content: /*
   * Copyright (C) 2007 The Android Open Source Project
   *
   * 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.taobao.android.dx.rop.code;
  
  import com.taobao.android.dx.rop.cst.CstString;
  import com.taobao.android.dx.util.Hex;
  
  /**
   * Information about a source position for code, which includes both a
   * line number and original bytecode address.
   */
  public final class SourcePosition {
      /** {@code non-null;} convenient "no information known" instance */
      public static final SourcePosition NO_INFO =
          new SourcePosition(null, -1, -1);
  
      /** {@code null-ok;} name of the file of origin or {@code null} if unknown */
      private final CstString sourceFile;
  
      /**
       * {@code >= -1;} the bytecode address, or {@code -1} if that
       * information is unknown
       */
      private final int address;
  
      /**
       * {@code >= -1;} the line number, or {@code -1} if that
       * information is unknown
       */
      private final int line;
  
      /**
       * Constructs an instance.
       *
       * @param sourceFile {@code null-ok;} name of the file of origin or
       * {@code null} if unknown
       * @param address {@code >= -1;} original bytecode address or {@code -1}
       * if unknown
       * @param line {@code >= -1;} original line number or {@code -1} if
       * unknown
       */
      public SourcePosition(CstString sourceFile, int address, int line) {
          if (address < -1) {
              throw new IllegalArgumentException("address < -1");
          }
  
          if (line < -1) {
              throw new IllegalArgumentException("line < -1");
          }
  
          this.sourceFile = sourceFile;
          this.address = address;
          this.line = line;
      }
  
      /** {@inheritDoc} */
      @Override
      public String toString() {
          StringBuffer sb = new StringBuffer(50);
  
          if (sourceFile != null) {
              sb.append(sourceFile.toHuman());
              sb.append(":");
          }
  
          if (line >= 0) {
              sb.append(line);
          }
  
          sb.append('@');
  
          if (address < 0) {
              sb.append("????");
          } else {
              sb.append(Hex.u2(address));
          }
  
          return sb.toString();
      }
  
      /** {@inheritDoc} */
      @Override
      public boolean equals(Object other) {
          if (!(other instanceof SourcePosition)) {
              return false;
          }
  
          if (this == other) {
              return true;
          }
  
          SourcePosition pos = (SourcePosition) other;
  
          return (address == pos.address) && sameLineAndFile(pos);
      }
  
      /** {@inheritDoc} */
      @Override
      public int hashCode() {
          return sourceFile.hashCode() + address + line;
      }
  
      /**
       * Returns whether the lines match between this instance and
       * the one given.
       *
       * @param other {@code non-null;} the instance to compare to
       * @return {@code true} iff the lines match
       */
      public boolean sameLine(SourcePosition other) {
          return (line == other.line);
      }
  
      /**
       * Returns whether the lines and files match between this instance and
       * the one given.
       *
       * @param other {@code non-null;} the instance to compare to
       * @return {@code true} iff the lines and files match
       */
      public boolean sameLineAndFile(SourcePosition other) {
          return (line == other.line) &&
              ((sourceFile == other.sourceFile) ||
               ((sourceFile != null) && sourceFile.equals(other.sourceFile)));
      }
  
      /**
       * Gets the source file, if known.
       *
       * @return {@code null-ok;} the source file or {@code null} if unknown
       */
      public CstString getSourceFile() {
          return sourceFile;
      }
  
      /**
       * Gets the original bytecode address.
       *
       * @return {@code >= -1;} the address or {@code -1} if unknown
       */
      public int getAddress() {
          return address;
      }
  
      /**
       * Gets the original line number.
       *
       * @return {@code >= -1;} the original line number or {@code -1} if
       * unknown
       */
      public int getLine() {
          return line;
      }
  }
  