From: Joel Brobecker <brobecker@adacore.com>
To: gdb-patches@sourceware.org
Subject: Re: [RFC] Strings and arrays without malloc
Date: Thu, 13 Mar 2008 19:22:00 -0000 [thread overview]
Message-ID: <20080313192157.GJ3738@adacore.com> (raw)
In-Reply-To: <20080309161335.GA26917@caradoc.them.org>
> Here's some things which call malloc today, and do not with the patch
> applied - yes, even the sizeof and ptype ones:
Woohoo! :)
> Here's some expressions which used to call malloc and still do; these
> are operations which involve pointers, so we need to call malloc to
> get a valid pointer for them.
>
> print *"abc"
> print "abc" + 1
> print &"abc"
> print strcmp ("abc", "def")
> print &{4, 5, 6}
Honestly, except maybe for the case where strcmp is involved, I find
that the semantics of the expressions could be debated. But you were
able to preserve the previous behavior, which is great.
> Here's some expressions which used to call malloc and will now produce
> an error about "value not located in memory":
>
> print &{4, 5, 6}[1]
> ptype &{4, 5, 6}[1]
As per the above, I personally am not really all that much concerned
about this kind of limitation, and I agree that subscripting is more
interesting than getting the address of a subscripted element.
It's still possible to get the answer by doing a sequence of
commands instead of one convenient expression, but the following
should work, right?
print &{4, 5, 6}
print &(*$)[1]
Or, in one expression (if I get my precedence right):
print &(*&{4, 5, 6})[1]
Perhaps we could add this to the documentation too.
I haven't looked at the code itself, but the benefits are really
exciting IMO.
--
Joel
next prev parent reply other threads:[~2008-03-13 19:22 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-09 16:14 Daniel Jacobowitz
2008-03-09 22:20 ` Eli Zaretskii
2008-03-11 6:58 ` Tom Tromey
2008-03-13 6:12 ` Tom Tromey
2008-03-13 14:16 ` Thiago Jung Bauermann
2008-03-13 14:54 ` Tom Tromey
2008-03-13 16:22 ` Thiago Jung Bauermann
2008-03-13 16:59 ` Tom Tromey
2008-03-13 20:47 ` Tom Tromey
2008-03-13 19:22 ` Joel Brobecker [this message]
2008-03-21 15:03 ` Daniel Jacobowitz
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