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