[clang] [llvm] [KeyInstr] Fix verifier check (PR #149043)

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llvmbot wrote:


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Author: Orlando Cazalet-Hyams (OCHyams)

<details>
<summary>Changes</summary>

The verifier check was in the wrong place, meaning it wasn't actually checking many instructions.

Fixing that causes a test failure (coro-dwarf-key-instrs.cpp) because coros turn off the feature but still annotate instructions with the metadata (which is a supported situation, but the verifier doesn't like it, and it's hard to teach the verifier to like it).

Fix that by avoiding emitting any key instruction metadata if the DISubprogram has opted out of key instructions.

---
Full diff: https://github.com/llvm/llvm-project/pull/149043.diff


2 Files Affected:

- (modified) clang/lib/CodeGen/CGDebugInfo.cpp (+4) 
- (modified) llvm/lib/IR/Verifier.cpp (+7-6) 


``````````diff
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index f97c7b6445984..0dde045453e3a 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -170,6 +170,10 @@ void CGDebugInfo::addInstToSpecificSourceAtom(llvm::Instruction *KeyInstruction,
   if (!Group || !CGM.getCodeGenOpts().DebugKeyInstructions)
     return;
 
+  llvm::DISubprogram *SP = KeyInstruction->getFunction()->getSubprogram();
+  if (!SP || !SP->getKeyInstructionsEnabled())
+    return;
+
   addInstSourceAtomMetadata(KeyInstruction, Group, /*Rank=*/1);
 
   llvm::Instruction *BackupI =
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 8004077b92665..ccaa8ccba085d 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -3185,12 +3185,6 @@ void Verifier::visitFunction(const Function &F) {
     CheckDI(SP->describes(&F),
             "!dbg attachment points at wrong subprogram for function", N, &F,
             &I, DL, Scope, SP);
-
-    if (DL->getAtomGroup())
-      CheckDI(DL->getScope()->getSubprogram()->getKeyInstructionsEnabled(),
-              "DbgLoc uses atomGroup but DISubprogram doesn't have Key "
-              "Instructions enabled",
-              DL, DL->getScope()->getSubprogram());
   };
   for (auto &BB : F)
     for (auto &I : BB) {
@@ -5492,6 +5486,13 @@ void Verifier::visitInstruction(Instruction &I) {
   if (MDNode *N = I.getDebugLoc().getAsMDNode()) {
     CheckDI(isa<DILocation>(N), "invalid !dbg metadata attachment", &I, N);
     visitMDNode(*N, AreDebugLocsAllowed::Yes);
+
+    auto *DL = cast<DILocation>(N);
+    if (DL->getAtomGroup())
+      CheckDI(DL->getScope()->getSubprogram()->getKeyInstructionsEnabled(),
+              "DbgLoc uses atomGroup but DISubprogram doesn't have Key "
+              "Instructions enabled",
+              DL, DL->getScope()->getSubprogram());
   }
 
   if (auto *DII = dyn_cast<DbgVariableIntrinsic>(&I)) {

``````````

</details>


https://github.com/llvm/llvm-project/pull/149043