Annotation of embedaddon/pcre/m4/ax_pthread.m4, revision 1.1.1.1

1.1       misho       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

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