applyEffect() — react Function Reference

Source Code

compiler/packages/babel-plugin-react-compiler/src/Inference/InferMutationAliasingEffects.ts lines 673–1308

function applyEffect(
  context: Context,
  state: InferenceState,
  _effect: AliasingEffect,
  initialized: Set<IdentifierId>,
  effects: Array<AliasingEffect>,
): void {
  const effect = context.internEffect(_effect);
  if (DEBUG) {
    console.log(printAliasingEffect(effect));
  }
  switch (effect.kind) {
    case 'Freeze': {
      const didFreeze = state.freeze(effect.value, effect.reason);
      if (didFreeze) {
        effects.push(effect);
      }
      break;
    }
    case 'Create': {
      CompilerError.invariant(!initialized.has(effect.into.identifier.id), {
        reason: `Cannot re-initialize variable within an instruction`,
        description: `Re-initialized ${printPlace(effect.into)} in ${printAliasingEffect(effect)}`,
        loc: effect.into.loc,
      });
      initialized.add(effect.into.identifier.id);

      let value = context.effectInstructionValueCache.get(effect);
      if (value == null) {
        value = {
          kind: 'ObjectExpression',
          properties: [],
          loc: effect.into.loc,
        };
        context.effectInstructionValueCache.set(effect, value);
      }
      state.initialize(value, {
        kind: effect.value,
        reason: new Set([effect.reason]),
      });
      state.define(effect.into, value);
      effects.push(effect);
      break;
    }
    case 'ImmutableCapture': {
      const kind = state.kind(effect.from).kind;
      switch (kind) {
        case ValueKind.Global:
        case ValueKind.Primitive: {
          // no-op: we don't need to track data flow for copy types
          break;
        }
        default: {
          effects.push(effect);
        }
      }
      break;
    }
    case 'CreateFrom': {
      CompilerError.invariant(!initialized.has(effect.into.identifier.id), {
        reason: `Cannot re-initialize variable within an instruction`,
        description: `Re-initialized ${printPlace(effect.into)} in ${printAliasingEffect(effect)}`,
        loc: effect.into.loc,
      });
      initialized.add(effect.into.identifier.id);

      const fromValue = state.kind(effect.from);
      let value = context.effectInstructionValueCache.get(effect);
      if (value == null) {
        value = {
          kind: 'ObjectExpression',
          properties: [],
          loc: effect.into.loc,
        };
        context.effectInstructionValueCache.set(effect, value);
      }
      state.initialize(value, {
        kind: fromValue.kind,
        reason: new Set(fromValue.reason),
      });
      state.define(effect.into, value);