cannam@48: # This file was copied to Cap'n Proto from the Protocol Buffers distribution, cannam@48: # version 2.3.0. cannam@48: cannam@48: # This was retrieved from cannam@48: # http://svn.0pointer.de/viewvc/trunk/common/acx_pthread.m4?revision=1277&root=avahi cannam@48: # See also (perhaps for new versions?) cannam@48: # http://svn.0pointer.de/viewvc/trunk/common/acx_pthread.m4?root=avahi cannam@48: # cannam@48: # We've rewritten the inconsistency check code (from avahi), to work cannam@48: # more broadly. In particular, it no longer assumes ld accepts -zdefs. cannam@48: # This caused a restructing of the code, but the functionality has only cannam@48: # changed a little. cannam@48: cannam@48: dnl @synopsis ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]]) cannam@48: dnl cannam@48: dnl @summary figure out how to build C programs using POSIX threads cannam@48: dnl cannam@48: dnl This macro figures out how to build C programs using POSIX threads. cannam@48: dnl It sets the PTHREAD_LIBS output variable to the threads library and cannam@48: dnl linker flags, and the PTHREAD_CFLAGS output variable to any special cannam@48: dnl C compiler flags that are needed. (The user can also force certain cannam@48: dnl compiler flags/libs to be tested by setting these environment cannam@48: dnl variables.) cannam@48: dnl cannam@48: dnl Also sets PTHREAD_CC to any special C compiler that is needed for cannam@48: dnl multi-threaded programs (defaults to the value of CC otherwise). cannam@48: dnl (This is necessary on AIX to use the special cc_r compiler alias.) cannam@48: dnl cannam@48: dnl NOTE: You are assumed to not only compile your program with these cannam@48: dnl flags, but also link it with them as well. e.g. you should link cannam@48: dnl with $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS cannam@48: dnl $LIBS cannam@48: dnl cannam@48: dnl If you are only building threads programs, you may wish to use cannam@48: dnl these variables in your default LIBS, CFLAGS, and CC: cannam@48: dnl cannam@48: dnl LIBS="$PTHREAD_LIBS $LIBS" cannam@48: dnl CFLAGS="$CFLAGS $PTHREAD_CFLAGS" cannam@48: dnl CC="$PTHREAD_CC" cannam@48: dnl cannam@48: dnl In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute cannam@48: dnl constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to cannam@48: dnl that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX). cannam@48: dnl cannam@48: dnl ACTION-IF-FOUND is a list of shell commands to run if a threads cannam@48: dnl library is found, and ACTION-IF-NOT-FOUND is a list of commands to cannam@48: dnl run it if it is not found. If ACTION-IF-FOUND is not specified, the cannam@48: dnl default action will define HAVE_PTHREAD. cannam@48: dnl cannam@48: dnl Please let the authors know if this macro fails on any platform, or cannam@48: dnl if you have any other suggestions or comments. This macro was based cannam@48: dnl on work by SGJ on autoconf scripts for FFTW (www.fftw.org) (with cannam@48: dnl help from M. Frigo), as well as ac_pthread and hb_pthread macros cannam@48: dnl posted by Alejandro Forero Cuervo to the autoconf macro repository. cannam@48: dnl We are also grateful for the helpful feedback of numerous users. cannam@48: dnl cannam@48: dnl @category InstalledPackages cannam@48: dnl @author Steven G. Johnson cannam@48: dnl @version 2006-05-29 cannam@48: dnl @license GPLWithACException cannam@48: dnl cannam@48: dnl Checks for GCC shared/pthread inconsistency based on work by cannam@48: dnl Marcin Owsiany cannam@48: cannam@48: cannam@48: AC_DEFUN([ACX_PTHREAD], [ cannam@48: AC_REQUIRE([AC_CANONICAL_HOST]) cannam@48: AC_LANG_SAVE cannam@48: AC_LANG_C cannam@48: acx_pthread_ok=no cannam@48: cannam@48: # We used to check for pthread.h first, but this fails if pthread.h cannam@48: # requires special compiler flags (e.g. on True64 or Sequent). cannam@48: # It gets checked for in the link test anyway. cannam@48: cannam@48: # First of all, check if the user has set any of the PTHREAD_LIBS, cannam@48: # etcetera environment variables, and if threads linking works using cannam@48: # them: cannam@48: if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then cannam@48: save_CFLAGS="$CFLAGS" cannam@48: CFLAGS="$CFLAGS $PTHREAD_CFLAGS" cannam@48: save_LIBS="$LIBS" cannam@48: LIBS="$PTHREAD_LIBS $LIBS" cannam@48: AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS]) cannam@48: AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes) cannam@48: AC_MSG_RESULT($acx_pthread_ok) cannam@48: if test x"$acx_pthread_ok" = xno; then cannam@48: PTHREAD_LIBS="" cannam@48: PTHREAD_CFLAGS="" cannam@48: fi cannam@48: LIBS="$save_LIBS" cannam@48: CFLAGS="$save_CFLAGS" cannam@48: fi cannam@48: cannam@48: # We must check for the threads library under a number of different cannam@48: # names; the ordering is very important because some systems cannam@48: # (e.g. DEC) have both -lpthread and -lpthreads, where one of the cannam@48: # libraries is broken (non-POSIX). cannam@48: cannam@48: # Create a list of thread flags to try. Items starting with a "-" are cannam@48: # C compiler flags, and other items are library names, except for "none" cannam@48: # which indicates that we try without any flags at all, and "pthread-config" cannam@48: # which is a program returning the flags for the Pth emulation library. cannam@48: cannam@48: acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config" cannam@48: cannam@48: # The ordering *is* (sometimes) important. Some notes on the cannam@48: # individual items follow: cannam@48: cannam@48: # pthreads: AIX (must check this before -lpthread) cannam@48: # none: in case threads are in libc; should be tried before -Kthread and cannam@48: # other compiler flags to prevent continual compiler warnings cannam@48: # -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h) cannam@48: # -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able) cannam@48: # lthread: LinuxThreads port on FreeBSD (also preferred to -pthread) cannam@48: # -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads) cannam@48: # -pthreads: Solaris/gcc cannam@48: # -mthreads: Mingw32/gcc, Lynx/gcc cannam@48: # -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it cannam@48: # doesn't hurt to check since this sometimes defines pthreads too; cannam@48: # also defines -D_REENTRANT) cannam@48: # ... -mt is also the pthreads flag for HP/aCC cannam@48: # pthread: Linux, etcetera cannam@48: # --thread-safe: KAI C++ cannam@48: # pthread-config: use pthread-config program (for GNU Pth library) cannam@48: cannam@48: case "${host_cpu}-${host_os}" in cannam@48: *solaris*) cannam@48: cannam@48: # On Solaris (at least, for some versions), libc contains stubbed cannam@48: # (non-functional) versions of the pthreads routines, so link-based cannam@48: # tests will erroneously succeed. (We need to link with -pthreads/-mt/ cannam@48: # -lpthread.) (The stubs are missing pthread_cleanup_push, or rather cannam@48: # a function called by this macro, so we could check for that, but cannam@48: # who knows whether they'll stub that too in a future libc.) So, cannam@48: # we'll just look for -pthreads and -lpthread first: cannam@48: cannam@48: acx_pthread_flags="-pthreads pthread -mt -pthread $acx_pthread_flags" cannam@48: ;; cannam@48: esac cannam@48: cannam@48: if test x"$acx_pthread_ok" = xno; then cannam@48: for flag in $acx_pthread_flags; do cannam@48: cannam@48: case $flag in cannam@48: none) cannam@48: AC_MSG_CHECKING([whether pthreads work without any flags]) cannam@48: ;; cannam@48: cannam@48: -*) cannam@48: AC_MSG_CHECKING([whether pthreads work with $flag]) cannam@48: PTHREAD_CFLAGS="$flag" cannam@48: ;; cannam@48: cannam@48: pthread-config) cannam@48: AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no) cannam@48: if test x"$acx_pthread_config" = xno; then continue; fi cannam@48: PTHREAD_CFLAGS="`pthread-config --cflags`" cannam@48: PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`" cannam@48: ;; cannam@48: cannam@48: *) cannam@48: AC_MSG_CHECKING([for the pthreads library -l$flag]) cannam@48: PTHREAD_LIBS="-l$flag" cannam@48: ;; cannam@48: esac cannam@48: cannam@48: save_LIBS="$LIBS" cannam@48: save_CFLAGS="$CFLAGS" cannam@48: LIBS="$PTHREAD_LIBS $LIBS" cannam@48: CFLAGS="$CFLAGS $PTHREAD_CFLAGS" cannam@48: cannam@48: # Check for various functions. We must include pthread.h, cannam@48: # since some functions may be macros. (On the Sequent, we cannam@48: # need a special flag -Kthread to make this header compile.) cannam@48: # We check for pthread_join because it is in -lpthread on IRIX cannam@48: # while pthread_create is in libc. We check for pthread_attr_init cannam@48: # due to DEC craziness with -lpthreads. We check for cannam@48: # pthread_cleanup_push because it is one of the few pthread cannam@48: # functions on Solaris that doesn't have a non-functional libc stub. cannam@48: # We try pthread_create on general principles. cannam@48: AC_TRY_LINK([#include ], cannam@48: [pthread_t th; pthread_join(th, 0); cannam@48: pthread_attr_init(0); pthread_cleanup_push(0, 0); cannam@48: pthread_create(0,0,0,0); pthread_cleanup_pop(0); ], cannam@48: [acx_pthread_ok=yes]) cannam@48: cannam@48: LIBS="$save_LIBS" cannam@48: CFLAGS="$save_CFLAGS" cannam@48: cannam@48: AC_MSG_RESULT($acx_pthread_ok) cannam@48: if test "x$acx_pthread_ok" = xyes; then cannam@48: break; cannam@48: fi cannam@48: cannam@48: PTHREAD_LIBS="" cannam@48: PTHREAD_CFLAGS="" cannam@48: done cannam@48: fi cannam@48: cannam@48: # Various other checks: cannam@48: if test "x$acx_pthread_ok" = xyes; then cannam@48: save_LIBS="$LIBS" cannam@48: LIBS="$PTHREAD_LIBS $LIBS" cannam@48: save_CFLAGS="$CFLAGS" cannam@48: CFLAGS="$CFLAGS $PTHREAD_CFLAGS" cannam@48: cannam@48: # Detect AIX lossage: JOINABLE attribute is called UNDETACHED. cannam@48: AC_MSG_CHECKING([for joinable pthread attribute]) cannam@48: attr_name=unknown cannam@48: for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do cannam@48: AC_TRY_LINK([#include ], [int attr=$attr; return attr;], cannam@48: [attr_name=$attr; break]) cannam@48: done cannam@48: AC_MSG_RESULT($attr_name) cannam@48: if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then cannam@48: AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name, cannam@48: [Define to necessary symbol if this constant cannam@48: uses a non-standard name on your system.]) cannam@48: fi cannam@48: cannam@48: AC_MSG_CHECKING([if more special flags are required for pthreads]) cannam@48: flag=no cannam@48: case "${host_cpu}-${host_os}" in cannam@48: *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";; cannam@48: *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";; cannam@48: esac cannam@48: AC_MSG_RESULT(${flag}) cannam@48: if test "x$flag" != xno; then cannam@48: PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS" cannam@48: fi cannam@48: cannam@48: LIBS="$save_LIBS" cannam@48: CFLAGS="$save_CFLAGS" cannam@48: # More AIX lossage: must compile with xlc_r or cc_r cannam@48: if test x"$GCC" != xyes; then cannam@48: AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC}) cannam@48: else cannam@48: PTHREAD_CC=$CC cannam@48: fi cannam@48: cannam@48: # The next part tries to detect GCC inconsistency with -shared on some cannam@48: # architectures and systems. The problem is that in certain cannam@48: # configurations, when -shared is specified, GCC "forgets" to cannam@48: # internally use various flags which are still necessary. cannam@48: cannam@48: # cannam@48: # Prepare the flags cannam@48: # cannam@48: save_CFLAGS="$CFLAGS" cannam@48: save_LIBS="$LIBS" cannam@48: save_CC="$CC" cannam@48: cannam@48: # Try with the flags determined by the earlier checks. cannam@48: # cannam@48: # -Wl,-z,defs forces link-time symbol resolution, so that the cannam@48: # linking checks with -shared actually have any value cannam@48: # cannam@48: # FIXME: -fPIC is required for -shared on many architectures, cannam@48: # so we specify it here, but the right way would probably be to cannam@48: # properly detect whether it is actually required. cannam@48: CFLAGS="-shared -fPIC -Wl,-z,defs $CFLAGS $PTHREAD_CFLAGS" cannam@48: LIBS="$PTHREAD_LIBS $LIBS" cannam@48: CC="$PTHREAD_CC" cannam@48: cannam@48: # In order not to create several levels of indentation, we test cannam@48: # the value of "$done" until we find the cure or run out of ideas. cannam@48: done="no" cannam@48: cannam@48: # First, make sure the CFLAGS we added are actually accepted by our cannam@48: # compiler. If not (and OS X's ld, for instance, does not accept -z), cannam@48: # then we can't do this test. cannam@48: if test x"$done" = xno; then cannam@48: AC_MSG_CHECKING([whether to check for GCC pthread/shared inconsistencies]) cannam@48: AC_TRY_LINK(,, , [done=yes]) cannam@48: cannam@48: if test "x$done" = xyes ; then cannam@48: AC_MSG_RESULT([no]) cannam@48: else cannam@48: AC_MSG_RESULT([yes]) cannam@48: fi cannam@48: fi cannam@48: cannam@48: if test x"$done" = xno; then cannam@48: AC_MSG_CHECKING([whether -pthread is sufficient with -shared]) cannam@48: AC_TRY_LINK([#include ], cannam@48: [pthread_t th; pthread_join(th, 0); cannam@48: pthread_attr_init(0); pthread_cleanup_push(0, 0); cannam@48: pthread_create(0,0,0,0); pthread_cleanup_pop(0); ], cannam@48: [done=yes]) cannam@48: cannam@48: if test "x$done" = xyes; then cannam@48: AC_MSG_RESULT([yes]) cannam@48: else cannam@48: AC_MSG_RESULT([no]) cannam@48: fi cannam@48: fi cannam@48: cannam@48: # cannam@48: # Linux gcc on some architectures such as mips/mipsel forgets cannam@48: # about -lpthread cannam@48: # cannam@48: if test x"$done" = xno; then cannam@48: AC_MSG_CHECKING([whether -lpthread fixes that]) cannam@48: LIBS="-lpthread $PTHREAD_LIBS $save_LIBS" cannam@48: AC_TRY_LINK([#include ], cannam@48: [pthread_t th; pthread_join(th, 0); cannam@48: pthread_attr_init(0); pthread_cleanup_push(0, 0); cannam@48: pthread_create(0,0,0,0); pthread_cleanup_pop(0); ], cannam@48: [done=yes]) cannam@48: cannam@48: if test "x$done" = xyes; then cannam@48: AC_MSG_RESULT([yes]) cannam@48: PTHREAD_LIBS="-lpthread $PTHREAD_LIBS" cannam@48: else cannam@48: AC_MSG_RESULT([no]) cannam@48: fi cannam@48: fi cannam@48: # cannam@48: # FreeBSD 4.10 gcc forgets to use -lc_r instead of -lc cannam@48: # cannam@48: if test x"$done" = xno; then cannam@48: AC_MSG_CHECKING([whether -lc_r fixes that]) cannam@48: LIBS="-lc_r $PTHREAD_LIBS $save_LIBS" cannam@48: AC_TRY_LINK([#include ], cannam@48: [pthread_t th; pthread_join(th, 0); cannam@48: pthread_attr_init(0); pthread_cleanup_push(0, 0); cannam@48: pthread_create(0,0,0,0); pthread_cleanup_pop(0); ], cannam@48: [done=yes]) cannam@48: cannam@48: if test "x$done" = xyes; then cannam@48: AC_MSG_RESULT([yes]) cannam@48: PTHREAD_LIBS="-lc_r $PTHREAD_LIBS" cannam@48: else cannam@48: AC_MSG_RESULT([no]) cannam@48: fi cannam@48: fi cannam@48: if test x"$done" = xno; then cannam@48: # OK, we have run out of ideas cannam@48: AC_MSG_WARN([Impossible to determine how to use pthreads with shared libraries]) cannam@48: cannam@48: # so it's not safe to assume that we may use pthreads cannam@48: acx_pthread_ok=no cannam@48: fi cannam@48: cannam@48: CFLAGS="$save_CFLAGS" cannam@48: LIBS="$save_LIBS" cannam@48: CC="$save_CC" cannam@48: else cannam@48: PTHREAD_CC="$CC" cannam@48: fi cannam@48: cannam@48: if test "x$acx_pthread_ok" = xyes; then cannam@48: # One more check: If we chose to use a compiler flag like -pthread but it is combined with cannam@48: # -nostdlib then the compiler won't implicitly link against libpthread. This can happen cannam@48: # in particular when using some versions of libtool on some distros. See: cannam@48: # https://bugzilla.redhat.com/show_bug.cgi?id=661333 cannam@48: cannam@48: save_CFLAGS="$CFLAGS" cannam@48: save_LIBS="$LIBS" cannam@48: save_CC="$CC" cannam@48: CFLAGS="$CFLAGS $PTHREAD_CFLAGS" cannam@48: LIBS="-nostdlib $PTHREAD_LIBS $LIBS -lc" cannam@48: CC="$PTHREAD_CC" cannam@48: cannam@48: AC_MSG_CHECKING([whether pthread flag is sufficient with -nostdlib]) cannam@48: AC_TRY_LINK([#include ], cannam@48: [pthread_t th; pthread_join(th, 0); cannam@48: pthread_attr_init(0); pthread_cleanup_push(0, 0); cannam@48: pthread_create(0,0,0,0); pthread_cleanup_pop(0); ], cannam@48: [AC_MSG_RESULT([yes])], [ cannam@48: AC_MSG_RESULT([no]) cannam@48: cannam@48: AC_MSG_CHECKING([whether adding -lpthread fixes that]) cannam@48: cannam@48: LIBS="-nostdlib $PTHREAD_LIBS -lpthread $save_LIBS -lc" cannam@48: AC_TRY_LINK([#include ], cannam@48: [pthread_t th; pthread_join(th, 0); cannam@48: pthread_attr_init(0); pthread_cleanup_push(0, 0); cannam@48: pthread_create(0,0,0,0); pthread_cleanup_pop(0); ], cannam@48: [ cannam@48: AC_MSG_RESULT([yes]) cannam@48: PTHREAD_LIBS="$PTHREAD_LIBS -lpthread" cannam@48: ], [AC_MSG_RESULT([no])]) cannam@48: ]) cannam@48: cannam@48: CFLAGS="$save_CFLAGS" cannam@48: LIBS="$save_LIBS" cannam@48: CC="$save_CC" cannam@48: fi cannam@48: cannam@48: AC_SUBST(PTHREAD_LIBS) cannam@48: AC_SUBST(PTHREAD_CFLAGS) cannam@48: AC_SUBST(PTHREAD_CC) cannam@48: cannam@48: # Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND: cannam@48: if test x"$acx_pthread_ok" = xyes; then cannam@48: ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1]) cannam@48: : cannam@48: else cannam@48: acx_pthread_ok=no cannam@48: $2 cannam@48: fi cannam@48: AC_LANG_RESTORE cannam@48: ])dnl ACX_PTHREAD