From: Michael Brown <mcb30@ipxe.org>
Date: Wed, 22 Sep 2010 18:59:37 +0000 (+0100)
Subject: [libc] Ensure that error numbers from EUNIQ() have the correct type
X-Git-Tag: v1.20.1~2485
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2a92697bda9405523d350c5698398d61468fa9fd;p=thirdparty%2Fipxe.git

[libc] Ensure that error numbers from EUNIQ() have the correct type

Error numbers are signed ints.  EUNIQ() should not allow implicit type
promotion based on the supplied error diambiguator, because this
causes problems with statements such as

  rc = ( condition ? -EUNIQ ( EBASE, disambiguator ) : -EBASE );

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---

diff --git a/src/include/errno.h b/src/include/errno.h
index 45d538235..a86573fc9 100644
--- a/src/include/errno.h
+++ b/src/include/errno.h
@@ -201,7 +201,7 @@ extern char missing_errfile_declaration[] __attribute__ (( deprecated ));
  */
 #define EUNIQ( errno, uniq, ... ) ( {					\
 	euniq_discard ( 0, ##__VA_ARGS__);				\
-	( (errno) | ( (uniq) << 8 ) ); } )
+	( ( int ) ( (errno) | ( (uniq) << 8 ) ) ); } )
 static inline void euniq_discard ( int dummy __unused, ... ) {}
 
 /**