Restore caching in SyntaxSniff

Author: Willem Stuursma

src/Config.php

@@ -1520,6 +1520,7 @@ public static function getExecutablePath($name)
             /*
              * For php, we know the executable path. There's no need to look it up.
              */
+
             return PHP_BINARY;
         }
 

src/Standards/Generic/Sniffs/PHP/SyntaxSniff.php

@@ -17,6 +17,13 @@
 class SyntaxSniff implements Sniff
 {
 
+    /**
+     * The path to the PHP version we are checking with.
+     *
+     * @var string
+     */
+    private $phpPath = null;
+
 
     /**
      * Returns an array of tokens this test wants to listen for.
@@ -41,8 +48,12 @@ public function register()
      */
     public function process(File $phpcsFile, $stackPtr)
     {
+        if ($this->phpPath === null) {
+            $this->phpPath = Config::getExecutablePath('php');
+        }
+
         $fileName = escapeshellarg($phpcsFile->getFilename());
-        $cmd      = escapeshellcmd(Config::getExecutablePath('php'))." -l -d display_errors=1 -d error_prepend_string='' $fileName 2>&1";
+        $cmd      = escapeshellcmd($this->phpPath)." -l -d display_errors=1 -d error_prepend_string='' $fileName 2>&1";
         $output   = shell_exec($cmd);
         $matches  = [];
         if (preg_match('/^.*error:(.*) in .* on line ([0-9]+)/m', trim($output), $matches) === 1) {