1
# This was retrieved from
2
# http://svn.0pointer.de/viewvc/trunk/common/acx_pthread.m4?revision=1277&root=avahi
3
# See also (perhaps for new versions?)
4
# http://svn.0pointer.de/viewvc/trunk/common/acx_pthread.m4?root=avahi
6
# We've rewritten the inconsistency check code (from avahi), to work
7
# more broadly. In particular, it no longer assumes ld accepts -zdefs.
8
# This caused a restructing of the code, but the functionality has only
11
dnl @synopsis ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
13
dnl @summary figure out how to build C programs using POSIX threads
15
dnl This macro figures out how to build C programs using POSIX threads.
16
dnl It sets the PTHREAD_LIBS output variable to the threads library and
17
dnl linker flags, and the PTHREAD_CFLAGS output variable to any special
18
dnl C compiler flags that are needed. (The user can also force certain
19
dnl compiler flags/libs to be tested by setting these environment
22
dnl Also sets PTHREAD_CC to any special C compiler that is needed for
23
dnl multi-threaded programs (defaults to the value of CC otherwise).
24
dnl (This is necessary on AIX to use the special cc_r compiler alias.)
26
dnl NOTE: You are assumed to not only compile your program with these
27
dnl flags, but also link it with them as well. e.g. you should link
28
dnl with $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS
31
dnl If you are only building threads programs, you may wish to use
32
dnl these variables in your default LIBS, CFLAGS, and CC:
34
dnl LIBS="$PTHREAD_LIBS $LIBS"
35
dnl CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
38
dnl In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute
39
dnl constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to
40
dnl that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
42
dnl ACTION-IF-FOUND is a list of shell commands to run if a threads
43
dnl library is found, and ACTION-IF-NOT-FOUND is a list of commands to
44
dnl run it if it is not found. If ACTION-IF-FOUND is not specified, the
45
dnl default action will define HAVE_PTHREAD.
47
dnl Please let the authors know if this macro fails on any platform, or
48
dnl if you have any other suggestions or comments. This macro was based
49
dnl on work by SGJ on autoconf scripts for FFTW (www.fftw.org) (with
50
dnl help from M. Frigo), as well as ac_pthread and hb_pthread macros
51
dnl posted by Alejandro Forero Cuervo to the autoconf macro repository.
52
dnl We are also grateful for the helpful feedback of numerous users.
54
dnl @category InstalledPackages
55
dnl @author Steven G. Johnson <stevenj@alum.mit.edu>
56
dnl @version 2006-05-29
57
dnl @license GPLWithACException
59
dnl Checks for GCC shared/pthread inconsistency based on work by
60
dnl Marcin Owsiany <marcin@owsiany.pl>
63
AC_DEFUN([ACX_PTHREAD], [
64
AC_REQUIRE([AC_CANONICAL_HOST])
69
# We used to check for pthread.h first, but this fails if pthread.h
70
# requires special compiler flags (e.g. on True64 or Sequent).
71
# It gets checked for in the link test anyway.
73
# First of all, check if the user has set any of the PTHREAD_LIBS,
74
# etcetera environment variables, and if threads linking works using
76
if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
78
CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
80
LIBS="$PTHREAD_LIBS $LIBS"
81
AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
82
AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes)
83
AC_MSG_RESULT($acx_pthread_ok)
84
if test x"$acx_pthread_ok" = xno; then
92
# We must check for the threads library under a number of different
93
# names; the ordering is very important because some systems
94
# (e.g. DEC) have both -lpthread and -lpthreads, where one of the
95
# libraries is broken (non-POSIX).
97
# Create a list of thread flags to try. Items starting with a "-" are
98
# C compiler flags, and other items are library names, except for "none"
99
# which indicates that we try without any flags at all, and "pthread-config"
100
# which is a program returning the flags for the Pth emulation library.
102
acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
104
# The ordering *is* (sometimes) important. Some notes on the
105
# individual items follow:
107
# pthreads: AIX (must check this before -lpthread)
108
# none: in case threads are in libc; should be tried before -Kthread and
109
# other compiler flags to prevent continual compiler warnings
110
# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
111
# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
112
# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
113
# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
114
# -pthreads: Solaris/gcc
115
# -mthreads: Mingw32/gcc, Lynx/gcc
116
# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
117
# doesn't hurt to check since this sometimes defines pthreads too;
118
# also defines -D_REENTRANT)
119
# ... -mt is also the pthreads flag for HP/aCC
120
# pthread: Linux, etcetera
121
# --thread-safe: KAI C++
122
# pthread-config: use pthread-config program (for GNU Pth library)
124
case "${host_cpu}-${host_os}" in
127
# On Solaris (at least, for some versions), libc contains stubbed
128
# (non-functional) versions of the pthreads routines, so link-based
129
# tests will erroneously succeed. (We need to link with -pthreads/-mt/
130
# -lpthread.) (The stubs are missing pthread_cleanup_push, or rather
131
# a function called by this macro, so we could check for that, but
132
# who knows whether they'll stub that too in a future libc.) So,
133
# we'll just look for -pthreads and -lpthread first:
135
acx_pthread_flags="-pthreads pthread -mt -pthread $acx_pthread_flags"
139
if test x"$acx_pthread_ok" = xno; then
140
for flag in $acx_pthread_flags; do
144
AC_MSG_CHECKING([whether pthreads work without any flags])
148
AC_MSG_CHECKING([whether pthreads work with $flag])
149
PTHREAD_CFLAGS="$flag"
153
AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no)
154
if test x"$acx_pthread_config" = xno; then continue; fi
155
PTHREAD_CFLAGS="`pthread-config --cflags`"
156
PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
160
AC_MSG_CHECKING([for the pthreads library -l$flag])
161
PTHREAD_LIBS="-l$flag"
166
save_CFLAGS="$CFLAGS"
167
LIBS="$PTHREAD_LIBS $LIBS"
168
CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
170
# Check for various functions. We must include pthread.h,
171
# since some functions may be macros. (On the Sequent, we
172
# need a special flag -Kthread to make this header compile.)
173
# We check for pthread_join because it is in -lpthread on IRIX
174
# while pthread_create is in libc. We check for pthread_attr_init
175
# due to DEC craziness with -lpthreads. We check for
176
# pthread_cleanup_push because it is one of the few pthread
177
# functions on Solaris that doesn't have a non-functional libc stub.
178
# We try pthread_create on general principles.
179
AC_TRY_LINK([#include <pthread.h>],
180
[pthread_t th; pthread_join(th, 0);
181
pthread_attr_init(0); pthread_cleanup_push(0, 0);
182
pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
183
[acx_pthread_ok=yes])
186
CFLAGS="$save_CFLAGS"
188
AC_MSG_RESULT($acx_pthread_ok)
189
if test "x$acx_pthread_ok" = xyes; then
198
# Various other checks:
199
if test "x$acx_pthread_ok" = xyes; then
201
LIBS="$PTHREAD_LIBS $LIBS"
202
save_CFLAGS="$CFLAGS"
203
CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
205
# Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
206
AC_MSG_CHECKING([for joinable pthread attribute])
208
for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
209
AC_TRY_LINK([#include <pthread.h>], [int attr=$attr; return attr;],
210
[attr_name=$attr; break])
212
AC_MSG_RESULT($attr_name)
213
if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then
214
AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name,
215
[Define to necessary symbol if this constant
216
uses a non-standard name on your system.])
219
AC_MSG_CHECKING([if more special flags are required for pthreads])
221
case "${host_cpu}-${host_os}" in
222
*-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";;
223
*solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
225
AC_MSG_RESULT(${flag})
226
if test "x$flag" != xno; then
227
PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
231
CFLAGS="$save_CFLAGS"
232
# More AIX lossage: must compile with xlc_r or cc_r
233
if test x"$GCC" != xyes; then
234
AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC})
239
# The next part tries to detect GCC inconsistency with -shared on some
240
# architectures and systems. The problem is that in certain
241
# configurations, when -shared is specified, GCC "forgets" to
242
# internally use various flags which are still necessary.
247
save_CFLAGS="$CFLAGS"
251
# Try with the flags determined by the earlier checks.
253
# -Wl,-z,defs forces link-time symbol resolution, so that the
254
# linking checks with -shared actually have any value
256
# FIXME: -fPIC is required for -shared on many architectures,
257
# so we specify it here, but the right way would probably be to
258
# properly detect whether it is actually required.
259
CFLAGS="-shared -fPIC -Wl,-z,defs $CFLAGS $PTHREAD_CFLAGS"
260
LIBS="$PTHREAD_LIBS $LIBS"
263
# In order not to create several levels of indentation, we test
264
# the value of "$done" until we find the cure or run out of ideas.
267
# First, make sure the CFLAGS we added are actually accepted by our
268
# compiler. If not (and OS X's ld, for instance, does not accept -z),
269
# then we can't do this test.
270
if test x"$done" = xno; then
271
AC_MSG_CHECKING([whether to check for GCC pthread/shared inconsistencies])
272
AC_TRY_LINK(,, , [done=yes])
274
if test "x$done" = xyes ; then
281
if test x"$done" = xno; then
282
AC_MSG_CHECKING([whether -pthread is sufficient with -shared])
283
AC_TRY_LINK([#include <pthread.h>],
284
[pthread_t th; pthread_join(th, 0);
285
pthread_attr_init(0); pthread_cleanup_push(0, 0);
286
pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
289
if test "x$done" = xyes; then
297
# Linux gcc on some architectures such as mips/mipsel forgets
300
if test x"$done" = xno; then
301
AC_MSG_CHECKING([whether -lpthread fixes that])
302
LIBS="-lpthread $PTHREAD_LIBS $save_LIBS"
303
AC_TRY_LINK([#include <pthread.h>],
304
[pthread_t th; pthread_join(th, 0);
305
pthread_attr_init(0); pthread_cleanup_push(0, 0);
306
pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
309
if test "x$done" = xyes; then
311
PTHREAD_LIBS="-lpthread $PTHREAD_LIBS"
317
# FreeBSD 4.10 gcc forgets to use -lc_r instead of -lc
319
if test x"$done" = xno; then
320
AC_MSG_CHECKING([whether -lc_r fixes that])
321
LIBS="-lc_r $PTHREAD_LIBS $save_LIBS"
322
AC_TRY_LINK([#include <pthread.h>],
323
[pthread_t th; pthread_join(th, 0);
324
pthread_attr_init(0); pthread_cleanup_push(0, 0);
325
pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
328
if test "x$done" = xyes; then
330
PTHREAD_LIBS="-lc_r $PTHREAD_LIBS"
335
if test x"$done" = xno; then
336
# OK, we have run out of ideas
337
AC_MSG_WARN([Impossible to determine how to use pthreads with shared libraries])
339
# so it's not safe to assume that we may use pthreads
343
CFLAGS="$save_CFLAGS"
350
AC_SUBST(PTHREAD_LIBS)
351
AC_SUBST(PTHREAD_CFLAGS)
354
# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
355
if test x"$acx_pthread_ok" = xyes; then
356
ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])