Re: [PATCH 3/8] add default for PCC_BITFIELD_TYPE_MATTERS

[Jakub Jelinek <jakub@redhat.com>]

On Thu, Apr 30, 2015 at 07:58:33AM -0400, Trevor Saunders wrote:
> On Thu, Apr 30, 2015 at 08:54:05AM +0200, Andreas Schwab wrote:
> > Trevor Saunders <tbsaunde@tbsaunde.org> writes:
> > 
> > >> diff --git a/libobjc/encoding.c b/libobjc/encoding.c
> > >> index 7333908..20ace46 100644
> > >> --- a/libobjc/encoding.c
> > >> +++ b/libobjc/encoding.c
> > >> @@ -1167,7 +1167,7 @@ objc_layout_structure_next_member (struct objc_struct_layout *layout)
> > >>    /* Record must have at least as much alignment as any field.
> > >>       Otherwise, the alignment of the field within the record
> > >>       is meaningless.  */
> > >> -#ifndef PCC_BITFIELD_TYPE_MATTERS
> > >> +#if !PCC_BITFIELD_TYPE_MATTERS
> > 
> > With `#define PCC_BITFIELD_TYPE_MATTERS true' this expands to `#if
> > !true' which evaluates to 1 since true isn't a defined identifier?
> 
> I think true is a defined identifier since this is compiled as c11.

true is not a defined identifier, neither in C89, nor in C99, nor in C11.
In C, true may be a macro if stdbool.h is included.
system.h has:
#undef TRUE
#undef FALSE

#ifdef __cplusplus
  /* Obsolete.  */
# define TRUE true
# define FALSE false
#else /* !__cplusplus */
# undef bool
# undef true
# undef false

# define bool unsigned char
# define true 1
# define false 0

  /* Obsolete.  */
# define TRUE true
# define FALSE false
#endif /* !__cplusplus */
if it is included.

	Jakub