Add a Sigchild compatibility mode (set to false by default)

This mode is required to use a hack to determine if the process finished with success when PHP has been compiled with the --enable-sigchild option

src/Symfony/Component/Process/Process.php

@@ -11,6 +11,8 @@
 
 namespace Symfony\Component\Process;
 
+use Symfony\Component\Process\Exception\RuntimeException;
+
 /**
  * Process is a thin wrapper around proc_* functions to ease
  * start independent PHP processes.
@@ -44,13 +46,16 @@ class Process
     private $stdout;
     private $stderr;
     private $enhanceWindowsCompatibility;
+    private $enhanceSigchildCompatibility;
     private $pipes;
     private $process;
     private $status = self::STATUS_READY;
 
     private $fileHandles;
     private $readBytes;
 
+    private static $sigchild;
+
     /**
      * Exit codes translation table.
      *
@@ -134,6 +139,7 @@ public function __construct($commandline, $cwd = null, array $env = null, $stdin
         $this->stdin = $stdin;
         $this->setTimeout($timeout);
         $this->enhanceWindowsCompatibility = true;
+        $this->enhanceSigchildCompatibility = !defined('PHP_WINDOWS_VERSION_BUILD') && $this->isSigchildEnabled();
         $this->options = array_replace(array('suppress_errors' => true, 'binary_pipes' => true), $options);
     }
 
@@ -216,9 +222,16 @@ public function start($callback = null)
                 array('pipe', 'r'), // stdin
                 array('pipe', 'w'), // stdout
                 array('pipe', 'w'), // stderr
-                array('pipe', 'w')  // last exit code is output on the fourth pipe and caught to work around --enable-sigchild
             );
-            $this->commandline = '('.$this->commandline.') 3>/dev/null; code=$?; echo $code >&3; exit $code';
+
+            if ($this->enhanceSigchildCompatibility && $this->isSigchildEnabled()) {
+                // last exit code is output on the fourth pipe and caught to work around --enable-sigchild
+                $descriptors = array_merge($descriptors, array(array('pipe', 'w')));
+
+                $this->commandline = '('.$this->commandline.') 3>/dev/null; code=$?; echo $code >&3; exit $code';
+            } else {
+                $this->commandline = 'exec ' . $this->commandline;
+            }
         }
 
         $commandline = $this->commandline;
@@ -418,10 +431,16 @@ public function getErrorOutput()
      *
      * @return integer The exit status code
      *
+     * @throws RuntimeException In case --enable-sigchild is activated and the sigchild compatibility mode is disabled
+     *
      * @api
      */
     public function getExitCode()
     {
+        if ($this->isSigchildEnabled() && !$this->enhanceSigchildCompatibility) {
+            throw new RuntimeException('This PHP has been compiled with --enable-sigchild. You must use setEnhanceSigchildCompatibility() to use this method');
+        }
+
         $this->updateStatus();
 
         return $this->exitcode;
@@ -435,28 +454,30 @@ public function getExitCode()
      *
      * @return string A string representation for the exit status code
      *
+     * @throws RuntimeException In case --enable-sigchild is activated and the sigchild compatibility mode is disabled
+     *
      * @see http://tldp.org/LDP/abs/html/exitcodes.html
      * @see http://en.wikipedia.org/wiki/Unix_signal
      */
     public function getExitCodeText()
     {
-        $this->updateStatus();
+        $exitcode = $this->getExitCode();
 
-        return isset(self::$exitCodes[$this->exitcode]) ? self::$exitCodes[$this->exitcode] : 'Unknown error';
+        return isset(self::$exitCodes[$exitcode]) ? self::$exitCodes[$exitcode] : 'Unknown error';
     }
 
     /**
      * Checks if the process ended successfully.
      *
      * @return Boolean true if the process ended successfully, false otherwise
      *
+     * @throws RuntimeException In case --enable-sigchild is activated and the sigchild compatibility mode is disabled
+     *
      * @api
      */
     public function isSuccessful()
     {
-        $this->updateStatus();
-
-        return 0 == $this->exitcode;
+        return 0 == $this->getExitCode();
     }
 
     /**
@@ -466,10 +487,16 @@ public function isSuccessful()
      *
      * @return Boolean
      *
+     * @throws RuntimeException In case --enable-sigchild is activated
+     *
      * @api
      */
     public function hasBeenSignaled()
     {
+        if ($this->isSigchildEnabled()) {
+            throw new RuntimeException('This PHP has been compiled with --enable-sigchild. Term signal can not be retrieved');
+        }
+
         $this->updateStatus();
 
         return $this->processInformation['signaled'];
@@ -482,10 +509,16 @@ public function hasBeenSignaled()
      *
      * @return integer
      *
+     * @throws RuntimeException In case --enable-sigchild is activated
+     *
      * @api
      */
     public function getTermSignal()
     {
+        if ($this->isSigchildEnabled()) {
+            throw new RuntimeException('This PHP has been compiled with --enable-sigchild. Term signal can not be retrieved');
+        }
+
         $this->updateStatus();
 
         return $this->processInformation['termsig'];
@@ -678,6 +711,30 @@ public function setEnhanceWindowsCompatibility($enhance)
         $this->enhanceWindowsCompatibility = (Boolean) $enhance;
     }
 
+    /**
+     * Return whether sigchild compatibility mode is activated or not
+     *
+     * @return Boolean
+     */
+    public function getEnhanceSigchildCompatibility()
+    {
+        return $this->enhanceSigchildCompatibility;
+    }
+
+    /**
+     * Activate sigchild compatibility mode
+     *
+     * Sigchild compatibility mode is required to get the exit code and
+     * determine the success of a process when PHP has been compiled with
+     * the --enable-sigchild option
+     *
+     * @param Boolean $enhance
+     */
+    public function setEnhanceSigchildCompatibility($enhance)
+    {
+        $this->enhanceSigchildCompatibility = (Boolean) $enhance;
+    }
+
     /**
      * Builds up the callback used by wait().
      *
@@ -743,6 +800,23 @@ protected function updateOutput()
         }
     }
 
+    /**
+     * Return whether PHP has been compiled with the '--enable-sigchild' option or not
+     *
+     * @return Boolean
+     */
+    protected function isSigchildEnabled()
+    {
+        if (null !== self::$sigchild) {
+            return self::$sigchild;
+        }
+
+        ob_start();
+        phpinfo(INFO_GENERAL);
+
+        return self::$sigchild = false !== strpos(ob_get_clean(), '--enable-sigchild');
+    }
+
     /**
      * Handles the windows file handles fallbacks
      *