symfony · fabpot · Dec 11, 2017 · Dec 6, 2017
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/RegisterServiceSubscribersPass.php b/src/Symfony/Component/DependencyInjection/Compiler/RegisterServiceSubscribersPass.php
@@ -94,7 +94,7 @@ protected function processValue($value, $isRoot = false)
             throw new InvalidArgumentException(sprintf('Service %s not exist in the map returned by "%s::getSubscribedServices()" for service "%s".', $message, $class, $this->currentId));
         }
 
-        $value->addTag('container.service_subscriber.locator', array('id' => (string) ServiceLocatorTagPass::register($this->container, $subscriberMap)));
+        $value->addTag('container.service_subscriber.locator', array('id' => (string) ServiceLocatorTagPass::register($this->container, $subscriberMap, $this->currentId)));
 
         return parent::processValue($value);
     }

diff --git a/src/Symfony/Component/DependencyInjection/Compiler/ServiceLocatorTagPass.php b/src/Symfony/Component/DependencyInjection/Compiler/ServiceLocatorTagPass.php
@@ -72,10 +72,11 @@ protected function processValue($value, $isRoot = false)
     /**
      * @param ContainerBuilder $container
      * @param Reference[]      $refMap
+     * @param string|null      $callerId
      *
      * @return Reference
      */
-    public static function register(ContainerBuilder $container, array $refMap)
+    public static function register(ContainerBuilder $container, array $refMap, $callerId = null)
     {
         foreach ($refMap as $id => $ref) {
             if (!$ref instanceof Reference) {
@@ -94,6 +95,18 @@ public static function register(ContainerBuilder $container, array $refMap)
             $container->setDefinition($id, $locator);
         }
 
+        if (null !== $callerId) {
+            $locatorId = $id;
+            // Locators are shared when they hold the exact same list of factories;
+            // to have them specialized per consumer service, we use a cloning factory
+            // to derivate customized instances from the prototype one.
+            $container->register($id .= '.'.$callerId, ServiceLocator::class)
+                ->setPublic(false)
+                ->setFactory(array(new Reference($locatorId), 'withContext'))
+                ->addArgument($callerId)
+                ->addArgument(new Reference('service_container'));
+        }
+
         return new Reference($id);
     }
 }
diff --git a/src/Symfony/Component/DependencyInjection/ServiceLocator.php b/src/Symfony/Component/DependencyInjection/ServiceLocator.php
@@ -22,6 +22,9 @@
 class ServiceLocator implements PsrContainerInterface
 {
     private $factories;
+    private $loading = array();
+    private $externalId;
+    private $container;
 
     /**
      * @param callable[] $factories
@@ -45,23 +48,98 @@ public function has($id)
     public function get($id)
     {
         if (!isset($this->factories[$id])) {
-            throw new ServiceNotFoundException($id, null, null, array_keys($this->factories));
+            throw new ServiceNotFoundException($id, end($this->loading) ?: null, null, array(), $this->createServiceNotFoundMessage($id));
         }
 
-        if (true === $factory = $this->factories[$id]) {
-            throw new ServiceCircularReferenceException($id, array($id, $id));
+        if (isset($this->loading[$id])) {
+            $ids = array_values($this->loading);
+            $ids = array_slice($this->loading, array_search($id, $ids));
+            $ids[] = $id;
+
+            throw new ServiceCircularReferenceException($id, $ids);
         }
 
-        $this->factories[$id] = true;
+        $this->loading[$id] = $id;
         try {
-            return $factory();
+            return $this->factories[$id]();
         } finally {
-            $this->factories[$id] = $factory;
+            unset($this->loading[$id]);
         }
     }
 
     public function __invoke($id)
     {
         return isset($this->factories[$id]) ? $this->get($id) : null;
     }
+
+    /**
+     * @internal
+     */
+    public function withContext($externalId, Container $container)
+    {
+        $locator = clone $this;
+        $locator->externalId = $externalId;
+        $locator->container = $container;
+
+        return $locator;
+    }
+
+    private function createServiceNotFoundMessage($id)
+    {
+        if ($this->loading) {
+            return sprintf('The service "%s" has a dependency on a non-existent service "%s". This locator %s', end($this->loading), $id, $this->formatAlternatives());
+        }
+
+        $class = debug_backtrace(DEBUG_BACKTRACE_PROVIDE_OBJECT | DEBUG_BACKTRACE_IGNORE_ARGS, 3);
+        $class = isset($class[2]['object']) ? get_class($class[2]['object']) : null;
+        $externalId = $this->externalId ?: $class;
+
+        $msg = sprintf('Service "%s" not found: ', $id);
+
+        if (!$this->container) {
+            $class = null;
+        } elseif ($this->container->has($id) || isset($this->container->getRemovedIds()[$id])) {
+            $msg .= 'even though it exists in the app\'s container, ';
+        } else {
+            try {
+                $this->container->get($id);
+                $class = null;
+            } catch (ServiceNotFoundException $e) {
+                if ($e->getAlternatives()) {
+                    $msg .= sprintf(' did you mean %s? Anyway, ', $this->formatAlternatives($e->getAlternatives(), 'or'));
+                } else {
+                    $class = null;
+                }
+            }
+        }
+        if ($externalId) {
+            $msg .= sprintf('the container inside "%s" is a smaller service locator that %s', $externalId, $this->formatAlternatives());
+        } else {
+            $msg .= sprintf('the current service locator %s', $this->formatAlternatives());
+        }
+
+        if (!$class) {
+            // no-op
+        } elseif (is_subclass_of($class, ServiceSubscriberInterface::class)) {
+            $msg .= sprintf(' Unless you need extra laziness, try using dependency injection instead. Otherwise, you need to declare it using "%s::getSubscribedServices()".', preg_replace('/([^\\\\]++\\\\)++/', '', $class));
+        } else {
+            $msg .= 'Try using dependency injection instead.';
+        }
+
+        return $msg;
+    }
+
+    private function formatAlternatives(array $alternatives = null, $separator = 'and')
+    {
+        $format = '"%s"%s';
+        if (null === $alternatives) {
+            if (!$alternatives = array_keys($this->factories)) {
+                return 'is empty...';
+            }
+            $format = sprintf('only knows about the %s service%s.', $format, 1 < count($alternatives) ? 's' : '');
+        }
+        $last = array_pop($alternatives);
+
+        return sprintf($format, $alternatives ? implode('", "', $alternatives) : $last, $alternatives ? sprintf(' %s "%s"', $separator, $last) : '');
+    }
 }
diff --git a/...mfony/Component/DependencyInjection/Tests/Compiler/RegisterServiceSubscribersPassTest.php b/...mfony/Component/DependencyInjection/Tests/Compiler/RegisterServiceSubscribersPassTest.php
@@ -85,7 +85,7 @@ public function testNoAttributes()
             'baz' => new ServiceClosureArgument(new TypedReference(CustomDefinition::class, CustomDefinition::class, TestServiceSubscriber::class, ContainerInterface::IGNORE_ON_INVALID_REFERENCE)),
         );
 
-        $this->assertEquals($expected, $locator->getArgument(0));
+        $this->assertEquals($expected, $container->getDefinition((string) $locator->getFactory()[0])->getArgument(0));
     }
 
     public function testWithAttributes()
@@ -115,7 +115,7 @@ public function testWithAttributes()
             'baz' => new ServiceClosureArgument(new TypedReference(CustomDefinition::class, CustomDefinition::class, TestServiceSubscriber::class, ContainerInterface::IGNORE_ON_INVALID_REFERENCE)),
         );
 
-        $this->assertEquals($expected, $locator->getArgument(0));
+        $this->assertEquals($expected, $container->getDefinition((string) $locator->getFactory()[0])->getArgument(0));
     }
 
     /**

diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_subscriber.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_subscriber.php
@@ -45,6 +45,7 @@ public function getRemovedIds()
             'Symfony\\Component\\DependencyInjection\\ContainerInterface' => true,
             'Symfony\\Component\\DependencyInjection\\Tests\\Fixtures\\CustomDefinition' => true,
             'service_locator.jmktfsv' => true,
+            'service_locator.jmktfsv.foo_service' => true,
         );
     }
 
@@ -82,15 +83,15 @@ protected function getTestServiceSubscriberService()
      */
     protected function getFooServiceService()
     {
-        return $this->services['foo_service'] = new \Symfony\Component\DependencyInjection\Tests\Fixtures\TestServiceSubscriber(new \Symfony\Component\DependencyInjection\ServiceLocator(array('Symfony\\Component\\DependencyInjection\\Tests\\Fixtures\\CustomDefinition' => function () {
+        return $this->services['foo_service'] = new \Symfony\Component\DependencyInjection\Tests\Fixtures\TestServiceSubscriber(\call_user_func(array(new \Symfony\Component\DependencyInjection\ServiceLocator(array('Symfony\\Component\\DependencyInjection\\Tests\\Fixtures\\CustomDefinition' => function () {
             $f = function (\Symfony\Component\DependencyInjection\Tests\Fixtures\CustomDefinition $v = null) { return $v; }; return $f(${($_ = isset($this->services['Symfony\Component\DependencyInjection\Tests\Fixtures\CustomDefinition']) ? $this->services['Symfony\Component\DependencyInjection\Tests\Fixtures\CustomDefinition'] : $this->services['Symfony\Component\DependencyInjection\Tests\Fixtures\CustomDefinition'] = new \Symfony\Component\DependencyInjection\Tests\Fixtures\CustomDefinition()) && false ?: '_'});
         }, 'Symfony\\Component\\DependencyInjection\\Tests\\Fixtures\\TestServiceSubscriber' => function () {
             $f = function (\Symfony\Component\DependencyInjection\Tests\Fixtures\TestServiceSubscriber $v) { return $v; }; return $f(${($_ = isset($this->services['Symfony\Component\DependencyInjection\Tests\Fixtures\TestServiceSubscriber']) ? $this->services['Symfony\Component\DependencyInjection\Tests\Fixtures\TestServiceSubscriber'] : $this->services['Symfony\Component\DependencyInjection\Tests\Fixtures\TestServiceSubscriber'] = new \Symfony\Component\DependencyInjection\Tests\Fixtures\TestServiceSubscriber()) && false ?: '_'});
         }, 'bar' => function () {
             $f = function (\Symfony\Component\DependencyInjection\Tests\Fixtures\CustomDefinition $v) { return $v; }; return $f(${($_ = isset($this->services['Symfony\Component\DependencyInjection\Tests\Fixtures\TestServiceSubscriber']) ? $this->services['Symfony\Component\DependencyInjection\Tests\Fixtures\TestServiceSubscriber'] : $this->services['Symfony\Component\DependencyInjection\Tests\Fixtures\TestServiceSubscriber'] = new \Symfony\Component\DependencyInjection\Tests\Fixtures\TestServiceSubscriber()) && false ?: '_'});
         }, 'baz' => function () {
             $f = function (\Symfony\Component\DependencyInjection\Tests\Fixtures\CustomDefinition $v = null) { return $v; }; return $f(${($_ = isset($this->services['Symfony\Component\DependencyInjection\Tests\Fixtures\CustomDefinition']) ? $this->services['Symfony\Component\DependencyInjection\Tests\Fixtures\CustomDefinition'] : $this->services['Symfony\Component\DependencyInjection\Tests\Fixtures\CustomDefinition'] = new \Symfony\Component\DependencyInjection\Tests\Fixtures\CustomDefinition()) && false ?: '_'});
-        })));
+        })), 'withContext'), 'foo_service', $this));
     }
 
     /**

diff --git a/src/Symfony/Component/DependencyInjection/Tests/ServiceLocatorTest.php b/src/Symfony/Component/DependencyInjection/Tests/ServiceLocatorTest.php
@@ -12,8 +12,9 @@
 namespace Symfony\Component\DependencyInjection\Tests;
 
 use PHPUnit\Framework\TestCase;
-use Symfony\Component\DependencyInjection\Exception\ServiceNotFoundException;
+use Symfony\Component\DependencyInjection\Container;
 use Symfony\Component\DependencyInjection\ServiceLocator;
+use Symfony\Component\DependencyInjection\ServiceSubscriberInterface;
 
 class ServiceLocatorTest extends TestCase
 {
@@ -59,7 +60,7 @@ public function testGetDoesNotMemoize()
 
     /**
      * @expectedException        \Psr\Container\NotFoundExceptionInterface
-     * @expectedExceptionMessage You have requested a non-existent service "dummy". Did you mean one of these: "foo", "bar"?
+     * @expectedExceptionMessage Service "dummy" not found: the container inside "Symfony\Component\DependencyInjection\Tests\ServiceLocatorTest" is a smaller service locator that only knows about the "foo" and "bar" services.
      */
     public function testGetThrowsOnUndefinedService()
     {
@@ -68,13 +69,50 @@ public function testGetThrowsOnUndefinedService()
             'bar' => function () { return 'baz'; },
         ));
 
-        try {
-            $locator->get('dummy');
-        } catch (ServiceNotFoundException $e) {
-            $this->assertSame(array('foo', 'bar'), $e->getAlternatives());
+        $locator->get('dummy');
+    }
+
+    /**
+     * @expectedException        \Psr\Container\NotFoundExceptionInterface
+     * @expectedExceptionMessage The service "foo" has a dependency on a non-existent service "bar". This locator only knows about the "foo" service.
+     */
+    public function testThrowsOnUndefinedInternalService()
+    {
+        $locator = new ServiceLocator(array(
+            'foo' => function () use (&$locator) { return $locator->get('bar'); },
+        ));
+
+        $locator->get('foo');
+    }
+
+    /**
+     * @expectedException        \Symfony\Component\DependencyInjection\Exception\ServiceCircularReferenceException
+     * @expectedExceptionMessage Circular reference detected for service "bar", path: "bar -> baz -> bar".
+     */
+    public function testThrowsOnCircularReference()
+    {
+        $locator = new ServiceLocator(array(
+            'foo' => function () use (&$locator) { return $locator->get('bar'); },
+            'bar' => function () use (&$locator) { return $locator->get('baz'); },
+            'baz' => function () use (&$locator) { return $locator->get('bar'); },
+        ));
 
-            throw $e;
-        }
+        $locator->get('foo');
+    }
+
+    /**
+     * @expectedException        \Psr\Container\NotFoundExceptionInterface
+     * @expectedExceptionMessage Service "foo" not found: even though it exists in the app's container, the container inside "caller" is a smaller service locator that only knows about the "bar" service. Unless you need extra laziness, try using dependency injection instead. Otherwise, you need to declare it using "SomeServiceSubscriber::getSubscribedServices()".
+     */
+    public function testThrowsInServiceSubscriber()
+    {
+        $container = new Container();
+        $container->set('foo', new \stdClass());
+        $subscriber = new SomeServiceSubscriber();
+        $subscriber->container = new ServiceLocator(array('bar' => function () {}));
+        $subscriber->container = $subscriber->container->withContext('caller', $container);
+
+        $subscriber->getFoo();
     }
 
     public function testInvoke()
@@ -89,3 +127,18 @@ public function testInvoke()
         $this->assertNull($locator('dummy'), '->__invoke() should return null on invalid service');
     }
 }
+
+class SomeServiceSubscriber implements ServiceSubscriberinterface
+{
+    public $container;
+
+    public function getFoo()
+    {
+        return $this->container->get('foo');
+    }
+
+    public static function getSubscribedServices()
+    {
+        return array('bar' => 'stdClass');
+    }
+}