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* [Bug c++/64759] New: The compiler does NOT show a warning in a case where it is reasonable to expect a warning message.
@ 2015-01-23 23:43 lakshayg at iitk dot ac.in
  2015-01-23 23:46 ` [Bug c++/64759] " pinskia at gcc dot gnu.org
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: lakshayg at iitk dot ac.in @ 2015-01-23 23:43 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64759

            Bug ID: 64759
           Summary: The compiler does NOT show a warning in a case where
                    it is reasonable to expect a warning message.
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: lakshayg at iitk dot ac.in

Created attachment 34558
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34558&action=edit
test code that I used

using the logical not operator on a double does not show a compiler warning.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/64759] The compiler does NOT show a warning in a case where it is reasonable to expect a warning message.
  2015-01-23 23:43 [Bug c++/64759] New: The compiler does NOT show a warning in a case where it is reasonable to expect a warning message lakshayg at iitk dot ac.in
@ 2015-01-23 23:46 ` pinskia at gcc dot gnu.org
  2015-01-23 23:54 ` lakshayg at iitk dot ac.in
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2015-01-23 23:46 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64759

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Version|4.8.2                       |unknown

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
!x is the same as x == 0.0  and yes sometimes it make sense to compare against
zero.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/64759] The compiler does NOT show a warning in a case where it is reasonable to expect a warning message.
  2015-01-23 23:43 [Bug c++/64759] New: The compiler does NOT show a warning in a case where it is reasonable to expect a warning message lakshayg at iitk dot ac.in
  2015-01-23 23:46 ` [Bug c++/64759] " pinskia at gcc dot gnu.org
@ 2015-01-23 23:54 ` lakshayg at iitk dot ac.in
  2015-01-24  8:03 ` schwab@linux-m68k.org
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: lakshayg at iitk dot ac.in @ 2015-01-23 23:54 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64759

--- Comment #2 from Lakshay Garg <lakshayg at iitk dot ac.in> ---
(In reply to Andrew Pinski from comment #1)
> !x is the same as x == 0.0  and yes sometimes it make sense to compare
> against zero.

It makes sense to compare against 0 but not 0.0 . NOT operation makes sense
when used with booleans and integers. If someone is using logical not with
doubles then there is a high chance that it was done unintentionally.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/64759] The compiler does NOT show a warning in a case where it is reasonable to expect a warning message.
  2015-01-23 23:43 [Bug c++/64759] New: The compiler does NOT show a warning in a case where it is reasonable to expect a warning message lakshayg at iitk dot ac.in
  2015-01-23 23:46 ` [Bug c++/64759] " pinskia at gcc dot gnu.org
  2015-01-23 23:54 ` lakshayg at iitk dot ac.in
@ 2015-01-24  8:03 ` schwab@linux-m68k.org
  2015-01-24 14:53 ` redi at gcc dot gnu.org
  2015-01-24 14:54 ` redi at gcc dot gnu.org
  4 siblings, 0 replies; 6+ messages in thread
From: schwab@linux-m68k.org @ 2015-01-24  8:03 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64759

--- Comment #3 from Andreas Schwab <schwab@linux-m68k.org> ---
How often does that occur in real life?


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/64759] The compiler does NOT show a warning in a case where it is reasonable to expect a warning message.
  2015-01-23 23:43 [Bug c++/64759] New: The compiler does NOT show a warning in a case where it is reasonable to expect a warning message lakshayg at iitk dot ac.in
                   ` (2 preceding siblings ...)
  2015-01-24  8:03 ` schwab@linux-m68k.org
@ 2015-01-24 14:53 ` redi at gcc dot gnu.org
  2015-01-24 14:54 ` redi at gcc dot gnu.org
  4 siblings, 0 replies; 6+ messages in thread
From: redi at gcc dot gnu.org @ 2015-01-24 14:53 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64759

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Lakshay Garg from comment #2)
> It makes sense to compare against 0 but not 0.0

Huh? Why not?

This code seems perfectly reasonable to me:

 double divisor;
 std::cin >> divisor;
 if (!divisor)
   throw std::invalid_argument("Divide by zero attempted");


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/64759] The compiler does NOT show a warning in a case where it is reasonable to expect a warning message.
  2015-01-23 23:43 [Bug c++/64759] New: The compiler does NOT show a warning in a case where it is reasonable to expect a warning message lakshayg at iitk dot ac.in
                   ` (3 preceding siblings ...)
  2015-01-24 14:53 ` redi at gcc dot gnu.org
@ 2015-01-24 14:54 ` redi at gcc dot gnu.org
  4 siblings, 0 replies; 6+ messages in thread
From: redi at gcc dot gnu.org @ 2015-01-24 14:54 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64759

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(well, apart from not checking if the input operation failed ;-)


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2015-01-24 14:54 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2015-01-23 23:43 [Bug c++/64759] New: The compiler does NOT show a warning in a case where it is reasonable to expect a warning message lakshayg at iitk dot ac.in
2015-01-23 23:46 ` [Bug c++/64759] " pinskia at gcc dot gnu.org
2015-01-23 23:54 ` lakshayg at iitk dot ac.in
2015-01-24  8:03 ` schwab@linux-m68k.org
2015-01-24 14:53 ` redi at gcc dot gnu.org
2015-01-24 14:54 ` redi at gcc dot gnu.org

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