Do not attribute static allocas to the call site's DebugLoc.

When functions are inlined, instructions without debug information are
attributed to the call site's DebugLoc. After inlining, inlined static
allocas are moved to the caller's entry block, adjacent to the caller's
original static alloca instructions. By retaining the call site's
DebugLoc, these instructions could cause instructions that were
subsequently inserted at the entry block to pick up the same DebugLoc.

Patch by Wolfgang Pieb!

llvm-svn: 220255

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Utils/InlineFunction.cpp b/llvm/lib/Transforms/Utils/InlineFunction.cpp
index ca33e338eda..1b2e2089415 100644
--- a/llvm/lib/Transforms/Utils/InlineFunction.cpp
+++ b/llvm/lib/Transforms/Utils/InlineFunction.cpp
@@ -856,6 +856,12 @@ static void fixupLineNumbers(Function *Fn, Function::iterator FI,
         // originates from the call location. This is important for
         // ((__always_inline__, __nodebug__)) functions which must use caller
         // location for all instructions in their function body.
+
+        // Don't update static allocas, as they may get moved later.
+        if (auto *AI = dyn_cast<AllocaInst>(BI))
+          if (isa<Constant>(AI->getArraySize()))
+            continue;
+
         BI->setDebugLoc(TheCallDL);
       } else {
         BI->setDebugLoc(updateInlinedAtInfo(DL, TheCallDL, BI->getContext()));