Revert "Debug Info: Using declarations/DW_TAG_imported_declaration of variables, types, and functions."

This reverts commit r181393 (git 3923d6a87f). This seems to be emitting too much extra debug info for two (known) reasons: * full class definitions are emitted when only declarations are expected * unused using declarations still produce DW_TAG_imported_declarations git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181947 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-15 23:46:19 +00:00 · 2013-05-15 23:46:19 +00:00 · 214c3d6c64
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@ -2173,30 +2173,6 @@ llvm::DIType CGDebugInfo::CreateMemberType(llvm::DIFile Unit, QualType FType,
  return Ty;
 }

-llvm::DIDescriptor CGDebugInfo::getDeclarationOrDefinition(const Decl *D) {
-  // We only need a declaration (not a definition) of the type - so use whatever
-  // we would otherwise do to get a type for a pointee. (forward declarations in
-  // limited debug info, full definitions (if the type definition is available)
-  // in unlimited debug info)
-  if (const TypeDecl *TD = dyn_cast<TypeDecl>(D)) {
-    llvm::DIFile DefUnit = getOrCreateFile(TD->getLocation());
-    return CreatePointeeType(CGM.getContext().getTypeDeclType(TD), DefUnit);
-  }
-  // Otherwise fall back to a fairly rudimentary cache of existing declarations.
-  // This doesn't handle providing declarations (for functions or variables) for
-  // entities without definitions in this TU, nor when the definition proceeds
-  // the call to this function.
-  // FIXME: This should be split out into more specific maps with support for
-  // emitting forward declarations and merging definitions with declarations,
-  // the same way as we do for types.
-  llvm::DenseMap<const Decl *, llvm::WeakVH>::iterator I =
-      DeclCache.find(D->getCanonicalDecl());
-  if (I == DeclCache.end())
-    return llvm::DIDescriptor();
-  llvm::Value *V = I->second;
-  return llvm::DIDescriptor(dyn_cast_or_null<llvm::MDNode>(V));
-}
-
 /// getFunctionDeclaration - Return debug info descriptor to describe method
 /// declaration for the given method definition.
 llvm::DISubprogram CGDebugInfo::getFunctionDeclaration(const Decl *D) {
@ -2368,8 +2344,6 @@ void CGDebugInfo::EmitFunctionStart(GlobalDecl GD, QualType FnType,
                               getLineNumber(CurLoc), Flags,
                               CGM.getLangOpts().Optimize,
                               Fn, TParamsArray, SPDecl);
-  if (HasDecl)
-    DeclCache.insert(std::make_pair(D->getCanonicalDecl(), llvm::WeakVH(SP)));

  // Push function on region stack.
  llvm::MDNode *SPN = SP;
@ -2980,11 +2954,10 @@ 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,
+  DBuilder.createStaticVariable(DContext, DeclName, LinkageName,
                                Unit, LineNo, getOrCreateType(T, Unit),
                                Var->hasInternalLinkage(), Var,
                                getStaticDataMemberDeclaration(D));
-  DeclCache.insert(std::make_pair(D->getCanonicalDecl(), llvm::WeakVH(GV)));
 }

 /// EmitGlobalVariable - Emit information about an objective-c interface.
@ -3029,38 +3002,22 @@ void CGDebugInfo::EmitGlobalVariable(const ValueDecl *VD,
  // Do not use DIGlobalVariable for enums.
  if (Ty.getTag() == llvm::dwarf::DW_TAG_enumeration_type)
    return;
-  llvm::DIGlobalVariable GV = DBuilder.createStaticVariable(Unit, Name, Name, Unit,
+  DBuilder.createStaticVariable(Unit, Name, Name, Unit,
                                getLineNumber(VD->getLocation()),
                                Ty, true, Init,
                                getStaticDataMemberDeclaration(VD));
-  DeclCache.insert(std::make_pair(VD->getCanonicalDecl(), llvm::WeakVH(GV)));
-}
-
-llvm::DIScope CGDebugInfo::getCurrentContextDescriptor(const Decl *D) {
-  if (!LexicalBlockStack.empty())
-    return llvm::DIScope(LexicalBlockStack.back());
-  return getContextDescriptor(D);
 }

 void CGDebugInfo::EmitUsingDirective(const UsingDirectiveDecl &UD) {
+  llvm::DIScope Scope =
+      LexicalBlockStack.empty()
+          ? getContextDescriptor(cast<Decl>(UD.getDeclContext()))
+          : llvm::DIScope(LexicalBlockStack.back());
  DBuilder.createImportedModule(
-      getCurrentContextDescriptor(cast<Decl>(UD.getDeclContext())),
-      getOrCreateNameSpace(UD.getNominatedNamespace()),
+      Scope, getOrCreateNameSpace(UD.getNominatedNamespace()),
      getLineNumber(UD.getLocation()));
 }

-void CGDebugInfo::EmitUsingDecl(const UsingDecl &UD) {
-  assert(UD.shadow_size() &&
-         "We shouldn't be codegening an invalid UsingDecl containing no decls");
-  // Emitting one decl is sufficient - debuggers can detect that this is an
-  // overloaded name & provide lookup for all the overloads.
-  const UsingShadowDecl &USD = **UD.shadow_begin();
-  if (llvm::DIDescriptor Target = getDeclarationOrDefinition(USD.getUnderlyingDecl()))
-    DBuilder.createImportedDeclaration(
-        getCurrentContextDescriptor(cast<Decl>(USD.getDeclContext())), Target,
-        getLineNumber(USD.getLocation()));
-}
-
 /// getOrCreateNamesSpace - Return namespace descriptor for the given
 /// namespace decl.
 llvm::DINameSpace 
--- a/lib/CodeGen/CGDebugInfo.h
+++ b/lib/CodeGen/CGDebugInfo.h
@ -35,7 +35,6 @@ namespace clang {
  class ObjCIvarDecl;
  class ClassTemplateSpecializationDecl;
  class GlobalDecl;
-  class UsingDecl;

 namespace CodeGen {
  class CodeGenModule;
@ -95,9 +94,6 @@ class CGDebugInfo {

  llvm::DenseMap<const char *, llvm::WeakVH> DIFileCache;
  llvm::DenseMap<const FunctionDecl *, llvm::WeakVH> SPCache;
-  /// \brief Cache declarations relevant to DW_TAG_imported_declarations (C++
-  /// using declarations) that aren't covered by other more specific caches.
-  llvm::DenseMap<const Decl *, llvm::WeakVH> DeclCache;
  llvm::DenseMap<const NamespaceDecl *, llvm::WeakVH> NameSpaceCache;
  llvm::DenseMap<const Decl *, llvm::WeakVH> StaticDataMemberCache;

@ -269,9 +265,6 @@ public:
  /// \brief - Emit C++ using directive.
  void EmitUsingDirective(const UsingDirectiveDecl &UD);

-  /// \brief - Emit C++ using declaration.
-  void EmitUsingDecl(const UsingDecl &UD);
-
  /// getOrCreateRecordType - Emit record type's standalone debug info. 
  llvm::DIType getOrCreateRecordType(QualType Ty, SourceLocation L);

@ -293,8 +286,6 @@ private:
  /// getContextDescriptor - Get context info for the decl.
  llvm::DIScope getContextDescriptor(const Decl *Decl);

-  llvm::DIScope getCurrentContextDescriptor(const Decl *Decl);
-
  /// createRecordFwdDecl - Create a forward decl for a RecordType in a given
  /// context.
  llvm::DIType createRecordFwdDecl(const RecordDecl *, llvm::DIDescriptor);
@ -338,10 +329,6 @@ private:
  llvm::DIType CreateMemberType(llvm::DIFile Unit, QualType FType,
                                StringRef Name, uint64_t *Offset);

-  /// \brief Retrieve the DIDescriptor, if any, for the canonical form of this
-  /// declaration.
-  llvm::DIDescriptor getDeclarationOrDefinition(const Decl *D);
-
  /// getFunctionDeclaration - Return debug info descriptor to describe method
  /// declaration for the given method definition.
  llvm::DISubprogram getFunctionDeclaration(const Decl *D);
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@ -72,13 +72,14 @@ void CodeGenFunction::EmitDecl(const Decl &D) {
  case Decl::Block:
  case Decl::Captured:
  case Decl::ClassScopeFunctionSpecialization:
-  case Decl::UsingShadow:
    llvm_unreachable("Declaration should not be in declstmts!");
  case Decl::Function:  // void X();
  case Decl::Record:    // struct/union/class X;
  case Decl::Enum:      // enum X;
  case Decl::EnumConstant: // enum ? { X = ? }
  case Decl::CXXRecord: // struct/union/class X; [C++]
+  case Decl::Using:          // using X; [C++]
+  case Decl::UsingShadow:
  case Decl::NamespaceAlias:
  case Decl::StaticAssert: // static_assert(X, ""); [C++0x]
  case Decl::Label:        // __label__ x;
@ -88,10 +89,6 @@ void CodeGenFunction::EmitDecl(const Decl &D) {
    // None of these decls require codegen support.
    return;

-  case Decl::Using:          // using X; [C++]
-    if (CGDebugInfo *DI = getDebugInfo())
-      DI->EmitUsingDecl(cast<UsingDecl>(D));
-    return;
  case Decl::UsingDirective: // using namespace X; [C++]
    if (CGDebugInfo *DI = getDebugInfo())
      DI->EmitUsingDirective(cast<UsingDirectiveDecl>(D));
--- a/test/CodeGenCXX/debug-info-namespace.cpp
+++ b/test/CodeGenCXX/debug-info-namespace.cpp
@ -4,11 +4,6 @@ namespace A {
 #line 1 "foo.cpp"
 namespace B {
 int i;
-void f1() { }
-void f1(int) { }
-struct foo;
-struct bar { };
-typedef bar baz;
 }
 using namespace B;
 }
@ -21,41 +16,22 @@ int func(bool b) {
    return i;
  }
  using namespace A;
-  using B::foo;
-  using B::bar;
-  using B::f1;
-  using B::i;
-  using B::baz;
-  bar x;
-  return i;
+  return B::i;
 }

-// This should work even if 'i' and 'func' were declarations & not definitions,
-// but it doesn't yet.
-
 // CHECK: [[CU:![0-9]*]] = {{.*}}[[MODULES:![0-9]*]], metadata !""} ; [ DW_TAG_compile_unit ]
 // CHECK: [[FILE:![0-9]*]] {{.*}}debug-info-namespace.cpp"
-// CHECK: [[FOOCPP:![0-9]*]] = metadata !{metadata !"foo.cpp", {{.*}}
-// CHECK: [[NS:![0-9]*]] = {{.*}}, metadata [[FILE2:![0-9]*]], metadata [[CTXT:![0-9]*]], {{.*}} ; [ DW_TAG_namespace ] [B] [line 1]
+// CHECK: [[FUNC:![0-9]*]] {{.*}} ; [ DW_TAG_subprogram ] [line 9] [def] [func]
+// CHECK: [[FILE2:![0-9]*]]} ; [ DW_TAG_file_type ] [{{.*}}foo.cpp]
+// CHECK: [[VAR:![0-9]*]] = {{.*}}, metadata [[NS:![0-9]*]], metadata !"i", {{.*}} ; [ DW_TAG_variable ] [i]
+// CHECK: [[NS]] = {{.*}}, metadata [[FILE2]], metadata [[CTXT:![0-9]*]], {{.*}} ; [ DW_TAG_namespace ] [B] [line 1]
 // CHECK: [[CTXT]] = {{.*}}, metadata [[FILE]], null, {{.*}} ; [ DW_TAG_namespace ] [A] [line 3]
-// CHECK: [[F1:![0-9]*]] {{.*}} ; [ DW_TAG_subprogram ] [line 4] [def] [f1]
-// CHECK: [[FUNC:![0-9]*]] {{.*}} ; [ DW_TAG_subprogram ] [line 14] [def] [func]
-// CHECK: [[FILE2]]} ; [ DW_TAG_file_type ] [{{.*}}foo.cpp]
-// CHECK: [[I:![0-9]*]] = {{.*}}, metadata [[NS]], metadata !"i", {{.*}} ; [ DW_TAG_variable ] [i]
-// CHECK: [[MODULES]] = metadata !{metadata [[M1:![0-9]*]], metadata [[M2:![0-9]*]], metadata [[M3:![0-9]*]], metadata [[M4:![0-9]*]], metadata [[M5:![0-9]*]], metadata [[M6:![0-9]*]], metadata [[M7:![0-9]*]], metadata [[M8:![0-9]*]], metadata [[M9:![0-9]*]]}
-// CHECK: [[M1]] = metadata !{i32 {{[0-9]*}}, metadata [[CTXT]], metadata [[NS]], i32 9} ; [ DW_TAG_imported_module ]
-// CHECK: [[M2]] = metadata !{i32 {{[0-9]*}}, metadata [[CU]], metadata [[CTXT]], i32 12} ; [ DW_TAG_imported_module ]
-// CHECK: [[M3]] = metadata !{i32 {{[0-9]*}}, metadata [[LEX:![0-9]*]], metadata [[NS]], i32 16} ; [ DW_TAG_imported_module ]
-// CHECK: [[LEX]] = metadata !{i32 {{[0-9]*}}, metadata [[FILE2]], metadata [[FUNC]], i32 15, i32 0, i32 0} ; [ DW_TAG_lexical_block ]
-// CHECK: [[M4]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[CTXT]], i32 19} ; [ DW_TAG_imported_module ]
-// CHECK: [[M5]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[FOO:![0-9]*]], i32 20} ; [ DW_TAG_imported_declaration ]
-// CHECK: [[FOO]] {{.*}} ; [ DW_TAG_structure_type ] [foo] [line 5, size 0, align 0, offset 0] [fwd] [from ]
-// CHECK: [[M6]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[BAR:![0-9]*]], i32 21} ; [ DW_TAG_imported_declaration ]
-// CHECK: [[BAR]] {{.*}} ; [ DW_TAG_structure_type ] [bar] [line 6, {{.*}}] [from ]
-// CHECK: [[M7]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[F1]], i32 22} ; [ DW_TAG_imported_declaration ]
-// CHECK: [[M8]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[I]], i32 23} ; [ DW_TAG_imported_declaration ]
-// CHECK: [[M9]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[BAZ:![0-9]*]], i32 24} ; [ DW_TAG_imported_declaration ]
-// CHECK: [[BAZ]] = metadata !{i32 {{[0-9]*}}, metadata [[FOOCPP]], metadata [[NS]], {{.*}} ; [ DW_TAG_typedef ] [baz] {{.*}} [from bar]
+// CHECK: [[MODULES]] = metadata !{metadata [[M1:![0-9]*]], metadata [[M2:![0-9]*]], metadata [[M3:![0-9]*]], metadata [[M4:![0-9]*]]}
+// CHECK: [[M1]] = metadata !{i32 {{[0-9]*}}, metadata [[CTXT]], metadata [[NS]], i32 4} ; [ DW_TAG_imported_module ]
+// CHECK: [[M2]] = metadata !{i32 {{[0-9]*}}, metadata [[CU]], metadata [[CTXT]], i32 7} ; [ DW_TAG_imported_module ]
+// CHECK: [[M3]] = metadata !{i32 {{[0-9]*}}, metadata [[LEX:![0-9]*]], metadata [[NS]], i32 11} ; [ DW_TAG_imported_module ]
+// CHECK: [[LEX]] = metadata !{i32 {{[0-9]*}}, metadata [[FILE2]], metadata [[FUNC]], i32 10, i32 0, i32 0} ; [ DW_TAG_lexical_block ]
+// CHECK: [[M4]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[CTXT]], i32 14} ; [ DW_TAG_imported_module ]

 // FIXME: It is confused on win32 to generate file entry when dosish filename is given.
 // REQUIRES: shell