[cfe-commits] r121322 - in /cfe/trunk: include/clang/Basic/DiagnosticSemaKinds.td lib/Sema/SemaTemplate.cpp test/SemaTemplate/typename-specifier-4.cpp

[Douglas Gregor]

Author: dgregor
Date: Wed Dec  8 18:06:27 2010
New Revision: 121322

URL: http://llvm.org/viewvc/llvm-project?rev=121322&view=rev
Log:
A typename specifier can end up referring to a unresolved using
declaration that is a value in ill-formed code. Instead of crashing,
treat this as a dependent typename specifier and suggest that the
using add "typename" into the using declaration. Fixes <rdar://problem/8740998>.

Modified:
    cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
    cfe/trunk/lib/Sema/SemaTemplate.cpp
    cfe/trunk/test/SemaTemplate/typename-specifier-4.cpp

Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=121322&r1=121321&r2=121322&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Wed Dec  8 18:06:27 2010
@@ -1782,6 +1782,11 @@
   "missing 'typename' prior to dependent type name '%0%1'">;
 def ext_typename_outside_of_template : ExtWarn<
   "'typename' occurs outside of a template">, InGroup<CXX0x>;
+def err_typename_refers_to_using_value_decl : Error<
+  "typename specifier refers to a dependent using declaration for a value "
+  "%0 in %1">;
+def note_using_value_decl_missing_typename : Note<
+  "add 'typename' to treat this using declaration as a type">;
 
 def err_template_kw_refers_to_non_template : Error<
     "%0 following the 'template' keyword does not refer to a template">;

Modified: cfe/trunk/lib/Sema/SemaTemplate.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplate.cpp?rev=121322&r1=121321&r2=121322&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplate.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplate.cpp Wed Dec  8 18:06:27 2010
@@ -5699,6 +5699,23 @@
   case LookupResult::NotFound:
     DiagID = diag::err_typename_nested_not_found;
     break;
+
+  case LookupResult::FoundUnresolvedValue: {
+    // We found a using declaration that is a value. Most likely, the using
+    // declaration itself is meant to have the 'typename' keyword.
+    SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : NNSRange.getBegin(),
+                          IILoc);
+    Diag(IILoc, diag::err_typename_refers_to_using_value_decl)
+      << Name << Ctx << FullRange;
+    if (UnresolvedUsingValueDecl *Using
+          = dyn_cast<UnresolvedUsingValueDecl>(Result.getRepresentativeDecl())){
+      SourceLocation Loc = Using->getTargetNestedNameRange().getBegin();
+      Diag(Loc, diag::note_using_value_decl_missing_typename)
+        << FixItHint::CreateInsertion(Loc, "typename ");
+    }
+  }
+  // Fall through to create a dependent typename type, from which we can recover
+  // better.
       
   case LookupResult::NotFoundInCurrentInstantiation:
     // Okay, it's a member of an unknown instantiation.
@@ -5716,7 +5733,7 @@
     Referenced = Result.getFoundDecl();
     break;
 
-  case LookupResult::FoundUnresolvedValue:
+    
     llvm_unreachable("unresolved using decl in non-dependent context");
     return QualType();
 

Modified: cfe/trunk/test/SemaTemplate/typename-specifier-4.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaTemplate/typename-specifier-4.cpp?rev=121322&r1=121321&r2=121322&view=diff
==============================================================================
--- cfe/trunk/test/SemaTemplate/typename-specifier-4.cpp (original)
+++ cfe/trunk/test/SemaTemplate/typename-specifier-4.cpp Wed Dec  8 18:06:27 2010
@@ -134,3 +134,23 @@
   template <typename T> typename T::Y::Z::W *S<T>::f() { }
   template <typename T> typename T::template Y<int>::template Z<float>::template W<double> S<T>::g() { }
 }
+
+namespace rdar8740998 {
+  template<typename T>
+  struct X : public T {
+    using T::iterator; // expected-note{{add 'typename' to treat this using declaration as a type}} \
+    // expected-error{{dependent using declaration resolved to type without 'typename'}}
+
+    void f() {
+      typename X<T>::iterator i; // expected-error{{typename specifier refers to a dependent using declaration for a value 'iterator' in 'X<T>'}}
+    }
+  };
+
+  struct HasIterator {
+    typedef int *iterator; // expected-note{{target of using declaration}}
+  };
+
+  void test_X(X<HasIterator> xi) { // expected-note{{in instantiation of template class}}
+    xi.f();
+  }
+}