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      1 /*
      2  [The "BSD license"]
      3  Copyright (c) 2005-2009 Terence Parr
      4  All rights reserved.
      5 
      6  Redistribution and use in source and binary forms, with or without
      7  modification, are permitted provided that the following conditions
      8  are met:
      9  1. Redistributions of source code must retain the above copyright
     10      notice, this list of conditions and the following disclaimer.
     11  2. Redistributions in binary form must reproduce the above copyright
     12      notice, this list of conditions and the following disclaimer in the
     13      documentation and/or other materials provided with the distribution.
     14  3. The name of the author may not be used to endorse or promote products
     15      derived from this software without specific prior written permission.
     16 
     17  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     18  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     19  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     20  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     21  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     22  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     26  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 package org.antlr.runtime;
     30 
     31 import java.io.IOException;
     32 import java.io.FileInputStream;
     33 import java.io.BufferedInputStream;
     34 import java.io.DataInputStream;
     35 import java.util.List;
     36 import java.util.ArrayList;
     37 
     38 public class SerializedGrammar {
     39     public static final String COOKIE = "$ANTLR";
     40     public static final int FORMAT_VERSION = 1;
     41     //public static org.antlr.tool.Grammar gr; // TESTING ONLY; remove later
     42 
     43     public String name;
     44     public char type; // in {l, p, t, c}
     45     public List rules;
     46 
     47     class Rule {
     48         String name;
     49         Block block;
     50         public Rule(String name, Block block) {
     51             this.name = name;
     52             this.block = block;
     53         }
     54         public String toString() {
     55             return name+":"+block;
     56         }
     57     }
     58 
     59     class Block {
     60         List[] alts;
     61         public Block(List[] alts) {
     62             this.alts = alts;
     63         }
     64         public String toString() {
     65             StringBuffer buf = new StringBuffer();
     66             buf.append("(");
     67             for (int i = 0; i < alts.length; i++) {
     68                 List alt = alts[i];
     69                 if ( i>0 ) buf.append("|");
     70                 buf.append(alt.toString());
     71             }
     72             buf.append(")");
     73             return buf.toString();
     74         }
     75     }
     76 
     77     class TokenRef {
     78         int ttype;
     79         public TokenRef(int ttype) { this.ttype = ttype; }
     80         public String toString() { return String.valueOf(ttype); }
     81     }
     82 
     83     class RuleRef {
     84         int ruleIndex;
     85         public RuleRef(int ruleIndex) { this.ruleIndex = ruleIndex; }
     86         public String toString() { return String.valueOf(ruleIndex); }
     87     }
     88 
     89     public SerializedGrammar(String filename) throws IOException {
     90         System.out.println("loading "+filename);
     91         FileInputStream fis = new FileInputStream(filename);
     92         BufferedInputStream bos = new BufferedInputStream(fis);
     93         DataInputStream in = new DataInputStream(bos);
     94         readFile(in);
     95         in.close();
     96     }
     97 
     98     protected void readFile(DataInputStream in) throws IOException {
     99         String cookie = readString(in); // get $ANTLR
    100         if ( !cookie.equals(COOKIE) ) throw new IOException("not a serialized grammar file");
    101         int version = in.readByte();
    102         char grammarType = (char)in.readByte();
    103         this.type = grammarType;
    104         String grammarName = readString(in);
    105         this.name = grammarName;
    106         System.out.println(grammarType+" grammar "+grammarName);
    107         int numRules = in.readShort();
    108         System.out.println("num rules = "+numRules);
    109         rules = readRules(in, numRules);
    110     }
    111 
    112     protected List readRules(DataInputStream in, int numRules) throws IOException {
    113         List rules = new ArrayList();
    114         for (int i=0; i<numRules; i++) {
    115             Rule r = readRule(in);
    116             rules.add(r);
    117         }
    118         return rules;
    119     }
    120 
    121     protected Rule readRule(DataInputStream in) throws IOException {
    122         byte R = in.readByte();
    123         if ( R!='R' ) throw new IOException("missing R on start of rule");
    124         String name = readString(in);
    125         System.out.println("rule: "+name);
    126         byte B = in.readByte();
    127         Block b = readBlock(in);
    128         byte period = in.readByte();
    129         if ( period!='.' ) throw new IOException("missing . on end of rule");
    130         return new Rule(name, b);
    131     }
    132 
    133     protected Block readBlock(DataInputStream in) throws IOException {
    134         int nalts = in.readShort();
    135         List[] alts = new List[nalts];
    136         //System.out.println("enter block n="+nalts);
    137         for (int i=0; i<nalts; i++) {
    138             List alt = readAlt(in);
    139             alts[i] = alt;
    140         }
    141         //System.out.println("exit block");
    142         return new Block(alts);
    143     }
    144 
    145     protected List readAlt(DataInputStream in) throws IOException {
    146         List alt = new ArrayList();
    147         byte A = in.readByte();
    148         if ( A!='A' ) throw new IOException("missing A on start of alt");
    149         byte cmd = in.readByte();
    150         while ( cmd!=';' ) {
    151             switch (cmd) {
    152                 case 't' :
    153                     int ttype = in.readShort();
    154                     alt.add(new TokenRef(ttype));
    155                     //System.out.println("read token "+gr.getTokenDisplayName(ttype));
    156                     break;
    157                 case 'r' :
    158                     int ruleIndex = in.readShort();
    159                     alt.add(new RuleRef(ruleIndex));
    160                     //System.out.println("read rule "+gr.getRuleName(ruleIndex));
    161                     break;
    162                 case '.' : // wildcard
    163                     break;
    164                 case '-' : // range
    165                     int from = in.readChar();
    166                     int to = in.readChar();
    167                     break;
    168                 case '~' : // not
    169                     int notThisTokenType = in.readShort();
    170                     break;
    171                 case 'B' : // nested block
    172                     Block b = readBlock(in);
    173                     alt.add(b);
    174                     break;
    175             }
    176             cmd = in.readByte();
    177         }
    178         //System.out.println("exit alt");
    179         return alt;
    180     }
    181 
    182     protected String readString(DataInputStream in) throws IOException {
    183         byte c = in.readByte();
    184         StringBuffer buf = new StringBuffer();
    185         while ( c!=';' ) {
    186             buf.append((char)c);
    187             c = in.readByte();
    188         }
    189         return buf.toString();
    190     }
    191 
    192     public String toString() {
    193         StringBuffer buf = new StringBuffer();
    194         buf.append(type+" grammar "+name);
    195         buf.append(rules);
    196         return buf.toString();
    197     }
    198 }
    199