1dnl ----------------------------------------------------------------------
2dnl This whole bit snagged from libgfortran.
3
4dnl Check whether the target supports __sync_*_compare_and_swap.
5AC_DEFUN([LIBGOMP_CHECK_SYNC_BUILTINS], [
6  AC_CACHE_CHECK([whether the target supports __sync_*_compare_and_swap],
7		 libgomp_cv_have_sync_builtins, [
8  AC_TRY_LINK([], [int foo; __sync_val_compare_and_swap(&foo, 0, 1);],
9	      libgomp_cv_have_sync_builtins=yes, libgomp_cv_have_sync_builtins=no)])
10  if test $libgomp_cv_have_sync_builtins = yes; then
11    AC_DEFINE(HAVE_SYNC_BUILTINS, 1,
12	      [Define to 1 if the target supports __sync_*_compare_and_swap])
13  fi])
14
15dnl Check whether the target supports hidden visibility.
16AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_VISIBILITY], [
17  AC_CACHE_CHECK([whether the target supports hidden visibility],
18		 libgomp_cv_have_attribute_visibility, [
19  save_CFLAGS="$CFLAGS"
20  CFLAGS="$CFLAGS -Werror"
21  AC_TRY_COMPILE([void __attribute__((visibility("hidden"))) foo(void) { }],
22		 [], libgomp_cv_have_attribute_visibility=yes,
23		 libgomp_cv_have_attribute_visibility=no)
24  CFLAGS="$save_CFLAGS"])
25  if test $libgomp_cv_have_attribute_visibility = yes; then
26    AC_DEFINE(HAVE_ATTRIBUTE_VISIBILITY, 1,
27      [Define to 1 if the target supports __attribute__((visibility(...))).])
28  fi])
29
30dnl Check whether the target supports dllexport
31AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_DLLEXPORT], [
32  AC_CACHE_CHECK([whether the target supports dllexport],
33		 libgomp_cv_have_attribute_dllexport, [
34  save_CFLAGS="$CFLAGS"
35  CFLAGS="$CFLAGS -Werror"
36  AC_TRY_COMPILE([void __attribute__((dllexport)) foo(void) { }],
37		 [], libgomp_cv_have_attribute_dllexport=yes,
38		 libgomp_cv_have_attribute_dllexport=no)
39  CFLAGS="$save_CFLAGS"])
40  if test $libgomp_cv_have_attribute_dllexport = yes; then
41    AC_DEFINE(HAVE_ATTRIBUTE_DLLEXPORT, 1,
42      [Define to 1 if the target supports __attribute__((dllexport)).])
43  fi])
44
45dnl Check whether the target supports symbol aliases.
46AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_ALIAS], [
47  AC_CACHE_CHECK([whether the target supports symbol aliases],
48		 libgomp_cv_have_attribute_alias, [
49  AC_TRY_LINK([
50void foo(void) { }
51extern void bar(void) __attribute__((alias("foo")));],
52    [bar();], libgomp_cv_have_attribute_alias=yes, libgomp_cv_have_attribute_alias=no)])
53  if test $libgomp_cv_have_attribute_alias = yes; then
54    AC_DEFINE(HAVE_ATTRIBUTE_ALIAS, 1,
55      [Define to 1 if the target supports __attribute__((alias(...))).])
56  fi])
57
58sinclude(../libtool.m4)
59sinclude(../config/cet.m4)
60dnl The lines below arrange for aclocal not to bring an installed
61dnl libtool.m4 into aclocal.m4, while still arranging for automake to
62dnl add a definition of LIBTOOL to Makefile.in.
63ifelse(,,,[AC_SUBST(LIBTOOL)
64AC_DEFUN([AM_PROG_LIBTOOL])
65AC_DEFUN([AC_LIBTOOL_DLOPEN])
66AC_DEFUN([AC_PROG_LD])
67])
68
69dnl ----------------------------------------------------------------------
70dnl This whole bit snagged from libstdc++-v3.
71
72dnl
73dnl LIBGOMP_ENABLE
74dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING)
75dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, permit a|b|c)
76dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, SHELL-CODE-HANDLER)
77dnl
78dnl See docs/html/17_intro/configury.html#enable for documentation.
79dnl
80m4_define([LIBGOMP_ENABLE],[dnl
81m4_define([_g_switch],[--enable-$1])dnl
82m4_define([_g_help],[AC_HELP_STRING(_g_switch$3,[$4 @<:@default=$2@:>@])])dnl
83 AC_ARG_ENABLE($1,_g_help,
84  m4_bmatch([$5],
85   [^permit ],
86     [[
87      case "$enableval" in
88       m4_bpatsubst([$5],[permit ])) ;;
89       *) AC_MSG_ERROR(Unknown argument to enable/disable $1) ;;
90          dnl Idea for future:  generate a URL pointing to
91          dnl "onlinedocs/configopts.html#whatever"
92      esac
93     ]],
94   [^$],
95     [[
96      case "$enableval" in
97       yes|no) ;;
98       *) AC_MSG_ERROR(Argument to enable/disable $1 must be yes or no) ;;
99      esac
100     ]],
101   [[$5]]),
102  [enable_]m4_bpatsubst([$1],-,_)[=][$2])
103m4_undefine([_g_switch])dnl
104m4_undefine([_g_help])dnl
105])
106
107
108dnl
109dnl If GNU ld is in use, check to see if tricky linker opts can be used.  If
110dnl the native linker is in use, all variables will be defined to something
111dnl safe (like an empty string).
112dnl
113dnl Defines:
114dnl  SECTION_LDFLAGS='-Wl,--gc-sections' if possible
115dnl  OPT_LDFLAGS='-Wl,-O1' if possible
116dnl  LD (as a side effect of testing)
117dnl Sets:
118dnl  with_gnu_ld
119dnl  libgomp_ld_is_gold (possibly)
120dnl  libgomp_gnu_ld_version (possibly)
121dnl
122dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
123dnl set libgomp_gnu_ld_version to 12345.  Zeros cause problems.
124dnl
125AC_DEFUN([LIBGOMP_CHECK_LINKER_FEATURES], [
126  # If we're not using GNU ld, then there's no point in even trying these
127  # tests.  Check for that first.  We should have already tested for gld
128  # by now (in libtool), but require it now just to be safe...
129  test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS=''
130  test -z "$OPT_LDFLAGS" && OPT_LDFLAGS=''
131  AC_REQUIRE([AC_PROG_LD])
132  AC_REQUIRE([AC_PROG_AWK])
133
134  # The name set by libtool depends on the version of libtool.  Shame on us
135  # for depending on an impl detail, but c'est la vie.  Older versions used
136  # ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on
137  # top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually
138  # makes sense).  We'll test with_gnu_ld everywhere else, so if that isn't
139  # set (hence we're using an older libtool), then set it.
140  if test x${with_gnu_ld+set} != xset; then
141    if test x${ac_cv_prog_gnu_ld+set} != xset; then
142      # We got through "ac_require(ac_prog_ld)" and still not set?  Huh?
143      with_gnu_ld=no
144    else
145      with_gnu_ld=$ac_cv_prog_gnu_ld
146    fi
147  fi
148
149  # Start by getting the version number.  I think the libtool test already
150  # does some of this, but throws away the result.
151  libgomp_ld_is_gold=no
152  if $LD --version 2>/dev/null | grep 'GNU gold'> /dev/null 2>&1; then
153    libgomp_ld_is_gold=yes
154  fi
155  changequote(,)
156  ldver=`$LD --version 2>/dev/null |
157         sed -e 's/[. ][0-9]\{8\}$//;s/.* \([^ ]\{1,\}\)$/\1/; q'`
158  changequote([,])
159  libgomp_gnu_ld_version=`echo $ldver | \
160         $AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`
161
162  # Set --gc-sections.
163  if test "$with_gnu_ld" = "notbroken"; then
164    # GNU ld it is!  Joy and bunny rabbits!
165
166    # All these tests are for C++; save the language and the compiler flags.
167    # Need to do this so that g++ won't try to link in libstdc++
168    ac_test_CFLAGS="${CFLAGS+set}"
169    ac_save_CFLAGS="$CFLAGS"
170    CFLAGS='-x c++  -Wl,--gc-sections'
171
172    # Check for -Wl,--gc-sections
173    # XXX This test is broken at the moment, as symbols required for linking
174    # are now in libsupc++ (not built yet).  In addition, this test has
175    # cored on solaris in the past.  In addition, --gc-sections doesn't
176    # really work at the moment (keeps on discarding used sections, first
177    # .eh_frame and now some of the glibc sections for iconv).
178    # Bzzzzt.  Thanks for playing, maybe next time.
179    AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
180    AC_TRY_RUN([
181     int main(void)
182     {
183       try { throw 1; }
184       catch (...) { };
185       return 0;
186     }
187    ], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes])
188    if test "$ac_test_CFLAGS" = set; then
189      CFLAGS="$ac_save_CFLAGS"
190    else
191      # this is the suspicious part
192      CFLAGS=''
193    fi
194    if test "$ac_sectionLDflags" = "yes"; then
195      SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
196    fi
197    AC_MSG_RESULT($ac_sectionLDflags)
198  fi
199
200  # Set linker optimization flags.
201  if test x"$with_gnu_ld" = x"yes"; then
202    OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
203  fi
204
205  AC_SUBST(SECTION_LDFLAGS)
206  AC_SUBST(OPT_LDFLAGS)
207])
208
209
210dnl
211dnl Add version tags to symbols in shared library (or not), additionally
212dnl marking other symbols as private/local (or not).
213dnl
214dnl --enable-symvers=style adds a version script to the linker call when
215dnl       creating the shared library.  The choice of version script is
216dnl       controlled by 'style'.
217dnl --disable-symvers does not.
218dnl  +  Usage:  LIBGOMP_ENABLE_SYMVERS[(DEFAULT)]
219dnl       Where DEFAULT is either 'yes' or 'no'.  Passing `yes' tries to
220dnl       choose a default style based on linker characteristics.  Passing
221dnl       'no' disables versioning.
222dnl
223AC_DEFUN([LIBGOMP_ENABLE_SYMVERS], [
224
225LIBGOMP_ENABLE(symvers,yes,[=STYLE],
226  [enables symbol versioning of the shared library],
227  [permit yes|no|gnu*|sun])
228
229# If we never went through the LIBGOMP_CHECK_LINKER_FEATURES macro, then we
230# don't know enough about $LD to do tricks...
231AC_REQUIRE([LIBGOMP_CHECK_LINKER_FEATURES])
232
233# Turn a 'yes' into a suitable default.
234if test x$enable_symvers = xyes ; then
235  # FIXME  The following test is too strict, in theory.
236  if test $enable_shared = no || test "x$LD" = x; then
237    enable_symvers=no
238  else
239    if test $with_gnu_ld = yes ; then
240      enable_symvers=gnu
241    else
242      case ${target_os} in
243        # Sun symbol versioning exists since Solaris 2.5.
244        solaris2.[[5-9]]* | solaris2.1[[0-9]]*)
245          enable_symvers=sun ;;
246        *)
247          enable_symvers=no ;;
248      esac
249    fi
250  fi
251fi
252
253# Check if 'sun' was requested on non-Solaris 2 platforms.
254if test x$enable_symvers = xsun ; then
255  case ${target_os} in
256    solaris2*)
257      # All fine.
258      ;;
259    *)
260      # Unlikely to work.
261      AC_MSG_WARN([=== You have requested Sun symbol versioning, but])
262      AC_MSG_WARN([=== you are not targetting Solaris 2.])
263      AC_MSG_WARN([=== Symbol versioning will be disabled.])
264      enable_symvers=no
265      ;;
266  esac
267fi
268
269# Check to see if libgcc_s exists, indicating that shared libgcc is possible.
270if test $enable_symvers != no; then
271  AC_MSG_CHECKING([for shared libgcc])
272  ac_save_CFLAGS="$CFLAGS"
273  CFLAGS=' -lgcc_s'
274  AC_TRY_LINK(, [return 0;], libgomp_shared_libgcc=yes, libgomp_shared_libgcc=no)
275  CFLAGS="$ac_save_CFLAGS"
276  if test $libgomp_shared_libgcc = no; then
277    cat > conftest.c <<EOF
278int main (void) { return 0; }
279EOF
280changequote(,)dnl
281    libgomp_libgcc_s_suffix=`${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \
282			     -shared -shared-libgcc -o conftest.so \
283			     conftest.c -v 2>&1 >/dev/null \
284			     | sed -n 's/^.* -lgcc_s\([^ ]*\) .*$/\1/p'`
285changequote([,])dnl
286    rm -f conftest.c conftest.so
287    if test x${libgomp_libgcc_s_suffix+set} = xset; then
288      CFLAGS=" -lgcc_s$libgomp_libgcc_s_suffix"
289      AC_TRY_LINK(, [return 0;], libgomp_shared_libgcc=yes)
290      CFLAGS="$ac_save_CFLAGS"
291    fi
292  fi
293  AC_MSG_RESULT($libgomp_shared_libgcc)
294fi
295
296# For GNU ld, we need at least this version.  The format is described in
297# LIBGOMP_CHECK_LINKER_FEATURES above.
298libgomp_min_gnu_ld_version=21400
299# XXXXXXXXXXX libgomp_gnu_ld_version=21390
300
301# Check to see if unspecified "yes" value can win, given results above.
302# Change "yes" into either "no" or a style name.
303if test $enable_symvers != no && test $libgomp_shared_libgcc = yes; then
304  if test $with_gnu_ld = yes; then
305    if test $libgomp_gnu_ld_version -ge $libgomp_min_gnu_ld_version ; then
306      enable_symvers=gnu
307    elif test $libgomp_ld_is_gold = yes ; then
308      enable_symvers=gnu
309    else
310      # The right tools, the right setup, but too old.  Fallbacks?
311      AC_MSG_WARN(=== Linker version $libgomp_gnu_ld_version is too old for)
312      AC_MSG_WARN(=== full symbol versioning support in this release of GCC.)
313      AC_MSG_WARN(=== You would need to upgrade your binutils to version)
314      AC_MSG_WARN(=== $libgomp_min_gnu_ld_version or later and rebuild GCC.)
315      if test $libgomp_gnu_ld_version -ge 21200 ; then
316        # Globbing fix is present, proper block support is not.
317        dnl AC_MSG_WARN([=== Dude, you are soooo close.  Maybe we can fake it.])
318        dnl enable_symvers=???
319        AC_MSG_WARN([=== Symbol versioning will be disabled.])
320        enable_symvers=no
321      else
322        # 2.11 or older.
323        AC_MSG_WARN([=== Symbol versioning will be disabled.])
324        enable_symvers=no
325      fi
326    fi
327  elif test $enable_symvers = sun; then
328    : All interesting versions of Sun ld support sun style symbol versioning.
329  else
330    # just fail for now
331    AC_MSG_WARN([=== You have requested some kind of symbol versioning, but])
332    AC_MSG_WARN([=== either you are not using a supported linker, or you are])
333    AC_MSG_WARN([=== not building a shared libgcc_s (which is required).])
334    AC_MSG_WARN([=== Symbol versioning will be disabled.])
335    enable_symvers=no
336  fi
337fi
338
339AC_CACHE_CHECK([whether the target supports .symver directive],
340	       libgomp_cv_have_as_symver_directive, [
341  AC_TRY_COMPILE([void foo (void); __asm (".symver foo, bar@SYMVER");],
342		 [], libgomp_cv_have_as_symver_directive=yes,
343		 libgomp_cv_have_as_symver_directive=no)])
344if test $libgomp_cv_have_as_symver_directive = yes; then
345  AC_DEFINE(HAVE_AS_SYMVER_DIRECTIVE, 1,
346    [Define to 1 if the target assembler supports .symver directive.])
347fi
348
349AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
350AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB_GNU, test $enable_symvers = gnu)
351AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB_SUN, test $enable_symvers = sun)
352AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers)
353
354if test $enable_symvers != no ; then
355   case ${target_os} in
356     # The Solaris 2 runtime linker doesn't support the GNU extension of
357     # binding the same symbol to different versions
358     solaris2*)
359       ;;
360     # Other platforms with GNU symbol versioning (GNU/Linux, more?) do.
361     *)
362       AC_DEFINE(HAVE_SYMVER_SYMBOL_RENAMING_RUNTIME_SUPPORT, 1,
363         [Define to 1 if the target runtime linker supports binding the same symbol to different versions.])
364       ;;
365    esac
366fi
367])
368