lib/string/: strerrno(): Use statement expression to perform lvalue conversion

Compound literals are lvalues.  This means it's possible to take their
address.  That is, it would be possible (albeit nonsensical) to do

	&strerrno();

It is also possible to assign to them (albeit also nonsensical):

	strerrno() = NULL;

The statement expression performs lvalue conversion, which turns the
lvalue into an "rvalue", as expected, and disallows all those issues.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

diff --git a/lib/string/strerrno.h b/lib/string/strerrno.h
index b82e1015c4a578c35e5ebff335cc04ca35c12607..9f28a86a492d55b29f36d641a7c3db9a9337051c 100644 (file)
--- a/lib/string/strerrno.h
+++ b/lib/string/strerrno.h
@@ -13,7 +13,7 @@
 
 
 // strerrno - string errno
-#define strerrno()  ((const char *){strerror(errno)})
+#define strerrno()  ({(const char *){strerror(errno)};})
 
 
 #endif  // include guard