src/main/java/com/android/tools/r8/ir/desugar/desugaredlibrary/legacyspecification/MultiAPILevelLegacyDesugaredLibrarySpecificationParser.java

// Copyright (c) 2021, the R8 project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

package com.android.tools.r8.ir.desugar.desugaredlibrary.legacyspecification;

import com.android.tools.r8.StringResource;
import com.android.tools.r8.graph.DexItemFactory;
import com.android.tools.r8.utils.Reporter;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import it.unimi.dsi.fastutil.ints.Int2ObjectArrayMap;
import it.unimi.dsi.fastutil.ints.Int2ObjectMap;

public class MultiAPILevelLegacyDesugaredLibrarySpecificationParser
    extends LegacyDesugaredLibrarySpecificationParser {

  public MultiAPILevelLegacyDesugaredLibrarySpecificationParser(
      DexItemFactory dexItemFactory, Reporter reporter) {
    super(dexItemFactory, reporter, false, 1);
  }

  public MultiAPILevelLegacyDesugaredLibrarySpecification parseMultiLevelConfiguration(
      StringResource stringResource) {

    String jsonConfigString = parseJson(stringResource);

    LegacyTopLevelFlags topLevelFlags = parseTopLevelFlags(jsonConfigString, builder -> {});

    Int2ObjectMap<LegacyRewritingFlags> commonFlags = parseAllFlags(COMMON_FLAGS_KEY);
    Int2ObjectMap<LegacyRewritingFlags> libraryFlags = parseAllFlags(LIBRARY_FLAGS_KEY);
    Int2ObjectMap<LegacyRewritingFlags> programFlags = parseAllFlags(PROGRAM_FLAGS_KEY);

    return new MultiAPILevelLegacyDesugaredLibrarySpecification(
        topLevelFlags, commonFlags, libraryFlags, programFlags);
  }

  private Int2ObjectMap<LegacyRewritingFlags> parseAllFlags(String flagKey) {
    JsonElement jsonFlags = required(getJsonConfig(), flagKey);
    Int2ObjectMap<LegacyRewritingFlags> flags = new Int2ObjectArrayMap<>();
    for (JsonElement jsonFlagSet : jsonFlags.getAsJsonArray()) {
      JsonObject flag = jsonFlagSet.getAsJsonObject();
      int api_level_below_or_equal = required(flag, API_LEVEL_BELOW_OR_EQUAL_KEY).getAsInt();
      LegacyRewritingFlags.Builder builder =
          flags.containsKey(api_level_below_or_equal)
              ? flags
                  .get(api_level_below_or_equal)
                  .newBuilder(dexItemFactory(), reporter(), getOrigin())
              : LegacyRewritingFlags.builder(dexItemFactory(), reporter(), getOrigin());
      parseFlags(flag, builder);
      flags.put(api_level_below_or_equal, builder.build());
    }
    return flags;
  }
}