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                  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 $libgomp_cv_have_sync_builtins = yes; then
  11     AC_DEFINE(HAVE_SYNC_BUILTINS, 1,
  12               [Define to 1 if the target supports __sync_*_compare_and_swap])
  13   fi])
  14
  15 dnl Check whether the target supports hidden visibility.
  16 AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_VISIBILITY], [
  17   AC_CACHE_CHECK([whether the target supports hidden visibility],
  18                  libgomp_cv_have_attribute_visibility, [
  19   save_CFLAGS="$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 $libgomp_cv_have_attribute_visibility = yes; then
  26     AC_DEFINE(HAVE_ATTRIBUTE_VISIBILITY, 1,
  27       [Define to 1 if the target supports __attribute__((visibility(...))).])
  28   fi])
  29
  30 dnl Check whether the target supports dllexport
  31 AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_DLLEXPORT], [
  32   AC_CACHE_CHECK([whether the target supports dllexport],
  33                  libgomp_cv_have_attribute_dllexport, [
  34   save_CFLAGS="$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
  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                  libgomp_cv_have_attribute_alias, [
  49   AC_TRY_LINK([
  50 void foo(void) { }
  51 extern 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
  58 sinclude(../libtool.m4)
  59 sinclude(../config/cet.m4)
  60 dnl The lines below arrange for aclocal not to bring an installed
  61 dnl libtool.m4 into aclocal.m4, while still arranging for automake to
  62 dnl add a definition of LIBTOOL to Makefile.in.
  63 ifelse(,,,[AC_SUBST(LIBTOOL)
  64 AC_DEFUN([AM_PROG_LIBTOOL])
  65 AC_DEFUN([AC_LIBTOOL_DLOPEN])
  66 AC_DEFUN([AC_PROG_LD])
  67 ])
  68
  69 dnl ----------------------------------------------------------------------
  70 dnl This whole bit snagged from libstdc++-v3.
  71
  72 dnl
  73 dnl LIBGOMP_ENABLE
  74 dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING)
  75 dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, permit a|b|c)
  76 dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, SHELL-CODE-HANDLER)
  77 dnl
  78 dnl See docs/html/17_intro/configury.html#enable for documentation.
  79 dnl
  80 m4_define([LIBGOMP_ENABLE],[dnl
  81 m4_define([_g_switch],[--enable-$1])dnl
  82 m4_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],-,_)[=][$2])
 103 m4_undefine([_g_switch])dnl
 104 m4_undefine([_g_help])dnl
 105 ])
 106
 107
 108 dnl
 109 dnl If GNU ld is in use, check to see if tricky linker opts can be used.  If
 110 dnl the native linker is in use, all variables will be defined to something
 111 dnl safe (like an empty string).
 112 dnl
 113 dnl Defines:
 114 dnl  SECTION_LDFLAGS='-Wl,--gc-sections' if possible
 115 dnl  OPT_LDFLAGS='-Wl,-O1' if possible
 116 dnl  LD (as a side effect of testing)
 117 dnl Sets:
 118 dnl  with_gnu_ld
 119 dnl  libgomp_ld_is_gold (possibly)
 120 dnl  libgomp_gnu_ld_version (possibly)
 121 dnl
 122 dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
 123 dnl set libgomp_gnu_ld_version to 12345.  Zeros cause problems.
 124 dnl
 125 AC_DEFUN([LIBGOMP_CHECK_LINKER_FEATURES], [
 126   # If we're not using GNU ld, then there's no point in even trying these
 127   # tests.  Check for that first.  We should have already tested for gld
 128   # by now (in libtool), but require it now just to be safe...
 129   test -z "$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
 210 dnl
 211 dnl Add version tags to symbols in shared library (or not), additionally
 212 dnl marking other symbols as private/local (or not).
 213 dnl
 214 dnl --enable-symvers=style adds a version script to the linker call when
 215 dnl       creating the shared library.  The choice of version script is
 216 dnl       controlled by 'style'.
 217 dnl --disable-symvers does not.
 218 dnl  +  Usage:  LIBGOMP_ENABLE_SYMVERS[(DEFAULT)]
 219 dnl       Where DEFAULT is either 'yes' or 'no'.  Passing `yes' tries to
 220 dnl       choose a default style based on linker characteristics.  Passing
 221 dnl       'no' disables versioning.
 222 dnl
 223 AC_DEFUN([LIBGOMP_ENABLE_SYMVERS], [
 224
 225 LIBGOMP_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 $LD to do tricks...
 231 AC_REQUIRE([LIBGOMP_CHECK_LINKER_FEATURES])
 232
 233 # Turn a 'yes' into a suitable default.
 234 if test x$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 ${target_os} in
 243         # Sun symbol versioning exists since Solaris 2.5.
 244         solaris2.[[5-9]]* | solaris2.1[[0-9]]*)
 245           enable_symvers=sun ;;
 246         *)
 247           enable_symvers=no ;;
 248       esac
 249     fi
 250   fi
 251 fi
 252
 253 # Check if 'sun' was requested on non-Solaris 2 platforms.
 254 if test x$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
 267 fi
 268
 269 # Check to see if libgcc_s exists, indicating that shared libgcc is possible.
 270 if 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 $libgomp_shared_libgcc = no; then
 277     cat > conftest.c <<EOF
 278 int main (void) { return 0; }
 279 EOF
 280 changequote(,)dnl
 281     libgomp_libgcc_s_suffix=`${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\([^ ]*\) .*$/\1/p'`
 285 changequote([,])dnl
 286     rm -f conftest.c conftest.so
 287     if test x${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)
 294 fi
 295
 296 # For GNU ld, we need at least this version.  The format is described in
 297 # LIBGOMP_CHECK_LINKER_FEATURES above.
 298 libgomp_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.
 303 if 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
 337 fi
 338
 339 AC_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)])
 344 if 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.])
 347 fi
 348
 349 AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
 350 AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB_GNU, test $enable_symvers = gnu)
 351 AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB_SUN, test $enable_symvers = sun)
 352 AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers)
 353
 354 if 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
 366 fi
 367 ])