collectTemporariesSidemapImpl() — react Function Reference

Source Code

compiler/packages/babel-plugin-react-compiler/src/HIR/PropagateScopeDependenciesHIR.ts lines 272–336

function collectTemporariesSidemapImpl(
  fn: HIRFunction,
  usedOutsideDeclaringScope: ReadonlySet<DeclarationId>,
  temporaries: Map<IdentifierId, ReactiveScopeDependency>,
  innerFnContext: {instrId: InstructionId} | null,
): void {
  for (const [_, block] of fn.body.blocks) {
    for (const {value, lvalue, id: origInstrId} of block.instructions) {
      const instrId =
        innerFnContext != null ? innerFnContext.instrId : origInstrId;
      const usedOutside = usedOutsideDeclaringScope.has(
        lvalue.identifier.declarationId,
      );

      if (value.kind === 'PropertyLoad' && !usedOutside) {
        if (
          innerFnContext == null ||
          temporaries.has(value.object.identifier.id)
        ) {
          /**
           * All dependencies of a inner / nested function must have a base
           * identifier from the outermost component / hook. This is because the
           * compiler cannot break an inner function into multiple granular
           * scopes.
           */
          const property = getProperty(
            value.object,
            value.property,
            false,
            temporaries,
          );
          temporaries.set(lvalue.identifier.id, property);
        }
      } else if (
        (value.kind === 'LoadLocal' || isLoadContextMutable(value, instrId)) &&
        lvalue.identifier.name == null &&
        value.place.identifier.name !== null &&
        !usedOutside
      ) {
        if (
          innerFnContext == null ||
          fn.context.some(
            context => context.identifier.id === value.place.identifier.id,
          )
        ) {
          temporaries.set(lvalue.identifier.id, {
            identifier: value.place.identifier,
            reactive: value.place.reactive,
            path: [],
          });
        }
      } else if (
        value.kind === 'FunctionExpression' ||
        value.kind === 'ObjectMethod'
      ) {
        collectTemporariesSidemapImpl(
          value.loweredFunc.func,
          usedOutsideDeclaringScope,
          temporaries,
          innerFnContext ?? {instrId},
        );
      }
    }
  }
}