PHP Fatal error: Class Foo cannot implement previously implemented interface Stringable in Unknown on line 0

[clearair]

Hi
I encountered an issue with the __toString method

rust 1.80
ext-php-rs 0.12.0
php 8.3

rust code

use ext_php_rs::{info_table_end, info_table_row, info_table_start, prelude::*};
use ext_php_rs::{exception::PhpResult, types::Zval, zend::ce};
use ext_php_rs::zend::ModuleEntry;

#[php_class(name = "Foo")]
#[implements(ce::stringable())]
#[implements(ce::countable())]
#[derive(Default)]
pub struct Foo {
}

#[php_impl]
impl Foo {
    #[constructor]
    pub fn __construct() -> Self {
        Foo {
           
        }
    }

    pub fn __to_string(&self) -> String {
        format!("string")
    }

    pub fn count(&self) -> i32 {
       1
    }
}

/// Used by the `phpinfo()` function and when you run `php -i`.
pub extern "C" fn php_module_info(_module: *mut ModuleEntry) {
    info_table_start!();
    info_table_row!("Foo", "enabled");
    info_table_end!();
}

#[php_module]
pub fn module(module: ModuleBuilder) -> ModuleBuilder {
    module
}

php code

<?php

$foo = new Foo();

echo $foo;

php -d extension=./target/debug/libphp_foo.so test.php
PHP Fatal error: Class Foo cannot implement previously implemented interface Stringable in Unknown on line 0
[1] 266183 IOT instruction php -d extension=./target/debug/libphp_foo.so test.php

[EdmondDantes]

static zend_string *zend_begin_method_decl(zend_op_array *op_array, zend_string *name, bool has_body) /* {{{ */
{
     ...some code here...


	zend_add_magic_method(ce, (zend_function *) op_array, lcname);
	if (zend_string_equals_literal(lcname, ZEND_TOSTRING_FUNC_NAME)
			&& !(ce->ce_flags & ZEND_ACC_TRAIT)) {
		add_stringable_interface(ce);
________________^^^^^^^^^^^^^^^^^
	}

	return lcname;
}
/* }}} */

If a class has a __toString() method, it automatically receives the Stringable interface, so there is no need to declare it explicitly. To fix the error, you just need to remove the line: #[implements(ce::stringable())] and the code will work.

[EdmondDantes]

@Xenira The behavior was tested on the latest version of the library in PHP 8.3, please update accordingly.

[Xenira]

As the php docu contains

Stringable is implicitly present on any class that has the magic __toString() method defined, although it can and should be declared explicitly.

we should at least provide a way to add it to stubs. As interface stubs are broken anyways, we should fix this in #326 and maybe add docu

Thanks for testing