1AS_IF(
2   [test "x$enable_maintainer_flags" = "xyes" && test "x$GCC" = "xyes"],
3   [
4    # clang only warns if it doesn't support a warning option, turn it into an
5    # error so we really know if whether it supports it.
6    AX_CHECK_COMPILE_FLAG(
7       "-Werror=unknown-warning-option",
8       [WERROR_UNKNOWN_OPTION="-Werror=unknown-warning-option"],
9       [WERROR_UNKNOWN_OPTION=""])
10
11    # Read maintainer-flags.txt and apply each flag that the compiler supports.
12    m4_foreach([MAINTAINER_FLAG], m4_split(m4_normalize(m4_esyscmd(cat build/maintainer-flags.txt))), [
13        AX_CHECK_COMPILE_FLAG(
14           MAINTAINER_FLAG,
15           [MAINTAINER_CFLAGS="$MAINTAINER_CFLAGS MAINTAINER_FLAG"],
16           [],
17           [$WERROR_UNKNOWN_OPTION])
18    ])
19   ]
20
21   AC_SUBST(MAINTAINER_CFLAGS)
22)
23