This document details all the possible changes that you should investigate when updating
your project from Doctrine Common 2.0.x to 2.1

## AnnotationReader changes

The annotation reader was heavily refactored between 2.0 and 2.1-RC1. In theory the operation of the new reader should be backwards compatible, but it has to be setup differently to work that way:

    $reader = new \Doctrine\Common\Annotations\AnnotationReader();
    $reader->setDefaultAnnotationNamespace('Doctrine\ORM\Mapping\\');
    // new code necessary starting here
    $reader->setIgnoreNotImportedAnnotations(true);
    $reader->setEnableParsePhpImports(false);
    $reader = new \Doctrine\Common\Annotations\CachedReader(
        new \Doctrine\Common\Annotations\IndexedReader($reader), new ArrayCache()
    );

## Annotation Base class or @Annotation

Beginning after 2.1-RC2 you have to either extend ``Doctrine\Common\Annotations\Annotation`` or add @Annotation to your annotations class-level docblock, otherwise the class will simply be ignored.

## Removed methods on AnnotationReader

* AnnotationReader::setAutoloadAnnotations()
* AnnotationReader::getAutoloadAnnotations()
* AnnotationReader::isAutoloadAnnotations()

## AnnotationRegistry

Autoloading through the PHP autoloader is removed from the 2.1 AnnotationReader. Instead you have to use the global AnnotationRegistry for loading purposes:

    \Doctrine\Common\Annotations\AnnotationRegistry::registerFile($fileWithAnnotations);
    \Doctrine\Common\Annotations\AnnotationRegistry::registerAutoloadNamespace($namespace, $dirs = null);
    \Doctrine\Common\Annotations\AnnotationRegistry::registerAutoloadNamespaces($namespaces);
    \Doctrine\Common\Annotations\AnnotationRegistry::registerLoader($callable);

The $callable for registering a loader accepts a class as first and only parameter and must try to silently autoload it. On success true has to be returned.
The registerAutoloadNamespace function registers a PSR-0 compatible silent autoloader for all classes with the given namespace in the given directories.
If null is passed as directory the include path will be used.