1 // Copyright 2005-2008 Google Inc. All Rights Reserved.
2 // Author: jrm@google.com (Jim Meehan)
4 #include <google/protobuf/stubs/common.h>
10 // These four-byte entries compactly encode how many bytes 0..255 to delete
11 // in making a string replacement, how many bytes to add 0..255, and the offset
12 // 0..64k-1 of the replacement string in remap_string.
19 // Exit type codes for state tables. All but the first get stuffed into
20 // signed one-byte entries. The first is only generated by executable code.
21 // To distinguish from next-state entries, these must be contiguous and
24 kExitDstSpaceFull = 239,
25 kExitIllegalStructure, // 240
44 // This struct represents one entire state table. The three initialized byte
45 // areas are state_table, remap_base, and remap_string. state0 and state0_size
46 // give the byte offset and length within state_table of the initial state --
47 // table lookups are expected to start and end in this state, but for
48 // truncated UTF-8 strings, may end in a different state. These allow a quick
49 // test for that condition. entry_shift is 8 for tables subscripted by a full
50 // byte value and 6 for space-optimized tables subscripted by only six
51 // significant bits in UTF-8 continuation bytes.
54 const uint32 state0_size;
55 const uint32 total_size;
57 const int entry_shift;
58 const int bytes_per_entry;
61 const uint8* state_table;
62 const RemapEntry* remap_base;
63 const uint8* remap_string;
64 const uint8* fast_state;
65 } UTF8StateMachineObj;
67 typedef UTF8StateMachineObj UTF8ScanObj;
69 #define X__ (kExitIllegalStructure)
70 #define RJ_ (kExitReject)
71 #define S1_ (kExitReplace1)
72 #define S2_ (kExitReplace2)
73 #define S3_ (kExitReplace3)
74 #define S21 (kExitReplace21)
75 #define S31 (kExitReplace31)
76 #define S32 (kExitReplace32)
77 #define T1_ (kExitReplaceOffset1)
78 #define T2_ (kExitReplaceOffset2)
79 #define S11 (kExitReplace1S0)
80 #define SP_ (kExitSpecial)
81 #define D__ (kExitDoAgain)
82 #define RJA (kExitRejectAlt)
84 // Entire table has 9 state blocks of 256 entries each
85 static const unsigned int utf8acceptnonsurrogates_STATE0 = 0; // state[0]
86 static const unsigned int utf8acceptnonsurrogates_STATE0_SIZE = 256; // =[1]
87 static const unsigned int utf8acceptnonsurrogates_TOTAL_SIZE = 2304;
88 static const unsigned int utf8acceptnonsurrogates_MAX_EXPAND_X4 = 0;
89 static const unsigned int utf8acceptnonsurrogates_SHIFT = 8;
90 static const unsigned int utf8acceptnonsurrogates_BYTES = 1;
91 static const unsigned int utf8acceptnonsurrogates_LOSUB = 0x20202020;
92 static const unsigned int utf8acceptnonsurrogates_HIADD = 0x00000000;
94 static const uint8 utf8acceptnonsurrogates[] = {
95 // state[0] 0x000000 Byte 1
96 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
97 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
98 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
99 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
101 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
102 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
103 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
104 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
106 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
107 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
108 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
109 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
111 X__, X__, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
112 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
113 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 7, 3, 3,
114 4, 5, 5, 5, 6, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
116 // state[1] 0x000080 Byte 2 of 2
117 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
118 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
119 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
120 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
122 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
123 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
124 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
125 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
127 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
128 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
129 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
130 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
132 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
133 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
134 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
135 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
137 // state[2] 0x000000 Byte 2 of 3
138 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
139 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
140 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
141 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
143 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
144 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
145 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
146 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
148 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
149 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
150 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
151 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
153 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
154 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
155 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
156 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
158 // state[3] 0x001000 Byte 2 of 3
159 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
160 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
161 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
162 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
164 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
165 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
166 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
167 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
169 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
170 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
171 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
172 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
174 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
175 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
176 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
177 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
179 // state[4] 0x000000 Byte 2 of 4
180 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
181 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
182 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
183 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
185 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
186 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
187 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
188 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
190 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
191 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
192 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
193 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
195 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
196 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
197 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
198 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
200 // state[5] 0x040000 Byte 2 of 4
201 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
202 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
203 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
204 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
206 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
207 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
208 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
209 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
211 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
212 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
213 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
214 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
216 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
217 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
218 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
219 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
221 // state[6] 0x100000 Byte 2 of 4
222 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
223 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
224 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
225 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
227 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
228 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
229 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
230 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
232 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
233 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
234 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
235 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
237 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
238 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
239 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
240 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
242 // state[7] 0x00d000 Byte 2 of 3
243 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
244 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
245 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
246 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
248 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
249 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
250 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
251 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
253 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
254 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
255 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
256 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
258 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
259 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
260 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
261 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
263 // state[8] 0x00d800 Byte 3 of 3
264 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
265 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
266 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
267 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
269 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
270 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
271 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
272 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
274 RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_,
275 RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_,
276 RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_,
277 RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_, RJ_,
279 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
280 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
281 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
282 X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__, X__,
285 // Remap base[0] = (del, add, string_offset)
286 static const RemapEntry utf8acceptnonsurrogates_remap_base[] = {
290 static const unsigned char utf8acceptnonsurrogates_remap_string[] = {
293 static const unsigned char utf8acceptnonsurrogates_fast[256] = {
294 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
295 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
296 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
297 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
299 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
300 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
301 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
302 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
304 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
305 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
306 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
307 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
309 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
310 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
311 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
312 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
315 static const UTF8ScanObj utf8acceptnonsurrogates_obj = {
316 utf8acceptnonsurrogates_STATE0,
317 utf8acceptnonsurrogates_STATE0_SIZE,
318 utf8acceptnonsurrogates_TOTAL_SIZE,
319 utf8acceptnonsurrogates_MAX_EXPAND_X4,
320 utf8acceptnonsurrogates_SHIFT,
321 utf8acceptnonsurrogates_BYTES,
322 utf8acceptnonsurrogates_LOSUB,
323 utf8acceptnonsurrogates_HIADD,
324 utf8acceptnonsurrogates,
325 utf8acceptnonsurrogates_remap_base,
326 utf8acceptnonsurrogates_remap_string,
327 utf8acceptnonsurrogates_fast
346 // Return true if current Tbl pointer is within state0 range
347 // Note that unsigned compare checks both ends of range simultaneously
348 static inline bool InStateZero(const UTF8ScanObj* st, const uint8* Tbl) {
349 const uint8* Tbl0 = &st->state_table[st->state0];
350 return (static_cast<uint32>(Tbl - Tbl0) < st->state0_size);
353 // Scan a UTF-8 string based on state table.
354 // Always scan complete UTF-8 characters
355 // Set number of bytes scanned. Return reason for exiting
356 int UTF8GenericScan(const UTF8ScanObj* st,
359 int* bytes_consumed) {
361 if (str_length == 0) return kExitOK;
363 int eshift = st->entry_shift;
364 const uint8* isrc = reinterpret_cast<const uint8*>(str);
365 const uint8* src = isrc;
366 const uint8* srclimit = isrc + str_length;
367 const uint8* srclimit8 = srclimit - 7;
368 const uint8* Tbl_0 = &st->state_table[st->state0];
371 // Do state-table scan
374 const uint8* Tbl2 = &st->fast_state[0];
375 const uint32 losub = st->losub;
376 const uint32 hiadd = st->hiadd;
377 // Check initial few bytes one at a time until 8-byte aligned
378 //----------------------------
379 while ((((uintptr_t)src & 0x07) != 0) &&
384 if (((uintptr_t)src & 0x07) == 0) {
385 // Do fast for groups of 8 identity bytes.
386 // This covers a lot of 7-bit ASCII ~8x faster then the 1-byte loop,
387 // including slowing slightly on cr/lf/ht
388 //----------------------------
389 while (src < srclimit8) {
390 uint32 s0123 = (reinterpret_cast<const uint32 *>(src))[0];
391 uint32 s4567 = (reinterpret_cast<const uint32 *>(src))[1];
393 // This is a fast range check for all bytes in [lowsub..0x80-hiadd)
394 uint32 temp = (s0123 - losub) | (s0123 + hiadd) |
395 (s4567 - losub) | (s4567 + hiadd);
396 if ((temp & 0x80808080) != 0) {
397 // We typically end up here on cr/lf/ht; src was incremented
398 int e0123 = (Tbl2[src[-8]] | Tbl2[src[-7]]) |
399 (Tbl2[src[-6]] | Tbl2[src[-5]]);
403 } // Exit on Non-interchange
404 e0123 = (Tbl2[src[-4]] | Tbl2[src[-3]]) |
405 (Tbl2[src[-2]] | Tbl2[src[-1]]);
409 } // Exit on Non-interchange
410 // Else OK, go around again
414 //----------------------------
416 // Byte-at-a-time scan
417 //----------------------------
418 const uint8* Tbl = Tbl_0;
419 while (src < srclimit) {
423 if (e >= kExitIllegalStructure) {break;}
424 Tbl = &Tbl_0[e << eshift];
426 //----------------------------
429 // Exit posibilities:
430 // Some exit code, !state0, back up over last char
431 // Some exit code, state0, back up one byte exactly
432 // source consumed, !state0, back up over partial char
433 // source consumed, state0, exit OK
434 // For illegal byte in state0, avoid backup up over PREVIOUS char
435 // For truncated last char, back up to beginning of it
437 if (e >= kExitIllegalStructure) {
438 // Back up over exactly one byte of rejected/illegal UTF-8 character
440 // Back up more if needed
441 if (!InStateZero(st, Tbl)) {
444 } while ((src > isrc) && ((src[0] & 0xc0) == 0x80));
446 } else if (!InStateZero(st, Tbl)) {
447 // Back up over truncated UTF-8 character
448 e = kExitIllegalStructure;
451 } while ((src > isrc) && ((src[0] & 0xc0) == 0x80));
453 // Normal termination, source fully consumed
457 if (e == kExitDoAgain) {
458 // Loop back up to the fast scan
462 *bytes_consumed = src - isrc;
466 int UTF8GenericScanFastAscii(const UTF8ScanObj* st,
469 int* bytes_consumed) {
471 if (str_length == 0) return kExitOK;
473 const uint8* isrc = reinterpret_cast<const uint8*>(str);
474 const uint8* src = isrc;
475 const uint8* srclimit = isrc + str_length;
476 const uint8* srclimit8 = srclimit - 7;
481 // Check initial few bytes one at a time until 8-byte aligned
482 while ((((uintptr_t)src & 0x07) != 0) &&
483 (src < srclimit) && (src[0] < 0x80)) {
486 if (((uintptr_t)src & 0x07) == 0) {
487 while ((src < srclimit8) &&
488 (((reinterpret_cast<const uint32*>(src)[0] |
489 reinterpret_cast<const uint32*>(src)[1]) & 0x80808080) == 0)) {
493 while ((src < srclimit) && (src[0] < 0x80)) {
496 // Run state table on the rest
498 exit_reason = UTF8GenericScan(st, str + n, str_length - n, &rest_consumed);
499 src += rest_consumed;
500 } while ( exit_reason == kExitDoAgain );
502 *bytes_consumed = src - isrc;
506 // Hack: On some compilers the static tables are initialized at startup.
507 // We can't use them until they are initialized. However, some Protocol
508 // Buffer parsing happens at static init time and may try to validate
509 // UTF-8 strings. Since UTF-8 validation is only used for debugging
510 // anyway, we simply always return success if initialization hasn't
514 bool module_initialized_ = false;
516 struct InitDetector {
518 module_initialized_ = true;
521 InitDetector init_detector;
525 bool IsStructurallyValidUTF8(const char* buf, int len) {
526 if (!module_initialized_) return true;
528 int bytes_consumed = 0;
529 UTF8GenericScanFastAscii(&utf8acceptnonsurrogates_obj,
530 buf, len, &bytes_consumed);
531 return (bytes_consumed == len);
534 } // namespace internal
535 } // namespace protobuf
536 } // namespace google