-
- # The next part tries to detect GCC inconsistency with -shared on some
- # architectures and systems. The problem is that in certain
- # configurations, when -shared is specified, GCC "forgets" to
- # internally use various flags which are still necessary.
-
- # First, check whether caller wants us to skip -shared checks
- # this is useful
- AC_MSG_CHECKING([whether to check for GCC pthread/shared inconsistencies])
- if test x"$3" = x1; then
- AC_MSG_RESULT([no])
- else
- AC_MSG_RESULT([yes])
-
- # In order not to create several levels of indentation, we test
- # the value of "$ok" until we find out the cure or run out of
- # ideas.
- ok="no"
-
- #
- # Prepare the flags
- #
- save_CFLAGS="$CFLAGS"
- save_LIBS="$LIBS"
- save_CC="$CC"
- # Try with the flags determined by the earlier checks.
- #
- # -Wl,-z,defs forces link-time symbol resolution, so that the
- # linking checks with -shared actually have any value
- #
- # FIXME: -fPIC is required for -shared on many architectures,
- # so we specify it here, but the right way would probably be to
- # properly detect whether it is actually required.
- CFLAGS="-shared -fPIC -Wl,-z,defs $CFLAGS $PTHREAD_CFLAGS"
- LIBS="$PTHREAD_LIBS $LIBS"
- CC="$PTHREAD_CC"
-
- AC_MSG_CHECKING([whether -pthread is sufficient with -shared])
- 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); ],
- [ok=yes])
-
- if test "x$ok" = xyes; then
- AC_MSG_RESULT([yes])
- else
- AC_MSG_RESULT([no])
- fi
-
- #
- # Linux gcc on some architectures such as mips/mipsel forgets
- # about -lpthread
- #
- if test x"$ok" = xno; then
- AC_MSG_CHECKING([whether -lpthread fixes that])
- LIBS="-lpthread $PTHREAD_LIBS $save_LIBS"
- AC_TRY_LINK([#include <pthread.h>],
- [pthread_t th; pthread_join(th, 0);
- pthread_attr_init(0); pthread_cleanup_push(0, 0);
- pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
- [ok=yes])
-
- if test "x$ok" = xyes; then
- AC_MSG_RESULT([yes])
- PTHREAD_LIBS="-lpthread $PTHREAD_LIBS"
- else
- AC_MSG_RESULT([no])
- fi
- fi
- #
- # FreeBSD 4.10 gcc forgets to use -lc_r instead of -lc
- #
- if test x"$ok" = xno; then
- AC_MSG_CHECKING([whether -lc_r fixes that])
- LIBS="-lc_r $PTHREAD_LIBS $save_LIBS"
- AC_TRY_LINK([#include <pthread.h>],
- [pthread_t th; pthread_join(th, 0);
- pthread_attr_init(0); pthread_cleanup_push(0, 0);
- pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
- [ok=yes])
-
- if test "x$ok" = xyes; then
- AC_MSG_RESULT([yes])
- PTHREAD_LIBS="-lc_r $PTHREAD_LIBS"
- else
- AC_MSG_RESULT([no])
- fi
- fi
- if test x"$ok" = xno; then
- # OK, we have run out of ideas
- AC_MSG_WARN([Impossible to determine how to use pthreads with shared libraries])
-
- # so it's not safe to assume that we may use pthreads
- acx_pthread_ok=no
- fi
-
- CFLAGS="$save_CFLAGS"
- LIBS="$save_LIBS"
- CC="$save_CC"
- fi