if debugVersion then "Debug" else "Release";
+
+  cmakeFlags = with stdenv; let
+    # These flags influence llvm-config's BuildVariables.inc in addition to the
+    # general build. We need to make sure these are also passed via
+    # CROSS_TOOLCHAIN_FLAGS_NATIVE when cross-compiling or llvm-config-native
+    # will return different results from the cross llvm-config.
+    #
+    # Some flags don't need to be repassed because LLVM already does so (like
+    # CMAKE_BUILD_TYPE), others are irrelevant to the result.
+    flagsForLlvmConfig = [
+      "-DLLVM_INSTALL_CMAKE_DIR=${placeholder "dev"}/lib/cmake/llvm/"
+      "-DLLVM_ENABLE_RTTI=ON"
+    ] ++ optionals enableSharedLibraries [
+      "-DLLVM_LINK_LLVM_DYLIB=ON"
+    ];
+  in flagsForLlvmConfig ++ [
+    "-DLLVM_INSTALL_UTILS=ON"  # Needed by rustc
+    "-DLLVM_BUILD_TESTS=${if doCheck then "ON" else "OFF"}"
+    "-DLLVM_ENABLE_FFI=ON"
+    "-DLLVM_HOST_TRIPLE=${stdenv.hostPlatform.config}"
+    "-DLLVM_DEFAULT_TARGET_TRIPLE=${stdenv.hostPlatform.config}"
+    "-DLLVM_ENABLE_DUMP=ON"
+  ] ++ optionals enableManpages [
+    "-DLLVM_BUILD_DOCS=ON"
+    "-DLLVM_ENABLE_SPHINX=ON"
+    "-DSPHINX_OUTPUT_MAN=ON"
+    "-DSPHINX_OUTPUT_HTML=OFF"
+    "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
+  ] ++ optionals (enableGoldPlugin) [
+    "-DLLVM_BINUTILS_INCDIR=${libbfd.dev}/include"
+  ] ++ optionals isDarwin [
+    "-DLLVM_ENABLE_LIBCXX=ON"
+    "-DCAN_TARGET_i386=false"
+  ] ++ optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+    "-DCMAKE_CROSSCOMPILING=True"
+    "-DLLVM_TABLEGEN=${buildLlvmTools.llvm}/bin/llvm-tblgen"
+    (
+      let
+        nativeCC = pkgsBuildBuild.targetPackages.stdenv.cc;
+        nativeBintools = nativeCC.bintools.bintools;
+        nativeToolchainFlags = [
+          "-DCMAKE_C_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}cc"
+          "-DCMAKE_CXX_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}c++"
+          "-DCMAKE_AR=${nativeBintools}/bin/${nativeBintools.targetPrefix}ar"
+          "-DCMAKE_STRIP=${nativeBintools}/bin/${nativeBintools.targetPrefix}strip"
+          "-DCMAKE_RANLIB=${nativeBintools}/bin/${nativeBintools.targetPrefix}ranlib"
+        ];
+        # We need to repass the custom GNUInstallDirs values, otherwise CMake
+        # will choose them for us, leading to wrong results in llvm-config-native
+        nativeInstallFlags = [
+          "-DCMAKE_INSTALL_PREFIX=${placeholder "out"}"
+          "-DCMAKE_INSTALL_BINDIR=${placeholder "out"}/bin"
+          "-DCMAKE_INSTALL_INCLUDEDIR=${placeholder "dev"}/include"
+          "-DCMAKE_INSTALL_LIBDIR=${placeholder "lib"}/lib"
+          "-DCMAKE_INSTALL_LIBEXECDIR=${placeholder "lib"}/libexec"
+        ];
+      in "-DCROSS_TOOLCHAIN_FLAGS_NATIVE:list="
+      + lib.concatStringsSep ";" (lib.concatLists [
+        flagsForLlvmConfig
+        nativeToolchainFlags
+        nativeInstallFlags
+      ])
+    )
+  ];
+
+  postBuild = ''
+    rm -fR $out
+  '';
+
+  preCheck = ''
+    export LD_LIBRARY_PATH=$LD_LIBRARY_PATH''${LD_LIBRARY_PATH:+:}$PWD/lib
+  '';
+
+  postInstall = ''
+    mkdir -p $python/share
+    mv $out/share/opt-viewer $python/share/opt-viewer
+    moveToOutput "bin/llvm-config*" "$dev"
+    substituteInPlace "$dev/lib/cmake/llvm/LLVMExports-${if debugVersion then "debug" else "release"}.cmake" \
+      --replace "\''${_IMPORT_PREFIX}/lib/lib" "$lib/lib/lib" \
+      --replace "$out/bin/llvm-config" "$dev/bin/llvm-config"
+    substituteInPlace "$dev/lib/cmake/llvm/LLVMConfig.cmake" \
+      --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}'"$lib"'")'
+  ''
+  + optionalString (stdenv.isDarwin && enableSharedLibraries) ''
+    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${shortVersion}.dylib
+    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
+  ''
+  + optionalString (stdenv.buildPlatform != stdenv.hostPlatform) ''
+    cp NATIVE/bin/llvm-config $dev/bin/llvm-config-native
+  '';
+
+  inherit doCheck;
+
+  checkTarget = "check-all";
+
+  requiredSystemFeatures = [ "big-parallel" ];
+  meta = llvm_meta // {
+    homepage = "https://llvm.org/";
+    description = "A collection of modular and reusable compiler and toolchain technologies";
+    longDescription = ''
+      The LLVM Project is a collection of modular and reusable compiler and
+      toolchain technologies. Despite its name, LLVM has little to do with
+      traditional virtual machines. The name "LLVM" itself is not an acronym; it
+      is the full name of the project.
+      LLVM began as a research project at the University of Illinois, with the
+      goal of providing a modern, SSA-based compilation strategy capable of
+      supporting both static and dynamic compilation of arbitrary programming
+      languages. Since then, LLVM has grown to be an umbrella project consisting
+      of a number of subprojects, many of which are being used in production by
+      a wide variety of commercial and open source projects as well as being
+      widely used in academic research. Code in the LLVM project is licensed
+      under the "Apache 2.0 License with LLVM exceptions".
+    '';
+  };
+} // lib.optionalAttrs enableManpages {
+  pname = "llvm-manpages";
+
+  buildPhase = ''
+    make docs-llvm-man
+  '';
+
+  propagatedBuildInputs = [];
+
+  installPhase = ''
+    make -C docs install
+  '';
+
+  postPatch = null;
+  postInstall = null;
+
+  outputs = [ "out" ];
+
+  doCheck = false;
+
+  meta = llvm_meta // {
+    description = "man pages for LLVM ${version}";
+  };
+})
--- a/llvm/10/llvm/gnu-install-dirs-polly.patch
+++ b/llvm/10/llvm/gnu-install-dirs-polly.patch
@ -0,0 +1,106 @@
+diff --git a/tools/polly/CMakeLists.txt b/tools/polly/CMakeLists.txt
+index 9939097f743e..8cc538da912a 100644
+--- a/tools/polly/CMakeLists.txt
+++ b/tools/polly/CMakeLists.txt
+@@ -2,7 +2,11 @@
+ if (NOT DEFINED LLVM_MAIN_SRC_DIR)
+   project(Polly)
+   cmake_minimum_required(VERSION 3.4.3)
+endif()
+
+include(GNUInstallDirs)
+ 
+if (NOT DEFINED LLVM_MAIN_SRC_DIR)
+   # Where is LLVM installed?
+   find_package(LLVM CONFIG REQUIRED)
+   set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${LLVM_CMAKE_DIR})
+@@ -145,14 +149,14 @@ include_directories(
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN ".svn" EXCLUDE
+     )
+ 
+   install(DIRECTORY ${POLLY_BINARY_DIR}/include/
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN "CMakeFiles" EXCLUDE
+diff --git a/tools/polly/cmake/CMakeLists.txt b/tools/polly/cmake/CMakeLists.txt
+index 211f95512717..f9e04a4844b6 100644
+--- a/tools/polly/cmake/CMakeLists.txt
+++ b/tools/polly/cmake/CMakeLists.txt
+@@ -79,18 +79,18 @@ file(GENERATE
+ 
+ # Generate PollyConfig.cmake for the install tree.
+ unset(POLLY_EXPORTS)
+-set(POLLY_INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX}")
+set(POLLY_INSTALL_PREFIX "")
+ set(POLLY_CONFIG_LLVM_CMAKE_DIR "${LLVM_BINARY_DIR}/${LLVM_INSTALL_PACKAGE_DIR}")
+-set(POLLY_CONFIG_CMAKE_DIR "${POLLY_INSTALL_PREFIX}/${POLLY_INSTALL_PACKAGE_DIR}")
+-set(POLLY_CONFIG_LIBRARY_DIRS "${POLLY_INSTALL_PREFIX}/lib${LLVM_LIBDIR_SUFFIX}")
+set(POLLY_CONFIG_CMAKE_DIR "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_PREFIX}/${POLLY_INSTALL_PACKAGE_DIR}")
+set(POLLY_CONFIG_LIBRARY_DIRS "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
+ if (POLLY_BUNDLED_ISL)
+   set(POLLY_CONFIG_INCLUDE_DIRS
+-    "${POLLY_INSTALL_PREFIX}/include"
+-    "${POLLY_INSTALL_PREFIX}/include/polly"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}/polly"
+     )
+ else()
+   set(POLLY_CONFIG_INCLUDE_DIRS
+-    "${POLLY_INSTALL_PREFIX}/include"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_INCLUDEDIR}"
+     ${ISL_INCLUDE_DIRS}
+     )
+ endif()
+@@ -100,12 +100,12 @@ endif()
+ foreach(tgt IN LISTS POLLY_CONFIG_EXPORTED_TARGETS)
+   get_target_property(tgt_type ${tgt} TYPE)
+   if (tgt_type STREQUAL "EXECUTABLE")
+-    set(tgt_prefix "bin/")
+    set(tgt_prefix "${CMAKE_INSTALL_BINDIR}/")
+   else()
+-    set(tgt_prefix "lib/")
+    set(tgt_prefix "${CMAKE_INSTALL_LIBDIR}/")
+   endif()
+ 
+-  set(tgt_path "${CMAKE_INSTALL_PREFIX}/${tgt_prefix}$<TARGET_FILE_NAME:${tgt}>")
+  set(tgt_path "${tgt_prefix}$<TARGET_FILE_NAME:${tgt}>")
+   file(RELATIVE_PATH tgt_path ${POLLY_CONFIG_CMAKE_DIR} ${tgt_path})
+ 
+   if (NOT tgt_type STREQUAL "INTERFACE_LIBRARY")
+diff --git a/tools/polly/cmake/polly_macros.cmake b/tools/polly/cmake/polly_macros.cmake
+index 86de6f10686e..91f30891ccbe 100644
+--- a/tools/polly/cmake/polly_macros.cmake
+++ b/tools/polly/cmake/polly_macros.cmake
+@@ -44,8 +44,8 @@ macro(add_polly_library name)
+   if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY OR ${name} STREQUAL "LLVMPolly")
+     install(TARGETS ${name}
+       EXPORT LLVMExports
+-      LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-      ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX})
+	  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+   endif()
+   set_property(GLOBAL APPEND PROPERTY LLVM_EXPORTS ${name})
+ endmacro(add_polly_library)
+diff --git a/tools/polly/lib/External/CMakeLists.txt b/tools/polly/lib/External/CMakeLists.txt
+index 8ffd984e542b..261cc19f3238 100644
+--- a/tools/polly/lib/External/CMakeLists.txt
+++ b/tools/polly/lib/External/CMakeLists.txt
+@@ -274,7 +274,7 @@ if (POLLY_BUNDLED_ISL)
+     install(DIRECTORY
+       ${ISL_SOURCE_DIR}/include/
+       ${ISL_BINARY_DIR}/include/
+-      DESTINATION include/polly
+      DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/polly
+       FILES_MATCHING
+       PATTERN "*.h"
+       PATTERN "CMakeFiles" EXCLUDE
--- a/llvm/10/llvm/gnu-install-dirs.patch
+++ b/llvm/10/llvm/gnu-install-dirs.patch
@ -0,0 +1,416 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 0e85afa82c76..3e700d9c5fae 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -253,15 +253,21 @@ if (CMAKE_BUILD_TYPE AND
+   message(FATAL_ERROR "Invalid value for CMAKE_BUILD_TYPE: ${CMAKE_BUILD_TYPE}")
+ endif()
+ 
+include(GNUInstallDirs)
+
+ set(LLVM_LIBDIR_SUFFIX "" CACHE STRING "Define suffix of library directory name (32/64)" )
+ 
+-set(LLVM_TOOLS_INSTALL_DIR "bin" CACHE STRING "Path for binary subdirectory (defaults to 'bin')")
+set(LLVM_TOOLS_INSTALL_DIR "${CMAKE_INSTALL_BINDIR}" CACHE STRING
+    "Path for binary subdirectory (defaults to 'bin')")
+ mark_as_advanced(LLVM_TOOLS_INSTALL_DIR)
+ 
+ set(LLVM_UTILS_INSTALL_DIR "${LLVM_TOOLS_INSTALL_DIR}" CACHE STRING
+     "Path to install LLVM utilities (enabled by LLVM_INSTALL_UTILS=ON) (defaults to LLVM_TOOLS_INSTALL_DIR)")
+ mark_as_advanced(LLVM_UTILS_INSTALL_DIR)
+ 
+set(LLVM_INSTALL_CMAKE_DIR "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/cmake/llvm" CACHE STRING
+	"Path for CMake subdirectory (defaults to lib/cmake/llvm)" )
+
+ # They are used as destination of target generators.
+ set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin)
+ set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
+@@ -527,9 +533,9 @@ option (LLVM_ENABLE_SPHINX "Use Sphinx to generate llvm documentation." OFF)
+ option (LLVM_ENABLE_OCAMLDOC "Build OCaml bindings documentation." ON)
+ option (LLVM_ENABLE_BINDINGS "Build bindings." ON)
+ 
+-set(LLVM_INSTALL_DOXYGEN_HTML_DIR "share/doc/llvm/doxygen-html"
+set(LLVM_INSTALL_DOXYGEN_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/doxygen-html"
+     CACHE STRING "Doxygen-generated HTML documentation install directory")
+-set(LLVM_INSTALL_OCAMLDOC_HTML_DIR "share/doc/llvm/ocaml-html"
+set(LLVM_INSTALL_OCAMLDOC_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/ocaml-html"
+     CACHE STRING "OCamldoc-generated HTML documentation install directory")
+ 
+ option (LLVM_BUILD_EXTERNAL_COMPILER_RT
+@@ -993,7 +999,7 @@ endif()
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/llvm include/llvm-c
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT llvm-headers
+     FILES_MATCHING
+     PATTERN "*.def"
+@@ -1005,7 +1011,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+     )
+ 
+   install(DIRECTORY ${LLVM_INCLUDE_DIR}/llvm ${LLVM_INCLUDE_DIR}/llvm-c
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT llvm-headers
+     FILES_MATCHING
+     PATTERN "*.def"
+@@ -1020,13 +1026,13 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+ 
+   if (LLVM_INSTALL_MODULEMAPS)
+     install(DIRECTORY include/llvm include/llvm-c
+-            DESTINATION include
+            DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+             COMPONENT llvm-headers
+             FILES_MATCHING
+             PATTERN "module.modulemap"
+             )
+     install(FILES include/llvm/module.install.modulemap
+-            DESTINATION include/llvm
+            DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm
+             COMPONENT llvm-headers
+             RENAME "module.extern.modulemap"
+             )
+diff --git a/cmake/modules/AddLLVM.cmake b/cmake/modules/AddLLVM.cmake
+index f5a1b0d6f238..a7387224d68f 100644
+--- a/cmake/modules/AddLLVM.cmake
+++ b/cmake/modules/AddLLVM.cmake
+@@ -729,9 +729,9 @@ macro(add_llvm_library name)
+ 
+       install(TARGETS ${name}
+               ${export_to_llvmexports}
+-              LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+-              ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+-              RUNTIME DESTINATION bin COMPONENT ${name})
+              LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+              ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+              RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT ${name})
+ 
+       if (NOT LLVM_ENABLE_IDE)
+         add_llvm_install_targets(install-${name}
+@@ -934,7 +934,7 @@ function(process_llvm_pass_plugins)
+           "set(LLVM_STATIC_EXTENSIONS ${LLVM_STATIC_EXTENSIONS})")
+       install(FILES
+           ${llvm_cmake_builddir}/LLVMConfigExtensions.cmake
+-          DESTINATION ${LLVM_INSTALL_PACKAGE_DIR}
+          DESTINATION ${LLVM_INSTALL_CMAKE_DIR}
+           COMPONENT cmake-exports)
+ 
+       set(ExtensionDef "${LLVM_BINARY_DIR}/include/llvm/Support/Extension.def")
+@@ -1147,7 +1147,7 @@ macro(add_llvm_example name)
+   endif()
+   add_llvm_executable(${name} ${ARGN})
+   if( LLVM_BUILD_EXAMPLES )
+-    install(TARGETS ${name} RUNTIME DESTINATION examples)
+    install(TARGETS ${name} RUNTIME DESTINATION ${CMAKE_INSTALL_DOCDIR}/examples)
+   endif()
+   set_target_properties(${name} PROPERTIES FOLDER "Examples")
+ endmacro(add_llvm_example name)
+@@ -1713,7 +1713,7 @@ function(llvm_install_library_symlink name dest type)
+   set(full_name ${CMAKE_${type}_LIBRARY_PREFIX}${name}${CMAKE_${type}_LIBRARY_SUFFIX})
+   set(full_dest ${CMAKE_${type}_LIBRARY_PREFIX}${dest}${CMAKE_${type}_LIBRARY_SUFFIX})
+ 
+-  set(output_dir lib${LLVM_LIBDIR_SUFFIX})
+  set(output_dir ${CMAKE_INSTALL_FULL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+   if(WIN32 AND "${type}" STREQUAL "SHARED")
+     set(output_dir bin)
+   endif()
+@@ -1730,7 +1730,7 @@ function(llvm_install_library_symlink name dest type)
+   endif()
+ endfunction()
+ 
+-function(llvm_install_symlink name dest)
+function(llvm_install_symlink name dest output_dir)
+   cmake_parse_arguments(ARG "ALWAYS_GENERATE" "COMPONENT" "" ${ARGN})
+   foreach(path ${CMAKE_MODULE_PATH})
+     if(EXISTS ${path}/LLVMInstallSymlink.cmake)
+@@ -1753,7 +1753,7 @@ function(llvm_install_symlink name dest)
+   set(full_dest ${dest}${CMAKE_EXECUTABLE_SUFFIX})
+ 
+   install(SCRIPT ${INSTALL_SYMLINK}
+-          CODE "install_symlink(${full_name} ${full_dest} ${LLVM_TOOLS_INSTALL_DIR})"
+          CODE "install_symlink(${full_name} ${full_dest} ${output_dir})"
+           COMPONENT ${component})
+ 
+   if (NOT LLVM_ENABLE_IDE AND NOT ARG_ALWAYS_GENERATE)
+@@ -1836,7 +1836,8 @@ function(add_llvm_tool_symlink link_name target)
+     endif()
+ 
+     if ((TOOL_IS_TOOLCHAIN OR NOT LLVM_INSTALL_TOOLCHAIN_ONLY) AND LLVM_BUILD_TOOLS)
+-      llvm_install_symlink(${link_name} ${target})
+      GNUInstallDirs_get_absolute_install_dir(output_dir LLVM_TOOLS_INSTALL_DIR)
+      llvm_install_symlink(${link_name} ${target} ${output_dir})
+     endif()
+   endif()
+ endfunction()
+@@ -1958,9 +1959,9 @@ function(llvm_setup_rpath name)
+ 
+   if (APPLE)
+     set(_install_name_dir INSTALL_NAME_DIR "@rpath")
+-    set(_install_rpath "@loader_path/../lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+    set(_install_rpath "@loader_path/../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+   elseif(UNIX)
+-    set(_install_rpath "\$ORIGIN/../lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+    set(_install_rpath "\$ORIGIN/../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+     if(${CMAKE_SYSTEM_NAME} MATCHES "(FreeBSD|DragonFly)")
+       set_property(TARGET ${name} APPEND_STRING PROPERTY
+                    LINK_FLAGS " -Wl,-z,origin ")
+diff --git a/cmake/modules/AddOCaml.cmake b/cmake/modules/AddOCaml.cmake
+index 554046b20edf..4d1ad980641e 100644
+--- a/cmake/modules/AddOCaml.cmake
+++ b/cmake/modules/AddOCaml.cmake
+@@ -144,9 +144,9 @@ function(add_ocaml_library name)
+   endforeach()
+ 
+   if( APPLE )
+-    set(ocaml_rpath "@executable_path/../../../lib${LLVM_LIBDIR_SUFFIX}")
+    set(ocaml_rpath "@executable_path/../../../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
+   elseif( UNIX )
+-    set(ocaml_rpath "\\$ORIGIN/../../../lib${LLVM_LIBDIR_SUFFIX}")
+    set(ocaml_rpath "\\$ORIGIN/../../../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
+   endif()
+   list(APPEND ocaml_flags "-ldopt" "-Wl,-rpath,${ocaml_rpath}")
+ 
+diff --git a/cmake/modules/AddSphinxTarget.cmake b/cmake/modules/AddSphinxTarget.cmake
+index 2bf654b60c44..450ee45d86e6 100644
+--- a/cmake/modules/AddSphinxTarget.cmake
+++ b/cmake/modules/AddSphinxTarget.cmake
+@@ -78,7 +78,7 @@ function (add_sphinx_target builder project)
+         endif()
+       elseif (builder STREQUAL html)
+         string(TOUPPER "${project}" project_upper)
+-        set(${project_upper}_INSTALL_SPHINX_HTML_DIR "share/doc/${project}/html"
+        set(${project_upper}_INSTALL_SPHINX_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/html"
+             CACHE STRING "HTML documentation install directory for ${project}")
+ 
+         # '/.' indicates: copy the contents of the directory directly into
+diff --git a/cmake/modules/CMakeLists.txt b/cmake/modules/CMakeLists.txt
+index af757d6199a8..b0fb7e7705d1 100644
+--- a/cmake/modules/CMakeLists.txt
+++ b/cmake/modules/CMakeLists.txt
+@@ -1,4 +1,4 @@
+-set(LLVM_INSTALL_PACKAGE_DIR lib${LLVM_LIBDIR_SUFFIX}/cmake/llvm)
+set(LLVM_INSTALL_PACKAGE_DIR ${LLVM_INSTALL_CMAKE_DIR} CACHE STRING "Path for CMake subdirectory (defaults to 'cmake/llvm')")
+ set(llvm_cmake_builddir "${LLVM_BINARY_DIR}/${LLVM_INSTALL_PACKAGE_DIR}")
+ 
+ # First for users who use an installed LLVM, create the LLVMExports.cmake file.
+@@ -96,13 +96,13 @@ foreach(p ${_count})
+   set(LLVM_CONFIG_CODE "${LLVM_CONFIG_CODE}
+ get_filename_component(LLVM_INSTALL_PREFIX \"\${LLVM_INSTALL_PREFIX}\" PATH)")
+ endforeach(p)
+-set(LLVM_CONFIG_INCLUDE_DIRS "\${LLVM_INSTALL_PREFIX}/include")
+set(LLVM_CONFIG_INCLUDE_DIRS "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_INCLUDEDIR}")
+ set(LLVM_CONFIG_INCLUDE_DIR "${LLVM_CONFIG_INCLUDE_DIRS}")
+ set(LLVM_CONFIG_MAIN_INCLUDE_DIR "${LLVM_CONFIG_INCLUDE_DIRS}")
+-set(LLVM_CONFIG_LIBRARY_DIRS "\${LLVM_INSTALL_PREFIX}/lib\${LLVM_LIBDIR_SUFFIX}")
+set(LLVM_CONFIG_LIBRARY_DIRS "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}\${LLVM_LIBDIR_SUFFIX}")
+ set(LLVM_CONFIG_CMAKE_DIR "\${LLVM_INSTALL_PREFIX}/${LLVM_INSTALL_PACKAGE_DIR}")
+ set(LLVM_CONFIG_BINARY_DIR "\${LLVM_INSTALL_PREFIX}")
+-set(LLVM_CONFIG_TOOLS_BINARY_DIR "\${LLVM_INSTALL_PREFIX}/bin")
+set(LLVM_CONFIG_TOOLS_BINARY_DIR "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_BINDIR}")
+ set(LLVM_CONFIG_EXPORTS_FILE "\${LLVM_CMAKE_DIR}/LLVMExports.cmake")
+ set(LLVM_CONFIG_EXPORTS "${LLVM_EXPORTS}")
+ configure_file(
+diff --git a/cmake/modules/LLVMInstallSymlink.cmake b/cmake/modules/LLVMInstallSymlink.cmake
+index 09fed8085c23..aa79f192abf0 100644
+--- a/cmake/modules/LLVMInstallSymlink.cmake
+++ b/cmake/modules/LLVMInstallSymlink.cmake
+@@ -10,7 +10,7 @@ function(install_symlink name target outdir)
+     set(LINK_OR_COPY copy)
+   endif()
+ 
+-  set(bindir "${DESTDIR}${CMAKE_INSTALL_PREFIX}/${outdir}/")
+  set(bindir "${DESTDIR}${outdir}/")
+ 
+   message(STATUS "Creating ${name}")
+ 
+diff --git a/docs/CMake.rst b/docs/CMake.rst
+index a86ebb3a37bd..e720711e2b3c 100644
+--- a/docs/CMake.rst
+++ b/docs/CMake.rst
+@@ -196,7 +196,7 @@ CMake manual, or execute ``cmake --help-variable VARIABLE_NAME``.
+ **LLVM_LIBDIR_SUFFIX**:STRING
+   Extra suffix to append to the directory where libraries are to be
+   installed. On a 64-bit architecture, one could use ``-DLLVM_LIBDIR_SUFFIX=64``
+-  to install libraries to ``/usr/lib64``.
+  to install libraries to ``/usr/lib64``. See also ``CMAKE_INSTALL_LIBDIR``.
+ 
+ **CMAKE_C_FLAGS**:STRING
+   Extra flags to use when compiling C source files.
+@@ -516,8 +516,8 @@ LLVM-specific variables
+ 
+ **LLVM_INSTALL_DOXYGEN_HTML_DIR**:STRING
+   The path to install Doxygen-generated HTML documentation to. This path can
+-  either be absolute or relative to the CMAKE_INSTALL_PREFIX. Defaults to
+-  `share/doc/llvm/doxygen-html`.
+  either be absolute or relative to the ``CMAKE_INSTALL_PREFIX``. Defaults to
+  `${CMAKE_INSTALL_DOCDIR}/${project}/doxygen-html`.
+ 
+ **LLVM_ENABLE_SPHINX**:BOOL
+   If specified, CMake will search for the ``sphinx-build`` executable and will make
+@@ -548,13 +548,33 @@ LLVM-specific variables
+ 
+ **LLVM_INSTALL_SPHINX_HTML_DIR**:STRING
+   The path to install Sphinx-generated HTML documentation to. This path can
+-  either be absolute or relative to the CMAKE_INSTALL_PREFIX. Defaults to
+-  `share/doc/llvm/html`.
+  either be absolute or relative to the ``CMAKE_INSTALL_PREFIX``. Defaults to
+  `${CMAKE_INSTALL_DOCDIR}/${project}/html`.
+ 
+ **LLVM_INSTALL_OCAMLDOC_HTML_DIR**:STRING
+   The path to install OCamldoc-generated HTML documentation to. This path can
+-  either be absolute or relative to the CMAKE_INSTALL_PREFIX. Defaults to
+-  `share/doc/llvm/ocaml-html`.
+  either be absolute or relative to the ``CMAKE_INSTALL_PREFIX``. Defaults to
+  `${CMAKE_INSTALL_DOCDIR}/${project}/ocaml-html`.
+
+**CMAKE_INSTALL_BINDIR**:STRING
+  The path to install binary tools, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `bin`.
+
+**CMAKE_INSTALL_LIBDIR**:STRING
+  The path to install libraries, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `lib`.
+
+**CMAKE_INSTALL_INCLUDEDIR**:STRING
+  The path to install header files, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `include`.
+
+**CMAKE_INSTALL_DOCDIR**:STRING
+  The path to install documentation, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `share/doc`.
+
+**CMAKE_INSTALL_MANDIR**:STRING
+  The path to install manpage files, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `share/man`.
+ 
+ **LLVM_CREATE_XCODE_TOOLCHAIN**:BOOL
+   macOS Only: If enabled CMake will generate a target named
+@@ -740,9 +760,11 @@ the ``cmake`` command or by setting it directly in ``ccmake`` or ``cmake-gui``).
+ 
+ This file is available in two different locations.
+ 
+-* ``<INSTALL_PREFIX>/lib/cmake/llvm/LLVMConfig.cmake`` where
+-  ``<INSTALL_PREFIX>`` is the install prefix of an installed version of LLVM.
+-  On Linux typically this is ``/usr/lib/cmake/llvm/LLVMConfig.cmake``.
+* ``<LLVM_INSTALL_PACKAGE_DIR>LLVMConfig.cmake`` where
+  ``<LLVM_INSTALL_PACKAGE_DIR>`` is the location where LLVM CMake modules are
+  installed as part of an installed version of LLVM. This is typically
+  ``cmake/llvm/`` within the lib directory. On Linux, this is typically
+  ``/usr/lib/cmake/llvm/LLVMConfig.cmake``.
+ 
+ * ``<LLVM_BUILD_ROOT>/lib/cmake/llvm/LLVMConfig.cmake`` where
+   ``<LLVM_BUILD_ROOT>`` is the root of the LLVM build tree. **Note: this is only
+diff --git a/examples/Bye/CMakeLists.txt b/examples/Bye/CMakeLists.txt
+index 3206f90d0916..1822965fc35f 100644
+--- a/examples/Bye/CMakeLists.txt
+++ b/examples/Bye/CMakeLists.txt
+@@ -9,5 +9,5 @@ add_llvm_pass_plugin(Bye
+   BUILDTREE_ONLY
+  )
+ 
+-install(TARGETS ${name} RUNTIME DESTINATION examples)
+install(TARGETS ${name} RUNTIME DESTINATION ${CMAKE_INSTALL_DOCDIR}/examples)
+ set_target_properties(${name} PROPERTIES FOLDER "Examples")
+diff --git a/include/llvm/CMakeLists.txt b/include/llvm/CMakeLists.txt
+index 1d5ca3ba92b0..026f5453c1da 100644
+--- a/include/llvm/CMakeLists.txt
+++ b/include/llvm/CMakeLists.txt
+@@ -4,5 +4,5 @@ add_subdirectory(Support)
+ # If we're doing an out-of-tree build, copy a module map for generated
+ # header files into the build area.
+ if (NOT "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
+-  configure_file(module.modulemap.build module.modulemap COPYONLY)
+  configure_file(module.modulemap.build ${LLVM_INCLUDE_DIR}/module.modulemap COPYONLY)
+ endif (NOT "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
+diff --git a/tools/llvm-config/BuildVariables.inc.in b/tools/llvm-config/BuildVariables.inc.in
+index 63cef75368b7..6295478b1f3d 100644
+--- a/tools/llvm-config/BuildVariables.inc.in
+++ b/tools/llvm-config/BuildVariables.inc.in
+@@ -23,6 +23,10 @@
+ #define LLVM_CXXFLAGS "@LLVM_CXXFLAGS@"
+ #define LLVM_BUILDMODE "@LLVM_BUILDMODE@"
+ #define LLVM_LIBDIR_SUFFIX "@LLVM_LIBDIR_SUFFIX@"
+#define LLVM_INSTALL_BINDIR "@CMAKE_INSTALL_BINDIR@"
+#define LLVM_INSTALL_LIBDIR "@CMAKE_INSTALL_LIBDIR@"
+#define LLVM_INSTALL_INCLUDEDIR "@CMAKE_INSTALL_INCLUDEDIR@"
+#define LLVM_INSTALL_CMAKEDIR "@LLVM_INSTALL_CMAKE_DIR@"
+ #define LLVM_TARGETS_BUILT "@LLVM_TARGETS_BUILT@"
+ #define LLVM_SYSTEM_LIBS "@LLVM_SYSTEM_LIBS@"
+ #define LLVM_BUILD_SYSTEM "@LLVM_BUILD_SYSTEM@"
+diff --git a/tools/llvm-config/llvm-config.cpp b/tools/llvm-config/llvm-config.cpp
+index fb12e29a36a8..dbb6c2b90332 100644
+--- a/tools/llvm-config/llvm-config.cpp
+++ b/tools/llvm-config/llvm-config.cpp
+@@ -358,12 +358,26 @@ int main(int argc, char **argv) {
+         ("-I" + ActiveIncludeDir + " " + "-I" + ActiveObjRoot + "/include");
+   } else {
+     ActivePrefix = CurrentExecPrefix;
+-    ActiveIncludeDir = ActivePrefix + "/include";
+-    SmallString<256> path(StringRef(LLVM_TOOLS_INSTALL_DIR));
+-    sys::fs::make_absolute(ActivePrefix, path);
+-    ActiveBinDir = path.str();
+-    ActiveLibDir = ActivePrefix + "/lib" + LLVM_LIBDIR_SUFFIX;
+-    ActiveCMakeDir = ActiveLibDir + "/cmake/llvm";
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_INCLUDEDIR));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveIncludeDir = std::string(path.str());
+    }
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_BINDIR));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveBinDir = std::string(path.str());
+    }
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_LIBDIR LLVM_LIBDIR_SUFFIX));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveLibDir = std::string(path.str());
+    }
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_CMAKEDIR));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveCMakeDir = std::string(path.str());
+    }
+     ActiveIncludeOption = "-I" + ActiveIncludeDir;
+   }
+ 
+diff --git a/tools/lto/CMakeLists.txt b/tools/lto/CMakeLists.txt
+index b86e4abd01a7..02ce5773f17d 100644
+--- a/tools/lto/CMakeLists.txt
+++ b/tools/lto/CMakeLists.txt
+@@ -23,7 +23,7 @@ set(LLVM_EXPORTED_SYMBOL_FILE ${CMAKE_CURRENT_SOURCE_DIR}/lto.exports)
+ add_llvm_library(LTO SHARED INSTALL_WITH_TOOLCHAIN ${SOURCES} DEPENDS intrinsics_gen)
+ 
+ install(FILES ${LLVM_MAIN_INCLUDE_DIR}/llvm-c/lto.h
+-  DESTINATION include/llvm-c
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm-c
+   COMPONENT LTO)
+ 
+ if (APPLE)
+diff --git a/tools/opt-viewer/CMakeLists.txt b/tools/opt-viewer/CMakeLists.txt
+index ead73ec13a8f..250362021f17 100644
+--- a/tools/opt-viewer/CMakeLists.txt
+++ b/tools/opt-viewer/CMakeLists.txt
+@@ -8,7 +8,7 @@ set (files
+ 
+ foreach (file ${files})
+   install(PROGRAMS ${file}
+-    DESTINATION share/opt-viewer
+    DESTINATION ${CMAKE_INSTALL_DATADIR}/opt-viewer
+     COMPONENT opt-viewer)
+ endforeach (file)
+ 
+diff --git a/tools/remarks-shlib/CMakeLists.txt b/tools/remarks-shlib/CMakeLists.txt
+index e948496c603a..1f4df8a98b10 100644
+--- a/tools/remarks-shlib/CMakeLists.txt
+++ b/tools/remarks-shlib/CMakeLists.txt
+@@ -11,7 +11,7 @@ set(LLVM_EXPORTED_SYMBOL_FILE ${CMAKE_CURRENT_SOURCE_DIR}/Remarks.exports)
+ add_llvm_library(Remarks SHARED INSTALL_WITH_TOOLCHAIN ${SOURCES})
+ 
+ install(FILES ${LLVM_MAIN_INCLUDE_DIR}/llvm-c/Remarks.h
+-  DESTINATION include/llvm-c
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm-c
+   COMPONENT Remarks)
+ 
+ if (APPLE)
--- a/llvm/10/openmp/default.nix
+++ b/llvm/10/openmp/default.nix
@ -0,0 +1,37 @@
+{ lib
+, stdenv
+, llvm_meta
+, fetch
+, cmake
+, llvm
+, targetLlvm
+, perl
+, version
+}:
+
+stdenv.mkDerivation rec {
+  pname = "openmp";
+  inherit version;
+
+  src = fetch pname "0i4bn84lkpm5w3qkpvwm5z6jdj8fynp7d3bcasa1xyq4is6757yi";
+
+  nativeBuildInputs = [ cmake perl ];
+  buildInputs = [
+    (if stdenv.buildPlatform == stdenv.hostPlatform then llvm else targetLlvm)
+  ];
+
+  meta = llvm_meta // {
+    homepage = "https://openmp.llvm.org/";
+    description = "Support for the OpenMP language";
+    longDescription = ''
+      The OpenMP subproject of LLVM contains the components required to build an
+      executable OpenMP program that are outside the compiler itself.
+      Contains the code for the runtime library against which code compiled by
+      "clang -fopenmp" must be linked before it can run and the library that
+      supports offload to target devices.
+    '';
+    # "All of the code is dual licensed under the MIT license and the UIUC
+    # License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}
--- a/llvm/11/clang/default.nix
+++ b/llvm/11/clang/default.nix
@ -0,0 +1,138 @@
+{ lib, stdenv, llvm_meta, fetch, fetchpatch, substituteAll, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
+, buildLlvmTools
+, fixDarwinDylibNames
+, enableManpages ? false
+, enablePolly ? false
+}:
+
+let
+  self = stdenv.mkDerivation ({
+    pname = "clang";
+    inherit version;
+
+    src = fetch "clang" "12sm91qx2m79cvj75a9aazf2x8xybjbd593dv6v7rxficpq8i0ha";
+    inherit clang-tools-extra_src;
+
+    unpackPhase = ''
+      unpackFile $src
+      mv clang-* clang
+      sourceRoot=$PWD/clang
+      unpackFile ${clang-tools-extra_src}
+      mv clang-tools-extra-* $sourceRoot/tools/extra
+    '';
+
+    nativeBuildInputs = [ cmake python3 ]
+      ++ lib.optional enableManpages python3.pkgs.sphinx
+      ++ lib.optional stdenv.hostPlatform.isDarwin fixDarwinDylibNames;
+
+    buildInputs = [ libxml2 libllvm ];
+
+    cmakeFlags = [
+      "-DCLANGD_BUILD_XPC=OFF"
+      "-DLLVM_ENABLE_RTTI=ON"
+    ] ++ lib.optionals enableManpages [
+      "-DCLANG_INCLUDE_DOCS=ON"
+      "-DLLVM_ENABLE_SPHINX=ON"
+      "-DSPHINX_OUTPUT_MAN=ON"
+      "-DSPHINX_OUTPUT_HTML=OFF"
+      "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
+    ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+      "-DLLVM_TABLEGEN_EXE=${buildLlvmTools.llvm}/bin/llvm-tblgen"
+      "-DCLANG_TABLEGEN=${buildLlvmTools.libclang.dev}/bin/clang-tblgen"
+    ] ++ lib.optionals enablePolly [
+      "-DWITH_POLLY=ON"
+      "-DLINK_POLLY_INTO_TOOLS=ON"
+    ];
+
+
+    patches = [
+      ./purity.patch
+      # https://reviews.llvm.org/D51899
+      ./gnu-install-dirs.patch
+      (substituteAll {
+        src = ../../clang-11-12-LLVMgold-path.patch;
+        libllvmLibdir = "${libllvm.lib}/lib";
+      })
+    ];
+
+    postPatch = ''
+      sed -i -e 's/DriverArgs.hasArg(options::OPT_nostdlibinc)/true/' \
+             -e 's/Args.hasArg(options::OPT_nostdlibinc)/true/' \
+             lib/Driver/ToolChains/*.cpp
+    '' + lib.optionalString stdenv.hostPlatform.isMusl ''
+      sed -i -e 's/lgcc_s/lgcc_eh/' lib/Driver/ToolChains/*.cpp
+    '' + lib.optionalString stdenv.hostPlatform.isDarwin ''
+      substituteInPlace tools/extra/clangd/CMakeLists.txt \
+        --replace "NOT HAVE_CXX_ATOMICS64_WITHOUT_LIB" FALSE
+    '';
+
+    outputs = [ "out" "lib" "dev" "python" ];
+
+    postInstall = ''
+      ln -sv $out/bin/clang $out/bin/cpp
+
+      # Move libclang to 'lib' output
+      moveToOutput "lib/libclang.*" "$lib"
+      moveToOutput "lib/libclang-cpp.*" "$lib"
+      substituteInPlace $out/lib/cmake/clang/ClangTargets-release.cmake \
+          --replace "\''${_IMPORT_PREFIX}/lib/libclang." "$lib/lib/libclang." \
+          --replace "\''${_IMPORT_PREFIX}/lib/libclang-cpp." "$lib/lib/libclang-cpp."
+
+      mkdir -p $python/bin $python/share/{clang,scan-view}
+      mv $out/bin/{git-clang-format,scan-view} $python/bin
+      if [ -e $out/bin/set-xcode-analyzer ]; then
+        mv $out/bin/set-xcode-analyzer $python/bin
+      fi
+      mv $out/share/clang/*.py $python/share/clang
+      mv $out/share/scan-view/*.py $python/share/scan-view
+      rm $out/bin/c-index-test
+      patchShebangs $python/bin
+
+      mkdir -p $dev/bin
+      cp bin/clang-tblgen $dev/bin
+    '';
+
+    passthru = {
+      inherit libllvm;
+      isClang = true;
+      hardeningUnsupportedFlags = [ "fortify3" ];
+    };
+
+    meta = llvm_meta // {
+      homepage = "https://clang.llvm.org/";
+      description = "A C language family frontend for LLVM";
+      longDescription = ''
+        The Clang project provides a language front-end and tooling
+        infrastructure for languages in the C language family (C, C++, Objective
+        C/C++, OpenCL, CUDA, and RenderScript) for the LLVM project.
+        It aims to deliver amazingly fast compiles, extremely useful error and
+        warning messages and to provide a platform for building great source
+        level tools. The Clang Static Analyzer and clang-tidy are tools that
+        automatically find bugs in your code, and are great examples of the sort
+        of tools that can be built using the Clang frontend as a library to
+        parse C/C++ code.
+      '';
+      mainProgram = "clang";
+    };
+  } // lib.optionalAttrs enableManpages {
+    pname = "clang-manpages";
+
+    buildPhase = ''
+      make docs-clang-man
+    '';
+
+    installPhase = ''
+      mkdir -p $out/share/man/man1
+      # Manually install clang manpage
+      cp docs/man/*.1 $out/share/man/man1/
+    '';
+
+    outputs = [ "out" ];
+
+    doCheck = false;
+
+    meta = llvm_meta // {
+      description = "man page for Clang ${version}";
+    };
+  });
+in self
--- a/llvm/11/clang/gnu-install-dirs.patch
+++ b/llvm/11/clang/gnu-install-dirs.patch
@ -0,0 +1,235 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index bb4b801f01c8..77a8b43b22c8 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -9,6 +9,8 @@ endif()
+ if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
+   project(Clang)
+ 
+  include(GNUInstallDirs)
+
+   set(CMAKE_CXX_STANDARD 14 CACHE STRING "C++ standard to conform to")
+   set(CMAKE_CXX_STANDARD_REQUIRED YES)
+   set(CMAKE_CXX_EXTENSIONS NO)
+@@ -447,7 +449,7 @@ include_directories(BEFORE
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/clang include/clang-c
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT clang-headers
+     FILES_MATCHING
+     PATTERN "*.def"
+@@ -457,7 +459,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+     )
+ 
+   install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/clang
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT clang-headers
+     FILES_MATCHING
+     PATTERN "CMakeFiles" EXCLUDE
+@@ -477,7 +479,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+ 
+   add_custom_target(bash-autocomplete DEPENDS utils/bash-autocomplete.sh)
+   install(PROGRAMS utils/bash-autocomplete.sh
+-          DESTINATION share/clang
+          DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+           COMPONENT bash-autocomplete)
+   if(NOT LLVM_ENABLE_IDE)
+     add_llvm_install_targets(install-bash-autocomplete
+diff --git a/cmake/modules/AddClang.cmake b/cmake/modules/AddClang.cmake
+index 704278a0e93b..d25c8d325c71 100644
+--- a/cmake/modules/AddClang.cmake
+++ b/cmake/modules/AddClang.cmake
+@@ -123,9 +123,9 @@ macro(add_clang_library name)
+         install(TARGETS ${lib}
+           COMPONENT ${lib}
+           ${export_to_clangtargets}
+-          LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-          ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-          RUNTIME DESTINATION bin)
+          LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+          ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+          RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+ 
+         if (NOT LLVM_ENABLE_IDE)
+           add_llvm_install_targets(install-${lib}
+@@ -170,7 +170,7 @@ macro(add_clang_tool name)
+ 
+     install(TARGETS ${name}
+       ${export_to_clangtargets}
+-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+       COMPONENT ${name})
+ 
+     if(NOT LLVM_ENABLE_IDE)
+@@ -185,7 +185,7 @@ endmacro()
+ macro(add_clang_symlink name dest)
+   add_llvm_tool_symlink(${name} ${dest} ALWAYS_GENERATE)
+   # Always generate install targets
+-  llvm_install_symlink(${name} ${dest} ALWAYS_GENERATE)
+  llvm_install_symlink(${name} ${dest} ${CMAKE_INSTALL_FULL_BINDIR} ALWAYS_GENERATE)
+ endmacro()
+ 
+ function(clang_target_link_libraries target type)
+diff --git a/lib/Headers/CMakeLists.txt b/lib/Headers/CMakeLists.txt
+index 0692fe75a441..6f201e7207d0 100644
+--- a/lib/Headers/CMakeLists.txt
+++ b/lib/Headers/CMakeLists.txt
+@@ -208,7 +208,7 @@ set_target_properties(clang-resource-headers PROPERTIES
+   FOLDER "Misc"
+   RUNTIME_OUTPUT_DIRECTORY "${output_dir}")
+ 
+-set(header_install_dir lib${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION}/include)
+set(header_install_dir ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION}/include)
+ 
+ install(
+   FILES ${files} ${generated_files}
+diff --git a/tools/c-index-test/CMakeLists.txt b/tools/c-index-test/CMakeLists.txt
+index ceef4b08637c..8efad5520ca4 100644
+--- a/tools/c-index-test/CMakeLists.txt
+++ b/tools/c-index-test/CMakeLists.txt
+@@ -54,7 +54,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+     set_property(TARGET c-index-test APPEND PROPERTY INSTALL_RPATH
+        "@executable_path/../../lib")
+   else()
+-    set(INSTALL_DESTINATION bin)
+    set(INSTALL_DESTINATION ${CMAKE_INSTALL_BINDIR})
+   endif()
+ 
+   install(TARGETS c-index-test
+diff --git a/tools/clang-format/CMakeLists.txt b/tools/clang-format/CMakeLists.txt
+index 35ecdb11253c..d77d75de0094 100644
+--- a/tools/clang-format/CMakeLists.txt
+++ b/tools/clang-format/CMakeLists.txt
+@@ -21,20 +21,20 @@ if( LLVM_LIB_FUZZING_ENGINE OR LLVM_USE_SANITIZE_COVERAGE )
+ endif()
+ 
+ install(PROGRAMS clang-format-bbedit.applescript
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format-diff.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format-sublime.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format.el
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS git-clang-format
+-  DESTINATION bin
+  DESTINATION ${CMAKE_INSTALL_BINDIR}
+   COMPONENT clang-format)
+diff --git a/tools/clang-rename/CMakeLists.txt b/tools/clang-rename/CMakeLists.txt
+index cda8e29ec5b1..0134d8ccd70b 100644
+--- a/tools/clang-rename/CMakeLists.txt
+++ b/tools/clang-rename/CMakeLists.txt
+@@ -19,8 +19,8 @@ clang_target_link_libraries(clang-rename
+   )
+ 
+ install(PROGRAMS clang-rename.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-rename)
+ install(PROGRAMS clang-rename.el
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-rename)
+diff --git a/tools/libclang/CMakeLists.txt b/tools/libclang/CMakeLists.txt
+index 5cd9ac5cddc1..a197676fedbd 100644
+--- a/tools/libclang/CMakeLists.txt
+++ b/tools/libclang/CMakeLists.txt
+@@ -165,7 +165,7 @@ endif()
+ if(INTERNAL_INSTALL_PREFIX)
+   set(LIBCLANG_HEADERS_INSTALL_DESTINATION "${INTERNAL_INSTALL_PREFIX}/include")
+ else()
+-  set(LIBCLANG_HEADERS_INSTALL_DESTINATION include)
+  set(LIBCLANG_HEADERS_INSTALL_DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+ endif()
+ 
+ install(DIRECTORY ../../include/clang-c
+@@ -196,7 +196,7 @@ foreach(PythonVersion ${CLANG_PYTHON_BINDINGS_VERSIONS})
+           COMPONENT
+             libclang-python-bindings
+           DESTINATION
+-            "lib${LLVM_LIBDIR_SUFFIX}/python${PythonVersion}/site-packages")
+            "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/python${PythonVersion}/site-packages")
+ endforeach()
+ if(NOT LLVM_ENABLE_IDE)
+   add_custom_target(libclang-python-bindings)
+diff --git a/tools/scan-build/CMakeLists.txt b/tools/scan-build/CMakeLists.txt
+index ec0702d76f18..d25d982f51da 100644
+--- a/tools/scan-build/CMakeLists.txt
+++ b/tools/scan-build/CMakeLists.txt
+@@ -47,7 +47,7 @@ if(CLANG_INSTALL_SCANBUILD)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bin/${BinFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/bin/${BinFile})
+     install(PROGRAMS bin/${BinFile}
+-            DESTINATION bin
+            DESTINATION ${CMAKE_INSTALL_BINDIR}
+             COMPONENT scan-build)
+   endforeach()
+ 
+@@ -61,7 +61,7 @@ if(CLANG_INSTALL_SCANBUILD)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/libexec/${LibexecFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/libexec/${LibexecFile})
+     install(PROGRAMS libexec/${LibexecFile}
+-            DESTINATION libexec
+            DESTINATION ${CMAKE_INSTALL_LIBEXECDIR}
+             COMPONENT scan-build)
+   endforeach()
+ 
+@@ -89,7 +89,7 @@ if(CLANG_INSTALL_SCANBUILD)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/share/scan-build/${ShareFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/share/scan-build/${ShareFile})
+     install(FILES share/scan-build/${ShareFile}
+-            DESTINATION share/scan-build
+            DESTINATION ${CMAKE_INSTALL_DATADIR}/scan-build
+             COMPONENT scan-build)
+   endforeach()
+ 
+diff --git a/tools/scan-view/CMakeLists.txt b/tools/scan-view/CMakeLists.txt
+index 22edb974bac7..9f140a9a4538 100644
+--- a/tools/scan-view/CMakeLists.txt
+++ b/tools/scan-view/CMakeLists.txt
+@@ -22,7 +22,7 @@ if(CLANG_INSTALL_SCANVIEW)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bin/${BinFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/bin/${BinFile})
+     install(PROGRAMS bin/${BinFile}
+-            DESTINATION bin
+            DESTINATION ${CMAKE_INSTALL_BINDIR}
+             COMPONENT scan-view)
+   endforeach()
+ 
+@@ -36,7 +36,7 @@ if(CLANG_INSTALL_SCANVIEW)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/share/${ShareFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/share/scan-view/${ShareFile})
+     install(FILES share/${ShareFile}
+-            DESTINATION share/scan-view
+            DESTINATION ${CMAKE_INSTALL_DATADIR}/scan-view
+             COMPONENT scan-view)
+   endforeach()
+ 
+diff --git a/utils/hmaptool/CMakeLists.txt b/utils/hmaptool/CMakeLists.txt
+index 62f2de0cb15c..6aa66825b6ec 100644
+--- a/utils/hmaptool/CMakeLists.txt
+++ b/utils/hmaptool/CMakeLists.txt
+@@ -10,7 +10,7 @@ add_custom_command(OUTPUT ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin/${CLANG_HM
+ 
+ list(APPEND Depends ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin/${CLANG_HMAPTOOL})
+ install(PROGRAMS ${CLANG_HMAPTOOL}
+-        DESTINATION bin
+        DESTINATION ${CMAKE_INSTALL_BINDIR}
+         COMPONENT hmaptool)
+ 
+ add_custom_target(hmaptool ALL DEPENDS ${Depends})
--- a/llvm/11/clang/purity.patch
+++ b/llvm/11/clang/purity.patch
@ -0,0 +1,28 @@
+From 4add81bba40dcec62c4ea4481be8e35ac53e89d8 Mon Sep 17 00:00:00 2001
+From: Will Dietz <w@wdtz.org>
+Date: Thu, 18 May 2017 11:56:12 -0500
+Subject: [PATCH] "purity" patch for 5.0
+
+---
+ lib/Driver/ToolChains/Gnu.cpp | 7 -------
+ 1 file changed, 7 deletions(-)
+
+diff --git a/lib/Driver/ToolChains/Gnu.cpp b/lib/Driver/ToolChains/Gnu.cpp
+index fe3c0191bb..c6a482bece 100644
+--- a/lib/Driver/ToolChains/Gnu.cpp
+++ b/lib/Driver/ToolChains/Gnu.cpp
+@@ -487,12 +487,6 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
+   if (!IsStatic) {
+     if (Args.hasArg(options::OPT_rdynamic))
+       CmdArgs.push_back("-export-dynamic");
+-
+-    if (!Args.hasArg(options::OPT_shared) && !IsStaticPIE) {
+-      CmdArgs.push_back("-dynamic-linker");
+-      CmdArgs.push_back(Args.MakeArgString(Twine(D.DyldPrefix) +
+-                                           ToolChain.getDynamicLinker(Args)));
+-    }
+   }
+ 
+   CmdArgs.push_back("-o");
+-- 
+2.11.0
--- a/llvm/11/compiler-rt/X86-support-extension.patch
+++ b/llvm/11/compiler-rt/X86-support-extension.patch
@ -0,0 +1,23 @@
+diff --git a/lib/builtins/CMakeLists.txt b/lib/builtins/CMakeLists.txt
+index 3a66dd9c3fb..7efc85d9f9f 100644
+--- a/lib/builtins/CMakeLists.txt
+++ b/lib/builtins/CMakeLists.txt
+@@ -301,6 +301,10 @@ if (NOT MSVC)
+     i386/umoddi3.S
+   )
+ 
+  set(i486_SOURCES ${i386_SOURCES})
+  set(i586_SOURCES ${i386_SOURCES})
+  set(i686_SOURCES ${i386_SOURCES})
+
+   if (WIN32)
+     set(i386_SOURCES
+       ${i386_SOURCES}
+@@ -608,6 +612,7 @@ else ()
+   endif()
+ 
+   foreach (arch ${BUILTIN_SUPPORTED_ARCH})
+      message("arch: ${arch}")
+     if (CAN_TARGET_${arch})
+       # For ARM archs, exclude any VFP builtins if VFP is not supported
+       if (${arch} MATCHES "^(arm|armhf|armv7|armv7s|armv7k|armv7m|armv7em)$")
--- a/llvm/11/compiler-rt/armv7l.patch
+++ b/llvm/11/compiler-rt/armv7l.patch
@ -0,0 +1,32 @@
+diff -ur compiler-rt-10.0.0.src/cmake/builtin-config-ix.cmake compiler-rt-10.0.0.src-patched/cmake/builtin-config-ix.cmake
+--- compiler-rt-10.0.0.src/cmake/builtin-config-ix.cmake	2020-03-24 00:01:02.000000000 +0900
+++ compiler-rt-10.0.0.src-patched/cmake/builtin-config-ix.cmake	2020-05-10 03:42:00.883450706 +0900
+@@ -24,7 +24,7 @@
+ 
+ 
+ set(ARM64 aarch64)
+-set(ARM32 arm armhf armv6m armv7m armv7em armv7 armv7s armv7k)
+set(ARM32 arm armhf armv6m armv7m armv7em armv7 armv7s armv7k armv7l)
+ set(HEXAGON hexagon)
+ set(X86 i386)
+ set(X86_64 x86_64)
+diff -ur compiler-rt-10.0.0.src/lib/builtins/CMakeLists.txt compiler-rt-10.0.0.src-patched/lib/builtins/CMakeLists.txt
+--- compiler-rt-10.0.0.src/lib/builtins/CMakeLists.txt	2020-03-24 00:01:02.000000000 +0900
+++ compiler-rt-10.0.0.src-patched/lib/builtins/CMakeLists.txt	2020-05-10 03:44:49.468579650 +0900
+@@ -474,6 +474,7 @@
+ set(armv7_SOURCES ${arm_SOURCES})
+ set(armv7s_SOURCES ${arm_SOURCES})
+ set(armv7k_SOURCES ${arm_SOURCES})
+set(armv7l_SOURCES ${arm_SOURCES})
+ set(arm64_SOURCES ${aarch64_SOURCES})
+ 
+ # macho_embedded archs
+@@ -595,7 +596,7 @@
+   foreach (arch ${BUILTIN_SUPPORTED_ARCH})
+     if (CAN_TARGET_${arch})
+       # For ARM archs, exclude any VFP builtins if VFP is not supported
+-      if (${arch} MATCHES "^(arm|armhf|armv7|armv7s|armv7k|armv7m|armv7em)$")
+      if (${arch} MATCHES "^(arm|armhf|armv7|armv7s|armv7k|armv7l|armv7m|armv7em)$")
+         string(REPLACE ";" " " _TARGET_${arch}_CFLAGS "${TARGET_${arch}_CFLAGS}")
+         check_compile_definition(__VFP_FP__ "${CMAKE_C_FLAGS} ${_TARGET_${arch}_CFLAGS}" COMPILER_RT_HAS_${arch}_VFP)
+         if(NOT COMPILER_RT_HAS_${arch}_VFP)
--- a/llvm/11/compiler-rt/default.nix
+++ b/llvm/11/compiler-rt/default.nix
@ -0,0 +1,140 @@
+{ lib, stdenv, llvm_meta, version, fetch, cmake, python3, xcbuild, libllvm, libcxxabi, libxcrypt
+, doFakeLibgcc ? stdenv.hostPlatform.isFreeBSD
+}:
+
+let
+
+  useLLVM = stdenv.hostPlatform.useLLVM or false;
+  isNewDarwinBootstrap = stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isAarch64;
+  bareMetal = stdenv.hostPlatform.parsed.kernel.name == "none";
+  haveLibc = stdenv.cc.libc != null;
+  inherit (stdenv.hostPlatform) isMusl;
+
+in
+
+stdenv.mkDerivation {
+  pname = "compiler-rt" + lib.optionalString (haveLibc) "-libc";
+  inherit version;
+  src = fetch "compiler-rt" "0x1j8ngf1zj63wlnns9vlibafq48qcm72p4jpaxkmkb4qw0grwfy";
+
+  nativeBuildInputs = [ cmake python3 libllvm.dev ]
+     ++ lib.optional stdenv.isDarwin xcbuild.xcrun;
+
+  env.NIX_CFLAGS_COMPILE = toString [
+    "-DSCUDO_DEFAULT_OPTIONS=DeleteSizeMismatch=0:DeallocationTypeMismatch=0"
+  ];
+
+  cmakeFlags = [
+    "-DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON"
+    "-DCMAKE_C_COMPILER_TARGET=${stdenv.hostPlatform.config}"
+    "-DCMAKE_ASM_COMPILER_TARGET=${stdenv.hostPlatform.config}"
+  ] ++ lib.optionals (haveLibc && stdenv.hostPlatform.isGnu) [
+    "-DSANITIZER_COMMON_CFLAGS=-I${libxcrypt}/include"
+  ] ++ lib.optionals (useLLVM || bareMetal || isMusl || isNewDarwinBootstrap) [
+    "-DCOMPILER_RT_BUILD_SANITIZERS=OFF"
+    "-DCOMPILER_RT_BUILD_XRAY=OFF"
+    "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
+  ] ++ lib.optionals (useLLVM || bareMetal) [
+    "-DCOMPILER_RT_BUILD_PROFILE=OFF"
+  ] ++ lib.optionals (!haveLibc || bareMetal) [
+    "-DCMAKE_C_COMPILER_WORKS=ON"
+    "-DCMAKE_CXX_COMPILER_WORKS=ON"
+    "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
+    "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
+  ] ++ lib.optionals (useLLVM || isNewDarwinBootstrap) [
+    "-DCOMPILER_RT_BUILD_BUILTINS=ON"
+    #https://stackoverflow.com/questions/53633705/cmake-the-c-compiler-is-not-able-to-compile-a-simple-test-program
+    "-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY"
+  ] ++ lib.optionals (bareMetal) [
+    "-DCOMPILER_RT_OS_DIR=baremetal"
+  ] ++ lib.optionals (stdenv.hostPlatform.isDarwin) [
+    "-DDARWIN_macosx_OVERRIDE_SDK_VERSION=ON"
+    "-DDARWIN_osx_ARCHS=${stdenv.hostPlatform.darwinArch}"
+    "-DDARWIN_osx_BUILTIN_ARCHS=${stdenv.hostPlatform.darwinArch}"
+  ];
+
+  outputs = [ "out" "dev" ];
+
+  patches = [
+    ../../common/compiler-rt/7-12-codesign.patch # Revert compiler-rt commit that makes codesign mandatory
+    ./X86-support-extension.patch # Add support for i486 i586 i686 by reusing i386 config
+    ./gnu-install-dirs.patch
+    # ld-wrapper dislikes `-rpath-link //nix/store`, so we normalize away the
+    # extra `/`.
+    ./normalize-var.patch
+    ../../common/compiler-rt/libsanitizer-no-cyclades-11.patch
+    ../../common/compiler-rt/darwin-plistbuddy-workaround.patch
+    ./armv7l.patch
+    # Fix build on armv6l
+    ../../common/compiler-rt/armv6-mcr-dmb.patch
+    ../../common/compiler-rt/armv6-sync-ops-no-thumb.patch
+    ../../common/compiler-rt/armv6-no-ldrexd-strexd.patch
+  ];
+
+  preConfigure = lib.optionalString stdenv.hostPlatform.isDarwin ''
+    cmakeFlagsArray+=("-DCMAKE_LIPO=$(command -v ${stdenv.cc.targetPrefix}lipo)")
+  '' + lib.optionalString (!haveLibc) ''
+    cmakeFlagsArray+=("-DCMAKE_C_FLAGS=-nodefaultlibs -ffreestanding")
+  '';
+
+  # TSAN requires XPC on Darwin, which we have no public/free source files for. We can depend on the Apple frameworks
+  # to get it, but they're unfree. Since LLVM is rather central to the stdenv, we patch out TSAN support so that Hydra
+  # can build this. If we didn't do it, basically the entire nixpkgs on Darwin would have an unfree dependency and we'd
+  # get no binary cache for the entire platform. If you really find yourself wanting the TSAN, make this controllable by
+  # a flag and turn the flag off during the stdenv build.
+  postPatch = lib.optionalString (!stdenv.isDarwin) ''
+    substituteInPlace cmake/builtin-config-ix.cmake \
+      --replace 'set(X86 i386)' 'set(X86 i386 i486 i586 i686)'
+    substituteInPlace cmake/config-ix.cmake \
+      --replace 'set(X86 i386)' 'set(X86 i386 i486 i586 i686)'
+  '' + lib.optionalString stdenv.isDarwin ''
+    substituteInPlace cmake/config-ix.cmake \
+      --replace 'set(COMPILER_RT_HAS_TSAN TRUE)' 'set(COMPILER_RT_HAS_TSAN FALSE)'
+  '' + lib.optionalString (useLLVM) ''
+    substituteInPlace lib/builtins/int_util.c \
+      --replace "#include <stdlib.h>" ""
+    substituteInPlace lib/builtins/clear_cache.c \
+      --replace "#include <assert.h>" ""
+    substituteInPlace lib/builtins/cpu_model.c \
+      --replace "#include <assert.h>" ""
+  '';
+
+  # Hack around weird upsream RPATH bug
+  postInstall = lib.optionalString (stdenv.hostPlatform.isDarwin || stdenv.hostPlatform.isWasm) ''
+    ln -s "$out/lib"/*/* "$out/lib"
+  '' + lib.optionalString (useLLVM) ''
+    ln -s $out/lib/*/clang_rt.crtbegin-*.o $out/lib/crtbegin.o
+    ln -s $out/lib/*/clang_rt.crtend-*.o $out/lib/crtend.o
+    ln -s $out/lib/*/clang_rt.crtbegin-*.o $out/lib/crtbeginS.o
+    ln -s $out/lib/*/clang_rt.crtend-*.o $out/lib/crtendS.o
+    ln -s $out/lib/*/clang_rt.crtbegin_shared-*.o $out/lib/crtbeginS.o
+    ln -s $out/lib/*/clang_rt.crtend_shared-*.o $out/lib/crtendS.o
+  ''
+  # See https://reviews.llvm.org/D37278 for why android exception
+  + lib.optionalString (stdenv.hostPlatform.isx86_32 && !stdenv.hostPlatform.isAndroid) ''
+    for f in $out/lib/*/*builtins-i?86*; do
+      ln -s "$f" $(echo "$f" | sed -e 's/builtins-i.86/builtins-i386/')
+    done
+  '' + lib.optionalString doFakeLibgcc ''
+    ln -s $out/lib/freebsd/libclang_rt.builtins-*.a $out/lib/libgcc.a
+  '';
+
+  meta = llvm_meta // {
+    homepage = "https://compiler-rt.llvm.org/";
+    description = "Compiler runtime libraries";
+    longDescription = ''
+      The compiler-rt project provides highly tuned implementations of the
+      low-level code generator support routines like "__fixunsdfdi" and other
+      calls generated when a target doesn't have a short sequence of native
+      instructions to implement a core IR operation. It also provides
+      implementations of run-time libraries for dynamic testing tools such as
+      AddressSanitizer, ThreadSanitizer, MemorySanitizer, and DataFlowSanitizer.
+    '';
+    # "All of the code in the compiler-rt project is dual licensed under the MIT
+    # license and the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+    # compiler-rt requires a Clang stdenv on 32-bit RISC-V:
+    # https://reviews.llvm.org/D43106#1019077
+    broken = stdenv.hostPlatform.isRiscV && stdenv.hostPlatform.is32bit && !stdenv.cc.isClang;
+  };
+}
--- a/llvm/11/compiler-rt/gnu-install-dirs.patch
+++ b/llvm/11/compiler-rt/gnu-install-dirs.patch
@ -0,0 +1,129 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index fa62814b635d..6328614d829e 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -12,6 +12,7 @@ endif()
+ # Check if compiler-rt is built as a standalone project.
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR COMPILER_RT_STANDALONE_BUILD)
+   project(CompilerRT C CXX ASM)
+  include(GNUInstallDirs)
+   set(COMPILER_RT_STANDALONE_BUILD TRUE)
+   set_property(GLOBAL PROPERTY USE_FOLDERS ON)
+ endif()
+diff --git a/cmake/Modules/AddCompilerRT.cmake b/cmake/Modules/AddCompilerRT.cmake
+index 7c127a93dfa7..6a95a65b70a7 100644
+--- a/cmake/Modules/AddCompilerRT.cmake
+++ b/cmake/Modules/AddCompilerRT.cmake
+@@ -524,7 +524,7 @@ macro(add_compiler_rt_resource_file target_name file_name component)
+   add_custom_target(${target_name} DEPENDS ${dst_file})
+   # Install in Clang resource directory.
+   install(FILES ${file_name}
+-    DESTINATION ${COMPILER_RT_INSTALL_PATH}/share
+    DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_DATADIR}
+     COMPONENT ${component})
+   add_dependencies(${component} ${target_name})
+ 
+@@ -541,7 +541,7 @@ macro(add_compiler_rt_script name)
+   add_custom_target(${name} DEPENDS ${dst})
+   install(FILES ${dst}
+     PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE
+-    DESTINATION ${COMPILER_RT_INSTALL_PATH}/bin)
+    DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_BINDIR})
+ endmacro(add_compiler_rt_script src name)
+ 
+ # Builds custom version of libc++ and installs it in <prefix>.
+diff --git a/cmake/Modules/CompilerRTDarwinUtils.cmake b/cmake/Modules/CompilerRTDarwinUtils.cmake
+index be8d7e733c7a..ab256bdff26c 100644
+--- a/cmake/Modules/CompilerRTDarwinUtils.cmake
+++ b/cmake/Modules/CompilerRTDarwinUtils.cmake
+@@ -498,7 +498,7 @@ macro(darwin_add_embedded_builtin_libraries)
+     set(DARWIN_macho_embedded_LIBRARY_OUTPUT_DIR
+       ${COMPILER_RT_OUTPUT_DIR}/lib/macho_embedded)
+     set(DARWIN_macho_embedded_LIBRARY_INSTALL_DIR
+-      ${COMPILER_RT_INSTALL_PATH}/lib/macho_embedded)
+      ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_LIBDIR}/macho_embedded)
+       
+     set(CFLAGS_armv7 "-target thumbv7-apple-darwin-eabi")
+     set(CFLAGS_i386 "-march=pentium")
+diff --git a/cmake/Modules/CompilerRTUtils.cmake b/cmake/Modules/CompilerRTUtils.cmake
+index 99b9f0e4af44..c5183ffa746e 100644
+--- a/cmake/Modules/CompilerRTUtils.cmake
+++ b/cmake/Modules/CompilerRTUtils.cmake
+@@ -375,7 +375,7 @@ endfunction()
+ function(get_compiler_rt_install_dir arch install_dir)
+   if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+     get_compiler_rt_target(${arch} target)
+-    set(${install_dir} ${COMPILER_RT_INSTALL_PATH}/lib/${target} PARENT_SCOPE)
+    set(${install_dir} ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_LIBDIR}/${target} PARENT_SCOPE)
+   else()
+     set(${install_dir} ${COMPILER_RT_LIBRARY_INSTALL_DIR} PARENT_SCOPE)
+   endif()
+diff --git a/cmake/base-config-ix.cmake b/cmake/base-config-ix.cmake
+index 964dd598f102..2acaab87d349 100644
+--- a/cmake/base-config-ix.cmake
+++ b/cmake/base-config-ix.cmake
+@@ -66,11 +66,11 @@ if (LLVM_TREE_AVAILABLE)
+ else()
+     # Take output dir and install path from the user.
+   set(COMPILER_RT_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR} CACHE PATH
+-    "Path where built compiler-rt libraries should be stored.")
+    "Path where built compiler-rt build artifacts should be stored.")
+   set(COMPILER_RT_EXEC_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/bin CACHE PATH
+     "Path where built compiler-rt executables should be stored.")
+-  set(COMPILER_RT_INSTALL_PATH ${CMAKE_INSTALL_PREFIX} CACHE PATH
+-    "Path where built compiler-rt libraries should be installed.")
+  set(COMPILER_RT_INSTALL_PATH "" CACHE PATH
+    "Prefix where built compiler-rt artifacts should be installed, comes before CMAKE_INSTALL_PREFIX.")
+   option(COMPILER_RT_INCLUDE_TESTS "Generate and build compiler-rt unit tests." OFF)
+   option(COMPILER_RT_ENABLE_WERROR "Fail and stop if warning is triggered" OFF)
+   # Use a host compiler to compile/link tests.
+@@ -98,7 +98,7 @@ else(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR)
+   set(COMPILER_RT_LIBRARY_OUTPUT_DIR
+     ${COMPILER_RT_OUTPUT_DIR}/lib/${COMPILER_RT_OS_DIR})
+   set(COMPILER_RT_LIBRARY_INSTALL_DIR
+-    ${COMPILER_RT_INSTALL_PATH}/lib/${COMPILER_RT_OS_DIR})
+    ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_LIBDIR}/${COMPILER_RT_OS_DIR})
+ endif()
+ 
+ if(APPLE)
+diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
+index d47d7baeb118..507c8e5c713e 100644
+--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
+@@ -62,22 +62,22 @@ set_target_properties(compiler-rt-headers PROPERTIES FOLDER "Compiler-RT Misc")
+ install(FILES ${SANITIZER_HEADERS}
+   COMPONENT compiler-rt-headers
+   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/sanitizer)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/sanitizer)
+ # Install fuzzer headers.
+ install(FILES ${FUZZER_HEADERS}
+   COMPONENT compiler-rt-headers
+   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/fuzzer)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/fuzzer)
+ # Install xray headers.
+ install(FILES ${XRAY_HEADERS}
+   COMPONENT compiler-rt-headers
+   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/xray)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/xray)
+ # Install profile headers.
+ install(FILES ${PROFILE_HEADERS}
+   COMPONENT compiler-rt-headers
+   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/profile)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/profile)
+ 
+ if (NOT CMAKE_CONFIGURATION_TYPES) # don't add this for IDEs.
+   add_custom_target(install-compiler-rt-headers
+diff --git a/lib/dfsan/CMakeLists.txt b/lib/dfsan/CMakeLists.txt
+index 051215edbeb7..ecce1f52efb0 100644
+--- a/lib/dfsan/CMakeLists.txt
+++ b/lib/dfsan/CMakeLists.txt
+@@ -56,4 +56,4 @@ add_custom_command(OUTPUT ${dfsan_abilist_filename}
+                    DEPENDS done_abilist.txt libc_ubuntu1404_abilist.txt)
+ add_dependencies(dfsan dfsan_abilist)
+ install(FILES ${dfsan_abilist_filename}
+-        DESTINATION ${COMPILER_RT_INSTALL_PATH}/share)
+        DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_DATADIR})
--- a/llvm/11/compiler-rt/normalize-var.patch
+++ b/llvm/11/compiler-rt/normalize-var.patch
@ -0,0 +1,16 @@
+diff --git a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
+index c5183ffa746e..e4e4a007335d 100644
+--- a/cmake/Modules/CompilerRTUtils.cmake
+++ b/cmake/Modules/CompilerRTUtils.cmake
+@@ -299,8 +299,9 @@ macro(load_llvm_config)
+     # Get some LLVM variables from LLVMConfig.
+     include("${LLVM_CMAKE_PATH}/LLVMConfig.cmake")
+ 
+-    set(LLVM_LIBRARY_OUTPUT_INTDIR
+-      ${LLVM_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
+    get_filename_component(LLVM_LIBRARY_OUTPUT_INTDIR
+      ${LLVM_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX}
+      REALPATH)
+   endif()
+ endmacro()
+ 
--- a/llvm/11/default.nix
+++ b/llvm/11/default.nix
@ -0,0 +1,299 @@
+{ lowPrio, newScope, pkgs, lib, stdenv, cmake
+, gccForLibs, preLibcCrossHeaders
+, libxml2, python3, isl, fetchurl, overrideCC, wrapCCWith, wrapBintoolsWith
+, buildLlvmTools # tools, but from the previous stage, for cross
+, targetLlvmLibraries # libraries, but from the next stage, for cross
+, targetLlvm
+# This is the default binutils, but with *this* version of LLD rather
+# than the default LLVM version's, if LLD is the choice. We use these for
+# the `useLLVM` bootstrapping below.
+, bootBintoolsNoLibc ?
+    if stdenv.targetPlatform.linker == "lld"
+    then null
+    else pkgs.bintoolsNoLibc
+, bootBintools ?
+    if stdenv.targetPlatform.linker == "lld"
+    then null
+    else pkgs.bintools
+}:
+
+let
+  release_version = "11.1.0";
+  candidate = ""; # empty or "rcN"
+  dash-candidate = lib.optionalString (candidate != "") "-${candidate}";
+  version = "${release_version}${dash-candidate}"; # differentiating these (variables) is important for RCs
+  targetConfig = stdenv.targetPlatform.config;
+
+  fetch = name: sha256: fetchurl {
+    url = "https://github.com/llvm/llvm-project/releases/download/llvmorg-${version}/${name}-${release_version}${candidate}.src.tar.xz";
+    inherit sha256;
+  };
+
+  clang-tools-extra_src = fetch "clang-tools-extra" "18n1w1hkv931xzq02b34wglbv6zd6sd0r5kb8piwvag7klj7qw3n";
+
+  llvm_meta = {
+    license     = lib.licenses.ncsa;
+    maintainers = lib.teams.llvm.members;
+
+    # See llvm/cmake/config-ix.cmake.
+    platforms   =
+      lib.platforms.aarch64 ++
+      lib.platforms.arm ++
+      lib.platforms.mips ++
+      lib.platforms.power ++
+      lib.platforms.riscv ++
+      lib.platforms.s390x ++
+      lib.platforms.wasi ++
+      lib.platforms.x86;
+  };
+
+  tools = lib.makeExtensible (tools: let
+    callPackage = newScope (tools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch buildLlvmTools; });
+    mkExtraBuildCommands0 = cc: ''
+      rsrc="$out/resource-root"
+      mkdir "$rsrc"
+      ln -s "${cc.lib}/lib/clang/${release_version}/include" "$rsrc"
+      echo "-resource-dir=$rsrc" >> $out/nix-support/cc-cflags
+    '';
+    mkExtraBuildCommands = cc: mkExtraBuildCommands0 cc + ''
+      ln -s "${targetLlvmLibraries.compiler-rt.out}/lib" "$rsrc/lib"
+      ln -s "${targetLlvmLibraries.compiler-rt.out}/share" "$rsrc/share"
+    '';
+
+  bintoolsNoLibc' =
+    if bootBintoolsNoLibc == null
+    then tools.bintoolsNoLibc
+    else bootBintoolsNoLibc;
+  bintools' =
+    if bootBintools == null
+    then tools.bintools
+    else bootBintools;
+
+  in {
+
+    libllvm = callPackage ./llvm {
+      inherit llvm_meta;
+    };
+
+    # `llvm` historically had the binaries.  When choosing an output explicitly,
+    # we need to reintroduce `outputSpecified` to get the expected behavior e.g. of lib.get*
+    llvm = tools.libllvm;
+
+    libllvm-polly = callPackage ./llvm {
+      inherit llvm_meta;
+      enablePolly = true;
+    };
+
+    llvm-polly = tools.libllvm-polly.lib // { outputSpecified = false; };
+
+    libclang = callPackage ./clang {
+      inherit clang-tools-extra_src llvm_meta;
+    };
+
+    clang-unwrapped = tools.libclang;
+
+    clang-polly-unwrapped = callPackage ./clang {
+      inherit llvm_meta;
+      inherit clang-tools-extra_src;
+      libllvm = tools.libllvm-polly;
+      enablePolly = true;
+    };
+
+    llvm-manpages = lowPrio (tools.libllvm.override {
+      enableManpages = true;
+      python3 = pkgs.python3;  # don't use python-boot
+    });
+
+    clang-manpages = lowPrio (tools.libclang.override {
+      enableManpages = true;
+      python3 = pkgs.python3;  # don't use python-boot
+    });
+
+    # disabled until recommonmark supports sphinx 3
+    # lldb-manpages = lowPrio (tools.lldb.override {
+    #   enableManpages = true;
+    #   python3 = pkgs.python3;  # don't use python-boot
+    # });
+
+    # pick clang appropriate for package set we are targeting
+    clang =
+      /**/ if stdenv.targetPlatform.libc == null then tools.clangNoLibc
+      else if stdenv.targetPlatform.useLLVM or false then tools.clangUseLLVM
+      else if (pkgs.targetPackages.stdenv or stdenv).cc.isGNU then tools.libstdcxxClang
+      else tools.libcxxClang;
+
+    libstdcxxClang = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      # libstdcxx is taken from gcc in an ad-hoc way in cc-wrapper.
+      libcxx = null;
+      extraPackages = [
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = mkExtraBuildCommands cc;
+    };
+
+    libcxxClang = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = targetLlvmLibraries.libcxx;
+      extraPackages = [
+        libcxx.cxxabi
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = mkExtraBuildCommands cc;
+    };
+
+    lld = callPackage ./lld {
+      inherit llvm_meta;
+    };
+
+    lldb = callPackage ../common/lldb.nix {
+      src = fetch "lldb" "1vlyg015dyng43xqb8cg2l6r9ix8klibxsajazbfnckdnh54hwxj";
+      patches = [
+        ./lldb/procfs.patch
+        ./lldb/gnu-install-dirs.patch
+      ];
+      inherit llvm_meta;
+    };
+
+    # Below, is the LLVM bootstrapping logic. It handles building a
+    # fully LLVM toolchain from scratch. No GCC toolchain should be
+    # pulled in. As a consequence, it is very quick to build different
+    # targets provided by LLVM and we can also build for what GCC
+    # doesn’t support like LLVM. Probably we should move to some other
+    # file.
+
+    bintools-unwrapped = callPackage ../common/bintools.nix { };
+
+    bintoolsNoLibc = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+      libc = preLibcCrossHeaders;
+    };
+
+    bintools = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+    };
+
+    clangUseLLVM = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = targetLlvmLibraries.libcxx;
+      bintools = bintools';
+      extraPackages = [
+        libcxx.cxxabi
+        targetLlvmLibraries.compiler-rt
+      ] ++ lib.optionals (!stdenv.targetPlatform.isWasm) [
+        targetLlvmLibraries.libunwind
+      ];
+      extraBuildCommands = ''
+        echo "-rtlib=compiler-rt -Wno-unused-command-line-argument" >> $out/nix-support/cc-cflags
+        echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
+      '' + lib.optionalString (!stdenv.targetPlatform.isWasm) ''
+        echo "--unwindlib=libunwind" >> $out/nix-support/cc-cflags
+      '' + lib.optionalString (!stdenv.targetPlatform.isWasm && stdenv.targetPlatform.useLLVM or false) ''
+        echo "-lunwind" >> $out/nix-support/cc-ldflags
+      '' + lib.optionalString stdenv.targetPlatform.isWasm ''
+        echo "-fno-exceptions" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands cc;
+    };
+
+    clangNoLibcxx = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintools';
+      extraPackages = [
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = ''
+        echo "-rtlib=compiler-rt" >> $out/nix-support/cc-cflags
+        echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
+        echo "-nostdlib++" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands cc;
+    };
+
+    clangNoLibc = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintoolsNoLibc';
+      extraPackages = [
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = ''
+        echo "-rtlib=compiler-rt" >> $out/nix-support/cc-cflags
+        echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands cc;
+    };
+
+    clangNoCompilerRt = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintoolsNoLibc';
+      extraPackages = [ ];
+      extraBuildCommands = ''
+        echo "-nostartfiles" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands0 cc;
+    };
+
+    clangNoCompilerRtWithLibc = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintools';
+      extraPackages = [ ];
+      extraBuildCommands = mkExtraBuildCommands0 cc;
+    };
+
+  });
+
+  libraries = lib.makeExtensible (libraries: let
+    callPackage = newScope (libraries // buildLlvmTools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch; });
+  in {
+
+    compiler-rt-libc = callPackage ./compiler-rt {
+      inherit llvm_meta;
+      stdenv = if (stdenv.hostPlatform.useLLVM or false) || (stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isAarch64) || (stdenv.hostPlatform.isRiscV && stdenv.hostPlatform.is32bit)
+               then overrideCC stdenv buildLlvmTools.clangNoCompilerRtWithLibc
+               else stdenv;
+    };
+
+    compiler-rt-no-libc = callPackage ./compiler-rt {
+      inherit llvm_meta;
+      stdenv = if (stdenv.hostPlatform.useLLVM or false) || (stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isAarch64)
+               then overrideCC stdenv buildLlvmTools.clangNoCompilerRt
+               else stdenv;
+    };
+
+    # N.B. condition is safe because without useLLVM both are the same.
+    compiler-rt = if stdenv.hostPlatform.isAndroid || (stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isAarch64) || (stdenv.hostPlatform.libc == "newlib")
+      then libraries.compiler-rt-libc
+      else libraries.compiler-rt-no-libc;
+
+    stdenv = overrideCC stdenv buildLlvmTools.clang;
+
+    libcxxStdenv = overrideCC stdenv buildLlvmTools.libcxxClang;
+
+    libcxx = callPackage ./libcxx {
+      inherit llvm_meta;
+      stdenv = if (stdenv.hostPlatform.useLLVM or false) || (stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isAarch64)
+               then overrideCC stdenv buildLlvmTools.clangNoLibcxx
+               else stdenv;
+    };
+
+    libcxxabi = callPackage ./libcxxabi {
+      inherit llvm_meta;
+      stdenv = if (stdenv.hostPlatform.useLLVM or false) || (stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isAarch64)
+               then overrideCC stdenv buildLlvmTools.clangNoLibcxx
+               else stdenv;
+    };
+
+    libunwind = callPackage ./libunwind {
+      inherit llvm_meta;
+      stdenv = if (stdenv.hostPlatform.useLLVM or false) || (stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isAarch64)
+               then overrideCC stdenv buildLlvmTools.clangNoLibcxx
+               else stdenv;
+    };
+
+    openmp = callPackage ./openmp {
+      inherit llvm_meta targetLlvm;
+    };
+  });
+  noExtend = extensible: lib.attrsets.removeAttrs extensible [ "extend" ];
+
+in { inherit tools libraries release_version; } // (noExtend libraries) // (noExtend tools)
--- a/llvm/11/libcxx/default.nix
+++ b/llvm/11/libcxx/default.nix
@ -0,0 +1,104 @@
+{ lib, stdenv, llvm_meta, fetch, fetchpatch, cmake, python3, llvm, fixDarwinDylibNames, version
+, cxxabi ? if stdenv.hostPlatform.isFreeBSD then libcxxrt else libcxxabi
+, libcxxabi, libcxxrt
+, enableShared ? !stdenv.hostPlatform.isStatic
+}:
+
+assert stdenv.isDarwin -> cxxabi.pname == "libcxxabi";
+
+stdenv.mkDerivation {
+  pname = "libcxx";
+  inherit version;
+
+  src = fetch "libcxx" "1rgqsqpgi0vkga5d7hy0iyfsqgzfz7q1xy7afdfa1snp1qjks8xv";
+
+  postUnpack = ''
+    unpackFile ${libcxxabi.src}
+    mv libcxxabi-* libcxxabi
+    unpackFile ${llvm.src}
+    mv llvm-* llvm
+  '';
+
+  outputs = [ "out" "dev" ];
+
+  patches = [
+    (fetchpatch {
+      # Backported from LLVM 12, avoids clashes with commonly used "block.h" header.
+      url = "https://github.com/llvm/llvm-project/commit/19bc9ea480b60b607a3e303f20c7a3a2ea553369.patch";
+      sha256 = "sha256-aWa66ogmPkG0xHzSfcpD0qZyZQcNKwLV44js4eiun78=";
+      stripLen = 1;
+    })
+    ./gnu-install-dirs.patch
+  ] ++ lib.optionals stdenv.hostPlatform.isMusl [
+    ../../libcxx-0001-musl-hacks.patch
+  ];
+
+  # Prevent errors like "error: 'foo' is unavailable: introduced in macOS yy.zz"
+  postPatch = ''
+    substituteInPlace include/__config \
+      --replace "#    define _LIBCPP_USE_AVAILABILITY_APPLE" ""
+  '';
+
+  preConfigure = lib.optionalString stdenv.hostPlatform.isMusl ''
+    patchShebangs utils/cat_files.py
+  '';
+
+  nativeBuildInputs = [ cmake python3 ]
+    ++ lib.optional stdenv.isDarwin fixDarwinDylibNames;
+
+  buildInputs = [ cxxabi ];
+
+  cmakeFlags = [
+    "-DLIBCXX_CXX_ABI=${cxxabi.pname}"
+  ] ++ lib.optional (stdenv.hostPlatform.isMusl || stdenv.hostPlatform.isWasi) "-DLIBCXX_HAS_MUSL_LIBC=1"
+    ++ lib.optional (stdenv.hostPlatform.useLLVM or false) "-DLIBCXX_USE_COMPILER_RT=ON"
+    ++ lib.optionals stdenv.hostPlatform.isWasm [
+      "-DLIBCXX_ENABLE_THREADS=OFF"
+      "-DLIBCXX_ENABLE_FILESYSTEM=OFF"
+      "-DLIBCXX_ENABLE_EXCEPTIONS=OFF"
+    ] ++ lib.optional (!enableShared) "-DLIBCXX_ENABLE_SHARED=OFF"
+
+    # TODO: this is a bit of a hack to cross compile to Apple Silicon.  libcxx
+    # starting with 11 enables CMAKE_BUILD_WITH_INSTALL_NAME_DIR which requires
+    # platform setup for rpaths. In cmake, this is enabled when macos is newer
+    # than 10.5. However CMAKE_SYSTEM_VERSION is set to empty (TODO: why?)
+    # which prevents the conditional configuration, and configure fails.  The
+    # value here corresponds to `uname -r`. If stdenv.hostPlatform.release is
+    # not null, then this property will be set via mkDerivation (TODO: how can
+    # we set this?).
+    ++ lib.optional (
+      stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isAarch64 &&
+      stdenv.hostPlatform != stdenv.buildPlatform
+    ) "-DCMAKE_SYSTEM_VERSION=20.1.0";
+
+  preInstall = lib.optionalString (stdenv.isDarwin) ''
+    for file in lib/*.dylib; do
+      if [ -L "$file" ]; then continue; fi
+
+      baseName=$(basename $(${stdenv.cc.targetPrefix}otool -D $file | tail -n 1))
+      installName="$out/lib/$baseName"
+      abiName=$(echo "$baseName" | sed -e 's/libc++/libc++abi/')
+
+      for other in $(${stdenv.cc.targetPrefix}otool -L $file | awk '$1 ~ "/libc\\+\\+abi" { print $1 }'); do
+        ${stdenv.cc.targetPrefix}install_name_tool -change $other ${cxxabi}/lib/$abiName $file
+      done
+    done
+  '';
+
+  passthru = {
+    isLLVM = true;
+    inherit cxxabi;
+  };
+
+  meta = llvm_meta // {
+    homepage = "https://libcxx.llvm.org/";
+    description = "C++ standard library";
+    longDescription = ''
+      libc++ is an implementation of the C++ standard library, targeting C++11,
+      C++14 and above.
+    '';
+    # "All of the code in libc++ is dual licensed under the MIT license and the
+    # UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}
--- a/llvm/11/libcxx/gnu-install-dirs.patch
+++ b/llvm/11/libcxx/gnu-install-dirs.patch
@ -0,0 +1,100 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 910d04b54b6d..80ef692d83eb 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -31,6 +31,8 @@ set(CMAKE_MODULE_PATH
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXX_STANDALONE_BUILD)
+   project(libcxx CXX C)
+ 
+  include(GNUInstallDirs)
+
+   set(PACKAGE_NAME libcxx)
+   set(PACKAGE_VERSION 11.1.0)
+   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+@@ -418,7 +420,7 @@ string(REGEX MATCH "[0-9]+\\.[0-9]+(\\.[0-9]+)?" CLANG_VERSION
+ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   set(LIBCXX_HEADER_DIR ${LLVM_BINARY_DIR})
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   if(LIBCXX_LIBDIR_SUBDIR)
+     string(APPEND LIBCXX_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
+     string(APPEND LIBCXX_INSTALL_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
+@@ -426,11 +428,11 @@ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+ elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+   set(LIBCXX_HEADER_DIR  ${LLVM_BINARY_DIR})
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX})
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXX_LIBDIR_SUFFIX})
+ else()
+   set(LIBCXX_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
+   set(LIBCXX_HEADER_DIR  ${CMAKE_BINARY_DIR})
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX})
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXX_LIBDIR_SUFFIX})
+ endif()
+ 
+ file(MAKE_DIRECTORY "${LIBCXX_BINARY_INCLUDE_DIR}")
+diff --git a/cmake/Modules/HandleLibCXXABI.cmake b/cmake/Modules/HandleLibCXXABI.cmake
+index c5aa26739e36..8841c4a5252d 100644
+--- a/cmake/Modules/HandleLibCXXABI.cmake
+++ b/cmake/Modules/HandleLibCXXABI.cmake
+@@ -63,7 +63,7 @@ macro(setup_abi_lib abidefines abishared abistatic abifiles abidirs)
+ 
+         if (LIBCXX_INSTALL_HEADERS)
+           install(FILES "${LIBCXX_BINARY_INCLUDE_DIR}/${fpath}"
+-            DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1/${dstdir}
+            DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${CMAKE_INSTALL_INCLUDEDIR}/c++/v1/${dstdir}
+             COMPONENT cxx-headers
+             PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+             )
+diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
+index be8141c98166..93847e5758cc 100644
+--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
+@@ -257,7 +257,7 @@ if (LIBCXX_INSTALL_HEADERS)
+   foreach(file ${files})
+     get_filename_component(dir ${file} DIRECTORY)
+     install(FILES ${file}
+-      DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1/${dir}
+      DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${CMAKE_INSTALL_INCLUDEDIR}/c++/v1/${dir}
+       COMPONENT ${CXX_HEADER_TARGET}
+       PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+     )
+@@ -265,7 +265,7 @@ if (LIBCXX_INSTALL_HEADERS)
+ 
+   # Install the generated header as __config.
+   install(FILES ${LIBCXX_BINARY_DIR}/__generated_config
+-    DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1
+    DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${CMAKE_INSTALL_INCLUDEDIR}/c++/v1
+     PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+     RENAME __config
+     COMPONENT ${CXX_HEADER_TARGET})
+diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
+index 2001c09761d9..5bd11ea6b400 100644
+--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
+@@ -344,21 +344,21 @@ if (LIBCXX_INSTALL_LIBRARY)
+     install(TARGETS cxx_shared
+       ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+       LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-      RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
+      RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+   endif()
+ 
+   if (LIBCXX_INSTALL_STATIC_LIBRARY)
+     install(TARGETS cxx_static
+       ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+       LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-      RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
+      RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+   endif()
+ 
+   if(LIBCXX_INSTALL_EXPERIMENTAL_LIBRARY)
+     install(TARGETS cxx_experimental
+       LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+       ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-      RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
+      RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+   endif()
+ 
+   # NOTE: This install command must go after the cxx install command otherwise
--- a/llvm/11/libcxxabi/default.nix
+++ b/llvm/11/libcxxabi/default.nix
@ -0,0 +1,89 @@
+{ lib, stdenv, llvm_meta, cmake, fetch, libcxx, libunwind, llvm, version
+, enableShared ? !stdenv.hostPlatform.isStatic
+, standalone ? stdenv.hostPlatform.useLLVM or false
+, withLibunwind ? !stdenv.isDarwin && !stdenv.hostPlatform.isWasm
+}:
+
+stdenv.mkDerivation {
+  pname = "libcxxabi";
+  inherit version;
+
+  src = fetch "libcxxabi" "1azcf31mxw59hb1x17xncnm3dyw90ylh8rqx462lvypqh3nr6c8l";
+
+  outputs = [ "out" "dev" ];
+
+  postUnpack = ''
+    unpackFile ${libcxx.src}
+    mv libcxx-* libcxx
+    unpackFile ${llvm.src}
+    mv llvm-* llvm
+  '' + lib.optionalString stdenv.isDarwin ''
+    export TRIPLE=x86_64-apple-darwin
+  '' + lib.optionalString stdenv.hostPlatform.isMusl ''
+    patch -p1 -d libcxx -i ${../../libcxx-0001-musl-hacks.patch}
+  '' + lib.optionalString stdenv.hostPlatform.isWasm ''
+    patch -p1 -d llvm -i ${../../common/libcxxabi/wasm.patch}
+  '';
+
+  patches = [
+    ../../common/libcxxabi/no-threads.patch
+    ./gnu-install-dirs.patch
+  ];
+
+  nativeBuildInputs = [ cmake ];
+  buildInputs = lib.optional withLibunwind libunwind;
+
+  cmakeFlags = lib.optionals standalone [
+    "-DLLVM_ENABLE_LIBCXX=ON"
+  ] ++ lib.optionals (standalone && withLibunwind) [
+    "-DLIBCXXABI_USE_LLVM_UNWINDER=ON"
+  ] ++ lib.optionals stdenv.hostPlatform.isWasm [
+    "-DLIBCXXABI_ENABLE_THREADS=OFF"
+    "-DLIBCXXABI_ENABLE_EXCEPTIONS=OFF"
+  ] ++ lib.optionals (!enableShared) [
+    "-DLIBCXXABI_ENABLE_SHARED=OFF"
+  ];
+
+  preInstall = lib.optionalString stdenv.isDarwin ''
+    for file in lib/*.dylib; do
+      if [ -L "$file" ]; then continue; fi
+
+      # Fix up the install name. Preserve the basename, just replace the path.
+      installName="$out/lib/$(basename $(${stdenv.cc.targetPrefix}otool -D $file | tail -n 1))"
+
+      # this should be done in CMake, but having trouble figuring out
+      # the magic combination of necessary CMake variables
+      # if you fancy a try, take a look at
+      # https://gitlab.kitware.com/cmake/community/-/wikis/doc/cmake/RPATH-handling
+      ${stdenv.cc.targetPrefix}install_name_tool -id $installName $file
+
+      # cc-wrapper passes '-lc++abi' to all c++ link steps, but that causes
+      # libcxxabi to sometimes link against a different version of itself.
+      # Here we simply make that second reference point to ourselves.
+      for other in $(${stdenv.cc.targetPrefix}otool -L $file | awk '$1 ~ "/libc\\+\\+abi" { print $1 }'); do
+        ${stdenv.cc.targetPrefix}install_name_tool -change $other $installName $file
+      done
+    done
+  '';
+
+  postInstall = ''
+    mkdir -p "$dev/include"
+    install -m 644 ../include/${if stdenv.isDarwin then "*" else "cxxabi.h"} "$dev/include"
+  '';
+
+  passthru = {
+    libName = "c++abi";
+  };
+
+  meta = llvm_meta // {
+    homepage = "https://libcxxabi.llvm.org/";
+    description = "Provides C++ standard library support";
+    longDescription = ''
+      libc++abi is a new implementation of low level support for a standard C++ library.
+    '';
+    # "All of the code in libc++abi is dual licensed under the MIT license and
+    # the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+    maintainers = llvm_meta.maintainers ++ [ lib.maintainers.vlstill ];
+  };
+}
--- a/llvm/11/libcxxabi/gnu-install-dirs.patch
+++ b/llvm/11/libcxxabi/gnu-install-dirs.patch
@ -0,0 +1,34 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 36c6b2249e2b..a93c13ccaed9 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -24,6 +24,8 @@ set(CMAKE_MODULE_PATH
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXXABI_STANDALONE_BUILD)
+   project(libcxxabi CXX C)
+ 
+  include(GNUInstallDirs)
+
+   set(PACKAGE_NAME libcxxabi)
+   set(PACKAGE_VERSION 11.1.0)
+   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+@@ -160,17 +162,17 @@ string(REGEX MATCH "[0-9]+\\.[0-9]+(\\.[0-9]+)?" CLANG_VERSION
+ 
+ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   if(LIBCXX_LIBDIR_SUBDIR)
+     string(APPEND LIBCXXABI_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
+     string(APPEND LIBCXXABI_INSTALL_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
+   endif()
+ elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX})
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXXABI_LIBDIR_SUFFIX})
+ else()
+   set(LIBCXXABI_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXXABI_LIBDIR_SUFFIX})
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX})
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXXABI_LIBDIR_SUFFIX})
+ endif()
+ 
+ set(LIBCXXABI_INSTALL_PREFIX "" CACHE STRING "Define libc++abi destination prefix.")
--- a/llvm/11/libunwind/default.nix
+++ b/llvm/11/libunwind/default.nix
@ -0,0 +1,32 @@
+{ lib, stdenv, llvm_meta, version, fetch, cmake, fetchpatch
+, enableShared ? !stdenv.hostPlatform.isStatic
+}:
+
+stdenv.mkDerivation rec {
+  pname = "libunwind";
+  inherit version;
+
+  src = fetch pname "1vpqs2c358v8fbr1r8jmzkfqk12jllimjcfmgxga127ksq9b37nj";
+
+  patches = [
+    ./gnu-install-dirs.patch
+  ];
+
+  outputs = [ "out" "dev" ];
+
+  nativeBuildInputs = [ cmake ];
+
+  cmakeFlags = lib.optional (!enableShared) "-DLIBUNWIND_ENABLE_SHARED=OFF";
+
+  meta = llvm_meta // {
+    # Details: https://github.com/llvm/llvm-project/blob/main/libunwind/docs/index.rst
+    homepage = "https://clang.llvm.org/docs/Toolchain.html#unwind-library";
+    description = "LLVM's unwinder library";
+    longDescription = ''
+      The unwind library provides a family of _Unwind_* functions implementing
+      the language-neutral stack unwinding portion of the Itanium C++ ABI (Level
+      I). It is a dependency of the C++ ABI library, and sometimes is a
+      dependency of other runtimes.
+    '';
+  };
+}
--- a/llvm/11/libunwind/gnu-install-dirs.patch
+++ b/llvm/11/libunwind/gnu-install-dirs.patch
@ -0,0 +1,34 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index e44a103648f9..aaf1f9555d7f 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -18,6 +18,8 @@ set(CMAKE_MODULE_PATH
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBUNWIND_STANDALONE_BUILD)
+   project(libunwind LANGUAGES C CXX ASM)
+ 
+  include(GNUInstallDirs)
+
+   # Rely on llvm-config.
+   set(CONFIG_OUTPUT)
+   if(NOT LLVM_CONFIG_PATH)
+@@ -192,17 +194,17 @@ string(REGEX MATCH "[0-9]+\\.[0-9]+(\\.[0-9]+)?" CLANG_VERSION
+ 
+ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   if(LIBCXX_LIBDIR_SUBDIR)
+     string(APPEND LIBUNWIND_LIBRARY_DIR /${LIBUNWIND_LIBDIR_SUBDIR})
+     string(APPEND LIBUNWIND_INSTALL_LIBRARY_DIR /${LIBUNWIND_LIBDIR_SUBDIR})
+   endif()
+ elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+   set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LIBUNWIND_LIBDIR_SUFFIX})
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBUNWIND_LIBDIR_SUFFIX})
+ else()
+   set(LIBUNWIND_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBUNWIND_LIBDIR_SUFFIX})
+-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LIBUNWIND_LIBDIR_SUFFIX})
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBUNWIND_LIBDIR_SUFFIX})
+ endif()
+ 
+ set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${LIBUNWIND_LIBRARY_DIR})
--- a/llvm/11/lld/default.nix
+++ b/llvm/11/lld/default.nix
@ -0,0 +1,46 @@
+{ lib, stdenv, llvm_meta
+, buildLlvmTools
+, fetch
+, cmake
+, libxml2
+, libllvm
+, version
+}:
+
+stdenv.mkDerivation rec {
+  pname = "lld";
+  inherit version;
+
+  src = fetch pname "1kk61i7z5bi9i11rzsd2b388d42if1c7a45zkaa4mk0yps67hyh1";
+
+  patches = [
+    ./gnu-install-dirs.patch
+  ];
+
+  nativeBuildInputs = [ cmake ];
+  buildInputs = [ libllvm libxml2 ];
+
+  cmakeFlags = [
+    "-DLLVM_CONFIG_PATH=${libllvm.dev}/bin/llvm-config${lib.optionalString (stdenv.hostPlatform != stdenv.buildPlatform) "-native"}"
+  ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+    "-DLLVM_TABLEGEN_EXE=${buildLlvmTools.llvm}/bin/llvm-tblgen"
+  ];
+
+  # Musl's default stack size is too small for lld to be able to link Firefox.
+  LDFLAGS = lib.optionalString stdenv.hostPlatform.isMusl "-Wl,-z,stack-size=2097152";
+
+  outputs = [ "out" "lib" "dev" ];
+
+  meta = llvm_meta // {
+    homepage = "https://lld.llvm.org/";
+    description = "The LLVM linker (unwrapped)";
+    longDescription = ''
+      LLD is a linker from the LLVM project that is a drop-in replacement for
+      system linkers and runs much faster than them. It also provides features
+      that are useful for toolchain developers.
+      The linker supports ELF (Unix), PE/COFF (Windows), Mach-O (macOS), and
+      WebAssembly in descending order of completeness. Internally, LLD consists
+      of several different linkers.
+    '';
+  };
+}
--- a/llvm/11/lld/gnu-install-dirs.patch
+++ b/llvm/11/lld/gnu-install-dirs.patch
@ -0,0 +1,68 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 040bb2c8f6d7..f765f0096d97 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -6,6 +6,8 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+   set(CMAKE_INCLUDE_CURRENT_DIR ON)
+   set(LLD_BUILT_STANDALONE TRUE)
+ 
+  include(GNUInstallDirs)
+
+   find_program(LLVM_CONFIG_PATH "llvm-config" DOC "Path to llvm-config binary")
+   if(NOT LLVM_CONFIG_PATH)
+     message(FATAL_ERROR "llvm-config not found: specify LLVM_CONFIG_PATH")
+@@ -205,7 +207,7 @@ include_directories(BEFORE
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN ".svn" EXCLUDE
+diff --git a/cmake/modules/AddLLD.cmake b/cmake/modules/AddLLD.cmake
+index 23df41312403..d62372c88de7 100644
+--- a/cmake/modules/AddLLD.cmake
+++ b/cmake/modules/AddLLD.cmake
+@@ -20,9 +20,9 @@ macro(add_lld_library name)
+     install(TARGETS ${name}
+       COMPONENT ${name}
+       ${export_to_lldtargets}
+-      LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-      ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-      RUNTIME DESTINATION bin)
+      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+ 
+     if (${ARG_SHARED} AND NOT CMAKE_CONFIGURATION_TYPES)
+       add_llvm_install_targets(install-${name}
+@@ -54,7 +54,7 @@ macro(add_lld_tool name)
+ 
+     install(TARGETS ${name}
+       ${export_to_lldtargets}
+-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+       COMPONENT ${name})
+ 
+     if(NOT CMAKE_CONFIGURATION_TYPES)
+@@ -69,5 +69,5 @@ endmacro()
+ macro(add_lld_symlink name dest)
+   add_llvm_tool_symlink(${name} ${dest} ALWAYS_GENERATE)
+   # Always generate install targets
+-  llvm_install_symlink(${name} ${dest} ALWAYS_GENERATE)
+  llvm_install_symlink(${name} ${dest} ${CMAKE_INSTALL_FULL_BINDIR} ALWAYS_GENERATE)
+ endmacro()
+diff --git a/tools/lld/CMakeLists.txt b/tools/lld/CMakeLists.txt
+index e6f72fcd3488..d903609e6e4f 100644
+--- a/tools/lld/CMakeLists.txt
+++ b/tools/lld/CMakeLists.txt
+@@ -21,7 +21,7 @@ target_link_libraries(lld
+   )
+ 
+ install(TARGETS lld
+-  RUNTIME DESTINATION bin)
+  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+ 
+ if(NOT LLD_SYMLINKS_TO_CREATE)
+   set(LLD_SYMLINKS_TO_CREATE lld-link ld.lld ld64.lld wasm-ld)
--- a/llvm/11/lldb/gnu-install-dirs.patch
+++ b/llvm/11/lldb/gnu-install-dirs.patch
@ -0,0 +1,91 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index bf748020ea40..34103d2b5e1a 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -17,6 +17,8 @@ set(CMAKE_MODULE_PATH
+ # If we are not building as part of LLVM, build LLDB as a standalone project,
+ # using LLVM as an external library.
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+  include(GNUInstallDirs)
+
+   project(lldb)
+   include(LLDBStandalone)
+ 
+diff --git a/cmake/modules/AddLLDB.cmake b/cmake/modules/AddLLDB.cmake
+index 4ed5c647c5d2..89f96e710d55 100644
+--- a/cmake/modules/AddLLDB.cmake
+++ b/cmake/modules/AddLLDB.cmake
+@@ -107,13 +107,13 @@ function(add_lldb_library name)
+   endif()
+ 
+   if(PARAM_SHARED)
+-    set(install_dest lib${LLVM_LIBDIR_SUFFIX})
+    set(install_dest ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+     if(PARAM_INSTALL_PREFIX)
+       set(install_dest ${PARAM_INSTALL_PREFIX})
+     endif()
+     # RUNTIME is relevant for DLL platforms, FRAMEWORK for macOS
+     install(TARGETS ${name} COMPONENT ${name}
+-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+       LIBRARY DESTINATION ${install_dest}
+       ARCHIVE DESTINATION ${install_dest}
+       FRAMEWORK DESTINATION ${install_dest})
+diff --git a/cmake/modules/LLDBConfig.cmake b/cmake/modules/LLDBConfig.cmake
+index 8465cfe3b7b7..01b7eae136e2 100644
+--- a/cmake/modules/LLDBConfig.cmake
+++ b/cmake/modules/LLDBConfig.cmake
+@@ -245,7 +245,7 @@ include_directories(BEFORE
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/
+     COMPONENT lldb-headers
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN ".svn" EXCLUDE
+@@ -254,7 +254,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+ 
+   install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/
+     COMPONENT lldb-headers
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN ".svn" EXCLUDE
+diff --git a/tools/intel-features/CMakeLists.txt b/tools/intel-features/CMakeLists.txt
+index efba2f74904f..e08413b1dbb1 100644
+--- a/tools/intel-features/CMakeLists.txt
+++ b/tools/intel-features/CMakeLists.txt
+@@ -65,4 +65,4 @@ if (LLDB_ENABLE_PYTHON AND LLDB_BUILD_INTEL_PT)
+ endif()
+ 
+ install(TARGETS lldbIntelFeatures
+-  LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX})
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+diff --git a/cmake/modules/LLDBStandalone.cmake b/cmake/modules/LLDBStandalone.cmake
+index 752113b..010f187 100644
+--- a/cmake/modules/LLDBStandalone.cmake
+++ b/cmake/modules/LLDBStandalone.cmake
+@@ -62,7 +62,7 @@ endif()
+
+ # They are used as destination of target generators.
+ set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin)
+-set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
+set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+ if(WIN32 OR CYGWIN)
+   # DLL platform -- put DLLs into bin.
+   set(LLVM_SHLIB_OUTPUT_INTDIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index bf74802..1c98cae 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -222,7 +222,7 @@ if (LLDB_ENABLE_PYTHON)
+   if(LLDB_BUILD_FRAMEWORK)
+     set(LLDB_PYTHON_INSTALL_PATH ${LLDB_FRAMEWORK_INSTALL_DIR}/LLDB.framework/Resources/Python)
+   else()
+-    set(LLDB_PYTHON_INSTALL_PATH ${LLDB_PYTHON_RELATIVE_PATH})
+    set(LLDB_PYTHON_INSTALL_PATH ${CMAKE_INSTALL_LIBDIR}/../${LLDB_PYTHON_RELATIVE_PATH})
+   endif()
+   if (NOT CMAKE_CFG_INTDIR STREQUAL  ".")
+     string(REPLACE ${CMAKE_CFG_INTDIR} "\$\{CMAKE_INSTALL_CONFIG_NAME\}" LLDB_PYTHON_INSTALL_PATH ${LLDB_PYTHON_INSTALL_PATH})
--- a/llvm/11/lldb/procfs.patch
+++ b/llvm/11/lldb/procfs.patch
@ -0,0 +1,31 @@
+--- a/source/Plugins/Process/Linux/Procfs.h
+++ b/source/Plugins/Process/Linux/Procfs.h
+@@ -11,21 +11,12 @@
+ // sys/procfs.h on Android/Linux for all supported architectures.
+ 
+ #include <sys/ptrace.h>
+#include <asm/ptrace.h>
+ 
+-#ifdef __ANDROID__
+-#if defined(__arm64__) || defined(__aarch64__)
+-typedef unsigned long elf_greg_t;
+-typedef elf_greg_t
+-    elf_gregset_t[(sizeof(struct user_pt_regs) / sizeof(elf_greg_t))];
+-typedef struct user_fpsimd_state elf_fpregset_t;
+-#ifndef NT_FPREGSET
+-#define NT_FPREGSET NT_PRFPREG
+-#endif // NT_FPREGSET
+-#elif defined(__mips__)
+-#ifndef NT_FPREGSET
+-#define NT_FPREGSET NT_PRFPREG
+-#endif // NT_FPREGSET
+-#endif
+-#else // __ANDROID__
+#if !defined(__GLIBC__) && defined(__powerpc__)
+#define pt_regs musl_pt_regs
+#include <sys/procfs.h>
+#undef pt_regs
+#else
+ #include <sys/procfs.h>
+-#endif // __ANDROID__
+#endif
--- a/llvm/11/llvm/default.nix
+++ b/llvm/11/llvm/default.nix
@ -0,0 +1,363 @@
+{ lib, stdenv, llvm_meta
+, pkgsBuildBuild
+, fetch
+, fetchpatch
+, cmake
+, python3
+, libffi
+, enableGoldPlugin ? libbfd.hasPluginAPI
+, libbfd
+, libpfm
+, libxml2
+, ncurses
+, version
+, release_version
+, zlib
+, buildLlvmTools
+, debugVersion ? false
+, doCheck ? stdenv.isLinux && (!stdenv.isx86_32) && (!stdenv.hostPlatform.isMusl) && (!stdenv.hostPlatform.isRiscV)
+  && (stdenv.hostPlatform == stdenv.buildPlatform)
+, enableManpages ? false
+, enableSharedLibraries ? !stdenv.hostPlatform.isStatic
+# broken for Ampere eMAG 8180 (c2.large.arm on Packet) #56245
+# broken for the armv7l builder
+, enablePFM ? stdenv.isLinux && !stdenv.hostPlatform.isAarch
+, enablePolly ? false # TODO should be on by default
+}:
+
+let
+  inherit (lib) optional optionals optionalString;
+
+  # Used when creating a version-suffixed symlink of libLLVM.dylib
+  shortVersion = with lib;
+    concatStringsSep "." (take 1 (splitString "." release_version));
+
+  # Ordinarily we would just the `doCheck` and `checkDeps` functionality
+  # `mkDerivation` gives us to manage our test dependencies (instead of breaking
+  # out `doCheck` as a package level attribute).
+  #
+  # Unfortunately `lit` does not forward `$PYTHONPATH` to children processes, in
+  # particular the children it uses to do feature detection.
+  #
+  # This means that python deps we add to `checkDeps` (which the python
+  # interpreter is made aware of via `$PYTHONPATH` – populated by the python
+  # setup hook) are not picked up by `lit` which causes it to skip tests.
+  #
+  # Adding `python3.withPackages (ps: [ ... ])` to `checkDeps` also doesn't work
+  # because this package is shadowed in `$PATH` by the regular `python3`
+  # package.
+  #
+  # So, we "manually" assemble one python derivation for the package to depend
+  # on, taking into account whether checks are enabled or not:
+  python = if doCheck then
+    let
+      checkDeps = ps: with ps; [ psutil ];
+    in python3.withPackages checkDeps
+  else python3;
+
+in stdenv.mkDerivation (rec {
+  pname = "llvm";
+  inherit version;
+
+  src = fetch pname "199yq3a214avcbi4kk2q0ajriifkvsr0l2dkx3a666m033ihi1ff";
+  polly_src = fetch "polly" "031r23ijhx7v93a5n33m2nc0x9xyqmx0d8xg80z7q971p6qd63sq";
+
+  unpackPhase = ''
+    unpackFile $src
+    mv llvm-${release_version}* llvm
+    sourceRoot=$PWD/llvm
+  '' + optionalString enablePolly ''
+    unpackFile $polly_src
+    mv polly-* $sourceRoot/tools/polly
+  '';
+
+  outputs = [ "out" "lib" "dev" "python" ];
+
+  nativeBuildInputs = [ cmake python ]
+    ++ optionals enableManpages [ python3.pkgs.sphinx python3.pkgs.recommonmark ];
+
+  buildInputs = [ libxml2 libffi ]
+    ++ optional enablePFM libpfm; # exegesis
+
+  propagatedBuildInputs = [ ncurses zlib ];
+
+  patches = [
+    # When cross-compiling we configure llvm-config-native with an approximation
+    # of the flags used for the normal LLVM build. To avoid the need for building
+    # a native libLLVM.so (which would fail) we force llvm-config to be linked
+    # statically against the necessary LLVM components always.
+    ../../llvm-config-link-static.patch
+
+    ./gnu-install-dirs.patch
+    # On older CPUs (e.g. Hydra/wendy) we'd be getting an error in this test.
+    (fetchpatch {
+      name = "uops-CMOV16rm-noreg.diff";
+      url = "https://github.com/llvm/llvm-project/commit/9e9f991ac033.diff";
+      sha256 = "sha256:12s8vr6ibri8b48h2z38f3afhwam10arfiqfy4yg37bmc054p5hi";
+      stripLen = 1;
+    })
+    # gcc-11 compat upstream patch
+    (fetchpatch {
+      url = "https://github.com/llvm/llvm-project/commit/b498303066a63a203d24f739b2d2e0e56dca70d1.patch";
+      sha256 = "sha256:0nh123kld0dgz2h941lng331dkj3wbm5lfxm375k1f569gv83hlk";
+      stripLen = 1;
+    })
+
+    # Fix invalid std::string(nullptr) for GCC 12
+    (fetchpatch {
+      name = "nvptx-gcc-12.patch";
+      url = "https://github.com/llvm/llvm-project/commit/99e64623ec9b31def9375753491cc6093c831809.patch";
+      sha256 = "0zjfjgavqzi2ypqwqnlvy6flyvdz8hi1anwv0ybwnm2zqixg7za3";
+      stripLen = 1;
+    })
+    (fetchpatch {
+      name = "dfaemitter-gcc-12.patch";
+      url = "https://github.com/llvm/llvm-project/commit/0841916e87a39e3c223c986e8da31e4a9a1432e3.patch";
+      sha256 = "1kckghvsngs51mqm82asy0s9vr19h8aqbw43a0w44mccqw6bzrwf";
+      stripLen = 1;
+    })
+
+    # Fix musl build.
+    (fetchpatch {
+      url = "https://github.com/llvm/llvm-project/commit/5cd554303ead0f8891eee3cd6d25cb07f5a7bf67.patch";
+      relative = "llvm";
+      hash = "sha256-XPbvNJ45SzjMGlNUgt/IgEvM2dHQpDOe6woUJY+nUYA=";
+    })
+
+    # Backport gcc-13 fixes with missing includes.
+    (fetchpatch {
+      name = "signals-gcc-13.patch";
+      url = "https://github.com/llvm/llvm-project/commit/ff1681ddb303223973653f7f5f3f3435b48a1983.patch";
+      hash = "sha256-CXwYxQezTq5vdmc8Yn88BUAEly6YZ5VEIA6X3y5NNOs=";
+      stripLen = 1;
+    })
+    (fetchpatch {
+      name = "base64-gcc-13.patch";
+      url = "https://github.com/llvm/llvm-project/commit/5e9be93566f39ee6cecd579401e453eccfbe81e5.patch";
+      hash = "sha256-PAwrVrvffPd7tphpwCkYiz+67szPRzRB2TXBvKfzQ7U=";
+      stripLen = 1;
+    })
+  ] ++ lib.optional enablePolly ./gnu-install-dirs-polly.patch;
+
+  postPatch = optionalString stdenv.isDarwin ''
+    substituteInPlace cmake/modules/AddLLVM.cmake \
+      --replace 'set(_install_name_dir INSTALL_NAME_DIR "@rpath")' "set(_install_name_dir)" \
+      --replace 'set(_install_rpath "@loader_path/../''${CMAKE_INSTALL_LIBDIR}''${LLVM_LIBDIR_SUFFIX}" ''${extra_libdir})' ""
+  '' + ''
+    # FileSystem permissions tests fail with various special bits
+    substituteInPlace unittests/Support/CMakeLists.txt \
+      --replace "Path.cpp" ""
+    rm unittests/Support/Path.cpp
+  '' + optionalString stdenv.hostPlatform.isMusl ''
+    patch -p1 -i ${../../TLI-musl.patch}
+    substituteInPlace unittests/Support/CMakeLists.txt \
+      --replace "add_subdirectory(DynamicLibrary)" ""
+    rm unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
+    # valgrind unhappy with musl or glibc, but fails w/musl only
+    rm test/CodeGen/AArch64/wineh4.mir
+  '' + optionalString stdenv.hostPlatform.isAarch32 ''
+    # skip failing X86 test cases on 32-bit ARM
+    rm test/DebugInfo/X86/convert-debugloc.ll
+    rm test/DebugInfo/X86/convert-inlined.ll
+    rm test/DebugInfo/X86/convert-linked.ll
+    rm test/tools/dsymutil/X86/op-convert.test
+    rm test/tools/gold/X86/split-dwarf.ll
+    rm test/tools/llvm-readobj/ELF/dependent-libraries.test
+  '' + optionalString (stdenv.hostPlatform.system == "armv6l-linux") ''
+    # Seems to require certain floating point hardware (NEON?)
+    rm test/ExecutionEngine/frem.ll
+  '' + ''
+    patchShebangs test/BugPoint/compile-custom.ll.py
+  '' + ''
+    # Tweak tests to ignore namespace part of type to support
+    # gcc-12: https://gcc.gnu.org/PR103598.
+    # The change below mangles strings like:
+    #    CHECK-NEXT: Starting llvm::Function pass manager run.
+    # to:
+    #    CHECK-NEXT: Starting {{.*}}Function pass manager run.
+    for f in \
+      test/Other/new-pass-manager.ll \
+      test/Other/new-pm-defaults.ll \
+      test/Other/new-pm-lto-defaults.ll \
+      test/Other/new-pm-thinlto-defaults.ll \
+      test/Other/pass-pipeline-parsing.ll \
+      test/Transforms/Inline/cgscc-incremental-invalidate.ll \
+      test/Transforms/Inline/clear-analyses.ll \
+      test/Transforms/LoopUnroll/unroll-loop-invalidation.ll \
+      test/Transforms/SCCP/ipsccp-preserve-analysis.ll \
+      test/Transforms/SCCP/preserve-analysis.ll \
+      test/Transforms/SROA/dead-inst.ll \
+      test/tools/gold/X86/new-pm.ll \
+      ; do
+      echo "PATCH: $f"
+      substituteInPlace $f \
+        --replace 'Starting llvm::' 'Starting {{.*}}' \
+        --replace 'Finished llvm::' 'Finished {{.*}}'
+    done
+  '';
+
+  preConfigure = ''
+    # Workaround for configure flags that need to have spaces
+    cmakeFlagsArray+=(
+      -DLLVM_LIT_ARGS='-svj''${NIX_BUILD_CORES} --no-progress-bar'
+    )
+  '';
+
+  # hacky fix: created binaries need to be run before installation
+  preBuild = ''
+    mkdir -p $out/
+    ln -sv $PWD/lib $out
+  '';
+
+  # E.g. mesa.drivers use the build-id as a cache key (see #93946):
+  LDFLAGS = optionalString (enableSharedLibraries && !stdenv.isDarwin) "-Wl,--build-id=sha1";
+
+  cmakeBuildType = if debugVersion then "Debug" else "Release";
+
+  cmakeFlags = with stdenv; let
+    # These flags influence llvm-config's BuildVariables.inc in addition to the
+    # general build. We need to make sure these are also passed via
+    # CROSS_TOOLCHAIN_FLAGS_NATIVE when cross-compiling or llvm-config-native
+    # will return different results from the cross llvm-config.
+    #
+    # Some flags don't need to be repassed because LLVM already does so (like
+    # CMAKE_BUILD_TYPE), others are irrelevant to the result.
+    flagsForLlvmConfig = [
+      "-DLLVM_INSTALL_CMAKE_DIR=${placeholder "dev"}/lib/cmake/llvm/"
+      "-DLLVM_ENABLE_RTTI=ON"
+    ] ++ optionals enableSharedLibraries [
+      "-DLLVM_LINK_LLVM_DYLIB=ON"
+    ];
+  in flagsForLlvmConfig ++ [
+    "-DLLVM_INSTALL_UTILS=ON"  # Needed by rustc
+    "-DLLVM_BUILD_TESTS=${if doCheck then "ON" else "OFF"}"
+    "-DLLVM_ENABLE_FFI=ON"
+    "-DLLVM_HOST_TRIPLE=${stdenv.hostPlatform.config}"
+    "-DLLVM_DEFAULT_TARGET_TRIPLE=${stdenv.hostPlatform.config}"
+    "-DLLVM_ENABLE_DUMP=ON"
+  ] ++ optionals stdenv.hostPlatform.isStatic [
+    # Disables building of shared libs, -fPIC is still injected by cc-wrapper
+    "-DLLVM_ENABLE_PIC=OFF"
+    "-DLLVM_BUILD_STATIC=ON"
+    # libxml2 needs to be disabled because the LLVM build system ignores its .la
+    # file and doesn't link zlib as well.
+    # https://github.com/ClangBuiltLinux/tc-build/issues/150#issuecomment-845418812
+    "-DLLVM_ENABLE_LIBXML2=OFF"
+    # This is a Shared Library not tied to LLVM_ENABLE_PIC
+    "-DLLVM_TOOL_REMARKS_SHLIB_BUILD=OFF"
+  ] ++ optionals enableManpages [
+    "-DLLVM_BUILD_DOCS=ON"
+    "-DLLVM_ENABLE_SPHINX=ON"
+    "-DSPHINX_OUTPUT_MAN=ON"
+    "-DSPHINX_OUTPUT_HTML=OFF"
+    "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
+  ] ++ optionals (enableGoldPlugin) [
+    "-DLLVM_BINUTILS_INCDIR=${libbfd.dev}/include"
+  ] ++ optionals isDarwin [
+    "-DLLVM_ENABLE_LIBCXX=ON"
+    "-DCAN_TARGET_i386=false"
+  ] ++ optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+    "-DCMAKE_CROSSCOMPILING=True"
+    "-DLLVM_TABLEGEN=${buildLlvmTools.llvm}/bin/llvm-tblgen"
+    (
+      let
+        nativeCC = pkgsBuildBuild.targetPackages.stdenv.cc;
+        nativeBintools = nativeCC.bintools.bintools;
+        nativeToolchainFlags = [
+          "-DCMAKE_C_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}cc"
+          "-DCMAKE_CXX_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}c++"
+          "-DCMAKE_AR=${nativeBintools}/bin/${nativeBintools.targetPrefix}ar"
+          "-DCMAKE_STRIP=${nativeBintools}/bin/${nativeBintools.targetPrefix}strip"
+          "-DCMAKE_RANLIB=${nativeBintools}/bin/${nativeBintools.targetPrefix}ranlib"
+        ];
+        # We need to repass the custom GNUInstallDirs values, otherwise CMake
+        # will choose them for us, leading to wrong results in llvm-config-native
+        nativeInstallFlags = [
+          "-DCMAKE_INSTALL_PREFIX=${placeholder "out"}"
+          "-DCMAKE_INSTALL_BINDIR=${placeholder "out"}/bin"
+          "-DCMAKE_INSTALL_INCLUDEDIR=${placeholder "dev"}/include"
+          "-DCMAKE_INSTALL_LIBDIR=${placeholder "lib"}/lib"
+          "-DCMAKE_INSTALL_LIBEXECDIR=${placeholder "lib"}/libexec"
+        ];
+      in "-DCROSS_TOOLCHAIN_FLAGS_NATIVE:list="
+      + lib.concatStringsSep ";" (lib.concatLists [
+        flagsForLlvmConfig
+        nativeToolchainFlags
+        nativeInstallFlags
+      ])
+    )
+  ];
+
+  postBuild = ''
+    rm -fR $out
+  '';
+
+  preCheck = ''
+    export LD_LIBRARY_PATH=$LD_LIBRARY_PATH''${LD_LIBRARY_PATH:+:}$PWD/lib
+  '';
+
+  postInstall = ''
+    mkdir -p $python/share
+    mv $out/share/opt-viewer $python/share/opt-viewer
+    moveToOutput "bin/llvm-config*" "$dev"
+    substituteInPlace "$dev/lib/cmake/llvm/LLVMExports-${if debugVersion then "debug" else "release"}.cmake" \
+      --replace "\''${_IMPORT_PREFIX}/lib/lib" "$lib/lib/lib" \
+      --replace "$out/bin/llvm-config" "$dev/bin/llvm-config"
+    substituteInPlace "$dev/lib/cmake/llvm/LLVMConfig.cmake" \
+      --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}'"$lib"'")'
+  ''
+  + optionalString (stdenv.isDarwin && enableSharedLibraries) ''
+    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${shortVersion}.dylib
+    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
+  ''
+  + optionalString (stdenv.buildPlatform != stdenv.hostPlatform) ''
+    cp NATIVE/bin/llvm-config $dev/bin/llvm-config-native
+  '';
+
+  inherit doCheck;
+
+  checkTarget = "check-all";
+
+  requiredSystemFeatures = [ "big-parallel" ];
+  meta = llvm_meta // {
+    homepage = "https://llvm.org/";
+    description = "A collection of modular and reusable compiler and toolchain technologies";
+    longDescription = ''
+      The LLVM Project is a collection of modular and reusable compiler and
+      toolchain technologies. Despite its name, LLVM has little to do with
+      traditional virtual machines. The name "LLVM" itself is not an acronym; it
+      is the full name of the project.
+      LLVM began as a research project at the University of Illinois, with the
+      goal of providing a modern, SSA-based compilation strategy capable of
+      supporting both static and dynamic compilation of arbitrary programming
+      languages. Since then, LLVM has grown to be an umbrella project consisting
+      of a number of subprojects, many of which are being used in production by
+      a wide variety of commercial and open source projects as well as being
+      widely used in academic research. Code in the LLVM project is licensed
+      under the "Apache 2.0 License with LLVM exceptions".
+    '';
+  };
+} // lib.optionalAttrs enableManpages {
+  pname = "llvm-manpages";
+
+  buildPhase = ''
+    make docs-llvm-man
+  '';
+
+  propagatedBuildInputs = [];
+
+  installPhase = ''
+    make -C docs install
+  '';
+
+  postPatch = null;
+  postInstall = null;
+
+  outputs = [ "out" ];
+
+  doCheck = false;
+
+  meta = llvm_meta // {
+    description = "man pages for LLVM ${version}";
+  };
+})
--- a/llvm/11/llvm/gnu-install-dirs-polly.patch
+++ b/llvm/11/llvm/gnu-install-dirs-polly.patch
@ -0,0 +1,106 @@
+diff --git a/tools/polly/CMakeLists.txt b/tools/polly/CMakeLists.txt
+index 9939097f743e..8cc538da912a 100644
+--- a/tools/polly/CMakeLists.txt
+++ b/tools/polly/CMakeLists.txt
+@@ -2,7 +2,11 @@
+ if (NOT DEFINED LLVM_MAIN_SRC_DIR)
+   project(Polly)
+   cmake_minimum_required(VERSION 3.4.3)
+endif()
+
+include(GNUInstallDirs)
+ 
+if (NOT DEFINED LLVM_MAIN_SRC_DIR)
+   # Where is LLVM installed?
+   find_package(LLVM CONFIG REQUIRED)
+   set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${LLVM_CMAKE_DIR})
+@@ -145,14 +149,14 @@ include_directories(
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN ".svn" EXCLUDE
+     )
+ 
+   install(DIRECTORY ${POLLY_BINARY_DIR}/include/
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN "CMakeFiles" EXCLUDE
+diff --git a/tools/polly/cmake/CMakeLists.txt b/tools/polly/cmake/CMakeLists.txt
+index 211f95512717..f9e04a4844b6 100644
+--- a/tools/polly/cmake/CMakeLists.txt
+++ b/tools/polly/cmake/CMakeLists.txt
+@@ -79,18 +79,18 @@ file(GENERATE
+ 
+ # Generate PollyConfig.cmake for the install tree.
+ unset(POLLY_EXPORTS)
+-set(POLLY_INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX}")
+set(POLLY_INSTALL_PREFIX "")
+ set(POLLY_CONFIG_LLVM_CMAKE_DIR "${LLVM_BINARY_DIR}/${LLVM_INSTALL_PACKAGE_DIR}")
+-set(POLLY_CONFIG_CMAKE_DIR "${POLLY_INSTALL_PREFIX}/${POLLY_INSTALL_PACKAGE_DIR}")
+-set(POLLY_CONFIG_LIBRARY_DIRS "${POLLY_INSTALL_PREFIX}/lib${LLVM_LIBDIR_SUFFIX}")
+set(POLLY_CONFIG_CMAKE_DIR "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_PREFIX}/${POLLY_INSTALL_PACKAGE_DIR}")
+set(POLLY_CONFIG_LIBRARY_DIRS "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
+ if (POLLY_BUNDLED_ISL)
+   set(POLLY_CONFIG_INCLUDE_DIRS
+-    "${POLLY_INSTALL_PREFIX}/include"
+-    "${POLLY_INSTALL_PREFIX}/include/polly"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}/polly"
+     )
+ else()
+   set(POLLY_CONFIG_INCLUDE_DIRS
+-    "${POLLY_INSTALL_PREFIX}/include"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_INCLUDEDIR}"
+     ${ISL_INCLUDE_DIRS}
+     )
+ endif()
+@@ -100,12 +100,12 @@ endif()
+ foreach(tgt IN LISTS POLLY_CONFIG_EXPORTED_TARGETS)
+   get_target_property(tgt_type ${tgt} TYPE)
+   if (tgt_type STREQUAL "EXECUTABLE")
+-    set(tgt_prefix "bin/")
+    set(tgt_prefix "${CMAKE_INSTALL_BINDIR}/")
+   else()
+-    set(tgt_prefix "lib/")
+    set(tgt_prefix "${CMAKE_INSTALL_LIBDIR}/")
+   endif()
+ 
+-  set(tgt_path "${CMAKE_INSTALL_PREFIX}/${tgt_prefix}$<TARGET_FILE_NAME:${tgt}>")
+  set(tgt_path "${tgt_prefix}$<TARGET_FILE_NAME:${tgt}>")
+   file(RELATIVE_PATH tgt_path ${POLLY_CONFIG_CMAKE_DIR} ${tgt_path})
+ 
+   if (NOT tgt_type STREQUAL "INTERFACE_LIBRARY")
+diff --git a/tools/polly/cmake/polly_macros.cmake b/tools/polly/cmake/polly_macros.cmake
+index 86de6f10686e..91f30891ccbe 100644
+--- a/tools/polly/cmake/polly_macros.cmake
+++ b/tools/polly/cmake/polly_macros.cmake
+@@ -44,8 +44,8 @@ macro(add_polly_library name)
+   if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY OR ${name} STREQUAL "LLVMPolly")
+     install(TARGETS ${name}
+       EXPORT LLVMExports
+-      LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-      ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX})
+	  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+   endif()
+   set_property(GLOBAL APPEND PROPERTY LLVM_EXPORTS ${name})
+ endmacro(add_polly_library)
+diff --git a/tools/polly/lib/External/CMakeLists.txt b/tools/polly/lib/External/CMakeLists.txt
+index 1039079cb49c..28b499ae1e9e 100644
+--- a/tools/polly/lib/External/CMakeLists.txt
+++ b/tools/polly/lib/External/CMakeLists.txt
+@@ -275,7 +275,7 @@ if (POLLY_BUNDLED_ISL)
+     install(DIRECTORY
+       ${ISL_SOURCE_DIR}/include/
+       ${ISL_BINARY_DIR}/include/
+-      DESTINATION include/polly
+      DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/polly
+       FILES_MATCHING
+       PATTERN "*.h"
+       PATTERN "CMakeFiles" EXCLUDE
--- a/llvm/11/llvm/gnu-install-dirs.patch
+++ b/llvm/11/llvm/gnu-install-dirs.patch
@ -0,0 +1,417 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 247ad36d3845..815e2c4ba955 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -269,15 +269,21 @@ if (CMAKE_BUILD_TYPE AND
+   message(FATAL_ERROR "Invalid value for CMAKE_BUILD_TYPE: ${CMAKE_BUILD_TYPE}")
+ endif()
+ 
+include(GNUInstallDirs)
+
+ set(LLVM_LIBDIR_SUFFIX "" CACHE STRING "Define suffix of library directory name (32/64)" )
+ 
+-set(LLVM_TOOLS_INSTALL_DIR "bin" CACHE STRING "Path for binary subdirectory (defaults to 'bin')")
+set(LLVM_TOOLS_INSTALL_DIR "${CMAKE_INSTALL_BINDIR}" CACHE STRING
+    "Path for binary subdirectory (defaults to 'bin')")
+ mark_as_advanced(LLVM_TOOLS_INSTALL_DIR)
+ 
+ set(LLVM_UTILS_INSTALL_DIR "${LLVM_TOOLS_INSTALL_DIR}" CACHE STRING
+     "Path to install LLVM utilities (enabled by LLVM_INSTALL_UTILS=ON) (defaults to LLVM_TOOLS_INSTALL_DIR)")
+ mark_as_advanced(LLVM_UTILS_INSTALL_DIR)
+ 
+set(LLVM_INSTALL_CMAKE_DIR "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/cmake/llvm" CACHE STRING
+	"Path for CMake subdirectory (defaults to lib/cmake/llvm)" )
+
+ # They are used as destination of target generators.
+ set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin)
+ set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
+@@ -559,9 +565,9 @@ option (LLVM_ENABLE_SPHINX "Use Sphinx to generate llvm documentation." OFF)
+ option (LLVM_ENABLE_OCAMLDOC "Build OCaml bindings documentation." ON)
+ option (LLVM_ENABLE_BINDINGS "Build bindings." ON)
+ 
+-set(LLVM_INSTALL_DOXYGEN_HTML_DIR "share/doc/llvm/doxygen-html"
+set(LLVM_INSTALL_DOXYGEN_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/doxygen-html"
+     CACHE STRING "Doxygen-generated HTML documentation install directory")
+-set(LLVM_INSTALL_OCAMLDOC_HTML_DIR "share/doc/llvm/ocaml-html"
+set(LLVM_INSTALL_OCAMLDOC_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/ocaml-html"
+     CACHE STRING "OCamldoc-generated HTML documentation install directory")
+ 
+ option (LLVM_BUILD_EXTERNAL_COMPILER_RT
+@@ -1107,7 +1113,7 @@ endif()
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/llvm include/llvm-c
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT llvm-headers
+     FILES_MATCHING
+     PATTERN "*.def"
+@@ -1119,7 +1125,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+     )
+ 
+   install(DIRECTORY ${LLVM_INCLUDE_DIR}/llvm ${LLVM_INCLUDE_DIR}/llvm-c
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT llvm-headers
+     FILES_MATCHING
+     PATTERN "*.def"
+@@ -1134,13 +1140,13 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+ 
+   if (LLVM_INSTALL_MODULEMAPS)
+     install(DIRECTORY include/llvm include/llvm-c
+-            DESTINATION include
+            DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+             COMPONENT llvm-headers
+             FILES_MATCHING
+             PATTERN "module.modulemap"
+             )
+     install(FILES include/llvm/module.install.modulemap
+-            DESTINATION include/llvm
+            DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm
+             COMPONENT llvm-headers
+             RENAME "module.extern.modulemap"
+             )
+diff --git a/cmake/modules/AddLLVM.cmake b/cmake/modules/AddLLVM.cmake
+index b74adc11ade9..a5aa258cde30 100644
+--- a/cmake/modules/AddLLVM.cmake
+++ b/cmake/modules/AddLLVM.cmake
+@@ -766,9 +766,9 @@ macro(add_llvm_library name)
+ 
+       install(TARGETS ${name}
+               ${export_to_llvmexports}
+-              LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+-              ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+-              RUNTIME DESTINATION bin COMPONENT ${name})
+              LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+              ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+              RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT ${name})
+ 
+       if (NOT LLVM_ENABLE_IDE)
+         add_llvm_install_targets(install-${name}
+@@ -981,7 +981,7 @@ function(process_llvm_pass_plugins)
+           "set(LLVM_STATIC_EXTENSIONS ${LLVM_STATIC_EXTENSIONS})")
+       install(FILES
+           ${llvm_cmake_builddir}/LLVMConfigExtensions.cmake
+-          DESTINATION ${LLVM_INSTALL_PACKAGE_DIR}
+          DESTINATION ${LLVM_INSTALL_CMAKE_DIR}
+           COMPONENT cmake-exports)
+ 
+       set(ExtensionDef "${LLVM_BINARY_DIR}/include/llvm/Support/Extension.def")
+@@ -1201,7 +1201,7 @@ macro(add_llvm_example name)
+   endif()
+   add_llvm_executable(${name} ${ARGN})
+   if( LLVM_BUILD_EXAMPLES )
+-    install(TARGETS ${name} RUNTIME DESTINATION examples)
+    install(TARGETS ${name} RUNTIME DESTINATION ${CMAKE_INSTALL_DOCDIR}/examples)
+   endif()
+   set_target_properties(${name} PROPERTIES FOLDER "Examples")
+ endmacro(add_llvm_example name)
+@@ -1819,7 +1819,7 @@ function(llvm_install_library_symlink name dest type)
+   set(full_name ${CMAKE_${type}_LIBRARY_PREFIX}${name}${CMAKE_${type}_LIBRARY_SUFFIX})
+   set(full_dest ${CMAKE_${type}_LIBRARY_PREFIX}${dest}${CMAKE_${type}_LIBRARY_SUFFIX})
+ 
+-  set(output_dir lib${LLVM_LIBDIR_SUFFIX})
+  set(output_dir ${CMAKE_INSTALL_FULL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+   if(WIN32 AND "${type}" STREQUAL "SHARED")
+     set(output_dir bin)
+   endif()
+@@ -1836,7 +1836,7 @@ function(llvm_install_library_symlink name dest type)
+   endif()
+ endfunction()
+ 
+-function(llvm_install_symlink name dest)
+function(llvm_install_symlink name dest output_dir)
+   cmake_parse_arguments(ARG "ALWAYS_GENERATE" "COMPONENT" "" ${ARGN})
+   foreach(path ${CMAKE_MODULE_PATH})
+     if(EXISTS ${path}/LLVMInstallSymlink.cmake)
+@@ -1859,7 +1859,7 @@ function(llvm_install_symlink name dest)
+   set(full_dest ${dest}${CMAKE_EXECUTABLE_SUFFIX})
+ 
+   install(SCRIPT ${INSTALL_SYMLINK}
+-          CODE "install_symlink(${full_name} ${full_dest} ${LLVM_TOOLS_INSTALL_DIR})"
+          CODE "install_symlink(${full_name} ${full_dest} ${output_dir})"
+           COMPONENT ${component})
+ 
+   if (NOT LLVM_ENABLE_IDE AND NOT ARG_ALWAYS_GENERATE)
+@@ -1942,7 +1942,8 @@ function(add_llvm_tool_symlink link_name target)
+     endif()
+ 
+     if ((TOOL_IS_TOOLCHAIN OR NOT LLVM_INSTALL_TOOLCHAIN_ONLY) AND LLVM_BUILD_TOOLS)
+-      llvm_install_symlink(${link_name} ${target})
+      GNUInstallDirs_get_absolute_install_dir(output_dir LLVM_TOOLS_INSTALL_DIR)
+      llvm_install_symlink(${link_name} ${target} ${output_dir})
+     endif()
+   endif()
+ endfunction()
+@@ -2064,9 +2065,9 @@ function(llvm_setup_rpath name)
+ 
+   if (APPLE)
+     set(_install_name_dir INSTALL_NAME_DIR "@rpath")
+-    set(_install_rpath "@loader_path/../lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+    set(_install_rpath "@loader_path/../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+   elseif(UNIX)
+-    set(_install_rpath "\$ORIGIN/../lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+    set(_install_rpath "\$ORIGIN/../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+     if(${CMAKE_SYSTEM_NAME} MATCHES "(FreeBSD|DragonFly)")
+       set_property(TARGET ${name} APPEND_STRING PROPERTY
+                    LINK_FLAGS " -Wl,-z,origin ")
+diff --git a/cmake/modules/AddOCaml.cmake b/cmake/modules/AddOCaml.cmake
+index 554046b20edf..4d1ad980641e 100644
+--- a/cmake/modules/AddOCaml.cmake
+++ b/cmake/modules/AddOCaml.cmake
+@@ -144,9 +144,9 @@ function(add_ocaml_library name)
+   endforeach()
+ 
+   if( APPLE )
+-    set(ocaml_rpath "@executable_path/../../../lib${LLVM_LIBDIR_SUFFIX}")
+    set(ocaml_rpath "@executable_path/../../../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
+   elseif( UNIX )
+-    set(ocaml_rpath "\\$ORIGIN/../../../lib${LLVM_LIBDIR_SUFFIX}")
+    set(ocaml_rpath "\\$ORIGIN/../../../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
+   endif()
+   list(APPEND ocaml_flags "-ldopt" "-Wl,-rpath,${ocaml_rpath}")
+ 
+diff --git a/cmake/modules/AddSphinxTarget.cmake b/cmake/modules/AddSphinxTarget.cmake
+index b5babb30abcf..190b1222a9f9 100644
+--- a/cmake/modules/AddSphinxTarget.cmake
+++ b/cmake/modules/AddSphinxTarget.cmake
+@@ -84,7 +84,7 @@ function (add_sphinx_target builder project)
+         endif()
+       elseif (builder STREQUAL html)
+         string(TOUPPER "${project}" project_upper)
+-        set(${project_upper}_INSTALL_SPHINX_HTML_DIR "share/doc/${project}/html"
+        set(${project_upper}_INSTALL_SPHINX_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/html"
+             CACHE STRING "HTML documentation install directory for ${project}")
+ 
+         # '/.' indicates: copy the contents of the directory directly into
+diff --git a/cmake/modules/CMakeLists.txt b/cmake/modules/CMakeLists.txt
+index 4b8879f65fe4..f01920bcc60f 100644
+--- a/cmake/modules/CMakeLists.txt
+++ b/cmake/modules/CMakeLists.txt
+@@ -1,4 +1,4 @@
+-set(LLVM_INSTALL_PACKAGE_DIR lib${LLVM_LIBDIR_SUFFIX}/cmake/llvm)
+set(LLVM_INSTALL_PACKAGE_DIR ${LLVM_INSTALL_CMAKE_DIR} CACHE STRING "Path for CMake subdirectory (defaults to 'cmake/llvm')")
+ set(llvm_cmake_builddir "${LLVM_BINARY_DIR}/${LLVM_INSTALL_PACKAGE_DIR}")
+ 
+ # First for users who use an installed LLVM, create the LLVMExports.cmake file.
+@@ -108,13 +108,13 @@ foreach(p ${_count})
+   set(LLVM_CONFIG_CODE "${LLVM_CONFIG_CODE}
+ get_filename_component(LLVM_INSTALL_PREFIX \"\${LLVM_INSTALL_PREFIX}\" PATH)")
+ endforeach(p)
+-set(LLVM_CONFIG_INCLUDE_DIRS "\${LLVM_INSTALL_PREFIX}/include")
+set(LLVM_CONFIG_INCLUDE_DIRS "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_INCLUDEDIR}")
+ set(LLVM_CONFIG_INCLUDE_DIR "${LLVM_CONFIG_INCLUDE_DIRS}")
+ set(LLVM_CONFIG_MAIN_INCLUDE_DIR "${LLVM_CONFIG_INCLUDE_DIRS}")
+-set(LLVM_CONFIG_LIBRARY_DIRS "\${LLVM_INSTALL_PREFIX}/lib\${LLVM_LIBDIR_SUFFIX}")
+set(LLVM_CONFIG_LIBRARY_DIRS "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}\${LLVM_LIBDIR_SUFFIX}")
+ set(LLVM_CONFIG_CMAKE_DIR "\${LLVM_INSTALL_PREFIX}/${LLVM_INSTALL_PACKAGE_DIR}")
+ set(LLVM_CONFIG_BINARY_DIR "\${LLVM_INSTALL_PREFIX}")
+-set(LLVM_CONFIG_TOOLS_BINARY_DIR "\${LLVM_INSTALL_PREFIX}/bin")
+set(LLVM_CONFIG_TOOLS_BINARY_DIR "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_BINDIR}")
+ 
+ # Generate a default location for lit
+ if (LLVM_INSTALL_UTILS AND LLVM_BUILD_UTILS)
+diff --git a/cmake/modules/LLVMInstallSymlink.cmake b/cmake/modules/LLVMInstallSymlink.cmake
+index 09fed8085c23..aa79f192abf0 100644
+--- a/cmake/modules/LLVMInstallSymlink.cmake
+++ b/cmake/modules/LLVMInstallSymlink.cmake
+@@ -10,7 +10,7 @@ function(install_symlink name target outdir)
+     set(LINK_OR_COPY copy)
+   endif()
+ 
+-  set(bindir "${DESTDIR}${CMAKE_INSTALL_PREFIX}/${outdir}/")
+  set(bindir "${DESTDIR}${outdir}/")
+ 
+   message(STATUS "Creating ${name}")
+ 
+diff --git a/docs/CMake.rst b/docs/CMake.rst
+index 1f908d3e95b1..1315e0aa40e1 100644
+--- a/docs/CMake.rst
+++ b/docs/CMake.rst
+@@ -196,7 +196,7 @@ CMake manual, or execute ``cmake --help-variable VARIABLE_NAME``.
+ **LLVM_LIBDIR_SUFFIX**:STRING
+   Extra suffix to append to the directory where libraries are to be
+   installed. On a 64-bit architecture, one could use ``-DLLVM_LIBDIR_SUFFIX=64``
+-  to install libraries to ``/usr/lib64``.
+  to install libraries to ``/usr/lib64``. See also ``CMAKE_INSTALL_LIBDIR``.
+ 
+ **CMAKE_C_FLAGS**:STRING
+   Extra flags to use when compiling C source files.
+@@ -516,8 +516,8 @@ LLVM-specific variables
+ 
+ **LLVM_INSTALL_DOXYGEN_HTML_DIR**:STRING
+   The path to install Doxygen-generated HTML documentation to. This path can
+-  either be absolute or relative to the CMAKE_INSTALL_PREFIX. Defaults to
+-  `share/doc/llvm/doxygen-html`.
+  either be absolute or relative to the ``CMAKE_INSTALL_PREFIX``. Defaults to
+  `${CMAKE_INSTALL_DOCDIR}/${project}/doxygen-html`.
+ 
+ **LLVM_ENABLE_SPHINX**:BOOL
+   If specified, CMake will search for the ``sphinx-build`` executable and will make
+@@ -548,13 +548,33 @@ LLVM-specific variables
+ 
+ **LLVM_INSTALL_SPHINX_HTML_DIR**:STRING
+   The path to install Sphinx-generated HTML documentation to. This path can
+-  either be absolute or relative to the CMAKE_INSTALL_PREFIX. Defaults to
+-  `share/doc/llvm/html`.
+  either be absolute or relative to the ``CMAKE_INSTALL_PREFIX``. Defaults to
+  `${CMAKE_INSTALL_DOCDIR}/${project}/html`.
+ 
+ **LLVM_INSTALL_OCAMLDOC_HTML_DIR**:STRING
+   The path to install OCamldoc-generated HTML documentation to. This path can
+-  either be absolute or relative to the CMAKE_INSTALL_PREFIX. Defaults to
+-  `share/doc/llvm/ocaml-html`.
+  either be absolute or relative to the ``CMAKE_INSTALL_PREFIX``. Defaults to
+  `${CMAKE_INSTALL_DOCDIR}/${project}/ocaml-html`.
+
+**CMAKE_INSTALL_BINDIR**:STRING
+  The path to install binary tools, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `bin`.
+
+**CMAKE_INSTALL_LIBDIR**:STRING
+  The path to install libraries, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `lib`.
+
+**CMAKE_INSTALL_INCLUDEDIR**:STRING
+  The path to install header files, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `include`.
+
+**CMAKE_INSTALL_DOCDIR**:STRING
+  The path to install documentation, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `share/doc`.
+
+**CMAKE_INSTALL_MANDIR**:STRING
+  The path to install manpage files, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `share/man`.
+ 
+ **LLVM_CREATE_XCODE_TOOLCHAIN**:BOOL
+   macOS Only: If enabled CMake will generate a target named
+@@ -752,9 +772,11 @@ the ``cmake`` command or by setting it directly in ``ccmake`` or ``cmake-gui``).
+ 
+ This file is available in two different locations.
+ 
+-* ``<INSTALL_PREFIX>/lib/cmake/llvm/LLVMConfig.cmake`` where
+-  ``<INSTALL_PREFIX>`` is the install prefix of an installed version of LLVM.
+-  On Linux typically this is ``/usr/lib/cmake/llvm/LLVMConfig.cmake``.
+* ``<LLVM_INSTALL_PACKAGE_DIR>LLVMConfig.cmake`` where
+  ``<LLVM_INSTALL_PACKAGE_DIR>`` is the location where LLVM CMake modules are
+  installed as part of an installed version of LLVM. This is typically
+  ``cmake/llvm/`` within the lib directory. On Linux, this is typically
+  ``/usr/lib/cmake/llvm/LLVMConfig.cmake``.
+ 
+ * ``<LLVM_BUILD_ROOT>/lib/cmake/llvm/LLVMConfig.cmake`` where
+   ``<LLVM_BUILD_ROOT>`` is the root of the LLVM build tree. **Note: this is only
+diff --git a/examples/Bye/CMakeLists.txt b/examples/Bye/CMakeLists.txt
+index bb96edb4b4bf..678c22fb43c8 100644
+--- a/examples/Bye/CMakeLists.txt
+++ b/examples/Bye/CMakeLists.txt
+@@ -14,6 +14,6 @@ if (NOT WIN32)
+     BUILDTREE_ONLY
+    )
+ 
+-  install(TARGETS ${name} RUNTIME DESTINATION examples)
+  install(TARGETS ${name} RUNTIME DESTINATION ${CMAKE_INSTALL_DOCDIR}/examples)
+   set_target_properties(${name} PROPERTIES FOLDER "Examples")
+ endif()
+diff --git a/include/llvm/CMakeLists.txt b/include/llvm/CMakeLists.txt
+index b46319f24fc8..2feabd1954e4 100644
+--- a/include/llvm/CMakeLists.txt
+++ b/include/llvm/CMakeLists.txt
+@@ -5,5 +5,5 @@ add_subdirectory(Frontend)
+ # If we're doing an out-of-tree build, copy a module map for generated
+ # header files into the build area.
+ if (NOT "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
+-  configure_file(module.modulemap.build module.modulemap COPYONLY)
+  configure_file(module.modulemap.build ${LLVM_INCLUDE_DIR}/module.modulemap COPYONLY)
+ endif (NOT "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
+diff --git a/tools/llvm-config/BuildVariables.inc.in b/tools/llvm-config/BuildVariables.inc.in
+index 63cef75368b7..6295478b1f3d 100644
+--- a/tools/llvm-config/BuildVariables.inc.in
+++ b/tools/llvm-config/BuildVariables.inc.in
+@@ -23,6 +23,10 @@
+ #define LLVM_CXXFLAGS "@LLVM_CXXFLAGS@"
+ #define LLVM_BUILDMODE "@LLVM_BUILDMODE@"
+ #define LLVM_LIBDIR_SUFFIX "@LLVM_LIBDIR_SUFFIX@"
+#define LLVM_INSTALL_BINDIR "@CMAKE_INSTALL_BINDIR@"
+#define LLVM_INSTALL_LIBDIR "@CMAKE_INSTALL_LIBDIR@"
+#define LLVM_INSTALL_INCLUDEDIR "@CMAKE_INSTALL_INCLUDEDIR@"
+#define LLVM_INSTALL_CMAKEDIR "@LLVM_INSTALL_CMAKE_DIR@"
+ #define LLVM_TARGETS_BUILT "@LLVM_TARGETS_BUILT@"
+ #define LLVM_SYSTEM_LIBS "@LLVM_SYSTEM_LIBS@"
+ #define LLVM_BUILD_SYSTEM "@LLVM_BUILD_SYSTEM@"
+diff --git a/tools/llvm-config/llvm-config.cpp b/tools/llvm-config/llvm-config.cpp
+index 7e74b7c90816..f185e9283f83 100644
+--- a/tools/llvm-config/llvm-config.cpp
+++ b/tools/llvm-config/llvm-config.cpp
+@@ -358,12 +358,26 @@ int main(int argc, char **argv) {
+         ("-I" + ActiveIncludeDir + " " + "-I" + ActiveObjRoot + "/include");
+   } else {
+     ActivePrefix = CurrentExecPrefix;
+-    ActiveIncludeDir = ActivePrefix + "/include";
+-    SmallString<256> path(StringRef(LLVM_TOOLS_INSTALL_DIR));
+-    sys::fs::make_absolute(ActivePrefix, path);
+-    ActiveBinDir = std::string(path.str());
+-    ActiveLibDir = ActivePrefix + "/lib" + LLVM_LIBDIR_SUFFIX;
+-    ActiveCMakeDir = ActiveLibDir + "/cmake/llvm";
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_INCLUDEDIR));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveIncludeDir = std::string(path.str());
+    }
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_BINDIR));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveBinDir = std::string(path.str());
+    }
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_LIBDIR LLVM_LIBDIR_SUFFIX));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveLibDir = std::string(path.str());
+    }
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_CMAKEDIR));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveCMakeDir = std::string(path.str());
+    }
+     ActiveIncludeOption = "-I" + ActiveIncludeDir;
+   }
+ 
+diff --git a/tools/lto/CMakeLists.txt b/tools/lto/CMakeLists.txt
+index 2963f97cad88..69d66c9c9ca1 100644
+--- a/tools/lto/CMakeLists.txt
+++ b/tools/lto/CMakeLists.txt
+@@ -25,7 +25,7 @@ add_llvm_library(LTO SHARED INSTALL_WITH_TOOLCHAIN ${SOURCES} DEPENDS
+     intrinsics_gen)
+ 
+ install(FILES ${LLVM_MAIN_INCLUDE_DIR}/llvm-c/lto.h
+-  DESTINATION include/llvm-c
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm-c
+   COMPONENT LTO)
+ 
+ if (APPLE)
+diff --git a/tools/opt-viewer/CMakeLists.txt b/tools/opt-viewer/CMakeLists.txt
+index ead73ec13a8f..250362021f17 100644
+--- a/tools/opt-viewer/CMakeLists.txt
+++ b/tools/opt-viewer/CMakeLists.txt
+@@ -8,7 +8,7 @@ set (files
+ 
+ foreach (file ${files})
+   install(PROGRAMS ${file}
+-    DESTINATION share/opt-viewer
+    DESTINATION ${CMAKE_INSTALL_DATADIR}/opt-viewer
+     COMPONENT opt-viewer)
+ endforeach (file)
+ 
+diff --git a/tools/remarks-shlib/CMakeLists.txt b/tools/remarks-shlib/CMakeLists.txt
+index e948496c603a..1f4df8a98b10 100644
+--- a/tools/remarks-shlib/CMakeLists.txt
+++ b/tools/remarks-shlib/CMakeLists.txt
+@@ -11,7 +11,7 @@ set(LLVM_EXPORTED_SYMBOL_FILE ${CMAKE_CURRENT_SOURCE_DIR}/Remarks.exports)
+ add_llvm_library(Remarks SHARED INSTALL_WITH_TOOLCHAIN ${SOURCES})
+ 
+ install(FILES ${LLVM_MAIN_INCLUDE_DIR}/llvm-c/Remarks.h
+-  DESTINATION include/llvm-c
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm-c
+   COMPONENT Remarks)
+ 
+ if (APPLE)
--- a/llvm/11/openmp/default.nix
+++ b/llvm/11/openmp/default.nix
@ -0,0 +1,47 @@
+{ lib
+, stdenv
+, llvm_meta
+, fetch
+, fetchpatch
+, cmake
+, llvm
+, targetLlvm
+, perl
+, version
+}:
+
+stdenv.mkDerivation rec {
+  pname = "openmp";
+  inherit version;
+
+  src = fetch pname "0bh5cswgpc79awlq8j5i7hp355adaac7s6zaz0zwp6mkflxli1yi";
+
+  patches = [
+    # Fix compilation on aarch64-darwin, remove after the next release.
+    (fetchpatch {
+      url = "https://github.com/llvm/llvm-project/commit/7b5254223acbf2ef9cd278070c5a84ab278d7e5f.patch";
+      sha256 = "sha256-A+9/IVIoazu68FK5H5CiXcOEYe1Hpp4xTx2mIw7m8Es=";
+      stripLen = 1;
+    })
+  ];
+
+  nativeBuildInputs = [ cmake perl ];
+  buildInputs = [
+    (if stdenv.buildPlatform == stdenv.hostPlatform then llvm else targetLlvm)
+  ];
+
+  meta = llvm_meta // {
+    homepage = "https://openmp.llvm.org/";
+    description = "Support for the OpenMP language";
+    longDescription = ''
+      The OpenMP subproject of LLVM contains the components required to build an
+      executable OpenMP program that are outside the compiler itself.
+      Contains the code for the runtime library against which code compiled by
+      "clang -fopenmp" must be linked before it can run and the library that
+      supports offload to target devices.
+    '';
+    # "All of the code is dual licensed under the MIT license and the UIUC
+    # License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}
--- a/llvm/12/clang/default.nix
+++ b/llvm/12/clang/default.nix
@ -0,0 +1,132 @@
+{ lib, stdenv, llvm_meta, fetch, substituteAll, cmake, libxml2, libllvm, version, clang-tools-extra_src, python3
+, buildLlvmTools
+, fixDarwinDylibNames
+, enableManpages ? false
+}:
+
+let
+  self = stdenv.mkDerivation ({
+    pname = "clang";
+    inherit version;
+
+    src = fetch "clang" "0px4gl27az6cdz6adds89qzdwb1cqpjsfvrldbz9qvpmphrj34bf";
+    inherit clang-tools-extra_src;
+
+    unpackPhase = ''
+      unpackFile $src
+      mv clang-* clang
+      sourceRoot=$PWD/clang
+      unpackFile ${clang-tools-extra_src}
+      mv clang-tools-extra-* $sourceRoot/tools/extra
+      substituteInPlace $sourceRoot/tools/extra/clangd/quality/CompletionModel.cmake \
+        --replace ' ''${CMAKE_SOURCE_DIR}/../clang-tools-extra' ' ''${CMAKE_SOURCE_DIR}/tools/extra'
+    '';
+
+    nativeBuildInputs = [ cmake python3 ]
+      ++ lib.optional enableManpages python3.pkgs.sphinx
+      ++ lib.optional stdenv.hostPlatform.isDarwin fixDarwinDylibNames;
+
+    buildInputs = [ libxml2 libllvm ];
+
+    cmakeFlags = [
+      "-DCLANGD_BUILD_XPC=OFF"
+      "-DLLVM_ENABLE_RTTI=ON"
+    ] ++ lib.optionals enableManpages [
+      "-DCLANG_INCLUDE_DOCS=ON"
+      "-DLLVM_ENABLE_SPHINX=ON"
+      "-DSPHINX_OUTPUT_MAN=ON"
+      "-DSPHINX_OUTPUT_HTML=OFF"
+      "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
+    ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+      "-DLLVM_TABLEGEN_EXE=${buildLlvmTools.llvm}/bin/llvm-tblgen"
+      "-DCLANG_TABLEGEN=${buildLlvmTools.libclang.dev}/bin/clang-tblgen"
+    ];
+
+    patches = [
+      ./purity.patch
+      # https://reviews.llvm.org/D51899
+      ./gnu-install-dirs.patch
+      (substituteAll {
+        src = ../../clang-11-12-LLVMgold-path.patch;
+        libllvmLibdir = "${libllvm.lib}/lib";
+      })
+    ];
+
+    postPatch = ''
+      sed -i -e 's/DriverArgs.hasArg(options::OPT_nostdlibinc)/true/' \
+             -e 's/Args.hasArg(options::OPT_nostdlibinc)/true/' \
+             lib/Driver/ToolChains/*.cpp
+    '' + lib.optionalString stdenv.hostPlatform.isMusl ''
+      sed -i -e 's/lgcc_s/lgcc_eh/' lib/Driver/ToolChains/*.cpp
+    '';
+
+    outputs = [ "out" "lib" "dev" "python" ];
+
+    postInstall = ''
+      ln -sv $out/bin/clang $out/bin/cpp
+
+      # Move libclang to 'lib' output
+      moveToOutput "lib/libclang.*" "$lib"
+      moveToOutput "lib/libclang-cpp.*" "$lib"
+      substituteInPlace $out/lib/cmake/clang/ClangTargets-release.cmake \
+          --replace "\''${_IMPORT_PREFIX}/lib/libclang." "$lib/lib/libclang." \
+          --replace "\''${_IMPORT_PREFIX}/lib/libclang-cpp." "$lib/lib/libclang-cpp."
+
+      mkdir -p $python/bin $python/share/{clang,scan-view}
+      mv $out/bin/{git-clang-format,scan-view} $python/bin
+      if [ -e $out/bin/set-xcode-analyzer ]; then
+        mv $out/bin/set-xcode-analyzer $python/bin
+      fi
+      mv $out/share/clang/*.py $python/share/clang
+      mv $out/share/scan-view/*.py $python/share/scan-view
+      rm $out/bin/c-index-test
+      patchShebangs $python/bin
+
+      mkdir -p $dev/bin
+      cp bin/clang-tblgen $dev/bin
+    '';
+
+    passthru = {
+      inherit libllvm;
+      isClang = true;
+      hardeningUnsupportedFlags = [ "fortify3" ];
+    };
+
+    meta = llvm_meta // {
+      homepage = "https://clang.llvm.org/";
+      description = "A C language family frontend for LLVM";
+      longDescription = ''
+        The Clang project provides a language front-end and tooling
+        infrastructure for languages in the C language family (C, C++, Objective
+        C/C++, OpenCL, CUDA, and RenderScript) for the LLVM project.
+        It aims to deliver amazingly fast compiles, extremely useful error and
+        warning messages and to provide a platform for building great source
+        level tools. The Clang Static Analyzer and clang-tidy are tools that
+        automatically find bugs in your code, and are great examples of the sort
+        of tools that can be built using the Clang frontend as a library to
+        parse C/C++ code.
+      '';
+      mainProgram = "clang";
+    };
+  } // lib.optionalAttrs enableManpages {
+    pname = "clang-manpages";
+
+    buildPhase = ''
+      make docs-clang-man
+    '';
+
+    installPhase = ''
+      mkdir -p $out/share/man/man1
+      # Manually install clang manpage
+      cp docs/man/*.1 $out/share/man/man1/
+    '';
+
+    outputs = [ "out" ];
+
+    doCheck = false;
+
+    meta = llvm_meta // {
+      description = "man page for Clang ${version}";
+    };
+  });
+in self
--- a/llvm/12/clang/gnu-install-dirs.patch
+++ b/llvm/12/clang/gnu-install-dirs.patch
@ -0,0 +1,235 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 9e74014134a0..976e6a1757fd 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -5,6 +5,8 @@ cmake_minimum_required(VERSION 3.13.4)
+ if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
+   project(Clang)
+ 
+  include(GNUInstallDirs)
+
+   set(CMAKE_CXX_STANDARD 14 CACHE STRING "C++ standard to conform to")
+   set(CMAKE_CXX_STANDARD_REQUIRED YES)
+   set(CMAKE_CXX_EXTENSIONS NO)
+@@ -416,7 +418,7 @@ include_directories(BEFORE
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/clang include/clang-c
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT clang-headers
+     FILES_MATCHING
+     PATTERN "*.def"
+@@ -425,7 +427,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+     )
+ 
+   install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/clang
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT clang-headers
+     FILES_MATCHING
+     PATTERN "CMakeFiles" EXCLUDE
+@@ -445,7 +447,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+ 
+   add_custom_target(bash-autocomplete DEPENDS utils/bash-autocomplete.sh)
+   install(PROGRAMS utils/bash-autocomplete.sh
+-          DESTINATION share/clang
+          DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+           COMPONENT bash-autocomplete)
+   if(NOT LLVM_ENABLE_IDE)
+     add_llvm_install_targets(install-bash-autocomplete
+diff --git a/cmake/modules/AddClang.cmake b/cmake/modules/AddClang.cmake
+index 704278a0e93b..d25c8d325c71 100644
+--- a/cmake/modules/AddClang.cmake
+++ b/cmake/modules/AddClang.cmake
+@@ -123,9 +123,9 @@ macro(add_clang_library name)
+         install(TARGETS ${lib}
+           COMPONENT ${lib}
+           ${export_to_clangtargets}
+-          LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-          ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-          RUNTIME DESTINATION bin)
+          LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+          ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+          RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+ 
+         if (NOT LLVM_ENABLE_IDE)
+           add_llvm_install_targets(install-${lib}
+@@ -170,7 +170,7 @@ macro(add_clang_tool name)
+ 
+     install(TARGETS ${name}
+       ${export_to_clangtargets}
+-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+       COMPONENT ${name})
+ 
+     if(NOT LLVM_ENABLE_IDE)
+@@ -185,7 +185,7 @@ endmacro()
+ macro(add_clang_symlink name dest)
+   add_llvm_tool_symlink(${name} ${dest} ALWAYS_GENERATE)
+   # Always generate install targets
+-  llvm_install_symlink(${name} ${dest} ALWAYS_GENERATE)
+  llvm_install_symlink(${name} ${dest} ${CMAKE_INSTALL_FULL_BINDIR} ALWAYS_GENERATE)
+ endmacro()
+ 
+ function(clang_target_link_libraries target type)
+diff --git a/lib/Headers/CMakeLists.txt b/lib/Headers/CMakeLists.txt
+index b2c0ce8dd4a0..19e5443d8c25 100644
+--- a/lib/Headers/CMakeLists.txt
+++ b/lib/Headers/CMakeLists.txt
+@@ -215,7 +215,7 @@ set_target_properties(clang-resource-headers PROPERTIES
+   FOLDER "Misc"
+   RUNTIME_OUTPUT_DIRECTORY "${output_dir}")
+ 
+-set(header_install_dir lib${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION}/include)
+set(header_install_dir ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION}/include)
+ 
+ install(
+   FILES ${files} ${generated_files}
+diff --git a/tools/c-index-test/CMakeLists.txt b/tools/c-index-test/CMakeLists.txt
+index ceef4b08637c..8efad5520ca4 100644
+--- a/tools/c-index-test/CMakeLists.txt
+++ b/tools/c-index-test/CMakeLists.txt
+@@ -54,7 +54,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+     set_property(TARGET c-index-test APPEND PROPERTY INSTALL_RPATH
+        "@executable_path/../../lib")
+   else()
+-    set(INSTALL_DESTINATION bin)
+    set(INSTALL_DESTINATION ${CMAKE_INSTALL_BINDIR})
+   endif()
+ 
+   install(TARGETS c-index-test
+diff --git a/tools/clang-format/CMakeLists.txt b/tools/clang-format/CMakeLists.txt
+index 35ecdb11253c..d77d75de0094 100644
+--- a/tools/clang-format/CMakeLists.txt
+++ b/tools/clang-format/CMakeLists.txt
+@@ -21,20 +21,20 @@ if( LLVM_LIB_FUZZING_ENGINE OR LLVM_USE_SANITIZE_COVERAGE )
+ endif()
+ 
+ install(PROGRAMS clang-format-bbedit.applescript
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format-diff.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format-sublime.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format.el
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS git-clang-format
+-  DESTINATION bin
+  DESTINATION ${CMAKE_INSTALL_BINDIR}
+   COMPONENT clang-format)
+diff --git a/tools/clang-rename/CMakeLists.txt b/tools/clang-rename/CMakeLists.txt
+index cda8e29ec5b1..0134d8ccd70b 100644
+--- a/tools/clang-rename/CMakeLists.txt
+++ b/tools/clang-rename/CMakeLists.txt
+@@ -19,8 +19,8 @@ clang_target_link_libraries(clang-rename
+   )
+ 
+ install(PROGRAMS clang-rename.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-rename)
+ install(PROGRAMS clang-rename.el
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-rename)
+diff --git a/tools/libclang/CMakeLists.txt b/tools/libclang/CMakeLists.txt
+index 51ff2e7e1565..1ed5f8a079a1 100644
+--- a/tools/libclang/CMakeLists.txt
+++ b/tools/libclang/CMakeLists.txt
+@@ -166,7 +166,7 @@ endif()
+ if(INTERNAL_INSTALL_PREFIX)
+   set(LIBCLANG_HEADERS_INSTALL_DESTINATION "${INTERNAL_INSTALL_PREFIX}/include")
+ else()
+-  set(LIBCLANG_HEADERS_INSTALL_DESTINATION include)
+  set(LIBCLANG_HEADERS_INSTALL_DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+ endif()
+ 
+ install(DIRECTORY ../../include/clang-c
+@@ -196,7 +196,7 @@ foreach(PythonVersion ${CLANG_PYTHON_BINDINGS_VERSIONS})
+           COMPONENT
+             libclang-python-bindings
+           DESTINATION
+-            "lib${LLVM_LIBDIR_SUFFIX}/python${PythonVersion}/site-packages")
+            "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/python${PythonVersion}/site-packages")
+ endforeach()
+ if(NOT LLVM_ENABLE_IDE)
+   add_custom_target(libclang-python-bindings)
+diff --git a/tools/scan-build/CMakeLists.txt b/tools/scan-build/CMakeLists.txt
+index ec0702d76f18..d25d982f51da 100644
+--- a/tools/scan-build/CMakeLists.txt
+++ b/tools/scan-build/CMakeLists.txt
+@@ -47,7 +47,7 @@ if(CLANG_INSTALL_SCANBUILD)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bin/${BinFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/bin/${BinFile})
+     install(PROGRAMS bin/${BinFile}
+-            DESTINATION bin
+            DESTINATION ${CMAKE_INSTALL_BINDIR}
+             COMPONENT scan-build)
+   endforeach()
+ 
+@@ -61,7 +61,7 @@ if(CLANG_INSTALL_SCANBUILD)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/libexec/${LibexecFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/libexec/${LibexecFile})
+     install(PROGRAMS libexec/${LibexecFile}
+-            DESTINATION libexec
+            DESTINATION ${CMAKE_INSTALL_LIBEXECDIR}
+             COMPONENT scan-build)
+   endforeach()
+ 
+@@ -89,7 +89,7 @@ if(CLANG_INSTALL_SCANBUILD)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/share/scan-build/${ShareFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/share/scan-build/${ShareFile})
+     install(FILES share/scan-build/${ShareFile}
+-            DESTINATION share/scan-build
+            DESTINATION ${CMAKE_INSTALL_DATADIR}/scan-build
+             COMPONENT scan-build)
+   endforeach()
+ 
+diff --git a/tools/scan-view/CMakeLists.txt b/tools/scan-view/CMakeLists.txt
+index dd3d33439299..fea19c12ce70 100644
+--- a/tools/scan-view/CMakeLists.txt
+++ b/tools/scan-view/CMakeLists.txt
+@@ -19,7 +19,7 @@ if(CLANG_INSTALL_SCANVIEW)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bin/${BinFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/bin/${BinFile})
+     install(PROGRAMS bin/${BinFile}
+-            DESTINATION bin
+            DESTINATION ${CMAKE_INSTALL_BINDIR}
+             COMPONENT scan-view)
+   endforeach()
+ 
+@@ -33,7 +33,7 @@ if(CLANG_INSTALL_SCANVIEW)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/share/${ShareFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/share/scan-view/${ShareFile})
+     install(FILES share/${ShareFile}
+-            DESTINATION share/scan-view
+            DESTINATION ${CMAKE_INSTALL_DATADIR}/scan-view
+             COMPONENT scan-view)
+   endforeach()
+ 
+diff --git a/utils/hmaptool/CMakeLists.txt b/utils/hmaptool/CMakeLists.txt
+index 62f2de0cb15c..6aa66825b6ec 100644
+--- a/utils/hmaptool/CMakeLists.txt
+++ b/utils/hmaptool/CMakeLists.txt
+@@ -10,7 +10,7 @@ add_custom_command(OUTPUT ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin/${CLANG_HM
+ 
+ list(APPEND Depends ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin/${CLANG_HMAPTOOL})
+ install(PROGRAMS ${CLANG_HMAPTOOL}
+-        DESTINATION bin
+        DESTINATION ${CMAKE_INSTALL_BINDIR}
+         COMPONENT hmaptool)
+ 
+ add_custom_target(hmaptool ALL DEPENDS ${Depends})
--- a/llvm/12/clang/purity.patch
+++ b/llvm/12/clang/purity.patch
@ -0,0 +1,28 @@
+From 4add81bba40dcec62c4ea4481be8e35ac53e89d8 Mon Sep 17 00:00:00 2001
+From: Will Dietz <w@wdtz.org>
+Date: Thu, 18 May 2017 11:56:12 -0500
+Subject: [PATCH] "purity" patch for 5.0
+
+---
+ lib/Driver/ToolChains/Gnu.cpp | 7 -------
+ 1 file changed, 7 deletions(-)
+
+diff --git a/lib/Driver/ToolChains/Gnu.cpp b/lib/Driver/ToolChains/Gnu.cpp
+index fe3c0191bb..c6a482bece 100644
+--- a/lib/Driver/ToolChains/Gnu.cpp
+++ b/lib/Driver/ToolChains/Gnu.cpp
+@@ -487,12 +487,6 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
+   if (!IsStatic) {
+     if (Args.hasArg(options::OPT_rdynamic))
+       CmdArgs.push_back("-export-dynamic");
+-
+-    if (!Args.hasArg(options::OPT_shared) && !IsStaticPIE) {
+-      CmdArgs.push_back("-dynamic-linker");
+-      CmdArgs.push_back(Args.MakeArgString(Twine(D.DyldPrefix) +
+-                                           ToolChain.getDynamicLinker(Args)));
+-    }
+   }
+ 
+   CmdArgs.push_back("-o");
+-- 
+2.11.0
--- a/llvm/12/compiler-rt/X86-support-extension.patch
+++ b/llvm/12/compiler-rt/X86-support-extension.patch
@ -0,0 +1,21 @@
+diff --git a/lib/builtins/CMakeLists.txt b/lib/builtins/CMakeLists.txt
+index 3a66dd9c3fb..7efc85d9f9f 100644
+--- a/lib/builtins/CMakeLists.txt
+++ b/lib/builtins/CMakeLists.txt
+@@ -345,4 +345,8 @@ if (NOT MSVC)
+ 
+  set(i486_SOURCES ${i386_SOURCES})
+  set(i586_SOURCES ${i386_SOURCES})
+  set(i686_SOURCES ${i386_SOURCES})
+
+   if (WIN32)
+     set(i386_SOURCES
+       ${i386_SOURCES}
+@@ -608,6 +612,7 @@ else ()
+   endif()
+ 
+   foreach (arch ${BUILTIN_SUPPORTED_ARCH})
+      message("arch: ${arch}")
+     if (CAN_TARGET_${arch})
+       # For ARM archs, exclude any VFP builtins if VFP is not supported
+       if (${arch} MATCHES "^(arm|armhf|armv7|armv7s|armv7k|armv7m|armv7em)$")
--- a/llvm/12/compiler-rt/armv7l.patch
+++ b/llvm/12/compiler-rt/armv7l.patch
@ -0,0 +1,32 @@
+diff -ur compiler-rt-10.0.0.src/cmake/builtin-config-ix.cmake compiler-rt-10.0.0.src-patched/cmake/builtin-config-ix.cmake
+--- compiler-rt-10.0.0.src/cmake/builtin-config-ix.cmake	2020-03-24 00:01:02.000000000 +0900
+++ compiler-rt-10.0.0.src-patched/cmake/builtin-config-ix.cmake	2020-05-10 03:42:00.883450706 +0900
+@@ -24,7 +24,7 @@
+ 
+ 
+ set(ARM64 aarch64)
+-set(ARM32 arm armhf armv6m armv7m armv7em armv7 armv7s armv7k)
+set(ARM32 arm armhf armv6m armv7m armv7em armv7 armv7s armv7k armv7l)
+ set(HEXAGON hexagon)
+ set(X86 i386)
+ set(X86_64 x86_64)
+diff -ur compiler-rt-10.0.0.src/lib/builtins/CMakeLists.txt compiler-rt-10.0.0.src-patched/lib/builtins/CMakeLists.txt
+--- compiler-rt-10.0.0.src/lib/builtins/CMakeLists.txt	2020-03-24 00:01:02.000000000 +0900
+++ compiler-rt-10.0.0.src-patched/lib/builtins/CMakeLists.txt	2020-05-10 03:44:49.468579650 +0900
+@@ -474,6 +474,7 @@
+ set(armv7_SOURCES ${arm_SOURCES})
+ set(armv7s_SOURCES ${arm_SOURCES})
+ set(armv7k_SOURCES ${arm_SOURCES})
+set(armv7l_SOURCES ${arm_SOURCES})
+ set(arm64_SOURCES ${aarch64_SOURCES})
+ 
+ # macho_embedded archs
+@@ -595,7 +596,7 @@
+   foreach (arch ${BUILTIN_SUPPORTED_ARCH})
+     if (CAN_TARGET_${arch})
+       # For ARM archs, exclude any VFP builtins if VFP is not supported
+-      if (${arch} MATCHES "^(arm|armhf|armv7|armv7s|armv7k|armv7m|armv7em)$")
+      if (${arch} MATCHES "^(arm|armhf|armv7|armv7s|armv7k|armv7l|armv7m|armv7em)$")
+         string(REPLACE ";" " " _TARGET_${arch}_CFLAGS "${TARGET_${arch}_CFLAGS}")
+         check_compile_definition(__VFP_FP__ "${CMAKE_C_FLAGS} ${_TARGET_${arch}_CFLAGS}" COMPILER_RT_HAS_${arch}_VFP)
+         if(NOT COMPILER_RT_HAS_${arch}_VFP)
--- a/llvm/12/compiler-rt/default.nix
+++ b/llvm/12/compiler-rt/default.nix
@ -0,0 +1,125 @@
+{ lib, stdenv, llvm_meta, version, fetch, cmake, python3, xcbuild, libllvm, libcxxabi, libxcrypt
+, doFakeLibgcc ? stdenv.hostPlatform.isFreeBSD
+}:
+
+let
+
+  useLLVM = stdenv.hostPlatform.useLLVM or false;
+  bareMetal = stdenv.hostPlatform.parsed.kernel.name == "none";
+  haveLibc = stdenv.cc.libc != null;
+  inherit (stdenv.hostPlatform) isMusl;
+
+in
+
+stdenv.mkDerivation {
+  pname = "compiler-rt" + lib.optionalString (haveLibc) "-libc";
+  inherit version;
+  src = fetch "compiler-rt" "1950rg294izdwkaasi7yjrmadc9mzdd5paf0q63jjcq2m3rdbj5l";
+
+  nativeBuildInputs = [ cmake python3 libllvm.dev ]
+    ++ lib.optional stdenv.isDarwin xcbuild.xcrun;
+  buildInputs = lib.optional stdenv.hostPlatform.isDarwin libcxxabi;
+
+  env.NIX_CFLAGS_COMPILE = toString [
+    "-DSCUDO_DEFAULT_OPTIONS=DeleteSizeMismatch=0:DeallocationTypeMismatch=0"
+  ];
+
+  cmakeFlags = [
+    "-DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON"
+    "-DCMAKE_C_COMPILER_TARGET=${stdenv.hostPlatform.config}"
+    "-DCMAKE_ASM_COMPILER_TARGET=${stdenv.hostPlatform.config}"
+  ] ++ lib.optionals (haveLibc && stdenv.hostPlatform.isGnu) [
+    "-DSANITIZER_COMMON_CFLAGS=-I${libxcrypt}/include"
+  ] ++ lib.optionals (useLLVM || bareMetal || isMusl) [
+    "-DCOMPILER_RT_BUILD_SANITIZERS=OFF"
+    "-DCOMPILER_RT_BUILD_XRAY=OFF"
+    "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
+    "-DCOMPILER_RT_BUILD_MEMPROF=OFF"
+  ] ++ lib.optionals (useLLVM || bareMetal) [
+    "-DCOMPILER_RT_BUILD_PROFILE=OFF"
+  ] ++ lib.optionals ((useLLVM && !haveLibc) || bareMetal) [
+    "-DCMAKE_C_COMPILER_WORKS=ON"
+    "-DCMAKE_CXX_COMPILER_WORKS=ON"
+    "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
+    "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
+  ] ++ lib.optionals (useLLVM) [
+    "-DCOMPILER_RT_BUILD_BUILTINS=ON"
+    #https://stackoverflow.com/questions/53633705/cmake-the-c-compiler-is-not-able-to-compile-a-simple-test-program
+    "-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY"
+  ] ++ lib.optionals (bareMetal) [
+    "-DCOMPILER_RT_OS_DIR=baremetal"
+  ] ++ lib.optionals (stdenv.hostPlatform.isDarwin) [
+    "-DDARWIN_macosx_OVERRIDE_SDK_VERSION=ON"
+    "-DDARWIN_osx_ARCHS=${stdenv.hostPlatform.darwinArch}"
+    "-DDARWIN_osx_BUILTIN_ARCHS=${stdenv.hostPlatform.darwinArch}"
+  ];
+
+  outputs = [ "out" "dev" ];
+
+  patches = [
+    ../../common/compiler-rt/7-12-codesign.patch # Revert compiler-rt commit that makes codesign mandatory
+    ./X86-support-extension.patch # Add support for i486 i586 i686 by reusing i386 config
+    ./gnu-install-dirs.patch
+    # ld-wrapper dislikes `-rpath-link //nix/store`, so we normalize away the
+    # extra `/`.
+    ./normalize-var.patch
+    ../../common/compiler-rt/darwin-plistbuddy-workaround.patch
+    ./armv7l.patch
+    # Fix build on armv6l
+    ../../common/compiler-rt/armv6-mcr-dmb.patch
+    ../../common/compiler-rt/armv6-sync-ops-no-thumb.patch
+    ../../common/compiler-rt/armv6-no-ldrexd-strexd.patch
+  ];
+
+  # TSAN requires XPC on Darwin, which we have no public/free source files for. We can depend on the Apple frameworks
+  # to get it, but they're unfree. Since LLVM is rather central to the stdenv, we patch out TSAN support so that Hydra
+  # can build this. If we didn't do it, basically the entire nixpkgs on Darwin would have an unfree dependency and we'd
+  # get no binary cache for the entire platform. If you really find yourself wanting the TSAN, make this controllable by
+  # a flag and turn the flag off during the stdenv build.
+  postPatch = lib.optionalString (!stdenv.isDarwin) ''
+    substituteInPlace cmake/builtin-config-ix.cmake \
+      --replace 'set(X86 i386)' 'set(X86 i386 i486 i586 i686)'
+  '' + lib.optionalString stdenv.isDarwin ''
+    substituteInPlace cmake/config-ix.cmake \
+      --replace 'set(COMPILER_RT_HAS_TSAN TRUE)' 'set(COMPILER_RT_HAS_TSAN FALSE)'
+  '' + lib.optionalString (useLLVM) ''
+    substituteInPlace lib/builtins/int_util.c \
+      --replace "#include <stdlib.h>" ""
+    substituteInPlace lib/builtins/clear_cache.c \
+      --replace "#include <assert.h>" ""
+    substituteInPlace lib/builtins/cpu_model.c \
+      --replace "#include <assert.h>" ""
+  '';
+
+  preConfigure = lib.optionalString (useLLVM && !haveLibc) ''
+    cmakeFlagsArray+=(-DCMAKE_C_FLAGS="-nodefaultlibs -ffreestanding")
+  '';
+
+  # Hack around weird upsream RPATH bug
+  postInstall = lib.optionalString (stdenv.hostPlatform.isDarwin || stdenv.hostPlatform.isWasm) ''
+    ln -s "$out/lib"/*/* "$out/lib"
+  '' + lib.optionalString (useLLVM) ''
+    ln -s $out/lib/*/clang_rt.crtbegin-*.o $out/lib/crtbegin.o
+    ln -s $out/lib/*/clang_rt.crtend-*.o $out/lib/crtend.o
+    ln -s $out/lib/*/clang_rt.crtbegin_shared-*.o $out/lib/crtbeginS.o
+    ln -s $out/lib/*/clang_rt.crtend_shared-*.o $out/lib/crtendS.o
+  '' + lib.optionalString doFakeLibgcc ''
+    ln -s $out/lib/freebsd/libclang_rt.builtins-*.a $out/lib/libgcc.a
+  '';
+
+  meta = llvm_meta // {
+    homepage = "https://compiler-rt.llvm.org/";
+    description = "Compiler runtime libraries";
+    longDescription = ''
+      The compiler-rt project provides highly tuned implementations of the
+      low-level code generator support routines like "__fixunsdfdi" and other
+      calls generated when a target doesn't have a short sequence of native
+      instructions to implement a core IR operation. It also provides
+      implementations of run-time libraries for dynamic testing tools such as
+      AddressSanitizer, ThreadSanitizer, MemorySanitizer, and DataFlowSanitizer.
+    '';
+    # "All of the code in the compiler-rt project is dual licensed under the MIT
+    # license and the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}
--- a/llvm/12/compiler-rt/gnu-install-dirs.patch
+++ b/llvm/12/compiler-rt/gnu-install-dirs.patch
@ -0,0 +1,129 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index b44ad2c2118e..d42f5664d448 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -8,6 +8,7 @@ cmake_minimum_required(VERSION 3.13.4)
+ # Check if compiler-rt is built as a standalone project.
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR COMPILER_RT_STANDALONE_BUILD)
+   project(CompilerRT C CXX ASM)
+  include(GNUInstallDirs)
+   set(COMPILER_RT_STANDALONE_BUILD TRUE)
+   set_property(GLOBAL PROPERTY USE_FOLDERS ON)
+ endif()
+diff --git a/cmake/Modules/AddCompilerRT.cmake b/cmake/Modules/AddCompilerRT.cmake
+index 361538a58e47..f0d8d9ab80f1 100644
+--- a/cmake/Modules/AddCompilerRT.cmake
+++ b/cmake/Modules/AddCompilerRT.cmake
+@@ -495,7 +495,7 @@ macro(add_compiler_rt_resource_file target_name file_name component)
+   add_custom_target(${target_name} DEPENDS ${dst_file})
+   # Install in Clang resource directory.
+   install(FILES ${file_name}
+-    DESTINATION ${COMPILER_RT_INSTALL_PATH}/share
+    DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_DATADIR}
+     COMPONENT ${component})
+   add_dependencies(${component} ${target_name})
+ 
+@@ -512,7 +512,7 @@ macro(add_compiler_rt_script name)
+   add_custom_target(${name} DEPENDS ${dst})
+   install(FILES ${dst}
+     PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE
+-    DESTINATION ${COMPILER_RT_INSTALL_PATH}/bin)
+    DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_BINDIR})
+ endmacro(add_compiler_rt_script src name)
+ 
+ # Builds custom version of libc++ and installs it in <prefix>.
+diff --git a/cmake/Modules/CompilerRTDarwinUtils.cmake b/cmake/Modules/CompilerRTDarwinUtils.cmake
+index 456a8dcda59f..7a09e74c7c79 100644
+--- a/cmake/Modules/CompilerRTDarwinUtils.cmake
+++ b/cmake/Modules/CompilerRTDarwinUtils.cmake
+@@ -508,7 +508,7 @@ macro(darwin_add_embedded_builtin_libraries)
+     set(DARWIN_macho_embedded_LIBRARY_OUTPUT_DIR
+       ${COMPILER_RT_OUTPUT_DIR}/lib/macho_embedded)
+     set(DARWIN_macho_embedded_LIBRARY_INSTALL_DIR
+-      ${COMPILER_RT_INSTALL_PATH}/lib/macho_embedded)
+      ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_LIBDIR}/macho_embedded)
+       
+     set(CFLAGS_armv7 "-target thumbv7-apple-darwin-eabi")
+     set(CFLAGS_i386 "-march=pentium")
+diff --git a/cmake/Modules/CompilerRTUtils.cmake b/cmake/Modules/CompilerRTUtils.cmake
+index f61d487e93a0..f1f46fb9599c 100644
+--- a/cmake/Modules/CompilerRTUtils.cmake
+++ b/cmake/Modules/CompilerRTUtils.cmake
+@@ -378,7 +378,7 @@ endfunction()
+ function(get_compiler_rt_install_dir arch install_dir)
+   if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+     get_compiler_rt_target(${arch} target)
+-    set(${install_dir} ${COMPILER_RT_INSTALL_PATH}/lib/${target} PARENT_SCOPE)
+    set(${install_dir} ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_LIBDIR}/${target} PARENT_SCOPE)
+   else()
+     set(${install_dir} ${COMPILER_RT_LIBRARY_INSTALL_DIR} PARENT_SCOPE)
+   endif()
+diff --git a/cmake/base-config-ix.cmake b/cmake/base-config-ix.cmake
+index 1edab43e7c0d..1aac6b73ff82 100644
+--- a/cmake/base-config-ix.cmake
+++ b/cmake/base-config-ix.cmake
+@@ -65,11 +65,11 @@ if (LLVM_TREE_AVAILABLE)
+ else()
+     # Take output dir and install path from the user.
+   set(COMPILER_RT_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR} CACHE PATH
+-    "Path where built compiler-rt libraries should be stored.")
+    "Path where built compiler-rt build artifacts should be stored.")
+   set(COMPILER_RT_EXEC_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/bin CACHE PATH
+     "Path where built compiler-rt executables should be stored.")
+-  set(COMPILER_RT_INSTALL_PATH ${CMAKE_INSTALL_PREFIX} CACHE PATH
+-    "Path where built compiler-rt libraries should be installed.")
+  set(COMPILER_RT_INSTALL_PATH "" CACHE PATH
+    "Prefix where built compiler-rt artifacts should be installed, comes before CMAKE_INSTALL_PREFIX.")
+   option(COMPILER_RT_INCLUDE_TESTS "Generate and build compiler-rt unit tests." OFF)
+   option(COMPILER_RT_ENABLE_WERROR "Fail and stop if warning is triggered" OFF)
+   # Use a host compiler to compile/link tests.
+@@ -97,7 +97,7 @@ else(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR)
+   set(COMPILER_RT_LIBRARY_OUTPUT_DIR
+     ${COMPILER_RT_OUTPUT_DIR}/lib/${COMPILER_RT_OS_DIR})
+   set(COMPILER_RT_LIBRARY_INSTALL_DIR
+-    ${COMPILER_RT_INSTALL_PATH}/lib/${COMPILER_RT_OS_DIR})
+    ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_LIBDIR}/${COMPILER_RT_OS_DIR})
+ endif()
+ 
+ if(APPLE)
+diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
+index b00e8caa1ddd..0fe64e4862c9 100644
+--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
+@@ -69,22 +69,22 @@ set_target_properties(compiler-rt-headers PROPERTIES FOLDER "Compiler-RT Misc")
+ install(FILES ${SANITIZER_HEADERS}
+   COMPONENT compiler-rt-headers
+   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/sanitizer)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/sanitizer)
+ # Install fuzzer headers.
+ install(FILES ${FUZZER_HEADERS}
+   COMPONENT compiler-rt-headers
+   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/fuzzer)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/fuzzer)
+ # Install xray headers.
+ install(FILES ${XRAY_HEADERS}
+   COMPONENT compiler-rt-headers
+   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/xray)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/xray)
+ # Install profile headers.
+ install(FILES ${PROFILE_HEADERS}
+   COMPONENT compiler-rt-headers
+   PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+-  DESTINATION ${COMPILER_RT_INSTALL_PATH}/include/profile)
+  DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_INCLUDEDIR}/profile)
+ 
+ if (NOT CMAKE_CONFIGURATION_TYPES) # don't add this for IDEs.
+   add_custom_target(install-compiler-rt-headers
+diff --git a/lib/dfsan/CMakeLists.txt b/lib/dfsan/CMakeLists.txt
+index a29de8deff1b..d39ff01613d2 100644
+--- a/lib/dfsan/CMakeLists.txt
+++ b/lib/dfsan/CMakeLists.txt
+@@ -57,4 +57,4 @@ add_custom_command(OUTPUT ${dfsan_abilist_filename}
+                    DEPENDS done_abilist.txt libc_ubuntu1404_abilist.txt)
+ add_dependencies(dfsan dfsan_abilist)
+ install(FILES ${dfsan_abilist_filename}
+-        DESTINATION ${COMPILER_RT_INSTALL_PATH}/share)
+        DESTINATION ${COMPILER_RT_INSTALL_PATH}/${CMAKE_INSTALL_FULL_DATADIR})
--- a/llvm/12/compiler-rt/normalize-var.patch
+++ b/llvm/12/compiler-rt/normalize-var.patch
@ -0,0 +1,16 @@
+diff --git a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
+index f1f46fb9599c..6f19e69507ba 100644
+--- a/cmake/Modules/CompilerRTUtils.cmake
+++ b/cmake/Modules/CompilerRTUtils.cmake
+@@ -302,8 +302,9 @@ macro(load_llvm_config)
+     # Get some LLVM variables from LLVMConfig.
+     include("${LLVM_CMAKE_PATH}/LLVMConfig.cmake")
+ 
+-    set(LLVM_LIBRARY_OUTPUT_INTDIR
+-      ${LLVM_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
+    get_filename_component(LLVM_LIBRARY_OUTPUT_INTDIR
+      ${LLVM_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX}
+      REALPATH)
+   endif()
+ endmacro()
+ 
--- a/llvm/12/default.nix
+++ b/llvm/12/default.nix
@ -0,0 +1,300 @@
+{ lowPrio, newScope, pkgs, lib, stdenv, cmake
+, gccForLibs, preLibcCrossHeaders
+, libxml2, python3, isl, fetchurl, overrideCC, wrapCCWith, wrapBintoolsWith
+, buildLlvmTools # tools, but from the previous stage, for cross
+, targetLlvmLibraries # libraries, but from the next stage, for cross
+, targetLlvm
+# This is the default binutils, but with *this* version of LLD rather
+# than the default LLVM version's, if LLD is the choice. We use these for
+# the `useLLVM` bootstrapping below.
+, bootBintoolsNoLibc ?
+    if stdenv.targetPlatform.linker == "lld"
+    then null
+    else pkgs.bintoolsNoLibc
+, bootBintools ?
+    if stdenv.targetPlatform.linker == "lld"
+    then null
+    else pkgs.bintools
+, darwin
+}:
+
+let
+  release_version = "12.0.1";
+  candidate = ""; # empty or "rcN"
+  dash-candidate = lib.optionalString (candidate != "") "-${candidate}";
+  version = "${release_version}${dash-candidate}"; # differentiating these (variables) is important for RCs
+  targetConfig = stdenv.targetPlatform.config;
+
+  fetch = name: sha256: fetchurl {
+    url = "https://github.com/llvm/llvm-project/releases/download/llvmorg-${version}/${name}-${release_version}${candidate}.src.tar.xz";
+    inherit sha256;
+  };
+
+  clang-tools-extra_src = fetch "clang-tools-extra" "1r9a4fdz9ci58b5z2inwvm4z4cdp6scrivnaw05dggkxz7yrwrb5";
+
+  llvm_meta = {
+    license     = lib.licenses.ncsa;
+    maintainers = lib.teams.llvm.members;
+
+    # See llvm/cmake/config-ix.cmake.
+    platforms   =
+      lib.platforms.aarch64 ++
+      lib.platforms.arm ++
+      lib.platforms.mips ++
+      lib.platforms.power ++
+      lib.platforms.riscv ++
+      lib.platforms.s390x ++
+      lib.platforms.wasi ++
+      lib.platforms.x86;
+  };
+
+  tools = lib.makeExtensible (tools: let
+    callPackage = newScope (tools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch buildLlvmTools; });
+    mkExtraBuildCommands0 = cc: ''
+      rsrc="$out/resource-root"
+      mkdir "$rsrc"
+      ln -s "${cc.lib}/lib/clang/${release_version}/include" "$rsrc"
+      echo "-resource-dir=$rsrc" >> $out/nix-support/cc-cflags
+    '';
+    mkExtraBuildCommands = cc: mkExtraBuildCommands0 cc + ''
+      ln -s "${targetLlvmLibraries.compiler-rt.out}/lib" "$rsrc/lib"
+      ln -s "${targetLlvmLibraries.compiler-rt.out}/share" "$rsrc/share"
+    '';
+
+  bintoolsNoLibc' =
+    if bootBintoolsNoLibc == null
+    then tools.bintoolsNoLibc
+    else bootBintoolsNoLibc;
+  bintools' =
+    if bootBintools == null
+    then tools.bintools
+    else bootBintools;
+
+  in {
+
+    libllvm = callPackage ./llvm {
+      inherit llvm_meta;
+    };
+
+    # `llvm` historically had the binaries.  When choosing an output explicitly,
+    # we need to reintroduce `outputSpecified` to get the expected behavior e.g. of lib.get*
+    llvm = tools.libllvm;
+
+    libclang = callPackage ./clang {
+      inherit clang-tools-extra_src llvm_meta;
+    };
+
+    clang-unwrapped = tools.libclang;
+
+    # disabled until recommonmark supports sphinx 3
+    #Llvm-manpages = lowPrio (tools.libllvm.override {
+    #  enableManpages = true;
+    #  python3 = pkgs.python3;  # don't use python-boot
+    #});
+
+    clang-manpages = lowPrio (tools.libclang.override {
+      enableManpages = true;
+      python3 = pkgs.python3;  # don't use python-boot
+    });
+
+    # disabled until recommonmark supports sphinx 3
+    # lldb-manpages = lowPrio (tools.lldb.override {
+    #   enableManpages = true;
+    #   python3 = pkgs.python3;  # don't use python-boot
+    # });
+
+    # pick clang appropriate for package set we are targeting
+    clang =
+      /**/ if stdenv.targetPlatform.libc == null then tools.clangNoLibc
+      else if stdenv.targetPlatform.useLLVM or false then tools.clangUseLLVM
+      else if (pkgs.targetPackages.stdenv or stdenv).cc.isGNU then tools.libstdcxxClang
+      else tools.libcxxClang;
+
+    libstdcxxClang = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      # libstdcxx is taken from gcc in an ad-hoc way in cc-wrapper.
+      libcxx = null;
+      extraPackages = [
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = mkExtraBuildCommands cc;
+    };
+
+    libcxxClang = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = targetLlvmLibraries.libcxx;
+      extraPackages = [
+        libcxx.cxxabi
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = mkExtraBuildCommands cc;
+    };
+
+    lld = callPackage ./lld {
+      inherit llvm_meta;
+      inherit (libraries) libunwind;
+    };
+
+    lldb = callPackage ../common/lldb.nix {
+      src = fetch "lldb" "0g3pj1m3chafavpr35r9fynm85y2hdyla6klj0h28khxs2613i78";
+      patches =
+        let
+          resourceDirPatch = callPackage
+            ({ substituteAll, libclang }: substituteAll
+              {
+                src = ./lldb/resource-dir.patch;
+                clangLibDir = "${libclang.lib}/lib";
+              })
+            { };
+        in
+        [
+          ./lldb/procfs.patch
+          resourceDirPatch
+          ./lldb/gnu-install-dirs.patch
+        ];
+      inherit llvm_meta;
+    };
+
+    # Below, is the LLVM bootstrapping logic. It handles building a
+    # fully LLVM toolchain from scratch. No GCC toolchain should be
+    # pulled in. As a consequence, it is very quick to build different
+    # targets provided by LLVM and we can also build for what GCC
+    # doesn’t support like LLVM. Probably we should move to some other
+    # file.
+
+    bintools-unwrapped = callPackage ../common/bintools.nix { };
+
+    bintoolsNoLibc = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+      libc = preLibcCrossHeaders;
+    };
+
+    bintools = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+    };
+
+    clangUseLLVM = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = targetLlvmLibraries.libcxx;
+      bintools = bintools';
+      extraPackages = [
+        libcxx.cxxabi
+        targetLlvmLibraries.compiler-rt
+      ] ++ lib.optionals (!stdenv.targetPlatform.isWasm) [
+        targetLlvmLibraries.libunwind
+      ];
+      extraBuildCommands = ''
+        echo "-rtlib=compiler-rt -Wno-unused-command-line-argument" >> $out/nix-support/cc-cflags
+        echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
+      '' + lib.optionalString (!stdenv.targetPlatform.isWasm) ''
+        echo "--unwindlib=libunwind" >> $out/nix-support/cc-cflags
+      '' + lib.optionalString (!stdenv.targetPlatform.isWasm && stdenv.targetPlatform.useLLVM or false) ''
+        echo "-lunwind" >> $out/nix-support/cc-ldflags
+      '' + lib.optionalString stdenv.targetPlatform.isWasm ''
+        echo "-fno-exceptions" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands cc;
+    };
+
+    clangNoLibcxx = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintools';
+      extraPackages = [
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = ''
+        echo "-rtlib=compiler-rt" >> $out/nix-support/cc-cflags
+        echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
+        echo "-nostdlib++" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands cc;
+    };
+
+    clangNoLibc = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintoolsNoLibc';
+      extraPackages = [
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = ''
+        echo "-rtlib=compiler-rt" >> $out/nix-support/cc-cflags
+        echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands cc;
+    };
+
+    clangNoCompilerRt = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintoolsNoLibc';
+      extraPackages = [ ];
+      extraBuildCommands = ''
+        echo "-nostartfiles" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands0 cc;
+    };
+
+    clangNoCompilerRtWithLibc = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintools';
+      extraPackages = [ ];
+      extraBuildCommands = mkExtraBuildCommands0 cc;
+    };
+
+  });
+
+  libraries = lib.makeExtensible (libraries: let
+    callPackage = newScope (libraries // buildLlvmTools // { inherit stdenv cmake libxml2 python3 isl release_version version fetch; });
+  in {
+
+    compiler-rt-libc = callPackage ./compiler-rt {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.clangNoCompilerRtWithLibc
+               else stdenv;
+    };
+
+    compiler-rt-no-libc = callPackage ./compiler-rt {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.clangNoCompilerRt
+               else stdenv;
+    };
+
+    # N.B. condition is safe because without useLLVM both are the same.
+    compiler-rt = if stdenv.hostPlatform.isAndroid
+      then libraries.compiler-rt-libc
+      else libraries.compiler-rt-no-libc;
+
+    stdenv = overrideCC stdenv buildLlvmTools.clang;
+
+    libcxxStdenv = overrideCC stdenv buildLlvmTools.libcxxClang;
+
+    libcxx = callPackage ./libcxx {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.clangNoLibcxx
+               else stdenv;
+    };
+
+    libcxxabi = callPackage ./libcxxabi {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.clangNoLibcxx
+               else stdenv;
+    };
+
+    libunwind = callPackage ./libunwind {
+      inherit llvm_meta;
+      inherit (buildLlvmTools) llvm;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.clangNoLibcxx
+               else stdenv;
+    };
+
+    openmp = callPackage ./openmp {
+      inherit llvm_meta targetLlvm;
+    };
+  });
+  noExtend = extensible: lib.attrsets.removeAttrs extensible [ "extend" ];
+
+in { inherit tools libraries release_version; } // (noExtend libraries) // (noExtend tools)
--- a/llvm/12/libcxx/default.nix
+++ b/llvm/12/libcxx/default.nix
@ -0,0 +1,79 @@
+{ lib, stdenv, llvm_meta, fetch, cmake, python3, llvm, fixDarwinDylibNames, version
+, cxxabi ? if stdenv.hostPlatform.isFreeBSD then libcxxrt else libcxxabi
+, libcxxabi, libcxxrt
+, enableShared ? !stdenv.hostPlatform.isStatic
+}:
+
+assert stdenv.isDarwin -> cxxabi.pname == "libcxxabi";
+
+stdenv.mkDerivation {
+  pname = "libcxx";
+  inherit version;
+
+  src = fetch "libcxx" "05cx39ldlxchck454lgfly1xj0c7x65iyx4hqhiihrlg6p6qj854";
+
+  postUnpack = ''
+    unpackFile ${libcxxabi.src}
+    mv libcxxabi-* libcxxabi
+    unpackFile ${llvm.src}
+    mv llvm-* llvm
+  '';
+
+  outputs = [ "out" "dev" ];
+
+  patches = [
+    ./gnu-install-dirs.patch
+  ] ++ lib.optionals stdenv.hostPlatform.isMusl [
+    ../../libcxx-0001-musl-hacks.patch
+  ];
+
+  preConfigure = lib.optionalString stdenv.hostPlatform.isMusl ''
+    patchShebangs utils/cat_files.py
+  '';
+
+  nativeBuildInputs = [ cmake python3 ]
+    ++ lib.optional stdenv.isDarwin fixDarwinDylibNames;
+
+  buildInputs = [ cxxabi ];
+
+  cmakeFlags = [
+    "-DLIBCXX_CXX_ABI=${cxxabi.pname}"
+  ] ++ lib.optional (stdenv.hostPlatform.isMusl || stdenv.hostPlatform.isWasi) "-DLIBCXX_HAS_MUSL_LIBC=1"
+    ++ lib.optional (stdenv.hostPlatform.useLLVM or false) "-DLIBCXX_USE_COMPILER_RT=ON"
+    ++ lib.optionals stdenv.hostPlatform.isWasm [
+      "-DLIBCXX_ENABLE_THREADS=OFF"
+      "-DLIBCXX_ENABLE_FILESYSTEM=OFF"
+      "-DLIBCXX_ENABLE_EXCEPTIONS=OFF"
+    ] ++ lib.optional (!enableShared) "-DLIBCXX_ENABLE_SHARED=OFF";
+
+  preInstall = lib.optionalString (stdenv.isDarwin) ''
+    for file in lib/*.dylib; do
+      if [ -L "$file" ]; then continue; fi
+
+      baseName=$(basename $(${stdenv.cc.targetPrefix}otool -D $file | tail -n 1))
+      installName="$out/lib/$baseName"
+      abiName=$(echo "$baseName" | sed -e 's/libc++/libc++abi/')
+
+      for other in $(${stdenv.cc.targetPrefix}otool -L $file | awk '$1 ~ "/libc\\+\\+abi" { print $1 }'); do
+        ${stdenv.cc.targetPrefix}install_name_tool -change $other ${cxxabi}/lib/$abiName $file
+      done
+    done
+  '';
+
+  passthru = {
+    isLLVM = true;
+    inherit cxxabi;
+  };
+
+  meta = llvm_meta // {
+    homepage = "https://libcxx.llvm.org/";
+    description = "C++ standard library";
+    longDescription = ''
+      libc++ is an implementation of the C++ standard library, targeting C++11,
+      C++14 and above.
+    '';
+    # "All of the code in libc++ is dual licensed under the MIT license and the
+    # UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}
--- a/llvm/12/libcxx/gnu-install-dirs.patch
+++ b/llvm/12/libcxx/gnu-install-dirs.patch
@ -0,0 +1,100 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 9bf1a02f0908..612cd4aab76c 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -28,6 +28,8 @@ set(LIBCXX_BINARY_INCLUDE_DIR "${LIBCXX_BINARY_DIR}/include/c++build")
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXX_STANDALONE_BUILD)
+   project(libcxx CXX C)
+ 
+  include(GNUInstallDirs)
+
+   set(PACKAGE_NAME libcxx)
+   set(PACKAGE_VERSION 12.0.0)
+   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+@@ -402,7 +404,7 @@ endif ()
+ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   set(LIBCXX_HEADER_DIR ${LLVM_BINARY_DIR})
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   if(LIBCXX_LIBDIR_SUBDIR)
+     string(APPEND LIBCXX_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
+     string(APPEND LIBCXX_INSTALL_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
+@@ -410,11 +412,11 @@ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+ elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+   set(LIBCXX_HEADER_DIR  ${LLVM_BINARY_DIR})
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX})
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXX_LIBDIR_SUFFIX})
+ else()
+   set(LIBCXX_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
+   set(LIBCXX_HEADER_DIR  ${CMAKE_BINARY_DIR})
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX})
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXX_LIBDIR_SUFFIX})
+ endif()
+ 
+ file(MAKE_DIRECTORY "${LIBCXX_BINARY_INCLUDE_DIR}")
+diff --git a/cmake/Modules/HandleLibCXXABI.cmake b/cmake/Modules/HandleLibCXXABI.cmake
+index 5d2764e870e9..bb1ec5de6ca2 100644
+--- a/cmake/Modules/HandleLibCXXABI.cmake
+++ b/cmake/Modules/HandleLibCXXABI.cmake
+@@ -63,7 +63,7 @@ macro(setup_abi_lib abidefines abishared abistatic abifiles abidirs)
+ 
+         if (LIBCXX_INSTALL_HEADERS)
+           install(FILES "${LIBCXX_BINARY_INCLUDE_DIR}/${fpath}"
+-            DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1/${dstdir}
+            DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${CMAKE_INSTALL_INCLUDEDIR}/c++/v1/${dstdir}
+             COMPONENT cxx-headers
+             PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+             )
+diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
+index 29a317b8ae9a..4747263cfd1b 100644
+--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
+@@ -252,7 +252,7 @@ if (LIBCXX_INSTALL_HEADERS)
+   foreach(file ${files})
+     get_filename_component(dir ${file} DIRECTORY)
+     install(FILES ${file}
+-      DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1/${dir}
+      DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${CMAKE_INSTALL_INCLUDEDIR}/c++/v1/${dir}
+       COMPONENT cxx-headers
+       PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+     )
+@@ -260,7 +260,7 @@ if (LIBCXX_INSTALL_HEADERS)
+ 
+   # Install the generated header as __config.
+   install(FILES ${LIBCXX_BINARY_DIR}/__generated_config
+-    DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1
+    DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}${CMAKE_INSTALL_INCLUDEDIR}/c++/v1
+     PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+     RENAME __config
+     COMPONENT cxx-headers)
+diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
+index 9965104cb5b2..9b55dbb1d822 100644
+--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
+@@ -352,21 +352,21 @@ if (LIBCXX_INSTALL_SHARED_LIBRARY)
+   install(TARGETS cxx_shared
+     ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+     LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
+    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+ endif()
+ 
+ if (LIBCXX_INSTALL_STATIC_LIBRARY)
+   install(TARGETS cxx_static
+     ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+     LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
+    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+ endif()
+ 
+ if(LIBCXX_INSTALL_EXPERIMENTAL_LIBRARY)
+   install(TARGETS cxx_experimental
+     LIBRARY DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+     ARCHIVE DESTINATION ${LIBCXX_INSTALL_PREFIX}${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}bin COMPONENT cxx)
+    RUNTIME DESTINATION ${LIBCXX_INSTALL_PREFIX}${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+ endif()
+ 
+ # NOTE: This install command must go after the cxx install command otherwise
--- a/llvm/12/libcxxabi/default.nix
+++ b/llvm/12/libcxxabi/default.nix
@ -0,0 +1,87 @@
+{ lib, stdenv, llvm_meta, cmake, python3, fetch, libcxx, libunwind, llvm, version
+, enableShared ? !stdenv.hostPlatform.isStatic
+, standalone ? stdenv.hostPlatform.useLLVM or false
+, withLibunwind ? !stdenv.isDarwin && !stdenv.hostPlatform.isWasm
+}:
+
+stdenv.mkDerivation {
+  pname = "libcxxabi";
+  inherit version;
+
+  src = fetch "libcxxabi" "1l4idd8npbkm168d26kqn529yv3npsd8f2dm8a7iwyknj7iyivw8";
+
+  outputs = [ "out" "dev" ];
+
+  postUnpack = ''
+    unpackFile ${libcxx.src}
+    mv libcxx-* libcxx
+    unpackFile ${llvm.src}
+    mv llvm-* llvm
+  '' + lib.optionalString stdenv.isDarwin ''
+    export TRIPLE=x86_64-apple-darwin
+  '' + lib.optionalString stdenv.hostPlatform.isMusl ''
+    patch -p1 -d libcxx -i ${../../libcxx-0001-musl-hacks.patch}
+  '' + lib.optionalString stdenv.hostPlatform.isWasm ''
+    patch -p1 -d llvm -i ${../../common/libcxxabi/wasm.patch}
+  '';
+
+  patches = [
+    ./gnu-install-dirs.patch
+  ];
+
+  nativeBuildInputs = [ cmake python3 ];
+  buildInputs = lib.optional withLibunwind libunwind;
+
+  cmakeFlags = lib.optionals standalone [
+    "-DLLVM_ENABLE_LIBCXX=ON"
+    "-DLIBCXXABI_USE_LLVM_UNWINDER=ON"
+  ] ++ lib.optionals stdenv.hostPlatform.isWasm [
+    "-DLIBCXXABI_ENABLE_THREADS=OFF"
+    "-DLIBCXXABI_ENABLE_EXCEPTIONS=OFF"
+  ] ++ lib.optionals (!enableShared) [
+    "-DLIBCXXABI_ENABLE_SHARED=OFF"
+  ];
+
+  preInstall = lib.optionalString stdenv.isDarwin ''
+    for file in lib/*.dylib; do
+      if [ -L "$file" ]; then continue; fi
+
+      # Fix up the install name. Preserve the basename, just replace the path.
+      installName="$out/lib/$(basename $(${stdenv.cc.targetPrefix}otool -D $file | tail -n 1))"
+
+      # this should be done in CMake, but having trouble figuring out
+      # the magic combination of necessary CMake variables
+      # if you fancy a try, take a look at
+      # https://gitlab.kitware.com/cmake/community/-/wikis/doc/cmake/RPATH-handling
+      ${stdenv.cc.targetPrefix}install_name_tool -id $installName $file
+
+      # cc-wrapper passes '-lc++abi' to all c++ link steps, but that causes
+      # libcxxabi to sometimes link against a different version of itself.
+      # Here we simply make that second reference point to ourselves.
+      for other in $(${stdenv.cc.targetPrefix}otool -L $file | awk '$1 ~ "/libc\\+\\+abi" { print $1 }'); do
+        ${stdenv.cc.targetPrefix}install_name_tool -change $other $installName $file
+      done
+    done
+  '';
+
+  postInstall = ''
+    mkdir -p "$dev/include"
+    install -m 644 ../include/${if stdenv.isDarwin then "*" else "cxxabi.h"} "$dev/include"
+  '';
+
+  passthru = {
+    libName = "c++abi";
+  };
+
+  meta = llvm_meta // {
+    homepage = "https://libcxxabi.llvm.org/";
+    description = "Provides C++ standard library support";
+    longDescription = ''
+      libc++abi is a new implementation of low level support for a standard C++ library.
+    '';
+    # "All of the code in libc++abi is dual licensed under the MIT license and
+    # the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+    maintainers = llvm_meta.maintainers ++ [ lib.maintainers.vlstill ];
+  };
+}
--- a/llvm/12/libcxxabi/gnu-install-dirs.patch
+++ b/llvm/12/libcxxabi/gnu-install-dirs.patch
@ -0,0 +1,34 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 426c855288fc..a9812a994f53 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -27,6 +27,8 @@ set(LIBCXXABI_LIBCXX_PATH "${CMAKE_CURRENT_LIST_DIR}/../libcxx" CACHE PATH
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXXABI_STANDALONE_BUILD)
+   project(libcxxabi CXX C)
+ 
+  include(GNUInstallDirs)
+
+   set(PACKAGE_NAME libcxxabi)
+   set(PACKAGE_VERSION 11.0.0)
+   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+@@ -180,17 +182,17 @@ set(CMAKE_MODULE_PATH
+ 
+ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   if(LIBCXX_LIBDIR_SUBDIR)
+     string(APPEND LIBCXXABI_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
+     string(APPEND LIBCXXABI_INSTALL_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
+   endif()
+ elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX})
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXXABI_LIBDIR_SUFFIX})
+ else()
+   set(LIBCXXABI_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXXABI_LIBDIR_SUFFIX})
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX})
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXXABI_LIBDIR_SUFFIX})
+ endif()
+ 
+ set(LIBCXXABI_INSTALL_PREFIX "" CACHE STRING "Define libc++abi destination prefix.")
--- a/llvm/12/libunwind/default.nix
+++ b/llvm/12/libunwind/default.nix
@ -0,0 +1,39 @@
+{ lib, stdenv, llvm_meta, version, fetch, libcxx, llvm, cmake
+, enableShared ? !stdenv.hostPlatform.isStatic
+}:
+
+stdenv.mkDerivation rec {
+  pname = "libunwind";
+  inherit version;
+
+  src = fetch pname "192ww6n81lj2mb9pj4043z79jp3cf58a9c2qrxjwm5c3a64n1shb";
+
+  postUnpack = ''
+    unpackFile ${libcxx.src}
+    mv libcxx-* libcxx
+    unpackFile ${llvm.src}
+    mv llvm-* llvm
+  '';
+
+  patches = [
+    ./gnu-install-dirs.patch
+  ];
+
+  outputs = [ "out" "dev" ];
+
+  nativeBuildInputs = [ cmake ];
+
+  cmakeFlags = lib.optional (!enableShared) "-DLIBUNWIND_ENABLE_SHARED=OFF";
+
+  meta = llvm_meta // {
+    # Details: https://github.com/llvm/llvm-project/blob/main/libunwind/docs/index.rst
+    homepage = "https://clang.llvm.org/docs/Toolchain.html#unwind-library";
+    description = "LLVM's unwinder library";
+    longDescription = ''
+      The unwind library provides a family of _Unwind_* functions implementing
+      the language-neutral stack unwinding portion of the Itanium C++ ABI (Level
+      I). It is a dependency of the C++ ABI library, and sometimes is a
+      dependency of other runtimes.
+    '';
+  };
+}
--- a/llvm/12/libunwind/gnu-install-dirs.patch
+++ b/llvm/12/libunwind/gnu-install-dirs.patch
@ -0,0 +1,34 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 48cb8e004e08..fec8144fb95a 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -23,6 +23,8 @@ set(LIBUNWIND_LIBCXX_PATH "${CMAKE_CURRENT_LIST_DIR}/../libcxx" CACHE PATH
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBUNWIND_STANDALONE_BUILD)
+   project(libunwind LANGUAGES C CXX ASM)
+ 
+  include(GNUInstallDirs)
+
+   set(PACKAGE_NAME libunwind)
+   set(PACKAGE_VERSION 12.0.0)
+   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+@@ -115,17 +117,17 @@ set(CMAKE_MODULE_PATH
+ 
+ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE}/c++)
+   if(LIBCXX_LIBDIR_SUBDIR)
+     string(APPEND LIBUNWIND_LIBRARY_DIR /${LIBUNWIND_LIBDIR_SUBDIR})
+     string(APPEND LIBUNWIND_INSTALL_LIBRARY_DIR /${LIBUNWIND_LIBDIR_SUBDIR})
+   endif()
+ elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+   set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LIBUNWIND_LIBDIR_SUFFIX})
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBUNWIND_LIBDIR_SUFFIX})
+ else()
+   set(LIBUNWIND_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBUNWIND_LIBDIR_SUFFIX})
+-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LIBUNWIND_LIBDIR_SUFFIX})
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBUNWIND_LIBDIR_SUFFIX})
+ endif()
+ 
+ set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${LIBUNWIND_LIBRARY_DIR})
--- a/llvm/12/lld/default.nix
+++ b/llvm/12/lld/default.nix
@ -0,0 +1,54 @@
+{ lib, stdenv, llvm_meta
+, buildLlvmTools
+, fetch
+, libunwind
+, cmake
+, libxml2
+, libllvm
+, version
+}:
+
+stdenv.mkDerivation rec {
+  pname = "lld";
+  inherit version;
+
+  src = fetch pname "0qg3fgc7wj34hdkqn21y03zcmsdd01szhhm1hfki63iifrm3y2v9";
+
+  patches = [
+    ./gnu-install-dirs.patch
+  ];
+
+  postPatch = ''
+    substituteInPlace MachO/CMakeLists.txt --replace \
+      '(''${LLVM_MAIN_SRC_DIR}/' '('
+    mkdir -p libunwind/include
+    tar -xf "${libunwind.src}" --wildcards -C libunwind/include --strip-components=2 "libunwind-*/include/"
+  '';
+
+  nativeBuildInputs = [ cmake ];
+  buildInputs = [ libllvm libxml2 ];
+
+  cmakeFlags = [
+    "-DLLVM_CONFIG_PATH=${libllvm.dev}/bin/llvm-config${lib.optionalString (stdenv.hostPlatform != stdenv.buildPlatform) "-native"}"
+  ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+    "-DLLVM_TABLEGEN_EXE=${buildLlvmTools.llvm}/bin/llvm-tblgen"
+  ];
+
+  # Musl's default stack size is too small for lld to be able to link Firefox.
+  LDFLAGS = lib.optionalString stdenv.hostPlatform.isMusl "-Wl,-z,stack-size=2097152";
+
+  outputs = [ "out" "lib" "dev" ];
+
+  meta = llvm_meta // {
+    homepage = "https://lld.llvm.org/";
+    description = "The LLVM linker (unwrapped)";
+    longDescription = ''
+      LLD is a linker from the LLVM project that is a drop-in replacement for
+      system linkers and runs much faster than them. It also provides features
+      that are useful for toolchain developers.
+      The linker supports ELF (Unix), PE/COFF (Windows), Mach-O (macOS), and
+      WebAssembly in descending order of completeness. Internally, LLD consists
+      of several different linkers.
+    '';
+  };
+}
--- a/llvm/12/lld/gnu-install-dirs.patch
+++ b/llvm/12/lld/gnu-install-dirs.patch
@ -0,0 +1,68 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index d4e561b50d8f..cfa5bdd79c2a 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -6,6 +6,8 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+   set(CMAKE_INCLUDE_CURRENT_DIR ON)
+   set(LLD_BUILT_STANDALONE TRUE)
+ 
+  include(GNUInstallDirs)
+
+   find_program(LLVM_CONFIG_PATH "llvm-config" DOC "Path to llvm-config binary")
+   if(NOT LLVM_CONFIG_PATH)
+     message(FATAL_ERROR "llvm-config not found: specify LLVM_CONFIG_PATH")
+@@ -179,7 +181,7 @@ include_directories(BEFORE
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     )
+diff --git a/cmake/modules/AddLLD.cmake b/cmake/modules/AddLLD.cmake
+index 23df41312403..d62372c88de7 100644
+--- a/cmake/modules/AddLLD.cmake
+++ b/cmake/modules/AddLLD.cmake
+@@ -20,9 +20,9 @@ macro(add_lld_library name)
+     install(TARGETS ${name}
+       COMPONENT ${name}
+       ${export_to_lldtargets}
+-      LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-      ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-      RUNTIME DESTINATION bin)
+      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+ 
+     if (${ARG_SHARED} AND NOT CMAKE_CONFIGURATION_TYPES)
+       add_llvm_install_targets(install-${name}
+@@ -54,7 +54,7 @@ macro(add_lld_tool name)
+ 
+     install(TARGETS ${name}
+       ${export_to_lldtargets}
+-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+       COMPONENT ${name})
+ 
+     if(NOT CMAKE_CONFIGURATION_TYPES)
+@@ -69,5 +69,5 @@ endmacro()
+ macro(add_lld_symlink name dest)
+   add_llvm_tool_symlink(${name} ${dest} ALWAYS_GENERATE)
+   # Always generate install targets
+-  llvm_install_symlink(${name} ${dest} ALWAYS_GENERATE)
+  llvm_install_symlink(${name} ${dest} ${CMAKE_INSTALL_FULL_BINDIR} ALWAYS_GENERATE)
+ endmacro()
+diff --git a/tools/lld/CMakeLists.txt b/tools/lld/CMakeLists.txt
+index 5cff736ff57f..64e775c771b9 100644
+--- a/tools/lld/CMakeLists.txt
+++ b/tools/lld/CMakeLists.txt
+@@ -21,7 +21,7 @@ target_link_libraries(lld
+   )
+ 
+ install(TARGETS lld
+-  RUNTIME DESTINATION bin)
+  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+ 
+ if(NOT LLD_SYMLINKS_TO_CREATE)
+   set(LLD_SYMLINKS_TO_CREATE
--- a/llvm/12/lldb/gnu-install-dirs.patch
+++ b/llvm/12/lldb/gnu-install-dirs.patch
@ -0,0 +1,91 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index b5633e21c56a..f2f1035e9238 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -10,6 +10,8 @@ set(CMAKE_MODULE_PATH
+ # If we are not building as part of LLVM, build LLDB as a standalone project,
+ # using LLVM as an external library.
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+  include(GNUInstallDirs)
+
+   project(lldb)
+   include(LLDBStandalone)
+ 
+diff --git a/cmake/modules/AddLLDB.cmake b/cmake/modules/AddLLDB.cmake
+index 4ed5c647c5d2..89f96e710d55 100644
+--- a/cmake/modules/AddLLDB.cmake
+++ b/cmake/modules/AddLLDB.cmake
+@@ -107,13 +107,13 @@ function(add_lldb_library name)
+   endif()
+ 
+   if(PARAM_SHARED)
+-    set(install_dest lib${LLVM_LIBDIR_SUFFIX})
+    set(install_dest ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+     if(PARAM_INSTALL_PREFIX)
+       set(install_dest ${PARAM_INSTALL_PREFIX})
+     endif()
+     # RUNTIME is relevant for DLL platforms, FRAMEWORK for macOS
+     install(TARGETS ${name} COMPONENT ${name}
+-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+       LIBRARY DESTINATION ${install_dest}
+       ARCHIVE DESTINATION ${install_dest}
+       FRAMEWORK DESTINATION ${install_dest})
+diff --git a/cmake/modules/LLDBConfig.cmake b/cmake/modules/LLDBConfig.cmake
+index 2fdf1502d055..37364341ff8b 100644
+--- a/cmake/modules/LLDBConfig.cmake
+++ b/cmake/modules/LLDBConfig.cmake
+@@ -225,7 +225,7 @@ include_directories(BEFORE
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/
+     COMPONENT lldb-headers
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN ".cmake" EXCLUDE
+@@ -233,7 +233,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+ 
+   install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/
+     COMPONENT lldb-headers
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN ".cmake" EXCLUDE
+diff --git a/tools/intel-features/CMakeLists.txt b/tools/intel-features/CMakeLists.txt
+index 734167e51bc5..f95761b5df58 100644
+--- a/tools/intel-features/CMakeLists.txt
+++ b/tools/intel-features/CMakeLists.txt
+@@ -65,4 +65,4 @@ if (LLDB_ENABLE_PYTHON AND LLDB_BUILD_INTEL_PT)
+ endif()
+ 
+ install(TARGETS lldbIntelFeatures
+-  LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX})
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+diff --git a/cmake/modules/LLDBStandalone.cmake b/cmake/modules/LLDBStandalone.cmake
+index 752113b..010f187 100644
+--- a/cmake/modules/LLDBStandalone.cmake
+++ b/cmake/modules/LLDBStandalone.cmake
+@@ -62,7 +62,7 @@ endif()
+
+ # They are used as destination of target generators.
+ set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin)
+-set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
+set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+ if(WIN32 OR CYGWIN)
+   # DLL platform -- put DLLs into bin.
+   set(LLVM_SHLIB_OUTPUT_INTDIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index b5633e2..86e4738 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -79,7 +79,7 @@ if (LLDB_ENABLE_PYTHON)
+   if(LLDB_BUILD_FRAMEWORK)
+     set(lldb_python_target_dir "${LLDB_FRAMEWORK_ABSOLUTE_BUILD_DIR}/LLDB.framework/Resources/Python/lldb")
+   else()
+-    set(lldb_python_target_dir "${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/${LLDB_PYTHON_RELATIVE_PATH}/lldb")
+    set(lldb_python_target_dir "${CMAKE_INSTALL_LIBDIR}/../${LLDB_PYTHON_RELATIVE_PATH}/lldb")
+   endif()
+   get_target_property(lldb_python_bindings_dir swig_wrapper_python BINARY_DIR)
+   finish_swig_python("lldb-python" "${lldb_python_bindings_dir}" "${lldb_python_target_dir}")
--- a/llvm/12/lldb/procfs.patch
+++ b/llvm/12/lldb/procfs.patch
@ -0,0 +1,31 @@
+--- a/source/Plugins/Process/Linux/Procfs.h
+++ b/source/Plugins/Process/Linux/Procfs.h
+@@ -11,21 +11,12 @@
+ // sys/procfs.h on Android/Linux for all supported architectures.
+ 
+ #include <sys/ptrace.h>
+#include <asm/ptrace.h>
+ 
+-#ifdef __ANDROID__
+-#if defined(__arm64__) || defined(__aarch64__)
+-typedef unsigned long elf_greg_t;
+-typedef elf_greg_t
+-    elf_gregset_t[(sizeof(struct user_pt_regs) / sizeof(elf_greg_t))];
+-typedef struct user_fpsimd_state elf_fpregset_t;
+-#ifndef NT_FPREGSET
+-#define NT_FPREGSET NT_PRFPREG
+-#endif // NT_FPREGSET
+-#elif defined(__mips__)
+-#ifndef NT_FPREGSET
+-#define NT_FPREGSET NT_PRFPREG
+-#endif // NT_FPREGSET
+-#endif
+-#else // __ANDROID__
+#if !defined(__GLIBC__) && defined(__powerpc__)
+#define pt_regs musl_pt_regs
+#include <sys/procfs.h>
+#undef pt_regs
+#else
+ #include <sys/procfs.h>
+-#endif // __ANDROID__
+#endif
--- a/llvm/12/lldb/resource-dir.patch
+++ b/llvm/12/lldb/resource-dir.patch
@ -0,0 +1,13 @@
+diff --git a/lldb/cmake/modules/LLDBConfig.cmake b/lldb/cmake/modules/LLDBConfig.cmake
+index 37364341ff8b..7f74c1a3e257 100644
+--- a/cmake/modules/LLDBConfig.cmake
+++ b/cmake/modules/LLDBConfig.cmake
+@@ -257,7 +257,7 @@ if (NOT TARGET clang-resource-headers)
+   # Iterate over the possible places where the external resource directory
+   # could be and pick the first that exists.
+   foreach(CANDIDATE "${Clang_DIR}/../.." "${LLVM_DIR}" "${LLVM_LIBRARY_DIRS}"
+-                    "${LLVM_BUILD_LIBRARY_DIR}"
+                    "${LLVM_BUILD_LIBRARY_DIR}" "@clangLibDir@"
+                     "${LLVM_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX}")
+     # Build the resource directory path by appending 'clang/<version number>'.
+     set(CANDIDATE_RESOURCE_DIR "${CANDIDATE}/clang/${LLDB_CLANG_RESOURCE_DIR_NAME}")
--- a/llvm/12/llvm/default.nix
+++ b/llvm/12/llvm/default.nix
@ -0,0 +1,351 @@
+{ lib, stdenv, llvm_meta
+, pkgsBuildBuild
+, fetch
+, fetchpatch
+, cmake
+, python3
+, libffi
+, enableGoldPlugin ? libbfd.hasPluginAPI
+, libbfd
+, libpfm
+, libxml2
+, ncurses
+, version
+, release_version
+, zlib
+, buildLlvmTools
+, debugVersion ? false
+, doCheck ? stdenv.isLinux && (!stdenv.isx86_32) && (!stdenv.hostPlatform.isMusl)
+  && (stdenv.hostPlatform == stdenv.buildPlatform)
+, enableManpages ? false
+, enableSharedLibraries ? !stdenv.hostPlatform.isStatic
+# broken for Ampere eMAG 8180 (c2.large.arm on Packet) #56245
+# broken for the armv7l builder
+, enablePFM ? stdenv.isLinux && !stdenv.hostPlatform.isAarch
+, enablePolly ? false
+}:
+
+let
+  inherit (lib) optional optionals optionalString;
+
+  # Used when creating a version-suffixed symlink of libLLVM.dylib
+  shortVersion = with lib;
+    concatStringsSep "." (take 1 (splitString "." release_version));
+
+  # Ordinarily we would just the `doCheck` and `checkDeps` functionality
+  # `mkDerivation` gives us to manage our test dependencies (instead of breaking
+  # out `doCheck` as a package level attribute).
+  #
+  # Unfortunately `lit` does not forward `$PYTHONPATH` to children processes, in
+  # particular the children it uses to do feature detection.
+  #
+  # This means that python deps we add to `checkDeps` (which the python
+  # interpreter is made aware of via `$PYTHONPATH` – populated by the python
+  # setup hook) are not picked up by `lit` which causes it to skip tests.
+  #
+  # Adding `python3.withPackages (ps: [ ... ])` to `checkDeps` also doesn't work
+  # because this package is shadowed in `$PATH` by the regular `python3`
+  # package.
+  #
+  # So, we "manually" assemble one python derivation for the package to depend
+  # on, taking into account whether checks are enabled or not:
+  python = if doCheck then
+    let
+      checkDeps = ps: with ps; [ psutil ];
+    in python3.withPackages checkDeps
+  else python3;
+
+in stdenv.mkDerivation (rec {
+  pname = "llvm";
+  inherit version;
+
+  src = fetch pname "1pzx9zrmd7r3481sbhwvkms68fwhffpp4mmz45dgrkjpyl2q96kx";
+  polly_src = fetch "polly" "1yfm9ixda4a2sx7ak5vswijx4ydk5lv1c1xh39xmd2kh299y4m12";
+
+  unpackPhase = ''
+    unpackFile $src
+    mv llvm-${release_version}* llvm
+    sourceRoot=$PWD/llvm
+  '' + optionalString enablePolly ''
+    unpackFile $polly_src
+    mv polly-* $sourceRoot/tools/polly
+  '';
+
+  outputs = [ "out" "lib" "dev" "python" ];
+
+  nativeBuildInputs = [ cmake python ]
+    ++ optionals enableManpages [ python3.pkgs.sphinx python3.pkgs.recommonmark ];
+
+  buildInputs = [ libxml2 libffi ]
+    ++ optional enablePFM libpfm; # exegesis
+
+  propagatedBuildInputs = optionals (stdenv.buildPlatform == stdenv.hostPlatform) [ ncurses ]
+    ++ [ zlib ];
+
+  patches = [
+    # When cross-compiling we configure llvm-config-native with an approximation
+    # of the flags used for the normal LLVM build. To avoid the need for building
+    # a native libLLVM.so (which would fail) we force llvm-config to be linked
+    # statically against the necessary LLVM components always.
+    ../../llvm-config-link-static.patch
+    # Fix llvm being miscompiled by some gccs. See llvm/llvm-project#49955
+    # Fix llvm being miscompiled by some gccs. See https://github.com/llvm/llvm-project/issues/49955
+    ./fix-llvm-issue-49955.patch
+
+    ./gnu-install-dirs.patch
+    # On older CPUs (e.g. Hydra/wendy) we'd be getting an error in this test.
+    (fetchpatch {
+      name = "uops-CMOV16rm-noreg.diff";
+      url = "https://github.com/llvm/llvm-project/commit/9e9f991ac033.diff";
+      sha256 = "sha256:12s8vr6ibri8b48h2z38f3afhwam10arfiqfy4yg37bmc054p5hi";
+      stripLen = 1;
+    })
+
+    # Fix musl build.
+    (fetchpatch {
+      url = "https://github.com/llvm/llvm-project/commit/5cd554303ead0f8891eee3cd6d25cb07f5a7bf67.patch";
+      relative = "llvm";
+      hash = "sha256-XPbvNJ45SzjMGlNUgt/IgEvM2dHQpDOe6woUJY+nUYA=";
+    })
+
+    # Backport gcc-13 fixes with missing includes.
+    (fetchpatch {
+      name = "signals-gcc-13.patch";
+      url = "https://github.com/llvm/llvm-project/commit/ff1681ddb303223973653f7f5f3f3435b48a1983.patch";
+      hash = "sha256-CXwYxQezTq5vdmc8Yn88BUAEly6YZ5VEIA6X3y5NNOs=";
+      stripLen = 1;
+    })
+    (fetchpatch {
+      name = "base64-gcc-13.patch";
+      url = "https://github.com/llvm/llvm-project/commit/5e9be93566f39ee6cecd579401e453eccfbe81e5.patch";
+      hash = "sha256-PAwrVrvffPd7tphpwCkYiz+67szPRzRB2TXBvKfzQ7U=";
+      stripLen = 1;
+    })
+  ] ++ lib.optional enablePolly ./gnu-install-dirs-polly.patch;
+
+  postPatch = optionalString stdenv.isDarwin ''
+    substituteInPlace cmake/modules/AddLLVM.cmake \
+      --replace 'set(_install_name_dir INSTALL_NAME_DIR "@rpath")' "set(_install_name_dir)" \
+      --replace 'set(_install_rpath "@loader_path/../''${CMAKE_INSTALL_LIBDIR}''${LLVM_LIBDIR_SUFFIX}" ''${extra_libdir})' ""
+  '' + ''
+    # FileSystem permissions tests fail with various special bits
+    substituteInPlace unittests/Support/CMakeLists.txt \
+      --replace "Path.cpp" ""
+    rm unittests/Support/Path.cpp
+    substituteInPlace unittests/IR/CMakeLists.txt \
+      --replace "PassBuilderCallbacksTest.cpp" ""
+    rm unittests/IR/PassBuilderCallbacksTest.cpp
+    # TODO: Fix failing tests:
+    rm test/DebugInfo/X86/vla-multi.ll
+  '' + optionalString stdenv.hostPlatform.isMusl ''
+    patch -p1 -i ${../../TLI-musl.patch}
+    substituteInPlace unittests/Support/CMakeLists.txt \
+      --replace "add_subdirectory(DynamicLibrary)" ""
+    rm unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
+    # valgrind unhappy with musl or glibc, but fails w/musl only
+    rm test/CodeGen/AArch64/wineh4.mir
+  '' + optionalString stdenv.hostPlatform.isAarch32 ''
+    # skip failing X86 test cases on 32-bit ARM
+    rm test/DebugInfo/X86/convert-debugloc.ll
+    rm test/DebugInfo/X86/convert-inlined.ll
+    rm test/DebugInfo/X86/convert-linked.ll
+    rm test/tools/dsymutil/X86/op-convert.test
+    rm test/tools/gold/X86/split-dwarf.ll
+    rm test/tools/llvm-objcopy/MachO/universal-object.test
+  '' + optionalString (stdenv.hostPlatform.system == "armv6l-linux") ''
+    # Seems to require certain floating point hardware (NEON?)
+    rm test/ExecutionEngine/frem.ll
+  '' + ''
+    patchShebangs test/BugPoint/compile-custom.ll.py
+  '' + ''
+    # Tweak tests to ignore namespace part of type to support
+    # gcc-12: https://gcc.gnu.org/PR103598.
+    # The change below mangles strings like:
+    #    CHECK-NEXT: Starting llvm::Function pass manager run.
+    # to:
+    #    CHECK-NEXT: Starting {{.*}}Function pass manager run.
+    for f in \
+      test/Other/new-pass-manager.ll \
+      test/Other/new-pm-O0-defaults.ll \
+      test/Other/new-pm-defaults.ll \
+      test/Other/new-pm-lto-defaults.ll \
+      test/Other/new-pm-thinlto-defaults.ll \
+      test/Other/pass-pipeline-parsing.ll \
+      test/Transforms/Inline/cgscc-incremental-invalidate.ll \
+      test/Transforms/Inline/clear-analyses.ll \
+      test/Transforms/LoopUnroll/unroll-loop-invalidation.ll \
+      test/Transforms/SCCP/ipsccp-preserve-analysis.ll \
+      test/Transforms/SCCP/preserve-analysis.ll \
+      test/Transforms/SROA/dead-inst.ll \
+      test/tools/gold/X86/new-pm.ll \
+      ; do
+      echo "PATCH: $f"
+      substituteInPlace $f \
+        --replace 'Starting llvm::' 'Starting {{.*}}' \
+        --replace 'Finished llvm::' 'Finished {{.*}}'
+    done
+  '';
+
+  preConfigure = ''
+    # Workaround for configure flags that need to have spaces
+    cmakeFlagsArray+=(
+      -DLLVM_LIT_ARGS='-svj''${NIX_BUILD_CORES} --no-progress-bar'
+    )
+  '';
+
+  # hacky fix: created binaries need to be run before installation
+  preBuild = ''
+    mkdir -p $out/
+    ln -sv $PWD/lib $out
+  '';
+
+  # E.g. mesa.drivers use the build-id as a cache key (see #93946):
+  LDFLAGS = optionalString (enableSharedLibraries && !stdenv.isDarwin) "-Wl,--build-id=sha1";
+
+  cmakeBuildType = if debugVersion then "Debug" else "Release";
+
+  cmakeFlags = with stdenv; let
+    # These flags influence llvm-config's BuildVariables.inc in addition to the
+    # general build. We need to make sure these are also passed via
+    # CROSS_TOOLCHAIN_FLAGS_NATIVE when cross-compiling or llvm-config-native
+    # will return different results from the cross llvm-config.
+    #
+    # Some flags don't need to be repassed because LLVM already does so (like
+    # CMAKE_BUILD_TYPE), others are irrelevant to the result.
+    flagsForLlvmConfig = [
+      "-DLLVM_INSTALL_CMAKE_DIR=${placeholder "dev"}/lib/cmake/llvm/"
+      "-DLLVM_ENABLE_RTTI=ON"
+    ] ++ optionals enableSharedLibraries [
+      "-DLLVM_LINK_LLVM_DYLIB=ON"
+    ];
+  in flagsForLlvmConfig ++ [
+    "-DLLVM_INSTALL_UTILS=ON"  # Needed by rustc
+    "-DLLVM_BUILD_TESTS=${if doCheck then "ON" else "OFF"}"
+    "-DLLVM_ENABLE_FFI=ON"
+    "-DLLVM_HOST_TRIPLE=${stdenv.hostPlatform.config}"
+    "-DLLVM_DEFAULT_TARGET_TRIPLE=${stdenv.hostPlatform.config}"
+    "-DLLVM_ENABLE_DUMP=ON"
+  ] ++ optionals stdenv.hostPlatform.isStatic [
+    # Disables building of shared libs, -fPIC is still injected by cc-wrapper
+    "-DLLVM_ENABLE_PIC=OFF"
+    "-DLLVM_BUILD_STATIC=ON"
+    # libxml2 needs to be disabled because the LLVM build system ignores its .la
+    # file and doesn't link zlib as well.
+    # https://github.com/ClangBuiltLinux/tc-build/issues/150#issuecomment-845418812
+    "-DLLVM_ENABLE_LIBXML2=OFF"
+  ] ++ optionals enableManpages [
+    "-DLLVM_BUILD_DOCS=ON"
+    "-DLLVM_ENABLE_SPHINX=ON"
+    "-DSPHINX_OUTPUT_MAN=ON"
+    "-DSPHINX_OUTPUT_HTML=OFF"
+    "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
+  ] ++ optionals (enableGoldPlugin) [
+    "-DLLVM_BINUTILS_INCDIR=${libbfd.dev}/include"
+  ] ++ optionals isDarwin [
+    "-DLLVM_ENABLE_LIBCXX=ON"
+    "-DCAN_TARGET_i386=false"
+  ] ++ optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+    "-DCMAKE_CROSSCOMPILING=True"
+    "-DLLVM_TABLEGEN=${buildLlvmTools.llvm}/bin/llvm-tblgen"
+    (
+      let
+        nativeCC = pkgsBuildBuild.targetPackages.stdenv.cc;
+        nativeBintools = nativeCC.bintools.bintools;
+        nativeToolchainFlags = [
+          "-DCMAKE_C_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}cc"
+          "-DCMAKE_CXX_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}c++"
+          "-DCMAKE_AR=${nativeBintools}/bin/${nativeBintools.targetPrefix}ar"
+          "-DCMAKE_STRIP=${nativeBintools}/bin/${nativeBintools.targetPrefix}strip"
+          "-DCMAKE_RANLIB=${nativeBintools}/bin/${nativeBintools.targetPrefix}ranlib"
+        ];
+        # We need to repass the custom GNUInstallDirs values, otherwise CMake
+        # will choose them for us, leading to wrong results in llvm-config-native
+        nativeInstallFlags = [
+          "-DCMAKE_INSTALL_PREFIX=${placeholder "out"}"
+          "-DCMAKE_INSTALL_BINDIR=${placeholder "out"}/bin"
+          "-DCMAKE_INSTALL_INCLUDEDIR=${placeholder "dev"}/include"
+          "-DCMAKE_INSTALL_LIBDIR=${placeholder "lib"}/lib"
+          "-DCMAKE_INSTALL_LIBEXECDIR=${placeholder "lib"}/libexec"
+        ];
+      in "-DCROSS_TOOLCHAIN_FLAGS_NATIVE:list="
+      + lib.concatStringsSep ";" (lib.concatLists [
+        flagsForLlvmConfig
+        nativeToolchainFlags
+        nativeInstallFlags
+      ])
+    )
+  ];
+
+  postBuild = ''
+    rm -fR $out
+  '';
+
+  preCheck = ''
+    export LD_LIBRARY_PATH=$LD_LIBRARY_PATH''${LD_LIBRARY_PATH:+:}$PWD/lib
+  '';
+
+  postInstall = ''
+    mkdir -p $python/share
+    mv $out/share/opt-viewer $python/share/opt-viewer
+    moveToOutput "bin/llvm-config*" "$dev"
+    substituteInPlace "$dev/lib/cmake/llvm/LLVMExports-${if debugVersion then "debug" else "release"}.cmake" \
+      --replace "\''${_IMPORT_PREFIX}/lib/lib" "$lib/lib/lib" \
+      --replace "$out/bin/llvm-config" "$dev/bin/llvm-config"
+    substituteInPlace "$dev/lib/cmake/llvm/LLVMConfig.cmake" \
+      --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}'"$lib"'")'
+  ''
+  + optionalString (stdenv.isDarwin && enableSharedLibraries) ''
+    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${shortVersion}.dylib
+    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
+  ''
+  + optionalString (stdenv.buildPlatform != stdenv.hostPlatform) ''
+    cp NATIVE/bin/llvm-config $dev/bin/llvm-config-native
+  '';
+
+  inherit doCheck;
+
+  checkTarget = "check-all";
+
+  requiredSystemFeatures = [ "big-parallel" ];
+  meta = llvm_meta // {
+    homepage = "https://llvm.org/";
+    description = "A collection of modular and reusable compiler and toolchain technologies";
+    longDescription = ''
+      The LLVM Project is a collection of modular and reusable compiler and
+      toolchain technologies. Despite its name, LLVM has little to do with
+      traditional virtual machines. The name "LLVM" itself is not an acronym; it
+      is the full name of the project.
+      LLVM began as a research project at the University of Illinois, with the
+      goal of providing a modern, SSA-based compilation strategy capable of
+      supporting both static and dynamic compilation of arbitrary programming
+      languages. Since then, LLVM has grown to be an umbrella project consisting
+      of a number of subprojects, many of which are being used in production by
+      a wide variety of commercial and open source projects as well as being
+      widely used in academic research. Code in the LLVM project is licensed
+      under the "Apache 2.0 License with LLVM exceptions".
+    '';
+  };
+} // lib.optionalAttrs enableManpages {
+  pname = "llvm-manpages";
+
+  buildPhase = ''
+    make docs-llvm-man
+  '';
+
+  propagatedBuildInputs = [];
+
+  installPhase = ''
+    make -C docs install
+  '';
+
+  postPatch = null;
+  postInstall = null;
+
+  outputs = [ "out" ];
+
+  doCheck = false;
+
+  meta = llvm_meta // {
+    description = "man pages for LLVM ${version}";
+  };
+})
--- a/llvm/12/llvm/fix-llvm-issue-49955.patch
+++ b/llvm/12/llvm/fix-llvm-issue-49955.patch
@ -0,0 +1,13 @@
+diff --git a/lib/CodeGen/AsmPrinter/CMakeLists.txt b/lib/CodeGen/AsmPrinter/CMakeLists.txt
+index eb924282..c77c140b 100644
+--- a/lib/CodeGen/AsmPrinter/CMakeLists.txt
+++ b/lib/CodeGen/AsmPrinter/CMakeLists.txt
+@@ -44,3 +44,8 @@ add_llvm_component_library(LLVMAsmPrinter
+   Support
+   Target
+   )
+
+if (CMAKE_COMPILER_IS_GNUCXX)
+  set_source_files_properties(DwarfCompileUnit.cpp PROPERTIES
+                              COMPILE_FLAGS -fno-strict-aliasing)
+endif()
--- a/llvm/12/llvm/gnu-install-dirs-polly.patch
+++ b/llvm/12/llvm/gnu-install-dirs-polly.patch
@ -0,0 +1,105 @@
+diff --git a/tools/polly/CMakeLists.txt b/tools/polly/CMakeLists.txt
+index ca7c04c565bb..6ed5db5dd4f8 100644
+--- a/tools/polly/CMakeLists.txt
+++ b/tools/polly/CMakeLists.txt
+@@ -2,7 +2,11 @@
+ if (NOT DEFINED LLVM_MAIN_SRC_DIR)
+   project(Polly)
+   cmake_minimum_required(VERSION 3.13.4)
+endif()
+
+include(GNUInstallDirs)
+ 
+if (NOT DEFINED LLVM_MAIN_SRC_DIR)
+   # Where is LLVM installed?
+   find_package(LLVM CONFIG REQUIRED)
+   set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${LLVM_CMAKE_DIR})
+@@ -122,13 +126,13 @@ include_directories(
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     )
+ 
+   install(DIRECTORY ${POLLY_BINARY_DIR}/include/
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN "CMakeFiles" EXCLUDE
+diff --git a/tools/polly/cmake/CMakeLists.txt b/tools/polly/cmake/CMakeLists.txt
+index 7cc129ba2e90..137be25e4b80 100644
+--- a/tools/polly/cmake/CMakeLists.txt
+++ b/tools/polly/cmake/CMakeLists.txt
+@@ -79,18 +79,18 @@ file(GENERATE
+ 
+ # Generate PollyConfig.cmake for the install tree.
+ unset(POLLY_EXPORTS)
+-set(POLLY_INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX}")
+set(POLLY_INSTALL_PREFIX "")
+ set(POLLY_CONFIG_LLVM_CMAKE_DIR "${LLVM_BINARY_DIR}/${LLVM_INSTALL_PACKAGE_DIR}")
+-set(POLLY_CONFIG_CMAKE_DIR "${POLLY_INSTALL_PREFIX}/${POLLY_INSTALL_PACKAGE_DIR}")
+-set(POLLY_CONFIG_LIBRARY_DIRS "${POLLY_INSTALL_PREFIX}/lib${LLVM_LIBDIR_SUFFIX}")
+set(POLLY_CONFIG_CMAKE_DIR "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_PREFIX}/${POLLY_INSTALL_PACKAGE_DIR}")
+set(POLLY_CONFIG_LIBRARY_DIRS "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
+ if (POLLY_BUNDLED_ISL)
+   set(POLLY_CONFIG_INCLUDE_DIRS
+-    "${POLLY_INSTALL_PREFIX}/include"
+-    "${POLLY_INSTALL_PREFIX}/include/polly"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}/polly"
+     )
+ else()
+   set(POLLY_CONFIG_INCLUDE_DIRS
+-    "${POLLY_INSTALL_PREFIX}/include"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_INCLUDEDIR}"
+     ${ISL_INCLUDE_DIRS}
+     )
+ endif()
+@@ -100,12 +100,12 @@ endif()
+ foreach(tgt IN LISTS POLLY_CONFIG_EXPORTED_TARGETS)
+   get_target_property(tgt_type ${tgt} TYPE)
+   if (tgt_type STREQUAL "EXECUTABLE")
+-    set(tgt_prefix "bin/")
+    set(tgt_prefix "${CMAKE_INSTALL_BINDIR}/")
+   else()
+-    set(tgt_prefix "lib/")
+    set(tgt_prefix "${CMAKE_INSTALL_LIBDIR}/")
+   endif()
+ 
+-  set(tgt_path "${CMAKE_INSTALL_PREFIX}/${tgt_prefix}$<TARGET_FILE_NAME:${tgt}>")
+  set(tgt_path "${tgt_prefix}$<TARGET_FILE_NAME:${tgt}>")
+   file(RELATIVE_PATH tgt_path ${POLLY_CONFIG_CMAKE_DIR} ${tgt_path})
+ 
+   if (NOT tgt_type STREQUAL "INTERFACE_LIBRARY")
+diff --git a/tools/polly/cmake/polly_macros.cmake b/tools/polly/cmake/polly_macros.cmake
+index 518a09b45a42..bd9d6f5542ad 100644
+--- a/tools/polly/cmake/polly_macros.cmake
+++ b/tools/polly/cmake/polly_macros.cmake
+@@ -44,8 +44,8 @@ macro(add_polly_library name)
+   if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY OR ${name} STREQUAL "LLVMPolly")
+     install(TARGETS ${name}
+       EXPORT LLVMExports
+-      LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-      ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX})
+	  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+   endif()
+   set_property(GLOBAL APPEND PROPERTY LLVM_EXPORTS ${name})
+ endmacro(add_polly_library)
+diff --git a/tools/polly/lib/External/CMakeLists.txt b/tools/polly/lib/External/CMakeLists.txt
+index 8991094d92c7..178d8ad606bb 100644
+--- a/tools/polly/lib/External/CMakeLists.txt
+++ b/tools/polly/lib/External/CMakeLists.txt
+@@ -275,7 +275,7 @@ if (POLLY_BUNDLED_ISL)
+     install(DIRECTORY
+       ${ISL_SOURCE_DIR}/include/
+       ${ISL_BINARY_DIR}/include/
+-      DESTINATION include/polly
+      DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/polly
+       FILES_MATCHING
+       PATTERN "*.h"
+       PATTERN "CMakeFiles" EXCLUDE
--- a/llvm/12/llvm/gnu-install-dirs.patch
+++ b/llvm/12/llvm/gnu-install-dirs.patch
@ -0,0 +1,417 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 277d0fe54d7b..af69c8be8745 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -256,15 +256,21 @@ if (CMAKE_BUILD_TYPE AND
+   message(FATAL_ERROR "Invalid value for CMAKE_BUILD_TYPE: ${CMAKE_BUILD_TYPE}")
+ endif()
+ 
+include(GNUInstallDirs)
+
+ set(LLVM_LIBDIR_SUFFIX "" CACHE STRING "Define suffix of library directory name (32/64)" )
+ 
+-set(LLVM_TOOLS_INSTALL_DIR "bin" CACHE STRING "Path for binary subdirectory (defaults to 'bin')")
+set(LLVM_TOOLS_INSTALL_DIR "${CMAKE_INSTALL_BINDIR}" CACHE STRING
+    "Path for binary subdirectory (defaults to 'bin')")
+ mark_as_advanced(LLVM_TOOLS_INSTALL_DIR)
+ 
+ set(LLVM_UTILS_INSTALL_DIR "${LLVM_TOOLS_INSTALL_DIR}" CACHE STRING
+     "Path to install LLVM utilities (enabled by LLVM_INSTALL_UTILS=ON) (defaults to LLVM_TOOLS_INSTALL_DIR)")
+ mark_as_advanced(LLVM_UTILS_INSTALL_DIR)
+ 
+set(LLVM_INSTALL_CMAKE_DIR "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/cmake/llvm" CACHE STRING
+	"Path for CMake subdirectory (defaults to lib/cmake/llvm)" )
+
+ # They are used as destination of target generators.
+ set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin)
+ set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
+@@ -567,9 +573,9 @@ option (LLVM_ENABLE_SPHINX "Use Sphinx to generate llvm documentation." OFF)
+ option (LLVM_ENABLE_OCAMLDOC "Build OCaml bindings documentation." ON)
+ option (LLVM_ENABLE_BINDINGS "Build bindings." ON)
+ 
+-set(LLVM_INSTALL_DOXYGEN_HTML_DIR "share/doc/llvm/doxygen-html"
+set(LLVM_INSTALL_DOXYGEN_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/doxygen-html"
+     CACHE STRING "Doxygen-generated HTML documentation install directory")
+-set(LLVM_INSTALL_OCAMLDOC_HTML_DIR "share/doc/llvm/ocaml-html"
+set(LLVM_INSTALL_OCAMLDOC_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/ocaml-html"
+     CACHE STRING "OCamldoc-generated HTML documentation install directory")
+ 
+ option (LLVM_BUILD_EXTERNAL_COMPILER_RT
+@@ -1027,7 +1033,7 @@ endif()
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/llvm include/llvm-c
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT llvm-headers
+     FILES_MATCHING
+     PATTERN "*.def"
+@@ -1038,7 +1044,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+     )
+ 
+   install(DIRECTORY ${LLVM_INCLUDE_DIR}/llvm ${LLVM_INCLUDE_DIR}/llvm-c
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT llvm-headers
+     FILES_MATCHING
+     PATTERN "*.def"
+@@ -1052,13 +1058,13 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+ 
+   if (LLVM_INSTALL_MODULEMAPS)
+     install(DIRECTORY include/llvm include/llvm-c
+-            DESTINATION include
+            DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+             COMPONENT llvm-headers
+             FILES_MATCHING
+             PATTERN "module.modulemap"
+             )
+     install(FILES include/llvm/module.install.modulemap
+-            DESTINATION include/llvm
+            DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm
+             COMPONENT llvm-headers
+             RENAME "module.extern.modulemap"
+             )
+diff --git a/cmake/modules/AddLLVM.cmake b/cmake/modules/AddLLVM.cmake
+index 97c9980c7de3..409e8b615f75 100644
+--- a/cmake/modules/AddLLVM.cmake
+++ b/cmake/modules/AddLLVM.cmake
+@@ -804,9 +804,9 @@ macro(add_llvm_library name)
+ 
+       install(TARGETS ${name}
+               ${export_to_llvmexports}
+-              LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+-              ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+-              RUNTIME DESTINATION bin COMPONENT ${name})
+              LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+              ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+              RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT ${name})
+ 
+       if (NOT LLVM_ENABLE_IDE)
+         add_llvm_install_targets(install-${name}
+@@ -1022,7 +1022,7 @@ function(process_llvm_pass_plugins)
+           "set(LLVM_STATIC_EXTENSIONS ${LLVM_STATIC_EXTENSIONS})")
+       install(FILES
+           ${llvm_cmake_builddir}/LLVMConfigExtensions.cmake
+-          DESTINATION ${LLVM_INSTALL_PACKAGE_DIR}
+          DESTINATION ${LLVM_INSTALL_CMAKE_DIR}
+           COMPONENT cmake-exports)
+ 
+       set(ExtensionDef "${LLVM_BINARY_DIR}/include/llvm/Support/Extension.def")
+@@ -1242,7 +1242,7 @@ macro(add_llvm_example name)
+   endif()
+   add_llvm_executable(${name} ${ARGN})
+   if( LLVM_BUILD_EXAMPLES )
+-    install(TARGETS ${name} RUNTIME DESTINATION examples)
+    install(TARGETS ${name} RUNTIME DESTINATION ${CMAKE_INSTALL_DOCDIR}/examples)
+   endif()
+   set_target_properties(${name} PROPERTIES FOLDER "Examples")
+ endmacro(add_llvm_example name)
+@@ -1854,7 +1854,7 @@ function(llvm_install_library_symlink name dest type)
+   set(full_name ${CMAKE_${type}_LIBRARY_PREFIX}${name}${CMAKE_${type}_LIBRARY_SUFFIX})
+   set(full_dest ${CMAKE_${type}_LIBRARY_PREFIX}${dest}${CMAKE_${type}_LIBRARY_SUFFIX})
+ 
+-  set(output_dir lib${LLVM_LIBDIR_SUFFIX})
+  set(output_dir ${CMAKE_INSTALL_FULL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+   if(WIN32 AND "${type}" STREQUAL "SHARED")
+     set(output_dir bin)
+   endif()
+@@ -1871,7 +1871,7 @@ function(llvm_install_library_symlink name dest type)
+   endif()
+ endfunction()
+ 
+-function(llvm_install_symlink name dest)
+function(llvm_install_symlink name dest output_dir)
+   cmake_parse_arguments(ARG "ALWAYS_GENERATE" "COMPONENT" "" ${ARGN})
+   foreach(path ${CMAKE_MODULE_PATH})
+     if(EXISTS ${path}/LLVMInstallSymlink.cmake)
+@@ -1894,7 +1894,7 @@ function(llvm_install_symlink name dest)
+   set(full_dest ${dest}${CMAKE_EXECUTABLE_SUFFIX})
+ 
+   install(SCRIPT ${INSTALL_SYMLINK}
+-          CODE "install_symlink(${full_name} ${full_dest} ${LLVM_TOOLS_INSTALL_DIR})"
+          CODE "install_symlink(${full_name} ${full_dest} ${output_dir})"
+           COMPONENT ${component})
+ 
+   if (NOT LLVM_ENABLE_IDE AND NOT ARG_ALWAYS_GENERATE)
+@@ -1977,7 +1977,8 @@ function(add_llvm_tool_symlink link_name target)
+     endif()
+ 
+     if ((TOOL_IS_TOOLCHAIN OR NOT LLVM_INSTALL_TOOLCHAIN_ONLY) AND LLVM_BUILD_TOOLS)
+-      llvm_install_symlink(${link_name} ${target})
+      GNUInstallDirs_get_absolute_install_dir(output_dir LLVM_TOOLS_INSTALL_DIR)
+      llvm_install_symlink(${link_name} ${target} ${output_dir})
+     endif()
+   endif()
+ endfunction()
+@@ -2100,9 +2101,9 @@ function(llvm_setup_rpath name)
+ 
+   if (APPLE)
+     set(_install_name_dir INSTALL_NAME_DIR "@rpath")
+-    set(_install_rpath "@loader_path/../lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+    set(_install_rpath "@loader_path/../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+   elseif(UNIX)
+-    set(_install_rpath "\$ORIGIN/../lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+    set(_install_rpath "\$ORIGIN/../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+     if(${CMAKE_SYSTEM_NAME} MATCHES "(FreeBSD|DragonFly)")
+       set_property(TARGET ${name} APPEND_STRING PROPERTY
+                    LINK_FLAGS " -Wl,-z,origin ")
+diff --git a/cmake/modules/AddOCaml.cmake b/cmake/modules/AddOCaml.cmake
+index 554046b20edf..4d1ad980641e 100644
+--- a/cmake/modules/AddOCaml.cmake
+++ b/cmake/modules/AddOCaml.cmake
+@@ -144,9 +144,9 @@ function(add_ocaml_library name)
+   endforeach()
+ 
+   if( APPLE )
+-    set(ocaml_rpath "@executable_path/../../../lib${LLVM_LIBDIR_SUFFIX}")
+    set(ocaml_rpath "@executable_path/../../../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
+   elseif( UNIX )
+-    set(ocaml_rpath "\\$ORIGIN/../../../lib${LLVM_LIBDIR_SUFFIX}")
+    set(ocaml_rpath "\\$ORIGIN/../../../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
+   endif()
+   list(APPEND ocaml_flags "-ldopt" "-Wl,-rpath,${ocaml_rpath}")
+ 
+diff --git a/cmake/modules/AddSphinxTarget.cmake b/cmake/modules/AddSphinxTarget.cmake
+index e80c3b5c1cac..482f6d715ef5 100644
+--- a/cmake/modules/AddSphinxTarget.cmake
+++ b/cmake/modules/AddSphinxTarget.cmake
+@@ -90,7 +90,7 @@ function (add_sphinx_target builder project)
+         endif()
+       elseif (builder STREQUAL html)
+         string(TOUPPER "${project}" project_upper)
+-        set(${project_upper}_INSTALL_SPHINX_HTML_DIR "share/doc/${project}/html"
+        set(${project_upper}_INSTALL_SPHINX_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/html"
+             CACHE STRING "HTML documentation install directory for ${project}")
+ 
+         # '/.' indicates: copy the contents of the directory directly into
+diff --git a/cmake/modules/CMakeLists.txt b/cmake/modules/CMakeLists.txt
+index 505dc9a29d70..36e6c63af3f4 100644
+--- a/cmake/modules/CMakeLists.txt
+++ b/cmake/modules/CMakeLists.txt
+@@ -1,4 +1,4 @@
+-set(LLVM_INSTALL_PACKAGE_DIR lib${LLVM_LIBDIR_SUFFIX}/cmake/llvm)
+set(LLVM_INSTALL_PACKAGE_DIR ${LLVM_INSTALL_CMAKE_DIR} CACHE STRING "Path for CMake subdirectory (defaults to 'cmake/llvm')")
+ set(llvm_cmake_builddir "${LLVM_BINARY_DIR}/${LLVM_INSTALL_PACKAGE_DIR}")
+ 
+ # First for users who use an installed LLVM, create the LLVMExports.cmake file.
+@@ -107,13 +107,13 @@ foreach(p ${_count})
+   set(LLVM_CONFIG_CODE "${LLVM_CONFIG_CODE}
+ get_filename_component(LLVM_INSTALL_PREFIX \"\${LLVM_INSTALL_PREFIX}\" PATH)")
+ endforeach(p)
+-set(LLVM_CONFIG_INCLUDE_DIRS "\${LLVM_INSTALL_PREFIX}/include")
+set(LLVM_CONFIG_INCLUDE_DIRS "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_INCLUDEDIR}")
+ set(LLVM_CONFIG_INCLUDE_DIR "${LLVM_CONFIG_INCLUDE_DIRS}")
+ set(LLVM_CONFIG_MAIN_INCLUDE_DIR "${LLVM_CONFIG_INCLUDE_DIRS}")
+-set(LLVM_CONFIG_LIBRARY_DIRS "\${LLVM_INSTALL_PREFIX}/lib\${LLVM_LIBDIR_SUFFIX}")
+set(LLVM_CONFIG_LIBRARY_DIRS "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}\${LLVM_LIBDIR_SUFFIX}")
+ set(LLVM_CONFIG_CMAKE_DIR "\${LLVM_INSTALL_PREFIX}/${LLVM_INSTALL_PACKAGE_DIR}")
+ set(LLVM_CONFIG_BINARY_DIR "\${LLVM_INSTALL_PREFIX}")
+-set(LLVM_CONFIG_TOOLS_BINARY_DIR "\${LLVM_INSTALL_PREFIX}/bin")
+set(LLVM_CONFIG_TOOLS_BINARY_DIR "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_BINDIR}")
+ 
+ # Generate a default location for lit
+ if (LLVM_INSTALL_UTILS AND LLVM_BUILD_UTILS)
+diff --git a/cmake/modules/LLVMInstallSymlink.cmake b/cmake/modules/LLVMInstallSymlink.cmake
+index 09fed8085c23..aa79f192abf0 100644
+--- a/cmake/modules/LLVMInstallSymlink.cmake
+++ b/cmake/modules/LLVMInstallSymlink.cmake
+@@ -10,7 +10,7 @@ function(install_symlink name target outdir)
+     set(LINK_OR_COPY copy)
+   endif()
+ 
+-  set(bindir "${DESTDIR}${CMAKE_INSTALL_PREFIX}/${outdir}/")
+  set(bindir "${DESTDIR}${outdir}/")
+ 
+   message(STATUS "Creating ${name}")
+ 
+diff --git a/docs/CMake.rst b/docs/CMake.rst
+index bb821b417ad9..6a528f7c2ad3 100644
+--- a/docs/CMake.rst
+++ b/docs/CMake.rst
+@@ -196,7 +196,7 @@ CMake manual, or execute ``cmake --help-variable VARIABLE_NAME``.
+ **LLVM_LIBDIR_SUFFIX**:STRING
+   Extra suffix to append to the directory where libraries are to be
+   installed. On a 64-bit architecture, one could use ``-DLLVM_LIBDIR_SUFFIX=64``
+-  to install libraries to ``/usr/lib64``.
+  to install libraries to ``/usr/lib64``. See also ``CMAKE_INSTALL_LIBDIR``.
+ 
+ **CMAKE_C_FLAGS**:STRING
+   Extra flags to use when compiling C source files.
+@@ -550,8 +550,8 @@ LLVM-specific variables
+ 
+ **LLVM_INSTALL_DOXYGEN_HTML_DIR**:STRING
+   The path to install Doxygen-generated HTML documentation to. This path can
+-  either be absolute or relative to the CMAKE_INSTALL_PREFIX. Defaults to
+-  `share/doc/llvm/doxygen-html`.
+  either be absolute or relative to the ``CMAKE_INSTALL_PREFIX``. Defaults to
+  `${CMAKE_INSTALL_DOCDIR}/${project}/doxygen-html`.
+ 
+ **LLVM_ENABLE_SPHINX**:BOOL
+   If specified, CMake will search for the ``sphinx-build`` executable and will make
+@@ -582,13 +582,33 @@ LLVM-specific variables
+ 
+ **LLVM_INSTALL_SPHINX_HTML_DIR**:STRING
+   The path to install Sphinx-generated HTML documentation to. This path can
+-  either be absolute or relative to the CMAKE_INSTALL_PREFIX. Defaults to
+-  `share/doc/llvm/html`.
+  either be absolute or relative to the ``CMAKE_INSTALL_PREFIX``. Defaults to
+  `${CMAKE_INSTALL_DOCDIR}/${project}/html`.
+ 
+ **LLVM_INSTALL_OCAMLDOC_HTML_DIR**:STRING
+   The path to install OCamldoc-generated HTML documentation to. This path can
+-  either be absolute or relative to the CMAKE_INSTALL_PREFIX. Defaults to
+-  `share/doc/llvm/ocaml-html`.
+  either be absolute or relative to the ``CMAKE_INSTALL_PREFIX``. Defaults to
+  `${CMAKE_INSTALL_DOCDIR}/${project}/ocaml-html`.
+
+**CMAKE_INSTALL_BINDIR**:STRING
+  The path to install binary tools, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `bin`.
+
+**CMAKE_INSTALL_LIBDIR**:STRING
+  The path to install libraries, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `lib`.
+
+**CMAKE_INSTALL_INCLUDEDIR**:STRING
+  The path to install header files, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `include`.
+
+**CMAKE_INSTALL_DOCDIR**:STRING
+  The path to install documentation, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `share/doc`.
+
+**CMAKE_INSTALL_MANDIR**:STRING
+  The path to install manpage files, relative to the ``CMAKE_INSTALL_PREFIX``.
+  Defaults to `share/man`.
+ 
+ **LLVM_CREATE_XCODE_TOOLCHAIN**:BOOL
+   macOS Only: If enabled CMake will generate a target named
+@@ -786,9 +806,11 @@ the ``cmake`` command or by setting it directly in ``ccmake`` or ``cmake-gui``).
+ 
+ This file is available in two different locations.
+ 
+-* ``<INSTALL_PREFIX>/lib/cmake/llvm/LLVMConfig.cmake`` where
+-  ``<INSTALL_PREFIX>`` is the install prefix of an installed version of LLVM.
+-  On Linux typically this is ``/usr/lib/cmake/llvm/LLVMConfig.cmake``.
+* ``<LLVM_INSTALL_PACKAGE_DIR>LLVMConfig.cmake`` where
+  ``<LLVM_INSTALL_PACKAGE_DIR>`` is the location where LLVM CMake modules are
+  installed as part of an installed version of LLVM. This is typically
+  ``cmake/llvm/`` within the lib directory. On Linux, this is typically
+  ``/usr/lib/cmake/llvm/LLVMConfig.cmake``.
+ 
+ * ``<LLVM_BUILD_ROOT>/lib/cmake/llvm/LLVMConfig.cmake`` where
+   ``<LLVM_BUILD_ROOT>`` is the root of the LLVM build tree. **Note: this is only
+diff --git a/examples/Bye/CMakeLists.txt b/examples/Bye/CMakeLists.txt
+index bb96edb4b4bf..678c22fb43c8 100644
+--- a/examples/Bye/CMakeLists.txt
+++ b/examples/Bye/CMakeLists.txt
+@@ -14,6 +14,6 @@ if (NOT WIN32)
+     BUILDTREE_ONLY
+    )
+ 
+-  install(TARGETS ${name} RUNTIME DESTINATION examples)
+  install(TARGETS ${name} RUNTIME DESTINATION ${CMAKE_INSTALL_DOCDIR}/examples)
+   set_target_properties(${name} PROPERTIES FOLDER "Examples")
+ endif()
+diff --git a/include/llvm/CMakeLists.txt b/include/llvm/CMakeLists.txt
+index b46319f24fc8..2feabd1954e4 100644
+--- a/include/llvm/CMakeLists.txt
+++ b/include/llvm/CMakeLists.txt
+@@ -5,5 +5,5 @@ add_subdirectory(Frontend)
+ # If we're doing an out-of-tree build, copy a module map for generated
+ # header files into the build area.
+ if (NOT "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
+-  configure_file(module.modulemap.build module.modulemap COPYONLY)
+  configure_file(module.modulemap.build ${LLVM_INCLUDE_DIR}/module.modulemap COPYONLY)
+ endif (NOT "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
+diff --git a/tools/llvm-config/BuildVariables.inc.in b/tools/llvm-config/BuildVariables.inc.in
+index ebe5b73a5c65..70c497be12f5 100644
+--- a/tools/llvm-config/BuildVariables.inc.in
+++ b/tools/llvm-config/BuildVariables.inc.in
+@@ -23,6 +23,10 @@
+ #define LLVM_CXXFLAGS "@LLVM_CXXFLAGS@"
+ #define LLVM_BUILDMODE "@LLVM_BUILDMODE@"
+ #define LLVM_LIBDIR_SUFFIX "@LLVM_LIBDIR_SUFFIX@"
+#define LLVM_INSTALL_BINDIR "@CMAKE_INSTALL_BINDIR@"
+#define LLVM_INSTALL_LIBDIR "@CMAKE_INSTALL_LIBDIR@"
+#define LLVM_INSTALL_INCLUDEDIR "@CMAKE_INSTALL_INCLUDEDIR@"
+#define LLVM_INSTALL_CMAKEDIR "@LLVM_INSTALL_CMAKE_DIR@"
+ #define LLVM_TARGETS_BUILT "@LLVM_TARGETS_BUILT@"
+ #define LLVM_SYSTEM_LIBS "@LLVM_SYSTEM_LIBS@"
+ #define LLVM_BUILD_SYSTEM "@LLVM_BUILD_SYSTEM@"
+diff --git a/tools/llvm-config/llvm-config.cpp b/tools/llvm-config/llvm-config.cpp
+index 1a2f04552d13..44fa7d3eec6b 100644
+--- a/tools/llvm-config/llvm-config.cpp
+++ b/tools/llvm-config/llvm-config.cpp
+@@ -357,12 +357,26 @@ int main(int argc, char **argv) {
+         ("-I" + ActiveIncludeDir + " " + "-I" + ActiveObjRoot + "/include");
+   } else {
+     ActivePrefix = CurrentExecPrefix;
+-    ActiveIncludeDir = ActivePrefix + "/include";
+-    SmallString<256> path(StringRef(LLVM_TOOLS_INSTALL_DIR));
+-    sys::fs::make_absolute(ActivePrefix, path);
+-    ActiveBinDir = std::string(path.str());
+-    ActiveLibDir = ActivePrefix + "/lib" + LLVM_LIBDIR_SUFFIX;
+-    ActiveCMakeDir = ActiveLibDir + "/cmake/llvm";
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_INCLUDEDIR));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveIncludeDir = std::string(path.str());
+    }
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_BINDIR));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveBinDir = std::string(path.str());
+    }
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_LIBDIR LLVM_LIBDIR_SUFFIX));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveLibDir = std::string(path.str());
+    }
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_CMAKEDIR));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveCMakeDir = std::string(path.str());
+    }
+     ActiveIncludeOption = "-I" + ActiveIncludeDir;
+   }
+ 
+diff --git a/tools/lto/CMakeLists.txt b/tools/lto/CMakeLists.txt
+index 2963f97cad88..69d66c9c9ca1 100644
+--- a/tools/lto/CMakeLists.txt
+++ b/tools/lto/CMakeLists.txt
+@@ -25,7 +25,7 @@ add_llvm_library(LTO SHARED INSTALL_WITH_TOOLCHAIN ${SOURCES} DEPENDS
+     intrinsics_gen)
+ 
+ install(FILES ${LLVM_MAIN_INCLUDE_DIR}/llvm-c/lto.h
+-  DESTINATION include/llvm-c
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm-c
+   COMPONENT LTO)
+ 
+ if (APPLE)
+diff --git a/tools/opt-viewer/CMakeLists.txt b/tools/opt-viewer/CMakeLists.txt
+index ead73ec13a8f..250362021f17 100644
+--- a/tools/opt-viewer/CMakeLists.txt
+++ b/tools/opt-viewer/CMakeLists.txt
+@@ -8,7 +8,7 @@ set (files
+ 
+ foreach (file ${files})
+   install(PROGRAMS ${file}
+-    DESTINATION share/opt-viewer
+    DESTINATION ${CMAKE_INSTALL_DATADIR}/opt-viewer
+     COMPONENT opt-viewer)
+ endforeach (file)
+ 
+diff --git a/tools/remarks-shlib/CMakeLists.txt b/tools/remarks-shlib/CMakeLists.txt
+index 865436247270..ce1daa62f6ab 100644
+--- a/tools/remarks-shlib/CMakeLists.txt
+++ b/tools/remarks-shlib/CMakeLists.txt
+@@ -19,7 +19,7 @@ if(LLVM_ENABLE_PIC)
+   endif()
+   
+   install(FILES ${LLVM_MAIN_INCLUDE_DIR}/llvm-c/Remarks.h
+-    DESTINATION include/llvm-c
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm-c
+     COMPONENT Remarks)
+ 
+   if (APPLE)
--- a/llvm/12/openmp/default.nix
+++ b/llvm/12/openmp/default.nix
@ -0,0 +1,48 @@
+{ lib
+, stdenv
+, llvm_meta
+, fetch
+, fetchpatch
+, cmake
+, llvm
+, targetLlvm
+, perl
+, version
+}:
+
+stdenv.mkDerivation rec {
+  pname = "openmp";
+  inherit version;
+
+  src = fetch pname "14dh0r6h2xh747ffgnsl4z08h0ri04azi9vf79cbz7ma1r27kzk0";
+
+  patches = [
+    # Fix cross.
+    (fetchpatch {
+      url = "https://github.com/llvm/llvm-project/commit/5e2358c781b85a18d1463fd924d2741d4ae5e42e.patch";
+      hash = "sha256-UxIlAifXnexF/MaraPW0Ut6q+sf3e7y1fMdEv1q103A=";
+    })
+  ];
+
+  patchFlags = [ "-p2" ];
+
+  nativeBuildInputs = [ cmake perl ];
+  buildInputs = [
+    (if stdenv.buildPlatform == stdenv.hostPlatform then llvm else targetLlvm)
+  ];
+
+  meta = llvm_meta // {
+    homepage = "https://openmp.llvm.org/";
+    description = "Support for the OpenMP language";
+    longDescription = ''
+      The OpenMP subproject of LLVM contains the components required to build an
+      executable OpenMP program that are outside the compiler itself.
+      Contains the code for the runtime library against which code compiled by
+      "clang -fopenmp" must be linked before it can run and the library that
+      supports offload to target devices.
+    '';
+    # "All of the code is dual licensed under the MIT license and the UIUC
+    # License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}
--- a/llvm/13/clang/default.nix
+++ b/llvm/13/clang/default.nix
@ -0,0 +1,126 @@
+{ lib, stdenv, llvm_meta, src, substituteAll, cmake, libxml2, libllvm, version, python3
+, buildLlvmTools
+, fixDarwinDylibNames
+, enableManpages ? false
+}:
+
+let
+  self = stdenv.mkDerivation ({
+    pname = "clang";
+    inherit version;
+
+    inherit src;
+    sourceRoot = "${src.name}/clang";
+
+    nativeBuildInputs = [ cmake python3 ]
+      ++ lib.optional enableManpages python3.pkgs.sphinx
+      ++ lib.optional stdenv.hostPlatform.isDarwin fixDarwinDylibNames;
+
+    buildInputs = [ libxml2 libllvm ];
+
+    cmakeFlags = [
+      "-DCLANGD_BUILD_XPC=OFF"
+      "-DLLVM_ENABLE_RTTI=ON"
+    ] ++ lib.optionals enableManpages [
+      "-DCLANG_INCLUDE_DOCS=ON"
+      "-DLLVM_ENABLE_SPHINX=ON"
+      "-DSPHINX_OUTPUT_MAN=ON"
+      "-DSPHINX_OUTPUT_HTML=OFF"
+      "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
+    ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+      "-DLLVM_TABLEGEN_EXE=${buildLlvmTools.llvm}/bin/llvm-tblgen"
+      "-DCLANG_TABLEGEN=${buildLlvmTools.libclang.dev}/bin/clang-tblgen"
+    ];
+
+    patches = [
+      ./purity.patch
+      # https://reviews.llvm.org/D51899
+      ./gnu-install-dirs.patch
+      # Revert of https://reviews.llvm.org/D100879
+      # The malloc alignment assumption is incorrect for jemalloc and causes
+      # mis-compilation in firefox.
+      # See: https://bugzilla.mozilla.org/show_bug.cgi?id=1741454
+      ./revert-malloc-alignment-assumption.patch
+      ../../common/clang/add-nostdlibinc-flag.patch
+      (substituteAll {
+        src = ../../clang-11-12-LLVMgold-path.patch;
+        libllvmLibdir = "${libllvm.lib}/lib";
+      })
+    ];
+
+    postPatch = ''
+      (cd tools && ln -s ../../clang-tools-extra extra)
+    '' + lib.optionalString stdenv.hostPlatform.isMusl ''
+      sed -i -e 's/lgcc_s/lgcc_eh/' lib/Driver/ToolChains/*.cpp
+    '';
+
+    outputs = [ "out" "lib" "dev" "python" ];
+
+    postInstall = ''
+      ln -sv $out/bin/clang $out/bin/cpp
+
+      # Move libclang to 'lib' output
+      moveToOutput "lib/libclang.*" "$lib"
+      moveToOutput "lib/libclang-cpp.*" "$lib"
+      substituteInPlace $out/lib/cmake/clang/ClangTargets-release.cmake \
+          --replace "\''${_IMPORT_PREFIX}/lib/libclang." "$lib/lib/libclang." \
+          --replace "\''${_IMPORT_PREFIX}/lib/libclang-cpp." "$lib/lib/libclang-cpp."
+
+      mkdir -p $python/bin $python/share/{clang,scan-view}
+      mv $out/bin/{git-clang-format,scan-view} $python/bin
+      if [ -e $out/bin/set-xcode-analyzer ]; then
+        mv $out/bin/set-xcode-analyzer $python/bin
+      fi
+      mv $out/share/clang/*.py $python/share/clang
+      mv $out/share/scan-view/*.py $python/share/scan-view
+      rm $out/bin/c-index-test
+      patchShebangs $python/bin
+
+      mkdir -p $dev/bin
+      cp bin/clang-tblgen $dev/bin
+    '';
+
+    passthru = {
+      inherit libllvm;
+      isClang = true;
+      hardeningUnsupportedFlags = [ "fortify3" ];
+    };
+
+    meta = llvm_meta // {
+      homepage = "https://clang.llvm.org/";
+      description = "A C language family frontend for LLVM";
+      longDescription = ''
+        The Clang project provides a language front-end and tooling
+        infrastructure for languages in the C language family (C, C++, Objective
+        C/C++, OpenCL, CUDA, and RenderScript) for the LLVM project.
+        It aims to deliver amazingly fast compiles, extremely useful error and
+        warning messages and to provide a platform for building great source
+        level tools. The Clang Static Analyzer and clang-tidy are tools that
+        automatically find bugs in your code, and are great examples of the sort
+        of tools that can be built using the Clang frontend as a library to
+        parse C/C++ code.
+      '';
+      mainProgram = "clang";
+    };
+  } // lib.optionalAttrs enableManpages {
+    pname = "clang-manpages";
+
+    buildPhase = ''
+      make docs-clang-man
+    '';
+
+    installPhase = ''
+      mkdir -p $out/share/man/man1
+      # Manually install clang manpage
+      cp docs/man/*.1 $out/share/man/man1/
+    '';
+
+    outputs = [ "out" ];
+
+    doCheck = false;
+
+    meta = llvm_meta // {
+      description = "man page for Clang ${version}";
+    };
+  });
+in self
--- a/llvm/13/clang/gnu-install-dirs.patch
+++ b/llvm/13/clang/gnu-install-dirs.patch
@ -0,0 +1,235 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 9e74014134a0..976e6a1757fd 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -5,6 +5,8 @@ cmake_minimum_required(VERSION 3.13.4)
+ if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
+   project(Clang)
+ 
+  include(GNUInstallDirs)
+
+   set(CMAKE_CXX_STANDARD 14 CACHE STRING "C++ standard to conform to")
+   set(CMAKE_CXX_STANDARD_REQUIRED YES)
+   set(CMAKE_CXX_EXTENSIONS NO)
+@@ -416,7 +418,7 @@ include_directories(BEFORE
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/clang include/clang-c
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT clang-headers
+     FILES_MATCHING
+     PATTERN "*.def"
+@@ -425,7 +427,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+     )
+ 
+   install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/clang
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT clang-headers
+     FILES_MATCHING
+     PATTERN "CMakeFiles" EXCLUDE
+@@ -445,7 +447,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+ 
+   add_custom_target(bash-autocomplete DEPENDS utils/bash-autocomplete.sh)
+   install(PROGRAMS utils/bash-autocomplete.sh
+-          DESTINATION share/clang
+          DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+           COMPONENT bash-autocomplete)
+   if(NOT LLVM_ENABLE_IDE)
+     add_llvm_install_targets(install-bash-autocomplete
+diff --git a/cmake/modules/AddClang.cmake b/cmake/modules/AddClang.cmake
+index 704278a0e93b..d25c8d325c71 100644
+--- a/cmake/modules/AddClang.cmake
+++ b/cmake/modules/AddClang.cmake
+@@ -123,9 +123,9 @@ macro(add_clang_library name)
+         install(TARGETS ${lib}
+           COMPONENT ${lib}
+           ${export_to_clangtargets}
+-          LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-          ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-          RUNTIME DESTINATION bin)
+          LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+          ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+          RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+ 
+         if (NOT LLVM_ENABLE_IDE)
+           add_llvm_install_targets(install-${lib}
+@@ -170,7 +170,7 @@ macro(add_clang_tool name)
+ 
+     install(TARGETS ${name}
+       ${export_to_clangtargets}
+-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+       COMPONENT ${name})
+ 
+     if(NOT LLVM_ENABLE_IDE)
+@@ -185,7 +185,7 @@ endmacro()
+ macro(add_clang_symlink name dest)
+   add_llvm_tool_symlink(${name} ${dest} ALWAYS_GENERATE)
+   # Always generate install targets
+-  llvm_install_symlink(${name} ${dest} ALWAYS_GENERATE)
+  llvm_install_symlink(${name} ${dest} ${CMAKE_INSTALL_FULL_BINDIR} ALWAYS_GENERATE)
+ endmacro()
+ 
+ function(clang_target_link_libraries target type)
+diff --git a/lib/Headers/CMakeLists.txt b/lib/Headers/CMakeLists.txt
+index b2c0ce8dd4a0..19e5443d8c25 100644
+--- a/lib/Headers/CMakeLists.txt
+++ b/lib/Headers/CMakeLists.txt
+@@ -215,7 +215,7 @@ set_target_properties(clang-resource-headers PROPERTIES
+   FOLDER "Misc"
+   RUNTIME_OUTPUT_DIRECTORY "${output_dir}")
+ 
+-set(header_install_dir lib${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION}/include)
+set(header_install_dir ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION}/include)
+ 
+ install(
+   FILES ${files} ${generated_files}
+diff --git a/tools/c-index-test/CMakeLists.txt b/tools/c-index-test/CMakeLists.txt
+index ceef4b08637c..8efad5520ca4 100644
+--- a/tools/c-index-test/CMakeLists.txt
+++ b/tools/c-index-test/CMakeLists.txt
+@@ -54,7 +54,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+     set_property(TARGET c-index-test APPEND PROPERTY INSTALL_RPATH
+        "@executable_path/../../lib")
+   else()
+-    set(INSTALL_DESTINATION bin)
+    set(INSTALL_DESTINATION ${CMAKE_INSTALL_BINDIR})
+   endif()
+ 
+   install(TARGETS c-index-test
+diff --git a/tools/clang-format/CMakeLists.txt b/tools/clang-format/CMakeLists.txt
+index 35ecdb11253c..d77d75de0094 100644
+--- a/tools/clang-format/CMakeLists.txt
+++ b/tools/clang-format/CMakeLists.txt
+@@ -21,20 +21,20 @@ if( LLVM_LIB_FUZZING_ENGINE OR LLVM_USE_SANITIZE_COVERAGE )
+ endif()
+ 
+ install(PROGRAMS clang-format-bbedit.applescript
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format-diff.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format-sublime.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format.el
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS clang-format.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-format)
+ install(PROGRAMS git-clang-format
+-  DESTINATION bin
+  DESTINATION ${CMAKE_INSTALL_BINDIR}
+   COMPONENT clang-format)
+diff --git a/tools/clang-rename/CMakeLists.txt b/tools/clang-rename/CMakeLists.txt
+index cda8e29ec5b1..0134d8ccd70b 100644
+--- a/tools/clang-rename/CMakeLists.txt
+++ b/tools/clang-rename/CMakeLists.txt
+@@ -19,8 +19,8 @@ clang_target_link_libraries(clang-rename
+   )
+ 
+ install(PROGRAMS clang-rename.py
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-rename)
+ install(PROGRAMS clang-rename.el
+-  DESTINATION share/clang
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/clang
+   COMPONENT clang-rename)
+diff --git a/tools/libclang/CMakeLists.txt b/tools/libclang/CMakeLists.txt
+index 51ff2e7e1565..1ed5f8a079a1 100644
+--- a/tools/libclang/CMakeLists.txt
+++ b/tools/libclang/CMakeLists.txt
+@@ -166,7 +166,7 @@ endif()
+ if(INTERNAL_INSTALL_PREFIX)
+   set(LIBCLANG_HEADERS_INSTALL_DESTINATION "${INTERNAL_INSTALL_PREFIX}/include")
+ else()
+-  set(LIBCLANG_HEADERS_INSTALL_DESTINATION include)
+  set(LIBCLANG_HEADERS_INSTALL_DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+ endif()
+ 
+ install(DIRECTORY ../../include/clang-c
+@@ -196,7 +196,7 @@ foreach(PythonVersion ${CLANG_PYTHON_BINDINGS_VERSIONS})
+           COMPONENT
+             libclang-python-bindings
+           DESTINATION
+-            "lib${LLVM_LIBDIR_SUFFIX}/python${PythonVersion}/site-packages")
+            "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/python${PythonVersion}/site-packages")
+ endforeach()
+ if(NOT LLVM_ENABLE_IDE)
+   add_custom_target(libclang-python-bindings)
+diff --git a/tools/scan-build/CMakeLists.txt b/tools/scan-build/CMakeLists.txt
+index ec0702d76f18..d25d982f51da 100644
+--- a/tools/scan-build/CMakeLists.txt
+++ b/tools/scan-build/CMakeLists.txt
+@@ -47,7 +47,7 @@ if(CLANG_INSTALL_SCANBUILD)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bin/${BinFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/bin/${BinFile})
+     install(PROGRAMS bin/${BinFile}
+-            DESTINATION bin
+            DESTINATION ${CMAKE_INSTALL_BINDIR}
+             COMPONENT scan-build)
+   endforeach()
+ 
+@@ -61,7 +61,7 @@ if(CLANG_INSTALL_SCANBUILD)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/libexec/${LibexecFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/libexec/${LibexecFile})
+     install(PROGRAMS libexec/${LibexecFile}
+-            DESTINATION libexec
+            DESTINATION ${CMAKE_INSTALL_LIBEXECDIR}
+             COMPONENT scan-build)
+   endforeach()
+ 
+@@ -89,7 +89,7 @@ if(CLANG_INSTALL_SCANBUILD)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/share/scan-build/${ShareFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/share/scan-build/${ShareFile})
+     install(FILES share/scan-build/${ShareFile}
+-            DESTINATION share/scan-build
+            DESTINATION ${CMAKE_INSTALL_DATADIR}/scan-build
+             COMPONENT scan-build)
+   endforeach()
+ 
+diff --git a/tools/scan-view/CMakeLists.txt b/tools/scan-view/CMakeLists.txt
+index dd3d33439299..fea19c12ce70 100644
+--- a/tools/scan-view/CMakeLists.txt
+++ b/tools/scan-view/CMakeLists.txt
+@@ -19,7 +19,7 @@ if(CLANG_INSTALL_SCANVIEW)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/bin/${BinFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/bin/${BinFile})
+     install(PROGRAMS bin/${BinFile}
+-            DESTINATION bin
+            DESTINATION ${CMAKE_INSTALL_BINDIR}
+             COMPONENT scan-view)
+   endforeach()
+ 
+@@ -33,7 +33,7 @@ if(CLANG_INSTALL_SCANVIEW)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/share/${ShareFile})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/share/scan-view/${ShareFile})
+     install(FILES share/${ShareFile}
+-            DESTINATION share/scan-view
+            DESTINATION ${CMAKE_INSTALL_DATADIR}/scan-view
+             COMPONENT scan-view)
+   endforeach()
+ 
+diff --git a/utils/hmaptool/CMakeLists.txt b/utils/hmaptool/CMakeLists.txt
+index 62f2de0cb15c..6aa66825b6ec 100644
+--- a/utils/hmaptool/CMakeLists.txt
+++ b/utils/hmaptool/CMakeLists.txt
+@@ -10,7 +10,7 @@ add_custom_command(OUTPUT ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin/${CLANG_HM
+ 
+ list(APPEND Depends ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin/${CLANG_HMAPTOOL})
+ install(PROGRAMS ${CLANG_HMAPTOOL}
+-        DESTINATION bin
+        DESTINATION ${CMAKE_INSTALL_BINDIR}
+         COMPONENT hmaptool)
+ 
+ add_custom_target(hmaptool ALL DEPENDS ${Depends})
--- a/llvm/13/clang/purity.patch
+++ b/llvm/13/clang/purity.patch
@ -0,0 +1,28 @@
+From 4add81bba40dcec62c4ea4481be8e35ac53e89d8 Mon Sep 17 00:00:00 2001
+From: Will Dietz <w@wdtz.org>
+Date: Thu, 18 May 2017 11:56:12 -0500
+Subject: [PATCH] "purity" patch for 5.0
+
+---
+ lib/Driver/ToolChains/Gnu.cpp | 7 -------
+ 1 file changed, 7 deletions(-)
+
+diff --git a/lib/Driver/ToolChains/Gnu.cpp b/lib/Driver/ToolChains/Gnu.cpp
+index fe3c0191bb..c6a482bece 100644
+--- a/lib/Driver/ToolChains/Gnu.cpp
+++ b/lib/Driver/ToolChains/Gnu.cpp
+@@ -487,12 +487,6 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
+   if (!IsStatic) {
+     if (Args.hasArg(options::OPT_rdynamic))
+       CmdArgs.push_back("-export-dynamic");
+-
+-    if (!Args.hasArg(options::OPT_shared) && !IsStaticPIE) {
+-      CmdArgs.push_back("-dynamic-linker");
+-      CmdArgs.push_back(Args.MakeArgString(Twine(D.DyldPrefix) +
+-                                           ToolChain.getDynamicLinker(Args)));
+-    }
+   }
+ 
+   CmdArgs.push_back("-o");
+-- 
+2.11.0
--- a/llvm/13/clang/revert-malloc-alignment-assumption.patch
+++ b/llvm/13/clang/revert-malloc-alignment-assumption.patch
@ -0,0 +1,78 @@
+--- b/include/clang/Basic/TargetInfo.h
+++ a/include/clang/Basic/TargetInfo.h
+@@ -612,8 +612,8 @@
+   }
+ 
+   /// Return the largest alignment for which a suitably-sized allocation with
+  /// '::operator new(size_t)' is guaranteed to produce a correctly-aligned
+  /// pointer.
+-  /// '::operator new(size_t)' or 'malloc' is guaranteed to produce a
+-  /// correctly-aligned pointer.
+   unsigned getNewAlign() const {
+     return NewAlign ? NewAlign : std::max(LongDoubleAlign, LongLongAlign);
+   }
+--- b/lib/CodeGen/CGCall.cpp
+++ a/lib/CodeGen/CGCall.cpp
+@@ -2048,24 +2048,6 @@
+       // allows it to work on indirect virtual function calls.
+       if (AttrOnCallSite && TargetDecl->hasAttr<NoMergeAttr>())
+         FuncAttrs.addAttribute(llvm::Attribute::NoMerge);
+-
+-      // Add known guaranteed alignment for allocation functions.
+-      if (unsigned BuiltinID = Fn->getBuiltinID()) {
+-        switch (BuiltinID) {
+-        case Builtin::BIaligned_alloc:
+-        case Builtin::BIcalloc:
+-        case Builtin::BImalloc:
+-        case Builtin::BImemalign:
+-        case Builtin::BIrealloc:
+-        case Builtin::BIstrdup:
+-        case Builtin::BIstrndup:
+-          RetAttrs.addAlignmentAttr(Context.getTargetInfo().getNewAlign() /
+-                                    Context.getTargetInfo().getCharWidth());
+-          break;
+-        default:
+-          break;
+-        }
+-      }
+     }
+ 
+     // 'const', 'pure' and 'noalias' attributed functions are also nounwind.
+--- b/test/CodeGen/alloc-fns-alignment.c
+++ /dev/null
+@@ -1,35 +0,0 @@
+-// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN16
+-// RUN: %clang_cc1 -triple x86_64-windows-msvc      -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN16
+-// RUN: %clang_cc1 -triple i386-apple-darwin        -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN16
+-// RUN: %clang_cc1 -triple i386-unknown-linux-gnu   -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN8
+-// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fno-builtin-malloc  -emit-llvm < %s  | FileCheck %s --check-prefix=NOBUILTIN-MALLOC
+-// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fno-builtin-calloc  -emit-llvm < %s  | FileCheck %s --check-prefix=NOBUILTIN-CALLOC
+-// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fno-builtin-realloc -emit-llvm < %s  | FileCheck %s --check-prefix=NOBUILTIN-REALLOC
+-
+-typedef __SIZE_TYPE__ size_t;
+-
+-void *malloc(size_t);
+-void *calloc(size_t, size_t);
+-void *realloc(void *, size_t);
+-
+-void *malloc_test(size_t n) {
+-  return malloc(n);
+-}
+-
+-void *calloc_test(size_t n) {
+-  return calloc(1, n);
+-}
+-
+-void *raalloc_test(void *p, size_t n) {
+-  return realloc(p, n);
+-}
+-
+-// ALIGN16: align 16 i8* @malloc
+-// ALIGN16: align 16 i8* @calloc
+-// ALIGN16: align 16 i8* @realloc
+-// ALIGN8: align 8 i8* @malloc
+-// ALIGN8: align 8 i8* @calloc
+-// ALIGN8: align 8 i8* @realloc
+-// NOBUILTIN-MALLOC: declare i8* @malloc
+-// NOBUILTIN-CALLOC: declare i8* @calloc
+-// NOBUILTIN-REALLOC: declare i8* @realloc
--- a/llvm/13/compiler-rt/X86-support-extension.patch
+++ b/llvm/13/compiler-rt/X86-support-extension.patch
@ -0,0 +1,21 @@
+diff --git a/lib/builtins/CMakeLists.txt b/lib/builtins/CMakeLists.txt
+index 3a66dd9c3fb..7efc85d9f9f 100644
+--- a/lib/builtins/CMakeLists.txt
+++ b/lib/builtins/CMakeLists.txt
+@@ -345,4 +345,8 @@ if (NOT MSVC)
+ 
+  set(i486_SOURCES ${i386_SOURCES})
+  set(i586_SOURCES ${i386_SOURCES})
+  set(i686_SOURCES ${i386_SOURCES})
+
+   if (WIN32)
+     set(i386_SOURCES
+       ${i386_SOURCES}
+@@ -608,6 +612,7 @@ else ()
+   endif()
+ 
+   foreach (arch ${BUILTIN_SUPPORTED_ARCH})
+      message("arch: ${arch}")
+     if (CAN_TARGET_${arch})
+       # For ARM archs, exclude any VFP builtins if VFP is not supported
+       if (${arch} MATCHES "^(arm|armhf|armv7|armv7s|armv7k|armv7m|armv7em)$")
--- a/llvm/13/compiler-rt/armv7l.patch
+++ b/llvm/13/compiler-rt/armv7l.patch
@ -0,0 +1,31 @@
+diff -ur compiler-rt-10.0.0.src/cmake/builtin-config-ix.cmake compiler-rt-10.0.0.src-patched/cmake/builtin-config-ix.cmake
+--- compiler-rt-10.0.0.src/cmake/builtin-config-ix.cmake	2020-03-24 00:01:02.000000000 +0900
+++ compiler-rt-10.0.0.src-patched/cmake/builtin-config-ix.cmake	2020-05-10 03:42:00.883450706 +0900
+@@ -37,6 +37,6 @@
+ 
+ set(ARM64 aarch64)
+-set(ARM32 arm armhf armv6m armv7m armv7em armv7 armv7s armv7k armv8m.main armv8.1m.main)
+set(ARM32 arm armhf armv6m armv7m armv7em armv7 armv7s armv7k armv7l armv8m.main armv8.1m.main)
+ set(HEXAGON hexagon)
+ set(X86 i386)
+ set(X86_64 x86_64)
+diff -ur compiler-rt-10.0.0.src/lib/builtins/CMakeLists.txt compiler-rt-10.0.0.src-patched/lib/builtins/CMakeLists.txt
+--- compiler-rt-10.0.0.src/lib/builtins/CMakeLists.txt	2020-03-24 00:01:02.000000000 +0900
+++ compiler-rt-10.0.0.src-patched/lib/builtins/CMakeLists.txt	2020-05-10 03:44:49.468579650 +0900
+@@ -555,6 +555,7 @@
+ set(armv7_SOURCES ${arm_SOURCES})
+ set(armv7s_SOURCES ${arm_SOURCES})
+ set(armv7k_SOURCES ${arm_SOURCES})
+set(armv7l_SOURCES ${arm_SOURCES})
+ set(arm64_SOURCES ${aarch64_SOURCES})
+ 
+ # macho_embedded archs
+@@ -705,7 +705,7 @@
+   foreach (arch ${BUILTIN_SUPPORTED_ARCH})
+     if (CAN_TARGET_${arch})
+       # For ARM archs, exclude any VFP builtins if VFP is not supported
+-      if (${arch} MATCHES "^(arm|armhf|armv7|armv7s|armv7k|armv7m|armv7em|armv8m.main|armv8.1m.main)$")
+      if (${arch} MATCHES "^(arm|armhf|armv7|armv7s|armv7k|armv7l|armv7m|armv7em|armv8m.main|armv8.1m.main)$")
+         string(REPLACE ";" " " _TARGET_${arch}_CFLAGS "${TARGET_${arch}_CFLAGS}")
+         check_compile_definition(__VFP_FP__ "${CMAKE_C_FLAGS} ${_TARGET_${arch}_CFLAGS}" COMPILER_RT_HAS_${arch}_VFP)
+         if(NOT COMPILER_RT_HAS_${arch}_VFP)
--- a/llvm/13/compiler-rt/codesign.patch
+++ b/llvm/13/compiler-rt/codesign.patch
@ -0,0 +1,33 @@
+From 3dec5f3475a26aeb4678627795c4b67c6b7b4785 Mon Sep 17 00:00:00 2001
+From: Will Dietz <w@wdtz.org>
+Date: Tue, 19 Sep 2017 13:13:06 -0500
+Subject: [PATCH] remove codesign use on Apple, disable ios sim testing that
+ needs it
+
+---
+ cmake/Modules/AddCompilerRT.cmake |  8 ------
+ test/asan/CMakeLists.txt          | 52 ---------------------------------------
+ test/tsan/CMakeLists.txt          | 47 -----------------------------------
+ 3 files changed, 107 deletions(-)
+
+diff --git a/cmake/Modules/AddCompilerRT.cmake b/cmake/Modules/AddCompilerRT.cmake
+index bc69ec95c419..9f100fdcec2f 100644
+--- a/cmake/Modules/AddCompilerRT.cmake
+++ b/cmake/Modules/AddCompilerRT.cmake
+@@ -366,14 +366,6 @@ function(add_compiler_rt_runtime name type)
+         set_target_properties(${libname} PROPERTIES IMPORT_PREFIX "")
+         set_target_properties(${libname} PROPERTIES IMPORT_SUFFIX ".lib")
+       endif()
+-      if(APPLE)
+-        # Ad-hoc sign the dylibs
+-        add_custom_command(TARGET ${libname}
+-          POST_BUILD  
+-          COMMAND codesign --sign - $<TARGET_FILE:${libname}>
+-          WORKING_DIRECTORY ${COMPILER_RT_OUTPUT_LIBRARY_DIR}
+-        )
+-      endif()
+     endif()
+ 
+     set(parent_target_arg)
+2.14.1
+
--- a/llvm/13/compiler-rt/darwin-targetconditionals.patch
+++ b/llvm/13/compiler-rt/darwin-targetconditionals.patch
@ -0,0 +1,71 @@
+diff --git a/lib/sanitizer_common/sanitizer_mac.cpp b/lib/sanitizer_common/sanitizer_mac.cpp
+--- a/lib/sanitizer_common/sanitizer_mac.cpp
+++ b/lib/sanitizer_common/sanitizer_mac.cpp
+@@ -613,9 +613,15 @@ HandleSignalMode GetHandleSignalMode(int signum) {
+ // Offset example:
+ // XNU 17 -- macOS 10.13 -- iOS 11 -- tvOS 11 -- watchOS 4
+ constexpr u16 GetOSMajorKernelOffset() {
+-  if (TARGET_OS_OSX) return 4;
+-  if (TARGET_OS_IOS || TARGET_OS_TV) return 6;
+-  if (TARGET_OS_WATCH) return 13;
+#if TARGET_OS_OSX
+  return 4;
+#endif
+#if TARGET_OS_IOS || TARGET_OS_TV
+  return 6;
+#endif
+#if TARGET_OS_WATCH
+  return 13;
+#endif
+ }
+ 
+ using VersStr = char[64];
+@@ -627,13 +633,13 @@ static uptr ApproximateOSVersionViaKernelVersion(VersStr vers) {
+   u16 os_major = kernel_major - offset;
+ 
+   const char *format = "%d.0";
+-  if (TARGET_OS_OSX) {
+-    if (os_major >= 16) {  // macOS 11+
+-      os_major -= 5;
+-    } else {  // macOS 10.15 and below
+-      format = "10.%d";
+-    }
+#if TARGET_OS_OSX
+  if (os_major >= 16) {  // macOS 11+
+    os_major -= 5;
+  } else {  // macOS 10.15 and below
+    format = "10.%d";
+   }
+#endif
+   return internal_snprintf(vers, sizeof(VersStr), format, os_major);
+ }
+ 
+@@ -681,15 +687,14 @@ void ParseVersion(const char *vers, u16 *major, u16 *minor) {
+ // Aligned versions example:
+ // macOS 10.15 -- iOS 13 -- tvOS 13 -- watchOS 6
+ static void MapToMacos(u16 *major, u16 *minor) {
+-  if (TARGET_OS_OSX)
+-    return;
+-
+-  if (TARGET_OS_IOS || TARGET_OS_TV)
+#if !TARGET_OS_OSX
+#if TARGET_OS_IOS || TARGET_OS_TV
+     *major += 2;
+-  else if (TARGET_OS_WATCH)
+#elif TARGET_OS_WATCH
+     *major += 9;
+-  else
+#else
+     UNREACHABLE("unsupported platform");
+#endif
+ 
+   if (*major >= 16) {  // macOS 11+
+     *major -= 5;
+@@ -697,6 +702,7 @@ static void MapToMacos(u16 *major, u16 *minor) {
+     *minor = *major;
+     *major = 10;
+   }
+#endif
+ }
+ 
+ static MacosVersion GetMacosAlignedVersionInternal() {
--- a/llvm/13/compiler-rt/default.nix
+++ b/llvm/13/compiler-rt/default.nix
@ -0,0 +1,132 @@
+{ lib, stdenv, llvm_meta, version, src, cmake, python3, xcbuild, libllvm, libcxxabi, libxcrypt
+, doFakeLibgcc ? stdenv.hostPlatform.isFreeBSD
+}:
+
+let
+
+  useLLVM = stdenv.hostPlatform.useLLVM or false;
+  bareMetal = stdenv.hostPlatform.parsed.kernel.name == "none";
+  haveLibc = stdenv.cc.libc != null;
+  inherit (stdenv.hostPlatform) isMusl isAarch64;
+
+in
+
+stdenv.mkDerivation {
+  pname = "compiler-rt" + lib.optionalString (haveLibc) "-libc";
+  inherit version;
+
+  inherit src;
+  sourceRoot = "${src.name}/compiler-rt";
+
+  nativeBuildInputs = [ cmake python3 libllvm.dev ]
+    ++ lib.optional stdenv.isDarwin xcbuild.xcrun;
+  buildInputs = lib.optional stdenv.hostPlatform.isDarwin libcxxabi;
+
+  env.NIX_CFLAGS_COMPILE = toString [
+    "-DSCUDO_DEFAULT_OPTIONS=DeleteSizeMismatch=0:DeallocationTypeMismatch=0"
+  ];
+
+  cmakeFlags = [
+    "-DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON"
+    "-DCMAKE_C_COMPILER_TARGET=${stdenv.hostPlatform.config}"
+    "-DCMAKE_ASM_COMPILER_TARGET=${stdenv.hostPlatform.config}"
+  ] ++ lib.optionals (haveLibc && stdenv.hostPlatform.isGnu) [
+    "-DSANITIZER_COMMON_CFLAGS=-I${libxcrypt}/include"
+  ] ++ lib.optionals (useLLVM || bareMetal || isMusl || isAarch64) [
+    "-DCOMPILER_RT_BUILD_LIBFUZZER=OFF"
+  ] ++ lib.optionals (useLLVM || bareMetal || isMusl) [
+    "-DCOMPILER_RT_BUILD_SANITIZERS=OFF"
+    "-DCOMPILER_RT_BUILD_XRAY=OFF"
+    "-DCOMPILER_RT_BUILD_MEMPROF=OFF"
+    "-DCOMPILER_RT_BUILD_ORC=OFF" # may be possible to build with musl if necessary
+  ] ++ lib.optionals (useLLVM || bareMetal) [
+    "-DCOMPILER_RT_BUILD_PROFILE=OFF"
+  ] ++ lib.optionals ((useLLVM && !haveLibc) || bareMetal) [
+    "-DCMAKE_C_COMPILER_WORKS=ON"
+    "-DCMAKE_CXX_COMPILER_WORKS=ON"
+    "-DCOMPILER_RT_BAREMETAL_BUILD=ON"
+    "-DCMAKE_SIZEOF_VOID_P=${toString (stdenv.hostPlatform.parsed.cpu.bits / 8)}"
+  ] ++ lib.optionals (useLLVM) [
+    "-DCOMPILER_RT_BUILD_BUILTINS=ON"
+    #https://stackoverflow.com/questions/53633705/cmake-the-c-compiler-is-not-able-to-compile-a-simple-test-program
+    "-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY"
+  ] ++ lib.optionals (bareMetal) [
+    "-DCOMPILER_RT_OS_DIR=baremetal"
+  ] ++ lib.optionals (stdenv.hostPlatform.isDarwin) [
+    "-DDARWIN_macosx_OVERRIDE_SDK_VERSION=ON"
+    "-DDARWIN_osx_ARCHS=${stdenv.hostPlatform.darwinArch}"
+    "-DDARWIN_osx_BUILTIN_ARCHS=${stdenv.hostPlatform.darwinArch}"
+  ];
+
+  outputs = [ "out" "dev" ];
+
+  patches = [
+    ./codesign.patch # Revert compiler-rt commit that makes codesign mandatory
+    ./X86-support-extension.patch # Add support for i486 i586 i686 by reusing i386 config
+    # ld-wrapper dislikes `-rpath-link //nix/store`, so we normalize away the
+    # extra `/`.
+    ./normalize-var.patch
+    # Prevent a compilation error on darwin
+    ./darwin-targetconditionals.patch
+    ../../common/compiler-rt/darwin-plistbuddy-workaround.patch
+    ./armv7l.patch
+    # Fix build on armv6l
+    ../../common/compiler-rt/armv6-mcr-dmb.patch
+    ../../common/compiler-rt/armv6-sync-ops-no-thumb.patch
+    ../../common/compiler-rt/armv6-no-ldrexd-strexd.patch
+    ../../common/compiler-rt/armv6-scudo-no-yield.patch
+    ../../common/compiler-rt/armv6-scudo-libatomic.patch
+  ];
+
+  # TSAN requires XPC on Darwin, which we have no public/free source files for. We can depend on the Apple frameworks
+  # to get it, but they're unfree. Since LLVM is rather central to the stdenv, we patch out TSAN support so that Hydra
+  # can build this. If we didn't do it, basically the entire nixpkgs on Darwin would have an unfree dependency and we'd
+  # get no binary cache for the entire platform. If you really find yourself wanting the TSAN, make this controllable by
+  # a flag and turn the flag off during the stdenv build.
+  postPatch = lib.optionalString (!stdenv.isDarwin) ''
+    substituteInPlace cmake/builtin-config-ix.cmake \
+      --replace 'set(X86 i386)' 'set(X86 i386 i486 i586 i686)'
+  '' + lib.optionalString stdenv.isDarwin ''
+    substituteInPlace cmake/config-ix.cmake \
+      --replace 'set(COMPILER_RT_HAS_TSAN TRUE)' 'set(COMPILER_RT_HAS_TSAN FALSE)'
+  '' + lib.optionalString (useLLVM) ''
+    substituteInPlace lib/builtins/int_util.c \
+      --replace "#include <stdlib.h>" ""
+    substituteInPlace lib/builtins/clear_cache.c \
+      --replace "#include <assert.h>" ""
+    substituteInPlace lib/builtins/cpu_model.c \
+      --replace "#include <assert.h>" ""
+  '';
+
+  preConfigure = lib.optionalString (useLLVM && !haveLibc) ''
+    cmakeFlagsArray+=(-DCMAKE_C_FLAGS="-nodefaultlibs -ffreestanding")
+  '';
+
+  # Hack around weird upsream RPATH bug
+  postInstall = lib.optionalString (stdenv.hostPlatform.isDarwin || stdenv.hostPlatform.isWasm) ''
+    ln -s "$out/lib"/*/* "$out/lib"
+  '' + lib.optionalString (useLLVM) ''
+    ln -s $out/lib/*/clang_rt.crtbegin-*.o $out/lib/crtbegin.o
+    ln -s $out/lib/*/clang_rt.crtend-*.o $out/lib/crtend.o
+    ln -s $out/lib/*/clang_rt.crtbegin_shared-*.o $out/lib/crtbeginS.o
+    ln -s $out/lib/*/clang_rt.crtend_shared-*.o $out/lib/crtendS.o
+  '' + lib.optionalString doFakeLibgcc ''
+    ln -s $out/lib/freebsd/libclang_rt.builtins-*.a $out/lib/libgcc.a
+  '';
+
+  meta = llvm_meta // {
+    homepage = "https://compiler-rt.llvm.org/";
+    description = "Compiler runtime libraries";
+    longDescription = ''
+      The compiler-rt project provides highly tuned implementations of the
+      low-level code generator support routines like "__fixunsdfdi" and other
+      calls generated when a target doesn't have a short sequence of native
+      instructions to implement a core IR operation. It also provides
+      implementations of run-time libraries for dynamic testing tools such as
+      AddressSanitizer, ThreadSanitizer, MemorySanitizer, and DataFlowSanitizer.
+    '';
+    # "All of the code in the compiler-rt project is dual licensed under the MIT
+    # license and the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}
--- a/llvm/13/compiler-rt/normalize-var.patch
+++ b/llvm/13/compiler-rt/normalize-var.patch
@ -0,0 +1,16 @@
+diff --git a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
+index f1f46fb9599c..6f19e69507ba 100644
+--- a/cmake/Modules/CompilerRTUtils.cmake
+++ b/cmake/Modules/CompilerRTUtils.cmake
+@@ -302,8 +302,9 @@ macro(load_llvm_config)
+     # Get some LLVM variables from LLVMConfig.
+     include("${LLVM_CMAKE_PATH}/LLVMConfig.cmake")
+ 
+-    set(LLVM_LIBRARY_OUTPUT_INTDIR
+-      ${LLVM_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
+    get_filename_component(LLVM_LIBRARY_OUTPUT_INTDIR
+      ${LLVM_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX}
+      REALPATH)
+   endif()
+ endmacro()
+ 
--- a/llvm/13/default.nix
+++ b/llvm/13/default.nix
@ -0,0 +1,322 @@
+{ lowPrio, newScope, pkgs, lib, stdenv, cmake
+, gccForLibs, preLibcCrossHeaders
+, libxml2, python3, isl, fetchFromGitHub, overrideCC, wrapCCWith, wrapBintoolsWith
+, buildLlvmTools # tools, but from the previous stage, for cross
+, targetLlvmLibraries # libraries, but from the next stage, for cross
+, targetLlvm
+# This is the default binutils, but with *this* version of LLD rather
+# than the default LLVM version's, if LLD is the choice. We use these for
+# the `useLLVM` bootstrapping below.
+, bootBintoolsNoLibc ?
+    if stdenv.targetPlatform.linker == "lld"
+    then null
+    else pkgs.bintoolsNoLibc
+, bootBintools ?
+    if stdenv.targetPlatform.linker == "lld"
+    then null
+    else pkgs.bintools
+, darwin
+}:
+
+let
+  release_version = "13.0.1";
+  candidate = ""; # empty or "rcN"
+  dash-candidate = lib.optionalString (candidate != "") "-${candidate}";
+  rev = ""; # When using a Git commit
+  rev-version = ""; # When using a Git commit
+  version = if rev != "" then rev-version else "${release_version}${dash-candidate}";
+  targetConfig = stdenv.targetPlatform.config;
+
+  src = fetchFromGitHub {
+    owner = "llvm";
+    repo = "llvm-project";
+    rev = if rev != "" then rev else "llvmorg-${version}";
+    sha256 = "06dv6h5dmvzdxbif2s8njki6h32796v368dyb5945x8gjj72xh7k";
+  };
+
+  llvm_meta = {
+    license     = lib.licenses.ncsa;
+    maintainers = lib.teams.llvm.members;
+
+    # See llvm/cmake/config-ix.cmake.
+    platforms   =
+      lib.platforms.aarch64 ++
+      lib.platforms.arm ++
+      lib.platforms.mips ++
+      lib.platforms.power ++
+      lib.platforms.riscv ++
+      lib.platforms.s390x ++
+      lib.platforms.wasi ++
+      lib.platforms.x86;
+  };
+
+  tools = lib.makeExtensible (tools: let
+    callPackage = newScope (tools // { inherit stdenv cmake libxml2 python3 isl release_version version src buildLlvmTools; });
+    mkExtraBuildCommands0 = cc: ''
+      rsrc="$out/resource-root"
+      mkdir "$rsrc"
+      ln -s "${cc.lib}/lib/clang/${release_version}/include" "$rsrc"
+      echo "-resource-dir=$rsrc" >> $out/nix-support/cc-cflags
+    '';
+    mkExtraBuildCommands = cc: mkExtraBuildCommands0 cc + ''
+      ln -s "${targetLlvmLibraries.compiler-rt.out}/lib" "$rsrc/lib"
+      ln -s "${targetLlvmLibraries.compiler-rt.out}/share" "$rsrc/share"
+    '';
+
+  bintoolsNoLibc' =
+    if bootBintoolsNoLibc == null
+    then tools.bintoolsNoLibc
+    else bootBintoolsNoLibc;
+  bintools' =
+    if bootBintools == null
+    then tools.bintools
+    else bootBintools;
+
+  in {
+
+    libllvm = callPackage ./llvm {
+      inherit llvm_meta;
+    };
+
+    # `llvm` historically had the binaries.  When choosing an output explicitly,
+    # we need to reintroduce `outputSpecified` to get the expected behavior e.g. of lib.get*
+    llvm = tools.libllvm;
+
+    libclang = callPackage ./clang {
+      inherit llvm_meta;
+    };
+
+    clang-unwrapped = tools.libclang;
+
+    llvm-manpages = lowPrio (tools.libllvm.override {
+      enableManpages = true;
+      python3 = pkgs.python3;  # don't use python-boot
+    });
+
+    clang-manpages = lowPrio (tools.libclang.override {
+      enableManpages = true;
+      python3 = pkgs.python3;  # don't use python-boot
+    });
+
+    # TODO: lldb/docs/index.rst:155:toctree contains reference to nonexisting document 'design/structureddataplugins'
+    # lldb-manpages = lowPrio (tools.lldb.override {
+    #   enableManpages = true;
+    #   python3 = pkgs.python3;  # don't use python-boot
+    # });
+
+    # pick clang appropriate for package set we are targeting
+    clang =
+      /**/ if stdenv.targetPlatform.libc == null then tools.clangNoLibc
+      else if stdenv.targetPlatform.useLLVM or false then tools.clangUseLLVM
+      else if (pkgs.targetPackages.stdenv or stdenv).cc.isGNU then tools.libstdcxxClang
+      else tools.libcxxClang;
+
+    libstdcxxClang = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      # libstdcxx is taken from gcc in an ad-hoc way in cc-wrapper.
+      libcxx = null;
+      extraPackages = [
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = mkExtraBuildCommands cc;
+    };
+
+    libcxxClang = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = targetLlvmLibraries.libcxx;
+      extraPackages = [
+        libcxx.cxxabi
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = mkExtraBuildCommands cc;
+    };
+
+    lld = callPackage ./lld {
+      inherit llvm_meta;
+    };
+
+    lldb = callPackage ../common/lldb.nix {
+      patches =
+        let
+          resourceDirPatch = callPackage
+            ({ substituteAll, libclang }: substituteAll
+              {
+                src = ./lldb/resource-dir.patch;
+                clangLibDir = "${libclang.lib}/lib";
+              })
+            { };
+        in
+        [
+          ./lldb/procfs.patch
+          resourceDirPatch
+          ./lldb/gnu-install-dirs.patch
+        ]
+        # This is a stopgap solution if/until the macOS SDK used for x86_64 is
+        # updated.
+        #
+        # The older 10.12 SDK used on x86_64 as of this writing has a `mach/machine.h`
+        # header that does not define `CPU_SUBTYPE_ARM64E` so we replace the one use
+        # of this preprocessor symbol in `lldb` with its expansion.
+        #
+        # See here for some context:
+        # https://github.com/NixOS/nixpkgs/pull/194634#issuecomment-1272129132
+        ++ lib.optional (
+          stdenv.targetPlatform.isDarwin
+            && !stdenv.targetPlatform.isAarch64
+            && (lib.versionOlder darwin.apple_sdk.sdk.version "11.0")
+        ) ./lldb/cpu_subtype_arm64e_replacement.patch;
+      inherit llvm_meta;
+    };
+
+    # Below, is the LLVM bootstrapping logic. It handles building a
+    # fully LLVM toolchain from scratch. No GCC toolchain should be
+    # pulled in. As a consequence, it is very quick to build different
+    # targets provided by LLVM and we can also build for what GCC
+    # doesn’t support like LLVM. Probably we should move to some other
+    # file.
+
+    bintools-unwrapped = callPackage ../common/bintools.nix { };
+
+    bintoolsNoLibc = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+      libc = preLibcCrossHeaders;
+    };
+
+    bintools = wrapBintoolsWith {
+      bintools = tools.bintools-unwrapped;
+    };
+
+    clangUseLLVM = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = targetLlvmLibraries.libcxx;
+      bintools = bintools';
+      extraPackages = [
+        libcxx.cxxabi
+        targetLlvmLibraries.compiler-rt
+      ] ++ lib.optionals (!stdenv.targetPlatform.isWasm) [
+        targetLlvmLibraries.libunwind
+      ];
+      extraBuildCommands = ''
+        echo "-rtlib=compiler-rt -Wno-unused-command-line-argument" >> $out/nix-support/cc-cflags
+        echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
+      '' + lib.optionalString (!stdenv.targetPlatform.isWasm) ''
+        echo "--unwindlib=libunwind" >> $out/nix-support/cc-cflags
+      '' + lib.optionalString (!stdenv.targetPlatform.isWasm && stdenv.targetPlatform.useLLVM or false) ''
+        echo "-lunwind" >> $out/nix-support/cc-ldflags
+      '' + lib.optionalString stdenv.targetPlatform.isWasm ''
+        echo "-fno-exceptions" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands cc;
+    };
+
+    clangNoLibcxx = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintools';
+      extraPackages = [
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = ''
+        echo "-rtlib=compiler-rt" >> $out/nix-support/cc-cflags
+        echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
+        echo "-nostdlib++" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands cc;
+    };
+
+    clangNoLibc = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintoolsNoLibc';
+      extraPackages = [
+        targetLlvmLibraries.compiler-rt
+      ];
+      extraBuildCommands = ''
+        echo "-rtlib=compiler-rt" >> $out/nix-support/cc-cflags
+        echo "-B${targetLlvmLibraries.compiler-rt}/lib" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands cc;
+    };
+
+    clangNoCompilerRt = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintoolsNoLibc';
+      extraPackages = [ ];
+      extraBuildCommands = ''
+        echo "-nostartfiles" >> $out/nix-support/cc-cflags
+      '' + mkExtraBuildCommands0 cc;
+    };
+
+    clangNoCompilerRtWithLibc = wrapCCWith rec {
+      cc = tools.clang-unwrapped;
+      libcxx = null;
+      bintools = bintools';
+      extraPackages = [ ];
+      extraBuildCommands = mkExtraBuildCommands0 cc;
+    };
+
+  });
+
+  libraries = lib.makeExtensible (libraries: let
+    callPackage = newScope (libraries // buildLlvmTools // { inherit stdenv cmake libxml2 python3 isl release_version version src; });
+  in {
+
+    compiler-rt-libc = callPackage ./compiler-rt {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.clangNoCompilerRtWithLibc
+               else stdenv;
+    };
+
+    compiler-rt-no-libc = callPackage ./compiler-rt {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.clangNoCompilerRt
+               else stdenv;
+    };
+
+    # N.B. condition is safe because without useLLVM both are the same.
+    compiler-rt = if stdenv.hostPlatform.isAndroid
+      then libraries.compiler-rt-libc
+      else libraries.compiler-rt-no-libc;
+
+    stdenv = overrideCC stdenv buildLlvmTools.clang;
+
+    libcxxStdenv = overrideCC stdenv buildLlvmTools.libcxxClang;
+
+    libcxx = callPackage ./libcxx {
+      inherit llvm_meta;
+      stdenv = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.clangNoLibcxx
+               else (
+                 # libcxx >= 13 does not build on gcc9
+                 if stdenv.cc.isGNU && lib.versionOlder stdenv.cc.version "10"
+                 then pkgs.gcc10Stdenv
+                 else stdenv
+               );
+    };
+
+    libcxxabi = let
+      stdenv_ = if stdenv.hostPlatform.useLLVM or false
+               then overrideCC stdenv buildLlvmTools.clangNoLibcxx
+               else stdenv;
+      cxx-headers = callPackage ./libcxx {
+        inherit llvm_meta;
+        stdenv = stdenv_;
+        headersOnly = true;
+      };
+    in callPackage ./libcxxabi {
+      stdenv = stdenv_;
+      inherit llvm_meta cxx-headers;
+    };
+
+    libunwind = callPackage ./libunwind {
+      inherit llvm_meta;
+      stdenv = overrideCC stdenv buildLlvmTools.clangNoLibcxx;
+    };
+
+    openmp = callPackage ./openmp {
+      inherit llvm_meta targetLlvm;
+    };
+  });
+  noExtend = extensible: lib.attrsets.removeAttrs extensible [ "extend" ];
+
+in { inherit tools libraries release_version; } // (noExtend libraries) // (noExtend tools)
--- a/llvm/13/libcxx/default.nix
+++ b/llvm/13/libcxx/default.nix
@ -0,0 +1,92 @@
+{ lib, stdenv, llvm_meta, src, cmake, python3, fixDarwinDylibNames, version
+, cxxabi ? if stdenv.hostPlatform.isFreeBSD then libcxxrt else libcxxabi
+, libcxxabi, libcxxrt
+, enableShared ? !stdenv.hostPlatform.isStatic
+
+# If headersOnly is true, the resulting package would only include the headers.
+# Use this to break the circular dependency between libcxx and libcxxabi.
+#
+# Some context:
+# https://reviews.llvm.org/rG1687f2bbe2e2aaa092f942d4a97d41fad43eedfb
+, headersOnly ? false
+}:
+
+assert stdenv.isDarwin -> cxxabi.pname == "libcxxabi";
+
+stdenv.mkDerivation rec {
+  pname = if headersOnly then "cxx-headers" else "libcxx";
+  inherit version;
+
+  inherit src;
+  sourceRoot = "${src.name}/libcxx";
+
+  outputs = [ "out" ] ++ lib.optional (!headersOnly) "dev";
+
+  patches = [
+    ./gnu-install-dirs.patch
+  ] ++ lib.optionals stdenv.hostPlatform.isMusl [
+    ../../libcxx-0001-musl-hacks.patch
+  ];
+
+  preConfigure = lib.optionalString stdenv.hostPlatform.isMusl ''
+    patchShebangs utils/cat_files.py
+  '';
+
+  nativeBuildInputs = [ cmake python3 ]
+    ++ lib.optional stdenv.isDarwin fixDarwinDylibNames;
+
+  buildInputs = lib.optionals (!headersOnly) [ cxxabi ];
+
+  cmakeFlags = [ "-DLIBCXX_CXX_ABI=${cxxabi.pname}" ]
+    ++ lib.optional (stdenv.hostPlatform.isMusl || stdenv.hostPlatform.isWasi) "-DLIBCXX_HAS_MUSL_LIBC=1"
+    ++ lib.optional (stdenv.hostPlatform.useLLVM or false) "-DLIBCXX_USE_COMPILER_RT=ON"
+    ++ lib.optionals stdenv.hostPlatform.isWasm [
+      "-DLIBCXX_ENABLE_THREADS=OFF"
+      "-DLIBCXX_ENABLE_FILESYSTEM=OFF"
+      "-DLIBCXX_ENABLE_EXCEPTIONS=OFF"
+    ] ++ lib.optional (!enableShared) "-DLIBCXX_ENABLE_SHARED=OFF";
+
+  buildFlags = lib.optional headersOnly "generate-cxx-headers";
+  installTargets = lib.optional headersOnly "install-cxx-headers";
+
+  preInstall = lib.optionalString (stdenv.isDarwin && !headersOnly) ''
+    for file in lib/*.dylib; do
+      if [ -L "$file" ]; then continue; fi
+
+      baseName=$(basename $(${stdenv.cc.targetPrefix}otool -D $file | tail -n 1))
+      installName="$out/lib/$baseName"
+      abiName=$(echo "$baseName" | sed -e 's/libc++/libc++abi/')
+
+      for other in $(${stdenv.cc.targetPrefix}otool -L $file | awk '$1 ~ "/libc\\+\\+abi" { print $1 }'); do
+        ${stdenv.cc.targetPrefix}install_name_tool -change $other ${cxxabi}/lib/$abiName $file
+      done
+    done
+  '';
+
+  # At this point, cxxabi headers would be installed in the dev output, which
+  # prevents moveToOutput from doing its job later in the build process.
+  postInstall = lib.optionalString (!headersOnly) ''
+    mv "$dev/include/c++/v1/"* "$out/include/c++/v1/"
+    pushd "$dev"
+    rmdir -p include/c++/v1
+    popd
+  '';
+
+  passthru = {
+    isLLVM = true;
+    inherit cxxabi;
+  };
+
+  meta = llvm_meta // {
+    homepage = "https://libcxx.llvm.org/";
+    description = "C++ standard library";
+    longDescription = ''
+      libc++ is an implementation of the C++ standard library, targeting C++11,
+      C++14 and above.
+    '';
+
+    # "All of the code in libc++ is dual licensed under the MIT license and the
+    # UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}
--- a/llvm/13/libcxx/gnu-install-dirs.patch
+++ b/llvm/13/libcxx/gnu-install-dirs.patch
@ -0,0 +1,82 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index b1e25358d41a..7fe1f4d85401 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -26,6 +26,8 @@ set(LIBCXX_BINARY_INCLUDE_DIR "${LIBCXX_BINARY_DIR}/include/c++build")
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXX_STANDALONE_BUILD)
+   project(libcxx CXX C)
+ 
+  include(GNUInstallDirs)
+
+   set(PACKAGE_NAME libcxx)
+   set(PACKAGE_VERSION 13.0.0git)
+   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+@@ -412,7 +414,7 @@ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
+   set(LIBCXX_GENERATED_INCLUDE_DIR "${LLVM_BINARY_DIR}/include/c++/v1")
+   set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LLVM_BINARY_DIR}/include/${LLVM_DEFAULT_TARGET_TRIPLE}/c++/v1")
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
+       "Path where built libc++ libraries should be installed.")
+   set(LIBCXX_INSTALL_INCLUDE_DIR "include/c++/v1" CACHE PATH
+       "Path where target-agnostic libc++ headers should be installed.")
+@@ -426,7 +428,7 @@ elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+   set(LIBCXX_GENERATED_INCLUDE_DIR "${LLVM_BINARY_DIR}/include/c++/v1")
+   set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LIBCXX_GENERATED_INCLUDE_DIR}")
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX} CACHE PATH
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXX_LIBDIR_SUFFIX} CACHE PATH
+       "Path where built libc++ libraries should be installed.")
+   set(LIBCXX_INSTALL_INCLUDE_DIR "include/c++/v1" CACHE PATH
+       "Path where target-agnostic libc++ headers should be installed.")
+@@ -436,7 +438,7 @@ else()
+   set(LIBCXX_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
+   set(LIBCXX_GENERATED_INCLUDE_DIR "${CMAKE_BINARY_DIR}/include/c++/v1")
+   set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LIBCXX_GENERATED_INCLUDE_DIR}")
+-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX} CACHE PATH
+  set(LIBCXX_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXX_LIBDIR_SUFFIX} CACHE PATH
+       "Path where built libc++ libraries should be installed.")
+   set(LIBCXX_INSTALL_INCLUDE_DIR "include/c++/v1" CACHE PATH
+       "Path where target-agnostic libc++ headers should be installed.")
+diff --git a/cmake/Modules/HandleLibCXXABI.cmake b/cmake/Modules/HandleLibCXXABI.cmake
+index 5a8a4a270a1a..c06bae0001aa 100644
+--- a/cmake/Modules/HandleLibCXXABI.cmake
+++ b/cmake/Modules/HandleLibCXXABI.cmake
+@@ -63,7 +63,7 @@ macro(setup_abi_lib abidefines abishared abistatic abifiles abidirs)
+ 
+         if (LIBCXX_INSTALL_HEADERS)
+           install(FILES "${LIBCXX_BINARY_INCLUDE_DIR}/${fpath}"
+-            DESTINATION include/c++/v1/${dstdir}
+            DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/c++/v1/${dstdir}
+             COMPONENT cxx-headers
+             PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+             )
+diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
+index 496429f3841e..1a0c9c0a3159 100644
+--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
+@@ -376,21 +376,21 @@ if (LIBCXX_INSTALL_SHARED_LIBRARY)
+   install(TARGETS cxx_shared
+     ARCHIVE DESTINATION ${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+     LIBRARY DESTINATION ${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-    RUNTIME DESTINATION bin COMPONENT cxx)
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+ endif()
+ 
+ if (LIBCXX_INSTALL_STATIC_LIBRARY)
+   install(TARGETS cxx_static
+     ARCHIVE DESTINATION ${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+     LIBRARY DESTINATION ${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-    RUNTIME DESTINATION bin COMPONENT cxx)
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+ endif()
+ 
+ if(LIBCXX_INSTALL_EXPERIMENTAL_LIBRARY)
+   install(TARGETS cxx_experimental
+     LIBRARY DESTINATION ${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+     ARCHIVE DESTINATION ${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
+-    RUNTIME DESTINATION bin COMPONENT cxx)
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT cxx)
+ endif()
+ 
+ # NOTE: This install command must go after the cxx install command otherwise
--- a/llvm/13/libcxxabi/default.nix
+++ b/llvm/13/libcxxabi/default.nix
@ -0,0 +1,84 @@
+{ lib, stdenv, llvm_meta, cmake, python3, src, cxx-headers, libunwind, version
+, enableShared ? !stdenv.hostPlatform.isStatic
+, standalone ? stdenv.hostPlatform.useLLVM or false
+, withLibunwind ? !stdenv.isDarwin && !stdenv.hostPlatform.isWasm
+}:
+
+stdenv.mkDerivation rec {
+  pname = "libcxxabi";
+  inherit version;
+
+  inherit src;
+  sourceRoot = "${src.name}/${pname}";
+
+  outputs = [ "out" "dev" ];
+
+  postUnpack = lib.optionalString stdenv.isDarwin ''
+    export TRIPLE=x86_64-apple-darwin
+  '' + lib.optionalString stdenv.hostPlatform.isWasm ''
+    patch -p1 -d llvm -i ${../../common/libcxxabi/wasm.patch}
+  '';
+
+  patches = [
+    ./gnu-install-dirs.patch
+  ];
+
+  nativeBuildInputs = [ cmake python3 ];
+  buildInputs = lib.optional withLibunwind libunwind;
+
+  cmakeFlags = [
+    "-DLIBCXXABI_LIBCXX_INCLUDES=${cxx-headers}/include/c++/v1"
+  ] ++ lib.optionals standalone [
+    "-DLLVM_ENABLE_LIBCXX=ON"
+  ] ++ lib.optionals (standalone && withLibunwind) [
+    "-DLIBCXXABI_USE_LLVM_UNWINDER=ON"
+  ] ++ lib.optionals stdenv.hostPlatform.isWasm [
+    "-DLIBCXXABI_ENABLE_THREADS=OFF"
+    "-DLIBCXXABI_ENABLE_EXCEPTIONS=OFF"
+  ] ++ lib.optionals (!enableShared) [
+    "-DLIBCXXABI_ENABLE_SHARED=OFF"
+  ];
+
+  preInstall = lib.optionalString stdenv.isDarwin ''
+    for file in lib/*.dylib; do
+      if [ -L "$file" ]; then continue; fi
+
+      # Fix up the install name. Preserve the basename, just replace the path.
+      installName="$out/lib/$(basename $(${stdenv.cc.targetPrefix}otool -D $file | tail -n 1))"
+
+      # this should be done in CMake, but having trouble figuring out
+      # the magic combination of necessary CMake variables
+      # if you fancy a try, take a look at
+      # https://gitlab.kitware.com/cmake/community/-/wikis/doc/cmake/RPATH-handling
+      ${stdenv.cc.targetPrefix}install_name_tool -id $installName $file
+
+      # cc-wrapper passes '-lc++abi' to all c++ link steps, but that causes
+      # libcxxabi to sometimes link against a different version of itself.
+      # Here we simply make that second reference point to ourselves.
+      for other in $(${stdenv.cc.targetPrefix}otool -L $file | awk '$1 ~ "/libc\\+\\+abi" { print $1 }'); do
+        ${stdenv.cc.targetPrefix}install_name_tool -change $other $installName $file
+      done
+    done
+  '';
+
+  postInstall = ''
+    mkdir -p "$dev/include"
+    install -m 644 ../include/${if stdenv.isDarwin then "*" else "cxxabi.h"} "$dev/include"
+  '';
+
+  passthru = {
+    libName = "c++abi";
+  };
+
+  meta = llvm_meta // {
+    homepage = "https://libcxxabi.llvm.org/";
+    description = "Provides C++ standard library support";
+    longDescription = ''
+      libc++abi is a new implementation of low level support for a standard C++ library.
+    '';
+    # "All of the code in libc++abi is dual licensed under the MIT license and
+    # the UIUC License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+    maintainers = llvm_meta.maintainers ++ [ lib.maintainers.vlstill ];
+  };
+}
--- a/llvm/13/libcxxabi/gnu-install-dirs.patch
+++ b/llvm/13/libcxxabi/gnu-install-dirs.patch
@ -0,0 +1,37 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 9fb35860d483..5739d9e8af62 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -27,6 +27,8 @@ set(LIBCXXABI_LIBCXX_PATH "${CMAKE_CURRENT_LIST_DIR}/../libcxx" CACHE PATH
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBCXXABI_STANDALONE_BUILD)
+   project(libcxxabi CXX C)
+ 
+  include(GNUInstallDirs)
+
+   set(PACKAGE_NAME libcxxabi)
+   set(PACKAGE_VERSION 11.0.0git)
+   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+@@ -195,7 +197,7 @@ set(CMAKE_MODULE_PATH
+ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   set(LIBCXXABI_HEADER_DIR ${LLVM_BINARY_DIR})
+   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
+       "Path where built libc++abi libraries should be installed.")
+   if(LIBCXX_LIBDIR_SUBDIR)
+     string(APPEND LIBCXXABI_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
+@@ -204,12 +206,12 @@ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+ elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+   set(LIBCXXABI_HEADER_DIR ${LLVM_BINARY_DIR})
+   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX} CACHE PATH
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXXABI_LIBDIR_SUFFIX} CACHE PATH
+       "Path where built libc++abi libraries should be installed.")
+ else()
+   set(LIBCXXABI_HEADER_DIR ${CMAKE_BINARY_DIR})
+   set(LIBCXXABI_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXXABI_LIBDIR_SUFFIX})
+-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX} CACHE PATH
+  set(LIBCXXABI_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LIBCXXABI_LIBDIR_SUFFIX} CACHE PATH
+       "Path where built libc++abi libraries should be installed.")
+ endif()
+ 
--- a/llvm/13/libunwind/default.nix
+++ b/llvm/13/libunwind/default.nix
@ -0,0 +1,33 @@
+{ lib, stdenv, llvm_meta, version, src, cmake
+, enableShared ? !stdenv.hostPlatform.isStatic
+}:
+
+stdenv.mkDerivation rec {
+  pname = "libunwind";
+  inherit version;
+
+  inherit src;
+  sourceRoot = "${src.name}/${pname}";
+
+  patches = [
+    ./gnu-install-dirs.patch
+  ];
+
+  outputs = [ "out" "dev" ];
+
+  nativeBuildInputs = [ cmake ];
+
+  cmakeFlags = lib.optional (!enableShared) "-DLIBUNWIND_ENABLE_SHARED=OFF";
+
+  meta = llvm_meta // {
+    # Details: https://github.com/llvm/llvm-project/blob/main/libunwind/docs/index.rst
+    homepage = "https://clang.llvm.org/docs/Toolchain.html#unwind-library";
+    description = "LLVM's unwinder library";
+    longDescription = ''
+      The unwind library provides a family of _Unwind_* functions implementing
+      the language-neutral stack unwinding portion of the Itanium C++ ABI (Level
+      I). It is a dependency of the C++ ABI library, and sometimes is a
+      dependency of other runtimes.
+    '';
+  };
+}
--- a/llvm/13/libunwind/gnu-install-dirs.patch
+++ b/llvm/13/libunwind/gnu-install-dirs.patch
@ -0,0 +1,36 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 81eddbc24879..e2afb2002150 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -23,6 +23,8 @@ set(LIBUNWIND_LIBCXX_PATH "${CMAKE_CURRENT_LIST_DIR}/../libcxx" CACHE PATH
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBUNWIND_STANDALONE_BUILD)
+   project(libunwind LANGUAGES C CXX ASM)
+ 
+  include(GNUInstallDirs)
+
+   set(PACKAGE_NAME libunwind)
+   set(PACKAGE_VERSION 13.0.0git)
+   set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+@@ -116,7 +118,7 @@ set(CMAKE_MODULE_PATH
+ 
+ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
+-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
+       "Path where built libunwind libraries should be installed.")
+   if(LIBCXX_LIBDIR_SUBDIR)
+     string(APPEND LIBUNWIND_LIBRARY_DIR /${LIBUNWIND_LIBDIR_SUBDIR})
+@@ -124,11 +126,11 @@ if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+   endif()
+ elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+   set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
+-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LIBUNWIND_LIBDIR_SUFFIX} CACHE PATH
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} CACHE PATH
+       "Path where built libunwind libraries should be installed.")
+ else()
+   set(LIBUNWIND_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBUNWIND_LIBDIR_SUFFIX})
+-  set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LIBUNWIND_LIBDIR_SUFFIX} CACHE PATH
+  set(LIBUNWIND_INSTALL_LIBRARY_DIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} CACHE PATH
+       "Path where built libunwind libraries should be installed.")
+ endif()
+ 
--- a/llvm/13/lld/default.nix
+++ b/llvm/13/lld/default.nix
@ -0,0 +1,55 @@
+{ lib, stdenv, llvm_meta
+, buildLlvmTools
+, src
+, cmake
+, libxml2
+, libllvm
+, version
+}:
+
+stdenv.mkDerivation rec {
+  pname = "lld";
+  inherit version;
+
+  inherit src;
+  sourceRoot = "${src.name}/${pname}";
+
+  patches = [
+    ./gnu-install-dirs.patch
+  ];
+
+  # On Darwin the llvm-config is perhaps not working fine as the
+  # LLVM_MAIN_SRC_DIR is not getting set correctly, and the build fails as the
+  # include path is not correct.
+  postPatch = lib.optionalString stdenv.isDarwin ''
+    substituteInPlace MachO/CMakeLists.txt --replace \
+      '(''${LLVM_MAIN_SRC_DIR}/' '(../'
+  '';
+
+  nativeBuildInputs = [ cmake ];
+  buildInputs = [ libllvm libxml2 ];
+
+  cmakeFlags = [
+    "-DLLVM_CONFIG_PATH=${libllvm.dev}/bin/llvm-config${lib.optionalString (stdenv.hostPlatform != stdenv.buildPlatform) "-native"}"
+  ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+    "-DLLVM_TABLEGEN_EXE=${buildLlvmTools.llvm}/bin/llvm-tblgen"
+  ];
+
+  # Musl's default stack size is too small for lld to be able to link Firefox.
+  LDFLAGS = lib.optionalString stdenv.hostPlatform.isMusl "-Wl,-z,stack-size=2097152";
+
+  outputs = [ "out" "lib" "dev" ];
+
+  meta = llvm_meta // {
+    homepage = "https://lld.llvm.org/";
+    description = "The LLVM linker (unwrapped)";
+    longDescription = ''
+      LLD is a linker from the LLVM project that is a drop-in replacement for
+      system linkers and runs much faster than them. It also provides features
+      that are useful for toolchain developers.
+      The linker supports ELF (Unix), PE/COFF (Windows), Mach-O (macOS), and
+      WebAssembly in descending order of completeness. Internally, LLD consists
+      of several different linkers.
+    '';
+  };
+}
--- a/llvm/13/lld/gnu-install-dirs.patch
+++ b/llvm/13/lld/gnu-install-dirs.patch
@ -0,0 +1,68 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index d4e561b50d8f..cfa5bdd79c2a 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -6,6 +6,8 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+   set(CMAKE_INCLUDE_CURRENT_DIR ON)
+   set(LLD_BUILT_STANDALONE TRUE)
+ 
+  include(GNUInstallDirs)
+
+   find_program(LLVM_CONFIG_PATH "llvm-config" DOC "Path to llvm-config binary")
+   if(NOT LLVM_CONFIG_PATH)
+     message(FATAL_ERROR "llvm-config not found: specify LLVM_CONFIG_PATH")
+@@ -179,7 +181,7 @@ include_directories(BEFORE
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     )
+diff --git a/cmake/modules/AddLLD.cmake b/cmake/modules/AddLLD.cmake
+index 23df41312403..d62372c88de7 100644
+--- a/cmake/modules/AddLLD.cmake
+++ b/cmake/modules/AddLLD.cmake
+@@ -20,9 +20,9 @@ macro(add_lld_library name)
+     install(TARGETS ${name}
+       COMPONENT ${name}
+       ${export_to_lldtargets}
+-      LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-      ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-      RUNTIME DESTINATION bin)
+      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+ 
+     if (${ARG_SHARED} AND NOT CMAKE_CONFIGURATION_TYPES)
+       add_llvm_install_targets(install-${name}
+@@ -54,7 +54,7 @@ macro(add_lld_tool name)
+ 
+     install(TARGETS ${name}
+       ${export_to_lldtargets}
+-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+       COMPONENT ${name})
+ 
+     if(NOT CMAKE_CONFIGURATION_TYPES)
+@@ -69,5 +69,5 @@ endmacro()
+ macro(add_lld_symlink name dest)
+   add_llvm_tool_symlink(${name} ${dest} ALWAYS_GENERATE)
+   # Always generate install targets
+-  llvm_install_symlink(${name} ${dest} ALWAYS_GENERATE)
+  llvm_install_symlink(${name} ${dest} ${CMAKE_INSTALL_FULL_BINDIR} ALWAYS_GENERATE)
+ endmacro()
+diff --git a/tools/lld/CMakeLists.txt b/tools/lld/CMakeLists.txt
+index 5cff736ff57f..64e775c771b9 100644
+--- a/tools/lld/CMakeLists.txt
+++ b/tools/lld/CMakeLists.txt
+@@ -21,7 +21,7 @@ target_link_libraries(lld
+   )
+ 
+ install(TARGETS lld
+-  RUNTIME DESTINATION bin)
+  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+ 
+ if(NOT LLD_SYMLINKS_TO_CREATE)
+   set(LLD_SYMLINKS_TO_CREATE
--- a/llvm/13/lldb/cpu_subtype_arm64e_replacement.patch
+++ b/llvm/13/lldb/cpu_subtype_arm64e_replacement.patch
@ -0,0 +1,12 @@
+diff --git a/source/Host/macosx/objcxx/HostInfoMacOSX.mm b/source/Host/macosx/objcxx/HostInfoMacOSX.mm
+--- a/source/Host/macosx/objcxx/HostInfoMacOSX.mm
+++ b/source/Host/macosx/objcxx/HostInfoMacOSX.mm
+@@ -233,7 +233,7 @@ void HostInfoMacOSX::ComputeHostArchitectureSupport(ArchSpec &arch_32,
+     len = sizeof(is_64_bit_capable);
+     ::sysctlbyname("hw.cpu64bit_capable", &is_64_bit_capable, &len, NULL, 0);
+ 
+-    if (cputype == CPU_TYPE_ARM64 && cpusubtype == CPU_SUBTYPE_ARM64E) {
+    if (cputype == CPU_TYPE_ARM64 && cpusubtype == ((cpu_subtype_t) 2)) { // CPU_SUBTYPE_ARM64E is not available in the macOS 10.12 headers
+       // The arm64e architecture is a preview. Pretend the host architecture
+       // is arm64.
+       cpusubtype = CPU_SUBTYPE_ARM64_ALL;
--- a/llvm/13/lldb/gnu-install-dirs.patch
+++ b/llvm/13/lldb/gnu-install-dirs.patch
@ -0,0 +1,91 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index b5633e21c56a..f2f1035e9238 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -10,6 +10,8 @@ set(CMAKE_MODULE_PATH
+ # If we are not building as part of LLVM, build LLDB as a standalone project,
+ # using LLVM as an external library.
+ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+  include(GNUInstallDirs)
+
+   project(lldb)
+   include(LLDBStandalone)
+ 
+diff --git a/cmake/modules/AddLLDB.cmake b/cmake/modules/AddLLDB.cmake
+index 4ed5c647c5d2..89f96e710d55 100644
+--- a/cmake/modules/AddLLDB.cmake
+++ b/cmake/modules/AddLLDB.cmake
+@@ -107,13 +107,13 @@ function(add_lldb_library name)
+   endif()
+ 
+   if(PARAM_SHARED)
+-    set(install_dest lib${LLVM_LIBDIR_SUFFIX})
+    set(install_dest ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+     if(PARAM_INSTALL_PREFIX)
+       set(install_dest ${PARAM_INSTALL_PREFIX})
+     endif()
+     # RUNTIME is relevant for DLL platforms, FRAMEWORK for macOS
+     install(TARGETS ${name} COMPONENT ${name}
+-      RUNTIME DESTINATION bin
+      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+       LIBRARY DESTINATION ${install_dest}
+       ARCHIVE DESTINATION ${install_dest}
+       FRAMEWORK DESTINATION ${install_dest})
+diff --git a/cmake/modules/LLDBConfig.cmake b/cmake/modules/LLDBConfig.cmake
+index 2fdf1502d055..37364341ff8b 100644
+--- a/cmake/modules/LLDBConfig.cmake
+++ b/cmake/modules/LLDBConfig.cmake
+@@ -225,7 +225,7 @@ include_directories(BEFORE
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/
+     COMPONENT lldb-headers
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN ".cmake" EXCLUDE
+@@ -233,7 +233,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+ 
+   install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/
+     COMPONENT lldb-headers
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN ".cmake" EXCLUDE
+diff --git a/tools/intel-features/CMakeLists.txt b/tools/intel-features/CMakeLists.txt
+index 734167e51bc5..f95761b5df58 100644
+--- a/tools/intel-features/CMakeLists.txt
+++ b/tools/intel-features/CMakeLists.txt
+@@ -65,4 +65,4 @@ if (LLDB_ENABLE_PYTHON AND LLDB_BUILD_INTEL_PT)
+ endif()
+ 
+ install(TARGETS lldbIntelFeatures
+-  LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX})
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+diff --git a/cmake/modules/LLDBStandalone.cmake b/cmake/modules/LLDBStandalone.cmake
+index 752113b..010f187 100644
+--- a/cmake/modules/LLDBStandalone.cmake
+++ b/cmake/modules/LLDBStandalone.cmake
+@@ -62,7 +62,7 @@ endif()
+
+ # They are used as destination of target generators.
+ set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin)
+-set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
+set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+ if(WIN32 OR CYGWIN)
+   # DLL platform -- put DLLs into bin.
+   set(LLVM_SHLIB_OUTPUT_INTDIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index b5633e2..86e4738 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -79,7 +79,7 @@ if (LLDB_ENABLE_PYTHON)
+   if(LLDB_BUILD_FRAMEWORK)
+     set(lldb_python_target_dir "${LLDB_FRAMEWORK_ABSOLUTE_BUILD_DIR}/LLDB.framework/Resources/Python/lldb")
+   else()
+-    set(lldb_python_target_dir "${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/${LLDB_PYTHON_RELATIVE_PATH}/lldb")
+    set(lldb_python_target_dir "${CMAKE_INSTALL_LIBDIR}/../${LLDB_PYTHON_RELATIVE_PATH}/lldb")
+   endif()
+   get_target_property(lldb_python_bindings_dir swig_wrapper_python BINARY_DIR)
+   finish_swig_python("lldb-python" "${lldb_python_bindings_dir}" "${lldb_python_target_dir}")
--- a/llvm/13/lldb/procfs.patch
+++ b/llvm/13/lldb/procfs.patch
@ -0,0 +1,31 @@
+--- a/source/Plugins/Process/Linux/Procfs.h
+++ b/source/Plugins/Process/Linux/Procfs.h
+@@ -11,21 +11,12 @@
+ // sys/procfs.h on Android/Linux for all supported architectures.
+ 
+ #include <sys/ptrace.h>
+#include <asm/ptrace.h>
+ 
+-#ifdef __ANDROID__
+-#if defined(__arm64__) || defined(__aarch64__)
+-typedef unsigned long elf_greg_t;
+-typedef elf_greg_t
+-    elf_gregset_t[(sizeof(struct user_pt_regs) / sizeof(elf_greg_t))];
+-typedef struct user_fpsimd_state elf_fpregset_t;
+-#ifndef NT_FPREGSET
+-#define NT_FPREGSET NT_PRFPREG
+-#endif // NT_FPREGSET
+-#elif defined(__mips__)
+-#ifndef NT_FPREGSET
+-#define NT_FPREGSET NT_PRFPREG
+-#endif // NT_FPREGSET
+-#endif
+-#else // __ANDROID__
+#if !defined(__GLIBC__) && defined(__powerpc__)
+#define pt_regs musl_pt_regs
+#include <sys/procfs.h>
+#undef pt_regs
+#else
+ #include <sys/procfs.h>
+-#endif // __ANDROID__
+#endif
--- a/llvm/13/lldb/resource-dir.patch
+++ b/llvm/13/lldb/resource-dir.patch
@ -0,0 +1,13 @@
+diff --git a/lldb/cmake/modules/LLDBConfig.cmake b/lldb/cmake/modules/LLDBConfig.cmake
+index 37364341ff8b..7f74c1a3e257 100644
+--- a/cmake/modules/LLDBConfig.cmake
+++ b/cmake/modules/LLDBConfig.cmake
+@@ -257,7 +257,7 @@ if (NOT TARGET clang-resource-headers)
+   # Iterate over the possible places where the external resource directory
+   # could be and pick the first that exists.
+   foreach(CANDIDATE "${Clang_DIR}/../.." "${LLVM_DIR}" "${LLVM_LIBRARY_DIRS}"
+-                    "${LLVM_BUILD_LIBRARY_DIR}"
+                    "${LLVM_BUILD_LIBRARY_DIR}" "@clangLibDir@"
+                     "${LLVM_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX}")
+     # Build the resource directory path by appending 'clang/<version number>'.
+     set(CANDIDATE_RESOURCE_DIR "${CANDIDATE}/clang/${LLDB_CLANG_RESOURCE_DIR_NAME}")
--- a/llvm/13/llvm/default.nix
+++ b/llvm/13/llvm/default.nix
@ -0,0 +1,313 @@
+{ lib, stdenv, llvm_meta
+, pkgsBuildBuild
+, src
+, fetchpatch
+, cmake
+, python3
+, libffi
+, enableGoldPlugin ? libbfd.hasPluginAPI
+, libbfd
+, libpfm
+, libxml2
+, ncurses
+, version
+, release_version
+, zlib
+, which
+, buildLlvmTools
+, debugVersion ? false
+, doCheck ? stdenv.isLinux && (!stdenv.isx86_32) && (!stdenv.hostPlatform.isMusl)
+  && (stdenv.hostPlatform == stdenv.buildPlatform)
+, enableManpages ? false
+, enableSharedLibraries ? !stdenv.hostPlatform.isStatic
+# broken for Ampere eMAG 8180 (c2.large.arm on Packet) #56245
+# broken for the armv7l builder
+, enablePFM ? stdenv.isLinux && !stdenv.hostPlatform.isAarch
+, enablePolly ? false
+}:
+
+let
+  inherit (lib) optional optionals optionalString;
+
+  # Used when creating a version-suffixed symlink of libLLVM.dylib
+  shortVersion = with lib;
+    concatStringsSep "." (take 1 (splitString "." release_version));
+
+  # Ordinarily we would just the `doCheck` and `checkDeps` functionality
+  # `mkDerivation` gives us to manage our test dependencies (instead of breaking
+  # out `doCheck` as a package level attribute).
+  #
+  # Unfortunately `lit` does not forward `$PYTHONPATH` to children processes, in
+  # particular the children it uses to do feature detection.
+  #
+  # This means that python deps we add to `checkDeps` (which the python
+  # interpreter is made aware of via `$PYTHONPATH` – populated by the python
+  # setup hook) are not picked up by `lit` which causes it to skip tests.
+  #
+  # Adding `python3.withPackages (ps: [ ... ])` to `checkDeps` also doesn't work
+  # because this package is shadowed in `$PATH` by the regular `python3`
+  # package.
+  #
+  # So, we "manually" assemble one python derivation for the package to depend
+  # on, taking into account whether checks are enabled or not:
+  python = if doCheck then
+    let
+      checkDeps = ps: with ps; [ psutil ];
+    in python3.withPackages checkDeps
+  else python3;
+
+in stdenv.mkDerivation (rec {
+  pname = "llvm";
+  inherit version;
+
+  inherit src;
+  sourceRoot = "${src.name}/${pname}";
+
+  outputs = [ "out" "lib" "dev" "python" ];
+
+  nativeBuildInputs = [ cmake python ]
+    ++ optionals enableManpages [ python3.pkgs.sphinx python3.pkgs.recommonmark ];
+
+  buildInputs = [ libxml2 libffi ]
+    ++ optional enablePFM libpfm; # exegesis
+
+  propagatedBuildInputs = optionals (stdenv.hostPlatform == stdenv.buildPlatform) [ ncurses ]
+    ++ [ zlib ];
+
+  nativeCheckInputs = [ which ];
+
+  patches = [
+    # When cross-compiling we configure llvm-config-native with an approximation
+    # of the flags used for the normal LLVM build. To avoid the need for building
+    # a native libLLVM.so (which would fail) we force llvm-config to be linked
+    # statically against the necessary LLVM components always.
+    ../../llvm-config-link-static.patch
+
+    ./gnu-install-dirs.patch
+
+    # Fix random compiler crashes: https://bugs.llvm.org/show_bug.cgi?id=50611
+    (fetchpatch {
+      url = "https://raw.githubusercontent.com/archlinux/svntogit-packages/4764a4f8c920912a2bfd8b0eea57273acfe0d8a8/trunk/no-strict-aliasing-DwarfCompileUnit.patch";
+      sha256 = "18l6mrvm2vmwm77ckcnbjvh6ybvn72rhrb799d4qzwac4x2ifl7g";
+      stripLen = 1;
+    })
+
+    # Fix musl build.
+    (fetchpatch {
+      url = "https://github.com/llvm/llvm-project/commit/5cd554303ead0f8891eee3cd6d25cb07f5a7bf67.patch";
+      relative = "llvm";
+      hash = "sha256-XPbvNJ45SzjMGlNUgt/IgEvM2dHQpDOe6woUJY+nUYA=";
+    })
+
+    # Backport gcc-13 fixes with missing includes.
+    (fetchpatch {
+      name = "signals-gcc-13.patch";
+      url = "https://github.com/llvm/llvm-project/commit/ff1681ddb303223973653f7f5f3f3435b48a1983.patch";
+      hash = "sha256-CXwYxQezTq5vdmc8Yn88BUAEly6YZ5VEIA6X3y5NNOs=";
+      stripLen = 1;
+    })
+    (fetchpatch {
+      name = "base64-gcc-13.patch";
+      url = "https://github.com/llvm/llvm-project/commit/5e9be93566f39ee6cecd579401e453eccfbe81e5.patch";
+      hash = "sha256-PAwrVrvffPd7tphpwCkYiz+67szPRzRB2TXBvKfzQ7U=";
+      stripLen = 1;
+    })
+  ] ++ lib.optional enablePolly ./gnu-install-dirs-polly.patch;
+
+  postPatch = optionalString stdenv.isDarwin ''
+    substituteInPlace cmake/modules/AddLLVM.cmake \
+      --replace 'set(_install_name_dir INSTALL_NAME_DIR "@rpath")' "set(_install_name_dir)" \
+      --replace 'set(_install_rpath "@loader_path/../''${CMAKE_INSTALL_LIBDIR}''${LLVM_LIBDIR_SUFFIX}" ''${extra_libdir})' ""
+  '' + ''
+    # FileSystem permissions tests fail with various special bits
+    substituteInPlace unittests/Support/CMakeLists.txt \
+      --replace "Path.cpp" ""
+    rm unittests/Support/Path.cpp
+    substituteInPlace unittests/IR/CMakeLists.txt \
+      --replace "PassBuilderCallbacksTest.cpp" ""
+    rm unittests/IR/PassBuilderCallbacksTest.cpp
+    rm test/tools/llvm-objcopy/ELF/mirror-permissions-unix.test
+  '' + optionalString stdenv.hostPlatform.isMusl ''
+    patch -p1 -i ${../../TLI-musl.patch}
+    substituteInPlace unittests/Support/CMakeLists.txt \
+      --replace "add_subdirectory(DynamicLibrary)" ""
+    rm unittests/Support/DynamicLibrary/DynamicLibraryTest.cpp
+    # valgrind unhappy with musl or glibc, but fails w/musl only
+    rm test/CodeGen/AArch64/wineh4.mir
+  '' + optionalString stdenv.hostPlatform.isAarch32 ''
+    # skip failing X86 test cases on 32-bit ARM
+    rm test/DebugInfo/X86/convert-debugloc.ll
+    rm test/DebugInfo/X86/convert-inlined.ll
+    rm test/DebugInfo/X86/convert-linked.ll
+    rm test/tools/dsymutil/X86/op-convert.test
+    rm test/tools/gold/X86/split-dwarf.ll
+  '' + optionalString (stdenv.hostPlatform.system == "armv6l-linux") ''
+    # Seems to require certain floating point hardware (NEON?)
+    rm test/ExecutionEngine/frem.ll
+  '' + ''
+    patchShebangs test/BugPoint/compile-custom.ll.py
+  '';
+
+  preConfigure = ''
+    # Workaround for configure flags that need to have spaces
+    cmakeFlagsArray+=(
+      -DLLVM_LIT_ARGS='-svj''${NIX_BUILD_CORES} --no-progress-bar'
+    )
+  '';
+
+  # hacky fix: created binaries need to be run before installation
+  preBuild = ''
+    mkdir -p $out/
+    ln -sv $PWD/lib $out
+  '';
+
+  # E.g. mesa.drivers use the build-id as a cache key (see #93946):
+  LDFLAGS = optionalString (enableSharedLibraries && !stdenv.isDarwin) "-Wl,--build-id=sha1";
+
+  cmakeBuildType = if debugVersion then "Debug" else "Release";
+
+  cmakeFlags = with stdenv; let
+    # These flags influence llvm-config's BuildVariables.inc in addition to the
+    # general build. We need to make sure these are also passed via
+    # CROSS_TOOLCHAIN_FLAGS_NATIVE when cross-compiling or llvm-config-native
+    # will return different results from the cross llvm-config.
+    #
+    # Some flags don't need to be repassed because LLVM already does so (like
+    # CMAKE_BUILD_TYPE), others are irrelevant to the result.
+    flagsForLlvmConfig = [
+      "-DLLVM_INSTALL_CMAKE_DIR=${placeholder "dev"}/lib/cmake/llvm/"
+      "-DLLVM_ENABLE_RTTI=ON"
+    ] ++ optionals enableSharedLibraries [
+      "-DLLVM_LINK_LLVM_DYLIB=ON"
+    ];
+  in flagsForLlvmConfig ++ [
+    "-DLLVM_INSTALL_UTILS=ON"  # Needed by rustc
+    "-DLLVM_BUILD_TESTS=${if doCheck then "ON" else "OFF"}"
+    "-DLLVM_ENABLE_FFI=ON"
+    "-DLLVM_HOST_TRIPLE=${stdenv.hostPlatform.config}"
+    "-DLLVM_DEFAULT_TARGET_TRIPLE=${stdenv.hostPlatform.config}"
+    "-DLLVM_ENABLE_DUMP=ON"
+  ] ++ optionals stdenv.hostPlatform.isStatic [
+    # Disables building of shared libs, -fPIC is still injected by cc-wrapper
+    "-DLLVM_ENABLE_PIC=OFF"
+    "-DLLVM_BUILD_STATIC=ON"
+    # libxml2 needs to be disabled because the LLVM build system ignores its .la
+    # file and doesn't link zlib as well.
+    # https://github.com/ClangBuiltLinux/tc-build/issues/150#issuecomment-845418812
+    "-DLLVM_ENABLE_LIBXML2=OFF"
+  ] ++ optionals enableManpages [
+    "-DLLVM_BUILD_DOCS=ON"
+    "-DLLVM_ENABLE_SPHINX=ON"
+    "-DSPHINX_OUTPUT_MAN=ON"
+    "-DSPHINX_OUTPUT_HTML=OFF"
+    "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
+  ] ++ optionals (enableGoldPlugin) [
+    "-DLLVM_BINUTILS_INCDIR=${libbfd.dev}/include"
+  ] ++ optionals isDarwin [
+    "-DLLVM_ENABLE_LIBCXX=ON"
+    "-DCAN_TARGET_i386=false"
+  ] ++ optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+    "-DCMAKE_CROSSCOMPILING=True"
+    "-DLLVM_TABLEGEN=${buildLlvmTools.llvm}/bin/llvm-tblgen"
+    (
+      let
+        nativeCC = pkgsBuildBuild.targetPackages.stdenv.cc;
+        nativeBintools = nativeCC.bintools.bintools;
+        nativeToolchainFlags = [
+          "-DCMAKE_C_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}cc"
+          "-DCMAKE_CXX_COMPILER=${nativeCC}/bin/${nativeCC.targetPrefix}c++"
+          "-DCMAKE_AR=${nativeBintools}/bin/${nativeBintools.targetPrefix}ar"
+          "-DCMAKE_STRIP=${nativeBintools}/bin/${nativeBintools.targetPrefix}strip"
+          "-DCMAKE_RANLIB=${nativeBintools}/bin/${nativeBintools.targetPrefix}ranlib"
+        ];
+        # We need to repass the custom GNUInstallDirs values, otherwise CMake
+        # will choose them for us, leading to wrong results in llvm-config-native
+        nativeInstallFlags = [
+          "-DCMAKE_INSTALL_PREFIX=${placeholder "out"}"
+          "-DCMAKE_INSTALL_BINDIR=${placeholder "out"}/bin"
+          "-DCMAKE_INSTALL_INCLUDEDIR=${placeholder "dev"}/include"
+          "-DCMAKE_INSTALL_LIBDIR=${placeholder "lib"}/lib"
+          "-DCMAKE_INSTALL_LIBEXECDIR=${placeholder "lib"}/libexec"
+        ];
+      in "-DCROSS_TOOLCHAIN_FLAGS_NATIVE:list="
+      + lib.concatStringsSep ";" (lib.concatLists [
+        flagsForLlvmConfig
+        nativeToolchainFlags
+        nativeInstallFlags
+      ])
+    )
+  ];
+
+  postBuild = ''
+    rm -fR $out
+  '';
+
+  preCheck = ''
+    export LD_LIBRARY_PATH=$LD_LIBRARY_PATH''${LD_LIBRARY_PATH:+:}$PWD/lib
+  '';
+
+  postInstall = ''
+    mkdir -p $python/share
+    mv $out/share/opt-viewer $python/share/opt-viewer
+    moveToOutput "bin/llvm-config*" "$dev"
+    substituteInPlace "$dev/lib/cmake/llvm/LLVMExports-${if debugVersion then "debug" else "release"}.cmake" \
+      --replace "\''${_IMPORT_PREFIX}/lib/lib" "$lib/lib/lib" \
+      --replace "$out/bin/llvm-config" "$dev/bin/llvm-config"
+    substituteInPlace "$dev/lib/cmake/llvm/LLVMConfig.cmake" \
+      --replace 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}")' 'set(LLVM_BINARY_DIR "''${LLVM_INSTALL_PREFIX}'"$lib"'")'
+  ''
+  + optionalString (stdenv.isDarwin && enableSharedLibraries) ''
+    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${shortVersion}.dylib
+    ln -s $lib/lib/libLLVM.dylib $lib/lib/libLLVM-${release_version}.dylib
+  ''
+  + optionalString (stdenv.buildPlatform != stdenv.hostPlatform) ''
+    cp NATIVE/bin/llvm-config $dev/bin/llvm-config-native
+  '';
+
+  inherit doCheck;
+
+  checkTarget = "check-all";
+
+  requiredSystemFeatures = [ "big-parallel" ];
+  meta = llvm_meta // {
+    homepage = "https://llvm.org/";
+    description = "A collection of modular and reusable compiler and toolchain technologies";
+    longDescription = ''
+      The LLVM Project is a collection of modular and reusable compiler and
+      toolchain technologies. Despite its name, LLVM has little to do with
+      traditional virtual machines. The name "LLVM" itself is not an acronym; it
+      is the full name of the project.
+      LLVM began as a research project at the University of Illinois, with the
+      goal of providing a modern, SSA-based compilation strategy capable of
+      supporting both static and dynamic compilation of arbitrary programming
+      languages. Since then, LLVM has grown to be an umbrella project consisting
+      of a number of subprojects, many of which are being used in production by
+      a wide variety of commercial and open source projects as well as being
+      widely used in academic research. Code in the LLVM project is licensed
+      under the "Apache 2.0 License with LLVM exceptions".
+    '';
+  };
+} // lib.optionalAttrs enableManpages {
+  pname = "llvm-manpages";
+
+  buildPhase = ''
+    make docs-llvm-man
+  '';
+
+  propagatedBuildInputs = [];
+
+  installPhase = ''
+    make -C docs install
+  '';
+
+  postPatch = null;
+  postInstall = null;
+
+  outputs = [ "out" ];
+
+  doCheck = false;
+
+  meta = llvm_meta // {
+    description = "man pages for LLVM ${version}";
+  };
+})
--- a/llvm/13/llvm/gnu-install-dirs-polly.patch
+++ b/llvm/13/llvm/gnu-install-dirs-polly.patch
@ -0,0 +1,105 @@
+diff --git a/tools/polly/CMakeLists.txt b/tools/polly/CMakeLists.txt
+index ca7c04c565bb..6ed5db5dd4f8 100644
+--- a/tools/polly/CMakeLists.txt
+++ b/tools/polly/CMakeLists.txt
+@@ -2,7 +2,11 @@
+ if (NOT DEFINED LLVM_MAIN_SRC_DIR)
+   project(Polly)
+   cmake_minimum_required(VERSION 3.13.4)
+endif()
+
+include(GNUInstallDirs)
+ 
+if (NOT DEFINED LLVM_MAIN_SRC_DIR)
+   # Where is LLVM installed?
+   find_package(LLVM CONFIG REQUIRED)
+   set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${LLVM_CMAKE_DIR})
+@@ -122,13 +126,13 @@ include_directories(
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     )
+ 
+   install(DIRECTORY ${POLLY_BINARY_DIR}/include/
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     FILES_MATCHING
+     PATTERN "*.h"
+     PATTERN "CMakeFiles" EXCLUDE
+diff --git a/tools/polly/cmake/CMakeLists.txt b/tools/polly/cmake/CMakeLists.txt
+index 7cc129ba2e90..137be25e4b80 100644
+--- a/tools/polly/cmake/CMakeLists.txt
+++ b/tools/polly/cmake/CMakeLists.txt
+@@ -79,18 +79,18 @@ file(GENERATE
+ 
+ # Generate PollyConfig.cmake for the install tree.
+ unset(POLLY_EXPORTS)
+-set(POLLY_INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX}")
+set(POLLY_INSTALL_PREFIX "")
+ set(POLLY_CONFIG_LLVM_CMAKE_DIR "${LLVM_BINARY_DIR}/${LLVM_INSTALL_PACKAGE_DIR}")
+-set(POLLY_CONFIG_CMAKE_DIR "${POLLY_INSTALL_PREFIX}/${POLLY_INSTALL_PACKAGE_DIR}")
+-set(POLLY_CONFIG_LIBRARY_DIRS "${POLLY_INSTALL_PREFIX}/lib${LLVM_LIBDIR_SUFFIX}")
+set(POLLY_CONFIG_CMAKE_DIR "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_PREFIX}/${POLLY_INSTALL_PACKAGE_DIR}")
+set(POLLY_CONFIG_LIBRARY_DIRS "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
+ if (POLLY_BUNDLED_ISL)
+   set(POLLY_CONFIG_INCLUDE_DIRS
+-    "${POLLY_INSTALL_PREFIX}/include"
+-    "${POLLY_INSTALL_PREFIX}/include/polly"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_LIBDIR}/polly"
+     )
+ else()
+   set(POLLY_CONFIG_INCLUDE_DIRS
+-    "${POLLY_INSTALL_PREFIX}/include"
+    "${POLLY_INSTALL_PREFIX}${CMAKE_INSTALL_FULL_INCLUDEDIR}"
+     ${ISL_INCLUDE_DIRS}
+     )
+ endif()
+@@ -100,12 +100,12 @@ endif()
+ foreach(tgt IN LISTS POLLY_CONFIG_EXPORTED_TARGETS)
+   get_target_property(tgt_type ${tgt} TYPE)
+   if (tgt_type STREQUAL "EXECUTABLE")
+-    set(tgt_prefix "bin/")
+    set(tgt_prefix "${CMAKE_INSTALL_BINDIR}/")
+   else()
+-    set(tgt_prefix "lib/")
+    set(tgt_prefix "${CMAKE_INSTALL_LIBDIR}/")
+   endif()
+ 
+-  set(tgt_path "${CMAKE_INSTALL_PREFIX}/${tgt_prefix}$<TARGET_FILE_NAME:${tgt}>")
+  set(tgt_path "${tgt_prefix}$<TARGET_FILE_NAME:${tgt}>")
+   file(RELATIVE_PATH tgt_path ${POLLY_CONFIG_CMAKE_DIR} ${tgt_path})
+ 
+   if (NOT tgt_type STREQUAL "INTERFACE_LIBRARY")
+diff --git a/tools/polly/cmake/polly_macros.cmake b/tools/polly/cmake/polly_macros.cmake
+index 518a09b45a42..bd9d6f5542ad 100644
+--- a/tools/polly/cmake/polly_macros.cmake
+++ b/tools/polly/cmake/polly_macros.cmake
+@@ -44,8 +44,8 @@ macro(add_polly_library name)
+   if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY OR ${name} STREQUAL "LLVMPolly")
+     install(TARGETS ${name}
+       EXPORT LLVMExports
+-      LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-      ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX})
+	  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+   endif()
+   set_property(GLOBAL APPEND PROPERTY LLVM_EXPORTS ${name})
+ endmacro(add_polly_library)
+diff --git a/tools/polly/lib/External/CMakeLists.txt b/tools/polly/lib/External/CMakeLists.txt
+index 8991094d92c7..178d8ad606bb 100644
+--- a/tools/polly/lib/External/CMakeLists.txt
+++ b/tools/polly/lib/External/CMakeLists.txt
+@@ -275,7 +275,7 @@ if (POLLY_BUNDLED_ISL)
+     install(DIRECTORY
+       ${ISL_SOURCE_DIR}/include/
+       ${ISL_BINARY_DIR}/include/
+-      DESTINATION include/polly
+      DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/polly
+       FILES_MATCHING
+       PATTERN "*.h"
+       PATTERN "CMakeFiles" EXCLUDE
--- a/llvm/13/llvm/gnu-install-dirs.patch
+++ b/llvm/13/llvm/gnu-install-dirs.patch
@ -0,0 +1,381 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 135036f509d2..265c36f8211b 100644
+--- a/CMakeLists.txt
+++ b/CMakeLists.txt
+@@ -270,15 +270,21 @@ if (CMAKE_BUILD_TYPE AND
+   message(FATAL_ERROR "Invalid value for CMAKE_BUILD_TYPE: ${CMAKE_BUILD_TYPE}")
+ endif()
+ 
+include(GNUInstallDirs)
+
+ set(LLVM_LIBDIR_SUFFIX "" CACHE STRING "Define suffix of library directory name (32/64)" )
+ 
+-set(LLVM_TOOLS_INSTALL_DIR "bin" CACHE STRING "Path for binary subdirectory (defaults to 'bin')")
+set(LLVM_TOOLS_INSTALL_DIR "${CMAKE_INSTALL_BINDIR}" CACHE STRING
+    "Path for binary subdirectory (defaults to 'bin')")
+ mark_as_advanced(LLVM_TOOLS_INSTALL_DIR)
+ 
+ set(LLVM_UTILS_INSTALL_DIR "${LLVM_TOOLS_INSTALL_DIR}" CACHE STRING
+     "Path to install LLVM utilities (enabled by LLVM_INSTALL_UTILS=ON) (defaults to LLVM_TOOLS_INSTALL_DIR)")
+ mark_as_advanced(LLVM_UTILS_INSTALL_DIR)
+ 
+set(LLVM_INSTALL_CMAKE_DIR "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/cmake/llvm" CACHE STRING
+	"Path for CMake subdirectory (defaults to lib/cmake/llvm)" )
+
+ # They are used as destination of target generators.
+ set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin)
+ set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
+@@ -581,9 +587,9 @@ option (LLVM_ENABLE_SPHINX "Use Sphinx to generate llvm documentation." OFF)
+ option (LLVM_ENABLE_OCAMLDOC "Build OCaml bindings documentation." ON)
+ option (LLVM_ENABLE_BINDINGS "Build bindings." ON)
+ 
+-set(LLVM_INSTALL_DOXYGEN_HTML_DIR "share/doc/llvm/doxygen-html"
+set(LLVM_INSTALL_DOXYGEN_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/doxygen-html"
+     CACHE STRING "Doxygen-generated HTML documentation install directory")
+-set(LLVM_INSTALL_OCAMLDOC_HTML_DIR "share/doc/llvm/ocaml-html"
+set(LLVM_INSTALL_OCAMLDOC_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/ocaml-html"
+     CACHE STRING "OCamldoc-generated HTML documentation install directory")
+ 
+ option (LLVM_BUILD_EXTERNAL_COMPILER_RT
+@@ -1048,7 +1054,7 @@ endif()
+ 
+ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+   install(DIRECTORY include/llvm include/llvm-c
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT llvm-headers
+     FILES_MATCHING
+     PATTERN "*.def"
+@@ -1059,7 +1065,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+     )
+ 
+   install(DIRECTORY ${LLVM_INCLUDE_DIR}/llvm ${LLVM_INCLUDE_DIR}/llvm-c
+-    DESTINATION include
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+     COMPONENT llvm-headers
+     FILES_MATCHING
+     PATTERN "*.def"
+@@ -1073,13 +1079,13 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+ 
+   if (LLVM_INSTALL_MODULEMAPS)
+     install(DIRECTORY include/llvm include/llvm-c
+-            DESTINATION include
+            DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+             COMPONENT llvm-headers
+             FILES_MATCHING
+             PATTERN "module.modulemap"
+             )
+     install(FILES include/llvm/module.install.modulemap
+-            DESTINATION include/llvm
+            DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm
+             COMPONENT llvm-headers
+             RENAME "module.extern.modulemap"
+             )
+diff --git a/cmake/modules/AddLLVM.cmake b/cmake/modules/AddLLVM.cmake
+index 9c2b85374307..5531ceeb2eeb 100644
+--- a/cmake/modules/AddLLVM.cmake
+++ b/cmake/modules/AddLLVM.cmake
+@@ -818,9 +818,9 @@ macro(add_llvm_library name)
+       get_target_export_arg(${name} LLVM export_to_llvmexports ${umbrella})
+       install(TARGETS ${name}
+               ${export_to_llvmexports}
+-              LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+-              ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+-              RUNTIME DESTINATION bin COMPONENT ${name})
+              LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+              ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+              RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT ${name})
+ 
+       if (NOT LLVM_ENABLE_IDE)
+         add_llvm_install_targets(install-${name}
+@@ -1036,7 +1036,7 @@ function(process_llvm_pass_plugins)
+           "set(LLVM_STATIC_EXTENSIONS ${LLVM_STATIC_EXTENSIONS})")
+       install(FILES
+           ${llvm_cmake_builddir}/LLVMConfigExtensions.cmake
+-          DESTINATION ${LLVM_INSTALL_PACKAGE_DIR}
+          DESTINATION ${LLVM_INSTALL_CMAKE_DIR}
+           COMPONENT cmake-exports)
+ 
+       set(ExtensionDef "${LLVM_BINARY_DIR}/include/llvm/Support/Extension.def")
+@@ -1250,7 +1250,7 @@ macro(add_llvm_example name)
+   endif()
+   add_llvm_executable(${name} ${ARGN})
+   if( LLVM_BUILD_EXAMPLES )
+-    install(TARGETS ${name} RUNTIME DESTINATION examples)
+    install(TARGETS ${name} RUNTIME DESTINATION ${CMAKE_INSTALL_DOCDIR}/examples)
+   endif()
+   set_target_properties(${name} PROPERTIES FOLDER "Examples")
+ endmacro(add_llvm_example name)
+@@ -1868,7 +1868,7 @@ function(llvm_install_library_symlink name dest type)
+   set(full_name ${CMAKE_${type}_LIBRARY_PREFIX}${name}${CMAKE_${type}_LIBRARY_SUFFIX})
+   set(full_dest ${CMAKE_${type}_LIBRARY_PREFIX}${dest}${CMAKE_${type}_LIBRARY_SUFFIX})
+ 
+-  set(output_dir lib${LLVM_LIBDIR_SUFFIX})
+  set(output_dir ${CMAKE_INSTALL_FULL_LIBDIR}${LLVM_LIBDIR_SUFFIX})
+   if(WIN32 AND "${type}" STREQUAL "SHARED")
+     set(output_dir bin)
+   endif()
+@@ -1879,7 +1879,7 @@ function(llvm_install_library_symlink name dest type)
+ 
+ endfunction()
+ 
+-function(llvm_install_symlink name dest)
+function(llvm_install_symlink name dest output_dir)
+   cmake_parse_arguments(ARG "ALWAYS_GENERATE" "COMPONENT" "" ${ARGN})
+   foreach(path ${CMAKE_MODULE_PATH})
+     if(EXISTS ${path}/LLVMInstallSymlink.cmake)
+@@ -1902,7 +1902,7 @@ function(llvm_install_symlink name dest)
+   set(full_dest ${dest}${CMAKE_EXECUTABLE_SUFFIX})
+ 
+   install(SCRIPT ${INSTALL_SYMLINK}
+-          CODE "install_symlink(${full_name} ${full_dest} ${LLVM_TOOLS_INSTALL_DIR})"
+          CODE "install_symlink(${full_name} ${full_dest} ${output_dir})"
+           COMPONENT ${component})
+ 
+   if (NOT LLVM_ENABLE_IDE AND NOT ARG_ALWAYS_GENERATE)
+@@ -1985,7 +1985,8 @@ function(add_llvm_tool_symlink link_name target)
+     endif()
+ 
+     if ((TOOL_IS_TOOLCHAIN OR NOT LLVM_INSTALL_TOOLCHAIN_ONLY) AND LLVM_BUILD_TOOLS)
+-      llvm_install_symlink(${link_name} ${target})
+      GNUInstallDirs_get_absolute_install_dir(output_dir LLVM_TOOLS_INSTALL_DIR)
+      llvm_install_symlink(${link_name} ${target} ${output_dir})
+     endif()
+   endif()
+ endfunction()
+@@ -2114,9 +2115,9 @@ function(llvm_setup_rpath name)
+     # Since BUILD_SHARED_LIBS is only recommended for use by developers,
+     # hardcode the rpath to build/install lib dir first in this mode.
+     # FIXME: update this when there is better solution.
+-    set(_install_rpath "${LLVM_LIBRARY_OUTPUT_INTDIR}" "${CMAKE_INSTALL_PREFIX}/lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+    set(_install_rpath "${LLVM_LIBRARY_OUTPUT_INTDIR}" "${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+   elseif(UNIX)
+-    set(_install_rpath "\$ORIGIN/../lib${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+    set(_install_rpath "\$ORIGIN/../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" ${extra_libdir})
+     if(${CMAKE_SYSTEM_NAME} MATCHES "(FreeBSD|DragonFly)")
+       set_property(TARGET ${name} APPEND_STRING PROPERTY
+                    LINK_FLAGS " -Wl,-z,origin ")
+diff --git a/cmake/modules/AddOCaml.cmake b/cmake/modules/AddOCaml.cmake
+index 554046b20edf..4d1ad980641e 100644
+--- a/cmake/modules/AddOCaml.cmake
+++ b/cmake/modules/AddOCaml.cmake
+@@ -144,9 +144,9 @@ function(add_ocaml_library name)
+   endforeach()
+ 
+   if( APPLE )
+-    set(ocaml_rpath "@executable_path/../../../lib${LLVM_LIBDIR_SUFFIX}")
+    set(ocaml_rpath "@executable_path/../../../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
+   elseif( UNIX )
+-    set(ocaml_rpath "\\$ORIGIN/../../../lib${LLVM_LIBDIR_SUFFIX}")
+    set(ocaml_rpath "\\$ORIGIN/../../../${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}")
+   endif()
+   list(APPEND ocaml_flags "-ldopt" "-Wl,-rpath,${ocaml_rpath}")
+ 
+diff --git a/cmake/modules/AddSphinxTarget.cmake b/cmake/modules/AddSphinxTarget.cmake
+index e80c3b5c1cac..482f6d715ef5 100644
+--- a/cmake/modules/AddSphinxTarget.cmake
+++ b/cmake/modules/AddSphinxTarget.cmake
+@@ -90,7 +90,7 @@ function (add_sphinx_target builder project)
+         endif()
+       elseif (builder STREQUAL html)
+         string(TOUPPER "${project}" project_upper)
+-        set(${project_upper}_INSTALL_SPHINX_HTML_DIR "share/doc/${project}/html"
+        set(${project_upper}_INSTALL_SPHINX_HTML_DIR "${CMAKE_INSTALL_DOCDIR}/${project}/html"
+             CACHE STRING "HTML documentation install directory for ${project}")
+ 
+         # '/.' indicates: copy the contents of the directory directly into
+diff --git a/cmake/modules/CMakeLists.txt b/cmake/modules/CMakeLists.txt
+index 51b6a4fdc284..4adc2acfc074 100644
+--- a/cmake/modules/CMakeLists.txt
+++ b/cmake/modules/CMakeLists.txt
+@@ -1,6 +1,6 @@
+ include(LLVMDistributionSupport)
+ 
+-set(LLVM_INSTALL_PACKAGE_DIR lib${LLVM_LIBDIR_SUFFIX}/cmake/llvm)
+set(LLVM_INSTALL_PACKAGE_DIR ${LLVM_INSTALL_CMAKE_DIR} CACHE STRING "Path for CMake subdirectory (defaults to 'cmake/llvm')")
+ set(llvm_cmake_builddir "${LLVM_BINARY_DIR}/${LLVM_INSTALL_PACKAGE_DIR}")
+ 
+ # First for users who use an installed LLVM, create the LLVMExports.cmake file.
+@@ -109,13 +109,13 @@ foreach(p ${_count})
+   set(LLVM_CONFIG_CODE "${LLVM_CONFIG_CODE}
+ get_filename_component(LLVM_INSTALL_PREFIX \"\${LLVM_INSTALL_PREFIX}\" PATH)")
+ endforeach(p)
+-set(LLVM_CONFIG_INCLUDE_DIRS "\${LLVM_INSTALL_PREFIX}/include")
+set(LLVM_CONFIG_INCLUDE_DIRS "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_INCLUDEDIR}")
+ set(LLVM_CONFIG_INCLUDE_DIR "${LLVM_CONFIG_INCLUDE_DIRS}")
+ set(LLVM_CONFIG_MAIN_INCLUDE_DIR "${LLVM_CONFIG_INCLUDE_DIRS}")
+-set(LLVM_CONFIG_LIBRARY_DIRS "\${LLVM_INSTALL_PREFIX}/lib\${LLVM_LIBDIR_SUFFIX}")
+set(LLVM_CONFIG_LIBRARY_DIRS "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}\${LLVM_LIBDIR_SUFFIX}")
+ set(LLVM_CONFIG_CMAKE_DIR "\${LLVM_INSTALL_PREFIX}/${LLVM_INSTALL_PACKAGE_DIR}")
+ set(LLVM_CONFIG_BINARY_DIR "\${LLVM_INSTALL_PREFIX}")
+-set(LLVM_CONFIG_TOOLS_BINARY_DIR "\${LLVM_INSTALL_PREFIX}/bin")
+set(LLVM_CONFIG_TOOLS_BINARY_DIR "\${LLVM_INSTALL_PREFIX}/${CMAKE_INSTALL_BINDIR}")
+ 
+ # Generate a default location for lit
+ if (LLVM_INSTALL_UTILS AND LLVM_BUILD_UTILS)
+diff --git a/cmake/modules/LLVMInstallSymlink.cmake b/cmake/modules/LLVMInstallSymlink.cmake
+index 3e6a2c9a2648..52e14d955c60 100644
+--- a/cmake/modules/LLVMInstallSymlink.cmake
+++ b/cmake/modules/LLVMInstallSymlink.cmake
+@@ -4,7 +4,7 @@
+ 
+ function(install_symlink name target outdir)
+   set(DESTDIR $ENV{DESTDIR})
+-  set(bindir "${DESTDIR}${CMAKE_INSTALL_PREFIX}/${outdir}/")
+  set(bindir "${DESTDIR}${outdir}/")
+ 
+   message(STATUS "Creating ${name}")
+ 
+diff --git a/docs/CMake.rst b/docs/CMake.rst
+index f1ac2c7d4934..c6e1469b5e13 100644
+--- a/docs/CMake.rst
+++ b/docs/CMake.rst
+@@ -202,7 +202,7 @@ CMake manual, or execute ``cmake --help-variable VARIABLE_NAME``.
+ **LLVM_LIBDIR_SUFFIX**:STRING
+   Extra suffix to append to the directory where libraries are to be
+   installed. On a 64-bit architecture, one could use ``-DLLVM_LIBDIR_SUFFIX=64``
+-  to install libraries to ``/usr/lib64``.
+  to install libraries to ``/usr/lib64``. See also ``CMAKE_INSTALL_LIBDIR``.
+ 
+ Rarely-used CMake variables
+ ---------------------------
+@@ -551,8 +551,8 @@ LLVM-specific variables
+ 
+ **LLVM_INSTALL_DOXYGEN_HTML_DIR**:STRING
+   The path to install Doxygen-generated HTML documentation to. This path can
+-  either be absolute or relative to the CMAKE_INSTALL_PREFIX. Defaults to
+-  `share/doc/llvm/doxygen-html`.
+  either be absolute or relative to the ``CMAKE_INSTALL_PREFIX``. Defaults to
+  `${CMAKE_INSTALL_DOCDIR}/${project}/doxygen-html`.
+ 
+ **LLVM_LINK_LLVM_DYLIB**:BOOL
+   If enabled, tools will be linked with the libLLVM shared library. Defaults
+@@ -792,9 +792,11 @@ the ``cmake`` command or by setting it directly in ``ccmake`` or ``cmake-gui``).
+ 
+ This file is available in two different locations.
+ 
+-* ``<INSTALL_PREFIX>/lib/cmake/llvm/LLVMConfig.cmake`` where
+-  ``<INSTALL_PREFIX>`` is the install prefix of an installed version of LLVM.
+-  On Linux typically this is ``/usr/lib/cmake/llvm/LLVMConfig.cmake``.
+* ``<LLVM_INSTALL_PACKAGE_DIR>LLVMConfig.cmake`` where
+  ``<LLVM_INSTALL_PACKAGE_DIR>`` is the location where LLVM CMake modules are
+  installed as part of an installed version of LLVM. This is typically
+  ``cmake/llvm/`` within the lib directory. On Linux, this is typically
+  ``/usr/lib/cmake/llvm/LLVMConfig.cmake``.
+ 
+ * ``<LLVM_BUILD_ROOT>/lib/cmake/llvm/LLVMConfig.cmake`` where
+   ``<LLVM_BUILD_ROOT>`` is the root of the LLVM build tree. **Note: this is only
+diff --git a/examples/Bye/CMakeLists.txt b/examples/Bye/CMakeLists.txt
+index bb96edb4b4bf..678c22fb43c8 100644
+--- a/examples/Bye/CMakeLists.txt
+++ b/examples/Bye/CMakeLists.txt
+@@ -14,6 +14,6 @@ if (NOT WIN32)
+     BUILDTREE_ONLY
+    )
+ 
+-  install(TARGETS ${name} RUNTIME DESTINATION examples)
+  install(TARGETS ${name} RUNTIME DESTINATION ${CMAKE_INSTALL_DOCDIR}/examples)
+   set_target_properties(${name} PROPERTIES FOLDER "Examples")
+ endif()
+diff --git a/include/llvm/CMakeLists.txt b/include/llvm/CMakeLists.txt
+index b46319f24fc8..2feabd1954e4 100644
+--- a/include/llvm/CMakeLists.txt
+++ b/include/llvm/CMakeLists.txt
+@@ -5,5 +5,5 @@ add_subdirectory(Frontend)
+ # If we're doing an out-of-tree build, copy a module map for generated
+ # header files into the build area.
+ if (NOT "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
+-  configure_file(module.modulemap.build module.modulemap COPYONLY)
+  configure_file(module.modulemap.build ${LLVM_INCLUDE_DIR}/module.modulemap COPYONLY)
+ endif (NOT "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
+diff --git a/tools/llvm-config/BuildVariables.inc.in b/tools/llvm-config/BuildVariables.inc.in
+index ebe5b73a5c65..70c497be12f5 100644
+--- a/tools/llvm-config/BuildVariables.inc.in
+++ b/tools/llvm-config/BuildVariables.inc.in
+@@ -23,6 +23,10 @@
+ #define LLVM_CXXFLAGS "@LLVM_CXXFLAGS@"
+ #define LLVM_BUILDMODE "@LLVM_BUILDMODE@"
+ #define LLVM_LIBDIR_SUFFIX "@LLVM_LIBDIR_SUFFIX@"
+#define LLVM_INSTALL_BINDIR "@CMAKE_INSTALL_BINDIR@"
+#define LLVM_INSTALL_LIBDIR "@CMAKE_INSTALL_LIBDIR@"
+#define LLVM_INSTALL_INCLUDEDIR "@CMAKE_INSTALL_INCLUDEDIR@"
+#define LLVM_INSTALL_CMAKEDIR "@LLVM_INSTALL_CMAKE_DIR@"
+ #define LLVM_TARGETS_BUILT "@LLVM_TARGETS_BUILT@"
+ #define LLVM_SYSTEM_LIBS "@LLVM_SYSTEM_LIBS@"
+ #define LLVM_BUILD_SYSTEM "@LLVM_BUILD_SYSTEM@"
+diff --git a/tools/llvm-config/llvm-config.cpp b/tools/llvm-config/llvm-config.cpp
+index 1a2f04552d13..44fa7d3eec6b 100644
+--- a/tools/llvm-config/llvm-config.cpp
+++ b/tools/llvm-config/llvm-config.cpp
+@@ -357,12 +357,26 @@ int main(int argc, char **argv) {
+         ("-I" + ActiveIncludeDir + " " + "-I" + ActiveObjRoot + "/include");
+   } else {
+     ActivePrefix = CurrentExecPrefix;
+-    ActiveIncludeDir = ActivePrefix + "/include";
+-    SmallString<256> path(StringRef(LLVM_TOOLS_INSTALL_DIR));
+-    sys::fs::make_absolute(ActivePrefix, path);
+-    ActiveBinDir = std::string(path.str());
+-    ActiveLibDir = ActivePrefix + "/lib" + LLVM_LIBDIR_SUFFIX;
+-    ActiveCMakeDir = ActiveLibDir + "/cmake/llvm";
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_INCLUDEDIR));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveIncludeDir = std::string(path.str());
+    }
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_BINDIR));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveBinDir = std::string(path.str());
+    }
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_LIBDIR LLVM_LIBDIR_SUFFIX));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveLibDir = std::string(path.str());
+    }
+    {
+      SmallString<256> path(StringRef(LLVM_INSTALL_CMAKEDIR));
+      sys::fs::make_absolute(ActivePrefix, path);
+      ActiveCMakeDir = std::string(path.str());
+    }
+     ActiveIncludeOption = "-I" + ActiveIncludeDir;
+   }
+ 
+diff --git a/tools/lto/CMakeLists.txt b/tools/lto/CMakeLists.txt
+index 0af29ad762c5..37b99b83e35c 100644
+--- a/tools/lto/CMakeLists.txt
+++ b/tools/lto/CMakeLists.txt
+@@ -33,7 +33,7 @@ add_llvm_library(${LTO_LIBRARY_NAME} ${LTO_LIBRARY_TYPE} INSTALL_WITH_TOOLCHAIN
+     ${SOURCES} DEPENDS intrinsics_gen)
+ 
+ install(FILES ${LLVM_MAIN_INCLUDE_DIR}/llvm-c/lto.h
+-  DESTINATION include/llvm-c
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm-c
+   COMPONENT LTO)
+ 
+ if (APPLE)
+diff --git a/tools/opt-viewer/CMakeLists.txt b/tools/opt-viewer/CMakeLists.txt
+index ead73ec13a8f..250362021f17 100644
+--- a/tools/opt-viewer/CMakeLists.txt
+++ b/tools/opt-viewer/CMakeLists.txt
+@@ -8,7 +8,7 @@ set (files
+ 
+ foreach (file ${files})
+   install(PROGRAMS ${file}
+-    DESTINATION share/opt-viewer
+    DESTINATION ${CMAKE_INSTALL_DATADIR}/opt-viewer
+     COMPONENT opt-viewer)
+ endforeach (file)
+ 
+diff --git a/tools/remarks-shlib/CMakeLists.txt b/tools/remarks-shlib/CMakeLists.txt
+index 865436247270..ce1daa62f6ab 100644
+--- a/tools/remarks-shlib/CMakeLists.txt
+++ b/tools/remarks-shlib/CMakeLists.txt
+@@ -19,7 +19,7 @@ if(LLVM_ENABLE_PIC)
+   endif()
+   
+   install(FILES ${LLVM_MAIN_INCLUDE_DIR}/llvm-c/Remarks.h
+-    DESTINATION include/llvm-c
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/llvm-c
+     COMPONENT Remarks)
+ 
+   if (APPLE)
--- a/llvm/13/openmp/default.nix
+++ b/llvm/13/openmp/default.nix
@ -0,0 +1,53 @@
+{ lib
+, stdenv
+, llvm_meta
+, src
+, fetchpatch
+, cmake
+, llvm
+, targetLlvm
+, perl
+, version
+}:
+
+stdenv.mkDerivation rec {
+  pname = "openmp";
+  inherit version;
+
+  inherit src;
+  sourceRoot = "${src.name}/${pname}";
+
+  patches = [
+    # Fix cross.
+    (fetchpatch {
+      url = "https://github.com/llvm/llvm-project/commit/5e2358c781b85a18d1463fd924d2741d4ae5e42e.patch";
+      hash = "sha256-UxIlAifXnexF/MaraPW0Ut6q+sf3e7y1fMdEv1q103A=";
+    })
+  ];
+
+  patchFlags = [ "-p2" ];
+
+  nativeBuildInputs = [ cmake perl ];
+  buildInputs = [
+    (if stdenv.buildPlatform == stdenv.hostPlatform then llvm else targetLlvm)
+  ];
+
+  cmakeFlags = [
+    "-DLIBOMPTARGET_BUILD_AMDGCN_BCLIB=OFF" # Building the AMDGCN device RTL currently fails
+  ];
+
+  meta = llvm_meta // {
+    homepage = "https://openmp.llvm.org/";
+    description = "Support for the OpenMP language";
+    longDescription = ''
+      The OpenMP subproject of LLVM contains the components required to build an
+      executable OpenMP program that are outside the compiler itself.
+      Contains the code for the runtime library against which code compiled by
+      "clang -fopenmp" must be linked before it can run and the library that
+      supports offload to target devices.
+    '';
+    # "All of the code is dual licensed under the MIT license and the UIUC
+    # License (a BSD-like license)":
+    license = with lib.licenses; [ mit ncsa ];
+  };
+}
--- a/llvm/14/clang/default.nix
+++ b/llvm/14/clang/default.nix
@ -0,0 +1,129 @@
+{ lib, stdenv, llvm_meta
+, monorepoSrc, runCommand
+, substituteAll, cmake, libxml2, libllvm, version, python3
+, buildLlvmTools
+, fixDarwinDylibNames
+, enableManpages ? false
+}:
+
+let
+  self = stdenv.mkDerivation (rec {
+    pname = "clang";
+    inherit version;
+
+    src = runCommand "${pname}-src-${version}" {} ''
+      mkdir -p "$out"
+      cp -r ${monorepoSrc}/cmake "$out"
+      cp -r ${monorepoSrc}/${pname} "$out"
+      cp -r ${monorepoSrc}/clang-tools-extra "$out"
+    '';
+
+    sourceRoot = "${src.name}/${pname}";
+
+    nativeBuildInputs = [ cmake python3 ]
+      ++ lib.optional enableManpages python3.pkgs.sphinx
+      ++ lib.optional stdenv.hostPlatform.isDarwin fixDarwinDylibNames;
+
+    buildInputs = [ libxml2 libllvm ];
+
+    cmakeFlags = [
+      "-DCLANGD_BUILD_XPC=OFF"
+      "-DLLVM_ENABLE_RTTI=ON"
+    ] ++ lib.optionals enableManpages [
+      "-DCLANG_INCLUDE_DOCS=ON"
+      "-DLLVM_ENABLE_SPHINX=ON"
+      "-DSPHINX_OUTPUT_MAN=ON"
+      "-DSPHINX_OUTPUT_HTML=OFF"
+      "-DSPHINX_WARNINGS_AS_ERRORS=OFF"
+    ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+      "-DLLVM_TABLEGEN_EXE=${buildLlvmTools.llvm}/bin/llvm-tblgen"
+      "-DCLANG_TABLEGEN=${buildLlvmTools.libclang.dev}/bin/clang-tblgen"
+    ];
+
+    patches = [
+      ./purity.patch
+      # https://reviews.llvm.org/D51899
+      ./gnu-install-dirs.patch
+      ../../common/clang/add-nostdlibinc-flag.patch
+      (substituteAll {
+        src = ../../clang-11-12-LLVMgold-path.patch;
+        libllvmLibdir = "${libllvm.lib}/lib";
+      })
+    ];
+
+    postPatch = ''
+      (cd tools && ln -s ../../clang-tools-extra extra)
+    '' + lib.optionalString stdenv.hostPlatform.isMusl ''
+      sed -i -e 's/lgcc_s/lgcc_eh/' lib/Driver/ToolChains/*.cpp
+    '';
+
+    outputs = [ "out" "lib" "dev" "python" ];
+
+    postInstall = ''
+      ln -sv $out/bin/clang $out/bin/cpp
+
+      # Move libclang to 'lib' output
+      moveToOutput "lib/libclang.*" "$lib"
+      moveToOutput "lib/libclang-cpp.*" "$lib"
+      substituteInPlace $out/lib/cmake/clang/ClangTargets-release.cmake \
+          --replace "\''${_IMPORT_PREFIX}/lib/libclang." "$lib/lib/libclang." \
+          --replace "\''${_IMPORT_PREFIX}/lib/libclang-cpp." "$lib/lib/libclang-cpp."
+
+      mkdir -p $python/bin $python/share/{clang,scan-view}
+      mv $out/bin/{git-clang-format,scan-view} $python/bin
+      if [ -e $out/bin/set-xcode-analyzer ]; then
+        mv $out/bin/set-xcode-analyzer $python/bin
+      fi
+      mv $out/share/clang/*.py $python/share/clang
+      mv $out/share/scan-view/*.py $python/share/scan-view
+      rm $out/bin/c-index-test
+      patchShebangs $python/bin
+
+      mkdir -p $dev/bin
+      cp bin/clang-tblgen $dev/bin
+    '';
+
+    passthru = {
+      inherit libllvm;
+      isClang = true;
+      hardeningUnsupportedFlags = [ "fortify3" ];
+    };
+
+    meta = llvm_meta // {
+      homepage = "https://clang.llvm.org/";
+      description = "A C language family frontend for LLVM";
+      longDescription = ''
+        The Clang project provides a language front-end and tooling
+        infrastructure for languages in the C language family (C, C++, Objective
+        C/C++, OpenCL, CUDA, and RenderScript) for the LLVM project.
+        It aims to deliver amazingly fast compiles, extremely useful error and
+        warning messages and to provide a platform for building great source
+        level tools. The Clang Static Analyzer and clang-tidy are tools that
+        automatically find bugs in your code, and are great examples of the sort
+        of tools that can be built using the Clang frontend as a library to
+        parse C/C++ code.
+      '';
+      mainProgram = "clang";
+    };
+  } // lib.optionalAttrs enableManpages {
+    pname = "clang-manpages";
+
+    buildPhase = ''
+      make docs-clang-man
+    '';
+
+    installPhase = ''
+      mkdir -p $out/share/man/man1
+      # Manually install clang manpage
+      cp docs/man/*.1 $out/share/man/man1/
+    '';
+
+    outputs = [ "out" ];
+
+    doCheck = false;
+
+    meta = llvm_meta // {
+      description = "man page for Clang ${version}";
+    };
+  });
+in self
--- a/Show More
+++ b/Show More