Re: TRAPINT doesn't work reliably

["Daniel Shahaf" <d.s@xxxxxxxxxxxxxxxxxx>]

Peter Stephenson wrote on Thu, 26 Sep 2019 15:27 +00:00:
> On Wed, 2019-09-25 at 18:46 +0000, Daniel Shahaf wrote:
> > Peter Stephenson wrote on Wed, Sep 25, 2019 at 18:04:45 +0100:
> > > 
> > > On Wed, 2019-09-25 at 16:25 +0000, Dennis Schwartz wrote:
> > > > 
> > > > I haven't tried compiling from the latest source code yet. If this is
> > > > desired I could try this again at a later point in time.
> > > I suspect that's going to have to be the next step, if you get the
> > > chance.  In the top-level directory, run configure as
> > > 
> > > ./configure --enable-zsh-debug
> > > 
> > Should Dennis use any of these flags as well? —
> 
> It's not clear anything else is going to help debugging, certainly
> if the build that's showing the problem was made (as almost all
> distro builds are made) using the system allocators.  In that
> case none of the zsh memory specials apply,

Even without any special configure flags, there's still zhalloc().  The source
of zhalloc() contains some blocks conditional on --enable-zsh-valgrind.
I assume passing that configure flag will let valgrind detect use-after-freeheap()
bugs.

Also, I thought --enable-zsh-secure-free and --enable-zsh-heap-debug were
independent of --enable-zsh-mem*.

> and if we turn on zsh memory management we are in a different world
> --- which might shows the problem but could well perturb it somewhere
> completely different.

Sure, any change could make the symptoms disappear, particularly
switching to a different allocator.

Cheers,

Daniel