1/*
2 * [The "BSD licence"]
3 * Copyright (c) 2005-2008 Terence Parr
4 * All rights reserved.
5 *
6 * Conversion to C#:
7 * Copyright (c) 2008-2009 Sam Harwell, Pixel Mine, Inc.
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33using System.Collections.Generic;
34using Antlr.Runtime.Tree;
35
36using BigInteger = java.math.BigInteger;
37using Console = System.Console;
38
39partial class DebugTreeGrammar
40{
41    /** Points to functions tracked by tree builder. */
42    private List<CommonTree> functionDefinitions;
43
44    /** Remember local variables. Currently, this is only the function parameter.
45     */
46    private readonly IDictionary<string, BigInteger> localMemory = new Dictionary<string, BigInteger>();
47
48    /** Remember global variables set by =. */
49    private IDictionary<string, BigInteger> globalMemory = new Dictionary<string, BigInteger>();
50
51    /** Set up an evaluator with a node stream; and a set of function definition ASTs. */
52    public DebugTreeGrammar( CommonTreeNodeStream nodes, List<CommonTree> functionDefinitions )
53        : this( nodes )
54    {
55        this.functionDefinitions = functionDefinitions;
56    }
57
58    /** Set up a local evaluator for a nested function call. The evaluator gets the definition
59     *  tree of the function; the set of all defined functions (to find locally called ones); a
60     *  pointer to the global variable memory; and the value of the function parameter to be
61     *  added to the local memory.
62     */
63    private DebugTreeGrammar( CommonTree function,
64                 List<CommonTree> functionDefinitions,
65                 IDictionary<string, BigInteger> globalMemory,
66                 BigInteger paramValue )
67        // Expected tree for function: ^(FUNC ID ( INT | ID ) expr)
68        : this( new CommonTreeNodeStream( function.GetChild( 2 ) ), functionDefinitions )
69    {
70        this.globalMemory = globalMemory;
71        localMemory[function.GetChild( 1 ).Text] = paramValue;
72    }
73
74    /** Find matching function definition for a function name and parameter
75     *  value. The first definition is returned where (a) the name matches
76     *  and (b) the formal parameter agrees if it is defined as constant.
77     */
78    private CommonTree findFunction( string name, BigInteger paramValue )
79    {
80        foreach ( CommonTree f in functionDefinitions )
81        {
82            // Expected tree for f: ^(FUNC ID (ID | INT) expr)
83            if ( f.GetChild( 0 ).Text.Equals( name ) )
84            {
85                // Check whether parameter matches
86                CommonTree formalPar = (CommonTree)f.GetChild( 1 );
87                if ( formalPar.Token.Type == INT
88                    && !new BigInteger( formalPar.Token.Text ).Equals( paramValue ) )
89                {
90                    // Constant in formalPar list does not match actual value -> no match.
91                    continue;
92                }
93                // Parameter (value for INT formal arg) as well as fct name agrees!
94                return f;
95            }
96        }
97        return null;
98    }
99
100    /** Get value of name up call stack. */
101    internal BigInteger getValue( string name )
102    {
103        BigInteger value;
104        if ( localMemory.TryGetValue( name, out value ) && value != null )
105        {
106            return value;
107        }
108        if ( globalMemory.TryGetValue( name, out value ) && value != null )
109        {
110            return value;
111        }
112        // not found in local memory or global memory
113        Console.Error.WriteLine( "undefined variable " + name );
114        return new BigInteger( "0" );
115    }
116}
117