ReferencingObjects

warning on by default quick-fix

Group: Confusing constructs · PhpStorm name: ReferencingObjectsInspection

Since PHP 5, object handles are passed and assigned by value of the handle: the callee already works on the same object. Taking objects by reference (Foo &$x parameters, $x = &new Foo()) is a PHP 4 leftover that only confuses readers — unless the reference is really used to replace the caller's variable.

Example

Before

<?php
$cache = & new ArrayObject([]);
$queue =&new SplQueue;
$plain = new SplStack();

function attach(DOMNode &$node, array &$list, &$any, int &$n) {}
function detach(?DOMNode& $node, ?string &$label, iterable &$it) {}

interface Visitor {
    public function visit(
        Tree & $tree,
        mixed &$extra
    );
}

function replace(DOMNode &$node) {
    $node = new DOMText('x');
}
function check(DOMNode &$a, DOMNode &$b, DOMNode &$c, DOMNode &$d = null) {
    if (($a)) {}
    return !$b || ($c ? 1 : 0);
}
$fn = function (DOMNode &$node) {};

After fix

<?php
$cache = new ArrayObject([]);
$queue = new SplQueue;
$plain = new SplStack();

function attach(DOMNode $node, array &$list, &$any, int &$n) {}
function detach(?DOMNode $node, ?string &$label, iterable &$it) {}

interface Visitor {
    public function visit(
        Tree $tree,
        mixed &$extra
    );
}

function replace(DOMNode &$node) {
    $node = new DOMText('x');
}
function check(DOMNode &$a, DOMNode &$b, DOMNode &$c, DOMNode &$d = null) {
    if (($a)) {}
    return !$b || ($c ? 1 : 0);
}
$fn = function (DOMNode &$node) {};

Reported:

• line 2: Objects are handed over by handle already; assign the new instance without '&'.
• line 3: Objects are handed over by handle already; assign the new instance without '&'.
• line 6: Objects are handed over by handle already; drop the '&' before '$node'.
• line 7: Objects are handed over by handle already; drop the '&' before '$node'.
• line 11: Objects are handed over by handle already; drop the '&' before '$tree'.

Configure

In custos.json:

{
  "rules": {
    "ReferencingObjects": {
      "enabled": false
    }
  }
}

Suppress

Before the statement or declaration (or the first statement of the file), either of:

// @custos-ignore ReferencingObjects

/**
 * @noinspection ReferencingObjectsInspection
 */