Implement more of C++0x 'auto'. A variable with an auto type specifier must have an initializer. Also, move some tests around to match the C++0x draft better.

llvm-svn: 75322

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -417,6 +417,8 @@ def err_illegal_decl_array_of_auto : Error<
 def err_auto_not_allowed : Error<
   "'auto' not allowed in %select{function prototype|struct member|union member"
   "|class member|exception declaration|template parameter|block literal}0">;
+def err_auto_var_requires_init : Error<
+  "declaration of variable %0 with type %1 requires an initializer">;
   
 // Objective-C++
 def err_objc_decls_may_only_appear_in_global_scope : Error<

clang/include/clang/Parse/Action.h

@@ -302,7 +302,10 @@ public:
 
   /// ActOnUninitializedDecl - This action is called immediately after
   /// ActOnDeclarator (when an initializer is *not* present).
-  virtual void ActOnUninitializedDecl(DeclPtrTy Dcl) {
+  /// If TypeContainsUndeducedAuto is true, then the type of the declarator
+  /// has an undeduced 'auto' type somewhere.
+  virtual void ActOnUninitializedDecl(DeclPtrTy Dcl, 
+                                      bool TypeContainsUndeducedAuto) {
     return;
   }
 

clang/lib/AST/Type.cpp

@@ -1006,7 +1006,7 @@ const char *BuiltinType::getName(const LangOptions &LO) const {
   case NullPtr:           return "nullptr_t";
   case Overload:          return "<overloaded function type>";
   case Dependent:         return "<dependent type>";
-  case UndeducedAuto:     return "<undeduced auto type>";
+  case UndeducedAuto:     return "auto";
   }
 }
 

clang/lib/Parse/ParseDecl.cpp

@@ -465,7 +465,9 @@ Parser::DeclPtrTy Parser::ParseDeclarationAfterDeclarator(Declarator &D,
                                             CommaLocs.data(), RParenLoc);
     }
   } else {
-    Actions.ActOnUninitializedDecl(ThisDecl);
+    bool TypeContainsUndeducedAuto = 
+      D.getDeclSpec().getTypeSpecType() == DeclSpec::TST_auto;
+    Actions.ActOnUninitializedDecl(ThisDecl, TypeContainsUndeducedAuto);
   }
 
   return ThisDecl;

clang/lib/Sema/Sema.h

@@ -473,7 +473,7 @@ public:
 
   virtual void AddInitializerToDecl(DeclPtrTy dcl, FullExprArg init);
   void AddInitializerToDecl(DeclPtrTy dcl, ExprArg init, bool DirectInit);
-  void ActOnUninitializedDecl(DeclPtrTy dcl);
+  void ActOnUninitializedDecl(DeclPtrTy dcl, bool TypeContainsUndeducedAuto);
   virtual void SetDeclDeleted(DeclPtrTy dcl, SourceLocation DelLoc);
   virtual DeclGroupPtrTy FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS,
                                                  DeclPtrTy *Group,

clang/lib/Sema/SemaDecl.cpp

@@ -2756,7 +2756,8 @@ void Sema::AddInitializerToDecl(DeclPtrTy dcl, ExprArg init, bool DirectInit) {
   return;
 }
 
-void Sema::ActOnUninitializedDecl(DeclPtrTy dcl) {
+void Sema::ActOnUninitializedDecl(DeclPtrTy dcl, 
+                                  bool TypeContainsUndeducedAuto) {
   Decl *RealDecl = dcl.getAs<Decl>();
 
   // If there is no declaration, there was an error parsing it. Just ignore it.
@@ -2784,6 +2785,14 @@ void Sema::ActOnUninitializedDecl(DeclPtrTy dcl) {
       return;
     }
 
+    // C++0x [dcl.spec.auto]p3
+    if (TypeContainsUndeducedAuto) {
+      Diag(Var->getLocation(), diag::err_auto_var_requires_init)
+        << Var->getDeclName() << Type;
+      Var->setInvalidDecl();
+      return;
+    }
+    
     // C++ [dcl.init]p9:
     //
     //   If no initializer is specified for an object, and the object