On Sat, Oct 19, 2013 at 07:23:20PM +0000, Joseph S. Myers wrote:
> On Wed, 16 Oct 2013, Marek Polacek wrote:
>
> > @@ -2946,7 +2957,8 @@ c_parser_declarator (c_parser *parser, b
> > struct c_declspecs *quals_attrs = build_null_declspecs ();
> > struct c_declarator *inner;
> > c_parser_consume_token (parser);
> > - c_parser_declspecs (parser, quals_attrs, false, false, true,
> > cla_prefer_id);
> > + c_parser_declspecs (parser, quals_attrs, false, false, true,
> > + true, cla_prefer_id);
> > inner = c_parser_declarator (parser, type_seen_p, kind, seen_id);
> > if (inner == NULL)
> > return NULL;
>
> Looking at this again, shouldn't the new argument be "false" (with
> associated testcase)? This is parsing pointer declarators, and _Alignas
> isn't allowed there any more than it is in array declarators....
Ah, yeah, I think so, fixed & testcase added. Thanks for catching it.
> > @@ -3715,7 +3730,8 @@ c_parser_type_name (c_parser *parser)
> > struct c_declarator *declarator;
> > struct c_type_name *ret;
> > bool dummy = false;
> > - c_parser_declspecs (parser, specs, false, true, true, cla_prefer_type);
> > + c_parser_declspecs (parser, specs, false, true, true, false,
> > + cla_prefer_type);
> > if (!specs->declspecs_seen_p)
> > {
> > c_parser_error (parser, "expected specifier-qualifier-list");
>
> And this should get a testcase added, that _Alignas is correctly rejected
> in type names where previously it would have been wrongly accepted.
I added the tests.
> (Strictly by the standard it should be "false" in
> c_parser_struct_declaration as well - the syntax there doesn't allow
> _Alignas - but it appears to have been intended to allow it there, so
> probably best not to change anything there until WG14 reaches a conclusion
> on the issues I raised in N1731.)
I added a comment there to that effect.
Tested via make check -C gcc RUNTESTFLAGS=dg.exp=c1x-*.c, ok for
trunk?
2013-10-21 Marek Polacek <pola...@redhat.com>
c/
* c-parser.c (c_parser_struct_declaration): Add a comment.
(c_parser_declarator): Don't allow _Alignas here.
testsuite/
* gcc.dg/c1x-align-5.c: Add more testing.
--- gcc/c/c-parser.c.mp 2013-10-21 19:34:17.877539421 +0200
+++ gcc/c/c-parser.c 2013-10-21 20:22:45.980220027 +0200
@@ -2645,6 +2645,11 @@ c_parser_struct_declaration (c_parser *p
}
specs = build_null_declspecs ();
decl_loc = c_parser_peek_token (parser)->location;
+ /* Strictly by the standard, we shouldn't allow _Alignas here,
+ but it appears to have been intended to allow it there, so
+ we're keeping it as it is until WG14 reaches a conclusion
+ of N1731.
+ <http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1731.pdf> */
c_parser_declspecs (parser, specs, false, true, true,
true, cla_nonabstract_decl);
if (parser->error)
@@ -2959,7 +2964,7 @@ c_parser_declarator (c_parser *parser, b
struct c_declarator *inner;
c_parser_consume_token (parser);
c_parser_declspecs (parser, quals_attrs, false, false, true,
- true, cla_prefer_id);
+ false, cla_prefer_id);
inner = c_parser_declarator (parser, type_seen_p, kind, seen_id);
if (inner == NULL)
return NULL;
--- gcc/testsuite/gcc.dg/c1x-align-5.c.mp 2013-10-21 19:41:20.088041095
+0200
+++ gcc/testsuite/gcc.dg/c1x-align-5.c 2013-10-21 20:16:55.096984545 +0200
@@ -14,6 +14,14 @@ void foo (int a[_Alignas (0) 10]) { } /*
void
test (void)
{
+ int *_Alignas (long) p; /* { dg-error "expected" } */
+ int *const _Alignas (long) *q; /* { dg-error "expected" } */
+ struct s { int n; };
+ __builtin_offsetof (struct s _Alignas (int), n); /* { dg-error "expected" }
*/
+ __typeof (long double _Alignas (0)) e; /* { dg-error "expected" } */
+ sizeof (int _Alignas (int)); /* { dg-error "expected" } */
+ _Alignas (int _Alignas (float)) int t; /* { dg-error "expected" } */
+ __builtin_types_compatible_p (signed _Alignas (0), unsigned); /* { dg-error
"expected" } */
int a[_Alignas (int) 10]; /* { dg-error "expected expression before" } */
int b[10];
foo (b);
Marek
