symfony
diff --git a/‎src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php
+4-1Lines changed: 4 additions & 1 deletion b/‎src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php
+4-1Lines changed: 4 additions & 1 deletion
diff --git a/‎src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services_underscore.yml
Copy file name to clipboard
+3Lines changed: 3 additions & 0 deletions b/‎src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services_underscore.yml
Copy file name to clipboard
+3Lines changed: 3 additions & 0 deletions
diff --git a/‎src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php
+11Lines changed: 11 additions & 0 deletions b/‎src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php
+11Lines changed: 11 additions & 0 deletions
@@ -210,7 +210,7 @@ private function parseDefaults(array &$content, $file)
             throw new InvalidArgumentException(sprintf('Service defaults must be an array, "%s" given in "%s".', gettype($defaults), $file));
         }
         if (isset($defaults['alias']) || isset($defaults['class']) || isset($defaults['factory'])) {
-            @trigger_error('Giving a service the "_defaults" name is deprecated since Symfony 3.3 and will be forbidden in 4.0. Rename your service.', E_USER_DEPRECATED);
+            // @deprecated code path, to be removed in 4.0
 
             return array();
         }
@@ -282,6 +282,9 @@ private function isUsingShortSyntax(array $service)
      */
     private function parseDefinition($id, $service, $file, array $defaults)
     {
+        if (preg_match('/^_[a-zA-Z0-9_]*$/', $id)) {
+            @trigger_error(sprintf('Service names that start with an underscore are deprecated since Symfony 3.3 and will be reserved in 4.0. Rename the "%s" service or define it in XML instead.', $id), E_USER_DEPRECATED);
+        }
         if (is_string($service) && 0 === strpos($service, '@')) {
             $public = isset($defaults['public']) ? $defaults['public'] : true;
             $this->container->setAlias($id, new Alias(substr($service, 1), $public));
 
@@ -0,0 +1,3 @@
+services:
+    _foo:
+        class: Foo
@@ -488,4 +488,15 @@ public function testInvalidTagsWithDefaults()
         $loader = new YamlFileLoader(new ContainerBuilder(), new FileLocator(self::$fixturesPath.'/yaml'));
         $loader->load('services31_invalid_tags.yml');
     }
+
+    /**
+     * @group legacy
+     * @expectedDeprecation Service names that start with an underscore are deprecated since Symfony 3.3 and will be reserved in 4.0. Rename the "_foo" service or define it in XML instead.
+     */
+    public function testUnderscoreServiceId()
+    {
+        $container = new ContainerBuilder();
+        $loader = new YamlFileLoader($container, new FileLocator(self::$fixturesPath.'/yaml'));
+        $loader->load('services_underscore.yml');
+    }
 }
Original file line number	Diff line number	Diff line change
`@@ -210,7 +210,7 @@ private function parseDefaults(array &$content, $file)`
`210`	`210`	`throw new InvalidArgumentException(sprintf('Service defaults must be an array, "%s" given in "%s".', gettype($defaults), $file));`
`211`	`211`	`}`
`212`	`212`	`if (isset($defaults['alias']) \|\| isset($defaults['class']) \|\| isset($defaults['factory'])) {`
`213`		`- @trigger_error('Giving a service the "_defaults" name is deprecated since Symfony 3.3 and will be forbidden in 4.0. Rename your service.', E_USER_DEPRECATED);`
	`213`	`+ // @deprecated code path, to be removed in 4.0`
`214`	`214`
`215`	`215`	`return array();`
`216`	`216`	`}`
`@@ -282,6 +282,9 @@ private function isUsingShortSyntax(array $service)`
`282`	`282`	`*/`
`283`	`283`	`private function parseDefinition($id, $service, $file, array $defaults)`
`284`	`284`	`{`
	`285`	`+ if (preg_match('/^_[a-zA-Z0-9_]*$/', $id)) {`
	`286`	`+ @trigger_error(sprintf('Service names that start with an underscore are deprecated since Symfony 3.3 and will be reserved in 4.0. Rename the "%s" service or define it in XML instead.', $id), E_USER_DEPRECATED);`
	`287`	`+ }`
`285`	`288`	`if (is_string($service) && 0 === strpos($service, '@')) {`
`286`	`289`	`$public = isset($defaults['public']) ? $defaults['public'] : true;`
`287`	`290`	`$this->container->setAlias($id, new Alias(substr($service, 1), $public));`