--- /dev/null
+<?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;
+ }
+}