object-introspection/oi/Features.h

/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#pragma once

#include <array>
#include <bitset>
#include <string_view>

#define OI_FEATURE_LIST                         \
  X(ChaseRawPointers, "chase-raw-pointers")     \
  X(PackStructs, "pack-structs")                \
  X(GenPaddingStats, "gen-padding-stats")       \
  X(CaptureThriftIsset, "capture-thrift-isset") \
  X(TypeGraph, "type-graph")                    \
  X(PolymorphicInheritance, "polymorphic-inheritance")

namespace ObjectIntrospection {

enum class Feature {
  UnknownFeature,
#define X(name, _) name,
  OI_FEATURE_LIST
#undef X
};

Feature featureFromStr(std::string_view);
const char* featureToStr(Feature);

constexpr std::array allFeatures = {
#define X(name, _) Feature::name,
    OI_FEATURE_LIST
#undef X
};

class FeatureSet {
 private:
  using BitsetType = std::bitset<allFeatures.size() + 1>;

 public:
  FeatureSet() = default;
  FeatureSet(std::initializer_list<Feature>);

  constexpr bool operator[](Feature f) const {
    return bitset[(size_t)f];
  }
  BitsetType::reference operator[](Feature f) {
    return bitset[(size_t)f];
  }

 private:
  BitsetType bitset;
};

}  // namespace ObjectIntrospection