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, bar; bar = __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 dnl The lines below arrange for aclocal not to bring an installed
  60 dnl libtool.m4 into aclocal.m4, while still arranging for automake to
  61 dnl add a definition of LIBTOOL to Makefile.in.
  62 ifelse(,,,[AC_SUBST(LIBTOOL)
  63 AC_DEFUN([AM_PROG_LIBTOOL])
  64 AC_DEFUN([AC_LIBTOOL_DLOPEN])
  65 AC_DEFUN([AC_PROG_LD])
  66 ])
  67
  68 dnl ----------------------------------------------------------------------
  69 dnl This whole bit snagged from libstdc++-v3.
  70
  71 dnl
  72 dnl LIBGOMP_ENABLE
  73 dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING)
  74 dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, permit a|b|c)
  75 dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, SHELL-CODE-HANDLER)
  76 dnl
  77 dnl See docs/html/17_intro/configury.html#enable for documentation.
  78 dnl
  79 m4_define([LIBGOMP_ENABLE],[dnl
  80 m4_define([_g_switch],[--enable-$1])dnl
  81 m4_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],-,_)[=][$2])
 102 m4_undefine([_g_switch])dnl
 103 m4_undefine([_g_help])dnl
 104 ])
 105
 106
 107 dnl
 108 dnl If GNU ld is in use, check to see if tricky linker opts can be used.  If
 109 dnl the native linker is in use, all variables will be defined to something
 110 dnl safe (like an empty string).
 111 dnl
 112 dnl Defines:
 113 dnl  SECTION_LDFLAGS='-Wl,--gc-sections' if possible
 114 dnl  OPT_LDFLAGS='-Wl,-O1' if possible
 115 dnl  LD (as a side effect of testing)
 116 dnl Sets:
 117 dnl  with_gnu_ld
 118 dnl  libgomp_ld_is_gold (possibly)
 119 dnl  libgomp_gnu_ld_version (possibly)
 120 dnl
 121 dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
 122 dnl set libgomp_gnu_ld_version to 12345.  Zeros cause problems.
 123 dnl
 124 AC_DEFUN([LIBGOMP_CHECK_LINKER_FEATURES], [
 125   # If we're not using GNU ld, then there's no point in even trying these
 126   # tests.  Check for that first.  We should have already tested for gld
 127   # by now (in libtool), but require it now just to be safe...
 128   test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS=''
 129   test -z "$OPT_LDFLAGS" && OPT_LDFLAGS=''
 130   AC_REQUIRE([AC_PROG_LD])
 131   AC_REQUIRE([AC_PROG_AWK])
 132
 133   # The name set by libtool depends on the version of libtool.  Shame on us
 134   # for depending on an impl detail, but c'est la vie.  Older versions used
 135   # ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on
 136   # top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually
 137   # makes sense).  We'll test with_gnu_ld everywhere else, so if that isn't
 138   # set (hence we're using an older libtool), then set it.
 139   if test x${with_gnu_ld+set} != xset; then
 140     if test x${ac_cv_prog_gnu_ld+set} != xset; then
 141       # We got through "ac_require(ac_prog_ld)" and still not set?  Huh?
 142       with_gnu_ld=no
 143     else
 144       with_gnu_ld=$ac_cv_prog_gnu_ld
 145     fi
 146   fi
 147
 148   # Start by getting the version number.  I think the libtool test already
 149   # does some of this, but throws away the result.
 150   libgomp_ld_is_gold=no
 151   if $LD --version 2>/dev/null | grep 'GNU gold'> /dev/null 2>&1; then
 152     libgomp_ld_is_gold=yes
 153   fi
 154   changequote(,)
 155   ldver=`$LD --version 2>/dev/null | head -1 | \
 156          sed -e 's/GNU \(go\)\{0,1\}ld \(version \)\{0,1\}\(([^)]*) \)\{0,1\}\([0-9.][0-9.]*\).*/\4/'`
 157   changequote([,])
 158   libgomp_gnu_ld_version=`echo $ldver | \
 159          $AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`
 160
 161   # Set --gc-sections.
 162   if test "$with_gnu_ld" = "notbroken"; then
 163     # GNU ld it is!  Joy and bunny rabbits!
 164
 165     # All these tests are for C++; save the language and the compiler flags.
 166     # Need to do this so that g++ won't try to link in libstdc++
 167     ac_test_CFLAGS="${CFLAGS+set}"
 168     ac_save_CFLAGS="$CFLAGS"
 169     CFLAGS='-x c++  -Wl,--gc-sections'
 170
 171     # Check for -Wl,--gc-sections
 172     # XXX This test is broken at the moment, as symbols required for linking
 173     # are now in libsupc++ (not built yet).  In addition, this test has
 174     # cored on solaris in the past.  In addition, --gc-sections doesn't
 175     # really work at the moment (keeps on discarding used sections, first
 176     # .eh_frame and now some of the glibc sections for iconv).
 177     # Bzzzzt.  Thanks for playing, maybe next time.
 178     AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
 179     AC_TRY_RUN([
 180      int main(void)
 181      {
 182        try { throw 1; }
 183        catch (...) { };
 184        return 0;
 185      }
 186     ], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes])
 187     if test "$ac_test_CFLAGS" = set; then
 188       CFLAGS="$ac_save_CFLAGS"
 189     else
 190       # this is the suspicious part
 191       CFLAGS=''
 192     fi
 193     if test "$ac_sectionLDflags" = "yes"; then
 194       SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
 195     fi
 196     AC_MSG_RESULT($ac_sectionLDflags)
 197   fi
 198
 199   # Set linker optimization flags.
 200   if test x"$with_gnu_ld" = x"yes"; then
 201     OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
 202   fi
 203
 204   AC_SUBST(SECTION_LDFLAGS)
 205   AC_SUBST(OPT_LDFLAGS)
 206 ])
 207
 208
 209 dnl
 210 dnl Add version tags to symbols in shared library (or not), additionally
 211 dnl marking other symbols as private/local (or not).
 212 dnl
 213 dnl --enable-symvers=style adds a version script to the linker call when
 214 dnl       creating the shared library.  The choice of version script is
 215 dnl       controlled by 'style'.
 216 dnl --disable-symvers does not.
 217 dnl  +  Usage:  LIBGOMP_ENABLE_SYMVERS[(DEFAULT)]
 218 dnl       Where DEFAULT is either 'yes' or 'no'.  Passing `yes' tries to
 219 dnl       choose a default style based on linker characteristics.  Passing
 220 dnl       'no' disables versioning.
 221 dnl
 222 AC_DEFUN([LIBGOMP_ENABLE_SYMVERS], [
 223
 224 LIBGOMP_ENABLE(symvers,yes,[=STYLE],
 225   [enables symbol versioning of the shared library],
 226   [permit yes|no|gnu])
 227
 228 # If we never went through the LIBGOMP_CHECK_LINKER_FEATURES macro, then we
 229 # don't know enough about $LD to do tricks...
 230 AC_REQUIRE([LIBGOMP_CHECK_LINKER_FEATURES])
 231 # FIXME  The following test is too strict, in theory.
 232 if test $enable_shared = no ||
 233         test "x$LD" = x ||
 234         test x$libgomp_gnu_ld_version = x; then
 235   enable_symvers=no
 236 fi
 237
 238 # Check to see if libgcc_s exists, indicating that shared libgcc is possible.
 239 if test $enable_symvers != no; then
 240   AC_MSG_CHECKING([for shared libgcc])
 241   ac_save_CFLAGS="$CFLAGS"
 242   CFLAGS=' -lgcc_s'
 243   AC_TRY_LINK(, [return 0;], libgomp_shared_libgcc=yes, libgomp_shared_libgcc=no)
 244   CFLAGS="$ac_save_CFLAGS"
 245   if test $libgomp_shared_libgcc = no; then
 246     cat > conftest.c <<EOF
 247 int main (void) { return 0; }
 248 EOF
 249 changequote(,)dnl
 250     libgomp_libgcc_s_suffix=`${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \
 251                              -shared -shared-libgcc -o conftest.so \
 252                              conftest.c -v 2>&1 >/dev/null \
 253                              | sed -n 's/^.* -lgcc_s\([^ ]*\) .*$/\1/p'`
 254 changequote([,])dnl
 255     rm -f conftest.c conftest.so
 256     if test x${libgomp_libgcc_s_suffix+set} = xset; then
 257       CFLAGS=" -lgcc_s$libgomp_libgcc_s_suffix"
 258       AC_TRY_LINK(, [return 0;], libgomp_shared_libgcc=yes)
 259       CFLAGS="$ac_save_CFLAGS"
 260     fi
 261   fi
 262   AC_MSG_RESULT($libgomp_shared_libgcc)
 263 fi
 264
 265 # For GNU ld, we need at least this version.  The format is described in
 266 # LIBGOMP_CHECK_LINKER_FEATURES above.
 267 libgomp_min_gnu_ld_version=21400
 268 # XXXXXXXXXXX libgomp_gnu_ld_version=21390
 269
 270 # Check to see if unspecified "yes" value can win, given results above.
 271 # Change "yes" into either "no" or a style name.
 272 if test $enable_symvers = yes; then
 273   if test $with_gnu_ld = yes &&
 274      test $libgomp_shared_libgcc = yes;
 275   then
 276     if test $libgomp_gnu_ld_version -ge $libgomp_min_gnu_ld_version ; then
 277       enable_symvers=gnu
 278     elif test $libgomp_ld_is_gold = yes ; then
 279       enable_symvers=gnu
 280     else
 281       # The right tools, the right setup, but too old.  Fallbacks?
 282       AC_MSG_WARN(=== Linker version $libgomp_gnu_ld_version is too old for)
 283       AC_MSG_WARN(=== full symbol versioning support in this release of GCC.)
 284       AC_MSG_WARN(=== You would need to upgrade your binutils to version)
 285       AC_MSG_WARN(=== $libgomp_min_gnu_ld_version or later and rebuild GCC.)
 286       if test $libgomp_gnu_ld_version -ge 21200 ; then
 287         # Globbing fix is present, proper block support is not.
 288         dnl AC_MSG_WARN([=== Dude, you are soooo close.  Maybe we can fake it.])
 289         dnl enable_symvers=???
 290         AC_MSG_WARN([=== Symbol versioning will be disabled.])
 291         enable_symvers=no
 292       else
 293         # 2.11 or older.
 294         AC_MSG_WARN([=== Symbol versioning will be disabled.])
 295         enable_symvers=no
 296       fi
 297     fi
 298   else
 299     # just fail for now
 300     AC_MSG_WARN([=== You have requested some kind of symbol versioning, but])
 301     AC_MSG_WARN([=== either you are not using a supported linker, or you are])
 302     AC_MSG_WARN([=== not building a shared libgcc_s (which is required).])
 303     AC_MSG_WARN([=== Symbol versioning will be disabled.])
 304     enable_symvers=no
 305   fi
 306 fi
 307
 308 AC_CACHE_CHECK([whether the target supports .symver directive],
 309                libgomp_cv_have_as_symver_directive, [
 310   AC_TRY_COMPILE([void foo (void); __asm (".symver foo, bar@SYMVER");],
 311                  [], libgomp_cv_have_as_symver_directive=yes,
 312                  libgomp_cv_have_as_symver_directive=no)])
 313 if test $libgomp_cv_have_as_symver_directive = yes; then
 314   AC_DEFINE(HAVE_AS_SYMVER_DIRECTIVE, 1,
 315     [Define to 1 if the target assembler supports .symver directive.])
 316 fi
 317
 318 AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
 319 AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers)
 320 ])