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

// Copyright (c) 2018, 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.DexType;
import com.android.tools.r8.graph.UseRegistry;
import com.android.tools.r8.ir.conversion.CfSourceCode;
import com.android.tools.r8.ir.conversion.CfState;
import com.android.tools.r8.ir.conversion.CfState.Slot;
import com.android.tools.r8.ir.conversion.IRBuilder;
import com.android.tools.r8.ir.optimize.Inliner.ConstraintWithTarget;
import com.android.tools.r8.ir.optimize.InliningConstraints;
import com.android.tools.r8.naming.NamingLens;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

public class CfCheckCast extends CfInstruction {

  private final DexType type;

  public CfCheckCast(DexType type) {
    this.type = type;
  }

  public DexType getType() {
    return type;
  }

  @Override
  public void write(MethodVisitor visitor, NamingLens lens) {
    visitor.visitTypeInsn(Opcodes.CHECKCAST, lens.lookupInternalName(type));
  }

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

  @Override
  public void registerUse(UseRegistry registry, DexType clazz) {
    registry.registerCheckCast(type);
  }

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

  @Override
  public void buildIR(IRBuilder builder, CfState state, CfSourceCode code) {
    // Pop the top value and push it back on with the checked type.
    state.pop();
    Slot object = state.push(type);
    builder.addCheckCast(object.register, type);
  }

  @Override
  public ConstraintWithTarget inliningConstraint(
      InliningConstraints inliningConstraints,
      DexType invocationContext) {
    return inliningConstraints.forCheckCast(type, invocationContext);
  }
}