From: "Ulrich Weigand" <uweigand@de.ibm.com>
To: sivachandra@google.com (Siva Chandra)
Cc: gdb-patches@sourceware.org (gdb-patches)
Subject: Re: [PATCH 0/2] Make chained function calls in expressions work
Date: Thu, 23 Oct 2014 16:09:00 -0000 [thread overview]
Message-ID: <201410231609.s9NG9ZvU004472@d06av02.portsmouth.uk.ibm.com> (raw)
In-Reply-To: <CAGyQ6gwpWzAWe01pUvd3Wgv1m1Yai-b3H2rw7Dq+3Hv_zca6pw@mail.gmail.com> from "Siva Chandra" at Oct 23, 2014 08:07:43 AM
Siva Chandra wrote:
> Restricting to just those values whose address is returned in a hidden
> param (per ABI) is OK, but an implementation detail made me to include
> all types of return values. There are two times when a return value's
> address is required:
>
> 1. When a method is invoked on the return value: GDB has to evaluate
> the 'this' pointer. This is done in eval.c.
Ah, I knew there was something else I was missing :-)
In this case, I agree with the rest of your explanation. Please add a
comment in the final version of the patch that explains why the extra
copy is necessary.
There's just one minor change I think would be good: can we allocate that
extra copy on the stack at least only for *class* types, then? I'd prefer
to avoid this for the common case of routines just returning a scalar.
Thanks,
Ulrich
--
Dr. Ulrich Weigand
GNU/Linux compilers and toolchain
Ulrich.Weigand@de.ibm.com
next prev parent reply other threads:[~2014-10-23 16:09 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-26 13:29 Siva Chandra
2014-10-01 0:42 ` Siva Chandra
2014-10-01 13:15 ` Ulrich Weigand
2014-10-01 18:05 ` Siva Chandra
2014-10-01 18:26 ` Siva Chandra
2014-10-20 16:01 ` Ulrich Weigand
2014-10-20 19:56 ` Siva Chandra
2014-10-21 11:15 ` Ulrich Weigand
2014-10-21 20:30 ` Siva Chandra
2014-10-21 21:07 ` Siva Chandra
2014-10-22 17:00 ` Ulrich Weigand
2014-10-23 15:07 ` Siva Chandra
2014-10-23 16:09 ` Ulrich Weigand [this message]
2014-10-23 23:31 ` Siva Chandra
2014-10-09 0:02 ` Siva Chandra
2014-10-15 13:43 ` Siva Chandra
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