From: Taylor Blau <me@ttaylorr.com>
To: git@vger.kernel.org
Cc: Jeff King <peff@peff.net>, Junio C Hamano <gitster@pobox.com>
Subject: [PATCH 5/5] banned.h: mark `strtok()`, `strtok_r()` as banned
Date: Thu, 13 Apr 2023 19:31:54 -0400 [thread overview]
Message-ID: <1d955f8bc6d2797def516897d019a186e461b648.1681428696.git.me@ttaylorr.com> (raw)
In-Reply-To: <cover.1681428696.git.me@ttaylorr.com>
`strtok_r()` is reentrant, but `strtok()` is not, meaning that using it
is not thread-safe.
We could ban `strtok()` and force callers to use its reentrant
counterpart, but there are a few drawbacks to doing so:
- `strtok_r()` forces the caller to maintain an extra string pointer
to pass as its `saveptr` value
- `strtok_r()` also requires that its `saveptr` value be unmodified
between calls.
- `strtok()` (and by extension, `strtok_r()`) is confusing when used
across multiple functions, since the caller is supposed to pass NULL
as its first argument after the first call. This makes it difficult
to determine what string is actually being tokenized without clear
dataflow.
So while we could ban only `strtok()`, there really is no good reason to
use either when callers could instead use the much friendlier
`string_list_split_in_place()` API, which avoids the above issues.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
banned.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/banned.h b/banned.h
index 6ccf46bc197..9bd23ce5732 100644
--- a/banned.h
+++ b/banned.h
@@ -18,6 +18,12 @@
#define strncpy(x,y,n) BANNED(strncpy)
#undef strncat
#define strncat(x,y,n) BANNED(strncat)
+#if 0
+#undef strtok
+#define strtok(x,y) BANNED(strtok)
+#undef strtok_r
+#define strtok_r(x,y,z) BANNED(strtok_r)
+#endif
#undef sprintf
#undef vsprintf
--
2.38.0.16.g393fd4c6db
next prev parent reply other threads:[~2023-04-13 23:32 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 ` Taylor Blau [this message]
2023-04-14 1:39 ` [PATCH 5/5] banned.h: mark `strtok()`, `strtok_r()` as banned 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 ` [PATCH v3 6/6] banned.h: mark `strtok()` and `strtok_r()` as banned Taylor Blau
2023-04-24 22:25 ` 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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