Revert "Revert "Revert "Revert "DebugInfo: Omit debug info for dynamic classes in TUs that do not have the vtable for that class""""

This reverts commit r188687 (reverts r188642 (reverts 188600 (reverts
188576))).

With added test coverage & fix for -gline-tables-only.

Thanks Michael Gottesman for reverting this patch when it demonstrated
problems & providing a reproduction/details to help me track this down.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188739 91177308-0d34-0410-b5e6-96231b3b80d8

Author: dwblaikie

Diff for: lib/CodeGen/CGDebugInfo.cpp

@@ -644,8 +644,24 @@ llvm::DIDescriptor CGDebugInfo::createContextChain(const Decl *Context) {
 
   if (const RecordDecl *RD = dyn_cast<RecordDecl>(Context)) {
     if (!RD->isDependentType()) {
-      llvm::DIType Ty = getOrCreateLimitedType(
-          CGM.getContext().getRecordType(RD)->castAs<RecordType>(), getOrCreateMainFile());
+      llvm::DICompositeType T(getTypeOrNull(CGM.getContext().getRecordType(RD)));
+      llvm::DICompositeType Ty(getOrCreateLimitedType(
+          CGM.getContext().getRecordType(RD)->castAs<RecordType>(),
+          getOrCreateMainFile()));
+      if (!Ty.getTypeArray().getNumElements()) {
+        if (T) {
+          llvm::DIArray PrevMem = T.getTypeArray();
+          unsigned NumElements = PrevMem.getNumElements();
+          if (NumElements == 1 && !PrevMem.getElement(0))
+            NumElements = 0;
+          SmallVector<llvm::Value *, 16> EltTys;
+          EltTys.reserve(NumElements);
+          for (unsigned i = 0; i != NumElements; ++i)
+            EltTys.push_back(PrevMem.getElement(i));
+          llvm::DIArray Elements = DBuilder.getOrCreateArray(EltTys);
+          Ty.setTypeArray(Elements);
+        }
+      }
       return llvm::DIDescriptor(Ty);
     }
   }
@@ -865,7 +881,7 @@ CollectRecordLambdaFields(const CXXRecordDecl *CXXDecl,
   }
 }
 
-/// CollectRecordStaticField - Helper for CollectRecordFields.
+/// Helper for CollectRecordFields.
 llvm::DIDerivedType
 CGDebugInfo::CreateRecordStaticField(const VarDecl *Var,
                                      llvm::DIType RecordTy) {
@@ -948,7 +964,7 @@ void CGDebugInfo::CollectRecordFields(const RecordDecl *record,
     for (RecordDecl::decl_iterator I = record->decls_begin(),
            E = record->decls_end(); I != E; ++I)
       if (const VarDecl *V = dyn_cast<VarDecl>(*I))
-        elements.push_back(CreateRecordStaticField(V, RecordTy));
+        elements.push_back(getOrCreateStaticDataMemberDeclaration(V, RecordTy));
       else if (FieldDecl *field = dyn_cast<FieldDecl>(*I)) {
         CollectRecordNormalField(field, layout.getFieldOffset(fieldNo),
                                  tunit, elements, RecordTy);
@@ -1123,8 +1139,14 @@ CollectCXXMemberFunctions(const CXXRecordDecl *RD, llvm::DIFile Unit,
     if (D->isImplicit())
       continue;
 
-    if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
-      EltTys.push_back(CreateCXXMemberFunction(Method, Unit, RecordTy));
+    if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
+      llvm::DenseMap<const FunctionDecl *, llvm::WeakVH>::iterator MI =
+          SPCache.find(Method->getCanonicalDecl());
+      if (MI == SPCache.end())
+        EltTys.push_back(CreateCXXMemberFunction(Method, Unit, RecordTy));
+      else
+        EltTys.push_back(MI->second);
+    }
   }
 }
 
@@ -1408,10 +1430,20 @@ void CGDebugInfo::completeType(const RecordDecl *RD) {
 }
 
 void CGDebugInfo::completeRequiredType(const RecordDecl *RD) {
+  if (const CXXRecordDecl *CXXDecl = dyn_cast<CXXRecordDecl>(RD))
+    if (CXXDecl->isDynamicClass())
+      return;
+
   QualType Ty = CGM.getContext().getRecordType(RD);
   llvm::DIType T = getTypeOrNull(Ty);
-  if (!T || !T.isForwardDecl())
+  if (T && T.isForwardDecl())
+    completeClassData(RD);
+}
+
+void CGDebugInfo::completeClassData(const RecordDecl *RD) {
+  if (DebugKind <= CodeGenOptions::DebugLineTablesOnly)
     return;
+  QualType Ty = CGM.getContext().getRecordType(RD);
   void* TyPtr = Ty.getAsOpaquePtr();
   if (CompletedTypeCache.count(TyPtr))
     return;
@@ -1424,14 +1456,23 @@ void CGDebugInfo::completeRequiredType(const RecordDecl *RD) {
 /// CreateType - get structure or union type.
 llvm::DIType CGDebugInfo::CreateType(const RecordType *Ty, bool Declaration) {
   RecordDecl *RD = Ty->getDecl();
+  const CXXRecordDecl *CXXDecl = dyn_cast<CXXRecordDecl>(RD);
   // Limited debug info should only remove struct definitions that can
   // safely be replaced by a forward declaration in the source code.
-  if (DebugKind <= CodeGenOptions::LimitedDebugInfo && Declaration &&
-      !RD->isCompleteDefinitionRequired() && CGM.getLangOpts().CPlusPlus) {
+  if ((DebugKind <= CodeGenOptions::LimitedDebugInfo && Declaration &&
+       !RD->isCompleteDefinitionRequired() && CGM.getLangOpts().CPlusPlus) ||
+      (CXXDecl && CXXDecl->hasDefinition() && CXXDecl->isDynamicClass())) {
     llvm::DIDescriptor FDContext =
       getContextDescriptor(cast<Decl>(RD->getDeclContext()));
     llvm::DIType RetTy = getOrCreateRecordFwdDecl(RD, FDContext);
-    return RetTy;
+    // FIXME: This is conservatively correct. If we return a non-forward decl
+    // that's not a full definition (such as those created by
+    // createContextChain) then getOrCreateType will record is as a complete
+    // type and we'll never record all its members. But this means we're
+    // emitting full debug info in TUs where GCC successfully emits a partial
+    // definition of the type.
+    if (RetTy.isForwardDecl())
+      return RetTy;
   }
 
   return CreateTypeDefinition(Ty);
@@ -1469,6 +1510,7 @@ llvm::DIType CGDebugInfo::CreateTypeDefinition(const RecordType *Ty) {
 
   // Convert all the elements.
   SmallVector<llvm::Value *, 16> EltTys;
+  // what about nested types?
 
   // Note: The split of CXXDecl information here is intentional, the
   // gdb tests will depend on a certain ordering at printout. The debug
@@ -2310,7 +2352,7 @@ llvm::DISubprogram CGDebugInfo::getFunctionDeclaration(const Decl *D) {
   llvm::DenseMap<const FunctionDecl *, llvm::WeakVH>::iterator
     MI = SPCache.find(FD->getCanonicalDecl());
   if (MI == SPCache.end()) {
-    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
+    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD->getCanonicalDecl())) {
       llvm::DICompositeType T(S);
       llvm::DISubprogram SP = CreateCXXMemberFunction(MD, getOrCreateFile(MD->getLocation()), T);
       T.addMember(SP);
@@ -3025,19 +3067,35 @@ void CGDebugInfo::EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
   DbgDecl->setDebugLoc(llvm::DebugLoc::get(line, column, scope));
 }
 
-/// getStaticDataMemberDeclaration - If D is an out-of-class definition of
-/// a static data member of a class, find its corresponding in-class
-/// declaration.
-llvm::DIDerivedType CGDebugInfo::getStaticDataMemberDeclaration(const VarDecl *D) {
-  if (D->isStaticDataMember()) {
-    llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator
-      MI = StaticDataMemberCache.find(D->getCanonicalDecl());
-    if (MI != StaticDataMemberCache.end())
-      // Verify the info still exists.
-      if (llvm::Value *V = MI->second)
-        return llvm::DIDerivedType(cast<llvm::MDNode>(V));
+/// If D is an out-of-class definition of a static data member of a class, find
+/// its corresponding in-class declaration.
+llvm::DIDerivedType
+CGDebugInfo::getOrCreateStaticDataMemberDeclarationOrNull(const VarDecl *D) {
+  if (!D->isStaticDataMember())
+    return llvm::DIDerivedType();
+  llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator MI =
+      StaticDataMemberCache.find(D->getCanonicalDecl());
+  if (MI != StaticDataMemberCache.end()) {
+    assert(MI->second && "Static data member declaration should still exist");
+    return llvm::DIDerivedType(cast<llvm::MDNode>(MI->second));
+  }
+  llvm::DICompositeType Ctxt(
+      getContextDescriptor(cast<Decl>(D->getDeclContext())));
+  llvm::DIDerivedType T = CreateRecordStaticField(D, Ctxt);
+  Ctxt.addMember(T);
+  return T;
+}
+
+llvm::DIDerivedType
+CGDebugInfo::getOrCreateStaticDataMemberDeclaration(const VarDecl *D,
+                                            llvm::DICompositeType Ctxt) {
+  llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator MI =
+      StaticDataMemberCache.find(D->getCanonicalDecl());
+  if (MI != StaticDataMemberCache.end()) {
+    assert(MI->second && "Static data member declaration should still exist");
+    return llvm::DIDerivedType(cast<llvm::MDNode>(MI->second));
   }
-  return llvm::DIDerivedType();
+  return CreateRecordStaticField(D, Ctxt);
 }
 
 /// EmitGlobalVariable - Emit information about a global variable.
@@ -3069,11 +3127,10 @@ void CGDebugInfo::EmitGlobalVariable(llvm::GlobalVariable *Var,
     LinkageName = StringRef();
   llvm::DIDescriptor DContext =
     getContextDescriptor(dyn_cast<Decl>(D->getDeclContext()));
-  llvm::DIGlobalVariable GV =
-      DBuilder.createStaticVariable(DContext, DeclName, LinkageName, Unit,
-                                    LineNo, getOrCreateType(T, Unit),
-                                    Var->hasInternalLinkage(), Var,
-                                    getStaticDataMemberDeclaration(D));
+  llvm::DIGlobalVariable GV = DBuilder.createStaticVariable(
+      DContext, DeclName, LinkageName, Unit, LineNo, getOrCreateType(T, Unit),
+      Var->hasInternalLinkage(), Var,
+      getOrCreateStaticDataMemberDeclarationOrNull(D));
   DeclCache.insert(std::make_pair(D->getCanonicalDecl(), llvm::WeakVH(GV)));
 }
 
@@ -3121,7 +3178,7 @@ void CGDebugInfo::EmitGlobalVariable(const ValueDecl *VD,
     return;
   llvm::DIGlobalVariable GV = DBuilder.createStaticVariable(
       Unit, Name, Name, Unit, getLineNumber(VD->getLocation()), Ty, true, Init,
-      getStaticDataMemberDeclaration(cast<VarDecl>(VD)));
+      getOrCreateStaticDataMemberDeclarationOrNull(cast<VarDecl>(VD)));
   DeclCache.insert(std::make_pair(VD->getCanonicalDecl(), llvm::WeakVH(GV)));
 }
 

Diff for: lib/CodeGen/CGDebugInfo.h

@@ -291,7 +291,7 @@ class CGDebugInfo {
 
   void completeType(const RecordDecl *RD);
   void completeRequiredType(const RecordDecl *RD);
-
+  void completeClassData(const RecordDecl *RD);
 
 private:
   /// EmitDeclare - Emit call to llvm.dbg.declare for a variable declaration.
@@ -354,10 +354,13 @@ class CGDebugInfo {
   /// declaration for the given method definition.
   llvm::DISubprogram getFunctionDeclaration(const Decl *D);
 
-  /// getStaticDataMemberDeclaration - Return debug info descriptor to
-  /// describe in-class static data member declaration for the given
-  /// out-of-class definition.
-  llvm::DIDerivedType getStaticDataMemberDeclaration(const VarDecl *D);
+  /// Return debug info descriptor to describe in-class static data member
+  /// declaration for the given out-of-class definition.
+  llvm::DIDerivedType
+  getOrCreateStaticDataMemberDeclarationOrNull(const VarDecl *D);
+  llvm::DIDerivedType
+  getOrCreateStaticDataMemberDeclaration(const VarDecl *D,
+                                         llvm::DICompositeType Ctxt);
 
   /// getFunctionName - Get function name for the given FunctionDecl. If the
   /// name is constructred on demand (e.g. C++ destructor) then the name

Diff for: lib/CodeGen/CGVTables.cpp

@@ -828,6 +828,9 @@ CodeGenVTables::GenerateClassData(const CXXRecordDecl *RD) {
     VFTContext->getVFPtrOffsets(RD);
   }
 
+  if (CGDebugInfo *DI = CGM.getModuleDebugInfo())
+    DI->completeClassData(RD);
+
   // First off, check whether we've already emitted the v-table and
   // associated stuff.
   llvm::GlobalVariable *VTable = GetAddrOfVTable(RD);

Diff for: test/CodeGenCXX/debug-info-class.cpp

@@ -13,7 +13,39 @@ class B {
   virtual ~B();
 };
 
+B::~B() {
+}
+
 struct C {
+  static int s;
+  virtual ~C();
+};
+
+C::~C() {
+}
+
+struct D {
+  D();
+  virtual ~D();
+  void func() {
+  }
+};
+
+struct E {
+  E();
+  virtual ~E();
+  virtual void func() {
+  }
+};
+
+struct F {
+  struct inner {
+  };
+  static const int i = 2;
+  virtual ~F();
+};
+
+struct G {
   virtual void func();
   struct inner {
     int j;
@@ -29,10 +61,17 @@ struct A {
   }
 };
 
+void f1() {
+  D x;
+  x.func();
+  E y;
+  int i = F::i;
+  F::inner z;
+}
 
 int main(int argc, char **argv) {
   B b;
-  C::inner c_i;
+  G::inner c_i;
   if (argc) {
     A a;
   }
@@ -49,15 +88,34 @@ int main(int argc, char **argv) {
 // CHECK: DW_TAG_structure_type ] [foo]
 // CHECK: DW_TAG_class_type ] [bar]
 // CHECK: DW_TAG_union_type ] [baz]
-// CHECK: DW_TAG_structure_type ] [A]
-// CHECK: HdrSize
 // CHECK: DW_TAG_class_type ] [B]
 // CHECK: metadata !"_vptr$B", {{.*}}, i32 64, metadata !{{.*}}} ; [ DW_TAG_member ]
-// CHECK: metadata [[C_INNER_MEM:![0-9]*]], i32 0, null, null} ; [ DW_TAG_structure_type ] [inner] {{.*}} [def]
+
+// CHECK: [[C:![0-9]*]] = {{.*}} metadata [[C_MEM:![0-9]*]], i32 0, metadata [[C]], null} ; [ DW_TAG_structure_type ] [C] {{.*}} [def]
+// CHECK: [[C_MEM]] = metadata !{metadata [[C_VPTR:![0-9]*]], metadata [[C_S:![0-9]*]], metadata [[C_DTOR:![0-9]*]]}
+// CHECK: [[C_VPTR]] = {{.*}} ; [ DW_TAG_member ] [_vptr$C] {{.*}} [artificial]
+// CHECK: [[C_S]] = {{.*}} ; [ DW_TAG_member ] [s] {{.*}} [static] [from int]
+// CHECK: [[C_DTOR]] = {{.*}} ; [ DW_TAG_subprogram ] {{.*}} [~C]
+
+// CHECK: ; [ DW_TAG_structure_type ] [A]
+// CHECK: HdrSize
+// CHECK: metadata [[D_MEM:![0-9]*]], i32 0, null} ; [ DW_TAG_structure_type ] [D] {{.*}} [decl]
+// CHECK: [[D_MEM]] = metadata !{metadata [[D_FUNC:![0-9]*]]}
+// CHECK: [[D_FUNC]] = {{.*}} ; [ DW_TAG_subprogram ] {{.*}} [func]
+
+// CHECK: [[F_I_DEF:![0-9]*]] = {{.*}}, metadata [[F_I:![0-9]*]]} ; [ DW_TAG_variable ] [i]
+// CHECK: [[F_I]] = {{.*}} ; [ DW_TAG_member ] [i]
+// CHECK: [[F:![0-9]*]] = {{.*}} metadata [[F_MEM:![0-9]*]], i32 0, null, null} ; [ DW_TAG_structure_type ] [F] {{.*}} [def]
+// CHECK: [[F_MEM]] = metadata !{metadata [[F_I]]}
+
+// CHECK: null, i32 0, null} ; [ DW_TAG_structure_type ] [E] {{.*}} [decl]
+
+// CHECK: metadata [[G_INNER_MEM:![0-9]*]], i32 0, null, null} ; [ DW_TAG_structure_type ] [inner] [line 50, {{.*}} [def]
 // Context chains (in Clang -flimit-debug-info and in GCC generally) contain
 // definitions without members (& without a vbase 'containing type'):
-// CHECK: null, i32 0, null, null} ; [ DW_TAG_structure_type ] [C] {{.*}} [def]
-// CHECK: [[C_INNER_MEM]] = metadata !{metadata [[C_INNER_I:![0-9]*]]}
-// CHECK: [[C_INNER_I]] = {{.*}} ; [ DW_TAG_member ] [j] {{.*}} [from int]
-// CHECK: ![[EXCEPTLOC]] = metadata !{i32 40,
-// CHECK: ![[RETLOC]] = metadata !{i32 39,
+// CHECK: null, i32 0, null, null} ; [ DW_TAG_structure_type ] [G] {{.*}} [def]
+// CHECK: [[G_INNER_MEM]] = metadata !{metadata [[G_INNER_I:![0-9]*]]}
+// CHECK: [[G_INNER_I]] = {{.*}} ; [ DW_TAG_member ] [j] {{.*}} [from int]
+
+// CHECK: ![[EXCEPTLOC]] = metadata !{i32 79,
+// CHECK: ![[RETLOC]] = metadata !{i32 78,

Diff for: test/CodeGenCXX/debug-info-gline-tables-only.cpp

@@ -13,9 +13,17 @@ class E : public C {
   // CHECK-NOT: DW_TAG_reference type
   void x(const D& d);
 };
+struct F {
+  enum X { };
+  void func(X);
+  virtual ~F();
+};
+F::~F() {
+}
 }
 
 // CHECK-NOT: DW_TAG_variable
 NS::C c;
 NS::D d;
 NS::E e;
+NS::F f;