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* [Bug c/109056] New: cppcheck: no warning for suspicious return type
@ 2023-03-07 16:50 dcb314 at hotmail dot com
2023-03-07 16:56 ` [Bug c/109056] " pinskia at gcc dot gnu.org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: dcb314 at hotmail dot com @ 2023-03-07 16:50 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109056
Bug ID: 109056
Summary: cppcheck: no warning for suspicious return type
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: dcb314 at hotmail dot com
Target Milestone: ---
For the following C code:
unsigned long f( int n)
{
return n * 1000;
}
where the programmer may have intended using an unsigned long constant
like 1000UL, then static analyser cppcheck can be made to say:
mar7b.cc:4:2: style: int result is returned as long value. If the return value
is long to avoid loss of information, then you have loss of information.
[truncLongCastReturn]
return n * 1000;
gcc says nothing:
$ ~/gcc/results/bin/gcc -c -g -O2 -Wall -Wextra mar7b.cc
$
The example code is derived from 10 examples in the source code of
linux-6.3-rc1, so the problem does really occur in practice.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/109056] cppcheck: no warning for suspicious return type
2023-03-07 16:50 [Bug c/109056] New: cppcheck: no warning for suspicious return type dcb314 at hotmail dot com
@ 2023-03-07 16:56 ` pinskia at gcc dot gnu.org
2023-03-07 16:56 ` pinskia at gcc dot gnu.org
2023-03-07 17:03 ` dcb314 at hotmail dot com
2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-03-07 16:56 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109056
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |INVALID
Status|UNCONFIRMED |RESOLVED
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
-Wconversion is needed for this warning in GCC.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/109056] cppcheck: no warning for suspicious return type
2023-03-07 16:50 [Bug c/109056] New: cppcheck: no warning for suspicious return type dcb314 at hotmail dot com
2023-03-07 16:56 ` [Bug c/109056] " pinskia at gcc dot gnu.org
@ 2023-03-07 16:56 ` pinskia at gcc dot gnu.org
2023-03-07 17:03 ` dcb314 at hotmail dot com
2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-03-07 16:56 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109056
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #1)
> -Wconversion is needed for this warning in GCC.
Which turns on -Wsign-conversion .
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/109056] cppcheck: no warning for suspicious return type
2023-03-07 16:50 [Bug c/109056] New: cppcheck: no warning for suspicious return type dcb314 at hotmail dot com
2023-03-07 16:56 ` [Bug c/109056] " pinskia at gcc dot gnu.org
2023-03-07 16:56 ` pinskia at gcc dot gnu.org
@ 2023-03-07 17:03 ` dcb314 at hotmail dot com
2 siblings, 0 replies; 4+ messages in thread
From: dcb314 at hotmail dot com @ 2023-03-07 17:03 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109056
--- Comment #3 from David Binderman <dcb314 at hotmail dot com> ---
(In reply to Andrew Pinski from comment #2)
> Which turns on -Wsign-conversion .
-Wsign-conversion seems close, but not quite right. The problem is
in potential overflow, not sign conversion.
-Woverflow doesn't seem to do anything. Nor does -Wconversion.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-03-07 17:03 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2023-03-07 16:50 [Bug c/109056] New: cppcheck: no warning for suspicious return type dcb314 at hotmail dot com
2023-03-07 16:56 ` [Bug c/109056] " pinskia at gcc dot gnu.org
2023-03-07 16:56 ` pinskia at gcc dot gnu.org
2023-03-07 17:03 ` dcb314 at hotmail dot com
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