|  | dnl | 
|  | dnl Unconditionally define a preprocessor macro, translating the shell | 
|  | dnl macro from yes/no to 1/0. | 
|  | dnl | 
|  | AC_DEFUN([LIBAT_DEFINE_YESNO], [ | 
|  | yesno=`echo $2 | tr 'yesno' '1  0 '` | 
|  | AC_DEFINE_UNQUOTED([$1], $yesno, [$3]) | 
|  | ]) | 
|  | dnl | 
|  | dnl Iterate over all of the modes we're prepared to check. | 
|  | dnl | 
|  | AC_DEFUN([LIBAT_FORALL_MODES], | 
|  | [$1(QI,1) | 
|  | $1(HI,2) | 
|  | $1(SI,4) | 
|  | $1(DI,8) | 
|  | $1(TI,16)] | 
|  | ) | 
|  | dnl | 
|  | dnl Check for builtin types by mode. | 
|  | dnl | 
|  | dnl A less interesting of size checking than autoconf normally provides. | 
|  | dnl We know that gcc always provides <stdint.h>, but we don't often | 
|  | dnl provide a builtin type for TImode. | 
|  | dnl | 
|  | AC_DEFUN([LIBAT_HAVE_INT_MODE],[ | 
|  | AC_CACHE_CHECK([for $2 byte integer],[libat_cv_have_mode_$1], | 
|  | [AC_COMPILE_IFELSE([AC_LANG_SOURCE([int x __attribute__((mode($1)));])], | 
|  | [libat_cv_have_mode_$1=yes],[libat_cv_have_mode_$1=no])]) | 
|  | LIBAT_DEFINE_YESNO([HAVE_INT$2], [$libat_cv_have_mode_$1], | 
|  | [Have support for $2 byte integers.]) | 
|  | if test x$libat_cv_have_mode_$1 = xyes; then | 
|  | SIZES="$SIZES $2" | 
|  | fi | 
|  | ]) | 
|  | dnl | 
|  | dnl Check for atomic builtins. | 
|  | dnl See: | 
|  | dnl http://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html | 
|  | dnl | 
|  | dnl This checks to see if the host supports the compiler-generated | 
|  | dnl builtins for atomic operations for various integral sizes. | 
|  | dnl | 
|  | AC_DEFUN([LIBAT_TEST_ATOMIC_INIT],[ | 
|  | # Do link tests if possible, instead asm tests, limited to some platforms | 
|  | # see discussion in PR target/40134, PR libstdc++/40133 and the thread | 
|  | # starting at http://gcc.gnu.org/ml/gcc-patches/2009-07/msg00322.html | 
|  | atomic_builtins_link_tests=no | 
|  | if test x$gcc_no_link != xyes; then | 
|  | # Can do link tests. Limit to some tested platforms | 
|  | case "$host" in | 
|  | *-*-linux* | *-*-uclinux* | *-*-kfreebsd*-gnu | *-*-gnu*) | 
|  | atomic_builtins_link_tests=yes | 
|  | ;; | 
|  | esac | 
|  | fi | 
|  | ]) | 
|  | AC_DEFUN([LIBAT_TEST_ATOMIC_BUILTIN],[ | 
|  | AC_CACHE_CHECK([$1],[$2],[ | 
|  | AC_LANG_CONFTEST([AC_LANG_PROGRAM([],[$3])]) | 
|  | if test x$atomic_builtins_link_tests = xyes; then | 
|  | if AC_TRY_EVAL(ac_link); then | 
|  | eval $2=yes | 
|  | else | 
|  | eval $2=no | 
|  | fi | 
|  | else | 
|  | old_CFLAGS="$CFLAGS" | 
|  | # Compile unoptimized. | 
|  | CFLAGS="$CFLAGS -O0 -S" | 
|  | if AC_TRY_EVAL(ac_compile); then | 
|  | if grep __atomic_ conftest.s >/dev/null 2>&1 ; then | 
|  | eval $2=no | 
|  | else | 
|  | eval $2=yes | 
|  | fi | 
|  | else | 
|  | eval $2=no | 
|  | fi | 
|  | CFLAGS="$old_CFLAGS" | 
|  | fi | 
|  | rm -f conftest* | 
|  | ]) | 
|  | ]) | 
|  |  | 
|  | dnl | 
|  | dnl Test if we have __atomic_load and __atomic_store for mode $1, size $2 | 
|  | dnl | 
|  | AC_DEFUN([LIBAT_HAVE_ATOMIC_LOADSTORE],[ | 
|  | LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_load/store for size $2], | 
|  | [libat_cv_have_at_ldst_$2], | 
|  | [typedef int T __attribute__((mode($1))); | 
|  | T *x; volatile T sink; asm("" : "=g"(x)); | 
|  | sink = __atomic_load_n(x, 0); | 
|  | __atomic_store_n(x, sink, 0);]) | 
|  | LIBAT_DEFINE_YESNO([HAVE_ATOMIC_LDST_$2], [$libat_cv_have_at_ldst_$2], | 
|  | [Have __atomic_load/store for $2 byte integers.]) | 
|  | AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_LDST_$2 HAVE_ATOMIC_LDST_$2]) | 
|  | AH_BOTTOM([#define FAST_ATOMIC_LDST_$2 HAVE_ATOMIC_LDST_$2]) | 
|  | ]) | 
|  |  | 
|  | dnl | 
|  | dnl Test if we have __atomic_test_and_set for mode $1, size $2 | 
|  | dnl | 
|  | AC_DEFUN([LIBAT_HAVE_ATOMIC_TAS],[ | 
|  | LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_test_and_set for size $2], | 
|  | [libat_cv_have_at_tas_$2], | 
|  | [typedef int T __attribute__((mode($1))); T *x; asm("" : "=g"(x)); | 
|  | __atomic_test_and_set(x, 0);]) | 
|  | LIBAT_DEFINE_YESNO([HAVE_ATOMIC_TAS_$2], [$libat_cv_have_at_tas_$2], | 
|  | [Have __atomic_test_and_set for $2 byte integers.]) | 
|  | AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_TAS_$2 HAVE_ATOMIC_TAS_$2]) | 
|  | ]) | 
|  |  | 
|  | dnl | 
|  | dnl Test if we have __atomic_exchange for mode $1, size $2 | 
|  | dnl | 
|  | AC_DEFUN([LIBAT_HAVE_ATOMIC_EXCHANGE],[ | 
|  | LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_exchange for size $2], | 
|  | [libat_cv_have_at_exch_$2], | 
|  | [typedef int T __attribute__((mode($1))); T *x; asm("" : "=g"(x)); | 
|  | __atomic_exchange_n(x, 0, 0);]) | 
|  | LIBAT_DEFINE_YESNO([HAVE_ATOMIC_EXCHANGE_$2], [$libat_cv_have_at_exch_$2], | 
|  | [Have __atomic_exchange for $2 byte integers.]) | 
|  | AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_EXCHANGE_$2 HAVE_ATOMIC_EXCHANGE_$2]) | 
|  | ]) | 
|  |  | 
|  | dnl | 
|  | dnl Test if we have __atomic_compare_exchange for mode $1, size $2 | 
|  | dnl | 
|  | AC_DEFUN([LIBAT_HAVE_ATOMIC_CAS],[ | 
|  | LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_compare_exchange for size $2], | 
|  | [libat_cv_have_at_cas_$2], | 
|  | [typedef int T __attribute__((mode($1))); T *x, *y; | 
|  | asm("" : "=g"(x), "=g"(y)); | 
|  | __atomic_compare_exchange_n(x, y, 0, 0, 0, 0);]) | 
|  | LIBAT_DEFINE_YESNO([HAVE_ATOMIC_CAS_$2], [$libat_cv_have_at_cas_$2], | 
|  | [Have __atomic_compare_exchange for $2 byte integers.]) | 
|  | AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_CAS_$2 HAVE_ATOMIC_CAS_$2]) | 
|  | ]) | 
|  |  | 
|  | dnl | 
|  | dnl Test if we have __atomic_fetch_add for mode $1, size $2 | 
|  | dnl | 
|  | AC_DEFUN([LIBAT_HAVE_ATOMIC_FETCH_ADD],[ | 
|  | LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_fetch_add for size $2], | 
|  | [libat_cv_have_at_fadd_$2], | 
|  | [typedef int T __attribute__((mode($1))); T *x, y; | 
|  | asm("" : "=g"(x), "=g"(y)); | 
|  | __atomic_fetch_add (x, y, 0); | 
|  | __atomic_add_fetch (x, y, 0);]) | 
|  | LIBAT_DEFINE_YESNO([HAVE_ATOMIC_FETCH_ADD_$2], [$libat_cv_have_at_fadd_$2], | 
|  | [Have __atomic_fetch_add for $2 byte integers.]) | 
|  | AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_FETCH_ADD_$2 HAVE_ATOMIC_FETCH_ADD_$2]) | 
|  | ]) | 
|  |  | 
|  | dnl | 
|  | dnl Test if we have __atomic_fetch_op for all op for mode $1, size $2 | 
|  | dnl | 
|  | AC_DEFUN([LIBAT_HAVE_ATOMIC_FETCH_OP],[ | 
|  | LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_fetch_op for size $2], | 
|  | [libat_cv_have_at_fop_$2], | 
|  | [typedef int T __attribute__((mode($1))); T *x, y; | 
|  | asm("" : "=g"(x), "=g"(y)); | 
|  | __atomic_fetch_add (x, y, 0); __atomic_add_fetch (x, y, 0); | 
|  | __atomic_fetch_sub (x, y, 0); __atomic_sub_fetch (x, y, 0); | 
|  | __atomic_fetch_and (x, y, 0); __atomic_and_fetch (x, y, 0); | 
|  | __atomic_fetch_nand (x, y, 0); __atomic_nand_fetch (x, y, 0); | 
|  | __atomic_fetch_xor (x, y, 0); __atomic_xor_fetch (x, y, 0); | 
|  | __atomic_fetch_or (x, y, 0);  __atomic_or_fetch (x, y, 0); ]) | 
|  | LIBAT_DEFINE_YESNO([HAVE_ATOMIC_FETCH_OP_$2], [$libat_cv_have_at_fop_$2], | 
|  | [Have __atomic_fetch_op for all op for $2 byte integers.]) | 
|  | AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_FETCH_OP_$2 HAVE_ATOMIC_FETCH_OP_$2]) | 
|  | ]) | 
|  |  | 
|  | dnl | 
|  | dnl Test for the size of the target word. | 
|  | dnl | 
|  | AC_DEFUN([LIBAT_WORDSIZE],[ | 
|  | AC_CACHE_CHECK([for the word size],[libat_cv_wordsize], | 
|  | [AC_COMPUTE_INT(libat_cv_wordsize, | 
|  | [sizeof(word)], [typedef int word __attribute__((mode(word)));], | 
|  | AC_ERROR([Could not determine word size.]))]) | 
|  | AC_DEFINE_UNQUOTED(WORDSIZE, $libat_cv_wordsize, | 
|  | [The word size in bytes of the machine.]) | 
|  | ]) | 
|  |  | 
|  | dnl | 
|  | dnl Check whether the target supports the ifunc attribute. | 
|  | dnl | 
|  | AC_DEFUN([LIBAT_CHECK_IFUNC], [ | 
|  | AC_CACHE_CHECK([whether the target supports the ifunc attribute], | 
|  | libat_cv_have_ifunc, [ | 
|  | save_CFLAGS="$CFLAGS" | 
|  | CFLAGS="$CFLAGS -Werror" | 
|  | AC_TRY_LINK([ | 
|  | int foo_alt(void) { return 0; } | 
|  | typedef int F (void); | 
|  | F *foo_sel(void) { return foo_alt; } | 
|  | int foo(void) __attribute__((ifunc("foo_sel")));], | 
|  | [return foo();], libat_cv_have_ifunc=yes, libat_cv_have_ifunc=no)]) | 
|  | LIBAT_DEFINE_YESNO([HAVE_IFUNC], [$libat_cv_have_ifunc], | 
|  | [Define to 1 if the target supports __attribute__((ifunc(...))).]) | 
|  | ]) | 
|  |  | 
|  | dnl ---------------------------------------------------------------------- | 
|  | dnl This whole bit snagged from libitm. | 
|  |  | 
|  | dnl Check whether the target supports hidden visibility. | 
|  | AC_DEFUN([LIBAT_CHECK_ATTRIBUTE_VISIBILITY], [ | 
|  | AC_CACHE_CHECK([whether the target supports hidden visibility], | 
|  | libat_cv_have_attribute_visibility, [ | 
|  | save_CFLAGS="$CFLAGS" | 
|  | CFLAGS="$CFLAGS -Werror" | 
|  | AC_TRY_COMPILE([void __attribute__((visibility("hidden"))) foo(void) { }], | 
|  | [], libat_cv_have_attribute_visibility=yes, | 
|  | libat_cv_have_attribute_visibility=no) | 
|  | CFLAGS="$save_CFLAGS"]) | 
|  | if test $libat_cv_have_attribute_visibility = yes; then | 
|  | AC_DEFINE(HAVE_ATTRIBUTE_VISIBILITY, 1, | 
|  | [Define to 1 if the target supports __attribute__((visibility(...))).]) | 
|  | fi]) | 
|  |  | 
|  | dnl Check whether the target supports dllexport | 
|  | AC_DEFUN([LIBAT_CHECK_ATTRIBUTE_DLLEXPORT], [ | 
|  | AC_CACHE_CHECK([whether the target supports dllexport], | 
|  | libat_cv_have_attribute_dllexport, [ | 
|  | save_CFLAGS="$CFLAGS" | 
|  | CFLAGS="$CFLAGS -Werror" | 
|  | AC_TRY_COMPILE([void __attribute__((dllexport)) foo(void) { }], | 
|  | [], libat_cv_have_attribute_dllexport=yes, | 
|  | libat_cv_have_attribute_dllexport=no) | 
|  | CFLAGS="$save_CFLAGS"]) | 
|  | if test $libat_cv_have_attribute_dllexport = yes; then | 
|  | AC_DEFINE(HAVE_ATTRIBUTE_DLLEXPORT, 1, | 
|  | [Define to 1 if the target supports __attribute__((dllexport)).]) | 
|  | fi]) | 
|  |  | 
|  | dnl Check whether the target supports symbol aliases. | 
|  | AC_DEFUN([LIBAT_CHECK_ATTRIBUTE_ALIAS], [ | 
|  | AC_CACHE_CHECK([whether the target supports symbol aliases], | 
|  | libat_cv_have_attribute_alias, [ | 
|  | AC_TRY_LINK([ | 
|  | void foo(void) { } | 
|  | extern void bar(void) __attribute__((alias("foo")));], | 
|  | [bar();], libat_cv_have_attribute_alias=yes, libat_cv_have_attribute_alias=no)]) | 
|  | if test $libat_cv_have_attribute_alias = yes; then | 
|  | AC_DEFINE(HAVE_ATTRIBUTE_ALIAS, 1, | 
|  | [Define to 1 if the target supports __attribute__((alias(...))).]) | 
|  | fi]) | 
|  |  | 
|  | dnl ---------------------------------------------------------------------- | 
|  | dnl This whole bit snagged from libstdc++-v3. | 
|  |  | 
|  | 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],-,_)[=][$2]) | 
|  | m4_undefine([_g_switch])dnl | 
|  | m4_undefine([_g_help])dnl | 
|  | ]) | 
|  |  | 
|  | dnl | 
|  | dnl If GNU ld is in use, check to see if tricky linker opts can be used.  If | 
|  | dnl the native linker is in use, all variables will be defined to something | 
|  | dnl safe (like an empty string). | 
|  | dnl | 
|  | dnl Defines: | 
|  | dnl  SECTION_LDFLAGS='-Wl,--gc-sections' if possible | 
|  | dnl  OPT_LDFLAGS='-Wl,-O1' if possible | 
|  | dnl  LD (as a side effect of testing) | 
|  | dnl Sets: | 
|  | dnl  with_gnu_ld | 
|  | dnl  libat_ld_is_gold (possibly) | 
|  | dnl  libat_ld_is_mold (possibly) | 
|  | dnl  libat_gnu_ld_version (possibly) | 
|  | dnl | 
|  | dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will | 
|  | dnl set libat_gnu_ld_version to 12345.  Zeros cause problems. | 
|  | dnl | 
|  | AC_DEFUN([LIBAT_CHECK_LINKER_FEATURES], [ | 
|  | # If we're not using GNU ld, then there's no point in even trying these | 
|  | # tests.  Check for that first.  We should have already tested for gld | 
|  | # by now (in libtool), but require it now just to be safe... | 
|  | test -z "$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 | 
|  | libat_ld_is_mold=no | 
|  | if $LD --version 2>/dev/null | grep 'GNU gold'> /dev/null 2>&1; then | 
|  | libat_ld_is_gold=yes | 
|  | elif $LD --version 2>/dev/null | grep 'mold' >/dev/null 2>&1; then | 
|  | libat_ld_is_mold=yes | 
|  | fi | 
|  | changequote(,) | 
|  | ldver=`$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 | 
|  | elif test $libat_ld_is_mold = 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) | 
|  | ]) | 
|  |  | 
|  | dnl ---------------------------------------------------------------------- | 
|  | sinclude(../libtool.m4) | 
|  | sinclude(../config/enable.m4) | 
|  | sinclude(../config/cet.m4) | 
|  | dnl The lines below arrange for aclocal not to bring an installed | 
|  | dnl libtool.m4 into aclocal.m4, while still arranging for automake to | 
|  | dnl add a definition of LIBTOOL to Makefile.in. | 
|  | ifelse(,,,[AC_SUBST(LIBTOOL) | 
|  | AC_DEFUN([AM_PROG_LIBTOOL]) | 
|  | AC_DEFUN([AC_LIBTOOL_DLOPEN]) | 
|  | AC_DEFUN([AC_PROG_LD]) | 
|  | ]) |