On 11/24/2021 12:41 PM, Zdenek Sojka wrote:
Hello Jeff,
---------- Původní e-mail ----------
Od: Jeff Law via Gcc <gcc@gcc.gnu.org>
Komu: Paul Floyd <pa...@free.fr>, gcc@gcc.gnu.org
Datum: 24. 11. 2021 20:33:02
Předmět: Re: distinguishing gcc compilation valgrind false positives
On 11/24/2021 12:15 PM, Paul Floyd via Gcc wrote:
>
> On 24/11/2021 20:05, Zdenek Sojka via Gcc wrote:
>> Hello,
>>
>> from time to time, I come upon a testcase that failed during the
>> automated
>> runs, but passes during reduction; there are valgrind warnings
present,
>> however. How do I distinguish what warnings are valid and which
are
>> false
>> positives? Is there any way gcc could prevent generating the false
>> positives?
>
>
> What makes you think that any are false positives?
>
> Memcheck generally has a low false positive rate (though I am
little
> biased).
>
> You need to read the source and decide based on that.
Agreed. Work from the assumption it's a real GCC issue until proven
otherwise.
I believe GCC has annotations to help valgrind that are turned on
by a
magic configuration option as well.
I have gcc configured with --enable-valgrind-annotations , if that is
the one you are talking about?
Almost certainly. I
I could also use a valgrind suppression file; this is also part of my
question, if there is one readily available
I'm not aware of a suppression file, but it'd be nice to have one.
jeff