+ if test "$gl_use_threads" = yes \
+ || test "$gl_use_threads" = isoc \
+ || test "$gl_use_threads" = posix \
+ || test "$gl_use_threads" = isoc+posix; then
+ # For using <threads.h> or <pthread.h>:
+ gl_ANYTHREADLIB_EARLY
+ fi
+])
+
+dnl Checks whether the compiler and linker support weak declarations of symbols.
+
+AC_DEFUN([gl_WEAK_SYMBOLS],
+[
+ AC_CACHE_CHECK([whether imported symbols can be declared weak],
+ [gl_cv_have_weak],
+ [gl_cv_have_weak=no
+ dnl First, test whether the compiler accepts it syntactically.
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[extern void xyzzy ();
+#pragma weak xyzzy]],
+ [[xyzzy();]])],
+ [gl_cv_have_weak=maybe])
+ if test $gl_cv_have_weak = maybe; then
+ dnl Second, test whether it actually works. On Cygwin 1.7.2, with
+ dnl gcc 4.3, symbols declared weak always evaluate to the address 0.
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#include <stdio.h>
+#pragma weak fputs
+int main ()
+{
+ return (fputs == NULL);
+}]])],
+ [gl_cv_have_weak=yes],
+ [gl_cv_have_weak=no],
+ [dnl When cross-compiling, assume that only ELF platforms support
+ dnl weak symbols.
+ AC_EGREP_CPP([Extensible Linking Format],
+ [#ifdef __ELF__
+ Extensible Linking Format
+ #endif
+ ],
+ [gl_cv_have_weak="guessing yes"],
+ [gl_cv_have_weak="guessing no"])
+ ])
+ fi
+ dnl But when linking statically, weak symbols don't work.
+ case " $LDFLAGS " in
+ *" -static "*) gl_cv_have_weak=no ;;
+ esac
+ ])
+ case "$gl_cv_have_weak" in
+ *yes)
+ AC_DEFINE([HAVE_WEAK_SYMBOLS], [1],
+ [Define to 1 if the compiler and linker support weak declarations of symbols.])
+ ;;
+ esac
+])
+
+dnl The guts of gl_PTHREADLIB. Needs to be expanded only once.
+
+AC_DEFUN([gl_PTHREADLIB_BODY],
+[
+ AC_REQUIRE([gl_ANYTHREADLIB_EARLY])
+ if test -z "$gl_threadlib_body_done"; then
+ gl_pthread_api=no
+ LIBPTHREAD=
+ LIBPMULTITHREAD=
+ # On OSF/1, the compiler needs the flag -pthread or -D_REENTRANT so that
+ # it groks <pthread.h>. It's added above, in gl_ANYTHREADLIB_EARLY.
+ AC_CHECK_HEADER([pthread.h],
+ [gl_have_pthread_h=yes], [gl_have_pthread_h=no])
+ if test "$gl_have_pthread_h" = yes; then
+ # Other possible tests:
+ # -lpthreads (FSU threads, PCthreads)
+ # -lgthreads
+ # Test whether both pthread_mutex_lock and pthread_mutexattr_init exist
+ # in libc. IRIX 6.5 has the first one in both libc and libpthread, but
+ # the second one only in libpthread, and lock.c needs it.
+ #
+ # If -pthread works, prefer it to -lpthread, since Ubuntu 14.04
+ # needs -pthread for some reason. See:
+ # https://lists.gnu.org/r/bug-gnulib/2014-09/msg00023.html
+ save_LIBS=$LIBS
+ for gl_pthread in '' '-pthread'; do
+ LIBS="$LIBS $gl_pthread"
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <pthread.h>
+ pthread_mutex_t m;
+ pthread_mutexattr_t ma;
+ ]],
+ [[pthread_mutex_lock (&m);
+ pthread_mutexattr_init (&ma);]])],
+ [gl_pthread_api=yes
+ LIBPTHREAD=$gl_pthread
+ LIBPMULTITHREAD=$gl_pthread])
+ LIBS=$save_LIBS
+ test $gl_pthread_api = yes && break
+ done
+
+ # Test for libpthread by looking for pthread_kill. (Not pthread_self,
+ # since it is defined as a macro on OSF/1.)
+ if test $gl_pthread_api = yes && test -z "$LIBPTHREAD"; then
+ # The program links fine without libpthread. But it may actually
+ # need to link with libpthread in order to create multiple threads.
+ AC_CHECK_LIB([pthread], [pthread_kill],
+ [LIBPMULTITHREAD=-lpthread
+ # On Solaris and HP-UX, most pthread functions exist also in libc.
+ # Therefore pthread_in_use() needs to actually try to create a
+ # thread: pthread_create from libc will fail, whereas
+ # pthread_create will actually create a thread.
+ # On Solaris 10 or newer, this test is no longer needed, because
+ # libc contains the fully functional pthread functions.
+ case "$host_os" in
+ solaris | solaris2.[1-9] | solaris2.[1-9].* | hpux*)
+ AC_DEFINE([PTHREAD_IN_USE_DETECTION_HARD], [1],
+ [Define if the pthread_in_use() detection is hard.])
+ esac
+ ])
+ elif test $gl_pthread_api != yes; then
+ # Some library is needed. Try libpthread and libc_r.
+ AC_CHECK_LIB([pthread], [pthread_kill],
+ [gl_pthread_api=yes
+ LIBPTHREAD=-lpthread
+ LIBPMULTITHREAD=-lpthread])
+ if test $gl_pthread_api != yes; then
+ # For FreeBSD 4.
+ AC_CHECK_LIB([c_r], [pthread_kill],
+ [gl_pthread_api=yes
+ LIBPTHREAD=-lc_r
+ LIBPMULTITHREAD=-lc_r])
+ fi
+ fi
+ fi
+ AC_MSG_CHECKING([whether POSIX threads API is available])
+ AC_MSG_RESULT([$gl_pthread_api])
+ AC_SUBST([LIBPTHREAD])
+ AC_SUBST([LIBPMULTITHREAD])
+ if test $gl_pthread_api = yes; then
+ AC_DEFINE([HAVE_PTHREAD_API], [1],
+ [Define if you have the <pthread.h> header and the POSIX threads API.])
+ fi
+ gl_threadlib_body_done=done
projects / deliverable / binutils-gdb.git / blobdiff