m4/ax_pthread.m4

   1 # ===========================================================================
   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
  87 AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD])
  88 AC_DEFUN([AX_PTHREAD], [
  89 AC_REQUIRE([AC_CANONICAL_HOST])
  90 AC_LANG_PUSH([C])
  91 ax_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:
 100 if 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"
 114 fi
 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
 126 ax_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
 148 case ${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 $ax_pthread_flags"
 164         ;;
 165 esac
 166
 167 if test x"$ax_pthread_ok" = xno; then
 168 for 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$ax_pthread_ok" = xyes; then
 224                 break;
 225         fi
 226
 227         PTHREAD_LIBS=""
 228         PTHREAD_CFLAGS=""
 229 done
 230 fi
 231
 232 # Various other checks:
 233 if test "x$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
 292 else
 293         PTHREAD_CC="$CC"
 294 fi
 295
 296 AC_SUBST(PTHREAD_LIBS)
 297 AC_SUBST(PTHREAD_CFLAGS)
 298 AC_SUBST(PTHREAD_CC)
 299
 300 # Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
 301 if test x"$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         :
 304 else
 305         ax_pthread_ok=no
 306         $2
 307 fi
 308 AC_LANG_POP
 309 ])dnl AX_PTHREAD