| # 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 LIBAT_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([LIBAT_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],-,_)[=][$2]) |
| m4_undefine([_g_switch])dnl |
| m4_undefine([_g_help])dnl |
| ]) |
| |
| dnl |
| dnl If GNU ld is in use, check to see if tricky linker opts can be used. If |
| dnl the native linker is in use, all variables will be defined to something |
| dnl safe (like an empty string). |
| dnl |
| dnl Defines: |
| dnl SECTION_LDFLAGS='-Wl,--gc-sections' if possible |
| dnl OPT_LDFLAGS='-Wl,-O1' if possible |
| dnl LD (as a side effect of testing) |
| dnl Sets: |
| dnl with_gnu_ld |
| dnl libat_ld_is_gold (possibly) |
| dnl libat_gnu_ld_version (possibly) |
| dnl |
| dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will |
| dnl set libat_gnu_ld_version to 12345. Zeros cause problems. |
| dnl |
| AC_DEFUN([LIBAT_CHECK_LINKER_FEATURES], [ |
| # If we're not using GNU ld, then there's no point in even trying these |
| # tests. Check for that first. We should have already tested for gld |
| # by now (in libtool), but require it now just to be safe... |
| test -z "$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/[. ][0-9]\{8\}$//;s/.* \([^ ]\{1,\}\)$/\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 $OPT_LDFLAGS" |
| fi |
| |
| AC_SUBST(SECTION_LDFLAGS) |
| AC_SUBST(OPT_LDFLAGS) |
| ]) |
| |
| |
| dnl |
| dnl If GNU ld is in use, check to see if tricky linker opts can be used. If |
| dnl the native linker is in use, all variables will be defined to something |
| dnl safe (like an empty string). |
| dnl |
| dnl Defines: |
| dnl SECTION_LDFLAGS='-Wl,--gc-sections' if possible |
| dnl OPT_LDFLAGS='-Wl,-O1' if possible |
| dnl LD (as a side effect of testing) |
| dnl Sets: |
| dnl with_gnu_ld |
| dnl libat_ld_is_gold (possibly) |
| dnl libat_gnu_ld_version (possibly) |
| dnl |
| dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will |
| dnl set libat_gnu_ld_version to 12345. Zeros cause problems. |
| dnl |
| AC_DEFUN([LIBAT_CHECK_LINKER_FEATURES], [ |
| # If we're not using GNU ld, then there's no point in even trying these |
| # tests. Check for that first. We should have already tested for gld |
| # by now (in libtool), but require it now just to be safe... |
| test -z "$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/[. ][0-9]\{8\}$//;s/.* \([^ ]\{1,\}\)$/\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: LIBAT_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([LIBAT_ENABLE_SYMVERS], [ |
| |
| LIBAT_ENABLE(symvers,yes,[=STYLE], |
| [enables symbol versioning of the shared library], |
| [permit yes|no|gnu*|sun]) |
| |
| # If we never went through the LIBAT_CHECK_LINKER_FEATURES macro, then we |
| # don't know enough about $LD to do tricks... |
| AC_REQUIRE([LIBAT_CHECK_LINKER_FEATURES]) |
| |
| # Turn a 'yes' into a suitable default. |
| if test x$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 |
| # LIBAT_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 |
| 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(LIBAT_GNU_SYMBOL_VERSIONING, 1, |
| [Define to 1 if GNU symbol versioning is used for libatomic.]) |
| fi |
| |
| AM_CONDITIONAL(LIBAT_BUILD_VERSIONED_SHLIB, test $enable_symvers != no) |
| AM_CONDITIONAL(LIBAT_BUILD_VERSIONED_SHLIB_GNU, test $enable_symvers = gnu) |
| AM_CONDITIONAL(LIBAT_BUILD_VERSIONED_SHLIB_SUN, test $enable_symvers = sun) |
| AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers) |
| ]) |
