Re: [Valgrind-developers] Merging stage2.c and vg_main.c [was Re: tool-specific CLOs] (fwd)

[Doug R. <df...@nl...>]

On Fri, 2004-01-23 at 18:07, Jeremy Fitzhardinge wrote:
> On Fri, 2004-01-23 at 09:20, Nicholas Nethercote wrote:
> > Which is bad news for detecting bugs in the JIT-compiler;  you can't do
> > the binary search technique for finding erroneous BBs.
> > 
> > (Well, you probably can if your error and the manifestation of it are
> > close enough, but if it's a subtle error that doesn't manifest for a
> > while, it won't work.)
> > 
> > Any way we can achieve the same effect?
> 
> Well, it was always a fairly crippled mechanism, since it never worked
> with threaded programs, or if signals happened.
> 
> I guess you could try to set up a limited environment which can coddle a
> bit more execution out of the client, but it might turn out to be a
> significant amount of work, which would be bad.  And the more we do to
> improve Valgrind's virtualization, the less likely it is that we can
> maintain this easily.
> 
> I agree with you about the debugging, but I don't really see how to
> achieve it.

Well if you are planning to drop this feature, it should tighten up the
code generation for the low-overhead tools since you won't need the
dec/test/branch at the beginning of each block, I guess.