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Diffstat (limited to 'm4/acx_pthread.m4')
| -rw-r--r-- | m4/acx_pthread.m4 | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/m4/acx_pthread.m4 b/m4/acx_pthread.m4 new file mode 100644 index 0000000..feeb01d --- /dev/null +++ b/m4/acx_pthread.m4 @@ -0,0 +1,254 @@ +dnl +dnl NOTE: This file was modified. See the comments starting with 'CS:' +dnl for more information. In particular, it was changed to use C++ +dnl instead of C. +dnl +dnl @synopsis ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]]) +dnl +dnl @summary figure out how to build C++ programs using POSIX threads +dnl +dnl This macro figures out how to build C++ programs using POSIX threads. +dnl It sets the PTHREAD_LIBS output variable to the threads library and +dnl linker flags, and the PTHREAD_CXXFLAGS output variable to any special +dnl C++ compiler flags that are needed. (The user can also force certain +dnl compiler flags/libs to be tested by setting these environment +dnl variables.) +dnl +dnl Also sets PTHREAD_CXX to any special C++ compiler that is needed for +dnl multi-threaded programs (defaults to the value of CXX otherwise). +dnl (This is necessary on AIX to use the special xlC_r compiler alias.) +dnl +dnl NOTE: You are assumed to not only compile your program with these +dnl flags, but also link it with them as well. e.g. you should link +dnl with $PTHREAD_CXX $CXXFLAGS $PTHREAD_CXXFLAGS $LDFLAGS ... $PTHREAD_LIBS +dnl $LIBS +dnl +dnl If you are only building threads programs, you may wish to use +dnl these variables in your default LIBS, CXXFLAGS, and CXX: +dnl +dnl LIBS="$PTHREAD_LIBS $LIBS" +dnl CXXFLAGS="$CXXFLAGS $PTHREAD_CXXFLAGS" +dnl CXX="$PTHREAD_CXX" +dnl +dnl In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute +dnl constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to +dnl that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX). +dnl +dnl ACTION-IF-FOUND is a list of shell commands to run if a threads +dnl library is found, and ACTION-IF-NOT-FOUND is a list of commands to +dnl run it if it is not found. If ACTION-IF-FOUND is not specified, the +dnl default action will define HAVE_PTHREAD. +dnl +dnl Please let the authors know if this macro fails on any platform, or +dnl if you have any other suggestions or comments. This macro was based +dnl on work by SGJ on autoconf scripts for FFTW (www.fftw.org) (with +dnl help from M. Frigo), as well as ac_pthread and hb_pthread macros +dnl posted by Alejandro Forero Cuervo to the autoconf macro repository. +dnl We are also grateful for the helpful feedback of numerous users. +dnl +dnl @category InstalledPackages +dnl @author Steven G. Johnson <stevenj@alum.mit.edu> +dnl @version 2006-05-29 +dnl @license GPLWithACException + +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_CXXFLAGS" != x; then + save_CXXFLAGS="$CXXFLAGS" + CXXFLAGS="$CXXFLAGS $PTHREAD_CXXFLAGS" + save_LIBS="$LIBS" + LIBS="$PTHREAD_LIBS $LIBS" + AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CXXFLAGS=$PTHREAD_CXXFLAGS]) + AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes) + AC_MSG_RESULT($acx_pthread_ok) + if test x"$acx_pthread_ok" = xno; then + PTHREAD_LIBS="" + PTHREAD_CXXFLAGS="" + fi + LIBS="$save_LIBS" + CXXFLAGS="$save_CXXFLAGS" +fi + +# We must check for the threads library under a number of different +# names; the ordering is very important because some systems +# (e.g. DEC) have both -lpthread and -lpthreads, where one of the +# libraries is broken (non-POSIX). + +# Create a list of thread flags to try. Items starting with a "-" are +# C compiler flags, and other items are library names, except for "none" +# which indicates that we try without any flags at all, and "pthread-config" +# which is a program returning the flags for the Pth emulation library. + +# CS: On GNU/Linux with gcc both -pthread and -lpthread are valid. +# However, libtool links libraries with -nostdlib which results in +# -pthread being stripped from the linker command line. To resolve +# this we move pthread from after -mthreads to after pthreads. +# +acx_pthread_flags="pthreads pthread none -Kthread -kthread lthread -pthread -pthreads -mthreads --thread-safe -mt pthread-config" + +# The ordering *is* (sometimes) important. Some notes on the +# individual items follow: + +# pthreads: AIX (must check this before -lpthread) +# none: in case threads are in libc; should be tried before -Kthread and +# other compiler flags to prevent continual compiler warnings +# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h) +# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able) +# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread) +# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads) +# -pthreads: Solaris/gcc +# -mthreads: Mingw32/gcc, Lynx/gcc +# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it +# doesn't hurt to check since this sometimes defines pthreads too; +# also defines -D_REENTRANT) +# ... -mt is also the pthreads flag for HP/aCC +# pthread: Linux, etcetera +# --thread-safe: KAI C++ +# pthread-config: use pthread-config program (for GNU Pth library) + +case "${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 $flag]) + PTHREAD_CXXFLAGS="$flag" + ;; + + pthread-config) + AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no) + if test x"$acx_pthread_config" = xno; then continue; fi + PTHREAD_CXXFLAGS="`pthread-config --cflags`" + PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`" + ;; + + *) + AC_MSG_CHECKING([for the pthreads library -l$flag]) + PTHREAD_LIBS="-l$flag" + ;; + esac + + save_LIBS="$LIBS" + save_CXXFLAGS="$CXXFLAGS" + LIBS="$PTHREAD_LIBS $LIBS" + CXXFLAGS="$CXXFLAGS $PTHREAD_CXXFLAGS" + + # Check for various functions. We must include pthread.h, + # since some functions may be macros. (On the Sequent, we + # need a special flag -Kthread to make this header compile.) + # We check for pthread_join because it is in -lpthread on IRIX + # while pthread_create is in libc. We check for pthread_attr_init + # due to DEC craziness with -lpthreads. We check for + # pthread_cleanup_push because it is one of the few pthread + # functions on Solaris that doesn't have a non-functional libc stub. + # We try pthread_create on general principles. + # + AC_TRY_LINK([#include <pthread.h>], + [pthread_t th; pthread_join(th, 0); + pthread_attr_init(0); pthread_cleanup_push(0, 0); + pthread_create(0,0,0,0); pthread_cleanup_pop(0);], + [acx_pthread_ok=yes]) + + LIBS="$save_LIBS" + CXXFLAGS="$save_CXXFLAGS" + + AC_MSG_RESULT($acx_pthread_ok) + if test "x$acx_pthread_ok" = xyes; then + break; + fi + + PTHREAD_LIBS="" + PTHREAD_CXXFLAGS="" +done +fi + +# Various other checks: +if test "x$acx_pthread_ok" = xyes; then + save_LIBS="$LIBS" + LIBS="$PTHREAD_LIBS $LIBS" + save_CXXFLAGS="$CXXFLAGS" + CXXFLAGS="$CXXFLAGS $PTHREAD_CXXFLAGS" + +dnl # Detect AIX lossage: JOINABLE attribute is called UNDETACHED. +dnl AC_MSG_CHECKING([for joinable pthread attribute]) +dnl attr_name=unknown +dnl for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do +dnl AC_TRY_LINK([#include <pthread.h>], [int attr=$attr; return attr;], +dnl [attr_name=$attr; break]) +dnl done +dnl AC_MSG_RESULT($attr_name) +dnl if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then +dnl AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name, +dnl [Define to necessary symbol if this constant +dnl uses a non-standard name on your system.]) +dnl fi + + AC_MSG_CHECKING([if more special flags are required for pthreads]) + flag=no + case "${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$flag" != xno; then + PTHREAD_CXXFLAGS="$flag $PTHREAD_CXXFLAGS" + fi + + LIBS="$save_LIBS" + CXXFLAGS="$save_CXXFLAGS" + +dnl # More AIX lossage: must compile with xlC_r +dnl if test x"$GXX" != xyes; then +dnl AC_CHECK_PROGS(PTHREAD_CXX, xlC_r, ${CXX}) +dnl else +dnl PTHREAD_CXX=$CXX +dnl fi + +else + PTHREAD_CXX="$CXX" +fi + +AC_SUBST(PTHREAD_LIBS) +AC_SUBST(PTHREAD_CXXFLAGS) +AC_SUBST(PTHREAD_CXX) + +# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND: +if test x"$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 |