[llvm] [DebugInfo][RemoveDIs] Support DPValues in HWAsan (PR #78731)

[Florian Mayer via llvm-commits]

================
@@ -1425,17 +1425,24 @@ bool HWAddressSanitizer::instrumentStack(memtag::StackInfo &SInfo,
       return User != AILong && User != AICast && !isLifetimeIntrinsic(User);
     });
 
-    for (auto *DDI : Info.DbgVariableIntrinsics) {
+    // Helper utility for adding DW_OP_LLVM_tag_offset to debug-info records,
+    // abstracted over whether they're intrinsic-stored or DPValue stored.
+    auto AnnotateDbgRecord = [&](auto *DPtr) {
       // Prepend "tag_offset, N" to the dwarf expression.
       // Tag offset logically applies to the alloca pointer, and it makes sense
       // to put it at the beginning of the expression.
       SmallVector<uint64_t, 8> NewOps = {dwarf::DW_OP_LLVM_tag_offset,
                                          retagMask(N)};
-      for (size_t LocNo = 0; LocNo < DDI->getNumVariableLocationOps(); ++LocNo)
-        if (DDI->getVariableLocationOp(LocNo) == AI)
-          DDI->setExpression(DIExpression::appendOpsToArg(DDI->getExpression(),
-                                                          NewOps, LocNo));
-    }
+      for (size_t LocNo = 0; LocNo < DPtr->getNumVariableLocationOps(); ++LocNo)
+        if (DPtr->getVariableLocationOp(LocNo) == AI)
+          DPtr->setExpression(DIExpression::appendOpsToArg(DPtr->getExpression(),
+                                                           NewOps, LocNo));
+    };
+
+    for (auto *DDI : Info.DbgVariableIntrinsics)
----------------
fmayer wrote:

optional nit: 

```
llvm::for_each(Info.DbgVariableIntrinsics, AnnotateDbgRecord);
llvm::for_each(Info.DbgVariableIntrinsics, DbgVariableRecords);
```

https://github.com/llvm/llvm-project/pull/78731