CallPositionFrames CallPositionFrames::propagate_crtex_frames()

in source/CallPositionFrames.cpp [485:569]

• 70 lines of code
• 10 McCabe index (conditional complexity)

CallPositionFrames CallPositionFrames::propagate_crtex_frames(
    const Method* callee,
    const AccessPath& callee_port,
    const Position* call_position,
    int maximum_source_sink_distance,
    Context& context,
    const std::vector<const DexType * MT_NULLABLE>& source_register_types,
    std::vector<std::reference_wrapper<const Frame>> frames) const {
  if (frames.size() == 0) {
    return CallPositionFrames::bottom();
  }

  CallPositionFrames result;
  const auto* kind = frames.begin()->get().kind();

  for (const Frame& frame : frames) {
    // Only frames sharing the same kind can be propagated this way.
    mt_assert(frame.kind() == kind);

    std::vector<const Feature*> via_type_of_features_added;
    auto propagated = propagate_frames(
        callee,
        callee_port,
        call_position,
        maximum_source_sink_distance,
        context,
        source_register_types,
        {}, // TODO: Support via-value-of for crtex frames
        {std::cref(frame)},
        via_type_of_features_added);

    if (propagated.is_bottom()) {
      continue;
    }

    auto canonical_names = frame.canonical_names();
    if (!canonical_names.is_value() || canonical_names.elements().empty()) {
      WARNING(
          2,
          "Encountered crtex frame without canonical names. Frame: `{}`",
          frame);
      continue;
    }

    CanonicalNameSetAbstractDomain instantiated_names;
    for (const auto& canonical_name : canonical_names.elements()) {
      auto instantiated_name = canonical_name.instantiate(
          propagated.callee(), via_type_of_features_added);
      if (!instantiated_name) {
        continue;
      }
      instantiated_names.add(*instantiated_name);
    }

    auto canonical_callee_port =
        propagated.callee_port().canonicalize_for_method(propagated.callee());

    // All fields should be propagated like other frames, except the crtex
    // fields. Ideally, origins should contain the canonical names as well,
    // but canonical names are strings and cannot be stored in MethodSet.
    // Frame is not propagated if none of the canonical names instantiated
    // successfully.
    if (instantiated_names.is_value() &&
        !instantiated_names.elements().empty()) {
      result.add(Frame(
          kind,
          canonical_callee_port,
          propagated.callee(),
          propagated.field_callee(),
          propagated.call_position(),
          /* distance (always leaves for crtex frames) */ 0,
          propagated.origins(),
          propagated.field_origins(),
          propagated.inferred_features(),
          propagated.locally_inferred_features(),
          propagated.user_features(),
          propagated.via_type_of_ports(),
          propagated.via_value_of_ports(),
          propagated.local_positions(),
          /* canonical_names */ instantiated_names));
    }
  }

  return result;
}