Check for the presence of _SC_NPROCESSORS_ONLN rather than using a list
of OS-specific macros to decide whether to use `sysconf' like elsewhere
across GCC sources, fixing a compilation error:
adaint.c: In function '__gnat_number_of_cpus':
adaint.c:2398:26: error: '_SC_NPROCESSORS_ONLN' undeclared (first use in this
function)
2398 | cores = (int) sysconf (_SC_NPROCESSORS_ONLN);
| ^~~~~~~~~~~~~~~~~~~~
adaint.c:2398:26: note: each undeclared identifier is reported only once for
each function it appears in
at least with with VAX/NetBSD 1.6.2.
gcc/ada/
* adaint.c (__gnat_number_of_cpus): Check for the presence of
_SC_NPROCESSORS_ONLN rather than a list of OS-specific macros
to decide whether to use `sysconf'.
---
On Sun, 15 Nov 2020, Arnaud Charlet wrote:
> > NB we could probably replace the list of OS #ifdefs with just a check for
> > _SC_NPROCESSORS_ONLN, making use of it automagically with any new OS that
> > supports it, as from the length of the list has grown up to I gather the
> > `sysconf' API for this variable has become a semi-established standard now
> > even though not actually listed by the relevant standards.
>
> Indeed, so a better patch would be to use
>
> #if defined (_SC_NPROCESSORS_ONLN)
>
> instead as you noted, so let's do that.
This is what I have committed then, thank you for your review.
Maciej
---
gcc/ada/adaint.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
Index: gcc/gcc/ada/adaint.c
===================================================================
--- gcc.orig/gcc/ada/adaint.c
+++ gcc/gcc/ada/adaint.c
@@ -2483,9 +2483,7 @@ __gnat_number_of_cpus (void)
{
int cores = 1;
-#if defined (__linux__) || defined (__sun__) || defined (_AIX) \
- || defined (__APPLE__) || defined (__FreeBSD__) || defined (__OpenBSD__) \
- || defined (__DragonFly__) || defined (__NetBSD__)
+#ifdef _SC_NPROCESSORS_ONLN
cores = (int) sysconf (_SC_NPROCESSORS_ONLN);
#elif defined (__QNX__)
