Re: [PATCH] run-command.c: Fix unused variables warning with gcc 4.6
- From
Andreas Ericsson <ae@op5.se>
- Date
- Apr 26, 2011, 13:45 UTC
- Message-ID
- <4DB6CC6D.1030105@op5.se>
- In-Reply-To
- <4DB6C83A.4040900@elegosoft.com>
On 04/26/2011 03:27 PM, Michael Schubert wrote:
Show 48 quoted lines
> On 04/26/2011 03:13 PM, Michael J Gruber wrote:
>> Michael Schubert venit, vidit, dixit 26.04.2011 14:28:
>>> As of gcc 4.6 -Wall includes -Wunused-but-set-variable. Remove all
>>> unused variables to prevent those warnings.
>>>
>>> Signed-off-by: Michael Schubert<mschub@elegosoft.com>
>>> ---
>>> run-command.c | 10 ++++------
>>> 1 files changed, 4 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/run-command.c b/run-command.c
>>> index f91e446..6e0be54 100644
>>> --- a/run-command.c
>>> +++ b/run-command.c
>>> @@ -67,21 +67,19 @@ static int child_notifier = -1;
>>>
>>> static void notify_parent(void)
>>> {
>>> - ssize_t unused;
>>> - unused = write(child_notifier, "", 1);
>>> + write(child_notifier, "", 1);
>>> }
>>>
>>> static NORETURN void die_child(const char *err, va_list params)
>>> {
>>> char msg[4096];
>>> - ssize_t unused;
>>> int len = vsnprintf(msg, sizeof(msg), err, params);
>>> if (len> sizeof(msg))
>>> len = sizeof(msg);
>>>
>>> - unused = write(child_err, "fatal: ", 7);
>>> - unused = write(child_err, msg, len);
>>> - unused = write(child_err, "\n", 1);
>>> + write(child_err, "fatal: ", 7);
>>> + write(child_err, msg, len);
>>> + write(child_err, "\n", 1);
>>> exit(128);
>>> }
>>> #endif
>>
>> git log -S"unused" origin/master run-command.c
>>
>> shows that these dummies were introduced for a reason. How do you
>> invalidate that?
>
> Sorry, just missed that.
> A better solution than reverting the prettifying commit ebec842773932e6f853acac70c80f84209b5f83e would be to rework it to use logical AND instead of logical OR, as the AND-chain won't short-circuit the statement chain early and prevent output from being printed when write() returns non-zero. When it *does* return zero, it's likely due to problems on the receiving ends, making further writing totally pointless anyway.
-- Andreas Ericsson andreas.ericsson@op5.se OP5 AB www.op5.se Tel: +46 8-230225 Fax: +46 8-230231 Considering the successes of the wars on alcohol, poverty, drugs and terror, I think we should give some serious thought to declaring war on peace.