Re: [boost] UBSan question

Subject: Re: [boost] UBSan question
From: Raffi Enficiaud (raffi.enficiaud_at_[hidden])
Date: 2019-01-25 19:33:26

On 25.01.19 20:23, Peter Dimov via Boost wrote:
> Raffi Enficiaud wrote:
>> On 25.01.19 20:08, Peter Dimov via Boost wrote:
>> > Are you setting the environment variable >
>> UBSAN_OPTIONS=print_stacktrace=1?
>>
>> Yes. Do I need to change that?
> 
> No, I was just wondering whether you were getting a stack trace on the
> failure, and if not, why not.

I do have the stacktrace (in my original post), it is not exactly
pointing to the line causing the issue though. I tried trillions of
combinations, and the read from NULL is apparently causing this.

> 
> What I do in cases like this, is set UBSAN=1 for the UBSan runs, then in
> the Jamfile or in the .cpp files disable the known-to-fail tests. Like
> for instance here:
> https://github.com/boostorg/system/blob/develop/test/Jamfile.v2#L75

Ok, right. So I can say I tried my best. I will just use something
similar to yours for avoiding this specific test then. I was quite happy
with the diagnostics though, it pointed me to nasty visibility issues.

I am tempted to think that this is a UBSAN/clang issue, I will try to
reach their community (I just cannot let this go :) )

Thanks,
Raffi