More C++ debugging comments

[Jim Blandy <jimb@zwingli.cygnus.com>]

Note that the first problem he mentions has to do with namespaces.

I'll ask him for test cases for the rest.

------- Start of forwarded message -------
Date: Mon, 2 Jul 2001 12:06:33 -0700 (PDT)
From: Benjamin Kosnik <bkoz@redhat.com>
To: jimb@redhat.com
Subject: Re: RFC c++ debugging thread (fwd)
Message-ID: <Pine.SOL.3.91.1010702120615.3597C-100000@taarna.cygnus.com>


can't see to get these c++ people to post on gdb's list...

---------- Forwarded message ----------
Date: Sat, 30 Jun 2001 17:44:03 +0200
From: Carlo Wood <carlo@alinoe.com>
To: Benjamin Kosnik <bkoz@redhat.com>
Cc: libstdc++@gcc.gnu.org
Subject: Re: RFC c++ debugging thread

On Fri, Jun 29, 2001 at 12:00:34PM -0700, Benjamin Kosnik wrote:
> 
> Hey C++ people. The gdb folks are doing inventory on C++ support in
> the debugger. People who use gdb with C++ should probably scope this
> thread and add constructive comments:
> 
> http://sources.redhat.com/ml/gdb/2001-06/msg00219.html
> 
> -benjamin

If you can pass this on:

1) When typing expressions that have a scope, it is extremely annoying that the current
   scope is often not known to gdb - especially the lack of namespace support is annoying.
   I am using anonymous namespaces frequently and that makes it impossible to set
   break-points other than by line number.
   I think that when gdb is in a function 'A::(unamed)::C::f()', and I ask for 'g()', it should
   use the same lookup as the compiler: "(gdb) b g" should set a break point in the same
   function as that is called when I'd have had: "void A::(unnamed)::C::f(void) { g(); }".
   The ideal situation being that using an expression that appears after a 'list' command
   of the current scope will resolve to the correct expression.  Another example being
   that in my current project ALL code that I am debugging is in namespace 'libcw::debug',
   so why do I constantly have to type: b 'libcw::debug::foo'?  I'd like to just type:
   "(gdb) b foo" (assuming the current code is in scope 'libcw::debug' thus).
2) The 'next' command often doesn't work: it just finishes the whole program.  I therefore
   have to use 'step' more often then I like, resulting in entering functions I don't
   want to enter (like libstdc++/STL stuff).  I don't know why/when this happens, but
   it seems to happen often when returning from a function (on a '}' of a function that
   I am exiting, I *always* type 's' to avoid losing the trace).
3) Often wrong source-file:line-numbers are given.  This might be a bug in the compiler.
4) Not all mangled names are demangled, and obviously the qualifiers are demangled wrongly,
   assuming you use libiberty's demangler then I suppose this will be fixed.  I'll get back
   to this after my own demangler finally works (I am working on getting adding of
   substitutions right now).

Regards,

-- 
Carlo Wood <carlo@alinoe.com>


------- End of forwarded message -------