11 * Set the reader error and return 0.
15 yaml_parser_set_reader_error(yaml_parser_t *parser, const char *problem,
16 size_t offset, int value)
18 parser->error = YAML_READER_ERROR;
19 parser->problem = problem;
20 parser->problem_offset = offset;
21 parser->problem_value = value;
28 * Ensure that the buffer contains at least length characters.
29 * Return 1 on success, 0 on failure.
31 * The length is supposed to be significantly less that the buffer size.
35 yaml_parser_update_buffer(yaml_parser_t *parser, size_t length)
37 /* If the EOF flag is set and the raw buffer is empty, do nothing. */
39 if (parser->eof && !parser->raw_unread)
42 /* Return if the buffer contains enough characters. */
44 if (parser->unread >= length)
47 /* Determine the input encoding if it is not known yet. */
49 if (!parser->encoding) {
50 if (!yaml_parser_determine_encoding(parser))
54 /* Move the unread characters to the beginning of the buffer. */
56 if (parser->buffer < parser->pointer
57 && parser->pointer < parser->buffer_end) {
58 size_t size = parser->buffer_end - parser->pointer;
59 memmove(parser->buffer, parser->pointer, size);
60 parser->pointer = parser->buffer;
61 parser->buffer_end -= size;
63 else if (parser->pointer == parser->buffer_end) {
64 parser->pointer = parser->buffer;
65 parser->buffer_end = parser->buffer;
68 /* Fill the buffer until it has enough characters. */
70 while (parser->unread < length)
72 /* Fill the raw buffer. */
74 if (!yaml_parser_update_raw_buffer(parser)) return 0;
76 /* Decode the raw buffer. */
78 while (parser->raw_unread)
80 unsigned int value, value2;
86 /* Decode the next character. */
88 switch (parser->encoding)
90 case YAML_UTF8_ENCODING:
93 * Decode a UTF-8 character. Check RFC 3629
94 * (http://www.ietf.org/rfc/rfc3629.txt) for more details.
96 * The following table (taken from the RFC) is used for
99 * Char. number range | UTF-8 octet sequence
100 * (hexadecimal) | (binary)
101 * --------------------+------------------------------------
102 * 0000 0000-0000 007F | 0xxxxxxx
103 * 0000 0080-0000 07FF | 110xxxxx 10xxxxxx
104 * 0000 0800-0000 FFFF | 1110xxxx 10xxxxxx 10xxxxxx
105 * 0001 0000-0010 FFFF | 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
107 * Additionally, the characters in the range 0xD800-0xDFFF
108 * are prohibited as they are reserved for use with UTF-16
112 /* Determine the length of the UTF-8 sequence. */
114 octet = parser->raw_pointer[0];
115 width = (octet & 0x80) == 0x00 ? 1 :
116 (octet & 0xE0) == 0xC0 ? 2 :
117 (octet & 0xF0) == 0xE0 ? 3 :
118 (octet & 0xF8) == 0xF0 ? 4 : 0;
120 /* Check if the leading octet is valid. */
123 return yaml_parser_set_reader_error(parser,
124 "Invalid leading UTF-8 octet",
125 parser->offset, octet);
127 /* Check if the raw buffer contains an incomplete character. */
129 if (width > parser->raw_unread) {
131 return yaml_parser_set_reader_error(parser,
132 "Incomplete UTF-8 octet sequence",
139 /* Decode the leading octet. */
141 value = (octet & 0x80) == 0x00 ? octet & 0x7F :
142 (octet & 0xE0) == 0xC0 ? octet & 0x1F :
143 (octet & 0xF0) == 0xE0 ? octet & 0x0F :
144 (octet & 0xF8) == 0xF0 ? octet & 0x07 : 0;
146 /* Check and decode the trailing octets. */
148 for (k = 1; k < width; k ++)
150 octet = parser->raw_pointer[k];
152 /* Check if the octet is valid. */
154 if ((octet & 0xC0) != 0x80)
155 return yaml_parser_set_reader_error(parser,
156 "Invalid trailing UTF-8 octet",
157 parser->offset+k, octet);
159 /* Decode the octet. */
161 value = (value << 6) + (octet & 0x3F);
164 /* Check the length of the sequence against the value. */
166 if (!((width == 1) ||
167 (width == 2 && value >= 0x80) ||
168 (width == 3 && value >= 0x800) ||
169 (width == 4 && value >= 0x10000)))
170 return yaml_parser_set_reader_error(parser,
171 "Invalid length of a UTF-8 sequence",
174 /* Check the range of the value. */
176 if ((value >= 0xD800 && value <= 0xDFFF) || value > 0x10FFFF)
177 return yaml_parser_set_reader_error(parser,
178 "Invalid Unicode character",
179 parser->offset, value);
183 case YAML_UTF16LE_ENCODING:
184 case YAML_UTF16BE_ENCODING:
186 low = (parser->encoding == YAML_UTF16LE_ENCODING ? 0 : 1);
187 high = (parser->encoding == YAML_UTF16LE_ENCODING ? 1 : 0);
190 * The UTF-16 encoding is not as simple as one might
191 * naively think. Check RFC 2781
192 * (http://www.ietf.org/rfc/rfc2781.txt).
194 * Normally, two subsequent bytes describe a Unicode
195 * character. However a special technique (called a
196 * surrogate pair) is used for specifying character
197 * values larger than 0xFFFF.
199 * A surrogate pair consists of two pseudo-characters:
200 * high surrogate area (0xD800-0xDBFF)
201 * low surrogate area (0xDC00-0xDFFF)
203 * The following formulas are used for decoding
204 * and encoding characters using surrogate pairs:
206 * U = U' + 0x10000 (0x01 00 00 <= U <= 0x10 FF FF)
207 * U' = yyyyyyyyyyxxxxxxxxxx (0 <= U' <= 0x0F FF FF)
208 * W1 = 110110yyyyyyyyyy
209 * W2 = 110111xxxxxxxxxx
211 * where U is the character value, W1 is the high surrogate
212 * area, W2 is the low surrogate area.
215 /* Check for incomplete UTF-16 character. */
217 if (parser->raw_unread < 2) {
219 return yaml_parser_set_reader_error(parser,
220 "Incomplete UTF-16 character",
227 /* Get the character. */
229 value = parser->raw_pointer[low]
230 + (parser->raw_pointer[high] << 8);
232 /* Check for unexpected low surrogate area. */
234 if ((value & 0xFC00) == 0xDC00)
235 return yaml_parser_set_reader_error(parser,
236 "Unexpected low surrogate area",
237 parser->offset, value);
239 /* Check for a high surrogate area. */
241 if ((value & 0xFC00) == 0xD800) {
245 /* Check for incomplete surrogate pair. */
247 if (parser->raw_unread < 4) {
249 return yaml_parser_set_reader_error(parser,
250 "Incomplete UTF-16 surrogate pair",
257 /* Get the next character. */
259 unsigned int value2 = parser->raw_pointer[low+2]
260 + (parser->raw_pointer[high+2] << 8);
262 /* Check for a low surrogate area. */
264 if ((value2 & 0xFC00) != 0xDC00)
265 return yaml_parser_set_reader_error(parser,
266 "Expected low surrogate area",
267 parser->offset+2, value2);
269 /* Generate the value of the surrogate pair. */
271 value = 0x10000 + ((value & 0x3FF) << 10) + (value2 & 0x3FF);
281 /* Check if the raw buffer contains enough bytes to form a character. */
283 if (incomplete) break;
286 * Check if the character is in the allowed range:
287 * #x9 | #xA | #xD | [#x20-#x7E] (8 bit)
288 * | #x85 | [#xA0-#xD7FF] | [#xE000-#xFFFD] (16 bit)
289 * | [#x10000-#x10FFFF] (32 bit)
292 if (! (value == 0x09 || value == 0x0A || value == 0x0D
293 || (value >= 0x20 && value <= 0x7E)
294 || (value == 0x85) || (value >= 0xA0 && value <= 0xD7FF)
295 || (value >= 0xE000 && value <= 0xFFFD)
296 || (value >= 0x10000 && value <= 0x10FFFF)))
297 return yaml_parser_set_reader_error(parser,
298 "Control characters are not allowed",
299 parser->offset, value);
301 /* Move the raw pointers. */
303 parser->raw_pointer += width;
304 parser->raw_unread -= width;
305 parser->offset += width;
307 /* Finally put the character into the buffer. */
309 /* 0000 0000-0000 007F -> 0xxxxxxx */
311 *(parser->buffer_end++) = value;
313 /* 0000 0080-0000 07FF -> 110xxxxx 10xxxxxx */
314 else if (value <= 0x7FF) {
315 *(parser->buffer_end++) = 0xC0 + (value >> 6);
316 *(parser->buffer_end++) = 0x80 + (value & 0x3F);
318 /* 0000 0800-0000 FFFF -> 1110xxxx 10xxxxxx 10xxxxxx */
319 else if (value <= 0xFFFF) {
320 *(parser->buffer_end++) = 0xE0 + (value >> 12);
321 *(parser->buffer_end++) = 0x80 + ((value >> 6) & 0x3F);
322 *(parser->buffer_end++) = 0x80 + (value & 0x3F);
324 /* 0001 0000-0010 FFFF -> 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */
326 *(parser->buffer_end++) = 0xF0 + (value >> 18);
327 *(parser->buffer_end++) = 0x80 + ((value >> 12) & 0x3F);
328 *(parser->buffer_end++) = 0x80 + ((value >> 6) & 0x3F);
329 *(parser->buffer_end++) = 0x80 + (value & 0x3F);
335 /* On EOF, put NUL into the buffer and return. */
338 *(parser->buffer_end++) = '\0';
349 * Determine the input stream encoding by checking the BOM symbol. If no BOM is
350 * found, the UTF-8 encoding is assumed. Return 1 on success, 0 on failure.
353 #define BOM_UTF8 "\xef\xbb\xbf"
354 #define BOM_UTF16LE "\xff\xfe"
355 #define BOM_UTF16BE "\xfe\xff"
358 yaml_parser_determine_encoding(yaml_parser_t *parser)
360 /* Ensure that we had enough bytes in the raw buffer. */
362 while (!parser->eof && parser->raw_unread < 3) {
363 if (!yaml_parser_update_raw_buffer(parser)) {
368 /* Determine the encoding. */
370 if (parser->raw_unread >= 2
371 && !memcmp(parser->raw_pointer, BOM_UTF16LE, 2)) {
372 parser->encoding = YAML_UTF16LE_ENCODING;
373 parser->raw_pointer += 2;
374 parser->raw_unread -= 2;
377 else if (parser->raw_unread >= 2
378 && !memcmp(parser->raw_pointer, BOM_UTF16BE, 2)) {
379 parser->encoding = YAML_UTF16BE_ENCODING;
380 parser->raw_pointer += 2;
381 parser->raw_unread -= 2;
384 else if (parser->raw_unread >= 3
385 && !memcmp(parser->raw_pointer, BOM_UTF8, 3)) {
386 parser->encoding = YAML_UTF8_ENCODING;
387 parser->raw_pointer += 3;
388 parser->raw_unread -= 3;
392 parser->encoding = YAML_UTF8_ENCODING;
399 * Update the raw buffer.
403 yaml_parser_update_raw_buffer(yaml_parser_t *parser)
405 size_t size_read = 0;
407 /* Return if the raw buffer is full. */
409 if (parser->raw_unread == YAML_RAW_BUFFER_SIZE) return 1;
413 if (parser->eof) return 1;
415 /* Move the remaining bytes in the raw buffer to the beginning. */
417 if (parser->raw_unread && parser->raw_buffer < parser->raw_pointer) {
418 memmove(parser->raw_buffer, parser->raw_pointer, parser->raw_unread);
420 parser->raw_pointer = parser->raw_buffer;
422 /* Call the read handler to fill the buffer. */
424 if (!parser->read_handler(parser->read_handler_data,
425 parser->raw_buffer + parser->raw_unread,
426 YAML_RAW_BUFFER_SIZE - parser->raw_unread,
428 return yaml_parser_set_reader_error(parser, "Input error",
431 parser->raw_unread += size_read;