Hi Sara,
> -----Original Message-----
> From: Sara Golemon [mailto:[EMAIL PROTECTED]
> Sent: Monday, April 03, 2006 9:03 PM
> To: "Dmitry Stogov"
> Cc: internals@lists.php.net
> Subject: Re: [PHP-DEV] RETURN_RT_STRING() and family leakage
>
>
> > Your first solution will not work. String passed to
> > ZVAL_RETURN_RT_STRING()
> > may be not allocated by emalloc().
> >
> duplicate should only ever be set to 0 on this (or any of the
> macros) when
> the string *is* allocated with emalloc. Otherwise the
> enegine would get in
> trouble freeing it later on.
No. :(
You can use ZVAL_RT_STRING(&fname, "strlen", 0), then call
zend_call_function(&fname) and do not destroy fname.
Thanks. Dmitry.
> I did just notice that I paste
> the wrong
> version into my post though.... it should have been: if
> (!duplicate &&
> UG(unicode) ...
>
> #define RETURN_RT_STRING(t, duplicate) \
> { RETVAL_RT_STRING(t, duplicate); if (!duplicate &&
> UG(unicode)) efree(t);
> return; }
>
> > The second solution will work.
> >
> > ZVAL_RETURN_RT_STRINGL(str, len, duplicate) ->
> > ZVAL_RETURN_RT_STRINGL(str, len, duplicate, auto_free)
> >
> There's one other we came up with:
>
> Leave existing protos as is, having them assume auto-free
> when duplicate==0
> (There is no issue when duplicate==1).
> Create an ad=ditional set of macros:
> (ZVAL|RETVAL)_RT_STRINGL_NOFREE(str,
> len) to be used when duplication (for the sake of owning the
> buffer) is not
> needed (because it's emalloc'd), but where (str) should not
> be freeded even
> in the eventuality that it's converted into a new buffer as unicode
> contents.
>
> This gives that edge 10% the ability to reuse (str) after
> populating it into
> the zval. A RETURN variant would be silly here as
> RETURN_RT_STRING_NOFREE(str) would be guaranteed to leak in
> unicode mode.
> (It converts into a new buffer then abandons the old one).
>
> > 3) It is possible to reuse "duplicate" argument
> > 0 - don't duplicate
> > 1 - duplicate
> > 2 - duplicate and free
> >
> Andrei and I tossed this around last night (and actually it's "don't
> duplicate and free" since the logic leading to the need for
> an auto_free
> assumes that the original string should not have been copied
> but the unicode
> conversion demanded that it was). The trouble with this
> approach is that
> it's terribly inconsistent with other ZVAL/RETVAL/RETURN
> macros in use
> everywhere else. e.g. duplicate has always been a binary
> value, not a
> trinary one.
>
> -Sara
>
>
>
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