Class ParameterVariable

src/ast/variables/ParameterVariable.ts:39–280

const UNKNOWN_DEOPTIMIZED_ENTITY = new Set<ExpressionEntity>([UNKNOWN_EXPRESSION]);

export default class ParameterVariable extends LocalVariable {
	protected includedPathTracker = new IncludedTopLevelPathTracker();
	private argumentsToBeDeoptimized = new Set<ExpressionEntity>();
	private deoptimizationInteractions: TrackedInteraction[] = [];
	private deoptimizations = new EntityPathTracker();
	private deoptimizedFields = new Set<ObjectPathKey>();
	private expressionsDependingOnKnownValue: DeoptimizableEntity[] = [];
	private knownValue: ExpressionEntity | null = null;
	private knownValueLiteral: LiteralValueOrUnknown = UnknownValue;

	constructor(
		name: string,
		declarator: Identifier | ExportDefaultDeclaration | null,
		argumentPath: ObjectPath,
		context: AstContext
	) {
		super(name, declarator, UNKNOWN_EXPRESSION, argumentPath, context, 'parameter');
	}

	addArgumentForDeoptimization(entity: ExpressionEntity): void {
		this.updateKnownValue(entity);
		if (entity === UNKNOWN_EXPRESSION) {
			// As unknown expressions fully deoptimize all interactions, we can clear
			// the interaction cache at this point provided we keep this optimization
			// in mind when adding new interactions
			if (!this.argumentsToBeDeoptimized.has(UNKNOWN_EXPRESSION)) {
				this.argumentsToBeDeoptimized.add(UNKNOWN_EXPRESSION);
				for (const { interaction } of this.deoptimizationInteractions) {
					deoptimizeInteraction(interaction);
				}
				this.deoptimizationInteractions = NO_INTERACTIONS;
			}
		} else if (this.deoptimizedFields.has(UnknownKey)) {
			// This means that we already deoptimized all interactions and no longer
			// track them
			entity.deoptimizePath([...this.initPath, UnknownKey]);
		} else if (!this.argumentsToBeDeoptimized.has(entity)) {
			this.argumentsToBeDeoptimized.add(entity);
			for (const field of this.deoptimizedFields) {
				entity.deoptimizePath([...this.initPath, field]);
			}
			for (const { interaction, path } of this.deoptimizationInteractions) {
				entity.deoptimizeArgumentsOnInteractionAtPath(
					interaction,
					[...this.initPath, ...path],
					SHARED_RECURSION_TRACKER
				);
			}
		}
	}

	/** This says we should not make assumptions about the value of the parameter.
	 *  This is different from deoptimization that will also cause argument values
	 *  to be deoptimized. */
	markReassigned(): void {
		if (this.isReassigned) {
			return;
		}