src/main/java/com/android/tools/r8/cf/code/CfConstString.java

// Copyright (c) 2017, 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.cf.code;

import com.android.tools.r8.cf.CfPrinter;
import com.android.tools.r8.graph.AppView;
import com.android.tools.r8.graph.CfCompareHelper;
import com.android.tools.r8.graph.DexItemFactory;
import com.android.tools.r8.graph.DexString;
import com.android.tools.r8.graph.ProgramMethod;
import com.android.tools.r8.graph.lens.GraphLens;
import com.android.tools.r8.graph.lens.InitClassLens;
import com.android.tools.r8.ir.conversion.CfSourceCode;
import com.android.tools.r8.ir.conversion.CfState;
import com.android.tools.r8.ir.conversion.IRBuilder;
import com.android.tools.r8.ir.conversion.LensCodeRewriterUtils;
import com.android.tools.r8.naming.NamingLens;
import com.android.tools.r8.optimize.interfaces.analysis.CfAnalysisConfig;
import com.android.tools.r8.optimize.interfaces.analysis.CfFrameState;
import com.android.tools.r8.utils.structural.CompareToVisitor;
import com.android.tools.r8.utils.structural.HashingVisitor;
import org.objectweb.asm.MethodVisitor;

public class CfConstString extends CfInstruction {

  private DexString string;

  public CfConstString(DexString string) {
    this.string = string;
  }

  @Override
  public int getCompareToId() {
    return CfCompareHelper.CONST_STRING_COMPARE_ID;
  }

  @Override
  public int internalAcceptCompareTo(
      CfInstruction other, CompareToVisitor visitor, CfCompareHelper helper) {
    return string.acceptCompareTo(other.asConstString().string, visitor);
  }

  @Override
  public void internalAcceptHashing(HashingVisitor visitor) {
    string.acceptHashing(visitor);
  }

  public DexString getString() {
    return string;
  }

  public void setString(DexString string) {
    this.string = string;
  }

  @Override
  public CfConstString asConstString() {
    return this;
  }

  @Override
  public boolean isConstString() {
    return true;
  }

  @Override
  public void write(
      AppView<?> appView,
      ProgramMethod context,
      DexItemFactory dexItemFactory,
      GraphLens graphLens,
      GraphLens codeLens,
      InitClassLens initClassLens,
      NamingLens namingLens,
      LensCodeRewriterUtils rewriter,
      MethodVisitor visitor) {
    visitor.visitLdcInsn(string.toString());
  }

  @Override
  public int bytecodeSizeUpperBound() {
    // ldc or ldc_w
    return 3;
  }

  @Override
  public void print(CfPrinter printer) {
    printer.print(this);
  }

  @Override
  public boolean canThrow() {
    // const-string* may throw in dex. (Not in CF, see CfSourceCode.canThrowHelper)
    return true;
  }

  @Override
  public void buildIR(IRBuilder builder, CfState state, CfSourceCode code) {
    builder.addConstString(
        state.push(builder.appView.dexItemFactory().stringType).register, string);
  }

  @Override
  public CfFrameState evaluate(CfFrameState frame, AppView<?> appView, CfAnalysisConfig config) {
    // ... →
    // ..., value
    return frame.push(config, appView.dexItemFactory().stringType);
  }
}