Fix phpstan/phpstan#15348: symfony/ux-css slow on big array shape

src/Analyser/Traverser/TransformStaticTypeTraverser.php

@@ -6,17 +6,21 @@
 use PHPStan\Turbo\ReferencedByTurboExtension;
 use PHPStan\Type\StaticType;
 use PHPStan\Type\ThisType;
+use PHPStan\Type\Traverser\MemoizingTraverser;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeTraverserCallable;
 
 #[ReferencedByTurboExtension(key: 'transformStaticTypeTraverser')]
 final class TransformStaticTypeTraverser implements TypeTraverserCallable
 {
 
+	private MemoizingTraverser $memoizingTraverser;
+
 	public function __construct(
 		private readonly Scope $scope,
 	)
 	{
+		$this->memoizingTraverser = new MemoizingTraverser($this->doTraverse(...));
 	}
 
 	/**
@@ -27,6 +31,15 @@ public function traverse(Type $type, callable $traverse): Type
 		if (!$this->scope->isInClass()) {
 			return $type;
 		}
+
+		return $this->memoizingTraverser->traverse($type, $traverse);
+	}
+
+	/**
+	 * @param callable(Type): Type $traverse
+	 */
+	private function doTraverse(Type $type, callable $traverse): Type
+	{
 		if ($type instanceof StaticType) {
 			$classReflection = $this->scope->getClassReflection();
 			$changedType = $type->changeBaseClass($classReflection);

src/Rules/Classes/LocalTypeAliasesCheck.php

@@ -23,6 +23,7 @@
 use PHPStan\Type\CircularTypeAliasErrorType;
 use PHPStan\Type\ErrorType;
 use PHPStan\Type\Generic\TemplateType;
+use PHPStan\Type\Traverser\MemoizingTraverser;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeTraverser;
 use PHPStan\Type\VerbosityLevel;
@@ -349,7 +350,7 @@ private function isAliasNameValid(string $aliasName, ?NameScope $nameScope): boo
 	private function hasErrorType(Type $type, string $aliasName, array &$errors): bool
 	{
 		$foundError = false;
-		TypeTraverser::map($type, static function (Type $type, callable $traverse) use (&$errors, &$foundError, $aliasName): Type {
+		TypeTraverser::map($type, new MemoizingTraverser(static function (Type $type, callable $traverse) use (&$errors, &$foundError, $aliasName): Type {
 			if ($foundError) {
 				return $type;
 			}
@@ -371,7 +372,7 @@ private function hasErrorType(Type $type, string $aliasName, array &$errors): bo
 			}
 
 			return $traverse($type);
-		});
+		}));
 
 		return $foundError;
 	}

src/Rules/Generics/GenericObjectTypeCheck.php

@@ -13,6 +13,7 @@
 use PHPStan\Type\Generic\TemplateTypeVariance;
 use PHPStan\Type\Generic\TemplateTypeVarianceMap;
 use PHPStan\Type\Generic\TypeProjectionHelper;
+use PHPStan\Type\Traverser\MemoizingTraverser;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeTraverser;
 use PHPStan\Type\VerbosityLevel;
@@ -182,7 +183,7 @@ public function check(
 	private function getGenericTypes(Type $phpDocType): array
 	{
 		$genericObjectTypes = [];
-		TypeTraverser::map($phpDocType, static function (Type $type, callable $traverse) use (&$genericObjectTypes): Type {
+		TypeTraverser::map($phpDocType, new MemoizingTraverser(static function (Type $type, callable $traverse) use (&$genericObjectTypes): Type {
 			if ($type instanceof GenericObjectType || $type instanceof GenericStaticType) {
 				$resolvedType = TemplateTypeHelper::resolveToBounds($type);
 				if (!$resolvedType instanceof GenericObjectType && !$resolvedType instanceof GenericStaticType) {
@@ -194,7 +195,7 @@ private function getGenericTypes(Type $phpDocType): array
 			}
 			$traverse($type);
 			return $type;
-		});
+		}));
 
 		return $genericObjectTypes;
 	}

src/Rules/MissingTypehintCheck.php

@@ -22,6 +22,7 @@
 use PHPStan\Type\IntersectionType;
 use PHPStan\Type\MixedType;
 use PHPStan\Type\ObjectType;
+use PHPStan\Type\Traverser\MemoizingTraverser;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeTraverser;
 use PHPStan\Type\UnionType;
@@ -73,7 +74,7 @@ public function __construct(
 	public function getIterableTypesWithMissingValueTypehint(Type $type): array
 	{
 		$descriptions = [];
-		TypeTraverser::map($type, function (Type $type, callable $traverse) use (&$descriptions): Type {
+		TypeTraverser::map($type, new MemoizingTraverser(function (Type $type, callable $traverse) use (&$descriptions): Type {
 			if ($type instanceof TemplateType) {
 				return $type;
 			}
@@ -108,7 +109,7 @@ public function getIterableTypesWithMissingValueTypehint(Type $type): array
 			}
 			if ($type->isIterable()->yes()) {
 				if ($type->isConstantArray()->yes()) {
-					$type = TypeTraverser::map($type, static function (Type $type, callable $traverse) {
+					$type = TypeTraverser::map($type, new MemoizingTraverser(static function (Type $type, callable $traverse): Type {
 						if ($type instanceof UnionType || $type instanceof IntersectionType) {
 							return $traverse($type);
 						}
@@ -121,7 +122,7 @@ public function getIterableTypesWithMissingValueTypehint(Type $type): array
 						}
 
 						return $traverse($type);
-					});
+					}));
 				}
 				$iterableValue = $type->getIterableValueType();
 				if ($iterableValue instanceof MixedType && !$iterableValue->isExplicitMixed()) {
@@ -136,7 +137,7 @@ public function getIterableTypesWithMissingValueTypehint(Type $type): array
 				}
 			}
 			return $traverse($type);
-		});
+		}));
 
 		return $descriptions;
 	}
@@ -147,7 +148,7 @@ public function getIterableTypesWithMissingValueTypehint(Type $type): array
 	public function getNonGenericObjectTypesWithGenericClass(Type $type): array
 	{
 		$objectTypes = [];
-		TypeTraverser::map($type, function (Type $type, callable $traverse) use (&$objectTypes): Type {
+		TypeTraverser::map($type, new MemoizingTraverser(function (Type $type, callable $traverse) use (&$objectTypes): Type {
 			if ($type instanceof GenericObjectType || $type instanceof GenericStaticType) {
 				$traverse($type);
 				return $type;
@@ -205,7 +206,7 @@ public function getNonGenericObjectTypesWithGenericClass(Type $type): array
 			}
 
 			return $traverse($type);
-		});
+		}));
 
 		return $objectTypes;
 	}
@@ -220,7 +221,7 @@ public function getCallablesWithMissingSignature(Type $type): array
 		}
 
 		$result = [];
-		TypeTraverser::map($type, static function (Type $type, callable $traverse) use (&$result): Type {
+		TypeTraverser::map($type, new MemoizingTraverser(static function (Type $type, callable $traverse) use (&$result): Type {
 			if (
 				($type instanceof CallableType && $type->isCommonCallable())
 				|| ($type instanceof ClosureType && $type->isCommonCallable())
@@ -229,7 +230,7 @@ public function getCallablesWithMissingSignature(Type $type): array
 				$result[] = $type;
 			}
 			return $traverse($type);
-		});
+		}));
 
 		return $result;
 	}

src/Rules/PhpDoc/ConditionalReturnTypeRuleHelper.php

@@ -10,6 +10,7 @@
 use PHPStan\Type\ConditionalTypeForParameter;
 use PHPStan\Type\Generic\TemplateType;
 use PHPStan\Type\StaticType;
+use PHPStan\Type\Traverser\MemoizingTraverser;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeTraverser;
 use PHPStan\Type\VerbosityLevel;
@@ -30,44 +31,44 @@ public function check(ExtendedParametersAcceptor $acceptor): array
 		$conditionalTypes = [];
 		$parametersByName = [];
 		foreach ($acceptor->getParameters() as $parameter) {
-			TypeTraverser::map($parameter->getType(), static function (Type $type, callable $traverse) use (&$conditionalTypes): Type {
+			TypeTraverser::map($parameter->getType(), new MemoizingTraverser(static function (Type $type, callable $traverse) use (&$conditionalTypes): Type {
 				if ($type instanceof ConditionalType || $type instanceof ConditionalTypeForParameter) {
 					$conditionalTypes[] = $type;
 				}
 
 				return $traverse($type);
-			});
+			}));
 
 			if ($parameter->getOutType() !== null) {
-				TypeTraverser::map($parameter->getOutType(), static function (Type $type, callable $traverse) use (&$conditionalTypes): Type {
+				TypeTraverser::map($parameter->getOutType(), new MemoizingTraverser(static function (Type $type, callable $traverse) use (&$conditionalTypes): Type {
 					if ($type instanceof ConditionalType || $type instanceof ConditionalTypeForParameter) {
 						$conditionalTypes[] = $type;
 					}
 
 					return $traverse($type);
-				});
+				}));
 			}
 
 			if ($parameter->getClosureThisType() !== null) {
-				TypeTraverser::map($parameter->getClosureThisType(), static function (Type $type, callable $traverse) use (&$conditionalTypes): Type {
+				TypeTraverser::map($parameter->getClosureThisType(), new MemoizingTraverser(static function (Type $type, callable $traverse) use (&$conditionalTypes): Type {
 					if ($type instanceof ConditionalType || $type instanceof ConditionalTypeForParameter) {
 						$conditionalTypes[] = $type;
 					}
 
 					return $traverse($type);
-				});
+				}));
 			}
 
 			$parametersByName[$parameter->getName()] = $parameter;
 		}
 
-		TypeTraverser::map($acceptor->getReturnType(), static function (Type $type, callable $traverse) use (&$conditionalTypes): Type {
+		TypeTraverser::map($acceptor->getReturnType(), new MemoizingTraverser(static function (Type $type, callable $traverse) use (&$conditionalTypes): Type {
 			if ($type instanceof ConditionalType || $type instanceof ConditionalTypeForParameter) {
 				$conditionalTypes[] = $type;
 			}
 
 			return $traverse($type);
-		});
+		}));
 
 		$errors = [];
 		foreach ($conditionalTypes as $conditionalType) {
@@ -77,14 +78,14 @@ public function check(ExtendedParametersAcceptor $acceptor): array
 					continue;
 				}
 				$templateTypes = [];
-				TypeTraverser::map($subjectType, static function (Type $type, callable $traverse) use (&$templateTypes): Type {
+				TypeTraverser::map($subjectType, new MemoizingTraverser(static function (Type $type, callable $traverse) use (&$templateTypes): Type {
 					if ($type instanceof TemplateType) {
 						$templateTypes[] = $type;
 						return $type;
 					}
 
 					return $traverse($type);
-				});
+				}));
 
 				if (count($templateTypes) === 0) {
 					$errors[] = RuleErrorBuilder::message(sprintf('Conditional return type uses subject type %s which is not part of PHPDoc @template tags.', $subjectType->describe(VerbosityLevel::typeOnly())))

src/Rules/PhpDoc/GenericCallableRuleHelper.php

@@ -13,6 +13,7 @@
 use PHPStan\Type\CallableType;
 use PHPStan\Type\ClosureType;
 use PHPStan\Type\Generic\TemplateTypeScope;
+use PHPStan\Type\Traverser\MemoizingTraverser;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeTraverser;
 use PHPStan\Type\VerbosityLevel;
@@ -46,7 +47,7 @@ public function check(
 	{
 		$errors = [];
 
-		TypeTraverser::map($callableType, function (Type $type, callable $traverse) use (&$errors, $node, $scope, $location, $functionName, $functionTemplateTags, $classReflection) {
+		TypeTraverser::map($callableType, new MemoizingTraverser(function (Type $type, callable $traverse) use (&$errors, $node, $scope, $location, $functionName, $functionTemplateTags, $classReflection) {
 			if (!($type instanceof CallableType || $type instanceof ClosureType)) {
 				return $traverse($type);
 			}
@@ -114,7 +115,7 @@ public function check(
 			}
 
 			return $traverse($type);
-		});
+		}));
 
 		return $errors;
 	}

src/Rules/RuleLevelHelper.php

@@ -19,6 +19,7 @@
 use PHPStan\Type\NeverType;
 use PHPStan\Type\NullType;
 use PHPStan\Type\StrictMixedType;
+use PHPStan\Type\Traverser\MemoizingTraverser;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeCombinator;
 use PHPStan\Type\TypeTraverser;
@@ -86,7 +87,7 @@ private function transformCommonType(Type $type): Type
 			return $type;
 		}
 
-		return TypeTraverser::map($type, function (Type $type, callable $traverse) {
+		return TypeTraverser::map($type, new MemoizingTraverser(function (Type $type, callable $traverse) {
 			if ($type instanceof TemplateMixedType) {
 				if ($this->checkExplicitMixed) {
 					return $type->toStrictMixedType();
@@ -103,7 +104,7 @@ private function transformCommonType(Type $type): Type
 			}
 
 			return $traverse($type);
-		});
+		}));
 	}
 
 	/**
@@ -112,7 +113,7 @@ private function transformCommonType(Type $type): Type
 	private function transformAcceptedType(Type $acceptingType, Type $acceptedType): array
 	{
 		$checkForUnion = $this->checkUnionTypes;
-		$acceptedType = TypeTraverser::map($acceptedType, function (Type $acceptedType, callable $traverse) use ($acceptingType, &$checkForUnion): Type {
+		$acceptedType = TypeTraverser::map($acceptedType, new MemoizingTraverser(function (Type $acceptedType, callable $traverse) use ($acceptingType, &$checkForUnion): Type {
 			if ($acceptedType instanceof CallableType) {
 				if ($acceptedType->isCommonCallable()) {
 					return $acceptedType;
@@ -175,7 +176,7 @@ private function transformAcceptedType(Type $acceptingType, Type $acceptedType):
 			}
 
 			return $traverse($acceptedType);
-		});
+		}));
 
 		return [$this->transformCommonType($acceptedType), $checkForUnion];
 	}

src/Type/Traverser/MemoizingTraverser.php

@@ -0,0 +1,49 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Type\Traverser;
+
+use PHPStan\Type\Type;
+use PHPStan\Type\TypeTraverserCallable;
+use function spl_object_id;
+
+/**
+ * Calls the wrapped callback only once per distinct Type object within a single
+ * TypeTraverser::map() call and reuses its result on repeated visits.
+ *
+ * Big array shapes built from type aliases share the same inner Type objects many
+ * times over, so a plain traversal visits orders of magnitude more nodes than there
+ * are distinct types. Only suitable for callbacks whose result depends on the visited
+ * type alone — callbacks collecting types into a list see each object once.
+ */
+final class MemoizingTraverser implements TypeTraverserCallable
+{
+
+	/** @var array<int, array{Type, Type}> */
+	private array $results = [];
+
+	/**
+	 * @param callable(Type $type, callable(Type): Type $traverse): Type $cb
+	 */
+	public function __construct(private $cb)
+	{
+	}
+
+	/**
+	 * @param callable(Type): Type $traverse
+	 */
+	public function traverse(Type $type, callable $traverse): Type
+	{
+		$id = spl_object_id($type);
+		if (isset($this->results[$id])) {
+			return $this->results[$id][1];
+		}
+
+		$result = ($this->cb)($type, $traverse);
+
+		// keeps the visited type alive so that its object id is not reused
+		$this->results[$id] = [$type, $result];
+
+		return $result;
+	}
+
+}