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From: Richard Palethorpe <rpalethorpe@suse.com>
To: linux-sparse@vger.kernel.org
Cc: ltp@lists.linux.it, Richard Palethorpe <rpalethorpe@suse.com>
Subject: [PATCH] sparse: Use offsetof macro to silence null ptr subtraction warning
Date: Mon, 21 Mar 2022 11:21:19 +0000	[thread overview]
Message-ID: <20220321112119.23308-1-rpalethorpe@suse.com> (raw)

Subtracting (char *)0 is undefined behavior. Newer compilers warn
about this unless it is done in system headers.

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
---
 token.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/token.h b/token.h
index bccac0e4..9000e0cb 100644
--- a/token.h
+++ b/token.h
@@ -201,7 +201,7 @@ struct token {
 
 static inline struct token *containing_token(struct token **p)
 {
-	void *addr = (char *)p - ((char *)&((struct token *)0)->next - (char *)0);
+	void *addr = (char *)p - offsetof(struct token, next);
 	return addr;
 }
 
-- 
2.35.1


WARNING: multiple messages have this Message-ID (diff)
From: Richard Palethorpe via ltp <ltp@lists.linux.it>
To: linux-sparse@vger.kernel.org
Cc: Richard Palethorpe <rpalethorpe@suse.com>, ltp@lists.linux.it
Subject: [LTP] [PATCH] sparse: Use offsetof macro to silence null ptr subtraction warning
Date: Mon, 21 Mar 2022 11:21:19 +0000	[thread overview]
Message-ID: <20220321112119.23308-1-rpalethorpe@suse.com> (raw)

Subtracting (char *)0 is undefined behavior. Newer compilers warn
about this unless it is done in system headers.

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
---
 token.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/token.h b/token.h
index bccac0e4..9000e0cb 100644
--- a/token.h
+++ b/token.h
@@ -201,7 +201,7 @@ struct token {
 
 static inline struct token *containing_token(struct token **p)
 {
-	void *addr = (char *)p - ((char *)&((struct token *)0)->next - (char *)0);
+	void *addr = (char *)p - offsetof(struct token, next);
 	return addr;
 }
 
-- 
2.35.1


-- 
Mailing list info: https://lists.linux.it/listinfo/ltp

             reply	other threads:[~2022-03-21 11:22 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-21 11:21 Richard Palethorpe [this message]
2022-03-21 11:21 ` [LTP] [PATCH] sparse: Use offsetof macro to silence null ptr subtraction warning Richard Palethorpe via ltp
2022-05-21 13:28 ` Luc Van Oostenryck
2022-05-21 13:28   ` [LTP] " Luc Van Oostenryck

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