Re: [MI] -file-list-exec-source-files

[Daniel Jacobowitz <drow@false.org>]

On Tue, Feb 17, 2004 at 02:30:01PM -0500, Bob Rossi wrote:
> On Tue, Feb 17, 2004 at 02:12:38PM -0500, Daniel Jacobowitz wrote:
> > On Tue, Feb 17, 2004 at 02:10:05PM -0500, Bob Rossi wrote:
> > > I have one last question that didn't get answered, could the psymtab be
> > > modified to contain the dirname?
> > 
> > Probably, but the dirname -> fullname conversion may be expensive - it
> > involves a lot of stat() calls.
> 
> I could definatly use some advice getting the dirname into the psymtab.
> I don't mind spending time implementing it if I could get a little
> pointer in the right direction. It seems I would have to change both the
> stabs reader and the dwarf2 reader. Is that correct?

Yes, I think so.  Dwarf2 should be easy.  Stabs will be a little
harder.  Take a look at patch_subfile_names.

> I don't think the dirname->fullname conversion is bad at all. Well, at
> least relative to looking up the fullname without the dirname.
> 
> Either, you lookup the fullname without the dirname, by using openp,
> which has say N lookup attempts ( N-1 dir search path entries + 1
> entry for the cwd ) 
>    or
> you lookup the fullname with dirname, by using open_source_file, which
> add's 1 to that value of N ( by putting dirname in front ), and then
> calls openp.
> 
> So, I think looking up the fullname with or without knowing the dirname
> yeilds the same magnitude of work. However, if openp is implemented poorly, 
> I could also look into that.

My point was not that one of these would be pricier than the other, but
that they are both pricy.  For a large application, doing this
conversion for all files will substantially penalize your startup time. 
Not to mention having to redo most of it when a new dir is added...

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer