- if test "$gl_threads_api" = posix; then
- if test $ac_cv_func_pthread_sigmask = yes; then
- dnl pthread_sigmask is available without -lpthread.
- :
- else
- if test -n "$LIBMULTITHREAD"; then
- AC_CACHE_CHECK([for pthread_sigmask in $LIBMULTITHREAD],
- [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD],
- [gl_save_LIBS="$LIBS"
- LIBS="$LIBS $LIBMULTITHREAD"
- AC_LINK_IFELSE(
- [AC_LANG_PROGRAM(
- [[#include <pthread.h>
- #include <signal.h>
- ]],
- [[return pthread_sigmask (0, (sigset_t *) 0, (sigset_t *) 0);]])
- ],
- [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=yes],
- [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=no])
- LIBS="$gl_save_LIBS"
- ])
- if test $gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD = yes; then
- dnl pthread_sigmask is available with -lpthread.
- LIB_PTHREAD_SIGMASK="$LIBMULTITHREAD"
+
+ dnl Test whether the gnulib module 'threadlib' is in use.
+ dnl Some packages like Emacs use --avoid=threadlib.
+ dnl Write the symbol in such a way that it does not cause 'aclocal' to pick
+ dnl the threadlib.m4 file that is installed in $PREFIX/share/aclocal/.
+ m4_ifdef([gl_[]THREADLIB], [
+ AC_REQUIRE([gl_[]THREADLIB])
+
+ if test "$gl_threads_api" = posix; then
+ if test $ac_cv_func_pthread_sigmask = yes; then
+ dnl pthread_sigmask is available without -lpthread.
+ :
+ else
+ if test -n "$LIBMULTITHREAD"; then
+ AC_CACHE_CHECK([for pthread_sigmask in $LIBMULTITHREAD],
+ [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD],
+ [gl_save_LIBS="$LIBS"
+ LIBS="$LIBS $LIBMULTITHREAD"
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <pthread.h>
+ #include <signal.h>
+ ]],
+ [[return pthread_sigmask (0, (sigset_t *) 0, (sigset_t *) 0);]])
+ ],
+ [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=yes],
+ [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=no])
+ LIBS="$gl_save_LIBS"
+ ])
+ if test $gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD = yes; then
+ dnl pthread_sigmask is available with -lpthread.
+ LIB_PTHREAD_SIGMASK="$LIBMULTITHREAD"
+ else
+ dnl pthread_sigmask is not available at all.
+ HAVE_PTHREAD_SIGMASK=0
+ fi