[Pkg-clamav-devel] build clamav with system LLVM

[Scott Kitterman]

On Friday, May 02, 2014 20:45:55 Andreas Cadhalpun wrote:
> Hi Scott,
> 
> On 02.05.2014 19:57, Scott Kitterman wrote:
> > On Friday, May 02, 2014 19:46:50 Andreas Cadhalpun wrote:
> >> in the branch aca_llvm I have created a patch to build clamav with the
> >> system LLVM.
> >> I think that would be good, because of security and other bugfixes in
> >> LLVM (the internal version is based on 2.8, while testing has 3.3 as
> >> default and 3.4 available).
> >> As a bonus, this drastically reduces build time.
> >> 
> >> To fix FTBFS with new versions, mostly header names had to be changed,
> >> 
> >> but two functions were removed, that I couldn't find a replacement for:
> >>    * Attribute::constructStackAlignmentFromInt used in
> >> 
> >> libclamav/c++/bytecode2llvm.cpp
> >> 
> >>    * JITExceptionHandling (defined as DwarfExceptionHandling) used in
> >> 
> >> libclamav/c++/bytecode2llvm.cpp
> >> 
> >> I don't think this is a major problem, but
> >> constructStackAlignmentFromInt was added to fix a bug [1]. Hopefully
> >> this is fixed now in LLVM directly.
> >> 
> >> What do you think about this?
> > 
> > I think using the system LLVM is a great step forward.  Before we switch,
> > however, I would send the change upstream for review.  You can ask them
> > about the constructStackAlignmentFromInt issue at the same time.
> 
> I just filed a bug about this upstream [1].
> 
> > This would also solve the array-bounds and pointer-cast-size-mismatch
> > issues identified in http://qa.debian.org/bls/packages/c/clamav.html
> 
> Yes, that would be another good side effect.
> 
> > I suspect they would appreciate the patch since using the system LLVM (or
> > at least updating to a newer one) is definitely in their plans.
> 
> I hope so. LLVM 2.8 is really a bit outdated (from 2010).

I harassed people on #clamav and got this:

<lattera> I could be wrong... llvm's not my area of expertise
<lattera> I asked my coworker, Kevin, to take a look at that bugzilla ticket
<lattera> after quick glance, he says he likes the patch overall

That's encouraging, but I'm not entirely comfortable yet (from what I know the 
patch looks good too).  How about we upload this patch to experimental and 
then we can see how it works out on multiple architectures?  Once upstream 
reviews/acks the patch and we see how it works then we can go to unstable.

Scott K