[llvm] [LLVM][Coroutines] Check variable decl scope instead of optimization level for hoisted DbgDeclare Loc (PR #92978)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: Billy Zhu (zyx-billy)

<details>
<summary>Changes</summary>

Minor patch following up on https://github.com/llvm/llvm-project/pull/75402.

The more generalized version of [this error](https://github.com/llvm/llvm-project/pull/75104#issuecomment-1853497609) is whenever we have a debug variable created in one subprogram scope inlined into another subprogram scope. So instead of checking optimization level, it is safer to just check whether the subprogram scope of the variable matches the subprogram scope of the hoisted position.

---
Full diff: https://github.com/llvm/llvm-project/pull/92978.diff


2 Files Affected:

- (modified) llvm/lib/Transforms/Coroutines/CoroFrame.cpp (+13-9) 
- (renamed) llvm/test/Transforms/Coroutines/coro-debug-frame-variable-inlined.ll (+2-2) 


``````````diff
diff --git a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
index dd9e77a855ef4..38b8dab984db3 100644
--- a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
+++ b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
@@ -2974,10 +2974,12 @@ void coro::salvageDebugInfo(
     std::optional<BasicBlock::iterator> InsertPt;
     if (auto *I = dyn_cast<Instruction>(Storage)) {
       InsertPt = I->getInsertionPointAfterDef();
-      // Update DILocation only in O0 since it is easy to get out of sync in
-      // optimizations. See https://github.com/llvm/llvm-project/pull/75104 for
-      // an example.
-      if (!OptimizeFrame && I->getDebugLoc())
+      // Update DILocation only if variable was not inlined.
+      DebugLoc ILoc = I->getDebugLoc();
+      DebugLoc DVILoc = DVI.getDebugLoc();
+      if (ILoc && DVILoc &&
+          DVILoc->getScope()->getSubprogram() ==
+              ILoc->getScope()->getSubprogram())
         DVI.setDebugLoc(I->getDebugLoc());
     } else if (isa<Argument>(Storage))
       InsertPt = F->getEntryBlock().begin();
@@ -3014,11 +3016,13 @@ void coro::salvageDebugInfo(
     std::optional<BasicBlock::iterator> InsertPt;
     if (auto *I = dyn_cast<Instruction>(Storage)) {
       InsertPt = I->getInsertionPointAfterDef();
-      // Update DILocation only in O0 since it is easy to get out of sync in
-      // optimizations. See https://github.com/llvm/llvm-project/pull/75104 for
-      // an example.
-      if (!OptimizeFrame && I->getDebugLoc())
-        DVR.setDebugLoc(I->getDebugLoc());
+      // Update DILocation only if variable was not inlined.
+      DebugLoc ILoc = I->getDebugLoc();
+      DebugLoc DVRLoc = DVR.getDebugLoc();
+      if (ILoc && DVRLoc &&
+          DVRLoc->getScope()->getSubprogram() ==
+              ILoc->getScope()->getSubprogram())
+        DVR.setDebugLoc(ILoc);
     } else if (isa<Argument>(Storage))
       InsertPt = F->getEntryBlock().begin();
     if (InsertPt) {
diff --git a/llvm/test/Transforms/Coroutines/coro-debug-frame-variable-O1.ll b/llvm/test/Transforms/Coroutines/coro-debug-frame-variable-inlined.ll
similarity index 96%
rename from llvm/test/Transforms/Coroutines/coro-debug-frame-variable-O1.ll
rename to llvm/test/Transforms/Coroutines/coro-debug-frame-variable-inlined.ll
index acd6a08d7c1b8..ff070d9b02acc 100644
--- a/llvm/test/Transforms/Coroutines/coro-debug-frame-variable-O1.ll
+++ b/llvm/test/Transforms/Coroutines/coro-debug-frame-variable-inlined.ll
@@ -1,5 +1,5 @@
-; RUN: opt < %s -passes='module(coro-early),cgscc(inline,coro-split<reuse-storage>)' -S | FileCheck %s
-; RUN: opt --try-experimental-debuginfo-iterators < %s -passes='module(coro-early),cgscc(inline,coro-split<reuse-storage>)' -S | FileCheck %s
+; RUN: opt < %s -passes='module(coro-early),cgscc(inline,coro-split)' -S | FileCheck %s
+; RUN: opt --try-experimental-debuginfo-iterators < %s -passes='module(coro-early),cgscc(inline,coro-split)' -S | FileCheck %s
 
 ; Simplified version from pr#75104.
 ; Make sure we do not update debug location for hosited dbg.declare intrinsics when optimizing coro frame.

``````````

</details>


https://github.com/llvm/llvm-project/pull/92978