Re: [RFA] Introduce notion of "search name"

[Daniel Jacobowitz <drow@false.org>]

On Thu, Apr 01, 2004 at 09:52:46AM -0500, Jim Blandy wrote:
> 
> Daniel Jacobowitz <drow@false.org> writes:
> > On Fri, Mar 05, 2004 at 05:39:25AM -0500, Paul Hilfinger wrote:
> > > Daniel,
> > > 
> > > > It doesn't address on of the thornier problems I hit when doing the
> > > > same thing, namely that of allocation.  OK, someone uses
> > > > SYMBOL_DEMANGLED_NAME, we lazily allocate a demangled name - where? The
> > > > objfile is not available.  I think there may be no option but to
> > > > pass the objfile to SYMBOL_DEMANGLED_NAME.  What did you do for Ada?
> > > 
> > > You're right, I did not address this in the patch proper.  I had
> > > prepared a patch in which I used that extra byte in struct symtab to
> > > tag the union and allow an objfile member.  However, I was aware from
> > > correspondence with you that you were working in this area, and that
> > > some of what you proposed to do might eventually allow us to re-do Ada
> > > symbol lookup.  So I decided not to modify the symtab struct for the
> > > moment, and instead submit a patch that would change as little as
> > > possible.  I figured it would be better not to do anything just now
> > > that might interfere with on-going work on the symbol table.
> > > 
> > > So as an interim measure, I use your suggestion of 21 Jan and first
> > > try to find an objfile via the BFD section.  When that doesn't work, I
> > > simply use a global hashtable to hold the demangled strings.  Yes,
> > > that is a memory leak, but on consideration, I realized that it's only
> > > REALLY a memory leak if (a) I routinely change the entire set of
> > > demangled names numerous times during a single GDB session, or (b)
> > > demangle entirely different, large sets of names each time I reload
> > > the symbol tables.  Yeah, I know, it's not pretty, but again I am hoping
> > > it will ensure that demangled names behave until the next interation of
> > > symtab modifications allow an entirely different strategy.
> > 
> > I'm not sure what others will think of this interim measure.  I don't
> > like it much, though.
> 
> Under what circumstances does finding an objfile by the minsym's BFD
> section not work?  That minsym must have come from somewhere.  Do we
> produce minsyms whose sections are unset, for some reason?

Well, (A) it's inefficient, since there's no pointer from the BFD
section to the GDB section; (B) I don't know whether we produce minsyms
whose sections are unset; (C) I really want to remove the section
pointer from general_symbol_info someday, and this will make that
harder.  I've abandoned that project for the moment while I catch up on
other projects, but I'll be back to it :)

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer