Re: [PHP-DEV] zend_call_method with arguments passed by reference

[Nikita Popov]

On Wed, Jan 8, 2020 at 3:59 PM mdolezal.noctuint.cz via internals <
internals@lists.php.net> wrote:

> Hello,
>
> I hope this is the appropriate mailing list, please redirect me to better
> please if required.
>
>
>
> I am currently rewriting our PHP extension from PHP5 to PHP7.
>
> To call PHP methods from our C/C++ code we use slightly modified
> zend_call_method from Zend/zend_interfaces.c (to use more arguments than
> 2).
>
>
> Now I found out that it does not work with arguments passed by reference,
> such as:
>
> public function FuncWithRef(array &$changeThis)
>
>
>
> if values are changed in the PHP code then zval values back in C part after
> zend_call_function call are not influenced.
>
> With PHP5 the value was overwritten and could be used later in C code.
>
> Previously the zend_fcall_info struct for function call was filled with
> params simply by
>
>
>
> params[0] = &arg1;
>
>
>
> In PHP7 this is changed to
>
>
>
> ZVAL_COPY_VALUE(&params[0], arg1);
>
>
>
> After function is executed (zend_call_function) both fci.params and arg1
> contain still the original zval values,
>
> changes made in PHP code are not available. Is there any way how to solve
> this?
>
> I am mainly searching for and comparing code snippets in PHP/ext folder to
> see how things were rewritten from PHP5 to PHP7.
>
> Sorry if I missed something obvious and thank you for your help.
>

It looks like the implementation of zend_call_method() does not support
this, as it does not copy parameters back after the call. I'd suggest to
use the lower level zend_call_function() for the cases where you need this
for now.

Nikita