Create a new InjectedClassNameType to represent bare-word references to the

injected class name of a class template or class template partial specialization.
This is a non-canonical type;  the canonical type is still a template 
specialization type.  This becomes the TypeForDecl of the pattern declaration,
which cleans up some amount of code (and complicates some other parts, but
whatever).

Fixes PR6326 and probably a few others, primarily by re-establishing a few
invariants about TypeLoc sizes.     



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@98134 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 77 insertions, 7 deletions

diff --git a/include/clang/AST/ASTContext.h b/include/clang/AST/ASTContext.h
index 0838a3d0eb..fab63f556b 100644
--- a/include/clang/AST/ASTContext.h
+++ b/include/clang/AST/ASTContext.h
@@ -586,6 +586,8 @@ public:
   /// specified typename decl.
   QualType getTypedefType(const TypedefDecl *Decl);
 
+  QualType getInjectedClassNameType(CXXRecordDecl *Decl, QualType TST);
+
   QualType getSubstTemplateTypeParmType(const TemplateTypeParmType *Replaced,
                                         QualType Replacement);
 
@@ -602,6 +604,11 @@ public:
                                          const TemplateArgumentListInfo &Args,
                                          QualType Canon = QualType());
 
+  TypeSourceInfo *
+  getTemplateSpecializationTypeInfo(TemplateName T, SourceLocation TLoc,
+                                    const TemplateArgumentListInfo &Args,
+                                    QualType Canon = QualType());
+
   QualType getQualifiedNameType(NestedNameSpecifier *NNS,
                                 QualType NamedType);
   QualType getTypenameType(NestedNameSpecifier *NNS,
diff --git a/include/clang/AST/Decl.h b/include/clang/AST/Decl.h
index 91aeff3439..bd9f01b0b5 100644
--- a/include/clang/AST/Decl.h
+++ b/include/clang/AST/Decl.h
@@ -1429,7 +1429,6 @@ class TypeDecl : public NamedDecl {
   friend class DeclContext;
   friend class TagDecl;
   friend class TemplateTypeParmDecl;
-  friend class ClassTemplateSpecializationDecl;
   friend class TagType;
 
 protected:
diff --git a/include/clang/AST/DeclTemplate.h b/include/clang/AST/DeclTemplate.h
index ced174716c..560ce46ede 100644
--- a/include/clang/AST/DeclTemplate.h
+++ b/include/clang/AST/DeclTemplate.h
@@ -771,6 +771,10 @@ class ClassTemplateSpecializationDecl
   llvm::PointerUnion<ClassTemplateDecl *, SpecializedPartialSpecialization *>
     SpecializedTemplate;
 
+  /// \brief The type-as-written of an explicit template specialization.
+  /// Does not apply to implicit specializations.
+  TypeSourceInfo *TypeAsWritten;
+
   /// \brief The template arguments used to describe this specialization.
   TemplateArgumentList TemplateArgs;
 
@@ -883,8 +887,14 @@ public:
 
   /// \brief Sets the type of this specialization as it was written by
   /// the user. This will be a class template specialization type.
-  void setTypeAsWritten(QualType T) {
-    TypeForDecl = T.getTypePtr();
+  void setTypeAsWritten(TypeSourceInfo *T) {
+    TypeAsWritten = T;
+  }
+
+  /// \brief Gets the type of this specialization as it was written by
+  /// the user, if it was so written.
+  TypeSourceInfo *getTypeAsWritten() const {
+    return TypeAsWritten;
   }
 
   void Profile(llvm::FoldingSetNodeID &ID) const {
@@ -921,6 +931,7 @@ class ClassTemplatePartialSpecializationDecl
   TemplateParameterList* TemplateParams;
 
   /// \brief The source info for the template arguments as written.
+  /// FIXME: redundant with TypeAsWritten?
   TemplateArgumentLoc *ArgsAsWritten;
   unsigned NumArgsAsWritten;
 
@@ -954,6 +965,7 @@ public:
          ClassTemplateDecl *SpecializedTemplate,
          TemplateArgumentListBuilder &Builder,
          const TemplateArgumentListInfo &ArgInfos,
+         QualType CanonInjectedType,
          ClassTemplatePartialSpecializationDecl *PrevDecl);
 
   /// Get the list of template parameters
@@ -1139,8 +1151,8 @@ public:
   /// the type \p T, or NULL if no such partial specialization exists.
   ClassTemplatePartialSpecializationDecl *findPartialSpecialization(QualType T);
 
-  /// \brief Retrieve the type of the injected-class-name for this
-  /// class template.
+  /// \brief Retrieve the template specialization type of the
+  /// injected-class-name for this class template.
   ///
   /// The injected-class-name for a class template \c X is \c
   /// X<template-args>, where \c template-args is formed from the
@@ -1153,7 +1165,7 @@ public:
   ///   typedef array this_type; // "array" is equivalent to "array<T, N>"
   /// };
   /// \endcode
-  QualType getInjectedClassNameType(ASTContext &Context);
+  QualType getInjectedClassNameSpecialization(ASTContext &Context);
 
   /// \brief Retrieve the member class template that this class template was
   /// derived from.
diff --git a/include/clang/AST/Type.h b/include/clang/AST/Type.h
index bd8a6bc846..111be55621 100644
--- a/include/clang/AST/Type.h
+++ b/include/clang/AST/Type.h
@@ -2440,6 +2440,47 @@ public:
   static bool classof(const TemplateSpecializationType *T) { return true; }
 };
 
+/// \brief The injected class name of a C++ class template.  Used to
+/// record that a type was spelled with a bare identifier rather than
+/// as a template-id; the equivalent for non-templated classes is just
+/// RecordType.
+///
+/// For consistency, template instantiation turns these into RecordTypes.
+///
+/// The desugared form is always a unqualified TemplateSpecializationType.
+/// The canonical form is always either a TemplateSpecializationType
+/// (when dependent) or a RecordType (otherwise).
+class InjectedClassNameType : public Type {
+  CXXRecordDecl *Decl;
+
+  QualType UnderlyingType;
+
+  friend class ASTContext; // ASTContext creates these.
+  InjectedClassNameType(CXXRecordDecl *D, QualType TST, QualType Canon)
+    : Type(InjectedClassName, Canon, Canon->isDependentType()),
+      Decl(D), UnderlyingType(TST) {
+    assert(isa<TemplateSpecializationType>(TST));
+    assert(!TST.hasQualifiers());
+    assert(TST->getCanonicalTypeInternal() == Canon);
+  }
+
+public:
+  QualType getUnderlyingType() const { return UnderlyingType; }
+  const TemplateSpecializationType *getUnderlyingTST() const {
+    return cast<TemplateSpecializationType>(UnderlyingType.getTypePtr());
+  }
+
+  CXXRecordDecl *getDecl() const { return Decl; }
+
+  bool isSugared() const { return true; }
+  QualType desugar() const { return UnderlyingType; }
+
+  static bool classof(const Type *T) {
+    return T->getTypeClass() == InjectedClassName;
+  }
+  static bool classof(const InjectedClassNameType *T) { return true; }
+};
+
 /// \brief Represents a type that was referred to via a qualified
 /// name, e.g., N::M::type.
 ///
diff --git a/include/clang/AST/TypeLoc.h b/include/clang/AST/TypeLoc.h
index 6fb51edb76..27659bd02f 100644
--- a/include/clang/AST/TypeLoc.h
+++ b/include/clang/AST/TypeLoc.h
@@ -488,6 +488,14 @@ public:
   }
 };
 
+/// \brief Wrapper for source info for injected class names of class
+/// templates.
+class InjectedClassNameTypeLoc :
+    public InheritingConcreteTypeLoc<TypeSpecTypeLoc,
+                                     InjectedClassNameTypeLoc,
+                                     InjectedClassNameType> {
+};
+
 /// \brief Wrapper for source info for unresolved typename using decls.
 class UnresolvedUsingTypeLoc :
     public InheritingConcreteTypeLoc<TypeSpecTypeLoc,
diff --git a/include/clang/AST/TypeNodes.def b/include/clang/AST/TypeNodes.def
index 8187caddc6..e75202e50a 100644
--- a/include/clang/AST/TypeNodes.def
+++ b/include/clang/AST/TypeNodes.def
@@ -91,6 +91,7 @@ DEPENDENT_TYPE(TemplateTypeParm, Type)
 NON_CANONICAL_TYPE(SubstTemplateTypeParm, Type)
 NON_CANONICAL_UNLESS_DEPENDENT_TYPE(TemplateSpecialization, Type)
 NON_CANONICAL_TYPE(QualifiedName, Type)
+NON_CANONICAL_TYPE(InjectedClassName, Type)
 DEPENDENT_TYPE(Typename, Type)
 TYPE(ObjCInterface, Type)
 TYPE(ObjCObjectPointer, Type)
diff --git a/include/clang/Frontend/PCHBitCodes.h b/include/clang/Frontend/PCHBitCodes.h
index d4014b3075..e234e9838a 100644
--- a/include/clang/Frontend/PCHBitCodes.h
+++ b/include/clang/Frontend/PCHBitCodes.h
@@ -408,7 +408,9 @@ namespace clang {
       /// \brief A SubstTemplateTypeParmType record.
       TYPE_SUBST_TEMPLATE_TYPE_PARM = 25,
       /// \brief An UnresolvedUsingType record.
-      TYPE_UNRESOLVED_USING         = 26
+      TYPE_UNRESOLVED_USING         = 26,
+      /// \brief An InjectedClassNameType record.
+      TYPE_INJECTED_CLASS_NAME      = 27
     };
 
     /// \brief The type IDs for special types constructed by semantic