4 * This file is part of Psy Shell.
6 * (c) 2012-2017 Justin Hileman
8 * For the full copyright and license information, please view the LICENSE
9 * file that was distributed with this source code.
12 namespace Psy\CodeCleaner;
14 use PhpParser\Node\Expr;
15 use PhpParser\Node\Expr\Exit_;
16 use PhpParser\Node\Expr\New_;
17 use PhpParser\Node\Name\FullyQualified as FullyQualifiedName;
18 use PhpParser\Node\Stmt;
19 use PhpParser\Node\Stmt\Break_;
20 use PhpParser\Node\Stmt\If_;
21 use PhpParser\Node\Stmt\Namespace_;
22 use PhpParser\Node\Stmt\Return_;
23 use PhpParser\Node\Stmt\Switch_;
26 * Add an implicit "return" to the last statement, provided it can be returned.
28 class ImplicitReturnPass extends CodeCleanerPass
35 public function beforeTraverse(array $nodes)
37 return $this->addImplicitReturn($nodes);
45 private function addImplicitReturn(array $nodes)
47 // If nodes is empty, it can't have a return value.
49 return array(new Return_(new New_(new FullyQualifiedName('Psy\CodeCleaner\NoReturnValue'))));
54 // Special case a few types of statements to add an implicit return
55 // value (even though they technically don't have any return value)
56 // because showing a return value in these instances is useful and not
58 if ($last instanceof If_) {
59 $last->stmts = $this->addImplicitReturn($last->stmts);
61 foreach ($last->elseifs as $elseif) {
62 $elseif->stmts = $this->addImplicitReturn($elseif->stmts);
66 $last->else->stmts = $this->addImplicitReturn($last->else->stmts);
68 } elseif ($last instanceof Switch_) {
69 foreach ($last->cases as $case) {
70 // only add an implicit return to cases which end in break
71 $caseLast = end($case->stmts);
72 if ($caseLast instanceof Break_) {
73 $case->stmts = $this->addImplicitReturn(array_slice($case->stmts, 0, -1));
74 $case->stmts[] = $caseLast;
77 } elseif ($last instanceof Expr && !($last instanceof Exit_)) {
78 $nodes[count($nodes) - 1] = new Return_($last, array(
79 'startLine' => $last->getLine(),
80 'endLine' => $last->getLine(),
82 } elseif ($last instanceof Namespace_) {
83 $last->stmts = $this->addImplicitReturn($last->stmts);
86 // Return a "no return value" for all non-expression statements, so that
87 // PsySH can suppress the `null` that `eval()` returns otherwise.
89 // Note that statements special cased above (if/elseif/else, switch)
90 // _might_ implicitly return a value before this catch-all return is
93 // We're not adding a fallback return after namespace statements,
94 // because code outside namespace statements doesn't really work, and
95 // there's already an implicit return in the namespace statement anyway.
96 if ($last instanceof Stmt && !$last instanceof Return_ && !$last instanceof Namespace_) {
97 $nodes[] = new Return_(new New_(new FullyQualifiedName('Psy\CodeCleaner\NoReturnValue')));