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From: Taylor Blau <me@ttaylorr.com>
To: git@vger.kernel.org
Cc: "Jeff King" <peff@peff.net>,
	"Chris Torek" <chris.torek@gmail.com>,
	"Junio C Hamano" <gitster@pobox.com>,
	"Jeff Hostetler" <jeffhostetler@github.com>,
	"René Scharfe" <l.s.r@web.de>
Subject: [PATCH v3 6/6] banned.h: mark `strtok()` and `strtok_r()` as banned
Date: Mon, 24 Apr 2023 18:20:26 -0400	[thread overview]
Message-ID: <da896aa358eab65f2629f85189c5be4ad9cec635.1682374789.git.me@ttaylorr.com> (raw)
In-Reply-To: <cover.1682374789.git.me@ttaylorr.com>

`strtok()` has a couple of drawbacks that make it undesirable to have
any new instances. In addition to being thread-unsafe, it also
encourages confusing data flows, where `strtok()` may be called from
multiple functions with its first argument as NULL, making it unclear
from the immediate context which string is being tokenized.

Now that we have removed all instances of `strtok()` from the tree,
let's ban `strtok()` to avoid introducing new ones in the future. If new
callers should arise, they are encouraged to use
`string_list_split_in_place()` (and `string_list_remove_empty_items()`,
if applicable).

string_list_split_in_place() is not a perfect drop-in replacement
for `strtok_r()`, particularly if the caller is processing a string with
an arbitrary number of tokens, and wants to process each token one at a
time.

But there are no instances of this in Git's tree which are more
well-suited to `strtok_r()` than the friendlier
`string_list_in_place()`, so ban `strtok_r()`, too.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 banned.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/banned.h b/banned.h
index 6ccf46bc19..44e76bd90a 100644
--- a/banned.h
+++ b/banned.h
@@ -18,6 +18,10 @@
 #define strncpy(x,y,n) BANNED(strncpy)
 #undef strncat
 #define strncat(x,y,n) BANNED(strncat)
+#undef strtok
+#define strtok(x,y) BANNED(strtok)
+#undef strtok_r
+#define strtok_r(x,y,z) BANNED(strtok_r)
 
 #undef sprintf
 #undef vsprintf
-- 
2.40.0.380.gd2df7d2365

  parent reply	other threads:[~2023-04-24 22:20 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-13 23:31 [PATCH 0/5] banned: mark `strok()`, `strtok_r()` as banned Taylor Blau
2023-04-13 23:31 ` [PATCH 1/5] string-list: introduce `string_list_split_in_place_multi()` Taylor Blau
2023-04-18 10:10   ` Jeff King
2023-04-18 17:08     ` Taylor Blau
2023-04-13 23:31 ` [PATCH 2/5] t/helper/test-hashmap.c: avoid using `strtok()` Taylor Blau
2023-04-18 10:23   ` Jeff King
2023-04-18 18:06     ` Taylor Blau
2023-04-13 23:31 ` [PATCH 3/5] t/helper/test-oidmap.c: " Taylor Blau
2023-04-13 23:31 ` [PATCH 4/5] t/helper/test-json-writer.c: " Taylor Blau
2023-04-13 23:31 ` [PATCH 5/5] banned.h: mark `strtok()`, `strtok_r()` as banned Taylor Blau
2023-04-14  1:39   ` Junio C Hamano
2023-04-14  2:08     ` Chris Torek
2023-04-14 13:41     ` Taylor Blau
2023-04-18 19:18 ` [PATCH v2 0/6] banned: mark `strok()` " Taylor Blau
2023-04-18 19:18   ` [PATCH v2 1/6] string-list: introduce `string_list_split_in_place_multi()` Taylor Blau
2023-04-18 19:39     ` Junio C Hamano
2023-04-18 20:54       ` Taylor Blau
2023-04-22 11:12     ` Jeff King
2023-04-22 15:53       ` René Scharfe
2023-04-23  0:35         ` Jeff King
2023-04-24 16:24           ` Junio C Hamano
2023-04-23  2:38       ` [PATCH v2 1/6] string-list: introduce `string_list_split_in_place_multi()`t Taylor Blau
2023-04-23  2:40         ` Taylor Blau
2023-04-18 19:18   ` [PATCH v2 2/6] string-list: introduce `string_list_setlen()` Taylor Blau
2023-04-22 11:14     ` Jeff King
2023-04-18 19:18   ` [PATCH v2 3/6] t/helper/test-hashmap.c: avoid using `strtok()` Taylor Blau
2023-04-22 11:16     ` Jeff King
2023-04-24 21:19       ` Taylor Blau
2023-04-18 19:18   ` [PATCH v2 4/6] t/helper/test-oidmap.c: " Taylor Blau
2023-04-18 19:18   ` [PATCH v2 5/6] t/helper/test-json-writer.c: " Taylor Blau
2023-04-18 19:18   ` [PATCH v2 6/6] banned.h: mark `strtok()` as banned Taylor Blau
2023-04-24 22:20 ` [PATCH v3 0/6] banned: mark `strok()`, `strtok_r()` " Taylor Blau
2023-04-24 22:20   ` [PATCH v3 1/6] string-list: multi-delimiter `string_list_split_in_place()` Taylor Blau
2023-04-24 22:20   ` [PATCH v3 2/6] string-list: introduce `string_list_setlen()` Taylor Blau
2023-04-25  6:21     ` Jeff King
2023-04-25 21:00       ` Taylor Blau
2023-04-24 22:20   ` [PATCH v3 3/6] t/helper/test-hashmap.c: avoid using `strtok()` Taylor Blau
2023-04-24 22:20   ` [PATCH v3 4/6] t/helper/test-oidmap.c: " Taylor Blau
2023-04-24 22:20   ` [PATCH v3 5/6] t/helper/test-json-writer.c: " Taylor Blau
2023-04-25 13:57     ` Jeff Hostetler
2023-04-24 22:20   ` Taylor Blau [this message]
2023-04-24 22:25     ` [PATCH v3 6/6] banned.h: mark `strtok()` and `strtok_r()` as banned Chris Torek
2023-04-24 23:00       ` Taylor Blau
2023-04-25  6:26     ` Jeff King
2023-04-25 21:02       ` Taylor Blau
2023-04-25  6:27   ` [PATCH v3 0/6] banned: mark `strok()`, " Jeff King
2023-04-25 21:03     ` Taylor Blau

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