git / moonbite-core / build-aux/m4/ax_pthread.m4 · raw
# ===========================================================================# https://www.gnu.org/software/autoconf-archive/ax_pthread.html# ===========================================================================## SYNOPSIS## AX_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 to link with them as well. For example, you might link with# $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS## If you are only building threaded programs, you may wish to use these# variables in your default LIBS, CFLAGS, and CC:## LIBS="$PTHREAD_LIBS $LIBS"# CFLAGS="$CFLAGS $PTHREAD_CFLAGS"# CC="$PTHREAD_CC"## In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute constant# has a nonstandard name, this macro defines PTHREAD_CREATE_JOINABLE to# that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX).## Also HAVE_PTHREAD_PRIO_INHERIT is defined if pthread is found and the# PTHREAD_PRIO_INHERIT symbol is defined when compiling with# PTHREAD_CFLAGS.## 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.## Updated for Autoconf 2.68 by Daniel Richard G.## LICENSE## Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu># Copyright (c) 2011 Daniel Richard G. <skunk@iSKUNK.ORG># Copyright (c) 2019 Marc Stevens <marc.stevens@cwi.nl>## 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 <https://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 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.#serial 27AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD])AC_DEFUN([AX_PTHREAD], [AC_REQUIRE([AC_CANONICAL_HOST])AC_REQUIRE([AC_PROG_CC])AC_REQUIRE([AC_PROG_SED])AC_LANG_PUSH([C])ax_pthread_ok=no# We used to check for pthread.h first, but this fails if pthread.h# requires special compiler flags (e.g. on Tru64 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$PTHREAD_CFLAGS$PTHREAD_LIBS" != "x"; then ax_pthread_save_CC="$CC" ax_pthread_save_CFLAGS="$CFLAGS" ax_pthread_save_LIBS="$LIBS" AS_IF([test "x$PTHREAD_CC" != "x"], [CC="$PTHREAD_CC"]) CFLAGS="$CFLAGS $PTHREAD_CFLAGS" LIBS="$PTHREAD_LIBS $LIBS" AC_MSG_CHECKING([for pthread_join using $CC $PTHREAD_CFLAGS $PTHREAD_LIBS]) AC_LINK_IFELSE([AC_LANG_CALL([], [pthread_join])], [ax_pthread_ok=yes]) AC_MSG_RESULT([$ax_pthread_ok]) if test "x$ax_pthread_ok" = "xno"; then PTHREAD_LIBS="" PTHREAD_CFLAGS="" fi CC="$ax_pthread_save_CC" CFLAGS="$ax_pthread_save_CFLAGS" LIBS="$ax_pthread_save_LIBS"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 with a "," contain both# C compiler flags (before ",") and linker flags (after ","). Other items# starting with a "-" are C compiler flags, and remaining 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.ax_pthread_flags="pthreads none -Kthread -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)# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads), Tru64# (Note: HP C rejects this with "bad form for `-t' option")# -pthreads: Solaris/gcc (Note: HP C also rejects)# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it# doesn't hurt to check since this sometimes defines pthreads and# -D_REENTRANT too), HP C (must be checked before -lpthread, which# is present but should not be used directly; and before -mthreads,# because the compiler interprets this as "-mt" + "-hreads")# -mthreads: Mingw32/gcc, Lynx/gcc# pthread: Linux, etcetera# --thread-safe: KAI C++# pthread-config: use pthread-config program (for GNU Pth library)case $host_os in freebsd*) # -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able) # lthread: LinuxThreads port on FreeBSD (also preferred to -pthread) ax_pthread_flags="-kthread lthread $ax_pthread_flags" ;; hpux*) # From the cc(1) man page: "[-mt] Sets various -D flags to enable # multi-threading and also sets -lpthread." ax_pthread_flags="-mt -pthread pthread $ax_pthread_flags" ;; openedition*) # IBM z/OS requires a feature-test macro to be defined in order to # enable POSIX threads at all, so give the user a hint if this is # not set. (We don't define these ourselves, as they can affect # other portions of the system API in unpredictable ways.) AC_EGREP_CPP([AX_PTHREAD_ZOS_MISSING], [# if !defined(_OPEN_THREADS) && !defined(_UNIX03_THREADS) AX_PTHREAD_ZOS_MISSING# endif ], [AC_MSG_WARN([IBM z/OS requires -D_OPEN_THREADS or -D_UNIX03_THREADS to enable pthreads support.])]) ;; 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. (N.B.: 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 check first for the # standard Solaris way of linking pthreads (-mt -lpthread). ax_pthread_flags="-mt,-lpthread pthread $ax_pthread_flags" ;;esac# Are we compiling with Clang?AC_CACHE_CHECK([whether $CC is Clang], [ax_cv_PTHREAD_CLANG], [ax_cv_PTHREAD_CLANG=no # Note that Autoconf sets GCC=yes for Clang as well as GCC if test "x$GCC" = "xyes"; then AC_EGREP_CPP([AX_PTHREAD_CC_IS_CLANG], [/* Note: Clang 2.7 lacks __clang_[a-z]+__ */# if defined(__clang__) && defined(__llvm__) AX_PTHREAD_CC_IS_CLANG# endif ], [ax_cv_PTHREAD_CLANG=yes]) fi ])ax_pthread_clang="$ax_cv_PTHREAD_CLANG"# GCC generally uses -pthread, or -pthreads on some platforms (e.g. SPARC)# Note that for GCC and Clang -pthread generally implies -lpthread,# except when -nostdlib is passed.# This is problematic using libtool to build C++ shared libraries with pthread:# [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25460# [2] https://bugzilla.redhat.com/show_bug.cgi?id=661333# [3] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=468555# To solve this, first try -pthread together with -lpthread for GCCAS_IF([test "x$GCC" = "xyes"], [ax_pthread_flags="-pthread,-lpthread -pthread -pthreads $ax_pthread_flags"])# Clang takes -pthread (never supported any other flag), but we'll try with -lpthread firstAS_IF([test "x$ax_pthread_clang" = "xyes"], [ax_pthread_flags="-pthread,-lpthread -pthread"])# The presence of a feature test macro requesting re-entrant function# definitions is, on some systems, a strong hint that pthreads support is# correctly enabledcase $host_os in darwin* | hpux* | linux* | osf* | solaris*) ax_pthread_check_macro="_REENTRANT" ;; aix*) ax_pthread_check_macro="_THREAD_SAFE" ;; *) ax_pthread_check_macro="--" ;;esacAS_IF([test "x$ax_pthread_check_macro" = "x--"], [ax_pthread_check_cond=0], [ax_pthread_check_cond="!defined($ax_pthread_check_macro)"])if test "x$ax_pthread_ok" = "xno"; thenfor ax_pthread_try_flag in $ax_pthread_flags; do case $ax_pthread_try_flag in none) AC_MSG_CHECKING([whether pthreads work without any flags]) ;; *,*) PTHREAD_CFLAGS=`echo $ax_pthread_try_flag | sed "s/^\(.*\),\(.*\)$/\1/"` PTHREAD_LIBS=`echo $ax_pthread_try_flag | sed "s/^\(.*\),\(.*\)$/\2/"` AC_MSG_CHECKING([whether pthreads work with "$PTHREAD_CFLAGS" and "$PTHREAD_LIBS"]) ;; -*) AC_MSG_CHECKING([whether pthreads work with $ax_pthread_try_flag]) PTHREAD_CFLAGS="$ax_pthread_try_flag" ;; pthread-config) AC_CHECK_PROG([ax_pthread_config], [pthread-config], [yes], [no]) AS_IF([test "x$ax_pthread_config" = "xno"], [continue]) PTHREAD_CFLAGS="`pthread-config --cflags`" PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`" ;; *) AC_MSG_CHECKING([for the pthreads library -l$ax_pthread_try_flag]) PTHREAD_LIBS="-l$ax_pthread_try_flag" ;; esac ax_pthread_save_CFLAGS="$CFLAGS" ax_pthread_save_LIBS="$LIBS" CFLAGS="$CFLAGS $PTHREAD_CFLAGS" LIBS="$PTHREAD_LIBS $LIBS" # 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_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h># if $ax_pthread_check_cond# error "$ax_pthread_check_macro must be defined"# endif static void *some_global = NULL; static void routine(void *a) { /* To avoid any unused-parameter or unused-but-set-parameter warning. */ some_global = a; } static void *start_routine(void *a) { return a; }], [pthread_t th; pthread_attr_t attr; pthread_create(&th, 0, start_routine, 0); pthread_join(th, 0); pthread_attr_init(&attr); pthread_cleanup_push(routine, 0); pthread_cleanup_pop(0) /* ; */])], [ax_pthread_ok=yes], []) CFLAGS="$ax_pthread_save_CFLAGS" LIBS="$ax_pthread_save_LIBS" AC_MSG_RESULT([$ax_pthread_ok]) AS_IF([test "x$ax_pthread_ok" = "xyes"], [break]) PTHREAD_LIBS="" PTHREAD_CFLAGS=""donefi# Clang needs special handling, because older versions handle the -pthread# option in a rather... idiosyncratic wayif test "x$ax_pthread_clang" = "xyes"; then # Clang takes -pthread; it has never supported any other flag # (Note 1: This will need to be revisited if a system that Clang # supports has POSIX threads in a separate library. This tends not # to be the way of modern systems, but it's conceivable.) # (Note 2: On some systems, notably Darwin, -pthread is not needed # to get POSIX threads support; the API is always present and # active. We could reasonably leave PTHREAD_CFLAGS empty. But # -pthread does define _REENTRANT, and while the Darwin headers # ignore this macro, third-party headers might not.) # However, older versions of Clang make a point of warning the user # that, in an invocation where only linking and no compilation is # taking place, the -pthread option has no effect ("argument unused # during compilation"). They expect -pthread to be passed in only # when source code is being compiled. # # Problem is, this is at odds with the way Automake and most other # C build frameworks function, which is that the same flags used in # compilation (CFLAGS) are also used in linking. Many systems # supported by AX_PTHREAD require exactly this for POSIX threads # support, and in fact it is often not straightforward to specify a # flag that is used only in the compilation phase and not in # linking. Such a scenario is extremely rare in practice. # # Even though use of the -pthread flag in linking would only print # a warning, this can be a nuisance for well-run software projects # that build with -Werror. So if the active version of Clang has # this misfeature, we search for an option to squash it. AC_CACHE_CHECK([whether Clang needs flag to prevent "argument unused" warning when linking with -pthread], [ax_cv_PTHREAD_CLANG_NO_WARN_FLAG], [ax_cv_PTHREAD_CLANG_NO_WARN_FLAG=unknown # Create an alternate version of $ac_link that compiles and # links in two steps (.c -> .o, .o -> exe) instead of one # (.c -> exe), because the warning occurs only in the second # step ax_pthread_save_ac_link="$ac_link" ax_pthread_sed='s/conftest\.\$ac_ext/conftest.$ac_objext/g' ax_pthread_link_step=`$as_echo "$ac_link" | sed "$ax_pthread_sed"` ax_pthread_2step_ac_link="($ac_compile) && (echo ==== >&5) && ($ax_pthread_link_step)" ax_pthread_save_CFLAGS="$CFLAGS" for ax_pthread_try in '' -Qunused-arguments -Wno-unused-command-line-argument unknown; do AS_IF([test "x$ax_pthread_try" = "xunknown"], [break]) CFLAGS="-Werror -Wunknown-warning-option $ax_pthread_try -pthread $ax_pthread_save_CFLAGS" ac_link="$ax_pthread_save_ac_link" AC_LINK_IFELSE([AC_LANG_SOURCE([[int main(void){return 0;}]])], [ac_link="$ax_pthread_2step_ac_link" AC_LINK_IFELSE([AC_LANG_SOURCE([[int main(void){return 0;}]])], [break]) ]) done ac_link="$ax_pthread_save_ac_link" CFLAGS="$ax_pthread_save_CFLAGS" AS_IF([test "x$ax_pthread_try" = "x"], [ax_pthread_try=no]) ax_cv_PTHREAD_CLANG_NO_WARN_FLAG="$ax_pthread_try" ]) case "$ax_cv_PTHREAD_CLANG_NO_WARN_FLAG" in no | unknown) ;; *) PTHREAD_CFLAGS="$ax_cv_PTHREAD_CLANG_NO_WARN_FLAG $PTHREAD_CFLAGS" ;; esacfi # $ax_pthread_clang = yes# Various other checks:if test "x$ax_pthread_ok" = "xyes"; then ax_pthread_save_CFLAGS="$CFLAGS" ax_pthread_save_LIBS="$LIBS" CFLAGS="$CFLAGS $PTHREAD_CFLAGS" LIBS="$PTHREAD_LIBS $LIBS" # Detect AIX lossage: JOINABLE attribute is called UNDETACHED. AC_CACHE_CHECK([for joinable pthread attribute], [ax_cv_PTHREAD_JOINABLE_ATTR], [ax_cv_PTHREAD_JOINABLE_ATTR=unknown for ax_pthread_attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>], [int attr = $ax_pthread_attr; return attr /* ; */])], [ax_cv_PTHREAD_JOINABLE_ATTR=$ax_pthread_attr; break], []) done ]) AS_IF([test "x$ax_cv_PTHREAD_JOINABLE_ATTR" != "xunknown" && \ test "x$ax_cv_PTHREAD_JOINABLE_ATTR" != "xPTHREAD_CREATE_JOINABLE" && \ test "x$ax_pthread_joinable_attr_defined" != "xyes"], [AC_DEFINE_UNQUOTED([PTHREAD_CREATE_JOINABLE], [$ax_cv_PTHREAD_JOINABLE_ATTR], [Define to necessary symbol if this constant uses a non-standard name on your system.]) ax_pthread_joinable_attr_defined=yes ]) AC_CACHE_CHECK([whether more special flags are required for pthreads], [ax_cv_PTHREAD_SPECIAL_FLAGS], [ax_cv_PTHREAD_SPECIAL_FLAGS=no case $host_os in solaris*) ax_cv_PTHREAD_SPECIAL_FLAGS="-D_POSIX_PTHREAD_SEMANTICS" ;; esac ]) AS_IF([test "x$ax_cv_PTHREAD_SPECIAL_FLAGS" != "xno" && \ test "x$ax_pthread_special_flags_added" != "xyes"], [PTHREAD_CFLAGS="$ax_cv_PTHREAD_SPECIAL_FLAGS $PTHREAD_CFLAGS" ax_pthread_special_flags_added=yes]) AC_CACHE_CHECK([for PTHREAD_PRIO_INHERIT], [ax_cv_PTHREAD_PRIO_INHERIT], [AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <pthread.h>]], [[int i = PTHREAD_PRIO_INHERIT; return i;]])], [ax_cv_PTHREAD_PRIO_INHERIT=yes], [ax_cv_PTHREAD_PRIO_INHERIT=no]) ]) AS_IF([test "x$ax_cv_PTHREAD_PRIO_INHERIT" = "xyes" && \ test "x$ax_pthread_prio_inherit_defined" != "xyes"], [AC_DEFINE([HAVE_PTHREAD_PRIO_INHERIT], [1], [Have PTHREAD_PRIO_INHERIT.]) ax_pthread_prio_inherit_defined=yes ]) CFLAGS="$ax_pthread_save_CFLAGS" LIBS="$ax_pthread_save_LIBS" # More AIX lossage: compile with *_r variant if test "x$GCC" != "xyes"; then case $host_os in aix*) AS_CASE(["x/$CC"], [x*/c89|x*/c89_128|x*/c99|x*/c99_128|x*/cc|x*/cc128|x*/xlc|x*/xlc_v6|x*/xlc128|x*/xlc128_v6], [#handle absolute path differently from PATH based program lookup AS_CASE(["x$CC"], [x/*], [AS_IF([AS_EXECUTABLE_P([${CC}_r])],[PTHREAD_CC="${CC}_r"])], [AC_CHECK_PROGS([PTHREAD_CC],[${CC}_r],[$CC])])]) ;; esac fifitest -n "$PTHREAD_CC" || PTHREAD_CC="$CC"AC_SUBST([PTHREAD_LIBS])AC_SUBST([PTHREAD_CFLAGS])AC_SUBST([PTHREAD_CC])# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:if test "x$ax_pthread_ok" = "xyes"; then ifelse([$1],,[AC_DEFINE([HAVE_PTHREAD],[1],[Define if you have POSIX threads libraries and header files.])],[$1]) :else ax_pthread_ok=no $2fiAC_LANG_POP])dnl AX_PTHREAD