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From: "Ulrich Weigand" <uweigand@de.ibm.com>
To: tromey@redhat.com (Tom Tromey)
Cc: swagiaal@redhat.com (sami wagiaalla), gdb-patches@sourceware.org
Subject: Re: [patch] smart pointer support
Date: Sun, 08 Aug 2010 15:01:00 -0000	[thread overview]
Message-ID: <201008081501.o78F18sq011585@d12av02.megacenter.de.ibm.com> (raw)
In-Reply-To: <m37hk3tzsn.fsf@fleche.redhat.com> from "Tom Tromey" at Aug 06, 2010 11:29:44 AM

Tom Tromey wrote:

> Along these lines, I'm curious to know why value_must_coerce_to_target
> returns 0 for TYPE_CODE_STRUCT.  Maybe that is just an oversight?
> Perhaps it should also check for lval_internalvar_component?

Well, I guess this is because the value-coerce-to-target mechanism was
introduced by Dan for a specific purpose, that is to allow lazy handling
of GDB-internally generated literal values (in particular string constants).

It was never intended to handle pushing arbitrary non-lvalues, like those
generated from inferior calls (or arbitray value arithmetic) to the target.

Now maybe this could be extended to do so; but it seems we'd have to carefully
think about exactly when we want this to happen.  For example, if you have
a variable residing in a register, you currently cannot take its address in
GDB.  If value_coerce_to_target were to blindly push *everything* to the
target, this would succeed, and you'd have a pointer to a malloc'ed location
holding a copy of the register value -- which is presumably not what you
intended ...

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com

  reply	other threads:[~2010-08-08 15:01 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-07-20 15:58 sami wagiaalla
2010-07-23 23:37 ` Tom Tromey
2010-08-05 18:46   ` sami wagiaalla
2010-08-05 22:57     ` Ulrich Weigand
2010-08-06 16:23       ` sami wagiaalla
2010-08-06 16:48         ` Ulrich Weigand
2010-08-06 17:29           ` Tom Tromey
2010-08-08 15:01             ` Ulrich Weigand [this message]
2010-08-06 21:33           ` sami wagiaalla
2010-08-06 22:20             ` Tom Tromey
2010-08-09 15:59               ` sami wagiaalla
2010-08-09 17:35                 ` Tom Tromey
2010-08-09 18:04                   ` sami wagiaalla
2010-08-09 18:23                     ` Jan Kratochvil
2010-08-16 20:31                       ` sami wagiaalla
2010-08-16 20:59                         ` Pedro Alves
2010-08-17 16:16                           ` sami wagiaalla
2010-08-17 17:15                             ` Tom Tromey
2010-10-19 20:55                               ` sami wagiaalla

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