[flang-commits] [flang] [flang][debug] Make common blocks data extraction more robust. (PR #168752)

[Abid Qadeer via flang-commits]

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@@ -144,70 +144,87 @@ bool AddDebugInfoPass::createCommonBlockGlobal(
     fir::DebugTypeGenerator &typeGen, mlir::SymbolTable *symbolTable) {
   mlir::MLIRContext *context = &getContext();
   mlir::OpBuilder builder(context);
-  std::optional<std::int64_t> optint;
-  mlir::Operation *op = declOp.getMemref().getDefiningOp();
 
-  if (auto conOp = mlir::dyn_cast_if_present<fir::ConvertOp>(op))
-    op = conOp.getValue().getDefiningOp();
+  std::optional<std::int64_t> offset;
+  mlir::Value storage = declOp.getStorage();
+  if (!storage)
+    return false;
+
+  // Extract offset from storage_offset attribute
+  uint64_t storageOffset = declOp.getStorageOffset();
+  if (storageOffset != 0)
+    offset = static_cast<std::int64_t>(storageOffset);
+
+  // Get the GlobalOp from the storage value.
+  // The storage may be wrapped in ConvertOp, so unwrap it first.
+  mlir::Operation *storageOp = storage.getDefiningOp();
+  if (auto convertOp = mlir::dyn_cast_if_present<fir::ConvertOp>(storageOp))
+    storageOp = convertOp.getValue().getDefiningOp();
+
+  auto addrOfOp = mlir::dyn_cast_if_present<fir::AddrOfOp>(storageOp);
+  if (!addrOfOp)
+    return false;
+
+  mlir::SymbolRefAttr sym = addrOfOp.getSymbol();
+  fir::GlobalOp global =
+      symbolTable->lookup<fir::GlobalOp>(sym.getRootReference());
+  if (!global)
+    return false;
+
+  // Check if the global is actually a common block by demangling its name.
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abidh wrote:

Exiting tests are fine. It just occurred to me that I should test it with module equivalance and I saw that those variables were also being marked as common block so I added this check to prevent this. I will add a test.

https://github.com/llvm/llvm-project/pull/168752