Merge branch '2.8' into 3.4

* 2.8: [travis] merge "same Symfony version" jobs in one
[travis] merge "same Symfony version" jobs in one
2026-03-25 01:32:09 +01:00 · 2018-08-03 12:42:44 +02:00 · 2018-08-03 11:45:57 +02:00 · 2018-07-26 13:19:56 +02:00 · 2018-07-26 13:13:39 +02:00 · 2018-07-26 11:06:28 +02:00
40 changed files with 830 additions and 296 deletions
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========

+3.4.0
+-----
+
+* deprecated `ErrorHandler::stackErrors()` and `ErrorHandler::unstackErrors()`
+
 3.3.0
 -----

--- a/Debug.php
+++ b/Debug.php
@@ -23,10 +23,7 @@ class Debug
    /**
     * Enables the debug tools.
     *
-     * This method registers an error handler and an exception handler.
-     *
-     * If the Symfony ClassLoader component is available, a special
-     * class loader is also registered.
+     * This method registers an error handler, an exception handler and a special class loader.
     *
     * @param int  $errorReportingLevel The level of error reporting you want
     * @param bool $displayErrors       Whether to display errors (for development) or just log them (for production)
@@ -45,7 +42,7 @@ class Debug
            error_reporting(E_ALL);
        }

-        if ('cli' !== PHP_SAPI) {
+        if (!\in_array(\PHP_SAPI, array('cli', 'phpdbg'), true)) {
            ini_set('display_errors', 0);
            ExceptionHandler::register();
        } elseif ($displayErrors && (!ini_get('log_errors') || ini_get('error_log'))) {
--- a/DebugClassLoader.php
+++ b/DebugClassLoader.php
@@ -26,26 +26,25 @@ class DebugClassLoader
 {
    private $classLoader;
    private $isFinder;
+    private $loaded = array();
    private static $caseCheck;
+    private static $checkedClasses = array();
    private static $final = array();
    private static $finalMethods = array();
    private static $deprecated = array();
-    private static $php7Reserved = array('int', 'float', 'bool', 'string', 'true', 'false', 'null');
+    private static $internal = array();
+    private static $internalMethods = array();
+    private static $php7Reserved = array('int' => 1, 'float' => 1, 'bool' => 1, 'string' => 1, 'true' => 1, 'false' => 1, 'null' => 1);
    private static $darwinCache = array('/' => array('/', array()));

-    /**
-     * Constructor.
-     *
-     * @param callable $classLoader A class loader
-     */
    public function __construct(callable $classLoader)
    {
        $this->classLoader = $classLoader;
-        $this->isFinder = is_array($classLoader) && method_exists($classLoader[0], 'findFile');
+        $this->isFinder = \is_array($classLoader) && method_exists($classLoader[0], 'findFile');

        if (!isset(self::$caseCheck)) {
-            $file = file_exists(__FILE__) ? __FILE__ : rtrim(realpath('.'), DIRECTORY_SEPARATOR);
-            $i = strrpos($file, DIRECTORY_SEPARATOR);
+            $file = file_exists(__FILE__) ? __FILE__ : rtrim(realpath('.'), \DIRECTORY_SEPARATOR);
+            $i = strrpos($file, \DIRECTORY_SEPARATOR);
            $dir = substr($file, 0, 1 + $i);
            $file = substr($file, 1 + $i);
            $test = strtoupper($file) === $file ? strtolower($file) : strtoupper($file);
@@ -54,7 +53,7 @@ class DebugClassLoader
            if (false === $test || false === $i) {
                // filesystem is case sensitive
                self::$caseCheck = 0;
-            } elseif (substr($test, -strlen($file)) === $file) {
+            } elseif (substr($test, -\strlen($file)) === $file) {
                // filesystem is case insensitive and realpath() normalizes the case of characters
                self::$caseCheck = 1;
            } elseif (false !== stripos(PHP_OS, 'darwin')) {
@@ -86,7 +85,7 @@ class DebugClassLoader
        class_exists('Symfony\Component\Debug\ErrorHandler');
        class_exists('Psr\Log\LogLevel');

-        if (!is_array($functions = spl_autoload_functions())) {
+        if (!\is_array($functions = spl_autoload_functions())) {
            return;
        }

@@ -95,7 +94,7 @@ class DebugClassLoader
        }

        foreach ($functions as $function) {
-            if (!is_array($function) || !$function[0] instanceof self) {
+            if (!\is_array($function) || !$function[0] instanceof self) {
                $function = array(new static($function), 'loadClass');
            }

@@ -108,7 +107,7 @@ class DebugClassLoader
     */
    public static function disable()
    {
-        if (!is_array($functions = spl_autoload_functions())) {
+        if (!\is_array($functions = spl_autoload_functions())) {
            return;
        }

@@ -117,7 +116,7 @@ class DebugClassLoader
        }

        foreach ($functions as $function) {
-            if (is_array($function) && $function[0] instanceof self) {
+            if (\is_array($function) && $function[0] instanceof self) {
                $function = $function[0]->getClassLoader();
            }

@@ -136,119 +135,152 @@ class DebugClassLoader
     */
    public function loadClass($class)
    {
-        ErrorHandler::stackErrors();
+        $e = error_reporting(error_reporting() | E_PARSE | E_ERROR | E_CORE_ERROR | E_COMPILE_ERROR);

        try {
-            if ($this->isFinder) {
-                if ($file = $this->classLoader[0]->findFile($class)) {
-                    require_once $file;
+            if ($this->isFinder && !isset($this->loaded[$class])) {
+                $this->loaded[$class] = true;
+                if ($file = $this->classLoader[0]->findFile($class) ?: false) {
+                    $wasCached = \function_exists('opcache_is_script_cached') && @opcache_is_script_cached($file);
+
+                    require $file;
+
+                    if ($wasCached) {
+                        return;
+                    }
                }
            } else {
-                call_user_func($this->classLoader, $class);
+                \call_user_func($this->classLoader, $class);
                $file = false;
            }
        } finally {
-            ErrorHandler::unstackErrors();
+            error_reporting($e);
        }

-        $exists = class_exists($class, false) || interface_exists($class, false) || trait_exists($class, false);
+        $this->checkClass($class, $file);
+    }

-        if ($class && '\\' === $class[0]) {
+    private function checkClass($class, $file = null)
+    {
+        $exists = null === $file || \class_exists($class, false) || \interface_exists($class, false) || \trait_exists($class, false);
+
+        if (null !== $file && $class && '\\' === $class[0]) {
            $class = substr($class, 1);
        }

        if ($exists) {
+            if (isset(self::$checkedClasses[$class])) {
+                return;
+            }
+            self::$checkedClasses[$class] = true;
+
            $refl = new \ReflectionClass($class);
+            if (null === $file && $refl->isInternal()) {
+                return;
+            }
            $name = $refl->getName();

-            if ($name !== $class && 0 === strcasecmp($name, $class)) {
+            if ($name !== $class && 0 === \strcasecmp($name, $class)) {
                throw new \RuntimeException(sprintf('Case mismatch between loaded and declared class names: "%s" vs "%s".', $class, $name));
            }

-            $parent = get_parent_class($class);
+            // Don't trigger deprecations for classes in the same vendor
+            if (2 > $len = 1 + (\strpos($name, '\\') ?: \strpos($name, '_'))) {
+                $len = 0;
+                $ns = '';
+            } else {
+                $ns = \substr($name, 0, $len);
+            }

-            // Not an interface nor a trait
-            if (class_exists($name, false)) {
-                if (preg_match('#\n \* @final(?:( .+?)\.?)?\r?\n \*(?: @|/$)#s', $refl->getDocComment(), $notice)) {
-                    self::$final[$name] = isset($notice[1]) ? preg_replace('#\s*\r?\n \* +#', ' ', $notice[1]) : '';
-                }
-
-                if ($parent && isset(self::$final[$parent])) {
-                    @trigger_error(sprintf('The "%s" class is considered final%s. It may change without further notice as of its next major version. You should not extend it from "%s".', $parent, self::$final[$parent], $name), E_USER_DEPRECATED);
-                }
-
-                // Inherit @final annotations
-                self::$finalMethods[$name] = $parent && isset(self::$finalMethods[$parent]) ? self::$finalMethods[$parent] : array();
-
-                foreach ($refl->getMethods(\ReflectionMethod::IS_PUBLIC | \ReflectionMethod::IS_PROTECTED) as $method) {
-                    if ($method->class !== $name) {
-                        continue;
-                    }
-
-                    if ($parent && isset(self::$finalMethods[$parent][$method->name])) {
-                        @trigger_error(sprintf('%s It may change without further notice as of its next major version. You should not extend it from "%s".', self::$finalMethods[$parent][$method->name], $name), E_USER_DEPRECATED);
-                    }
-
-                    $doc = $method->getDocComment();
-                    if (false === $doc || false === strpos($doc, '@final')) {
-                        continue;
-                    }
-
-                    if (preg_match('#\n\s+\* @final(?:( .+?)\.?)?\r?\n\s+\*(?: @|/$)#s', $doc, $notice)) {
-                        $message = isset($notice[1]) ? preg_replace('#\s*\r?\n \* +#', ' ', $notice[1]) : '';
-                        self::$finalMethods[$name][$method->name] = sprintf('The "%s::%s()" method is considered final%s.', $name, $method->name, $message);
+            // Detect annotations on the class
+            if (false !== $doc = $refl->getDocComment()) {
+                foreach (array('final', 'deprecated', 'internal') as $annotation) {
+                    if (false !== \strpos($doc, $annotation) && preg_match('#\n \* @'.$annotation.'(?:( .+?)\.?)?\r?\n \*(?: @|/$)#s', $doc, $notice)) {
+                        self::${$annotation}[$name] = isset($notice[1]) ? preg_replace('#\s*\r?\n \* +#', ' ', $notice[1]) : '';
                    }
                }
            }

-            if (in_array(strtolower($refl->getShortName()), self::$php7Reserved)) {
+            $parentAndTraits = \class_uses($name, false);
+            if ($parent = \get_parent_class($class)) {
+                $parentAndTraits[] = $parent;
+
+                if (!isset(self::$checkedClasses[$parent])) {
+                    $this->checkClass($parent);
+                }
+
+                if (isset(self::$final[$parent])) {
+                    @trigger_error(sprintf('The "%s" class is considered final%s. It may change without further notice as of its next major version. You should not extend it from "%s".', $parent, self::$final[$parent], $name), E_USER_DEPRECATED);
+                }
+            }
+
+            // Detect if the parent is annotated
+            foreach ($parentAndTraits + $this->getOwnInterfaces($name, $parent) as $use) {
+                if (!isset(self::$checkedClasses[$use])) {
+                    $this->checkClass($use);
+                }
+                if (isset(self::$deprecated[$use]) && \strncmp($ns, $use, $len)) {
+                    $type = class_exists($name, false) ? 'class' : (interface_exists($name, false) ? 'interface' : 'trait');
+                    $verb = class_exists($use, false) || interface_exists($name, false) ? 'extends' : (interface_exists($use, false) ? 'implements' : 'uses');
+
+                    @trigger_error(sprintf('The "%s" %s %s "%s" that is deprecated%s.', $name, $type, $verb, $use, self::$deprecated[$use]), E_USER_DEPRECATED);
+                }
+                if (isset(self::$internal[$use]) && \strncmp($ns, $use, $len)) {
+                    @trigger_error(sprintf('The "%s" %s is considered internal%s. It may change without further notice. You should not use it from "%s".', $use, class_exists($use, false) ? 'class' : (interface_exists($use, false) ? 'interface' : 'trait'), self::$internal[$use], $name), E_USER_DEPRECATED);
+                }
+            }
+
+            // Inherit @final and @internal annotations for methods
+            self::$finalMethods[$name] = array();
+            self::$internalMethods[$name] = array();
+            foreach ($parentAndTraits as $use) {
+                foreach (array('finalMethods', 'internalMethods') as $property) {
+                    if (isset(self::${$property}[$use])) {
+                        self::${$property}[$name] = self::${$property}[$name] ? self::${$property}[$use] + self::${$property}[$name] : self::${$property}[$use];
+                    }
+                }
+            }
+
+            $isClass = \class_exists($name, false);
+            foreach ($refl->getMethods(\ReflectionMethod::IS_PUBLIC | \ReflectionMethod::IS_PROTECTED) as $method) {
+                if ($method->class !== $name) {
+                    continue;
+                }
+
+                // Method from a trait
+                if ($method->getFilename() !== $refl->getFileName()) {
+                    continue;
+                }
+
+                if ($isClass && $parent && isset(self::$finalMethods[$parent][$method->name])) {
+                    list($declaringClass, $message) = self::$finalMethods[$parent][$method->name];
+                    @trigger_error(sprintf('The "%s::%s()" method is considered final%s. It may change without further notice as of its next major version. You should not extend it from "%s".', $declaringClass, $method->name, $message, $name), E_USER_DEPRECATED);
+                }
+
+                foreach ($parentAndTraits as $use) {
+                    if (isset(self::$internalMethods[$use][$method->name])) {
+                        list($declaringClass, $message) = self::$internalMethods[$use][$method->name];
+                        if (\strncmp($ns, $declaringClass, $len)) {
+                            @trigger_error(sprintf('The "%s::%s()" method is considered internal%s. It may change without further notice. You should not extend it from "%s".', $declaringClass, $method->name, $message, $name), E_USER_DEPRECATED);
+                        }
+                    }
+                }
+
+                // Detect method annotations
+                if (false === $doc = $method->getDocComment()) {
+                    continue;
+                }
+
+                foreach (array('final', 'internal') as $annotation) {
+                    if (false !== \strpos($doc, $annotation) && preg_match('#\n\s+\* @'.$annotation.'(?:( .+?)\.?)?\r?\n\s+\*(?: @|/$)#s', $doc, $notice)) {
+                        $message = isset($notice[1]) ? preg_replace('#\s*\r?\n \* +#', ' ', $notice[1]) : '';
+                        self::${$annotation.'Methods'}[$name][$method->name] = array($name, $message);
+                    }
+                }
+            }
+
+            if (isset(self::$php7Reserved[\strtolower($refl->getShortName())])) {
                @trigger_error(sprintf('The "%s" class uses the reserved name "%s", it will break on PHP 7 and higher', $name, $refl->getShortName()), E_USER_DEPRECATED);
-            } elseif (preg_match('#\n \* @deprecated (.*?)\r?\n \*(?: @|/$)#s', $refl->getDocComment(), $notice)) {
-                self::$deprecated[$name] = preg_replace('#\s*\r?\n \* +#', ' ', $notice[1]);
-            } else {
-                // Don't trigger deprecations for classes in the same vendor
-                if (2 > $len = 1 + (strpos($name, '\\', 1 + strpos($name, '\\')) ?: strpos($name, '_'))) {
-                    $len = 0;
-                    $ns = '';
-                } else {
-                    switch ($ns = substr($name, 0, $len)) {
-                        case 'Symfony\Bridge\\':
-                        case 'Symfony\Bundle\\':
-                        case 'Symfony\Component\\':
-                            $ns = 'Symfony\\';
-                            $len = strlen($ns);
-                            break;
-                    }
-                }
-
-                if (!$parent || strncmp($ns, $parent, $len)) {
-                    if ($parent && isset(self::$deprecated[$parent]) && strncmp($ns, $parent, $len)) {
-                        @trigger_error(sprintf('The "%s" class extends "%s" that is deprecated %s', $name, $parent, self::$deprecated[$parent]), E_USER_DEPRECATED);
-                    }
-
-                    $parentInterfaces = array();
-                    $deprecatedInterfaces = array();
-                    if ($parent) {
-                        foreach (class_implements($parent) as $interface) {
-                            $parentInterfaces[$interface] = 1;
-                        }
-                    }
-
-                    foreach ($refl->getInterfaceNames() as $interface) {
-                        if (isset(self::$deprecated[$interface]) && strncmp($ns, $interface, $len)) {
-                            $deprecatedInterfaces[] = $interface;
-                        }
-                        foreach (class_implements($interface) as $interface) {
-                            $parentInterfaces[$interface] = 1;
-                        }
-                    }
-
-                    foreach ($deprecatedInterfaces as $interface) {
-                        if (!isset($parentInterfaces[$interface])) {
-                            @trigger_error(sprintf('The "%s" %s "%s" that is deprecated %s', $name, $refl->isInterface() ? 'interface extends' : 'class implements', $interface, self::$deprecated[$interface]), E_USER_DEPRECATED);
-                        }
-                    }
-                }
            }
        }

@@ -262,10 +294,10 @@ class DebugClassLoader
            }
            if (self::$caseCheck) {
                $real = explode('\\', $class.strrchr($file, '.'));
-                $tail = explode(DIRECTORY_SEPARATOR, str_replace('/', DIRECTORY_SEPARATOR, $file));
+                $tail = explode(\DIRECTORY_SEPARATOR, str_replace('/', \DIRECTORY_SEPARATOR, $file));

-                $i = count($tail) - 1;
-                $j = count($real) - 1;
+                $i = \count($tail) - 1;
+                $j = \count($real) - 1;

                while (isset($tail[$i], $real[$j]) && $tail[$i] === $real[$j]) {
                    --$i;
@@ -275,8 +307,8 @@ class DebugClassLoader
                array_splice($tail, 0, $i + 1);
            }
            if (self::$caseCheck && $tail) {
-                $tail = DIRECTORY_SEPARATOR.implode(DIRECTORY_SEPARATOR, $tail);
-                $tailLen = strlen($tail);
+                $tail = \DIRECTORY_SEPARATOR.implode(\DIRECTORY_SEPARATOR, $tail);
+                $tailLen = \strlen($tail);
                $real = $refl->getFileName();

                if (2 === self::$caseCheck) {
@@ -301,7 +333,7 @@ class DebugClassLoader

                            $dir = $real;
                            $k = $kDir;
-                            $i = strlen($dir) - 1;
+                            $i = \strlen($dir) - 1;
                            while (!isset(self::$darwinCache[$k])) {
                                self::$darwinCache[$k] = array($dir, array());
                                self::$darwinCache[$dir] = &self::$darwinCache[$k];
@@ -345,8 +377,33 @@ class DebugClassLoader
                    throw new \RuntimeException(sprintf('Case mismatch between class and real file names: "%s" vs "%s" in "%s".', substr($tail, -$tailLen + 1), substr($real, -$tailLen + 1), substr($real, 0, -$tailLen + 1)));
                }
            }
-
-            return true;
        }
    }
+
+    /**
+     * `class_implements` includes interfaces from the parents so we have to manually exclude them.
+     *
+     * @param string       $class
+     * @param string|false $parent
+     *
+     * @return string[]
+     */
+    private function getOwnInterfaces($class, $parent)
+    {
+        $ownInterfaces = class_implements($class, false);
+
+        if ($parent) {
+            foreach (class_implements($parent, false) as $interface) {
+                unset($ownInterfaces[$interface]);
+            }
+        }
+
+        foreach ($ownInterfaces as $interface) {
+            foreach (class_implements($interface) as $interface) {
+                unset($ownInterfaces[$interface]);
+            }
+        }
+
+        return $ownInterfaces;
+    }
 }
--- a/ErrorHandler.php
+++ b/ErrorHandler.php
@@ -11,17 +11,17 @@

 namespace Symfony\Component\Debug;

-use Psr\Log\LogLevel;
 use Psr\Log\LoggerInterface;
+use Psr\Log\LogLevel;
 use Symfony\Component\Debug\Exception\ContextErrorException;
 use Symfony\Component\Debug\Exception\FatalErrorException;
 use Symfony\Component\Debug\Exception\FatalThrowableError;
 use Symfony\Component\Debug\Exception\OutOfMemoryException;
 use Symfony\Component\Debug\Exception\SilencedErrorContext;
-use Symfony\Component\Debug\FatalErrorHandler\UndefinedFunctionFatalErrorHandler;
-use Symfony\Component\Debug\FatalErrorHandler\UndefinedMethodFatalErrorHandler;
 use Symfony\Component\Debug\FatalErrorHandler\ClassNotFoundFatalErrorHandler;
 use Symfony\Component\Debug\FatalErrorHandler\FatalErrorHandlerInterface;
+use Symfony\Component\Debug\FatalErrorHandler\UndefinedFunctionFatalErrorHandler;
+use Symfony\Component\Debug\FatalErrorHandler\UndefinedMethodFatalErrorHandler;

 /**
 * A generic ErrorHandler for the PHP engine.
@@ -100,6 +100,8 @@ class ErrorHandler
    private static $stackedErrors = array();
    private static $stackedErrorLevels = array();
    private static $toStringException = null;
+    private static $silencedErrorCache = array();
+    private static $silencedErrorCount = 0;
    private static $exitCode = 0;

    /**
@@ -128,14 +130,28 @@ class ErrorHandler
            $handler->isRoot = true;
        }

-        if ($handlerIsNew && is_array($prev) && $prev[0] instanceof self) {
+        if ($handlerIsNew && \is_array($prev) && $prev[0] instanceof self) {
            $handler = $prev[0];
            $replace = false;
        }
-        if ($replace || !$prev) {
-            $handler->setExceptionHandler(set_exception_handler(array($handler, 'handleException')));
-        } else {
+        if (!$replace && $prev) {
            restore_error_handler();
+            $handlerIsRegistered = \is_array($prev) && $handler === $prev[0];
+        } else {
+            $handlerIsRegistered = true;
+        }
+        if (\is_array($prev = set_exception_handler(array($handler, 'handleException'))) && $prev[0] instanceof self) {
+            restore_exception_handler();
+            if (!$handlerIsRegistered) {
+                $handler = $prev[0];
+            } elseif ($handler !== $prev[0] && $replace) {
+                set_exception_handler(array($handler, 'handleException'));
+                $p = $prev[0]->setExceptionHandler(null);
+                $handler->setExceptionHandler($p);
+                $prev[0]->setExceptionHandler($p);
+            }
+        } else {
+            $handler->setExceptionHandler($prev);
        }

        $handler->throwAt(E_ALL & $handler->thrownErrors, true);
@@ -164,7 +180,7 @@ class ErrorHandler
    {
        $loggers = array();

-        if (is_array($levels)) {
+        if (\is_array($levels)) {
            foreach ($levels as $type => $logLevel) {
                if (empty($this->loggers[$type][0]) || $replace || $this->loggers[$type][0] === $this->bootstrappingLogger) {
                    $loggers[$type] = array($logger, $logLevel);
@@ -204,7 +220,7 @@ class ErrorHandler
            if (!isset($prev[$type])) {
                throw new \InvalidArgumentException('Unknown error type: '.$type);
            }
-            if (!is_array($log)) {
+            if (!\is_array($log)) {
                $log = array($log);
            } elseif (!array_key_exists(0, $log)) {
                throw new \InvalidArgumentException('No logger provided');
@@ -337,7 +353,7 @@ class ErrorHandler
    {
        if ($prev !== $this->thrownErrors | $this->loggedErrors) {
            $handler = set_error_handler('var_dump');
-            $handler = is_array($handler) ? $handler[0] : null;
+            $handler = \is_array($handler) ? $handler[0] : null;
            restore_error_handler();
            if ($handler === $this) {
                restore_error_handler();
@@ -367,18 +383,20 @@ class ErrorHandler
    public function handleError($type, $message, $file, $line)
    {
        // Level is the current error reporting level to manage silent error.
+        $level = error_reporting();
+        $silenced = 0 === ($level & $type);
        // Strong errors are not authorized to be silenced.
-        $level = error_reporting() | E_RECOVERABLE_ERROR | E_USER_ERROR | E_DEPRECATED | E_USER_DEPRECATED;
+        $level |= E_RECOVERABLE_ERROR | E_USER_ERROR | E_DEPRECATED | E_USER_DEPRECATED;
        $log = $this->loggedErrors & $type;
        $throw = $this->thrownErrors & $type & $level;
        $type &= $level | $this->screamedErrors;

        if (!$type || (!$log && !$throw)) {
-            return $type && $log;
+            return !$silenced && $type && $log;
        }
        $scope = $this->scopedErrors & $type;

-        if (4 < $numArgs = func_num_args()) {
+        if (4 < $numArgs = \func_num_args()) {
            $context = $scope ? (func_get_arg(4) ?: array()) : array();
            $backtrace = 5 < $numArgs ? func_get_arg(5) : null; // defined on HHVM
        } else {
@@ -407,7 +425,28 @@ class ErrorHandler
            $errorAsException = self::$toStringException;
            self::$toStringException = null;
        } elseif (!$throw && !($type & $level)) {
-            $errorAsException = new SilencedErrorContext($type, $file, $line);
+            if (!isset(self::$silencedErrorCache[$id = $file.':'.$line])) {
+                $lightTrace = $this->tracedErrors & $type ? $this->cleanTrace(debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 3), $type, $file, $line, false) : array();
+                $errorAsException = new SilencedErrorContext($type, $file, $line, $lightTrace);
+            } elseif (isset(self::$silencedErrorCache[$id][$message])) {
+                $lightTrace = null;
+                $errorAsException = self::$silencedErrorCache[$id][$message];
+                ++$errorAsException->count;
+            } else {
+                $lightTrace = array();
+                $errorAsException = null;
+            }
+
+            if (100 < ++self::$silencedErrorCount) {
+                self::$silencedErrorCache = $lightTrace = array();
+                self::$silencedErrorCount = 1;
+            }
+            if ($errorAsException) {
+                self::$silencedErrorCache[$id][$message] = $errorAsException;
+            }
+            if (null === $lightTrace) {
+                return;
+            }
        } else {
            if ($scope) {
                $errorAsException = new ContextErrorException($logMessage, 0, $type, $file, $line, $context);
@@ -418,19 +457,7 @@ class ErrorHandler
            // Clean the trace by removing function arguments and the first frames added by the error handler itself.
            if ($throw || $this->tracedErrors & $type) {
                $backtrace = $backtrace ?: $errorAsException->getTrace();
-                $lightTrace = $backtrace;
-
-                for ($i = 0; isset($backtrace[$i]); ++$i) {
-                    if (isset($backtrace[$i]['file'], $backtrace[$i]['line']) && $backtrace[$i]['line'] === $line && $backtrace[$i]['file'] === $file) {
-                        $lightTrace = array_slice($lightTrace, 1 + $i);
-                        break;
-                    }
-                }
-                if (!($throw || $this->scopedErrors & $type)) {
-                    for ($i = 0; isset($lightTrace[$i]); ++$i) {
-                        unset($lightTrace[$i]['args']);
-                    }
-                }
+                $lightTrace = $this->cleanTrace($backtrace, $type, $file, $line, $throw);
                $this->traceReflector->setValue($errorAsException, $lightTrace);
            } else {
                $this->traceReflector->setValue($errorAsException, array());
@@ -487,19 +514,19 @@ class ErrorHandler
                $this->loggers[$type][0],
                ($type & $level) ? $this->loggers[$type][1] : LogLevel::DEBUG,
                $logMessage,
-                array('exception' => $errorAsException),
+                $errorAsException ? array('exception' => $errorAsException) : array(),
            );
        } else {
            try {
                $this->isRecursive = true;
                $level = ($type & $level) ? $this->loggers[$type][1] : LogLevel::DEBUG;
-                $this->loggers[$type][0]->log($level, $logMessage, array('exception' => $errorAsException));
+                $this->loggers[$type][0]->log($level, $logMessage, $errorAsException ? array('exception' => $errorAsException) : array());
            } finally {
                $this->isRecursive = false;
            }
        }

-        return $type && $log;
+        return !$silenced && $type && $log;
    }

    /**
@@ -519,6 +546,7 @@ class ErrorHandler
            $exception = new FatalThrowableError($exception);
        }
        $type = $exception instanceof FatalErrorException ? $exception->getSeverity() : E_ERROR;
+        $handlerException = null;

        if (($this->loggedErrors & $type) || $exception instanceof FatalThrowableError) {
            if ($exception instanceof FatalErrorException) {
@@ -553,18 +581,21 @@ class ErrorHandler
                }
            }
        }
-        if (empty($this->exceptionHandler)) {
-            throw $exception; // Give back $exception to the native handler
-        }
+        $exceptionHandler = $this->exceptionHandler;
+        $this->exceptionHandler = null;
        try {
-            call_user_func($this->exceptionHandler, $exception);
+            if (null !== $exceptionHandler) {
+                return \call_user_func($exceptionHandler, $exception);
+            }
+            $handlerException = $handlerException ?: $exception;
        } catch (\Exception $handlerException) {
        } catch (\Throwable $handlerException) {
        }
-        if (isset($handlerException)) {
-            $this->exceptionHandler = null;
-            $this->handleException($handlerException);
+        if ($exception === $handlerException) {
+            self::$reservedMemory = null; // Disable the fatal error handler
+            throw $exception; // Give back $exception to the native handler
        }
+        $this->handleException($handlerException);
    }

    /**
@@ -580,15 +611,39 @@ class ErrorHandler
            return;
        }

-        self::$reservedMemory = null;
+        $handler = self::$reservedMemory = null;
+        $handlers = array();
+        $previousHandler = null;
+        $sameHandlerLimit = 10;

-        $handler = set_error_handler('var_dump');
-        $handler = is_array($handler) ? $handler[0] : null;
-        restore_error_handler();
+        while (!\is_array($handler) || !$handler[0] instanceof self) {
+            $handler = set_exception_handler('var_dump');
+            restore_exception_handler();

-        if (!$handler instanceof self) {
+            if (!$handler) {
+                break;
+            }
+            restore_exception_handler();
+
+            if ($handler !== $previousHandler) {
+                array_unshift($handlers, $handler);
+                $previousHandler = $handler;
+            } elseif (0 === --$sameHandlerLimit) {
+                $handler = null;
+                break;
+            }
+        }
+        foreach ($handlers as $h) {
+            set_exception_handler($h);
+        }
+        if (!$handler) {
            return;
        }
+        if ($handler !== $h) {
+            $handler[0]->setExceptionHandler($h);
+        }
+        $handler = $handler[0];
+        $handlers = array();

        if ($exit = null === $error) {
            $error = error_get_last();
@@ -641,17 +696,25 @@ class ErrorHandler
     *
     * The most important feature of this is to prevent
     * autoloading until unstackErrors() is called.
+     *
+     * @deprecated since version 3.4, to be removed in 4.0.
     */
    public static function stackErrors()
    {
+        @trigger_error('Support for stacking errors is deprecated since Symfony 3.4 and will be removed in 4.0.', E_USER_DEPRECATED);
+
        self::$stackedErrorLevels[] = error_reporting(error_reporting() | E_PARSE | E_ERROR | E_CORE_ERROR | E_COMPILE_ERROR);
    }

    /**
     * Unstacks stacked errors and forwards to the logger.
+     *
+     * @deprecated since version 3.4, to be removed in 4.0.
     */
    public static function unstackErrors()
    {
+        @trigger_error('Support for unstacking errors is deprecated since Symfony 3.4 and will be removed in 4.0.', E_USER_DEPRECATED);
+
        $level = array_pop(self::$stackedErrorLevels);

        if (null !== $level) {
@@ -687,4 +750,23 @@ class ErrorHandler
            new ClassNotFoundFatalErrorHandler(),
        );
    }
+
+    private function cleanTrace($backtrace, $type, $file, $line, $throw)
+    {
+        $lightTrace = $backtrace;
+
+        for ($i = 0; isset($backtrace[$i]); ++$i) {
+            if (isset($backtrace[$i]['file'], $backtrace[$i]['line']) && $backtrace[$i]['line'] === $line && $backtrace[$i]['file'] === $file) {
+                $lightTrace = \array_slice($lightTrace, 1 + $i);
+                break;
+            }
+        }
+        if (!($throw || $this->scopedErrors & $type)) {
+            for ($i = 0; isset($lightTrace[$i]); ++$i) {
+                unset($lightTrace[$i]['args'], $lightTrace[$i]['object']);
+            }
+        }
+
+        return $lightTrace;
+    }
 }
--- a/Exception/ClassNotFoundException.php
+++ b/Exception/ClassNotFoundException.php
@@ -26,6 +26,9 @@ class ClassNotFoundException extends FatalErrorException
            $previous->getSeverity(),
            $previous->getFile(),
            $previous->getLine(),
+            null,
+            true,
+            null,
            $previous->getPrevious()
        );
        $this->setTrace($previous->getTrace());
--- a/Exception/ContextErrorException.php
+++ b/Exception/ContextErrorException.php
@@ -33,7 +33,7 @@ class ContextErrorException extends \ErrorException
     */
    public function getContext()
    {
-        @trigger_error(sprintf('The %s class is deprecated since version 3.3 and will be removed in 4.0.', __CLASS__), E_USER_DEPRECATED);
+        @trigger_error(sprintf('The %s class is deprecated since Symfony 3.3 and will be removed in 4.0.', __CLASS__), E_USER_DEPRECATED);

        return $this->context;
    }
--- a/Exception/FatalErrorException.php
+++ b/Exception/FatalErrorException.php
@@ -18,9 +18,9 @@ namespace Symfony\Component\Debug\Exception;
 */
 class FatalErrorException extends \ErrorException
 {
-    public function __construct($message, $code, $severity, $filename, $lineno, $traceOffset = null, $traceArgs = true, array $trace = null)
+    public function __construct($message, $code, $severity, $filename, $lineno, $traceOffset = null, $traceArgs = true, array $trace = null, $previous = null)
    {
-        parent::__construct($message, $code, $severity, $filename, $lineno);
+        parent::__construct($message, $code, $severity, $filename, $lineno, $previous);

        if (null !== $trace) {
            if (!$traceArgs) {
@@ -31,7 +31,7 @@ class FatalErrorException extends \ErrorException

            $this->setTrace($trace);
        } elseif (null !== $traceOffset) {
-            if (function_exists('xdebug_get_function_stack')) {
+            if (\function_exists('xdebug_get_function_stack')) {
                $trace = xdebug_get_function_stack();
                if (0 < $traceOffset) {
                    array_splice($trace, -$traceOffset);
@@ -60,7 +60,7 @@ class FatalErrorException extends \ErrorException

                unset($frame);
                $trace = array_reverse($trace);
-            } elseif (function_exists('symfony_debug_backtrace')) {
+            } elseif (\function_exists('symfony_debug_backtrace')) {
                $trace = symfony_debug_backtrace();
                if (0 < $traceOffset) {
                    array_splice($trace, 0, $traceOffset);
--- a/Exception/FatalThrowableError.php
+++ b/Exception/FatalThrowableError.php
@@ -36,7 +36,8 @@ class FatalThrowableError extends FatalErrorException
            $e->getCode(),
            $severity,
            $e->getFile(),
-            $e->getLine()
+            $e->getLine(),
+            $e->getPrevious()
        );

        $this->setTrace($e->getTrace());
--- a/Exception/FlattenException.php
+++ b/Exception/FlattenException.php
@@ -53,7 +53,7 @@ class FlattenException
        $e->setStatusCode($statusCode);
        $e->setHeaders($headers);
        $e->setTraceFromException($exception);
-        $e->setClass(get_class($exception));
+        $e->setClass(\get_class($exception));
        $e->setFile($exception->getFile());
        $e->setLine($exception->getLine());

@@ -157,7 +157,7 @@ class FlattenException
        return $this->previous;
    }

-    public function setPrevious(FlattenException $previous)
+    public function setPrevious(self $previous)
    {
        $this->previous = $previous;
    }
@@ -228,9 +228,9 @@ class FlattenException
            if ($value instanceof \__PHP_Incomplete_Class) {
                // is_object() returns false on PHP<=7.1
                $result[$key] = array('incomplete-object', $this->getClassNameFromIncomplete($value));
-            } elseif (is_object($value)) {
-                $result[$key] = array('object', get_class($value));
-            } elseif (is_array($value)) {
+            } elseif (\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 {
@@ -238,13 +238,13 @@ class FlattenException
                }
            } elseif (null === $value) {
                $result[$key] = array('null', null);
-            } elseif (is_bool($value)) {
+            } elseif (\is_bool($value)) {
                $result[$key] = array('boolean', $value);
-            } elseif (is_int($value)) {
+            } elseif (\is_int($value)) {
                $result[$key] = array('integer', $value);
-            } elseif (is_float($value)) {
+            } elseif (\is_float($value)) {
                $result[$key] = array('float', $value);
-            } elseif (is_resource($value)) {
+            } elseif (\is_resource($value)) {
                $result[$key] = array('resource', get_resource_type($value));
            } else {
                $result[$key] = array('string', (string) $value);
--- a/Exception/SilencedErrorContext.php
+++ b/Exception/SilencedErrorContext.php
@@ -18,15 +18,20 @@ namespace Symfony\Component\Debug\Exception;
 */
 class SilencedErrorContext implements \JsonSerializable
 {
+    public $count = 1;
+
    private $severity;
    private $file;
    private $line;
+    private $trace;

-    public function __construct($severity, $file, $line)
+    public function __construct($severity, $file, $line, array $trace = array(), $count = 1)
    {
        $this->severity = $severity;
        $this->file = $file;
        $this->line = $line;
+        $this->trace = $trace;
+        $this->count = $count;
    }

    public function getSeverity()
@@ -44,12 +49,19 @@ class SilencedErrorContext implements \JsonSerializable
        return $this->line;
    }

+    public function getTrace()
+    {
+        return $this->trace;
+    }
+
    public function JsonSerialize()
    {
        return array(
            'severity' => $this->severity,
            'file' => $this->file,
            'line' => $this->line,
+            'trace' => $this->trace,
+            'count' => $this->count,
        );
    }
 }
--- a/Exception/UndefinedFunctionException.php
+++ b/Exception/UndefinedFunctionException.php
@@ -26,6 +26,9 @@ class UndefinedFunctionException extends FatalErrorException
            $previous->getSeverity(),
            $previous->getFile(),
            $previous->getLine(),
+            null,
+            true,
+            null,
            $previous->getPrevious()
        );
        $this->setTrace($previous->getTrace());
--- a/Exception/UndefinedMethodException.php
+++ b/Exception/UndefinedMethodException.php
@@ -26,6 +26,9 @@ class UndefinedMethodException extends FatalErrorException
            $previous->getSeverity(),
            $previous->getFile(),
            $previous->getLine(),
+            null,
+            true,
+            null,
            $previous->getPrevious()
        );
        $this->setTrace($previous->getTrace());
--- a/ExceptionHandler.php
+++ b/ExceptionHandler.php
@@ -40,7 +40,7 @@ class ExceptionHandler
    {
        $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->fileLinkFormat = $fileLinkFormat;
    }

    /**
@@ -57,7 +57,7 @@ class ExceptionHandler
        $handler = new static($debug, $charset, $fileLinkFormat);

        $prev = set_exception_handler(array($handler, 'handle'));
-        if (is_array($prev) && $prev[0] instanceof ErrorHandler) {
+        if (\is_array($prev) && $prev[0] instanceof ErrorHandler) {
            restore_exception_handler();
            $prev[0]->setExceptionHandler(array($handler, 'handle'));
        }
@@ -142,7 +142,7 @@ class ExceptionHandler
        $this->caughtBuffer = null;

        try {
-            call_user_func($this->handler, $exception);
+            \call_user_func($this->handler, $exception);
            $this->caughtLength = $caughtLength;
        } catch (\Exception $e) {
            if (!$caughtLength) {
@@ -196,8 +196,6 @@ class ExceptionHandler
    /**
     * Gets the HTML content associated with the given exception.
     *
-     * @param FlattenException $exception A FlattenException instance
-     *
     * @return string The content as a string
     */
    public function getContent(FlattenException $exception)
@@ -210,48 +208,54 @@ class ExceptionHandler
                $title = 'Whoops, looks like something went wrong.';
        }

-        $content = '';
-        if ($this->debug) {
-            try {
-                $count = count($exception->getAllPrevious());
-                $total = $count + 1;
-                foreach ($exception->toArray() as $position => $e) {
-                    $ind = $count - $position + 1;
-                    $class = $this->formatClass($e['class']);
-                    $message = nl2br($this->escapeHtml($e['message']));
-                    $content .= sprintf(<<<'EOF'
-                        <div class="trace trace-as-html">
-                            <table class="trace-details">
-                                <thead class="trace-head"><tr><th>
-                                    <h3 class="trace-class">
-                                        <span class="text-muted">(%d/%d)</span>
-                                        <span class="exception_title">%s</span>
-                                    </h3>
-                                    <p class="break-long-words trace-message">%s</p>
-                                </th></tr></thead>
-                                <tbody>
-EOF
-                        , $ind, $total, $class, $message);
-                    foreach ($e['trace'] as $trace) {
-                        $content .= '<tr><td>';
-                        if ($trace['function']) {
-                            $content .= sprintf('at <span class="trace-class">%s</span><span class="trace-type">%s</span><span class="trace-method">%s</span>(<span class="trace-arguments">%s</span>)', $this->formatClass($trace['class']), $trace['type'], $trace['function'], $this->formatArgs($trace['args']));
-                        }
-                        if (isset($trace['file']) && isset($trace['line'])) {
-                            $content .= $this->formatPath($trace['file'], $trace['line']);
-                        }
-                        $content .= "</td></tr>\n";
-                    }
+        if (!$this->debug) {
+            return <<<EOF
+                <div class="container">
+                    <h1>$title</h1>
+                </div>
+EOF;
+        }

-                    $content .= "</tbody>\n</table>\n</div>\n";
-                }
-            } catch (\Exception $e) {
-                // something nasty happened and we cannot throw an exception anymore
-                if ($this->debug) {
-                    $title = sprintf('Exception thrown when handling an exception (%s: %s)', get_class($e), $this->escapeHtml($e->getMessage()));
-                } else {
-                    $title = 'Whoops, looks like something went wrong.';
+        $content = '';
+        try {
+            $count = \count($exception->getAllPrevious());
+            $total = $count + 1;
+            foreach ($exception->toArray() as $position => $e) {
+                $ind = $count - $position + 1;
+                $class = $this->formatClass($e['class']);
+                $message = nl2br($this->escapeHtml($e['message']));
+                $content .= sprintf(<<<'EOF'
+                    <div class="trace trace-as-html">
+                        <table class="trace-details">
+                            <thead class="trace-head"><tr><th>
+                                <h3 class="trace-class">
+                                    <span class="text-muted">(%d/%d)</span>
+                                    <span class="exception_title">%s</span>
+                                </h3>
+                                <p class="break-long-words trace-message">%s</p>
+                            </th></tr></thead>
+                            <tbody>
+EOF
+                    , $ind, $total, $class, $message);
+                foreach ($e['trace'] as $trace) {
+                    $content .= '<tr><td>';
+                    if ($trace['function']) {
+                        $content .= sprintf('at <span class="trace-class">%s</span><span class="trace-type">%s</span><span class="trace-method">%s</span>(<span class="trace-arguments">%s</span>)', $this->formatClass($trace['class']), $trace['type'], $trace['function'], $this->formatArgs($trace['args']));
+                    }
+                    if (isset($trace['file']) && isset($trace['line'])) {
+                        $content .= $this->formatPath($trace['file'], $trace['line']);
+                    }
+                    $content .= "</td></tr>\n";
                }
+
+                $content .= "</tbody>\n</table>\n</div>\n";
+            }
+        } catch (\Exception $e) {
+            // something nasty happened and we cannot throw an exception anymore
+            if ($this->debug) {
+                $title = sprintf('Exception thrown when handling an exception (%s: %s)', \get_class($e), $this->escapeHtml($e->getMessage()));
+            } else {
+                $title = 'Whoops, looks like something went wrong.';
            }
        }

@@ -276,12 +280,18 @@ EOF;
    /**
     * Gets the stylesheet associated with the given exception.
     *
-     * @param FlattenException $exception A FlattenException instance
-     *
     * @return string The stylesheet as a string
     */
    public function getStylesheet(FlattenException $exception)
    {
+        if (!$this->debug) {
+            return <<<'EOF'
+                body { background-color: #fff; color: #222; font: 16px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; margin: 0; }
+                .container { margin: 30px; max-width: 600px; }
+                h1 { color: #dc3545; font-size: 24px; }
+EOF;
+        }
+
        return <<<'EOF'
            body { background-color: #F9F9F9; color: #222; font: 14px/1.4 Helvetica, Arial, sans-serif; margin: 0; padding-bottom: 45px; }

@@ -310,22 +320,21 @@ EOF;
            .exception-message { flex-grow: 1; padding: 30px 0; }
            .exception-message, .exception-message a { color: #FFF; font-size: 21px; font-weight: 400; margin: 0; }
            .exception-message.long { font-size: 18px; }
-            .exception-message a { text-decoration: none; }
-            .exception-message a:hover { text-decoration: underline; }
+            .exception-message a { border-bottom: 1px solid rgba(255, 255, 255, 0.5); font-size: inherit; text-decoration: none; }
+            .exception-message a:hover { border-bottom-color: #ffffff; }

            .exception-illustration { flex-basis: 111px; flex-shrink: 0; height: 66px; margin-left: 15px; opacity: .7; }

            .trace + .trace { margin-top: 30px; }
-            .trace-head { -webkit-user-select: none; -moz-user-select: none; -ms-user-select: none; user-select: none; }
            .trace-head .trace-class { color: #222; font-size: 18px; font-weight: bold; line-height: 1.3; margin: 0; position: relative; }

            .trace-message { font-size: 14px; font-weight: normal; margin: .5em 0 0; }

-            .trace-file-path, .trace-file-path a { margin-top: 3px; color: #999; color: #795da3; color: #B0413E; color: #222; font-size: 13px; }
+            .trace-file-path, .trace-file-path a { color: #222; margin-top: 3px; font-size: 13px; }
            .trace-class { color: #B0413E; }
            .trace-type { padding: 0 2px; }
-            .trace-method { color: #B0413E; color: #222; font-weight: bold; color: #B0413E; }
-            .trace-arguments { color: #222; color: #999; font-weight: normal; color: #795da3; color: #777; padding-left: 2px; }
+            .trace-method { color: #B0413E; font-weight: bold; }
+            .trace-arguments { color: #777; font-weight: normal; padding-left: 2px; }

            @media (min-width: 575px) {
                .hidden-xs-down { display: initial; }
@@ -360,13 +369,29 @@ EOF;
    private function formatPath($path, $line)
    {
        $file = $this->escapeHtml(preg_match('#[^/\\\\]*+$#', $path, $file) ? $file[0] : $path);
-        $fmt = $this->fileLinkFormat;
+        $fmt = $this->fileLinkFormat ?: ini_get('xdebug.file_link_format') ?: get_cfg_var('xdebug.file_link_format');

-        if ($fmt && $link = is_string($fmt) ? strtr($fmt, array('%f' => $path, '%l' => $line)) : $fmt->format($path, $line)) {
-            return sprintf('<span class="block trace-file-path">in <a href="%s" title="Go to source">%s (line %d)</a></span>', $this->escapeHtml($link), $file, $line);
+        if (!$fmt) {
+            return sprintf('<span class="block trace-file-path">in <a title="%s%3$s"><strong>%s</strong>%s</a></span>', $this->escapeHtml($path), $file, 0 < $line ? ' line '.$line : '');
        }

-        return sprintf('<span class="block trace-file-path">in <a title="%s line %3$d"><strong>%s</strong> (line %d)</a></span>', $this->escapeHtml($path), $file, $line);
+        if (\is_string($fmt)) {
+            $i = strpos($f = $fmt, '&', max(strrpos($f, '%f'), strrpos($f, '%l'))) ?: \strlen($f);
+            $fmt = array(substr($f, 0, $i)) + preg_split('/&([^>]++)>/', substr($f, $i), -1, PREG_SPLIT_DELIM_CAPTURE);
+
+            for ($i = 1; isset($fmt[$i]); ++$i) {
+                if (0 === strpos($path, $k = $fmt[$i++])) {
+                    $path = substr_replace($path, $fmt[$i], 0, \strlen($k));
+                    break;
+                }
+            }
+
+            $link = strtr($fmt[0], array('%f' => $path, '%l' => $line));
+        } else {
+            $link = $fmt->format($path, $line);
+        }
+
+        return sprintf('<span class="block trace-file-path">in <a href="%s" title="Go to source"><strong>%s</string>%s</a></span>', $this->escapeHtml($link), $file, 0 < $line ? ' line '.$line : '');
    }

    /**
@@ -383,7 +408,7 @@ EOF;
            if ('object' === $item[0]) {
                $formattedValue = sprintf('<em>object</em>(%s)', $this->formatClass($item[1]));
            } elseif ('array' === $item[0]) {
-                $formattedValue = sprintf('<em>array</em>(%s)', is_array($item[1]) ? $this->formatArgs($item[1]) : $item[1]);
+                $formattedValue = sprintf('<em>array</em>(%s)', \is_array($item[1]) ? $this->formatArgs($item[1]) : $item[1]);
            } elseif ('null' === $item[0]) {
                $formattedValue = '<em>null</em>';
            } elseif ('boolean' === $item[0]) {
@@ -394,7 +419,7 @@ EOF;
                $formattedValue = str_replace("\n", '', $this->escapeHtml(var_export($item[1], true)));
            }

-            $result[] = is_int($key) ? $formattedValue : sprintf("'%s' => %s", $key, $formattedValue);
+            $result[] = \is_int($key) ? $formattedValue : sprintf("'%s' => %s", $this->escapeHtml($key), $formattedValue);
        }

        return implode(', ', $result);
--- a/FatalErrorHandler/ClassNotFoundFatalErrorHandler.php
+++ b/FatalErrorHandler/ClassNotFoundFatalErrorHandler.php
@@ -11,11 +11,11 @@

 namespace Symfony\Component\Debug\FatalErrorHandler;

-use Symfony\Component\Debug\Exception\ClassNotFoundException;
-use Symfony\Component\Debug\Exception\FatalErrorException;
-use Symfony\Component\Debug\DebugClassLoader;
 use Composer\Autoload\ClassLoader as ComposerClassLoader;
 use Symfony\Component\ClassLoader\ClassLoader as SymfonyClassLoader;
+use Symfony\Component\Debug\DebugClassLoader;
+use Symfony\Component\Debug\Exception\ClassNotFoundException;
+use Symfony\Component\Debug\Exception\FatalErrorException;

 /**
 * ErrorHandler for classes that do not exist.
@@ -29,9 +29,9 @@ class ClassNotFoundFatalErrorHandler implements FatalErrorHandlerInterface
     */
    public function handleError(array $error, FatalErrorException $exception)
    {
-        $messageLen = strlen($error['message']);
+        $messageLen = \strlen($error['message']);
        $notFoundSuffix = '\' not found';
-        $notFoundSuffixLen = strlen($notFoundSuffix);
+        $notFoundSuffixLen = \strlen($notFoundSuffix);
        if ($notFoundSuffixLen > $messageLen) {
            return;
        }
@@ -42,7 +42,7 @@ class ClassNotFoundFatalErrorHandler implements FatalErrorHandlerInterface

        foreach (array('class', 'interface', 'trait') as $typeName) {
            $prefix = ucfirst($typeName).' \'';
-            $prefixLen = strlen($prefix);
+            $prefixLen = \strlen($prefix);
            if (0 !== strpos($error['message'], $prefix)) {
                continue;
            }
@@ -85,7 +85,7 @@ class ClassNotFoundFatalErrorHandler implements FatalErrorHandlerInterface
     */
    private function getClassCandidates($class)
    {
-        if (!is_array($functions = spl_autoload_functions())) {
+        if (!\is_array($functions = spl_autoload_functions())) {
            return array();
        }

@@ -93,14 +93,14 @@ class ClassNotFoundFatalErrorHandler implements FatalErrorHandlerInterface
        $classes = array();

        foreach ($functions as $function) {
-            if (!is_array($function)) {
+            if (!\is_array($function)) {
                continue;
            }
            // get class loaders wrapped by DebugClassLoader
            if ($function[0] instanceof DebugClassLoader) {
                $function = $function[0]->getClassLoader();

-                if (!is_array($function)) {
+                if (!\is_array($function)) {
                    continue;
                }
            }
@@ -133,7 +133,7 @@ class ClassNotFoundFatalErrorHandler implements FatalErrorHandlerInterface
     */
    private function findClassInPath($path, $class, $prefix)
    {
-        if (!$path = realpath($path.'/'.strtr($prefix, '\\_', '//')) ?: realpath($path.'/'.dirname(strtr($prefix, '\\_', '//'))) ?: realpath($path)) {
+        if (!$path = realpath($path.'/'.strtr($prefix, '\\_', '//')) ?: realpath($path.'/'.\dirname(strtr($prefix, '\\_', '//'))) ?: realpath($path)) {
            return array();
        }

@@ -159,7 +159,7 @@ class ClassNotFoundFatalErrorHandler implements FatalErrorHandlerInterface
    {
        $candidates = array(
            // namespaced class
-            $namespacedClass = str_replace(array($path.DIRECTORY_SEPARATOR, '.php', '/'), array('', '', '\\'), $file),
+            $namespacedClass = str_replace(array($path.\DIRECTORY_SEPARATOR, '.php', '/'), array('', '', '\\'), $file),
            // namespaced class (with target dir)
            $prefix.$namespacedClass,
            // namespaced class (with target dir and separator)
--- a/FatalErrorHandler/UndefinedFunctionFatalErrorHandler.php
+++ b/FatalErrorHandler/UndefinedFunctionFatalErrorHandler.php
@@ -11,8 +11,8 @@

 namespace Symfony\Component\Debug\FatalErrorHandler;

-use Symfony\Component\Debug\Exception\UndefinedFunctionException;
 use Symfony\Component\Debug\Exception\FatalErrorException;
+use Symfony\Component\Debug\Exception\UndefinedFunctionException;

 /**
 * ErrorHandler for undefined functions.
@@ -26,9 +26,9 @@ class UndefinedFunctionFatalErrorHandler implements FatalErrorHandlerInterface
     */
    public function handleError(array $error, FatalErrorException $exception)
    {
-        $messageLen = strlen($error['message']);
+        $messageLen = \strlen($error['message']);
        $notFoundSuffix = '()';
-        $notFoundSuffixLen = strlen($notFoundSuffix);
+        $notFoundSuffixLen = \strlen($notFoundSuffix);
        if ($notFoundSuffixLen > $messageLen) {
            return;
        }
@@ -38,7 +38,7 @@ class UndefinedFunctionFatalErrorHandler implements FatalErrorHandlerInterface
        }

        $prefix = 'Call to undefined function ';
-        $prefixLen = strlen($prefix);
+        $prefixLen = \strlen($prefix);
        if (0 !== strpos($error['message'], $prefix)) {
            return;
        }
--- a/FatalErrorHandler/UndefinedMethodFatalErrorHandler.php
+++ b/FatalErrorHandler/UndefinedMethodFatalErrorHandler.php
@@ -44,7 +44,7 @@ class UndefinedMethodFatalErrorHandler implements FatalErrorHandlerInterface
        $candidates = array();
        foreach ($methods as $definedMethodName) {
            $lev = levenshtein($methodName, $definedMethodName);
-            if ($lev <= strlen($methodName) / 3 || false !== strpos($definedMethodName, $methodName)) {
+            if ($lev <= \strlen($methodName) / 3 || false !== strpos($definedMethodName, $methodName)) {
                $candidates[] = $definedMethodName;
            }
        }
--- a/2
+++ b/2
@@ -1,4 +1,4 @@
-Copyright (c) 2004-2017 Fabien Potencier
+Copyright (c) 2004-2018 Fabien Potencier

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
--- a/Resources/ext/tests/001.phpt
+++ b/Resources/ext/tests/001.phpt
@@ -1,7 +1,9 @@
 --TEST--
 Test symfony_zval_info API
 --SKIPIF--
-<?php if (!extension_loaded('symfony_debug')) print 'skip'; ?>
+<?php if (!extension_loaded('symfony_debug')) {
+    echo 'skip';
+} ?>
 --FILE--
 <?php

--- a/Resources/ext/tests/002.phpt
+++ b/Resources/ext/tests/002.phpt
@@ -1,7 +1,9 @@
 --TEST--
 Test symfony_debug_backtrace in case of fatal error
 --SKIPIF--
-<?php if (!extension_loaded('symfony_debug')) print 'skip'; ?>
+<?php if (!extension_loaded('symfony_debug')) {
+    echo 'skip';
+} ?>
 --FILE--
 <?php

--- a/Resources/ext/tests/002_1.phpt
+++ b/Resources/ext/tests/002_1.phpt
@@ -1,7 +1,9 @@
 --TEST--
 Test symfony_debug_backtrace in case of non fatal error
 --SKIPIF--
-<?php if (!extension_loaded('symfony_debug')) print 'skip'; ?>
+<?php if (!extension_loaded('symfony_debug')) {
+    echo 'skip';
+} ?>
 --FILE--
 <?php

--- a/Resources/ext/tests/003.phpt
+++ b/Resources/ext/tests/003.phpt
@@ -1,7 +1,9 @@
 --TEST--
 Test ErrorHandler in case of fatal error
 --SKIPIF--
-<?php if (!extension_loaded('symfony_debug')) print 'skip'; ?>
+<?php if (!extension_loaded('symfony_debug')) {
+    echo 'skip';
+} ?>
 --FILE--
 <?php

@@ -43,7 +45,7 @@ function foo()
 $handler = ErrorHandler::register();
 $handler->setExceptionHandler('print_r');

-if (function_exists('xdebug_disable')) {
+if (\function_exists('xdebug_disable')) {
    xdebug_disable();
 }

--- a/Tests/DebugClassLoaderTest.php
+++ b/Tests/DebugClassLoaderTest.php
@@ -59,9 +59,26 @@ class DebugClassLoaderTest extends TestCase
        $this->fail('DebugClassLoader did not register');
    }

+    /**
+     * @expectedException \Exception
+     * @expectedExceptionMessage boo
+     */
+    public function testThrowingClass()
+    {
+        try {
+            class_exists(__NAMESPACE__.'\Fixtures\Throwing');
+            $this->fail('Exception expected');
+        } catch (\Exception $e) {
+            $this->assertSame('boo', $e->getMessage());
+        }
+
+        // the second call also should throw
+        class_exists(__NAMESPACE__.'\Fixtures\Throwing');
+    }
+
    public function testUnsilencing()
    {
-        if (PHP_VERSION_ID >= 70000) {
+        if (\PHP_VERSION_ID >= 70000) {
            $this->markTestSkipped('PHP7 throws exceptions, unsilencing is not required anymore.');
        }
        if (defined('HHVM_VERSION')) {
@@ -109,7 +126,7 @@ class DebugClassLoaderTest extends TestCase
        } catch (\ErrorException $exception) {
            // if an exception is thrown, the test passed
            $this->assertStringStartsWith(__FILE__, $exception->getFile());
-            if (PHP_VERSION_ID < 70000) {
+            if (\PHP_VERSION_ID < 70000) {
                $this->assertRegExp('/^Runtime Notice: Declaration/', $exception->getMessage());
                $this->assertEquals(E_STRICT, $exception->getSeverity());
            } else {
@@ -124,6 +141,7 @@ class DebugClassLoaderTest extends TestCase

    /**
     * @expectedException \RuntimeException
+     * @expectedExceptionMessage Case mismatch between loaded and declared class names
     */
    public function testNameCaseMismatch()
    {
@@ -145,6 +163,7 @@ class DebugClassLoaderTest extends TestCase

    /**
     * @expectedException \RuntimeException
+     * @expectedExceptionMessage Case mismatch between loaded and declared class names
     */
    public function testPsr4CaseMismatch()
    {
@@ -245,7 +264,7 @@ class DebugClassLoaderTest extends TestCase

    public function testReservedForPhp7()
    {
-        if (PHP_VERSION_ID >= 70000) {
+        if (\PHP_VERSION_ID >= 70000) {
            $this->markTestSkipped('PHP7 already prevents using reserved names.');
        }

@@ -312,6 +331,42 @@ class DebugClassLoaderTest extends TestCase

        $this->assertSame($xError, $lastError);
    }
+
+    public function testExtendedDeprecatedMethodDoesntTriggerAnyNotice()
+    {
+        set_error_handler(function () { return false; });
+        $e = error_reporting(0);
+        trigger_error('', E_USER_NOTICE);
+
+        class_exists('Test\\'.__NAMESPACE__.'\\ExtendsAnnotatedClass', true);
+
+        error_reporting($e);
+        restore_error_handler();
+
+        $lastError = error_get_last();
+        unset($lastError['file'], $lastError['line']);
+
+        $this->assertSame(array('type' => E_USER_NOTICE, 'message' => ''), $lastError);
+    }
+
+    public function testInternalsUse()
+    {
+        $deprecations = array();
+        set_error_handler(function ($type, $msg) use (&$deprecations) { $deprecations[] = $msg; });
+        $e = error_reporting(E_USER_DEPRECATED);
+
+        class_exists('Test\\'.__NAMESPACE__.'\\ExtendsInternals', true);
+
+        error_reporting($e);
+        restore_error_handler();
+
+        $this->assertSame($deprecations, array(
+            'The "Symfony\Component\Debug\Tests\Fixtures\InternalClass" class is considered internal since version 3.4. It may change without further notice. You should not use it from "Test\Symfony\Component\Debug\Tests\ExtendsInternalsParent".',
+            'The "Symfony\Component\Debug\Tests\Fixtures\InternalInterface" interface is considered internal. It may change without further notice. You should not use it from "Test\Symfony\Component\Debug\Tests\ExtendsInternalsParent".',
+            'The "Symfony\Component\Debug\Tests\Fixtures\InternalTrait" trait is considered internal. It may change without further notice. You should not use it from "Test\Symfony\Component\Debug\Tests\ExtendsInternals".',
+            'The "Symfony\Component\Debug\Tests\Fixtures\InternalTrait2::internalMethod()" method is considered internal since version 3.4. It may change without further notice. You should not extend it from "Test\Symfony\Component\Debug\Tests\ExtendsInternals".',
+        ));
+    }
 }

 class ClassLoader
@@ -335,22 +390,12 @@ class ClassLoader
            eval('namespace '.__NAMESPACE__.'; class TestingStacking { function foo() {} }');
        } elseif (__NAMESPACE__.'\TestingCaseMismatch' === $class) {
            eval('namespace '.__NAMESPACE__.'; class TestingCaseMisMatch {}');
-        } elseif (__NAMESPACE__.'\Fixtures\CaseMismatch' === $class) {
-            return $fixtureDir.'CaseMismatch.php';
        } elseif (__NAMESPACE__.'\Fixtures\Psr4CaseMismatch' === $class) {
            return $fixtureDir.'psr4'.DIRECTORY_SEPARATOR.'Psr4CaseMismatch.php';
        } elseif (__NAMESPACE__.'\Fixtures\NotPSR0' === $class) {
            return $fixtureDir.'reallyNotPsr0.php';
        } elseif (__NAMESPACE__.'\Fixtures\NotPSR0bis' === $class) {
            return $fixtureDir.'notPsr0Bis.php';
-        } elseif (__NAMESPACE__.'\Fixtures\DeprecatedInterface' === $class) {
-            return $fixtureDir.'DeprecatedInterface.php';
-        } elseif (__NAMESPACE__.'\Fixtures\FinalClass' === $class) {
-            return $fixtureDir.'FinalClass.php';
-        } elseif (__NAMESPACE__.'\Fixtures\FinalMethod' === $class) {
-            return $fixtureDir.'FinalMethod.php';
-        } elseif (__NAMESPACE__.'\Fixtures\ExtendedFinalMethod' === $class) {
-            return $fixtureDir.'ExtendedFinalMethod.php';
        } elseif ('Symfony\Bridge\Debug\Tests\Fixtures\ExtendsDeprecatedParent' === $class) {
            eval('namespace Symfony\Bridge\Debug\Tests\Fixtures; class ExtendsDeprecatedParent extends \\'.__NAMESPACE__.'\Fixtures\DeprecatedClass {}');
        } elseif ('Test\\'.__NAMESPACE__.'\DeprecatedParentClass' === $class) {
@@ -363,6 +408,18 @@ class ClassLoader
            eval('namespace Test\\'.__NAMESPACE__.'; class Float {}');
        } elseif ('Test\\'.__NAMESPACE__.'\ExtendsFinalClass' === $class) {
            eval('namespace Test\\'.__NAMESPACE__.'; class ExtendsFinalClass extends \\'.__NAMESPACE__.'\Fixtures\FinalClass {}');
+        } elseif ('Test\\'.__NAMESPACE__.'\ExtendsAnnotatedClass' === $class) {
+            eval('namespace Test\\'.__NAMESPACE__.'; class ExtendsAnnotatedClass extends \\'.__NAMESPACE__.'\Fixtures\AnnotatedClass {
+                public function deprecatedMethod() { }
+            }');
+        } elseif ('Test\\'.__NAMESPACE__.'\ExtendsInternals' === $class) {
+            eval('namespace Test\\'.__NAMESPACE__.'; class ExtendsInternals extends ExtendsInternalsParent {
+                use \\'.__NAMESPACE__.'\Fixtures\InternalTrait;
+
+                public function internalMethod() { }
+            }');
+        } elseif ('Test\\'.__NAMESPACE__.'\ExtendsInternalsParent' === $class) {
+            eval('namespace Test\\'.__NAMESPACE__.'; class ExtendsInternalsParent extends \\'.__NAMESPACE__.'\Fixtures\InternalClass implements \\'.__NAMESPACE__.'\Fixtures\InternalInterface { }');
        }
    }
 }
--- a/Tests/ErrorHandlerTest.php
+++ b/Tests/ErrorHandlerTest.php
@@ -35,7 +35,7 @@ class ErrorHandlerTest extends TestCase

            $newHandler = new ErrorHandler();

-            $this->assertSame($newHandler, ErrorHandler::register($newHandler, false));
+            $this->assertSame($handler, ErrorHandler::register($newHandler, false));
            $h = set_error_handler('var_dump');
            restore_error_handler();
            $this->assertSame(array($handler, 'handleError'), $h);
@@ -65,6 +65,30 @@ class ErrorHandlerTest extends TestCase
        }
    }

+    public function testErrorGetLast()
+    {
+        $handler = ErrorHandler::register();
+        $logger = $this->getMockBuilder('Psr\Log\LoggerInterface')->getMock();
+        $handler->setDefaultLogger($logger);
+        $handler->screamAt(E_ALL);
+
+        try {
+            @trigger_error('Hello', E_USER_WARNING);
+            $expected = array(
+                'type' => E_USER_WARNING,
+                'message' => 'Hello',
+                'file' => __FILE__,
+                'line' => __LINE__ - 5,
+            );
+            $this->assertSame($expected, error_get_last());
+        } catch (\Exception $e) {
+            restore_error_handler();
+            restore_exception_handler();
+
+            throw $e;
+        }
+    }
+
    public function testNotice()
    {
        ErrorHandler::register();
@@ -98,8 +122,6 @@ class ErrorHandlerTest extends TestCase
    // dummy function to test trace in error handler.
    private static function triggerNotice($that)
    {
-        // dummy variable to check for in error handler.
-        $foobar = 123;
        $that->assertSame('', $foo.$foo.$bar);
    }

@@ -221,12 +243,17 @@ class ErrorHandlerTest extends TestCase

            $logger = $this->getMockBuilder('Psr\Log\LoggerInterface')->getMock();

-            $logArgCheck = function ($level, $message, $context) {
+            $line = null;
+            $logArgCheck = function ($level, $message, $context) use (&$line) {
                $this->assertEquals('Notice: Undefined variable: undefVar', $message);
                $this->assertArrayHasKey('exception', $context);
                $exception = $context['exception'];
                $this->assertInstanceOf(SilencedErrorContext::class, $exception);
                $this->assertSame(E_NOTICE, $exception->getSeverity());
+                $this->assertSame(__FILE__, $exception->getFile());
+                $this->assertSame($line, $exception->getLine());
+                $this->assertNotEmpty($exception->getTrace());
+                $this->assertSame(1, $exception->count);
            };

            $logger
@@ -239,6 +266,7 @@ class ErrorHandlerTest extends TestCase
            $handler->setDefaultLogger($logger, E_NOTICE);
            $handler->screamAt(E_NOTICE);
            unset($undefVar);
+            $line = __LINE__ + 1;
            @$undefVar++;

            restore_error_handler();
@@ -295,6 +323,9 @@ class ErrorHandlerTest extends TestCase
        @$handler->handleError(E_USER_DEPRECATED, 'Foo deprecation', __FILE__, __LINE__, array());
    }

+    /**
+     * @group no-hhvm
+     */
    public function testHandleException()
    {
        try {
@@ -336,6 +367,9 @@ class ErrorHandlerTest extends TestCase
        }
    }

+    /**
+     * @group legacy
+     */
    public function testErrorStacking()
    {
        try {
@@ -416,6 +450,9 @@ class ErrorHandlerTest extends TestCase
        $handler->setLoggers(array(E_DEPRECATED => array($mockLogger, LogLevel::WARNING)));
    }

+    /**
+     * @group no-hhvm
+     */
    public function testSettingLoggerWhenExceptionIsBuffered()
    {
        $bootLogger = new BufferingLogger();
@@ -435,6 +472,9 @@ class ErrorHandlerTest extends TestCase
        $handler->handleException($exception);
    }

+    /**
+     * @group no-hhvm
+     */
    public function testHandleFatalError()
    {
        try {
@@ -484,7 +524,7 @@ class ErrorHandlerTest extends TestCase

        $handler = new ErrorHandler();
        $handler->setExceptionHandler(function () use (&$args) {
-            $args = func_get_args();
+            $args = \func_get_args();
        });

        $handler->handleException($exception);
@@ -493,6 +533,9 @@ class ErrorHandlerTest extends TestCase
        $this->assertStringStartsWith("Attempted to load class \"Foo\" from the global namespace.\nDid you forget a \"use\" statement", $args[0]->getMessage());
    }

+    /**
+     * @group no-hhvm
+     */
    public function testHandleFatalErrorOnHHVM()
    {
        try {
@@ -519,11 +562,25 @@ class ErrorHandlerTest extends TestCase
                'backtrace' => array(456),
            );

-            call_user_func_array(array($handler, 'handleError'), $error);
+            \call_user_func_array(array($handler, 'handleError'), $error);
            $handler->handleFatalError($error);
        } finally {
            restore_error_handler();
            restore_exception_handler();
        }
    }
+
+    /**
+     * @expectedException \Exception
+     * @group no-hhvm
+     */
+    public function testCustomExceptionHandler()
+    {
+        $handler = new ErrorHandler();
+        $handler->setExceptionHandler(function ($e) use ($handler) {
+            $handler->handleException($e);
+        });
+
+        $handler->handleException(new \Exception());
+    }
 }
--- a/Tests/Exception/FlattenExceptionTest.php
+++ b/Tests/Exception/FlattenExceptionTest.php
@@ -14,19 +14,19 @@ namespace Symfony\Component\Debug\Tests\Exception;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Debug\Exception\FlattenException;
 use Symfony\Component\HttpFoundation\Exception\SuspiciousOperationException;
-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\BadRequestHttpException;
+use Symfony\Component\HttpKernel\Exception\ConflictHttpException;
 use Symfony\Component\HttpKernel\Exception\GoneHttpException;
 use Symfony\Component\HttpKernel\Exception\LengthRequiredHttpException;
+use Symfony\Component\HttpKernel\Exception\MethodNotAllowedHttpException;
+use Symfony\Component\HttpKernel\Exception\NotAcceptableHttpException;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 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\UnauthorizedHttpException;
 use Symfony\Component\HttpKernel\Exception\UnsupportedMediaTypeHttpException;

 class FlattenExceptionTest extends TestCase
@@ -111,7 +111,7 @@ class FlattenExceptionTest extends TestCase
    /**
     * @dataProvider flattenDataProvider
     */
-    public function testFlattenHttpException(\Exception $exception, $statusCode)
+    public function testFlattenHttpException(\Exception $exception)
    {
        $flattened = FlattenException::create($exception);
        $flattened2 = FlattenException::create($exception);
@@ -126,7 +126,7 @@ class FlattenExceptionTest extends TestCase
    /**
     * @dataProvider flattenDataProvider
     */
-    public function testPrevious(\Exception $exception, $statusCode)
+    public function testPrevious(\Exception $exception)
    {
        $flattened = FlattenException::create($exception);
        $flattened2 = FlattenException::create($exception);
@@ -173,7 +173,7 @@ class FlattenExceptionTest extends TestCase
    /**
     * @dataProvider flattenDataProvider
     */
-    public function testToArray(\Exception $exception, $statusCode)
+    public function testToArray(\Exception $exception)
    {
        $flattened = FlattenException::create($exception);
        $flattened->setTrace(array(), 'foo.php', 123);
@@ -193,7 +193,7 @@ class FlattenExceptionTest extends TestCase
    public function flattenDataProvider()
    {
        return array(
-            array(new \Exception('test', 123), 500),
+            array(new \Exception('test', 123)),
        );
    }

@@ -236,7 +236,7 @@ class FlattenExceptionTest extends TestCase
        $this->assertSame(array('object', 'stdClass'), $array[$i++]);
        $this->assertSame(array('object', 'Symfony\Component\HttpKernel\Exception\NotFoundHttpException'), $array[$i++]);
        $this->assertSame(array('incomplete-object', 'BogusTestClass'), $array[$i++]);
-        $this->assertSame(array('resource', defined('HHVM_VERSION') ? 'Directory' : 'stream'), $array[$i++]);
+        $this->assertSame(array('resource', \defined('HHVM_VERSION') ? 'Directory' : 'stream'), $array[$i++]);
        $this->assertSame(array('resource', 'stream'), $array[$i++]);

        $args = $array[$i++];
@@ -261,6 +261,7 @@ class FlattenExceptionTest extends TestCase

    public function testRecursionInArguments()
    {
+        $a = null;
        $a = array('foo', array(2, &$a));
        $exception = $this->createException($a);

--- a/Tests/ExceptionHandlerTest.php
+++ b/Tests/ExceptionHandlerTest.php
@@ -12,10 +12,10 @@
 namespace Symfony\Component\Debug\Tests;

 use PHPUnit\Framework\TestCase;
-use Symfony\Component\Debug\ExceptionHandler;
 use Symfony\Component\Debug\Exception\OutOfMemoryException;
-use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+use Symfony\Component\Debug\ExceptionHandler;
 use Symfony\Component\HttpKernel\Exception\MethodNotAllowedHttpException;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;

 require_once __DIR__.'/HeaderMock.php';

--- a/Tests/FatalErrorHandler/ClassNotFoundFatalErrorHandlerTest.php
+++ b/Tests/FatalErrorHandler/ClassNotFoundFatalErrorHandlerTest.php
@@ -11,18 +11,18 @@

 namespace Symfony\Component\Debug\Tests\FatalErrorHandler;

+use Composer\Autoload\ClassLoader as ComposerClassLoader;
 use PHPUnit\Framework\TestCase;
+use Symfony\Component\Debug\DebugClassLoader;
 use Symfony\Component\Debug\Exception\FatalErrorException;
 use Symfony\Component\Debug\FatalErrorHandler\ClassNotFoundFatalErrorHandler;
-use Symfony\Component\Debug\DebugClassLoader;
-use Composer\Autoload\ClassLoader as ComposerClassLoader;

 class ClassNotFoundFatalErrorHandlerTest extends TestCase
 {
    public static function setUpBeforeClass()
    {
        foreach (spl_autoload_functions() as $function) {
-            if (!is_array($function)) {
+            if (!\is_array($function)) {
                continue;
            }

@@ -32,7 +32,7 @@ class ClassNotFoundFatalErrorHandlerTest extends TestCase
            }

            if ($function[0] instanceof ComposerClassLoader) {
-                $function[0]->add('Symfony_Component_Debug_Tests_Fixtures', dirname(dirname(dirname(dirname(dirname(__DIR__))))));
+                $function[0]->add('Symfony_Component_Debug_Tests_Fixtures', \dirname(\dirname(\dirname(\dirname(\dirname(__DIR__))))));
                break;
            }
        }
--- a/Tests/Fixtures/AnnotatedClass.php
+++ b/Tests/Fixtures/AnnotatedClass.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Symfony\Component\Debug\Tests\Fixtures;
+
+class AnnotatedClass
+{
+    /**
+     * @deprecated since version 3.4.
+     */
+    public function deprecatedMethod()
+    {
+    }
+}
--- a/Tests/Fixtures/DeprecatedClass.php
+++ b/Tests/Fixtures/DeprecatedClass.php
@@ -4,7 +4,7 @@ namespace Symfony\Component\Debug\Tests\Fixtures;

 /**
 * @deprecated but this is a test
- *             deprecation notice.
+ *             deprecation notice
 * @foobar
 */
 class DeprecatedClass
--- a/Tests/Fixtures/DeprecatedInterface.php
+++ b/Tests/Fixtures/DeprecatedInterface.php
@@ -4,7 +4,7 @@ namespace Symfony\Component\Debug\Tests\Fixtures;

 /**
 * @deprecated but this is a test
- *             deprecation notice.
+ *             deprecation notice
 * @foobar
 */
 interface DeprecatedInterface
--- a/Tests/Fixtures/InternalClass.php
+++ b/Tests/Fixtures/InternalClass.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace Symfony\Component\Debug\Tests\Fixtures;
+
+/**
+ * @internal since version 3.4.
+ */
+class InternalClass
+{
+    use InternalTrait2;
+
+    public function usedInInternalClass()
+    {
+    }
+}
--- a/Tests/Fixtures/InternalInterface.php
+++ b/Tests/Fixtures/InternalInterface.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace Symfony\Component\Debug\Tests\Fixtures;
+
+/**
+ * @internal
+ */
+interface InternalInterface
+{
+}
--- a/Tests/Fixtures/InternalTrait.php
+++ b/Tests/Fixtures/InternalTrait.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace Symfony\Component\Debug\Tests\Fixtures;
+
+/**
+ * @internal
+ */
+trait InternalTrait
+{
+}
--- a/Tests/Fixtures/InternalTrait2.php
+++ b/Tests/Fixtures/InternalTrait2.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Symfony\Component\Debug\Tests\Fixtures;
+
+/**
+ * @internal
+ */
+trait InternalTrait2
+{
+    /**
+     * @internal since version 3.4
+     */
+    public function internalMethod()
+    {
+    }
+
+    /**
+     * @internal but should not trigger a deprecation
+     */
+    public function usedInInternalClass()
+    {
+    }
+}
--- a/Tests/Fixtures/Throwing.php
+++ b/Tests/Fixtures/Throwing.php
@@ -0,0 +1,3 @@
+<?php
+
+throw new \Exception('boo');
--- a/Tests/HeaderMock.php
+++ b/Tests/HeaderMock.php
@@ -27,12 +27,12 @@ function testHeader()
 {
    static $headers = array();

-    if (!$h = func_get_args()) {
+    if (!$h = \func_get_args()) {
        $h = $headers;
        $headers = array();

        return $h;
    }

-    $headers[] = func_get_args();
+    $headers[] = \func_get_args();
 }
--- a/Tests/phpt/debug_class_loader.phpt
+++ b/Tests/phpt/debug_class_loader.phpt
@@ -0,0 +1,26 @@
+--TEST--
+Test DebugClassLoader with previously loaded parents
+--FILE--
+<?php
+
+namespace Symfony\Component\Debug\Tests\Fixtures;
+
+use Symfony\Component\Debug\DebugClassLoader;
+
+$vendor = __DIR__;
+while (!file_exists($vendor.'/vendor')) {
+    $vendor = \dirname($vendor);
+}
+require $vendor.'/vendor/autoload.php';
+
+class_exists(FinalMethod::class);
+
+set_error_handler(function ($type, $msg) { echo $msg, "\n"; });
+
+DebugClassLoader::enable();
+
+class_exists(ExtendedFinalMethod::class);
+
+?>
+--EXPECTF--
+The "Symfony\Component\Debug\Tests\Fixtures\FinalMethod::finalMethod()" method is considered final since version 3.3. It may change without further notice as of its next major version. You should not extend it from "Symfony\Component\Debug\Tests\Fixtures\ExtendedFinalMethod".
--- a/Tests/phpt/decorate_exception_hander.phpt
+++ b/Tests/phpt/decorate_exception_hander.phpt
@@ -0,0 +1,46 @@
+--TEST--
+Test catching fatal errors when handlers are nested
+--FILE--
+<?php
+
+namespace Symfony\Component\Debug;
+
+$vendor = __DIR__;
+while (!file_exists($vendor.'/vendor')) {
+    $vendor = \dirname($vendor);
+}
+require $vendor.'/vendor/autoload.php';
+
+set_error_handler('var_dump');
+set_exception_handler('var_dump');
+
+ErrorHandler::register(null, false);
+
+if (true) {
+    class foo extends missing
+    {
+    }
+}
+
+?>
+--EXPECTF--
+Fatal error: Class 'Symfony\Component\Debug\missing' not found in %s on line %d
+object(Symfony\Component\Debug\Exception\ClassNotFoundException)#%d (8) {
+  ["message":protected]=>
+  string(131) "Attempted to load class "missing" from namespace "Symfony\Component\Debug".
+Did you forget a "use" statement for another namespace?"
+  ["string":"Exception":private]=>
+  string(0) ""
+  ["code":protected]=>
+  int(0)
+  ["file":protected]=>
+  string(%d) "%s"
+  ["line":protected]=>
+  int(%d)
+  ["trace":"Exception":private]=>
+  array(%d) {%A}
+  ["previous":"Exception":private]=>
+  NULL
+  ["severity":protected]=>
+  int(1)
+}
--- a/Tests/phpt/exception_rethrown.phpt
+++ b/Tests/phpt/exception_rethrown.phpt
@@ -0,0 +1,35 @@
+--TEST--
+Test rethrowing in custom exception handler
+--FILE--
+<?php
+
+namespace Symfony\Component\Debug;
+
+$vendor = __DIR__;
+while (!file_exists($vendor.'/vendor')) {
+    $vendor = \dirname($vendor);
+}
+require $vendor.'/vendor/autoload.php';
+
+if (true) {
+    class TestLogger extends \Psr\Log\AbstractLogger
+    {
+        public function log($level, $message, array $context = array())
+        {
+            echo $message, "\n";
+        }
+    }
+}
+
+set_exception_handler(function ($e) { echo 123; throw $e; });
+ErrorHandler::register()->setDefaultLogger(new TestLogger());
+ini_set('display_errors', 1);
+
+throw new \Exception('foo');
+?>
+--EXPECTF--
+Uncaught Exception: foo
+123
+Fatal error: Uncaught %s:25
+Stack trace:
+%a
--- a/Tests/phpt/fatal_with_nested_handlers.phpt
+++ b/Tests/phpt/fatal_with_nested_handlers.phpt
@@ -0,0 +1,42 @@
+--TEST--
+Test catching fatal errors when handlers are nested
+--FILE--
+<?php
+
+namespace Symfony\Component\Debug;
+
+$vendor = __DIR__;
+while (!file_exists($vendor.'/vendor')) {
+    $vendor = \dirname($vendor);
+}
+require $vendor.'/vendor/autoload.php';
+
+Debug::enable();
+ini_set('display_errors', 0);
+
+$eHandler = set_error_handler('var_dump');
+$xHandler = set_exception_handler('var_dump');
+
+var_dump(array(
+    $eHandler[0] === $xHandler[0] ? 'Error and exception handlers do match' : 'Error and exception handlers are different',
+));
+
+$eHandler[0]->setExceptionHandler('print_r');
+
+if (true) {
+    class Broken implements \Serializable
+    {
+    }
+}
+
+?>
+--EXPECTF--
+array(1) {
+  [0]=>
+  string(37) "Error and exception handlers do match"
+}
+object(Symfony\Component\Debug\Exception\FatalErrorException)#%d (%d) {
+  ["message":protected]=>
+  string(199) "Error: Class Symfony\Component\Debug\Broken contains 2 abstract methods and must therefore be declared abstract or implement the remaining methods (Serializable::serialize, Serializable::unserialize)"
+%a
+}
--- a/composer.json
+++ b/composer.json
@@ -16,14 +16,14 @@
        }
    ],
    "require": {
-        "php": ">=5.5.9",
+        "php": "^5.5.9|>=7.0.8",
        "psr/log": "~1.0"
    },
    "conflict": {
        "symfony/http-kernel": ">=2.3,<2.3.24|~2.4.0|>=2.5,<2.5.9|>=2.6,<2.6.2"
    },
    "require-dev": {
-        "symfony/http-kernel": "~2.8|~3.0"
+        "symfony/http-kernel": "~2.8|~3.0|~4.0"
    },
    "autoload": {
        "psr-4": { "Symfony\\Component\\Debug\\": "" },
@@ -34,7 +34,7 @@
    "minimum-stability": "dev",
    "extra": {
        "branch-alias": {
-            "dev-master": "3.3-dev"
+            "dev-master": "3.4-dev"
        }
    }
 }