Re: C++ debugging progress

[Daniel Berlin <dan@cgsoftware.com>]

On Wed, 28 Nov 2001, Daniel Jacobowitz wrote:

> For the curious, I've gotten all but two of the virtual function tests to
> pass in virtfuncs.exp.  I'm not entirely sure what's wrong with one of the
> others, and the other goes up as far as the parser (pEe->D::fd() yields
> "attempt to take address of value not in memory").  There's also a bunch of
> namespace problems, of course.
>
> I'll not be posting the patches for another day or two.  The way I do it now
> is grossly inefficient; I look through RTTI at every lookup instead of once
> per type.  It also depends on presence of RTTI.  There's not much I can do
> about that - or rather, I could, but AFAICT it would require walking the
> inheritance graph in the proper order and I don't have the machinery to do
> that easily.  I'm not heartbroken that we need RTTI for debugging though.

Nor am I.
However:
     * To: gdb-patches at sources dot redhat dot com
     * Subject: Re: Using typeinfo functions to determine RTTI
     * From: Tom Tromey <tromey at cygnus dot com>
     * Date: 03 May 2000 09:41:50 -0600
     * Newsgroups: cygnus.patches.gdb
     * Organization: Cygnus Solutions
     * References:
<Pine.LNX.4.10.10005020923450.14281-100000@propylaea.anduin.com>
<npu2ggf8g3.fsf@zwingli.cygnus.com>
     * Reply-To: tromey at cygnus dot com
 (This was me):
 >> Does anyone mind if i use the typeinfo name, rather than
 >> the virtual table name, to figure out th real type of an object? It
 >> only matters if someone does -fno-rtti, i believe. But I have no
 >> idea how many people actually use that flag to save time/space in
 >> debugging executables.

 Jim> Almost all of Cygnus's customers use GDB to debug embedded apps,
 Jim> and space is often an issue there.  But I don't actually know how
 Jim> many of them use -fno-rtti.

 All Java programs are compiled with -fno-rtti.  This includes the C++
 component.  So presumably if this change is made it will make it even
 harder for me to debug libgcj.

 Tom