public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
From: Andrew Burgess <aburgess@broadcom.com>
To: Ian Lance Taylor <iant@google.com>
Cc: gcc-patches <gcc-patches@gcc.gnu.org>,
	Jason Merrill <jason@redhat.com>,	<gdb-patches@sourceware.org>
Subject: Re: [PATCH] cplus-demangler, free resource after a failed call to gnu_special.
Date: Sat, 10 May 2014 19:14:00 -0000	[thread overview]
Message-ID: <536E7A72.1040203@broadcom.com> (raw)
In-Reply-To: <CAKOQZ8zCbzpkwR_HkraUsNoDHEPt2pUXsQEk8kf_Mc43DGTHJw@mail.gmail.com>

On 09/05/2014 9:53 PM, Ian Lance Taylor wrote:
> On Fri, May 9, 2014 at 7:35 AM, Andrew Burgess <aburgess@broadcom.com> wrote:
> 
>>        if ((AUTO_DEMANGLING || GNU_DEMANGLING))
>>         {
>>           success = gnu_special (work, &mangled, &decl);
>> +          if (!success)
>> +            {
>> +              delete_work_stuff (work);
>> +              string_delete (&decl);
>> +            }
> 
> As far as I can see, decl may be uninitialized at this point.  I don't
> think you can call string_delete.  You need to ensure that decl is
> initialized somehow.

There's a call to string_init on decl about 10 lines above the
above diff, just outside of context, but it's unconditional, so
I figured that would be enough.

Also, if gnu_special returns false, and the call to
demangle_prefix returns false then we call (near the bottom of
internal_cplus_demangle) mop_up, which calls string_delete.

Given that decl is initialised once, assuming that the string is
only released using delete_string then the internal state will
have been reset back to NULL, so calling delete_string should
be safe again.

Could you let me know if this is enough, or give me more details
on where you think the problem is as I'm missing it :)

Thanks for taking a look at this.

Andrew



  reply	other threads:[~2014-05-10 19:14 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-09 14:35 Andrew Burgess
2014-05-09 20:53 ` Ian Lance Taylor
2014-05-10 19:14   ` Andrew Burgess [this message]
2014-05-12  5:40     ` Ian Lance Taylor
2014-05-14  9:01       ` Gary Benson
2014-05-14  9:30         ` Andrew Burgess
2014-05-14 14:20           ` Gary Benson
2014-05-22 11:58             ` Thomas Schwinge
2014-05-22 16:02               ` Gary Benson
2014-05-22 16:13                 ` Thomas Schwinge
2014-05-22 19:34                   ` Gary Benson
2014-05-28 22:17               ` Pedro Alves

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=536E7A72.1040203@broadcom.com \
    --to=aburgess@broadcom.com \
    --cc=gcc-patches@gcc.gnu.org \
    --cc=gdb-patches@sourceware.org \
    --cc=iant@google.com \
    --cc=jason@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).