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
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+3Lines changed: 3 additions & 0 deletions b/‎src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services_underscore.yml
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+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
@@ -182,7 +182,7 @@ 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();
         }
@@ -239,6 +239,9 @@ private function parseDefaults(array &$content, $file)
      */
     private function parseDefinition($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
@@ -436,4 +436,15 @@ 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'));
+        $loader->load('services_underscore.yml');
+    }
 }
Original file line number	Diff line number	Diff line change
`@@ -182,7 +182,7 @@ private function parseDefaults(array &$content, $file)`
`182`	`182`	`throw new InvalidArgumentException(sprintf('Service defaults must be an array, "%s" given in "%s".', gettype($defaults), $file));`
`183`	`183`	`}`
`184`	`184`	`if (isset($defaults['alias']) \|\| isset($defaults['class']) \|\| isset($defaults['factory'])) {`
`185`		`- @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);`
	`185`	`+ // @deprecated code path, to be removed in 4.0`
`186`	`186`
`187`	`187`	`return array();`
`188`	`188`	`}`
`@@ -239,6 +239,9 @@ private function parseDefaults(array &$content, $file)`
`239`	`239`	`*/`
`240`	`240`	`private function parseDefinition($id, $service, $file, array $defaults)`
`241`	`241`	`{`
	`242`	`+ if (preg_match('/^_[a-zA-Z0-9_]*$/', $id)) {`
	`243`	`+ @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.', $id), E_USER_DEPRECATED);`
	`244`	`+ }`
`242`	`245`	`if (is_string($service) && 0 === strpos($service, '@')) {`
`243`	`246`	`$public = isset($defaults['public']) ? $defaults['public'] : true;`
`244`	`247`	`$this->container->setAlias($id, new Alias(substr($service, 1), $public));`