re PR c++/54276 (Lambda in a Template Function Undefined Reference to local static)

	PR c++/54276
	* semantics.c (finish_id_expression): Also return the identifier
	for an outer local static.

From-SVN: r196091

gcc/cp/ChangeLog

 2013-02-15  Jason Merrill  <jason@redhat.com>
 
+	PR c++/54276
+	* semantics.c (finish_id_expression): Also return the identifier
+	for an outer local static.
+
 	PR c++/56343
 	* class.c (check_bases_and_members): Deduce noexcept after
 	checking bases.

gcc/cp/semantics.c

@@ -2876,18 +2876,26 @@ baselink_for_fns (tree fns)
   return build_baselink (cl, cl, fns, /*optype=*/NULL_TREE);
 }
 
-/* Returns true iff DECL is an automatic variable from a function outside
+/* Returns true iff DECL is a variable from a function outside
    the current one.  */
 
 static bool
-outer_automatic_var_p (tree decl)
+outer_var_p (tree decl)
 {
   return ((TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL)
 	  && DECL_FUNCTION_SCOPE_P (decl)
-	  && !TREE_STATIC (decl)
 	  && DECL_CONTEXT (decl) != current_function_decl);
 }
 
+/* As above, but also checks that DECL is automatic.  */
+
+static bool
+outer_automatic_var_p (tree decl)
+{
+  return (outer_var_p (decl)
+	  && !TREE_STATIC (decl));
+}
+
 /* ID_EXPRESSION is a representation of parsed, but unprocessed,
    id-expression.  (See cp_parser_id_expression for details.)  SCOPE,
    if non-NULL, is the type or namespace used to explicitly qualify
@@ -2994,9 +3002,18 @@ finish_id_expression (tree id_expression,
 
       /* Disallow uses of local variables from containing functions, except
 	 within lambda-expressions.  */
-      if (outer_automatic_var_p (decl)
+      if (!outer_var_p (decl)
 	  /* It's not a use (3.2) if we're in an unevaluated context.  */
-	  && !cp_unevaluated_operand)
+	  || cp_unevaluated_operand)
+	/* OK.  */;
+      else if (TREE_STATIC (decl))
+	{
+	  if (processing_template_decl)
+	    /* For a use of an outer static var, return the identifier so
+	       that we'll look it up again in the instantiation.  */
+	    return id_expression;
+	}
+      else
 	{
 	  tree context = DECL_CONTEXT (decl);
 	  tree containing_function = current_function_decl;

gcc/testsuite/g++.dg/cpp0x/lambda/lambda-template9.C

+// PR c++/54276
+// { dg-do link { target c++11 } }
+
+template <typename T>
+void foo(T)
+{
+  static int x = 1;
+  auto f = [] { return x + 1; };
+  f();
+}
+
+int main()
+{
+  foo(4);
+}