Subject: Re: [PATCH v2 1/2] banned.h: mark non-reentrant gmtime, etc as banned

From: SZEDER Gábor <[email-masked]>
Date: Sun, 6 Dec 2020 15:56:42 +0100

On Tue, Dec 01, 2020 at 01:11:37PM -0800, Junio C Hamano wrote:
> From: Jeff King <[email-masked]>
> 
> The traditional gmtime(), localtime(), ctime(), and asctime() functions
> return pointers to shared storage. This means they're not thread-safe,
> and they also run the risk of somebody holding onto the result across
> multiple calls (where each call invalidates the previous result).
> 
> All callers should be using their reentrant counterparts.
> 
> Signed-off-by: Jeff King <[email-masked]>
> Signed-off-by: Junio C Hamano <[email-masked]>
> ---
>  banned.h | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/banned.h b/banned.h
> index 60a18d4403..ed11300bb2 100644
> --- a/banned.h
> +++ b/banned.h
> @@ -29,4 +29,13 @@
>  #define vsprintf(buf,fmt,arg) BANNED(vsprintf)
>  #endif
>  
> +#undef gmtime
> +#define gmtime(t) BANNED(gmtime)
> +#undef localtime
> +#define localtime(t) BANNED(localtime)
> +#undef ctime
> +#define ctime(t) BANNED(ctime)
> +#undef asctime
> +#define asctime(t) BANNED(asctime)
> +
>  #endif /* BANNED_H */

This patch should be queued on top of topic
'tb/bugreport-no-localtime'.  Currently they are on parallel branches:

  * 91aef03015 (refs/upstream/jk/banned) banned.h: mark ctime_r() and asctime_r() as banned
  * 1fbfdf556f banned.h: mark non-reentrant gmtime, etc as banned
  | * 4f6460df55 (refs/upstream/tb/bugreport-no-localtime) builtin/bugreport.c: use thread-safe localtime_r()
  |/  
  * 72ffeb997e Ninth batch

and because of the not-yet-removed localtime() call in
'builtin/bugreport.c' commits 1fbfdf556f and 91aef03015 can't be
built.