@@ -0,0 +1,3584 @@
1+
2+/*
3+ * Introduction
4+ * ************
5+ *
6+ * The following notes assume that you are familiar with the YAML specification
7+ * (http://yaml.org/spec/cvs/current.html). We mostly follow it, although in
8+ * some cases we are less restrictive that it requires.
9+ *
10+ * The process of transforming a YAML stream into a sequence of events is
11+ * divided on two steps: Scanning and Parsing.
12+ *
13+ * The Scanner transforms the input stream into a sequence of tokens, while the
14+ * parser transform the sequence of tokens produced by the Scanner into a
15+ * sequence of parsing events.
16+ *
17+ * The Scanner is rather clever and complicated. The Parser, on the contrary,
18+ * is a straightforward implementation of a recursive-descendant parser (or,
19+ * LL(1) parser, as it is usually called).
20+ *
21+ * Actually there are two issues of Scanning that might be called "clever", the
22+ * rest is quite straightforward. The issues are "block collection start" and
23+ * "simple keys". Both issues are explained below in details.
24+ *
25+ * Here the Scanning step is explained and implemented. We start with the list
26+ * of all the tokens produced by the Scanner together with short descriptions.
27+ *
28+ * Now, tokens:
29+ *
30+ * STREAM-START(encoding) # The stream start.
31+ * STREAM-END # The stream end.
32+ * VERSION-DIRECTIVE(major,minor) # The '%YAML' directive.
33+ * TAG-DIRECTIVE(handle,prefix) # The '%TAG' directive.
34+ * DOCUMENT-START # '---'
35+ * DOCUMENT-END # '...'
36+ * BLOCK-SEQUENCE-START # Indentation increase denoting a block
37+ * BLOCK-MAPPING-START # sequence or a block mapping.
38+ * BLOCK-END # Indentation decrease.
39+ * FLOW-SEQUENCE-START # '['
40+ * FLOW-SEQUENCE-END # ']'
41+ * BLOCK-SEQUENCE-START # '{'
42+ * BLOCK-SEQUENCE-END # '}'
43+ * BLOCK-ENTRY # '-'
44+ * FLOW-ENTRY # ','
45+ * KEY # '?' or nothing (simple keys).
46+ * VALUE # ':'
47+ * ALIAS(anchor) # '*anchor'
48+ * ANCHOR(anchor) # '&anchor'
49+ * TAG(handle,suffix) # '!handle!suffix'
50+ * SCALAR(value,style) # A scalar.
51+ *
52+ * The following two tokens are "virtual" tokens denoting the beginning and the
53+ * end of the stream:
54+ *
55+ * STREAM-START(encoding)
56+ * STREAM-END
57+ *
58+ * We pass the information about the input stream encoding with the
59+ * STREAM-START token.
60+ *
61+ * The next two tokens are responsible for tags:
62+ *
63+ * VERSION-DIRECTIVE(major,minor)
64+ * TAG-DIRECTIVE(handle,prefix)
65+ *
66+ * Example:
67+ *
68+ * %YAML 1.1
69+ * %TAG ! !foo
70+ * %TAG !yaml! tag:yaml.org,2002:
71+ * ---
72+ *
73+ * The corresponding sequence of tokens:
74+ *
75+ * STREAM-START(utf-8)
76+ * VERSION-DIRECTIVE(1,1)
77+ * TAG-DIRECTIVE("!","!foo")
78+ * TAG-DIRECTIVE("!yaml","tag:yaml.org,2002:")
79+ * DOCUMENT-START
80+ * STREAM-END
81+ *
82+ * Note that the VERSION-DIRECTIVE and TAG-DIRECTIVE tokens occupy a whole
83+ * line.
84+ *
85+ * The document start and end indicators are represented by:
86+ *
87+ * DOCUMENT-START
88+ * DOCUMENT-END
89+ *
90+ * Note that if a YAML stream contains an implicit document (without '---'
91+ * and '...' indicators), no DOCUMENT-START and DOCUMENT-END tokens will be
92+ * produced.
93+ *
94+ * In the following examples, we present whole documents together with the
95+ * produced tokens.
96+ *
97+ * 1. An implicit document:
98+ *
99+ * 'a scalar'
100+ *
101+ * Tokens:
102+ *
103+ * STREAM-START(utf-8)
104+ * SCALAR("a scalar",single-quoted)
105+ * STREAM-END
106+ *
107+ * 2. An explicit document:
108+ *
109+ * ---
110+ * 'a scalar'
111+ * ...
112+ *
113+ * Tokens:
114+ *
115+ * STREAM-START(utf-8)
116+ * DOCUMENT-START
117+ * SCALAR("a scalar",single-quoted)
118+ * DOCUMENT-END
119+ * STREAM-END
120+ *
121+ * 3. Several documents in a stream:
122+ *
123+ * 'a scalar'
124+ * ---
125+ * 'another scalar'
126+ * ---
127+ * 'yet another scalar'
128+ *
129+ * Tokens:
130+ *
131+ * STREAM-START(utf-8)
132+ * SCALAR("a scalar",single-quoted)
133+ * DOCUMENT-START
134+ * SCALAR("another scalar",single-quoted)
135+ * DOCUMENT-START
136+ * SCALAR("yet another scalar",single-quoted)
137+ * STREAM-END
138+ *
139+ * We have already introduced the SCALAR token above. The following tokens are
140+ * used to describe aliases, anchors, tag, and scalars:
141+ *
142+ * ALIAS(anchor)
143+ * ANCHOR(anchor)
144+ * TAG(handle,suffix)
145+ * SCALAR(value,style)
146+ *
147+ * The following series of examples illustrate the usage of these tokens:
148+ *
149+ * 1. A recursive sequence:
150+ *
151+ * &A [ *A ]
152+ *
153+ * Tokens:
154+ *
155+ * STREAM-START(utf-8)
156+ * ANCHOR("A")
157+ * FLOW-SEQUENCE-START
158+ * ALIAS("A")
159+ * FLOW-SEQUENCE-END
160+ * STREAM-END
161+ *
162+ * 2. A tagged scalar:
163+ *
164+ * !!float "3.14" # A good approximation.
165+ *
166+ * Tokens:
167+ *
168+ * STREAM-START(utf-8)
169+ * TAG("!!","float")
170+ * SCALAR("3.14",double-quoted)
171+ * STREAM-END
172+ *
173+ * 3. Various scalar styles:
174+ *
175+ * --- # Implicit empty plain scalars do not produce tokens.
176+ * --- a plain scalar
177+ * --- 'a single-quoted scalar'
178+ * --- "a double-quoted scalar"
179+ * --- |-
180+ * a literal scalar
181+ * --- >-
182+ * a folded
183+ * scalar
184+ *
185+ * Tokens:
186+ *
187+ * STREAM-START(utf-8)
188+ * DOCUMENT-START
189+ * DOCUMENT-START
190+ * SCALAR("a plain scalar",plain)
191+ * DOCUMENT-START
192+ * SCALAR("a single-quoted scalar",single-quoted)
193+ * DOCUMENT-START
194+ * SCALAR("a double-quoted scalar",double-quoted)
195+ * DOCUMENT-START
196+ * SCALAR("a literal scalar",literal)
197+ * DOCUMENT-START
198+ * SCALAR("a folded scalar",folded)
199+ * STREAM-END
200+ *
201+ * Now it's time to review collection-related tokens. We will start with
202+ * flow collections:
203+ *
204+ * FLOW-SEQUENCE-START
205+ * FLOW-SEQUENCE-END
206+ * FLOW-MAPPING-START
207+ * FLOW-MAPPING-END
208+ * FLOW-ENTRY
209+ * KEY
210+ * VALUE
211+ *
212+ * The tokens FLOW-SEQUENCE-START, FLOW-SEQUENCE-END, FLOW-MAPPING-START, and
213+ * FLOW-MAPPING-END represent the indicators '[', ']', '{', and '}'
214+ * correspondingly. FLOW-ENTRY represent the ',' indicator. Finally the
215+ * indicators '?' and ':', which are used for denoting mapping keys and values,
216+ * are represented by the KEY and VALUE tokens.
217+ *
218+ * The following examples show flow collections:
219+ *
220+ * 1. A flow sequence:
221+ *
222+ * [item 1, item 2, item 3]
223+ *
224+ * Tokens:
225+ *
226+ * STREAM-START(utf-8)
227+ * FLOW-SEQUENCE-START
228+ * SCALAR("item 1",plain)
229+ * FLOW-ENTRY
230+ * SCALAR("item 2",plain)
231+ * FLOW-ENTRY
232+ * SCALAR("item 3",plain)
233+ * FLOW-SEQUENCE-END
234+ * STREAM-END
235+ *
236+ * 2. A flow mapping:
237+ *
238+ * {
239+ * a simple key: a value, # Note that the KEY token is produced.
240+ * ? a complex key: another value,
241+ * }
242+ *
243+ * Tokens:
244+ *
245+ * STREAM-START(utf-8)
246+ * FLOW-MAPPING-START
247+ * KEY
248+ * SCALAR("a simple key",plain)
249+ * VALUE
250+ * SCALAR("a value",plain)
251+ * FLOW-ENTRY
252+ * KEY
253+ * SCALAR("a complex key",plain)
254+ * VALUE
255+ * SCALAR("another value",plain)
256+ * FLOW-ENTRY
257+ * FLOW-MAPPING-END
258+ * STREAM-END
259+ *
260+ * A simple key is a key which is not denoted by the '?' indicator. Note that
261+ * the Scanner still produce the KEY token whenever it encounters a simple key.
262+ *
263+ * For scanning block collections, the following tokens are used (note that we
264+ * repeat KEY and VALUE here):
265+ *
266+ * BLOCK-SEQUENCE-START
267+ * BLOCK-MAPPING-START
268+ * BLOCK-END
269+ * BLOCK-ENTRY
270+ * KEY
271+ * VALUE
272+ *
273+ * The tokens BLOCK-SEQUENCE-START and BLOCK-MAPPING-START denote indentation
274+ * increase that precedes a block collection (cf. the INDENT token in Python).
275+ * The token BLOCK-END denote indentation decrease that ends a block collection
276+ * (cf. the DEDENT token in Python). However YAML has some syntax pecularities
277+ * that makes detections of these tokens more complex.
278+ *
279+ * The tokens BLOCK-ENTRY, KEY, and VALUE are used to represent the indicators
280+ * '-', '?', and ':' correspondingly.
281+ *
282+ * The following examples show how the tokens BLOCK-SEQUENCE-START,
283+ * BLOCK-MAPPING-START, and BLOCK-END are emitted by the Scanner:
284+ *
285+ * 1. Block sequences:
286+ *
287+ * - item 1
288+ * - item 2
289+ * -
290+ * - item 3.1
291+ * - item 3.2
292+ * -
293+ * key 1: value 1
294+ * key 2: value 2
295+ *
296+ * Tokens:
297+ *
298+ * STREAM-START(utf-8)
299+ * BLOCK-SEQUENCE-START
300+ * BLOCK-ENTRY
301+ * SCALAR("item 1",plain)
302+ * BLOCK-ENTRY
303+ * SCALAR("item 2",plain)
304+ * BLOCK-ENTRY
305+ * BLOCK-SEQUENCE-START
306+ * BLOCK-ENTRY
307+ * SCALAR("item 3.1",plain)
308+ * BLOCK-ENTRY
309+ * SCALAR("item 3.2",plain)
310+ * BLOCK-END
311+ * BLOCK-ENTRY
312+ * BLOCK-MAPPING-START
313+ * KEY
314+ * SCALAR("key 1",plain)
315+ * VALUE
316+ * SCALAR("value 1",plain)
317+ * KEY
318+ * SCALAR("key 2",plain)
319+ * VALUE
320+ * SCALAR("value 2",plain)
321+ * BLOCK-END
322+ * BLOCK-END
323+ * STREAM-END
324+ *
325+ * 2. Block mappings:
326+ *
327+ * a simple key: a value # The KEY token is produced here.
328+ * ? a complex key
329+ * : another value
330+ * a mapping:
331+ * key 1: value 1
332+ * key 2: value 2
333+ * a sequence:
334+ * - item 1
335+ * - item 2
336+ *
337+ * Tokens:
338+ *
339+ * STREAM-START(utf-8)
340+ * BLOCK-MAPPING-START
341+ * KEY
342+ * SCALAR("a simple key",plain)
343+ * VALUE
344+ * SCALAR("a value",plain)
345+ * KEY
346+ * SCALAR("a complex key",plain)
347+ * VALUE
348+ * SCALAR("another value",plain)
349+ * KEY
350+ * SCALAR("a mapping",plain)
351+ * BLOCK-MAPPING-START
352+ * KEY
353+ * SCALAR("key 1",plain)
354+ * VALUE
355+ * SCALAR("value 1",plain)
356+ * KEY
357+ * SCALAR("key 2",plain)
358+ * VALUE
359+ * SCALAR("value 2",plain)
360+ * BLOCK-END
361+ * KEY
362+ * SCALAR("a sequence",plain)
363+ * VALUE
364+ * BLOCK-SEQUENCE-START
365+ * BLOCK-ENTRY
366+ * SCALAR("item 1",plain)
367+ * BLOCK-ENTRY
368+ * SCALAR("item 2",plain)
369+ * BLOCK-END
370+ * BLOCK-END
371+ * STREAM-END
372+ *
373+ * YAML does not always require to start a new block collection from a new
374+ * line. If the current line contains only '-', '?', and ':' indicators, a new
375+ * block collection may start at the current line. The following examples
376+ * illustrate this case:
377+ *
378+ * 1. Collections in a sequence:
379+ *
380+ * - - item 1
381+ * - item 2
382+ * - key 1: value 1
383+ * key 2: value 2
384+ * - ? complex key
385+ * : complex value
386+ *
387+ * Tokens:
388+ *
389+ * STREAM-START(utf-8)
390+ * BLOCK-SEQUENCE-START
391+ * BLOCK-ENTRY
392+ * BLOCK-SEQUENCE-START
393+ * BLOCK-ENTRY
394+ * SCALAR("item 1",plain)
395+ * BLOCK-ENTRY
396+ * SCALAR("item 2",plain)
397+ * BLOCK-END
398+ * BLOCK-ENTRY
399+ * BLOCK-MAPPING-START
400+ * KEY
401+ * SCALAR("key 1",plain)
402+ * VALUE
403+ * SCALAR("value 1",plain)
404+ * KEY
405+ * SCALAR("key 2",plain)
406+ * VALUE
407+ * SCALAR("value 2",plain)
408+ * BLOCK-END
409+ * BLOCK-ENTRY
410+ * BLOCK-MAPPING-START
411+ * KEY
412+ * SCALAR("complex key")
413+ * VALUE
414+ * SCALAR("complex value")
415+ * BLOCK-END
416+ * BLOCK-END
417+ * STREAM-END
418+ *
419+ * 2. Collections in a mapping:
420+ *
421+ * ? a sequence
422+ * : - item 1
423+ * - item 2
424+ * ? a mapping
425+ * : key 1: value 1
426+ * key 2: value 2
427+ *
428+ * Tokens:
429+ *
430+ * STREAM-START(utf-8)
431+ * BLOCK-MAPPING-START
432+ * KEY
433+ * SCALAR("a sequence",plain)
434+ * VALUE
435+ * BLOCK-SEQUENCE-START
436+ * BLOCK-ENTRY
437+ * SCALAR("item 1",plain)
438+ * BLOCK-ENTRY
439+ * SCALAR("item 2",plain)
440+ * BLOCK-END
441+ * KEY
442+ * SCALAR("a mapping",plain)
443+ * VALUE
444+ * BLOCK-MAPPING-START
445+ * KEY
446+ * SCALAR("key 1",plain)
447+ * VALUE
448+ * SCALAR("value 1",plain)
449+ * KEY
450+ * SCALAR("key 2",plain)
451+ * VALUE
452+ * SCALAR("value 2",plain)
453+ * BLOCK-END
454+ * BLOCK-END
455+ * STREAM-END
456+ *
457+ * YAML also permits non-indented sequences if they are included into a block
458+ * mapping. In this case, the token BLOCK-SEQUENCE-START is not produced:
459+ *
460+ * key:
461+ * - item 1 # BLOCK-SEQUENCE-START is NOT produced here.
462+ * - item 2
463+ *
464+ * Tokens:
465+ *
466+ * STREAM-START(utf-8)
467+ * BLOCK-MAPPING-START
468+ * KEY
469+ * SCALAR("key",plain)
470+ * VALUE
471+ * BLOCK-ENTRY
472+ * SCALAR("item 1",plain)
473+ * BLOCK-ENTRY
474+ * SCALAR("item 2",plain)
475+ * BLOCK-END
476+ */
477+
478+#include "yaml_private.h"
479+
480+/*
481+ * Ensure that the buffer contains the required number of characters.
482+ * Return 1 on success, 0 on failure (reader error or memory error).
483+ */
484+
485+#define CACHE(parser,length) \
486+ (parser->unread >= (length) \
487+ ? 1 \
488+ : yaml_parser_update_buffer(parser, (length)))
489+
490+/*
491+ * Advance the buffer pointer.
492+ */
493+
494+#define SKIP(parser) \
495+ (parser->mark.index ++, \
496+ parser->mark.column ++, \
497+ parser->unread --, \
498+ parser->buffer.pointer += WIDTH(parser->buffer))
499+
500+#define SKIP_LINE(parser) \
501+ (IS_CRLF(parser->buffer) ? \
502+ (parser->mark.index += 2, \
503+ parser->mark.column = 0, \
504+ parser->mark.line ++, \
505+ parser->unread -= 2, \
506+ parser->buffer.pointer += 2) : \
507+ IS_BREAK(parser->buffer) ? \
508+ (parser->mark.index ++, \
509+ parser->mark.column = 0, \
510+ parser->mark.line ++, \
511+ parser->unread --, \
512+ parser->buffer.pointer += WIDTH(parser->buffer)) : 0)
513+
514+/*
515+ * Copy a character to a string buffer and advance pointers.
516+ */
517+
518+#define READ(parser,string) \
519+ (STRING_EXTEND(parser,string) ? \
520+ (COPY(string,parser->buffer), \
521+ parser->mark.index ++, \
522+ parser->mark.column ++, \
523+ parser->unread --, \
524+ 1) : 0)
525+
526+/*
527+ * Copy a line break character to a string buffer and advance pointers.
528+ */
529+
530+#define READ_LINE(parser,string) \
531+ (STRING_EXTEND(parser,string) ? \
532+ (((CHECK_AT(parser->buffer,'\r',0) \
533+ && CHECK_AT(parser->buffer,'\n',1)) ? /* CR LF -> LF */ \
534+ (*((string).pointer++) = (yaml_char_t) '\n', \
535+ parser->buffer.pointer += 2, \
536+ parser->mark.index += 2, \
537+ parser->mark.column = 0, \
538+ parser->mark.line ++, \
539+ parser->unread -= 2) : \
540+ (CHECK_AT(parser->buffer,'\r',0) \
541+ || CHECK_AT(parser->buffer,'\n',0)) ? /* CR|LF -> LF */ \
542+ (*((string).pointer++) = (yaml_char_t) '\n', \
543+ parser->buffer.pointer ++, \
544+ parser->mark.index ++, \
545+ parser->mark.column = 0, \
546+ parser->mark.line ++, \
547+ parser->unread --) : \
548+ (CHECK_AT(parser->buffer,'\xC2',0) \
549+ && CHECK_AT(parser->buffer,'\x85',1)) ? /* NEL -> LF */ \
550+ (*((string).pointer++) = (yaml_char_t) '\n', \
551+ parser->buffer.pointer += 2, \
552+ parser->mark.index ++, \
553+ parser->mark.column = 0, \
554+ parser->mark.line ++, \
555+ parser->unread --) : \
556+ (CHECK_AT(parser->buffer,'\xE2',0) && \
557+ CHECK_AT(parser->buffer,'\x80',1) && \
558+ (CHECK_AT(parser->buffer,'\xA8',2) || \
559+ CHECK_AT(parser->buffer,'\xA9',2))) ? /* LS|PS -> LS|PS */ \
560+ (*((string).pointer++) = *(parser->buffer.pointer++), \
561+ *((string).pointer++) = *(parser->buffer.pointer++), \
562+ *((string).pointer++) = *(parser->buffer.pointer++), \
563+ parser->mark.index ++, \
564+ parser->mark.column = 0, \
565+ parser->mark.line ++, \
566+ parser->unread --) : 0), \
567+ 1) : 0)
568+
569+/*
570+ * Public API declarations.
571+ */
572+
573+YAML_DECLARE(int)
574+yaml_parser_scan(yaml_parser_t *parser, yaml_token_t *token);
575+
576+/*
577+ * Error handling.
578+ */
579+
580+static int
581+yaml_parser_set_scanner_error(yaml_parser_t *parser, const char *context,
582+ yaml_mark_t context_mark, const char *problem);
583+
584+/*
585+ * High-level token API.
586+ */
587+
588+YAML_DECLARE(int)
589+yaml_parser_fetch_more_tokens(yaml_parser_t *parser);
590+
591+static int
592+yaml_parser_fetch_next_token(yaml_parser_t *parser);
593+
594+/*
595+ * Potential simple keys.
596+ */
597+
598+static int
599+yaml_parser_stale_simple_keys(yaml_parser_t *parser);
600+
601+static int
602+yaml_parser_save_simple_key(yaml_parser_t *parser);
603+
604+static int
605+yaml_parser_remove_simple_key(yaml_parser_t *parser);
606+
607+static int
608+yaml_parser_increase_flow_level(yaml_parser_t *parser);
609+
610+static int
611+yaml_parser_decrease_flow_level(yaml_parser_t *parser);
612+
613+/*
614+ * Indentation treatment.
615+ */
616+
617+static int
618+yaml_parser_roll_indent(yaml_parser_t *parser, ptrdiff_t column,
619+ ptrdiff_t number, yaml_token_type_t type, yaml_mark_t mark);
620+
621+static int
622+yaml_parser_unroll_indent(yaml_parser_t *parser, ptrdiff_t column);
623+
624+/*
625+ * Token fetchers.
626+ */
627+
628+static int
629+yaml_parser_fetch_stream_start(yaml_parser_t *parser);
630+
631+static int
632+yaml_parser_fetch_stream_end(yaml_parser_t *parser);
633+
634+static int
635+yaml_parser_fetch_directive(yaml_parser_t *parser);
636+
637+static int
638+yaml_parser_fetch_document_indicator(yaml_parser_t *parser,
639+ yaml_token_type_t type);
640+
641+static int
642+yaml_parser_fetch_flow_collection_start(yaml_parser_t *parser,
643+ yaml_token_type_t type);
644+
645+static int
646+yaml_parser_fetch_flow_collection_end(yaml_parser_t *parser,
647+ yaml_token_type_t type);
648+
649+static int
650+yaml_parser_fetch_flow_entry(yaml_parser_t *parser);
651+
652+static int
653+yaml_parser_fetch_block_entry(yaml_parser_t *parser);
654+
655+static int
656+yaml_parser_fetch_key(yaml_parser_t *parser);
657+
658+static int
659+yaml_parser_fetch_value(yaml_parser_t *parser);
660+
661+static int
662+yaml_parser_fetch_anchor(yaml_parser_t *parser, yaml_token_type_t type);
663+
664+static int
665+yaml_parser_fetch_tag(yaml_parser_t *parser);
666+
667+static int
668+yaml_parser_fetch_block_scalar(yaml_parser_t *parser, int literal);
669+
670+static int
671+yaml_parser_fetch_flow_scalar(yaml_parser_t *parser, int single);
672+
673+static int
674+yaml_parser_fetch_plain_scalar(yaml_parser_t *parser);
675+
676+/*
677+ * Token scanners.
678+ */
679+
680+static int
681+yaml_parser_scan_to_next_token(yaml_parser_t *parser);
682+
683+static int
684+yaml_parser_scan_directive(yaml_parser_t *parser, yaml_token_t *token);
685+
686+static int
687+yaml_parser_scan_directive_name(yaml_parser_t *parser,
688+ yaml_mark_t start_mark, yaml_char_t **name);
689+
690+static int
691+yaml_parser_scan_version_directive_value(yaml_parser_t *parser,
692+ yaml_mark_t start_mark, int *major, int *minor);
693+
694+static int
695+yaml_parser_scan_version_directive_number(yaml_parser_t *parser,
696+ yaml_mark_t start_mark, int *number);
697+
698+static int
699+yaml_parser_scan_tag_directive_value(yaml_parser_t *parser,
700+ yaml_mark_t mark, yaml_char_t **handle, yaml_char_t **prefix);
701+
702+static int
703+yaml_parser_scan_anchor(yaml_parser_t *parser, yaml_token_t *token,
704+ yaml_token_type_t type);
705+
706+static int
707+yaml_parser_scan_tag(yaml_parser_t *parser, yaml_token_t *token);
708+
709+static int
710+yaml_parser_scan_tag_handle(yaml_parser_t *parser, int directive,
711+ yaml_mark_t start_mark, yaml_char_t **handle);
712+
713+static int
714+yaml_parser_scan_tag_uri(yaml_parser_t *parser, int directive,
715+ yaml_char_t *head, yaml_mark_t start_mark, yaml_char_t **uri);
716+
717+static int
718+yaml_parser_scan_uri_escapes(yaml_parser_t *parser, int directive,
719+ yaml_mark_t start_mark, yaml_string_t *string);
720+
721+static int
722+yaml_parser_scan_block_scalar(yaml_parser_t *parser, yaml_token_t *token,
723+ int literal);
724+
725+static int
726+yaml_parser_scan_block_scalar_breaks(yaml_parser_t *parser,
727+ int *indent, yaml_string_t *breaks,
728+ yaml_mark_t start_mark, yaml_mark_t *end_mark);
729+
730+static int
731+yaml_parser_scan_flow_scalar(yaml_parser_t *parser, yaml_token_t *token,
732+ int single);
733+
734+static int
735+yaml_parser_scan_plain_scalar(yaml_parser_t *parser, yaml_token_t *token);
736+
737+/*
738+ * Get the next token.
739+ */
740+
741+YAML_DECLARE(int)
742+yaml_parser_scan(yaml_parser_t *parser, yaml_token_t *token)
743+{
744+ assert(parser); /* Non-NULL parser object is expected. */
745+ assert(token); /* Non-NULL token object is expected. */
746+
747+ /* Erase the token object. */
748+
749+ memset(token, 0, sizeof(yaml_token_t));
750+
751+ /* No tokens after STREAM-END or error. */
752+
753+ if (parser->stream_end_produced || parser->error) {
754+ return 1;
755+ }
756+
757+ /* Ensure that the tokens queue contains enough tokens. */
758+
759+ if (!parser->token_available) {
760+ if (!yaml_parser_fetch_more_tokens(parser))
761+ return 0;
762+ }
763+
764+ /* Fetch the next token from the queue. */
765+
766+ *token = DEQUEUE(parser, parser->tokens);
767+ parser->token_available = 0;
768+ parser->tokens_parsed ++;
769+
770+ if (token->type == YAML_STREAM_END_TOKEN) {
771+ parser->stream_end_produced = 1;
772+ }
773+
774+ return 1;
775+}
776+
777+/*
778+ * Set the scanner error and return 0.
779+ */
780+
781+static int
782+yaml_parser_set_scanner_error(yaml_parser_t *parser, const char *context,
783+ yaml_mark_t context_mark, const char *problem)
784+{
785+ parser->error = YAML_SCANNER_ERROR;
786+ parser->context = context;
787+ parser->context_mark = context_mark;
788+ parser->problem = problem;
789+ parser->problem_mark = parser->mark;
790+
791+ return 0;
792+}
793+
794+/*
795+ * Ensure that the tokens queue contains at least one token which can be
796+ * returned to the Parser.
797+ */
798+
799+YAML_DECLARE(int)
800+yaml_parser_fetch_more_tokens(yaml_parser_t *parser)
801+{
802+ int need_more_tokens;
803+
804+ /* While we need more tokens to fetch, do it. */
805+
806+ while (1)
807+ {
808+ /*
809+ * Check if we really need to fetch more tokens.
810+ */
811+
812+ need_more_tokens = 0;
813+
814+ if (parser->tokens.head == parser->tokens.tail)
815+ {
816+ /* Queue is empty. */
817+
818+ need_more_tokens = 1;
819+ }
820+ else
821+ {
822+ yaml_simple_key_t *simple_key;
823+
824+ /* Check if any potential simple key may occupy the head position. */
825+
826+ if (!yaml_parser_stale_simple_keys(parser))
827+ return 0;
828+
829+ for (simple_key = parser->simple_keys.start;
830+ simple_key != parser->simple_keys.top; simple_key++) {
831+ if (simple_key->possible
832+ && simple_key->token_number == parser->tokens_parsed) {
833+ need_more_tokens = 1;
834+ break;
835+ }
836+ }
837+ }
838+
839+ /* We are finished. */
840+
841+ if (!need_more_tokens)
842+ break;
843+
844+ /* Fetch the next token. */
845+
846+ if (!yaml_parser_fetch_next_token(parser))
847+ return 0;
848+ }
849+
850+ parser->token_available = 1;
851+
852+ return 1;
853+}
854+
855+/*
856+ * The dispatcher for token fetchers.
857+ */
858+
859+static int
860+yaml_parser_fetch_next_token(yaml_parser_t *parser)
861+{
862+ /* Ensure that the buffer is initialized. */
863+
864+ if (!CACHE(parser, 1))
865+ return 0;
866+
867+ /* Check if we just started scanning. Fetch STREAM-START then. */
868+
869+ if (!parser->stream_start_produced)
870+ return yaml_parser_fetch_stream_start(parser);
871+
872+ /* Eat whitespaces and comments until we reach the next token. */
873+
874+ if (!yaml_parser_scan_to_next_token(parser))
875+ return 0;
876+
877+ /* Remove obsolete potential simple keys. */
878+
879+ if (!yaml_parser_stale_simple_keys(parser))
880+ return 0;
881+
882+ /* Check the indentation level against the current column. */
883+
884+ if (!yaml_parser_unroll_indent(parser, parser->mark.column))
885+ return 0;
886+
887+ /*
888+ * Ensure that the buffer contains at least 4 characters. 4 is the length
889+ * of the longest indicators ('--- ' and '... ').
890+ */
891+
892+ if (!CACHE(parser, 4))
893+ return 0;
894+
895+ /* Is it the end of the stream? */
896+
897+ if (IS_Z(parser->buffer))
898+ return yaml_parser_fetch_stream_end(parser);
899+
900+ /* Is it a directive? */
901+
902+ if (parser->mark.column == 0 && CHECK(parser->buffer, '%'))
903+ return yaml_parser_fetch_directive(parser);
904+
905+ /* Is it the document start indicator? */
906+
907+ if (parser->mark.column == 0
908+ && CHECK_AT(parser->buffer, '-', 0)
909+ && CHECK_AT(parser->buffer, '-', 1)
910+ && CHECK_AT(parser->buffer, '-', 2)
911+ && IS_BLANKZ_AT(parser->buffer, 3))
912+ return yaml_parser_fetch_document_indicator(parser,
913+ YAML_DOCUMENT_START_TOKEN);
914+
915+ /* Is it the document end indicator? */
916+
917+ if (parser->mark.column == 0
918+ && CHECK_AT(parser->buffer, '.', 0)
919+ && CHECK_AT(parser->buffer, '.', 1)
920+ && CHECK_AT(parser->buffer, '.', 2)
921+ && IS_BLANKZ_AT(parser->buffer, 3))
922+ return yaml_parser_fetch_document_indicator(parser,
923+ YAML_DOCUMENT_END_TOKEN);
924+
925+ /* Is it the flow sequence start indicator? */
926+
927+ if (CHECK(parser->buffer, '['))
928+ return yaml_parser_fetch_flow_collection_start(parser,
929+ YAML_FLOW_SEQUENCE_START_TOKEN);
930+
931+ /* Is it the flow mapping start indicator? */
932+
933+ if (CHECK(parser->buffer, '{'))
934+ return yaml_parser_fetch_flow_collection_start(parser,
935+ YAML_FLOW_MAPPING_START_TOKEN);
936+
937+ /* Is it the flow sequence end indicator? */
938+
939+ if (CHECK(parser->buffer, ']'))
940+ return yaml_parser_fetch_flow_collection_end(parser,
941+ YAML_FLOW_SEQUENCE_END_TOKEN);
942+
943+ /* Is it the flow mapping end indicator? */
944+
945+ if (CHECK(parser->buffer, '}'))
946+ return yaml_parser_fetch_flow_collection_end(parser,
947+ YAML_FLOW_MAPPING_END_TOKEN);
948+
949+ /* Is it the flow entry indicator? */
950+
951+ if (CHECK(parser->buffer, ','))
952+ return yaml_parser_fetch_flow_entry(parser);
953+
954+ /* Is it the block entry indicator? */
955+
956+ if (CHECK(parser->buffer, '-') && IS_BLANKZ_AT(parser->buffer, 1))
957+ return yaml_parser_fetch_block_entry(parser);
958+
959+ /* Is it the key indicator? */
960+
961+ if (CHECK(parser->buffer, '?')
962+ && (parser->flow_level || IS_BLANKZ_AT(parser->buffer, 1)))
963+ return yaml_parser_fetch_key(parser);
964+
965+ /* Is it the value indicator? */
966+
967+ if (CHECK(parser->buffer, ':')
968+ && (parser->flow_level || IS_BLANKZ_AT(parser->buffer, 1)))
969+ return yaml_parser_fetch_value(parser);
970+
971+ /* Is it an alias? */
972+
973+ if (CHECK(parser->buffer, '*'))
974+ return yaml_parser_fetch_anchor(parser, YAML_ALIAS_TOKEN);
975+
976+ /* Is it an anchor? */
977+
978+ if (CHECK(parser->buffer, '&'))
979+ return yaml_parser_fetch_anchor(parser, YAML_ANCHOR_TOKEN);
980+
981+ /* Is it a tag? */
982+
983+ if (CHECK(parser->buffer, '!'))
984+ return yaml_parser_fetch_tag(parser);
985+
986+ /* Is it a literal scalar? */
987+
988+ if (CHECK(parser->buffer, '|') && !parser->flow_level)
989+ return yaml_parser_fetch_block_scalar(parser, 1);
990+
991+ /* Is it a folded scalar? */
992+
993+ if (CHECK(parser->buffer, '>') && !parser->flow_level)
994+ return yaml_parser_fetch_block_scalar(parser, 0);
995+
996+ /* Is it a single-quoted scalar? */
997+
998+ if (CHECK(parser->buffer, '\''))
999+ return yaml_parser_fetch_flow_scalar(parser, 1);
1000+
1001+ /* Is it a double-quoted scalar? */
1002+
1003+ if (CHECK(parser->buffer, '"'))
1004+ return yaml_parser_fetch_flow_scalar(parser, 0);
1005+
1006+ /*
1007+ * Is it a plain scalar?
1008+ *
1009+ * A plain scalar may start with any non-blank characters except
1010+ *
1011+ * '-', '?', ':', ',', '[', ']', '{', '}',
1012+ * '#', '&', '*', '!', '|', '>', '\'', '\"',
1013+ * '%', '@', '`'.
1014+ *
1015+ * In the block context (and, for the '-' indicator, in the flow context
1016+ * too), it may also start with the characters
1017+ *
1018+ * '-', '?', ':'
1019+ *
1020+ * if it is followed by a non-space character.
1021+ *
1022+ * The last rule is more restrictive than the specification requires.
1023+ */
1024+
1025+ if (!(IS_BLANKZ(parser->buffer) || CHECK(parser->buffer, '-')
1026+ || CHECK(parser->buffer, '?') || CHECK(parser->buffer, ':')
1027+ || CHECK(parser->buffer, ',') || CHECK(parser->buffer, '[')
1028+ || CHECK(parser->buffer, ']') || CHECK(parser->buffer, '{')
1029+ || CHECK(parser->buffer, '}') || CHECK(parser->buffer, '#')
1030+ || CHECK(parser->buffer, '&') || CHECK(parser->buffer, '*')
1031+ || CHECK(parser->buffer, '!') || CHECK(parser->buffer, '|')
1032+ || CHECK(parser->buffer, '>') || CHECK(parser->buffer, '\'')
1033+ || CHECK(parser->buffer, '"') || CHECK(parser->buffer, '%')
1034+ || CHECK(parser->buffer, '@') || CHECK(parser->buffer, '`')) ||
1035+ (CHECK(parser->buffer, '-') && !IS_BLANK_AT(parser->buffer, 1)) ||
1036+ (!parser->flow_level &&
1037+ (CHECK(parser->buffer, '?') || CHECK(parser->buffer, ':'))
1038+ && !IS_BLANKZ_AT(parser->buffer, 1)))
1039+ return yaml_parser_fetch_plain_scalar(parser);
1040+
1041+ /*
1042+ * If we don't determine the token type so far, it is an error.
1043+ */
1044+
1045+ return yaml_parser_set_scanner_error(parser,
1046+ "while scanning for the next token", parser->mark,
1047+ "found character that cannot start any token");
1048+}
1049+
1050+/*
1051+ * Check the list of potential simple keys and remove the positions that
1052+ * cannot contain simple keys anymore.
1053+ */
1054+
1055+static int
1056+yaml_parser_stale_simple_keys(yaml_parser_t *parser)
1057+{
1058+ yaml_simple_key_t *simple_key;
1059+
1060+ /* Check for a potential simple key for each flow level. */
1061+
1062+ for (simple_key = parser->simple_keys.start;
1063+ simple_key != parser->simple_keys.top; simple_key ++)
1064+ {
1065+ /*
1066+ * The specification requires that a simple key
1067+ *
1068+ * - is limited to a single line,
1069+ * - is shorter than 1024 characters.
1070+ */
1071+
1072+ if (simple_key->possible
1073+ && (simple_key->mark.line < parser->mark.line
1074+ || simple_key->mark.index+1024 < parser->mark.index)) {
1075+
1076+ /* Check if the potential simple key to be removed is required. */
1077+
1078+ if (simple_key->required) {
1079+ return yaml_parser_set_scanner_error(parser,
1080+ "while scanning a simple key", simple_key->mark,
1081+ "could not find expected ':'");
1082+ }
1083+
1084+ simple_key->possible = 0;
1085+ }
1086+ }
1087+
1088+ return 1;
1089+}
1090+
1091+/*
1092+ * Check if a simple key may start at the current position and add it if
1093+ * needed.
1094+ */
1095+
1096+static int
1097+yaml_parser_save_simple_key(yaml_parser_t *parser)
1098+{
1099+ /*
1100+ * A simple key is required at the current position if the scanner is in
1101+ * the block context and the current column coincides with the indentation
1102+ * level.
1103+ */
1104+
1105+ int required = (!parser->flow_level
1106+ && parser->indent == (ptrdiff_t)parser->mark.column);
1107+
1108+ /*
1109+ * If the current position may start a simple key, save it.
1110+ */
1111+
1112+ if (parser->simple_key_allowed)
1113+ {
1114+ yaml_simple_key_t simple_key;
1115+ simple_key.possible = 1;
1116+ simple_key.required = required;
1117+ simple_key.token_number =
1118+ parser->tokens_parsed + (parser->tokens.tail - parser->tokens.head);
1119+ simple_key.mark = parser->mark;
1120+
1121+ if (!yaml_parser_remove_simple_key(parser)) return 0;
1122+
1123+ *(parser->simple_keys.top-1) = simple_key;
1124+ }
1125+
1126+ return 1;
1127+}
1128+
1129+/*
1130+ * Remove a potential simple key at the current flow level.
1131+ */
1132+
1133+static int
1134+yaml_parser_remove_simple_key(yaml_parser_t *parser)
1135+{
1136+ yaml_simple_key_t *simple_key = parser->simple_keys.top-1;
1137+
1138+ if (simple_key->possible)
1139+ {
1140+ /* If the key is required, it is an error. */
1141+
1142+ if (simple_key->required) {
1143+ return yaml_parser_set_scanner_error(parser,
1144+ "while scanning a simple key", simple_key->mark,
1145+ "could not find expected ':'");
1146+ }
1147+ }
1148+
1149+ /* Remove the key from the stack. */
1150+
1151+ simple_key->possible = 0;
1152+
1153+ return 1;
1154+}
1155+
1156+/*
1157+ * Increase the flow level and resize the simple key list if needed.
1158+ */
1159+
1160+static int
1161+yaml_parser_increase_flow_level(yaml_parser_t *parser)
1162+{
1163+ yaml_simple_key_t empty_simple_key = { 0, 0, 0, { 0, 0, 0 } };
1164+
1165+ /* Reset the simple key on the next level. */
1166+
1167+ if (!PUSH(parser, parser->simple_keys, empty_simple_key))
1168+ return 0;
1169+
1170+ /* Increase the flow level. */
1171+
1172+ if (parser->flow_level == INT_MAX) {
1173+ parser->error = YAML_MEMORY_ERROR;
1174+ return 0;
1175+ }
1176+
1177+ parser->flow_level++;
1178+
1179+ return 1;
1180+}
1181+
1182+/*
1183+ * Decrease the flow level.
1184+ */
1185+
1186+static int
1187+yaml_parser_decrease_flow_level(yaml_parser_t *parser)
1188+{
1189+ yaml_simple_key_t dummy_key; /* Used to eliminate a compiler warning. */
1190+
1191+ if (parser->flow_level) {
1192+ parser->flow_level --;
1193+ dummy_key = POP(parser, parser->simple_keys);
1194+ }
1195+
1196+ return 1;
1197+}
1198+
1199+/*
1200+ * Push the current indentation level to the stack and set the new level
1201+ * the current column is greater than the indentation level. In this case,
1202+ * append or insert the specified token into the token queue.
1203+ *
1204+ */
1205+
1206+static int
1207+yaml_parser_roll_indent(yaml_parser_t *parser, ptrdiff_t column,
1208+ ptrdiff_t number, yaml_token_type_t type, yaml_mark_t mark)
1209+{
1210+ yaml_token_t token;
1211+
1212+ /* In the flow context, do nothing. */
1213+
1214+ if (parser->flow_level)
1215+ return 1;
1216+
1217+ if (parser->indent < column)
1218+ {
1219+ /*
1220+ * Push the current indentation level to the stack and set the new
1221+ * indentation level.
1222+ */
1223+
1224+ if (!PUSH(parser, parser->indents, parser->indent))
1225+ return 0;
1226+
1227+ if (column > INT_MAX) {
1228+ parser->error = YAML_MEMORY_ERROR;
1229+ return 0;
1230+ }
1231+
1232+ parser->indent = column;
1233+
1234+ /* Create a token and insert it into the queue. */
1235+
1236+ TOKEN_INIT(token, type, mark, mark);
1237+
1238+ if (number == -1) {
1239+ if (!ENQUEUE(parser, parser->tokens, token))
1240+ return 0;
1241+ }
1242+ else {
1243+ if (!QUEUE_INSERT(parser,
1244+ parser->tokens, number - parser->tokens_parsed, token))
1245+ return 0;
1246+ }
1247+ }
1248+
1249+ return 1;
1250+}
1251+
1252+/*
1253+ * Pop indentation levels from the indents stack until the current level
1254+ * becomes less or equal to the column. For each indentation level, append
1255+ * the BLOCK-END token.
1256+ */
1257+
1258+
1259+static int
1260+yaml_parser_unroll_indent(yaml_parser_t *parser, ptrdiff_t column)
1261+{
1262+ yaml_token_t token;
1263+
1264+ /* In the flow context, do nothing. */
1265+
1266+ if (parser->flow_level)
1267+ return 1;
1268+
1269+ /* Loop through the indentation levels in the stack. */
1270+
1271+ while (parser->indent > column)
1272+ {
1273+ /* Create a token and append it to the queue. */
1274+
1275+ TOKEN_INIT(token, YAML_BLOCK_END_TOKEN, parser->mark, parser->mark);
1276+
1277+ if (!ENQUEUE(parser, parser->tokens, token))
1278+ return 0;
1279+
1280+ /* Pop the indentation level. */
1281+
1282+ parser->indent = POP(parser, parser->indents);
1283+ }
1284+
1285+ return 1;
1286+}
1287+
1288+/*
1289+ * Initialize the scanner and produce the STREAM-START token.
1290+ */
1291+
1292+static int
1293+yaml_parser_fetch_stream_start(yaml_parser_t *parser)
1294+{
1295+ yaml_simple_key_t simple_key = { 0, 0, 0, { 0, 0, 0 } };
1296+ yaml_token_t token;
1297+
1298+ /* Set the initial indentation. */
1299+
1300+ parser->indent = -1;
1301+
1302+ /* Initialize the simple key stack. */
1303+
1304+ if (!PUSH(parser, parser->simple_keys, simple_key))
1305+ return 0;
1306+
1307+ /* A simple key is allowed at the beginning of the stream. */
1308+
1309+ parser->simple_key_allowed = 1;
1310+
1311+ /* We have started. */
1312+
1313+ parser->stream_start_produced = 1;
1314+
1315+ /* Create the STREAM-START token and append it to the queue. */
1316+
1317+ STREAM_START_TOKEN_INIT(token, parser->encoding,
1318+ parser->mark, parser->mark);
1319+
1320+ if (!ENQUEUE(parser, parser->tokens, token))
1321+ return 0;
1322+
1323+ return 1;
1324+}
1325+
1326+/*
1327+ * Produce the STREAM-END token and shut down the scanner.
1328+ */
1329+
1330+static int
1331+yaml_parser_fetch_stream_end(yaml_parser_t *parser)
1332+{
1333+ yaml_token_t token;
1334+
1335+ /* Force new line. */
1336+
1337+ if (parser->mark.column != 0) {
1338+ parser->mark.column = 0;
1339+ parser->mark.line ++;
1340+ }
1341+
1342+ /* Reset the indentation level. */
1343+
1344+ if (!yaml_parser_unroll_indent(parser, -1))
1345+ return 0;
1346+
1347+ /* Reset simple keys. */
1348+
1349+ if (!yaml_parser_remove_simple_key(parser))
1350+ return 0;
1351+
1352+ parser->simple_key_allowed = 0;
1353+
1354+ /* Create the STREAM-END token and append it to the queue. */
1355+
1356+ STREAM_END_TOKEN_INIT(token, parser->mark, parser->mark);
1357+
1358+ if (!ENQUEUE(parser, parser->tokens, token))
1359+ return 0;
1360+
1361+ return 1;
1362+}
1363+
1364+/*
1365+ * Produce a VERSION-DIRECTIVE or TAG-DIRECTIVE token.
1366+ */
1367+
1368+static int
1369+yaml_parser_fetch_directive(yaml_parser_t *parser)
1370+{
1371+ yaml_token_t token;
1372+
1373+ /* Reset the indentation level. */
1374+
1375+ if (!yaml_parser_unroll_indent(parser, -1))
1376+ return 0;
1377+
1378+ /* Reset simple keys. */
1379+
1380+ if (!yaml_parser_remove_simple_key(parser))
1381+ return 0;
1382+
1383+ parser->simple_key_allowed = 0;
1384+
1385+ /* Create the YAML-DIRECTIVE or TAG-DIRECTIVE token. */
1386+
1387+ if (!yaml_parser_scan_directive(parser, &token))
1388+ return 0;
1389+
1390+ /* Append the token to the queue. */
1391+
1392+ if (!ENQUEUE(parser, parser->tokens, token)) {
1393+ yaml_token_delete(&token);
1394+ return 0;
1395+ }
1396+
1397+ return 1;
1398+}
1399+
1400+/*
1401+ * Produce the DOCUMENT-START or DOCUMENT-END token.
1402+ */
1403+
1404+static int
1405+yaml_parser_fetch_document_indicator(yaml_parser_t *parser,
1406+ yaml_token_type_t type)
1407+{
1408+ yaml_mark_t start_mark, end_mark;
1409+ yaml_token_t token;
1410+
1411+ /* Reset the indentation level. */
1412+
1413+ if (!yaml_parser_unroll_indent(parser, -1))
1414+ return 0;
1415+
1416+ /* Reset simple keys. */
1417+
1418+ if (!yaml_parser_remove_simple_key(parser))
1419+ return 0;
1420+
1421+ parser->simple_key_allowed = 0;
1422+
1423+ /* Consume the token. */
1424+
1425+ start_mark = parser->mark;
1426+
1427+ SKIP(parser);
1428+ SKIP(parser);
1429+ SKIP(parser);
1430+
1431+ end_mark = parser->mark;
1432+
1433+ /* Create the DOCUMENT-START or DOCUMENT-END token. */
1434+
1435+ TOKEN_INIT(token, type, start_mark, end_mark);
1436+
1437+ /* Append the token to the queue. */
1438+
1439+ if (!ENQUEUE(parser, parser->tokens, token))
1440+ return 0;
1441+
1442+ return 1;
1443+}
1444+
1445+/*
1446+ * Produce the FLOW-SEQUENCE-START or FLOW-MAPPING-START token.
1447+ */
1448+
1449+static int
1450+yaml_parser_fetch_flow_collection_start(yaml_parser_t *parser,
1451+ yaml_token_type_t type)
1452+{
1453+ yaml_mark_t start_mark, end_mark;
1454+ yaml_token_t token;
1455+
1456+ /* The indicators '[' and '{' may start a simple key. */
1457+
1458+ if (!yaml_parser_save_simple_key(parser))
1459+ return 0;
1460+
1461+ /* Increase the flow level. */
1462+
1463+ if (!yaml_parser_increase_flow_level(parser))
1464+ return 0;
1465+
1466+ /* A simple key may follow the indicators '[' and '{'. */
1467+
1468+ parser->simple_key_allowed = 1;
1469+
1470+ /* Consume the token. */
1471+
1472+ start_mark = parser->mark;
1473+ SKIP(parser);
1474+ end_mark = parser->mark;
1475+
1476+ /* Create the FLOW-SEQUENCE-START of FLOW-MAPPING-START token. */
1477+
1478+ TOKEN_INIT(token, type, start_mark, end_mark);
1479+
1480+ /* Append the token to the queue. */
1481+
1482+ if (!ENQUEUE(parser, parser->tokens, token))
1483+ return 0;
1484+
1485+ return 1;
1486+}
1487+
1488+/*
1489+ * Produce the FLOW-SEQUENCE-END or FLOW-MAPPING-END token.
1490+ */
1491+
1492+static int
1493+yaml_parser_fetch_flow_collection_end(yaml_parser_t *parser,
1494+ yaml_token_type_t type)
1495+{
1496+ yaml_mark_t start_mark, end_mark;
1497+ yaml_token_t token;
1498+
1499+ /* Reset any potential simple key on the current flow level. */
1500+
1501+ if (!yaml_parser_remove_simple_key(parser))
1502+ return 0;
1503+
1504+ /* Decrease the flow level. */
1505+
1506+ if (!yaml_parser_decrease_flow_level(parser))
1507+ return 0;
1508+
1509+ /* No simple keys after the indicators ']' and '}'. */
1510+
1511+ parser->simple_key_allowed = 0;
1512+
1513+ /* Consume the token. */
1514+
1515+ start_mark = parser->mark;
1516+ SKIP(parser);
1517+ end_mark = parser->mark;
1518+
1519+ /* Create the FLOW-SEQUENCE-END of FLOW-MAPPING-END token. */
1520+
1521+ TOKEN_INIT(token, type, start_mark, end_mark);
1522+
1523+ /* Append the token to the queue. */
1524+
1525+ if (!ENQUEUE(parser, parser->tokens, token))
1526+ return 0;
1527+
1528+ return 1;
1529+}
1530+
1531+/*
1532+ * Produce the FLOW-ENTRY token.
1533+ */
1534+
1535+static int
1536+yaml_parser_fetch_flow_entry(yaml_parser_t *parser)
1537+{
1538+ yaml_mark_t start_mark, end_mark;
1539+ yaml_token_t token;
1540+
1541+ /* Reset any potential simple keys on the current flow level. */
1542+
1543+ if (!yaml_parser_remove_simple_key(parser))
1544+ return 0;
1545+
1546+ /* Simple keys are allowed after ','. */
1547+
1548+ parser->simple_key_allowed = 1;
1549+
1550+ /* Consume the token. */
1551+
1552+ start_mark = parser->mark;
1553+ SKIP(parser);
1554+ end_mark = parser->mark;
1555+
1556+ /* Create the FLOW-ENTRY token and append it to the queue. */
1557+
1558+ TOKEN_INIT(token, YAML_FLOW_ENTRY_TOKEN, start_mark, end_mark);
1559+
1560+ if (!ENQUEUE(parser, parser->tokens, token))
1561+ return 0;
1562+
1563+ return 1;
1564+}
1565+
1566+/*
1567+ * Produce the BLOCK-ENTRY token.
1568+ */
1569+
1570+static int
1571+yaml_parser_fetch_block_entry(yaml_parser_t *parser)
1572+{
1573+ yaml_mark_t start_mark, end_mark;
1574+ yaml_token_t token;
1575+
1576+ /* Check if the scanner is in the block context. */
1577+
1578+ if (!parser->flow_level)
1579+ {
1580+ /* Check if we are allowed to start a new entry. */
1581+
1582+ if (!parser->simple_key_allowed) {
1583+ return yaml_parser_set_scanner_error(parser, NULL, parser->mark,
1584+ "block sequence entries are not allowed in this context");
1585+ }
1586+
1587+ /* Add the BLOCK-SEQUENCE-START token if needed. */
1588+
1589+ if (!yaml_parser_roll_indent(parser, parser->mark.column, -1,
1590+ YAML_BLOCK_SEQUENCE_START_TOKEN, parser->mark))
1591+ return 0;
1592+ }
1593+ else
1594+ {
1595+ /*
1596+ * It is an error for the '-' indicator to occur in the flow context,
1597+ * but we let the Parser detect and report about it because the Parser
1598+ * is able to point to the context.
1599+ */
1600+ }
1601+
1602+ /* Reset any potential simple keys on the current flow level. */
1603+
1604+ if (!yaml_parser_remove_simple_key(parser))
1605+ return 0;
1606+
1607+ /* Simple keys are allowed after '-'. */
1608+
1609+ parser->simple_key_allowed = 1;
1610+
1611+ /* Consume the token. */
1612+
1613+ start_mark = parser->mark;
1614+ SKIP(parser);
1615+ end_mark = parser->mark;
1616+
1617+ /* Create the BLOCK-ENTRY token and append it to the queue. */
1618+
1619+ TOKEN_INIT(token, YAML_BLOCK_ENTRY_TOKEN, start_mark, end_mark);
1620+
1621+ if (!ENQUEUE(parser, parser->tokens, token))
1622+ return 0;
1623+
1624+ return 1;
1625+}
1626+
1627+/*
1628+ * Produce the KEY token.
1629+ */
1630+
1631+static int
1632+yaml_parser_fetch_key(yaml_parser_t *parser)
1633+{
1634+ yaml_mark_t start_mark, end_mark;
1635+ yaml_token_t token;
1636+
1637+ /* In the block context, additional checks are required. */
1638+
1639+ if (!parser->flow_level)
1640+ {
1641+ /* Check if we are allowed to start a new key (not nessesary simple). */
1642+
1643+ if (!parser->simple_key_allowed) {
1644+ return yaml_parser_set_scanner_error(parser, NULL, parser->mark,
1645+ "mapping keys are not allowed in this context");
1646+ }
1647+
1648+ /* Add the BLOCK-MAPPING-START token if needed. */
1649+
1650+ if (!yaml_parser_roll_indent(parser, parser->mark.column, -1,
1651+ YAML_BLOCK_MAPPING_START_TOKEN, parser->mark))
1652+ return 0;
1653+ }
1654+
1655+ /* Reset any potential simple keys on the current flow level. */
1656+
1657+ if (!yaml_parser_remove_simple_key(parser))
1658+ return 0;
1659+
1660+ /* Simple keys are allowed after '?' in the block context. */
1661+
1662+ parser->simple_key_allowed = (!parser->flow_level);
1663+
1664+ /* Consume the token. */
1665+
1666+ start_mark = parser->mark;
1667+ SKIP(parser);
1668+ end_mark = parser->mark;
1669+
1670+ /* Create the KEY token and append it to the queue. */
1671+
1672+ TOKEN_INIT(token, YAML_KEY_TOKEN, start_mark, end_mark);
1673+
1674+ if (!ENQUEUE(parser, parser->tokens, token))
1675+ return 0;
1676+
1677+ return 1;
1678+}
1679+
1680+/*
1681+ * Produce the VALUE token.
1682+ */
1683+
1684+static int
1685+yaml_parser_fetch_value(yaml_parser_t *parser)
1686+{
1687+ yaml_mark_t start_mark, end_mark;
1688+ yaml_token_t token;
1689+ yaml_simple_key_t *simple_key = parser->simple_keys.top-1;
1690+
1691+ /* Have we found a simple key? */
1692+
1693+ if (simple_key->possible)
1694+ {
1695+
1696+ /* Create the KEY token and insert it into the queue. */
1697+
1698+ TOKEN_INIT(token, YAML_KEY_TOKEN, simple_key->mark, simple_key->mark);
1699+
1700+ if (!QUEUE_INSERT(parser, parser->tokens,
1701+ simple_key->token_number - parser->tokens_parsed, token))
1702+ return 0;
1703+
1704+ /* In the block context, we may need to add the BLOCK-MAPPING-START token. */
1705+
1706+ if (!yaml_parser_roll_indent(parser, simple_key->mark.column,
1707+ simple_key->token_number,
1708+ YAML_BLOCK_MAPPING_START_TOKEN, simple_key->mark))
1709+ return 0;
1710+
1711+ /* Remove the simple key. */
1712+
1713+ simple_key->possible = 0;
1714+
1715+ /* A simple key cannot follow another simple key. */
1716+
1717+ parser->simple_key_allowed = 0;
1718+ }
1719+ else
1720+ {
1721+ /* The ':' indicator follows a complex key. */
1722+
1723+ /* In the block context, extra checks are required. */
1724+
1725+ if (!parser->flow_level)
1726+ {
1727+ /* Check if we are allowed to start a complex value. */
1728+
1729+ if (!parser->simple_key_allowed) {
1730+ return yaml_parser_set_scanner_error(parser, NULL, parser->mark,
1731+ "mapping values are not allowed in this context");
1732+ }
1733+
1734+ /* Add the BLOCK-MAPPING-START token if needed. */
1735+
1736+ if (!yaml_parser_roll_indent(parser, parser->mark.column, -1,
1737+ YAML_BLOCK_MAPPING_START_TOKEN, parser->mark))
1738+ return 0;
1739+ }
1740+
1741+ /* Simple keys after ':' are allowed in the block context. */
1742+
1743+ parser->simple_key_allowed = (!parser->flow_level);
1744+ }
1745+
1746+ /* Consume the token. */
1747+
1748+ start_mark = parser->mark;
1749+ SKIP(parser);
1750+ end_mark = parser->mark;
1751+
1752+ /* Create the VALUE token and append it to the queue. */
1753+
1754+ TOKEN_INIT(token, YAML_VALUE_TOKEN, start_mark, end_mark);
1755+
1756+ if (!ENQUEUE(parser, parser->tokens, token))
1757+ return 0;
1758+
1759+ return 1;
1760+}
1761+
1762+/*
1763+ * Produce the ALIAS or ANCHOR token.
1764+ */
1765+
1766+static int
1767+yaml_parser_fetch_anchor(yaml_parser_t *parser, yaml_token_type_t type)
1768+{
1769+ yaml_token_t token;
1770+
1771+ /* An anchor or an alias could be a simple key. */
1772+
1773+ if (!yaml_parser_save_simple_key(parser))
1774+ return 0;
1775+
1776+ /* A simple key cannot follow an anchor or an alias. */
1777+
1778+ parser->simple_key_allowed = 0;
1779+
1780+ /* Create the ALIAS or ANCHOR token and append it to the queue. */
1781+
1782+ if (!yaml_parser_scan_anchor(parser, &token, type))
1783+ return 0;
1784+
1785+ if (!ENQUEUE(parser, parser->tokens, token)) {
1786+ yaml_token_delete(&token);
1787+ return 0;
1788+ }
1789+ return 1;
1790+}
1791+
1792+/*
1793+ * Produce the TAG token.
1794+ */
1795+
1796+static int
1797+yaml_parser_fetch_tag(yaml_parser_t *parser)
1798+{
1799+ yaml_token_t token;
1800+
1801+ /* A tag could be a simple key. */
1802+
1803+ if (!yaml_parser_save_simple_key(parser))
1804+ return 0;
1805+
1806+ /* A simple key cannot follow a tag. */
1807+
1808+ parser->simple_key_allowed = 0;
1809+
1810+ /* Create the TAG token and append it to the queue. */
1811+
1812+ if (!yaml_parser_scan_tag(parser, &token))
1813+ return 0;
1814+
1815+ if (!ENQUEUE(parser, parser->tokens, token)) {
1816+ yaml_token_delete(&token);
1817+ return 0;
1818+ }
1819+
1820+ return 1;
1821+}
1822+
1823+/*
1824+ * Produce the SCALAR(...,literal) or SCALAR(...,folded) tokens.
1825+ */
1826+
1827+static int
1828+yaml_parser_fetch_block_scalar(yaml_parser_t *parser, int literal)
1829+{
1830+ yaml_token_t token;
1831+
1832+ /* Remove any potential simple keys. */
1833+
1834+ if (!yaml_parser_remove_simple_key(parser))
1835+ return 0;
1836+
1837+ /* A simple key may follow a block scalar. */
1838+
1839+ parser->simple_key_allowed = 1;
1840+
1841+ /* Create the SCALAR token and append it to the queue. */
1842+
1843+ if (!yaml_parser_scan_block_scalar(parser, &token, literal))
1844+ return 0;
1845+
1846+ if (!ENQUEUE(parser, parser->tokens, token)) {
1847+ yaml_token_delete(&token);
1848+ return 0;
1849+ }
1850+
1851+ return 1;
1852+}
1853+
1854+/*
1855+ * Produce the SCALAR(...,single-quoted) or SCALAR(...,double-quoted) tokens.
1856+ */
1857+
1858+static int
1859+yaml_parser_fetch_flow_scalar(yaml_parser_t *parser, int single)
1860+{
1861+ yaml_token_t token;
1862+
1863+ /* A plain scalar could be a simple key. */
1864+
1865+ if (!yaml_parser_save_simple_key(parser))
1866+ return 0;
1867+
1868+ /* A simple key cannot follow a flow scalar. */
1869+
1870+ parser->simple_key_allowed = 0;
1871+
1872+ /* Create the SCALAR token and append it to the queue. */
1873+
1874+ if (!yaml_parser_scan_flow_scalar(parser, &token, single))
1875+ return 0;
1876+
1877+ if (!ENQUEUE(parser, parser->tokens, token)) {
1878+ yaml_token_delete(&token);
1879+ return 0;
1880+ }
1881+
1882+ return 1;
1883+}
1884+
1885+/*
1886+ * Produce the SCALAR(...,plain) token.
1887+ */
1888+
1889+static int
1890+yaml_parser_fetch_plain_scalar(yaml_parser_t *parser)
1891+{
1892+ yaml_token_t token;
1893+
1894+ /* A plain scalar could be a simple key. */
1895+
1896+ if (!yaml_parser_save_simple_key(parser))
1897+ return 0;
1898+
1899+ /* A simple key cannot follow a flow scalar. */
1900+
1901+ parser->simple_key_allowed = 0;
1902+
1903+ /* Create the SCALAR token and append it to the queue. */
1904+
1905+ if (!yaml_parser_scan_plain_scalar(parser, &token))
1906+ return 0;
1907+
1908+ if (!ENQUEUE(parser, parser->tokens, token)) {
1909+ yaml_token_delete(&token);
1910+ return 0;
1911+ }
1912+
1913+ return 1;
1914+}
1915+
1916+/*
1917+ * Eat whitespaces and comments until the next token is found.
1918+ */
1919+
1920+static int
1921+yaml_parser_scan_to_next_token(yaml_parser_t *parser)
1922+{
1923+ /* Until the next token is not found. */
1924+
1925+ while (1)
1926+ {
1927+ /* Allow the BOM mark to start a line. */
1928+
1929+ if (!CACHE(parser, 1)) return 0;
1930+
1931+ if (parser->mark.column == 0 && IS_BOM(parser->buffer))
1932+ SKIP(parser);
1933+
1934+ /*
1935+ * Eat whitespaces.
1936+ *
1937+ * Tabs are allowed:
1938+ *
1939+ * - in the flow context;
1940+ * - in the block context, but not at the beginning of the line or
1941+ * after '-', '?', or ':' (complex value).
1942+ */
1943+
1944+ if (!CACHE(parser, 1)) return 0;
1945+
1946+ while (CHECK(parser->buffer,' ') ||
1947+ ((parser->flow_level || !parser->simple_key_allowed) &&
1948+ CHECK(parser->buffer, '\t'))) {
1949+ SKIP(parser);
1950+ if (!CACHE(parser, 1)) return 0;
1951+ }
1952+
1953+ /* Eat a comment until a line break. */
1954+
1955+ if (CHECK(parser->buffer, '#')) {
1956+ while (!IS_BREAKZ(parser->buffer)) {
1957+ SKIP(parser);
1958+ if (!CACHE(parser, 1)) return 0;
1959+ }
1960+ }
1961+
1962+ /* If it is a line break, eat it. */
1963+
1964+ if (IS_BREAK(parser->buffer))
1965+ {
1966+ if (!CACHE(parser, 2)) return 0;
1967+ SKIP_LINE(parser);
1968+
1969+ /* In the block context, a new line may start a simple key. */
1970+
1971+ if (!parser->flow_level) {
1972+ parser->simple_key_allowed = 1;
1973+ }
1974+ }
1975+ else
1976+ {
1977+ /* We have found a token. */
1978+
1979+ break;
1980+ }
1981+ }
1982+
1983+ return 1;
1984+}
1985+
1986+/*
1987+ * Scan a YAML-DIRECTIVE or TAG-DIRECTIVE token.
1988+ *
1989+ * Scope:
1990+ * %YAML 1.1 # a comment \n
1991+ * ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1992+ * %TAG !yaml! tag:yaml.org,2002: \n
1993+ * ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1994+ */
1995+
1996+int
1997+yaml_parser_scan_directive(yaml_parser_t *parser, yaml_token_t *token)
1998+{
1999+ yaml_mark_t start_mark, end_mark;
2000+ yaml_char_t *name = NULL;
2001+ int major, minor;
2002+ yaml_char_t *handle = NULL, *prefix = NULL;
2003+
2004+ /* Eat '%'. */
2005+
2006+ start_mark = parser->mark;
2007+
2008+ SKIP(parser);
2009+
2010+ /* Scan the directive name. */
2011+
2012+ if (!yaml_parser_scan_directive_name(parser, start_mark, &name))
2013+ goto error;
2014+
2015+ /* Is it a YAML directive? */
2016+
2017+ if (strcmp((char *)name, "YAML") == 0)
2018+ {
2019+ /* Scan the VERSION directive value. */
2020+
2021+ if (!yaml_parser_scan_version_directive_value(parser, start_mark,
2022+ &major, &minor))
2023+ goto error;
2024+
2025+ end_mark = parser->mark;
2026+
2027+ /* Create a VERSION-DIRECTIVE token. */
2028+
2029+ VERSION_DIRECTIVE_TOKEN_INIT(*token, major, minor,
2030+ start_mark, end_mark);
2031+ }
2032+
2033+ /* Is it a TAG directive? */
2034+
2035+ else if (strcmp((char *)name, "TAG") == 0)
2036+ {
2037+ /* Scan the TAG directive value. */
2038+
2039+ if (!yaml_parser_scan_tag_directive_value(parser, start_mark,
2040+ &handle, &prefix))
2041+ goto error;
2042+
2043+ end_mark = parser->mark;
2044+
2045+ /* Create a TAG-DIRECTIVE token. */
2046+
2047+ TAG_DIRECTIVE_TOKEN_INIT(*token, handle, prefix,
2048+ start_mark, end_mark);
2049+ }
2050+
2051+ /* Unknown directive. */
2052+
2053+ else
2054+ {
2055+ yaml_parser_set_scanner_error(parser, "while scanning a directive",
2056+ start_mark, "found unknown directive name");
2057+ goto error;
2058+ }
2059+
2060+ /* Eat the rest of the line including any comments. */
2061+
2062+ if (!CACHE(parser, 1)) goto error;
2063+
2064+ while (IS_BLANK(parser->buffer)) {
2065+ SKIP(parser);
2066+ if (!CACHE(parser, 1)) goto error;
2067+ }
2068+
2069+ if (CHECK(parser->buffer, '#')) {
2070+ while (!IS_BREAKZ(parser->buffer)) {
2071+ SKIP(parser);
2072+ if (!CACHE(parser, 1)) goto error;
2073+ }
2074+ }
2075+
2076+ /* Check if we are at the end of the line. */
2077+
2078+ if (!IS_BREAKZ(parser->buffer)) {
2079+ yaml_parser_set_scanner_error(parser, "while scanning a directive",
2080+ start_mark, "did not find expected comment or line break");
2081+ goto error;
2082+ }
2083+
2084+ /* Eat a line break. */
2085+
2086+ if (IS_BREAK(parser->buffer)) {
2087+ if (!CACHE(parser, 2)) goto error;
2088+ SKIP_LINE(parser);
2089+ }
2090+
2091+ yaml_free(name);
2092+
2093+ return 1;
2094+
2095+error:
2096+ yaml_free(prefix);
2097+ yaml_free(handle);
2098+ yaml_free(name);
2099+ return 0;
2100+}
2101+
2102+/*
2103+ * Scan the directive name.
2104+ *
2105+ * Scope:
2106+ * %YAML 1.1 # a comment \n
2107+ * ^^^^
2108+ * %TAG !yaml! tag:yaml.org,2002: \n
2109+ * ^^^
2110+ */
2111+
2112+static int
2113+yaml_parser_scan_directive_name(yaml_parser_t *parser,
2114+ yaml_mark_t start_mark, yaml_char_t **name)
2115+{
2116+ yaml_string_t string = NULL_STRING;
2117+
2118+ if (!STRING_INIT(parser, string, INITIAL_STRING_SIZE)) goto error;
2119+
2120+ /* Consume the directive name. */
2121+
2122+ if (!CACHE(parser, 1)) goto error;
2123+
2124+ while (IS_ALPHA(parser->buffer))
2125+ {
2126+ if (!READ(parser, string)) goto error;
2127+ if (!CACHE(parser, 1)) goto error;
2128+ }
2129+
2130+ /* Check if the name is empty. */
2131+
2132+ if (string.start == string.pointer) {
2133+ yaml_parser_set_scanner_error(parser, "while scanning a directive",
2134+ start_mark, "could not find expected directive name");
2135+ goto error;
2136+ }
2137+
2138+ /* Check for an blank character after the name. */
2139+
2140+ if (!IS_BLANKZ(parser->buffer)) {
2141+ yaml_parser_set_scanner_error(parser, "while scanning a directive",
2142+ start_mark, "found unexpected non-alphabetical character");
2143+ goto error;
2144+ }
2145+
2146+ *name = string.start;
2147+
2148+ return 1;
2149+
2150+error:
2151+ STRING_DEL(parser, string);
2152+ return 0;
2153+}
2154+
2155+/*
2156+ * Scan the value of VERSION-DIRECTIVE.
2157+ *
2158+ * Scope:
2159+ * %YAML 1.1 # a comment \n
2160+ * ^^^^^^
2161+ */
2162+
2163+static int
2164+yaml_parser_scan_version_directive_value(yaml_parser_t *parser,
2165+ yaml_mark_t start_mark, int *major, int *minor)
2166+{
2167+ /* Eat whitespaces. */
2168+
2169+ if (!CACHE(parser, 1)) return 0;
2170+
2171+ while (IS_BLANK(parser->buffer)) {
2172+ SKIP(parser);
2173+ if (!CACHE(parser, 1)) return 0;
2174+ }
2175+
2176+ /* Consume the major version number. */
2177+
2178+ if (!yaml_parser_scan_version_directive_number(parser, start_mark, major))
2179+ return 0;
2180+
2181+ /* Eat '.'. */
2182+
2183+ if (!CHECK(parser->buffer, '.')) {
2184+ return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
2185+ start_mark, "did not find expected digit or '.' character");
2186+ }
2187+
2188+ SKIP(parser);
2189+
2190+ /* Consume the minor version number. */
2191+
2192+ if (!yaml_parser_scan_version_directive_number(parser, start_mark, minor))
2193+ return 0;
2194+
2195+ return 1;
2196+}
2197+
2198+#define MAX_NUMBER_LENGTH 9
2199+
2200+/*
2201+ * Scan the version number of VERSION-DIRECTIVE.
2202+ *
2203+ * Scope:
2204+ * %YAML 1.1 # a comment \n
2205+ * ^
2206+ * %YAML 1.1 # a comment \n
2207+ * ^
2208+ */
2209+
2210+static int
2211+yaml_parser_scan_version_directive_number(yaml_parser_t *parser,
2212+ yaml_mark_t start_mark, int *number)
2213+{
2214+ int value = 0;
2215+ size_t length = 0;
2216+
2217+ /* Repeat while the next character is digit. */
2218+
2219+ if (!CACHE(parser, 1)) return 0;
2220+
2221+ while (IS_DIGIT(parser->buffer))
2222+ {
2223+ /* Check if the number is too long. */
2224+
2225+ if (++length > MAX_NUMBER_LENGTH) {
2226+ return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
2227+ start_mark, "found extremely long version number");
2228+ }
2229+
2230+ value = value*10 + AS_DIGIT(parser->buffer);
2231+
2232+ SKIP(parser);
2233+
2234+ if (!CACHE(parser, 1)) return 0;
2235+ }
2236+
2237+ /* Check if the number was present. */
2238+
2239+ if (!length) {
2240+ return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
2241+ start_mark, "did not find expected version number");
2242+ }
2243+
2244+ *number = value;
2245+
2246+ return 1;
2247+}
2248+
2249+/*
2250+ * Scan the value of a TAG-DIRECTIVE token.
2251+ *
2252+ * Scope:
2253+ * %TAG !yaml! tag:yaml.org,2002: \n
2254+ * ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2255+ */
2256+
2257+static int
2258+yaml_parser_scan_tag_directive_value(yaml_parser_t *parser,
2259+ yaml_mark_t start_mark, yaml_char_t **handle, yaml_char_t **prefix)
2260+{
2261+ yaml_char_t *handle_value = NULL;
2262+ yaml_char_t *prefix_value = NULL;
2263+
2264+ /* Eat whitespaces. */
2265+
2266+ if (!CACHE(parser, 1)) goto error;
2267+
2268+ while (IS_BLANK(parser->buffer)) {
2269+ SKIP(parser);
2270+ if (!CACHE(parser, 1)) goto error;
2271+ }
2272+
2273+ /* Scan a handle. */
2274+
2275+ if (!yaml_parser_scan_tag_handle(parser, 1, start_mark, &handle_value))
2276+ goto error;
2277+
2278+ /* Expect a whitespace. */
2279+
2280+ if (!CACHE(parser, 1)) goto error;
2281+
2282+ if (!IS_BLANK(parser->buffer)) {
2283+ yaml_parser_set_scanner_error(parser, "while scanning a %TAG directive",
2284+ start_mark, "did not find expected whitespace");
2285+ goto error;
2286+ }
2287+
2288+ /* Eat whitespaces. */
2289+
2290+ while (IS_BLANK(parser->buffer)) {
2291+ SKIP(parser);
2292+ if (!CACHE(parser, 1)) goto error;
2293+ }
2294+
2295+ /* Scan a prefix. */
2296+
2297+ if (!yaml_parser_scan_tag_uri(parser, 1, NULL, start_mark, &prefix_value))
2298+ goto error;
2299+
2300+ /* Expect a whitespace or line break. */
2301+
2302+ if (!CACHE(parser, 1)) goto error;
2303+
2304+ if (!IS_BLANKZ(parser->buffer)) {
2305+ yaml_parser_set_scanner_error(parser, "while scanning a %TAG directive",
2306+ start_mark, "did not find expected whitespace or line break");
2307+ goto error;
2308+ }
2309+
2310+ *handle = handle_value;
2311+ *prefix = prefix_value;
2312+
2313+ return 1;
2314+
2315+error:
2316+ yaml_free(handle_value);
2317+ yaml_free(prefix_value);
2318+ return 0;
2319+}
2320+
2321+static int
2322+yaml_parser_scan_anchor(yaml_parser_t *parser, yaml_token_t *token,
2323+ yaml_token_type_t type)
2324+{
2325+ int length = 0;
2326+ yaml_mark_t start_mark, end_mark;
2327+ yaml_string_t string = NULL_STRING;
2328+
2329+ if (!STRING_INIT(parser, string, INITIAL_STRING_SIZE)) goto error;
2330+
2331+ /* Eat the indicator character. */
2332+
2333+ start_mark = parser->mark;
2334+
2335+ SKIP(parser);
2336+
2337+ /* Consume the value. */
2338+
2339+ if (!CACHE(parser, 1)) goto error;
2340+
2341+ while (IS_ALPHA(parser->buffer)) {
2342+ if (!READ(parser, string)) goto error;
2343+ if (!CACHE(parser, 1)) goto error;
2344+ length ++;
2345+ }
2346+
2347+ end_mark = parser->mark;
2348+
2349+ /*
2350+ * Check if length of the anchor is greater than 0 and it is followed by
2351+ * a whitespace character or one of the indicators:
2352+ *
2353+ * '?', ':', ',', ']', '}', '%', '@', '`'.
2354+ */
2355+
2356+ if (!length || !(IS_BLANKZ(parser->buffer) || CHECK(parser->buffer, '?')
2357+ || CHECK(parser->buffer, ':') || CHECK(parser->buffer, ',')
2358+ || CHECK(parser->buffer, ']') || CHECK(parser->buffer, '}')
2359+ || CHECK(parser->buffer, '%') || CHECK(parser->buffer, '@')
2360+ || CHECK(parser->buffer, '`'))) {
2361+ yaml_parser_set_scanner_error(parser, type == YAML_ANCHOR_TOKEN ?
2362+ "while scanning an anchor" : "while scanning an alias", start_mark,
2363+ "did not find expected alphabetic or numeric character");
2364+ goto error;
2365+ }
2366+
2367+ /* Create a token. */
2368+
2369+ if (type == YAML_ANCHOR_TOKEN) {
2370+ ANCHOR_TOKEN_INIT(*token, string.start, start_mark, end_mark);
2371+ }
2372+ else {
2373+ ALIAS_TOKEN_INIT(*token, string.start, start_mark, end_mark);
2374+ }
2375+
2376+ return 1;
2377+
2378+error:
2379+ STRING_DEL(parser, string);
2380+ return 0;
2381+}
2382+
2383+/*
2384+ * Scan a TAG token.
2385+ */
2386+
2387+static int
2388+yaml_parser_scan_tag(yaml_parser_t *parser, yaml_token_t *token)
2389+{
2390+ yaml_char_t *handle = NULL;
2391+ yaml_char_t *suffix = NULL;
2392+ yaml_mark_t start_mark, end_mark;
2393+
2394+ start_mark = parser->mark;
2395+
2396+ /* Check if the tag is in the canonical form. */
2397+
2398+ if (!CACHE(parser, 2)) goto error;
2399+
2400+ if (CHECK_AT(parser->buffer, '<', 1))
2401+ {
2402+ /* Set the handle to '' */
2403+
2404+ handle = yaml_malloc(1);
2405+ if (!handle) goto error;
2406+ handle[0] = '\0';
2407+
2408+ /* Eat '!<' */
2409+
2410+ SKIP(parser);
2411+ SKIP(parser);
2412+
2413+ /* Consume the tag value. */
2414+
2415+ if (!yaml_parser_scan_tag_uri(parser, 0, NULL, start_mark, &suffix))
2416+ goto error;
2417+
2418+ /* Check for '>' and eat it. */
2419+
2420+ if (!CHECK(parser->buffer, '>')) {
2421+ yaml_parser_set_scanner_error(parser, "while scanning a tag",
2422+ start_mark, "did not find the expected '>'");
2423+ goto error;
2424+ }
2425+
2426+ SKIP(parser);
2427+ }
2428+ else
2429+ {
2430+ /* The tag has either the '!suffix' or the '!handle!suffix' form. */
2431+
2432+ /* First, try to scan a handle. */
2433+
2434+ if (!yaml_parser_scan_tag_handle(parser, 0, start_mark, &handle))
2435+ goto error;
2436+
2437+ /* Check if it is, indeed, handle. */
2438+
2439+ if (handle[0] == '!' && handle[1] != '\0' && handle[strlen((char *)handle)-1] == '!')
2440+ {
2441+ /* Scan the suffix now. */
2442+
2443+ if (!yaml_parser_scan_tag_uri(parser, 0, NULL, start_mark, &suffix))
2444+ goto error;
2445+ }
2446+ else
2447+ {
2448+ /* It wasn't a handle after all. Scan the rest of the tag. */
2449+
2450+ if (!yaml_parser_scan_tag_uri(parser, 0, handle, start_mark, &suffix))
2451+ goto error;
2452+
2453+ /* Set the handle to '!'. */
2454+
2455+ yaml_free(handle);
2456+ handle = yaml_malloc(2);
2457+ if (!handle) goto error;
2458+ handle[0] = '!';
2459+ handle[1] = '\0';
2460+
2461+ /*
2462+ * A special case: the '!' tag. Set the handle to '' and the
2463+ * suffix to '!'.
2464+ */
2465+
2466+ if (suffix[0] == '\0') {
2467+ yaml_char_t *tmp = handle;
2468+ handle = suffix;
2469+ suffix = tmp;
2470+ }
2471+ }
2472+ }
2473+
2474+ /* Check the character which ends the tag. */
2475+
2476+ if (!CACHE(parser, 1)) goto error;
2477+
2478+ if (!IS_BLANKZ(parser->buffer)) {
2479+ yaml_parser_set_scanner_error(parser, "while scanning a tag",
2480+ start_mark, "did not find expected whitespace or line break");
2481+ goto error;
2482+ }
2483+
2484+ end_mark = parser->mark;
2485+
2486+ /* Create a token. */
2487+
2488+ TAG_TOKEN_INIT(*token, handle, suffix, start_mark, end_mark);
2489+
2490+ return 1;
2491+
2492+error:
2493+ yaml_free(handle);
2494+ yaml_free(suffix);
2495+ return 0;
2496+}
2497+
2498+/*
2499+ * Scan a tag handle.
2500+ */
2501+
2502+static int
2503+yaml_parser_scan_tag_handle(yaml_parser_t *parser, int directive,
2504+ yaml_mark_t start_mark, yaml_char_t **handle)
2505+{
2506+ yaml_string_t string = NULL_STRING;
2507+
2508+ if (!STRING_INIT(parser, string, INITIAL_STRING_SIZE)) goto error;
2509+
2510+ /* Check the initial '!' character. */
2511+
2512+ if (!CACHE(parser, 1)) goto error;
2513+
2514+ if (!CHECK(parser->buffer, '!')) {
2515+ yaml_parser_set_scanner_error(parser, directive ?
2516+ "while scanning a tag directive" : "while scanning a tag",
2517+ start_mark, "did not find expected '!'");
2518+ goto error;
2519+ }
2520+
2521+ /* Copy the '!' character. */
2522+
2523+ if (!READ(parser, string)) goto error;
2524+
2525+ /* Copy all subsequent alphabetical and numerical characters. */
2526+
2527+ if (!CACHE(parser, 1)) goto error;
2528+
2529+ while (IS_ALPHA(parser->buffer))
2530+ {
2531+ if (!READ(parser, string)) goto error;
2532+ if (!CACHE(parser, 1)) goto error;
2533+ }
2534+
2535+ /* Check if the trailing character is '!' and copy it. */
2536+
2537+ if (CHECK(parser->buffer, '!'))
2538+ {
2539+ if (!READ(parser, string)) goto error;
2540+ }
2541+ else
2542+ {
2543+ /*
2544+ * It's either the '!' tag or not really a tag handle. If it's a %TAG
2545+ * directive, it's an error. If it's a tag token, it must be a part of
2546+ * URI.
2547+ */
2548+
2549+ if (directive && !(string.start[0] == '!' && string.start[1] == '\0')) {
2550+ yaml_parser_set_scanner_error(parser, "while parsing a tag directive",
2551+ start_mark, "did not find expected '!'");
2552+ goto error;
2553+ }
2554+ }
2555+
2556+ *handle = string.start;
2557+
2558+ return 1;
2559+
2560+error:
2561+ STRING_DEL(parser, string);
2562+ return 0;
2563+}
2564+
2565+/*
2566+ * Scan a tag.
2567+ */
2568+
2569+static int
2570+yaml_parser_scan_tag_uri(yaml_parser_t *parser, int directive,
2571+ yaml_char_t *head, yaml_mark_t start_mark, yaml_char_t **uri)
2572+{
2573+ size_t length = head ? strlen((char *)head) : 0;
2574+ yaml_string_t string = NULL_STRING;
2575+
2576+ if (!STRING_INIT(parser, string, INITIAL_STRING_SIZE)) goto error;
2577+
2578+ /* Resize the string to include the head. */
2579+
2580+ while ((size_t)(string.end - string.start) <= length) {
2581+ if (!yaml_string_extend(&string.start, &string.pointer, &string.end)) {
2582+ parser->error = YAML_MEMORY_ERROR;
2583+ goto error;
2584+ }
2585+ }
2586+
2587+ /*
2588+ * Copy the head if needed.
2589+ *
2590+ * Note that we don't copy the leading '!' character.
2591+ */
2592+
2593+ if (length > 1) {
2594+ memcpy(string.start, head+1, length-1);
2595+ string.pointer += length-1;
2596+ }
2597+
2598+ /* Scan the tag. */
2599+
2600+ if (!CACHE(parser, 1)) goto error;
2601+
2602+ /*
2603+ * The set of characters that may appear in URI is as follows:
2604+ *
2605+ * '0'-'9', 'A'-'Z', 'a'-'z', '_', '-', ';', '/', '?', ':', '@', '&',
2606+ * '=', '+', '$', ',', '.', '!', '~', '*', '\'', '(', ')', '[', ']',
2607+ * '%'.
2608+ */
2609+
2610+ while (IS_ALPHA(parser->buffer) || CHECK(parser->buffer, ';')
2611+ || CHECK(parser->buffer, '/') || CHECK(parser->buffer, '?')
2612+ || CHECK(parser->buffer, ':') || CHECK(parser->buffer, '@')
2613+ || CHECK(parser->buffer, '&') || CHECK(parser->buffer, '=')
2614+ || CHECK(parser->buffer, '+') || CHECK(parser->buffer, '$')
2615+ || CHECK(parser->buffer, ',') || CHECK(parser->buffer, '.')
2616+ || CHECK(parser->buffer, '!') || CHECK(parser->buffer, '~')
2617+ || CHECK(parser->buffer, '*') || CHECK(parser->buffer, '\'')
2618+ || CHECK(parser->buffer, '(') || CHECK(parser->buffer, ')')
2619+ || CHECK(parser->buffer, '[') || CHECK(parser->buffer, ']')
2620+ || CHECK(parser->buffer, '%'))
2621+ {
2622+ /* Check if it is a URI-escape sequence. */
2623+
2624+ if (CHECK(parser->buffer, '%')) {
2625+ if (!STRING_EXTEND(parser, string))
2626+ goto error;
2627+
2628+ if (!yaml_parser_scan_uri_escapes(parser,
2629+ directive, start_mark, &string)) goto error;
2630+ }
2631+ else {
2632+ if (!READ(parser, string)) goto error;
2633+ }
2634+
2635+ length ++;
2636+ if (!CACHE(parser, 1)) goto error;
2637+ }
2638+
2639+ /* Check if the tag is non-empty. */
2640+
2641+ if (!length) {
2642+ if (!STRING_EXTEND(parser, string))
2643+ goto error;
2644+
2645+ yaml_parser_set_scanner_error(parser, directive ?
2646+ "while parsing a %TAG directive" : "while parsing a tag",
2647+ start_mark, "did not find expected tag URI");
2648+ goto error;
2649+ }
2650+
2651+ *uri = string.start;
2652+
2653+ return 1;
2654+
2655+error:
2656+ STRING_DEL(parser, string);
2657+ return 0;
2658+}
2659+
2660+/*
2661+ * Decode an URI-escape sequence corresponding to a single UTF-8 character.
2662+ */
2663+
2664+static int
2665+yaml_parser_scan_uri_escapes(yaml_parser_t *parser, int directive,
2666+ yaml_mark_t start_mark, yaml_string_t *string)
2667+{
2668+ int width = 0;
2669+
2670+ /* Decode the required number of characters. */
2671+
2672+ do {
2673+
2674+ unsigned char octet = 0;
2675+
2676+ /* Check for a URI-escaped octet. */
2677+
2678+ if (!CACHE(parser, 3)) return 0;
2679+
2680+ if (!(CHECK(parser->buffer, '%')
2681+ && IS_HEX_AT(parser->buffer, 1)
2682+ && IS_HEX_AT(parser->buffer, 2))) {
2683+ return yaml_parser_set_scanner_error(parser, directive ?
2684+ "while parsing a %TAG directive" : "while parsing a tag",
2685+ start_mark, "did not find URI escaped octet");
2686+ }
2687+
2688+ /* Get the octet. */
2689+
2690+ octet = (AS_HEX_AT(parser->buffer, 1) << 4) + AS_HEX_AT(parser->buffer, 2);
2691+
2692+ /* If it is the leading octet, determine the length of the UTF-8 sequence. */
2693+
2694+ if (!width)
2695+ {
2696+ width = (octet & 0x80) == 0x00 ? 1 :
2697+ (octet & 0xE0) == 0xC0 ? 2 :
2698+ (octet & 0xF0) == 0xE0 ? 3 :
2699+ (octet & 0xF8) == 0xF0 ? 4 : 0;
2700+ if (!width) {
2701+ return yaml_parser_set_scanner_error(parser, directive ?
2702+ "while parsing a %TAG directive" : "while parsing a tag",
2703+ start_mark, "found an incorrect leading UTF-8 octet");
2704+ }
2705+ }
2706+ else
2707+ {
2708+ /* Check if the trailing octet is correct. */
2709+
2710+ if ((octet & 0xC0) != 0x80) {
2711+ return yaml_parser_set_scanner_error(parser, directive ?
2712+ "while parsing a %TAG directive" : "while parsing a tag",
2713+ start_mark, "found an incorrect trailing UTF-8 octet");
2714+ }
2715+ }
2716+
2717+ /* Copy the octet and move the pointers. */
2718+
2719+ *(string->pointer++) = octet;
2720+ SKIP(parser);
2721+ SKIP(parser);
2722+ SKIP(parser);
2723+
2724+ } while (--width);
2725+
2726+ return 1;
2727+}
2728+
2729+/*
2730+ * Scan a block scalar.
2731+ */
2732+
2733+static int
2734+yaml_parser_scan_block_scalar(yaml_parser_t *parser, yaml_token_t *token,
2735+ int literal)
2736+{
2737+ yaml_mark_t start_mark;
2738+ yaml_mark_t end_mark;
2739+ yaml_string_t string = NULL_STRING;
2740+ yaml_string_t leading_break = NULL_STRING;
2741+ yaml_string_t trailing_breaks = NULL_STRING;
2742+ int chomping = 0;
2743+ int increment = 0;
2744+ int indent = 0;
2745+ int leading_blank = 0;
2746+ int trailing_blank = 0;
2747+
2748+ if (!STRING_INIT(parser, string, INITIAL_STRING_SIZE)) goto error;
2749+ if (!STRING_INIT(parser, leading_break, INITIAL_STRING_SIZE)) goto error;
2750+ if (!STRING_INIT(parser, trailing_breaks, INITIAL_STRING_SIZE)) goto error;
2751+
2752+ /* Eat the indicator '|' or '>'. */
2753+
2754+ start_mark = parser->mark;
2755+
2756+ SKIP(parser);
2757+
2758+ /* Scan the additional block scalar indicators. */
2759+
2760+ if (!CACHE(parser, 1)) goto error;
2761+
2762+ /* Check for a chomping indicator. */
2763+
2764+ if (CHECK(parser->buffer, '+') || CHECK(parser->buffer, '-'))
2765+ {
2766+ /* Set the chomping method and eat the indicator. */
2767+
2768+ chomping = CHECK(parser->buffer, '+') ? +1 : -1;
2769+
2770+ SKIP(parser);
2771+
2772+ /* Check for an indentation indicator. */
2773+
2774+ if (!CACHE(parser, 1)) goto error;
2775+
2776+ if (IS_DIGIT(parser->buffer))
2777+ {
2778+ /* Check that the indentation is greater than 0. */
2779+
2780+ if (CHECK(parser->buffer, '0')) {
2781+ yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
2782+ start_mark, "found an indentation indicator equal to 0");
2783+ goto error;
2784+ }
2785+
2786+ /* Get the indentation level and eat the indicator. */
2787+
2788+ increment = AS_DIGIT(parser->buffer);
2789+
2790+ SKIP(parser);
2791+ }
2792+ }
2793+
2794+ /* Do the same as above, but in the opposite order. */
2795+
2796+ else if (IS_DIGIT(parser->buffer))
2797+ {
2798+ if (CHECK(parser->buffer, '0')) {
2799+ yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
2800+ start_mark, "found an indentation indicator equal to 0");
2801+ goto error;
2802+ }
2803+
2804+ increment = AS_DIGIT(parser->buffer);
2805+
2806+ SKIP(parser);
2807+
2808+ if (!CACHE(parser, 1)) goto error;
2809+
2810+ if (CHECK(parser->buffer, '+') || CHECK(parser->buffer, '-')) {
2811+ chomping = CHECK(parser->buffer, '+') ? +1 : -1;
2812+
2813+ SKIP(parser);
2814+ }
2815+ }
2816+
2817+ /* Eat whitespaces and comments to the end of the line. */
2818+
2819+ if (!CACHE(parser, 1)) goto error;
2820+
2821+ while (IS_BLANK(parser->buffer)) {
2822+ SKIP(parser);
2823+ if (!CACHE(parser, 1)) goto error;
2824+ }
2825+
2826+ if (CHECK(parser->buffer, '#')) {
2827+ while (!IS_BREAKZ(parser->buffer)) {
2828+ SKIP(parser);
2829+ if (!CACHE(parser, 1)) goto error;
2830+ }
2831+ }
2832+
2833+ /* Check if we are at the end of the line. */
2834+
2835+ if (!IS_BREAKZ(parser->buffer)) {
2836+ yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
2837+ start_mark, "did not find expected comment or line break");
2838+ goto error;
2839+ }
2840+
2841+ /* Eat a line break. */
2842+
2843+ if (IS_BREAK(parser->buffer)) {
2844+ if (!CACHE(parser, 2)) goto error;
2845+ SKIP_LINE(parser);
2846+ }
2847+
2848+ end_mark = parser->mark;
2849+
2850+ /* Set the indentation level if it was specified. */
2851+
2852+ if (increment) {
2853+ indent = parser->indent >= 0 ? parser->indent+increment : increment;
2854+ }
2855+
2856+ /* Scan the leading line breaks and determine the indentation level if needed. */
2857+
2858+ if (!yaml_parser_scan_block_scalar_breaks(parser, &indent, &trailing_breaks,
2859+ start_mark, &end_mark)) goto error;
2860+
2861+ /* Scan the block scalar content. */
2862+
2863+ if (!CACHE(parser, 1)) goto error;
2864+
2865+ while ((int)parser->mark.column == indent && !IS_Z(parser->buffer))
2866+ {
2867+ /*
2868+ * We are at the beginning of a non-empty line.
2869+ */
2870+
2871+ /* Is it a trailing whitespace? */
2872+
2873+ trailing_blank = IS_BLANK(parser->buffer);
2874+
2875+ /* Check if we need to fold the leading line break. */
2876+
2877+ if (!literal && (*leading_break.start == '\n')
2878+ && !leading_blank && !trailing_blank)
2879+ {
2880+ /* Do we need to join the lines by space? */
2881+
2882+ if (*trailing_breaks.start == '\0') {
2883+ if (!STRING_EXTEND(parser, string)) goto error;
2884+ *(string.pointer ++) = ' ';
2885+ }
2886+
2887+ CLEAR(parser, leading_break);
2888+ }
2889+ else {
2890+ if (!JOIN(parser, string, leading_break)) goto error;
2891+ CLEAR(parser, leading_break);
2892+ }
2893+
2894+ /* Append the remaining line breaks. */
2895+
2896+ if (!JOIN(parser, string, trailing_breaks)) goto error;
2897+ CLEAR(parser, trailing_breaks);
2898+
2899+ /* Is it a leading whitespace? */
2900+
2901+ leading_blank = IS_BLANK(parser->buffer);
2902+
2903+ /* Consume the current line. */
2904+
2905+ while (!IS_BREAKZ(parser->buffer)) {
2906+ if (!READ(parser, string)) goto error;
2907+ if (!CACHE(parser, 1)) goto error;
2908+ }
2909+
2910+ /* Consume the line break. */
2911+
2912+ if (!CACHE(parser, 2)) goto error;
2913+
2914+ if (!READ_LINE(parser, leading_break)) goto error;
2915+
2916+ /* Eat the following indentation spaces and line breaks. */
2917+
2918+ if (!yaml_parser_scan_block_scalar_breaks(parser,
2919+ &indent, &trailing_breaks, start_mark, &end_mark)) goto error;
2920+ }
2921+
2922+ /* Chomp the tail. */
2923+
2924+ if (chomping != -1) {
2925+ if (!JOIN(parser, string, leading_break)) goto error;
2926+ }
2927+ if (chomping == 1) {
2928+ if (!JOIN(parser, string, trailing_breaks)) goto error;
2929+ }
2930+
2931+ /* Create a token. */
2932+
2933+ SCALAR_TOKEN_INIT(*token, string.start, string.pointer-string.start,
2934+ literal ? YAML_LITERAL_SCALAR_STYLE : YAML_FOLDED_SCALAR_STYLE,
2935+ start_mark, end_mark);
2936+
2937+ STRING_DEL(parser, leading_break);
2938+ STRING_DEL(parser, trailing_breaks);
2939+
2940+ return 1;
2941+
2942+error:
2943+ STRING_DEL(parser, string);
2944+ STRING_DEL(parser, leading_break);
2945+ STRING_DEL(parser, trailing_breaks);
2946+
2947+ return 0;
2948+}
2949+
2950+/*
2951+ * Scan indentation spaces and line breaks for a block scalar. Determine the
2952+ * indentation level if needed.
2953+ */
2954+
2955+static int
2956+yaml_parser_scan_block_scalar_breaks(yaml_parser_t *parser,
2957+ int *indent, yaml_string_t *breaks,
2958+ yaml_mark_t start_mark, yaml_mark_t *end_mark)
2959+{
2960+ int max_indent = 0;
2961+
2962+ *end_mark = parser->mark;
2963+
2964+ /* Eat the indentation spaces and line breaks. */
2965+
2966+ while (1)
2967+ {
2968+ /* Eat the indentation spaces. */
2969+
2970+ if (!CACHE(parser, 1)) return 0;
2971+
2972+ while ((!*indent || (int)parser->mark.column < *indent)
2973+ && IS_SPACE(parser->buffer)) {
2974+ SKIP(parser);
2975+ if (!CACHE(parser, 1)) return 0;
2976+ }
2977+
2978+ if ((int)parser->mark.column > max_indent)
2979+ max_indent = (int)parser->mark.column;
2980+
2981+ /* Check for a tab character messing the indentation. */
2982+
2983+ if ((!*indent || (int)parser->mark.column < *indent)
2984+ && IS_TAB(parser->buffer)) {
2985+ return yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
2986+ start_mark, "found a tab character where an indentation space is expected");
2987+ }
2988+
2989+ /* Have we found a non-empty line? */
2990+
2991+ if (!IS_BREAK(parser->buffer)) break;
2992+
2993+ /* Consume the line break. */
2994+
2995+ if (!CACHE(parser, 2)) return 0;
2996+ if (!READ_LINE(parser, *breaks)) return 0;
2997+ *end_mark = parser->mark;
2998+ }
2999+
3000+ /* Determine the indentation level if needed. */
3001+
3002+ if (!*indent) {
3003+ *indent = max_indent;
3004+ if (*indent < parser->indent + 1)
3005+ *indent = parser->indent + 1;
3006+ if (*indent < 1)
3007+ *indent = 1;
3008+ }
3009+
3010+ return 1;
3011+}
3012+
3013+/*
3014+ * Scan a quoted scalar.
3015+ */
3016+
3017+static int
3018+yaml_parser_scan_flow_scalar(yaml_parser_t *parser, yaml_token_t *token,
3019+ int single)
3020+{
3021+ yaml_mark_t start_mark;
3022+ yaml_mark_t end_mark;
3023+ yaml_string_t string = NULL_STRING;
3024+ yaml_string_t leading_break = NULL_STRING;
3025+ yaml_string_t trailing_breaks = NULL_STRING;
3026+ yaml_string_t whitespaces = NULL_STRING;
3027+ int leading_blanks;
3028+
3029+ if (!STRING_INIT(parser, string, INITIAL_STRING_SIZE)) goto error;
3030+ if (!STRING_INIT(parser, leading_break, INITIAL_STRING_SIZE)) goto error;
3031+ if (!STRING_INIT(parser, trailing_breaks, INITIAL_STRING_SIZE)) goto error;
3032+ if (!STRING_INIT(parser, whitespaces, INITIAL_STRING_SIZE)) goto error;
3033+
3034+ /* Eat the left quote. */
3035+
3036+ start_mark = parser->mark;
3037+
3038+ SKIP(parser);
3039+
3040+ /* Consume the content of the quoted scalar. */
3041+
3042+ while (1)
3043+ {
3044+ /* Check that there are no document indicators at the beginning of the line. */
3045+
3046+ if (!CACHE(parser, 4)) goto error;
3047+
3048+ if (parser->mark.column == 0 &&
3049+ ((CHECK_AT(parser->buffer, '-', 0) &&
3050+ CHECK_AT(parser->buffer, '-', 1) &&
3051+ CHECK_AT(parser->buffer, '-', 2)) ||
3052+ (CHECK_AT(parser->buffer, '.', 0) &&
3053+ CHECK_AT(parser->buffer, '.', 1) &&
3054+ CHECK_AT(parser->buffer, '.', 2))) &&
3055+ IS_BLANKZ_AT(parser->buffer, 3))
3056+ {
3057+ yaml_parser_set_scanner_error(parser, "while scanning a quoted scalar",
3058+ start_mark, "found unexpected document indicator");
3059+ goto error;
3060+ }
3061+
3062+ /* Check for EOF. */
3063+
3064+ if (IS_Z(parser->buffer)) {
3065+ yaml_parser_set_scanner_error(parser, "while scanning a quoted scalar",
3066+ start_mark, "found unexpected end of stream");
3067+ goto error;
3068+ }
3069+
3070+ /* Consume non-blank characters. */
3071+
3072+ if (!CACHE(parser, 2)) goto error;
3073+
3074+ leading_blanks = 0;
3075+
3076+ while (!IS_BLANKZ(parser->buffer))
3077+ {
3078+ /* Check for an escaped single quote. */
3079+
3080+ if (single && CHECK_AT(parser->buffer, '\'', 0)
3081+ && CHECK_AT(parser->buffer, '\'', 1))
3082+ {
3083+ if (!STRING_EXTEND(parser, string)) goto error;
3084+ *(string.pointer++) = '\'';
3085+ SKIP(parser);
3086+ SKIP(parser);
3087+ }
3088+
3089+ /* Check for the right quote. */
3090+
3091+ else if (CHECK(parser->buffer, single ? '\'' : '"'))
3092+ {
3093+ break;
3094+ }
3095+
3096+ /* Check for an escaped line break. */
3097+
3098+ else if (!single && CHECK(parser->buffer, '\\')
3099+ && IS_BREAK_AT(parser->buffer, 1))
3100+ {
3101+ if (!CACHE(parser, 3)) goto error;
3102+ SKIP(parser);
3103+ SKIP_LINE(parser);
3104+ leading_blanks = 1;
3105+ break;
3106+ }
3107+
3108+ /* Check for an escape sequence. */
3109+
3110+ else if (!single && CHECK(parser->buffer, '\\'))
3111+ {
3112+ size_t code_length = 0;
3113+
3114+ if (!STRING_EXTEND(parser, string)) goto error;
3115+
3116+ /* Check the escape character. */
3117+
3118+ switch (parser->buffer.pointer[1])
3119+ {
3120+ case '0':
3121+ *(string.pointer++) = '\0';
3122+ break;
3123+
3124+ case 'a':
3125+ *(string.pointer++) = '\x07';
3126+ break;
3127+
3128+ case 'b':
3129+ *(string.pointer++) = '\x08';
3130+ break;
3131+
3132+ case 't':
3133+ case '\t':
3134+ *(string.pointer++) = '\x09';
3135+ break;
3136+
3137+ case 'n':
3138+ *(string.pointer++) = '\x0A';
3139+ break;
3140+
3141+ case 'v':
3142+ *(string.pointer++) = '\x0B';
3143+ break;
3144+
3145+ case 'f':
3146+ *(string.pointer++) = '\x0C';
3147+ break;
3148+
3149+ case 'r':
3150+ *(string.pointer++) = '\x0D';
3151+ break;
3152+
3153+ case 'e':
3154+ *(string.pointer++) = '\x1B';
3155+ break;
3156+
3157+ case ' ':
3158+ *(string.pointer++) = '\x20';
3159+ break;
3160+
3161+ case '"':
3162+ *(string.pointer++) = '"';
3163+ break;
3164+
3165+ case '/':
3166+ *(string.pointer++) = '/';
3167+ break;
3168+
3169+ case '\'':
3170+ *(string.pointer++) = '\'';
3171+ break;
3172+
3173+ case '\\':
3174+ *(string.pointer++) = '\\';
3175+ break;
3176+
3177+ case 'N': /* NEL (#x85) */
3178+ *(string.pointer++) = '\xC2';
3179+ *(string.pointer++) = '\x85';
3180+ break;
3181+
3182+ case '_': /* #xA0 */
3183+ *(string.pointer++) = '\xC2';
3184+ *(string.pointer++) = '\xA0';
3185+ break;
3186+
3187+ case 'L': /* LS (#x2028) */
3188+ *(string.pointer++) = '\xE2';
3189+ *(string.pointer++) = '\x80';
3190+ *(string.pointer++) = '\xA8';
3191+ break;
3192+
3193+ case 'P': /* PS (#x2029) */
3194+ *(string.pointer++) = '\xE2';
3195+ *(string.pointer++) = '\x80';
3196+ *(string.pointer++) = '\xA9';
3197+ break;
3198+
3199+ case 'x':
3200+ code_length = 2;
3201+ break;
3202+
3203+ case 'u':
3204+ code_length = 4;
3205+ break;
3206+
3207+ case 'U':
3208+ code_length = 8;
3209+ break;
3210+
3211+ default:
3212+ yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
3213+ start_mark, "found unknown escape character");
3214+ goto error;
3215+ }
3216+
3217+ SKIP(parser);
3218+ SKIP(parser);
3219+
3220+ /* Consume an arbitrary escape code. */
3221+
3222+ if (code_length)
3223+ {
3224+ unsigned int value = 0;
3225+ size_t k;
3226+
3227+ /* Scan the character value. */
3228+
3229+ if (!CACHE(parser, code_length)) goto error;
3230+
3231+ for (k = 0; k < code_length; k ++) {
3232+ if (!IS_HEX_AT(parser->buffer, k)) {
3233+ yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
3234+ start_mark, "did not find expected hexdecimal number");
3235+ goto error;
3236+ }
3237+ value = (value << 4) + AS_HEX_AT(parser->buffer, k);
3238+ }
3239+
3240+ /* Check the value and write the character. */
3241+
3242+ if ((value >= 0xD800 && value <= 0xDFFF) || value > 0x10FFFF) {
3243+ yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
3244+ start_mark, "found invalid Unicode character escape code");
3245+ goto error;
3246+ }
3247+
3248+ if (value <= 0x7F) {
3249+ *(string.pointer++) = value;
3250+ }
3251+ else if (value <= 0x7FF) {
3252+ *(string.pointer++) = 0xC0 + (value >> 6);
3253+ *(string.pointer++) = 0x80 + (value & 0x3F);
3254+ }
3255+ else if (value <= 0xFFFF) {
3256+ *(string.pointer++) = 0xE0 + (value >> 12);
3257+ *(string.pointer++) = 0x80 + ((value >> 6) & 0x3F);
3258+ *(string.pointer++) = 0x80 + (value & 0x3F);
3259+ }
3260+ else {
3261+ *(string.pointer++) = 0xF0 + (value >> 18);
3262+ *(string.pointer++) = 0x80 + ((value >> 12) & 0x3F);
3263+ *(string.pointer++) = 0x80 + ((value >> 6) & 0x3F);
3264+ *(string.pointer++) = 0x80 + (value & 0x3F);
3265+ }
3266+
3267+ /* Advance the pointer. */
3268+
3269+ for (k = 0; k < code_length; k ++) {
3270+ SKIP(parser);
3271+ }
3272+ }
3273+ }
3274+
3275+ else
3276+ {
3277+ /* It is a non-escaped non-blank character. */
3278+
3279+ if (!READ(parser, string)) goto error;
3280+ }
3281+
3282+ if (!CACHE(parser, 2)) goto error;
3283+ }
3284+
3285+ /* Check if we are at the end of the scalar. */
3286+
3287+ /* Fix for crash unitialized value crash
3288+ * Credit for the bug and input is to OSS Fuzz
3289+ * Credit for the fix to Alex Gaynor
3290+ */
3291+ if (!CACHE(parser, 1)) goto error;
3292+ if (CHECK(parser->buffer, single ? '\'' : '"'))
3293+ break;
3294+
3295+ /* Consume blank characters. */
3296+
3297+ if (!CACHE(parser, 1)) goto error;
3298+
3299+ while (IS_BLANK(parser->buffer) || IS_BREAK(parser->buffer))
3300+ {
3301+ if (IS_BLANK(parser->buffer))
3302+ {
3303+ /* Consume a space or a tab character. */
3304+
3305+ if (!leading_blanks) {
3306+ if (!READ(parser, whitespaces)) goto error;
3307+ }
3308+ else {
3309+ SKIP(parser);
3310+ }
3311+ }
3312+ else
3313+ {
3314+ if (!CACHE(parser, 2)) goto error;
3315+
3316+ /* Check if it is a first line break. */
3317+
3318+ if (!leading_blanks)
3319+ {
3320+ CLEAR(parser, whitespaces);
3321+ if (!READ_LINE(parser, leading_break)) goto error;
3322+ leading_blanks = 1;
3323+ }
3324+ else
3325+ {
3326+ if (!READ_LINE(parser, trailing_breaks)) goto error;
3327+ }
3328+ }
3329+ if (!CACHE(parser, 1)) goto error;
3330+ }
3331+
3332+ /* Join the whitespaces or fold line breaks. */
3333+
3334+ if (leading_blanks)
3335+ {
3336+ /* Do we need to fold line breaks? */
3337+
3338+ if (leading_break.start[0] == '\n') {
3339+ if (trailing_breaks.start[0] == '\0') {
3340+ if (!STRING_EXTEND(parser, string)) goto error;
3341+ *(string.pointer++) = ' ';
3342+ }
3343+ else {
3344+ if (!JOIN(parser, string, trailing_breaks)) goto error;
3345+ CLEAR(parser, trailing_breaks);
3346+ }
3347+ CLEAR(parser, leading_break);
3348+ }
3349+ else {
3350+ if (!JOIN(parser, string, leading_break)) goto error;
3351+ if (!JOIN(parser, string, trailing_breaks)) goto error;
3352+ CLEAR(parser, leading_break);
3353+ CLEAR(parser, trailing_breaks);
3354+ }
3355+ }
3356+ else
3357+ {
3358+ if (!JOIN(parser, string, whitespaces)) goto error;
3359+ CLEAR(parser, whitespaces);
3360+ }
3361+ }
3362+
3363+ /* Eat the right quote. */
3364+
3365+ SKIP(parser);
3366+
3367+ end_mark = parser->mark;
3368+
3369+ /* Create a token. */
3370+
3371+ SCALAR_TOKEN_INIT(*token, string.start, string.pointer-string.start,
3372+ single ? YAML_SINGLE_QUOTED_SCALAR_STYLE : YAML_DOUBLE_QUOTED_SCALAR_STYLE,
3373+ start_mark, end_mark);
3374+
3375+ STRING_DEL(parser, leading_break);
3376+ STRING_DEL(parser, trailing_breaks);
3377+ STRING_DEL(parser, whitespaces);
3378+
3379+ return 1;
3380+
3381+error:
3382+ STRING_DEL(parser, string);
3383+ STRING_DEL(parser, leading_break);
3384+ STRING_DEL(parser, trailing_breaks);
3385+ STRING_DEL(parser, whitespaces);
3386+
3387+ return 0;
3388+}
3389+
3390+/*
3391+ * Scan a plain scalar.
3392+ */
3393+
3394+static int
3395+yaml_parser_scan_plain_scalar(yaml_parser_t *parser, yaml_token_t *token)
3396+{
3397+ yaml_mark_t start_mark;
3398+ yaml_mark_t end_mark;
3399+ yaml_string_t string = NULL_STRING;
3400+ yaml_string_t leading_break = NULL_STRING;
3401+ yaml_string_t trailing_breaks = NULL_STRING;
3402+ yaml_string_t whitespaces = NULL_STRING;
3403+ int leading_blanks = 0;
3404+ int indent = parser->indent+1;
3405+
3406+ if (!STRING_INIT(parser, string, INITIAL_STRING_SIZE)) goto error;
3407+ if (!STRING_INIT(parser, leading_break, INITIAL_STRING_SIZE)) goto error;
3408+ if (!STRING_INIT(parser, trailing_breaks, INITIAL_STRING_SIZE)) goto error;
3409+ if (!STRING_INIT(parser, whitespaces, INITIAL_STRING_SIZE)) goto error;
3410+
3411+ start_mark = end_mark = parser->mark;
3412+
3413+ /* Consume the content of the plain scalar. */
3414+
3415+ while (1)
3416+ {
3417+ /* Check for a document indicator. */
3418+
3419+ if (!CACHE(parser, 4)) goto error;
3420+
3421+ if (parser->mark.column == 0 &&
3422+ ((CHECK_AT(parser->buffer, '-', 0) &&
3423+ CHECK_AT(parser->buffer, '-', 1) &&
3424+ CHECK_AT(parser->buffer, '-', 2)) ||
3425+ (CHECK_AT(parser->buffer, '.', 0) &&
3426+ CHECK_AT(parser->buffer, '.', 1) &&
3427+ CHECK_AT(parser->buffer, '.', 2))) &&
3428+ IS_BLANKZ_AT(parser->buffer, 3)) break;
3429+
3430+ /* Check for a comment. */
3431+
3432+ if (CHECK(parser->buffer, '#'))
3433+ break;
3434+
3435+ /* Consume non-blank characters. */
3436+
3437+ while (!IS_BLANKZ(parser->buffer))
3438+ {
3439+ /* Check for 'x:x' in the flow context. TODO: Fix the test "spec-08-13". */
3440+
3441+ if (parser->flow_level
3442+ && CHECK(parser->buffer, ':')
3443+ && !IS_BLANKZ_AT(parser->buffer, 1)) {
3444+ yaml_parser_set_scanner_error(parser, "while scanning a plain scalar",
3445+ start_mark, "found unexpected ':'");
3446+ goto error;
3447+ }
3448+
3449+ /* Check for indicators that may end a plain scalar. */
3450+
3451+ if ((CHECK(parser->buffer, ':') && IS_BLANKZ_AT(parser->buffer, 1))
3452+ || (parser->flow_level &&
3453+ (CHECK(parser->buffer, ',') || CHECK(parser->buffer, ':')
3454+ || CHECK(parser->buffer, '?') || CHECK(parser->buffer, '[')
3455+ || CHECK(parser->buffer, ']') || CHECK(parser->buffer, '{')
3456+ || CHECK(parser->buffer, '}'))))
3457+ break;
3458+
3459+ /* Check if we need to join whitespaces and breaks. */
3460+
3461+ if (leading_blanks || whitespaces.start != whitespaces.pointer)
3462+ {
3463+ if (leading_blanks)
3464+ {
3465+ /* Do we need to fold line breaks? */
3466+
3467+ if (leading_break.start[0] == '\n') {
3468+ if (trailing_breaks.start[0] == '\0') {
3469+ if (!STRING_EXTEND(parser, string)) goto error;
3470+ *(string.pointer++) = ' ';
3471+ }
3472+ else {
3473+ if (!JOIN(parser, string, trailing_breaks)) goto error;
3474+ CLEAR(parser, trailing_breaks);
3475+ }
3476+ CLEAR(parser, leading_break);
3477+ }
3478+ else {
3479+ if (!JOIN(parser, string, leading_break)) goto error;
3480+ if (!JOIN(parser, string, trailing_breaks)) goto error;
3481+ CLEAR(parser, leading_break);
3482+ CLEAR(parser, trailing_breaks);
3483+ }
3484+
3485+ leading_blanks = 0;
3486+ }
3487+ else
3488+ {
3489+ if (!JOIN(parser, string, whitespaces)) goto error;
3490+ CLEAR(parser, whitespaces);
3491+ }
3492+ }
3493+
3494+ /* Copy the character. */
3495+
3496+ if (!READ(parser, string)) goto error;
3497+
3498+ end_mark = parser->mark;
3499+
3500+ if (!CACHE(parser, 2)) goto error;
3501+ }
3502+
3503+ /* Is it the end? */
3504+
3505+ if (!(IS_BLANK(parser->buffer) || IS_BREAK(parser->buffer)))
3506+ break;
3507+
3508+ /* Consume blank characters. */
3509+
3510+ if (!CACHE(parser, 1)) goto error;
3511+
3512+ while (IS_BLANK(parser->buffer) || IS_BREAK(parser->buffer))
3513+ {
3514+ if (IS_BLANK(parser->buffer))
3515+ {
3516+ /* Check for tab character that abuse indentation. */
3517+
3518+ if (leading_blanks && (int)parser->mark.column < indent
3519+ && IS_TAB(parser->buffer)) {
3520+ yaml_parser_set_scanner_error(parser, "while scanning a plain scalar",
3521+ start_mark, "found a tab character that violate indentation");
3522+ goto error;
3523+ }
3524+
3525+ /* Consume a space or a tab character. */
3526+
3527+ if (!leading_blanks) {
3528+ if (!READ(parser, whitespaces)) goto error;
3529+ }
3530+ else {
3531+ SKIP(parser);
3532+ }
3533+ }
3534+ else
3535+ {
3536+ if (!CACHE(parser, 2)) goto error;
3537+
3538+ /* Check if it is a first line break. */
3539+
3540+ if (!leading_blanks)
3541+ {
3542+ CLEAR(parser, whitespaces);
3543+ if (!READ_LINE(parser, leading_break)) goto error;
3544+ leading_blanks = 1;
3545+ }
3546+ else
3547+ {
3548+ if (!READ_LINE(parser, trailing_breaks)) goto error;
3549+ }
3550+ }
3551+ if (!CACHE(parser, 1)) goto error;
3552+ }
3553+
3554+ /* Check indentation level. */
3555+
3556+ if (!parser->flow_level && (int)parser->mark.column < indent)
3557+ break;
3558+ }
3559+
3560+ /* Create a token. */
3561+
3562+ SCALAR_TOKEN_INIT(*token, string.start, string.pointer-string.start,
3563+ YAML_PLAIN_SCALAR_STYLE, start_mark, end_mark);
3564+
3565+ /* Note that we change the 'simple_key_allowed' flag. */
3566+
3567+ if (leading_blanks) {
3568+ parser->simple_key_allowed = 1;
3569+ }
3570+
3571+ STRING_DEL(parser, leading_break);
3572+ STRING_DEL(parser, trailing_breaks);
3573+ STRING_DEL(parser, whitespaces);
3574+
3575+ return 1;
3576+
3577+error:
3578+ STRING_DEL(parser, string);
3579+ STRING_DEL(parser, leading_break);
3580+ STRING_DEL(parser, trailing_breaks);
3581+ STRING_DEL(parser, whitespaces);
3582+
3583+ return 0;
3584+}