Module debugging: Don't emit forward declarations in module scopes.

A forward declaration inside a module header does not belong to the module.

llvm-svn: 249157

clang/lib/CodeGen/CGDebugInfo.cpp

@@ -2172,6 +2172,9 @@ ObjCInterfaceDecl *CGDebugInfo::getObjCInterfaceDecl(QualType Ty) {
 }
 
 llvm::DIModule *CGDebugInfo::getParentModuleOrNull(const Decl *D) {
+  // A forward declaration inside a module header does not belong to the module.
+  if (isa<RecordDecl>(D) && !cast<RecordDecl>(D)->getDefinition())
+    return nullptr;
   if (DebugTypeExtRefs && D->isFromASTFile()) {
     // Record a reference to an imported clang module or precompiled header.
     auto *Reader = CGM.getContext().getExternalSource();

clang/test/Modules/Inputs/DebugObjC.h

@@ -5,6 +5,7 @@
 }
 + classMethod;
 - instanceMethodWithInt:(int)i;
+- (struct OpaqueData*) getSomethingOpaque;
 @property int property;
 @end
 

clang/test/Modules/ModuleDebugInfo.m

@@ -41,3 +41,6 @@
 // MODULE-CHECK: !DICompositeType(tag: DW_TAG_structure_type,
 // MODULE-CHECK-SAME:             name: "ObjCClass",
 // MODULE-CHECK-SAME:             scope: ![[MODULE]],
+
+// The forward declaration should not be in the module scope.
+// MODULE-CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "OpaqueData", file