comparison vendor/psy/psysh/src/Command/TimeitCommand/TimeitVisitor.php @ 0:c75dbcec494b

Initial commit from drush-created site

+<?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\Command\TimeitCommand;
+
+use PhpParser\Node;
+use PhpParser\Node\Arg;
+use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\StaticCall;
+use PhpParser\Node\FunctionLike;
+use PhpParser\Node\Name\FullyQualified as FullyQualifiedName;
+use PhpParser\Node\Stmt\Expression;
+use PhpParser\Node\Stmt\Return_;
+use PhpParser\NodeVisitorAbstract;
+use Psy\CodeCleaner\NoReturnValue;
+
+/**
+ * A node visitor for instrumenting code to be executed by the `timeit` command.
+ *
+ * Injects `TimeitCommand::markStart()` at the start of code to be executed, and
+ * `TimeitCommand::markEnd()` at the end, and on top-level return statements.
+ */
+class TimeitVisitor extends NodeVisitorAbstract
+{
+    private $functionDepth;
+
+    /**
+     * {@inheritdoc}
+     */
+    public function beforeTraverse(array $nodes)
+    {
+        $this->functionDepth = 0;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function enterNode(Node $node)
+    {
+        // keep track of nested function-like nodes, because they can have
+        // returns statements... and we don't want to call markEnd for those.
+        if ($node instanceof FunctionLike) {
+            $this->functionDepth++;
+
+            return;
+        }
+
+        // replace any top-level `return` statements with a `markEnd` call
+        if ($this->functionDepth === 0 && $node instanceof Return_) {
+            return new Return_($this->getEndCall($node->expr), $node->getAttributes());
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function leaveNode(Node $node)
+    {
+        if ($node instanceof FunctionLike) {
+            $this->functionDepth--;
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function afterTraverse(array $nodes)
+    {
+        // prepend a `markStart` call
+        array_unshift($nodes, $this->maybeExpression($this->getStartCall()));
+
+        // append a `markEnd` call (wrapping the final node, if it's an expression)
+        $last = $nodes[count($nodes) - 1];
+        if ($last instanceof Expr) {
+            array_pop($nodes);
+            $nodes[] = $this->getEndCall($last);
+        } elseif ($last instanceof Expression) {
+            array_pop($nodes);
+            $nodes[] = new Expression($this->getEndCall($last->expr), $last->getAttributes());
+        } elseif ($last instanceof Return_) {
+            // nothing to do here, we're already ending with a return call
+        } else {
+            $nodes[] = $this->maybeExpression($this->getEndCall());
+        }
+
+        return $nodes;
+    }
+
+    /**
+     * Get PhpParser AST nodes for a `markStart` call.
+     *
+     * @return PhpParser\Node\Expr\StaticCall
+     */
+    private function getStartCall()
+    {
+        return new StaticCall(new FullyQualifiedName('Psy\Command\TimeitCommand'), 'markStart');
+    }
+
+    /**
+     * Get PhpParser AST nodes for a `markEnd` call.
+     *
+     * Optionally pass in a return value.
+     *
+     * @param Expr|null $arg
+     *
+     * @return PhpParser\Node\Expr\StaticCall
+     */
+    private function getEndCall(Expr $arg = null)
+    {
+        if ($arg === null) {
+            $arg = NoReturnValue::create();
+        }
+
+        return new StaticCall(new FullyQualifiedName('Psy\Command\TimeitCommand'), 'markEnd', [new Arg($arg)]);
+    }
+
+    /**
+     * Compatibility shim for PHP Parser 3.x.
+     *
+     * Wrap $expr in a PhpParser\Node\Stmt\Expression if the class exists.
+     *
+     * @param PhpParser\Node $expr
+     * @param array          $attrs
+     *
+     * @return PhpParser\Node\Expr|PhpParser\Node\Stmt\Expression
+     */
+    private function maybeExpression($expr, $attrs = [])
+    {
+        return class_exists('PhpParser\Node\Stmt\Expression') ? new Expression($expr, $attrs) : $expr;
+    }
+}