<?php
/*
* This file is part of Psy Shell.
*
* (c) 2012-2020 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;
use Psy\Command\TimeitCommand;
/**
* 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(TimeitCommand::class), '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) {
$arg = NoReturnValue::create();
}
return new StaticCall(new FullyQualifiedName(TimeitCommand::class), 'markEnd', [new Arg($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, $attrs = [])
{
return \class_exists(Expression::class) ? new Expression($expr, $attrs) : $expr;
}
}