use std::env; fn main() { println!("cargo:rerun-if-changed=build.rs"); let target = env::var("TARGET").unwrap(); let cwd = env::current_dir().unwrap(); println!("cargo:compiler-rt={}", cwd.join("compiler-rt").display()); // Activate libm's unstable features to make full use of Nightly. println!("cargo:rustc-cfg=feature=\"unstable\""); // Emscripten's runtime includes all the builtins if target.contains("emscripten") { return; } // OpenBSD provides compiler_rt by default, use it instead of rebuilding it from source if target.contains("openbsd") { println!("cargo:rustc-link-search=native=/usr/lib"); println!("cargo:rustc-link-lib=compiler_rt"); return; } // Forcibly enable memory intrinsics on wasm32 & SGX as we don't have a libc to // provide them. if (target.contains("wasm32") && !target.contains("wasi")) || (target.contains("sgx") && target.contains("fortanix")) { println!("cargo:rustc-cfg=feature=\"mem\""); } // NOTE we are going to assume that llvm-target, what determines our codegen option, matches the // target triple. This is usually correct for our built-in targets but can break in presence of // custom targets, which can have arbitrary names. let llvm_target = target.split('-').collect::>(); // Build missing intrinsics from compiler-rt C source code. If we're // mangling names though we assume that we're also in test mode so we don't // build anything and we rely on the upstream implementation of compiler-rt // functions if !cfg!(feature = "mangled-names") && cfg!(feature = "c") { // Don't use a C compiler for these targets: // // * wasm32 - clang 8 for wasm is somewhat hard to come by and it's // unlikely that the C is really that much better than our own Rust. // * nvptx - everything is bitcode, not compatible with mixed C/Rust // * riscv - the rust-lang/rust distribution container doesn't have a C // compiler nor is cc-rs ready for compilation to riscv (at this // time). This can probably be removed in the future if !target.contains("wasm32") && !target.contains("nvptx") && !target.starts_with("riscv") { #[cfg(feature = "c")] c::compile(&llvm_target); } } // To compile intrinsics.rs for thumb targets, where there is no libc if llvm_target[0].starts_with("thumb") { println!("cargo:rustc-cfg=thumb") } // compiler-rt `cfg`s away some intrinsics for thumbv6m and thumbv8m.base because // these targets do not have full Thumb-2 support but only original Thumb-1. // We have to cfg our code accordingly. if llvm_target[0] == "thumbv6m" || llvm_target[0] == "thumbv8m.base" { println!("cargo:rustc-cfg=thumb_1") } // Only emit the ARM Linux atomic emulation on pre-ARMv6 architectures. if llvm_target[0] == "armv4t" || llvm_target[0] == "armv5te" { println!("cargo:rustc-cfg=kernel_user_helpers") } } #[cfg(feature = "c")] mod c { extern crate cc; use std::collections::BTreeMap; use std::env; use std::path::PathBuf; struct Sources { // SYMBOL -> PATH TO SOURCE map: BTreeMap<&'static str, &'static str>, } impl Sources { fn new() -> Sources { Sources { map: BTreeMap::new(), } } fn extend(&mut self, sources: &[(&'static str, &'static str)]) { // NOTE Some intrinsics have both a generic implementation (e.g. // `floatdidf.c`) and an arch optimized implementation // (`x86_64/floatdidf.c`). In those cases, we keep the arch optimized // implementation and discard the generic implementation. If we don't // and keep both implementations, the linker will yell at us about // duplicate symbols! for (symbol, src) in sources { if src.contains("/") { // Arch-optimized implementation (preferred) self.map.insert(symbol, src); } else { // Generic implementation if !self.map.contains_key(symbol) { self.map.insert(symbol, src); } } } } fn remove(&mut self, symbols: &[&str]) { for symbol in symbols { self.map.remove(*symbol).unwrap(); } } } /// Compile intrinsics from the compiler-rt C source code pub fn compile(llvm_target: &[&str]) { let target_arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap(); let target_env = env::var("CARGO_CFG_TARGET_ENV").unwrap(); let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap(); let target_vendor = env::var("CARGO_CFG_TARGET_VENDOR").unwrap(); let cfg = &mut cc::Build::new(); cfg.warnings(false); if target_env == "msvc" { // Don't pull in extra libraries on MSVC cfg.flag("/Zl"); // Emulate C99 and C++11's __func__ for MSVC prior to 2013 CTP cfg.define("__func__", Some("__FUNCTION__")); } else { // Turn off various features of gcc and such, mostly copying // compiler-rt's build system already cfg.flag("-fno-builtin"); cfg.flag("-fvisibility=hidden"); cfg.flag("-ffreestanding"); // Avoid the following warning appearing once **per file**: // clang: warning: optimization flag '-fomit-frame-pointer' is not supported for target 'armv7' [-Wignored-optimization-argument] // // Note that compiler-rt's build system also checks // // `check_cxx_compiler_flag(-fomit-frame-pointer COMPILER_RT_HAS_FOMIT_FRAME_POINTER_FLAG)` // // in https://github.com/rust-lang/compiler-rt/blob/c8fbcb3/cmake/config-ix.cmake#L19. cfg.flag_if_supported("-fomit-frame-pointer"); cfg.define("VISIBILITY_HIDDEN", None); } let mut sources = Sources::new(); sources.extend(&[ ("__absvdi2", "absvdi2.c"), ("__absvsi2", "absvsi2.c"), ("__addvdi3", "addvdi3.c"), ("__addvsi3", "addvsi3.c"), ("apple_versioning", "apple_versioning.c"), ("__clzdi2", "clzdi2.c"), ("__clzsi2", "clzsi2.c"), ("__cmpdi2", "cmpdi2.c"), ("__ctzdi2", "ctzdi2.c"), ("__ctzsi2", "ctzsi2.c"), ("__divdc3", "divdc3.c"), ("__divsc3", "divsc3.c"), ("__divxc3", "divxc3.c"), ("__extendhfsf2", "extendhfsf2.c"), ("__int_util", "int_util.c"), ("__muldc3", "muldc3.c"), ("__mulsc3", "mulsc3.c"), ("__mulvdi3", "mulvdi3.c"), ("__mulvsi3", "mulvsi3.c"), ("__mulxc3", "mulxc3.c"), ("__negdf2", "negdf2.c"), ("__negdi2", "negdi2.c"), ("__negsf2", "negsf2.c"), ("__negvdi2", "negvdi2.c"), ("__negvsi2", "negvsi2.c"), ("__paritydi2", "paritydi2.c"), ("__paritysi2", "paritysi2.c"), ("__popcountdi2", "popcountdi2.c"), ("__popcountsi2", "popcountsi2.c"), ("__powixf2", "powixf2.c"), ("__subvdi3", "subvdi3.c"), ("__subvsi3", "subvsi3.c"), ("__truncdfhf2", "truncdfhf2.c"), ("__truncdfsf2", "truncdfsf2.c"), ("__truncsfhf2", "truncsfhf2.c"), ("__ucmpdi2", "ucmpdi2.c"), ]); // When compiling in rustbuild (the rust-lang/rust repo) this library // also needs to satisfy intrinsics that jemalloc or C in general may // need, so include a few more that aren't typically needed by // LLVM/Rust. if cfg!(feature = "rustbuild") { sources.extend(&[("__ffsdi2", "ffsdi2.c")]); } // On iOS and 32-bit OSX these are all just empty intrinsics, no need to // include them. if target_os != "ios" && (target_vendor != "apple" || target_arch != "x86") { sources.extend(&[ ("__absvti2", "absvti2.c"), ("__addvti3", "addvti3.c"), ("__clzti2", "clzti2.c"), ("__cmpti2", "cmpti2.c"), ("__ctzti2", "ctzti2.c"), ("__ffsti2", "ffsti2.c"), ("__mulvti3", "mulvti3.c"), ("__negti2", "negti2.c"), ("__negvti2", "negvti2.c"), ("__parityti2", "parityti2.c"), ("__popcountti2", "popcountti2.c"), ("__subvti3", "subvti3.c"), ("__ucmpti2", "ucmpti2.c"), ]); } if target_vendor == "apple" { sources.extend(&[ ("atomic_flag_clear", "atomic_flag_clear.c"), ("atomic_flag_clear_explicit", "atomic_flag_clear_explicit.c"), ("atomic_flag_test_and_set", "atomic_flag_test_and_set.c"), ( "atomic_flag_test_and_set_explicit", "atomic_flag_test_and_set_explicit.c", ), ("atomic_signal_fence", "atomic_signal_fence.c"), ("atomic_thread_fence", "atomic_thread_fence.c"), ]); } if target_env == "msvc" { if target_arch == "x86_64" { sources.extend(&[ ("__floatdisf", "x86_64/floatdisf.c"), ("__floatdixf", "x86_64/floatdixf.c"), ]); } } else { // None of these seem to be used on x86_64 windows, and they've all // got the wrong ABI anyway, so we want to avoid them. if target_os != "windows" { if target_arch == "x86_64" { sources.extend(&[ ("__floatdisf", "x86_64/floatdisf.c"), ("__floatdixf", "x86_64/floatdixf.c"), ("__floatundidf", "x86_64/floatundidf.S"), ("__floatundisf", "x86_64/floatundisf.S"), ("__floatundixf", "x86_64/floatundixf.S"), ]); } } if target_arch == "x86" { sources.extend(&[ ("__ashldi3", "i386/ashldi3.S"), ("__ashrdi3", "i386/ashrdi3.S"), ("__divdi3", "i386/divdi3.S"), ("__floatdidf", "i386/floatdidf.S"), ("__floatdisf", "i386/floatdisf.S"), ("__floatdixf", "i386/floatdixf.S"), ("__floatundidf", "i386/floatundidf.S"), ("__floatundisf", "i386/floatundisf.S"), ("__floatundixf", "i386/floatundixf.S"), ("__lshrdi3", "i386/lshrdi3.S"), ("__moddi3", "i386/moddi3.S"), ("__muldi3", "i386/muldi3.S"), ("__udivdi3", "i386/udivdi3.S"), ("__umoddi3", "i386/umoddi3.S"), ]); } } if target_arch == "arm" && target_os != "ios" && target_env != "msvc" { sources.extend(&[ ("__aeabi_div0", "arm/aeabi_div0.c"), ("__aeabi_drsub", "arm/aeabi_drsub.c"), ("__aeabi_frsub", "arm/aeabi_frsub.c"), ("__bswapdi2", "arm/bswapdi2.S"), ("__bswapsi2", "arm/bswapsi2.S"), ("__clzdi2", "arm/clzdi2.S"), ("__clzsi2", "arm/clzsi2.S"), ("__divmodsi4", "arm/divmodsi4.S"), ("__divsi3", "arm/divsi3.S"), ("__modsi3", "arm/modsi3.S"), ("__switch16", "arm/switch16.S"), ("__switch32", "arm/switch32.S"), ("__switch8", "arm/switch8.S"), ("__switchu8", "arm/switchu8.S"), ("__sync_synchronize", "arm/sync_synchronize.S"), ("__udivmodsi4", "arm/udivmodsi4.S"), ("__udivsi3", "arm/udivsi3.S"), ("__umodsi3", "arm/umodsi3.S"), ]); if target_os == "freebsd" { sources.extend(&[("__clear_cache", "clear_cache.c")]); } // First of all aeabi_cdcmp and aeabi_cfcmp are never called by LLVM. // Second are little-endian only, so build fail on big-endian targets. // Temporally workaround: exclude these files for big-endian targets. if !llvm_target[0].starts_with("thumbeb") && !llvm_target[0].starts_with("armeb") { sources.extend(&[ ("__aeabi_cdcmp", "arm/aeabi_cdcmp.S"), ("__aeabi_cdcmpeq_check_nan", "arm/aeabi_cdcmpeq_check_nan.c"), ("__aeabi_cfcmp", "arm/aeabi_cfcmp.S"), ("__aeabi_cfcmpeq_check_nan", "arm/aeabi_cfcmpeq_check_nan.c"), ]); } } if llvm_target[0] == "armv7" { sources.extend(&[ ("__sync_fetch_and_add_4", "arm/sync_fetch_and_add_4.S"), ("__sync_fetch_and_add_8", "arm/sync_fetch_and_add_8.S"), ("__sync_fetch_and_and_4", "arm/sync_fetch_and_and_4.S"), ("__sync_fetch_and_and_8", "arm/sync_fetch_and_and_8.S"), ("__sync_fetch_and_max_4", "arm/sync_fetch_and_max_4.S"), ("__sync_fetch_and_max_8", "arm/sync_fetch_and_max_8.S"), ("__sync_fetch_and_min_4", "arm/sync_fetch_and_min_4.S"), ("__sync_fetch_and_min_8", "arm/sync_fetch_and_min_8.S"), ("__sync_fetch_and_nand_4", "arm/sync_fetch_and_nand_4.S"), ("__sync_fetch_and_nand_8", "arm/sync_fetch_and_nand_8.S"), ("__sync_fetch_and_or_4", "arm/sync_fetch_and_or_4.S"), ("__sync_fetch_and_or_8", "arm/sync_fetch_and_or_8.S"), ("__sync_fetch_and_sub_4", "arm/sync_fetch_and_sub_4.S"), ("__sync_fetch_and_sub_8", "arm/sync_fetch_and_sub_8.S"), ("__sync_fetch_and_umax_4", "arm/sync_fetch_and_umax_4.S"), ("__sync_fetch_and_umax_8", "arm/sync_fetch_and_umax_8.S"), ("__sync_fetch_and_umin_4", "arm/sync_fetch_and_umin_4.S"), ("__sync_fetch_and_umin_8", "arm/sync_fetch_and_umin_8.S"), ("__sync_fetch_and_xor_4", "arm/sync_fetch_and_xor_4.S"), ("__sync_fetch_and_xor_8", "arm/sync_fetch_and_xor_8.S"), ]); } if llvm_target.last().unwrap().ends_with("eabihf") { if !llvm_target[0].starts_with("thumbv7em") && !llvm_target[0].starts_with("thumbv8m.main") { // The FPU option chosen for these architectures in cc-rs, ie: // -mfpu=fpv4-sp-d16 for thumbv7em // -mfpu=fpv5-sp-d16 for thumbv8m.main // do not support double precision floating points conversions so the files // that include such instructions are not included for these targets. sources.extend(&[ ("__fixdfsivfp", "arm/fixdfsivfp.S"), ("__fixunsdfsivfp", "arm/fixunsdfsivfp.S"), ("__floatsidfvfp", "arm/floatsidfvfp.S"), ("__floatunssidfvfp", "arm/floatunssidfvfp.S"), ]); } sources.extend(&[ ("__fixsfsivfp", "arm/fixsfsivfp.S"), ("__fixunssfsivfp", "arm/fixunssfsivfp.S"), ("__floatsisfvfp", "arm/floatsisfvfp.S"), ("__floatunssisfvfp", "arm/floatunssisfvfp.S"), ("__floatunssisfvfp", "arm/floatunssisfvfp.S"), ("__restore_vfp_d8_d15_regs", "arm/restore_vfp_d8_d15_regs.S"), ("__save_vfp_d8_d15_regs", "arm/save_vfp_d8_d15_regs.S"), ("__negdf2vfp", "arm/negdf2vfp.S"), ("__negsf2vfp", "arm/negsf2vfp.S"), ]); } if target_arch == "aarch64" { sources.extend(&[ ("__comparetf2", "comparetf2.c"), ("__extenddftf2", "extenddftf2.c"), ("__extendsftf2", "extendsftf2.c"), ("__fixtfdi", "fixtfdi.c"), ("__fixtfsi", "fixtfsi.c"), ("__fixtfti", "fixtfti.c"), ("__fixunstfdi", "fixunstfdi.c"), ("__fixunstfsi", "fixunstfsi.c"), ("__fixunstfti", "fixunstfti.c"), ("__floatditf", "floatditf.c"), ("__floatsitf", "floatsitf.c"), ("__floatunditf", "floatunditf.c"), ("__floatunsitf", "floatunsitf.c"), ("__trunctfdf2", "trunctfdf2.c"), ("__trunctfsf2", "trunctfsf2.c"), ]); if target_os != "windows" { sources.extend(&[("__multc3", "multc3.c")]); } } // Remove the assembly implementations that won't compile for the target if llvm_target[0] == "thumbv6m" || llvm_target[0] == "thumbv8m.base" { let mut to_remove = Vec::new(); for (k, v) in sources.map.iter() { if v.ends_with(".S") { to_remove.push(*k); } } sources.remove(&to_remove); // But use some generic implementations where possible sources.extend(&[("__clzdi2", "clzdi2.c"), ("__clzsi2", "clzsi2.c")]) } if llvm_target[0] == "thumbv7m" || llvm_target[0] == "thumbv7em" { sources.remove(&["__aeabi_cdcmp", "__aeabi_cfcmp"]); } // When compiling the C code we require the user to tell us where the // source code is, and this is largely done so when we're compiling as // part of rust-lang/rust we can use the same llvm-project repository as // rust-lang/rust. let root = match env::var_os("RUST_COMPILER_RT_ROOT") { Some(s) => PathBuf::from(s), None => panic!("RUST_COMPILER_RT_ROOT is not set"), }; if !root.exists() { panic!("RUST_COMPILER_RT_ROOT={} does not exist", root.display()); } // Support deterministic builds by remapping the __FILE__ prefix if the // compiler supports it. This fixes the nondeterminism caused by the // use of that macro in lib/builtins/int_util.h in compiler-rt. cfg.flag_if_supported(&format!("-ffile-prefix-map={}=.", root.display())); let src_dir = root.join("lib/builtins"); for (sym, src) in sources.map.iter() { let src = src_dir.join(src); cfg.file(&src); println!("cargo:rerun-if-changed={}", src.display()); println!("cargo:rustc-cfg={}=\"optimized-c\"", sym); } cfg.compile("libcompiler-rt.a"); } }