/** * Visit a node with kind `\ast\AST_DIM` * * @param Node $node * A node of the type indicated by the method name that we'd * like to figure out the type that it produces. * * @return UnionType * The set of types that are possibly produced by the * given node */ public function visitDim(Node $node) : UnionType { $union_type = UnionType::fromNode($this->context, $this->code_base, $node->children['expr']); if ($union_type->isEmpty()) { return new UnionType(); } // Figure out what the types of accessed array // elements would be $generic_types = $union_type->genericArrayElementTypes(); // If we have generics, we're all set if (!$generic_types->isEmpty()) { return $generic_types; } // If the only type is null, we don't know what // accessed items will be if ($union_type->isType(NullType::instance())) { return new UnionType(); } $element_types = new UnionType(); // You can access string characters via array index, // so we'll add the string type to the result if we're // indexing something that could be a string if ($union_type->isType(StringType::instance()) || $union_type->canCastToUnionType(StringType::instance()->asUnionType())) { $element_types->addType(StringType::instance()); } // array offsets work on strings, unfortunately // Double check that any classes in the type don't // have ArrayAccess $array_access_type = Type::fromNamespaceAndName('\\', 'ArrayAccess'); // Hunt for any types that are viable class names and // see if they inherit from ArrayAccess foreach ($union_type->getTypeList() as $type) { if ($type->isNativeType()) { continue; } $class_fqsen = FullyQualifiedClassName::fromType($type); // If we can't find the class, the type probably // wasn't a class. if (!$this->code_base->hasClassWithFQSEN($class_fqsen)) { continue; } $clazz = $this->code_base->getClassByFQSEN($class_fqsen); // If the class has type ArrayAccess, it can be indexed // as if it were an array. That being said, we still don't // know the types of the elements, but at least we don't // error out. if ($clazz->getUnionType()->hasType($array_access_type)) { return $element_types; } } if ($element_types->isEmpty()) { Log::err(Log::ETYPE, "Suspicious array access to {$union_type}", $this->context->getFile(), $node->lineno); } return $element_types; }
/** * Takes "a|b[]|c|d[]|e" and returns "b|d" * * @return UnionType * The subset of types in this */ public function genericArrayElementTypes() : UnionType { // If array is in there, then it can be any type // Same for mixed if ($this->hasType(ArrayType::instance()) || $this->hasType(MixedType::instance())) { return MixedType::instance()->asUnionType(); } if ($this->hasType(ArrayType::instance())) { return NullType::instance()->asUnionType(); } return new UnionType(array_filter(array_map(function (Type $type) { if (!$type->isGenericArray()) { return null; } return $type->genericArrayElementType(); }, $this->getTypeList()))); }
public function testEvaluate() { $object = new NullType(); $this->assertNull($object->evaluate(['unused'])); }