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* Re: Proposal: offset based member name (or type) lookup
@ 2004-02-27 21:09 Christoph Jaeschke
  0 siblings, 0 replies; 6+ messages in thread
From: Christoph Jaeschke @ 2004-02-27 21:09 UTC (permalink / raw)
  To: gdb

On Sun, Jan 04, 2004 at 12:25:37PM -0500, Daniel Jacobowitz wrote:
> On Sun, Jan 04, 2004 at 06:56:05PM +0100, Christoph Jaeschke wrote:
> > Hi,
> > 
> > I would like to propose a offset based member name lookup of
> > structs/classes. Assume:
> > 
> >     struct X {
> >         int a;
> >         int b;
> >     };
> > 
> >     struct Y {
> >         struct X x[4];
> >         int c;
> >     };
> > 
> >     struct Z {
> >         Y  y;
> >     };
> > 
> > If you apply a patch for gdb 6.0 I've prepared, you can ask gdb by
> > 
> >     ptype Z + 28
> > 
> > about Z's relative name at offset 28
> > 
> >     .y.x[3].b
> > 
> > using
> > 
> >     ptype Z+28, typechain
> > 
> > gdb will append also the typechain
> > 
> >     .y.x[3].b, typechain = ::Y::X[4]::int
> > 
> > 
> > There may be a better suited command than 'ptype' for it, it was choosen 
> > just because it was the simplest way to add it.
> > 
> > The patch contains also a caching mechanism, speeding up a lot if you do 
> > many lookups in big nested structures. It has a minimal memory 
> > requirement and will not hurt for single lookups.
> > 
> > The patch can be send if you are interested in.
> 
> Well, I don't like the syntax, but I think this is a wonderful idea.
> The other feature I've been meaning to add since forever is a variant
> of ptype which shows byte offsets for every field.
> 
> The problem with using ptype is that "Z+28" already has a meaning; gdb
> will try to add the two, or call an overloaded + operator in C++, et
> cetera.  This should probably be a new command; that'll be more useful
> for MI anyway.

I did filed a copyright assignment form now.
The patch can be send, no problem, but perhaps there should be consensus about the user interface.
Should a new command name be created? Is the typechain print ok?

Christoph Jaeschke


^ permalink raw reply	[flat|nested] 6+ messages in thread
* Proposal: offset based member name (or type) lookup
@ 2004-01-04 17:09 Christoph Jaeschke
  2004-01-04 17:25 ` Daniel Jacobowitz
  0 siblings, 1 reply; 6+ messages in thread
From: Christoph Jaeschke @ 2004-01-04 17:09 UTC (permalink / raw)
  To: gdb

Hi,

I would like to propose a offset based member name lookup of
structs/classes. Assume:

     struct X {
         int a;
         int b;
     };

     struct Y {
         struct X x[4];
         int c;
     };

     struct Z {
         Y  y;
     };

If you apply a patch for gdb 6.0 I've prepared, you can ask gdb by

     ptype Z + 28

about Z's relative name at offset 28

     .y.x[3].b

using

     ptype Z+28, typechain

gdb will append also the typechain

     .y.x[3].b, typechain = ::Y::X[4]::int


There may be a better suited command than 'ptype' for it, it was choosen 
just because it was the simplest way to add it.

The patch contains also a caching mechanism, speeding up a lot if you do 
many lookups in big nested structures. It has a minimal memory 
requirement and will not hurt for single lookups.

The patch can be send if you are interested in.

     Christoph Jaeschke


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2004-02-27 21:09 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-02-27 21:09 Proposal: offset based member name (or type) lookup Christoph Jaeschke
  -- strict thread matches above, loose matches on Subject: below --
2004-01-04 17:09 Christoph Jaeschke
2004-01-04 17:25 ` Daniel Jacobowitz
2004-01-04 17:30   ` Daniel Jacobowitz
2004-01-04 19:10     ` Christoph Jaeschke
2004-01-08  1:28     ` Andrew Cagney

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