path: root/plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/exps/FunctionExprent.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 org.jetbrains.java.decompiler.modules.decompiler.exps;

import org.jetbrains.java.decompiler.code.CodeConstants;
import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
import org.jetbrains.java.decompiler.modules.decompiler.vars.CheckTypesResult;
import org.jetbrains.java.decompiler.struct.gen.VarType;
import org.jetbrains.java.decompiler.util.InterpreterUtil;
import org.jetbrains.java.decompiler.util.ListStack;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;


public class FunctionExprent extends Exprent {

  public static final int FUNCTION_ADD = 0;
  public static final int FUNCTION_SUB = 1;
  public static final int FUNCTION_MUL = 2;
  public static final int FUNCTION_DIV = 3;

  public static final int FUNCTION_AND = 4;
  public static final int FUNCTION_OR = 5;
  public static final int FUNCTION_XOR = 6;

  public static final int FUNCTION_REM = 7;

  public static final int FUNCTION_SHL = 8;
  public static final int FUNCTION_SHR = 9;
  public static final int FUNCTION_USHR = 10;

  public static final int FUNCTION_BITNOT = 11;
  public static final int FUNCTION_BOOLNOT = 12;
  public static final int FUNCTION_NEG = 13;

  public final static int FUNCTION_I2L = 14;
  public final static int FUNCTION_I2F = 15;
  public final static int FUNCTION_I2D = 16;
  public final static int FUNCTION_L2I = 17;
  public final static int FUNCTION_L2F = 18;
  public final static int FUNCTION_L2D = 19;
  public final static int FUNCTION_F2I = 20;
  public final static int FUNCTION_F2L = 21;
  public final static int FUNCTION_F2D = 22;
  public final static int FUNCTION_D2I = 23;
  public final static int FUNCTION_D2L = 24;
  public final static int FUNCTION_D2F = 25;
  public final static int FUNCTION_I2B = 26;
  public final static int FUNCTION_I2C = 27;
  public final static int FUNCTION_I2S = 28;

  public final static int FUNCTION_CAST = 29;
  public final static int FUNCTION_INSTANCEOF = 30;

  public final static int FUNCTION_ARRAYLENGTH = 31;

  public final static int FUNCTION_IMM = 32;
  public final static int FUNCTION_MMI = 33;

  public final static int FUNCTION_IPP = 34;
  public final static int FUNCTION_PPI = 35;

  public final static int FUNCTION_IIF = 36;

  public final static int FUNCTION_LCMP = 37;
  public final static int FUNCTION_FCMPL = 38;
  public final static int FUNCTION_FCMPG = 39;
  public final static int FUNCTION_DCMPL = 40;
  public final static int FUNCTION_DCMPG = 41;

  public static final int FUNCTION_EQ = 42;
  public static final int FUNCTION_NE = 43;
  public static final int FUNCTION_LT = 44;
  public static final int FUNCTION_GE = 45;
  public static final int FUNCTION_GT = 46;
  public static final int FUNCTION_LE = 47;

  public static final int FUNCTION_CADD = 48;
  public static final int FUNCTION_COR = 49;

  public static final int FUNCTION_STRCONCAT = 50;

  private static final VarType[] types = new VarType[]{
    VarType.VARTYPE_LONG,
    VarType.VARTYPE_FLOAT,
    VarType.VARTYPE_DOUBLE,
    VarType.VARTYPE_INT,
    VarType.VARTYPE_FLOAT,
    VarType.VARTYPE_DOUBLE,
    VarType.VARTYPE_INT,
    VarType.VARTYPE_LONG,
    VarType.VARTYPE_DOUBLE,
    VarType.VARTYPE_INT,
    VarType.VARTYPE_LONG,
    VarType.VARTYPE_FLOAT,
    VarType.VARTYPE_BYTE,
    VarType.VARTYPE_CHAR,
    VarType.VARTYPE_SHORT
  };

  private static final String[] operators = new String[]{
    " + ",
    " - ",
    " * ",
    " / ",
    " & ",
    " | ",
    " ^ ",
    " % ",
    " << ",
    " >> ",
    " >>> ",
    " == ",
    " != ",
    " < ",
    " >= ",
    " > ",
    " <= ",
    " && ",
    " || ",
    " + "
  };

  private static final int[] precedence = new int[]{
    3,        //		FUNCTION_ADD
    3,        //		FUNCTION_SUB
    2,        //		FUNCTION_MUL
    2,        //		FUNCTION_DIV
    7,        //		FUNCTION_AND
    9,        //		FUNCTION_OR
    8,        //		FUNCTION_XOR
    2,        //		FUNCTION_REM
    4,        //		FUNCTION_SHL
    4,        //		FUNCTION_SHR
    4,        //		FUNCTION_USHR
    1,        //		FUNCTION_BITNOT
    1,        //		FUNCTION_BOOLNOT
    1,        //		FUNCTION_NEG
    1,        //		FUNCTION_I2L
    1,        //		FUNCTION_I2F
    1,        //		FUNCTION_I2D
    1,        //		FUNCTION_L2I
    1,        //		FUNCTION_L2F
    1,        //		FUNCTION_L2D
    1,        //		FUNCTION_F2I
    1,        //		FUNCTION_F2L
    1,        //		FUNCTION_F2D
    1,        //		FUNCTION_D2I
    1,        //		FUNCTION_D2L
    1,        //		FUNCTION_D2F
    1,        //		FUNCTION_I2B
    1,        //		FUNCTION_I2C
    1,        //		FUNCTION_I2S
    1,        //		FUNCTION_CAST
    6,        //		FUNCTION_INSTANCEOF
    0,        //		FUNCTION_ARRAYLENGTH
    1,        //		FUNCTION_IMM
    1,        //		FUNCTION_MMI
    1,        //		FUNCTION_IPP
    1,        //		FUNCTION_PPI
    12,        //		FUNCTION_IFF
    -1,        //		FUNCTION_LCMP
    -1,        //		FUNCTION_FCMPL
    -1,        //		FUNCTION_FCMPG
    -1,        //		FUNCTION_DCMPL
    -1,        //		FUNCTION_DCMPG
    6,        //		FUNCTION_EQ = 41;
    6,        //		FUNCTION_NE = 42;
    5,        //		FUNCTION_LT = 43;
    5,        //		FUNCTION_GE = 44;
    5,        //		FUNCTION_GT = 45;
    5,        //		FUNCTION_LE = 46;
    10,        //		FUNCTION_CADD = 47;
    11,        //		FUNCTION_COR = 48;
    3        //		FUNCTION_STRCONCAT = 49;
  };

  private static final HashSet<Integer> associativity =
    new HashSet<Integer>(Arrays.asList(new Integer[]{FUNCTION_ADD, FUNCTION_MUL, FUNCTION_AND,
      FUNCTION_OR, FUNCTION_XOR, FUNCTION_CADD, FUNCTION_COR, FUNCTION_STRCONCAT}));

  private int functype;

  private VarType implicitType;

  private List<Exprent> lstOperands = new ArrayList<Exprent>();

  {
    this.type = EXPRENT_FUNCTION;
  }

  public FunctionExprent(int functype, ListStack<Exprent> stack) {
    this.functype = functype;
    if (functype >= FUNCTION_BITNOT && functype <= FUNCTION_PPI && functype != FUNCTION_CAST
        && functype != FUNCTION_INSTANCEOF) {
      lstOperands.add(stack.pop());
    }
    else if (functype == FUNCTION_IIF) {
      throw new RuntimeException("no direct instantiation possible");
    }
    else {
      Exprent expr = stack.pop();
      lstOperands.add(stack.pop());
      lstOperands.add(expr);
    }
  }

  public FunctionExprent(int functype, List<Exprent> operands) {
    this.functype = functype;
    this.lstOperands = operands;
  }

  public VarType getExprType() {
    VarType exprType = null;

    if (functype <= FUNCTION_NEG || functype == FUNCTION_IPP || functype == FUNCTION_PPI
        || functype == FUNCTION_IMM || functype == FUNCTION_MMI) {

      VarType type1 = lstOperands.get(0).getExprType();
      VarType type2 = null;
      if (lstOperands.size() > 1) {
        type2 = lstOperands.get(1).getExprType();
      }

      switch (functype) {
        case FUNCTION_IMM:
        case FUNCTION_MMI:
        case FUNCTION_IPP:
        case FUNCTION_PPI:
          exprType = implicitType;
          break;
        case FUNCTION_BOOLNOT:
          exprType = VarType.VARTYPE_BOOLEAN;
          break;
        case FUNCTION_SHL:
        case FUNCTION_SHR:
        case FUNCTION_USHR:
        case FUNCTION_BITNOT:
        case FUNCTION_NEG:
          exprType = getMaxVarType(new VarType[]{type1});
          break;
        case FUNCTION_ADD:
        case FUNCTION_SUB:
        case FUNCTION_MUL:
        case FUNCTION_DIV:
        case FUNCTION_REM:
          exprType = getMaxVarType(new VarType[]{type1, type2});
          break;
        case FUNCTION_AND:
        case FUNCTION_OR:
        case FUNCTION_XOR:
          if (type1.type == CodeConstants.TYPE_BOOLEAN & type2.type == CodeConstants.TYPE_BOOLEAN) {
            exprType = VarType.VARTYPE_BOOLEAN;
          }
          else {
            exprType = getMaxVarType(new VarType[]{type1, type2});
          }
      }
    }
    else if (functype == FUNCTION_CAST) {
      exprType = lstOperands.get(1).getExprType();
    }
    else if (functype == FUNCTION_IIF) {
      Exprent param1 = lstOperands.get(1);
      Exprent param2 = lstOperands.get(2);
      VarType supertype = VarType.getCommonSupertype(param1.getExprType(), param2.getExprType());

      if (param1.type == Exprent.EXPRENT_CONST && param2.type == Exprent.EXPRENT_CONST &&
          supertype.type != CodeConstants.TYPE_BOOLEAN && VarType.VARTYPE_INT.isSuperset(supertype)) {
        exprType = VarType.VARTYPE_INT;
      }
      else {
        exprType = supertype;
      }
    }
    else if (functype == FUNCTION_STRCONCAT) {
      exprType = VarType.VARTYPE_STRING;
    }
    else if (functype >= FUNCTION_EQ || functype == FUNCTION_INSTANCEOF) {
      exprType = VarType.VARTYPE_BOOLEAN;
    }
    else if (functype >= FUNCTION_ARRAYLENGTH) {
      exprType = VarType.VARTYPE_INT;
    }
    else {
      exprType = types[functype - FUNCTION_I2L];
    }

    return exprType;
  }

  public int getExprentUse() {

    if (functype >= FUNCTION_IMM && functype <= FUNCTION_PPI) {
      return 0;
    }
    else {
      int ret = Exprent.MULTIPLE_USES | Exprent.SIDE_EFFECTS_FREE;
      for (Exprent expr : lstOperands) {
        ret &= expr.getExprentUse();
      }
      return ret;
    }
  }

  public CheckTypesResult checkExprTypeBounds() {
    CheckTypesResult result = new CheckTypesResult();

    Exprent param1 = lstOperands.get(0);
    VarType type1 = param1.getExprType();
    Exprent param2 = null;
    VarType type2 = null;

    if (lstOperands.size() > 1) {
      param2 = lstOperands.get(1);
      type2 = param2.getExprType();
    }

    switch (functype) {
      case FUNCTION_IIF:
        VarType supertype = getExprType();
        if (supertype == null) {
          supertype = getExprType();
        }
        result.addMinTypeExprent(param1, VarType.VARTYPE_BOOLEAN);
        result.addMinTypeExprent(param2, VarType.getMinTypeInFamily(supertype.type_family));
        result.addMinTypeExprent(lstOperands.get(2), VarType.getMinTypeInFamily(supertype.type_family));
        break;
      case FUNCTION_I2L:
      case FUNCTION_I2F:
      case FUNCTION_I2D:
      case FUNCTION_I2B:
      case FUNCTION_I2C:
      case FUNCTION_I2S:
        result.addMinTypeExprent(param1, VarType.VARTYPE_BYTECHAR);
        result.addMaxTypeExprent(param1, VarType.VARTYPE_INT);
        break;
      case FUNCTION_IMM:
      case FUNCTION_IPP:
      case FUNCTION_MMI:
      case FUNCTION_PPI:
        result.addMinTypeExprent(param1, implicitType);
        result.addMaxTypeExprent(param1, implicitType);
        break;
      case FUNCTION_ADD:
      case FUNCTION_SUB:
      case FUNCTION_MUL:
      case FUNCTION_DIV:
      case FUNCTION_REM:
      case FUNCTION_SHL:
      case FUNCTION_SHR:
      case FUNCTION_USHR:
      case FUNCTION_LT:
      case FUNCTION_GE:
      case FUNCTION_GT:
      case FUNCTION_LE:
        result.addMinTypeExprent(param2, VarType.VARTYPE_BYTECHAR);
      case FUNCTION_BITNOT:
        // case FUNCTION_BOOLNOT:
      case FUNCTION_NEG:
        result.addMinTypeExprent(param1, VarType.VARTYPE_BYTECHAR);
        break;
      case FUNCTION_AND:
      case FUNCTION_OR:
      case FUNCTION_XOR:
      case FUNCTION_EQ:
      case FUNCTION_NE: {
        if (type1.type == CodeConstants.TYPE_BOOLEAN) {

          if (type2.isStrictSuperset(type1)) {

            result.addMinTypeExprent(param1, VarType.VARTYPE_BYTECHAR);
          }
          else { // both are booleans

            boolean param1_false_boolean =
              type1.isFalseBoolean() || (param1.type == Exprent.EXPRENT_CONST && !((ConstExprent)param1).hasBooleanValue());
            boolean param2_false_boolean =
              type1.isFalseBoolean() || (param2.type == Exprent.EXPRENT_CONST && !((ConstExprent)param2).hasBooleanValue());

            if (param1_false_boolean || param2_false_boolean) {
              result.addMinTypeExprent(param1, VarType.VARTYPE_BYTECHAR);
              result.addMinTypeExprent(param2, VarType.VARTYPE_BYTECHAR);
            }
          }
        }
        else if (type2.type == CodeConstants.TYPE_BOOLEAN) {

          if (type1.isStrictSuperset(type2)) {
            result.addMinTypeExprent(param2, VarType.VARTYPE_BYTECHAR);
          }
        }
      }
    }

    return result;
  }

  public List<Exprent> getAllExprents() {
    List<Exprent> lst = new ArrayList<Exprent>();
    lst.addAll(lstOperands);
    return lst;
  }

  public Exprent copy() {
    List<Exprent> lst = new ArrayList<Exprent>();
    for (Exprent expr : lstOperands) {
      lst.add(expr.copy());
    }
    FunctionExprent func = new FunctionExprent(functype, lst);
    func.setImplicitType(implicitType);

    return func;
  }

  public boolean equals(Object o) {
    if (o == this) return true;
    if (o == null || !(o instanceof FunctionExprent)) return false;

    FunctionExprent fe = (FunctionExprent)o;
    return functype == fe.getFunctype() &&
           InterpreterUtil.equalLists(lstOperands, fe.getLstOperands()); // TODO: order of operands insignificant
  }

  public void replaceExprent(Exprent oldexpr, Exprent newexpr) {
    for (int i = 0; i < lstOperands.size(); i++) {
      if (oldexpr == lstOperands.get(i)) {
        lstOperands.set(i, newexpr);
      }
    }
  }

  public String toJava(int indent) {

    if (functype <= FUNCTION_USHR) {
      return wrapOperandString(lstOperands.get(0), false, indent) + operators[functype] +
             wrapOperandString(lstOperands.get(1), true, indent);
    }

    if (functype >= FUNCTION_EQ) {
      return wrapOperandString(lstOperands.get(0), false, indent) + operators[functype - FUNCTION_EQ + 11] +
             wrapOperandString(lstOperands.get(1), true, indent);
    }

    switch (functype) {
      case FUNCTION_BITNOT:
        return "~" + wrapOperandString(lstOperands.get(0), true, indent);
      case FUNCTION_BOOLNOT:
        return "!" + wrapOperandString(lstOperands.get(0), true, indent);
      case FUNCTION_NEG:
        return "-" + wrapOperandString(lstOperands.get(0), true, indent);
      case FUNCTION_CAST:
        return "(" + lstOperands.get(1).toJava(indent) + ")" + wrapOperandString(lstOperands.get(0), true, indent);
      case FUNCTION_ARRAYLENGTH:
        Exprent arr = lstOperands.get(0);

        String res = wrapOperandString(arr, false, indent);
        if (arr.getExprType().arraydim == 0) {
          VarType objarr = VarType.VARTYPE_OBJECT.copy();
          objarr.arraydim = 1; // type family does not change

          res = "((" + ExprProcessor.getCastTypeName(objarr) + ")" + res + ")";
        }
        return res + ".length";
      case FUNCTION_IIF:
        return wrapOperandString(lstOperands.get(0), true, indent) + "?" + wrapOperandString(lstOperands.get(1), true, indent) + ":" +
               wrapOperandString(lstOperands.get(2), true, indent);
      case FUNCTION_IPP:
        return wrapOperandString(lstOperands.get(0), true, indent) + "++";
      case FUNCTION_PPI:
        return "++" + wrapOperandString(lstOperands.get(0), true, indent);
      case FUNCTION_IMM:
        return wrapOperandString(lstOperands.get(0), true, indent) + "--";
      case FUNCTION_MMI:
        return "--" + wrapOperandString(lstOperands.get(0), true, indent);
      case FUNCTION_INSTANCEOF:
        return wrapOperandString(lstOperands.get(0), true, indent) + " instanceof " + wrapOperandString(lstOperands.get(1), true, indent);
      case FUNCTION_LCMP: // shouldn't appear in the final code
        return "__lcmp__(" +
               wrapOperandString(lstOperands.get(0), true, indent) +
               "," +
               wrapOperandString(lstOperands.get(1), true, indent) +
               ")";
      case FUNCTION_FCMPL: // shouldn't appear in the final code
        return "__fcmpl__(" +
               wrapOperandString(lstOperands.get(0), true, indent) +
               "," +
               wrapOperandString(lstOperands.get(1), true, indent) +
               ")";
      case FUNCTION_FCMPG: // shouldn't appear in the final code
        return "__fcmpg__(" +
               wrapOperandString(lstOperands.get(0), true, indent) +
               "," +
               wrapOperandString(lstOperands.get(1), true, indent) +
               ")";
      case FUNCTION_DCMPL: // shouldn't appear in the final code
        return "__dcmpl__(" +
               wrapOperandString(lstOperands.get(0), true, indent) +
               "," +
               wrapOperandString(lstOperands.get(1), true, indent) +
               ")";
      case FUNCTION_DCMPG: // shouldn't appear in the final code
        return "__dcmpg__(" +
               wrapOperandString(lstOperands.get(0), true, indent) +
               "," +
               wrapOperandString(lstOperands.get(1), true, indent) +
               ")";
    }

    if (functype <= FUNCTION_I2S) {
      return "(" + ExprProcessor.getTypeName(types[functype - FUNCTION_I2L]) + ")" + wrapOperandString(lstOperands.get(0), true, indent);
    }

    //		return "<unknown function>";
    throw new RuntimeException("invalid function");
  }

  public int getPrecedence() {
    return getPrecedence(functype);
  }

  public static int getPrecedence(int func) {
    return precedence[func];
  }

  public VarType getSimpleCastType() {
    return types[functype - FUNCTION_I2L];
  }

  private String wrapOperandString(Exprent expr, boolean eq, int indent) {

    int myprec = getPrecedence();
    int exprprec = expr.getPrecedence();

    boolean parentheses = exprprec > myprec;
    if (!parentheses && eq) {
      parentheses = (exprprec == myprec);
      if (parentheses) {
        if (expr.type == Exprent.EXPRENT_FUNCTION &&
            ((FunctionExprent)expr).getFunctype() == functype) {
          parentheses = !associativity.contains(functype);
        }
      }
    }

    String res = expr.toJava(indent);

    if (parentheses) {
      res = "(" + res + ")";
    }

    return res;
  }

  private static VarType getMaxVarType(VarType[] arr) {

    int[] types = new int[]{CodeConstants.TYPE_DOUBLE, CodeConstants.TYPE_FLOAT, CodeConstants.TYPE_LONG};
    VarType[] vartypes = new VarType[]{VarType.VARTYPE_DOUBLE, VarType.VARTYPE_FLOAT, VarType.VARTYPE_LONG};

    for (int i = 0; i < types.length; i++) {
      for (int j = 0; j < arr.length; j++) {
        if (arr[j].type == types[i]) {
          return vartypes[i];
        }
      }
    }

    return VarType.VARTYPE_INT;
  }

  // *****************************************************************************
  // getter and setter methods
  // *****************************************************************************

  public int getFunctype() {
    return functype;
  }

  public void setFunctype(int functype) {
    this.functype = functype;
  }

  public List<Exprent> getLstOperands() {
    return lstOperands;
  }

  public void setLstOperands(List<Exprent> lstOperands) {
    this.lstOperands = lstOperands;
  }

  public VarType getImplicitType() {
    return implicitType;
  }

  public void setImplicitType(VarType implicitType) {
    this.implicitType = implicitType;
  }
}