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 21
  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 $ax_pthread_flags"
 164         ;;
 165 esac
 166
 167 # Clang doesn't consider unrecognized options an error unless we specify
 168 # -Werror. We throw in some extra Clang-specific options to ensure that
 169 # this doesn't happen for GCC, which also accepts -Werror.
 170
 171 AC_MSG_CHECKING([if compiler needs -Werror to reject unknown flags])
 172 save_CFLAGS="$CFLAGS"
 173 ax_pthread_extra_flags="-Werror"
 174 CFLAGS="$CFLAGS $ax_pthread_extra_flags -Wunknown-warning-option -Wsizeof-array-argument"
 175 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([int foo(void);],[foo()])],
 176                   [AC_MSG_RESULT([yes])],
 177                   [ax_pthread_extra_flags=
 178                    AC_MSG_RESULT([no])])
 179 CFLAGS="$save_CFLAGS"
 180
 181 if test x"$ax_pthread_ok" = xno; then
 182 for flag in $ax_pthread_flags; do
 183
 184         case $flag in
 185                 none)
 186                 AC_MSG_CHECKING([whether pthreads work without any flags])
 187                 ;;
 188
 189                 -*)
 190                 AC_MSG_CHECKING([whether pthreads work with $flag])
 191                 PTHREAD_CFLAGS="$flag"
 192                 ;;
 193
 194                 pthread-config)
 195                 AC_CHECK_PROG([ax_pthread_config], [pthread-config], [yes], [no])
 196                 if test x"$ax_pthread_config" = xno; then continue; fi
 197                 PTHREAD_CFLAGS="`pthread-config --cflags`"
 198                 PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
 199                 ;;
 200
 201                 *)
 202                 AC_MSG_CHECKING([for the pthreads library -l$flag])
 203                 PTHREAD_LIBS="-l$flag"
 204                 ;;
 205         esac
 206
 207         save_LIBS="$LIBS"
 208         save_CFLAGS="$CFLAGS"
 209         LIBS="$PTHREAD_LIBS $LIBS"
 210         CFLAGS="$CFLAGS $PTHREAD_CFLAGS $ax_pthread_extra_flags"
 211
 212         # Check for various functions.  We must include pthread.h,
 213         # since some functions may be macros.  (On the Sequent, we
 214         # need a special flag -Kthread to make this header compile.)
 215         # We check for pthread_join because it is in -lpthread on IRIX
 216         # while pthread_create is in libc.  We check for pthread_attr_init
 217         # due to DEC craziness with -lpthreads.  We check for
 218         # pthread_cleanup_push because it is one of the few pthread
 219         # functions on Solaris that doesn't have a non-functional libc stub.
 220         # We try pthread_create on general principles.
 221         AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>
 222                         static void routine(void *a) { a = 0; }
 223                         static void *start_routine(void *a) { return a; }],
 224                        [pthread_t th; pthread_attr_t attr;
 225                         pthread_create(&th, 0, start_routine, 0);
 226                         pthread_join(th, 0);
 227                         pthread_attr_init(&attr);
 228                         pthread_cleanup_push(routine, 0);
 229                         pthread_cleanup_pop(0) /* ; */])],
 230                 [ax_pthread_ok=yes],
 231                 [])
 232
 233         LIBS="$save_LIBS"
 234         CFLAGS="$save_CFLAGS"
 235
 236         AC_MSG_RESULT([$ax_pthread_ok])
 237         if test "x$ax_pthread_ok" = xyes; then
 238                 break;
 239         fi
 240
 241         PTHREAD_LIBS=""
 242         PTHREAD_CFLAGS=""
 243 done
 244 fi
 245
 246 # Various other checks:
 247 if test "x$ax_pthread_ok" = xyes; then
 248         save_LIBS="$LIBS"
 249         LIBS="$PTHREAD_LIBS $LIBS"
 250         save_CFLAGS="$CFLAGS"
 251         CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
 252
 253         # Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
 254         AC_MSG_CHECKING([for joinable pthread attribute])
 255         attr_name=unknown
 256         for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
 257             AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>],
 258                            [int attr = $attr; return attr /* ; */])],
 259                 [attr_name=$attr; break],
 260                 [])
 261         done
 262         AC_MSG_RESULT([$attr_name])
 263         if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then
 264             AC_DEFINE_UNQUOTED([PTHREAD_CREATE_JOINABLE], [$attr_name],
 265                                [Define to necessary symbol if this constant
 266                                 uses a non-standard name on your system.])
 267         fi
 268
 269         AC_MSG_CHECKING([if more special flags are required for pthreads])
 270         flag=no
 271         case ${host_os} in
 272             aix* | freebsd* | darwin*) flag="-D_THREAD_SAFE";;
 273             osf* | hpux*) flag="-D_REENTRANT";;
 274             solaris*)
 275             if test "$GCC" = "yes"; then
 276                 flag="-D_REENTRANT"
 277             else
 278                 # TODO: What about Clang on Solaris?
 279                 flag="-mt -D_REENTRANT"
 280             fi
 281             ;;
 282         esac
 283         AC_MSG_RESULT([$flag])
 284         if test "x$flag" != xno; then
 285             PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
 286         fi
 287
 288         AC_CACHE_CHECK([for PTHREAD_PRIO_INHERIT],
 289             [ax_cv_PTHREAD_PRIO_INHERIT], [
 290                 AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <pthread.h>]],
 291                                                 [[int i = PTHREAD_PRIO_INHERIT;]])],
 292                     [ax_cv_PTHREAD_PRIO_INHERIT=yes],
 293                     [ax_cv_PTHREAD_PRIO_INHERIT=no])
 294             ])
 295         AS_IF([test "x$ax_cv_PTHREAD_PRIO_INHERIT" = "xyes"],
 296             [AC_DEFINE([HAVE_PTHREAD_PRIO_INHERIT], [1], [Have PTHREAD_PRIO_INHERIT.])])
 297
 298         LIBS="$save_LIBS"
 299         CFLAGS="$save_CFLAGS"
 300
 301         # More AIX lossage: compile with *_r variant
 302         if test "x$GCC" != xyes; then
 303             case $host_os in
 304                 aix*)
 305                 AS_CASE(["x/$CC"],
 306                   [x*/c89|x*/c89_128|x*/c99|x*/c99_128|x*/cc|x*/cc128|x*/xlc|x*/xlc_v6|x*/xlc128|x*/xlc128_v6],
 307                   [#handle absolute path differently from PATH based program lookup
 308                    AS_CASE(["x$CC"],
 309                      [x/*],
 310                      [AS_IF([AS_EXECUTABLE_P([${CC}_r])],[PTHREAD_CC="${CC}_r"])],
 311                      [AC_CHECK_PROGS([PTHREAD_CC],[${CC}_r],[$CC])])])
 312                 ;;
 313             esac
 314         fi
 315 fi
 316
 317 test -n "$PTHREAD_CC" || PTHREAD_CC="$CC"
 318
 319 AC_SUBST([PTHREAD_LIBS])
 320 AC_SUBST([PTHREAD_CFLAGS])
 321 AC_SUBST([PTHREAD_CC])
 322
 323 # Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
 324 if test x"$ax_pthread_ok" = xyes; then
 325         ifelse([$1],,[AC_DEFINE([HAVE_PTHREAD],[1],[Define if you have POSIX threads libraries and header files.])],[$1])
 326         :
 327 else
 328         ax_pthread_ok=no
 329         $2
 330 fi
 331 AC_LANG_POP
 332 ])dnl AX_PTHREAD