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? " Finally, there is an issue with sparsesets that will trigger a warning from valgrind. Those are the only ones I would consistently ignore from GCC. Jeff " Yes I remember those - but it would be nice to get rid of them anyway, at least to simplify testcase reduction by having no valgrind warning on a clean build. I could also use a valgrind suppression file; this is also part of my question, if there is one readily available Thanks, Zdenek " "
