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* [Bug c/65452] New: strcmp (foo, foo) could give a warning
@ 2015-03-17 14:33 rstrode at redhat dot com
  2015-03-17 14:36 ` [Bug c/65452] " dmalcolm at gcc dot gnu.org
                   ` (5 more replies)
  0 siblings, 6 replies; 7+ messages in thread
From: rstrode at redhat dot com @ 2015-03-17 14:33 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65452

            Bug ID: 65452
           Summary: strcmp (foo, foo) could give a warning
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rstrode at redhat dot com

Created attachment 35043
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35043&action=edit
example that could warn

sometimes gcc will give a warning like:

warning: the address of 'foo' will always evaluate as 'true'

if the address foo is used in a conditional expression.

It would be useful if there was also a warning of the form:

warning: the comparison of 'foo' with itself will always evaluate as 'true'

if the code does "if (strcmp (foo, foo) == 0)" or similar.


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [Bug c/65452] strcmp (foo, foo) could give a warning
  2015-03-17 14:33 [Bug c/65452] New: strcmp (foo, foo) could give a warning rstrode at redhat dot com
@ 2015-03-17 14:36 ` dmalcolm at gcc dot gnu.org
  2015-03-17 14:41 ` dmalcolm at gcc dot gnu.org
                   ` (4 subsequent siblings)
  5 siblings, 0 replies; 7+ messages in thread
From: dmalcolm at gcc dot gnu.org @ 2015-03-17 14:36 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65452

David Malcolm <dmalcolm at gcc dot gnu.org> changed:

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

--- Comment #1 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Some context from our IRC chat, for other gcc devs:
 I just wrote:
   if (strcmp (foo, foo) == 0)
 instead of
   if (strcmp (self->priv->foo, foo) == 0)
 in a patch... thankfully got noticed in review.


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [Bug c/65452] strcmp (foo, foo) could give a warning
  2015-03-17 14:33 [Bug c/65452] New: strcmp (foo, foo) could give a warning rstrode at redhat dot com
  2015-03-17 14:36 ` [Bug c/65452] " dmalcolm at gcc dot gnu.org
@ 2015-03-17 14:41 ` dmalcolm at gcc dot gnu.org
  2015-03-17 15:21 ` rstrode at redhat dot com
                   ` (3 subsequent siblings)
  5 siblings, 0 replies; 7+ messages in thread
From: dmalcolm at gcc dot gnu.org @ 2015-03-17 14:41 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65452

David Malcolm <dmalcolm at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [Bug c/65452] strcmp (foo, foo) could give a warning
  2015-03-17 14:33 [Bug c/65452] New: strcmp (foo, foo) could give a warning rstrode at redhat dot com
  2015-03-17 14:36 ` [Bug c/65452] " dmalcolm at gcc dot gnu.org
  2015-03-17 14:41 ` dmalcolm at gcc dot gnu.org
@ 2015-03-17 15:21 ` rstrode at redhat dot com
  2015-03-25  8:48 ` mpolacek at gcc dot gnu.org
                   ` (2 subsequent siblings)
  5 siblings, 0 replies; 7+ messages in thread
From: rstrode at redhat dot com @ 2015-03-17 15:21 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65452

--- Comment #2 from Ray Strode <rstrode at redhat dot com> ---
probably should catch

if (foo == foo) {
}

type situations too.


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [Bug c/65452] strcmp (foo, foo) could give a warning
  2015-03-17 14:33 [Bug c/65452] New: strcmp (foo, foo) could give a warning rstrode at redhat dot com
                   ` (2 preceding siblings ...)
  2015-03-17 15:21 ` rstrode at redhat dot com
@ 2015-03-25  8:48 ` mpolacek at gcc dot gnu.org
  2015-03-25  8:53 ` mpolacek at gcc dot gnu.org
  2015-08-12 11:02 ` mpolacek at gcc dot gnu.org
  5 siblings, 0 replies; 7+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2015-03-25  8:48 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65452

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-03-25
                 CC|                            |mpolacek at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Confirmed.


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [Bug c/65452] strcmp (foo, foo) could give a warning
  2015-03-17 14:33 [Bug c/65452] New: strcmp (foo, foo) could give a warning rstrode at redhat dot com
                   ` (3 preceding siblings ...)
  2015-03-25  8:48 ` mpolacek at gcc dot gnu.org
@ 2015-03-25  8:53 ` mpolacek at gcc dot gnu.org
  2015-08-12 11:02 ` mpolacek at gcc dot gnu.org
  5 siblings, 0 replies; 7+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2015-03-25  8:53 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65452

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
   Target Milestone|---                         |6.0


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [Bug c/65452] strcmp (foo, foo) could give a warning
  2015-03-17 14:33 [Bug c/65452] New: strcmp (foo, foo) could give a warning rstrode at redhat dot com
                   ` (4 preceding siblings ...)
  2015-03-25  8:53 ` mpolacek at gcc dot gnu.org
@ 2015-08-12 11:02 ` mpolacek at gcc dot gnu.org
  5 siblings, 0 replies; 7+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2015-08-12 11:02 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65452

--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
We now warn for the testcase in Comment 2.


^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2015-08-12 11:02 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-03-17 14:33 [Bug c/65452] New: strcmp (foo, foo) could give a warning rstrode at redhat dot com
2015-03-17 14:36 ` [Bug c/65452] " dmalcolm at gcc dot gnu.org
2015-03-17 14:41 ` dmalcolm at gcc dot gnu.org
2015-03-17 15:21 ` rstrode at redhat dot com
2015-03-25  8:48 ` mpolacek at gcc dot gnu.org
2015-03-25  8:53 ` mpolacek at gcc dot gnu.org
2015-08-12 11:02 ` mpolacek at gcc dot gnu.org

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