Reduce use of PreviousConnectingVisitor:: ATTRIBUTE_PARENT to assist garbage collector (#729)

Author: staabm

src/Ast/ExpressionFinder.php

@@ -10,7 +10,6 @@
 use PhpParser\Node\Expr\AssignOp;
 use PhpParser\Node\Expr\MethodCall;
 use PhpParser\Node\Expr\Variable;
-use PhpParser\Node\FunctionLike;
 use PhpParser\NodeFinder;
 use PHPStan\ShouldNotHappenException;
 
@@ -147,15 +146,6 @@ private function findFirstPreviousOfNode(Node $node, callable $filter): ?Node
  return $this->findFirstPreviousOfNode($previousStatement, $filter);
  }
 
- $parent = $node->getAttribute(PreviousConnectingVisitor::ATTRIBUTE_PARENT);
- if ($parent instanceof FunctionLike) {
- return null;
- }
-
- if ($parent instanceof Node) {
- return $this->findFirstPreviousOfNode($parent, $filter);
- }
-
  return null;
  }
 

src/Ast/PreviousConnectingVisitor.php

@@ -6,20 +6,13 @@
 
 use PhpParser\Node;
 use PhpParser\NodeVisitorAbstract;
+use PHPStan\Node\VirtualNode;
 use staabm\PHPStanDba\QueryReflection\DIContainerBridge;
-use function array_pop;
 
 final class PreviousConnectingVisitor extends NodeVisitorAbstract
 {
- public const ATTRIBUTE_PARENT = 'dba-parent';
-
  public const ATTRIBUTE_PREVIOUS = 'dba-previous';
 
- /**
- * @var list<Node>
- */
- private array $stack = [];
-
  private ?Node $previous;
 
  // a dummy property to force instantiation of DIContainerBridge
@@ -33,33 +26,29 @@ public function __construct(DIContainerBridge $dummyParameter)
 
  public function beforeTraverse(array $nodes)
  {
- $this->stack = [];
  $this->previous = null;
 
  return null;
  }
 
  public function enterNode(Node $node)
  {
- if ([] !== $this->stack) {
- $node->setAttribute(self::ATTRIBUTE_PARENT, $this->stack[\count($this->stack) - 1]);
- }
-
- if (null !== $this->previous && $this->previous->getAttribute(self::ATTRIBUTE_PARENT) === $node->getAttribute(self::ATTRIBUTE_PARENT)) {
+ if (
+ null !== $this->previous
+ && ! $this->previous instanceof Node\FunctionLike
+ && ! $this->previous instanceof Node\Stmt\ClassLike
+ && ! $this->previous instanceof VirtualNode
+ ) {
  $node->setAttribute(self::ATTRIBUTE_PREVIOUS, $this->previous);
  }
 
- $this->stack[] = $node;
-
  return null;
  }
 
  public function leaveNode(Node $node)
  {
  $this->previous = $node;
 
- array_pop($this->stack);
-
  return null;
  }
 }