commit 19ffcb900f98ecd84bd1f423d213e8ccabecfc76
author Alexey Samsonov <vonosmas@gmail.com> Tue Jun 23 21:00:08 2015 +0000
committer Alexey Samsonov <vonosmas@gmail.com> Tue Jun 23 21:00:08 2015 +0000
tree 710ffa91ae333bd3664391a590fe8e040a2cbd8a
parent 5bd81f32647945a8bd88d5df2b646a6d8083653b

Let llvm::ReplaceInstWithInst copy debug location from old to new instruction.

Currently some users of this function do this explicitly, and all the
rest forget to do this.

ThreadSanitizer was one of such users, and had missing debug
locations for calls into TSan runtime handling atomic operations,
eventually leading to poorly symbolized stack traces and malfunctioning
suppressions.

This is another change relevant to PR23837.

llvm-svn: 240460

llvm/lib/Transforms/Utils/BasicBlockUtils.cpp

diff --git a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
index 798376e..53471de 100644
--- a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -211,6 +211,11 @@
   assert(I->getParent() == nullptr &&
          "ReplaceInstWithInst: Instruction already inserted into basic block!");
 
+  // Copy debug location to newly added instruction, if it wasn't already set
+  // by the caller.
+  if (!I->getDebugLoc())
+    I->setDebugLoc(BI->getDebugLoc());
+
   // Insert the new instruction into the basic block...
   BasicBlock::iterator New = BIL.insert(BI, I);
 
@@ -716,7 +721,6 @@
   CheckTerm->setDebugLoc(SplitBefore->getDebugLoc());
   BranchInst *HeadNewTerm =
     BranchInst::Create(/*ifTrue*/ThenBlock, /*ifFalse*/Tail, Cond);
-  HeadNewTerm->setDebugLoc(SplitBefore->getDebugLoc());
   HeadNewTerm->setMetadata(LLVMContext::MD_prof, BranchWeights);
   ReplaceInstWithInst(HeadOldTerm, HeadNewTerm);
 
@@ -766,7 +770,6 @@
   (*ElseTerm)->setDebugLoc(SplitBefore->getDebugLoc());
   BranchInst *HeadNewTerm =
     BranchInst::Create(/*ifTrue*/ThenBlock, /*ifFalse*/ElseBlock, Cond);
-  HeadNewTerm->setDebugLoc(SplitBefore->getDebugLoc());
   HeadNewTerm->setMetadata(LLVMContext::MD_prof, BranchWeights);
   ReplaceInstWithInst(HeadOldTerm, HeadNewTerm);
 }