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Re: Macro code crasher on re-run
On Mon, Nov 03, 2003 at 04:33:44PM -0500, Jim Blandy wrote:
>
> Daniel Jacobowitz <drow@mvista.com> writes:
> > On Mon, Nov 03, 2003 at 03:59:41PM -0500, Jim Blandy wrote:
> > >
> > > Daniel Jacobowitz <drow@mvista.com> writes:
> > > > > I don't follow. All default_macro_scope's callers check for null
> > > > > return; it's documented to return zero at times. So you must be
> > > > > talking about that code in sal_macro_scope itself. Line 39 refers to
> > > > > sal.symtab, initialized by line 115, so you must be talking about line
> > > > > 40. But sal.symtab must be non-zero, or else we wouldn't reach the
> > > > > right operand of the ||.
> > > > >
> > > > > Or should I sleep and try again?
> > > > >
> > > >
> > > > Right. sal.symtab is nonzero. sal.symtab->macro_table, however, is
> > > > uninitialized. The short-circuit if on line 40 does not trigger, but
> > > > the remainder of sal_macro_scope assumes that sal.symtab->macro_table
> > > > is valid.
> > > >
> > > > In my case it happens to be 0xB.
> > >
> > > Every symtab's macro_table field should be initialized, at least to
> > > zero. Which symtab is it? Who creates it?
> >
> > If you thought I wasn't making sense, you were right. I really needed
> > some sleep when I wrote that.
> >
> > My best guess is that the returned symtab belongs to the old (already
> > unloaded) binary. Which would put the bug somewhere else.
>
> I haven't debugged it (only Daniel J. has seen the problem, as far as
> I know), but I kind of suspect this change:
>
> 2003-10-22 Andrew Cagney <cagney@redhat.com>
>
> * target.c (target_close): New function.
> (debug_to_close): Use "target_close".
> (push_target): Use "target_close".
> (unpush_target): Use "target_close".
> (pop_target): Use "target_close".
> * target.h (struct target_ops): Add "to_xclose".
> (target_open): Delete macro. Move comment to "to_open".
> (target_close): Replace macro with function that takes a target.
> * top.c (quit_target): Pass "current_target" to "target_close".
>
> The to_close method of the "exec" target calls free_objfile, which
> assumes that its callers call clear_symtab_users at some appropriate
> time. This change seems to have introduced several new callers to
> target_close, so it may have broken that assumption.
>
> Having free_objfile require its callers to take care of things this
> way is not very nice.
I was using the 6.0 branch when I found the problem, so that's not it.
It may be a related problem in a caller of free_objfile, though. Or
reread_objfile?
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer