re PR c/28280 (bogus "statement with no effect" warning with VLA and typeof)

	PR c/28280
	* c-parser.c (c_parser_typeof_specifier): Don't use
	c_finish_expr_stmt, open code desired semantics instead.

From-SVN: r115369

gcc/ChangeLog

 2006-07-12  Mike Stump  <mrs@apple.com>
 
+	PR c/28280
+	* c-parser.c (c_parser_typeof_specifier): Don't use
+	c_finish_expr_stmt, open code desired semantics instead.
+
 	* protoize.c (edit_fn_definition): Add volatile to clean_text_p.
 
 2006-07-10  Eric Christopher  <echristo@apple.com>

gcc/c-parser.c

@@ -2164,7 +2164,19 @@ c_parser_typeof_specifier (c_parser *parser)
 	 is evaluated, this can be evaluated.  For now, we avoid
 	 evaluation when the context might.  */
       if (!skip_evaluation && was_vm)
-	c_finish_expr_stmt (expr.value);
+	{
+	  tree e = expr.value;
+
+	  /* If the expression is not of a type to which we cannot assign a line
+	     number, wrap the thing in a no-op NOP_EXPR.  */
+	  if (DECL_P (e) || CONSTANT_CLASS_P (e))
+	    e = build1 (NOP_EXPR, void_type_node, e);
+
+	  if (EXPR_P (e))
+	    SET_EXPR_LOCATION (e, input_location);
+
+	  add_stmt (e);
+	}
       pop_maybe_used (was_vm);
     }
   c_parser_skip_until_found (parser, CPP_CLOSE_PAREN, "expected %<)%>");

gcc/testsuite/gcc.dg/vla-9.c

+/* { dg-do compile  } */
+/* { dg-options "-std=c99 -pedantic-errors -W -Wall" } */
+/* PR c/28280 */
+
+void f(__SIZE_TYPE__ d)
+{
+  typedef int t[d];
+  t *g = (__typeof (g)) d;
+}