[thirdparty/gcc.git] / libgomp / acinclude.m4

dnl ----------------------------------------------------------------------
dnl This whole bit snagged from libgfortran.

dnl Check whether the target supports __sync_*_compare_and_swap.
AC_DEFUN([LIBGOMP_CHECK_SYNC_BUILTINS], [
  AC_CACHE_CHECK([whether the target supports __sync_*_compare_and_swap],
		 libgomp_cv_have_sync_builtins, [
  AC_TRY_LINK([], [int foo; __sync_val_compare_and_swap(&foo, 0, 1);],
	      libgomp_cv_have_sync_builtins=yes, libgomp_cv_have_sync_builtins=no)])
  if test $libgomp_cv_have_sync_builtins = yes; then
    AC_DEFINE(HAVE_SYNC_BUILTINS, 1,
	      [Define to 1 if the target supports __sync_*_compare_and_swap])
  fi])

dnl Check whether the target supports hidden visibility.
AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_VISIBILITY], [
  AC_CACHE_CHECK([whether the target supports hidden visibility],
		 libgomp_cv_have_attribute_visibility, [
  save_CFLAGS="$CFLAGS"
  CFLAGS="$CFLAGS -Werror"
  AC_TRY_COMPILE([void __attribute__((visibility("hidden"))) foo(void) { }],
		 [], libgomp_cv_have_attribute_visibility=yes,
		 libgomp_cv_have_attribute_visibility=no)
  CFLAGS="$save_CFLAGS"])
  if test $libgomp_cv_have_attribute_visibility = yes; then
    AC_DEFINE(HAVE_ATTRIBUTE_VISIBILITY, 1,
      [Define to 1 if the target supports __attribute__((visibility(...))).])
  fi])

dnl Check whether the target supports dllexport
AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_DLLEXPORT], [
  AC_CACHE_CHECK([whether the target supports dllexport],
		 libgomp_cv_have_attribute_dllexport, [
  save_CFLAGS="$CFLAGS"
  CFLAGS="$CFLAGS -Werror"
  AC_TRY_COMPILE([void __attribute__((dllexport)) foo(void) { }],
		 [], libgomp_cv_have_attribute_dllexport=yes,
		 libgomp_cv_have_attribute_dllexport=no)
  CFLAGS="$save_CFLAGS"])
  if test $libgomp_cv_have_attribute_dllexport = yes; then
    AC_DEFINE(HAVE_ATTRIBUTE_DLLEXPORT, 1,
      [Define to 1 if the target supports __attribute__((dllexport)).])
  fi])

dnl Check whether the target supports symbol aliases.
AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_ALIAS], [
  AC_CACHE_CHECK([whether the target supports symbol aliases],
		 libgomp_cv_have_attribute_alias, [
  AC_TRY_LINK([
void foo(void) { }
extern void bar(void) __attribute__((alias("foo")));],
    [bar();], libgomp_cv_have_attribute_alias=yes, libgomp_cv_have_attribute_alias=no)])
  if test $libgomp_cv_have_attribute_alias = yes; then
    AC_DEFINE(HAVE_ATTRIBUTE_ALIAS, 1,
      [Define to 1 if the target supports __attribute__((alias(...))).])
  fi])

sinclude(../libtool.m4)
sinclude(../config/cet.m4)
dnl The lines below arrange for aclocal not to bring an installed
dnl libtool.m4 into aclocal.m4, while still arranging for automake to
dnl add a definition of LIBTOOL to Makefile.in.
ifelse(,,,[AC_SUBST(LIBTOOL)
AC_DEFUN([AM_PROG_LIBTOOL])
AC_DEFUN([AC_LIBTOOL_DLOPEN])
AC_DEFUN([AC_PROG_LD])
])

dnl ----------------------------------------------------------------------
dnl This whole bit snagged from libstdc++-v3.

dnl
dnl LIBGOMP_ENABLE
dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING)
dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, permit a|b|c)
dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, SHELL-CODE-HANDLER)
dnl
dnl See docs/html/17_intro/configury.html#enable for documentation.
dnl
m4_define([LIBGOMP_ENABLE],[dnl
m4_define([_g_switch],[--enable-$1])dnl
m4_define([_g_help],[AC_HELP_STRING(_g_switch$3,[$4 @<:@default=$2@:>@])])dnl
 AC_ARG_ENABLE($1,_g_help,
  m4_bmatch([$5],
   [^permit ],
     [[
      case "$enableval" in
       m4_bpatsubst([$5],[permit ])) ;;
       *) AC_MSG_ERROR(Unknown argument to enable/disable $1) ;;
          dnl Idea for future:  generate a URL pointing to
          dnl "onlinedocs/configopts.html#whatever"
      esac
     ]],
   [^$],
     [[
      case "$enableval" in
       yes|no) ;;
       *) AC_MSG_ERROR(Argument to enable/disable $1 must be yes or no) ;;
      esac
     ]],
   [[$5]]),
  [enable_]m4_bpatsubst([$1],-,_)[=][$2])
m4_undefine([_g_switch])dnl
m4_undefine([_g_help])dnl
])


dnl
dnl If GNU ld is in use, check to see if tricky linker opts can be used.  If
dnl the native linker is in use, all variables will be defined to something
dnl safe (like an empty string).
dnl
dnl Defines:
dnl  SECTION_LDFLAGS='-Wl,--gc-sections' if possible
dnl  OPT_LDFLAGS='-Wl,-O1' if possible
dnl  LD (as a side effect of testing)
dnl Sets:
dnl  with_gnu_ld
dnl  libgomp_ld_is_gold (possibly)
dnl  libgomp_gnu_ld_version (possibly)
dnl
dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
dnl set libgomp_gnu_ld_version to 12345.  Zeros cause problems.
dnl
AC_DEFUN([LIBGOMP_CHECK_LINKER_FEATURES], [
  # If we're not using GNU ld, then there's no point in even trying these
  # tests.  Check for that first.  We should have already tested for gld
  # by now (in libtool), but require it now just to be safe...
  test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS=''
  test -z "$OPT_LDFLAGS" && OPT_LDFLAGS=''
  AC_REQUIRE([AC_PROG_LD])
  AC_REQUIRE([AC_PROG_AWK])

  # The name set by libtool depends on the version of libtool.  Shame on us
  # for depending on an impl detail, but c'est la vie.  Older versions used
  # ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on
  # top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually
  # makes sense).  We'll test with_gnu_ld everywhere else, so if that isn't
  # set (hence we're using an older libtool), then set it.
  if test x${with_gnu_ld+set} != xset; then
    if test x${ac_cv_prog_gnu_ld+set} != xset; then
      # We got through "ac_require(ac_prog_ld)" and still not set?  Huh?
      with_gnu_ld=no
    else
      with_gnu_ld=$ac_cv_prog_gnu_ld
    fi
  fi

  # Start by getting the version number.  I think the libtool test already
  # does some of this, but throws away the result.
  libgomp_ld_is_gold=no
  if $LD --version 2>/dev/null | grep 'GNU gold'> /dev/null 2>&1; then
    libgomp_ld_is_gold=yes
  fi
  changequote(,)
  ldver=`$LD --version 2>/dev/null |
         sed -e 's/GNU gold /GNU ld /;s/GNU ld version /GNU ld /;s/GNU ld ([^)]*) /GNU ld /;s/GNU ld \([0-9.][0-9.]*\).*/\1/; q'`
  changequote([,])
  libgomp_gnu_ld_version=`echo $ldver | \
         $AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`

  # Set --gc-sections.
  if test "$with_gnu_ld" = "notbroken"; then
    # GNU ld it is!  Joy and bunny rabbits!

    # All these tests are for C++; save the language and the compiler flags.
    # Need to do this so that g++ won't try to link in libstdc++
    ac_test_CFLAGS="${CFLAGS+set}"
    ac_save_CFLAGS="$CFLAGS"
    CFLAGS='-x c++  -Wl,--gc-sections'

    # Check for -Wl,--gc-sections
    # XXX This test is broken at the moment, as symbols required for linking
    # are now in libsupc++ (not built yet).  In addition, this test has
    # cored on solaris in the past.  In addition, --gc-sections doesn't
    # really work at the moment (keeps on discarding used sections, first
    # .eh_frame and now some of the glibc sections for iconv).
    # Bzzzzt.  Thanks for playing, maybe next time.
    AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
    AC_TRY_RUN([
     int main(void)
     {
       try { throw 1; }
       catch (...) { };
       return 0;
     }
    ], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes])
    if test "$ac_test_CFLAGS" = set; then
      CFLAGS="$ac_save_CFLAGS"
    else
      # this is the suspicious part
      CFLAGS=''
    fi
    if test "$ac_sectionLDflags" = "yes"; then
      SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
    fi
    AC_MSG_RESULT($ac_sectionLDflags)
  fi

  # Set linker optimization flags.
  if test x"$with_gnu_ld" = x"yes"; then
    OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
  fi

  AC_SUBST(SECTION_LDFLAGS)
  AC_SUBST(OPT_LDFLAGS)
])


dnl
dnl Add version tags to symbols in shared library (or not), additionally
dnl marking other symbols as private/local (or not).
dnl
dnl --enable-symvers=style adds a version script to the linker call when
dnl       creating the shared library.  The choice of version script is
dnl       controlled by 'style'.
dnl --disable-symvers does not.
dnl  +  Usage:  LIBGOMP_ENABLE_SYMVERS[(DEFAULT)]
dnl       Where DEFAULT is either 'yes' or 'no'.  Passing `yes' tries to
dnl       choose a default style based on linker characteristics.  Passing
dnl       'no' disables versioning.
dnl
AC_DEFUN([LIBGOMP_ENABLE_SYMVERS], [

LIBGOMP_ENABLE(symvers,yes,[=STYLE],
  [enables symbol versioning of the shared library],
  [permit yes|no|gnu*|sun])

# If we never went through the LIBGOMP_CHECK_LINKER_FEATURES macro, then we
# don't know enough about $LD to do tricks...
AC_REQUIRE([LIBGOMP_CHECK_LINKER_FEATURES])

# Turn a 'yes' into a suitable default.
if test x$enable_symvers = xyes ; then
  # FIXME  The following test is too strict, in theory.
  if test $enable_shared = no || test "x$LD" = x; then
    enable_symvers=no
  else
    if test $with_gnu_ld = yes ; then
      enable_symvers=gnu
    else
      case ${target_os} in
        # Sun symbol versioning exists since Solaris 2.5.
        solaris2.[[5-9]]* | solaris2.1[[0-9]]*)
          enable_symvers=sun ;;
        *)
          enable_symvers=no ;;
      esac
    fi
  fi
fi

# Check if 'sun' was requested on non-Solaris 2 platforms.
if test x$enable_symvers = xsun ; then
  case ${target_os} in
    solaris2*)
      # All fine.
      ;;
    *)
      # Unlikely to work.
      AC_MSG_WARN([=== You have requested Sun symbol versioning, but])
      AC_MSG_WARN([=== you are not targetting Solaris 2.])
      AC_MSG_WARN([=== Symbol versioning will be disabled.])
      enable_symvers=no
      ;;
  esac
fi

# Check to see if libgcc_s exists, indicating that shared libgcc is possible.
if test $enable_symvers != no; then
  AC_MSG_CHECKING([for shared libgcc])
  ac_save_CFLAGS="$CFLAGS"
  CFLAGS=' -lgcc_s'
  AC_TRY_LINK(, [return 0;], libgomp_shared_libgcc=yes, libgomp_shared_libgcc=no)
  CFLAGS="$ac_save_CFLAGS"
  if test $libgomp_shared_libgcc = no; then
    cat > conftest.c <<EOF
int main (void) { return 0; }
EOF
changequote(,)dnl
    libgomp_libgcc_s_suffix=`${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \
			     -shared -shared-libgcc -o conftest.so \
			     conftest.c -v 2>&1 >/dev/null \
			     | sed -n 's/^.* -lgcc_s\([^ ]*\) .*$/\1/p'`
changequote([,])dnl
    rm -f conftest.c conftest.so
    if test x${libgomp_libgcc_s_suffix+set} = xset; then
      CFLAGS=" -lgcc_s$libgomp_libgcc_s_suffix"
      AC_TRY_LINK(, [return 0;], libgomp_shared_libgcc=yes)
      CFLAGS="$ac_save_CFLAGS"
    fi
  fi
  AC_MSG_RESULT($libgomp_shared_libgcc)
fi

# For GNU ld, we need at least this version.  The format is described in
# LIBGOMP_CHECK_LINKER_FEATURES above.
libgomp_min_gnu_ld_version=21400
# XXXXXXXXXXX libgomp_gnu_ld_version=21390

# Check to see if unspecified "yes" value can win, given results above.
# Change "yes" into either "no" or a style name.
if test $enable_symvers != no && test $libgomp_shared_libgcc = yes; then
  if test $with_gnu_ld = yes; then
    if test $libgomp_gnu_ld_version -ge $libgomp_min_gnu_ld_version ; then
      enable_symvers=gnu
    elif test $libgomp_ld_is_gold = yes ; then
      enable_symvers=gnu
    else
      # The right tools, the right setup, but too old.  Fallbacks?
      AC_MSG_WARN(=== Linker version $libgomp_gnu_ld_version is too old for)
      AC_MSG_WARN(=== full symbol versioning support in this release of GCC.)
      AC_MSG_WARN(=== You would need to upgrade your binutils to version)
      AC_MSG_WARN(=== $libgomp_min_gnu_ld_version or later and rebuild GCC.)
      if test $libgomp_gnu_ld_version -ge 21200 ; then
        # Globbing fix is present, proper block support is not.
        dnl AC_MSG_WARN([=== Dude, you are soooo close.  Maybe we can fake it.])
        dnl enable_symvers=???
        AC_MSG_WARN([=== Symbol versioning will be disabled.])
        enable_symvers=no
      else
        # 2.11 or older.
        AC_MSG_WARN([=== Symbol versioning will be disabled.])
        enable_symvers=no
      fi
    fi
  elif test $enable_symvers = sun; then
    : All interesting versions of Sun ld support sun style symbol versioning.
  else
    # just fail for now
    AC_MSG_WARN([=== You have requested some kind of symbol versioning, but])
    AC_MSG_WARN([=== either you are not using a supported linker, or you are])
    AC_MSG_WARN([=== not building a shared libgcc_s (which is required).])
    AC_MSG_WARN([=== Symbol versioning will be disabled.])
    enable_symvers=no
  fi
fi

AC_CACHE_CHECK([whether the target supports .symver directive],
	       libgomp_cv_have_as_symver_directive, [
  AC_TRY_COMPILE([void foo (void); __asm (".symver foo, bar@SYMVER");],
		 [], libgomp_cv_have_as_symver_directive=yes,
		 libgomp_cv_have_as_symver_directive=no)])
if test $libgomp_cv_have_as_symver_directive = yes; then
  AC_DEFINE(HAVE_AS_SYMVER_DIRECTIVE, 1,
    [Define to 1 if the target assembler supports .symver directive.])
fi

AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB_GNU, test $enable_symvers = gnu)
AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB_SUN, test $enable_symvers = sun)
AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers)

if test $enable_symvers != no ; then
   case ${target_os} in
     # The Solaris 2 runtime linker doesn't support the GNU extension of
     # binding the same symbol to different versions
     solaris2*)
       ;;
     # Other platforms with GNU symbol versioning (GNU/Linux, more?) do.
     *)
       AC_DEFINE(HAVE_SYMVER_SYMBOL_RENAMING_RUNTIME_SUPPORT, 1,
         [Define to 1 if the target runtime linker supports binding the same symbol to different versions.])
       ;;
    esac
fi
])
Commit	Line	Data
1e8e9920	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],
6992582a	7	libgomp_cv_have_sync_builtins, [
14a88549	8	AC_TRY_LINK([], [int foo; __sync_val_compare_and_swap(&foo, 0, 1);],
6992582a	9	libgomp_cv_have_sync_builtins=yes, libgomp_cv_have_sync_builtins=no)])
6992582a	10	if test $libgomp_cv_have_sync_builtins = yes; then
1e8e9920	11	AC_DEFINE(HAVE_SYNC_BUILTINS, 1,
	12	[Define to 1 if the target supports __sync_*_compare_and_swap])
	13	fi])
	14
	15	dnl Check whether the target supports hidden visibility.
	16	AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_VISIBILITY], [
	17	AC_CACHE_CHECK([whether the target supports hidden visibility],
6992582a	18	libgomp_cv_have_attribute_visibility, [
1e8e9920	19	save_CFLAGS="$CFLAGS"
	20	CFLAGS="$CFLAGS -Werror"
	21	AC_TRY_COMPILE([void __attribute__((visibility("hidden"))) foo(void) { }],
6992582a	22	[], libgomp_cv_have_attribute_visibility=yes,
6992582a	23	libgomp_cv_have_attribute_visibility=no)
1e8e9920	24	CFLAGS="$save_CFLAGS"])
6992582a	25	if test $libgomp_cv_have_attribute_visibility = yes; then
1e8e9920	26	AC_DEFINE(HAVE_ATTRIBUTE_VISIBILITY, 1,
	27	[Define to 1 if the target supports __attribute__((visibility(...))).])
	28	fi])
	29
	30	dnl Check whether the target supports dllexport
	31	AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_DLLEXPORT], [
	32	AC_CACHE_CHECK([whether the target supports dllexport],
6992582a	33	libgomp_cv_have_attribute_dllexport, [
1e8e9920	34	save_CFLAGS="$CFLAGS"
	35	CFLAGS="$CFLAGS -Werror"
	36	AC_TRY_COMPILE([void __attribute__((dllexport)) foo(void) { }],
6992582a	37	[], libgomp_cv_have_attribute_dllexport=yes,
6992582a	38	libgomp_cv_have_attribute_dllexport=no)
1e8e9920	39	CFLAGS="$save_CFLAGS"])
6992582a	40	if test $libgomp_cv_have_attribute_dllexport = yes; then
1e8e9920	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],
6992582a	48	libgomp_cv_have_attribute_alias, [
1e8e9920	49	AC_TRY_LINK([
1e8e9920	50	void foo(void) { }
c812091b	51	extern void bar(void) __attribute__((alias("foo")));],
6992582a	52	[bar();], libgomp_cv_have_attribute_alias=yes, libgomp_cv_have_attribute_alias=no)])
6992582a	53	if test $libgomp_cv_have_attribute_alias = yes; then
1e8e9920	54	AC_DEFINE(HAVE_ATTRIBUTE_ALIAS, 1,
	55	[Define to 1 if the target supports __attribute__((alias(...))).])
	56	fi])
	57
	58	sinclude(../libtool.m4)
79e3a293	59	sinclude(../config/cet.m4)
1e8e9920	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],-,_)[=][$2])
	103	m4_undefine([_g_switch])dnl
	104	m4_undefine([_g_help])dnl
	105	])
	106
	107
	108	dnl
	109	dnl If GNU ld is in use, check to see if tricky linker opts can be used. If
	110	dnl the native linker is in use, all variables will be defined to something
	111	dnl safe (like an empty string).
	112	dnl
	113	dnl Defines:
	114	dnl SECTION_LDFLAGS='-Wl,--gc-sections' if possible
	115	dnl OPT_LDFLAGS='-Wl,-O1' if possible
	116	dnl LD (as a side effect of testing)
	117	dnl Sets:
	118	dnl with_gnu_ld
d3d87030	119	dnl libgomp_ld_is_gold (possibly)
1e8e9920	120	dnl libgomp_gnu_ld_version (possibly)
	121	dnl
	122	dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
	123	dnl set libgomp_gnu_ld_version to 12345. Zeros cause problems.
	124	dnl
	125	AC_DEFUN([LIBGOMP_CHECK_LINKER_FEATURES], [
	126	# If we're not using GNU ld, then there's no point in even trying these
	127	# tests. Check for that first. We should have already tested for gld
	128	# by now (in libtool), but require it now just to be safe...
	129	test -z "$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.
d3d87030	151	libgomp_ld_is_gold=no
	152	if $LD --version 2>/dev/null \| grep 'GNU gold'> /dev/null 2>&1; then
	153	libgomp_ld_is_gold=yes
	154	fi
1e8e9920	155	changequote(,)
8dc52806	156	ldver=`$LD --version 2>/dev/null \|
8b501d36	157	sed -e 's/GNU gold /GNU ld /;s/GNU ld version /GNU ld /;s/GNU ld ([^)]) /GNU ld /;s/GNU ld \([0-9.][0-9.]\).*/\1/; q'`
1e8e9920	158	changequote([,])
	159	libgomp_gnu_ld_version=`echo $ldver \| \
	160	$AWK -F. '{ if (NF<3) [$]3=0; print ([$]1100+[$]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],
de656189	227	[permit yes\|no\|gnu*\|sun])
1e8e9920	228
	229	# If we never went through the LIBGOMP_CHECK_LINKER_FEATURES macro, then we
	230	# don't know enough about $LD to do tricks...
	231	AC_REQUIRE([LIBGOMP_CHECK_LINKER_FEATURES])
bbb514dc	232
	233	# Turn a 'yes' into a suitable default.
	234	if test x$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
71cbce26	238	else
bbb514dc	239	if test $with_gnu_ld = yes ; then
	240	enable_symvers=gnu
	241	else
	242	case ${target_os} in
	243	# Sun symbol versioning exists since Solaris 2.5.
	244	solaris2.[[5-9]]* \| solaris2.1[[0-9]]*)
	245	enable_symvers=sun ;;
	246	*)
	247	enable_symvers=no ;;
	248	esac
	249	fi
71cbce26	250	fi
	251	fi
	252
	253	# Check if 'sun' was requested on non-Solaris 2 platforms.
	254	if test x$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
1e8e9920	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.
71cbce26	303	if test $enable_symvers != no && test $libgomp_shared_libgcc = yes; then
71cbce26	304	if test $with_gnu_ld = yes; then
1e8e9920	305	if test $libgomp_gnu_ld_version -ge $libgomp_min_gnu_ld_version ; then
1e8e9920	306	enable_symvers=gnu
d3d87030	307	elif test $libgomp_ld_is_gold = yes ; then
d3d87030	308	enable_symvers=gnu
1e8e9920	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
71cbce26	327	elif test $enable_symvers = sun; then
71cbce26	328	: All interesting versions of Sun ld support sun style symbol versioning.
1e8e9920	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
8a75144c	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
1e8e9920	349	AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
71cbce26	350	AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB_GNU, test $enable_symvers = gnu)
71cbce26	351	AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB_SUN, test $enable_symvers = sun)
1e8e9920	352	AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers)
71cbce26	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*)
fb6822c1	359	;;
71cbce26	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.])
fb6822c1	364	;;
71cbce26	365	esac
71cbce26	366	fi
1e8e9920	367	])