Move dbg.declare intrinsics when merging and replacing allocas.

Place new and update dbg.declare calls immediately after the
corresponding alloca.

Current code in replaceDbgDeclareForAlloca puts the new dbg.declare
at the end of the basic block. LLVM codegen has problems emitting
debug info in a situation when dbg.declare appears after all uses of
the variable. This usually kinda works for inlining and ASan (two
users of this function) but not for SafeStack (see the pending change
in http://reviews.llvm.org/D13178).

llvm-svn: 248769

1 files changed, 4 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 5efa128090f..adee3f6c985 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1157,10 +1157,10 @@ bool llvm::replaceDbgDeclareForAlloca(AllocaInst *AI, Value *NewAllocaAddress,
     DIExpr = Builder.createExpression(NewDIExpr);
   }
 
-  // Insert llvm.dbg.declare in the same basic block as the original alloca,
-  // and remove old llvm.dbg.declare.
-  BasicBlock *BB = AI->getParent();
-  Builder.insertDeclare(NewAllocaAddress, DIVar, DIExpr, Loc, BB);
+  // Insert llvm.dbg.declare immediately after the original alloca, and remove
+  // old llvm.dbg.declare.
+  Builder.insertDeclare(NewAllocaAddress, DIVar, DIExpr, Loc,
+                        AI->getNextNode());
   DDI->eraseFromParent();
   return true;
 }