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* [Bug c/24016] Missing warning for unspecified evaluation order
       [not found] <bug-24016-4@http.gcc.gnu.org/bugzilla/>
@ 2015-05-23  6:09 ` miyuki at gcc dot gnu.org
  2015-05-23 13:45 ` mpolacek at gcc dot gnu.org
  2021-12-31  1:58 ` egallager at gcc dot gnu.org
  2 siblings, 0 replies; 5+ messages in thread
From: miyuki at gcc dot gnu.org @ 2015-05-23  6:09 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=24016

Mikhail Maltsev <miyuki at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |miyuki at gcc dot gnu.org

--- Comment #3 from Mikhail Maltsev <miyuki at gcc dot gnu.org> ---
It seems to me that __extension__ also inhibits some other useful warnings. For
example:

#include <string.h>
int foo(void *x) {
    return strcmp(x + 1, "test");
}

does not cause warnings when compiled with -Wpointer-arith -O1 (glibc v. 2.17).
It can be reduced to:

int foo(void *x) {
    return __extension__({ __builtin_strcmp(x + 1, "test"); });
}

Note, that we do warn about

int foo(void *x) {
    return ({ __builtin_strcmp(x + 1, "test"); });
}


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [Bug c/24016] Missing warning for unspecified evaluation order
       [not found] <bug-24016-4@http.gcc.gnu.org/bugzilla/>
  2015-05-23  6:09 ` [Bug c/24016] Missing warning for unspecified evaluation order miyuki at gcc dot gnu.org
@ 2015-05-23 13:45 ` mpolacek at gcc dot gnu.org
  2021-12-31  1:58 ` egallager at gcc dot gnu.org
  2 siblings, 0 replies; 5+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2015-05-23 13:45 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=24016

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mpolacek at gcc dot gnu.org

--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Since arithmetic on void * (treating sizeof(void) as 1) is a GNU extension,
that behavior is desirable.


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [Bug c/24016] Missing warning for unspecified evaluation order
       [not found] <bug-24016-4@http.gcc.gnu.org/bugzilla/>
  2015-05-23  6:09 ` [Bug c/24016] Missing warning for unspecified evaluation order miyuki at gcc dot gnu.org
  2015-05-23 13:45 ` mpolacek at gcc dot gnu.org
@ 2021-12-31  1:58 ` egallager at gcc dot gnu.org
  2 siblings, 0 replies; 5+ messages in thread
From: egallager at gcc dot gnu.org @ 2021-12-31  1:58 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=24016

Eric Gallager <egallager at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |egallager at gcc dot gnu.org

--- Comment #5 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to Manuel López-Ibáñez from comment #2)
> (In reply to comment #1)
> > 
> > It is, however, at least unspecified order of evaluation and a warning 
> > here would still make sense.
> > 
> 
> A candidate for -Wsequence-points ?

...or a new flag?

^ permalink raw reply	[flat|nested] 5+ messages in thread

* [Bug c/24016] Missing warning for unspecified evaluation order
       [not found] <bug-24016-6528@http.gcc.gnu.org/bugzilla/>
  2005-11-26  7:50 ` gdr at gcc dot gnu dot org
@ 2007-03-12 17:48 ` manu at gcc dot gnu dot org
  1 sibling, 0 replies; 5+ messages in thread
From: manu at gcc dot gnu dot org @ 2007-03-12 17:48 UTC (permalink / raw)
  To: gcc-bugs



------- Comment #2 from manu at gcc dot gnu dot org  2007-03-12 17:48 -------
(In reply to comment #1)
> 
> It is, however, at least unspecified order of evaluation and a warning 
> here would still make sense.
> 

A candidate for -Wsequence-points ?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24016


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [Bug c/24016] Missing warning for unspecified evaluation order
       [not found] <bug-24016-6528@http.gcc.gnu.org/bugzilla/>
@ 2005-11-26  7:50 ` gdr at gcc dot gnu dot org
  2007-03-12 17:48 ` manu at gcc dot gnu dot org
  1 sibling, 0 replies; 5+ messages in thread
From: gdr at gcc dot gnu dot org @ 2005-11-26  7:50 UTC (permalink / raw)
  To: gcc-bugs



-- 

gdr at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |gdr at gcc dot gnu dot org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-11-26 07:50:22
               date|                            |
            Summary|Missing "operation on xxx   |Missing warning for
                   |may be undefined" on obvious|unspecified evaluation order
                   |undefined code              |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24016


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2021-12-31  1:58 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <bug-24016-4@http.gcc.gnu.org/bugzilla/>
2015-05-23  6:09 ` [Bug c/24016] Missing warning for unspecified evaluation order miyuki at gcc dot gnu.org
2015-05-23 13:45 ` mpolacek at gcc dot gnu.org
2021-12-31  1:58 ` egallager at gcc dot gnu.org
     [not found] <bug-24016-6528@http.gcc.gnu.org/bugzilla/>
2005-11-26  7:50 ` gdr at gcc dot gnu dot org
2007-03-12 17:48 ` manu at gcc dot gnu dot org

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