[packages/amavis.git] / amavis-acx_pthread.m4

dnl @synopsis ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
dnl
dnl This macro figures out how to build C programs using POSIX
dnl threads.  It sets the PTHREAD_LIBS output variable to the threads
dnl library and linker flags, and the PTHREAD_CFLAGS output variable
dnl to any special C compiler flags that are needed.  (The user can also
dnl force certain compiler flags/libs to be tested by setting these
dnl environment variables.)
dnl
dnl Also sets PTHREAD_CC to any special C compiler that is needed for
dnl multi-threaded programs (defaults to the value of CC otherwise).
dnl (This is necessary on AIX to use the special cc_r compiler alias.)
dnl
dnl If you are only building threads programs, you may wish to
dnl use these variables in your default LIBS, CFLAGS, and CC:
dnl
dnl        LIBS="$PTHREAD_LIBS $LIBS"
dnl        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
dnl        CC="$PTHREAD_CC"
dnl
dnl In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute
dnl constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE
dnl to that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
dnl
dnl ACTION-IF-FOUND is a list of shell commands to run if a threads
dnl library is found, and ACTION-IF-NOT-FOUND is a list of commands
dnl to run it if it is not found.  If ACTION-IF-FOUND is not specified,
dnl the default action will define HAVE_PTHREAD.
dnl
dnl Please let the authors know if this macro fails on any platform,
dnl or if you have any other suggestions or comments.  This macro was
dnl based on work by SGJ on autoconf scripts for FFTW (www.fftw.org)
dnl (with help from M. Frigo), as well as ac_pthread and hb_pthread
dnl macros posted by AFC to the autoconf macro repository.  We are also
dnl grateful for the helpful feedback of numerous users.
dnl
dnl @version $Id$
dnl @author Steven G. Johnson <stevenj@alum.mit.edu> and Alejandro Forero Cuervo <bachue@bachue.com>

AC_DEFUN([ACX_PTHREAD], [
AC_REQUIRE([AC_CANONICAL_HOST])
acx_pthread_ok=no

# First, check if the POSIX threads header, pthread.h, is available.
# If it isn't, don't bother looking for the threads libraries.
AC_CHECK_HEADER(pthread.h, , acx_pthread_ok=noheader)

# 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).

# 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 $LIBS"
        AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
        AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes)
        AC_MSG_RESULT($acx_pthread_ok)
        if test x"$acx_pthread_ok" = xno; then
                PTHREAD_LIBS=""
                PTHREAD_CFLAGS=""
        fi
        LIBS="$save_LIBS"
        CFLAGS="$save_CFLAGS"
fi

# 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.

acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt"

# 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)
# -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)
# pthread: Linux, etcetera
# --thread-safe: KAI C++

case "${host_cpu}-${host_os}" in
        *solaris*)

        # On Solaris (at least, for some versions), libc contains stubbed
        # (non-functional) versions of the pthreads routines, so link-based
        # tests will erroneously succeed.  (We need to link with -pthread or
        # -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:

        acx_pthread_flags="-pthread -pthreads pthread -mt $acx_pthread_flags"
        ;;
esac

if test x"$acx_pthread_ok" = xno; then
for flag in $acx_pthread_flags; do

        case $flag in
                none)
                AC_MSG_CHECKING([whether pthreads work without any flags])
                ;;

                -*)
                AC_MSG_CHECKING([whether pthreads work with $flag])
                PTHREAD_CFLAGS="$flag"
                ;;

                *)
                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"

        # 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_TRY_LINK([#include <pthread.h>],
                    [pthread_t th; pthread_join(th, 0);
                     pthread_attr_init(0); pthread_cleanup_push(0, 0);
                     pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
                    [acx_pthread_ok=yes])

        LIBS="$save_LIBS"
        CFLAGS="$save_CFLAGS"

        AC_MSG_RESULT($acx_pthread_ok)
        if test "x$acx_pthread_ok" = xyes; then
                break;
        fi

        PTHREAD_LIBS=""
        PTHREAD_CFLAGS=""
done
fi

# Various other checks:
if test "x$acx_pthread_ok" = xyes; then
        save_LIBS="$LIBS"
        LIBS="$PTHREAD_LIBS $LIBS"
        save_CFLAGS="$CFLAGS"
        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"

        # Detect AIX lossage: threads are created detached by default
        # and the JOINABLE attribute has a nonstandard name (UNDETACHED).
        AC_MSG_CHECKING([for joinable pthread attribute])
        AC_TRY_LINK([#include <pthread.h>],
                    [int attr=PTHREAD_CREATE_JOINABLE;],
                    ok=PTHREAD_CREATE_JOINABLE, ok=unknown)
        if test x"$ok" = xunknown; then
                AC_TRY_LINK([#include <pthread.h>],
                            [int attr=PTHREAD_CREATE_UNDETACHED;],
                            ok=PTHREAD_CREATE_UNDETACHED, ok=unknown)
        fi
        if test x"$ok" != xPTHREAD_CREATE_JOINABLE; then
                AC_DEFINE(PTHREAD_CREATE_JOINABLE, $ok,
                          [Define to the necessary symbol if this constant
                           uses a non-standard name on your system.])
        fi
        AC_MSG_RESULT(${ok})
        if test x"$ok" = xunknown; then
                AC_MSG_WARN([we do not know how to create joinable pthreads])
        fi

        AC_MSG_CHECKING([if more special flags are required for pthreads])
        flag=no
        case "${host_cpu}-${host_os}" in
                *-aix* | *-freebsd*)     flag="-D_THREAD_SAFE";;
                *solaris* | alpha*-osf*) flag="-D_REENTRANT";;
        esac
        AC_MSG_RESULT(${flag})
        if test "x$flag" != xno; then
                PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
        fi

        LIBS="$save_LIBS"
        CFLAGS="$save_CFLAGS"

        # More AIX lossage: must compile with cc_r
        AC_CHECK_PROG(PTHREAD_CC, cc_r, cc_r, ${CC})
else
        PTHREAD_CC="$CC"
fi

AC_SUBST(PTHREAD_LIBS)
AC_SUBST(PTHREAD_CFLAGS)
AC_SUBST(PTHREAD_CC)

# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
if test x"$acx_pthread_ok" = xyes; then
        ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])
        :
else
        acx_pthread_ok=no
        $2
fi

])dnl ACX_PTHREAD
Commit	Line	Data
57530a1c AA	1	dnl @synopsis ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
	2	dnl
	3	dnl This macro figures out how to build C programs using POSIX
	4	dnl threads. It sets the PTHREAD_LIBS output variable to the threads
	5	dnl library and linker flags, and the PTHREAD_CFLAGS output variable
	6	dnl to any special C compiler flags that are needed. (The user can also
	7	dnl force certain compiler flags/libs to be tested by setting these
	8	dnl environment variables.)
	9	dnl
	10	dnl Also sets PTHREAD_CC to any special C compiler that is needed for
	11	dnl multi-threaded programs (defaults to the value of CC otherwise).
	12	dnl (This is necessary on AIX to use the special cc_r compiler alias.)
	13	dnl
	14	dnl If you are only building threads programs, you may wish to
	15	dnl use these variables in your default LIBS, CFLAGS, and CC:
	16	dnl
	17	dnl LIBS="$PTHREAD_LIBS $LIBS"
	18	dnl CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
	19	dnl CC="$PTHREAD_CC"
	20	dnl
	21	dnl In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute
	22	dnl constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE
	23	dnl to that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
	24	dnl
	25	dnl ACTION-IF-FOUND is a list of shell commands to run if a threads
	26	dnl library is found, and ACTION-IF-NOT-FOUND is a list of commands
	27	dnl to run it if it is not found. If ACTION-IF-FOUND is not specified,
	28	dnl the default action will define HAVE_PTHREAD.
	29	dnl
	30	dnl Please let the authors know if this macro fails on any platform,
	31	dnl or if you have any other suggestions or comments. This macro was
	32	dnl based on work by SGJ on autoconf scripts for FFTW (www.fftw.org)
	33	dnl (with help from M. Frigo), as well as ac_pthread and hb_pthread
	34	dnl macros posted by AFC to the autoconf macro repository. We are also
	35	dnl grateful for the helpful feedback of numerous users.
	36	dnl
	37	dnl @version $Id$
	38	dnl @author Steven G. Johnson <stevenj@alum.mit.edu> and Alejandro Forero Cuervo <bachue@bachue.com>
	39
	40	AC_DEFUN([ACX_PTHREAD], [
	41	AC_REQUIRE([AC_CANONICAL_HOST])
	42	acx_pthread_ok=no
	43
	44	# First, check if the POSIX threads header, pthread.h, is available.
	45	# If it isn't, don't bother looking for the threads libraries.
	46	AC_CHECK_HEADER(pthread.h, , acx_pthread_ok=noheader)
	47
	48	# We must check for the threads library under a number of different
	49	# names; the ordering is very important because some systems
	50	# (e.g. DEC) have both -lpthread and -lpthreads, where one of the
	51	# libraries is broken (non-POSIX).
	52
	53	# First of all, check if the user has set any of the PTHREAD_LIBS,
	54	# etcetera environment variables, and if threads linking works using
	55	# them:
	56	if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
	57	save_CFLAGS="$CFLAGS"
	58	CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
	59	save_LIBS="$LIBS"
	60	LIBS="$PTHREAD_LIBS $LIBS"
	61	AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
	62	AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes)
	63	AC_MSG_RESULT($acx_pthread_ok)
	64	if test x"$acx_pthread_ok" = xno; then
65	PTHREAD_LIBS=""
66	PTHREAD_CFLAGS=""
67	fi
68	LIBS="$save_LIBS"
69	CFLAGS="$save_CFLAGS"
70	fi
71
72	# Create a list of thread flags to try. Items starting with a "-" are
73	# C compiler flags, and other items are library names, except for "none"
74	# which indicates that we try without any flags at all.
75
76	acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt"
77
78	# The ordering is (sometimes) important. Some notes on the
79	# individual items follow:
80
81	# pthreads: AIX (must check this before -lpthread)
82	# none: in case threads are in libc; should be tried before -Kthread and
83	# other compiler flags to prevent continual compiler warnings
84	# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
85	# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
86	# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
87	# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
88	# -pthreads: Solaris/gcc
89	# -mthreads: Mingw32/gcc, Lynx/gcc
90	# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
91	# doesn't hurt to check since this sometimes defines pthreads too;
92	# also defines -D_REENTRANT)
93	# pthread: Linux, etcetera
94	# --thread-safe: KAI C++
95
96	case "${host_cpu}-${host_os}" in
97	solaris)
98
99	# On Solaris (at least, for some versions), libc contains stubbed
100	# (non-functional) versions of the pthreads routines, so link-based
101	# tests will erroneously succeed. (We need to link with -pthread or
102	# -lpthread.) (The stubs are missing pthread_cleanup_push, or rather
103	# a function called by this macro, so we could check for that, but
104	# who knows whether they'll stub that too in a future libc.) So,
105	# we'll just look for -pthreads and -lpthread first:
106
107	acx_pthread_flags="-pthread -pthreads pthread -mt $acx_pthread_flags"
108	;;
109	esac
110
111	if test x"$acx_pthread_ok" = xno; then
112	for flag in $acx_pthread_flags; do
113
114	case $flag in
115	none)
116	AC_MSG_CHECKING([whether pthreads work without any flags])
117	;;
118
119	-*)
120	AC_MSG_CHECKING([whether pthreads work with $flag])
121	PTHREAD_CFLAGS="$flag"
122	;;
123
124	*)
125	AC_MSG_CHECKING([for the pthreads library -l$flag])
126	PTHREAD_LIBS="-l$flag"
127	;;
128	esac
129
130	save_LIBS="$LIBS"
131	save_CFLAGS="$CFLAGS"
132	LIBS="$PTHREAD_LIBS $LIBS"
133	CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
134
135	# Check for various functions. We must include pthread.h,
136	# since some functions may be macros. (On the Sequent, we
137	# need a special flag -Kthread to make this header compile.)
138	# We check for pthread_join because it is in -lpthread on IRIX
139	# while pthread_create is in libc. We check for pthread_attr_init
140	# due to DEC craziness with -lpthreads. We check for
141	# pthread_cleanup_push because it is one of the few pthread
142	# functions on Solaris that doesn't have a non-functional libc stub.
143	# We try pthread_create on general principles.
144	AC_TRY_LINK([#include <pthread.h>],
145	[pthread_t th; pthread_join(th, 0);
146	pthread_attr_init(0); pthread_cleanup_push(0, 0);
147	pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
148	[acx_pthread_ok=yes])
149
150	LIBS="$save_LIBS"
151	CFLAGS="$save_CFLAGS"
152
153	AC_MSG_RESULT($acx_pthread_ok)
154	if test "x$acx_pthread_ok" = xyes; then
155	break;
156	fi
157
158	PTHREAD_LIBS=""
159	PTHREAD_CFLAGS=""
160	done
161	fi
162
163	# Various other checks:
164	if test "x$acx_pthread_ok" = xyes; then
165	save_LIBS="$LIBS"
166	LIBS="$PTHREAD_LIBS $LIBS"
167	save_CFLAGS="$CFLAGS"
168	CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
169
170	# Detect AIX lossage: threads are created detached by default
171	# and the JOINABLE attribute has a nonstandard name (UNDETACHED).
172	AC_MSG_CHECKING([for joinable pthread attribute])
173	AC_TRY_LINK([#include <pthread.h>],
174	[int attr=PTHREAD_CREATE_JOINABLE;],
175	ok=PTHREAD_CREATE_JOINABLE, ok=unknown)
176	if test x"$ok" = xunknown; then
177	AC_TRY_LINK([#include <pthread.h>],
178	[int attr=PTHREAD_CREATE_UNDETACHED;],
179	ok=PTHREAD_CREATE_UNDETACHED, ok=unknown)
180	fi
181	if test x"$ok" != xPTHREAD_CREATE_JOINABLE; then
182	AC_DEFINE(PTHREAD_CREATE_JOINABLE, $ok,
183	[Define to the necessary symbol if this constant
184	uses a non-standard name on your system.])
185	fi
186	AC_MSG_RESULT(${ok})
187	if test x"$ok" = xunknown; then
188	AC_MSG_WARN([we do not know how to create joinable pthreads])
189	fi
190
191	AC_MSG_CHECKING([if more special flags are required for pthreads])
192	flag=no
193	case "${host_cpu}-${host_os}" in
194	-aix \| -freebsd) flag="-D_THREAD_SAFE";;
195	solaris \| alpha-osf) flag="-D_REENTRANT";;
196	esac
197	AC_MSG_RESULT(${flag})
198	if test "x$flag" != xno; then
199	PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
200	fi
201
202	LIBS="$save_LIBS"
203	CFLAGS="$save_CFLAGS"
204
205	# More AIX lossage: must compile with cc_r
206	AC_CHECK_PROG(PTHREAD_CC, cc_r, cc_r, ${CC})
207	else
208	PTHREAD_CC="$CC"
209	fi
210
211	AC_SUBST(PTHREAD_LIBS)
212	AC_SUBST(PTHREAD_CFLAGS)
213	AC_SUBST(PTHREAD_CC)
214
215	# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
216	if test x"$acx_pthread_ok" = xyes; then
217	ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])
218	:
219	else
220	acx_pthread_ok=no
221	$2
222	fi
223
224	])dnl ACX_PTHREAD