dnl Copyright © 2010-2011 Nick Bowler
dnl
dnl License WTFPL2: Do What The Fuck You Want To Public License, version 2.
dnl This is free software: you are free to do what the fuck you want to.
dnl There is NO WARRANTY, to the extent permitted by law.

m4_pattern_forbid([^_?DX_])

dnl DX_PKG_CONFIG(env-base, [pkg-id], [pkg-help])
AC_DEFUN([DX_PKG_CONFIG], [dnl
AC_ARG_VAR(m4_toupper([$1])[_CFLAGS], [C compiler flags for ]ifelse(
	[$3], [], [$1], [$3]))dnl
AC_ARG_VAR(m4_toupper([$1])[_LIBS],   [linker flags for ]ifelse(
	[$3], [], [$1], [$3]))dnl

ifelse([$2], [], [], [dnl
AC_REQUIRE([PKG_PROG_PKG_CONFIG])dnl
if test x"$PKG_CONFIG" != x; then
	AC_MSG_CHECKING([pkg-config database for $2])
	pkg_failed=no
	_PKG_CONFIG(m4_tolower([$1])[_cflags], [cflags], [$2])
	_PKG_CONFIG(m4_tolower([$1])[_libs],   [libs],   [$2])
	if test x$pkg_failed = xyes; then
		errors=`$PKG_CONFIG --errors-to-stdout --print-errors $2`
		echo "$errors" >&AS_MESSAGE_LOG_FD
		AC_MSG_RESULT([no])
	else
		AC_MSG_RESULT([yes])
	fi
fi])])

dnl _DX_CHECK_LIB(env-base, check-func, [cflags], [libs], [test])
AC_DEFUN([_DX_CHECK_LIB], [dnl
if test x"$dx_cv_[]m4_tolower([$1])_found" = x"no"; then
if ifelse([$5], [], [:], [$5]); then
	CFLAGS="$3 $dx_old_cflags"
	LIBS="$4 $dx_old_libs"

	$2([dnl
		dx_cv_[]m4_tolower([$1])_found="yes"
		dx_cv_[]m4_tolower([$1])_cflags="$3"
		dx_cv_[]m4_tolower([$1])_libs="$4"
	])
fi
fi
])

dnl DX_CHECK_LIB_EXT(env-base, message, check-func,
dnl              [[[cflags1],[libs1],[test1]],[[cflags2],[libs2],[test2]],...])
AC_DEFUN([DX_CHECK_LIB_EXT], [dnl
AC_LANG_PUSH([C])
dx_old_cflags=$CFLAGS
dx_old_libs=$LIBS

AC_CACHE_CHECK([$2], [dx_cv_]m4_tolower([$1])[_found], [dnl
AC_CACHE_VAL([dx_cv_]m4_tolower([$1])[_libs],   [dnl
AC_CACHE_VAL([dx_cv_]m4_tolower([$1])[_cflags], [dnl
	dx_cv_[]m4_tolower([$1])_found=no
	m4_foreach([dx_tuple], [$4], [_DX_CHECK_LIB([$1], [$3], dx_tuple)])
])])])

if test x"$dx_cv_[]m4_tolower([$1])_found" = x"yes"; then
	m4_toupper([$1])_CFLAGS=$dx_cv_[]m4_tolower([$1])_cflags
	m4_toupper([$1])_LIBS=$dx_cv_[]m4_tolower([$1])_libs
	AC_SUBST(m4_toupper([$1])[_CFLAGS])
	AC_SUBST(m4_toupper([$1])[_LIBS])
fi

CFLAGS=$dx_old_cflags
LIBS=$dx_old_libs
AC_LANG_POP([C])
])

dnl DX_CHECK_LIB(env-base, message, test-program,
dnl              [[[cflags1],[libs1],[test1]],[[cflags2],[libs2],[test2]],...])
AC_DEFUN([DX_CHECK_LIB], [dnl
	DX_CHECK_LIB_EXT([$1], [$2], [m4_curry([AC_LINK_IFELSE], [$3])], [$4])
])