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      1 /*
      2  * Copyright (C) 2007 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.dexgen.rop.code;
     18 
     19 import com.android.dexgen.rop.cst.CstUtf8;
     20 import com.android.dexgen.util.Hex;
     21 
     22 /**
     23  * Information about a source position for code, which includes both a
     24  * line number and original bytecode address.
     25  */
     26 public final class SourcePosition {
     27     /** {@code non-null;} convenient "no information known" instance */
     28     public static final SourcePosition NO_INFO =
     29         new SourcePosition(null, -1, -1);
     30 
     31     /** {@code null-ok;} name of the file of origin or {@code null} if unknown */
     32     private final CstUtf8 sourceFile;
     33 
     34     /**
     35      * {@code >= -1;} the bytecode address, or {@code -1} if that
     36      * information is unknown
     37      */
     38     private final int address;
     39 
     40     /**
     41      * {@code >= -1;} the line number, or {@code -1} if that
     42      * information is unknown
     43      */
     44     private final int line;
     45 
     46     /**
     47      * Constructs an instance.
     48      *
     49      * @param sourceFile {@code null-ok;} name of the file of origin or
     50      * {@code null} if unknown
     51      * @param address {@code >= -1;} original bytecode address or {@code -1}
     52      * if unknown
     53      * @param line {@code >= -1;} original line number or {@code -1} if
     54      * unknown
     55      */
     56     public SourcePosition(CstUtf8 sourceFile, int address, int line) {
     57         if (address < -1) {
     58             throw new IllegalArgumentException("address < -1");
     59         }
     60 
     61         if (line < -1) {
     62             throw new IllegalArgumentException("line < -1");
     63         }
     64 
     65         this.sourceFile = sourceFile;
     66         this.address = address;
     67         this.line = line;
     68     }
     69 
     70     /** {@inheritDoc} */
     71     @Override
     72     public String toString() {
     73         StringBuffer sb = new StringBuffer(50);
     74 
     75         if (sourceFile != null) {
     76             sb.append(sourceFile.toHuman());
     77             sb.append(":");
     78         }
     79 
     80         if (line >= 0) {
     81             sb.append(line);
     82         }
     83 
     84         sb.append('@');
     85 
     86         if (address < 0) {
     87             sb.append("????");
     88         } else {
     89             sb.append(Hex.u2(address));
     90         }
     91 
     92         return sb.toString();
     93     }
     94 
     95     /** {@inheritDoc} */
     96     @Override
     97     public boolean equals(Object other) {
     98         if (!(other instanceof SourcePosition)) {
     99             return false;
    100         }
    101 
    102         if (this == other) {
    103             return true;
    104         }
    105 
    106         SourcePosition pos = (SourcePosition) other;
    107 
    108         return (address == pos.address) && sameLineAndFile(pos);
    109     }
    110 
    111     /** {@inheritDoc} */
    112     @Override
    113     public int hashCode() {
    114         return sourceFile.hashCode() + address + line;
    115     }
    116 
    117     /**
    118      * Returns whether the lines match between this instance and
    119      * the one given.
    120      *
    121      * @param other {@code non-null;} the instance to compare to
    122      * @return {@code true} iff the lines match
    123      */
    124     public boolean sameLine(SourcePosition other) {
    125         return (line == other.line);
    126     }
    127 
    128     /**
    129      * Returns whether the lines and files match between this instance and
    130      * the one given.
    131      *
    132      * @param other {@code non-null;} the instance to compare to
    133      * @return {@code true} iff the lines and files match
    134      */
    135     public boolean sameLineAndFile(SourcePosition other) {
    136         return (line == other.line) &&
    137             ((sourceFile == other.sourceFile) ||
    138              ((sourceFile != null) && sourceFile.equals(other.sourceFile)));
    139     }
    140 
    141     /**
    142      * Gets the source file, if known.
    143      *
    144      * @return {@code null-ok;} the source file or {@code null} if unknown
    145      */
    146     public CstUtf8 getSourceFile() {
    147         return sourceFile;
    148     }
    149 
    150     /**
    151      * Gets the original bytecode address.
    152      *
    153      * @return {@code >= -1;} the address or {@code -1} if unknown
    154      */
    155     public int getAddress() {
    156         return address;
    157     }
    158 
    159     /**
    160      * Gets the original line number.
    161      *
    162      * @return {@code >= -1;} the original line number or {@code -1} if
    163      * unknown
    164      */
    165     public int getLine() {
    166         return line;
    167     }
    168 }
    169