[mirror_zfs-debian.git] / config / always-no-unused-but-set-variable.m4

dnl #
dnl # Check if gcc supports -Wno-unused-but-set-variable option.
dnl #
dnl # We actually invoke gcc with the -Wunused-but-set-variable option
dnl # and infer the 'no-' version does or doesn't exist based upon
dnl # the results.  This is required because when checking any of
dnl # no- prefixed options gcc always returns success.
dnl #
AC_DEFUN([ZFS_AC_CONFIG_ALWAYS_NO_UNUSED_BUT_SET_VARIABLE], [
	AC_MSG_CHECKING([for -Wno-unused-but-set-variable support])

	saved_flags="$CFLAGS"
	CFLAGS="$CFLAGS -Wunused-but-set-variable"

	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [])],
	[
		NO_UNUSED_BUT_SET_VARIABLE=-Wno-unused-but-set-variable
		AC_MSG_RESULT([yes])
	],
	[
		NO_UNUSED_BUT_SET_VARIABLE=
		AC_MSG_RESULT([no])
	])

	CFLAGS="$saved_flags"
	AC_SUBST([NO_UNUSED_BUT_SET_VARIABLE])
])
Commit	Line	Data
8a7e1cee BB	1	dnl #
	2	dnl # Check if gcc supports -Wno-unused-but-set-variable option.
	3	dnl #
	4	dnl # We actually invoke gcc with the -Wunused-but-set-variable option
	5	dnl # and infer the 'no-' version does or doesn't exist based upon
	6	dnl # the results. This is required because when checking any of
	7	dnl # no- prefixed options gcc always returns success.
	8	dnl #
2e08aedb	9	AC_DEFUN([ZFS_AC_CONFIG_ALWAYS_NO_UNUSED_BUT_SET_VARIABLE], [
8a7e1cee BB	10	AC_MSG_CHECKING([for -Wno-unused-but-set-variable support])
	11
	12	saved_flags="$CFLAGS"
	13	CFLAGS="$CFLAGS -Wunused-but-set-variable"
	14
ea04106b	15	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [])],
8a7e1cee BB	16	[
	17	NO_UNUSED_BUT_SET_VARIABLE=-Wno-unused-but-set-variable
	18	AC_MSG_RESULT([yes])
	19	],
	20	[
	21	NO_UNUSED_BUT_SET_VARIABLE=
	22	AC_MSG_RESULT([no])
	23	])
	24
	25	CFLAGS="$saved_flags"
	26	AC_SUBST([NO_UNUSED_BUT_SET_VARIABLE])
	27	])