InferenceState Class — react Architecture

Source Code

compiler/packages/babel-plugin-react-compiler/src/Inference/InferMutationAliasingEffects.ts lines 1310–1668

class InferenceState {
  env: Environment;
  #isFunctionExpression: boolean;

  // The kind of each value, based on its allocation site
  #values: Map<InstructionValue, AbstractValue>;
  /*
   * The set of values pointed to by each identifier. This is a set
   * to accomodate phi points (where a variable may have different
   * values from different control flow paths).
   */
  #variables: Map<IdentifierId, Set<InstructionValue>>;

  constructor(
    env: Environment,
    isFunctionExpression: boolean,
    values: Map<InstructionValue, AbstractValue>,
    variables: Map<IdentifierId, Set<InstructionValue>>,
  ) {
    this.env = env;
    this.#isFunctionExpression = isFunctionExpression;
    this.#values = values;
    this.#variables = variables;
  }

  static empty(
    env: Environment,
    isFunctionExpression: boolean,
  ): InferenceState {
    return new InferenceState(env, isFunctionExpression, new Map(), new Map());
  }

  get isFunctionExpression(): boolean {
    return this.#isFunctionExpression;
  }

  // (Re)initializes a @param value with its default @param kind.
  initialize(value: InstructionValue, kind: AbstractValue): void {
    CompilerError.invariant(value.kind !== 'LoadLocal', {
      reason:
        '[InferMutationAliasingEffects] Expected all top-level identifiers to be defined as variables, not values',
      loc: value.loc,
    });
    this.#values.set(value, kind);
  }

  values(place: Place): Array<InstructionValue> {
    const values = this.#variables.get(place.identifier.id);
    CompilerError.invariant(values != null, {
      reason: `[InferMutationAliasingEffects] Expected value kind to be initialized`,
      description: `${printPlace(place)}`,
      message: 'this is uninitialized',
      loc: place.loc,
    });
    return Array.from(values);
  }

  // Lookup the kind of the given @param value.
  kind(place: Place): AbstractValue {
    const values = this.#variables.get(place.identifier.id);
    CompilerError.invariant(values != null, {
      reason: `[InferMutationAliasingEffects] Expected value kind to be initialized`,
      description: `${printPlace(place)}`,
      message: 'this is uninitialized',
      loc: place.loc,
    });
    let mergedKind: AbstractValue | null = null;
    for (const value of values) {
      const kind = this.#values.get(value)!;
      mergedKind =
        mergedKind !== null ? mergeAbstractValues(mergedKind, kind) : kind;
    }
    CompilerError.invariant(mergedKind !== null, {
      reason: `[InferMutationAliasingEffects] Expected at least one value`,
      description: `No value found at \`${printPlace(place)}\``,
      loc: place.loc,
    });
    return mergedKind;
  }

  // Updates the value at @param place to point to the same value as @param value.