xref: /netbsd-src/external/gpl3/gcc/dist/libgomp/acinclude.m4 (revision b1e838363e3c6fc78a55519254d99869742dd33c)
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],-,_)[=][$2])
103m4_undefine([_g_switch])dnl
104m4_undefine([_g_help])dnl
105])
106
107
108dnl
109dnl If GNU ld is in use, check to see if tricky linker opts can be used.  If
110dnl the native linker is in use, all variables will be defined to something
111dnl safe (like an empty string).
112dnl
113dnl Defines:
114dnl  SECTION_LDFLAGS='-Wl,--gc-sections' if possible
115dnl  OPT_LDFLAGS='-Wl,-O1' if possible
116dnl  LD (as a side effect of testing)
117dnl Sets:
118dnl  with_gnu_ld
119dnl  libgomp_ld_is_gold (possibly)
120dnl  libgomp_ld_is_mold (possibly)
121dnl  libgomp_gnu_ld_version (possibly)
122dnl
123dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
124dnl set libgomp_gnu_ld_version to 12345.  Zeros cause problems.
125dnl
126AC_DEFUN([LIBGOMP_CHECK_LINKER_FEATURES], [
127  # If we're not using GNU ld, then there's no point in even trying these
128  # tests.  Check for that first.  We should have already tested for gld
129  # by now (in libtool), but require it now just to be safe...
130  test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS=''
131  test -z "$OPT_LDFLAGS" && OPT_LDFLAGS=''
132  AC_REQUIRE([AC_PROG_LD])
133  AC_REQUIRE([AC_PROG_AWK])
134
135  # The name set by libtool depends on the version of libtool.  Shame on us
136  # for depending on an impl detail, but c'est la vie.  Older versions used
137  # ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on
138  # top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually
139  # makes sense).  We'll test with_gnu_ld everywhere else, so if that isn't
140  # set (hence we're using an older libtool), then set it.
141  if test x${with_gnu_ld+set} != xset; then
142    if test x${ac_cv_prog_gnu_ld+set} != xset; then
143      # We got through "ac_require(ac_prog_ld)" and still not set?  Huh?
144      with_gnu_ld=no
145    else
146      with_gnu_ld=$ac_cv_prog_gnu_ld
147    fi
148  fi
149
150  # Start by getting the version number.  I think the libtool test already
151  # does some of this, but throws away the result.
152  libgomp_ld_is_gold=no
153  libgomp_ld_is_mold=no
154  if $LD --version 2>/dev/null | grep 'GNU gold'> /dev/null 2>&1; then
155    libgomp_ld_is_gold=yes
156  elif $LD --version 2>/dev/null | grep 'mold'> /dev/null 2>&1; then
157    libgomp_ld_is_mold=yes
158  fi
159  changequote(,)
160  ldver=`$LD --version 2>/dev/null |
161         sed -e 's/[. ][0-9]\{8\}$//;s/.* \([^ ]\{1,\}\)$/\1/; q'`
162  changequote([,])
163  libgomp_gnu_ld_version=`echo $ldver | \
164         $AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`
165
166  # Set --gc-sections.
167  if test "$with_gnu_ld" = "notbroken"; then
168    # GNU ld it is!  Joy and bunny rabbits!
169
170    # All these tests are for C++; save the language and the compiler flags.
171    # Need to do this so that g++ won't try to link in libstdc++
172    ac_test_CFLAGS="${CFLAGS+set}"
173    ac_save_CFLAGS="$CFLAGS"
174    CFLAGS='-x c++  -Wl,--gc-sections'
175
176    # Check for -Wl,--gc-sections
177    # XXX This test is broken at the moment, as symbols required for linking
178    # are now in libsupc++ (not built yet).  In addition, this test has
179    # cored on solaris in the past.  In addition, --gc-sections doesn't
180    # really work at the moment (keeps on discarding used sections, first
181    # .eh_frame and now some of the glibc sections for iconv).
182    # Bzzzzt.  Thanks for playing, maybe next time.
183    AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
184    AC_TRY_RUN([
185     int main(void)
186     {
187       try { throw 1; }
188       catch (...) { };
189       return 0;
190     }
191    ], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes])
192    if test "$ac_test_CFLAGS" = set; then
193      CFLAGS="$ac_save_CFLAGS"
194    else
195      # this is the suspicious part
196      CFLAGS=''
197    fi
198    if test "$ac_sectionLDflags" = "yes"; then
199      SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
200    fi
201    AC_MSG_RESULT($ac_sectionLDflags)
202  fi
203
204  # Set linker optimization flags.
205  if test x"$with_gnu_ld" = x"yes"; then
206    OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
207  fi
208
209  AC_SUBST(SECTION_LDFLAGS)
210  AC_SUBST(OPT_LDFLAGS)
211])
212
213
214dnl
215dnl Add version tags to symbols in shared library (or not), additionally
216dnl marking other symbols as private/local (or not).
217dnl
218dnl --enable-symvers=style adds a version script to the linker call when
219dnl       creating the shared library.  The choice of version script is
220dnl       controlled by 'style'.
221dnl --disable-symvers does not.
222dnl  +  Usage:  LIBGOMP_ENABLE_SYMVERS[(DEFAULT)]
223dnl       Where DEFAULT is either 'yes' or 'no'.  Passing `yes' tries to
224dnl       choose a default style based on linker characteristics.  Passing
225dnl       'no' disables versioning.
226dnl
227AC_DEFUN([LIBGOMP_ENABLE_SYMVERS], [
228
229LIBGOMP_ENABLE(symvers,yes,[=STYLE],
230  [enables symbol versioning of the shared library],
231  [permit yes|no|gnu*|sun])
232
233# If we never went through the LIBGOMP_CHECK_LINKER_FEATURES macro, then we
234# don't know enough about $LD to do tricks...
235AC_REQUIRE([LIBGOMP_CHECK_LINKER_FEATURES])
236
237# Turn a 'yes' into a suitable default.
238if test x$enable_symvers = xyes ; then
239  # FIXME  The following test is too strict, in theory.
240  if test $enable_shared = no || test "x$LD" = x; then
241    enable_symvers=no
242  else
243    if test $with_gnu_ld = yes ; then
244      enable_symvers=gnu
245    else
246      case ${target_os} in
247        # Sun symbol versioning exists since Solaris 2.5.
248        solaris2.[[5-9]]* | solaris2.1[[0-9]]*)
249          enable_symvers=sun ;;
250        *)
251          enable_symvers=no ;;
252      esac
253    fi
254  fi
255fi
256
257# Check if 'sun' was requested on non-Solaris 2 platforms.
258if test x$enable_symvers = xsun ; then
259  case ${target_os} in
260    solaris2*)
261      # All fine.
262      ;;
263    *)
264      # Unlikely to work.
265      AC_MSG_WARN([=== You have requested Sun symbol versioning, but])
266      AC_MSG_WARN([=== you are not targetting Solaris 2.])
267      AC_MSG_WARN([=== Symbol versioning will be disabled.])
268      enable_symvers=no
269      ;;
270  esac
271fi
272
273# Check to see if libgcc_s exists, indicating that shared libgcc is possible.
274if test $enable_symvers != no; then
275  AC_MSG_CHECKING([for shared libgcc])
276  ac_save_CFLAGS="$CFLAGS"
277  CFLAGS=' -lgcc_s'
278  AC_TRY_LINK(, [return 0;], libgomp_shared_libgcc=yes, libgomp_shared_libgcc=no)
279  CFLAGS="$ac_save_CFLAGS"
280  if test $libgomp_shared_libgcc = no; then
281    cat > conftest.c <<EOF
282int main (void) { return 0; }
283EOF
284changequote(,)dnl
285    libgomp_libgcc_s_suffix=`${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\([^ ]*\) .*$/\1/p'`
289changequote([,])dnl
290    rm -f conftest.c conftest.so
291    if test x${libgomp_libgcc_s_suffix+set} = xset; then
292      CFLAGS=" -lgcc_s$libgomp_libgcc_s_suffix"
293      AC_TRY_LINK(, [return 0;], libgomp_shared_libgcc=yes)
294      CFLAGS="$ac_save_CFLAGS"
295    fi
296  fi
297  AC_MSG_RESULT($libgomp_shared_libgcc)
298fi
299
300# For GNU ld, we need at least this version.  The format is described in
301# LIBGOMP_CHECK_LINKER_FEATURES above.
302libgomp_min_gnu_ld_version=21400
303# XXXXXXXXXXX libgomp_gnu_ld_version=21390
304
305# Check to see if unspecified "yes" value can win, given results above.
306# Change "yes" into either "no" or a style name.
307if test $enable_symvers != no && test $libgomp_shared_libgcc = yes; then
308  if test $with_gnu_ld = yes; then
309    if test $libgomp_gnu_ld_version -ge $libgomp_min_gnu_ld_version ; then
310      enable_symvers=gnu
311    elif test $libgomp_ld_is_gold = yes ; then
312      enable_symvers=gnu
313    elif test $libgomp_ld_is_mold = yes ; then
314      enable_symvers=gnu
315    else
316      # The right tools, the right setup, but too old.  Fallbacks?
317      AC_MSG_WARN(=== Linker version $libgomp_gnu_ld_version is too old for)
318      AC_MSG_WARN(=== full symbol versioning support in this release of GCC.)
319      AC_MSG_WARN(=== You would need to upgrade your binutils to version)
320      AC_MSG_WARN(=== $libgomp_min_gnu_ld_version or later and rebuild GCC.)
321      if test $libgomp_gnu_ld_version -ge 21200 ; then
322        # Globbing fix is present, proper block support is not.
323        dnl AC_MSG_WARN([=== Dude, you are soooo close.  Maybe we can fake it.])
324        dnl enable_symvers=???
325        AC_MSG_WARN([=== Symbol versioning will be disabled.])
326        enable_symvers=no
327      else
328        # 2.11 or older.
329        AC_MSG_WARN([=== Symbol versioning will be disabled.])
330        enable_symvers=no
331      fi
332    fi
333  elif test $enable_symvers = sun; then
334    : All interesting versions of Sun ld support sun style symbol versioning.
335  else
336    # just fail for now
337    AC_MSG_WARN([=== You have requested some kind of symbol versioning, but])
338    AC_MSG_WARN([=== either you are not using a supported linker, or you are])
339    AC_MSG_WARN([=== not building a shared libgcc_s (which is required).])
340    AC_MSG_WARN([=== Symbol versioning will be disabled.])
341    enable_symvers=no
342  fi
343fi
344
345AC_CACHE_CHECK([whether the target supports .symver directive],
346	       libgomp_cv_have_as_symver_directive, [
347  AC_TRY_COMPILE([void foo (void); __asm (".symver foo, bar@SYMVER");],
348		 [], libgomp_cv_have_as_symver_directive=yes,
349		 libgomp_cv_have_as_symver_directive=no)])
350if test $libgomp_cv_have_as_symver_directive = yes; then
351  AC_DEFINE(HAVE_AS_SYMVER_DIRECTIVE, 1,
352    [Define to 1 if the target assembler supports .symver directive.])
353fi
354
355AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
356AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB_GNU, test $enable_symvers = gnu)
357AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB_SUN, test $enable_symvers = sun)
358AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers)
359
360if test $enable_symvers != no ; then
361   case ${target_os} in
362     # The Solaris 2 runtime linker doesn't support the GNU extension of
363     # binding the same symbol to different versions
364     solaris2*)
365       ;;
366     # Other platforms with GNU symbol versioning (GNU/Linux, more?) do.
367     *)
368       AC_DEFINE(HAVE_SYMVER_SYMBOL_RENAMING_RUNTIME_SUPPORT, 1,
369         [Define to 1 if the target runtime linker supports binding the same symbol to different versions.])
370       ;;
371    esac
372fi
373])
374