1  /*
 2   * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
 3   *
 4   * Permission is hereby granted, free of charge, to any person obtaining 
 5   * a copy of this software and associated documentation files (the
 6   * "Software"), to deal in the Software without restriction, including
 7   * without limitation the rights to use, copy, modify, merge, publish,
 8   * distribute, sublicense, and/or sell copies of the Software, and to
 9   * permit persons to whom the Software is furnished to do so, subject to
10   * the following conditions:
11   *
12   * The above copyright notice and this permission notice shall be 
13   * included in all copies or substantial portions of the Software.
14   *
15   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
16   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
18   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19   * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20   * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22   * SOFTWARE.
23   */
24  
25  using System;
26  using System.Collections.Generic;
27  
28  class WordData : Word {
29  
30  	ConstData blob;
31  	string baseBlobName;
32  	int offset;
33  	bool ongoingResolution;
34  
35  	internal WordData(T0Comp owner, string name,
36  		ConstData blob, int offset)
37  		: base(owner, name)
38  	{
39  		this.blob = blob;
40  		this.offset = offset;
41  		StackEffect = new SType(0, 1);
42  	}
43  
44  	internal WordData(T0Comp owner, string name,
45  		string baseBlobName, int offset)
46  		: base(owner, name)
47  	{
48  		this.baseBlobName = baseBlobName;
49  		this.offset = offset;
50  		StackEffect = new SType(0, 1);
51  	}
52  
53  	internal override void Resolve()
54  	{
55  		if (blob != null) {
56  			return;
57  		}
58  		if (ongoingResolution) {
59  			throw new Exception(String.Format(
60  				"circular reference in blobs ({0})", Name));
61  		}
62  		ongoingResolution = true;
63  		WordData wd = TC.Lookup(baseBlobName) as WordData;
64  		if (wd == null) {
65  			throw new Exception(String.Format(
66  				"data word '{0}' based on non-data word '{1}'",
67  				Name, baseBlobName));
68  		}
69  		wd.Resolve();
70  		blob = wd.blob;
71  		offset += wd.offset;
72  		ongoingResolution = false;
73  	}
74  
75  	internal override void Run(CPU cpu)
76  	{
77  		Resolve();
78  		cpu.Push(new TValue(offset, new TPointerBlob(blob)));
79  	}
80  
81  	internal override List<ConstData> GetDataBlocks()
82  	{
83  		Resolve();
84  		List<ConstData> r = new List<ConstData>();
85  		r.Add(blob);
86  		return r;
87  	}
88  
89  	internal override void GenerateCodeElements(List<CodeElement> dst)
90  	{
91  		Resolve();
92  		dst.Add(new CodeElementUInt(0));
93  		dst.Add(new CodeElementUIntInt(1, blob.Address + offset));
94  		dst.Add(new CodeElementUInt(0));
95  	}
96  }