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;
     }
 }