1/*
2 * Copyright (C) 2012, 2013 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef ExpressionRangeInfo_h
27#define ExpressionRangeInfo_h
28
29#include <wtf/StdLibExtras.h>
30
31namespace JSC {
32
33struct ExpressionRangeInfo {
34 // Line and column values are encoded in 1 of 3 modes depending on the size
35 // of their values. These modes are:
36 //
37 // 1. FatLine: 22-bit line, 8-bit column.
38 // 2. FatColumn: 8-bit line, 22-bit column.
39 // 3. FatLineAndColumn: 32-bit line, 32-bit column.
40 //
41 // For the first 2 modes, the line and column will be encoded in the 30-bit
42 // position field in the ExpressionRangeInfo. For the FatLineAndColumn mode,
43 // the position field will hold an index into a FatPosition vector which
44 // holds the FatPosition records with the full 32-bit line and column values.
45
46 enum {
47 FatLineMode,
48 FatColumnMode,
49 FatLineAndColumnMode
50 };
51
52 struct FatPosition {
53 uint32_t line;
54 uint32_t column;
55 };
56
57 enum {
58 FatLineModeLineShift = 8,
59 FatLineModeLineMask = (1 << 22) - 1,
60 FatLineModeColumnMask = (1 << 8) - 1,
61 FatColumnModeLineShift = 22,
62 FatColumnModeLineMask = (1 << 8) - 1,
63 FatColumnModeColumnMask = (1 << 22) - 1
64 };
65
66 enum {
67 MaxOffset = (1 << 7) - 1,
68 MaxDivot = (1 << 25) - 1,
69 MaxFatLineModeLine = (1 << 22) - 1,
70 MaxFatLineModeColumn = (1 << 8) - 1,
71 MaxFatColumnModeLine = (1 << 8) - 1,
72 MaxFatColumnModeColumn = (1 << 22) - 1
73 };
74
75 void encodeFatLineMode(unsigned line, unsigned column)
76 {
77 ASSERT(line <= MaxFatLineModeLine);
78 ASSERT(column <= MaxFatLineModeColumn);
79 position = ((line & FatLineModeLineMask) << FatLineModeLineShift | (column & FatLineModeColumnMask));
80 }
81
82 void encodeFatColumnMode(unsigned line, unsigned column)
83 {
84 ASSERT(line <= MaxFatColumnModeLine);
85 ASSERT(column <= MaxFatColumnModeColumn);
86 position = ((line & FatColumnModeLineMask) << FatColumnModeLineShift | (column & FatColumnModeColumnMask));
87 }
88
89 void decodeFatLineMode(unsigned& line, unsigned& column)
90 {
91 line = (position >> FatLineModeLineShift) & FatLineModeLineMask;
92 column = position & FatLineModeColumnMask;
93 }
94
95 void decodeFatColumnMode(unsigned& line, unsigned& column)
96 {
97 line = (position >> FatColumnModeLineShift) & FatColumnModeLineMask;
98 column = position & FatColumnModeColumnMask;
99 }
100
101 uint32_t instructionOffset : 25;
102 uint32_t startOffset : 7;
103 uint32_t divotPoint : 25;
104 uint32_t endOffset : 7;
105 uint32_t mode : 2;
106 uint32_t position : 30;
107};
108
109} // namespace JSC
110
111#endif // ExpressionRangeInfo_h
112
113