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1 // Copyright 2011 the V8 project authors. All rights reserved. | |
2 // Redistribution and use in source and binary forms, with or without | |
3 // modification, are permitted provided that the following conditions are | |
4 // met: | |
5 // | |
6 // * Redistributions of source code must retain the above copyright | |
7 // notice, this list of conditions and the following disclaimer. | |
8 // * Redistributions in binary form must reproduce the above | |
9 // copyright notice, this list of conditions and the following | |
10 // disclaimer in the documentation and/or other materials provided | |
11 // with the distribution. | |
12 // * Neither the name of Google Inc. nor the names of its | |
13 // contributors may be used to endorse or promote products derived | |
14 // from this software without specific prior written permission. | |
15 // | |
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
22 // 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 | |
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
27 | |
28 #ifdef _MSC_VER | |
29 #define V8_WIN32_LEAN_AND_MEAN | |
30 #include "win32-headers.h" | |
31 #endif | |
32 | |
33 #include "../include/v8-preparser.h" | |
34 | |
35 #include "globals.h" | |
36 #include "checks.h" | |
37 #include "allocation.h" | |
38 #include "utils.h" | |
39 #include "list.h" | |
40 #include "hashmap.h" | |
41 #include "preparse-data-format.h" | |
42 #include "preparse-data.h" | |
43 #include "preparser.h" | |
44 | |
45 namespace v8 { | |
46 namespace internal { | |
47 | |
48 // UTF16Buffer based on a v8::UnicodeInputStream. | |
49 class InputStreamUtf16Buffer : public Utf16CharacterStream { | |
50 public: | |
51 /* The InputStreamUtf16Buffer maintains an internal buffer | |
52 * that is filled in chunks from the Utf16CharacterStream. | |
53 * It also maintains unlimited pushback capability, but optimized | |
54 * for small pushbacks. | |
55 * The pushback_buffer_ pointer points to the limit of pushbacks | |
56 * in the current buffer. There is room for a few pushback'ed chars before | |
57 * the buffer containing the most recently read chunk. If this is overflowed, | |
58 * an external buffer is allocated/reused to hold further pushbacks, and | |
59 * pushback_buffer_ and buffer_cursor_/buffer_end_ now points to the | |
60 * new buffer. When this buffer is read to the end again, the cursor is | |
61 * switched back to the internal buffer | |
62 */ | |
63 explicit InputStreamUtf16Buffer(v8::UnicodeInputStream* stream) | |
64 : Utf16CharacterStream(), | |
65 stream_(stream), | |
66 pushback_buffer_(buffer_), | |
67 pushback_buffer_end_cache_(NULL), | |
68 pushback_buffer_backing_(NULL), | |
69 pushback_buffer_backing_size_(0) { | |
70 buffer_cursor_ = buffer_end_ = buffer_ + kPushBackSize; | |
71 } | |
72 | |
73 virtual ~InputStreamUtf16Buffer() { | |
74 if (pushback_buffer_backing_ != NULL) { | |
75 DeleteArray(pushback_buffer_backing_); | |
76 } | |
77 } | |
78 | |
79 virtual void PushBack(uc32 ch) { | |
80 ASSERT(pos_ > 0); | |
81 if (ch == kEndOfInput) { | |
82 pos_--; | |
83 return; | |
84 } | |
85 if (buffer_cursor_ <= pushback_buffer_) { | |
86 // No more room in the current buffer to do pushbacks. | |
87 if (pushback_buffer_end_cache_ == NULL) { | |
88 // We have overflowed the pushback space at the beginning of buffer_. | |
89 // Switch to using a separate allocated pushback buffer. | |
90 if (pushback_buffer_backing_ == NULL) { | |
91 // Allocate a buffer the first time we need it. | |
92 pushback_buffer_backing_ = NewArray<uc16>(kPushBackSize); | |
93 pushback_buffer_backing_size_ = kPushBackSize; | |
94 } | |
95 pushback_buffer_ = pushback_buffer_backing_; | |
96 pushback_buffer_end_cache_ = buffer_end_; | |
97 buffer_end_ = pushback_buffer_backing_ + pushback_buffer_backing_size_; | |
98 buffer_cursor_ = buffer_end_ - 1; | |
99 } else { | |
100 // Hit the bottom of the allocated pushback buffer. | |
101 // Double the buffer and continue. | |
102 uc16* new_buffer = NewArray<uc16>(pushback_buffer_backing_size_ * 2); | |
103 OS::MemCopy(new_buffer + pushback_buffer_backing_size_, | |
104 pushback_buffer_backing_, | |
105 pushback_buffer_backing_size_); | |
106 DeleteArray(pushback_buffer_backing_); | |
107 buffer_cursor_ = new_buffer + pushback_buffer_backing_size_; | |
108 pushback_buffer_backing_ = pushback_buffer_ = new_buffer; | |
109 buffer_end_ = pushback_buffer_backing_ + pushback_buffer_backing_size_; | |
110 } | |
111 } | |
112 pushback_buffer_[buffer_cursor_ - pushback_buffer_- 1] = | |
113 static_cast<uc16>(ch); | |
114 pos_--; | |
115 } | |
116 | |
117 protected: | |
118 virtual bool ReadBlock() { | |
119 if (pushback_buffer_end_cache_ != NULL) { | |
120 buffer_cursor_ = buffer_; | |
121 buffer_end_ = pushback_buffer_end_cache_; | |
122 pushback_buffer_end_cache_ = NULL; | |
123 return buffer_end_ > buffer_cursor_; | |
124 } | |
125 // Copy the top of the buffer into the pushback area. | |
126 int32_t value; | |
127 uc16* buffer_start = buffer_ + kPushBackSize; | |
128 buffer_cursor_ = buffer_end_ = buffer_start; | |
129 while ((value = stream_->Next()) >= 0) { | |
130 if (value > | |
131 static_cast<int32_t>(unibrow::Utf16::kMaxNonSurrogateCharCode)) { | |
132 buffer_start[buffer_end_++ - buffer_start] = | |
133 unibrow::Utf16::LeadSurrogate(value); | |
134 buffer_start[buffer_end_++ - buffer_start] = | |
135 unibrow::Utf16::TrailSurrogate(value); | |
136 } else { | |
137 // buffer_end_ is a const pointer, but buffer_ is writable. | |
138 buffer_start[buffer_end_++ - buffer_start] = static_cast<uc16>(value); | |
139 } | |
140 // Stop one before the end of the buffer in case we get a surrogate pair. | |
141 if (buffer_end_ <= buffer_ + 1 + kPushBackSize + kBufferSize) break; | |
142 } | |
143 return buffer_end_ > buffer_start; | |
144 } | |
145 | |
146 virtual unsigned SlowSeekForward(unsigned pos) { | |
147 // Seeking in the input is not used by preparsing. | |
148 // It's only used by the real parser based on preparser data. | |
149 UNIMPLEMENTED(); | |
150 return 0; | |
151 } | |
152 | |
153 private: | |
154 static const unsigned kBufferSize = 512; | |
155 static const unsigned kPushBackSize = 16; | |
156 v8::UnicodeInputStream* const stream_; | |
157 // Buffer holding first kPushBackSize characters of pushback buffer, | |
158 // then kBufferSize chars of read-ahead. | |
159 // The pushback buffer is only used if pushing back characters past | |
160 // the start of a block. | |
161 uc16 buffer_[kPushBackSize + kBufferSize]; | |
162 // Limit of pushbacks before new allocation is necessary. | |
163 uc16* pushback_buffer_; | |
164 // Only if that pushback buffer at the start of buffer_ isn't sufficient | |
165 // is the following used. | |
166 const uc16* pushback_buffer_end_cache_; | |
167 uc16* pushback_buffer_backing_; | |
168 unsigned pushback_buffer_backing_size_; | |
169 }; | |
170 | |
171 } // namespace internal. | |
172 | |
173 | |
174 UnicodeInputStream::~UnicodeInputStream() { } | |
175 | |
176 | |
177 PreParserData Preparse(UnicodeInputStream* input, size_t max_stack) { | |
178 internal::InputStreamUtf16Buffer buffer(input); | |
179 uintptr_t stack_limit = reinterpret_cast<uintptr_t>(&buffer) - max_stack; | |
180 internal::UnicodeCache unicode_cache; | |
181 internal::Scanner scanner(&unicode_cache); | |
182 scanner.Initialize(&buffer); | |
183 internal::CompleteParserRecorder recorder; | |
184 preparser::PreParser preparser(&scanner, &recorder, stack_limit); | |
185 preparser.set_allow_lazy(true); | |
186 preparser::PreParser::PreParseResult result = preparser.PreParseProgram(); | |
187 if (result == preparser::PreParser::kPreParseStackOverflow) { | |
188 return PreParserData::StackOverflow(); | |
189 } | |
190 internal::Vector<unsigned> pre_data = recorder.ExtractData(); | |
191 size_t size = pre_data.length() * sizeof(pre_data[0]); | |
192 unsigned char* data = reinterpret_cast<unsigned char*>(pre_data.start()); | |
193 return PreParserData(size, data); | |
194 } | |
195 | |
196 } // namespace v8. | |
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