From b02990564aab19c2cd7c42edf6afc1a1d5038a2c Mon Sep 17 00:00:00 2001
From: Yonel Ceruto <yonelceruto@gmail.com>
Date: Wed, 17 Dec 2025 11:56:53 +0100
Subject: [PATCH] [HttpKernel] Add support for bundles as compiler passes

---
 src/Symfony/Component/HttpKernel/CHANGELOG.md |  5 ++++
 src/Symfony/Component/HttpKernel/Kernel.php   |  4 +++
 .../HttpKernel/Tests/Bundle/BundleTest.php    | 26 +++++++++++++++++++
 .../BundleAsCompilerPassBundle.php            | 25 ++++++++++++++++++
 4 files changed, 60 insertions(+)
 create mode 100644 src/Symfony/Component/HttpKernel/Tests/Fixtures/BundleCompilerPass/BundleAsCompilerPassBundle.php

diff --git a/src/Symfony/Component/HttpKernel/CHANGELOG.md b/src/Symfony/Component/HttpKernel/CHANGELOG.md
index 61f5c9a95ea9e..d858d72857071 100644
--- a/src/Symfony/Component/HttpKernel/CHANGELOG.md
+++ b/src/Symfony/Component/HttpKernel/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+8.1
+---
+
+ * Add support for bundles as compiler pass
+
 8.0
 ---
 
diff --git a/src/Symfony/Component/HttpKernel/Kernel.php b/src/Symfony/Component/HttpKernel/Kernel.php
index 6d5f80c329351..bb73e0895e36d 100644
--- a/src/Symfony/Component/HttpKernel/Kernel.php
+++ b/src/Symfony/Component/HttpKernel/Kernel.php
@@ -616,6 +616,10 @@ protected function prepareContainer(ContainerBuilder $container): void
             if ($this->debug) {
                 $container->addObjectResource($bundle);
             }
+
+            if ($bundle instanceof CompilerPassInterface) {
+                $container->addCompilerPass($bundle, PassConfig::TYPE_BEFORE_OPTIMIZATION, -10000);
+            }
         }
 
         foreach ($this->bundles as $bundle) {
diff --git a/src/Symfony/Component/HttpKernel/Tests/Bundle/BundleTest.php b/src/Symfony/Component/HttpKernel/Tests/Bundle/BundleTest.php
index b0035e395d187..63af89998ac4e 100644
--- a/src/Symfony/Component/HttpKernel/Tests/Bundle/BundleTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/Bundle/BundleTest.php
@@ -12,7 +12,10 @@
 namespace Symfony\Component\HttpKernel\Tests\Bundle;
 
 use PHPUnit\Framework\TestCase;
+use Symfony\Component\Config\Loader\LoaderInterface;
 use Symfony\Component\HttpKernel\Bundle\Bundle;
+use Symfony\Component\HttpKernel\Kernel;
+use Symfony\Component\HttpKernel\Tests\Fixtures\BundleCompilerPass\BundleAsCompilerPassBundle;
 use Symfony\Component\HttpKernel\Tests\Fixtures\ExtensionPresentBundle\ExtensionPresentBundle;
 
 class BundleTest extends TestCase
@@ -43,6 +46,29 @@ public function testBundleNameCanBeExplicitlyProvided()
         $this->assertSame('Symfony\Component\HttpKernel\Tests\Bundle', $bundle->getNamespace());
         $this->assertSame('ExplicitlyNamedBundle', $bundle->getName());
     }
+
+    public function testBundleAsCompilerPass()
+    {
+        $kernel = new class('test', true) extends Kernel {
+            public function registerBundles(): iterable
+            {
+                yield new BundleAsCompilerPassBundle();
+            }
+
+            public function registerContainerConfiguration(LoaderInterface $loader): void
+            {
+            }
+
+            public function getProjectDir(): string
+            {
+                return sys_get_temp_dir().'/bundle_as_compiler_pass';
+            }
+        };
+
+        $kernel->boot();
+
+        $this->assertTrue($kernel->getContainer()->has('foo'));
+    }
 }
 
 class NamedBundle extends Bundle
diff --git a/src/Symfony/Component/HttpKernel/Tests/Fixtures/BundleCompilerPass/BundleAsCompilerPassBundle.php b/src/Symfony/Component/HttpKernel/Tests/Fixtures/BundleCompilerPass/BundleAsCompilerPassBundle.php
new file mode 100644
index 0000000000000..98c66eb844b05
--- /dev/null
+++ b/src/Symfony/Component/HttpKernel/Tests/Fixtures/BundleCompilerPass/BundleAsCompilerPassBundle.php
@@ -0,0 +1,25 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpKernel\Tests\Fixtures\BundleCompilerPass;
+
+use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\HttpKernel\Bundle\AbstractBundle;
+
+class BundleAsCompilerPassBundle extends AbstractBundle implements CompilerPassInterface
+{
+    public function process(ContainerBuilder $container): void
+    {
+        $container->register('foo', \stdClass::class)
+            ->setPublic(true);
+    }
+}