Clang as default compiler

[Roland Smith]

On Tue, Sep 18, 2012 at 12:02:20AM +0200, Dimitry Andric wrote:
> On 2012-09-17 21:43, Roland Smith wrote:
> > On Wed, Sep 12, 2012 at 01:04:20AM -0500, Mark Linimon wrote:
> ...
> >> For most of the failures, we are already aware of them, as a result of
> >> our periodic runs.  So, just filing a PR to say "broken on clang" doesn't
> >> really help us all that much.
> >
> > Those are build failures. What about crashes? E.g. I've recently had
> > crashes with x11-wm/i3 and x11/rxvt-unicode. Both problems disappeared after
> > recompiling them with gcc46.
> 
> We can't figure them all out without *your* help. :-)  Please attempt to
> run the program in a debugger, gather core dumps, etc.  Or at least, try
> to make it into a reproducible case, so somebody else can attempt to
> diagnose it.  And please specify the exact version of clang you used.

I was using the clang that is in base in 9.0-RELEASE-p3:

FreeBSD clang version 3.0 (branches/release_30 142614) 20111021
Target: x86_64-unknown-freebsd9.0
Thread model: posix

I was thinking of installing the most recent clang-devel since it seemed to
have a lot of improvements, but I was wondering what is the correct way of
makeing sure that it is used in preference to the one in base? I thought about
moving /usr/local/bin before /usr/bin in $PATH, but I'm not sure that is a
good idea.

> Now, most of the time this is because programs contain bugs, or
> undefined behavior, which happens to go unnoticed with gcc, for example
> because it optimized by accident in such a way to mask the bug.  In a
> few other cases, real clang bugs are found, and most of the time, those
> can be fixed quickly.
> 
> That said, in these cases specifically, how do the applications crash?
> Right at startup, or after specific inputs or user actions?

Rxvt-unicode seemed to crash reliably whenever I was scrolling through a
document with less(1). If I reached the end of the document, and pressed Page
Down (keysim Next), it would crash. It was quite weird. 

I couldn't pinpoint a concrete action that crashed x11-wm/i3.

Roland
-- 
R.F.Smith                                   http://rsmith.home.xs4all.nl/
[plain text _non-HTML_ PGP/GnuPG encrypted/signed email much appreciated]
pgp: 1A2B 477F 9970 BA3C 2914  B7CE 1277 EFB0 C321 A725 (KeyID: C321A725)
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 196 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20120919/f9b1408e/attachment.pgp