In a testdir on AIX 7, with xlc and xlC, I'm seeing this compilation error:
source='../../gltests/test-sys_select-c++.cc' object='test-sys_select-c++.o'
libtool=no DEPDIR=.deps depmode=xlc /bin/sh ../../build-aux/depcomp xlC -q64
-qthreaded -qtls -DHAVE_CONFIG_H -DEXEEXT=\"\" -I. -I../../gltests -I..
-DGNULIB_STRICT_CHECKING=1 -DIN_GNULIB_TESTS=1 -I. -I../../gltests -I..
-I../../gltests/.. -I../gllib -I../../gltests/../gllib
-I/home/haible/prefix64/include -D_THREAD_SAFE -g -c -o test-sys_select-c++.o
../../gltests/test-sys_select-c++.cc
"../gllib/sys/select.h", line 763.1: 1540-0258 (S) A return value of type "int
(*)(int, fd_set * restrict, fd_set * restrict, fd_set * restrict, const
timespec * restrict, const sigset_t * restrict)" cannot be initialized with an
expression of type "extern "C" int (int, void * restrict, void * restrict, void
* restrict, const timespec * restrict, const sigset_t * restrict)".
make: 1254-004 The error code from the last command is 1.
The problem is the declaration of 'pselect', which is POSIX compliant
extern int pselect(int, fd_set *__restrict__, fd_set *__restrict__, fd_set
*__restrict__, const struct timespec *__restrict__, const sigset_t
*__restrict__);
if _ALL_SOURCE is not defined, but looks like this if _ALL_SOURCE is defined:
extern int pselect(int, void *__restrict__, void *__restrict__, void
*__restrict__, const struct timespec *__restrict__, const sigset_t
*__restrict__);
2021-12-26 Bruno Haible <br...@clisp.org>
pselect: Fix compilation error in C++ mode on AIX 7.
* lib/sys_select.in.h (pselect): Use _GL_CXXALIAS_SYS_CAST instead of
_GL_CXXALIAS_SYS.
* doc/posix-functions/pselect.texi: Mention the AIX problem.
diff --git a/doc/posix-functions/pselect.texi b/doc/posix-functions/pselect.texi
index ce26c1688..83323e5c5 100644
--- a/doc/posix-functions/pselect.texi
+++ b/doc/posix-functions/pselect.texi
@@ -20,6 +20,9 @@ FreeBSD 8.2.
Portability problems not fixed by Gnulib:
@itemize
@item
+This function has a slightly incompatible declaration on some platforms:
+AIX 7.1 (when @code{_ALL_SOURCE} is defined).
+@item
When the @var{sigmask} argument is nonnull on platforms that do not
natively support this function, race conditions are possible when its
gnulib implementation temporarily modifies the signal mask, and the
diff --git a/lib/sys_select.in.h b/lib/sys_select.in.h
index 910bea5d1..e95e7e77c 100644
--- a/lib/sys_select.in.h
+++ b/lib/sys_select.in.h
@@ -279,9 +279,13 @@ _GL_FUNCDECL_SYS (pselect, int,
(int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
struct timespec const *restrict, const sigset_t *restrict));
# endif
-_GL_CXXALIAS_SYS (pselect, int,
- (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
- struct timespec const *restrict, const sigset_t *restrict));
+/* Need to cast, because on AIX 7, the second, third, fourth argument may be
+ void *restrict, void *restrict, void *restrict. */
+_GL_CXXALIAS_SYS_CAST (pselect, int,
+ (int,
+ fd_set *restrict, fd_set *restrict, fd_set *restrict,
+ struct timespec const *restrict,
+ const sigset_t *restrict));
# endif
_GL_CXXALIASWARN (pselect);
#elif defined GNULIB_POSIXCHECK
