<?php
/*
* This file is part of composer/xdebug-handler.
*
* (c) Composer <https://github.com/composer>
*
* For the full copyright and license information, please view
* the LICENSE file that was distributed with this source code.
*/
namespace Composer\XdebugHandler;
use Psr\Log\LoggerInterface;
/**
* @author John Stevenson <john-stevenson@blueyonder.co.uk>
*/
class XdebugHandler
{
const SUFFIX_ALLOW = '_ALLOW_XDEBUG';
const SUFFIX_INIS = '_ORIGINAL_INIS';
const RESTART_ID = 'internal';
const RESTART_SETTINGS = 'XDEBUG_HANDLER_SETTINGS';
const DEBUG = 'XDEBUG_HANDLER_DEBUG';
/** @var string|null */
protected $tmpIni;
private static $inRestart;
private static $name;
private static $skipped;
private $cli;
private $colorOption;
private $debug;
private $envAllowXdebug;
private $envOriginalInis;
private $loaded;
private $persistent;
private $script;
/** @var Status|null */
private $statusWriter;
/**
* Constructor
*
* The $envPrefix is used to create distinct environment variables. It is
* uppercased and prepended to the default base values. For example 'myapp'
* would result in MYAPP_ALLOW_XDEBUG and MYAPP_ORIGINAL_INIS.
*
* @param string $envPrefix Value used in environment variables
* @param string $colorOption Command-line long option to force color output
* @throws \RuntimeException If a parameter is invalid
*/
public function __construct($envPrefix, $colorOption = '')
{
if (!is_string($envPrefix) || empty($envPrefix) || !is_string($colorOption)) {
throw new \RuntimeException('Invalid constructor parameter');
}
self::$name = strtoupper($envPrefix);
$this->envAllowXdebug = self::$name.self::SUFFIX_ALLOW;
$this->envOriginalInis = self::$name.self::SUFFIX_INIS;
$this->colorOption = $colorOption;
if (extension_loaded('xdebug')) {
$ext = new \ReflectionExtension('xdebug');
$this->loaded = $ext->getVersion() ?: 'unknown';
}
if ($this->cli = PHP_SAPI === 'cli') {
$this->debug = getenv(self::DEBUG);
}
$this->statusWriter = new Status($this->envAllowXdebug, (bool) $this->debug);
}
/**
* Activates status message output to a PSR3 logger
*
* @param LoggerInterface $logger
*
* @return $this
*/
public function setLogger(LoggerInterface $logger)
{
$this->statusWriter->setLogger($logger);
return $this;
}
/**
* Sets the main script location if it cannot be called from argv
*
* @param string $script
*
* @return $this
*/
public function setMainScript($script)
{
$this->script = $script;
return $this;
}
/**
* Persist the settings to keep Xdebug out of sub-processes
*
* @return $this
*/
public function setPersistent()
{
$this->persistent = true;
return $this;
}
/**
* Checks if Xdebug is loaded and the process needs to be restarted
*
* This behaviour can be disabled by setting the MYAPP_ALLOW_XDEBUG
* environment variable to 1. This variable is used internally so that
* the restarted process is created only once.
*/
public function check()
{
$this->notify(Status::CHECK, $this->loaded);
$envArgs = explode('|', (string) getenv($this->envAllowXdebug));
if (empty($envArgs[0]) && $this->requiresRestart((bool) $this->loaded)) {
// Restart required
$this->notify(Status::RESTART);
if ($this->prepareRestart()) {
$command = $this->getCommand();
$this->restart($command);
}
return;
}
if (self::RESTART_ID === $envArgs[0] && count($envArgs) === 5) {
// Restarted, so unset environment variable and use saved values
$this->notify(Status::RESTARTED);
Process::setEnv($this->envAllowXdebug);
self::$inRestart = true;
if (!$this->loaded) {
// Skipped version is only set if Xdebug is not loaded
self::$skipped = $envArgs[1];
}
$this->tryEnableSignals();
// Put restart settings in the environment
$this->setEnvRestartSettings($envArgs);
return;
}
$this->notify(Status::NORESTART);
if ($settings = self::getRestartSettings()) {
// Called with existing settings, so sync our settings
$this->syncSettings($settings);
}
}
/**
* Returns an array of php.ini locations with at least one entry
*
* The equivalent of calling php_ini_loaded_file then php_ini_scanned_files.
* The loaded ini location is the first entry and may be empty.
*
* @return array
*/
public static function getAllIniFiles()
{
if (!empty(self::$name)) {
$env = getenv(self::$name.self::SUFFIX_INIS);
if (false !== $env) {
return explode(PATH_SEPARATOR, $env);
}
}
$paths = array((string) php_ini_loaded_file());
if ($scanned = php_ini_scanned_files()) {
$paths = array_merge($paths, array_map('trim', explode(',', $scanned)));
}
return $paths;
}
/**
* Returns an array of restart settings or null
*
* Settings will be available if the current process was restarted, or
* called with the settings from an existing restart.
*
* @return array|null
*/
public static function getRestartSettings()
{
$envArgs = explode('|', (string) getenv(self::RESTART_SETTINGS));
if (count($envArgs) !== 6
|| (!self::$inRestart && php_ini_loaded_file() !== $envArgs[0])) {
return;
}
return array(
'tmpIni' => $envArgs[0],
'scannedInis' => (bool) $envArgs[1],
'scanDir' => '*' === $envArgs[2] ? false : $envArgs[2],
'phprc' => '*' === $envArgs[3] ? false : $envArgs[3],
'inis' => explode(PATH_SEPARATOR, $envArgs[4]),
'skipped' => $envArgs[5],
);
}
/**
* Returns the Xdebug version that triggered a successful restart
*
* @return string
*/
public static function getSkippedVersion()
{
return (string) self::$skipped;
}
/**
* Returns true if Xdebug is loaded, or as directed by an extending class
*
* @param bool $isLoaded Whether Xdebug is loaded
*
* @return bool
*/
protected function requiresRestart($isLoaded)
{
return $isLoaded;
}
/**
* Allows an extending class to access the tmpIni
*
* @param string $command
*/
protected function restart($command)
{
$this->doRestart($command);
}
/**
* Executes the restarted command then deletes the tmp ini
*
* @param string $command
*/
private function doRestart($command)
{
$this->tryEnableSignals();
$this->notify(Status::RESTARTING, $command);
passthru($command, $exitCode);
$this->notify(Status::INFO, 'Restarted process exited '.$exitCode);
if ($this->debug === '2') {
$this->notify(Status::INFO, 'Temp ini saved: '.$this->tmpIni);
} else {
@unlink($this->tmpIni);
}
exit($exitCode);
}
/**
* Returns true if everything was written for the restart
*
* If any of the following fails (however unlikely) we must return false to
* stop potential recursion:
* - tmp ini file creation
* - environment variable creation
*
* @return bool
*/
private function prepareRestart()
{
$error = '';
$iniFiles = self::getAllIniFiles();
$scannedInis = count($iniFiles) > 1;
$tmpDir = sys_get_temp_dir();
if (!$this->cli) {
$error = 'Unsupported SAPI: '.PHP_SAPI;
} elseif (!defined('PHP_BINARY')) {
$error = 'PHP version is too old: '.PHP_VERSION;
} elseif (!$this->checkConfiguration($info)) {
$error = $info;
} elseif (!$this->checkScanDirConfig()) {
$error = 'PHP version does not report scanned inis: '.PHP_VERSION;
} elseif (!$this->checkMainScript()) {
$error = 'Unable to access main script: '.$this->script;
} elseif (!$this->writeTmpIni($iniFiles, $tmpDir, $error)) {
$error = $error ?: 'Unable to create temp ini file at: '.$tmpDir;
} elseif (!$this->setEnvironment($scannedInis, $iniFiles)) {
$error = 'Unable to set environment variables';
}
if ($error) {
$this->notify(Status::ERROR, $error);
}
return empty($error);
}
/**
* Returns true if the tmp ini file was written
*
* @param array $iniFiles All ini files used in the current process
* @param string $tmpDir The system temporary directory
* @param string $error Set by method if ini file cannot be read
*
* @return bool
*/
private function writeTmpIni(array $iniFiles, $tmpDir, &$error)
{
if (!$this->tmpIni = @tempnam($tmpDir, '')) {
return false;
}
// $iniFiles has at least one item and it may be empty
if (empty($iniFiles[0])) {
array_shift($iniFiles);
}
$content = '';
$regex = '/^\s*(zend_extension\s*=.*xdebug.*)$/mi';
foreach ($iniFiles as $file) {
// Check for inaccessible ini files
if (($data = @file_get_contents($file)) === false) {
$error = 'Unable to read ini: '.$file;
return false;
}
$content .= preg_replace($regex, ';$1', $data).PHP_EOL;
}
// Merge loaded settings into our ini content, if it is valid
if ($config = parse_ini_string($content)) {
$loaded = ini_get_all(null, false);
$content .= $this->mergeLoadedConfig($loaded, $config);
}
// Work-around for https://bugs.php.net/bug.php?id=75932
$content .= 'opcache.enable_cli=0'.PHP_EOL;
return @file_put_contents($this->tmpIni, $content);
}
/**
* Returns the restart command line
*
* @return string
*/
private function getCommand()
{
$php = array(PHP_BINARY);
$args = array_slice($_SERVER['argv'], 1);
if (!$this->persistent) {
// Use command-line options
array_push($php, '-n', '-c', $this->tmpIni);
}
if (defined('STDOUT') && Process::supportsColor(STDOUT)) {
$args = Process::addColorOption($args, $this->colorOption);
}
$args = array_merge($php, array($this->script), $args);
$cmd = Process::escape(array_shift($args), true, true);
foreach ($args as $arg) {
$cmd .= ' '.Process::escape($arg);
}
return $cmd;
}
/**
* Returns true if the restart environment variables were set
*
* No need to update $_SERVER since this is set in the restarted process.
*
* @param bool $scannedInis Whether there were scanned ini files
* @param array $iniFiles All ini files used in the current process
*
* @return bool
*/
private function setEnvironment($scannedInis, array $iniFiles)
{
$scanDir = getenv('PHP_INI_SCAN_DIR');
$phprc = getenv('PHPRC');
// Make original inis available to restarted process
if (!putenv($this->envOriginalInis.'='.implode(PATH_SEPARATOR, $iniFiles))) {
return false;
}
if ($this->persistent) {
// Use the environment to persist the settings
if (!putenv('PHP_INI_SCAN_DIR=') || !putenv('PHPRC='.$this->tmpIni)) {
return false;
}
}
// Flag restarted process and save values for it to use
$envArgs = array(
self::RESTART_ID,
$this->loaded,
(int) $scannedInis,
false === $scanDir ? '*' : $scanDir,
false === $phprc ? '*' : $phprc,
);
return putenv($this->envAllowXdebug.'='.implode('|', $envArgs));
}
/**
* Logs status messages
*
* @param string $op Status handler constant
* @param null|string $data Optional data
*/
private function notify($op, $data = null)
{
$this->statusWriter->report($op, $data);
}
/**
* Returns default, changed and command-line ini settings
*
* @param array $loadedConfig All current ini settings
* @param array $iniConfig Settings from user ini files
*
* @return string
*/
private function mergeLoadedConfig(array $loadedConfig, array $iniConfig)
{
$content = '';
foreach ($loadedConfig as $name => $value) {
// Value will either be null, string or array (HHVM only)
if (!is_string($value)
|| strpos($name, 'xdebug') === 0
|| $name === 'apc.mmap_file_mask') {
continue;
}
if (!isset($iniConfig[$name]) || $iniConfig[$name] !== $value) {
// Double-quote escape each value
$content .= $name.'="'.addcslashes($value, '\\"').'"'.PHP_EOL;
}
}
return $content;
}
/**
* Returns true if the script name can be used
*
* @return bool
*/
private function checkMainScript()
{
if (null !== $this->script) {
// Allow an application to set -- for standard input
return file_exists($this->script) || '--' === $this->script;
}
if (file_exists($this->script = $_SERVER['argv'][0])) {
return true;
}
// Use a backtrace to resolve Phar and chdir issues
$options = PHP_VERSION_ID >= 50306 ? DEBUG_BACKTRACE_IGNORE_ARGS : false;
$trace = debug_backtrace($options);
if (($main = end($trace)) && isset($main['file'])) {
return file_exists($this->script = $main['file']);
}
return false;
}
/**
* Adds restart settings to the environment
*
* @param string $envArgs
*/
private function setEnvRestartSettings($envArgs)
{
$settings = array(
php_ini_loaded_file(),
$envArgs[2],
$envArgs[3],
$envArgs[4],
getenv($this->envOriginalInis),
self::$skipped,
);
Process::setEnv(self::RESTART_SETTINGS, implode('|', $settings));
}
/**
* Syncs settings and the environment if called with existing settings
*
* @param array $settings
*/
private function syncSettings(array $settings)
{
if (false === getenv($this->envOriginalInis)) {
// Called by another app, so make original inis available
Process::setEnv($this->envOriginalInis, implode(PATH_SEPARATOR, $settings['inis']));
}
self::$skipped = $settings['skipped'];
$this->notify(Status::INFO, 'Process called with existing restart settings');
}
/**
* Returns true if there are scanned inis and PHP is able to report them
*
* php_ini_scanned_files will fail when PHP_CONFIG_FILE_SCAN_DIR is empty.
* Fixed in 7.1.13 and 7.2.1
*
* @return bool
*/
private function checkScanDirConfig()
{
return !(getenv('PHP_INI_SCAN_DIR')
&& !PHP_CONFIG_FILE_SCAN_DIR
&& (PHP_VERSION_ID < 70113
|| PHP_VERSION_ID === 70200));
}
/**
* Returns true if there are no known configuration issues
*
* @param string $info Set by method
*/
private function checkConfiguration(&$info)
{
if (false !== strpos(ini_get('disable_functions'), 'passthru')) {
$info = 'passthru function is disabled';
return false;
}
if (extension_loaded('uopz') && !ini_get('uopz.disable')) {
// uopz works at opcode level and disables exit calls
if (function_exists('uopz_allow_exit')) {
@uopz_allow_exit(true);
} else {
$info = 'uopz extension is not compatible';
return false;
}
}
return true;
}
/**
* Enables async signals and control interrupts in the restarted process
*
* Only available on Unix PHP 7.1+ with the pcntl extension. To replicate on
* Windows would require PHP 7.4+ using proc_open rather than passthru.
*/
private function tryEnableSignals()
{
if (!function_exists('pcntl_async_signals') || !function_exists('pcntl_signal')) {
return;
}
pcntl_async_signals(true);
$message = 'Async signals enabled';
if (!self::$inRestart) {
// Restarting, so ignore SIGINT in parent
pcntl_signal(SIGINT, SIG_IGN);
$message .= ' (SIGINT = SIG_IGN)';
} elseif (is_int(pcntl_signal_get_handler(SIGINT))) {
// Restarted, no handler set so force default action
pcntl_signal(SIGINT, SIG_DFL);
$message .= ' (SIGINT = SIG_DFL)';
}
$this->notify(Status::INFO, $message);
}
}