1# SPDX-License-Identifier: GPL-3.0-or-later WITH Autoconf-exception-macro 2# =========================================================================== 3# https://www.gnu.org/software/autoconf-archive/ax_pthread.html 4# =========================================================================== 5# 6# SYNOPSIS 7# 8# AX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]]) 9# 10# DESCRIPTION 11# 12# This macro figures out how to build C programs using POSIX threads. It 13# sets the PTHREAD_LIBS output variable to the threads library and linker 14# flags, and the PTHREAD_CFLAGS output variable to any special C compiler 15# flags that are needed. (The user can also force certain compiler 16# flags/libs to be tested by setting these environment variables.) 17# 18# Also sets PTHREAD_CC and PTHREAD_CXX to any special C compiler that is 19# needed for multi-threaded programs (defaults to the value of CC 20# respectively CXX otherwise). (This is necessary on e.g. AIX to use the 21# special cc_r/CC_r compiler alias.) 22# 23# NOTE: You are assumed to not only compile your program with these flags, 24# but also to link with them as well. For example, you might link with 25# $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS 26# $PTHREAD_CXX $CXXFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS 27# 28# If you are only building threaded programs, you may wish to use these 29# variables in your default LIBS, CFLAGS, and CC: 30# 31# LIBS="$PTHREAD_LIBS $LIBS" 32# CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 33# CXXFLAGS="$CXXFLAGS $PTHREAD_CFLAGS" 34# CC="$PTHREAD_CC" 35# CXX="$PTHREAD_CXX" 36# 37# In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute constant 38# has a nonstandard name, this macro defines PTHREAD_CREATE_JOINABLE to 39# that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX). 40# 41# Also HAVE_PTHREAD_PRIO_INHERIT is defined if pthread is found and the 42# PTHREAD_PRIO_INHERIT symbol is defined when compiling with 43# PTHREAD_CFLAGS. 44# 45# ACTION-IF-FOUND is a list of shell commands to run if a threads library 46# is found, and ACTION-IF-NOT-FOUND is a list of commands to run it if it 47# is not found. If ACTION-IF-FOUND is not specified, the default action 48# will define HAVE_PTHREAD. 49# 50# Please let the authors know if this macro fails on any platform, or if 51# you have any other suggestions or comments. This macro was based on work 52# by SGJ on autoconf scripts for FFTW (http://www.fftw.org/) (with help 53# from M. Frigo), as well as ac_pthread and hb_pthread macros posted by 54# Alejandro Forero Cuervo to the autoconf macro repository. We are also 55# grateful for the helpful feedback of numerous users. 56# 57# Updated for Autoconf 2.68 by Daniel Richard G. 58# 59# LICENSE 60# 61# Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu> 62# Copyright (c) 2011 Daniel Richard G. <skunk@iSKUNK.ORG> 63# Copyright (c) 2019 Marc Stevens <marc.stevens@cwi.nl> 64# 65# This program is free software: you can redistribute it and/or modify it 66# under the terms of the GNU General Public License as published by the 67# Free Software Foundation, either version 3 of the License, or (at your 68# option) any later version. 69# 70# This program is distributed in the hope that it will be useful, but 71# WITHOUT ANY WARRANTY; without even the implied warranty of 72# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General 73# Public License for more details. 74# 75# You should have received a copy of the GNU General Public License along 76# with this program. If not, see <https://www.gnu.org/licenses/>. 77# 78# As a special exception, the respective Autoconf Macro's copyright owner 79# gives unlimited permission to copy, distribute and modify the configure 80# scripts that are the output of Autoconf when processing the Macro. You 81# need not follow the terms of the GNU General Public License when using 82# or distributing such scripts, even though portions of the text of the 83# Macro appear in them. The GNU General Public License (GPL) does govern 84# all other use of the material that constitutes the Autoconf Macro. 85# 86# This special exception to the GPL applies to versions of the Autoconf 87# Macro released by the Autoconf Archive. When you make and distribute a 88# modified version of the Autoconf Macro, you may extend this special 89# exception to the GPL to apply to your modified version as well. 90 91#serial 31 92 93AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD]) 94AC_DEFUN([AX_PTHREAD], [ 95AC_REQUIRE([AC_CANONICAL_HOST]) 96AC_REQUIRE([AC_PROG_CC]) 97AC_REQUIRE([AC_PROG_SED]) 98AC_LANG_PUSH([C]) 99ax_pthread_ok=no 100 101# We used to check for pthread.h first, but this fails if pthread.h 102# requires special compiler flags (e.g. on Tru64 or Sequent). 103# It gets checked for in the link test anyway. 104 105# First of all, check if the user has set any of the PTHREAD_LIBS, 106# etcetera environment variables, and if threads linking works using 107# them: 108if test "x$PTHREAD_CFLAGS$PTHREAD_LIBS" != "x"; then 109 ax_pthread_save_CC="$CC" 110 ax_pthread_save_CFLAGS="$CFLAGS" 111 ax_pthread_save_LIBS="$LIBS" 112 AS_IF([test "x$PTHREAD_CC" != "x"], [CC="$PTHREAD_CC"]) 113 AS_IF([test "x$PTHREAD_CXX" != "x"], [CXX="$PTHREAD_CXX"]) 114 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 115 LIBS="$PTHREAD_LIBS $LIBS" 116 AC_MSG_CHECKING([for pthread_join using $CC $PTHREAD_CFLAGS $PTHREAD_LIBS]) 117 AC_LINK_IFELSE([AC_LANG_CALL([], [pthread_join])], [ax_pthread_ok=yes]) 118 AC_MSG_RESULT([$ax_pthread_ok]) 119 if test "x$ax_pthread_ok" = "xno"; then 120 PTHREAD_LIBS="" 121 PTHREAD_CFLAGS="" 122 fi 123 CC="$ax_pthread_save_CC" 124 CFLAGS="$ax_pthread_save_CFLAGS" 125 LIBS="$ax_pthread_save_LIBS" 126fi 127 128# We must check for the threads library under a number of different 129# names; the ordering is very important because some systems 130# (e.g. DEC) have both -lpthread and -lpthreads, where one of the 131# libraries is broken (non-POSIX). 132 133# Create a list of thread flags to try. Items with a "," contain both 134# C compiler flags (before ",") and linker flags (after ","). Other items 135# starting with a "-" are C compiler flags, and remaining items are 136# library names, except for "none" which indicates that we try without 137# any flags at all, and "pthread-config" which is a program returning 138# the flags for the Pth emulation library. 139 140ax_pthread_flags="pthreads none -Kthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config" 141 142# The ordering *is* (sometimes) important. Some notes on the 143# individual items follow: 144 145# pthreads: AIX (must check this before -lpthread) 146# none: in case threads are in libc; should be tried before -Kthread and 147# other compiler flags to prevent continual compiler warnings 148# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h) 149# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads), Tru64 150# (Note: HP C rejects this with "bad form for `-t' option") 151# -pthreads: Solaris/gcc (Note: HP C also rejects) 152# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it 153# doesn't hurt to check since this sometimes defines pthreads and 154# -D_REENTRANT too), HP C (must be checked before -lpthread, which 155# is present but should not be used directly; and before -mthreads, 156# because the compiler interprets this as "-mt" + "-hreads") 157# -mthreads: Mingw32/gcc, Lynx/gcc 158# pthread: Linux, etcetera 159# --thread-safe: KAI C++ 160# pthread-config: use pthread-config program (for GNU Pth library) 161 162case $host_os in 163 164 freebsd*) 165 166 # -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able) 167 # lthread: LinuxThreads port on FreeBSD (also preferred to -pthread) 168 169 ax_pthread_flags="-kthread lthread $ax_pthread_flags" 170 ;; 171 172 hpux*) 173 174 # From the cc(1) man page: "[-mt] Sets various -D flags to enable 175 # multi-threading and also sets -lpthread." 176 177 ax_pthread_flags="-mt -pthread pthread $ax_pthread_flags" 178 ;; 179 180 openedition*) 181 182 # IBM z/OS requires a feature-test macro to be defined in order to 183 # enable POSIX threads at all, so give the user a hint if this is 184 # not set. (We don't define these ourselves, as they can affect 185 # other portions of the system API in unpredictable ways.) 186 187 AC_EGREP_CPP([AX_PTHREAD_ZOS_MISSING], 188 [ 189# if !defined(_OPEN_THREADS) && !defined(_UNIX03_THREADS) 190 AX_PTHREAD_ZOS_MISSING 191# endif 192 ], 193 [AC_MSG_WARN([IBM z/OS requires -D_OPEN_THREADS or -D_UNIX03_THREADS to enable pthreads support.])]) 194 ;; 195 196 solaris*) 197 198 # On Solaris (at least, for some versions), libc contains stubbed 199 # (non-functional) versions of the pthreads routines, so link-based 200 # tests will erroneously succeed. (N.B.: The stubs are missing 201 # pthread_cleanup_push, or rather a function called by this macro, 202 # so we could check for that, but who knows whether they'll stub 203 # that too in a future libc.) So we'll check first for the 204 # standard Solaris way of linking pthreads (-mt -lpthread). 205 206 ax_pthread_flags="-mt,-lpthread pthread $ax_pthread_flags" 207 ;; 208esac 209 210# Are we compiling with Clang? 211 212AC_CACHE_CHECK([whether $CC is Clang], 213 [ax_cv_PTHREAD_CLANG], 214 [ax_cv_PTHREAD_CLANG=no 215 # Note that Autoconf sets GCC=yes for Clang as well as GCC 216 if test "x$GCC" = "xyes"; then 217 AC_EGREP_CPP([AX_PTHREAD_CC_IS_CLANG], 218 [/* Note: Clang 2.7 lacks __clang_[a-z]+__ */ 219# if defined(__clang__) && defined(__llvm__) 220 AX_PTHREAD_CC_IS_CLANG 221# endif 222 ], 223 [ax_cv_PTHREAD_CLANG=yes]) 224 fi 225 ]) 226ax_pthread_clang="$ax_cv_PTHREAD_CLANG" 227 228 229# GCC generally uses -pthread, or -pthreads on some platforms (e.g. SPARC) 230 231# Note that for GCC and Clang -pthread generally implies -lpthread, 232# except when -nostdlib is passed. 233# This is problematic using libtool to build C++ shared libraries with pthread: 234# [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25460 235# [2] https://bugzilla.redhat.com/show_bug.cgi?id=661333 236# [3] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=468555 237# To solve this, first try -pthread together with -lpthread for GCC 238 239AS_IF([test "x$GCC" = "xyes"], 240 [ax_pthread_flags="-pthread,-lpthread -pthread -pthreads $ax_pthread_flags"]) 241 242# Clang takes -pthread (never supported any other flag), but we'll try with -lpthread first 243 244AS_IF([test "x$ax_pthread_clang" = "xyes"], 245 [ax_pthread_flags="-pthread,-lpthread -pthread"]) 246 247 248# The presence of a feature test macro requesting re-entrant function 249# definitions is, on some systems, a strong hint that pthreads support is 250# correctly enabled 251 252case $host_os in 253 darwin* | hpux* | linux* | osf* | solaris*) 254 ax_pthread_check_macro="_REENTRANT" 255 ;; 256 257 aix*) 258 ax_pthread_check_macro="_THREAD_SAFE" 259 ;; 260 261 *) 262 ax_pthread_check_macro="--" 263 ;; 264esac 265AS_IF([test "x$ax_pthread_check_macro" = "x--"], 266 [ax_pthread_check_cond=0], 267 [ax_pthread_check_cond="!defined($ax_pthread_check_macro)"]) 268 269 270if test "x$ax_pthread_ok" = "xno"; then 271for ax_pthread_try_flag in $ax_pthread_flags; do 272 273 case $ax_pthread_try_flag in 274 none) 275 AC_MSG_CHECKING([whether pthreads work without any flags]) 276 ;; 277 278 *,*) 279 PTHREAD_CFLAGS=`echo $ax_pthread_try_flag | sed "s/^\(.*\),\(.*\)$/\1/"` 280 PTHREAD_LIBS=`echo $ax_pthread_try_flag | sed "s/^\(.*\),\(.*\)$/\2/"` 281 AC_MSG_CHECKING([whether pthreads work with "$PTHREAD_CFLAGS" and "$PTHREAD_LIBS"]) 282 ;; 283 284 -*) 285 AC_MSG_CHECKING([whether pthreads work with $ax_pthread_try_flag]) 286 PTHREAD_CFLAGS="$ax_pthread_try_flag" 287 ;; 288 289 pthread-config) 290 AC_CHECK_PROG([ax_pthread_config], [pthread-config], [yes], [no]) 291 AS_IF([test "x$ax_pthread_config" = "xno"], [continue]) 292 PTHREAD_CFLAGS="`pthread-config --cflags`" 293 PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`" 294 ;; 295 296 *) 297 AC_MSG_CHECKING([for the pthreads library -l$ax_pthread_try_flag]) 298 PTHREAD_LIBS="-l$ax_pthread_try_flag" 299 ;; 300 esac 301 302 ax_pthread_save_CFLAGS="$CFLAGS" 303 ax_pthread_save_LIBS="$LIBS" 304 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 305 LIBS="$PTHREAD_LIBS $LIBS" 306 307 # Check for various functions. We must include pthread.h, 308 # since some functions may be macros. (On the Sequent, we 309 # need a special flag -Kthread to make this header compile.) 310 # We check for pthread_join because it is in -lpthread on IRIX 311 # while pthread_create is in libc. We check for pthread_attr_init 312 # due to DEC craziness with -lpthreads. We check for 313 # pthread_cleanup_push because it is one of the few pthread 314 # functions on Solaris that doesn't have a non-functional libc stub. 315 # We try pthread_create on general principles. 316 317 AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h> 318# if $ax_pthread_check_cond 319# error "$ax_pthread_check_macro must be defined" 320# endif 321 static void *some_global = NULL; 322 static void routine(void *a) 323 { 324 /* To avoid any unused-parameter or 325 unused-but-set-parameter warning. */ 326 some_global = a; 327 } 328 static void *start_routine(void *a) { return a; }], 329 [pthread_t th; pthread_attr_t attr; 330 pthread_create(&th, 0, start_routine, 0); 331 pthread_join(th, 0); 332 pthread_attr_init(&attr); 333 pthread_cleanup_push(routine, 0); 334 pthread_cleanup_pop(0) /* ; */])], 335 [ax_pthread_ok=yes], 336 []) 337 338 CFLAGS="$ax_pthread_save_CFLAGS" 339 LIBS="$ax_pthread_save_LIBS" 340 341 AC_MSG_RESULT([$ax_pthread_ok]) 342 AS_IF([test "x$ax_pthread_ok" = "xyes"], [break]) 343 344 PTHREAD_LIBS="" 345 PTHREAD_CFLAGS="" 346done 347fi 348 349 350# Clang needs special handling, because older versions handle the -pthread 351# option in a rather... idiosyncratic way 352 353if test "x$ax_pthread_clang" = "xyes"; then 354 355 # Clang takes -pthread; it has never supported any other flag 356 357 # (Note 1: This will need to be revisited if a system that Clang 358 # supports has POSIX threads in a separate library. This tends not 359 # to be the way of modern systems, but it's conceivable.) 360 361 # (Note 2: On some systems, notably Darwin, -pthread is not needed 362 # to get POSIX threads support; the API is always present and 363 # active. We could reasonably leave PTHREAD_CFLAGS empty. But 364 # -pthread does define _REENTRANT, and while the Darwin headers 365 # ignore this macro, third-party headers might not.) 366 367 # However, older versions of Clang make a point of warning the user 368 # that, in an invocation where only linking and no compilation is 369 # taking place, the -pthread option has no effect ("argument unused 370 # during compilation"). They expect -pthread to be passed in only 371 # when source code is being compiled. 372 # 373 # Problem is, this is at odds with the way Automake and most other 374 # C build frameworks function, which is that the same flags used in 375 # compilation (CFLAGS) are also used in linking. Many systems 376 # supported by AX_PTHREAD require exactly this for POSIX threads 377 # support, and in fact it is often not straightforward to specify a 378 # flag that is used only in the compilation phase and not in 379 # linking. Such a scenario is extremely rare in practice. 380 # 381 # Even though use of the -pthread flag in linking would only print 382 # a warning, this can be a nuisance for well-run software projects 383 # that build with -Werror. So if the active version of Clang has 384 # this misfeature, we search for an option to squash it. 385 386 AC_CACHE_CHECK([whether Clang needs flag to prevent "argument unused" warning when linking with -pthread], 387 [ax_cv_PTHREAD_CLANG_NO_WARN_FLAG], 388 [ax_cv_PTHREAD_CLANG_NO_WARN_FLAG=unknown 389 # Create an alternate version of $ac_link that compiles and 390 # links in two steps (.c -> .o, .o -> exe) instead of one 391 # (.c -> exe), because the warning occurs only in the second 392 # step 393 ax_pthread_save_ac_link="$ac_link" 394 ax_pthread_sed='s/conftest\.\$ac_ext/conftest.$ac_objext/g' 395 ax_pthread_link_step=`AS_ECHO(["$ac_link"]) | sed "$ax_pthread_sed"` 396 ax_pthread_2step_ac_link="($ac_compile) && (echo ==== >&5) && ($ax_pthread_link_step)" 397 ax_pthread_save_CFLAGS="$CFLAGS" 398 for ax_pthread_try in '' -Qunused-arguments -Wno-unused-command-line-argument unknown; do 399 AS_IF([test "x$ax_pthread_try" = "xunknown"], [break]) 400 CFLAGS="-Werror -Wunknown-warning-option $ax_pthread_try -pthread $ax_pthread_save_CFLAGS" 401 ac_link="$ax_pthread_save_ac_link" 402 AC_LINK_IFELSE([AC_LANG_SOURCE([[int main(void){return 0;}]])], 403 [ac_link="$ax_pthread_2step_ac_link" 404 AC_LINK_IFELSE([AC_LANG_SOURCE([[int main(void){return 0;}]])], 405 [break]) 406 ]) 407 done 408 ac_link="$ax_pthread_save_ac_link" 409 CFLAGS="$ax_pthread_save_CFLAGS" 410 AS_IF([test "x$ax_pthread_try" = "x"], [ax_pthread_try=no]) 411 ax_cv_PTHREAD_CLANG_NO_WARN_FLAG="$ax_pthread_try" 412 ]) 413 414 case "$ax_cv_PTHREAD_CLANG_NO_WARN_FLAG" in 415 no | unknown) ;; 416 *) PTHREAD_CFLAGS="$ax_cv_PTHREAD_CLANG_NO_WARN_FLAG $PTHREAD_CFLAGS" ;; 417 esac 418 419fi # $ax_pthread_clang = yes 420 421 422 423# Various other checks: 424if test "x$ax_pthread_ok" = "xyes"; then 425 ax_pthread_save_CFLAGS="$CFLAGS" 426 ax_pthread_save_LIBS="$LIBS" 427 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 428 LIBS="$PTHREAD_LIBS $LIBS" 429 430 # Detect AIX lossage: JOINABLE attribute is called UNDETACHED. 431 AC_CACHE_CHECK([for joinable pthread attribute], 432 [ax_cv_PTHREAD_JOINABLE_ATTR], 433 [ax_cv_PTHREAD_JOINABLE_ATTR=unknown 434 for ax_pthread_attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do 435 AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>], 436 [int attr = $ax_pthread_attr; return attr /* ; */])], 437 [ax_cv_PTHREAD_JOINABLE_ATTR=$ax_pthread_attr; break], 438 []) 439 done 440 ]) 441 AS_IF([test "x$ax_cv_PTHREAD_JOINABLE_ATTR" != "xunknown" && \ 442 test "x$ax_cv_PTHREAD_JOINABLE_ATTR" != "xPTHREAD_CREATE_JOINABLE" && \ 443 test "x$ax_pthread_joinable_attr_defined" != "xyes"], 444 [AC_DEFINE_UNQUOTED([PTHREAD_CREATE_JOINABLE], 445 [$ax_cv_PTHREAD_JOINABLE_ATTR], 446 [Define to necessary symbol if this constant 447 uses a non-standard name on your system.]) 448 ax_pthread_joinable_attr_defined=yes 449 ]) 450 451 AC_CACHE_CHECK([whether more special flags are required for pthreads], 452 [ax_cv_PTHREAD_SPECIAL_FLAGS], 453 [ax_cv_PTHREAD_SPECIAL_FLAGS=no 454 case $host_os in 455 solaris*) 456 ax_cv_PTHREAD_SPECIAL_FLAGS="-D_POSIX_PTHREAD_SEMANTICS" 457 ;; 458 esac 459 ]) 460 AS_IF([test "x$ax_cv_PTHREAD_SPECIAL_FLAGS" != "xno" && \ 461 test "x$ax_pthread_special_flags_added" != "xyes"], 462 [PTHREAD_CFLAGS="$ax_cv_PTHREAD_SPECIAL_FLAGS $PTHREAD_CFLAGS" 463 ax_pthread_special_flags_added=yes]) 464 465 AC_CACHE_CHECK([for PTHREAD_PRIO_INHERIT], 466 [ax_cv_PTHREAD_PRIO_INHERIT], 467 [AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <pthread.h>]], 468 [[int i = PTHREAD_PRIO_INHERIT; 469 return i;]])], 470 [ax_cv_PTHREAD_PRIO_INHERIT=yes], 471 [ax_cv_PTHREAD_PRIO_INHERIT=no]) 472 ]) 473 AS_IF([test "x$ax_cv_PTHREAD_PRIO_INHERIT" = "xyes" && \ 474 test "x$ax_pthread_prio_inherit_defined" != "xyes"], 475 [AC_DEFINE([HAVE_PTHREAD_PRIO_INHERIT], [1], [Have PTHREAD_PRIO_INHERIT.]) 476 ax_pthread_prio_inherit_defined=yes 477 ]) 478 479 CFLAGS="$ax_pthread_save_CFLAGS" 480 LIBS="$ax_pthread_save_LIBS" 481 482 # More AIX lossage: compile with *_r variant 483 if test "x$GCC" != "xyes"; then 484 case $host_os in 485 aix*) 486 AS_CASE(["x/$CC"], 487 [x*/c89|x*/c89_128|x*/c99|x*/c99_128|x*/cc|x*/cc128|x*/xlc|x*/xlc_v6|x*/xlc128|x*/xlc128_v6], 488 [#handle absolute path differently from PATH based program lookup 489 AS_CASE(["x$CC"], 490 [x/*], 491 [ 492 AS_IF([AS_EXECUTABLE_P([${CC}_r])],[PTHREAD_CC="${CC}_r"]) 493 AS_IF([test "x${CXX}" != "x"], [AS_IF([AS_EXECUTABLE_P([${CXX}_r])],[PTHREAD_CXX="${CXX}_r"])]) 494 ], 495 [ 496 AC_CHECK_PROGS([PTHREAD_CC],[${CC}_r],[$CC]) 497 AS_IF([test "x${CXX}" != "x"], [AC_CHECK_PROGS([PTHREAD_CXX],[${CXX}_r],[$CXX])]) 498 ] 499 ) 500 ]) 501 ;; 502 esac 503 fi 504fi 505 506test -n "$PTHREAD_CC" || PTHREAD_CC="$CC" 507test -n "$PTHREAD_CXX" || PTHREAD_CXX="$CXX" 508 509AC_SUBST([PTHREAD_LIBS]) 510AC_SUBST([PTHREAD_CFLAGS]) 511AC_SUBST([PTHREAD_CC]) 512AC_SUBST([PTHREAD_CXX]) 513 514# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND: 515if test "x$ax_pthread_ok" = "xyes"; then 516 ifelse([$1],,[AC_DEFINE([HAVE_PTHREAD],[1],[Define if you have POSIX threads libraries and header files.])],[$1]) 517 : 518else 519 ax_pthread_ok=no 520 $2 521fi 522AC_LANG_POP 523])dnl AX_PTHREAD 524