MagicPlugin.php

<?php declare(strict_types=1);

use ast\Node;
use Phan\CodeBase;
use Phan\Language\Element\Clazz;
use Phan\Language\UnionType;
use Phan\Language\Element\Method;
use Phan\PluginV3;
use Phan\PluginV3\AnalyzeFunctionCapability;
use Phan\PluginV3\AnalyzeMethodCapability;
use Phan\PluginV3\AnalyzeClassCapability;
use Phan\PluginV3\PluginAwarePostAnalysisVisitor;
use Phan\PluginV3\PostAnalyzeNodeCapability;
use Phan\Language\FQSEN\FullyQualifiedMethodName;

final class MagicPlugin extends PluginV3 implements PostAnalyzeNodeCapability
{

    /**
     * @return string - name of PluginAwarePostAnalysisVisitor subclass
     */
    public static function getPostAnalyzeNodeVisitorClassName() : string
    {
        return MagicVisitor::class;
    }

}

class MagicVisitor extends PluginAwarePostAnalysisVisitor
{

    // A plugin's visitors should not override visit() unless they need to.

    /**
     * @param Node $node
     * A node to analyze
     * @override
     */
    public function visitMethodCall(Node $node) : void
    {
        if (!isset($node->children['method']) || $node->children['method'] !== 'registerMagicMethod') {
            return;
        }

        if (!isset($node->children['args']->children[0]) || !is_string($node->children['args']->children[0])) {
            return;
        }

        $method_name = $node->children['args']->children[0];
        $return_type = UnionType::fromFullyQualifiedRealString("mixed");
        $fqsen = FullyQualifiedMethodName::make($this->context->getClassFQSEN(), $method_name);
        $method = new Method(
            $this->context,
            $method_name,
            $return_type,
            $flags = 0,
            $fqsen,
            $parameter_list = null
        );
        $this->code_base->addMethod($method);
        return;
    }

}

// Every plugin needs to return an instance of itself at the
// end of the file in which it's defined.
return new MagicPlugin();

output.txt

$ ./vendor/bin/phan -p -j 1 test.php
test.php:36 PhanUndeclaredMethod Call to undeclared method \Child::magic2 (Did you mean expr->magic1())
test.php:37 PhanUndeclaredMethod Call to undeclared method \Child::methodDoesntExist

test.php

<?php

/**
 * @phan-forbid-undeclared-magic-methods
 */
abstract class Base {

    private $magic_methods = [];

    protected function registerMagicMethod($name) {
        $this->magic_methods[$name] = true;
    }

    public function __call(string $name, array $arguments) {
        if (!isset($this->magic_methods[$name])) {
            throw new Exception("Method '$name' not implemented");
        }

        var_dump($name, $arguments);
    }

}

class Child extends Base {

    public function __construct() {
        $this->registerMagicMethod("magic1");
        $magic_meth_name = "magic2";
        $this->registerMagicMethod($magic_meth_name);
    }

}

$c = new Child();
$c->magic1();
$c->magic2();
$c->methodDoesntExist();