From: Junio C Hamano <gitster@pobox.com>
To: Jonathan Nieder <jrnieder@gmail.com>
Cc: Jeff King <peff@peff.net>, git@vger.kernel.org
Subject: Re: [PATCH 1/4] wt-status: fix possible use of uninitialized variable
Date: Thu, 21 Mar 2013 12:55:12 -0700 [thread overview]
Message-ID: <7vip4ka5pb.fsf@alter.siamese.dyndns.org> (raw)
In-Reply-To: <20130321194949.GG29311@google.com> (Jonathan Nieder's message of "Thu, 21 Mar 2013 12:49:50 -0700")
Jonathan Nieder <jrnieder@gmail.com> writes:
> Jeff King wrote:
>
>> Instead of using the "x = x" hack, let's handle the default
>> case in the switch() statement with a die("BUG"). That tells
>> the compiler and any readers of the code exactly what the
>> function's input assumptions are.
>
> Sounds reasonable.
>
>> We could also convert the flag to an enum, which would
>> provide a compile-time check on the function input.
>
> Unfortunately C permits out-of-bounds values for enums.
>
> [...]
>> --- a/wt-status.c
>> +++ b/wt-status.c
>> @@ -264,7 +264,7 @@ static void wt_status_print_change_data(struct wt_status *s,
>> {
>> struct wt_status_change_data *d = it->util;
>> const char *c = color(change_type, s);
>> - int status = status;
>> + int status;
>> char *one_name;
>> char *two_name;
>> const char *one, *two;
>> @@ -292,6 +292,9 @@ static void wt_status_print_change_data(struct wt_status *s,
>> }
>> status = d->worktree_status;
>> break;
>> + default:
>> + die("BUG: unhandled change_type %d in wt_status_print_change_data",
>> + change_type);
>
> Micronit: s/unhandled/invalid/.
I actually think "unhandled" is more correct for this one; we may
add new change_type later in the caller, and we do not want to
forget to add a new case arm that handles the new value.
next prev parent reply other threads:[~2013-03-21 19:56 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-21 11:03 [PATCH 0/4] drop some "int x = x" hacks to silence gcc warnings Jeff King
2013-03-21 11:05 ` [PATCH 1/4] wt-status: fix possible use of uninitialized variable Jeff King
2013-03-21 19:49 ` Jonathan Nieder
2013-03-21 19:55 ` Junio C Hamano [this message]
2013-03-21 19:58 ` Jonathan Nieder
2013-03-22 16:15 ` Jeff King
2013-03-21 11:08 ` [PATCH 2/4] fast-import: use pointer-to-pointer to keep list tail Jeff King
2013-03-21 20:43 ` Jonathan Nieder
2013-03-21 11:10 ` [PATCH 3/4] drop some obsolete "x = x" compiler warning hacks Jeff King
2013-03-21 15:16 ` Erik Faye-Lund
2013-03-21 20:47 ` Jonathan Nieder
2013-03-24 7:17 ` Torsten Bögershausen
2013-03-21 11:13 ` [PATCH 4/4] transport: drop "int cmp = cmp" hack Jeff King
2013-03-21 20:59 ` Jonathan Nieder
2013-03-24 4:00 ` Junio C Hamano
2013-03-24 9:32 ` Jeff King
2013-03-24 14:54 ` Torsten Bögershausen
2013-03-25 19:50 ` Junio C Hamano
2013-03-25 21:06 ` Jeff King
2013-03-25 21:55 ` Junio C Hamano
2013-03-21 11:45 ` [PATCH 0/4] drop some "int x = x" hacks to silence gcc warnings Johannes Sixt
2013-03-21 11:55 ` Jeff King
2013-03-21 14:58 ` Junio C Hamano
2013-03-21 15:19 ` Junio C Hamano
2013-03-21 15:44 ` Jeff King
2013-03-21 15:44 ` [PATCH 5/4] fast-import: clarify "inline" logic in file_change_m Jeff King
2013-03-21 15:45 ` [PATCH 6/4] run-command: always set failed_errno in start_command Jeff King
2013-03-21 21:02 ` [PATCH 0/4] drop some "int x = x" hacks to silence gcc warnings Jonathan Nieder
2013-03-22 16:18 ` Jeff King
2013-03-22 16:19 ` [PATCH 7/4] submodule: clarify logic in show_submodule_summary Jeff King
2013-03-22 21:10 ` Junio C Hamano
2013-03-22 16:21 ` [PATCH 8/4] match-trees: drop "x = x" initializations Jeff King
2013-03-22 21:26 ` Junio C Hamano
2013-03-22 21:33 ` Junio C Hamano
2013-03-22 21:36 ` Jeff King
2013-03-23 18:57 ` René Scharfe
2013-03-24 4:55 ` Junio C Hamano
2013-03-24 10:01 ` Jeff King
2013-03-24 22:46 ` René Scharfe
2013-03-25 16:10 ` Junio C Hamano
2013-03-21 13:44 ` [PATCH 0/4] drop some "int x = x" hacks to silence gcc warnings Joachim Schmitz
2013-03-21 13:56 ` Joachim Schmitz
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