AC_INIT(object.cpp)
AC_CONFIG_AUX_DIR(ac)
AM_INIT_AUTOMAKE(msgpack, 0.4.3)
AC_CONFIG_HEADER(config.h)

AC_SUBST(CFLAGS)
CFLAGS="-O4 -Wall $CFLAGS"

AC_SUBST(CXXFLAGS)
CXXFLAGS="-O4 -Wall $CXXFLAGS"

AC_PROG_CC
AC_PROG_CXX

AC_PROG_LIBTOOL
AM_PROG_AS
AM_PROG_CC_C_O

AC_LANG_PUSH([C++])
AC_CHECK_HEADERS(tr1/unordered_map)
AC_CHECK_HEADERS(tr1/unordered_set)
AC_LANG_POP([C++])

AC_CACHE_CHECK([for __sync_* atomic operations], msgpack_cv_atomic_ops, [
	AC_TRY_LINK([
		int atomic_sub(int i) { return __sync_sub_and_fetch(&i, 1); }
		int atomic_add(int i) { return __sync_add_and_fetch(&i, 1); }
	], [], msgpack_cv_atomic_ops="yes")
	])
if test "$msgpack_cv_atomic_ops" != "yes"; then
	AC_MSG_ERROR([__sync_* atomic operations are not supported.

Note that gcc < 4.1 is not supported.

If you are using gcc >= 4.1 and the default target CPU architecture is "i386", try to
add CFLAGS="--march=i686" and CXXFLAGS="-march=i668" options to ./configure as follows:

  $ ./configure CFLAGS="-march=i686" CXXFLAGS="-march=i686"
])
fi

AC_OUTPUT([Makefile])