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From: Aleksandar Ristovski <aristovski@qnx.com>
To: Daniel Jacobowitz <drow@false.org>
Cc: gdb-patches@sourceware.org
Subject: Re: [patch] fix for c++/2416
Date: Wed, 27 Feb 2008 21:26:00 -0000	[thread overview]
Message-ID: <47C5D138.6020909@qnx.com> (raw)
In-Reply-To: <20080227200019.GB12434@caradoc.them.org>

Daniel Jacobowitz wrote:
> 
> For expressions, casting one reference to another is OK; casting a
> reference to a non-reference is also fine.  Only non-reference to
> reference is trouble.
> 
>>> The new error is incorrect, which does suggest some missing tests.
>>> You can cast from a reference type; value_cast follows references,
>>> so an int is just like an int &.
>>>
>>> Like Michael, I don't understand the value.c changes.  Could you
>>> explain them?
>>>
>> I replied to that.
> 
> What about the changes to coerce_array?
> 

I haven't made any changes to coerce_array itself, only made sure we do not call 
it if it's not an array. But I find its implementation somewhat confusing: it 
looks like it can be called with all kinds of TYPE_CODE for the arg... if that 
is correct than the name is misfortunate... and if not, then we should determine 
why is it being called with TYPE_CODE_REF (my patch eliminates one place where 
this is being done).

Another thing that confuses me is such a special treatment for references to 
something... in my mind, (talking about C++) we should be able to internally 
treat them as pointers to that something. For example, in the fix I provided if 
you comment out

   //if (TYPE_CODE (value_type (val)) == TYPE_CODE_ARRAY)

in value.c:1042 (after applying my patch) it will call, as without the patch, 
coerce_array; then if you follow to coerce_ref you will see that after 
coerce_ref, address is messed up causing printing garbage (no surprise since the 
address is wrong).


Unfortunately I do not have time at the moment to get any deeper than this, but 
I will reiterate (and please feel free to enlighten me with the reasons) that I 
do not see reasons for treating TYPE_CODE_REF in a different way than TYPE_CODE_PTR.


  reply	other threads:[~2008-02-27 21:08 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-27 18:43 Aleksandar Ristovski
2008-02-27 19:30 ` Michael Snyder
2008-02-27 19:36   ` Aleksandar Ristovski
2008-02-27 19:47 ` Daniel Jacobowitz
2008-02-27 20:00   ` Aleksandar Ristovski
2008-02-27 20:09     ` Daniel Jacobowitz
2008-02-27 21:26       ` Aleksandar Ristovski [this message]
2008-02-27 23:50         ` Daniel Jacobowitz
2008-02-28 19:12           ` Aleksandar Ristovski
2008-02-28 19:39             ` Daniel Jacobowitz
2008-02-29 10:10               ` Aleksandar Ristovski
2008-03-04 19:39                 ` Aleksandar Ristovski
2008-04-01 14:51                 ` Daniel Jacobowitz
2008-02-29  2:44             ` Michael Snyder
2008-03-31 19:01 Aleksandar Ristovski
2008-04-01 16:26 Aleksandar Ristovski
2008-04-01 17:06 ` Daniel Jacobowitz
2008-04-01 18:10 Aleksandar Ristovski
2008-04-01 18:52 ` Daniel Jacobowitz

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