From: Alejandro Colomar <alx@kernel.org>
Date: Tue, 25 Nov 2025 21:51:28 +0000 (+0100)
Subject: lib/string/: strerrno(): Use statement expression to perform lvalue conversion
X-Git-Tag: 4.19.0-rc1~62
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=910f54c083a74496cccbcea8e77490b9ce66b456;p=thirdparty%2Fshadow.git

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 b82e1015c..9f28a86a4 100644
--- 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