Improve diagnostics when an elaborated-type-specifer containing a

nested-name-specifier (e.g., "class T::foo") fails to find a tag
member in the scope nominated by the
nested-name-specifier. Previously, we gave a bland

  error: 'Nested' does not name a tag member in the specified scope

which didn't actually say where we were looking, which was rather
horrible when the nested-name-specifier was instantiated. Now, we give
something a bit better:

  error: no class named 'Nested' in 'NoDepBase<T>'

llvm-svn: 100060

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -2182,7 +2182,7 @@ def err_invalid_declarator_global_scope : Error<
 def err_invalid_declarator_in_function : Error<
   "definition or redeclaration of %0 not allowed inside a function">;
 def err_not_tag_in_scope : Error<
-  "%0 does not name a tag member in the specified scope">;
+  "no %select{struct|union|class|enum}0 named %1 in %2">;
 
 def err_cannot_form_pointer_to_member_of_reference_type : Error<
   "cannot form a pointer-to-member to member %0 of reference type %1">;

clang/lib/Sema/SemaDecl.cpp

@@ -4786,7 +4786,8 @@ Sema::DeclPtrTy Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
       }
 
       // A tag 'foo::bar' must already exist.
-      Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange();
+      Diag(NameLoc, diag::err_not_tag_in_scope) 
+        << Kind << Name << DC << SS.getRange();
       Name = 0;
       Invalid = true;
       goto CreateNewDecl;

clang/lib/Sema/SemaTemplateInstantiateDecl.cpp

@@ -693,7 +693,8 @@ Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
 
     if (!PrevClassTemplate && Qualifier) {
       SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
-        << Pattern->getDeclName() << Pattern->getQualifierRange();
+        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
+        << Pattern->getQualifierRange();
       return 0;
     }
 

clang/lib/Sema/TreeTransform.h

@@ -618,9 +618,9 @@ public:
     }
 
     if (!Tag) {
-      // FIXME: Crummy diagnostic
+      // FIXME: Would be nice to highlight just the source range.
       SemaRef.Diag(SR.getEnd(), diag::err_not_tag_in_scope)
-        << Id << SR;
+        << Kind << Id << DC;
       return QualType();
     }
     

clang/test/CXX/dcl.dcl/dcl.spec/dcl.type/dcl.type.elab/p3.cpp

@@ -40,10 +40,10 @@ void c2(class B<float>::Member);
 void c3(union B<float>::Member); // expected-error {{use of 'Member' with tag type that does not match previous declaration}}
 void c4(enum B<float>::Member); // expected-error {{use of 'Member' with tag type that does not match previous declaration}}
 
-void d1(struct B<int>::Member); // expected-error {{'Member' does not name a tag member in the specified scope}}
+void d1(struct B<int>::Member); // expected-error {{no struct named 'Member' in 'B<int>'}}
-void d2(class B<int>::Member); // expected-error {{'Member' does not name a tag member in the specified scope}}
+void d2(class B<int>::Member); // expected-error {{no class named 'Member' in 'B<int>'}}
-void d3(union B<int>::Member); // expected-error {{'Member' does not name a tag member in the specified scope}}
+void d3(union B<int>::Member); // expected-error {{no union named 'Member' in 'B<int>'}}
-void d4(enum B<int>::Member); // expected-error {{'Member' does not name a tag member in the specified scope}}
+void d4(enum B<int>::Member); // expected-error {{no enum named 'Member' in 'B<int>'}}
 
 void e1(struct B<A>::Member); // expected-error {{use of 'Member' with tag type that does not match previous declaration}}
 void e2(class B<A>::Member); // expected-error {{use of 'Member' with tag type that does not match previous declaration}}
@@ -51,7 +51,7 @@ void e3(union B<A>::Member);
 void e4(enum B<A>::Member); // expected-error {{use of 'Member' with tag type that does not match previous declaration}}
 
 template <class T> struct C {
-  void foo(class B<T>::Member); // expected-error{{'Member' does not name a tag member in the specified scope}} \
+  void foo(class B<T>::Member); // expected-error{{no class named 'Member' in 'B<int>'}} \
                                 // expected-error{{use of 'Member' with tag type that does not match previous declaration}}
 };
 

clang/test/SemaCXX/nested-name-spec.cpp

@@ -64,7 +64,7 @@ void f2() {
 A::C c1;
 struct A::C c2;
 struct S : public A::C {};
-struct A::undef; // expected-error {{'undef' does not name a tag member in the specified scope}}
+struct A::undef; // expected-error {{no struct named 'undef' in namespace 'A'}}
 
 namespace A2 {
   typedef int INT;

clang/test/SemaTemplate/dependent-base-classes.cpp

@@ -55,7 +55,7 @@ namespace PR6031 {
   template<typename T>
   struct NoDepBase {
     int foo() {
-      class NoDepBase::Nested nested; // expected-error{{'Nested' does not name a tag member in the specified scope}}
+      class NoDepBase::Nested nested; // expected-error{{no class named 'Nested' in 'NoDepBase<T>'}}
       typedef typename NoDepBase::template MemberTemplate<T>::type type; // expected-error{{'MemberTemplate' following the 'template' keyword does not refer to a template}} \
       // FIXME: expected-error{{unqualified-id}}
       return NoDepBase::a; // expected-error{{no member named 'a' in 'NoDepBase<T>'}}

clang/test/SemaTemplate/instantiate-declref.cpp

@@ -36,7 +36,7 @@ namespace N {
 
 typedef int INT;
 template struct N::Outer::Inner::InnerTemplate<INT>::VeryInner;
-template struct N::Outer::Inner::InnerTemplate<INT>::UeberInner; // expected-error{{'UeberInner' does not name a tag member}}
+template struct N::Outer::Inner::InnerTemplate<INT>::UeberInner; // expected-error{{no struct named 'UeberInner' in 'N::Outer::Inner::InnerTemplate<int>'}}
 
 namespace N2 {
   struct Outer2 {