1 // Copyright 2006 Nemanja Trifunovic
4 Permission is hereby granted, free of charge, to any person or organization
5 obtaining a copy of the software and accompanying documentation covered by
6 this license (the "Software") to use, reproduce, display, distribute,
7 execute, and transmit the Software, and to prepare derivative works of the
8 Software, and to permit third-parties to whom the Software is furnished to
9 do so, all subject to the following:
11 The copyright notices in the Software and this entire statement, including
12 the above license grant, this restriction and the following disclaimer,
13 must be included in all copies of the Software, in whole or in part, and
14 all derivative works of the Software, unless such copies or derivative
15 works are solely in the form of machine-executable object code generated by
16 a source language processor.
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19 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
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22 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
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24 DEALINGS IN THE SOFTWARE.
28 #ifndef UTF8_FOR_CPP_CORE_H_2675DCD0_9480_4c0c_B92A_CC14C027B731
29 #define UTF8_FOR_CPP_CORE_H_2675DCD0_9480_4c0c_B92A_CC14C027B731
35 // The typedefs for 8-bit, 16-bit and 32-bit unsigned integers
36 // You may need to change them to match your system.
37 // These typedefs have the same names as ones from cstdint, or boost/cstdint
38 typedef unsigned char uint8_t;
39 typedef unsigned short uint16_t;
40 typedef unsigned int uint32_t;
42 // Helper code - not intended to be directly called by the library users. May be changed at any time
46 // Leading (high) surrogates: 0xd800 - 0xdbff
47 // Trailing (low) surrogates: 0xdc00 - 0xdfff
48 const uint16_t LEAD_SURROGATE_MIN = 0xd800u;
49 const uint16_t LEAD_SURROGATE_MAX = 0xdbffu;
50 const uint16_t TRAIL_SURROGATE_MIN = 0xdc00u;
51 const uint16_t TRAIL_SURROGATE_MAX = 0xdfffu;
52 const uint16_t LEAD_OFFSET = LEAD_SURROGATE_MIN - (0x10000 >> 10);
53 const uint32_t SURROGATE_OFFSET = 0x10000u - (LEAD_SURROGATE_MIN << 10) - TRAIL_SURROGATE_MIN;
55 // Maximum valid value for a Unicode code point
56 const uint32_t CODE_POINT_MAX = 0x0010ffffu;
58 template<typename octet_type>
59 inline uint8_t mask8(octet_type oc)
61 return static_cast<uint8_t>(0xff & oc);
63 template<typename u16_type>
64 inline uint16_t mask16(u16_type oc)
66 return static_cast<uint16_t>(0xffff & oc);
68 template<typename octet_type>
69 inline bool is_trail(octet_type oc)
71 return ((utf8::internal::mask8(oc) >> 6) == 0x2);
74 template <typename u16>
75 inline bool is_lead_surrogate(u16 cp)
77 return (cp >= LEAD_SURROGATE_MIN && cp <= LEAD_SURROGATE_MAX);
80 template <typename u16>
81 inline bool is_trail_surrogate(u16 cp)
83 return (cp >= TRAIL_SURROGATE_MIN && cp <= TRAIL_SURROGATE_MAX);
86 template <typename u16>
87 inline bool is_surrogate(u16 cp)
89 return (cp >= LEAD_SURROGATE_MIN && cp <= TRAIL_SURROGATE_MAX);
92 template <typename u32>
93 inline bool is_code_point_valid(u32 cp)
95 return (cp <= CODE_POINT_MAX && !utf8::internal::is_surrogate(cp));
98 template <typename octet_iterator>
99 inline typename std::iterator_traits<octet_iterator>::difference_type
100 sequence_length(octet_iterator lead_it)
102 uint8_t lead = utf8::internal::mask8(*lead_it);
105 else if ((lead >> 5) == 0x6)
107 else if ((lead >> 4) == 0xe)
109 else if ((lead >> 3) == 0x1e)
115 template <typename octet_difference_type>
116 inline bool is_overlong_sequence(uint32_t cp, octet_difference_type length)
122 else if (cp < 0x800) {
126 else if (cp < 0x10000) {
134 enum utf_error {UTF8_OK, NOT_ENOUGH_ROOM, INVALID_LEAD, INCOMPLETE_SEQUENCE, OVERLONG_SEQUENCE, INVALID_CODE_POINT};
136 /// Helper for get_sequence_x
137 template <typename octet_iterator>
138 utf_error increase_safely(octet_iterator& it, octet_iterator end)
141 return NOT_ENOUGH_ROOM;
143 if (!utf8::internal::is_trail(*it))
144 return INCOMPLETE_SEQUENCE;
149 #define UTF8_CPP_INCREASE_AND_RETURN_ON_ERROR(IT, END) {utf_error ret = increase_safely(IT, END); if (ret != UTF8_OK) return ret;}
151 /// get_sequence_x functions decode utf-8 sequences of the length x
152 template <typename octet_iterator>
153 utf_error get_sequence_1(octet_iterator& it, octet_iterator end, uint32_t& code_point)
156 return NOT_ENOUGH_ROOM;
158 code_point = utf8::internal::mask8(*it);
163 template <typename octet_iterator>
164 utf_error get_sequence_2(octet_iterator& it, octet_iterator end, uint32_t& code_point)
167 return NOT_ENOUGH_ROOM;
169 code_point = utf8::internal::mask8(*it);
171 UTF8_CPP_INCREASE_AND_RETURN_ON_ERROR(it, end)
173 code_point = ((code_point << 6) & 0x7ff) + ((*it) & 0x3f);
178 template <typename octet_iterator>
179 utf_error get_sequence_3(octet_iterator& it, octet_iterator end, uint32_t& code_point)
182 return NOT_ENOUGH_ROOM;
184 code_point = utf8::internal::mask8(*it);
186 UTF8_CPP_INCREASE_AND_RETURN_ON_ERROR(it, end)
188 code_point = ((code_point << 12) & 0xffff) + ((utf8::internal::mask8(*it) << 6) & 0xfff);
190 UTF8_CPP_INCREASE_AND_RETURN_ON_ERROR(it, end)
192 code_point += (*it) & 0x3f;
197 template <typename octet_iterator>
198 utf_error get_sequence_4(octet_iterator& it, octet_iterator end, uint32_t& code_point)
201 return NOT_ENOUGH_ROOM;
203 code_point = utf8::internal::mask8(*it);
205 UTF8_CPP_INCREASE_AND_RETURN_ON_ERROR(it, end)
207 code_point = ((code_point << 18) & 0x1fffff) + ((utf8::internal::mask8(*it) << 12) & 0x3ffff);
209 UTF8_CPP_INCREASE_AND_RETURN_ON_ERROR(it, end)
211 code_point += (utf8::internal::mask8(*it) << 6) & 0xfff;
213 UTF8_CPP_INCREASE_AND_RETURN_ON_ERROR(it, end)
215 code_point += (*it) & 0x3f;
220 #undef UTF8_CPP_INCREASE_AND_RETURN_ON_ERROR
222 template <typename octet_iterator>
223 utf_error validate_next(octet_iterator& it, octet_iterator end, uint32_t& code_point)
225 // Save the original value of it so we can go back in case of failure
226 // Of course, it does not make much sense with i.e. stream iterators
227 octet_iterator original_it = it;
230 // Determine the sequence length based on the lead octet
231 typedef typename std::iterator_traits<octet_iterator>::difference_type octet_difference_type;
232 const octet_difference_type length = utf8::internal::sequence_length(it);
234 // Get trail octets and calculate the code point
235 utf_error err = UTF8_OK;
240 err = utf8::internal::get_sequence_1(it, end, cp);
243 err = utf8::internal::get_sequence_2(it, end, cp);
246 err = utf8::internal::get_sequence_3(it, end, cp);
249 err = utf8::internal::get_sequence_4(it, end, cp);
253 if (err == UTF8_OK) {
254 // Decoding succeeded. Now, security checks...
255 if (utf8::internal::is_code_point_valid(cp)) {
256 if (!utf8::internal::is_overlong_sequence(cp, length)){
257 // Passed! Return here.
263 err = OVERLONG_SEQUENCE;
266 err = INVALID_CODE_POINT;
269 // Failure branch - restore the original value of the iterator
274 template <typename octet_iterator>
275 inline utf_error validate_next(octet_iterator& it, octet_iterator end) {
277 return utf8::internal::validate_next(it, end, ignored);
280 } // namespace internal
282 /// The library API - functions intended to be called by the users
285 const uint8_t bom[] = {0xef, 0xbb, 0xbf};
287 template <typename octet_iterator>
288 octet_iterator find_invalid(octet_iterator start, octet_iterator end)
290 octet_iterator result = start;
291 while (result != end) {
292 utf8::internal::utf_error err_code = utf8::internal::validate_next(result, end);
293 if (err_code != internal::UTF8_OK)
299 template <typename octet_iterator>
300 inline bool is_valid(octet_iterator start, octet_iterator end)
302 return (utf8::find_invalid(start, end) == end);
305 template <typename octet_iterator>
306 inline bool starts_with_bom (octet_iterator it, octet_iterator end)
309 ((it != end) && (utf8::internal::mask8(*it++)) == bom[0]) &&
310 ((it != end) && (utf8::internal::mask8(*it++)) == bom[1]) &&
311 ((it != end) && (utf8::internal::mask8(*it)) == bom[2])
315 //Deprecated in release 2.3
316 template <typename octet_iterator>
317 inline bool is_bom (octet_iterator it)
320 (utf8::internal::mask8(*it++)) == bom[0] &&
321 (utf8::internal::mask8(*it++)) == bom[1] &&
322 (utf8::internal::mask8(*it)) == bom[2]
327 #endif // header guard