[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_ld_is_mold (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
  libgomp_ld_is_mold=no
  if $LD --version 2>/dev/null | grep 'GNU gold'> /dev/null 2>&1; then
    libgomp_ld_is_gold=yes
  elif $LD --version 2>/dev/null | grep 'mold'> /dev/null 2>&1; then
    libgomp_ld_is_mold=yes
  fi
  changequote(,)
  ldver=`$LD --version 2>/dev/null |
         sed -e 's/[. ][0-9]\{8\}$//;s/.* \([^ ]\{1,\}\)$/\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
    elif test $libgomp_ld_is_mold = 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
953ff289 DN	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],
6d26724a	7	libgomp_cv_have_sync_builtins, [
289a9f86	8	AC_TRY_LINK([], [int foo; __sync_val_compare_and_swap(&foo, 0, 1);],
6d26724a RW	9	libgomp_cv_have_sync_builtins=yes, libgomp_cv_have_sync_builtins=no)])
6d26724a RW	10	if test $libgomp_cv_have_sync_builtins = yes; then
953ff289 DN	11	AC_DEFINE(HAVE_SYNC_BUILTINS, 1,
	12	[Define to 1 if the target supports __sync_*_compare_and_swap])
	13	fi])
	14
	15	dnl Check whether the target supports hidden visibility.
	16	AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_VISIBILITY], [
	17	AC_CACHE_CHECK([whether the target supports hidden visibility],
6d26724a	18	libgomp_cv_have_attribute_visibility, [
953ff289 DN	19	save_CFLAGS="$CFLAGS"
	20	CFLAGS="$CFLAGS -Werror"
	21	AC_TRY_COMPILE([void __attribute__((visibility("hidden"))) foo(void) { }],
6d26724a RW	22	[], libgomp_cv_have_attribute_visibility=yes,
6d26724a RW	23	libgomp_cv_have_attribute_visibility=no)
953ff289	24	CFLAGS="$save_CFLAGS"])
6d26724a	25	if test $libgomp_cv_have_attribute_visibility = yes; then
953ff289 DN	26	AC_DEFINE(HAVE_ATTRIBUTE_VISIBILITY, 1,
	27	[Define to 1 if the target supports __attribute__((visibility(...))).])
	28	fi])
	29
	30	dnl Check whether the target supports dllexport
	31	AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_DLLEXPORT], [
	32	AC_CACHE_CHECK([whether the target supports dllexport],
6d26724a	33	libgomp_cv_have_attribute_dllexport, [
953ff289 DN	34	save_CFLAGS="$CFLAGS"
	35	CFLAGS="$CFLAGS -Werror"
	36	AC_TRY_COMPILE([void __attribute__((dllexport)) foo(void) { }],
6d26724a RW	37	[], libgomp_cv_have_attribute_dllexport=yes,
6d26724a RW	38	libgomp_cv_have_attribute_dllexport=no)
953ff289	39	CFLAGS="$save_CFLAGS"])
6d26724a	40	if test $libgomp_cv_have_attribute_dllexport = yes; then
953ff289 DN	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],
6d26724a	48	libgomp_cv_have_attribute_alias, [
953ff289	49	AC_TRY_LINK([
953ff289	50	void foo(void) { }
8887708e	51	extern void bar(void) __attribute__((alias("foo")));],
6d26724a RW	52	[bar();], libgomp_cv_have_attribute_alias=yes, libgomp_cv_have_attribute_alias=no)])
6d26724a RW	53	if test $libgomp_cv_have_attribute_alias = yes; then
953ff289 DN	54	AC_DEFINE(HAVE_ATTRIBUTE_ALIAS, 1,
	55	[Define to 1 if the target supports __attribute__((alias(...))).])
	56	fi])
	57
	58	sinclude(../libtool.m4)
efe33ced	59	sinclude(../config/cet.m4)
953ff289 DN	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],-,_)[=][$2])
	103	m4_undefine([_g_switch])dnl
	104	m4_undefine([_g_help])dnl
	105	])
	106
	107
	108	dnl
	109	dnl If GNU ld is in use, check to see if tricky linker opts can be used. If
	110	dnl the native linker is in use, all variables will be defined to something
	111	dnl safe (like an empty string).
	112	dnl
	113	dnl Defines:
	114	dnl SECTION_LDFLAGS='-Wl,--gc-sections' if possible
	115	dnl OPT_LDFLAGS='-Wl,-O1' if possible
	116	dnl LD (as a side effect of testing)
	117	dnl Sets:
	118	dnl with_gnu_ld
b39dea08	119	dnl libgomp_ld_is_gold (possibly)
c99a6eb0	120	dnl libgomp_ld_is_mold (possibly)
953ff289 DN	121	dnl libgomp_gnu_ld_version (possibly)
	122	dnl
	123	dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
	124	dnl set libgomp_gnu_ld_version to 12345. Zeros cause problems.
	125	dnl
	126	AC_DEFUN([LIBGOMP_CHECK_LINKER_FEATURES], [
	127	# If we're not using GNU ld, then there's no point in even trying these
	128	# tests. Check for that first. We should have already tested for gld
	129	# by now (in libtool), but require it now just to be safe...
	130	test -z "$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.
b39dea08	152	libgomp_ld_is_gold=no
c99a6eb0	153	libgomp_ld_is_mold=no
b39dea08 ILT	154	if $LD --version 2>/dev/null \| grep 'GNU gold'> /dev/null 2>&1; then
b39dea08 ILT	155	libgomp_ld_is_gold=yes
c99a6eb0	156	elif $LD --version 2>/dev/null \| grep 'mold'> /dev/null 2>&1; then
6835baee	157	libgomp_ld_is_mold=yes
b39dea08	158	fi
953ff289	159	changequote(,)
c82852f7	160	ldver=`$LD --version 2>/dev/null \|
c6c2d1bc	161	sed -e 's/[. ][0-9]\{8\}$//;s/.* \([^ ]\{1,\}\)$/\1/; q'`
953ff289 DN	162	changequote([,])
	163	libgomp_gnu_ld_version=`echo $ldver \| \
	164	$AWK -F. '{ if (NF<3) [$]3=0; print ([$]1100+[$]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],
bddd6626	231	[permit yes\|no\|gnu*\|sun])
953ff289 DN	232
	233	# If we never went through the LIBGOMP_CHECK_LINKER_FEATURES macro, then we
	234	# don't know enough about $LD to do tricks...
	235	AC_REQUIRE([LIBGOMP_CHECK_LINKER_FEATURES])
bf382f5f RO	236
	237	# Turn a 'yes' into a suitable default.
	238	if test x$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
6d28b933	242	else
bf382f5f RO	243	if test $with_gnu_ld = yes ; then
	244	enable_symvers=gnu
	245	else
	246	case ${target_os} in
	247	# Sun symbol versioning exists since Solaris 2.5.
	248	solaris2.[[5-9]]* \| solaris2.1[[0-9]]*)
	249	enable_symvers=sun ;;
	250	*)
	251	enable_symvers=no ;;
	252	esac
	253	fi
6d28b933 RO	254	fi
	255	fi
	256
	257	# Check if 'sun' was requested on non-Solaris 2 platforms.
	258	if test x$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
953ff289 DN	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.
6d28b933 RO	307	if test $enable_symvers != no && test $libgomp_shared_libgcc = yes; then
6d28b933 RO	308	if test $with_gnu_ld = yes; then
953ff289 DN	309	if test $libgomp_gnu_ld_version -ge $libgomp_min_gnu_ld_version ; then
953ff289 DN	310	enable_symvers=gnu
b39dea08 ILT	311	elif test $libgomp_ld_is_gold = yes ; then
b39dea08 ILT	312	enable_symvers=gnu
c99a6eb0 ML	313	elif test $libgomp_ld_is_mold = yes ; then
c99a6eb0 ML	314	enable_symvers=gnu
953ff289 DN	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
6d28b933 RO	333	elif test $enable_symvers = sun; then
6d28b933 RO	334	: All interesting versions of Sun ld support sun style symbol versioning.
953ff289 DN	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
876080ff JJ	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
953ff289	355	AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
6d28b933 RO	356	AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB_GNU, test $enable_symvers = gnu)
6d28b933 RO	357	AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB_SUN, test $enable_symvers = sun)
953ff289	358	AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers)
6d28b933 RO	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*)
cc2de92d	365	;;
6d28b933 RO	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.])
cc2de92d	370	;;
6d28b933 RO	371	esac
6d28b933 RO	372	fi
953ff289	373	])