1 dnl ----------------------------------------------------------------------
2 dnl This whole bit snagged from libgfortran.
4 dnl Check whether the target supports __sync_*_compare_and_swap.
5 AC_DEFUN([LIBITM_CHECK_SYNC_BUILTINS], [
6 AC_CACHE_CHECK([whether the target supports __sync_*_compare_and_swap],
7 libitm_cv_have_sync_builtins, [
8 AC_TRY_LINK([], [int foo, bar; bar = __sync_val_compare_and_swap(&foo, 0, 1);],
9 libitm_cv_have_sync_builtins=yes, libitm_cv_have_sync_builtins=no)])
10 if test $libitm_cv_have_sync_builtins = yes; then
11 AC_DEFINE(HAVE_SYNC_BUILTINS, 1,
12 [Define to 1 if the target supports __sync_*_compare_and_swap])
15 dnl Check whether the target supports 64-bit __sync_*_compare_and_swap.
16 AC_DEFUN([LIBITM_CHECK_64BIT_SYNC_BUILTINS], [
17 AC_CACHE_CHECK([whether the target supports 64-bit __sync_*_compare_and_swap],
18 libitm_cv_have_64bit_sync_builtins, [
19 AC_TRY_LINK([#include <stdint.h>],
21 bar = __sync_val_compare_and_swap(&foo, 0, 1);],
22 libitm_cv_have_64bit_sync_builtins=yes,
23 libitm_cv_have_64bit_sync_builtins=no)])
24 if test $libitm_cv_have_64bit_sync_builtins = yes; then
25 AC_DEFINE(HAVE_64BIT_SYNC_BUILTINS, 1,
26 [Define to 1 if the target supports 64-bit __sync_*_compare_and_swap])
29 dnl Check whether the target supports hidden visibility.
30 AC_DEFUN([LIBITM_CHECK_ATTRIBUTE_VISIBILITY], [
31 AC_CACHE_CHECK([whether the target supports hidden visibility],
32 libitm_cv_have_attribute_visibility, [
34 CFLAGS="$CFLAGS -Werror"
35 AC_TRY_COMPILE([void __attribute__((visibility("hidden"))) foo(void) { }],
36 [], libitm_cv_have_attribute_visibility=yes,
37 libitm_cv_have_attribute_visibility=no)
38 CFLAGS="$save_CFLAGS"])
39 if test $libitm_cv_have_attribute_visibility = yes; then
40 AC_DEFINE(HAVE_ATTRIBUTE_VISIBILITY, 1,
41 [Define to 1 if the target supports __attribute__((visibility(...))).])
44 dnl Check whether the target supports dllexport
45 AC_DEFUN([LIBITM_CHECK_ATTRIBUTE_DLLEXPORT], [
46 AC_CACHE_CHECK([whether the target supports dllexport],
47 libitm_cv_have_attribute_dllexport, [
49 CFLAGS="$CFLAGS -Werror"
50 AC_TRY_COMPILE([void __attribute__((dllexport)) foo(void) { }],
51 [], libitm_cv_have_attribute_dllexport=yes,
52 libitm_cv_have_attribute_dllexport=no)
53 CFLAGS="$save_CFLAGS"])
54 if test $libitm_cv_have_attribute_dllexport = yes; then
55 AC_DEFINE(HAVE_ATTRIBUTE_DLLEXPORT, 1,
56 [Define to 1 if the target supports __attribute__((dllexport)).])
59 dnl Check whether the target supports symbol aliases.
60 AC_DEFUN([LIBITM_CHECK_ATTRIBUTE_ALIAS], [
61 AC_CACHE_CHECK([whether the target supports symbol aliases],
62 libitm_cv_have_attribute_alias, [
65 extern void bar(void) __attribute__((alias("foo")));],
66 [bar();], libitm_cv_have_attribute_alias=yes, libitm_cv_have_attribute_alias=no)])
67 if test $libitm_cv_have_attribute_alias = yes; then
68 AC_DEFINE(HAVE_ATTRIBUTE_ALIAS, 1,
69 [Define to 1 if the target supports __attribute__((alias(...))).])
72 dnl Check how size_t is mangled.
73 AC_DEFUN([LIBITM_CHECK_SIZE_T_MANGLING], [
74 AC_CACHE_CHECK([how size_t is mangled],
75 libitm_cv_size_t_mangling, [
76 AC_TRY_COMPILE([], [extern __SIZE_TYPE__ x; extern unsigned long x;],
77 [libitm_cv_size_t_mangling=m], [
78 AC_TRY_COMPILE([], [extern __SIZE_TYPE__ x; extern unsigned int x;],
79 [libitm_cv_size_t_mangling=j], [
81 [extern __SIZE_TYPE__ x; extern unsigned long long x;],
82 [libitm_cv_size_t_mangling=y], [
84 [extern __SIZE_TYPE__ x; extern unsigned short x;],
85 [libitm_cv_size_t_mangling=t],
86 [libitm_cv_size_t_mangling=x])
91 if test $libitm_cv_size_t_mangling = x; then
92 AC_MSG_ERROR([Unknown underlying type for size_t])
94 AC_DEFINE_UNQUOTED(MANGLE_SIZE_T, [$libitm_cv_size_t_mangling],
95 [Define to the letter to which size_t is mangled.])
98 sinclude(../libtool.m4)
99 dnl The lines below arrange for aclocal not to bring an installed
100 dnl libtool.m4 into aclocal.m4, while still arranging for automake to
101 dnl add a definition of LIBTOOL to Makefile.in.
102 ifelse(,,,[AC_SUBST(LIBTOOL)
103 AC_DEFUN([AM_PROG_LIBTOOL])
104 AC_DEFUN([AC_LIBTOOL_DLOPEN])
105 AC_DEFUN([AC_PROG_LD])
108 dnl ----------------------------------------------------------------------
109 dnl This whole bit snagged from libstdc++-v3.
113 dnl (FEATURE, DEFAULT, HELP-ARG, HELP-STRING)
114 dnl (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, permit a|b|c)
115 dnl (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, SHELL-CODE-HANDLER)
117 dnl See docs/html/17_intro/configury.html#enable for documentation.
119 m4_define([LIBITM_ENABLE],[dnl
120 m4_define([_g_switch],[--enable-$1])dnl
121 m4_define([_g_help],[AC_HELP_STRING(_g_switch$3,[$4 @<:@default=$2@:>@])])dnl
122 AC_ARG_ENABLE($1,_g_help,
127 m4_bpatsubst([$5],[permit ])) ;;
128 *) AC_MSG_ERROR(Unknown argument to enable/disable $1) ;;
129 dnl Idea for future: generate a URL pointing to
130 dnl "onlinedocs/configopts.html#whatever"
137 *) AC_MSG_ERROR(Argument to enable/disable $1 must be yes or no) ;;
141 [enable_]m4_bpatsubst([$1],-,_)[=][$2])
142 m4_undefine([_g_switch])dnl
143 m4_undefine([_g_help])dnl
148 dnl If GNU ld is in use, check to see if tricky linker opts can be used. If
149 dnl the native linker is in use, all variables will be defined to something
150 dnl safe (like an empty string).
153 dnl SECTION_LDFLAGS='-Wl,--gc-sections' if possible
154 dnl OPT_LDFLAGS='-Wl,-O1' if possible
155 dnl LD (as a side effect of testing)
158 dnl libitm_gnu_ld_version (possibly)
160 dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
161 dnl set libitm_gnu_ld_version to 12345. Zeros cause problems.
163 AC_DEFUN([LIBITM_CHECK_LINKER_FEATURES], [
164 # If we're not using GNU ld, then there's no point in even trying these
165 # tests. Check for that first. We should have already tested for gld
166 # by now (in libtool), but require it now just to be safe...
167 test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS=''
168 test -z "$OPT_LDFLAGS" && OPT_LDFLAGS=''
169 AC_REQUIRE([AC_PROG_LD])
170 AC_REQUIRE([AC_PROG_AWK])
172 # The name set by libtool depends on the version of libtool. Shame on us
173 # for depending on an impl detail, but c'est la vie. Older versions used
174 # ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on
175 # top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually
176 # makes sense). We'll test with_gnu_ld everywhere else, so if that isn't
177 # set (hence we're using an older libtool), then set it.
178 if test x${with_gnu_ld+set} != xset; then
179 if test x${ac_cv_prog_gnu_ld+set} != xset; then
180 # We got through "ac_require(ac_prog_ld)" and still not set? Huh?
183 with_gnu_ld=$ac_cv_prog_gnu_ld
187 # Start by getting the version number. I think the libtool test already
188 # does some of this, but throws away the result.
190 ldver=`$LD --version 2>/dev/null | head -1 | \
191 sed -e 's/GNU ld \(version \)\{0,1\}\(([^)]*) \)\{0,1\}\([0-9.][0-9.]*\).*/\3/'`
193 libitm_gnu_ld_version=`echo $ldver | \
194 $AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`
197 if test "$with_gnu_ld" = "notbroken"; then
198 # GNU ld it is! Joy and bunny rabbits!
200 # All these tests are for C++; save the language and the compiler flags.
201 # Need to do this so that g++ won't try to link in libstdc++
202 ac_test_CFLAGS="${CFLAGS+set}"
203 ac_save_CFLAGS="$CFLAGS"
204 CFLAGS='-x c++ -Wl,--gc-sections'
206 # Check for -Wl,--gc-sections
207 # XXX This test is broken at the moment, as symbols required for linking
208 # are now in libsupc++ (not built yet). In addition, this test has
209 # cored on solaris in the past. In addition, --gc-sections doesn't
210 # really work at the moment (keeps on discarding used sections, first
211 # .eh_frame and now some of the glibc sections for iconv).
212 # Bzzzzt. Thanks for playing, maybe next time.
213 AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
221 ], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes])
222 if test "$ac_test_CFLAGS" = set; then
223 CFLAGS="$ac_save_CFLAGS"
225 # this is the suspicious part
228 if test "$ac_sectionLDflags" = "yes"; then
229 SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
231 AC_MSG_RESULT($ac_sectionLDflags)
234 # Set linker optimization flags.
235 if test x"$with_gnu_ld" = x"yes"; then
236 OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
239 AC_SUBST(SECTION_LDFLAGS)
240 AC_SUBST(OPT_LDFLAGS)
245 dnl Add version tags to symbols in shared library (or not), additionally
246 dnl marking other symbols as private/local (or not).
248 dnl --enable-symvers=style adds a version script to the linker call when
249 dnl creating the shared library. The choice of version script is
250 dnl controlled by 'style'.
251 dnl --disable-symvers does not.
252 dnl + Usage: LIBITM_ENABLE_SYMVERS[(DEFAULT)]
253 dnl Where DEFAULT is either 'yes' or 'no'. Passing `yes' tries to
254 dnl choose a default style based on linker characteristics. Passing
255 dnl 'no' disables versioning.
257 AC_DEFUN([LIBITM_ENABLE_SYMVERS], [
259 LIBITM_ENABLE(symvers,yes,[=STYLE],
260 [enables symbol versioning of the shared library],
263 # If we never went through the LIBITM_CHECK_LINKER_FEATURES macro, then we
264 # don't know enough about $LD to do tricks...
265 AC_REQUIRE([LIBITM_CHECK_LINKER_FEATURES])
266 # FIXME The following test is too strict, in theory.
267 if test $enable_shared = no ||
269 test x$libitm_gnu_ld_version = x; then
273 # Check to see if libgcc_s exists, indicating that shared libgcc is possible.
274 if test $enable_symvers != no; then
275 AC_MSG_CHECKING([for shared libgcc])
276 ac_save_CFLAGS="$CFLAGS"
278 AC_TRY_LINK(, [return 0;], libitm_shared_libgcc=yes, libitm_shared_libgcc=no)
279 CFLAGS="$ac_save_CFLAGS"
280 if test $libitm_shared_libgcc = no; then
281 cat > conftest.c <<EOF
282 int main (void) { return 0; }
285 libitm_libgcc_s_suffix=`${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \
286 -shared -shared-libgcc -o conftest.so \
287 conftest.c -v 2>&1 >/dev/null \
288 | sed -n 's/^.* -lgcc_s\([^ ]*\) .*$/\1/p'`
290 rm -f conftest.c conftest.so
291 if test x${libitm_libgcc_s_suffix+set} = xset; then
292 CFLAGS=" -lgcc_s$libitm_libgcc_s_suffix"
293 AC_TRY_LINK(, [return 0;], libitm_shared_libgcc=yes)
294 CFLAGS="$ac_save_CFLAGS"
297 AC_MSG_RESULT($libitm_shared_libgcc)
300 # For GNU ld, we need at least this version. The format is described in
301 # LIBITM_CHECK_LINKER_FEATURES above.
302 libitm_min_gnu_ld_version=21400
303 # XXXXXXXXXXX libitm_gnu_ld_version=21390
305 # Check to see if unspecified "yes" value can win, given results above.
306 # Change "yes" into either "no" or a style name.
307 if test $enable_symvers = yes; then
308 if test $with_gnu_ld = yes &&
309 test $libitm_shared_libgcc = yes;
311 if test $libitm_gnu_ld_version -ge $libitm_min_gnu_ld_version ; then
314 # The right tools, the right setup, but too old. Fallbacks?
315 AC_MSG_WARN(=== Linker version $libitm_gnu_ld_version is too old for)
316 AC_MSG_WARN(=== full symbol versioning support in this release of GCC.)
317 AC_MSG_WARN(=== You would need to upgrade your binutils to version)
318 AC_MSG_WARN(=== $libitm_min_gnu_ld_version or later and rebuild GCC.)
319 if test $libitm_gnu_ld_version -ge 21200 ; then
320 # Globbing fix is present, proper block support is not.
321 dnl AC_MSG_WARN([=== Dude, you are soooo close. Maybe we can fake it.])
322 dnl enable_symvers=???
323 AC_MSG_WARN([=== Symbol versioning will be disabled.])
327 AC_MSG_WARN([=== Symbol versioning will be disabled.])
333 AC_MSG_WARN([=== You have requested some kind of symbol versioning, but])
334 AC_MSG_WARN([=== either you are not using a supported linker, or you are])
335 AC_MSG_WARN([=== not building a shared libgcc_s (which is required).])
336 AC_MSG_WARN([=== Symbol versioning will be disabled.])
341 AM_CONDITIONAL(LIBITM_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
342 AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers)