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],-,_)[=][$2])
 103 m4_undefine([_g_switch])dnl
 104 m4_undefine([_g_help])dnl
 105 ])
 106
 107
 108 dnl
 109 dnl If GNU ld is in use, check to see if tricky linker opts can be used.  If
 110 dnl the native linker is in use, all variables will be defined to something
 111 dnl safe (like an empty string).
 112 dnl
 113 dnl Defines:
 114 dnl  SECTION_LDFLAGS='-Wl,--gc-sections' if possible
 115 dnl  OPT_LDFLAGS='-Wl,-O1' if possible
 116 dnl  LD (as a side effect of testing)
 117 dnl Sets:
 118 dnl  with_gnu_ld
 119 dnl  libgomp_ld_is_gold (possibly)
 120 dnl  libgomp_ld_is_mold (possibly)
 121 dnl  libgomp_gnu_ld_version (possibly)
 122 dnl
 123 dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
 124 dnl set libgomp_gnu_ld_version to 12345.  Zeros cause problems.
 125 dnl
 126 AC_DEFUN([LIBGOMP_CHECK_LINKER_FEATURES], [
 127   # If we're not using GNU ld, then there's no point in even trying these
 128   # tests.  Check for that first.  We should have already tested for gld
 129   # by now (in libtool), but require it now just to be safe...
 130   test -z "$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   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
 214 dnl
 215 dnl Add version tags to symbols in shared library (or not), additionally
 216 dnl marking other symbols as private/local (or not).
 217 dnl
 218 dnl --enable-symvers=style adds a version script to the linker call when
 219 dnl       creating the shared library.  The choice of version script is
 220 dnl       controlled by 'style'.
 221 dnl --disable-symvers does not.
 222 dnl  +  Usage:  LIBGOMP_ENABLE_SYMVERS[(DEFAULT)]
 223 dnl       Where DEFAULT is either 'yes' or 'no'.  Passing `yes' tries to
 224 dnl       choose a default style based on linker characteristics.  Passing
 225 dnl       'no' disables versioning.
 226 dnl
 227 AC_DEFUN([LIBGOMP_ENABLE_SYMVERS], [
 228
 229 LIBGOMP_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 $LD to do tricks...
 235 AC_REQUIRE([LIBGOMP_CHECK_LINKER_FEATURES])
 236
 237 # Turn a 'yes' into a suitable default.
 238 if test x$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 ${target_os} in
 247         # Sun symbol versioning exists since Solaris 2.5.
 248         solaris2.[[5-9]]* | solaris2.1[[0-9]]*)
 249           enable_symvers=sun ;;
 250         *)
 251           enable_symvers=no ;;
 252       esac
 253     fi
 254   fi
 255 fi
 256
 257 # Check if 'sun' was requested on non-Solaris 2 platforms.
 258 if test x$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
 271 fi
 272
 273 # Check to see if libgcc_s exists, indicating that shared libgcc is possible.
 274 if 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 $libgomp_shared_libgcc = no; then
 281     cat > conftest.c <<EOF
 282 int main (void) { return 0; }
 283 EOF
 284 changequote(,)dnl
 285     libgomp_libgcc_s_suffix=`${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\([^ ]*\) .*$/\1/p'`
 289 changequote([,])dnl
 290     rm -f conftest.c conftest.so
 291     if test x${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)
 298 fi
 299
 300 # For GNU ld, we need at least this version.  The format is described in
 301 # LIBGOMP_CHECK_LINKER_FEATURES above.
 302 libgomp_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.
 307 if 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
 343 fi
 344
 345 AC_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)])
 350 if 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.])
 353 fi
 354
 355 AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
 356 AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB_GNU, test $enable_symvers = gnu)
 357 AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB_SUN, test $enable_symvers = sun)
 358 AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers)
 359
 360 if 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
 372 fi
 373 ])