-# threadlib.m4 serial 10 (gettext-0.18.2)
-dnl Copyright (C) 2005-2013 Free Software Foundation, Inc.
+# threadlib.m4 serial 13
+dnl Copyright (C) 2005-2018 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
dnl Sets the variables LIBMULTITHREAD and LTLIBMULTITHREAD similarly, for
dnl programs that really need multithread functionality. The difference
dnl between LIBTHREAD and LIBMULTITHREAD is that on platforms supporting weak
-dnl symbols, typically LIBTHREAD="" whereas LIBMULTITHREAD="-lpthread".
+dnl symbols, typically LIBTHREAD is empty whereas LIBMULTITHREAD is not.
dnl Adds to CPPFLAGS the flag -D_REENTRANT or -D_THREAD_SAFE if needed for
dnl multithread-safe programs.
dnl child process gets an endless segmentation fault inside execvp().
dnl Disable multithreading by default on Cygwin 1.5.x, because it has
dnl bugs that lead to endless loops or crashes. See
- dnl <http://cygwin.com/ml/cygwin/2009-08/msg00283.html>.
+ dnl <https://cygwin.com/ml/cygwin/2009-08/msg00283.html>.
osf*) gl_use_threads=no ;;
cygwin*)
case `uname -r` in
[gl_cv_have_weak="guessing no"])
])
fi
+ dnl But when linking statically, weak symbols don't work.
+ case " $LDFLAGS " in
+ *" -static "*) gl_cv_have_weak=no ;;
+ esac
])
if test "$gl_use_threads" = yes || test "$gl_use_threads" = posix; then
# On OSF/1, the compiler needs the flag -pthread or -D_REENTRANT so that
# Test whether both pthread_mutex_lock and pthread_mutexattr_init exist
# in libc. IRIX 6.5 has the first one in both libc and libpthread, but
# the second one only in libpthread, and lock.c needs it.
- AC_LINK_IFELSE(
- [AC_LANG_PROGRAM(
- [[#include <pthread.h>]],
- [[pthread_mutex_lock((pthread_mutex_t*)0);
- pthread_mutexattr_init((pthread_mutexattr_t*)0);]])],
- [gl_have_pthread=yes])
+ #
+ # If -pthread works, prefer it to -lpthread, since Ubuntu 14.04
+ # needs -pthread for some reason. See:
+ # https://lists.gnu.org/r/bug-gnulib/2014-09/msg00023.html
+ save_LIBS=$LIBS
+ for gl_pthread in '' '-pthread'; do
+ LIBS="$LIBS $gl_pthread"
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <pthread.h>
+ pthread_mutex_t m;
+ pthread_mutexattr_t ma;
+ ]],
+ [[pthread_mutex_lock (&m);
+ pthread_mutexattr_init (&ma);]])],
+ [gl_have_pthread=yes
+ LIBTHREAD=$gl_pthread LTLIBTHREAD=$gl_pthread
+ LIBMULTITHREAD=$gl_pthread LTLIBMULTITHREAD=$gl_pthread])
+ LIBS=$save_LIBS
+ test -n "$gl_have_pthread" && break
+ done
+
# Test for libpthread by looking for pthread_kill. (Not pthread_self,
# since it is defined as a macro on OSF/1.)
- if test -n "$gl_have_pthread"; then
+ if test -n "$gl_have_pthread" && test -z "$LIBTHREAD"; then
# The program links fine without libpthread. But it may actually
# need to link with libpthread in order to create multiple threads.
AC_CHECK_LIB([pthread], [pthread_kill],
# Therefore pthread_in_use() needs to actually try to create a
# thread: pthread_create from libc will fail, whereas
# pthread_create will actually create a thread.
+ # On Solaris 10 or newer, this test is no longer needed, because
+ # libc contains the fully functional pthread functions.
case "$host_os" in
- solaris* | hpux*)
+ solaris | solaris2.[1-9] | solaris2.[1-9].* | hpux*)
AC_DEFINE([PTHREAD_IN_USE_DETECTION_HARD], [1],
[Define if the pthread_in_use() detection is hard.])
esac
])
- else
+ elif test -z "$gl_have_pthread"; then
# Some library is needed. Try libpthread and libc_r.
AC_CHECK_LIB([pthread], [pthread_kill],
[gl_have_pthread=yes
dnl
dnl GNU Hurd/glibc posix
dnl
+dnl Ubuntu 14.04 posix -pthread Y OK
+dnl
dnl FreeBSD 5.3 posix -lc_r Y
dnl posix -lkse ? Y
dnl posix -lpthread ? Y