diff --git a/src/Symfony/Bridge/Twig/CHANGELOG.md b/src/Symfony/Bridge/Twig/CHANGELOG.md
index b4df596fa2c05..ea99cb17d15c4 100644
--- a/src/Symfony/Bridge/Twig/CHANGELOG.md
+++ b/src/Symfony/Bridge/Twig/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+2.8.0
+-----
+
+ * added TwigFlattenExceptionProcessor which adds twig files into the FlattenException
+
 2.7.0
 -----
 
diff --git a/src/Symfony/Bridge/Twig/Debug/TwigFlattenExceptionProcessor.php b/src/Symfony/Bridge/Twig/Debug/TwigFlattenExceptionProcessor.php
new file mode 100644
index 0000000000000..64555864ea95b
--- /dev/null
+++ b/src/Symfony/Bridge/Twig/Debug/TwigFlattenExceptionProcessor.php
@@ -0,0 +1,140 @@
+<?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\Bridge\Twig\Debug;
+
+use Symfony\Component\Debug\Exception\FlattenException;
+use Symfony\Component\Debug\FlattenExceptionProcessorInterface;
+
+/**
+ * TwigFlattener adds twig files into FlattenException.
+ *
+ * @author Martin Hasoň <martin.hason@gmail.com>
+ */
+class TwigFlattenExceptionProcessor implements FlattenExceptionProcessorInterface
+{
+    private $files = array();
+    private $twig;
+    private $loadedTemplates;
+
+    public function __construct(\Twig_Environment $twig)
+    {
+        $this->twig = $twig;
+        $this->loadedTemplates = new \ReflectionProperty($twig, 'loadedTemplates');
+        $this->loadedTemplates->setAccessible(true);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function process(\Exception $exception, FlattenException $flattenException, $master)
+    {
+        $trace = $flattenException->getTrace();
+        $origTrace = $exception->getTrace();
+
+        foreach ($origTrace as $key => $entry) {
+            $prevKey = $key - 1;
+
+            if (!isset($origTrace[$prevKey]) || !isset($entry['class']) || 'Twig_Template' === $entry['class'] || !is_subclass_of($entry['class'], 'Twig_Template')) {
+                continue;
+            }
+
+            $template = $this->getLoadedTemplate($entry['class']);
+
+            if (!$template instanceof \Twig_Template) {
+                continue;
+            }
+
+            $file = $this->findOrCreateFile($template);
+
+            $data = array('file' => $file);
+            if (isset($origTrace[$prevKey]['line'])) {
+                $data['line'] = $this->findLineInTemplate($origTrace[$prevKey]['line'], $template);
+            }
+
+            $trace[$prevKey]['related_codes'][] = $data;
+        }
+
+        if (isset($trace[-1]) && $exception instanceof \Twig_Error) {
+            $name = $exception->getTemplateFile();
+            $file = $this->findOrCreateFile($name, $name);
+
+            $trace[-1]['related_codes'][] = array('file' => $file, 'line' => $exception->getTemplateLine());
+        }
+
+        $flattenException->replaceTrace($trace);
+    }
+
+    private function getLoadedTemplate($class)
+    {
+        $loadedTemplates = $this->loadedTemplates->getValue($this->twig);
+
+        return isset($loadedTemplates[$class]) ? $loadedTemplates[$class] : null;
+    }
+
+    private function findOrCreateFile($template, $path = null)
+    {
+        $name = $template instanceof \Twig_Template ? $template->getTemplateName() : $template;
+
+        if (isset($this->files[$name])) {
+            return $this->files[$name];
+        }
+
+        foreach ($this->files as $key => $file) {
+            if (isset($file->path) && $file->path == $name) {
+                return $file;
+            }
+        }
+
+        $file = (object) array('name' => $name, 'type' => 'twig');
+
+        try {
+            $path = $path ?: $this->twig->getLoader()->getCacheKey($name);
+        } catch (\Twig_Error_Loader $e) {
+        }
+
+        if (is_file($path)) {
+            $file->path = $path;
+        } else {
+            $source = null;
+
+            if (method_exists($template, 'getSource')) {
+                $source = $template->getSource();
+            }
+
+            if (null === $source) {
+                try {
+                    $source = $this->twig->getLoader()->getSource($name);
+                } catch (\Twig_Error_Loader $e) {
+                }
+            }
+
+            $file->content = $source;
+        }
+
+        return $this->files[$name] = $file;
+    }
+
+    private function findLineInTemplate($line, $template)
+    {
+        if (!method_exists($template, 'getDebugInfo')) {
+            return 1;
+        }
+
+        foreach ($template->getDebugInfo() as $codeLine => $templateLine) {
+            if ($codeLine <= $line) {
+                return $templateLine;
+            }
+        }
+
+        return 1;
+    }
+}
diff --git a/src/Symfony/Bridge/Twig/Debug/TwigHighlighter.php b/src/Symfony/Bridge/Twig/Debug/TwigHighlighter.php
new file mode 100644
index 0000000000000..e80d7a5bb57b8
--- /dev/null
+++ b/src/Symfony/Bridge/Twig/Debug/TwigHighlighter.php
@@ -0,0 +1,82 @@
+<?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\Bridge\Twig\Debug;
+
+use Symfony\Component\Debug\Highlighter\Highlighter;
+
+/**
+ * Simple Twig syntax highlighter
+ *
+ * @author Martin Hasoň <martin.hason@gmail.com>
+ */
+class TwigHighlighter extends Highlighter
+{
+    protected $regexString = '"[^"\\\\]*?(?:\\\\.[^"\\\\]*?)*?"|\'[^\'\\\\]*?(?:\\\\.[^\'\\\\]*?)*?\'';
+    protected $regexTags;
+    protected $regex;
+
+    public function __construct()
+    {
+        $this->regexTags = '{({{-?|{%-?|{#-?)((?:'.$this->regexString.'|[^"\']*?)+?)(-?}}|-?%}|-?#})}s';
+        $this->regexKeywords = 'and|or|with';
+        $this->regex = '
+            /(?:
+                (?P<string>'.$this->regexString.')|
+                (?P<number>\b\d+(?:\.\d+)?\b)|
+                (?P<variable>(?<!\.)\b[a-z][a-z0-9_]*(?=\.|\[|\s*=))|
+                (?P<name>\b[a-z0-9_]+(?=\s*\()|(?<=\||\|\s)[a-z0-9_]+\b)|
+                (?P<operator>(?:\*\*|\.\.|==|!=|>=|<=|\/\/|\?:|[+\-~\*\/%\.=><\|\(\)\[\]\{\}\?:,]))|
+                (?P<keyword>\b(?:if|and|or|b-and|b-xor|b-or|in|matches|starts with|ends with|is|not|as|import|with|true|false|null|none)\b)
+            )/xi'
+        ;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function highlight($code, $from = 1, $to = -1, $line = -1)
+    {
+        $oldCode = htmlspecialchars(str_replace(array("\r\n", "\r"), "\n", $code), ENT_NOQUOTES);
+        $regex = $this->regex;
+        $code = preg_replace_callback($this->regexTags, function ($matches) use ($regex) {
+            if ($matches[1] == '{#') {
+                return '<span class="comment">' . $matches[0] . '</span>';
+            }
+
+            $matches[2] = preg_replace_callback($regex, function ($match) {
+                $keys = array_keys($match);
+
+                return sprintf('<span class="%s">%s</span>', $keys[count($match) - 2], $match[0]);
+            }, $matches[2]);
+
+            if ($matches[1][1] == '%') {
+                $matches[2] = preg_replace('/^(\s*)([a-z0-9_]+)/i', '\\1<span class="keyword">\\2</span>', $matches[2]);
+            }
+
+            return '<span class="tag">'.$matches[1].'</span>'.$matches[2].'<span class="tag">'.$matches[3].'</span>';
+        }, $oldCode);
+
+        if ('' == $code) {
+            $code = $oldCode;
+        }
+
+        return $this->createLines(explode("\n", $code), $from, $to, $line);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supports($file)
+    {
+        return 'twig' === pathinfo($file, PATHINFO_EXTENSION);
+    }
+}
diff --git a/src/Symfony/Bridge/Twig/Extension/CodeExtension.php b/src/Symfony/Bridge/Twig/Extension/CodeExtension.php
index b7c3605d9572f..d5744e8755f49 100644
--- a/src/Symfony/Bridge/Twig/Extension/CodeExtension.php
+++ b/src/Symfony/Bridge/Twig/Extension/CodeExtension.php
@@ -10,6 +10,8 @@
  */
 
 namespace Symfony\Bridge\Twig\Extension;
+use Symfony\Component\Debug\Exception\FlattenException;
+use Symfony\Component\Debug\Utils\HtmlUtils;
 
 /**
  * Twig extension relate to PHP code and used by the profiler and the default exception templates.
@@ -21,6 +23,7 @@ class CodeExtension extends \Twig_Extension
     private $fileLinkFormat;
     private $rootDir;
     private $charset;
+    private $htmlUtils;
 
     /**
      * Constructor.
@@ -29,11 +32,12 @@ class CodeExtension extends \Twig_Extension
      * @param string $rootDir        The project root directory
      * @param string $charset        The charset
      */
-    public function __construct($fileLinkFormat, $rootDir, $charset)
+    public function __construct($fileLinkFormat, $rootDir, $charset, HtmlUtils $htmlUtils = null)
     {
         $this->fileLinkFormat = $fileLinkFormat ?: ini_get('xdebug.file_link_format') ?: get_cfg_var('xdebug.file_link_format');
         $this->rootDir = str_replace('/', DIRECTORY_SEPARATOR, dirname($rootDir)).DIRECTORY_SEPARATOR;
         $this->charset = $charset;
+        $this->htmlUtils = $htmlUtils;
     }
 
     /**
@@ -50,6 +54,7 @@ public function getFilters()
             new \Twig_SimpleFilter('format_file', array($this, 'formatFile'), array('is_safe' => array('html'))),
             new \Twig_SimpleFilter('format_file_from_text', array($this, 'formatFileFromText'), array('is_safe' => array('html'))),
             new \Twig_SimpleFilter('file_link', array($this, 'getFileLink')),
+            new \Twig_SimpleFilter('highlight_code', array($this->htmlUtils, 'highlight'), array('is_safe' => array('html'))),
         );
     }
 
@@ -78,48 +83,27 @@ public function abbrMethod($method)
     /**
      * Formats an array as a string.
      *
-     * @param array $args The argument array
+     * @param array                 $args      The argument array
+     * @param FlattenException|null $exception The flatten exception
      *
      * @return string
      */
-    public function formatArgs($args)
+    public function formatArgs($args, $exception = null)
     {
-        $result = array();
-        foreach ($args as $key => $item) {
-            if ('object' === $item[0]) {
-                $parts = explode('\\', $item[1]);
-                $short = array_pop($parts);
-                $formattedValue = sprintf('<em>object</em>(<abbr title="%s">%s</abbr>)', $item[1], $short);
-            } elseif ('array' === $item[0]) {
-                $formattedValue = sprintf('<em>array</em>(%s)', is_array($item[1]) ? $this->formatArgs($item[1]) : $item[1]);
-            } elseif ('string' === $item[0]) {
-                $formattedValue = sprintf("'%s'", htmlspecialchars($item[1], ENT_QUOTES, $this->charset));
-            } elseif ('null' === $item[0]) {
-                $formattedValue = '<em>null</em>';
-            } elseif ('boolean' === $item[0]) {
-                $formattedValue = '<em>'.strtolower(var_export($item[1], true)).'</em>';
-            } elseif ('resource' === $item[0]) {
-                $formattedValue = '<em>resource</em>';
-            } else {
-                $formattedValue = str_replace("\n", '', var_export(htmlspecialchars((string) $item[1], ENT_QUOTES, $this->charset), true));
-            }
-
-            $result[] = is_int($key) ? $formattedValue : sprintf("'%s' => %s", $key, $formattedValue);
-        }
-
-        return implode(', ', $result);
+        return $this->htmlUtils->formatArgs($args, $exception);
     }
 
     /**
      * Formats an array as a string.
      *
-     * @param array $args The argument array
+     * @param array                 $args      The argument array
+     * @param FlattenException|null $exception The flatten exception
      *
      * @return string
      */
-    public function formatArgsAsText($args)
+    public function formatArgsAsText($args, $exception = null)
     {
-        return strip_tags($this->formatArgs($args));
+        return strip_tags($this->formatArgs($args, $exception));
     }
 
     /**
diff --git a/src/Symfony/Bridge/Twig/Tests/Debug/TwigFlattenExceptionProcessorTest.php b/src/Symfony/Bridge/Twig/Tests/Debug/TwigFlattenExceptionProcessorTest.php
new file mode 100644
index 0000000000000..fd067e3593e16
--- /dev/null
+++ b/src/Symfony/Bridge/Twig/Tests/Debug/TwigFlattenExceptionProcessorTest.php
@@ -0,0 +1,71 @@
+<?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\Bridge\Twig\Tests;
+
+use Symfony\Bridge\Twig\Debug\TwigFlattenExceptionProcessor;
+use Symfony\Component\Debug\ExceptionFlattener;
+
+class TwigFlattenExceptionProcessorTest extends \PHPUnit_Framework_TestCase
+{
+    public function testProcess()
+    {
+        $contents = array(
+            'base' => "{% block content '' %}",
+            'layout' => "{% extends 'base' %}\n{% block content %}\nfoo\n{{ foo.foo }}\n{% endblock %}",
+            'index' => "{% extends 'layout' %}\n{% block content %}\n{{ parent() }}\n{% endblock %}",
+        );
+
+        $files = array(
+            'base' => (object) array('name' => 'base', 'content' => $contents['base'], 'type' => 'twig'),
+            'layout' => (object) array('name' => 'layout', 'content' => $contents['layout'], 'type' => 'twig'),
+            'index' => (object) array('name' => 'index', 'content' => $contents['index'], 'type' => 'twig'),
+        );
+
+        $twig = new \Twig_Environment(new \Twig_Loader_Array($contents), array('strict_variables' => true));
+
+        try {
+            $twig->render('index', array('foo' => 'foo'));
+        } catch (\Twig_Error $exception) {
+        }
+
+        $flattener = new ExceptionFlattener(array(new TwigFlattenExceptionProcessor($twig)));
+        $trace = $flattener->flatten($exception)->getTrace();
+
+        $this->assertEquals(array(array('line' => 4, 'file' => $files['layout'])), $trace[-1]['related_codes']);
+        $this->assertEquals(array(array('line' => 4, 'file' => $files['layout'])), $trace[0]['related_codes']);
+        $this->assertEquals(array(array('line' => 3, 'file' => $files['index'])), $trace[3]['related_codes']);
+        $this->assertEquals(array(array('line' => 1, 'file' => $files['base'])), $trace[5]['related_codes']);
+        $this->assertEquals(array(array('line' => 1, 'file' => $files['layout'])), $trace[8]['related_codes']);
+        $this->assertEquals(array(array('line' => 1, 'file' => $files['index'])), $trace[11]['related_codes']);
+    }
+
+    public function testProcessRealTwigFile()
+    {
+        $file = (object) array(
+            'name' => 'error.html.twig',
+            'path' => dirname(__DIR__).'/Fixtures/templates/error.html.twig',
+            'type' => 'twig',
+        );
+
+        $twig = new \Twig_Environment(new \Twig_Loader_Filesystem(array(dirname($file->path))), array('strict_variables' => true));
+
+        try {
+            $twig->render($file->name, array('foo' => 'foo'));
+        } catch (\Twig_Error $exception) {
+        }
+
+        $flattener = new ExceptionFlattener(array(new TwigFlattenExceptionProcessor($twig)));
+        $trace = $flattener->flatten($exception)->getTrace();
+
+        $this->assertEquals(array(array('line' => 2, 'file' => $file)), $trace[-1]['related_codes']);
+    }
+}
diff --git a/src/Symfony/Bridge/Twig/Tests/Fixtures/templates/error.html.twig b/src/Symfony/Bridge/Twig/Tests/Fixtures/templates/error.html.twig
new file mode 100644
index 0000000000000..ba8e5ea576957
--- /dev/null
+++ b/src/Symfony/Bridge/Twig/Tests/Fixtures/templates/error.html.twig
@@ -0,0 +1,2 @@
+foo
+{{ foo.foo }}
diff --git a/src/Symfony/Bridge/Twig/composer.json b/src/Symfony/Bridge/Twig/composer.json
index f56133daaab53..42d185d298577 100644
--- a/src/Symfony/Bridge/Twig/composer.json
+++ b/src/Symfony/Bridge/Twig/composer.json
@@ -35,7 +35,8 @@
         "symfony/stopwatch": "~2.2|~3.0.0",
         "symfony/console": "~2.7|~3.0.0",
         "symfony/var-dumper": "~2.6|~3.0.0",
-        "symfony/expression-language": "~2.4|~3.0.0"
+        "symfony/expression-language": "~2.4|~3.0.0",
+        "symfony/debug": "~2.6|~3.0.0"
     },
     "suggest": {
         "symfony/finder": "",
@@ -48,6 +49,7 @@
         "symfony/yaml": "For using the YamlExtension",
         "symfony/security": "For using the SecurityExtension",
         "symfony/stopwatch": "For using the StopwatchExtension",
+        "symfony/debug": "For using the TwigFlattenExceptionProcessor",
         "symfony/var-dumper": "For using the DumpExtension",
         "symfony/expression-language": "For using the ExpressionExtension"
     },
diff --git a/src/Symfony/Bundle/DebugBundle/DebugBundle.php b/src/Symfony/Bundle/DebugBundle/DebugBundle.php
index 3aa536dba7860..3be1cd0cdf271 100644
--- a/src/Symfony/Bundle/DebugBundle/DebugBundle.php
+++ b/src/Symfony/Bundle/DebugBundle/DebugBundle.php
@@ -11,6 +11,8 @@
 
 namespace Symfony\Bundle\DebugBundle;
 
+use Symfony\Bundle\DebugBundle\DependencyInjection\Compiler\AddFlattenExceptionProcessorPass;
+use Symfony\Bundle\DebugBundle\DependencyInjection\Compiler\AddHighlighterPass;
 use Symfony\Bundle\DebugBundle\DependencyInjection\Compiler\DumpDataCollectorPass;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\HttpKernel\Bundle\Bundle;
@@ -48,6 +50,8 @@ public function build(ContainerBuilder $container)
     {
         parent::build($container);
 
+        $container->addCompilerPass(new AddFlattenExceptionProcessorPass());
         $container->addCompilerPass(new DumpDataCollectorPass());
+        $container->addCompilerPass(new AddHighlighterPass());
     }
 }
diff --git a/src/Symfony/Bundle/DebugBundle/DependencyInjection/Compiler/AddFlattenExceptionProcessorPass.php b/src/Symfony/Bundle/DebugBundle/DependencyInjection/Compiler/AddFlattenExceptionProcessorPass.php
new file mode 100644
index 0000000000000..726ef19a1ee99
--- /dev/null
+++ b/src/Symfony/Bundle/DebugBundle/DependencyInjection/Compiler/AddFlattenExceptionProcessorPass.php
@@ -0,0 +1,50 @@
+<?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\Bundle\DebugBundle\DependencyInjection\Compiler;
+
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
+use Symfony\Component\DependencyInjection\Reference;
+
+/**
+ * Registers the exception processors.
+ *
+ * @author Martin Hasoň <martin.hason@gmail.com>
+ */
+class AddFlattenExceptionProcessorPass implements CompilerPassInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function process(ContainerBuilder $container)
+    {
+        if (!$container->hasDefinition('exception_flattener')) {
+            return;
+        }
+
+        $processors = array();
+        foreach ($container->findTaggedServiceIds('exception.processor') as $id => $tags) {
+            $priority = isset($tags[0]['priority']) ? $tags[0]['priority'] : 0;
+            $processors[$priority][] = new Reference($id);
+        }
+
+        if (empty($processors)) {
+            return;
+        }
+
+        // sort by priority and flatten
+        krsort($processors);
+        $processors = call_user_func_array('array_merge', $processors);
+
+        $container->getDefinition('exception_flattener')->replaceArgument(0, $processors);
+    }
+}
diff --git a/src/Symfony/Bundle/DebugBundle/DependencyInjection/Compiler/AddHighlighterPass.php b/src/Symfony/Bundle/DebugBundle/DependencyInjection/Compiler/AddHighlighterPass.php
new file mode 100644
index 0000000000000..cb78aff87f43e
--- /dev/null
+++ b/src/Symfony/Bundle/DebugBundle/DependencyInjection/Compiler/AddHighlighterPass.php
@@ -0,0 +1,56 @@
+<?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\Bundle\DebugBundle\DependencyInjection\Compiler;
+
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
+use Symfony\Component\DependencyInjection\Reference;
+
+/**
+ * Registers the code highlighters.
+ *
+ * @author Martin Hasoň <martin.hason@gmail.com>
+ */
+class AddHighlighterPass implements CompilerPassInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function process(ContainerBuilder $container)
+    {
+        if (!$container->hasDefinition('debug.html_utils')) {
+            return;
+        }
+
+        $highlighters = array();
+        foreach ($container->findTaggedServiceIds('code_highlighter') as $id => $attributes) {
+            $priority = isset($attributes[0]['priority']) ? $attributes[0]['priority'] : 0;
+            $alias = isset($attributes[0]['alias']) ? $attributes[0]['alias'] : null;
+
+            if (null === $alias) {
+                $highlighters[$priority][] = new Reference($id);
+            } else {
+                $highlighters[$priority][$alias] = new Reference($id);
+            }
+        }
+
+        if (empty($highlighters)) {
+            return;
+        }
+
+        // sort by priority and flatten
+        krsort($highlighters);
+        $highlighters = call_user_func_array('array_merge', $highlighters);
+
+        $container->getDefinition('debug.html_utils')->replaceArgument(0, $highlighters);
+    }
+}
diff --git a/src/Symfony/Bundle/DebugBundle/Resources/config/services.xml b/src/Symfony/Bundle/DebugBundle/Resources/config/services.xml
index 16e27a22c584d..160924dead051 100644
--- a/src/Symfony/Bundle/DebugBundle/Resources/config/services.xml
+++ b/src/Symfony/Bundle/DebugBundle/Resources/config/services.xml
@@ -30,6 +30,27 @@
             <argument>null</argument><!-- debug.dump_destination -->
             <argument>%kernel.charset%</argument>
         </service>
+
+        <service id="exception_flattener" class="Symfony\Component\Debug\ExceptionFlattener">
+            <argument type="collection" />
+        </service>
+
+        <service id="debug.exception_processor.http" class="Symfony\Component\HttpKernel\Debug\HttpFlattenExceptionProcessor" public="false">
+            <tag name="exception.processor" />
+        </service>
+
+        <service id="debug.exception_processor.arguments" class="Symfony\Component\Debug\ArgumentsFlattenExceptionProcessor" public="false">
+            <tag name="exception.processor" />
+            <argument type="service" id="var_dumper.cloner" />
+        </service>
+
+        <service id="debug.html_utils" class="Symfony\Component\Debug\Utils\HtmlUtils">
+            <argument type="collection" />
+        </service>
+
+        <service id="debug.php_highlighter" class="Symfony\Component\Debug\Highlighter\PHPHighlighter" public="false">
+            <tag name="code_highlighter" alias="php" />
+        </service>
     </services>
 
 </container>
diff --git a/src/Symfony/Bundle/DebugBundle/Tests/DependencyInjection/Compiler/AddFlattenExceptionProcessorPassTest.php b/src/Symfony/Bundle/DebugBundle/Tests/DependencyInjection/Compiler/AddFlattenExceptionProcessorPassTest.php
new file mode 100644
index 0000000000000..5dfe88018dcfe
--- /dev/null
+++ b/src/Symfony/Bundle/DebugBundle/Tests/DependencyInjection/Compiler/AddFlattenExceptionProcessorPassTest.php
@@ -0,0 +1,42 @@
+<?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\Bundle\DebugBundle\Tests\DependencyInjection\Compiler;
+
+use Symfony\Bundle\DebugBundle\DependencyInjection\Compiler\AddFlattenExceptionProcessorPass;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Definition;
+use Symfony\Component\DependencyInjection\Reference;
+
+class AddFlattenExceptionProcessorPassTest extends \PHPUnit_Framework_TestCase
+{
+    public function testProcess()
+    {
+        $container = new ContainerBuilder();
+        $container->addCompilerPass(new AddFlattenExceptionProcessorPass());
+
+        $definition = new Definition('Symfony\Component\Debug\ExceptionFlattener', array(array()));
+        $container->setDefinition('exception_flattener', $definition);
+
+        $processor1 = new Definition('Symfony\Component\Debug\FlattenExceptionProcessorInterface');
+        $processor1->addTag('exception.processor', array('priority' => -100));
+
+        $processor2 = new Definition('Symfony\Component\Debug\FlattenExceptionProcessorInterface');
+        $processor2->addTag('exception.processor', array('priority' => 100));
+
+        $container->setDefinition('processor_1', $processor1);
+        $container->setDefinition('processor_2', $processor2);
+
+        $container->compile();
+
+        $this->assertEquals(array(array(new Reference('processor_2'), new Reference('processor_1'))), $definition->getArguments());
+    }
+}
diff --git a/src/Symfony/Bundle/DebugBundle/composer.json b/src/Symfony/Bundle/DebugBundle/composer.json
index 66d77643479dd..c767a61746b02 100644
--- a/src/Symfony/Bundle/DebugBundle/composer.json
+++ b/src/Symfony/Bundle/DebugBundle/composer.json
@@ -19,7 +19,8 @@
         "php": ">=5.3.9",
         "symfony/http-kernel": "~2.6|~3.0.0",
         "symfony/twig-bridge": "~2.6|~3.0.0",
-        "symfony/var-dumper": "~2.6|~3.0.0"
+        "symfony/var-dumper": "~2.6|~3.0.0",
+        "symfony/debug": "~2.6|~3.0.0"
     },
     "require-dev": {
         "symfony/phpunit-bridge": "~2.7|~3.0.0",
diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/collectors.xml b/src/Symfony/Bundle/FrameworkBundle/Resources/config/collectors.xml
index 01a271797ae94..396332c9d1ccb 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Resources/config/collectors.xml
+++ b/src/Symfony/Bundle/FrameworkBundle/Resources/config/collectors.xml
@@ -32,6 +32,7 @@
 
         <service id="data_collector.exception" class="%data_collector.exception.class%" public="false">
             <tag name="data_collector" template="@WebProfiler/Collector/exception.html.twig" id="exception" priority="255" />
+            <argument type="service" id="exception_flattener" on-invalid="ignore" />
         </service>
 
         <service id="data_collector.events" class="%data_collector.events.class%" public="false">
diff --git a/src/Symfony/Bundle/TwigBundle/Controller/PreviewErrorController.php b/src/Symfony/Bundle/TwigBundle/Controller/PreviewErrorController.php
index a907ef0abe5b2..7c5c4f9857118 100644
--- a/src/Symfony/Bundle/TwigBundle/Controller/PreviewErrorController.php
+++ b/src/Symfony/Bundle/TwigBundle/Controller/PreviewErrorController.php
@@ -12,6 +12,7 @@
 namespace Symfony\Bundle\TwigBundle\Controller;
 
 use Symfony\Component\Debug\Exception\FlattenException;
+use Symfony\Component\Debug\ExceptionFlattener;
 use Symfony\Component\HttpKernel\HttpKernelInterface;
 use Symfony\Component\HttpFoundation\Request;
 
@@ -26,16 +27,20 @@ class PreviewErrorController
 {
     protected $kernel;
     protected $controller;
+    protected $flattener;
 
-    public function __construct(HttpKernelInterface $kernel, $controller)
+    public function __construct(HttpKernelInterface $kernel, $controller, ExceptionFlattener $flattener = null)
     {
         $this->kernel = $kernel;
         $this->controller = $controller;
+        $this->flattener = $flattener;
     }
 
     public function previewErrorPageAction(Request $request, $code)
     {
-        $exception = FlattenException::create(new \Exception('Something has intentionally gone wrong.'), $code);
+        $e = new \Exception('Something has intentionally gone wrong.');
+        $exception = null === $this->flattener ? FlattenException::create($e, $code) : $this->flattener->flatten($e);
+        $exception->setStatusCode($code);
 
         /*
          * This Request mimics the parameters set by
diff --git a/src/Symfony/Bundle/TwigBundle/Resources/config/twig.xml b/src/Symfony/Bundle/TwigBundle/Resources/config/twig.xml
index bb871f440a20d..d748503ceb7dc 100644
--- a/src/Symfony/Bundle/TwigBundle/Resources/config/twig.xml
+++ b/src/Symfony/Bundle/TwigBundle/Resources/config/twig.xml
@@ -101,6 +101,7 @@
             <argument /> <!-- %templating.helper.code.file_link_format% -->
             <argument>%kernel.root_dir%</argument>
             <argument>%kernel.charset%</argument>
+            <argument type="service" id="debug.html_utils" on-invalid="ignore" />
         </service>
 
         <service id="twig.extension.routing" class="%twig.extension.routing.class%" public="false">
@@ -154,6 +155,7 @@
             <tag name="monolog.logger" channel="request" />
             <argument>%twig.exception_listener.controller%</argument>
             <argument type="service" id="logger" on-invalid="null" />
+            <argument type="service" id="exception_flattener" on-invalid="null" />
         </service>
 
         <service id="twig.controller.exception" class="%twig.controller.exception.class%">
@@ -174,5 +176,14 @@
             <argument /> <!-- decimal point, set in TwigExtension -->
             <argument /> <!-- thousands separator, set in TwigExtension -->
         </service>
+
+        <service id="debug.exception_processor.twig" class="Symfony\Bridge\Twig\Debug\TwigFlattenExceptionProcessor" public="false">
+            <tag name="exception.processor" />
+            <argument type="service" id="twig" />
+        </service>
+
+        <service id="twig.twig_highlighter" class="Symfony\Bridge\Twig\Debug\TwigHighlighter" public="false">
+            <tag name="code_highlighter" alias="twig" />
+        </service>
     </services>
 </container>
diff --git a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/exception.html.twig b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/exception.html.twig
index f09ffb3c658de..8279cc6aebd2a 100644
--- a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/exception.html.twig
+++ b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/exception.html.twig
@@ -36,7 +36,7 @@
     </div>
 </div>
 
-{% for position, e in exception.toarray %}
+{% for position, e in [exception]|merge(exception.allprevious) %}
     {% include 'TwigBundle:Exception:traces.html.twig' with { 'exception': e, 'position': position, 'count': previous_count } only %}
 {% endfor %}
 
diff --git a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/exception.xml.twig b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/exception.xml.twig
index fa99d447f7585..90c5e143bc4af 100644
--- a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/exception.xml.twig
+++ b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/exception.xml.twig
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="{{ _charset }}" ?>
 
 <error code="{{ status_code }}" message="{{ status_text }}">
-{% for e in exception.toarray %}
+{% for e in [exception]|merge(exception.allprevious) %}
     <exception class="{{ e.class }}" message="{{ e.message }}">
 {% include 'TwigBundle:Exception:traces.xml.twig' with { 'exception': e } only %}
     </exception>
diff --git a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/trace.html.twig b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/trace.html.twig
index d00a376a4589e..530e2fbba8bd4 100644
--- a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/trace.html.twig
+++ b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/trace.html.twig
@@ -4,7 +4,7 @@
         <abbr title="{{ trace.class }}">{{ trace.short_class }}</abbr>
         {{ trace.type ~ trace.function }}
     </strong>
-    ({{ trace.args|format_args }})
+    ({{ trace.args|format_args(exception|default) }})
 {% endif %}
 
 {% if trace.file is defined and trace.file and trace.line is defined and trace.line %}
@@ -16,7 +16,20 @@
         <img class="toggle" id="icon-{{ prefix ~ '-' ~ i }}-open" alt="+" src="data:image/gif;base64,R0lGODlhEgASAMQTANft99/v+Ga44bHb8ITG52S44dXs9+z1+uPx+YvK6WC24G+944/M6W28443L6dnu+Ge54v/+/l614P///wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAEAABMALAAAAAASABIAQAVS4DQBTiOd6LkwgJgeUSzHSDoNaZ4PU6FLgYBA5/vFID/DbylRGiNIZu74I0h1hNsVxbNuUV4d9SsZM2EzWe1qThVzwWFOAFCQFa1RQq6DJB4iIQA7" style="display: {{ 0 == i ? 'none' : 'inline' }}" />
     </a>
     {% endspaceless %}
+
     <div id="trace-{{ prefix ~ '-' ~ i }}" style="display: {{ 0 == i ? 'block' : 'none' }}" class="trace">
-        {{ trace.file|file_excerpt(trace.line) }}
+        {% if trace.file is defined and trace.file and trace.line is defined and trace.line %}
+            <em>{{ trace.file|format_file(trace.line) }}</em>
+            <div class="trace">
+                {{ trace.file|highlight_code(trace.line, highlighter='php') }}
+            </div>
+        {% endif %}
+
+        {% for code in trace.related_codes|default([]) if code.file.path is defined %}
+            <em>{{ code.file.path|format_file(code.line|default(1), code.file.name|default) }}</em>
+            <div class="trace">
+                {{ code.file.path|highlight_code(code.line|default(1), highlighter=code.file.type|default) }}
+            </div>
+        {% endfor %}
     </div>
 {% endif %}
diff --git a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/trace.txt.twig b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/trace.txt.twig
index ff20469bdbee8..5dd8cb698a261 100644
--- a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/trace.txt.twig
+++ b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/trace.txt.twig
@@ -1,5 +1,5 @@
 {% if trace.function %}
-    at {{ trace.class ~ trace.type ~ trace.function }}({{ trace.args|format_args_as_text }})
+    at {{ trace.class ~ trace.type ~ trace.function }}({{ trace.args|format_args_as_text(exception|default) }})
 {% else %}
     at n/a
 {% endif %}
diff --git a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces.html.twig b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces.html.twig
index cf49082cf4ecf..dfb4c2694c4e5 100644
--- a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces.html.twig
+++ b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces.html.twig
@@ -18,7 +18,7 @@
     <ol class="traces list-exception" id="traces-{{ position }}" style="display: {{ 0 == count ? 'block' : 'none' }}">
         {% for i, trace in exception.trace %}
             <li>
-                {% include 'TwigBundle:Exception:trace.html.twig' with { 'prefix': position, 'i': i, 'trace': trace } only %}
+                {% include 'TwigBundle:Exception:trace.html.twig' with { exception: exception, 'prefix': position, 'i': i, 'trace': trace } only %}
             </li>
         {% endfor %}
     </ol>
diff --git a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces.txt.twig b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces.txt.twig
index 2cb3ba4e09d45..f973cf1ee35df 100644
--- a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces.txt.twig
+++ b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces.txt.twig
@@ -1,6 +1,6 @@
 {% if exception.trace|length %}
 {% for trace in exception.trace %}
-{% include 'TwigBundle:Exception:trace.txt.twig' with { 'trace': trace } only %}
+{% include 'TwigBundle:Exception:trace.txt.twig' with { exception: exception, 'trace': trace } only %}
 
 {% endfor %}
 {% endif %}
diff --git a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces.xml.twig b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces.xml.twig
index 133a6260f8caf..c0940e4d91e1b 100644
--- a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces.xml.twig
+++ b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces.xml.twig
@@ -1,7 +1,7 @@
         <traces>
 {% for trace in exception.trace %}
             <trace>
-{% include 'TwigBundle:Exception:trace.txt.twig' with { 'trace': trace } only %}
+{% include 'TwigBundle:Exception:trace.txt.twig' with { exception: exception, 'trace': trace } only %}
 
             </trace>
 {% endfor %}
diff --git a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces_text.html.twig b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces_text.html.twig
index 3ea3d7bba8ccf..829260c0d3f5d 100644
--- a/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces_text.html.twig
+++ b/src/Symfony/Bundle/TwigBundle/Resources/views/Exception/traces_text.html.twig
@@ -10,7 +10,7 @@
     </h2>
 
     <div id="traces-text" class="trace" style="display: none;">
-<pre>{% for i, e in exception.toarray %}
+<pre>{% for i, e in [exception]|merge(exception.allprevious) %}
 [{{ i + 1 }}] {{ e.class }}: {{ e.message }}
 {% include 'TwigBundle:Exception:traces.txt.twig' with { 'exception': e } only %}
 {% endfor %}</pre>
diff --git a/src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/exception.css.twig b/src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/exception.css.twig
index 8d5eaf7e1ac46..fb79839215364 100644
--- a/src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/exception.css.twig
+++ b/src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/exception.css.twig
@@ -9,7 +9,7 @@
     padding-bottom: 2px;
 }
 .sf-reset .traces li {
-    ccolor: #222;
+    color: #222;
     font-size: 14px;
     padding: 5px 0;
     list-style-type: decimal;
@@ -31,8 +31,6 @@
     background: #FFCC00;
 }
 .sf-reset .trace {
-    border: 1px solid #DDD;
-    background: #FFF;
     padding: 10px;
     overflow: auto;
     margin: 1em 0;
@@ -95,3 +93,70 @@
 .sf-reset .toggle {
     vertical-align: middle;
 }
+.sf-reset .linked ul,
+.sf-reset .linked li {
+    display: inline;
+}
+.sf-reset #output-content {
+    color: #000;
+    font-size: 12px;
+}
+
+.sf-reset .trace ol {
+    padding: 0;
+}
+.sf-reset .trace li {
+    margin: 0;
+    padding: 3px 0;
+    margin-left: 8ex;
+    list-style-position: outside;
+    background: #18171B;
+    word-wrap: break-word;
+    overflow-wrap: break-word;
+}
+.sf-reset .trace li.selected {
+    background-color: #373831;
+}
+.sf-reset .trace li code {
+    color: #ccc;
+    font-size: 1em;
+    padding: 0;
+    margin: 0 1ex;
+    white-space: pre-wrap;
+    word-spacing: normal;
+    word-break: normal;
+
+    -moz-tab-size: 4;
+    -o-tab-size: 4;
+    tab-size: 4;
+
+    -webkit-hyphens: none;
+    -moz-hyphens: none;
+    -ms-hyphens: none;
+    hyphens: none;
+}
+.sf-reset .code .comment {
+    color: #B729D9;
+    font-style: italic;
+}
+.sf-reset .code .operator {
+    color: #E67700;
+}
+.sf-reset .code .tag {
+    color: #A0A0A0;
+}
+.sf-reset .code .string {
+    color: #56DB3A;
+}
+.sf-reset .code .variable {
+    color: #FFFFFF;
+}
+.sf-reset .code .keyword {
+    color: #FF8400;
+}
+.sf-reset .code .name {
+    color: #FFFFFF;
+}
+.sf-reset .code .number {
+    color: #1299da;
+}
diff --git a/src/Symfony/Component/Debug/ArgumentsFlattenExceptionProcessor.php b/src/Symfony/Component/Debug/ArgumentsFlattenExceptionProcessor.php
new file mode 100644
index 0000000000000..60ca3c86633a9
--- /dev/null
+++ b/src/Symfony/Component/Debug/ArgumentsFlattenExceptionProcessor.php
@@ -0,0 +1,168 @@
+<?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\Debug;
+
+use Symfony\Component\Debug\Exception\FlattenException;
+use Symfony\Component\VarDumper\Cloner\ClonerInterface;
+
+/**
+ * @author Martin Hasoň <martin.hason@gmail.com>
+ */
+class ArgumentsFlattenExceptionProcessor implements FlattenExceptionProcessorInterface
+{
+    private $cloner;
+    private $shareArguments;
+
+    public function __construct(ClonerInterface $cloner = null, $shareArguments = true)
+    {
+        $this->cloner = $cloner;
+        $this->shareArguments = $shareArguments;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function process(\Exception $exception, FlattenException $flattenException, $master)
+    {
+        if (!$master) {
+            return;
+        }
+
+        $variables = array();
+        $values = array();
+
+        $e = $exception;
+        $f = $flattenException;
+
+        do {
+            $trace = $f->getTrace();
+            foreach ($e->getTrace() as $key => $entry) {
+                if (!isset($entry['args']) || !isset($trace[$key])) {
+                    continue;
+                }
+
+                $parameters = $this->getParameters($entry);
+
+                $arguments = array();
+                foreach ($entry['args'] as $position => $argument) {
+                    $link = array_search($argument, $variables, true);
+
+                    if (false === $link) {
+                        $link = hash('md5', uniqid(mt_rand(), true), false);
+                        $variables[$link] = $argument;
+                        $values[$link] = $this->shareArguments ? array('link', $link) : $this->flatten($argument);
+                    }
+
+                    if (isset($parameters[$position])) {
+                        $arguments[$parameters[$position]->getName()] = $values[$link];
+                    } else {
+                        $arguments[] = $values[$link];
+                    }
+                }
+
+                $trace[$key]['args'] = $arguments;
+            }
+            $f->replaceTrace($trace);
+        } while (($e = $e->getPrevious()) && ($f = $f->getPrevious()));
+
+        if (!$this->shareArguments) {
+            return;
+        }
+
+        $flattenVariables = $this->flatten($variables);
+        foreach (array_merge(array($flattenException), $flattenException->getAllPrevious()) as $f) {
+            $f->setExtra('trace_arguments', $flattenVariables);
+        }
+    }
+
+    private function getParameters($entry)
+    {
+        if (!isset($entry['function'])) {
+            return array();
+        }
+
+        try {
+            if (isset($entry['class'])) {
+                $ref = new \ReflectionMethod($entry['class'], $entry['function']);
+            } else {
+                $ref = new \ReflectionFunction($entry['function']);
+            }
+        } catch (\ReflectionException $e) {
+            return array();
+        }
+
+        return $ref->getParameters();
+    }
+
+    private function flatten($variable)
+    {
+        if (null === $this->cloner) {
+            return $this->flattenValue($variable);
+        } else {
+            return $this->cloner->cloneVar($variable);
+        }
+    }
+
+    private function flattenValue($value, $level = 0, &$count = 0)
+    {
+        if ($count++ > 1e4) {
+            return array('array', '*SKIPPED over 10000 entries*');
+        }
+
+        if (is_object($value)) {
+            return array('object', get_class($value));
+        }
+
+        if (is_array($value)) {
+            if ($level > 10) {
+                return array('array', '*DEEP NESTED ARRAY*');
+            }
+
+            $array = array();
+            foreach ($value as $k => $v) {
+                $array[$k] = $this->flattenValue($v, $level + 1, $count);
+            }
+
+            return array('array', $array);
+        }
+
+        if (null === $value) {
+            return array('null', null);
+        }
+
+        if (is_bool($value)) {
+            return array('boolean', $value);
+        }
+
+        if (is_float($value) || is_int($value)) {
+            return array('number', $value);
+        }
+
+        if (is_resource($value)) {
+            return array('resource', get_resource_type($value));
+        }
+
+        if ($value instanceof \__PHP_Incomplete_Class) {
+            // Special case of object, is_object will return false
+            return array('incomplete-object', $this->getClassNameFromIncomplete($value));
+        }
+
+        return array('string', (string) $value);
+    }
+
+    private function getClassNameFromIncomplete(\__PHP_Incomplete_Class $value)
+    {
+        $array = new \ArrayObject($value);
+
+        return $array['__PHP_Incomplete_Class_Name'];
+    }
+}
diff --git a/src/Symfony/Component/Debug/CHANGELOG.md b/src/Symfony/Component/Debug/CHANGELOG.md
index ab07458a94a84..142e9dcd0e514 100644
--- a/src/Symfony/Component/Debug/CHANGELOG.md
+++ b/src/Symfony/Component/Debug/CHANGELOG.md
@@ -7,6 +7,7 @@ CHANGELOG
 * added BufferingLogger for errors that happen before a proper logger is configured
 * allow throwing from `__toString()` with `return trigger_error($e, E_USER_ERROR);`
 * deprecate ExceptionHandler::createResponse
+* added ExceptionFlattener
 
 2.7.0
 -----
diff --git a/src/Symfony/Component/Debug/Exception/FlattenException.php b/src/Symfony/Component/Debug/Exception/FlattenException.php
index d8d5c5b9214d5..a59e7841ff963 100644
--- a/src/Symfony/Component/Debug/Exception/FlattenException.php
+++ b/src/Symfony/Component/Debug/Exception/FlattenException.php
@@ -51,6 +51,7 @@ public function __call($method, $args)
 
 namespace Symfony\Component\Debug\Exception;
 
+use Symfony\Component\Debug\ArgumentsFlattenExceptionProcessor;
 use Symfony\Component\HttpKernel\Exception\FlattenException as LegacyFlattenException;
 use Symfony\Component\HttpKernel\Exception\HttpExceptionInterface;
 
@@ -69,9 +70,10 @@ class FlattenException extends LegacyFlattenException
     private $trace;
     private $class;
     private $statusCode;
-    private $headers;
+    private $headers = array();
     private $file;
     private $line;
+    private $extras = array();
 
     public static function create(\Exception $exception, $statusCode = null, array $headers = array())
     {
@@ -94,10 +96,14 @@ public static function create(\Exception $exception, $statusCode = null, array $
         $e->setClass(get_class($exception));
         $e->setFile($exception->getFile());
         $e->setLine($exception->getLine());
+
         if ($exception->getPrevious()) {
-            $e->setPrevious(static::create($exception->getPrevious()));
+            $e->setPrevious(static::create($exception->getPrevious(), -1));
         }
 
+        $processor = new ArgumentsFlattenExceptionProcessor(null, false);
+        $processor->process($exception, $e, -1 !== $statusCode);
+
         return $e;
     }
 
@@ -219,7 +225,8 @@ public function setTraceFromException(\Exception $exception)
     public function setTrace($trace, $file, $line)
     {
         $this->trace = array();
-        $this->trace[] = array(
+
+        $this->trace[-1] = array(
             'namespace' => '',
             'short_class' => '',
             'class' => '',
@@ -229,7 +236,8 @@ public function setTrace($trace, $file, $line)
             'line' => $line,
             'args' => array(),
         );
-        foreach ($trace as $entry) {
+
+        foreach ($trace as $key => $entry) {
             $class = '';
             $namespace = '';
             if (isset($entry['class'])) {
@@ -238,7 +246,7 @@ public function setTrace($trace, $file, $line)
                 $namespace = implode('\\', $parts);
             }
 
-            $this->trace[] = array(
+            $this->trace[$key] = array(
                 'namespace' => $namespace,
                 'short_class' => $class,
                 'class' => isset($entry['class']) ? $entry['class'] : '',
@@ -246,47 +254,52 @@ public function setTrace($trace, $file, $line)
                 'function' => isset($entry['function']) ? $entry['function'] : null,
                 'file' => isset($entry['file']) ? $entry['file'] : null,
                 'line' => isset($entry['line']) ? $entry['line'] : null,
-                'args' => isset($entry['args']) ? $this->flattenArgs($entry['args']) : array(),
+                'args' => array(),
             );
         }
     }
 
-    private function flattenArgs($args, $level = 0, &$count = 0)
+    /**
+     * Replaces trace.
+     *
+     * @param array $trace The trace
+     */
+    public function replaceTrace($trace)
     {
-        $result = array();
-        foreach ($args as $key => $value) {
-            if (++$count > 1e4) {
-                return array('array', '*SKIPPED over 10000 entries*');
-            }
-            if (is_object($value)) {
-                $result[$key] = array('object', get_class($value));
-            } elseif (is_array($value)) {
-                if ($level > 10) {
-                    $result[$key] = array('array', '*DEEP NESTED ARRAY*');
-                } else {
-                    $result[$key] = array('array', $this->flattenArgs($value, $level + 1, $count));
-                }
-            } elseif (null === $value) {
-                $result[$key] = array('null', null);
-            } elseif (is_bool($value)) {
-                $result[$key] = array('boolean', $value);
-            } elseif (is_resource($value)) {
-                $result[$key] = array('resource', get_resource_type($value));
-            } elseif ($value instanceof \__PHP_Incomplete_Class) {
-                // Special case of object, is_object will return false
-                $result[$key] = array('incomplete-object', $this->getClassNameFromIncomplete($value));
-            } else {
-                $result[$key] = array('string', (string) $value);
-            }
-        }
+        $this->trace = (array) $trace;
+    }
 
-        return $result;
+    /**
+     * Returns all extras.
+     *
+     * @return array
+     */
+    public function getExtras()
+    {
+        return $this->extras;
     }
 
-    private function getClassNameFromIncomplete(\__PHP_Incomplete_Class $value)
+    /**
+     * Returns an extra value.
+     *
+     * @param string $name    The name of the extra
+     * @param mixed  $default The value to return if the extra doesn't exist
+     *
+     * @return mixed
+     */
+    public function getExtra($name, $default = null)
     {
-        $array = new \ArrayObject($value);
+        return array_key_exists($name, $this->extras) ? $this->extras[$name] : $default;
+    }
 
-        return $array['__PHP_Incomplete_Class_Name'];
+    /**
+     * Sets an extra value.
+     *
+     * @param string $name  The name of the extra
+     * @param mixed  $value The value
+     */
+    public function setExtra($name, $value)
+    {
+        $this->extras[$name] = $value;
     }
 }
diff --git a/src/Symfony/Component/Debug/ExceptionFlattener.php b/src/Symfony/Component/Debug/ExceptionFlattener.php
new file mode 100644
index 0000000000000..d31d169762782
--- /dev/null
+++ b/src/Symfony/Component/Debug/ExceptionFlattener.php
@@ -0,0 +1,88 @@
+<?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\Debug;
+
+use Symfony\Component\Debug\Exception\FlattenException;
+
+/**
+ * ExceptionFlattener converts an Exception to FlattenException.
+ *
+ * @author Martin Hasoň <martin.hason@gmail.com>
+ */
+class ExceptionFlattener
+{
+    /**
+     * @var FlattenExceptionProcessorInterface[]
+     */
+    private $processors = array();
+
+    /**
+     * Constructor.
+     *
+     * @param array $processors The collection of processors
+     */
+    public function __construct($processors = array())
+    {
+        foreach ($processors as $processor) {
+            $this->addProcessor($processor);
+        }
+    }
+
+    /**
+     * Adds an exception processor.
+     *
+     * @param FlattenExceptionProcessorInterface $processor
+     */
+    public function addProcessor(FlattenExceptionProcessorInterface $processor)
+    {
+        $this->processors[] = $processor;
+    }
+
+    /**
+     * Flattens an exception.
+     *
+     * @param \Exception $exception The raw exception
+     *
+     * @return FlattenException
+     */
+    public function flatten(\Exception $exception)
+    {
+        $exceptions = array();
+        do {
+            $exceptions[] = $exception;
+        } while ($exception = $exception->getPrevious());
+
+        $previous = null;
+        foreach (array_reverse($exceptions, true) as $position => $exception) {
+            $e = new FlattenException();
+            $e->setMessage($exception->getMessage());
+            $e->setCode($exception->getCode());
+            $e->setClass(get_class($exception));
+            $e->setFile($exception->getFile());
+            $e->setLine($exception->getLine());
+            $e->setTraceFromException($exception);
+            if (null !== $previous) {
+                $e->setPrevious($previous);
+            }
+
+            foreach ($this->processors as $processor) {
+                if ($newE = $processor->process($exception, $e, 0 === $position)) {
+                    $e = $newE;
+                }
+            }
+
+            $previous = $e;
+        }
+
+        return $e;
+    }
+}
diff --git a/src/Symfony/Component/Debug/ExceptionHandler.php b/src/Symfony/Component/Debug/ExceptionHandler.php
index 4889b18562789..7176a12425fe8 100644
--- a/src/Symfony/Component/Debug/ExceptionHandler.php
+++ b/src/Symfony/Component/Debug/ExceptionHandler.php
@@ -36,7 +36,7 @@ class ExceptionHandler
     private $caughtLength;
     private $fileLinkFormat;
 
-    public function __construct($debug = true, $charset = null, $fileLinkFormat = null)
+    public function __construct($debug = true, $charset = null, $fileLinkFormat = null, ExceptionFlattener $flattener = null)
     {
         if (false !== strpos($charset, '%')) {
             // Swap $charset and $fileLinkFormat for BC reasons
@@ -47,6 +47,7 @@ public function __construct($debug = true, $charset = null, $fileLinkFormat = nu
         $this->debug = $debug;
         $this->charset = $charset ?: ini_get('default_charset') ?: 'UTF-8';
         $this->fileLinkFormat = $fileLinkFormat ?: ini_get('xdebug.file_link_format') ?: get_cfg_var('xdebug.file_link_format');
+        $this->flattener = $flattener;
     }
 
     /**
@@ -183,7 +184,7 @@ private function failSafeHandle(\Exception $exception)
     public function sendPhpResponse($exception)
     {
         if (!$exception instanceof FlattenException) {
-            $exception = FlattenException::create($exception);
+            $exception = null !== $this->flattener ? $this->flattener->flatten($exception) : FlattenException::create($exception);
         }
 
         if (!headers_sent()) {
@@ -211,7 +212,7 @@ public function createResponse($exception)
         @trigger_error('The '.__METHOD__.' method is deprecated since version 2.8 and will be removed in 3.0.', E_USER_DEPRECATED);
 
         if (!$exception instanceof FlattenException) {
-            $exception = FlattenException::create($exception);
+            $exception = null !== $this->flattener ? $this->flattener->flatten($exception) : FlattenException::create($exception);
         }
 
         return Response::create($this->getHtml($exception), $exception->getStatusCode(), $exception->getHeaders())->setCharset($this->charset);
@@ -227,7 +228,7 @@ public function createResponse($exception)
     public function getHtml($exception)
     {
         if (!$exception instanceof FlattenException) {
-            $exception = FlattenException::create($exception);
+            $exception = null !== $this->flattener ? $this->flattener->flatten($exception) : FlattenException::create($exception);
         }
 
         return $this->decorate($this->getContent($exception), $this->getStylesheet($exception));
diff --git a/src/Symfony/Component/Debug/FlattenExceptionProcessorInterface.php b/src/Symfony/Component/Debug/FlattenExceptionProcessorInterface.php
new file mode 100644
index 0000000000000..4a867a4e2d959
--- /dev/null
+++ b/src/Symfony/Component/Debug/FlattenExceptionProcessorInterface.php
@@ -0,0 +1,31 @@
+<?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\Debug;
+
+use Symfony\Component\Debug\Exception\FlattenException;
+
+/**
+ * @author Martin Hasoň <martin.hason@gmail.com>
+ */
+interface FlattenExceptionProcessorInterface
+{
+    /**
+     * Process a flattened exception.
+     *
+     * @param \Exception       $exception        The raw exception
+     * @param FlattenException $flattenException The flattened exception
+     * @param bool             $master           Whether it is a master exception
+     *
+     * @return FlattenException
+     */
+    public function process(\Exception $exception, FlattenException $flattenException, $master);
+}
diff --git a/src/Symfony/Component/Debug/Highlighter/Highlighter.php b/src/Symfony/Component/Debug/Highlighter/Highlighter.php
new file mode 100644
index 0000000000000..3808dadfa4df8
--- /dev/null
+++ b/src/Symfony/Component/Debug/Highlighter/Highlighter.php
@@ -0,0 +1,74 @@
+<?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\Debug\Highlighter;
+
+/**
+ * The base class for syntax highlighters
+ *
+ * @author Martin Hasoň <martin.hason@gmail.com>
+ */
+abstract class Highlighter
+{
+    /**
+     * Highlights a code
+     *
+     * @param string $code  The code
+     * @param int    $line  The selected line number
+     * @param int    $count The number of lines above and below the selected line
+     *
+     * @return string The highlighted code
+     */
+    abstract public function highlight($code, $from = 1, $to = -1, $line = -1);
+
+    /**
+     * Returns true if this class is able to highlight the given file name.
+     *
+     * @param string $name The file name
+     *
+     * @return bool true if this class supports the given file name, false otherwise
+     */
+    abstract public function supports($file);
+
+    protected function createLines($lines, $from, $to, $line = null)
+    {
+        $code = '';
+        $lastOpenSpan = '';
+        $to = -1 === $to ? count($lines) : $to;
+
+        $slice = array_slice($lines, $from - 1, $to - $from + 1, true);
+        $key = key($slice);
+        if (isset($lines[$key - 1]) && 0 !== strpos($lines[$key - 1], '<span')) {
+            for ($i = $key - 2; $i >= 0; $i--) {
+                if (isset($lines[$i]) && preg_match('#^.*(</?span[^>]*>)#', $lines[$i], $match) && '/' != $match[1][1]) {
+                    $lastOpenSpan = $match[1];
+                    break;
+                }
+            }
+        }
+
+        --$line;
+        foreach ($slice as $number => $content) {
+            $code .= '<li'.($number === $line ? ' class="selected"' : '').'><code>'.($lastOpenSpan.$content);
+            if (preg_match('#^.*(</?span[^>]*>)#', $content, $match)) {
+                $lastOpenSpan = '/' != $match[1][1] ? $match[1] : '';
+            }
+
+            if ($lastOpenSpan) {
+                $code .= '</span>';
+            }
+
+            $code .= "</code></li>\n";
+        }
+
+        return '<ol class="code" start="'.($key+1).'">'.$code.'</ol>';
+    }
+}
diff --git a/src/Symfony/Component/Debug/Highlighter/PHPHighlighter.php b/src/Symfony/Component/Debug/Highlighter/PHPHighlighter.php
new file mode 100644
index 0000000000000..b009329ddf0f5
--- /dev/null
+++ b/src/Symfony/Component/Debug/Highlighter/PHPHighlighter.php
@@ -0,0 +1,79 @@
+<?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\Debug\Highlighter;
+
+/**
+ * Simple PHP syntax highlighter
+ *
+ * @author Martin Hasoň <martin.hason@gmail.com>
+ */
+class PHPHighlighter extends Highlighter
+{
+    private $styles;
+    private $regex;
+
+    public function __construct()
+    {
+        $style = ' style="color: %s"';
+        $this->styles = array(
+            ' class="comment"' => sprintf($style, ini_get('highlight.comment')),
+            ' class="name"' => sprintf($style, ini_get('highlight.default')),
+            ' class="tag"' => sprintf($style, ini_get('highlight.html')),
+            ' class="operator"' => sprintf($style, ini_get('highlight.keyword')),
+            ' class="string"' => sprintf($style, ini_get('highlight.string')),
+        );
+
+        $this->regex = '
+            /(?:
+                (?P<variable>\$[a-zA-Z0-9]+)|
+                (?P<keyword>
+                    \b(?:__halt_compiler|abstract|and|array|as|break|callable|case|catch|class|clone|const|continue|
+                    declare|default|die|do|echo|else|elseif|empty|enddeclare|endfor|endforeach|endif|endswitch|endwhile|eval|exit|extends|
+                    final|finally|for|foreach|function|global|goto|if|implements|include|include_once|instanceof|insteadof|interface|isset|
+                    list|namespace|new|or|print|private|protected|public|require|require_once|return|static|switch|throw|trait|try|
+                    unset|use|var|while|xor|yield)(?![^<"\']*?["\'])\b
+                )
+            )/ix'
+        ;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function highlight($code, $from = 1, $to = -1, $line = -1)
+    {
+        // highlight_file could throw warnings
+        // see https://bugs.php.net/bug.php?id=25725
+        $code = @highlight_string($code, true);
+        // remove main code/span tags
+        $code = preg_replace('#^<code.*?>\s*<span.*?>(.*)</span>\s*</code>#s', '\\1', $code);
+
+        $code = $this->createLines(preg_split('#<br />#', $code), $from, $to, $line);
+
+        $code = str_replace('&nbsp;', ' ', $code);
+        $code = str_replace(array_values($this->styles), array_keys($this->styles), $code);
+        $code = preg_replace_callback($this->regex, function ($match) {
+            $keys = array_keys($match);
+            return sprintf('<span class="%s">%s</span>', $keys[count($match) - 2], $match[0]);
+        }, $code);
+
+        return $code;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supports($file)
+    {
+        return 'php' === pathinfo($file, PATHINFO_EXTENSION);
+    }
+}
diff --git a/src/Symfony/Component/Debug/Tests/ArgumentsFlattenExceptionProcessorTest.php b/src/Symfony/Component/Debug/Tests/ArgumentsFlattenExceptionProcessorTest.php
new file mode 100644
index 0000000000000..ad1f6bd14f88e
--- /dev/null
+++ b/src/Symfony/Component/Debug/Tests/ArgumentsFlattenExceptionProcessorTest.php
@@ -0,0 +1,110 @@
+<?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\Debug\Tests;
+
+use Symfony\Component\Debug\ArgumentsFlattenExceptionProcessor;
+use Symfony\Component\Debug\ExceptionFlattener;
+use Symfony\Component\VarDumper\Cloner\VarCloner;
+
+class ArgumentsFlattenExceptionProcessorTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @var ExceptionFlattener
+     */
+    private $flattener;
+
+    protected function setUp()
+    {
+        $this->flattener = new ExceptionFlattener();
+    }
+
+    public function testProcessOnlyMasterException()
+    {
+        $exception = new \Exception('Previous exception');
+        $flattenedException = $this->flattener->flatten($exception);
+
+        $processor = new ArgumentsFlattenExceptionProcessor();
+        $processor->process($exception, $flattenedException, false);
+
+        $this->assertEmpty($flattenedException->getExtras());
+        foreach ($flattenedException->getTrace() as $trace) {
+            $this->assertEmpty($trace['args']);
+        }
+    }
+
+    public function testMasterException()
+    {
+        $exception = new \Exception('Master exception');
+        $flattenedException = $this->flattener->flatten($exception);
+
+        $processor = new ArgumentsFlattenExceptionProcessor();
+        $processor->process($exception, $flattenedException, true);
+
+        $extras = $flattenedException->getExtras();
+        $this->assertArrayHasKey('trace_arguments', $extras);
+
+        foreach ($flattenedException->getTrace() as $trace) {
+            foreach ($trace['args'] as $arg) {
+                $this->assertEquals('link', $arg[0]);
+                $this->assertArrayHasKey($arg[1], $extras['trace_arguments'][1]);
+            }
+        }
+    }
+
+    public function testMasterExceptionWithoutSharedVariables()
+    {
+        $exception = new \Exception('Master exception');
+        $flattenedException = $this->flattener->flatten($exception);
+
+        $processor = new ArgumentsFlattenExceptionProcessor(null, false);
+        $processor->process($exception, $flattenedException, true);
+
+        $this->assertArrayNotHasKey('trace_arguments', $flattenedException->getExtras());
+
+        foreach ($flattenedException->getTrace() as $trace) {
+            foreach ($trace['args'] as $arg) {
+                $this->assertNotEquals('link', $arg[0]);
+            }
+        }
+    }
+
+    public function testWithLinksToVariablesAndCloner()
+    {
+        $exception = new \Exception('Master exception');
+        $flattenedException = $this->flattener->flatten($exception);
+
+        $processor = new ArgumentsFlattenExceptionProcessor(new VarCloner());
+        $processor->process($exception, $flattenedException, true);
+
+        $extras = $flattenedException->getExtras();
+        $this->assertArrayHasKey('trace_arguments', $extras);
+        $this->assertInstanceOf('Symfony\Component\VarDumper\Cloner\Data', $extras['trace_arguments']);
+
+        foreach ($flattenedException->getTrace() as $trace) {
+            foreach ($trace['args'] as $arg) {
+                $this->assertEquals('link', $arg[0]);
+            }
+        }
+    }
+
+    public function testIdenticalFlattenedArguments()
+    {
+        $previousException = new \Exception('Previous exception');
+        $exception = new \Exception('Master exception', 0, $previousException);
+        $flattenedException = $this->flattener->flatten($exception);
+
+        $processor = new ArgumentsFlattenExceptionProcessor(new VarCloner());
+        $processor->process($exception, $flattenedException, true);
+
+        $this->assertSame($flattenedException->getExtra('trace_arguments'), $flattenedException->getPrevious()->getExtra('trace_arguments'));
+    }
+}
diff --git a/src/Symfony/Component/Debug/Tests/Exception/FlattenExceptionTest.php b/src/Symfony/Component/Debug/Tests/Exception/FlattenExceptionTest.php
index 99eaf497d5b4d..9113b82280466 100644
--- a/src/Symfony/Component/Debug/Tests/Exception/FlattenExceptionTest.php
+++ b/src/Symfony/Component/Debug/Tests/Exception/FlattenExceptionTest.php
@@ -161,7 +161,7 @@ public function testToArray(\Exception $exception, $statusCode)
             array(
                 'message' => 'test',
                 'class' => 'Exception',
-                'trace' => array(array(
+                'trace' => array(-1 => array(
                     'namespace' => '', 'short_class' => '', 'class' => '', 'type' => '', 'function' => '', 'file' => 'foo.php', 'line' => 123,
                     'args' => array(),
                 )),
@@ -215,32 +215,33 @@ private function createException($foo)
 
     public function testSetTraceIncompleteClass()
     {
-        $flattened = FlattenException::create(new \Exception('test', 123));
-        $flattened->setTrace(
+        $exception = new \Exception('test', 123);
+        $traceReflection = new \ReflectionProperty($exception, 'trace');
+        $traceReflection->setAccessible(true);
+        $traceReflection->setValue($exception, array(
             array(
-                array(
-                    'file' => __FILE__,
-                    'line' => 123,
-                    'function' => 'test',
-                    'args' => array(
-                        unserialize('O:14:"BogusTestClass":0:{}'),
-                    ),
+                'file' => __FILE__,
+                'line' => 123,
+                'function' => 'test',
+                'args' => array(
+                    unserialize('O:14:"BogusTestClass":0:{}'),
                 ),
             ),
-            'foo.php', 123
-        );
+        ));
+
+        $flattened = FlattenException::create($exception);
 
         $this->assertEquals(array(
             array(
                 'message' => 'test',
                 'class' => 'Exception',
                 'trace' => array(
-                    array(
+                    -1 => array(
                         'namespace' => '', 'short_class' => '', 'class' => '', 'type' => '', 'function' => '',
-                        'file' => 'foo.php', 'line' => 123,
+                        'file' => __FILE__, 'line' => 218,
                         'args' => array(),
                     ),
-                    array(
+                    0 => array(
                         'namespace' => '', 'short_class' => '', 'class' => '', 'type' => '', 'function' => 'test',
                         'file' => __FILE__, 'line' => 123,
                         'args' => array(
diff --git a/src/Symfony/Component/Debug/Tests/ExceptionFlattenerTest.php b/src/Symfony/Component/Debug/Tests/ExceptionFlattenerTest.php
new file mode 100644
index 0000000000000..ea1e20b24eedc
--- /dev/null
+++ b/src/Symfony/Component/Debug/Tests/ExceptionFlattenerTest.php
@@ -0,0 +1,134 @@
+<?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\Debug\Tests;
+
+use Symfony\Component\Debug\Exception\FlattenException;
+use Symfony\Component\Debug\ExceptionFlattener;
+use Symfony\Component\Debug\FlattenExceptionProcessorInterface;
+
+class ExceptionFlattenerTest extends \PHPUnit_Framework_TestCase
+{
+    private $flattener;
+
+    protected function setUp()
+    {
+        $this->flattener = new ExceptionFlattener();
+    }
+
+    public function testFlattenException()
+    {
+        $exception = new \RuntimeException('Runtime exception');
+        $flattened = $this->flattener->flatten($exception);
+
+        $this->assertEquals($exception->getMessage(), $flattened->getMessage());
+        $this->assertEquals($exception->getCode(), $flattened->getCode());
+        $this->assertEquals($exception->getFile(), $flattened->getFile());
+        $this->assertEquals($exception->getLine(), $flattened->getLine());
+        $this->assertInstanceOf($flattened->getClass(), $exception);
+    }
+
+    public function testFlattenPreviousException()
+    {
+        $exception1 = new \OutOfRangeException('Out of range exception');
+        $exception2 = new \InvalidArgumentException('Invalid argument exception', null, $exception1);
+        $exception3 = new \RuntimeException('Runtime exception', null, $exception2);
+
+        $flattened = $this->flattener->flatten($exception3);
+        $this->assertCount(2, $flattened->getAllPrevious());
+        $this->assertInstanceOf('Symfony\Component\Debug\Exception\FlattenException', $flattened->getPrevious());
+        $this->assertInstanceOf(
+            'Symfony\Component\Debug\Exception\FlattenException',
+            $flattened->getPrevious()->getPrevious()
+        );
+    }
+
+    public function testFlattenWithProcessor()
+    {
+        $this->flattener->addProcessor(new TagTraceProcessor());
+
+        $exception = new \RuntimeException('Runtime exception');
+        $flattened = $this->flattener->flatten($exception);
+        foreach ($flattened->getTrace() as $position => $entry) {
+            if (-1 === $position) {
+                $this->assertFalse(array_key_exists('tag', $entry));
+            } else {
+                $this->assertArrayHasKey('tag', $entry);
+            }
+        }
+    }
+
+    public function testProcessorReplaceException()
+    {
+        $this->flattener->addProcessor(new EmptyExceptionProcessor());
+
+        $exception = new \RuntimeException('Runtime exception');
+        $flattened = $this->flattener->flatten($exception);
+
+        $this->assertNull($flattened->getMessage());
+        $this->assertNull($flattened->getCode());
+        $this->assertNull($flattened->getFile());
+        $this->assertNull($flattened->getLine());
+    }
+
+    public function testProcessOnlyMaterException()
+    {
+        $exception1 = new \OutOfRangeException('Out of range exception');
+        $exception2 = new \InvalidArgumentException('Invalid argument exception', null, $exception1);
+        $exception3 = new \RuntimeException('Runtime exception', null, $exception2);
+
+        $this->flattener->addProcessor(new MasterExtraProcessor());
+        $flattened = $this->flattener->flatten($exception3);
+
+        $this->assertEquals(array('tags' => array('master')), $flattened->getExtras());
+        foreach ($flattened->getAllPrevious() as $exception) {
+            $this->assertEquals(array(), $exception->getExtras());
+        }
+    }
+}
+
+class TagTraceProcessor implements FlattenExceptionProcessorInterface
+{
+    public function process(\Exception $exception, FlattenException $flattenException, $master)
+    {
+        $trace = $flattenException->getTrace();
+
+        foreach ($exception->getTrace() as $key => $entry) {
+            if (!isset($trace[$key])) {
+                continue;
+            }
+
+            $trace[$key]['tag'] = 'value';
+        }
+
+        $flattenException->replaceTrace($trace);
+    }
+}
+
+class EmptyExceptionProcessor implements FlattenExceptionProcessorInterface
+{
+    public function process(\Exception $exception, FlattenException $flattenException, $master)
+    {
+        return new FlattenException();
+    }
+}
+
+class MasterExtraProcessor implements FlattenExceptionProcessorInterface
+{
+    public function process(\Exception $exception, FlattenException $flattenException, $master)
+    {
+        if (!$master) {
+            return;
+        }
+
+        $flattenException->setExtra('tags', array('master'));
+    }
+}
diff --git a/src/Symfony/Component/Debug/Utils/HtmlUtils.php b/src/Symfony/Component/Debug/Utils/HtmlUtils.php
new file mode 100644
index 0000000000000..a5a2e26992d4d
--- /dev/null
+++ b/src/Symfony/Component/Debug/Utils/HtmlUtils.php
@@ -0,0 +1,130 @@
+<?php
+
+namespace Symfony\Component\Debug\Utils;
+
+use Symfony\Component\Debug\Exception\FlattenException;
+use Symfony\Component\Debug\Highlighter\Highlighter;
+use Symfony\Component\VarDumper\Cloner\Data;
+use Symfony\Component\VarDumper\Cloner\Stub;
+
+class HtmlUtils
+{
+    /**
+     * @var Highlighter[]
+     */
+    private $highlighters = array();
+
+    /**
+     * Constructor.
+     *
+     * @param Highlighter[] $highlighters
+     */
+    public function __construct(array $highlighters)
+    {
+        $this->highlighters = $highlighters;
+    }
+
+    /**
+     * Formats an array as a string.
+     *
+     * @param array                 $args      The argument array
+     * @param FlattenException|null $exception The flatten exception
+     *
+     * @return string
+     */
+    public function formatArgs(array $args, $exception = null)
+    {
+        $arguments = $exception instanceof FlattenException ? $exception->getExtra('trace_arguments') : null;
+
+        $result = array();
+        foreach ($args as $key => $item) {
+            $formattedValue = $this->dumpArg($item, true, $arguments);
+            $result[] = $formattedValue;
+        }
+
+        return implode(', ', $result);
+    }
+
+    public function dumpArg($arg, $compact = true, $arguments = null)
+    {
+        switch ($arg[0]) {
+            case 'object':
+                $parts = explode('\\', $arg[1]);
+                $short = array_pop($parts);
+                return sprintf('<abbr title="%s">%s</abbr>', $arg[1], $short);
+            case 'array':
+                if ($compact) {
+                    return sprintf('<em>array:%d</em>', count((array) $arg[1]));
+                }
+
+                $result = array();
+                foreach ((array) $arg[1] as $key => $value) {
+                    $formattedValue = is_array($value) ? $this->dumpArg($value, $compact) : $value;
+                    $result[] = is_int($key) ? $formattedValue : sprintf("'%s' => %s", $key, $formattedValue);
+                }
+
+                return sprintf('[%s]', implode(', ', $result));
+            case 'string':
+                return sprintf("'%s'", htmlspecialchars((string) $arg[1], ENT_QUOTES));
+            case 'number':
+                return $arg[1];
+            case 'null':
+                return '<em>null</em>';
+            case 'boolean':
+                return '<em>'.strtolower(var_export($arg[1], true)).'</em>';
+            case 'resource':
+                return '<em>resource</em>';
+            case 'link':
+                if ($arguments instanceof Data && ($data = $arguments->getRawData()) && array_key_exists($arg[1], $data[1])) {
+                    $value = $data[1][$arg[1]];
+                    $type = gettype($value);
+
+                    if (!$value instanceof Stub) {
+                        return $this->dumpArg(array(strtolower($type), $value), $compact);
+                    }
+
+                    switch ($value->type) {
+                        case Stub::TYPE_OBJECT:
+                            return $this->dumpArg(array('object', $value->class), $compact);
+                        case Stub::TYPE_STRING:
+                            return $this->dumpArg(array('string', $value->value), $compact);
+                        case Stub::TYPE_ARRAY:
+                            return $this->dumpArg(array('array', $value->value), $compact);
+                        case Stub::TYPE_RESOURCE:
+                            return $this->dumpArg(array('resource', $value->value), $compact);
+                        default:
+                            return '<em>_</em>';
+                    }
+                } elseif (is_array($arguments) && isset($arguments[1][$arg[1]])) {
+                    return $this->dumpArg($arguments[1][$arg[1]], $compact);
+                }
+
+                return '<em>_</em>';
+            default:
+                return str_replace("\n", '', var_export(htmlspecialchars((string) $arg[1], ENT_QUOTES), true));
+        }
+    }
+
+    public function highlight($fileOrCode, $line = null, $from = null, $to = null, $highlighter = null)
+    {
+        $code = is_readable($fileOrCode) ? file_get_contents($fileOrCode) : $fileOrCode;
+
+        if (null !== $line) {
+            $from = null === $from ? $line - 3 : 1;
+            $to = null === $to ? $line + 3 : -1;
+        }
+
+        $from = null === $from ? 1 : $from;
+        $to = null === $to ? -1 : $to;
+
+        if (isset($this->highlighters[$highlighter])) {
+            return $this->highlighters[$highlighter]->highlight($code, $from, $to, $line);
+        }
+
+        foreach ($this->highlighters as $highlighter) {
+            if ($highlighter->supports($fileOrCode)) {
+                return $highlighter->highlight($code, $from, $to, $line);
+            }
+        }
+    }
+}
diff --git a/src/Symfony/Component/HttpKernel/DataCollector/ExceptionDataCollector.php b/src/Symfony/Component/HttpKernel/DataCollector/ExceptionDataCollector.php
index 9fe826446b195..bb88145860e52 100644
--- a/src/Symfony/Component/HttpKernel/DataCollector/ExceptionDataCollector.php
+++ b/src/Symfony/Component/HttpKernel/DataCollector/ExceptionDataCollector.php
@@ -12,6 +12,7 @@
 namespace Symfony\Component\HttpKernel\DataCollector;
 
 use Symfony\Component\Debug\Exception\FlattenException;
+use Symfony\Component\Debug\ExceptionFlattener;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 
@@ -22,16 +23,25 @@
  */
 class ExceptionDataCollector extends DataCollector
 {
+    private $flattener;
+
+    public function __construct(ExceptionFlattener $flattener = null)
+    {
+        $this->flattener = $flattener;
+    }
+
     /**
      * {@inheritdoc}
      */
     public function collect(Request $request, Response $response, \Exception $exception = null)
     {
-        if (null !== $exception) {
-            $this->data = array(
-                'exception' => FlattenException::create($exception),
-            );
+        if (null === $exception) {
+            return;
         }
+
+        $this->data = array(
+            'exception' => null === $this->flattener ? FlattenException::create($exception) : $this->flattener->flatten($exception),
+        );
     }
 
     /**
diff --git a/src/Symfony/Component/HttpKernel/Debug/HttpFlattenExceptionProcessor.php b/src/Symfony/Component/HttpKernel/Debug/HttpFlattenExceptionProcessor.php
new file mode 100644
index 0000000000000..d91c2c562ce06
--- /dev/null
+++ b/src/Symfony/Component/HttpKernel/Debug/HttpFlattenExceptionProcessor.php
@@ -0,0 +1,37 @@
+<?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\Debug;
+
+use Symfony\Component\Debug\Exception\FlattenException;
+use Symfony\Component\Debug\FlattenExceptionProcessorInterface;
+use Symfony\Component\HttpKernel\Exception\HttpExceptionInterface;
+
+/**
+ * @author Martin Hasoň <martin.hason@gmail.com>
+ */
+class HttpFlattenExceptionProcessor implements FlattenExceptionProcessorInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function process(\Exception $exception, FlattenException $flattenException, $master)
+    {
+        if (!$exception instanceof HttpExceptionInterface) {
+            $flattenException->setStatusCode($flattenException->getStatusCode() ?: 500);
+
+            return;
+        }
+
+        $flattenException->setStatusCode($exception->getStatusCode() ?: 500);
+        $flattenException->setHeaders(array_merge($flattenException->getHeaders(), $exception->getHeaders()));
+    }
+}
diff --git a/src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php b/src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php
index fc2efed86bd6a..3b8bd24f277be 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php
@@ -13,6 +13,7 @@
 
 use Psr\Log\LoggerInterface;
 use Symfony\Component\Debug\Exception\FlattenException;
+use Symfony\Component\Debug\ExceptionFlattener;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpKernel\Log\DebugLoggerInterface;
 use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
@@ -30,11 +31,13 @@ class ExceptionListener implements EventSubscriberInterface
 {
     protected $controller;
     protected $logger;
+    protected $flattener;
 
-    public function __construct($controller, LoggerInterface $logger = null)
+    public function __construct($controller, LoggerInterface $logger = null, ExceptionFlattener $flattener = null)
     {
         $this->controller = $controller;
         $this->logger = $logger;
+        $this->flattener = $flattener;
     }
 
     public function onKernelException(GetResponseForExceptionEvent $event)
@@ -103,9 +106,11 @@ protected function logException(\Exception $exception, $message)
      */
     protected function duplicateRequest(\Exception $exception, Request $request)
     {
+        $flattenException = null === $this->flattener ? FlattenException::create($exception) : $this->flattener->flatten($exception);
+
         $attributes = array(
             '_controller' => $this->controller,
-            'exception' => FlattenException::create($exception),
+            'exception' => $flattenException,
             'logger' => $this->logger instanceof DebugLoggerInterface ? $this->logger : null,
             // keep for BC -- as $format can be an argument of the controller callable
             // see src/Symfony/Bundle/TwigBundle/Controller/ExceptionController.php
diff --git a/src/Symfony/Component/HttpKernel/Tests/DataCollector/ExceptionDataCollectorTest.php b/src/Symfony/Component/HttpKernel/Tests/DataCollector/ExceptionDataCollectorTest.php
index 6c71f4c9ebdd5..2ee19a4dae338 100644
--- a/src/Symfony/Component/HttpKernel/Tests/DataCollector/ExceptionDataCollectorTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/DataCollector/ExceptionDataCollectorTest.php
@@ -12,17 +12,18 @@
 namespace Symfony\Component\HttpKernel\Tests\DataCollector;
 
 use Symfony\Component\Debug\Exception\FlattenException;
+use Symfony\Component\Debug\ExceptionFlattener;
 use Symfony\Component\HttpKernel\DataCollector\ExceptionDataCollector;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 
 class ExceptionDataCollectorTest extends \PHPUnit_Framework_TestCase
 {
-    public function testCollect()
+    /**
+     * @dataProvider getData
+     */
+    public function testCollect($c, $e, $flattened)
     {
-        $e = new \Exception('foo', 500);
-        $c = new ExceptionDataCollector();
-        $flattened = FlattenException::create($e);
         $trace = $flattened->getTrace();
 
         $this->assertFalse($c->hasException());
@@ -34,6 +35,17 @@ public function testCollect()
         $this->assertSame('foo', $c->getMessage());
         $this->assertSame(500, $c->getCode());
         $this->assertSame('exception', $c->getName());
-        $this->assertSame($trace, $c->getTrace());
+        $this->assertEquals($trace, $c->getTrace());
+    }
+
+    public function getData()
+    {
+        $e = new \Exception('foo', 500);
+        $flattener = new ExceptionFlattener();
+
+        return array(
+            array(new ExceptionDataCollector(), $e, FlattenException::create($e)),
+            array(new ExceptionDataCollector($flattener), $e, $flattener->flatten($e)),
+        );
     }
 }
diff --git a/src/Symfony/Component/HttpKernel/Tests/Debug/HttpFlattenExceptionProcessorTest.php b/src/Symfony/Component/HttpKernel/Tests/Debug/HttpFlattenExceptionProcessorTest.php
new file mode 100644
index 0000000000000..c3c3103b3b9f4
--- /dev/null
+++ b/src/Symfony/Component/HttpKernel/Tests/Debug/HttpFlattenExceptionProcessorTest.php
@@ -0,0 +1,100 @@
+<?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\Debug;
+
+use Symfony\Component\Debug\Exception\FlattenException;
+use Symfony\Component\HttpKernel\Debug\HttpFlattenExceptionProcessor;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+use Symfony\Component\HttpKernel\Exception\MethodNotAllowedHttpException;
+use Symfony\Component\HttpKernel\Exception\UnauthorizedHttpException;
+use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
+use Symfony\Component\HttpKernel\Exception\NotAcceptableHttpException;
+use Symfony\Component\HttpKernel\Exception\ConflictHttpException;
+use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
+use Symfony\Component\HttpKernel\Exception\GoneHttpException;
+use Symfony\Component\HttpKernel\Exception\LengthRequiredHttpException;
+use Symfony\Component\HttpKernel\Exception\PreconditionFailedHttpException;
+use Symfony\Component\HttpKernel\Exception\PreconditionRequiredHttpException;
+use Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException;
+use Symfony\Component\HttpKernel\Exception\TooManyRequestsHttpException;
+use Symfony\Component\HttpKernel\Exception\UnsupportedMediaTypeHttpException;
+
+class HttpFlattenExceptionProcessorTest extends \PHPUnit_Framework_TestCase
+{
+    private $processor;
+
+    protected function setUp()
+    {
+        $this->processor = new HttpFlattenExceptionProcessor();
+    }
+
+    public function getStatusCode()
+    {
+        return array(
+            array(400, new BadRequestHttpException()),
+            array(401, new UnauthorizedHttpException('Basic realm="My Realm"')),
+            array(403, new AccessDeniedHttpException()),
+            array(404, new NotFoundHttpException()),
+            array(405, new MethodNotAllowedHttpException(array('POST'))),
+            array(406, new NotAcceptableHttpException()),
+            array(409, new ConflictHttpException()),
+            array(410, new GoneHttpException()),
+            array(411, new LengthRequiredHttpException()),
+            array(412, new PreconditionFailedHttpException()),
+            array(415, new UnsupportedMediaTypeHttpException()),
+            array(428, new PreconditionRequiredHttpException()),
+            array(429, new TooManyRequestsHttpException()),
+            array(500, new \RuntimeException()),
+            array(503, new ServiceUnavailableHttpException()),
+        );
+    }
+
+    /**
+     * @dataProvider getStatusCode
+     */
+    public function testStatusCode($code, $exception)
+    {
+        $flattened = new FlattenException();
+        $this->processor->process($exception, $flattened, true);
+        $this->assertEquals($code, $flattened->getStatusCode());
+    }
+
+    public function testCustomStatusCode()
+    {
+        $flattened = new FlattenException();
+        $flattened->setStatusCode(403);
+        $this->processor->process(new \RuntimeException(), $flattened, true);
+        $this->assertEquals(403, $flattened->getStatusCode());
+    }
+
+    public function getHeaders()
+    {
+        return array(
+            array(array('Allow' => 'POST'), new MethodNotAllowedHttpException(array('POST'))),
+            array(array('WWW-Authenticate' => 'Basic realm="My Realm"'), new UnauthorizedHttpException('Basic realm="My Realm"')),
+            array(array('Retry-After' => 'Fri, 31 Dec 1999 23:59:59 GMT'), new ServiceUnavailableHttpException('Fri, 31 Dec 1999 23:59:59 GMT')),
+            array(array('Retry-After' => 120), new ServiceUnavailableHttpException(120)),
+            array(array('Retry-After' => 'Fri, 31 Dec 1999 23:59:59 GMT'), new TooManyRequestsHttpException('Fri, 31 Dec 1999 23:59:59 GMT')),
+            array(array('Retry-After' => 120), new TooManyRequestsHttpException(120)),
+        );
+    }
+
+    /**
+     * @dataProvider getHeaders
+     */
+    public function testHeadersForHttpException($headers, $exception)
+    {
+        $flattened = new FlattenException();
+        $this->processor->process($exception, $flattened, true);
+        $this->assertEquals($headers, $flattened->getHeaders());
+    }
+}
diff --git a/src/Symfony/Component/HttpKernel/Tests/EventListener/ExceptionListenerTest.php b/src/Symfony/Component/HttpKernel/Tests/EventListener/ExceptionListenerTest.php
index 8fb00f51c1e6e..27f093d10ade8 100644
--- a/src/Symfony/Component/HttpKernel/Tests/EventListener/ExceptionListenerTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/EventListener/ExceptionListenerTest.php
@@ -119,6 +119,25 @@ public function testSubRequestFormat()
         $response = $event->getResponse();
         $this->assertEquals('xml', $response->getContent());
     }
+
+    public function testUseFlattener()
+    {
+        $exception = new \Exception('foo');
+
+        $flattener = $this->getMock('Symfony\Component\Debug\ExceptionFlattener');
+        $flattener->expects($this->once())->method('flatten')->with($exception);
+
+        $listener = new ExceptionListener('foo', null, $flattener);
+
+        $kernel = $this->getMock('Symfony\Component\HttpKernel\HttpKernelInterface');
+        $kernel->expects($this->once())->method('handle')->will($this->returnCallback(function () {
+            return new Response();
+        }));
+
+        $request = Request::create('/');
+        $event = new GetResponseForExceptionEvent($kernel, $request, 'foo', $exception);
+        $listener->onKernelException($event);
+    }
 }
 
 class TestLogger extends Logger implements DebugLoggerInterface