[KeyInstr][Inline] Don't propagate atoms to inlined nodebug instructions (#133485)

RFC: https://discourse.llvm.org/t/rfc-improving-is-stmt-placement-for-better-interactive-debugging/82668

1 files changed, 8 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/Utils/InlineFunction.cpp b/llvm/lib/Transforms/Utils/InlineFunction.cpp
index eaf57e7..2412146 100644
--- a/llvm/lib/Transforms/Utils/InlineFunction.cpp
+++ b/llvm/lib/Transforms/Utils/InlineFunction.cpp
@@ -1827,10 +1827,16 @@ static DebugLoc inlineDebugLoc(DebugLoc OrigDL, DILocation *InlinedAt,
 /// to encode location where these instructions are inlined.
 static void fixupLineNumbers(Function *Fn, Function::iterator FI,
                              Instruction *TheCall, bool CalleeHasDebugInfo) {
-  const DebugLoc &TheCallDL = TheCall->getDebugLoc();
-  if (!TheCallDL)
+  if (!TheCall->getDebugLoc())
     return;
 
+  // Don't propagate the source location atom from the call to inlined nodebug
+  // instructions, and avoid putting it in the InlinedAt field of inlined
+  // not-nodebug instructions. FIXME: Possibly worth transferring/generating
+  // an atom for the returned value, otherwise we miss stepping on inlined
+  // nodebug functions (which is different to existing behaviour).
+  DebugLoc TheCallDL = TheCall->getDebugLoc().get()->getWithoutAtom();
+
   auto &Ctx = Fn->getContext();
   DILocation *InlinedAtNode = TheCallDL;