Viewing file:  Wattributes-8.c (1.4 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/* PR middle-end/84108 - incorrect -Wattributes warning for packed/aligned
conflict on struct members
{ dg-do compile }
{ dg-options "-Wall -Wattributes" } */
#define ATTR(list) __attribute__ (list)
#define ASSERT(e) _Static_assert (e, #e)
/* GCC is inconsistent in how it treats attribute aligned between
variable and member declarations. Attribute aligned alone is
sufficient to reduce a variable's alignment requirement but
the attribute must be paired with packed to have the same
effect on a member. Worse, declaring a variable both aligned
and packed emits a warning. */
/* Avoid exercising this since emitting a warning for these given
the requirement for members seems like a misfeature:
int a ATTR ((packed, aligned (2))); // -Wattributes
int b ATTR ((aligned (2), packed)); // -Wattributes
ASSERT (_Alignof (a) == 2);
ASSERT (_Alignof (b) == 2); */
int c ATTR ((aligned (2))); // okay (reduces alignment)
ASSERT (_Alignof (c) == 2);
struct {
int a ATTR ((packed, aligned (2))); /* { dg-bogus "\\\[-Wattributes" } */
int b ATTR ((aligned (2), packed)); /* { dg-bogus "\\\[-Wattributes" } */
/* Avoid exercising this since the attribute has no effect yet
there is no warning.
int c ATTR ((aligned (2))); // missing warning? */
} s;
ASSERT (_Alignof (s.a) == 2);
ASSERT (_Alignof (s.b) == 2);
/* ASSERT (_Alignof (s.c) == 4); */
|
