mirror of
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updated m4/ax_*.m4 macros
This commit is contained in:
@@ -30,33 +30,12 @@
|
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#
|
||||
# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
|
||||
#
|
||||
# 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.
|
||||
# Copying and distribution of this file, with or without modification, are
|
||||
# permitted in any medium without royalty provided the copyright notice
|
||||
# and this notice are preserved. This file is offered as-is, without any
|
||||
# warranty.
|
||||
|
||||
#serial 6
|
||||
#serial 7
|
||||
|
||||
AC_DEFUN([AX_APPEND_COMPILE_FLAGS],
|
||||
[AX_REQUIRE_DEFINED([AX_CHECK_COMPILE_FLAG])
|
||||
|
||||
+5
-26
@@ -23,33 +23,12 @@
|
||||
# Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
|
||||
# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
|
||||
#
|
||||
# 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.
|
||||
# Copying and distribution of this file, with or without modification, are
|
||||
# permitted in any medium without royalty provided the copyright notice
|
||||
# and this notice are preserved. This file is offered as-is, without any
|
||||
# warranty.
|
||||
|
||||
#serial 7
|
||||
#serial 8
|
||||
|
||||
AC_DEFUN([AX_APPEND_FLAG],
|
||||
[dnl
|
||||
|
||||
@@ -28,33 +28,12 @@
|
||||
#
|
||||
# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
|
||||
#
|
||||
# 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.
|
||||
# Copying and distribution of this file, with or without modification, are
|
||||
# permitted in any medium without royalty provided the copyright notice
|
||||
# and this notice are preserved. This file is offered as-is, without any
|
||||
# warranty.
|
||||
|
||||
#serial 6
|
||||
#serial 7
|
||||
|
||||
AC_DEFUN([AX_APPEND_LINK_FLAGS],
|
||||
[AX_REQUIRE_DEFINED([AX_CHECK_LINK_FLAG])
|
||||
|
||||
@@ -29,33 +29,12 @@
|
||||
# Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
|
||||
# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
|
||||
#
|
||||
# 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.
|
||||
# Copying and distribution of this file, with or without modification, are
|
||||
# permitted in any medium without royalty provided the copyright notice
|
||||
# and this notice are preserved. This file is offered as-is, without any
|
||||
# warranty.
|
||||
|
||||
#serial 5
|
||||
#serial 6
|
||||
|
||||
AC_DEFUN([AX_CHECK_COMPILE_FLAG],
|
||||
[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
|
||||
|
||||
@@ -29,33 +29,12 @@
|
||||
# Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
|
||||
# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
|
||||
#
|
||||
# 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.
|
||||
# Copying and distribution of this file, with or without modification, are
|
||||
# permitted in any medium without royalty provided the copyright notice
|
||||
# and this notice are preserved. This file is offered as-is, without any
|
||||
# warranty.
|
||||
|
||||
#serial 5
|
||||
#serial 6
|
||||
|
||||
AC_DEFUN([AX_CHECK_LINK_FLAG],
|
||||
[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
|
||||
|
||||
+6
-6
@@ -42,7 +42,7 @@
|
||||
# and this notice are preserved. This file is offered as-is, without any
|
||||
# warranty.
|
||||
|
||||
#serial 11
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||||
#serial 12
|
||||
|
||||
AC_DEFUN([AX_HAVE_EPOLL], [dnl
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||||
ax_have_epoll_cppflags="${CPPFLAGS}"
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||||
@@ -59,10 +59,10 @@ AC_DEFUN([AX_HAVE_EPOLL], [dnl
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||||
# endif
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||||
#endif
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||||
], [dnl
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||||
int fd, rc;
|
||||
int fd;
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||||
struct epoll_event ev;
|
||||
fd = epoll_create(128);
|
||||
rc = epoll_wait(fd, &ev, 1, 0);])],
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||||
epoll_wait(fd, &ev, 1, 0);])],
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||||
[ax_cv_have_epoll=yes],
|
||||
[ax_cv_have_epoll=no])])
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||||
CPPFLAGS="${ax_have_epoll_cppflags}"
|
||||
@@ -89,11 +89,11 @@ AC_DEFUN([AX_HAVE_EPOLL_PWAIT], [dnl
|
||||
#include <sys/epoll.h>
|
||||
#include <signal.h>
|
||||
], [dnl
|
||||
int fd, rc;
|
||||
int fd;
|
||||
struct epoll_event ev;
|
||||
fd = epoll_create(128);
|
||||
rc = epoll_wait(fd, &ev, 1, 0);
|
||||
rc = epoll_pwait(fd, &ev, 1, 0, (sigset_t const *)(0));])],
|
||||
epoll_wait(fd, &ev, 1, 0);
|
||||
epoll_pwait(fd, &ev, 1, 0, (sigset_t const *)(0));])],
|
||||
[ax_cv_have_epoll_pwait=yes],
|
||||
[ax_cv_have_epoll_pwait=no])])
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||||
CPPFLAGS="${ax_have_epoll_cppflags}"
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||||
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||||
+121
-106
@@ -55,6 +55,7 @@
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||||
#
|
||||
# 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
|
||||
@@ -82,7 +83,7 @@
|
||||
# modified version of the Autoconf Macro, you may extend this special
|
||||
# exception to the GPL to apply to your modified version as well.
|
||||
|
||||
#serial 26
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||||
#serial 27
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||||
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AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD])
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AC_DEFUN([AX_PTHREAD], [
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||||
@@ -123,10 +124,12 @@ fi
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||||
# (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.
|
||||
# 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.
|
||||
|
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ax_pthread_flags="pthreads none -Kthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
|
||||
|
||||
@@ -194,14 +197,47 @@ case $host_os in
|
||||
# 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,pthread pthread $ax_pthread_flags"
|
||||
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 -pthreads $ax_pthread_flags"])
|
||||
[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
|
||||
@@ -224,101 +260,6 @@ AS_IF([test "x$ax_pthread_check_macro" = "x--"],
|
||||
[ax_pthread_check_cond=0],
|
||||
[ax_pthread_check_cond="!defined($ax_pthread_check_macro)"])
|
||||
|
||||
# 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="$ax_cv_PTHREAD_CLANG"
|
||||
|
||||
ax_pthread_clang_warning=no
|
||||
|
||||
# Clang needs special handling, because older versions handle the -pthread
|
||||
# option in a rather... idiosyncratic way
|
||||
|
||||
if test "x$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.)
|
||||
|
||||
PTHREAD_CFLAGS="-pthread"
|
||||
PTHREAD_LIBS=
|
||||
|
||||
ax_pthread_ok=yes
|
||||
|
||||
# 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 # $ax_pthread_clang = yes
|
||||
|
||||
if test "x$ax_pthread_ok" = "xno"; then
|
||||
for ax_pthread_try_flag in $ax_pthread_flags; do
|
||||
@@ -328,10 +269,10 @@ for ax_pthread_try_flag in $ax_pthread_flags; do
|
||||
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"
|
||||
*,*)
|
||||
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"])
|
||||
;;
|
||||
|
||||
-*)
|
||||
@@ -399,6 +340,80 @@ for ax_pthread_try_flag in $ax_pthread_flags; do
|
||||
done
|
||||
fi
|
||||
|
||||
|
||||
# Clang needs special handling, because older versions handle the -pthread
|
||||
# option in a rather... idiosyncratic way
|
||||
|
||||
if test "x$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"
|
||||
|
||||
Reference in New Issue
Block a user