comparison vendor/psy/psysh/src/CodeCleaner/ValidFunctionNamePass.php @ 13:5fb285c0d0e3

Update Drupal core to 8.4.7 via Composer. Security update; I *think* we've
been lucky to get away with this so far, as we don't support self-registration
which seems to be used by the so-called "drupalgeddon 2" attack that 8.4.5
was vulnerable to.

+<?php
+
+/*
+ * This file is part of Psy Shell.
+ *
+ * (c) 2012-2018 Justin Hileman
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Psy\CodeCleaner;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\FuncCall;
+use PhpParser\Node\Expr\Variable;
+use PhpParser\Node\Stmt\Do_;
+use PhpParser\Node\Stmt\Function_;
+use PhpParser\Node\Stmt\If_;
+use PhpParser\Node\Stmt\Switch_;
+use PhpParser\Node\Stmt\While_;
+use Psy\Exception\FatalErrorException;
+
+/**
+ * Validate that function calls will succeed.
+ *
+ * This pass throws a FatalErrorException rather than letting PHP run
+ * headfirst into a real fatal error and die.
+ */
+class ValidFunctionNamePass extends NamespaceAwarePass
+{
+    private $conditionalScopes = 0;
+
+    /**
+     * Store newly defined function names on the way in, to allow recursion.
+     *
+     * @param Node $node
+     */
+    public function enterNode(Node $node)
+    {
+        parent::enterNode($node);
+
+        if (self::isConditional($node)) {
+            $this->conditionalScopes++;
+        } elseif ($node instanceof Function_) {
+            $name = $this->getFullyQualifiedName($node->name);
+
+            // @todo add an "else" here which adds a runtime check for instances where we can't tell
+            // whether a function is being redefined by static analysis alone.
+            if ($this->conditionalScopes === 0) {
+                if (function_exists($name) ||
+                    isset($this->currentScope[strtolower($name)])) {
+                    $msg = sprintf('Cannot redeclare %s()', $name);
+                    throw new FatalErrorException($msg, 0, E_ERROR, null, $node->getLine());
+                }
+            }
+
+            $this->currentScope[strtolower($name)] = true;
+        }
+    }
+
+    /**
+     * Validate that function calls will succeed.
+     *
+     * @throws FatalErrorException if a function is redefined
+     * @throws FatalErrorException if the function name is a string (not an expression) and is not defined
+     *
+     * @param Node $node
+     */
+    public function leaveNode(Node $node)
+    {
+        if (self::isConditional($node)) {
+            $this->conditionalScopes--;
+        } elseif ($node instanceof FuncCall) {
+            // if function name is an expression or a variable, give it a pass for now.
+            $name = $node->name;
+            if (!$name instanceof Expr && !$name instanceof Variable) {
+                $shortName = implode('\\', $name->parts);
+                $fullName  = $this->getFullyQualifiedName($name);
+                $inScope   = isset($this->currentScope[strtolower($fullName)]);
+                if (!$inScope && !function_exists($shortName) && !function_exists($fullName)) {
+                    $message = sprintf('Call to undefined function %s()', $name);
+                    throw new FatalErrorException($message, 0, E_ERROR, null, $node->getLine());
+                }
+            }
+        }
+    }
+
+    private static function isConditional(Node $node)
+    {
+        return $node instanceof If_ ||
+            $node instanceof While_ ||
+            $node instanceof Do_ ||
+            $node instanceof Switch_;
+    }
+}