Revert "[DebugMetadata][DwarfDebug] Support function-local types in lexical block scopes (4/7)"

This caused asserts:

  llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp:2331:
  virtual void llvm::DwarfDebug::endFunctionImpl(const llvm::MachineFunction *):
  Assertion `LScopes.getAbstractScopesList().size() == NumAbstractSubprograms &&
  "getOrCreateAbstractScope() inserted an abstract subprogram scope"' failed.

See comment on the code review for reproducer.

> RFC https://discourse.llvm.org/t/rfc-dwarfdebug-fix-and-improve-handling-imported-entities-types-and-static-local-in-subprogram-and-lexical-block-scopes/68544
>
> Similar to imported declarations, the patch tracks function-local types in
> DISubprogram's 'retainedNodes' field. DwarfDebug is adjusted in accordance with
> the aforementioned metadata change and provided a support of function-local
> types scoped within a lexical block.
>
> The patch assumes that DICompileUnit's 'enums field' no longer tracks local
> types and DwarfDebug would assert if any locally-scoped types get placed there.
>
> Reviewed By: jmmartinez
>
> Differential Revision: https://reviews.llvm.org/D144006

This reverts commit f8aab289b5549086062588fba627b0e4d3a5ab15.

1 files changed, 33 insertions, 53 deletions

diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
index e124354..74ccb2dd 100644
--- a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -549,8 +549,6 @@ class MetadataLoader::MetadataLoaderImpl {
 
   /// Move local imports from DICompileUnit's 'imports' field to
   /// DISubprogram's retainedNodes.
-  /// Move fucntion-local enums from DICompileUnit's enums
-  /// to DISubprogram's retainedNodes.
   void upgradeCULocals() {
     if (NamedMDNode *CUNodes = TheModule.getNamedMetadata("llvm.dbg.cu")) {
       for (unsigned I = 0, E = CUNodes->getNumOperands(); I != E; ++I) {
@@ -558,66 +556,48 @@ class MetadataLoader::MetadataLoaderImpl {
         if (!CU)
           continue;
 
-        SetVector<Metadata *> MetadataToRemove;
-        // Collect imported entities to be moved.
-        if (CU->getRawImportedEntities())
+        if (CU->getRawImportedEntities()) {
+          // Collect a set of imported entities to be moved.
+          SetVector<Metadata *> EntitiesToRemove;
           for (Metadata *Op : CU->getImportedEntities()->operands()) {
             auto *IE = cast<DIImportedEntity>(Op);
-            if (dyn_cast_or_null<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 (dyn_cast_or_null<DILocalScope>(Enum->getScope()))
-              MetadataToRemove.insert(Enum);
+            if (dyn_cast_or_null<DILocalScope>(IE->getScope())) {
+              EntitiesToRemove.insert(IE);
+            }
           }
 
-        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))
+          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))) {
                 NewImports.push_back(Op);
+              }
+            }
 
-          // 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;
-          for (auto *I : MetadataToRemove) {
-            DILocalScope *Scope = nullptr;
-            if (auto *Entity = dyn_cast<DIImportedEntity>(I))
-              Scope = cast<DILocalScope>(Entity->getScope());
-            else if (auto *Enum = dyn_cast<DICompositeType>(I))
-              Scope = cast<DILocalScope>(Enum->getScope());
-
-            if (auto *SP = findEnclosingSubprogram(Scope))
-              SPToEntities[SP].push_back(I);
-          }
+            // 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);
+              }
+            }
 
-          // Update DISubprograms' retainedNodes.
-          for (auto I = SPToEntities.begin(); I != SPToEntities.end(); ++I) {
-            auto *SP = I->first;
-            auto RetainedNodes = SP->getRetainedNodes();
-            SmallVector<Metadata *> MDs(RetainedNodes.begin(),
-                                        RetainedNodes.end());
-            MDs.append(I->second);
-            SP->replaceRetainedNodes(MDNode::get(Context, MDs));
-          }
+            // Update DISubprograms' retainedNodes.
+            for (auto I = SPToEntities.begin(); I != SPToEntities.end(); ++I) {
+              auto *SP = I->first;
+              auto RetainedNodes = SP->getRetainedNodes();
+              SmallVector<Metadata *> MDs(RetainedNodes.begin(),
+                                          RetainedNodes.end());
+              MDs.append(I->second);
+              SP->replaceRetainedNodes(MDNode::get(Context, MDs));
+            }
 
-          // Remove entities with local scope from CU.
-          if (CU->getRawImportedEntities())
+            // Remove entities with local scope from CU.
             CU->replaceImportedEntities(MDTuple::get(Context, NewImports));
-          // Remove enums with local scope from CU.
-          if (CU->getRawEnumTypes())
-            CU->replaceEnumTypes(MDTuple::get(Context, NewEnums));
+          }
         }
       }
     }