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