PHP RFC: #[Deprecated] Attribute

• Version: 1.1
• Date: 2020-05-06
• Author: Benjamin Ebelei
• Status: Under Discussion
• First Published at: http://wiki.php.net/rfc/deprecated_attribute

With the Attributes RFC accepted for PHP 8, this is a first proposal for an internal attribute hooking into the engine.

It also serves as a good prototype and first step, as usually all languages with attributes also have a Deprecated attribute in their language core.

Developers can put an attribute #[Deprecated] on the following elements:

• Functions
• Methods

It is not possible to target classes, constants, properties or arguments at the moment. This might be added in other RFCs later.

Using attribute will add “ZEND_ACC_DEPERACTED” function flag to the op_array, which will automatically (with only small changes to the VM) lead to a deprecation warning already, since this functionality is present for internal functions already. This attribute exposes a this deprecation feature for functions to userland and close a gap between internal and userland functions.

<?php
 
<<Deprecated>>
function test() {}
// Deprecated: Function test() is deprecated
 
<<Deprecated("use test3() instead")>>
function test2() {}
// Deprecated: Function test2() is deprecated, use test3() instead
 
class Foo {
    <<Deprecated>>
    public function test() {}
    // Deprecated: Method Foo::test() is deprecated in %s
}

A class with the name “Deprecated” is introduced into the global namespace.

8.1 for function/method deprecations

None

None

None

None

None

A few things tracked in https://github.com/php/php-src/pull/6521

Accept #[Deprecated] attribute into core?

https://github.com/php/php-src/pull/6521

No implementation for deprecated class constants, properties and parameters yet.