* lib/autoconf/headers.m4 (AC_CHECK_HEADERS_ONCE): Divide into a public macro that AC_REQUIREs _AC_INCLUDES_DEFAULT_REQUIREMENTS, and ... (_AC_CHECK_HEADERS_ONCE): ... a private macro, that doesn't. (_AC_HEADERS_EXPANSION): Use $ac_includes_default, not AC_INCLUDES_DEFAULT. (_AC_INCLUDES_DEFAULT_REQUIREMENTS): Use AC_CHECK_HEADERS_ONCE. (all of the above): Sprinkle dnl's around.
Signed-off-by: Zack Weinberg <za...@panix.com> --- lib/autoconf/headers.m4 | 24 +++++++++++++++--------- 1 files changed, 15 insertions(+), 9 deletions(-)
diff --git a/lib/autoconf/headers.m4 b/lib/autoconf/headers.m4 index 6fe1380..8f2272a 100644 --- a/lib/autoconf/headers.m4 +++ b/lib/autoconf/headers.m4 @@ -203,14 +203,20 @@ _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 ]) @@ -255,19 +261,19 @@ ac_includes_default="\ # include <unistd.h> #endif" ])dnl -AC_CHECK_HEADERS([sys/types.h sys/stat.h strings.h inttypes.h stdint.h unistd.h], - [], [], [$ac_includes_default]) +_AC_CHECK_HEADERS_ONCE([sys/types.h sys/stat.h strings.h inttypes.h stdint.h + unistd.h])dnl dnl For backward compatibility, provide unconditional AC_DEFINEs of dnl HAVE_STDLIB_H, HAVE_STRING_H, and STDC_HEADERS. AC_DEFINE(HAVE_STDLIB_H, 1, [Always define to 1, for backward compatibility. - You can assume <stdlib.h> exists.]) + You can assume <stdlib.h> exists.])dnl AC_DEFINE(HAVE_STRING_H, 1, [Always define to 1, for backward compatibility. - You can assume <string.h> exists.]) + You can assume <string.h> exists.])dnl AC_DEFINE(STDC_HEADERS, 1, [Always define to 1, for backward compatibility. - You can assume the C90 standard headers exist.]) + You can assume the C90 standard headers exist.])dnl ])# _AC_INCLUDES_DEFAULT_REQUIREMENTS
