|  | # mmap(2) blacklisting.  Some platforms provide the mmap library routine | 
|  | # but don't support all of the features we need from it. | 
|  | AC_DEFUN([AC_FUNC_MMAP_BLACKLIST], | 
|  | [ | 
|  | AC_CHECK_HEADER([sys/mman.h], | 
|  | [libffi_header_sys_mman_h=yes], [libffi_header_sys_mman_h=no]) | 
|  | AC_CHECK_FUNC([mmap], [libffi_func_mmap=yes], [libffi_func_mmap=no]) | 
|  | if test "$libffi_header_sys_mman_h" != yes \ | 
|  | || test "$libffi_func_mmap" != yes; then | 
|  | ac_cv_func_mmap_file=no | 
|  | ac_cv_func_mmap_dev_zero=no | 
|  | ac_cv_func_mmap_anon=no | 
|  | else | 
|  | AC_CACHE_CHECK([whether read-only mmap of a plain file works], | 
|  | ac_cv_func_mmap_file, | 
|  | [# Add a system to this blacklist if | 
|  | # mmap(0, stat_size, PROT_READ, MAP_PRIVATE, fd, 0) doesn't return a | 
|  | # memory area containing the same data that you'd get if you applied | 
|  | # read() to the same fd.  The only system known to have a problem here | 
|  | # is VMS, where text files have record structure. | 
|  | case "$host_os" in | 
|  | vms* | ultrix*) | 
|  | ac_cv_func_mmap_file=no ;; | 
|  | *) | 
|  | ac_cv_func_mmap_file=yes;; | 
|  | esac]) | 
|  | AC_CACHE_CHECK([whether mmap from /dev/zero works], | 
|  | ac_cv_func_mmap_dev_zero, | 
|  | [# Add a system to this blacklist if it has mmap() but /dev/zero | 
|  | # does not exist, or if mmapping /dev/zero does not give anonymous | 
|  | # zeroed pages with both the following properties: | 
|  | # 1. If you map N consecutive pages in with one call, and then | 
|  | #    unmap any subset of those pages, the pages that were not | 
|  | #    explicitly unmapped remain accessible. | 
|  | # 2. If you map two adjacent blocks of memory and then unmap them | 
|  | #    both at once, they must both go away. | 
|  | # Systems known to be in this category are Windows (all variants), | 
|  | # VMS, and Darwin. | 
|  | case "$host_os" in | 
|  | vms* | cygwin* | pe | mingw* | darwin* | ultrix* | hpux10* | hpux11.00) | 
|  | ac_cv_func_mmap_dev_zero=no ;; | 
|  | *) | 
|  | ac_cv_func_mmap_dev_zero=yes;; | 
|  | esac]) | 
|  |  | 
|  | # Unlike /dev/zero, the MAP_ANON(YMOUS) defines can be probed for. | 
|  | AC_CACHE_CHECK([for MAP_ANON(YMOUS)], ac_cv_decl_map_anon, | 
|  | [AC_TRY_COMPILE( | 
|  | [#include <sys/types.h> | 
|  | #include <sys/mman.h> | 
|  | #include <unistd.h> | 
|  |  | 
|  | #ifndef MAP_ANONYMOUS | 
|  | #define MAP_ANONYMOUS MAP_ANON | 
|  | #endif | 
|  | ], | 
|  | [int n = MAP_ANONYMOUS;], | 
|  | ac_cv_decl_map_anon=yes, | 
|  | ac_cv_decl_map_anon=no)]) | 
|  |  | 
|  | if test $ac_cv_decl_map_anon = no; then | 
|  | ac_cv_func_mmap_anon=no | 
|  | else | 
|  | AC_CACHE_CHECK([whether mmap with MAP_ANON(YMOUS) works], | 
|  | ac_cv_func_mmap_anon, | 
|  | [# Add a system to this blacklist if it has mmap() and MAP_ANON or | 
|  | # MAP_ANONYMOUS, but using mmap(..., MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) | 
|  | # doesn't give anonymous zeroed pages with the same properties listed | 
|  | # above for use of /dev/zero. | 
|  | # Systems known to be in this category are Windows, VMS, and SCO Unix. | 
|  | case "$host_os" in | 
|  | vms* | cygwin* | pe | mingw* | sco* | udk* ) | 
|  | ac_cv_func_mmap_anon=no ;; | 
|  | *) | 
|  | ac_cv_func_mmap_anon=yes;; | 
|  | esac]) | 
|  | fi | 
|  | fi | 
|  |  | 
|  | if test $ac_cv_func_mmap_file = yes; then | 
|  | AC_DEFINE(HAVE_MMAP_FILE, 1, | 
|  | [Define if read-only mmap of a plain file works.]) | 
|  | fi | 
|  | if test $ac_cv_func_mmap_dev_zero = yes; then | 
|  | AC_DEFINE(HAVE_MMAP_DEV_ZERO, 1, | 
|  | [Define if mmap of /dev/zero works.]) | 
|  | fi | 
|  | if test $ac_cv_func_mmap_anon = yes; then | 
|  | AC_DEFINE(HAVE_MMAP_ANON, 1, | 
|  | [Define if mmap with MAP_ANON(YMOUS) works.]) | 
|  | fi | 
|  | ]) | 
|  |  | 
|  | dnl ---------------------------------------------------------------------- | 
|  | dnl This whole bit snagged from libstdc++-v3, via libatomic. | 
|  |  | 
|  | dnl | 
|  | dnl LIBFFI_ENABLE | 
|  | dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING) | 
|  | dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, permit a|b|c) | 
|  | dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, SHELL-CODE-HANDLER) | 
|  | dnl | 
|  | dnl See docs/html/17_intro/configury.html#enable for documentation. | 
|  | dnl | 
|  | m4_define([LIBFFI_ENABLE],[dnl | 
|  | m4_define([_g_switch],[--enable-$1])dnl | 
|  | m4_define([_g_help],[AC_HELP_STRING(_g_switch$3,[$4 @<:@default=$2@:>@])])dnl | 
|  | AC_ARG_ENABLE($1,_g_help, | 
|  | m4_bmatch([$5], | 
|  | [^permit ], | 
|  | [[ | 
|  | case "$enableval" in | 
|  | m4_bpatsubst([$5],[permit ])) ;; | 
|  | *) AC_MSG_ERROR(Unknown argument to enable/disable $1) ;; | 
|  | dnl Idea for future:  generate a URL pointing to | 
|  | dnl "onlinedocs/configopts.html#whatever" | 
|  | esac | 
|  | ]], | 
|  | [^$], | 
|  | [[ | 
|  | case "$enableval" in | 
|  | yes|no) ;; | 
|  | *) AC_MSG_ERROR(Argument to enable/disable $1 must be yes or no) ;; | 
|  | esac | 
|  | ]], | 
|  | [[$5]]), | 
|  | [enable_]m4_bpatsubst([$1],-,_)[=][$2]) | 
|  | m4_undefine([_g_switch])dnl | 
|  | m4_undefine([_g_help])dnl | 
|  | ]) | 
|  |  | 
|  | dnl | 
|  | dnl If GNU ld is in use, check to see if tricky linker opts can be used.  If | 
|  | dnl the native linker is in use, all variables will be defined to something | 
|  | dnl safe (like an empty string). | 
|  | dnl | 
|  | dnl Defines: | 
|  | dnl  SECTION_LDFLAGS='-Wl,--gc-sections' if possible | 
|  | dnl  OPT_LDFLAGS='-Wl,-O1' if possible | 
|  | dnl  LD (as a side effect of testing) | 
|  | dnl Sets: | 
|  | dnl  with_gnu_ld | 
|  | dnl  libat_ld_is_gold (possibly) | 
|  | dnl  libat_gnu_ld_version (possibly) | 
|  | dnl | 
|  | dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will | 
|  | dnl set libat_gnu_ld_version to 12345.  Zeros cause problems. | 
|  | dnl | 
|  | AC_DEFUN([LIBFFI_CHECK_LINKER_FEATURES], [ | 
|  | # If we're not using GNU ld, then there's no point in even trying these | 
|  | # tests.  Check for that first.  We should have already tested for gld | 
|  | # by now (in libtool), but require it now just to be safe... | 
|  | test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS='' | 
|  | test -z "$OPT_LDFLAGS" && OPT_LDFLAGS='' | 
|  | AC_REQUIRE([AC_PROG_LD]) | 
|  | AC_REQUIRE([AC_PROG_AWK]) | 
|  |  | 
|  | # The name set by libtool depends on the version of libtool.  Shame on us | 
|  | # for depending on an impl detail, but c'est la vie.  Older versions used | 
|  | # ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on | 
|  | # top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually | 
|  | # makes sense).  We'll test with_gnu_ld everywhere else, so if that isn't | 
|  | # set (hence we're using an older libtool), then set it. | 
|  | if test x${with_gnu_ld+set} != xset; then | 
|  | if test x${ac_cv_prog_gnu_ld+set} != xset; then | 
|  | # We got through "ac_require(ac_prog_ld)" and still not set?  Huh? | 
|  | with_gnu_ld=no | 
|  | else | 
|  | with_gnu_ld=$ac_cv_prog_gnu_ld | 
|  | fi | 
|  | fi | 
|  |  | 
|  | # Start by getting the version number.  I think the libtool test already | 
|  | # does some of this, but throws away the result. | 
|  | libat_ld_is_gold=no | 
|  | if $LD --version 2>/dev/null | grep 'GNU gold'> /dev/null 2>&1; then | 
|  | libat_ld_is_gold=yes | 
|  | fi | 
|  | changequote(,) | 
|  | ldver=`$LD --version 2>/dev/null | | 
|  | sed -e 's/GNU gold /GNU ld /;s/GNU ld version /GNU ld /;s/GNU ld ([^)]*) /GNU ld /;s/GNU ld \([0-9.][0-9.]*\).*/\1/; q'` | 
|  | changequote([,]) | 
|  | libat_gnu_ld_version=`echo $ldver | \ | 
|  | $AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'` | 
|  |  | 
|  | # Set --gc-sections. | 
|  | if test "$with_gnu_ld" = "notbroken"; then | 
|  | # GNU ld it is!  Joy and bunny rabbits! | 
|  |  | 
|  | # All these tests are for C++; save the language and the compiler flags. | 
|  | # Need to do this so that g++ won't try to link in libstdc++ | 
|  | ac_test_CFLAGS="${CFLAGS+set}" | 
|  | ac_save_CFLAGS="$CFLAGS" | 
|  | CFLAGS='-x c++  -Wl,--gc-sections' | 
|  |  | 
|  | # Check for -Wl,--gc-sections | 
|  | # XXX This test is broken at the moment, as symbols required for linking | 
|  | # are now in libsupc++ (not built yet).  In addition, this test has | 
|  | # cored on solaris in the past.  In addition, --gc-sections doesn't | 
|  | # really work at the moment (keeps on discarding used sections, first | 
|  | # .eh_frame and now some of the glibc sections for iconv). | 
|  | # Bzzzzt.  Thanks for playing, maybe next time. | 
|  | AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections]) | 
|  | AC_TRY_RUN([ | 
|  | int main(void) | 
|  | { | 
|  | try { throw 1; } | 
|  | catch (...) { }; | 
|  | return 0; | 
|  | } | 
|  | ], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes]) | 
|  | if test "$ac_test_CFLAGS" = set; then | 
|  | CFLAGS="$ac_save_CFLAGS" | 
|  | else | 
|  | # this is the suspicious part | 
|  | CFLAGS='' | 
|  | fi | 
|  | if test "$ac_sectionLDflags" = "yes"; then | 
|  | SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS" | 
|  | fi | 
|  | AC_MSG_RESULT($ac_sectionLDflags) | 
|  | fi | 
|  |  | 
|  | # Set linker optimization flags. | 
|  | if test x"$with_gnu_ld" = x"yes"; then | 
|  | OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS" | 
|  | fi | 
|  |  | 
|  | AC_SUBST(SECTION_LDFLAGS) | 
|  | AC_SUBST(OPT_LDFLAGS) | 
|  | ]) | 
|  |  | 
|  |  | 
|  | dnl | 
|  | dnl If GNU ld is in use, check to see if tricky linker opts can be used.  If | 
|  | dnl the native linker is in use, all variables will be defined to something | 
|  | dnl safe (like an empty string). | 
|  | dnl | 
|  | dnl Defines: | 
|  | dnl  SECTION_LDFLAGS='-Wl,--gc-sections' if possible | 
|  | dnl  OPT_LDFLAGS='-Wl,-O1' if possible | 
|  | dnl  LD (as a side effect of testing) | 
|  | dnl Sets: | 
|  | dnl  with_gnu_ld | 
|  | dnl  libat_ld_is_gold (possibly) | 
|  | dnl  libat_gnu_ld_version (possibly) | 
|  | dnl | 
|  | dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will | 
|  | dnl set libat_gnu_ld_version to 12345.  Zeros cause problems. | 
|  | dnl | 
|  | AC_DEFUN([LIBFFI_CHECK_LINKER_FEATURES], [ | 
|  | # If we're not using GNU ld, then there's no point in even trying these | 
|  | # tests.  Check for that first.  We should have already tested for gld | 
|  | # by now (in libtool), but require it now just to be safe... | 
|  | test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS='' | 
|  | test -z "$OPT_LDFLAGS" && OPT_LDFLAGS='' | 
|  | AC_REQUIRE([AC_PROG_LD]) | 
|  | AC_REQUIRE([AC_PROG_AWK]) | 
|  |  | 
|  | # The name set by libtool depends on the version of libtool.  Shame on us | 
|  | # for depending on an impl detail, but c'est la vie.  Older versions used | 
|  | # ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on | 
|  | # top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually | 
|  | # makes sense).  We'll test with_gnu_ld everywhere else, so if that isn't | 
|  | # set (hence we're using an older libtool), then set it. | 
|  | if test x${with_gnu_ld+set} != xset; then | 
|  | if test x${ac_cv_prog_gnu_ld+set} != xset; then | 
|  | # We got through "ac_require(ac_prog_ld)" and still not set?  Huh? | 
|  | with_gnu_ld=no | 
|  | else | 
|  | with_gnu_ld=$ac_cv_prog_gnu_ld | 
|  | fi | 
|  | fi | 
|  |  | 
|  | # Start by getting the version number.  I think the libtool test already | 
|  | # does some of this, but throws away the result. | 
|  | libat_ld_is_gold=no | 
|  | if $LD --version 2>/dev/null | grep 'GNU gold'> /dev/null 2>&1; then | 
|  | libat_ld_is_gold=yes | 
|  | fi | 
|  | libat_ld_is_lld=no | 
|  | if $LD --version 2>/dev/null | grep 'LLD '> /dev/null 2>&1; then | 
|  | libat_ld_is_lld=yes | 
|  | fi | 
|  | changequote(,) | 
|  | ldver=`$LD --version 2>/dev/null | | 
|  | sed -e 's/GNU gold /GNU ld /;s/GNU ld version /GNU ld /;s/GNU ld ([^)]*) /GNU ld /;s/GNU ld \([0-9.][0-9.]*\).*/\1/; q'` | 
|  | changequote([,]) | 
|  | libat_gnu_ld_version=`echo $ldver | \ | 
|  | $AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'` | 
|  |  | 
|  | # Set --gc-sections. | 
|  | if test "$with_gnu_ld" = "notbroken"; then | 
|  | # GNU ld it is!  Joy and bunny rabbits! | 
|  |  | 
|  | # All these tests are for C++; save the language and the compiler flags. | 
|  | # Need to do this so that g++ won't try to link in libstdc++ | 
|  | ac_test_CFLAGS="${CFLAGS+set}" | 
|  | ac_save_CFLAGS="$CFLAGS" | 
|  | CFLAGS='-x c++  -Wl,--gc-sections' | 
|  |  | 
|  | # Check for -Wl,--gc-sections | 
|  | # XXX This test is broken at the moment, as symbols required for linking | 
|  | # are now in libsupc++ (not built yet).  In addition, this test has | 
|  | # cored on solaris in the past.  In addition, --gc-sections doesn't | 
|  | # really work at the moment (keeps on discarding used sections, first | 
|  | # .eh_frame and now some of the glibc sections for iconv). | 
|  | # Bzzzzt.  Thanks for playing, maybe next time. | 
|  | AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections]) | 
|  | AC_TRY_RUN([ | 
|  | int main(void) | 
|  | { | 
|  | try { throw 1; } | 
|  | catch (...) { }; | 
|  | return 0; | 
|  | } | 
|  | ], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes]) | 
|  | if test "$ac_test_CFLAGS" = set; then | 
|  | CFLAGS="$ac_save_CFLAGS" | 
|  | else | 
|  | # this is the suspicious part | 
|  | CFLAGS='' | 
|  | fi | 
|  | if test "$ac_sectionLDflags" = "yes"; then | 
|  | SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS" | 
|  | fi | 
|  | AC_MSG_RESULT($ac_sectionLDflags) | 
|  | fi | 
|  |  | 
|  | # Set linker optimization flags. | 
|  | if test x"$with_gnu_ld" = x"yes"; then | 
|  | OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS" | 
|  | fi | 
|  |  | 
|  | AC_SUBST(SECTION_LDFLAGS) | 
|  | AC_SUBST(OPT_LDFLAGS) | 
|  | ]) | 
|  |  | 
|  |  | 
|  | dnl | 
|  | dnl Add version tags to symbols in shared library (or not), additionally | 
|  | dnl marking other symbols as private/local (or not). | 
|  | dnl | 
|  | dnl --enable-symvers=style adds a version script to the linker call when | 
|  | dnl       creating the shared library.  The choice of version script is | 
|  | dnl       controlled by 'style'. | 
|  | dnl --disable-symvers does not. | 
|  | dnl  +  Usage:  LIBFFI_ENABLE_SYMVERS[(DEFAULT)] | 
|  | dnl       Where DEFAULT is either 'yes' or 'no'.  Passing `yes' tries to | 
|  | dnl       choose a default style based on linker characteristics.  Passing | 
|  | dnl       'no' disables versioning. | 
|  | dnl | 
|  | AC_DEFUN([LIBFFI_ENABLE_SYMVERS], [ | 
|  |  | 
|  | LIBFFI_ENABLE(symvers,yes,[=STYLE], | 
|  | [enables symbol versioning of the shared library], | 
|  | [permit yes|no|gnu*|sun]) | 
|  |  | 
|  | # If we never went through the LIBFFI_CHECK_LINKER_FEATURES macro, then we | 
|  | # don't know enough about $LD to do tricks... | 
|  | AC_REQUIRE([LIBFFI_CHECK_LINKER_FEATURES]) | 
|  |  | 
|  | # Turn a 'yes' into a suitable default. | 
|  | if test x$enable_symvers = xyes ; then | 
|  | # FIXME  The following test is too strict, in theory. | 
|  | if test $enable_shared = no || test "x$LD" = x; then | 
|  | enable_symvers=no | 
|  | else | 
|  | if test $with_gnu_ld = yes ; then | 
|  | enable_symvers=gnu | 
|  | else | 
|  | case ${target_os} in | 
|  | # Sun symbol versioning exists since Solaris 2.5. | 
|  | solaris2.[[5-9]]* | solaris2.1[[0-9]]*) | 
|  | enable_symvers=sun ;; | 
|  | *) | 
|  | enable_symvers=no ;; | 
|  | esac | 
|  | fi | 
|  | fi | 
|  | fi | 
|  |  | 
|  | # Check if 'sun' was requested on non-Solaris 2 platforms. | 
|  | if test x$enable_symvers = xsun ; then | 
|  | case ${target_os} in | 
|  | solaris2*) | 
|  | # All fine. | 
|  | ;; | 
|  | *) | 
|  | # Unlikely to work. | 
|  | AC_MSG_WARN([=== You have requested Sun symbol versioning, but]) | 
|  | AC_MSG_WARN([=== you are not targetting Solaris 2.]) | 
|  | AC_MSG_WARN([=== Symbol versioning will be disabled.]) | 
|  | enable_symvers=no | 
|  | ;; | 
|  | esac | 
|  | fi | 
|  |  | 
|  | # Check to see if libgcc_s exists, indicating that shared libgcc is possible. | 
|  | if test $enable_symvers != no; then | 
|  | AC_MSG_CHECKING([for shared libgcc]) | 
|  | ac_save_CFLAGS="$CFLAGS" | 
|  | CFLAGS=' -lgcc_s' | 
|  | AC_TRY_LINK(, [return 0;], libat_shared_libgcc=yes, libat_shared_libgcc=no) | 
|  | CFLAGS="$ac_save_CFLAGS" | 
|  | if test $libat_shared_libgcc = no; then | 
|  | cat > conftest.c <<EOF | 
|  | int main (void) { return 0; } | 
|  | EOF | 
|  | changequote(,)dnl | 
|  | libat_libgcc_s_suffix=`${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \ | 
|  | -shared -shared-libgcc -o conftest.so \ | 
|  | conftest.c -v 2>&1 >/dev/null \ | 
|  | | sed -n 's/^.* -lgcc_s\([^ ]*\) .*$/\1/p'` | 
|  | changequote([,])dnl | 
|  | rm -f conftest.c conftest.so | 
|  | if test x${libat_libgcc_s_suffix+set} = xset; then | 
|  | CFLAGS=" -lgcc_s$libat_libgcc_s_suffix" | 
|  | AC_TRY_LINK(, [return 0;], libat_shared_libgcc=yes) | 
|  | CFLAGS="$ac_save_CFLAGS" | 
|  | fi | 
|  | fi | 
|  | AC_MSG_RESULT($libat_shared_libgcc) | 
|  | fi | 
|  |  | 
|  | # For GNU ld, we need at least this version.  The format is described in | 
|  | # LIBFFI_CHECK_LINKER_FEATURES above. | 
|  | libat_min_gnu_ld_version=21400 | 
|  | # XXXXXXXXXXX libat_gnu_ld_version=21390 | 
|  |  | 
|  | # Check to see if unspecified "yes" value can win, given results above. | 
|  | # Change "yes" into either "no" or a style name. | 
|  | if test $enable_symvers != no && test $libat_shared_libgcc = yes; then | 
|  | if test $with_gnu_ld = yes; then | 
|  | if test $libat_gnu_ld_version -ge $libat_min_gnu_ld_version ; then | 
|  | enable_symvers=gnu | 
|  | elif test $libat_ld_is_gold = yes ; then | 
|  | enable_symvers=gnu | 
|  | elif test $libat_ld_is_lld = yes ; then | 
|  | enable_symvers=gnu | 
|  | else | 
|  | # The right tools, the right setup, but too old.  Fallbacks? | 
|  | AC_MSG_WARN(=== Linker version $libat_gnu_ld_version is too old for) | 
|  | AC_MSG_WARN(=== full symbol versioning support in this release of GCC.) | 
|  | AC_MSG_WARN(=== You would need to upgrade your binutils to version) | 
|  | AC_MSG_WARN(=== $libat_min_gnu_ld_version or later and rebuild GCC.) | 
|  | if test $libat_gnu_ld_version -ge 21200 ; then | 
|  | # Globbing fix is present, proper block support is not. | 
|  | dnl AC_MSG_WARN([=== Dude, you are soooo close.  Maybe we can fake it.]) | 
|  | dnl enable_symvers=??? | 
|  | AC_MSG_WARN([=== Symbol versioning will be disabled.]) | 
|  | enable_symvers=no | 
|  | else | 
|  | # 2.11 or older. | 
|  | AC_MSG_WARN([=== Symbol versioning will be disabled.]) | 
|  | enable_symvers=no | 
|  | fi | 
|  | fi | 
|  | elif test $enable_symvers = sun; then | 
|  | : All interesting versions of Sun ld support sun style symbol versioning. | 
|  | else | 
|  | # just fail for now | 
|  | AC_MSG_WARN([=== You have requested some kind of symbol versioning, but]) | 
|  | AC_MSG_WARN([=== either you are not using a supported linker, or you are]) | 
|  | AC_MSG_WARN([=== not building a shared libgcc_s (which is required).]) | 
|  | AC_MSG_WARN([=== Symbol versioning will be disabled.]) | 
|  | enable_symvers=no | 
|  | fi | 
|  | fi | 
|  | if test $enable_symvers = gnu; then | 
|  | AC_DEFINE(LIBFFI_GNU_SYMBOL_VERSIONING, 1, | 
|  | [Define to 1 if GNU symbol versioning is used for libatomic.]) | 
|  | fi | 
|  |  | 
|  | AM_CONDITIONAL(LIBFFI_BUILD_VERSIONED_SHLIB, test $enable_symvers != no) | 
|  | AM_CONDITIONAL(LIBFFI_BUILD_VERSIONED_SHLIB_GNU, test $enable_symvers = gnu) | 
|  | AM_CONDITIONAL(LIBFFI_BUILD_VERSIONED_SHLIB_SUN, test $enable_symvers = sun) | 
|  | AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers) | 
|  | ]) |