From 89326fb1898aefa8b215696b4ca29bfe9e075767 Mon Sep 17 00:00:00 2001
From: whitequark <whitequark@whitequark.org>
Date: Sat, 2 Apr 2016 18:29:36 +0000
Subject: [PATCH] compiler: purge generated functions from backtraces.

---
 artiq/compiler/ir.py                            | 3 +++
 artiq/compiler/transforms/artiq_ir_generator.py | 1 +
 artiq/compiler/transforms/llvm_ir_generator.py  | 9 +++++----
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/artiq/compiler/ir.py b/artiq/compiler/ir.py
index 7dab3e3c3..8414c45c9 100644
--- a/artiq/compiler/ir.py
+++ b/artiq/compiler/ir.py
@@ -425,6 +425,8 @@ class Function:
         the module it is contained in
     :ivar is_cold:
         (bool) if True, the function should be considered rarely called
+    :ivar is_generated:
+        (bool) if True, the function will not appear in backtraces
     :ivar flags: (set of str) Code generation flags.
         Flag ``fast-math`` is the equivalent of gcc's ``-ffast-math``.
     """
@@ -436,6 +438,7 @@ class Function:
         self.set_arguments(arguments)
         self.is_internal = False
         self.is_cold = False
+        self.is_generated = False
         self.flags = {}
 
     def _remove_name(self, name):
diff --git a/artiq/compiler/transforms/artiq_ir_generator.py b/artiq/compiler/transforms/artiq_ir_generator.py
index 5e5fd81b6..a42cbe213 100644
--- a/artiq/compiler/transforms/artiq_ir_generator.py
+++ b/artiq/compiler/transforms/artiq_ir_generator.py
@@ -944,6 +944,7 @@ class ARTIQIRGenerator(algorithm.Visitor):
             func = ir.Function(typ, ".".join(self.name + [name]), args, loc=loc)
             func.is_internal = True
             func.is_cold = True
+            func.is_generated = True
             self.functions.append(func)
             old_func, self.current_function = self.current_function, func
 
diff --git a/artiq/compiler/transforms/llvm_ir_generator.py b/artiq/compiler/transforms/llvm_ir_generator.py
index e338143a0..46e3f9b18 100644
--- a/artiq/compiler/transforms/llvm_ir_generator.py
+++ b/artiq/compiler/transforms/llvm_ir_generator.py
@@ -544,8 +544,9 @@ class LLVMIRGenerator:
             self.llbuilder = ll.IRBuilder()
             llblock_map = {}
 
-            disubprogram = self.debug_info_emitter.emit_subprogram(func, self.llfunction)
-            self.llfunction.set_metadata('dbg', disubprogram)
+            if not func.is_generated:
+                lldisubprogram = self.debug_info_emitter.emit_subprogram(func, self.llfunction)
+                self.llfunction.set_metadata('dbg', lldisubprogram)
 
             # First, map arguments.
             if self.has_sret(func.type):
@@ -566,9 +567,9 @@ class LLVMIRGenerator:
             for block in func.basic_blocks:
                 self.llbuilder.position_at_end(self.llmap[block])
                 for insn in block.instructions:
-                    if insn.loc is not None:
+                    if insn.loc is not None and not func.is_generated:
                         self.llbuilder.debug_metadata = \
-                            self.debug_info_emitter.emit_loc(insn.loc, disubprogram)
+                            self.debug_info_emitter.emit_loc(insn.loc, lldisubprogram)
 
                     llinsn = getattr(self, "process_" + type(insn).__name__)(insn)
                     assert llinsn is not None