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Date: Fri, 10 Oct 2014 22:27:59 +0200
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Subject: Deprecation of func_get_args(), call_user_func_array() and related API
From: ocramius@gmail.com (Marco Pivetta)

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Hello folks,

While rambling with some code today, I realized that `call_user_func`
behaves strangely, appearing and disappearing from stack traces depending
on versions of PHP. For an example, compare
http://3v4l.org/fGpIk#vphp7@20140901, http://3v4l.org/fGpIk#v530 and
http://3v4l.org/fGpIk#vhhvm-301.

This makes debugging code quite complicated if not just annoying and
frustrating.
Additionally, it seems like `call_user_func` and similars are impacting
performance in some parts of my codebase (event dispatcher logic).

Therefore, here comes my idea of simply getting rid of `call_user_func`,
`call_user_func_array`, `func_get_args`, `func_num_args` and `func_get_arg`.

My plan for it would be to add a deprecation (notice? not sure about that)
in PHP 5.7, and a complete removal of those methods in PHP 7.0.

BC compatibility is easily achieved as variadics (
https://wiki.php.net/rfc/variadics) allow for writing cleaner and less
complex versions:

 - http://3v4l.org/HDQb6 (call_user_func)
 - http://3v4l.org/AgEG5 (call_user_func_array)
 - http://3v4l.org/O3G6T (func_get_args) (broken in HHVM)
 - http://3v4l.org/vcYso (func_get_arg) (broken in HHVM)
 - http://3v4l.org/cg8i0 (func_num_args) (broken in HHVM)

Those files could moved to a library and included when running on legacy
codebases. Eventually, grepping for those function calls is also trivial.

Here's also the example with the exception and the userland implementation
of `call_user_func`, which has a much more readable/clear/inspectable stack
trace: http://3v4l.org/i4G8c

Thoughts? If this idea gets enough traction, I'd gladly go and ask for
karma, open an RFC and eventually provide a patch if I'm able to.

Greets,

Marco Pivetta

http://twitter.com/Ocramius

http://ocramius.github.com/

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