Data.java

/*
 * Copyright 2000-2014 JetBrains s.r.o.
 *
 * 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.
 */
package com.intellij.codeInspection.bytecodeAnalysis;

import com.intellij.openapi.util.text.StringUtil;
import one.util.streamex.StreamEx;
import org.jetbrains.org.objectweb.asm.Handle;
import org.jetbrains.org.objectweb.asm.Type;
import org.jetbrains.org.objectweb.asm.tree.InvokeDynamicInsnNode;
import org.jetbrains.org.objectweb.asm.tree.MethodInsnNode;
import org.jetbrains.org.objectweb.asm.tree.analysis.BasicValue;

import java.util.List;
import java.util.function.Function;

import static org.jetbrains.org.objectweb.asm.Opcodes.*;

final class Method {
  final String internalClassName;
  final String methodName;
  final String methodDesc;

  @Override
  public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;
    Method method = (Method) o;
    return internalClassName.equals(method.internalClassName) && methodDesc.equals(method.methodDesc) && methodName.equals(method.methodName);
  }

  @Override
  public int hashCode() {
    int result = internalClassName.hashCode();
    result = 31 * result + methodName.hashCode();
    result = 31 * result + methodDesc.hashCode();
    return result;
  }

  /**
   * Primary constructor
   *
   * @param internalClassName class name in asm format
   * @param methodName method name
   * @param methodDesc method descriptor in asm format
   */
  Method(String internalClassName, String methodName, String methodDesc) {
    this.internalClassName = internalClassName;
    this.methodName = methodName;
    this.methodDesc = methodDesc;
  }

  /**
   * Convenient constructor to convert asm instruction into method key
   *
   * @param mNode asm node from which method key is extracted
   */
  Method(MethodInsnNode mNode) {
    this.internalClassName = mNode.owner;
    this.methodName = mNode.name;
    this.methodDesc = mNode.desc;
  }

  @Override
  public String toString() {
    return internalClassName + ' ' + methodName + ' ' + methodDesc;
  }
}

enum Value {
  Bot, NotNull, Null, True, False, Pure, Top
}

interface Direction {
  final class In implements Direction {
    final int paramIndex;

    static final int NOT_NULL_MASK = 0;
    static final int NULLABLE_MASK = 1;
    /**
     * @see #NOT_NULL_MASK
     * @see #NULLABLE_MASK
     */
    final int nullityMask;

    In(int paramIndex, int nullityMask) {
      this.paramIndex = paramIndex;
      this.nullityMask = nullityMask;
    }

    @Override
    public String toString() {
      return "In " + paramIndex;
    }

    @Override
    public boolean equals(Object o) {
      if (this == o) return true;
      if (o == null || getClass() != o.getClass()) return false;
      In in = (In)o;
      if (paramIndex != in.paramIndex) return false;
      if (nullityMask != in.nullityMask) return false;
      return true;
    }

    @Override
    public int hashCode() {
      return 31 * paramIndex + nullityMask;
    }

    public int paramId() {
      return paramIndex;
    }
  }

  final class InOut implements Direction {
    final int paramIndex;
    final Value inValue;

    InOut(int paramIndex, Value inValue) {
      this.paramIndex = paramIndex;
      this.inValue = inValue;
    }

    @Override
    public boolean equals(Object o) {
      if (this == o) return true;
      if (o == null || getClass() != o.getClass()) return false;

      InOut inOut = (InOut)o;

      if (paramIndex != inOut.paramIndex) return false;
      if (inValue != inOut.inValue) return false;

      return true;
    }

    @Override
    public int hashCode() {
      int result = paramIndex;
      result = 31 * result + inValue.ordinal();
      return result;
    }

    @Override
    public String toString() {
      return "InOut " + paramIndex + " " + inValue.toString();
    }

    public int paramId() {
      return paramIndex;
    }

    public int valueId() {
      return inValue.ordinal();
    }
  }

  Direction Out = new Direction() {
    @Override
    public String toString() {
      return "Out";
    }

    @Override
    public int hashCode() {
      return -1;
    }
  };

  Direction NullableOut = new Direction() {
    @Override
    public String toString() {
      return "NullableOut";
    }

    @Override
    public int hashCode() {
      return -2;
    }
  };

  Direction Pure = new Direction() {
    @Override
    public int hashCode() {
      return -3;
    }

    @Override
    public String toString() {
      return "Pure";
    }
  };
}

final class Key {
  final Method method;
  final Direction direction;
  final boolean stable;
  final boolean negated;

  Key(Method method, Direction direction, boolean stable) {
    this.method = method;
    this.direction = direction;
    this.stable = stable;
    this.negated = false;
  }

  Key(Method method, Direction direction, boolean stable, boolean negated) {
    this.method = method;
    this.direction = direction;
    this.stable = stable;
    this.negated = negated;
  }

  @Override
  public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;

    Key key = (Key) o;

    if (!direction.equals(key.direction)) return false;
    if (!method.equals(key.method)) return false;
    if (stable != key.stable) return false;
    return true;
  }

  @Override
  public int hashCode() {
    int result = method.hashCode();
    result = 31 * result + direction.hashCode();
    result = 31 * result + (stable ? 1 : 0);
    return result;
  }

  @Override
  public String toString() {
    return method + " " + direction + " " + stable;
  }
}

final class LambdaIndy {
  private static final String LAMBDA_METAFACTORY_CLASS = "java/lang/invoke/LambdaMetafactory";
  private static final String LAMBDA_METAFACTORY_METHOD = "metafactory";
  private static final String LAMBDA_METAFACTORY_DESCRIPTOR =
    "(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;";
  private final int myTag;
  private final Type myFunctionalMethodType;
  private final Method myMethod;
  private final Type myFunctionalInterfaceType;

  private LambdaIndy(int tag, Type functionalMethodType, Method lambdaMethod, Type functionalInterfaceType) {
    myTag = tag;
    myFunctionalMethodType = functionalMethodType;
    myMethod = lambdaMethod;
    myFunctionalInterfaceType = functionalInterfaceType;
  }

  public int getTag() {
    return myTag;
  }

  /**
   * @return an opcode which corresponds to target method handle or -1 if method handle tag has no corresponding opcode
   */
  public int getAssociatedOpcode() {
    switch (myTag) {
      case H_INVOKESTATIC:
        return INVOKESTATIC;
      case H_INVOKESPECIAL:
        return INVOKESPECIAL;
      case H_INVOKEINTERFACE:
        return INVOKEINTERFACE;
      case H_INVOKEVIRTUAL:
        return INVOKEVIRTUAL;
    }
    return -1;
  }

  public Type getFunctionalMethodType() {
    return myFunctionalMethodType;
  }

  public Method getMethod() {
    return myMethod;
  }

  public Type getFunctionalInterfaceType() {
    return myFunctionalInterfaceType;
  }

  /**
   * Creates list of argument values which should be passed to lambda runtime representation method
   *
   * @param captured list of captured arguments
   * @param valueSupplier function to create new values by type
   * @return list of lambda argument values
   */
  List<BasicValue> getLambdaMethodArguments(List<? extends BasicValue> captured, Function<Type, BasicValue> valueSupplier) {
    // Lambda runtime representation args consist of captured values and invocation values
    // E.g.:
    // IntUnaryOperator getAdder(int addend) { return x -> addend + x; }
    // will generate
    // static int lambda$getAdder$0(int addend, int x) {return addend + x;}
    return StreamEx.of(getFunctionalMethodType().getArgumentTypes()).map(valueSupplier).prepend(captured).toList();
  }

  public String toString() {
    return "Lambda [" + myMethod.methodName + "]: " + StringUtil.getShortName(myFunctionalInterfaceType.getClassName());
  }

  static LambdaIndy from(InvokeDynamicInsnNode indyNode) {
    Handle bsm = indyNode.bsm;
    if(LAMBDA_METAFACTORY_CLASS.equals(bsm.getOwner()) &&
       LAMBDA_METAFACTORY_METHOD.equals(bsm.getName()) &&
       LAMBDA_METAFACTORY_DESCRIPTOR.equals(bsm.getDesc()) &&
       indyNode.bsmArgs.length >= 3 && indyNode.bsmArgs[1] instanceof Handle && indyNode.bsmArgs[2] instanceof Type) {
      Handle lambdaBody = (Handle)indyNode.bsmArgs[1];
      Type targetType = (Type)indyNode.bsmArgs[2];
      Method targetMethod = new Method(lambdaBody.getOwner(), lambdaBody.getName(), lambdaBody.getDesc());
      Type retType = Type.getReturnType(indyNode.desc);
      return new LambdaIndy(lambdaBody.getTag(), targetType, targetMethod, retType);
    }
    return null;
  }
}