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Matt Turner7da12422012-09-18 20:21:47 -07001# ===========================================================================
2# http://www.gnu.org/software/autoconf-archive/ax_pthread.html
3# ===========================================================================
4#
5# SYNOPSIS
6#
7# AX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
8#
9# DESCRIPTION
10#
11# This macro figures out how to build C programs using POSIX threads. It
12# sets the PTHREAD_LIBS output variable to the threads library and linker
13# flags, and the PTHREAD_CFLAGS output variable to any special C compiler
14# flags that are needed. (The user can also force certain compiler
15# flags/libs to be tested by setting these environment variables.)
16#
17# Also sets PTHREAD_CC to any special C compiler that is needed for
18# multi-threaded programs (defaults to the value of CC otherwise). (This
19# is necessary on AIX to use the special cc_r compiler alias.)
20#
21# NOTE: You are assumed to not only compile your program with these flags,
22# but also link it with them as well. e.g. you should link with
23# $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS
24#
25# If you are only building threads programs, you may wish to use these
26# variables in your default LIBS, CFLAGS, and CC:
27#
28# LIBS="$PTHREAD_LIBS $LIBS"
29# CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
30# CC="$PTHREAD_CC"
31#
32# In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute constant
33# has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to that name
34# (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
35#
36# Also HAVE_PTHREAD_PRIO_INHERIT is defined if pthread is found and the
37# PTHREAD_PRIO_INHERIT symbol is defined when compiling with
38# PTHREAD_CFLAGS.
39#
40# ACTION-IF-FOUND is a list of shell commands to run if a threads library
41# is found, and ACTION-IF-NOT-FOUND is a list of commands to run it if it
42# is not found. If ACTION-IF-FOUND is not specified, the default action
43# will define HAVE_PTHREAD.
44#
45# Please let the authors know if this macro fails on any platform, or if
46# you have any other suggestions or comments. This macro was based on work
47# by SGJ on autoconf scripts for FFTW (http://www.fftw.org/) (with help
48# from M. Frigo), as well as ac_pthread and hb_pthread macros posted by
49# Alejandro Forero Cuervo to the autoconf macro repository. We are also
50# grateful for the helpful feedback of numerous users.
51#
52# Updated for Autoconf 2.68 by Daniel Richard G.
53#
54# LICENSE
55#
56# Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu>
57# Copyright (c) 2011 Daniel Richard G. <skunk@iSKUNK.ORG>
58#
59# This program is free software: you can redistribute it and/or modify it
60# under the terms of the GNU General Public License as published by the
61# Free Software Foundation, either version 3 of the License, or (at your
62# option) any later version.
63#
64# This program is distributed in the hope that it will be useful, but
65# WITHOUT ANY WARRANTY; without even the implied warranty of
66# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
67# Public License for more details.
68#
69# You should have received a copy of the GNU General Public License along
70# with this program. If not, see <http://www.gnu.org/licenses/>.
71#
72# As a special exception, the respective Autoconf Macro's copyright owner
73# gives unlimited permission to copy, distribute and modify the configure
74# scripts that are the output of Autoconf when processing the Macro. You
75# need not follow the terms of the GNU General Public License when using
76# or distributing such scripts, even though portions of the text of the
77# Macro appear in them. The GNU General Public License (GPL) does govern
78# all other use of the material that constitutes the Autoconf Macro.
79#
80# This special exception to the GPL applies to versions of the Autoconf
81# Macro released by the Autoconf Archive. When you make and distribute a
82# modified version of the Autoconf Macro, you may extend this special
83# exception to the GPL to apply to your modified version as well.
84
85#serial 18
86
87AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD])
88AC_DEFUN([AX_PTHREAD], [
89AC_REQUIRE([AC_CANONICAL_HOST])
90AC_LANG_PUSH([C])
91ax_pthread_ok=no
92
93# We used to check for pthread.h first, but this fails if pthread.h
94# requires special compiler flags (e.g. on True64 or Sequent).
95# It gets checked for in the link test anyway.
96
97# First of all, check if the user has set any of the PTHREAD_LIBS,
98# etcetera environment variables, and if threads linking works using
99# them:
100if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
101 save_CFLAGS="$CFLAGS"
102 CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
103 save_LIBS="$LIBS"
104 LIBS="$PTHREAD_LIBS $LIBS"
105 AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
106 AC_TRY_LINK_FUNC(pthread_join, ax_pthread_ok=yes)
107 AC_MSG_RESULT($ax_pthread_ok)
108 if test x"$ax_pthread_ok" = xno; then
109 PTHREAD_LIBS=""
110 PTHREAD_CFLAGS=""
111 fi
112 LIBS="$save_LIBS"
113 CFLAGS="$save_CFLAGS"
114fi
115
116# We must check for the threads library under a number of different
117# names; the ordering is very important because some systems
118# (e.g. DEC) have both -lpthread and -lpthreads, where one of the
119# libraries is broken (non-POSIX).
120
121# Create a list of thread flags to try. Items starting with a "-" are
122# C compiler flags, and other items are library names, except for "none"
123# which indicates that we try without any flags at all, and "pthread-config"
124# which is a program returning the flags for the Pth emulation library.
125
126ax_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
127
128# The ordering *is* (sometimes) important. Some notes on the
129# individual items follow:
130
131# pthreads: AIX (must check this before -lpthread)
132# none: in case threads are in libc; should be tried before -Kthread and
133# other compiler flags to prevent continual compiler warnings
134# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
135# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
136# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
137# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
138# -pthreads: Solaris/gcc
139# -mthreads: Mingw32/gcc, Lynx/gcc
140# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
141# doesn't hurt to check since this sometimes defines pthreads too;
142# also defines -D_REENTRANT)
143# ... -mt is also the pthreads flag for HP/aCC
144# pthread: Linux, etcetera
145# --thread-safe: KAI C++
146# pthread-config: use pthread-config program (for GNU Pth library)
147
148case ${host_os} in
149 solaris*)
150
151 # On Solaris (at least, for some versions), libc contains stubbed
152 # (non-functional) versions of the pthreads routines, so link-based
153 # tests will erroneously succeed. (We need to link with -pthreads/-mt/
154 # -lpthread.) (The stubs are missing pthread_cleanup_push, or rather
155 # a function called by this macro, so we could check for that, but
156 # who knows whether they'll stub that too in a future libc.) So,
157 # we'll just look for -pthreads and -lpthread first:
158
159 ax_pthread_flags="-pthreads pthread -mt -pthread $ax_pthread_flags"
160 ;;
161
162 darwin*)
163 ax_pthread_flags="-pthread $ax_pthread_flags"
164 ;;
165esac
166
167if test x"$ax_pthread_ok" = xno; then
168for flag in $ax_pthread_flags; do
169
170 case $flag in
171 none)
172 AC_MSG_CHECKING([whether pthreads work without any flags])
173 ;;
174
175 -*)
176 AC_MSG_CHECKING([whether pthreads work with $flag])
177 PTHREAD_CFLAGS="$flag"
178 ;;
179
180 pthread-config)
181 AC_CHECK_PROG(ax_pthread_config, pthread-config, yes, no)
182 if test x"$ax_pthread_config" = xno; then continue; fi
183 PTHREAD_CFLAGS="`pthread-config --cflags`"
184 PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
185 ;;
186
187 *)
188 AC_MSG_CHECKING([for the pthreads library -l$flag])
189 PTHREAD_LIBS="-l$flag"
190 ;;
191 esac
192
193 save_LIBS="$LIBS"
194 save_CFLAGS="$CFLAGS"
195 LIBS="$PTHREAD_LIBS $LIBS"
196 CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
197
198 # Check for various functions. We must include pthread.h,
199 # since some functions may be macros. (On the Sequent, we
200 # need a special flag -Kthread to make this header compile.)
201 # We check for pthread_join because it is in -lpthread on IRIX
202 # while pthread_create is in libc. We check for pthread_attr_init
203 # due to DEC craziness with -lpthreads. We check for
204 # pthread_cleanup_push because it is one of the few pthread
205 # functions on Solaris that doesn't have a non-functional libc stub.
206 # We try pthread_create on general principles.
207 AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>
208 static void routine(void *a) { a = 0; }
209 static void *start_routine(void *a) { return a; }],
210 [pthread_t th; pthread_attr_t attr;
211 pthread_create(&th, 0, start_routine, 0);
212 pthread_join(th, 0);
213 pthread_attr_init(&attr);
214 pthread_cleanup_push(routine, 0);
215 pthread_cleanup_pop(0) /* ; */])],
216 [ax_pthread_ok=yes],
217 [])
218
219 LIBS="$save_LIBS"
220 CFLAGS="$save_CFLAGS"
221
222 AC_MSG_RESULT($ax_pthread_ok)
223 if test "x$ax_pthread_ok" = xyes; then
224 break;
225 fi
226
227 PTHREAD_LIBS=""
228 PTHREAD_CFLAGS=""
229done
230fi
231
232# Various other checks:
233if test "x$ax_pthread_ok" = xyes; then
234 save_LIBS="$LIBS"
235 LIBS="$PTHREAD_LIBS $LIBS"
236 save_CFLAGS="$CFLAGS"
237 CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
238
239 # Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
240 AC_MSG_CHECKING([for joinable pthread attribute])
241 attr_name=unknown
242 for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
243 AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>],
244 [int attr = $attr; return attr /* ; */])],
245 [attr_name=$attr; break],
246 [])
247 done
248 AC_MSG_RESULT($attr_name)
249 if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then
250 AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name,
251 [Define to necessary symbol if this constant
252 uses a non-standard name on your system.])
253 fi
254
255 AC_MSG_CHECKING([if more special flags are required for pthreads])
256 flag=no
257 case ${host_os} in
258 aix* | freebsd* | darwin*) flag="-D_THREAD_SAFE";;
259 osf* | hpux*) flag="-D_REENTRANT";;
260 solaris*)
261 if test "$GCC" = "yes"; then
262 flag="-D_REENTRANT"
263 else
264 flag="-mt -D_REENTRANT"
265 fi
266 ;;
267 esac
268 AC_MSG_RESULT(${flag})
269 if test "x$flag" != xno; then
270 PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
271 fi
272
273 AC_CACHE_CHECK([for PTHREAD_PRIO_INHERIT],
274 ax_cv_PTHREAD_PRIO_INHERIT, [
275 AC_LINK_IFELSE([
276 AC_LANG_PROGRAM([[#include <pthread.h>]], [[int i = PTHREAD_PRIO_INHERIT;]])],
277 [ax_cv_PTHREAD_PRIO_INHERIT=yes],
278 [ax_cv_PTHREAD_PRIO_INHERIT=no])
279 ])
280 AS_IF([test "x$ax_cv_PTHREAD_PRIO_INHERIT" = "xyes"],
281 AC_DEFINE([HAVE_PTHREAD_PRIO_INHERIT], 1, [Have PTHREAD_PRIO_INHERIT.]))
282
283 LIBS="$save_LIBS"
284 CFLAGS="$save_CFLAGS"
285
286 # More AIX lossage: must compile with xlc_r or cc_r
287 if test x"$GCC" != xyes; then
288 AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC})
289 else
290 PTHREAD_CC=$CC
291 fi
292else
293 PTHREAD_CC="$CC"
294fi
295
296AC_SUBST(PTHREAD_LIBS)
297AC_SUBST(PTHREAD_CFLAGS)
298AC_SUBST(PTHREAD_CC)
299
300# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
301if test x"$ax_pthread_ok" = xyes; then
302 ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])
303 :
304else
305 ax_pthread_ok=no
306 $2
307fi
308AC_LANG_POP
309])dnl AX_PTHREAD