diff options
Diffstat (limited to 'third_party/glog/m4/acx_pthread.m4')
| -rw-r--r-- | third_party/glog/m4/acx_pthread.m4 | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/third_party/glog/m4/acx_pthread.m4 b/third_party/glog/m4/acx_pthread.m4 new file mode 100644 index 000000000000..2cf20de144a1 --- /dev/null +++ b/third_party/glog/m4/acx_pthread.m4 @@ -0,0 +1,363 @@ +# This was retrieved from +# http://svn.0pointer.de/viewvc/trunk/common/acx_pthread.m4?revision=1277&root=avahi +# See also (perhaps for new versions?) +# http://svn.0pointer.de/viewvc/trunk/common/acx_pthread.m4?root=avahi +# +# We've rewritten the inconsistency check code (from avahi), to work +# more broadly. In particular, it no longer assumes ld accepts -zdefs. +# This caused a restructing of the code, but the functionality has only +# changed a little. + +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_CFLAGS 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_CC to any special C compiler that is needed for +dnl multi-threaded programs (defaults to the value of CC otherwise). +dnl (This is necessary on AIX to use the special cc_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_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS +dnl $LIBS +dnl +dnl If you are only building threads programs, you may wish to use +dnl these variables in your default LIBS, CFLAGS, and CC: +dnl +dnl LIBS="$PTHREAD_LIBS $LIBS" +dnl CFLAGS="$CFLAGS $PTHREAD_CFLAGS" +dnl CC="$PTHREAD_CC" +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 +dnl +dnl Checks for GCC shared/pthread inconsistency based on work by +dnl Marcin Owsiany <marcin@owsiany.pl> + + +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 + + # The next part tries to detect GCC inconsistency with -shared on some + # architectures and systems. The problem is that in certain + # configurations, when -shared is specified, GCC "forgets" to + # internally use various flags which are still necessary. + + # + # Prepare the flags + # + save_CFLAGS="$CFLAGS" + save_LIBS="$LIBS" + save_CC="$CC" + + # Try with the flags determined by the earlier checks. + # + # -Wl,-z,defs forces link-time symbol resolution, so that the + # linking checks with -shared actually have any value + # + # FIXME: -fPIC is required for -shared on many architectures, + # so we specify it here, but the right way would probably be to + # properly detect whether it is actually required. + CFLAGS="-shared -fPIC -Wl,-z,defs $CFLAGS $PTHREAD_CFLAGS" + LIBS="$PTHREAD_LIBS $LIBS" + CC="$PTHREAD_CC" + + # In order not to create several levels of indentation, we test + # the value of "$done" until we find the cure or run out of ideas. + done="no" + + # First, make sure the CFLAGS we added are actually accepted by our + # compiler. If not (and OS X's ld, for instance, does not accept -z), + # then we can't do this test. + if test x"$done" = xno; then + AC_MSG_CHECKING([whether to check for GCC pthread/shared inconsistencies]) + AC_TRY_LINK(,, , [done=yes]) + + if test "x$done" = xyes ; then + AC_MSG_RESULT([no]) + else + AC_MSG_RESULT([yes]) + fi + fi + + if test x"$done" = xno; then + AC_MSG_CHECKING([whether -pthread is sufficient with -shared]) + 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); ], + [done=yes]) + + if test "x$done" = xyes; then + AC_MSG_RESULT([yes]) + else + AC_MSG_RESULT([no]) + fi + fi + + # + # Linux gcc on some architectures such as mips/mipsel forgets + # about -lpthread + # + if test x"$done" = xno; then + AC_MSG_CHECKING([whether -lpthread fixes that]) + LIBS="-lpthread $PTHREAD_LIBS $save_LIBS" + AC_TRY_LINK([#include <pthread.h>], + [pthread_t th; pthread_join(th, 0); + pthread_attr_init(0); pthread_cleanup_push(0, 0); + pthread_create(0,0,0,0); pthread_cleanup_pop(0); ], + [done=yes]) + + if test "x$done" = xyes; then + AC_MSG_RESULT([yes]) + PTHREAD_LIBS="-lpthread $PTHREAD_LIBS" + else + AC_MSG_RESULT([no]) + fi + fi + # + # FreeBSD 4.10 gcc forgets to use -lc_r instead of -lc + # + if test x"$done" = xno; then + AC_MSG_CHECKING([whether -lc_r fixes that]) + LIBS="-lc_r $PTHREAD_LIBS $save_LIBS" + AC_TRY_LINK([#include <pthread.h>], + [pthread_t th; pthread_join(th, 0); + pthread_attr_init(0); pthread_cleanup_push(0, 0); + pthread_create(0,0,0,0); pthread_cleanup_pop(0); ], + [done=yes]) + + if test "x$done" = xyes; then + AC_MSG_RESULT([yes]) + PTHREAD_LIBS="-lc_r $PTHREAD_LIBS" + else + AC_MSG_RESULT([no]) + fi + fi + if test x"$done" = xno; then + # OK, we have run out of ideas + AC_MSG_WARN([Impossible to determine how to use pthreads with shared libraries]) + + # so it's not safe to assume that we may use pthreads + acx_pthread_ok=no + fi + + CFLAGS="$save_CFLAGS" + LIBS="$save_LIBS" + CC="$save_CC" +else + PTHREAD_CC="$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 |