src/main/java/com/android/tools/r8/optimize/interfaces/analysis/CfOpenClosedInterfacesAnalysis.java

// Copyright (c) 2022, 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.optimize.interfaces.analysis;

import com.android.tools.r8.cf.code.CfInstruction;
import com.android.tools.r8.graph.AppView;
import com.android.tools.r8.graph.CfCode;
import com.android.tools.r8.graph.Code;
import com.android.tools.r8.graph.DexEncodedMethod;
import com.android.tools.r8.graph.DexMethod;
import com.android.tools.r8.graph.DexProgramClass;
import com.android.tools.r8.graph.DexType;
import com.android.tools.r8.graph.ProgramMethod;
import com.android.tools.r8.ir.analysis.framework.intraprocedural.AbstractTransferFunction;
import com.android.tools.r8.ir.analysis.framework.intraprocedural.DataflowAnalysisResult;
import com.android.tools.r8.ir.analysis.framework.intraprocedural.TransferFunctionResult;
import com.android.tools.r8.ir.analysis.framework.intraprocedural.cf.CfBlock;
import com.android.tools.r8.ir.analysis.framework.intraprocedural.cf.CfControlFlowGraph;
import com.android.tools.r8.ir.analysis.framework.intraprocedural.cf.CfIntraproceduralDataflowAnalysis;
import com.android.tools.r8.shaking.AppInfoWithLiveness;

public class CfOpenClosedInterfacesAnalysis {

  private final AppView<AppInfoWithLiveness> appView;

  public CfOpenClosedInterfacesAnalysis(AppView<AppInfoWithLiveness> appView) {
    this.appView = appView;
  }

  public void run() {
    // TODO(b/214496607): Parallelize the analysis.
    for (DexProgramClass clazz : appView.appInfo().classes()) {
      clazz.forEachProgramMethodMatching(DexEncodedMethod::hasCode, this::processMethod);
    }
  }

  private void processMethod(ProgramMethod method) {
    Code code = method.getDefinition().getCode();
    if (!code.isCfCode()) {
      assert code.isDefaultInstanceInitializerCode() || code.isThrowNullCode();
      return;
    }

    CfCode cfCode = code.asCfCode();
    CfControlFlowGraph cfg = CfControlFlowGraph.create(cfCode);
    CfIntraproceduralDataflowAnalysis<CfFrameState> analysis =
        new CfIntraproceduralDataflowAnalysis<>(
            CfFrameState.bottom(), cfg, new TransferFunction(method));
    DataflowAnalysisResult result = analysis.run(cfg.getEntryBlock());
    // TODO(b/214496607): Determine open interfaces.
  }

  private class TransferFunction
      implements AbstractTransferFunction<CfBlock, CfInstruction, CfFrameState> {

    private final CfAnalysisConfig config;

    TransferFunction(ProgramMethod context) {
      CfCode code = context.getDefinition().getCode().asCfCode();
      int maxLocals = code.getMaxLocals();
      int maxStack = code.getMaxStack();
      this.config =
          new CfAnalysisConfig() {

            @Override
            public DexMethod getCurrentContext() {
              return context.getReference();
            }

            @Override
            public int getMaxLocals() {
              return maxLocals;
            }

            @Override
            public int getMaxStack() {
              return maxStack;
            }

            @Override
            public boolean isImmediateSuperClassOfCurrentContext(DexType type) {
              return type == context.getHolder().getSuperType();
            }
          };
    }

    @Override
    public TransferFunctionResult<CfFrameState> apply(
        CfInstruction instruction, CfFrameState state) {
      return instruction.evaluate(state, appView, config, appView.dexItemFactory());
    }

    @Override
    public CfFrameState computeBlockEntryState(
        CfBlock block, CfBlock predecessor, CfFrameState predecessorExitState) {
      return predecessorExitState;
    }
  }
}