m4/acx_pthread.m4 - jrn/xz - Git at Google

 ##### http://autoconf-archive.cryp.to/acx_pthread.html
 #
 # SYNOPSIS
 #
 #   ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
 #
 # DESCRIPTION
 #
 #   This macro figures out how to build C programs using POSIX threads.
 #   It sets the PTHREAD_LIBS output variable to the threads library and
 #   linker flags, and the PTHREAD_CFLAGS output variable to any special
 #   C compiler flags that are needed. (The user can also force certain
 #   compiler flags/libs to be tested by setting these environment
 #   variables.)
 #
 #   Also sets PTHREAD_CC to any special C compiler that is needed for
 #   multi-threaded programs (defaults to the value of CC otherwise).
 #   (This is necessary on AIX to use the special cc_r compiler alias.)
 #
 #   NOTE: You are assumed to not only compile your program with these
 #   flags, but also link it with them as well. e.g. you should link
 #   with $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS
 #   $LIBS
 #
 #   If you are only building threads programs, you may wish to use
 #   these variables in your default LIBS, CFLAGS, and CC:
 #
 #          LIBS="$PTHREAD_LIBS $LIBS"
 #          CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
 #          CC="$PTHREAD_CC"
 #
 #   In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute
 #   constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to
 #   that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
 #
 #   ACTION-IF-FOUND is a list of shell commands to run if a threads
 #   library is found, and ACTION-IF-NOT-FOUND is a list of commands to
 #   run it if it is not found. If ACTION-IF-FOUND is not specified, the
 #   default action will define HAVE_PTHREAD.
 #
 #   Please let the authors know if this macro fails on any platform, or
 #   if you have any other suggestions or comments. This macro was based
 #   on work by SGJ on autoconf scripts for FFTW (http://www.fftw.org/)
 #   (with help from M. Frigo), as well as ac_pthread and hb_pthread
 #   macros posted by Alejandro Forero Cuervo to the autoconf macro
 #   repository. We are also grateful for the helpful feedback of
 #   numerous users.
 #
 # LAST MODIFICATION
 #
 #   2007-07-29
 #
 # COPYLEFT
 #
 #   Copyright (c) 2007 Steven G. Johnson <stevenj@alum.mit.edu>
 #
 #   This program is free software: you can redistribute it and/or
 #   modify it under the terms of the GNU General Public License as
 #   published by the Free Software Foundation, either version 3 of the
 #   License, or (at your option) any later version.
 #
 #   This program is distributed in the hope that it will be useful, but
 #   WITHOUT ANY WARRANTY; without even the implied warranty of
 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 #   General Public License for more details.
 #
 #   You should have received a copy of the GNU General Public License
 #   along with this program. If not, see
 #   <http://www.gnu.org/licenses/>.
 #
 #   As a special exception, the respective Autoconf Macro's copyright
 #   owner gives unlimited permission to copy, distribute and modify the
 #   configure scripts that are the output of Autoconf when processing
 #   the Macro. You need not follow the terms of the GNU General Public
 #   License when using or distributing such scripts, even though
 #   portions of the text of the Macro appear in them. The GNU General
 #   Public License (GPL) does govern all other use of the material that
 #   constitutes the Autoconf Macro.
 #
 #   This special exception to the GPL applies to versions of the
 #   Autoconf Macro released by the Autoconf Macro Archive. When you
 #   make and distribute a modified version of the Autoconf Macro, you
 #   may extend this special exception to the GPL to apply to your
 #   modified version as well.

 AC_DEFUN([ACX_PTHREAD], [
 AC_REQUIRE([AC_CANONICAL_HOST])
 AC_LANG_SAVE
 AC_LANG_C
 acx_pthread_ok=no

 # We used to check for pthread.h first, but this fails if pthread.h
 # requires special compiler flags (e.g. on True64 or Sequent).
 # It gets checked for in the link test anyway.

 # First of all, check if the user has set any of the PTHREAD_LIBS,
 # etcetera environment variables, and if threads linking works using
 # them:
 if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
         save_CFLAGS="$CFLAGS"
         CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
         save_LIBS="$LIBS"
         LIBS="$PTHREAD_LIBS $LIBS"
         AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
         AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes)
         AC_MSG_RESULT($acx_pthread_ok)
         if test x"$acx_pthread_ok" = xno; then
                 PTHREAD_LIBS=""
                 PTHREAD_CFLAGS=""
         fi
         LIBS="$save_LIBS"
         CFLAGS="$save_CFLAGS"
 fi

 # We must check for the threads library under a number of different
 # names; the ordering is very important because some systems
 # (e.g. DEC) have both -lpthread and -lpthreads, where one of the
 # libraries is broken (non-POSIX).

 # Create a list of thread flags to try.  Items starting with a "-" are
 # C compiler flags, and other items are library names, except for "none"
 # which indicates that we try without any flags at all, and "pthread-config"
 # which is a program returning the flags for the Pth emulation library.

 acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"

 # The ordering *is* (sometimes) important.  Some notes on the
 # individual items follow:

 # pthreads: AIX (must check this before -lpthread)
 # none: in case threads are in libc; should be tried before -Kthread and
 #       other compiler flags to prevent continual compiler warnings
 # -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
 # -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
 # lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
 # -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
 # -pthreads: Solaris/gcc
 # -mthreads: Mingw32/gcc, Lynx/gcc
 # -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
 #      doesn't hurt to check since this sometimes defines pthreads too;
 #      also defines -D_REENTRANT)
 #      ... -mt is also the pthreads flag for HP/aCC
 # pthread: Linux, etcetera
 # --thread-safe: KAI C++
 # pthread-config: use pthread-config program (for GNU Pth library)

 case "${host_cpu}-${host_os}" in
         *solaris*)

         # On Solaris (at least, for some versions), libc contains stubbed
         # (non-functional) versions of the pthreads routines, so link-based
         # tests will erroneously succeed.  (We need to link with -pthreads/-mt/
         # -lpthread.)  (The stubs are missing pthread_cleanup_push, or rather
         # a function called by this macro, so we could check for that, but
         # who knows whether they'll stub that too in a future libc.)  So,
         # we'll just look for -pthreads and -lpthread first:

         acx_pthread_flags="-pthreads pthread -mt -pthread $acx_pthread_flags"
         ;;
 esac

 if test x"$acx_pthread_ok" = xno; then
 for flag in $acx_pthread_flags; do

         case $flag in
                 none)
                 AC_MSG_CHECKING([whether pthreads work without any flags])
                 ;;

                 -*)
                 AC_MSG_CHECKING([whether pthreads work with $flag])
                 PTHREAD_CFLAGS="$flag"
                 ;;

 		pthread-config)
 		AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no)
 		if test x"$acx_pthread_config" = xno; then continue; fi
 		PTHREAD_CFLAGS="`pthread-config --cflags`"
 		PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
 		;;

                 *)
                 AC_MSG_CHECKING([for the pthreads library -l$flag])
                 PTHREAD_LIBS="-l$flag"
                 ;;
         esac

         save_LIBS="$LIBS"
         save_CFLAGS="$CFLAGS"
         LIBS="$PTHREAD_LIBS $LIBS"
         CFLAGS="$CFLAGS $PTHREAD_CFLAGS"

         # Check for various functions.  We must include pthread.h,
         # since some functions may be macros.  (On the Sequent, we
         # need a special flag -Kthread to make this header compile.)
         # We check for pthread_join because it is in -lpthread on IRIX
         # while pthread_create is in libc.  We check for pthread_attr_init
         # due to DEC craziness with -lpthreads.  We check for
         # pthread_cleanup_push because it is one of the few pthread
         # functions on Solaris that doesn't have a non-functional libc stub.
         # We try pthread_create on general principles.
         AC_TRY_LINK([#include <pthread.h>],
                     [pthread_t th; pthread_join(th, 0);
                      pthread_attr_init(0); pthread_cleanup_push(0, 0);
                      pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
                     [acx_pthread_ok=yes])

         LIBS="$save_LIBS"
         CFLAGS="$save_CFLAGS"

         AC_MSG_RESULT($acx_pthread_ok)
         if test "x$acx_pthread_ok" = xyes; then
                 break;
         fi

         PTHREAD_LIBS=""
         PTHREAD_CFLAGS=""
 done
 fi

 # Various other checks:
 if test "x$acx_pthread_ok" = xyes; then
         save_LIBS="$LIBS"
         LIBS="$PTHREAD_LIBS $LIBS"
         save_CFLAGS="$CFLAGS"
         CFLAGS="$CFLAGS $PTHREAD_CFLAGS"

         # Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
 	AC_MSG_CHECKING([for joinable pthread attribute])
 	attr_name=unknown
 	for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
 	    AC_TRY_LINK([#include <pthread.h>], [int attr=$attr; return attr;],
                         [attr_name=$attr; break])
 	done
         AC_MSG_RESULT($attr_name)
         if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then
             AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name,
                                [Define to necessary symbol if this constant
                                 uses a non-standard name on your system.])
         fi

         AC_MSG_CHECKING([if more special flags are required for pthreads])
         flag=no
         case "${host_cpu}-${host_os}" in
             *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";;
             *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
         esac
         AC_MSG_RESULT(${flag})
         if test "x$flag" != xno; then
             PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
         fi

         LIBS="$save_LIBS"
         CFLAGS="$save_CFLAGS"

         # More AIX lossage: must compile with xlc_r or cc_r
 	if test x"$GCC" != xyes; then
           AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC})
         else
           PTHREAD_CC=$CC
 	fi
 else
         PTHREAD_CC="$CC"
 fi

 AC_SUBST(PTHREAD_LIBS)
 AC_SUBST(PTHREAD_CFLAGS)
 AC_SUBST(PTHREAD_CC)

 # Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
 if test x"$acx_pthread_ok" = xyes; then
         ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])
         :
 else
         acx_pthread_ok=no
         $2
 fi
 AC_LANG_RESTORE
 ])dnl ACX_PTHREAD
	##### http://autoconf-archive.cryp.to/acx_pthread.html
	#
	# SYNOPSIS
	#
	# ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
	#
	# DESCRIPTION
	#
	# This macro figures out how to build C programs using POSIX threads.
	# It sets the PTHREAD_LIBS output variable to the threads library and
	# linker flags, and the PTHREAD_CFLAGS output variable to any special
	# C compiler flags that are needed. (The user can also force certain
	# compiler flags/libs to be tested by setting these environment
	# variables.)
	#
	# Also sets PTHREAD_CC to any special C compiler that is needed for
	# multi-threaded programs (defaults to the value of CC otherwise).
	# (This is necessary on AIX to use the special cc_r compiler alias.)
	#
	# NOTE: You are assumed to not only compile your program with these
	# flags, but also link it with them as well. e.g. you should link
	# with $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS
	# $LIBS
	#
	# If you are only building threads programs, you may wish to use
	# these variables in your default LIBS, CFLAGS, and CC:
	#
	# LIBS="$PTHREAD_LIBS $LIBS"
	# CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
	# CC="$PTHREAD_CC"
	#
	# In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute
	# constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to
	# that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
	#
	# ACTION-IF-FOUND is a list of shell commands to run if a threads
	# library is found, and ACTION-IF-NOT-FOUND is a list of commands to
	# run it if it is not found. If ACTION-IF-FOUND is not specified, the
	# default action will define HAVE_PTHREAD.
	#
	# Please let the authors know if this macro fails on any platform, or
	# if you have any other suggestions or comments. This macro was based
	# on work by SGJ on autoconf scripts for FFTW (http://www.fftw.org/)
	# (with help from M. Frigo), as well as ac_pthread and hb_pthread
	# macros posted by Alejandro Forero Cuervo to the autoconf macro
	# repository. We are also grateful for the helpful feedback of
	# numerous users.
	#
	# LAST MODIFICATION
	#
	# 2007-07-29
	#
	# COPYLEFT
	#
	# Copyright (c) 2007 Steven G. Johnson <stevenj@alum.mit.edu>
	#
	# This program is free software: you can redistribute it and/or
	# modify it under the terms of the GNU General Public License as
	# published by the Free Software Foundation, either version 3 of the
	# License, or (at your option) any later version.
	#
	# This program is distributed in the hope that it will be useful, but
	# WITHOUT ANY WARRANTY; without even the implied warranty of
	# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	# General Public License for more details.
	#
	# You should have received a copy of the GNU General Public License
	# along with this program. If not, see
	# <http://www.gnu.org/licenses/>.
	#
	# As a special exception, the respective Autoconf Macro's copyright
	# owner gives unlimited permission to copy, distribute and modify the
	# configure scripts that are the output of Autoconf when processing
	# the Macro. You need not follow the terms of the GNU General Public
	# License when using or distributing such scripts, even though
	# portions of the text of the Macro appear in them. The GNU General
	# Public License (GPL) does govern all other use of the material that
	# constitutes the Autoconf Macro.
	#
	# This special exception to the GPL applies to versions of the
	# Autoconf Macro released by the Autoconf Macro Archive. When you
	# make and distribute a modified version of the Autoconf Macro, you
	# may extend this special exception to the GPL to apply to your
	# modified version as well.

	AC_DEFUN([ACX_PTHREAD], [
	AC_REQUIRE([AC_CANONICAL_HOST])
	AC_LANG_SAVE
	AC_LANG_C
	acx_pthread_ok=no

	# We used to check for pthread.h first, but this fails if pthread.h
	# requires special compiler flags (e.g. on True64 or Sequent).
	# It gets checked for in the link test anyway.

	# First of all, check if the user has set any of the PTHREAD_LIBS,
	# etcetera environment variables, and if threads linking works using
	# them:
	if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
	save_CFLAGS="$CFLAGS"
	CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
	save_LIBS="$LIBS"
	LIBS="$PTHREAD_LIBS $LIBS"
	AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
	AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes)
	AC_MSG_RESULT($acx_pthread_ok)
	if test x"$acx_pthread_ok" = xno; then
	PTHREAD_LIBS=""
	PTHREAD_CFLAGS=""
	fi
	LIBS="$save_LIBS"
	CFLAGS="$save_CFLAGS"
	fi

	# We must check for the threads library under a number of different
	# names; the ordering is very important because some systems
	# (e.g. DEC) have both -lpthread and -lpthreads, where one of the
	# libraries is broken (non-POSIX).

	# Create a list of thread flags to try. Items starting with a "-" are
	# C compiler flags, and other items are library names, except for "none"
	# which indicates that we try without any flags at all, and "pthread-config"
	# which is a program returning the flags for the Pth emulation library.

	acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"

	# The ordering is (sometimes) important. Some notes on the
	# individual items follow:

	# pthreads: AIX (must check this before -lpthread)
	# none: in case threads are in libc; should be tried before -Kthread and
	# other compiler flags to prevent continual compiler warnings
	# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
	# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
	# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
	# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
	# -pthreads: Solaris/gcc
	# -mthreads: Mingw32/gcc, Lynx/gcc
	# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
	# doesn't hurt to check since this sometimes defines pthreads too;
	# also defines -D_REENTRANT)
	# ... -mt is also the pthreads flag for HP/aCC
	# pthread: Linux, etcetera
	# --thread-safe: KAI C++
	# pthread-config: use pthread-config program (for GNU Pth library)

	case "${host_cpu}-${host_os}" in
	solaris)

	# On Solaris (at least, for some versions), libc contains stubbed
	# (non-functional) versions of the pthreads routines, so link-based
	# tests will erroneously succeed. (We need to link with -pthreads/-mt/
	# -lpthread.) (The stubs are missing pthread_cleanup_push, or rather
	# a function called by this macro, so we could check for that, but
	# who knows whether they'll stub that too in a future libc.) So,
	# we'll just look for -pthreads and -lpthread first:

	acx_pthread_flags="-pthreads pthread -mt -pthread $acx_pthread_flags"
	;;
	esac

	if test x"$acx_pthread_ok" = xno; then
	for flag in $acx_pthread_flags; do

	case $flag in
	none)
	AC_MSG_CHECKING([whether pthreads work without any flags])
	;;

	-*)
	AC_MSG_CHECKING([whether pthreads work with $flag])
	PTHREAD_CFLAGS="$flag"
	;;

	pthread-config)
	AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no)
	if test x"$acx_pthread_config" = xno; then continue; fi
	PTHREAD_CFLAGS="`pthread-config --cflags`"
	PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
	;;

	*)
	AC_MSG_CHECKING([for the pthreads library -l$flag])
	PTHREAD_LIBS="-l$flag"
	;;
	esac

	save_LIBS="$LIBS"
	save_CFLAGS="$CFLAGS"
	LIBS="$PTHREAD_LIBS $LIBS"
	CFLAGS="$CFLAGS $PTHREAD_CFLAGS"

	# Check for various functions. We must include pthread.h,
	# since some functions may be macros. (On the Sequent, we
	# need a special flag -Kthread to make this header compile.)
	# We check for pthread_join because it is in -lpthread on IRIX
	# while pthread_create is in libc. We check for pthread_attr_init
	# due to DEC craziness with -lpthreads. We check for
	# pthread_cleanup_push because it is one of the few pthread
	# functions on Solaris that doesn't have a non-functional libc stub.
	# We try pthread_create on general principles.
	AC_TRY_LINK([#include <pthread.h>],
	[pthread_t th; pthread_join(th, 0);
	pthread_attr_init(0); pthread_cleanup_push(0, 0);
	pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
	[acx_pthread_ok=yes])

	LIBS="$save_LIBS"
	CFLAGS="$save_CFLAGS"

	AC_MSG_RESULT($acx_pthread_ok)
	if test "x$acx_pthread_ok" = xyes; then
	break;
	fi

	PTHREAD_LIBS=""
	PTHREAD_CFLAGS=""
	done
	fi

	# Various other checks:
	if test "x$acx_pthread_ok" = xyes; then
	save_LIBS="$LIBS"
	LIBS="$PTHREAD_LIBS $LIBS"
	save_CFLAGS="$CFLAGS"
	CFLAGS="$CFLAGS $PTHREAD_CFLAGS"

	# Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
	AC_MSG_CHECKING([for joinable pthread attribute])
	attr_name=unknown
	for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
	AC_TRY_LINK([#include <pthread.h>], [int attr=$attr; return attr;],
	[attr_name=$attr; break])
	done
	AC_MSG_RESULT($attr_name)
	if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then
	AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name,
	[Define to necessary symbol if this constant
	uses a non-standard name on your system.])
	fi

	AC_MSG_CHECKING([if more special flags are required for pthreads])
	flag=no
	case "${host_cpu}-${host_os}" in
	-aix \| -freebsd \| -darwin) flag="-D_THREAD_SAFE";;
	solaris \| -osf \| -hpux) flag="-D_REENTRANT";;
	esac
	AC_MSG_RESULT(${flag})
	if test "x$flag" != xno; then
	PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
	fi

	LIBS="$save_LIBS"
	CFLAGS="$save_CFLAGS"

	# More AIX lossage: must compile with xlc_r or cc_r
	if test x"$GCC" != xyes; then
	AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC})
	else
	PTHREAD_CC=$CC
	fi
	else
	PTHREAD_CC="$CC"
	fi

	AC_SUBST(PTHREAD_LIBS)
	AC_SUBST(PTHREAD_CFLAGS)
	AC_SUBST(PTHREAD_CC)

	# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
	if test x"$acx_pthread_ok" = xyes; then
	ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])
	:
	else
	acx_pthread_ok=no
	$2
	fi
	AC_LANG_RESTORE
	])dnl ACX_PTHREAD