Re: [PATCH] CLEANUP: use "offsetof" macro where appropriate

[Willy Tarreau]

Hi Ilya,

On Sat, Apr 15, 2023 at 11:55:14PM +0200,  ??? wrote:
> From: Ilya Shipitsin 
> Date: Sat, 15 Apr 2023 23:39:43 +0200
> Subject: [PATCH] CLEANUP: use "offsetof" where appropriate
> 
> let's use the C library macro "offsetof"

Good point. In the past we didn't because it was not always defined, but
now we define it and already use it at a few other places, so let's use
it.

Applied, thanks!
Willy

[PATCH] CLEANUP: use "offsetof" macro where appropriate

[Илья Шипицин]

Hello,

small cleanup patch attached.

Ilya
From 77babd04c417709bb41c951701d62dec0574eb35 Mon Sep 17 00:00:00 2001
From: Ilya Shipitsin 
Date: Sat, 15 Apr 2023 23:39:43 +0200
Subject: [PATCH] CLEANUP: use "offsetof" where appropriate

let's use the C library macro "offsetof"
---
 src/cache.c| 4 ++--
 src/ssl_sock.c | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/cache.c b/src/cache.c
index 39e947820..4deb34ea8 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -425,12 +425,12 @@ static void delete_entry(struct cache_entry *del_entry)
 
 static inline struct shared_context *shctx_ptr(struct cache *cache)
 {
-	return (struct shared_context *)((unsigned char *)cache - ((struct shared_context *)NULL)->data);
+	return (struct shared_context *)((unsigned char *)cache -  offsetof(struct shared_context, data));
 }
 
 static inline struct shared_block *block_ptr(struct cache_entry *entry)
 {
-	return (struct shared_block *)((unsigned char *)entry - ((struct shared_block *)NULL)->data);
+	return (struct shared_block *)((unsigned char *)entry - offsetof(struct shared_block, data));
 }
 
 
diff --git a/src/ssl_sock.c b/src/ssl_sock.c
index abbcfa6af..740fc0aeb 100644
--- a/src/ssl_sock.c
+++ b/src/ssl_sock.c
@@ -4205,7 +4205,7 @@ static inline void sh_ssl_sess_free_blocks(struct shared_block *first, struct sh
 /* return first block from sh_ssl_sess  */
 static inline struct shared_block *sh_ssl_sess_first_block(struct sh_ssl_sess_hdr *sh_ssl_sess)
 {
-	return (struct shared_block *)((unsigned char *)sh_ssl_sess - ((struct shared_block *)NULL)->data);
+	return (struct shared_block *)((unsigned char *)sh_ssl_sess - offsetof(struct shared_block, data));
 
 }
 
-- 
2.40.0