From 2cb54158b80cdbd97ca3b36df83f9255e923ae3f Mon Sep 17 00:00:00 2001
From: James Le Cuirot <chewi@aura-online.co.uk>
Date: Sat, 23 Aug 2014 09:46:39 +0100
Subject: [PATCH] Check size of uid_t and gid_t using AC_CHECK_SIZEOF

This built-in check is simpler than the previous method and, most
importantly, works when cross-compiling.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
---
 configure.in | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/configure.in b/configure.in
index 1a3f841..4a4d6d0 100644
--- a/configure.in
+++ b/configure.in
@@ -335,16 +335,10 @@ if test "$enable_subids" != "no"; then
 	dnl
 	dnl FIXME: check if 32 bit UIDs/GIDs are supported by libc
 	dnl
-	AC_RUN_IFELSE([AC_LANG_SOURCE([
-#include <sys/types.h>
-int main(void) {
-	uid_t u;
-	gid_t g;
-	return (sizeof u < 4) || (sizeof g < 4);
-}
-	])], [id32bit="yes"], [id32bit="no"])
-
-	if test "x$id32bit" = "xyes"; then
+	AC_CHECK_SIZEOF([uid_t],, [#include "sys/types.h"])
+	AC_CHECK_SIZEOF([gid_t],, [#include "sys/types.h"])
+
+	if test "$ac_cv_sizeof_uid_t" -ge 4 && test "$ac_cv_sizeof_gid_t" -ge 4; then
 		AC_DEFINE(ENABLE_SUBIDS, 1, [Define to support the subordinate IDs.])
 		enable_subids="yes"
 	else
-- 
2.3.6