libgomp/acinclude.m4

   1 dnl ----------------------------------------------------------------------
   2 dnl This whole bit snagged from libgfortran.
   3
   4 dnl Check whether the target supports __sync_*_compare_and_swap.
   5 AC_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 $have_sync_builtins = yes; then
  11     AC_DEFINE(HAVE_SYNC_BUILTINS, 1,
  12               [Define to 1 if the target supports __sync_*_compare_and_swap])
  13   fi])
  14
  15 dnl Check whether the target supports hidden visibility.
  16 AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_VISIBILITY], [
  17   AC_CACHE_CHECK([whether the target supports hidden visibility],
  18                  have_attribute_visibility, [
  19   save_CFLAGS="$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 $have_attribute_visibility = yes; then
  26     AC_DEFINE(HAVE_ATTRIBUTE_VISIBILITY, 1,
  27       [Define to 1 if the target supports __attribute__((visibility(...))).])
  28   fi])
  29
  30 dnl Check whether the target supports dllexport
  31 AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_DLLEXPORT], [
  32   AC_CACHE_CHECK([whether the target supports dllexport],
  33                  have_attribute_dllexport, [
  34   save_CFLAGS="$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
  45 dnl Check whether the target supports symbol aliases.
  46 AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_ALIAS], [
  47   AC_CACHE_CHECK([whether the target supports symbol aliases],
  48                  have_attribute_alias, [
  49   AC_TRY_LINK([
  50 #define ULP     STR1(__USER_LABEL_PREFIX__)
  51 #define STR1(x) STR2(x)
  52 #define STR2(x) #x
  53 void foo(void) { }
  54 extern void bar(void) __attribute__((alias(ULP "foo")));],
  55     [bar();], have_attribute_alias=yes, have_attribute_alias=no)])
  56   if test $have_attribute_alias = yes; then
  57     AC_DEFINE(HAVE_ATTRIBUTE_ALIAS, 1,
  58       [Define to 1 if the target supports __attribute__((alias(...))).])
  59   fi])
  60
  61 sinclude(../libtool.m4)
  62 dnl The lines below arrange for aclocal not to bring an installed
  63 dnl libtool.m4 into aclocal.m4, while still arranging for automake to
  64 dnl add a definition of LIBTOOL to Makefile.in.
  65 ifelse(,,,[AC_SUBST(LIBTOOL)
  66 AC_DEFUN([AM_PROG_LIBTOOL])
  67 AC_DEFUN([AC_LIBTOOL_DLOPEN])
  68 AC_DEFUN([AC_PROG_LD])
  69 ])
  70
  71 dnl ----------------------------------------------------------------------
  72 dnl This whole bit snagged from libstdc++-v3.
  73
  74 dnl
  75 dnl LIBGOMP_ENABLE
  76 dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING)
  77 dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, permit a|b|c)
  78 dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, SHELL-CODE-HANDLER)
  79 dnl
  80 dnl See docs/html/17_intro/configury.html#enable for documentation.
  81 dnl
  82 m4_define([LIBGOMP_ENABLE],[dnl
  83 m4_define([_g_switch],[--enable-$1])dnl
  84 m4_define([_g_help],[AC_HELP_STRING(_g_switch$3,[$4 @<:@default=$2@:>@])])dnl
  85  AC_ARG_ENABLE($1,_g_help,
  86   m4_bmatch([$5],
  87    [^permit ],
  88      [[
  89       case "$enableval" in
  90        m4_bpatsubst([$5],[permit ])) ;;
  91        *) AC_MSG_ERROR(Unknown argument to enable/disable $1) ;;
  92           dnl Idea for future:  generate a URL pointing to
  93           dnl "onlinedocs/configopts.html#whatever"
  94       esac
  95      ]],
  96    [^$],
  97      [[
  98       case "$enableval" in
  99        yes|no) ;;
 100        *) AC_MSG_ERROR(Argument to enable/disable $1 must be yes or no) ;;
 101       esac
 102      ]],
 103    [[$5]]),
 104   [enable_]m4_bpatsubst([$1],-,_)[=][$2])
 105 m4_undefine([_g_switch])dnl
 106 m4_undefine([_g_help])dnl
 107 ])
 108
 109
 110 dnl
 111 dnl If GNU ld is in use, check to see if tricky linker opts can be used.  If
 112 dnl the native linker is in use, all variables will be defined to something
 113 dnl safe (like an empty string).
 114 dnl
 115 dnl Defines:
 116 dnl  SECTION_LDFLAGS='-Wl,--gc-sections' if possible
 117 dnl  OPT_LDFLAGS='-Wl,-O1' if possible
 118 dnl  LD (as a side effect of testing)
 119 dnl Sets:
 120 dnl  with_gnu_ld
 121 dnl  libgomp_gnu_ld_version (possibly)
 122 dnl
 123 dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
 124 dnl set libgomp_gnu_ld_version to 12345.  Zeros cause problems.
 125 dnl
 126 AC_DEFUN([LIBGOMP_CHECK_LINKER_FEATURES], [
 127   # If we're not using GNU ld, then there's no point in even trying these
 128   # tests.  Check for that first.  We should have already tested for gld
 129   # by now (in libtool), but require it now just to be safe...
 130   test -z "$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   changequote(,)
 153   ldver=`$LD --version 2>/dev/null | head -1 | \
 154          sed -e 's/GNU ld version \([0-9.][0-9.]*\).*/\1/'`
 155   changequote([,])
 156   libgomp_gnu_ld_version=`echo $ldver | \
 157          $AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`
 158
 159   # Set --gc-sections.
 160   if test "$with_gnu_ld" = "notbroken"; then
 161     # GNU ld it is!  Joy and bunny rabbits!
 162
 163     # All these tests are for C++; save the language and the compiler flags.
 164     # Need to do this so that g++ won't try to link in libstdc++
 165     ac_test_CFLAGS="${CFLAGS+set}"
 166     ac_save_CFLAGS="$CFLAGS"
 167     CFLAGS='-x c++  -Wl,--gc-sections'
 168
 169     # Check for -Wl,--gc-sections
 170     # XXX This test is broken at the moment, as symbols required for linking
 171     # are now in libsupc++ (not built yet).  In addition, this test has
 172     # cored on solaris in the past.  In addition, --gc-sections doesn't
 173     # really work at the moment (keeps on discarding used sections, first
 174     # .eh_frame and now some of the glibc sections for iconv).
 175     # Bzzzzt.  Thanks for playing, maybe next time.
 176     AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
 177     AC_TRY_RUN([
 178      int main(void)
 179      {
 180        try { throw 1; }
 181        catch (...) { };
 182        return 0;
 183      }
 184     ], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes])
 185     if test "$ac_test_CFLAGS" = set; then
 186       CFLAGS="$ac_save_CFLAGS"
 187     else
 188       # this is the suspicious part
 189       CFLAGS=''
 190     fi
 191     if test "$ac_sectionLDflags" = "yes"; then
 192       SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
 193     fi
 194     AC_MSG_RESULT($ac_sectionLDflags)
 195   fi
 196
 197   # Set linker optimization flags.
 198   if test x"$with_gnu_ld" = x"yes"; then
 199     OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
 200   fi
 201
 202   AC_SUBST(SECTION_LDFLAGS)
 203   AC_SUBST(OPT_LDFLAGS)
 204 ])
 205
 206
 207 dnl
 208 dnl Add version tags to symbols in shared library (or not), additionally
 209 dnl marking other symbols as private/local (or not).
 210 dnl
 211 dnl --enable-symvers=style adds a version script to the linker call when
 212 dnl       creating the shared library.  The choice of version script is
 213 dnl       controlled by 'style'.
 214 dnl --disable-symvers does not.
 215 dnl  +  Usage:  LIBGOMP_ENABLE_SYMVERS[(DEFAULT)]
 216 dnl       Where DEFAULT is either 'yes' or 'no'.  Passing `yes' tries to
 217 dnl       choose a default style based on linker characteristics.  Passing
 218 dnl       'no' disables versioning.
 219 dnl
 220 AC_DEFUN([LIBGOMP_ENABLE_SYMVERS], [
 221
 222 LIBGOMP_ENABLE(symvers,yes,[=STYLE],
 223   [enables symbol versioning of the shared library],
 224   [permit yes|no|gnu])
 225
 226 # If we never went through the LIBGOMP_CHECK_LINKER_FEATURES macro, then we
 227 # don't know enough about $LD to do tricks...
 228 AC_REQUIRE([LIBGOMP_CHECK_LINKER_FEATURES])
 229 # FIXME  The following test is too strict, in theory.
 230 if test $enable_shared = no ||
 231         test "x$LD" = x ||
 232         test x$libgomp_gnu_ld_version = x; then
 233   enable_symvers=no
 234 fi
 235
 236 # Check to see if libgcc_s exists, indicating that shared libgcc is possible.
 237 if test $enable_symvers != no; then
 238   AC_MSG_CHECKING([for shared libgcc])
 239   ac_save_CFLAGS="$CFLAGS"
 240   CFLAGS=' -lgcc_s'
 241   AC_TRY_LINK(, [return 0;], libgomp_shared_libgcc=yes, libgomp_shared_libgcc=no)
 242   CFLAGS="$ac_save_CFLAGS"
 243   if test $libgomp_shared_libgcc = no; then
 244     cat > conftest.c <<EOF
 245 int main (void) { return 0; }
 246 EOF
 247 changequote(,)dnl
 248     libgomp_libgcc_s_suffix=`${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \
 249                              -shared -shared-libgcc -o conftest.so \
 250                              conftest.c -v 2>&1 >/dev/null \
 251                              | sed -n 's/^.* -lgcc_s\([^ ]*\) .*$/\1/p'`
 252 changequote([,])dnl
 253     rm -f conftest.c conftest.so
 254     if test x${libgomp_libgcc_s_suffix+set} = xset; then
 255       CFLAGS=" -lgcc_s$libgomp_libgcc_s_suffix"
 256       AC_TRY_LINK(, [return 0;], libgomp_shared_libgcc=yes)
 257       CFLAGS="$ac_save_CFLAGS"
 258     fi
 259   fi
 260   AC_MSG_RESULT($libgomp_shared_libgcc)
 261 fi
 262
 263 # For GNU ld, we need at least this version.  The format is described in
 264 # LIBGOMP_CHECK_LINKER_FEATURES above.
 265 libgomp_min_gnu_ld_version=21400
 266 # XXXXXXXXXXX libgomp_gnu_ld_version=21390
 267
 268 # Check to see if unspecified "yes" value can win, given results above.
 269 # Change "yes" into either "no" or a style name.
 270 if test $enable_symvers = yes; then
 271   if test $with_gnu_ld = yes &&
 272      test $libgomp_shared_libgcc = yes;
 273   then
 274     if test $libgomp_gnu_ld_version -ge $libgomp_min_gnu_ld_version ; then
 275       enable_symvers=gnu
 276     else
 277       # The right tools, the right setup, but too old.  Fallbacks?
 278       AC_MSG_WARN(=== Linker version $libgomp_gnu_ld_version is too old for)
 279       AC_MSG_WARN(=== full symbol versioning support in this release of GCC.)
 280       AC_MSG_WARN(=== You would need to upgrade your binutils to version)
 281       AC_MSG_WARN(=== $libgomp_min_gnu_ld_version or later and rebuild GCC.)
 282       if test $libgomp_gnu_ld_version -ge 21200 ; then
 283         # Globbing fix is present, proper block support is not.
 284         dnl AC_MSG_WARN([=== Dude, you are soooo close.  Maybe we can fake it.])
 285         dnl enable_symvers=???
 286         AC_MSG_WARN([=== Symbol versioning will be disabled.])
 287         enable_symvers=no
 288       else
 289         # 2.11 or older.
 290         AC_MSG_WARN([=== Symbol versioning will be disabled.])
 291         enable_symvers=no
 292       fi
 293     fi
 294   else
 295     # just fail for now
 296     AC_MSG_WARN([=== You have requested some kind of symbol versioning, but])
 297     AC_MSG_WARN([=== either you are not using a supported linker, or you are])
 298     AC_MSG_WARN([=== not building a shared libgcc_s (which is required).])
 299     AC_MSG_WARN([=== Symbol versioning will be disabled.])
 300     enable_symvers=no
 301   fi
 302 fi
 303
 304 AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
 305 AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers)
 306 ])