Re: lib/51363: ubsan (undef behaviour sanitizer) faults

[David Holland <dholland-bugs%netbsd.org@localhost>]

The following reply was made to PR lib/51363; it has been noted by GNATS.

From: David Holland <dholland-bugs%netbsd.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: lib/51363: ubsan (undef behaviour sanitizer) faults
Date: Mon, 1 Aug 2016 18:22:39 +0000

 On Sun, Jul 31, 2016 at 11:10:01PM +0000, bch wrote:
  >  This is something I don't understand --
  >  
  >  I'm using clang from pkgsrc, and there are *no* ubsan components
  >  installed that I can see. The clang documentation says that issuing
  >  -fsanitize=* might only instrument the code, or require a lib for
  >  runtime support. W/ the -fsanitize=undefined clang reports that it
  >  wants to be linked to ubsan, and linking (w/ clang, which is supposed
  >  to be used to pick the correct ubsan), still links as you see.
 
 Me either; unfortunately, I don't know much about it. I asked Joerg
 and the only helpful information I was able to acquire is that it
 shouldn't be using the gcc library.
 
 My guess would be that (maybe at config time when you built it) clang
 detected the gcc libubsan and decided it should use that; or
 alternatively it's just generating -lubsan and assuming the library
 that finds is going to be the right one.
 
 I have no idea how it's supposed to work. Probably the best bet is to
 find a clang list to ask on :-/
 
 -- 
 David A. Holland
 dholland%netbsd.org@localhost