re PR c/46015 (-Wunused-but-set-variable warns for arrays used in gotos)

	PR c/46015
	* c-parser.c (c_parser_statement_after_labels): Call mark_exp_read
	on computed goto argument.

	* semantics.c (finish_goto_stmt): Call mark_rvalue_use on computed
	goto destination.

	* c-c++-common/Wunused-var-13.c: New test.

From-SVN: r165643

gcc/ChangeLog

+2010-10-18  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/46015
+	* c-parser.c (c_parser_statement_after_labels): Call mark_exp_read
+	on computed goto argument.
+
 2010-10-18  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/45967

gcc/c-parser.c

@@ -4151,9 +4151,12 @@ c_parser_statement_after_labels (c_parser *parser)
 	    }
 	  else if (c_parser_next_token_is (parser, CPP_MULT))
 	    {
+	      tree val;
+
 	      c_parser_consume_token (parser);
-	      stmt = c_finish_goto_ptr (loc,
-					c_parser_expression (parser).value);
+	      val = c_parser_expression (parser).value;
+	      mark_exp_read (val);
+	      stmt = c_finish_goto_ptr (loc, val);
 	    }
 	  else
 	    c_parser_error (parser, "expected identifier or %<*%>");

gcc/cp/ChangeLog

+2010-10-18  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/46015
+	* semantics.c (finish_goto_stmt): Call mark_rvalue_use on computed
+	goto destination.
+
 2010-10-17  Nicola Pero  <nicola.pero@meta-innovation.com>
 	
 	Merge from apple/trunk branch on FSF servers.

gcc/cp/semantics.c

@@ -537,6 +537,7 @@ finish_goto_stmt (tree destination)
     TREE_USED (destination) = 1;
   else
     {
+      destination = mark_rvalue_use (destination);
       if (!processing_template_decl)
 	{
 	  destination = cp_convert (ptr_type_node, destination);

gcc/testsuite/ChangeLog

+2010-10-18  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/46015
+	* c-c++-common/Wunused-var-13.c: New test.
+
 2010-10-18  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/45967

gcc/testsuite/c-c++-common/Wunused-var-13.c

+/* PR c/46015 */
+/* { dg-options "-Wunused" } */
+/* { dg-do compile } */
+
+int
+f1 (int i)
+{
+  static void *labs[2] = { &&lab1, &&lab2 };
+  goto *(labs[i & 1]);
+
+lab1:
+  return 1;
+lab2:
+  return 2;
+}
+
+int
+f2 (int i)
+{
+  void *labs[2] = { &&lab1, &&lab2 };
+  goto *labs[i & 1];
+
+lab1:
+  return 1;
+lab2:
+  return 2;
+}