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 */
28package org.antlr.codegen;
29
30import org.antlr.Tool;
31import org.stringtemplate.v4.ST;
32import org.antlr.tool.Grammar;
33
34public 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