(stable) Promote 2021 Week 9

src/__phutil_library_map__.php

@@ -744,6 +744,7 @@ phutil_register_library_map(array(
     'PhutilEnglishCanadaLocale' => 'internationalization/locales/PhutilEnglishCanadaLocale.php',
     'PhutilErrorHandler' => 'error/PhutilErrorHandler.php',
     'PhutilErrorHandlerTestCase' => 'error/__tests__/PhutilErrorHandlerTestCase.php',
+    'PhutilErrorLog' => 'filesystem/PhutilErrorLog.php',
     'PhutilErrorTrap' => 'error/PhutilErrorTrap.php',
     'PhutilEvent' => 'events/PhutilEvent.php',
     'PhutilEventConstants' => 'events/constant/PhutilEventConstants.php',
@@ -849,6 +850,7 @@ phutil_register_library_map(array(
     'PhutilRawEnglishLocale' => 'internationalization/locales/PhutilRawEnglishLocale.php',
     'PhutilReadableSerializer' => 'readableserializer/PhutilReadableSerializer.php',
     'PhutilReadableSerializerTestCase' => 'readableserializer/__tests__/PhutilReadableSerializerTestCase.php',
+    'PhutilRegexException' => 'exception/PhutilRegexException.php',
     'PhutilRope' => 'utils/PhutilRope.php',
     'PhutilRopeTestCase' => 'utils/__tests__/PhutilRopeTestCase.php',
     'PhutilServiceProfiler' => 'serviceprofiler/PhutilServiceProfiler.php',
@@ -1009,6 +1011,9 @@ phutil_register_library_map(array(
     'phutil_partition' => 'utils/utils.php',
     'phutil_passthru' => 'future/exec/execx.php',
     'phutil_person' => 'internationalization/pht.php',
+    'phutil_preg_match' => 'utils/utils.php',
+    'phutil_preg_match_all' => 'utils/utils.php',
+    'phutil_raise_preg_exception' => 'utils/utils.php',
     'phutil_register_library' => 'init/lib/core.php',
     'phutil_register_library_map' => 'init/lib/core.php',
     'phutil_set_system_locale' => 'utils/utf8.php',
@@ -1812,6 +1817,7 @@ phutil_register_library_map(array(
     'PhutilEnglishCanadaLocale' => 'PhutilLocale',
     'PhutilErrorHandler' => 'Phobject',
     'PhutilErrorHandlerTestCase' => 'PhutilTestCase',
+    'PhutilErrorLog' => 'Phobject',
     'PhutilErrorTrap' => 'Phobject',
     'PhutilEvent' => 'Phobject',
     'PhutilEventConstants' => 'Phobject',
@@ -1925,6 +1931,7 @@ phutil_register_library_map(array(
     'PhutilRawEnglishLocale' => 'PhutilLocale',
     'PhutilReadableSerializer' => 'Phobject',
     'PhutilReadableSerializerTestCase' => 'PhutilTestCase',
+    'PhutilRegexException' => 'Exception',
     'PhutilRope' => 'Phobject',
     'PhutilRopeTestCase' => 'PhutilTestCase',
     'PhutilServiceProfiler' => 'Phobject',

src/exception/PhutilRegexException.php

@@ -0,0 +1,3 @@
+<?php
+
+final class PhutilRegexException extends Exception {}

src/filesystem/Filesystem.php

@@ -52,7 +52,7 @@ final class Filesystem extends Phobject {
    * Make assertions about the state of path in preparation for
    * writeFile() and writeFileIfChanged().
    */
-  private static function assertWritableFile($path) {
+  public static function assertWritableFile($path) {
     $path = self::resolvePath($path);
     $dir = dirname($path);
 

src/filesystem/PhutilErrorLog.php

@@ -0,0 +1,101 @@
+<?php
+
+
+final class PhutilErrorLog
+  extends Phobject {
+
+  private $logName;
+  private $logPath;
+
+  public function setLogName($log_name) {
+    $this->logName = $log_name;
+    return $this;
+  }
+
+  public function getLogName() {
+    return $this->logName;
+  }
+
+  public function setLogPath($log_path) {
+    $this->logPath = $log_path;
+    return $this;
+  }
+
+  public function getLogPath() {
+    return $this->logPath;
+  }
+
+  public function activateLog() {
+    $log_path = $this->getLogPath();
+
+    if ($log_path !== null) {
+      // Test that the path is writable.
+      $write_exception = null;
+      try {
+        Filesystem::assertWritableFile($log_path);
+      } catch (FilesystemException $ex) {
+        $write_exception = $ex;
+      }
+
+      // If we hit an exception, try to create the containing directory.
+      if ($write_exception) {
+        $log_dir = dirname($log_path);
+        if (!Filesystem::pathExists($log_dir)) {
+          try {
+            Filesystem::createDirectory($log_dir, 0755, true);
+          } catch (FilesystemException $ex) {
+            throw new PhutilProxyException(
+              pht(
+                'Unable to write log "%s" to path "%s". The containing '.
+                'directory ("%s") does not exist or is not readable, and '.
+                'could not be created.',
+                $this->getLogName(),
+                $log_path,
+                $log_dir),
+              $ex);
+          }
+        }
+
+        // If we created the parent directory, test if the path is writable
+        // again.
+        try {
+          Filesystem::assertWritableFile($log_path);
+          $write_exception = null;
+        } catch (FilesystemException $ex) {
+          $write_exception = $ex;
+        }
+      }
+
+      // If we ran into a write exception and couldn't resolve it, fail.
+      if ($write_exception) {
+        throw new PhutilProxyException(
+          pht(
+            'Unable to write log "%s" to path "%s" because the path is not '.
+            'writable.',
+            $this->getLogName(),
+            $log_path),
+          $write_exception);
+      }
+    }
+
+    ini_set('error_log', $log_path);
+    PhutilErrorHandler::setErrorListener(array($this, 'onError'));
+  }
+
+  public function onError($event, $value, array $metadata) {
+    // If we've set "error_log" to a real file, so messages won't be output to
+    // stderr by default. Copy them to stderr.
+
+    if ($this->logPath === null) {
+      return;
+    }
+
+    $message = idx($metadata, 'default_message');
+
+    if (strlen($message)) {
+      $message = tsprintf("%B\n", $message);
+      @fwrite(STDERR, $message);
+    }
+  }
+
+}

src/utils/utils.php

@@ -2008,3 +2008,89 @@ function phutil_partition(array $map) {
 
   return $partitions;
 }
+
+function phutil_preg_match(
+  $pattern,
+  $subject,
+  $flags = 0,
+  $offset = 0) {
+
+  $matches = null;
+  $result = @preg_match($pattern, $subject, $matches, $flags, $offset);
+  if ($result === false || $result === null) {
+    phutil_raise_preg_exception(
+      'preg_match',
+      array(
+        $pattern,
+        $subject,
+        $matches,
+        $flags,
+        $offset,
+      ));
+  }
+
+  return $matches;
+}
+
+function phutil_preg_match_all(
+  $pattern,
+  $subject,
+  $flags = 0,
+  $offset = 0) {
+
+  $matches = null;
+  $result = @preg_match_all($pattern, $subject, $matches, $flags, $offset);
+  if ($result === false || $result === null) {
+    phutil_raise_preg_exception(
+      'preg_match_all',
+      array(
+        $pattern,
+        $subject,
+        $matches,
+        $flags,
+        $offset,
+      ));
+  }
+
+  return $matches;
+}
+
+function phutil_raise_preg_exception($function, array $argv) {
+  $trap = new PhutilErrorTrap();
+
+  // NOTE: This ugly construction to avoid issues with reference behavior when
+  // passing values through "call_user_func_array()".
+
+  switch ($function) {
+    case 'preg_match':
+      @preg_match($argv[0], $argv[1], $argv[2], $argv[3], $argv[4]);
+      break;
+    case 'preg_match_all':
+      @preg_match_all($argv[0], $argv[1], $argv[2], $argv[3], $argv[4]);
+      break;
+  }
+  $error_message = $trap->getErrorsAsString();
+
+  $trap->destroy();
+
+  $pattern = $argv[0];
+  $pattern_display = sprintf(
+    '"%s"',
+    addcslashes($pattern, '\\\"'));
+
+  $message = array();
+  $message[] = pht(
+    'Call to %s(%s, ...) failed.',
+    $function,
+    $pattern_display);
+
+  if (strlen($error_message)) {
+    $message[] = pht(
+      'Regular expression engine emitted message: %s',
+      $error_message);
+  }
+
+  $message = implode("\n\n", $message);
+
+  throw new PhutilRegexException($message);
+}

support/init/init-script.php

@@ -56,6 +56,15 @@ function __arcanist_init_script__() {
     // inspect "args", and this option generally obscures useful debugging
     // information without any benefit in the context of Phabricator.
     'zend.exception_ignore_args' => 0,
+
+    // See T13100. We'd like the regex engine to fail, rather than segfault,
+    // if handed a pathological regular expression.
+    'pcre.backtrack_limit' => 10000,
+    'pcre.recusion_limit' => 10000,
+
+    // NOTE: Phabricator applies a similar set of startup options for Web
+    // environments in "PhabricatorStartup". Changes here may also be
+    // appropriate to apply there.
   );
 
   foreach ($config_map as $config_key => $config_value) {
@@ -106,8 +115,6 @@ function __arcanist_init_script__() {
 
   PhutilErrorHandler::initialize();
 
-  PhutilErrorHandler::initialize();
-
   // If "variables_order" excludes "E", silently repair it so that $_ENV has
   // the values we expect.
   PhutilExecutionEnvironment::repairMissingVariablesOrder();