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