1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
/*
* Copyright 2017 WebAssembly Community Group participants
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "wabt/lexer-source-line-finder.h"
#include <algorithm>
#include "wabt/lexer-source.h"
namespace wabt {
LexerSourceLineFinder::LexerSourceLineFinder(
std::unique_ptr<LexerSource> source)
: source_(std::move(source)),
next_line_start_(0),
last_cr_(false),
eof_(false) {
source_->Seek(0);
// Line 0 should not be used; but it makes indexing simpler.
line_ranges_.emplace_back(0, 0);
}
Result LexerSourceLineFinder::GetSourceLine(const Location& loc,
Offset max_line_length,
SourceLine* out_source_line) {
ColumnRange column_range(loc.first_column, loc.last_column);
OffsetRange original;
CHECK_RESULT(GetLineOffsets(loc.line, &original));
OffsetRange clamped =
ClampSourceLineOffsets(original, column_range, max_line_length);
bool has_start_ellipsis = original.start != clamped.start;
bool has_end_ellipsis = original.end != clamped.end;
out_source_line->column_offset = clamped.start - original.start;
if (has_start_ellipsis) {
out_source_line->line += "...";
clamped.start += 3;
}
if (has_end_ellipsis) {
clamped.end -= 3;
}
std::vector<char> read_line;
CHECK_RESULT(source_->ReadRange(clamped, &read_line));
out_source_line->line.append(read_line.begin(), read_line.end());
if (has_end_ellipsis) {
out_source_line->line += "...";
}
return Result::Ok;
}
bool LexerSourceLineFinder::IsLineCached(int line) const {
return static_cast<size_t>(line) < line_ranges_.size();
}
OffsetRange LexerSourceLineFinder::GetCachedLine(int line) const {
assert(IsLineCached(line));
return line_ranges_[line];
}
Result LexerSourceLineFinder::GetLineOffsets(int find_line,
OffsetRange* out_range) {
if (IsLineCached(find_line)) {
*out_range = GetCachedLine(find_line);
return Result::Ok;
}
const size_t kBufferSize = 1 << 16;
std::vector<char> buffer(kBufferSize);
assert(!line_ranges_.empty());
Offset buffer_file_offset = 0;
while (!IsLineCached(find_line) && !eof_) {
CHECK_RESULT(source_->Tell(&buffer_file_offset));
size_t read_size = source_->Fill(buffer.data(), buffer.size());
if (read_size < buffer.size()) {
eof_ = true;
}
for (auto iter = buffer.begin(), end = iter + read_size; iter < end;
++iter) {
if (*iter == '\n') {
// Don't include \n or \r in the line range.
Offset line_offset =
buffer_file_offset + (iter - buffer.begin()) - last_cr_;
line_ranges_.emplace_back(next_line_start_, line_offset);
next_line_start_ = line_offset + last_cr_ + 1;
}
last_cr_ = *iter == '\r';
}
if (eof_) {
// Add the final line as an empty range.
Offset end = buffer_file_offset + read_size;
line_ranges_.emplace_back(next_line_start_, end);
}
}
if (IsLineCached(find_line)) {
*out_range = GetCachedLine(find_line);
return Result::Ok;
} else {
assert(eof_);
return Result::Error;
}
}
// static
OffsetRange LexerSourceLineFinder::ClampSourceLineOffsets(
OffsetRange offset_range,
ColumnRange column_range,
Offset max_line_length) {
Offset line_length = offset_range.size();
if (line_length > max_line_length) {
size_t column_count = column_range.size();
size_t center_on;
if (column_count > max_line_length) {
// The column range doesn't fit, just center on first_column.
center_on = column_range.start - 1;
} else {
// the entire range fits, display it all in the center.
center_on = (column_range.start + column_range.end) / 2 - 1;
}
if (center_on > max_line_length / 2) {
offset_range.start += center_on - max_line_length / 2;
}
offset_range.start =
std::min(offset_range.start, offset_range.end - max_line_length);
offset_range.end = offset_range.start + max_line_length;
}
return offset_range;
}
} // namespace wabt
|
