DebugInfo: Remove MDString-based type references

Eliminate DITypeIdentifierMap and make DITypeRef a thin wrapper around
DIType*.  It is no longer legal to refer to a DICompositeType by its
'identifier:', and DIBuilder no longer retains all types with an
'identifier:' automatically.

Aside from the bitcode upgrade, this is mainly removing logic to resolve
an MDString-based reference to an actualy DIType.  The commits leading
up to this have made the implicit type map in DICompileUnit's
'retainedTypes:' field superfluous.

This does not remove DITypeRef, DIScopeRef, DINodeRef, and
DITypeRefArray, or stop using them in DI-related metadata.  Although as
of this commit they aren't serving a useful purpose, there are patchces
under review to reuse them for CodeView support.

The tests in LLVM were updated with deref-typerefs.sh, which is attached
to the thread "[RFC] Lazy-loading of debug info metadata":

  http://lists.llvm.org/pipermail/llvm-dev/2016-April/098318.html

llvm-svn: 267296

1 files changed, 71 insertions, 103 deletions

diff --git a/llvm/lib/IR/DIBuilder.cpp b/llvm/lib/IR/DIBuilder.cpp
index e46de24..f0baff7 100644
--- a/llvm/lib/IR/DIBuilder.cpp
+++ b/llvm/lib/IR/DIBuilder.cpp
@@ -206,8 +206,7 @@ DIImportedEntity *DIBuilder::createImportedDeclaration(DIScope *Context,
   // Make sure to use the unique identifier based metadata reference for
   // types that have one.
   return ::createImportedModule(VMContext, dwarf::DW_TAG_imported_declaration,
-                                Context, DINodeRef::get(Decl), Line, Name,
-                                AllImportedModules);
+                                Context, Decl, Line, Name, AllImportedModules);
 }
 
 DIFile *DIBuilder::createFile(StringRef Filename, StringRef Directory) {
@@ -237,8 +236,8 @@ DIBasicType *DIBuilder::createBasicType(StringRef Name, uint64_t SizeInBits,
 }
 
 DIDerivedType *DIBuilder::createQualifiedType(unsigned Tag, DIType *FromTy) {
-  return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr,
-                            DITypeRef::get(FromTy), 0, 0, 0, 0);
+  return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, FromTy, 0,
+                            0, 0, 0);
 }
 
 DIDerivedType *DIBuilder::createPointerType(DIType *PointeeTy,
@@ -247,8 +246,8 @@ DIDerivedType *DIBuilder::createPointerType(DIType *PointeeTy,
                                             StringRef Name) {
   // FIXME: Why is there a name here?
   return DIDerivedType::get(VMContext, dwarf::DW_TAG_pointer_type, Name,
-                            nullptr, 0, nullptr, DITypeRef::get(PointeeTy),
-                            SizeInBits, AlignInBits, 0, 0);
+                            nullptr, 0, nullptr, PointeeTy, SizeInBits,
+                            AlignInBits, 0, 0);
 }
 
 DIDerivedType *DIBuilder::createMemberPointerType(DIType *PointeeTy,
@@ -256,34 +255,31 @@ DIDerivedType *DIBuilder::createMemberPointerType(DIType *PointeeTy,
                                                   uint64_t SizeInBits,
                                                   uint64_t AlignInBits) {
   return DIDerivedType::get(VMContext, dwarf::DW_TAG_ptr_to_member_type, "",
-                            nullptr, 0, nullptr, DITypeRef::get(PointeeTy),
-                            SizeInBits, AlignInBits, 0, 0,
-                            DITypeRef::get(Base));
+                            nullptr, 0, nullptr, PointeeTy, SizeInBits,
+                            AlignInBits, 0, 0, Base);
 }
 
 DIDerivedType *DIBuilder::createReferenceType(unsigned Tag, DIType *RTy,
                                               uint64_t SizeInBits,
                                               uint64_t AlignInBits) {
   assert(RTy && "Unable to create reference type");
-  return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr,
-                            DITypeRef::get(RTy), SizeInBits, AlignInBits, 0, 0);
+  return DIDerivedType::get(VMContext, Tag, "", nullptr, 0, nullptr, RTy,
+                            SizeInBits, AlignInBits, 0, 0);
 }
 
 DIDerivedType *DIBuilder::createTypedef(DIType *Ty, StringRef Name,
                                         DIFile *File, unsigned LineNo,
                                         DIScope *Context) {
   return DIDerivedType::get(VMContext, dwarf::DW_TAG_typedef, Name, File,
-                            LineNo,
-                            DIScopeRef::get(getNonCompileUnitScope(Context)),
-                            DITypeRef::get(Ty), 0, 0, 0, 0);
+                            LineNo, getNonCompileUnitScope(Context), Ty, 0, 0,
+                            0, 0);
 }
 
 DIDerivedType *DIBuilder::createFriend(DIType *Ty, DIType *FriendTy) {
   assert(Ty && "Invalid type!");
   assert(FriendTy && "Invalid friend type!");
-  return DIDerivedType::get(VMContext, dwarf::DW_TAG_friend, "", nullptr, 0,
-                            DITypeRef::get(Ty), DITypeRef::get(FriendTy), 0, 0,
-                            0, 0);
+  return DIDerivedType::get(VMContext, dwarf::DW_TAG_friend, "", nullptr, 0, Ty,
+                            FriendTy, 0, 0, 0, 0);
 }
 
 DIDerivedType *DIBuilder::createInheritance(DIType *Ty, DIType *BaseTy,
@@ -291,8 +287,7 @@ DIDerivedType *DIBuilder::createInheritance(DIType *Ty, DIType *BaseTy,
                                             unsigned Flags) {
   assert(Ty && "Unable to create inheritance");
   return DIDerivedType::get(VMContext, dwarf::DW_TAG_inheritance, "", nullptr,
-                            0, DITypeRef::get(Ty), DITypeRef::get(BaseTy), 0, 0,
-                            BaseOffset, Flags);
+                            0, Ty, BaseTy, 0, 0, BaseOffset, Flags);
 }
 
 DIDerivedType *DIBuilder::createMemberType(DIScope *Scope, StringRef Name,
@@ -301,10 +296,9 @@ DIDerivedType *DIBuilder::createMemberType(DIScope *Scope, StringRef Name,
                                            uint64_t AlignInBits,
                                            uint64_t OffsetInBits,
                                            unsigned Flags, DIType *Ty) {
-  return DIDerivedType::get(
-      VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
-      DIScopeRef::get(getNonCompileUnitScope(Scope)), DITypeRef::get(Ty),
-      SizeInBits, AlignInBits, OffsetInBits, Flags);
+  return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
+                            LineNumber, getNonCompileUnitScope(Scope), Ty,
+                            SizeInBits, AlignInBits, OffsetInBits, Flags);
 }
 
 static ConstantAsMetadata *getConstantOrNull(Constant *C) {
@@ -319,10 +313,9 @@ DIDerivedType *DIBuilder::createStaticMemberType(DIScope *Scope, StringRef Name,
                                                  DIType *Ty, unsigned Flags,
                                                  llvm::Constant *Val) {
   Flags |= DINode::FlagStaticMember;
-  return DIDerivedType::get(
-      VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
-      DIScopeRef::get(getNonCompileUnitScope(Scope)), DITypeRef::get(Ty), 0, 0,
-      0, Flags, getConstantOrNull(Val));
+  return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
+                            LineNumber, getNonCompileUnitScope(Scope), Ty, 0, 0,
+                            0, Flags, getConstantOrNull(Val));
 }
 
 DIDerivedType *DIBuilder::createObjCIVar(StringRef Name, DIFile *File,
@@ -331,10 +324,10 @@ DIDerivedType *DIBuilder::createObjCIVar(StringRef Name, DIFile *File,
                                          uint64_t AlignInBits,
                                          uint64_t OffsetInBits, unsigned Flags,
                                          DIType *Ty, MDNode *PropertyNode) {
-  return DIDerivedType::get(
-      VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
-      DIScopeRef::get(getNonCompileUnitScope(File)), DITypeRef::get(Ty),
-      SizeInBits, AlignInBits, OffsetInBits, Flags, PropertyNode);
+  return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
+                            LineNumber, getNonCompileUnitScope(File), Ty,
+                            SizeInBits, AlignInBits, OffsetInBits, Flags,
+                            PropertyNode);
 }
 
 DIObjCProperty *
@@ -342,15 +335,14 @@ DIBuilder::createObjCProperty(StringRef Name, DIFile *File, unsigned LineNumber,
                               StringRef GetterName, StringRef SetterName,
                               unsigned PropertyAttributes, DIType *Ty) {
   return DIObjCProperty::get(VMContext, Name, File, LineNumber, GetterName,
-                             SetterName, PropertyAttributes,
-                             DITypeRef::get(Ty));
+                             SetterName, PropertyAttributes, Ty);
 }
 
 DITemplateTypeParameter *
 DIBuilder::createTemplateTypeParameter(DIScope *Context, StringRef Name,
                                        DIType *Ty) {
   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
-  return DITemplateTypeParameter::get(VMContext, Name, DITypeRef::get(Ty));
+  return DITemplateTypeParameter::get(VMContext, Name, Ty);
 }
 
 static DITemplateValueParameter *
@@ -358,8 +350,7 @@ createTemplateValueParameterHelper(LLVMContext &VMContext, unsigned Tag,
                                    DIScope *Context, StringRef Name, DIType *Ty,
                                    Metadata *MD) {
   assert((!Context || isa<DICompileUnit>(Context)) && "Expected compile unit");
-  return DITemplateValueParameter::get(VMContext, Tag, Name, DITypeRef::get(Ty),
-                                       MD);
+  return DITemplateValueParameter::get(VMContext, Tag, Name, Ty, MD);
 }
 
 DITemplateValueParameter *
@@ -396,12 +387,9 @@ DICompositeType *DIBuilder::createClassType(
 
   auto *R = DICompositeType::get(
       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
-      DIScopeRef::get(getNonCompileUnitScope(Context)),
-      DITypeRef::get(DerivedFrom), SizeInBits, AlignInBits, OffsetInBits, Flags,
-      Elements, 0, DITypeRef::get(VTableHolder),
+      getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits,
+      OffsetInBits, Flags, Elements, 0, VTableHolder,
       cast_or_null<MDTuple>(TemplateParams), UniqueIdentifier);
-  if (!UniqueIdentifier.empty())
-    retainType(R);
   trackIfUnresolved(R);
   return R;
 }
@@ -413,11 +401,8 @@ DICompositeType *DIBuilder::createStructType(
     DIType *VTableHolder, StringRef UniqueIdentifier) {
   auto *R = DICompositeType::get(
       VMContext, dwarf::DW_TAG_structure_type, Name, File, LineNumber,
-      DIScopeRef::get(getNonCompileUnitScope(Context)),
-      DITypeRef::get(DerivedFrom), SizeInBits, AlignInBits, 0, Flags, Elements,
-      RunTimeLang, DITypeRef::get(VTableHolder), nullptr, UniqueIdentifier);
-  if (!UniqueIdentifier.empty())
-    retainType(R);
+      getNonCompileUnitScope(Context), DerivedFrom, SizeInBits, AlignInBits, 0,
+      Flags, Elements, RunTimeLang, VTableHolder, nullptr, UniqueIdentifier);
   trackIfUnresolved(R);
   return R;
 }
@@ -428,11 +413,8 @@ DICompositeType *DIBuilder::createUnionType(
     DINodeArray Elements, unsigned RunTimeLang, StringRef UniqueIdentifier) {
   auto *R = DICompositeType::get(
       VMContext, dwarf::DW_TAG_union_type, Name, File, LineNumber,
-      DIScopeRef::get(getNonCompileUnitScope(Scope)), nullptr, SizeInBits,
-      AlignInBits, 0, Flags, Elements, RunTimeLang, nullptr, nullptr,
-      UniqueIdentifier);
-  if (!UniqueIdentifier.empty())
-    retainType(R);
+      getNonCompileUnitScope(Scope), nullptr, SizeInBits, AlignInBits, 0, Flags,
+      Elements, RunTimeLang, nullptr, nullptr, UniqueIdentifier);
   trackIfUnresolved(R);
   return R;
 }
@@ -445,13 +427,9 @@ DISubroutineType *DIBuilder::createSubroutineType(DITypeRefArray ParameterTypes,
 DICompositeType *DIBuilder::createExternalTypeRef(unsigned Tag, DIFile *File,
                                                   StringRef UniqueIdentifier) {
   assert(!UniqueIdentifier.empty() && "external type ref without uid");
-  auto *CTy =
-      DICompositeType::get(VMContext, Tag, "", nullptr, 0, nullptr, nullptr, 0,
-                           0, 0, DINode::FlagExternalTypeRef, nullptr, 0,
-                           nullptr, nullptr, UniqueIdentifier);
-  // Types with unique IDs need to be in the type map.
-  retainType(CTy);
-  return CTy;
+  return DICompositeType::get(VMContext, Tag, "", nullptr, 0, nullptr, nullptr,
+                              0, 0, 0, DINode::FlagExternalTypeRef, nullptr, 0,
+                              nullptr, nullptr, UniqueIdentifier);
 }
 
 DICompositeType *DIBuilder::createEnumerationType(
@@ -460,12 +438,9 @@ DICompositeType *DIBuilder::createEnumerationType(
     DIType *UnderlyingType, StringRef UniqueIdentifier) {
   auto *CTy = DICompositeType::get(
       VMContext, dwarf::DW_TAG_enumeration_type, Name, File, LineNumber,
-      DIScopeRef::get(getNonCompileUnitScope(Scope)),
-      DITypeRef::get(UnderlyingType), SizeInBits, AlignInBits, 0, 0, Elements,
-      0, nullptr, nullptr, UniqueIdentifier);
+      getNonCompileUnitScope(Scope), UnderlyingType, SizeInBits, AlignInBits, 0,
+      0, Elements, 0, nullptr, nullptr, UniqueIdentifier);
   AllEnumTypes.push_back(CTy);
-  if (!UniqueIdentifier.empty())
-    retainType(CTy);
   trackIfUnresolved(CTy);
   return CTy;
 }
@@ -474,8 +449,8 @@ DICompositeType *DIBuilder::createArrayType(uint64_t Size, uint64_t AlignInBits,
                                             DIType *Ty,
                                             DINodeArray Subscripts) {
   auto *R = DICompositeType::get(VMContext, dwarf::DW_TAG_array_type, "",
-                                 nullptr, 0, nullptr, DITypeRef::get(Ty), Size,
-                                 AlignInBits, 0, 0, Subscripts, 0, nullptr);
+                                 nullptr, 0, nullptr, Ty, Size, AlignInBits, 0,
+                                 0, Subscripts, 0, nullptr);
   trackIfUnresolved(R);
   return R;
 }
@@ -483,10 +458,9 @@ DICompositeType *DIBuilder::createArrayType(uint64_t Size, uint64_t AlignInBits,
 DICompositeType *DIBuilder::createVectorType(uint64_t Size,
                                              uint64_t AlignInBits, DIType *Ty,
                                              DINodeArray Subscripts) {
-  auto *R =
-      DICompositeType::get(VMContext, dwarf::DW_TAG_array_type, "", nullptr, 0,
-                           nullptr, DITypeRef::get(Ty), Size, AlignInBits, 0,
-                           DINode::FlagVector, Subscripts, 0, nullptr);
+  auto *R = DICompositeType::get(VMContext, dwarf::DW_TAG_array_type, "",
+                                 nullptr, 0, nullptr, Ty, Size, AlignInBits, 0,
+                                 DINode::FlagVector, Subscripts, 0, nullptr);
   trackIfUnresolved(R);
   return R;
 }
@@ -531,12 +505,9 @@ DIBuilder::createForwardDecl(unsigned Tag, StringRef Name, DIScope *Scope,
   // FIXME: Define in terms of createReplaceableForwardDecl() by calling
   // replaceWithUniqued().
   auto *RetTy = DICompositeType::get(
-      VMContext, Tag, Name, F, Line,
-      DIScopeRef::get(getNonCompileUnitScope(Scope)), nullptr, SizeInBits,
-      AlignInBits, 0, DINode::FlagFwdDecl, nullptr, RuntimeLang, nullptr,
-      nullptr, UniqueIdentifier);
-  if (!UniqueIdentifier.empty())
-    retainType(RetTy);
+      VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
+      SizeInBits, AlignInBits, 0, DINode::FlagFwdDecl, nullptr, RuntimeLang,
+      nullptr, nullptr, UniqueIdentifier);
   trackIfUnresolved(RetTy);
   return RetTy;
 }
@@ -545,14 +516,12 @@ DICompositeType *DIBuilder::createReplaceableCompositeType(
     unsigned Tag, StringRef Name, DIScope *Scope, DIFile *F, unsigned Line,
     unsigned RuntimeLang, uint64_t SizeInBits, uint64_t AlignInBits,
     unsigned Flags, StringRef UniqueIdentifier) {
-  auto *RetTy = DICompositeType::getTemporary(
-                    VMContext, Tag, Name, F, Line,
-                    DIScopeRef::get(getNonCompileUnitScope(Scope)), nullptr,
-                    SizeInBits, AlignInBits, 0, Flags, nullptr, RuntimeLang,
-                    nullptr, nullptr, UniqueIdentifier)
-                    .release();
-  if (!UniqueIdentifier.empty())
-    retainType(RetTy);
+  auto *RetTy =
+      DICompositeType::getTemporary(
+          VMContext, Tag, Name, F, Line, getNonCompileUnitScope(Scope), nullptr,
+          SizeInBits, AlignInBits, 0, Flags, nullptr, RuntimeLang, nullptr,
+          nullptr, UniqueIdentifier)
+          .release();
   trackIfUnresolved(RetTy);
   return RetTy;
 }
@@ -565,7 +534,7 @@ DITypeRefArray DIBuilder::getOrCreateTypeArray(ArrayRef<Metadata *> Elements) {
   SmallVector<llvm::Metadata *, 16> Elts;
   for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
     if (Elements[i] && isa<MDNode>(Elements[i]))
-      Elts.push_back(DITypeRef::get(cast<DIType>(Elements[i])));
+      Elts.push_back(cast<DIType>(Elements[i]));
     else
       Elts.push_back(Elements[i]);
   }
@@ -591,10 +560,10 @@ DIGlobalVariable *DIBuilder::createGlobalVariable(
     MDNode *Decl) {
   checkGlobalVariableScope(Context);
 
-  auto *N = DIGlobalVariable::get(VMContext, cast_or_null<DIScope>(Context),
-                                  Name, LinkageName, F, LineNumber,
-                                  DITypeRef::get(Ty), isLocalToUnit, true, Val,
-                                  cast_or_null<DIDerivedType>(Decl));
+  auto *N =
+      DIGlobalVariable::get(VMContext, cast_or_null<DIScope>(Context), Name,
+                            LinkageName, F, LineNumber, Ty, isLocalToUnit, true,
+                            Val, cast_or_null<DIDerivedType>(Decl));
   AllGVs.push_back(N);
   return N;
 }
@@ -607,7 +576,7 @@ DIGlobalVariable *DIBuilder::createTempGlobalVariableFwdDecl(
 
   return DIGlobalVariable::getTemporary(
              VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
-             LineNumber, DITypeRef::get(Ty), isLocalToUnit, false, Val,
+             LineNumber, Ty, isLocalToUnit, false, Val,
              cast_or_null<DIDerivedType>(Decl))
       .release();
 }
@@ -625,7 +594,7 @@ static DILocalVariable *createLocalVariable(
 
   auto *Node =
       DILocalVariable::get(VMContext, cast_or_null<DILocalScope>(Context), Name,
-                           File, LineNo, DITypeRef::get(Ty), ArgNo, Flags);
+                           File, LineNo, Ty, ArgNo, Flags);
   if (AlwaysPreserve) {
     // The optimizer may remove local variables. If there is an interest
     // to preserve variable info in such situation then stash it in a
@@ -684,9 +653,9 @@ DISubprogram *DIBuilder::createFunction(
     DITemplateParameterArray TParams, DISubprogram *Decl) {
   auto *Node = getSubprogram(
       /* IsDistinct = */ isDefinition, VMContext,
-      DIScopeRef::get(getNonCompileUnitScope(Context)), Name, LinkageName, File,
-      LineNo, Ty, isLocalToUnit, isDefinition, ScopeLine, nullptr, 0, 0, Flags,
-      isOptimized, isDefinition ? CUNode : nullptr, TParams, Decl,
+      getNonCompileUnitScope(Context), Name, LinkageName, File, LineNo, Ty,
+      isLocalToUnit, isDefinition, ScopeLine, nullptr, 0, 0, Flags, isOptimized,
+      isDefinition ? CUNode : nullptr, TParams, Decl,
       MDTuple::getTemporary(VMContext, None).release());
 
   if (isDefinition)
@@ -701,10 +670,10 @@ DISubprogram *DIBuilder::createTempFunctionFwdDecl(
     bool isDefinition, unsigned ScopeLine, unsigned Flags, bool isOptimized,
     DITemplateParameterArray TParams, DISubprogram *Decl) {
   return DISubprogram::getTemporary(
-             VMContext, DIScopeRef::get(getNonCompileUnitScope(Context)), Name,
-             LinkageName, File, LineNo, Ty, isLocalToUnit, isDefinition,
-             ScopeLine, nullptr, 0, 0, Flags, isOptimized,
-             isDefinition ? CUNode : nullptr, TParams, Decl, nullptr)
+             VMContext, getNonCompileUnitScope(Context), Name, LinkageName,
+             File, LineNo, Ty, isLocalToUnit, isDefinition, ScopeLine, nullptr,
+             0, 0, Flags, isOptimized, isDefinition ? CUNode : nullptr, TParams,
+             Decl, nullptr)
       .release();
 }
 
@@ -719,11 +688,10 @@ DIBuilder::createMethod(DIScope *Context, StringRef Name, StringRef LinkageName,
          "the compile unit.");
   // FIXME: Do we want to use different scope/lines?
   auto *SP = getSubprogram(
-      /* IsDistinct = */ isDefinition, VMContext,
-      DIScopeRef::get(cast<DIScope>(Context)), Name, LinkageName, F, LineNo, Ty,
-      isLocalToUnit, isDefinition, LineNo, DITypeRef::get(VTableHolder), VK,
-      VIndex, Flags, isOptimized, isDefinition ? CUNode : nullptr, TParams,
-      nullptr, nullptr);
+      /* IsDistinct = */ isDefinition, VMContext, cast<DIScope>(Context), Name,
+      LinkageName, F, LineNo, Ty, isLocalToUnit, isDefinition, LineNo,
+      VTableHolder, VK, VIndex, Flags, isOptimized,
+      isDefinition ? CUNode : nullptr, TParams, nullptr, nullptr);
 
   if (isDefinition)
     AllSubprograms.push_back(SP);
@@ -863,7 +831,7 @@ void DIBuilder::replaceVTableHolder(DICompositeType *&T,
                                     DICompositeType *VTableHolder) {
   {
     TypedTrackingMDRef<DICompositeType> N(T);
-    N->replaceVTableHolder(DITypeRef::get(VTableHolder));
+    N->replaceVTableHolder(VTableHolder);
     T = N.get();
   }