#
# 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
# modified version of the Autoconf Macro, you may extend this special
# exception to the GPL to apply to your modified version as well.
-#serial 25
+#serial 27
AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD])
AC_DEFUN([AX_PTHREAD], [
# (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.
ax_pthread_flags="pthreads none -Kthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
# 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
[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="$ax_cv_PTHREAD_CLANG"
+if test "x$ax_pthread_ok" = "xno"; then
+for ax_pthread_try_flag in $ax_pthread_flags; do
+
+ case $ax_pthread_try_flag in
+ none)
+ AC_MSG_CHECKING([whether pthreads work without any flags])
+ ;;
+
+ *,*)
+ PTHREAD_CFLAGS=`echo $ax_pthread_try_flag | sed "s/^\(.*\),\(.*\)$/\1/"`
+ PTHREAD_LIBS=`echo $ax_pthread_try_flag | sed "s/^\(.*\),\(.*\)$/\2/"`
+ AC_MSG_CHECKING([whether pthreads work with "$PTHREAD_CFLAGS" and "$PTHREAD_LIBS"])
+ ;;
+
+ -*)
+ AC_MSG_CHECKING([whether pthreads work with $ax_pthread_try_flag])
+ PTHREAD_CFLAGS="$ax_pthread_try_flag"
+ ;;
+
+ pthread-config)
+ AC_CHECK_PROG([ax_pthread_config], [pthread-config], [yes], [no])
+ AS_IF([test "x$ax_pthread_config" = "xno"], [continue])
+ PTHREAD_CFLAGS="`pthread-config --cflags`"
+ PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
+ ;;
+
+ *)
+ AC_MSG_CHECKING([for the pthreads library -l$ax_pthread_try_flag])
+ PTHREAD_LIBS="-l$ax_pthread_try_flag"
+ ;;
+ esac
+
+ ax_pthread_save_CFLAGS="$CFLAGS"
+ ax_pthread_save_LIBS="$LIBS"
+ CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+ LIBS="$PTHREAD_LIBS $LIBS"
+
+ # Check for various functions. We must include pthread.h,
+ # since some functions may be macros. (On the Sequent, we
+ # need a special flag -Kthread to make this header compile.)
+ # We check for pthread_join because it is in -lpthread on IRIX
+ # while pthread_create is in libc. We check for pthread_attr_init
+ # due to DEC craziness with -lpthreads. We check for
+ # pthread_cleanup_push because it is one of the few pthread
+ # functions on Solaris that doesn't have a non-functional libc stub.
+ # We try pthread_create on general principles.
+
+ AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>
+# if $ax_pthread_check_cond
+# error "$ax_pthread_check_macro must be defined"
+# endif
+ static void *some_global = NULL;
+ static void routine(void *a)
+ {
+ /* To avoid any unused-parameter or
+ unused-but-set-parameter warning. */
+ some_global = a;
+ }
+ static void *start_routine(void *a) { return a; }],
+ [pthread_t th; pthread_attr_t attr;
+ pthread_create(&th, 0, start_routine, 0);
+ pthread_join(th, 0);
+ pthread_attr_init(&attr);
+ pthread_cleanup_push(routine, 0);
+ pthread_cleanup_pop(0) /* ; */])],
+ [ax_pthread_ok=yes],
+ [])
+
+ CFLAGS="$ax_pthread_save_CFLAGS"
+ LIBS="$ax_pthread_save_LIBS"
+
+ AC_MSG_RESULT([$ax_pthread_ok])
+ AS_IF([test "x$ax_pthread_ok" = "xyes"], [break])
+
+ PTHREAD_LIBS=""
+ PTHREAD_CFLAGS=""
+done
+fi
-ax_pthread_clang_warning=no
# Clang needs special handling, because older versions handle the -pthread
# option in a rather... idiosyncratic way
# -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
# 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 "$ax_pthread_sed"`
+ ax_pthread_link_step=`AS_ECHO(["$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
fi # $ax_pthread_clang = yes
-if test "x$ax_pthread_ok" = "xno"; then
-for ax_pthread_try_flag in $ax_pthread_flags; do
-
- case $ax_pthread_try_flag in
- none)
- AC_MSG_CHECKING([whether pthreads work without any flags])
- ;;
-
- -mt,pthread)
- AC_MSG_CHECKING([whether pthreads work with -mt -lpthread])
- PTHREAD_CFLAGS="-mt"
- PTHREAD_LIBS="-lpthread"
- ;;
-
- -*)
- AC_MSG_CHECKING([whether pthreads work with $ax_pthread_try_flag])
- PTHREAD_CFLAGS="$ax_pthread_try_flag"
- ;;
-
- pthread-config)
- AC_CHECK_PROG([ax_pthread_config], [pthread-config], [yes], [no])
- AS_IF([test "x$ax_pthread_config" = "xno"], [continue])
- PTHREAD_CFLAGS="`pthread-config --cflags`"
- PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
- ;;
- *)
- AC_MSG_CHECKING([for the pthreads library -l$ax_pthread_try_flag])
- PTHREAD_LIBS="-l$ax_pthread_try_flag"
- ;;
- esac
-
- ax_pthread_save_CFLAGS="$CFLAGS"
- ax_pthread_save_LIBS="$LIBS"
- CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
- LIBS="$PTHREAD_LIBS $LIBS"
-
- # Check for various functions. We must include pthread.h,
- # since some functions may be macros. (On the Sequent, we
- # need a special flag -Kthread to make this header compile.)
- # We check for pthread_join because it is in -lpthread on IRIX
- # while pthread_create is in libc. We check for pthread_attr_init
- # due to DEC craziness with -lpthreads. We check for
- # pthread_cleanup_push because it is one of the few pthread
- # functions on Solaris that doesn't have a non-functional libc stub.
- # We try pthread_create on general principles.
-
- AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>
-# if $ax_pthread_check_cond
-# error "$ax_pthread_check_macro must be defined"
-# endif
- static void 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],
- [])
-
- CFLAGS="$ax_pthread_save_CFLAGS"
- LIBS="$ax_pthread_save_LIBS"
-
- AC_MSG_RESULT([$ax_pthread_ok])
- AS_IF([test "x$ax_pthread_ok" = "xyes"], [break])
-
- PTHREAD_LIBS=""
- PTHREAD_CFLAGS=""
-done
-fi
# Various other checks:
if test "x$ax_pthread_ok" = "xyes"; then
projects / userspace-rcu.git / commitdiff
