Generate per-function ZPP macros in gen_stub.php

[dktapps]

Description

Writing extension classes is a breeze these days for conventional methods thanks to stub generation. But one thing that's still a chore is zend_parse_parameters() (or the fast ZPP macro API).

It would be great if function-specific ZPP macros and variable definitions could be generated from stubs. This way parsing args would be able to avoid manually writing those macros in, I'd imagine, almost all cases?

For example, these lines could be easily generated as a macro from my stub, I'd think: https://github.com/pmmp/ext-encoding/blob/a076df5718df5cb4e3bddb21da550258efe4e67f/classes/ByteBufferReader.cpp#L124-L128

[iluuu1994]

I'll leave it up for @kocsismate and @DanielEScherzer to decide what to do here. I don't find ZPP particularly complex/problematic.

[dktapps]

It's just tedious, much like writing manual arginfos was before stub generation was a thing

[kocsismate]

Surprise-surprise, a very similar feature would have been one of my first contributions to php-src, but Nikita didn't like the idea and provided some valid counter-arguments, so I stopped working on the topic afterwards.

What's sure that not all ZPPs could be generated via gen_stub.php, and the feature would require quite a few extra C-code specific meta info to be added to the stubs - if a string param is char * or zend_string, if an array param is zend_array or HashTable, if separation is needed etc.

[dktapps]

Is that really such a concern? It's easy enough to get char* from zend_string* anyway. Probably similar for HT vs zend_array too. I've also never found the need to use separation in any of my extensions. (I'm not actually even sure what separation is - if it's referring to zend_string_separate() et al I'd think code doing that would probably benefit in readability from doing that explicitly rather than an opaque 1 or 0.)

[bwoebi]

I agree that separate support could be removed. It's basically a carry-over from PHP 5 times. An explicit SEPARATE_ARRAY() would be definitely better than doing it as part of fast zpp.

But otherwise, I agree with Nikita; I prefer the code being explicit towards variable definition and what parameter reads into which variable.

[dktapps]

Is there a conceivable path towards generating function signatures that would be wrapped?

For example, a pattern I use a lot in my extensions is like

static void my_function_impl(zend_execute_data* execute_data, zend_long my_param1, zend_string* my_param2) {
    //pure impl code here
}

PHP_FUNCTION(my_function) {
    zend_long my_param1;
    zend_string* my_param2;

    ZEND_PARSE_PARAMETERS_START(2, 2)
        Z_PARAM_LONG(my_param1)
        Z_PARAM_STR(my_param2)
    ZEND_PARSE_PARAMETERS_END();

    my_function_impl(execute_data, my_param1, my_param2);
}

It'd be nice if the PHP_FUNCTION and a forward declaration for my_function_impl could be generated for this, and then I could just write the impl directly following the generated fwd declaration. Though there'd probably have to be a way to opt out of generating stuff like this if custom arg parsing is needed since it'd be a bit more intrusive than generating some ZPP macros.

[iluuu1994]

You may create a PR to evaluate whether it's a net-positive. And if not, potentially it may be merged into gen_stub.php with an opt-in flag. But currently, it doesn't seem like anybody internal is interested in working on this.