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.tool;
29
30import org.antlr.runtime.Token;
31
32public class RuleLabelScope extends AttributeScope {
33	/** Rules have a predefined set of attributes as well as
34	 *  the return values.  'text' needs to be computed though so.
35	 */
36	public static AttributeScope predefinedRulePropertiesScope =
37		new AttributeScope("RulePredefined",null) {{
38			addAttribute("text", null);
39			addAttribute("start", null);
40			addAttribute("stop", null);
41			addAttribute("tree", null);
42			addAttribute("st", null);
43			isPredefinedRuleScope = true;
44		}};
45
46	public static AttributeScope predefinedTreeRulePropertiesScope =
47		new AttributeScope("RulePredefined",null) {{
48			addAttribute("text", null);
49			addAttribute("start", null); // note: no stop; not meaningful
50			addAttribute("tree", null);
51			addAttribute("st", null);
52			isPredefinedRuleScope = true;
53		}};
54
55	public static AttributeScope predefinedLexerRulePropertiesScope =
56		new AttributeScope("LexerRulePredefined",null) {{
57			addAttribute("text", null);
58			addAttribute("type", null);
59			addAttribute("line", null);
60			addAttribute("index", null);
61			addAttribute("pos", null);
62			addAttribute("channel", null);
63			addAttribute("start", null);
64			addAttribute("stop", null);
65			addAttribute("int", null);
66			isPredefinedLexerRuleScope = true;
67		}};
68
69	public static AttributeScope[] grammarTypeToRulePropertiesScope =
70		{
71			null,
72			predefinedLexerRulePropertiesScope,	// LEXER
73			predefinedRulePropertiesScope,		// PARSER
74			predefinedTreeRulePropertiesScope,	// TREE_PARSER
75			predefinedRulePropertiesScope,		// COMBINED
76		};
77
78	public Rule referencedRule;
79
80	public RuleLabelScope(Rule referencedRule, Token actionToken) {
81		super("ref_"+referencedRule.name,actionToken);
82		this.referencedRule = referencedRule;
83	}
84
85	/** If you label a rule reference, you can access that rule's
86	 *  return values as well as any predefined attributes.
87	 */
88	public Attribute getAttribute(String name) {
89		AttributeScope rulePropertiesScope =
90			RuleLabelScope.grammarTypeToRulePropertiesScope[grammar.type];
91		if ( rulePropertiesScope.getAttribute(name)!=null ) {
92			return rulePropertiesScope.getAttribute(name);
93		}
94
95		if ( referencedRule.returnScope!=null ) {
96			return referencedRule.returnScope.getAttribute(name);
97		}
98		return null;
99	}
100}
101