檢測註冊表全局變量的使用

Question

PHP有什麼方法可以執行靜態代碼分析並檢測對register_globals主動性的依賴嗎？手動檢查文件並查找尚未初始化的變量並從中推斷出這些可能依賴它，這是相對直接的，但我需要爲數百個腳本執行此操作，因此我正在尋找一種自動化解決方案。

我最後的手段是設置一個開發環境，關閉指令並嚴格報告錯誤並讓QA長時間播放，然後修復錯誤日誌捕獲的實例，但不能保證找到100 ％的情況下，如果存在自動化解決方案，肯定不會很好地利用資源。

Answer 1

一個小腳本我砍死在一起，檢測簡單不確定的變量。你需要PHP-Parser此：

<?php 

error_reporting(E_ALL); 

$dir = './foo'; 

require_once './lib/bootstrap.php'; 

class Scope { 
    protected $stack; 
    protected $pos; 

    public function __construct() { 
     $this->stack = array(); 
     $this->pos = -1; 
    } 

    public function addVar($name) { 
     $this->stack[$this->pos][$name] = true; 
    } 

    public function hasVar($name) { 
     return isset($this->stack[$this->pos][$name]); 
    } 

    public function pushScope() { 
     $this->stack[++$this->pos] = array(); 
    } 

    public function popScope() { 
     --$this->pos; 
    } 
} 

class UndefinedVariableVisitor extends PHPParser_NodeVisitorAbstract { 
    protected $scope; 
    protected $parser; 
    protected $traverser; 

    public function __construct(Scope $scope, PHPParser_Parser $parser, PHPParser_NodeTraverser $traverser) { 
     $this->scope = $scope; 
     $this->parser = $parser; 
     $this->traverser = $traverser; 
    } 

    public function enterNode(PHPParser_Node $node) { 
     if (($node instanceof PHPParser_Node_Expr_Assign || $node instanceof PHPParser_Node_Expr_AssignRef) 
      && $node->var instanceof PHPParser_Node_Expr_Variable 
      && is_string($node->var->name) 
     ) { 
      $this->scope->addVar($node->var->name); 
     } elseif ($node instanceof PHPParser_Node_Stmt_Global || $node instanceof PHPParser_Node_Stmt_Static) { 
      foreach ($node->vars as $var) { 
       if (is_string($var->name)) { 
        $this->scope->addVar($var->name); 
       } 
      } 
     } elseif ($node instanceof PHPParser_Node_Expr_Variable && is_string($node->name)) { 
      if (!$this->scope->hasVar($node->name)) { 
       echo 'Undefined variable $' . $node->name . ' on line ' . $node->getLine() . "\n"; 
      } 
     } elseif ($node instanceof PHPParser_Node_Stmt_Function || $node instanceof PHPParser_Node_Stmt_ClassMethod) { 
      $this->scope->pushScope(); 

      // params are always available 
      foreach ($node->params as $param) { 
       $this->scope->addVar($param->name); 
      } 

      // methods always have $this 
      if ($node instanceof PHPParser_Node_Stmt_ClassMethod) { 
       $this->scope->addVar('this'); 
      } 
     } elseif ($node instanceof PHPParser_Node_Expr_Include && $node->expr instanceof PHPParser_Node_Scalar_String) { 
      $file = $node->expr->value; 
      $code = file_get_contents($file); 
      $stmts = $this->parser->parse($code); 

      // for includes within the file 
      $cwd = getcwd(); 
      chdir(dirname($file)); 

      $this->traverser->traverse($stmts); 

      chdir($cwd); 
     } 
    } 

    public function leaveNode(PHPParser_Node $node) { 
     if ($node instanceof PHPParser_Node_Stmt_Function || $node instanceof PHPParser_Node_Stmt_ClassMethod) { 
      $this->scope->popScope(); 
     } 
    } 
} 

$parser = new PHPParser_Parser(new PHPParser_Lexer()); 

$scope = new Scope; 

$traverser = new PHPParser_NodeTraverser; 
$traverser->addVisitor(new UndefinedVariableVisitor($scope, $parser, $traverser)); 

foreach (new RecursiveIteratorIterator(
      new RecursiveDirectoryIterator($dir), 
      RecursiveIteratorIterator::LEAVES_ONLY) 
     as $file 
) { 
    if (!preg_match('/\.php$/', $file)) continue; 

    echo 'Checking ' . $file . ':', "\n"; 

    $code = file_get_contents($file); 
    $stmts = $parser->parse($code); 

    // for includes within the file 
    $cwd = getcwd(); 
    chdir(dirname($file)); 

    $scope->pushScope(); 
    $traverser->traverse($stmts); 
    $scope->popScope(); 

    chdir($cwd); 

    echo "\n"; 
} 

這只是一個非常基本的實現，我沒有進行廣泛的測試，但它應該爲腳本，不要去野外與$GLOBALS和$$varVars工作。它的基本包括解決方案。

Answer 2

這應該（從PHP手冊中的意見之一）工作：

if (ini_get('register_globals')) { 
    foreach ($GLOBALS as $int_temp_name => $int_temp_value) { 
     if (!in_array($int_temp_name, array (
       'GLOBALS', 
       '_FILES', 
       '_REQUEST', 
       '_COOKIE', 
       '_SERVER', 
       '_ENV', 
       '_SESSION', 
       ini_get('session.name'), 
       'int_temp_name', 
       'int_temp_value' 
      ))) { 
      unset ($GLOBALS[$int_temp_name]); 
     } 
    } 
}