# configure.ac -- Go library configure script.

# Copyright 2009 The Go Authors. All rights reserved.
# Use of this source code is governed by a BSD-style
# license that can be found in the LICENSE file.

# Process this file with autoreconf to produce configure.

AC_PREREQ(2.64)
AC_INIT(package-unused, version-unused,, libgo)
AC_CONFIG_SRCDIR(Makefile.am)
AC_CONFIG_HEADER(config.h)

libtool_VERSION=3:1:0
AC_SUBST(libtool_VERSION)

AM_ENABLE_MULTILIB(, ..)

AC_CANONICAL_SYSTEM
target_alias=${target_alias-$host_alias}

AM_INIT_AUTOMAKE([1.9.3 no-define foreign no-dist -Wall -Wno-portability])
AH_TEMPLATE(PACKAGE, [Name of package])
AH_TEMPLATE(VERSION, [Version number of package])

m4_rename([_AC_ARG_VAR_PRECIOUS],[glibgo_PRECIOUS])
m4_define([_AC_ARG_VAR_PRECIOUS],[])
AC_PROG_CC
AC_PROG_GO
m4_rename_force([glibgo_PRECIOUS],[_AC_ARG_VAR_PRECIOUS])

AC_SUBST(CFLAGS)

AM_MAINTAINER_MODE

AC_PROG_LD
AC_PROG_RANLIB
AC_CHECK_TOOL(OBJCOPY, objcopy, missing-objcopy)

AC_LIBTOOL_DLOPEN
AM_PROG_LIBTOOL
AC_SUBST(enable_shared)
AC_SUBST(enable_static)

CC_FOR_BUILD=${CC_FOR_BUILD:-gcc}
AC_SUBST(CC_FOR_BUILD)

AC_PROG_AWK

WARN_FLAGS='-Wall -Wextra -Wwrite-strings -Wcast-qual'
AC_SUBST(WARN_FLAGS)

AC_ARG_ENABLE(werror, [AS_HELP_STRING([--enable-werror],
                                      [turns on -Werror @<:@default=yes@:>@])])
if test "x$enable_werror" != "xno"; then
  WERROR="-Werror"
fi
AC_SUBST(WERROR)

glibgo_toolexecdir=no
glibgo_toolexeclibdir=no

AC_MSG_CHECKING([for --enable-version-specific-runtime-libs])
AC_ARG_ENABLE([version-specific-runtime-libs],
  AC_HELP_STRING([--enable-version-specific-runtime-libs],
                 [Specify that runtime libraries should be installed in a compiler-specific directory]),
  [case "$enableval" in
    yes) version_specific_libs=yes ;;
    no)  version_specific_libs=no ;;
    *)   AC_MSG_ERROR([Unknown argument to enable/disable version-specific libs]);;
   esac],
  [version_specific_libs=no])
AC_MSG_RESULT($version_specific_libs)

# Version-specific runtime libs processing.
if test $version_specific_libs = yes; then
  glibgo_toolexecdir='${libdir}/gcc/${host_alias}'
  glibgo_toolexeclibdir='${toolexecdir}/${gcc_version}$(MULTISUBDIR)'
fi

# Calculate glibgo_toolexecdir, glibgo_toolexeclibdir
# Install a library built with a cross compiler in tooldir, not libdir.
if test -n "$with_cross_host" &&
   test x"$with_cross_host" != x"no"; then
  nover_glibgo_toolexecdir='${exec_prefix}/${host_alias}'
  nover_glibgo_toolexeclibdir='${toolexecdir}/lib'
else
  nover_glibgo_toolexecdir='${libdir}/gcc/${host_alias}'
  nover_glibgo_toolexeclibdir='${libdir}'
fi
multi_os_directory=`$CC -print-multi-os-directory`
case $multi_os_directory in
  .) ;; # Avoid trailing /.
  *) nover_glibgo_toolexeclibdir=${nover_glibgo_toolexeclibdir}/${multi_os_directory} ;;
esac

if test x"$glibgo_toolexecdir" = x"no"; then
  glibgo_toolexecdir="${nover_glibgo_toolexecdir}"
  glibgo_toolexeclibdir="${nover_glibgo_toolexeclibdir}"
fi

AC_SUBST(glibgo_toolexecdir)
AC_SUBST(glibgo_toolexeclibdir)
AC_SUBST(nover_glibgo_toolexeclibdir)

# See if the user wants to configure without libffi.  Some
# architectures don't support it.  FIXME: We should set a default
# based on the host.
AC_ARG_WITH(libffi,
  AS_HELP_STRING([--without-libffi],
                 [don't use libffi]),
  [:],
  [with_libffi=${with_libffi_default-yes}])

LIBFFI=
LIBFFIINCS=
if test "$with_libffi" != no; then
   AC_DEFINE(USE_LIBFFI, 1, [Define if we're to use libffi.])
   LIBFFI=../libffi/libffi_convenience.la
   LIBFFIINCS='-I$(top_srcdir)/../libffi/include -I../libffi/include'
fi
AC_SUBST(LIBFFI)
AC_SUBST(LIBFFIINCS)

# Used to tell GNU make to include a file without telling automake to
# include it.
go_include="-include"
AC_SUBST(go_include)

is_darwin=no
is_freebsd=no
is_irix=no
is_linux=no
is_netbsd=no
is_openbsd=no
is_rtems=no
is_solaris=no
GOOS=unknown
case ${host} in
  *-*-darwin*)   is_darwin=yes;  GOOS=darwin ;;
  *-*-freebsd*)  is_freebsd=yes; GOOS=freebsd ;;
  *-*-irix6*)    is_irix=yes;    GOOS=irix ;;
  *-*-linux*)    is_linux=yes;   GOOS=linux ;;
  *-*-netbsd*)	 is_netbsd=yes;  GOOS=netbsd ;;
  *-*-openbsd*)  is_openbsd=yes; GOOS=openbsd ;;
  *-*-rtems*)    is_rtems=yes;   GOOS=rtems ;;
  *-*-solaris2*) is_solaris=yes; GOOS=solaris ;;
esac
AM_CONDITIONAL(LIBGO_IS_DARWIN, test $is_darwin = yes)
AM_CONDITIONAL(LIBGO_IS_FREEBSD, test $is_freebsd = yes)
AM_CONDITIONAL(LIBGO_IS_IRIX, test $is_irix = yes)
AM_CONDITIONAL(LIBGO_IS_LINUX, test $is_linux = yes)
AM_CONDITIONAL(LIBGO_IS_NETBSD, test $is_netbsd = yes)
AM_CONDITIONAL(LIBGO_IS_OPENBSD, test $is_openbsd = yes)
AM_CONDITIONAL(LIBGO_IS_RTEMS, test $is_rtems = yes)
AM_CONDITIONAL(LIBGO_IS_SOLARIS, test $is_solaris = yes)
AC_SUBST(GOOS)

dnl Test whether we need to use DejaGNU or whether we can use the
dnl simpler gotest approach.  We can only use gotest for a native
dnl build.
USE_DEJAGNU=no
case ${host} in
  *-*-rtems*) USE_DEJAGNU=yes ;;
  ${build}) ;;
  *) USE_DEJAGNU=yes ;;
esac
AC_SUBST(USE_DEJAGNU)

dnl N.B. Keep in sync with gcc/testsuite/go.test/go-test.exp (go-set-goarch).
is_386=no
is_alpha=no
is_arm=no
is_m68k=no
mips_abi=unknown
is_ppc=no
is_ppc64=no
is_sparc=no
is_sparc64=no
is_x86_64=no
GOARCH=unknown
case ${host} in
  alpha*-*-*)
    is_alpha=yes
    GOARCH=alpha
    ;;
  arm*-*-* | strongarm*-*-* | ep9312*-*-* | xscale-*-*)
    is_arm=yes
    GOARCH=arm
    ;;
changequote(,)dnl
  i[34567]86-*-* | x86_64-*-*)
changequote([,])dnl
    AC_COMPILE_IFELSE([
#ifdef __x86_64__
#error 64-bit
#endif],
[is_386=yes], [is_x86_64=yes])
    if test "$is_386" = "yes"; then
      GOARCH=386
    else
      GOARCH=amd64
    fi
    ;;
  m68k*-*-*)
    is_m68k=yes
    GOARCH=m68k
    ;;
  mips*-*-*)
    AC_COMPILE_IFELSE([
#if _MIPS_SIM != _ABIO32
#error not o32
#endif],
[mips_abi="o32"],
	[AC_COMPILE_IFELSE([
#if _MIPS_SIM != _ABIN32
#error not n32
#endif],
[mips_abi="n32"],
	[AC_COMPILE_IFELSE([
#if _MIPS_SIM != _ABI64
#error not n64
#endif],
[mips_abi="n64"],
	[AC_COMPILE_IFELSE([
#if _MIPS_SIM != _ABIO64
#error not o64
#endif],
[mips_abi="o64"],
	[AC_MSG_ERROR([unknown MIPS ABI])
[mips_abi="n32"]])])])])
    case "$mips_abi" in
    "o32") GOARCH=mipso32 ;;
    "n32") GOARCH=mipsn32 ;;
    "n64") GOARCH=mipsn64 ;;
    "o64") GOARCH=mipso64 ;;
    esac
    ;;
  rs6000*-*-* | powerpc*-*-*)
    AC_COMPILE_IFELSE([
#ifdef _ARCH_PPC64
#error 64-bit
#endif],
[is_ppc=yes], [is_ppc64=yes])
    if test "$is_ppc" = "yes"; then
      GOARCH=ppc
    else
      GOARCH=ppc64
    fi
    ;;
  sparc*-*-*)
    AC_COMPILE_IFELSE([
#if defined(__sparcv9) || defined(__arch64__)
#error 64-bit
#endif],
[is_sparc=yes], [is_sparc64=yes])
    if test "$is_sparc" = "yes"; then
      GOARCH=sparc
    else
      GOARCH=sparc64
    fi
    ;;
esac
AM_CONDITIONAL(LIBGO_IS_386, test $is_386 = yes)
AM_CONDITIONAL(LIBGO_IS_ALPHA, test $is_alpha = yes)
AM_CONDITIONAL(LIBGO_IS_ARM, test $is_arm = yes)
AM_CONDITIONAL(LIBGO_IS_M68K, test $is_m68k = yes)
AM_CONDITIONAL(LIBGO_IS_MIPS, test $mips_abi != unknown)
AM_CONDITIONAL(LIBGO_IS_MIPSO32, test $mips_abi = o32)
AM_CONDITIONAL(LIBGO_IS_MIPSN32, test $mips_abi = n32)
AM_CONDITIONAL(LIBGO_IS_MIPSN64, test $mips_abi = n64)
AM_CONDITIONAL(LIBGO_IS_MIPSO64, test $mips_abi = o64)
AM_CONDITIONAL(LIBGO_IS_PPC, test $is_ppc = yes)
AM_CONDITIONAL(LIBGO_IS_PPC64, test $is_ppc64 = yes)
AM_CONDITIONAL(LIBGO_IS_SPARC, test $is_sparc = yes)
AM_CONDITIONAL(LIBGO_IS_SPARC64, test $is_sparc64 = yes)
AM_CONDITIONAL(LIBGO_IS_X86_64, test $is_x86_64 = yes)
AC_SUBST(GOARCH)

dnl Some files are only present when needed for specific architectures.
GO_LIBCALL_OS_FILE=
GO_LIBCALL_OS_ARCH_FILE=
GO_SYSCALL_OS_FILE=
GO_SYSCALL_OS_ARCH_FILE=
if test -f ${srcdir}/go/syscall/libcall_${GOOS}.go; then
  GO_LIBCALL_OS_FILE=go/syscall/libcall_${GOOS}.go
fi
if test -f ${srcdir}/go/syscall/libcall_${GOOS}_${GOARCH}.go; then
  GO_LIBCALL_OS_ARCH_FILE=go/syscall/libcall_${GOOS}_${GOARCH}.go
fi
if test -f ${srcdir}/go/syscall/syscall_${GOOS}.go; then
  GO_SYSCALL_OS_FILE=go/syscall/syscall_${GOOS}.go
fi
if test -f ${srcdir}/go/syscall/syscall_${GOOS}_${GOARCH}.go; then
  GO_SYSCALL_OS_ARCH_FILE=go/syscall/syscall_${GOOS}_${GOARCH}.go
fi
AC_SUBST(GO_LIBCALL_OS_FILE)
AC_SUBST(GO_LIBCALL_OS_ARCH_FILE)
AC_SUBST(GO_SYSCALL_OS_FILE)
AC_SUBST(GO_SYSCALL_OS_ARCH_FILE)

dnl Special flags used to generate sysinfo.go.
OSCFLAGS="-D_GNU_SOURCE -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"
case "$target" in
    mips-sgi-irix6.5*)
	# IRIX 6 needs _XOPEN_SOURCE=500 for the XPG5 version of struct
	# msghdr in <sys/socket.h>.
	OSCFLAGS="$OSCFLAGS -D_XOPEN_SOURCE=500"
	;;
    *-*-solaris2.[[89]])
	# Solaris 8/9 need this so struct msghdr gets the msg_control
	# etc. fields in <sys/socket.h> (_XPG4_2).
	OSCFLAGS="$OSCFLAGS -D_XOPEN_SOURCE=500 -D_XOPEN_SOURCE_EXTENDED -D__EXTENSIONS__"
	;;
    *-*-solaris2.1[[01]])
	# Solaris 10+ needs this so struct msghdr gets the msg_control
	# etc. fields in <sys/socket.h> (_XPG4_2).  _XOPEN_SOURCE=600 as
	# above doesn't work with C99.
	OSCFLAGS="$OSCFLAGS -std=gnu99 -D_XOPEN_SOURCE=600 -D__EXTENSIONS__"
	;;
esac
AC_SUBST(OSCFLAGS)

dnl Use -fsplit-stack when compiling C code if available.
AC_CACHE_CHECK([whether -fsplit-stack is supported],
[libgo_cv_c_split_stack_supported],
[CFLAGS_hold=$CFLAGS
CFLAGS="$CFLAGS -fsplit-stack"
AC_COMPILE_IFELSE([[int i;]],
[libgo_cv_c_split_stack_supported=yes],
[libgo_cv_c_split_stack_supported=no])
CFLAGS=$CFLAGS_hold])
if test "$libgo_cv_c_split_stack_supported" = yes; then
  SPLIT_STACK=-fsplit-stack
  AC_DEFINE(USING_SPLIT_STACK, 1,
		[Define if the compiler supports -fsplit-stack])
else
  SPLIT_STACK=
fi
AC_SUBST(SPLIT_STACK)
AM_CONDITIONAL(USING_SPLIT_STACK,
	test "$libgo_cv_c_split_stack_supported" = yes)

dnl Check whether the linker does stack munging when calling from
dnl split-stack into non-split-stack code.  We check this by looking
dnl at the --help output.  FIXME: This is only half right: it's
dnl possible for the linker to support this for some targets but not
dnl others.
AC_CACHE_CHECK([whether linker supports split stack],
[libgo_cv_c_linker_supports_split_stack],
libgo_cv_c_linker_supports_split_stack=no
if $LD --help 2>/dev/null | grep split-stack-adjust-size >/dev/null 2>&1; then
  libgo_cv_c_linker_supports_split_stack=yes
fi)
if test "$libgo_cv_c_linker_supports_split_stack" = yes; then
  AC_DEFINE(LINKER_SUPPORTS_SPLIT_STACK, 1,
	    [Define if the linker support split stack adjustments])
fi

dnl Test for the -lm library.
MATH_LIBS=
AC_CHECK_LIB([m], [sqrt], MATH_LIBS=-lm)
AC_SUBST(MATH_LIBS)

dnl Test for -lsocket and -lnsl.  Copied from libjava/configure.ac.
AC_CACHE_CHECK([for socket libraries], libgo_cv_lib_sockets,
  [libgo_cv_lib_sockets=
   libgo_check_both=no
   AC_CHECK_FUNC(connect, libgo_check_socket=no, libgo_check_socket=yes)
   if test "$libgo_check_socket" = "yes"; then
     unset ac_cv_func_connect
     AC_CHECK_LIB(socket, main, libgo_cv_lib_sockets="-lsocket",
     		  libgo_check_both=yes)
   fi
   if test "$libgo_check_both" = "yes"; then
     libgo_old_libs=$LIBS
     LIBS="$LIBS -lsocket -lnsl"
     unset ac_cv_func_accept
     AC_CHECK_FUNC(accept,
		   [libgo_check_nsl=no
		    libgo_cv_lib_sockets="-lsocket -lnsl"])
     unset ac_cv_func_accept
     LIBS=$libgo_old_libs
   fi
   unset ac_cv_func_gethostbyname
   libgo_old_libs="$LIBS"
   AC_CHECK_FUNC(gethostbyname, ,
		 [AC_CHECK_LIB(nsl, main,
		 	[libgo_cv_lib_sockets="$libgo_cv_lib_sockets -lnsl"])])
   unset ac_cv_func_gethostbyname
   LIBS=$libgo_old_libs
])
NET_LIBS="$libgo_cv_lib_sockets"
AC_SUBST(NET_LIBS)

dnl Test whether the compiler supports the -pthread option.
AC_CACHE_CHECK([whether -pthread is supported],
[libgo_cv_lib_pthread],
[CFLAGS_hold=$CFLAGS
CFLAGS="$CFLAGS -pthread"
AC_COMPILE_IFELSE([[int i;]],
[libgo_cv_lib_pthread=yes],
[libgo_cv_lib_pthread=no])
CFLAGS=$CFLAGS_hold])
PTHREAD_CFLAGS=
if test "$libgo_cv_lib_pthread" = yes; then
  PTHREAD_CFLAGS=-pthread
fi
AC_SUBST(PTHREAD_CFLAGS)

dnl Test for the -lpthread library.
PTHREAD_LIBS=
AC_CHECK_LIB([pthread], [pthread_create], PTHREAD_LIBS=-lpthread)
AC_SUBST(PTHREAD_LIBS)

dnl Test if -lrt is required for sched_yield.
AC_SEARCH_LIBS([sched_yield], [rt])

AC_C_BIGENDIAN

GCC_CHECK_UNWIND_GETIPINFO

AC_ARG_ENABLE(sjlj-exceptions,
  AC_HELP_STRING([--enable-sjlj-exceptions],
		 [force use of builtin_setjmp for exceptions]),
  [case "$enableval" in
   yes|no|auto) ;;
   *) AC_MSG_ERROR([unknown argument to --enable-sjlj-exceptions]) ;;
   esac],
  [enable_sjlj_exceptions=auto])

AC_CACHE_CHECK([whether to use setjmp/longjmp exceptions],
[libgo_cv_lib_sjlj_exceptions],
[AC_LANG_CONFTEST(
  [AC_LANG_SOURCE([
void bar ();
void clean (int *);
void foo ()
{
  int i __attribute__ ((cleanup (clean)));
  bar();
}
])])
CFLAGS_hold=$CFLAGS
CFLAGS="--save-temps -fexceptions"
libgo_cv_lib_sjlj_exceptions=unknown
AS_IF([ac_fn_c_try_compile],
  [if grep _Unwind_SjLj_Resume conftest.s >/dev/null 2>&1; then
    libgo_cv_lib_sjlj_exceptions=yes
  elif grep _Unwind_Resume conftest.s >/dev/null 2>&1; then
    libgo_cv_lib_sjlj_exceptions=no
  fi])
CFLAGS=$CFLAGS_hold
rm -f conftest*
])

if test "$enable_sjlj_exceptions" = "auto"; then
  enable_sjlj_exceptions=$libgo_cv_lib_sjlj_exceptions
fi

case $enable_sjlj_exceptions in
yes)
  AC_DEFINE(LIBGO_SJLJ_EXCEPTIONS, 1,
	[Define if the C++ compiler is configured for setjmp/longjmp exceptions.])
  ;;
no)
  ;;
*)
  AC_MSG_ERROR([unable to detect exception model])
  ;;
esac

AC_CHECK_HEADERS(sys/file.h sys/mman.h syscall.h sys/epoll.h sys/inotify.h sys/ptrace.h sys/syscall.h sys/user.h sys/utsname.h sys/select.h sys/socket.h net/if.h net/if_arp.h net/route.h netpacket/packet.h sys/prctl.h sys/mount.h sys/vfs.h sys/statfs.h sys/timex.h sys/sysinfo.h utime.h linux/ether.h linux/fs.h linux/reboot.h netinet/in_syst.h netinet/ip.h netinet/ip_mroute.h netinet/if_ether.h)

AC_CHECK_HEADERS([linux/filter.h linux/if_addr.h linux/if_ether.h linux/if_tun.h linux/netlink.h linux/rtnetlink.h], [], [],
[#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
])

AC_CACHE_CHECK([whether <ustat.h> can be used],
[libgo_cv_c_ustat_h],
[CFLAGS_hold=$CFLAGS
CFLAGS="$CFLAGS -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE $OSCFLAGS"
AC_COMPILE_IFELSE(
[AC_LANG_SOURCE([
#include <sys/types.h>
#ifdef HAVE_LINUX_FILTER_H
#include <linux/filter.h>
#endif
#include <ustat.h>
])], [libgo_cv_c_ustat_h=yes], [libgo_cv_c_ustat_h=no])
CFLAGS=$CFLAGS_hold])
if test $libgo_cv_c_ustat_h = yes; then
  AC_DEFINE(HAVE_USTAT_H, 1,
    [Define to 1 if you have the <ustat.h> header file and it works.])
fi

AM_CONDITIONAL(HAVE_SYS_MMAN_H, test "$ac_cv_header_sys_mman_h" = yes)

AC_CHECK_FUNCS(strerror_r strsignal wait4 mincore setenv dl_iterate_phdr)
AM_CONDITIONAL(HAVE_STRERROR_R, test "$ac_cv_func_strerror_r" = yes)
AM_CONDITIONAL(HAVE_WAIT4, test "$ac_cv_func_wait4" = yes)

AC_CHECK_FUNCS(accept4 epoll_create1 faccessat fallocate fchmodat fchownat futimesat inotify_add_watch inotify_init inotify_init1 inotify_rm_watch mkdirat mknodat openat pipe2 renameat sync_file_range splice tee unlinkat unshare utimensat)
AC_TYPE_OFF_T
AC_CHECK_TYPES([loff_t])

LIBS_hold="$LIBS"
LIBS="$LIBS -lm"
AC_CHECK_FUNCS(cosl expl logl sinl tanl acosl asinl atanl atan2l expm1l ldexpl log10l log1pl)
LIBS="$LIBS_hold"

CFLAGS_hold="$CFLAGS"
CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
LIBS_hold="$LIBS"
LIBS="$LIBS $PTHREAD_LIBS"
AC_CHECK_FUNCS(sem_timedwait)
CFLAGS="$CFLAGS_hold"
LIBS="$LIBS_hold"

LIBS_hold="$LIBS"
LIBS="$LIBS $MATH_LIBS"
AC_CHECK_FUNCS(matherr)
LIBS="$LIBS_hold"

AC_CACHE_CHECK([for __sync_bool_compare_and_swap_4],
[libgo_cv_func___sync_bool_compare_and_swap_4],
[AC_LINK_IFELSE([
typedef unsigned int uint32  __attribute__ ((mode (SI)));
uint32 i;
int main() { return __sync_bool_compare_and_swap (&i, 0, 1); }
],
[libgo_cv_func___sync_bool_compare_and_swap_4=yes],
[libgo_cv_func___sync_bool_compare_and_swap_4=no])])
if test "$libgo_cv_func___sync_bool_compare_and_swap_4" = "yes"; then
  AC_DEFINE(HAVE_SYNC_BOOL_COMPARE_AND_SWAP_4, 1,
    [Define to 1 if the compiler provides the __sync_bool_compare_and_swap function for uint32])
fi

AC_CACHE_CHECK([for __sync_bool_compare_and_swap_8],
[libgo_cv_func___sync_bool_compare_and_swap_8],
[AC_LINK_IFELSE([
typedef unsigned int uint64  __attribute__ ((mode (DI)));
uint64 i;
int main() { return __sync_bool_compare_and_swap (&i, 0, 1); }
],
[libgo_cv_func___sync_bool_compare_and_swap_8=yes],
[libgo_cv_func___sync_bool_compare_and_swap_8=no])])
if test "$libgo_cv_func___sync_bool_compare_and_swap_8" = "yes"; then
  AC_DEFINE(HAVE_SYNC_BOOL_COMPARE_AND_SWAP_8, 1,
    [Define to 1 if the compiler provides the __sync_bool_compare_and_swap function for uint64])
fi

AC_CACHE_CHECK([for __sync_fetch_and_add_4],
[libgo_cv_func___sync_fetch_and_add_4],
[AC_LINK_IFELSE([
typedef unsigned int uint32  __attribute__ ((mode (SI)));
uint32 i;
int main() { return __sync_fetch_and_add (&i, 1); }
],
[libgo_cv_func___sync_fetch_and_add_4=yes],
[libgo_cv_func___sync_fetch_and_add_4=no])])
if test "$libgo_cv_func___sync_fetch_and_add_4" = "yes"; then
  AC_DEFINE(HAVE_SYNC_FETCH_AND_ADD_4, 1,
    [Define to 1 if the compiler provides the __sync_fetch_and_add function for uint32])
fi

AC_CACHE_CHECK([for __sync_add_and_fetch_8],
[libgo_cv_func___sync_add_and_fetch_8],
[AC_LINK_IFELSE([
typedef unsigned int uint64  __attribute__ ((mode (DI)));
uint64 i;
int main() { return __sync_add_and_fetch (&i, 1); }
],
[libgo_cv_func___sync_add_and_fetch_8=yes],
[libgo_cv_func___sync_add_and_fetch_8=no])])
if test "$libgo_cv_func___sync_add_and_fetch_8" = "yes"; then
  AC_DEFINE(HAVE_SYNC_ADD_AND_FETCH_8, 1,
    [Define to 1 if the compiler provides the __sync_add_and_fetch function for uint64])
fi

dnl For x86 we want to use the -minline-all-stringops option to avoid
dnl forcing a stack split when calling memcpy and friends.
AC_CACHE_CHECK([whether compiler supports -minline-all-stringops],
[libgo_cv_c_stringops],
[CFLAGS_hold=$CFLAGS
CFLAGS="$CFLAGS -minline-all-stringops"
AC_COMPILE_IFELSE([int i;],
[libgo_cv_c_stringops=yes],
[libgo_cv_c_stringops=no])
CFLAGS=$CFLAGS_hold])
STRINGOPS_FLAG=
if test "$libgo_cv_c_stringops" = yes; then
  STRINGOPS_FLAG=-minline-all-stringops
fi
AC_SUBST(STRINGOPS_FLAG)

dnl For x86 we want to compile the math library with -mfancy-math-387
dnl -funsafe-math-optimizations so that we can use the builtin
dnl instructions directly.
AC_CACHE_CHECK([whether compiler supports -mfancy-math-387],
[libgo_cv_c_fancymath],
[CFLAGS_hold=$CFLAGS
CFLAGS="$CFLAGS -mfancy-math-387"
AC_COMPILE_IFELSE([int i;],
[libgo_cv_c_fancymath=yes],
[libgo_cv_c_fancymath=no])
CFLAGS=$CFLAGS_hold])
MATH_FLAG=
if test "$libgo_cv_c_fancymath" = yes; then
  MATH_FLAG="-mfancy-math-387 -funsafe-math-optimizations"
fi
AC_SUBST(MATH_FLAG)

CFLAGS_hold=$CFLAGS
CFLAGS="$CFLAGS -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE"
AC_CHECK_TYPES([off64_t])
CFLAGS=$CFLAGS_hold

dnl Work out the size of the epoll_events struct on GNU/Linux.
AC_CACHE_CHECK([epoll_event size],
[libgo_cv_c_epoll_event_size],
[AC_COMPUTE_INT(libgo_cv_c_epoll_event_size,
[sizeof (struct epoll_event)],
[#include <sys/epoll.h>],
[libgo_cv_c_epoll_event_size=0])])
SIZEOF_STRUCT_EPOLL_EVENT=${libgo_cv_c_epoll_event_size}
AC_SUBST(SIZEOF_STRUCT_EPOLL_EVENT)

dnl Work out the offset of the fd field in the epoll_events struct on
dnl GNU/Linux.
AC_CACHE_CHECK([epoll_event data.fd offset],
[libgo_cv_c_epoll_event_fd_offset],
[AC_COMPUTE_INT(libgo_cv_c_epoll_event_fd_offset,
[offsetof (struct epoll_event, data.fd)],
[#include <stddef.h>
#include <sys/epoll.h>],
[libgo_cv_c_epoll_event_fd_offset=0])])
STRUCT_EPOLL_EVENT_FD_OFFSET=${libgo_cv_c_epoll_event_fd_offset}
AC_SUBST(STRUCT_EPOLL_EVENT_FD_OFFSET)

dnl See if struct exception is defined in <math.h>.
AC_CHECK_TYPE([struct exception],
[libgo_has_struct_exception=yes],
[libgo_has_struct_exception=no],
[#include <math.h>])
if test "$libgo_has_struct_exception" = "yes"; then
  AC_DEFINE(HAVE_STRUCT_EXCEPTION, 1,
            [Define to 1 if <math.h> defines struct exception])
fi

dnl Check if makecontext expects the uc_stack member of ucontext to point
dnl to the top of the stack.
case "$target" in
  sparc*-*-solaris2.[[89]]*)
    libgo_cv_lib_makecontext_stack_top=yes
    ;;
  *)
    libgo_cv_lib_makecontext_stack_top=no
    ;;
esac
if test "$libgo_cv_lib_makecontext_stack_top" = "yes"; then
  AC_DEFINE(MAKECONTEXT_STACK_TOP, 1,
	    [Define if makecontext expects top of stack in uc_stack.])
fi

dnl See whether setcontext changes the value of TLS variables.
AC_CACHE_CHECK([whether setcontext clobbers TLS variables],
[libgo_cv_lib_setcontext_clobbers_tls],
[CFLAGS_hold="$CFLAGS"
CFLAGS="$PTHREAD_CFLAGS"
LIBS_hold="$LIBS"
LIBS="$LIBS $PTHREAD_LIBS"
AC_CHECK_SIZEOF([void *])
AS_VAR_ARITH([ptr_type_size], [$ac_cv_sizeof_void_p \* 8])
AC_RUN_IFELSE(
  [AC_LANG_SOURCE([
#include <pthread.h>
#include <stdlib.h>
#include <ucontext.h>
#include <unistd.h>

__thread int tls;

static char stack[[10 * 1024 * 1024]];
static ucontext_t c;

/* Called via makecontext/setcontext.  */

static void
cfn (void)
{
  exit (tls);
}

/* Called via pthread_create.  */

static void *
tfn (void *dummy)
{
  /* The thread should still see this value after calling
     setcontext.  */
  tls = 0;

  setcontext (&c);

  /* The call to setcontext should not return.  */
  abort ();
}

int
main ()
{
  pthread_t tid;

  /* The thread should not see this value.  */
  tls = 1;

  if (getcontext (&c) < 0)
    abort ();

  c.uc_stack.ss_sp = stack;
#ifdef MAKECONTEXT_STACK_TOP
  c.uc_stack.ss_sp += sizeof stack;
#endif
  c.uc_stack.ss_flags = 0;
  c.uc_stack.ss_size = sizeof stack;
  c.uc_link = NULL;
  makecontext (&c, cfn, 0);

  if (pthread_create (&tid, NULL, tfn, NULL) != 0)
    abort ();

  if (pthread_join (tid, NULL) != 0)
    abort ();

  /* The thread should have called exit.  */
  abort ();
}
])],
[libgo_cv_lib_setcontext_clobbers_tls=no],
[libgo_cv_lib_setcontext_clobbers_tls=yes],
[case "$target:$ptr_type_size" in
  i?86-*-solaris2.1[[01]]:64 | x86_64*-*-solaris2.1[[01]]:64)
    libgo_cv_lib_setcontext_clobbers_tls=yes ;;
  *)
    libgo_cv_lib_setcontext_clobbers_tls=no ;;
 esac
])
CFLAGS="$CFLAGS_hold"
LIBS="$LIBS_hold"
])
if test "$libgo_cv_lib_setcontext_clobbers_tls" = "yes"; then
  AC_DEFINE(SETCONTEXT_CLOBBERS_TLS, 1,
	    [Define if setcontext clobbers TLS variables])
fi

AC_CACHE_SAVE

if test ${multilib} = yes; then
  multilib_arg="--enable-multilib"
else
  multilib_arg=
fi

AC_CONFIG_FILES(Makefile testsuite/Makefile)

AC_CONFIG_COMMANDS([default],
[if test -n "$CONFIG_FILES"; then
   # Multilibs need MULTISUBDIR defined correctly in certain makefiles so
   # that multilib installs will end up installed in the correct place.
   # The testsuite needs it for multilib-aware ABI baseline files.
   # To work around this not being passed down from config-ml.in ->
   # srcdir/Makefile.am -> srcdir/{src,libsupc++,...}/Makefile.am, manually
   # append it here.  Only modify Makefiles that have just been created.
   #
   # Also, get rid of this simulated-VPATH thing that automake does.
   cat > vpsed << \_EOF
s!`test -f '$<' || echo '$(srcdir)/'`!!
_EOF
   for i in $SUBDIRS; do
    case $CONFIG_FILES in
     *${i}/Makefile*)
       #echo "Adding MULTISUBDIR to $i/Makefile"
       sed -f vpsed $i/Makefile > tmp
       grep '^MULTISUBDIR =' Makefile >> tmp
       mv tmp $i/Makefile
       ;;
    esac
   done
   rm vpsed
 fi
],
[
# Variables needed in config.status (file generation) which aren't already
# passed by autoconf.
SUBDIRS="$SUBDIRS"
])

AC_OUTPUT