[clang] [llvm] Reland "[DebugMetadata][DwarfDebug] Support function-local types in lexical block scopes (4/7)" (PR #165032)

[Jeremy Morse via llvm-commits]

================
@@ -538,55 +546,71 @@ class MetadataLoader::MetadataLoaderImpl {
 
   /// Move local imports from DICompileUnit's 'imports' field to
   /// DISubprogram's retainedNodes.
+  /// Move function-local enums from DICompileUnit's enums
+  /// to DISubprogram's retainedNodes.
   void upgradeCULocals() {
     if (NamedMDNode *CUNodes = TheModule.getNamedMetadata("llvm.dbg.cu")) {
       for (MDNode *N : CUNodes->operands()) {
         auto *CU = dyn_cast<DICompileUnit>(N);
         if (!CU)
           continue;
 
-        if (CU->getRawImportedEntities()) {
-          // Collect a set of imported entities to be moved.
-          SetVector<Metadata *> EntitiesToRemove;
+        SetVector<Metadata *> MetadataToRemove;
+        // Collect imported entities to be moved.
+        if (CU->getRawImportedEntities())
           for (Metadata *Op : CU->getImportedEntities()->operands()) {
             auto *IE = cast<DIImportedEntity>(Op);
-            if (isa_and_nonnull<DILocalScope>(IE->getScope())) {
-              EntitiesToRemove.insert(IE);
-            }
+            if (isa_and_nonnull<DILocalScope>(IE->getScope()))
+              MetadataToRemove.insert(IE);
+          }
+        // Collect enums to be moved.
+        if (CU->getRawEnumTypes())
+          for (Metadata *Op : CU->getEnumTypes()->operands()) {
+            auto *Enum = cast<DICompositeType>(Op);
+            if (isa_and_nonnull<DILocalScope>(Enum->getScope()))
+              MetadataToRemove.insert(Enum);
           }
 
-          if (!EntitiesToRemove.empty()) {
-            // Make a new list of CU's 'imports'.
-            SmallVector<Metadata *> NewImports;
-            for (Metadata *Op : CU->getImportedEntities()->operands()) {
-              if (!EntitiesToRemove.contains(cast<DIImportedEntity>(Op))) {
+        if (!MetadataToRemove.empty()) {
+          // Make a new list of CU's 'imports'.
+          SmallVector<Metadata *> NewImports;
+          if (CU->getRawImportedEntities())
+            for (Metadata *Op : CU->getImportedEntities()->operands())
+              if (!MetadataToRemove.contains(Op))
                 NewImports.push_back(Op);
-              }
-            }
 
-            // Find DISubprogram corresponding to each entity.
-            std::map<DISubprogram *, SmallVector<Metadata *>> SPToEntities;
-            for (auto *I : EntitiesToRemove) {
-              auto *Entity = cast<DIImportedEntity>(I);
-              if (auto *SP = findEnclosingSubprogram(
-                      cast<DILocalScope>(Entity->getScope()))) {
-                SPToEntities[SP].push_back(Entity);
-              }
-            }
+          // Make a new list of CU's 'enums'.
+          SmallVector<Metadata *> NewEnums;
+          if (CU->getRawEnumTypes())
+            for (Metadata *Op : CU->getEnumTypes()->operands())
+              if (!MetadataToRemove.contains(Op))
+                NewEnums.push_back(Op);
+
+          // Find DISubprogram corresponding to each entity.
+          std::map<DISubprogram *, SmallVector<Metadata *>> SPToEntities;
----------------
jmorse wrote:

Note that std::map is usually discouraged due to allocating for each new element; I think we can get away with this as it's on the autoupgrade path, which isn't going to be fast anyway.

https://github.com/llvm/llvm-project/pull/165032