<?php declare(strict_types = 1);

namespace PHPStan\Type;

use PHPStan\Turbo\ReferencedByTurboExtension;

use function spl_object_id;

#[ReferencedByTurboExtension(key: 'recursionGuard')]

final class RecursionGuard

{

/**

* While this is non-empty, run() and runOnObjectIdentity() short-circuit to ErrorType,

* so a type operation's result depends on the call stack and not only on its arguments.

* The native extension reads this property to know when it must not memoize

* TypeCombinator's operations (see PHPStanTurbo\TypeCombinatorCache).

*

* @var true[]

*/

private static array $context = [];

/**

* @template T

* @param callable(): T $callback

* @return T|ErrorType

*/

public static function run(Type $type, callable $callback)

{

$key = $type->describe(VerbosityLevel::value());

if (isset(self::$context[$key])) {

return new ErrorType();

}

try {

self::$context[$key] = true;

return $callback();

} finally {

unset(self::$context[$key]);

}

}

/**

* @template T

* @param callable(): T $callback

* @return T|ErrorType

*/

public static function runOnObjectIdentity(Type $type, callable $callback)

{

$key = spl_object_id($type);

if (isset(self::$context[$key])) {

return new ErrorType();

}

try {

self::$context[$key] = true;

return $callback();

} finally {

unset(self::$context[$key]);

}

}

}