Move the construction of the RecordDecl representing the runtime

layout of a constant NSString from the ASTContext over to CodeGen,
since this is solely CodeGen's responsibility. Eliminates one of the
unnecessary "special" types that we serialize.

llvm-svn: 137121

5 files changed, 55 insertions, 52 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 92695f2398e..3f8cf37a68e 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -222,7 +222,7 @@ ASTContext::ASTContext(const LangOptions& LOpts, SourceManager &SM,
   DependentTemplateSpecializationTypes(this_()),
   SubstTemplateTemplateParmPacks(this_()),
   GlobalNestedNameSpecifier(0), IsInt128Installed(false),
-  CFConstantStringTypeDecl(0), NSConstantStringTypeDecl(0),
+  CFConstantStringTypeDecl(0),
   ObjCFastEnumerationStateTypeDecl(0), FILEDecl(0), 
   jmp_bufDecl(0), sigjmp_bufDecl(0), BlockDescriptorType(0), 
   BlockDescriptorExtendedType(0), cudaConfigureCallDecl(0),
@@ -3639,48 +3639,6 @@ void ASTContext::setCFConstantStringType(QualType T) {
   CFConstantStringTypeDecl = Rec->getDecl();
 }
 
-// getNSConstantStringType - Return the type used for constant NSStrings.
-QualType ASTContext::getNSConstantStringType() const {
-  if (!NSConstantStringTypeDecl) {
-    NSConstantStringTypeDecl =
-    CreateRecordDecl(*this, TTK_Struct, TUDecl,
-                     &Idents.get("__builtin_NSString"));
-    NSConstantStringTypeDecl->startDefinition();
-    
-    QualType FieldTypes[3];
-    
-    // const int *isa;
-    FieldTypes[0] = getPointerType(IntTy.withConst());
-    // const char *str;
-    FieldTypes[1] = getPointerType(CharTy.withConst());
-    // unsigned int length;
-    FieldTypes[2] = UnsignedIntTy;
-    
-    // Create fields
-    for (unsigned i = 0; i < 3; ++i) {
-      FieldDecl *Field = FieldDecl::Create(*this, NSConstantStringTypeDecl,
-                                           SourceLocation(),
-                                           SourceLocation(), 0,
-                                           FieldTypes[i], /*TInfo=*/0,
-                                           /*BitWidth=*/0,
-                                           /*Mutable=*/false,
-                                           /*HasInit=*/false);
-      Field->setAccess(AS_public);
-      NSConstantStringTypeDecl->addDecl(Field);
-    }
-    
-    NSConstantStringTypeDecl->completeDefinition();
-  }
-  
-  return getTagDeclType(NSConstantStringTypeDecl);
-}
-
-void ASTContext::setNSConstantStringType(QualType T) {
-  const RecordType *Rec = T->getAs<RecordType>();
-  assert(Rec && "Invalid NSConstantStringType");
-  NSConstantStringTypeDecl = Rec->getDecl();
-}
-
 QualType ASTContext::getObjCFastEnumerationStateType() const {
   if (!ObjCFastEnumerationStateTypeDecl) {
     ObjCFastEnumerationStateTypeDecl =
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 5341f22ab97..13c8f6080ff 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -66,6 +66,7 @@ CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO,
     TBAA(0),
     VTables(*this), ObjCRuntime(0), DebugInfo(0), ARCData(0), RRData(0),
     CFConstantStringClassRef(0), ConstantStringClassRef(0),
+    NSConstantStringType(0),
     VMContext(M.getContext()),
     NSConcreteGlobalBlockDecl(0), NSConcreteStackBlockDecl(0),
     NSConcreteGlobalBlock(0), NSConcreteStackBlock(0),
@@ -1800,6 +1801,16 @@ CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
   return GV;
 }
 
+static RecordDecl *
+CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK,
+                 DeclContext *DC, IdentifierInfo *Id) {
+  SourceLocation Loc;
+  if (Ctx.getLangOptions().CPlusPlus)
+    return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id);
+  else
+    return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id);
+}
+
 llvm::Constant *
 CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) {
   unsigned StringLength = 0;
@@ -1838,11 +1849,40 @@ CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) {
         llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
     }
   }
-  
-  QualType NSTy = getContext().getNSConstantStringType();
-  
-  llvm::StructType *STy =
-  cast<llvm::StructType>(getTypes().ConvertType(NSTy));
+
+  if (!NSConstantStringType) {
+    // Construct the type for a constant NSString.
+    RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 
+                                     Context.getTranslationUnitDecl(),
+                                   &Context.Idents.get("__builtin_NSString"));
+    D->startDefinition();
+      
+    QualType FieldTypes[3];
+    
+    // const int *isa;
+    FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst());
+    // const char *str;
+    FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst());
+    // unsigned int length;
+    FieldTypes[2] = Context.UnsignedIntTy;
+    
+    // Create fields
+    for (unsigned i = 0; i < 3; ++i) {
+      FieldDecl *Field = FieldDecl::Create(Context, D,
+                                           SourceLocation(),
+                                           SourceLocation(), 0,
+                                           FieldTypes[i], /*TInfo=*/0,
+                                           /*BitWidth=*/0,
+                                           /*Mutable=*/false,
+                                           /*HasInit=*/false);
+      Field->setAccess(AS_public);
+      D->addDecl(Field);
+    }
+    
+    D->completeDefinition();
+    QualType NSTy = Context.getTagDeclType(D);
+    NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy));
+  }
   
   std::vector<llvm::Constant*> Fields(3);
   
@@ -1870,7 +1910,7 @@ CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) {
   Fields[2] = llvm::ConstantInt::get(Ty, StringLength);
   
   // The struct.
-  C = llvm::ConstantStruct::get(STy, Fields);
+  C = llvm::ConstantStruct::get(NSConstantStringType, Fields);
   GV = new llvm::GlobalVariable(getModule(), C->getType(), true,
                                 llvm::GlobalVariable::PrivateLinkage, C,
                                 "_unnamed_nsstring_");
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index ca72230559e..56ff68cc8d3 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -286,6 +286,9 @@ class CodeGenModule : public CodeGenTypeCache {
   /// run on termination.
   std::vector<std::pair<llvm::WeakVH,llvm::Constant*> > CXXGlobalDtors;
 
+  /// @name Cache for Objective-C runtime types
+  /// @{
+
   /// CFConstantStringClassRef - Cached reference to the class for constant
   /// strings. This value has type int * but is actually an Obj-C class pointer.
   llvm::Constant *CFConstantStringClassRef;
@@ -294,6 +297,11 @@ class CodeGenModule : public CodeGenTypeCache {
   /// strings. This value has type int * but is actually an Obj-C class pointer.
   llvm::Constant *ConstantStringClassRef;
 
+  /// \brief The LLVM type corresponding to NSConstantString.
+  llvm::StructType *NSConstantStringType;
+  
+  /// @}
+
   /// Lazily create the Objective-C runtime
   void createObjCRuntime();
 
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 9659f46f17a..d5cb6a6cedf 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -3041,8 +3041,6 @@ void ASTReader::InitializeContext(ASTContext &Ctx) {
     if (unsigned ObjCSelRedef
         = SpecialTypes[SPECIAL_TYPE_OBJC_SEL_REDEFINITION])
       Context->ObjCSelRedefinitionType = GetType(ObjCSelRedef);
-    if (unsigned String = SpecialTypes[SPECIAL_TYPE_NS_CONSTANT_STRING])
-      Context->setNSConstantStringType(GetType(String));
 
     if (SpecialTypes[SPECIAL_TYPE_INT128_INSTALLED])
       Context->setInt128Installed();
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 256bf9da3e5..6cdd6cad607 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -2943,7 +2943,6 @@ void ASTWriter::WriteASTCore(Sema &SemaRef, MemorizeStatCalls *StatCalls,
   AddTypeRef(Context.getRawBlockdescriptorType(), SpecialTypes);
   AddTypeRef(Context.getRawBlockdescriptorExtendedType(), SpecialTypes);
   AddTypeRef(Context.ObjCSelRedefinitionType, SpecialTypes);
-  AddTypeRef(Context.getRawNSConstantStringType(), SpecialTypes);
   SpecialTypes.push_back(Context.isInt128Installed());
 
   // Keep writing types and declarations until all types and