Home | History | Annotate | Download | only in codegen 
      1 /*
      2  * [The "BSD license"]
      3  *  Copyright (c) 2010 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 package org.antlr.codegen;
     29 
     30 import org.antlr.Tool;
     31 import org.stringtemplate.v4.ST;
     32 import org.antlr.tool.Grammar;
     33 
     34 public class ActionScriptTarget extends Target {
     35 
     36     public String getTargetCharLiteralFromANTLRCharLiteral(
     37             CodeGenerator generator,
     38             String literal) {
     39 
     40         int c = Grammar.getCharValueFromGrammarCharLiteral(literal);
     41         return String.valueOf(c);
     42     }
     43 
     44     public String getTokenTypeAsTargetLabel(CodeGenerator generator,
     45                                             int ttype) {
     46         // use ints for predefined types;
     47         // <invalid> <EOR> <DOWN> <UP>
     48         if (ttype >= 0 && ttype <= 3) {
     49             return String.valueOf(ttype);
     50         }
     51 
     52         String name = generator.grammar.getTokenDisplayName(ttype);
     53 
     54         // If name is a literal, return the token type instead
     55         if (name.charAt(0) == '\'') {
     56             return String.valueOf(ttype);
     57         }
     58 
     59         return name;
     60     }
     61 
     62     /**
     63      * ActionScript doesn't support Unicode String literals that are considered "illegal"
     64      * or are in the surrogate pair ranges.  For example "/uffff" will not encode properly
     65      * nor will "/ud800".  To keep things as compact as possible we use the following encoding
     66      * if the int is below 255, we encode as hex literal
     67      * If the int is between 255 and 0x7fff we use a single unicode literal with the value
     68      * If the int is above 0x7fff, we use a unicode literal of 0x80hh, where hh is the high-order
     69      * bits followed by \xll where ll is the lower order bits of a 16-bit number.
     70      *
     71      * Ideally this should be improved at a future date.  The most optimal way to encode this
     72      * may be a compressed AMF encoding that is embedded using an Embed tag in ActionScript.
     73      *
     74      * @param v
     75      * @return
     76      */
     77     public String encodeIntAsCharEscape(int v) {
     78         // encode as hex
     79         if ( v<=255 ) {
     80 			return "\\x"+ Integer.toHexString(v|0x100).substring(1,3);
     81 		}
     82         if (v <= 0x7fff) {
     83             String hex = Integer.toHexString(v|0x10000).substring(1,5);
     84 		    return "\\u"+hex;
     85         }
     86         if (v > 0xffff) {
     87             System.err.println("Warning: character literal out of range for ActionScript target " + v);
     88             return "";
     89         }
     90         StringBuffer buf = new StringBuffer("\\u80");
     91         buf.append(Integer.toHexString((v >> 8) | 0x100).substring(1, 3)); // high - order bits
     92         buf.append("\\x");
     93         buf.append(Integer.toHexString((v & 0xff) | 0x100).substring(1, 3)); // low -order bits
     94         return buf.toString();
     95     }
     96 
     97     /** Convert long to two 32-bit numbers separted by a comma.
     98      *  ActionScript does not support 64-bit numbers, so we need to break
     99      *  the number into two 32-bit literals to give to the Bit.  A number like
    100      *  0xHHHHHHHHLLLLLLLL is broken into the following string:
    101      *  "0xLLLLLLLL, 0xHHHHHHHH"
    102 	 *  Note that the low order bits are first, followed by the high order bits.
    103      *  This is to match how the BitSet constructor works, where the bits are
    104      *  passed in in 32-bit chunks with low-order bits coming first.
    105 	 */
    106 	public String getTarget64BitStringFromValue(long word) {
    107 		StringBuffer buf = new StringBuffer(22); // enough for the two "0x", "," and " "
    108 		buf.append("0x");
    109         writeHexWithPadding(buf, Integer.toHexString((int)(word & 0x00000000ffffffffL)));
    110         buf.append(", 0x");
    111         writeHexWithPadding(buf, Integer.toHexString((int)(word >> 32)));
    112 
    113         return buf.toString();
    114 	}
    115 
    116     private void writeHexWithPadding(StringBuffer buf, String digits) {
    117        digits = digits.toUpperCase();
    118 		int padding = 8 - digits.length();
    119 		// pad left with zeros
    120 		for (int i=1; i<=padding; i++) {
    121 			buf.append('0');
    122 		}
    123 		buf.append(digits);
    124     }
    125 
    126     protected ST chooseWhereCyclicDFAsGo(Tool tool,
    127                                                      CodeGenerator generator,
    128                                                      Grammar grammar,
    129                                                      ST recognizerST,
    130                                                      ST cyclicDFAST) {
    131         return recognizerST;
    132     }
    133 }
    134 
    135