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Date: Fri, 25 Nov 2016 17:47:14 -0700
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Subject: Re: [PHP-DEV] Translating optional zval ** with
 zend_parse_parameters() to PHP 7
From: thruska@cubiclesoft.com (Thomas Hruska)

On 11/25/2016 4:32 PM, Jakub Zelenka wrote:
> On 25 Nov 2016 20:43, "Kalle Sommer Nielsen" <kalle@php.net> wrote:
>
> 2016-11-25 13:30 GMT+01:00 Thomas Hruska <thruska@cubiclesoft.com>:
>> I need to be able to *modify* the original variable that was passed in.
> I already use "|l" and zend_long
>> elsewhere in the extension
>
> Ah my bad I misread it!
>
> In that case take a look at where such is implemented in php-src,
> dns_get_record() is an example despite the slightly clouded code:
> http://git.php.net/?p=php-src.git;a=blob;f=ext/standard/dns.c;h=
> f92015eee90d3e93a801e93d6381d89923825166;hb=refs/heads/master#l1011
>
> See $weight_list:
>
> - Check if the argument is passed
> - zval_dtor()
> - Populate it (ZVAL_LONG is the same)
>
> The main difference from your code is to use 'z' (lower case) in ZPP,
> and then use zval* (which is what 'z' returns).
>
>
>
> You also need set 1 for the first param of ZEND_ARG_INFO (specify that it
> is a ref param) otherwise it won't use the changed val...
>
> Jakub

Okay, everyone has been helpful.  Thanks.  I'll go with:


     zval *zprevcount = NULL;
     zend_long count;

     if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "|z/", 
&zprevcount) == FAILURE)  return;

     ...

     if (zprevcount != NULL)
     {
         count = (zend_long)PrevCount;

         zval_dtor(zprevcount);
         ZVAL_LONG(zprevcount, count);
     }


Just one little thing I found in php_str_replace_common() in 
ext/standard/string.c.  That particular function calls zval_ptr_dtor() 
instead of zval_dtor() on zcount.  Just wondering why it does that - I'm 
thinking it has something to do with removing the ZPP call for PHP 7 and 
using the (mostly undocumented?) Z_PARAM_ZVAL_EX() macro.  However, 
php_do_pcre_match() over in ext/pcre/php_pcre.c calls zval_dtor() on 
subpats but also uses the Z_PARAM_ZVAL_EX() macro in a similar fashion. 
Looking back at PHP 5.6's php_str_replace_common() shows that it 
previously called zval_dtor().  So it might also be a bug of some sort.

-- 
Thomas Hruska
CubicleSoft President

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