Don't automatically assume that an id-expression refers to a

ValueDecl, because that isn't always the case in ill-formed
code. Diagnose a common mistake (forgetting to provide a template
argument list for a class template, PR5655) and dyn_cast so that we
handle the general problem of referring to a non-value declaration
gracefully.

llvm-svn: 90239

1 files changed, 17 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index f653cf63d80..bf14d0d3032 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -1246,7 +1246,23 @@ Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS,
   if (CheckDeclInExpr(*this, Loc, D))
     return ExprError();
 
-  ValueDecl *VD = cast<ValueDecl>(D);
+  if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D)) {
+    // Specifically diagnose references to class templates that are missing
+    // a template argument list.
+    Diag(Loc, diag::err_template_decl_ref)
+      << Template << SS.getRange();
+    Diag(Template->getLocation(), diag::note_template_decl_here);
+    return ExprError();
+  }
+
+  // Make sure that we're referring to a value.
+  ValueDecl *VD = dyn_cast<ValueDecl>(D);
+  if (!VD) {
+    Diag(Loc, diag::err_ref_non_value) 
+      << D << SS.getRange();
+    Diag(D->getLocation(), diag::note_previous_decl);
+    return ExprError();
+  }
 
   // Check whether this declaration can be used. Note that we suppress
   // this check when we're going to perform argument-dependent lookup