C FE: use correct location range for static assertions

gcc/c/ChangeLog:
	* c-parser.c (c_parser_static_assert_declaration_no_semi): Use the
	expression location, falling back on the first token location,
	rather than always using the latter.

gcc/testsuite/ChangeLog:
	* gcc.dg/diagnostic-range-static-assert.c: New test case.

From-SVN: r231704

gcc/c/ChangeLog

+2015-12-16  David Malcolm  <dmalcolm@redhat.com>
+
+	* c-parser.c (c_parser_static_assert_declaration_no_semi): Use the
+	expression location, falling back on the first token location,
+	rather than always using the latter.
+
 2015-12-16  Marek Polacek  <polacek@redhat.com>
 
 	PR c/64637

gcc/c/c-parser.c

@@ -2097,8 +2097,9 @@ c_parser_static_assert_declaration_no_semi (c_parser *parser)
   c_parser_consume_token (parser);
   if (!c_parser_require (parser, CPP_OPEN_PAREN, "expected %<(%>"))
     return;
-  value_loc = c_parser_peek_token (parser)->location;
+  location_t value_tok_loc = c_parser_peek_token (parser)->location;
   value = c_parser_expr_no_commas (parser, NULL).value;
+  value_loc = EXPR_LOC_OR_LOC (value, value_tok_loc);
   parser->lex_untranslated_string = true;
   if (!c_parser_require (parser, CPP_COMMA, "expected %<,%>"))
     {

gcc/testsuite/ChangeLog

+2015-12-16  David Malcolm  <dmalcolm@redhat.com>
+
+	* gcc.dg/diagnostic-range-static-assert.c: New test case.
+
 2015-12-16  Marek Polacek  <polacek@redhat.com>
 
 	PR c/64637

gcc/testsuite/gcc.dg/diagnostic-range-static-assert.c

+/* { dg-options "-fdiagnostics-show-caret" } */
+
+void test_nonconst_static_assert (int param)
+{
+  int local = 0;
+
+  _Static_assert (param > 0, "message"); /* { dg-error "expression in static assertion is not constant" } */
+/* { dg-begin-multiline-output "" }
+   _Static_assert (param > 0, "message");
+                   ~~~~~~^~~
+{ dg-end-multiline-output "" } */
+
+  _Static_assert (param, "message"); /* { dg-error "expression in static assertion is not constant" } */
+/* { dg-begin-multiline-output "" }
+   _Static_assert (param, "message");
+                   ^~~~~
+{ dg-end-multiline-output "" } */
+
+  _Static_assert (local, "message"); /* { dg-error "expression in static assertion is not constant" } */
+/* { dg-begin-multiline-output "" }
+   _Static_assert (local, "message");
+                   ^~~~~
+{ dg-end-multiline-output "" } */
+}