Re: gcc_assert() and inhibit_libc

[Jason Merrill <jason@redhat.com>]

On Thu, Jul 22, 2021 at 8:18 AM Richard Biener via Gcc <gcc@gcc.gnu.org> wrote:
>
> On Wed, Jul 21, 2021 at 2:45 PM Sebastian Huber
> <sebastian.huber@embedded-brains.de> wrote:
> >
> > Hello,
> >
> > while testing this patch
> >
> > https://www.google.com/search?client=firefox-b-e&q=gcc+enable_runtime_checking
> >
> > I noticed that __gcov_info_to_gcda() uses abort(). This is due to (from
> > tsystem.h):
> >
> > #ifdef ENABLE_RUNTIME_CHECKING
> > #define gcc_assert(EXPR) ((void)(!(EXPR) ? abort (), 0 : 0))
> > #else
> > /* Include EXPR, so that unused variable warnings do not occur.  */
> > #define gcc_assert(EXPR) ((void)(0 && (EXPR)))
> > #endif
> >
> > In tsystem.h there is this if inhibit_libc is defined:
> >
> > #ifndef abort
> > extern void abort (void) __attribute__ ((__noreturn__));
> > #endif
> >
> > Who is supposed to define abort here optionally? Can this be defined for
> > example by a target configuration header like gcc/config/rtems.h?
>
> I suppose for inhibit_libc we could use __builtin_trap () (but that might
> expand to abort() on some targets)

That seems straightforward.  Does it address the RTEMS concern?

Or, should we suppress ENABLE_RUNTIME_CHECKING when inhibit_libc?

Jason