Include unreferenced nested types in member list only for CodeView

[amccarth]

Summary

Unreferenced nested structs and classes were omitted from the debug info. In DWARF, this was intentional, to avoid bloat. But, for CodeView, we want this information to be consistent with what Microsoft tools would produce and expect.

This is essentially my earlier patch with a switch to apply it only when generating CodeView.

[rnk]

lib/CodeGen/CGDebugInfo.cpp

1096

Is getOrCreateMainFile correct here? I thought we'd use getOrCreateFile(RD->getLocation()), like this other code:

llvm::DIType *CGDebugInfo::getOrCreateRecordType(QualType RTy,
                                                 SourceLocation Loc) {
  assert(DebugKind >= codegenoptions::LimitedDebugInfo);
  llvm::DIType *T = getOrCreateType(RTy, getOrCreateFile(Loc));
  return T;
}

test/CodeGenCXX/debug-info-ms-abi.cpp

16

We should check what shows up in elements:, something like:

// CHECK-SAME: elements: ![[elements:[0-9]+]]

// CHECK: ![[elements]] = {![[f:[0-9]+]], ![[g:[0-9]+]], ![[h:[0-9]+]], ![[Nested:[0-9]+]]}

// CHECK: ![[Nested]] = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Nested",

And we can look for [[f]], g, and h, before the DISubprograms below.

[amccarth]

Addressed feedback.

[rnk]

lgtm

[Eugene.Zelenko]

Committed in r276271. Please specify Differential revision in commit message.

lib/CodeGen/CGDebugInfo.h

void CollectRecordLambdaFields(const CXXRecordDecl *CXXDecl,
                                  llvm::DIType *RecordTy);
   llvm::DIDerivedType *CreateRecordStaticField(const VarDecl *Var,
                                                llvm::DIType *RecordTy,
                                                const RecordDecl *RD);
   void CollectRecordNormalField(const FieldDecl *Field, uint64_t OffsetInBits,
                                 llvm::DIFile *F,
                                 SmallVectorImpl<llvm::Metadata *> &E,
                                 llvm::DIType *RecordTy, const RecordDecl *RD);
+  void CollectRecordNestedRecord(const RecordDecl *RD,
+                                 SmallVectorImpl<llvm::Metadata *> &E);
   void CollectRecordFields(const RecordDecl *Decl, llvm::DIFile *F,
                            SmallVectorImpl<llvm::Metadata *> &E,
                            llvm::DICompositeType *RecordTy);
 
   /// If the C++ class has vtable info then insert appropriate debug
   /// info entry in EltTys vector.
   void CollectVTableInfo(const CXXRecordDecl *Decl, llvm::DIFile *F,
                          SmallVectorImpl<llvm::Metadata *> &EltTys);

lib/CodeGen/CGDebugInfo.cpp

if (field->isBitField()) {
     FieldType =
         createFieldType(name, type, field->getLocation(), field->getAccess(),
                         OffsetInBits, tunit, RecordTy, RD);
   }
 
   elements.push_back(FieldType);
 }
 
+void CGDebugInfo::CollectRecordNestedRecord(
+    const RecordDecl *RD, SmallVectorImpl<llvm::Metadata *> &elements) {
+  QualType Ty = CGM.getContext().getTypeDeclType(RD);
+  SourceLocation Loc = RD->getLocation();
+  llvm::DIType *nestedType = getOrCreateType(Ty, getOrCreateFile(Loc));
+  elements.push_back(nestedType);
+}
+
 void CGDebugInfo::CollectRecordFields(
     const RecordDecl *record, llvm::DIFile *tunit,
     SmallVectorImpl<llvm::Metadata *> &elements,
     llvm::DICompositeType *RecordTy) {
   const auto *CXXDecl = dyn_cast<CXXRecordDecl>(record);
 
   if (CXXDecl && CXXDecl->isLambda())
     CollectRecordLambdaFields(CXXDecl, elements, RecordTy);
   else {
     const ASTRecordLayout &layout = CGM.getContext().getASTRecordLayout(record);
 
+    // Debug info for nested records is included in the member list only for
+    // CodeView.
+    bool IncludeNestedRecords = CGM.getCodeGenOpts().EmitCodeView;
+
     // Field number for non-static fields.
     unsigned fieldNo = 0;
 
     // Static and non-static members should appear in the same order as
     // the corresponding declarations in the source program.
     for (const auto *I : record->decls())
       if (const auto *V = dyn_cast<VarDecl>(I)) {
         if (V->hasAttr<NoDebugAttr>())
for (const auto *I : record->decls())
           elements.push_back(Field);
         }
       } else if (const auto *field = dyn_cast<FieldDecl>(I)) {
         CollectRecordNormalField(field, layout.getFieldOffset(fieldNo), tunit,
                                  elements, RecordTy, record);
 
         // Bump field number for next field.
         ++fieldNo;
-      }
+      } else if (const auto *nestedRec = dyn_cast<CXXRecordDecl>(I))
+        if (IncludeNestedRecords && !nestedRec->isImplicit() &&
+            nestedRec->getDeclContext() == record)
+          CollectRecordNestedRecord(nestedRec, elements);
   }
 }
 
 llvm::DISubroutineType *
 CGDebugInfo::getOrCreateMethodType(const CXXMethodDecl *Method,
                                    llvm::DIFile *Unit) {
   const FunctionProtoType *Func = Method->getType()->getAs<FunctionProtoType>();
   if (Method->isStatic())
llvm::DIScope *CGDebugInfo::getCurrentContextDescriptor(const Decl *D) {
   llvm::DIScope *Mod = getParentModuleOrNull(D);
   return getContextDescriptor(D, Mod ? Mod : TheCU);
 }
 
 void CGDebugInfo::EmitUsingDirective(const UsingDirectiveDecl &UD) {
   if (CGM.getCodeGenOpts().getDebugInfo() < codegenoptions::LimitedDebugInfo)
     return;
   const NamespaceDecl *NSDecl = UD.getNominatedNamespace();
-  if (!NSDecl->isAnonymousNamespace() || 
-      CGM.getCodeGenOpts().DebugExplicitImport) { 
+  if (!NSDecl->isAnonymousNamespace() ||
+      CGM.getCodeGenOpts().DebugExplicitImport) {
     DBuilder.createImportedModule(
         getCurrentContextDescriptor(cast<Decl>(UD.getDeclContext())),
         getOrCreateNameSpace(NSDecl),
         getLineNumber(UD.getLocation()));
   }
 }
 
 void CGDebugInfo::EmitUsingDecl(const UsingDecl &UD) {

test/CodeGenCXX/debug-info-dup-fwd-decl.cpp

protected:
     struct data {
         unsigned objectID;
     };
     data* reserved;
 };
 
 Test t;
 
-// CHECK: !DIDerivedType(tag: DW_TAG_pointer_type
 // CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "data"
+// CHECK: !DIDerivedType(tag: DW_TAG_pointer_type
 // CHECK-NOT: !DICompositeType(tag: DW_TAG_structure_type, name: "data"

test/CodeGenCXX/debug-info-ms-abi.cpp

-// RUN: %clang_cc1 %s -triple=i686-pc-windows-msvc -debug-info-kind=limited -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 %s -triple=i686-pc-windows-msvc -debug-info-kind=limited -gcodeview -emit-llvm -o - | FileCheck %s
 
 // Tests that certain miscellaneous features work in the MS ABI.
 
 struct Foo {
   virtual void f();
   virtual void g();
   virtual void h();
   struct Nested {};
 };
 Foo f;
 Foo::Nested n;
 
 // CHECK: ![[Foo:[^ ]*]] = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Foo",
+// CHECK-SAME: elements: ![[elements:[0-9]+]]
 // CHECK-SAME: identifier: ".?AUFoo@@"
 
-// CHECK: !DISubprogram(name: "f",
+// CHECK: ![[elements]] = !{![[vptr:[0-9]+]], ![[Nested:[0-9]+]], ![[f:[0-9]+]], ![[g:[0-9]+]], ![[h:[0-9]+]]}
+
+// CHECK: ![[Nested]] = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Nested",
+// CHECK-SAME: identifier: ".?AUNested@Foo@@"
+
+// CHECK: ![[f]] = !DISubprogram(name: "f",
 // CHECK-SAME: containingType: ![[Foo]], virtuality: DW_VIRTUALITY_virtual, virtualIndex: 0,
 // CHECK-SAME: flags: DIFlagPrototyped | DIFlagIntroducedVirtual,
 
-// CHECK: !DISubprogram(name: "g",
+// CHECK: ![[g]] = !DISubprogram(name: "g",
 // CHECK-SAME: containingType: ![[Foo]], virtuality: DW_VIRTUALITY_virtual, virtualIndex: 1,
 // CHECK-SAME: flags: DIFlagPrototyped | DIFlagIntroducedVirtual,
 
-// CHECK: !DISubprogram(name: "h",
+// CHECK: ![[h]] = !DISubprogram(name: "h",
 // CHECK-SAME: containingType: ![[Foo]], virtuality: DW_VIRTUALITY_virtual, virtualIndex: 2,
 // CHECK-SAME: flags: DIFlagPrototyped | DIFlagIntroducedVirtual,
-
-// CHECK: distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Nested",
-// CHECK-SAME: identifier: ".?AUNested@Foo@@"

test/Modules/ModuleDebugInfo.cpp

 
 // CHECK: !DIDerivedType(tag: DW_TAG_typedef, name: "TypedefTemplate",
 // CHECK-SAME:           baseType: ![[BASE:.*]])
 // CHECK: ![[BASE]] = !DICompositeType(tag: DW_TAG_class_type,
 // CHECK-SAME:                         name: "Template1<void *>",
 // CHECK-SAME:                         flags: DIFlagFwdDecl,
 // CHECK-SAME:                         identifier: "_ZTS9Template1IPvE")
 
-// Explicit instatiation.
+// Explicit instantiation.
 // CHECK: !DICompositeType(tag: DW_TAG_class_type, name: "Template1<int>",
 // CHECK-SAME:             templateParams:
 // CHECK-SAME:             identifier: "_ZTS9Template1IiE")
 
 // CHECK: !DICompositeType(tag: DW_TAG_class_type, name: "FwdDeclTemplate<int>",
 // CHECK-SAME:             flags: DIFlagFwdDecl
 // CHECK-SAME:             identifier: "_ZTS15FwdDeclTemplateIiE")
 
+// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "Member",
+// CHECK-SAME:             flags: DIFlagFwdDecl
+// CHECK-SAME:             identifier: "_ZTSN11SpecializedIiE6MemberE")
+
 // Forward-declared member of a template.
 // CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "Member",
 // CHECK-SAME:             flags: DIFlagFwdDecl
 // CHECK-SAME:             identifier: "_ZTSN21FwdDeclTemplateMemberIiE6MemberE")
 
 // CHECK-NEG-NOT: !DICompositeType(tag: DW_TAG_structure_type, name: "PureForwardDecl"