public inbox for gcc-help@gcc.gnu.org
 help / color / mirror / Atom feed
* Strange warning text
@ 2004-03-23 18:12 Christoph Rabel
  2004-03-24  0:44 ` Felix Lee
  0 siblings, 1 reply; 3+ messages in thread
From: Christoph Rabel @ 2004-03-23 18:12 UTC (permalink / raw)
  To: gcc-help

Hi!

Compiling the following program with -Wall

struct MyType{};

int main()
{
  int size = 0;
  int temp1[size];
}

I get the following warning:

x12.cpp: In function `int main()':
x12.cpp:6: warning: unused variable `int temp1[((size - 1) + 1)]'

I was rather surprised by "((size - 1) + 1)" part.

While this is a rather unimportant issue I would be interested to know 
why 1 is subtracted and then added again. I see no sense in this and 
really would like to get an explanation for this warning text.

Thx very much!

Christoph

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Strange warning text
  2004-03-23 18:12 Strange warning text Christoph Rabel
@ 2004-03-24  0:44 ` Felix Lee
  2004-03-24  4:30   ` Christoph Rabel
  0 siblings, 1 reply; 3+ messages in thread
From: Felix Lee @ 2004-03-24  0:44 UTC (permalink / raw)
  To: Christoph Rabel; +Cc: gcc-help

Christoph Rabel <odie@hal9000.vc-graz.ac.at>:
> x12.cpp: In function `int main()':
> x12.cpp:6: warning: unused variable `int temp1[((size - 1) + 1)]'
> I was rather surprised by "((size - 1) + 1)" part.

fixed in gcc 3.4
I think this is the relevant change:
http://gcc.gnu.org/ml/gcc-patches/2003-02/msg02468.html
--

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Strange warning text
  2004-03-24  0:44 ` Felix Lee
@ 2004-03-24  4:30   ` Christoph Rabel
  0 siblings, 0 replies; 3+ messages in thread
From: Christoph Rabel @ 2004-03-24  4:30 UTC (permalink / raw)
  To: gcc-help

Felix Lee wrote:

>Christoph Rabel <odie@hal9000.vc-graz.ac.at>:
>  
>
>>x12.cpp: In function `int main()':
>>x12.cpp:6: warning: unused variable `int temp1[((size - 1) + 1)]'
>>I was rather surprised by "((size - 1) + 1)" part.
>>    
>>
>
>fixed in gcc 3.4
>I think this is the relevant change:
>http://gcc.gnu.org/ml/gcc-patches/2003-02/msg02468.html
>  
>

Thanx for your answer!

Christoph

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2004-03-24  0:44 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-03-23 18:12 Strange warning text Christoph Rabel
2004-03-24  0:44 ` Felix Lee
2004-03-24  4:30   ` Christoph Rabel

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).