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Diffstat (limited to 'm4')
| -rw-r--r-- | m4/ax_pthread.m4 | 522 |
1 files changed, 522 insertions, 0 deletions
diff --git a/m4/ax_pthread.m4 b/m4/ax_pthread.m4 new file mode 100644 index 0000000000..e5858e50c3 --- /dev/null +++ b/m4/ax_pthread.m4 @@ -0,0 +1,522 @@ +# =========================================================================== +# 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 and PTHREAD_CXX to any special C compiler that is +# needed for multi-threaded programs (defaults to the value of CC +# respectively CXX otherwise). (This is necessary on e.g. AIX to use the +# special cc_r/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 +# $PTHREAD_CXX $CXXFLAGS $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 $PTHREAD_CFLAGS" +# CXXFLAGS="$CXXFLAGS $PTHREAD_CFLAGS" +# CC="$PTHREAD_CC" +# CXX="$PTHREAD_CXX" +# +# 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 30 + +AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD]) +AC_DEFUN([AX_PTHREAD], [ +AC_REQUIRE([AC_CANONICAL_TARGET]) +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"]) + AS_IF([test "x$PTHREAD_CXX" != "x"], [CXX="$PTHREAD_CXX"]) + 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 $target_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="$ax_cv_PTHREAD_CLANG" + + +# GCC generally uses -pthread, or -pthreads on some platforms (e.g. SPARC) + +# Note that for GCC and Clang -pthread generally implies -lpthread, +# except when -nostdlib is passed. +# This is problematic using libtool to build C++ shared libraries with pthread: +# [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25460 +# [2] https://bugzilla.redhat.com/show_bug.cgi?id=661333 +# [3] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=468555 +# To solve this, first try -pthread together with -lpthread for GCC + +AS_IF([test "x$GCC" = "xyes"], + [ax_pthread_flags="-pthread,-lpthread -pthread -pthreads $ax_pthread_flags"]) + +# Clang takes -pthread (never supported any other flag), but we'll try with -lpthread first + +AS_IF([test "x$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 enabled + +case $target_os in + darwin* | hpux* | linux* | osf* | solaris*) + ax_pthread_check_macro="_REENTRANT" + ;; + + aix*) + ax_pthread_check_macro="_THREAD_SAFE" + ;; + + *) + ax_pthread_check_macro="--" + ;; +esac +AS_IF([test "x$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"; then +for 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="" +done +fi + + +# Clang needs special handling, because older versions handle the -pthread +# option in a rather... idiosyncratic way + +if 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" ;; + esac + +fi # $ax_pthread_clang = yes + + + +# Various other checks: +if test "x$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 $target_os in + solaris*) + ax_cv_PTHREAD_SPECIAL_FLAGS="-D_POSIX_PTHREAD_SEMANTICS" + ;; + esac + ]) + AS_IF([test "x$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 $target_os in + aix*) + AS_CASE(["x/$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="${CC}_r"]) + AS_IF([test "x${CXX}" != "x"], [AS_IF([AS_EXECUTABLE_P([${CXX}_r])],[PTHREAD_CXX="${CXX}_r"])]) + ], + [ + AC_CHECK_PROGS([PTHREAD_CC],[${CC}_r],[$CC]) + AS_IF([test "x${CXX}" != "x"], [AC_CHECK_PROGS([PTHREAD_CXX],[${CXX}_r],[$CXX])]) + ] + ) + ]) + ;; + esac + fi +fi + +test -n "$PTHREAD_CC" || PTHREAD_CC="$CC" +test -n "$PTHREAD_CXX" || PTHREAD_CXX="$CXX" + +AC_SUBST([PTHREAD_LIBS]) +AC_SUBST([PTHREAD_CFLAGS]) +AC_SUBST([PTHREAD_CC]) +AC_SUBST([PTHREAD_CXX]) + +# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND: +if test "x$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 + $2 +fi +AC_LANG_POP +])dnl AX_PTHREAD |