[DI] Add way to register service with implicit name using the PHP DSL

src/Symfony/Component/DependencyInjection/Loader/Configurator/ContainerConfigurator.php

@@ -31,6 +31,7 @@ class ContainerConfigurator extends AbstractConfigurator
     private $instanceof;
     private $path;
     private $file;
+    private $anonymousCount = 0;
 
     public function __construct(ContainerBuilder $container, PhpFileLoader $loader, array &$instanceof, string $path, string $file)
     {
@@ -70,7 +71,7 @@ final public function parameters(): ParametersConfigurator
 
     final public function services(): ServicesConfigurator
     {
-        return new ServicesConfigurator($this->container, $this->loader, $this->instanceof);
+        return new ServicesConfigurator($this->container, $this->loader, $this->instanceof, $this->path, $this->anonymousCount);
     }
 }
 

src/Symfony/Component/DependencyInjection/Loader/Configurator/ServicesConfigurator.php

@@ -29,13 +29,17 @@ class ServicesConfigurator extends AbstractConfigurator
     private $container;
     private $loader;
     private $instanceof;
+    private $anonymousHash;
+    private $anonymousCount;
 
-    public function __construct(ContainerBuilder $container, PhpFileLoader $loader, array &$instanceof)
+    public function __construct(ContainerBuilder $container, PhpFileLoader $loader, array &$instanceof, string $path = null, int &$anonymousCount = 0)
     {
         $this->defaults = new Definition();
         $this->container = $container;
         $this->loader = $loader;
         $this->instanceof = &$instanceof;
+        $this->anonymousHash = ContainerBuilder::hash($path ?: mt_rand());
+        $this->anonymousCount = &$anonymousCount;
         $instanceof = array();
     }
 
@@ -59,14 +63,29 @@ final public function instanceof(string $fqcn): InstanceofConfigurator
 
     /**
      * Registers a service.
+     *
+     * @param string|null $id    The service id, or null to create an anonymous service
+     * @param string|null $class The class of the service, or null when $id is also the class name
      */
-    final public function set(string $id, string $class = null): ServiceConfigurator
+    final public function set(?string $id, string $class = null): ServiceConfigurator
     {
         $defaults = $this->defaults;
         $allowParent = !$defaults->getChanges() && empty($this->instanceof);
 
         $definition = new Definition();
-        $definition->setPublic($defaults->isPublic());
+
+
+        if ($id === null) {
+            if (!$class) {
+                throw new \LogicException('Anonymous services must have a class name.');
+            }
+
+            $id = sprintf('%d_%s', ++$this->anonymousCount, preg_replace('/^.*\\\\/', '', $class).'~'.$this->anonymousHash);
+            $definition->setPublic(false);
+        } else {
+            $definition->setPublic($defaults->isPublic());
+        }
+
         $definition->setAutowired($defaults->isAutowired());
         $definition->setAutoconfigured($defaults->isAutoconfigured());
         $definition->setBindings($defaults->getBindings());

src/Symfony/Component/DependencyInjection/Tests/Fixtures/StdClassDecorator.php

@@ -0,0 +1,11 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Fixtures;
+
+final class StdClassDecorator
+{
+    public function __construct(\stdClass $foo)
+    {
+        $this->foo = $foo;
+    }
+}

src/Symfony/Component/DependencyInjection/Tests/Fixtures/config/anonymous.expected.yml

@@ -0,0 +1,19 @@
+
+services:
+    service_container:
+        class: Symfony\Component\DependencyInjection\ContainerInterface
+        public: true
+        synthetic: true
+    listener_aggregator:
+        class: Bar\FooClass
+        public: true
+        arguments: [!tagged listener]
+    2_stdClass~uWxhfdJ:
+        class: stdClass
+        public: false
+        tags:
+            - { name: listener }
+    decorated:
+        class: Symfony\Component\DependencyInjection\Tests\Fixtures\StdClassDecorator
+        public: true
+        arguments: [!service { class: stdClass, public: false }]

src/Symfony/Component/DependencyInjection/Tests/Fixtures/config/anonymous.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+use Bar\FooClass;
+use stdClass;
+use Symfony\Component\DependencyInjection\Tests\Fixtures\StdClassDecorator;
+
+return function (ContainerConfigurator $c) {
+    $s = $c->services();
+
+    $s->set('decorated', stdClass::class);
+
+    $s->set(null, StdClassDecorator::class)
+        ->decorate('decorated', 'decorator42')
+        ->args(array(ref('decorator42')));
+
+    $s->set('listener_aggregator', FooClass::class)->public()->args(array(tagged('listener')));
+
+    $s->set(null, stdClass::class)->tag('listener');
+};

src/Symfony/Component/DependencyInjection/Tests/Loader/PhpFileLoaderTest.php

@@ -72,6 +72,7 @@ public function provideConfig()
         yield array('prototype');
         yield array('child');
         yield array('php7');
+        yield array('anonymous');
     }
 
     /**