]> git.saurik.com Git - cycript.git/commitdiff
Avoid error caused by passing -pthread to libtool.
authorJay Freeman (saurik) <saurik@saurik.com>
Thu, 5 Nov 2015 09:43:38 +0000 (01:43 -0800)
committerJay Freeman (saurik) <saurik@saurik.com>
Thu, 5 Nov 2015 09:43:38 +0000 (01:43 -0800)
Makefile.in
configure
m4/ax_pthread.m4 [new file with mode: 0644]

index 5d81b348b15498e5fd49580ef3688b3b6292cb61..dc06265e177766ab233a2b4389ded8938e09eeb5 100644 (file)
@@ -123,10 +123,10 @@ DIST_COMMON = $(srcdir)/Makefile.in $(srcdir)/Makefile.am \
        ltmain.sh
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps = $(top_srcdir)/m4/ax_cxx_compile_stdcxx_11.m4 \
-       $(top_srcdir)/m4/framework.m4 $(top_srcdir)/m4/libtool.m4 \
-       $(top_srcdir)/m4/ltoptions.m4 $(top_srcdir)/m4/ltsugar.m4 \
-       $(top_srcdir)/m4/ltversion.m4 $(top_srcdir)/m4/lt~obsolete.m4 \
-       $(top_srcdir)/configure.ac
+       $(top_srcdir)/m4/ax_pthread.m4 $(top_srcdir)/m4/framework.m4 \
+       $(top_srcdir)/m4/libtool.m4 $(top_srcdir)/m4/ltoptions.m4 \
+       $(top_srcdir)/m4/ltsugar.m4 $(top_srcdir)/m4/ltversion.m4 \
+       $(top_srcdir)/m4/lt~obsolete.m4 $(top_srcdir)/configure.ac
 am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
        $(ACLOCAL_M4)
 am__CONFIG_DISTCLEAN_FILES = config.status config.cache config.log \
index 07b7889d492f67251a7b39a8caecadd687bce79b..1973916abcea3b02a6c98cbd528ff9c7a9da3339 100755 (executable)
--- a/configure
+++ b/configure
@@ -19008,6 +19008,7 @@ ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
 
 
 
+
 ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'
 ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -19017,7 +19018,7 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 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 True64 or Sequent).
+# 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,
@@ -19028,8 +19029,8 @@ if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
         CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
         save_LIBS="$LIBS"
         LIBS="$PTHREAD_LIBS $LIBS"
-        { $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS" >&5
-$as_echo_n "checking for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS... " >&6; }
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_join using $CC $PTHREAD_CFLAGS $PTHREAD_LIBS" >&5
+$as_echo_n "checking for pthread_join using $CC $PTHREAD_CFLAGS $PTHREAD_LIBS... " >&6; }
         cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -19073,7 +19074,7 @@ fi
 # 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 -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
+ax_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mt -mthreads pthread --thread-safe pthread-config"
 
 # The ordering *is* (sometimes) important.  Some notes on the
 # individual items follow:
@@ -19084,46 +19085,80 @@ ax_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mt
 # -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)
+# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads), Tru64
 # -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
+#      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)
+# -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
+case $host_os in
+
+        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 $ax_pthread_flags"
+        ;;
+
+        openedition*)
+
+        # IBM z/OS requires a feature-test macro to be defined in order to
+        # enable POSIX threads at all, so give the user a hint if this is
+        # not set. (We don't define these ourselves, as they can affect
+        # other portions of the system API in unpredictable ways.)
+
+        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#            if !defined(_OPEN_THREADS) && !defined(_UNIX03_THREADS)
+             AX_PTHREAD_ZOS_MISSING
+#            endif
+
+_ACEOF
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+  $EGREP "AX_PTHREAD_ZOS_MISSING" >/dev/null 2>&1; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: IBM z/OS requires -D_OPEN_THREADS or -D_UNIX03_THREADS to enable pthreads support." >&5
+$as_echo "$as_me: WARNING: IBM z/OS requires -D_OPEN_THREADS or -D_UNIX03_THREADS to enable pthreads support." >&2;}
+fi
+rm -f conftest*
+
+        ;;
+
         solaris*)
 
-        # On Solaris (at least, for some versions), libc contains stubbed
+        # Newer versions of Solaris require the "-mt -lpthread" pair, and we
+        # check that first.  On some older 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:
-
-        ax_pthread_flags="-pthreads pthread -mt -pthread $ax_pthread_flags"
-        ;;
+        # who knows whether they'll stub that too in a future libc.)  So
+        # we'll look for -pthreads and -lpthread shortly thereafter.
 
-        darwin*)
-        ax_pthread_flags="-pthread $ax_pthread_flags"
+        ax_pthread_flags="-mt,pthread -pthreads -pthread pthread $ax_pthread_flags"
         ;;
 esac
 
-# Clang doesn't consider unrecognized options an error unless we specify
-# -Werror. We throw in some extra Clang-specific options to ensure that
-# this doesn't happen for GCC, which also accepts -Werror.
+# Older versions of Clang only give a warning instead of an error for an
+# unrecognized option, unless we specify -Werror. (We throw in some extra
+# Clang warning flags for good measure.)
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if compiler needs -Werror to reject unknown flags" >&5
-$as_echo_n "checking if compiler needs -Werror to reject unknown flags... " >&6; }
-save_CFLAGS="$CFLAGS"
-ax_pthread_extra_flags="-Werror"
-CFLAGS="$CFLAGS $ax_pthread_extra_flags -Wunknown-warning-option -Wsizeof-array-argument"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if compiler needs certain flags to reject unknown flags" >&5
+$as_echo_n "checking if compiler needs certain flags to reject unknown flags... " >&6; }
+if ${ax_cv_PTHREAD_REJECT_UNKNOWN+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ax_cv_PTHREAD_REJECT_UNKNOWN=unknown
+     save_CFLAGS="$CFLAGS"
+     ax_pthread_extra_flags="-Wunknown-warning-option -Wunused-command-line-argument"
+     CFLAGS="$CFLAGS $ax_pthread_extra_flags -Wfoobaz -foobaz"
+     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 int foo(void);
 int
@@ -19135,15 +19170,20 @@ foo()
 }
 _ACEOF
 if ac_fn_c_try_compile "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
+  ax_cv_PTHREAD_REJECT_UNKNOWN="-Werror $ax_pthread_extra_flags"
 else
-  ax_pthread_extra_flags=
-                   { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
+  ax_cv_PTHREAD_REJECT_UNKNOWN=no
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-CFLAGS="$save_CFLAGS"
+     CFLAGS="$save_CFLAGS"
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_PTHREAD_REJECT_UNKNOWN" >&5
+$as_echo "$ax_cv_PTHREAD_REJECT_UNKNOWN" >&6; }
+ax_pthread_extra_flags=
+if test "x$ax_cv_PTHREAD_REJECT_UNKNOWN" != "xno"; then :
+  ax_pthread_extra_flags="$ax_cv_PTHREAD_REJECT_UNKNOWN"
+fi
 
 if test x"$ax_pthread_ok" = xno; then
 for flag in $ax_pthread_flags; do
@@ -19154,6 +19194,13 @@ for flag in $ax_pthread_flags; do
 $as_echo_n "checking whether pthreads work without any flags... " >&6; }
                 ;;
 
+                -mt,pthread)
+                { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether pthreads work with -mt -lpthread" >&5
+$as_echo_n "checking whether pthreads work with -mt -lpthread... " >&6; }
+                PTHREAD_CFLAGS="-mt"
+                PTHREAD_LIBS="-lpthread"
+                ;;
+
                 -*)
                 { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether pthreads work with $flag" >&5
 $as_echo_n "checking whether pthreads work with $flag... " >&6; }
@@ -19273,9 +19320,12 @@ if test "x$ax_pthread_ok" = xyes; then
         # Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
         { $as_echo "$as_me:${as_lineno-$LINENO}: checking for joinable pthread attribute" >&5
 $as_echo_n "checking for joinable pthread attribute... " >&6; }
-        attr_name=unknown
-        for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
-            cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+if ${ax_cv_PTHREAD_JOINABLE_ATTR+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ax_cv_PTHREAD_JOINABLE_ATTR=unknown
+             for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
+                 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <pthread.h>
 int
@@ -19287,49 +19337,69 @@ int attr = $attr; return attr /* ; */
 }
 _ACEOF
 if ac_fn_c_try_link "$LINENO"; then :
-  attr_name=$attr; break
+  ax_cv_PTHREAD_JOINABLE_ATTR=$attr; break
 fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext conftest.$ac_ext
-        done
-        { $as_echo "$as_me:${as_lineno-$LINENO}: result: $attr_name" >&5
-$as_echo "$attr_name" >&6; }
-        if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then
+             done
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_PTHREAD_JOINABLE_ATTR" >&5
+$as_echo "$ax_cv_PTHREAD_JOINABLE_ATTR" >&6; }
+        if test "$ax_cv_PTHREAD_JOINABLE_ATTR" != unknown && \
+               test "$ax_cv_PTHREAD_JOINABLE_ATTR" != PTHREAD_CREATE_JOINABLE; then :
 
 cat >>confdefs.h <<_ACEOF
-#define PTHREAD_CREATE_JOINABLE $attr_name
+#define PTHREAD_CREATE_JOINABLE $ax_cv_PTHREAD_JOINABLE_ATTR
 _ACEOF
 
-        fi
+fi
 
         { $as_echo "$as_me:${as_lineno-$LINENO}: checking if more special flags are required for pthreads" >&5
 $as_echo_n "checking if more special flags are required for pthreads... " >&6; }
-        flag=no
-        case ${host_os} in
-            aix* | freebsd* | darwin*) flag="-D_THREAD_SAFE";;
-            osf* | hpux*) flag="-D_REENTRANT";;
-            solaris*)
-            if test "$GCC" = "yes"; then
-                flag="-D_REENTRANT"
-            else
-                # TODO: What about Clang on Solaris?
-                flag="-mt -D_REENTRANT"
-            fi
-            ;;
-        esac
-        { $as_echo "$as_me:${as_lineno-$LINENO}: result: $flag" >&5
-$as_echo "$flag" >&6; }
-        if test "x$flag" != xno; then
-            PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
-        fi
+if ${ax_cv_PTHREAD_SPECIAL_FLAGS+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ax_cv_PTHREAD_SPECIAL_FLAGS=no
+             ax_pthread_special_flags_added=no
+             cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#                 if !defined(_REENTRANT) && !defined(_THREAD_SAFE)
+                  AX_PTHREAD_NEED_SPECIAL_FLAG
+#                 endif
+
+_ACEOF
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+  $EGREP "AX_PTHREAD_NEED_SPECIAL_FLAG" >/dev/null 2>&1; then :
+  case $host_os in
+                  aix* | freebsd*)
+                  ax_cv_PTHREAD_SPECIAL_FLAGS="-D_THREAD_SAFE"
+                  ;;
+                  darwin* | hpux* | osf* | solaris*)
+                  ax_cv_PTHREAD_SPECIAL_FLAGS="-D_REENTRANT"
+                  ;;
+                  esac
+
+fi
+rm -f conftest*
+
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_PTHREAD_SPECIAL_FLAGS" >&5
+$as_echo "$ax_cv_PTHREAD_SPECIAL_FLAGS" >&6; }
+        if test "x$ax_cv_PTHREAD_SPECIAL_FLAGS" != "xno" && \
+               test "x$ax_pthread_special_flags_added" != "xyes"; then :
+  PTHREAD_CFLAGS="$ax_cv_PTHREAD_SPECIAL_FLAGS $PTHREAD_CFLAGS"
+               ax_pthread_special_flags_added=yes
+fi
 
         { $as_echo "$as_me:${as_lineno-$LINENO}: checking for PTHREAD_PRIO_INHERIT" >&5
 $as_echo_n "checking for PTHREAD_PRIO_INHERIT... " >&6; }
 if ${ax_cv_PTHREAD_PRIO_INHERIT+:} false; then :
   $as_echo_n "(cached) " >&6
 else
-
-                cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <pthread.h>
 int
diff --git a/m4/ax_pthread.m4 b/m4/ax_pthread.m4
new file mode 100644 (file)
index 0000000..f6445a6
--- /dev/null
@@ -0,0 +1,374 @@
+# ===========================================================================
+#        http://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 link it with them as well. e.g. you should link with
+#   $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS
+#
+#   If you are only building threads programs, you may wish to use these
+#   variables in your default LIBS, CFLAGS, and CC:
+#
+#     LIBS="$PTHREAD_LIBS $LIBS"
+#     CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+#     CC="$PTHREAD_CC"
+#
+#   In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute constant
+#   has a nonstandard name, 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>
+#
+#   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 <http://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 21
+
+AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD])
+AC_DEFUN([AX_PTHREAD], [
+AC_REQUIRE([AC_CANONICAL_HOST])
+AC_REQUIRE([AC_PROG_CC])
+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"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
+        save_CFLAGS="$CFLAGS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+        save_LIBS="$LIBS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        AC_MSG_CHECKING([for pthread_join 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"$ax_pthread_ok" = xno; then
+                PTHREAD_LIBS=""
+                PTHREAD_CFLAGS=""
+        fi
+        LIBS="$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.
+
+ax_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mt -mthreads pthread --thread-safe 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), Tru64
+# -pthreads: Solaris/gcc
+# -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)
+# -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
+
+        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*)
+
+        # Newer versions of Solaris require the "-mt -lpthread" pair, and we
+        # check that first.  On some older 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 look for -pthreads and -lpthread shortly thereafter.
+
+        ax_pthread_flags="-mt,pthread -pthreads -pthread pthread $ax_pthread_flags"
+        ;;
+esac
+
+# Older versions of Clang only give a warning instead of an error for an
+# unrecognized option, unless we specify -Werror. (We throw in some extra
+# Clang warning flags for good measure.)
+
+AC_CACHE_CHECK([if compiler needs certain flags to reject unknown flags],
+    [ax_cv_PTHREAD_REJECT_UNKNOWN],
+    [ax_cv_PTHREAD_REJECT_UNKNOWN=unknown
+     save_CFLAGS="$CFLAGS"
+     ax_pthread_extra_flags="-Wunknown-warning-option -Wunused-command-line-argument"
+     CFLAGS="$CFLAGS $ax_pthread_extra_flags -Wfoobaz -foobaz"
+     AC_COMPILE_IFELSE([AC_LANG_PROGRAM([int foo(void);],[foo()])],
+                       [ax_cv_PTHREAD_REJECT_UNKNOWN="-Werror $ax_pthread_extra_flags"],
+                       [ax_cv_PTHREAD_REJECT_UNKNOWN=no])
+     CFLAGS="$save_CFLAGS"
+    ])
+ax_pthread_extra_flags=
+AS_IF([test "x$ax_cv_PTHREAD_REJECT_UNKNOWN" != "xno"],
+      [ax_pthread_extra_flags="$ax_cv_PTHREAD_REJECT_UNKNOWN"])
+
+if test x"$ax_pthread_ok" = xno; then
+for flag in $ax_pthread_flags; do
+
+        case $flag in
+                none)
+                AC_MSG_CHECKING([whether pthreads work without any flags])
+                ;;
+
+                -mt,pthread)
+                AC_MSG_CHECKING([whether pthreads work with -mt -lpthread])
+                PTHREAD_CFLAGS="-mt"
+                PTHREAD_LIBS="-lpthread"
+                ;;
+
+                -*)
+                AC_MSG_CHECKING([whether pthreads work with $flag])
+                PTHREAD_CFLAGS="$flag"
+                ;;
+
+                pthread-config)
+                AC_CHECK_PROG([ax_pthread_config], [pthread-config], [yes], [no])
+                if test x"$ax_pthread_config" = xno; then continue; fi
+                PTHREAD_CFLAGS="`pthread-config --cflags`"
+                PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
+                ;;
+
+                *)
+                AC_MSG_CHECKING([for the pthreads library -l$flag])
+                PTHREAD_LIBS="-l$flag"
+                ;;
+        esac
+
+        save_LIBS="$LIBS"
+        save_CFLAGS="$CFLAGS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS $ax_pthread_extra_flags"
+
+        # Check for various functions.  We must include pthread.h,
+        # since some functions may be macros.  (On the Sequent, we
+        # need a special flag -Kthread to make this header compile.)
+        # We check for pthread_join because it is in -lpthread on IRIX
+        # while pthread_create is in libc.  We check for pthread_attr_init
+        # due to DEC craziness with -lpthreads.  We check for
+        # pthread_cleanup_push because it is one of the few pthread
+        # functions on Solaris that doesn't have a non-functional libc stub.
+        # We try pthread_create on general principles.
+        AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>
+                        static void routine(void *a) { a = 0; }
+                        static void *start_routine(void *a) { return a; }],
+                       [pthread_t th; pthread_attr_t attr;
+                        pthread_create(&th, 0, start_routine, 0);
+                        pthread_join(th, 0);
+                        pthread_attr_init(&attr);
+                        pthread_cleanup_push(routine, 0);
+                        pthread_cleanup_pop(0) /* ; */])],
+                [ax_pthread_ok=yes],
+                [])
+
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+
+        AC_MSG_RESULT([$ax_pthread_ok])
+        if test "x$ax_pthread_ok" = xyes; then
+                break;
+        fi
+
+        PTHREAD_LIBS=""
+        PTHREAD_CFLAGS=""
+done
+fi
+
+# Various other checks:
+if test "x$ax_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_CACHE_CHECK([for joinable pthread attribute],
+            [ax_cv_PTHREAD_JOINABLE_ATTR],
+            [ax_cv_PTHREAD_JOINABLE_ATTR=unknown
+             for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
+                 AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>],
+                                                 [int attr = $attr; return attr /* ; */])],
+                                [ax_cv_PTHREAD_JOINABLE_ATTR=$attr; break],
+                                [])
+             done
+            ])
+        AS_IF([test "$ax_cv_PTHREAD_JOINABLE_ATTR" != unknown && \
+               test "$ax_cv_PTHREAD_JOINABLE_ATTR" != PTHREAD_CREATE_JOINABLE],
+              [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.])])
+
+        AC_CACHE_CHECK([if more special flags are required for pthreads],
+            [ax_cv_PTHREAD_SPECIAL_FLAGS],
+            [ax_cv_PTHREAD_SPECIAL_FLAGS=no
+             ax_pthread_special_flags_added=no
+             AC_EGREP_CPP([AX_PTHREAD_NEED_SPECIAL_FLAG],
+                 [
+#                 if !defined(_REENTRANT) && !defined(_THREAD_SAFE)
+                  AX_PTHREAD_NEED_SPECIAL_FLAG
+#                 endif
+                 ],
+                 [case $host_os in
+                  aix* | freebsd*)
+                  ax_cv_PTHREAD_SPECIAL_FLAGS="-D_THREAD_SAFE"
+                  ;;
+                  darwin* | hpux* | osf* | solaris*)
+                  ax_cv_PTHREAD_SPECIAL_FLAGS="-D_REENTRANT"
+                  ;;
+                  esac
+                 ])
+            ])
+        AS_IF([test "x$ax_cv_PTHREAD_SPECIAL_FLAGS" != "xno" && \
+               test "x$ax_pthread_special_flags_added" != "xyes"],
+              [PTHREAD_CFLAGS="$ax_cv_PTHREAD_SPECIAL_FLAGS $PTHREAD_CFLAGS"
+               ax_pthread_special_flags_added=yes])
+
+        AC_CACHE_CHECK([for PTHREAD_PRIO_INHERIT],
+            [ax_cv_PTHREAD_PRIO_INHERIT],
+            [AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <pthread.h>]],
+                                             [[int i = PTHREAD_PRIO_INHERIT;]])],
+                            [ax_cv_PTHREAD_PRIO_INHERIT=yes],
+                            [ax_cv_PTHREAD_PRIO_INHERIT=no])
+            ])
+        AS_IF([test "x$ax_cv_PTHREAD_PRIO_INHERIT" = "xyes"],
+            [AC_DEFINE([HAVE_PTHREAD_PRIO_INHERIT], [1], [Have PTHREAD_PRIO_INHERIT.])])
+
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+
+        # 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],[$CC])])])
+                ;;
+            esac
+        fi
+fi
+
+test -n "$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
+        $2
+fi
+AC_LANG_POP
+])dnl AX_PTHREAD