diff --git a/lib/autoconf/headers.m4 b/lib/autoconf/headers.m4 index 634cf45..eb3aec8 100644 --- a/lib/autoconf/headers.m4 +++ b/lib/autoconf/headers.m4 @@ -204,14 +204,20 @@ _AC_HEADERS_EXPANSION])AC_REQUIRE([_AC_Header_]m4_translit([[$1]], # ------------------------------------- # Add each whitespace-separated name in HEADER-FILE to the list of # headers to check once. +# Note: has intimate knowledge of how AC_INCLUDES_DEFAULT works, +# and vice versa. + AC_DEFUN([AC_CHECK_HEADERS_ONCE], +[AC_REQUIRE([_AC_INCLUDES_DEFAULT_REQUIREMENTS])dnl +_AC_CHECK_HEADERS_ONCE([$1])]) +AC_DEFUN([_AC_CHECK_HEADERS_ONCE], [m4_map_args_w([$1], [_AC_CHECK_HEADER_ONCE(], [)])]) m4_define([_AC_HEADERS_EXPANSION], -[ - m4_divert_text([DEFAULTS], [ac_header_list=]) - AC_CHECK_HEADERS([$ac_header_list], [], [], [AC_INCLUDES_DEFAULT]) - m4_define([_AC_HEADERS_EXPANSION], []) +[dnl + m4_divert_text([DEFAULTS], [ac_header_list=])dnl + AC_CHECK_HEADERS([$ac_header_list], [], [], [$ac_includes_default])dnl + m4_define([_AC_HEADERS_EXPANSION], [])dnl ]) @@ -256,7 +262,7 @@ ac_includes_default="\ # include #endif" ])]dnl -[AC_CHECK_HEADERS( +[_AC_CHECK_HEADERS_ONCE( [sys/types.h sys/stat.h strings.h inttypes.h stdint.h unistd.h], [], [], [$ac_includes_default])]dnl dnl For backward compatibility, provide unconditional AC_DEFINEs of