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1 /*
2  * pattern.c: Implemetation of selectors for nodes
3  *
4  * Reference:
5  *   http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/
6  *   to some extent
7  *   http://www.w3.org/TR/1999/REC-xml-19991116
8  *
9  * See Copyright for the status of this software.
10  *
11  * daniel@veillard.com
12  */
13 
14 /*
15  * TODO:
16  * - compilation flags to check for specific syntaxes
17  *   using flags of xmlPatterncompile()
18  * - making clear how pattern starting with / or . need to be handled,
19  *   currently push(NULL, NULL) means a reset of the streaming context
20  *   and indicating we are on / (the document node), probably need
21  *   something similar for .
22  * - get rid of the "compile" starting with lowercase
23  * - DONE (2006-05-16): get rid of the Strdup/Strndup in case of dictionary
24  */
25 
26 #define IN_LIBXML
27 #include "libxml.h"
28 
29 #include <string.h>
30 #include <libxml/xmlmemory.h>
31 #include <libxml/tree.h>
32 #include <libxml/hash.h>
33 #include <libxml/dict.h>
34 #include <libxml/xmlerror.h>
35 #include <libxml/parserInternals.h>
36 #include <libxml/pattern.h>
37 
38 #ifdef LIBXML_PATTERN_ENABLED
39 
40 /* #define DEBUG_STREAMING */
41 
42 #define ERROR(a, b, c, d)
43 #define ERROR5(a, b, c, d, e)
44 
45 #define XML_STREAM_STEP_DESC	1
46 #define XML_STREAM_STEP_FINAL	2
47 #define XML_STREAM_STEP_ROOT	4
48 #define XML_STREAM_STEP_ATTR	8
49 #define XML_STREAM_STEP_NODE	16
50 #define XML_STREAM_STEP_IN_SET	32
51 
52 /*
53 * NOTE: Those private flags (XML_STREAM_xxx) are used
54 *   in _xmlStreamCtxt->flag. They extend the public
55 *   xmlPatternFlags, so be carefull not to interfere with the
56 *   reserved values for xmlPatternFlags.
57 */
58 #define XML_STREAM_FINAL_IS_ANY_NODE 1<<14
59 #define XML_STREAM_FROM_ROOT 1<<15
60 #define XML_STREAM_DESC 1<<16
61 
62 /*
63 * XML_STREAM_ANY_NODE is used for comparison against
64 * xmlElementType enums, to indicate a node of any type.
65 */
66 #define XML_STREAM_ANY_NODE 100
67 
68 #define XML_PATTERN_NOTPATTERN  (XML_PATTERN_XPATH | \
69 				 XML_PATTERN_XSSEL | \
70 				 XML_PATTERN_XSFIELD)
71 
72 #define XML_STREAM_XS_IDC(c) ((c)->flags & \
73     (XML_PATTERN_XSSEL | XML_PATTERN_XSFIELD))
74 
75 #define XML_STREAM_XS_IDC_SEL(c) ((c)->flags & XML_PATTERN_XSSEL)
76 
77 #define XML_STREAM_XS_IDC_FIELD(c) ((c)->flags & XML_PATTERN_XSFIELD)
78 
79 #define XML_PAT_COPY_NSNAME(c, r, nsname) \
80     if ((c)->comp->dict) \
81 	r = (xmlChar *) xmlDictLookup((c)->comp->dict, BAD_CAST nsname, -1); \
82     else r = xmlStrdup(BAD_CAST nsname);
83 
84 #define XML_PAT_FREE_STRING(c, r) if ((c)->comp->dict == NULL) xmlFree(r);
85 
86 typedef struct _xmlStreamStep xmlStreamStep;
87 typedef xmlStreamStep *xmlStreamStepPtr;
88 struct _xmlStreamStep {
89     int flags;			/* properties of that step */
90     const xmlChar *name;	/* first string value if NULL accept all */
91     const xmlChar *ns;		/* second string value */
92     int nodeType;		/* type of node */
93 };
94 
95 typedef struct _xmlStreamComp xmlStreamComp;
96 typedef xmlStreamComp *xmlStreamCompPtr;
97 struct _xmlStreamComp {
98     xmlDict *dict;		/* the dictionary if any */
99     int nbStep;			/* number of steps in the automata */
100     int maxStep;		/* allocated number of steps */
101     xmlStreamStepPtr steps;	/* the array of steps */
102     int flags;
103 };
104 
105 struct _xmlStreamCtxt {
106     struct _xmlStreamCtxt *next;/* link to next sub pattern if | */
107     xmlStreamCompPtr comp;	/* the compiled stream */
108     int nbState;		/* number of states in the automata */
109     int maxState;		/* allocated number of states */
110     int level;			/* how deep are we ? */
111     int *states;		/* the array of step indexes */
112     int flags;			/* validation options */
113     int blockLevel;
114 };
115 
116 static void xmlFreeStreamComp(xmlStreamCompPtr comp);
117 
118 /*
119  * Types are private:
120  */
121 
122 typedef enum {
123     XML_OP_END=0,
124     XML_OP_ROOT,
125     XML_OP_ELEM,
126     XML_OP_CHILD,
127     XML_OP_ATTR,
128     XML_OP_PARENT,
129     XML_OP_ANCESTOR,
130     XML_OP_NS,
131     XML_OP_ALL
132 } xmlPatOp;
133 
134 
135 typedef struct _xmlStepState xmlStepState;
136 typedef xmlStepState *xmlStepStatePtr;
137 struct _xmlStepState {
138     int step;
139     xmlNodePtr node;
140 };
141 
142 typedef struct _xmlStepStates xmlStepStates;
143 typedef xmlStepStates *xmlStepStatesPtr;
144 struct _xmlStepStates {
145     int nbstates;
146     int maxstates;
147     xmlStepStatePtr states;
148 };
149 
150 typedef struct _xmlStepOp xmlStepOp;
151 typedef xmlStepOp *xmlStepOpPtr;
152 struct _xmlStepOp {
153     xmlPatOp op;
154     const xmlChar *value;
155     const xmlChar *value2; /* The namespace name */
156 };
157 
158 #define PAT_FROM_ROOT	(1<<8)
159 #define PAT_FROM_CUR	(1<<9)
160 
161 struct _xmlPattern {
162     void *data;    		/* the associated template */
163     xmlDictPtr dict;		/* the optional dictionary */
164     struct _xmlPattern *next;	/* next pattern if | is used */
165     const xmlChar *pattern;	/* the pattern */
166     int flags;			/* flags */
167     int nbStep;
168     int maxStep;
169     xmlStepOpPtr steps;        /* ops for computation */
170     xmlStreamCompPtr stream;	/* the streaming data if any */
171 };
172 
173 typedef struct _xmlPatParserContext xmlPatParserContext;
174 typedef xmlPatParserContext *xmlPatParserContextPtr;
175 struct _xmlPatParserContext {
176     const xmlChar *cur;			/* the current char being parsed */
177     const xmlChar *base;		/* the full expression */
178     int	           error;		/* error code */
179     xmlDictPtr     dict;		/* the dictionary if any */
180     xmlPatternPtr  comp;		/* the result */
181     xmlNodePtr     elem;		/* the current node if any */
182     const xmlChar **namespaces;		/* the namespaces definitions */
183     int   nb_namespaces;		/* the number of namespaces */
184 };
185 
186 /************************************************************************
187  * 									*
188  * 			Type functions 					*
189  * 									*
190  ************************************************************************/
191 
192 /**
193  * xmlNewPattern:
194  *
195  * Create a new XSLT Pattern
196  *
197  * Returns the newly allocated xmlPatternPtr or NULL in case of error
198  */
199 static xmlPatternPtr
xmlNewPattern(void)200 xmlNewPattern(void) {
201     xmlPatternPtr cur;
202 
203     cur = (xmlPatternPtr) xmlMalloc(sizeof(xmlPattern));
204     if (cur == NULL) {
205 	ERROR(NULL, NULL, NULL,
206 		"xmlNewPattern : malloc failed\n");
207 	return(NULL);
208     }
209     memset(cur, 0, sizeof(xmlPattern));
210     cur->maxStep = 10;
211     cur->steps = (xmlStepOpPtr) xmlMalloc(cur->maxStep * sizeof(xmlStepOp));
212     if (cur->steps == NULL) {
213         xmlFree(cur);
214 	ERROR(NULL, NULL, NULL,
215 		"xmlNewPattern : malloc failed\n");
216 	return(NULL);
217     }
218     return(cur);
219 }
220 
221 /**
222  * xmlFreePattern:
223  * @comp:  an XSLT comp
224  *
225  * Free up the memory allocated by @comp
226  */
227 void
xmlFreePattern(xmlPatternPtr comp)228 xmlFreePattern(xmlPatternPtr comp) {
229     xmlStepOpPtr op;
230     int i;
231 
232     if (comp == NULL)
233 	return;
234     if (comp->next != NULL)
235         xmlFreePattern(comp->next);
236     if (comp->stream != NULL)
237         xmlFreeStreamComp(comp->stream);
238     if (comp->pattern != NULL)
239 	xmlFree((xmlChar *)comp->pattern);
240     if (comp->steps != NULL) {
241         if (comp->dict == NULL) {
242 	    for (i = 0;i < comp->nbStep;i++) {
243 		op = &comp->steps[i];
244 		if (op->value != NULL)
245 		    xmlFree((xmlChar *) op->value);
246 		if (op->value2 != NULL)
247 		    xmlFree((xmlChar *) op->value2);
248 	    }
249 	}
250 	xmlFree(comp->steps);
251     }
252     if (comp->dict != NULL)
253         xmlDictFree(comp->dict);
254 
255     memset(comp, -1, sizeof(xmlPattern));
256     xmlFree(comp);
257 }
258 
259 /**
260  * xmlFreePatternList:
261  * @comp:  an XSLT comp list
262  *
263  * Free up the memory allocated by all the elements of @comp
264  */
265 void
xmlFreePatternList(xmlPatternPtr comp)266 xmlFreePatternList(xmlPatternPtr comp) {
267     xmlPatternPtr cur;
268 
269     while (comp != NULL) {
270 	cur = comp;
271 	comp = comp->next;
272 	cur->next = NULL;
273 	xmlFreePattern(cur);
274     }
275 }
276 
277 /**
278  * xmlNewPatParserContext:
279  * @pattern:  the pattern context
280  * @dict:  the inherited dictionary or NULL
281  * @namespaces: the prefix definitions, array of [URI, prefix] terminated
282  *              with [NULL, NULL] or NULL if no namespace is used
283  *
284  * Create a new XML pattern parser context
285  *
286  * Returns the newly allocated xmlPatParserContextPtr or NULL in case of error
287  */
288 static xmlPatParserContextPtr
xmlNewPatParserContext(const xmlChar * pattern,xmlDictPtr dict,const xmlChar ** namespaces)289 xmlNewPatParserContext(const xmlChar *pattern, xmlDictPtr dict,
290                        const xmlChar **namespaces) {
291     xmlPatParserContextPtr cur;
292 
293     if (pattern == NULL)
294         return(NULL);
295 
296     cur = (xmlPatParserContextPtr) xmlMalloc(sizeof(xmlPatParserContext));
297     if (cur == NULL) {
298 	ERROR(NULL, NULL, NULL,
299 		"xmlNewPatParserContext : malloc failed\n");
300 	return(NULL);
301     }
302     memset(cur, 0, sizeof(xmlPatParserContext));
303     cur->dict = dict;
304     cur->cur = pattern;
305     cur->base = pattern;
306     if (namespaces != NULL) {
307         int i;
308 	for (i = 0;namespaces[2 * i] != NULL;i++);
309         cur->nb_namespaces = i;
310     } else {
311         cur->nb_namespaces = 0;
312     }
313     cur->namespaces = namespaces;
314     return(cur);
315 }
316 
317 /**
318  * xmlFreePatParserContext:
319  * @ctxt:  an XSLT parser context
320  *
321  * Free up the memory allocated by @ctxt
322  */
323 static void
xmlFreePatParserContext(xmlPatParserContextPtr ctxt)324 xmlFreePatParserContext(xmlPatParserContextPtr ctxt) {
325     if (ctxt == NULL)
326 	return;
327     memset(ctxt, -1, sizeof(xmlPatParserContext));
328     xmlFree(ctxt);
329 }
330 
331 /**
332  * xmlPatternAdd:
333  * @comp:  the compiled match expression
334  * @op:  an op
335  * @value:  the first value
336  * @value2:  the second value
337  *
338  * Add a step to an XSLT Compiled Match
339  *
340  * Returns -1 in case of failure, 0 otherwise.
341  */
342 static int
xmlPatternAdd(xmlPatParserContextPtr ctxt ATTRIBUTE_UNUSED,xmlPatternPtr comp,xmlPatOp op,xmlChar * value,xmlChar * value2)343 xmlPatternAdd(xmlPatParserContextPtr ctxt ATTRIBUTE_UNUSED,
344                 xmlPatternPtr comp,
345                 xmlPatOp op, xmlChar * value, xmlChar * value2)
346 {
347     if (comp->nbStep >= comp->maxStep) {
348         xmlStepOpPtr temp;
349 	temp = (xmlStepOpPtr) xmlRealloc(comp->steps, comp->maxStep * 2 *
350 	                                 sizeof(xmlStepOp));
351         if (temp == NULL) {
352 	    ERROR(ctxt, NULL, NULL,
353 			     "xmlPatternAdd: realloc failed\n");
354 	    return (-1);
355 	}
356 	comp->steps = temp;
357 	comp->maxStep *= 2;
358     }
359     comp->steps[comp->nbStep].op = op;
360     comp->steps[comp->nbStep].value = value;
361     comp->steps[comp->nbStep].value2 = value2;
362     comp->nbStep++;
363     return (0);
364 }
365 
366 #if 0
367 /**
368  * xsltSwapTopPattern:
369  * @comp:  the compiled match expression
370  *
371  * reverse the two top steps.
372  */
373 static void
374 xsltSwapTopPattern(xmlPatternPtr comp) {
375     int i;
376     int j = comp->nbStep - 1;
377 
378     if (j > 0) {
379 	register const xmlChar *tmp;
380 	register xmlPatOp op;
381 	i = j - 1;
382 	tmp = comp->steps[i].value;
383 	comp->steps[i].value = comp->steps[j].value;
384 	comp->steps[j].value = tmp;
385 	tmp = comp->steps[i].value2;
386 	comp->steps[i].value2 = comp->steps[j].value2;
387 	comp->steps[j].value2 = tmp;
388 	op = comp->steps[i].op;
389 	comp->steps[i].op = comp->steps[j].op;
390 	comp->steps[j].op = op;
391     }
392 }
393 #endif
394 
395 /**
396  * xmlReversePattern:
397  * @comp:  the compiled match expression
398  *
399  * reverse all the stack of expressions
400  *
401  * returns 0 in case of success and -1 in case of error.
402  */
403 static int
xmlReversePattern(xmlPatternPtr comp)404 xmlReversePattern(xmlPatternPtr comp) {
405     int i, j;
406 
407     /*
408      * remove the leading // for //a or .//a
409      */
410     if ((comp->nbStep > 0) && (comp->steps[0].op == XML_OP_ANCESTOR)) {
411         for (i = 0, j = 1;j < comp->nbStep;i++,j++) {
412 	    comp->steps[i].value = comp->steps[j].value;
413 	    comp->steps[i].value2 = comp->steps[j].value2;
414 	    comp->steps[i].op = comp->steps[j].op;
415 	}
416 	comp->nbStep--;
417     }
418     if (comp->nbStep >= comp->maxStep) {
419         xmlStepOpPtr temp;
420 	temp = (xmlStepOpPtr) xmlRealloc(comp->steps, comp->maxStep * 2 *
421 	                                 sizeof(xmlStepOp));
422         if (temp == NULL) {
423 	    ERROR(ctxt, NULL, NULL,
424 			     "xmlReversePattern: realloc failed\n");
425 	    return (-1);
426 	}
427 	comp->steps = temp;
428 	comp->maxStep *= 2;
429     }
430     i = 0;
431     j = comp->nbStep - 1;
432     while (j > i) {
433 	register const xmlChar *tmp;
434 	register xmlPatOp op;
435 	tmp = comp->steps[i].value;
436 	comp->steps[i].value = comp->steps[j].value;
437 	comp->steps[j].value = tmp;
438 	tmp = comp->steps[i].value2;
439 	comp->steps[i].value2 = comp->steps[j].value2;
440 	comp->steps[j].value2 = tmp;
441 	op = comp->steps[i].op;
442 	comp->steps[i].op = comp->steps[j].op;
443 	comp->steps[j].op = op;
444 	j--;
445 	i++;
446     }
447     comp->steps[comp->nbStep].value = NULL;
448     comp->steps[comp->nbStep].value2 = NULL;
449     comp->steps[comp->nbStep++].op = XML_OP_END;
450     return(0);
451 }
452 
453 /************************************************************************
454  * 									*
455  * 		The interpreter for the precompiled patterns		*
456  * 									*
457  ************************************************************************/
458 
459 static int
xmlPatPushState(xmlStepStates * states,int step,xmlNodePtr node)460 xmlPatPushState(xmlStepStates *states, int step, xmlNodePtr node) {
461     if ((states->states == NULL) || (states->maxstates <= 0)) {
462         states->maxstates = 4;
463 	states->nbstates = 0;
464 	states->states = xmlMalloc(4 * sizeof(xmlStepState));
465     }
466     else if (states->maxstates <= states->nbstates) {
467         xmlStepState *tmp;
468 
469 	tmp = (xmlStepStatePtr) xmlRealloc(states->states,
470 			       2 * states->maxstates * sizeof(xmlStepState));
471 	if (tmp == NULL)
472 	    return(-1);
473 	states->states = tmp;
474 	states->maxstates *= 2;
475     }
476     states->states[states->nbstates].step = step;
477     states->states[states->nbstates++].node = node;
478 #if 0
479     fprintf(stderr, "Push: %d, %s\n", step, node->name);
480 #endif
481     return(0);
482 }
483 
484 /**
485  * xmlPatMatch:
486  * @comp: the precompiled pattern
487  * @node: a node
488  *
489  * Test whether the node matches the pattern
490  *
491  * Returns 1 if it matches, 0 if it doesn't and -1 in case of failure
492  */
493 static int
xmlPatMatch(xmlPatternPtr comp,xmlNodePtr node)494 xmlPatMatch(xmlPatternPtr comp, xmlNodePtr node) {
495     int i;
496     xmlStepOpPtr step;
497     xmlStepStates states = {0, 0, NULL}; /* // may require backtrack */
498 
499     if ((comp == NULL) || (node == NULL)) return(-1);
500     i = 0;
501 restart:
502     for (;i < comp->nbStep;i++) {
503 	step = &comp->steps[i];
504 	switch (step->op) {
505             case XML_OP_END:
506 		goto found;
507             case XML_OP_ROOT:
508 		if (node->type == XML_NAMESPACE_DECL)
509 		    goto rollback;
510 		node = node->parent;
511 		if ((node->type == XML_DOCUMENT_NODE) ||
512 #ifdef LIBXML_DOCB_ENABLED
513 		    (node->type == XML_DOCB_DOCUMENT_NODE) ||
514 #endif
515 		    (node->type == XML_HTML_DOCUMENT_NODE))
516 		    continue;
517 		goto rollback;
518             case XML_OP_ELEM:
519 		if (node->type != XML_ELEMENT_NODE)
520 		    goto rollback;
521 		if (step->value == NULL)
522 		    continue;
523 		if (step->value[0] != node->name[0])
524 		    goto rollback;
525 		if (!xmlStrEqual(step->value, node->name))
526 		    goto rollback;
527 
528 		/* Namespace test */
529 		if (node->ns == NULL) {
530 		    if (step->value2 != NULL)
531 			goto rollback;
532 		} else if (node->ns->href != NULL) {
533 		    if (step->value2 == NULL)
534 			goto rollback;
535 		    if (!xmlStrEqual(step->value2, node->ns->href))
536 			goto rollback;
537 		}
538 		continue;
539             case XML_OP_CHILD: {
540 		xmlNodePtr lst;
541 
542 		if ((node->type != XML_ELEMENT_NODE) &&
543 		    (node->type != XML_DOCUMENT_NODE) &&
544 #ifdef LIBXML_DOCB_ENABLED
545 		    (node->type != XML_DOCB_DOCUMENT_NODE) &&
546 #endif
547 		    (node->type != XML_HTML_DOCUMENT_NODE))
548 		    goto rollback;
549 
550 		lst = node->children;
551 
552 		if (step->value != NULL) {
553 		    while (lst != NULL) {
554 			if ((lst->type == XML_ELEMENT_NODE) &&
555 			    (step->value[0] == lst->name[0]) &&
556 			    (xmlStrEqual(step->value, lst->name)))
557 			    break;
558 			lst = lst->next;
559 		    }
560 		    if (lst != NULL)
561 			continue;
562 		}
563 		goto rollback;
564 	    }
565             case XML_OP_ATTR:
566 		if (node->type != XML_ATTRIBUTE_NODE)
567 		    goto rollback;
568 		if (step->value != NULL) {
569 		    if (step->value[0] != node->name[0])
570 			goto rollback;
571 		    if (!xmlStrEqual(step->value, node->name))
572 			goto rollback;
573 		}
574 		/* Namespace test */
575 		if (node->ns == NULL) {
576 		    if (step->value2 != NULL)
577 			goto rollback;
578 		} else if (step->value2 != NULL) {
579 		    if (!xmlStrEqual(step->value2, node->ns->href))
580 			goto rollback;
581 		}
582 		continue;
583             case XML_OP_PARENT:
584 		if ((node->type == XML_DOCUMENT_NODE) ||
585 		    (node->type == XML_HTML_DOCUMENT_NODE) ||
586 #ifdef LIBXML_DOCB_ENABLED
587 		    (node->type == XML_DOCB_DOCUMENT_NODE) ||
588 #endif
589 		    (node->type == XML_NAMESPACE_DECL))
590 		    goto rollback;
591 		node = node->parent;
592 		if (node == NULL)
593 		    goto rollback;
594 		if (step->value == NULL)
595 		    continue;
596 		if (step->value[0] != node->name[0])
597 		    goto rollback;
598 		if (!xmlStrEqual(step->value, node->name))
599 		    goto rollback;
600 		/* Namespace test */
601 		if (node->ns == NULL) {
602 		    if (step->value2 != NULL)
603 			goto rollback;
604 		} else if (node->ns->href != NULL) {
605 		    if (step->value2 == NULL)
606 			goto rollback;
607 		    if (!xmlStrEqual(step->value2, node->ns->href))
608 			goto rollback;
609 		}
610 		continue;
611             case XML_OP_ANCESTOR:
612 		/* TODO: implement coalescing of ANCESTOR/NODE ops */
613 		if (step->value == NULL) {
614 		    i++;
615 		    step = &comp->steps[i];
616 		    if (step->op == XML_OP_ROOT)
617 			goto found;
618 		    if (step->op != XML_OP_ELEM)
619 			goto rollback;
620 		    if (step->value == NULL)
621 			return(-1);
622 		}
623 		if (node == NULL)
624 		    goto rollback;
625 		if ((node->type == XML_DOCUMENT_NODE) ||
626 		    (node->type == XML_HTML_DOCUMENT_NODE) ||
627 #ifdef LIBXML_DOCB_ENABLED
628 		    (node->type == XML_DOCB_DOCUMENT_NODE) ||
629 #endif
630 		    (node->type == XML_NAMESPACE_DECL))
631 		    goto rollback;
632 		node = node->parent;
633 		while (node != NULL) {
634 		    if ((node->type == XML_ELEMENT_NODE) &&
635 			(step->value[0] == node->name[0]) &&
636 			(xmlStrEqual(step->value, node->name))) {
637 			/* Namespace test */
638 			if (node->ns == NULL) {
639 			    if (step->value2 == NULL)
640 				break;
641 			} else if (node->ns->href != NULL) {
642 			    if ((step->value2 != NULL) &&
643 			        (xmlStrEqual(step->value2, node->ns->href)))
644 				break;
645 			}
646 		    }
647 		    node = node->parent;
648 		}
649 		if (node == NULL)
650 		    goto rollback;
651 		/*
652 		 * prepare a potential rollback from here
653 		 * for ancestors of that node.
654 		 */
655 		if (step->op == XML_OP_ANCESTOR)
656 		    xmlPatPushState(&states, i, node);
657 		else
658 		    xmlPatPushState(&states, i - 1, node);
659 		continue;
660             case XML_OP_NS:
661 		if (node->type != XML_ELEMENT_NODE)
662 		    goto rollback;
663 		if (node->ns == NULL) {
664 		    if (step->value != NULL)
665 			goto rollback;
666 		} else if (node->ns->href != NULL) {
667 		    if (step->value == NULL)
668 			goto rollback;
669 		    if (!xmlStrEqual(step->value, node->ns->href))
670 			goto rollback;
671 		}
672 		break;
673             case XML_OP_ALL:
674 		if (node->type != XML_ELEMENT_NODE)
675 		    goto rollback;
676 		break;
677 	}
678     }
679 found:
680     if (states.states != NULL) {
681         /* Free the rollback states */
682 	xmlFree(states.states);
683     }
684     return(1);
685 rollback:
686     /* got an error try to rollback */
687     if (states.states == NULL)
688 	return(0);
689     if (states.nbstates <= 0) {
690 	xmlFree(states.states);
691 	return(0);
692     }
693     states.nbstates--;
694     i = states.states[states.nbstates].step;
695     node = states.states[states.nbstates].node;
696 #if 0
697     fprintf(stderr, "Pop: %d, %s\n", i, node->name);
698 #endif
699     goto restart;
700 }
701 
702 /************************************************************************
703  *									*
704  *			Dedicated parser for templates			*
705  *									*
706  ************************************************************************/
707 
708 #define TODO 								\
709     xmlGenericError(xmlGenericErrorContext,				\
710 	    "Unimplemented block at %s:%d\n",				\
711             __FILE__, __LINE__);
712 #define CUR (*ctxt->cur)
713 #define SKIP(val) ctxt->cur += (val)
714 #define NXT(val) ctxt->cur[(val)]
715 #define PEEKPREV(val) ctxt->cur[-(val)]
716 #define CUR_PTR ctxt->cur
717 
718 #define SKIP_BLANKS 							\
719     while (IS_BLANK_CH(CUR)) NEXT
720 
721 #define CURRENT (*ctxt->cur)
722 #define NEXT ((*ctxt->cur) ?  ctxt->cur++: ctxt->cur)
723 
724 
725 #define PUSH(op, val, val2) 						\
726     if (xmlPatternAdd(ctxt, ctxt->comp, (op), (val), (val2))) goto error;
727 
728 #define XSLT_ERROR(X)							\
729     { xsltError(ctxt, __FILE__, __LINE__, X);				\
730       ctxt->error = (X); return; }
731 
732 #define XSLT_ERROR0(X)							\
733     { xsltError(ctxt, __FILE__, __LINE__, X);				\
734       ctxt->error = (X); return(0); }
735 
736 #if 0
737 /**
738  * xmlPatScanLiteral:
739  * @ctxt:  the XPath Parser context
740  *
741  * Parse an XPath Litteral:
742  *
743  * [29] Literal ::= '"' [^"]* '"'
744  *                | "'" [^']* "'"
745  *
746  * Returns the Literal parsed or NULL
747  */
748 
749 static xmlChar *
750 xmlPatScanLiteral(xmlPatParserContextPtr ctxt) {
751     const xmlChar *q, *cur;
752     xmlChar *ret = NULL;
753     int val, len;
754 
755     SKIP_BLANKS;
756     if (CUR == '"') {
757         NEXT;
758 	cur = q = CUR_PTR;
759 	val = xmlStringCurrentChar(NULL, cur, &len);
760 	while ((IS_CHAR(val)) && (val != '"')) {
761 	    cur += len;
762 	    val = xmlStringCurrentChar(NULL, cur, &len);
763 	}
764 	if (!IS_CHAR(val)) {
765 	    ctxt->error = 1;
766 	    return(NULL);
767 	} else {
768 	    if (ctxt->dict)
769 		ret = (xmlChar *) xmlDictLookup(ctxt->dict, q, cur - q);
770 	    else
771 		ret = xmlStrndup(q, cur - q);
772         }
773 	cur += len;
774 	CUR_PTR = cur;
775     } else if (CUR == '\'') {
776         NEXT;
777 	cur = q = CUR_PTR;
778 	val = xmlStringCurrentChar(NULL, cur, &len);
779 	while ((IS_CHAR(val)) && (val != '\'')) {
780 	    cur += len;
781 	    val = xmlStringCurrentChar(NULL, cur, &len);
782 	}
783 	if (!IS_CHAR(val)) {
784 	    ctxt->error = 1;
785 	    return(NULL);
786 	} else {
787 	    if (ctxt->dict)
788 		ret = (xmlChar *) xmlDictLookup(ctxt->dict, q, cur - q);
789 	    else
790 		ret = xmlStrndup(q, cur - q);
791         }
792 	cur += len;
793 	CUR_PTR = cur;
794     } else {
795 	/* XP_ERROR(XPATH_START_LITERAL_ERROR); */
796 	ctxt->error = 1;
797 	return(NULL);
798     }
799     return(ret);
800 }
801 #endif
802 
803 /**
804  * xmlPatScanName:
805  * @ctxt:  the XPath Parser context
806  *
807  * [4] NameChar ::= Letter | Digit | '.' | '-' | '_' |
808  *                  CombiningChar | Extender
809  *
810  * [5] Name ::= (Letter | '_' | ':') (NameChar)*
811  *
812  * [6] Names ::= Name (S Name)*
813  *
814  * Returns the Name parsed or NULL
815  */
816 
817 static xmlChar *
xmlPatScanName(xmlPatParserContextPtr ctxt)818 xmlPatScanName(xmlPatParserContextPtr ctxt) {
819     const xmlChar *q, *cur;
820     xmlChar *ret = NULL;
821     int val, len;
822 
823     SKIP_BLANKS;
824 
825     cur = q = CUR_PTR;
826     val = xmlStringCurrentChar(NULL, cur, &len);
827     if (!IS_LETTER(val) && (val != '_') && (val != ':'))
828 	return(NULL);
829 
830     while ((IS_LETTER(val)) || (IS_DIGIT(val)) ||
831            (val == '.') || (val == '-') ||
832 	   (val == '_') ||
833 	   (IS_COMBINING(val)) ||
834 	   (IS_EXTENDER(val))) {
835 	cur += len;
836 	val = xmlStringCurrentChar(NULL, cur, &len);
837     }
838     if (ctxt->dict)
839 	ret = (xmlChar *) xmlDictLookup(ctxt->dict, q, cur - q);
840     else
841 	ret = xmlStrndup(q, cur - q);
842     CUR_PTR = cur;
843     return(ret);
844 }
845 
846 /**
847  * xmlPatScanNCName:
848  * @ctxt:  the XPath Parser context
849  *
850  * Parses a non qualified name
851  *
852  * Returns the Name parsed or NULL
853  */
854 
855 static xmlChar *
xmlPatScanNCName(xmlPatParserContextPtr ctxt)856 xmlPatScanNCName(xmlPatParserContextPtr ctxt) {
857     const xmlChar *q, *cur;
858     xmlChar *ret = NULL;
859     int val, len;
860 
861     SKIP_BLANKS;
862 
863     cur = q = CUR_PTR;
864     val = xmlStringCurrentChar(NULL, cur, &len);
865     if (!IS_LETTER(val) && (val != '_'))
866 	return(NULL);
867 
868     while ((IS_LETTER(val)) || (IS_DIGIT(val)) ||
869            (val == '.') || (val == '-') ||
870 	   (val == '_') ||
871 	   (IS_COMBINING(val)) ||
872 	   (IS_EXTENDER(val))) {
873 	cur += len;
874 	val = xmlStringCurrentChar(NULL, cur, &len);
875     }
876     if (ctxt->dict)
877 	ret = (xmlChar *) xmlDictLookup(ctxt->dict, q, cur - q);
878     else
879 	ret = xmlStrndup(q, cur - q);
880     CUR_PTR = cur;
881     return(ret);
882 }
883 
884 #if 0
885 /**
886  * xmlPatScanQName:
887  * @ctxt:  the XPath Parser context
888  * @prefix:  the place to store the prefix
889  *
890  * Parse a qualified name
891  *
892  * Returns the Name parsed or NULL
893  */
894 
895 static xmlChar *
896 xmlPatScanQName(xmlPatParserContextPtr ctxt, xmlChar **prefix) {
897     xmlChar *ret = NULL;
898 
899     *prefix = NULL;
900     ret = xmlPatScanNCName(ctxt);
901     if (CUR == ':') {
902         *prefix = ret;
903 	NEXT;
904 	ret = xmlPatScanNCName(ctxt);
905     }
906     return(ret);
907 }
908 #endif
909 
910 /**
911  * xmlCompileAttributeTest:
912  * @ctxt:  the compilation context
913  *
914  * Compile an attribute test.
915  */
916 static void
xmlCompileAttributeTest(xmlPatParserContextPtr ctxt)917 xmlCompileAttributeTest(xmlPatParserContextPtr ctxt) {
918     xmlChar *token = NULL;
919     xmlChar *name = NULL;
920     xmlChar *URL = NULL;
921 
922     SKIP_BLANKS;
923     name = xmlPatScanNCName(ctxt);
924     if (name == NULL) {
925 	if (CUR == '*') {
926 	    PUSH(XML_OP_ATTR, NULL, NULL);
927 	    NEXT;
928 	} else {
929 	    ERROR(NULL, NULL, NULL,
930 		"xmlCompileAttributeTest : Name expected\n");
931 	    ctxt->error = 1;
932 	}
933 	return;
934     }
935     if (CUR == ':') {
936 	int i;
937 	xmlChar *prefix = name;
938 
939 	NEXT;
940 
941 	if (IS_BLANK_CH(CUR)) {
942 	    ERROR5(NULL, NULL, NULL, "Invalid QName.\n", NULL);
943 	    XML_PAT_FREE_STRING(ctxt, prefix);
944 	    ctxt->error = 1;
945 	    goto error;
946 	}
947 	/*
948 	* This is a namespace match
949 	*/
950 	token = xmlPatScanName(ctxt);
951 	if ((prefix[0] == 'x') &&
952 	    (prefix[1] == 'm') &&
953 	    (prefix[2] == 'l') &&
954 	    (prefix[3] == 0))
955 	{
956 	    XML_PAT_COPY_NSNAME(ctxt, URL, XML_XML_NAMESPACE);
957 	} else {
958 	    for (i = 0;i < ctxt->nb_namespaces;i++) {
959 		if (xmlStrEqual(ctxt->namespaces[2 * i + 1], prefix)) {
960 		    XML_PAT_COPY_NSNAME(ctxt, URL, ctxt->namespaces[2 * i])
961 		    break;
962 		}
963 	    }
964 	    if (i >= ctxt->nb_namespaces) {
965 		ERROR5(NULL, NULL, NULL,
966 		    "xmlCompileAttributeTest : no namespace bound to prefix %s\n",
967 		    prefix);
968 		ctxt->error = 1;
969 		goto error;
970 	    }
971 	}
972 	XML_PAT_FREE_STRING(ctxt, prefix);
973 	if (token == NULL) {
974 	    if (CUR == '*') {
975 		NEXT;
976 		PUSH(XML_OP_ATTR, NULL, URL);
977 	    } else {
978 		ERROR(NULL, NULL, NULL,
979 		    "xmlCompileAttributeTest : Name expected\n");
980 		ctxt->error = 1;
981 		goto error;
982 	    }
983 	} else {
984 	    PUSH(XML_OP_ATTR, token, URL);
985 	}
986     } else {
987 	PUSH(XML_OP_ATTR, name, NULL);
988     }
989     return;
990 error:
991     if (URL != NULL)
992 	XML_PAT_FREE_STRING(ctxt, URL)
993     if (token != NULL)
994 	XML_PAT_FREE_STRING(ctxt, token);
995 }
996 
997 /**
998  * xmlCompileStepPattern:
999  * @ctxt:  the compilation context
1000  *
1001  * Compile the Step Pattern and generates a precompiled
1002  * form suitable for fast matching.
1003  *
1004  * [3]    Step    ::=    '.' | NameTest
1005  * [4]    NameTest    ::=    QName | '*' | NCName ':' '*'
1006  */
1007 
1008 static void
xmlCompileStepPattern(xmlPatParserContextPtr ctxt)1009 xmlCompileStepPattern(xmlPatParserContextPtr ctxt) {
1010     xmlChar *token = NULL;
1011     xmlChar *name = NULL;
1012     xmlChar *URL = NULL;
1013     int hasBlanks = 0;
1014 
1015     SKIP_BLANKS;
1016     if (CUR == '.') {
1017 	/*
1018 	* Context node.
1019 	*/
1020 	NEXT;
1021 	PUSH(XML_OP_ELEM, NULL, NULL);
1022 	return;
1023     }
1024     if (CUR == '@') {
1025 	/*
1026 	* Attribute test.
1027 	*/
1028 	if (XML_STREAM_XS_IDC_SEL(ctxt->comp)) {
1029 	    ERROR5(NULL, NULL, NULL,
1030 		"Unexpected attribute axis in '%s'.\n", ctxt->base);
1031 	    ctxt->error = 1;
1032 	    return;
1033 	}
1034 	NEXT;
1035 	xmlCompileAttributeTest(ctxt);
1036 	if (ctxt->error != 0)
1037 	    goto error;
1038 	return;
1039     }
1040     name = xmlPatScanNCName(ctxt);
1041     if (name == NULL) {
1042 	if (CUR == '*') {
1043 	    NEXT;
1044 	    PUSH(XML_OP_ALL, NULL, NULL);
1045 	    return;
1046 	} else {
1047 	    ERROR(NULL, NULL, NULL,
1048 		    "xmlCompileStepPattern : Name expected\n");
1049 	    ctxt->error = 1;
1050 	    return;
1051 	}
1052     }
1053     if (IS_BLANK_CH(CUR)) {
1054 	hasBlanks = 1;
1055 	SKIP_BLANKS;
1056     }
1057     if (CUR == ':') {
1058 	NEXT;
1059 	if (CUR != ':') {
1060 	    xmlChar *prefix = name;
1061 	    int i;
1062 
1063 	    if (hasBlanks || IS_BLANK_CH(CUR)) {
1064 		ERROR5(NULL, NULL, NULL, "Invalid QName.\n", NULL);
1065 		ctxt->error = 1;
1066 		goto error;
1067 	    }
1068 	    /*
1069 	     * This is a namespace match
1070 	     */
1071 	    token = xmlPatScanName(ctxt);
1072 	    if ((prefix[0] == 'x') &&
1073 		(prefix[1] == 'm') &&
1074 		(prefix[2] == 'l') &&
1075 		(prefix[3] == 0))
1076 	    {
1077 		XML_PAT_COPY_NSNAME(ctxt, URL, XML_XML_NAMESPACE)
1078 	    } else {
1079 		for (i = 0;i < ctxt->nb_namespaces;i++) {
1080 		    if (xmlStrEqual(ctxt->namespaces[2 * i + 1], prefix)) {
1081 			XML_PAT_COPY_NSNAME(ctxt, URL, ctxt->namespaces[2 * i])
1082 			break;
1083 		    }
1084 		}
1085 		if (i >= ctxt->nb_namespaces) {
1086 		    ERROR5(NULL, NULL, NULL,
1087 			"xmlCompileStepPattern : no namespace bound to prefix %s\n",
1088 			prefix);
1089 		    ctxt->error = 1;
1090 		    goto error;
1091 		}
1092 	    }
1093 	    XML_PAT_FREE_STRING(ctxt, prefix);
1094 	    name = NULL;
1095 	    if (token == NULL) {
1096 		if (CUR == '*') {
1097 		    NEXT;
1098 		    PUSH(XML_OP_NS, URL, NULL);
1099 		} else {
1100 		    ERROR(NULL, NULL, NULL,
1101 			    "xmlCompileStepPattern : Name expected\n");
1102 		    ctxt->error = 1;
1103 		    goto error;
1104 		}
1105 	    } else {
1106 		PUSH(XML_OP_ELEM, token, URL);
1107 	    }
1108 	} else {
1109 	    NEXT;
1110 	    if (xmlStrEqual(name, (const xmlChar *) "child")) {
1111 		XML_PAT_FREE_STRING(ctxt, name);
1112 		name = xmlPatScanName(ctxt);
1113 		if (name == NULL) {
1114 		    if (CUR == '*') {
1115 			NEXT;
1116 			PUSH(XML_OP_ALL, NULL, NULL);
1117 			return;
1118 		    } else {
1119 			ERROR(NULL, NULL, NULL,
1120 			    "xmlCompileStepPattern : QName expected\n");
1121 			ctxt->error = 1;
1122 			goto error;
1123 		    }
1124 		}
1125 		if (CUR == ':') {
1126 		    xmlChar *prefix = name;
1127 		    int i;
1128 
1129 		    NEXT;
1130 		    if (IS_BLANK_CH(CUR)) {
1131 			ERROR5(NULL, NULL, NULL, "Invalid QName.\n", NULL);
1132 			ctxt->error = 1;
1133 			goto error;
1134 		    }
1135 		    /*
1136 		    * This is a namespace match
1137 		    */
1138 		    token = xmlPatScanName(ctxt);
1139 		    if ((prefix[0] == 'x') &&
1140 			(prefix[1] == 'm') &&
1141 			(prefix[2] == 'l') &&
1142 			(prefix[3] == 0))
1143 		    {
1144 			XML_PAT_COPY_NSNAME(ctxt, URL, XML_XML_NAMESPACE)
1145 		    } else {
1146 			for (i = 0;i < ctxt->nb_namespaces;i++) {
1147 			    if (xmlStrEqual(ctxt->namespaces[2 * i + 1], prefix)) {
1148 				XML_PAT_COPY_NSNAME(ctxt, URL, ctxt->namespaces[2 * i])
1149 				break;
1150 			    }
1151 			}
1152 			if (i >= ctxt->nb_namespaces) {
1153 			    ERROR5(NULL, NULL, NULL,
1154 				"xmlCompileStepPattern : no namespace bound "
1155 				"to prefix %s\n", prefix);
1156 			    ctxt->error = 1;
1157 			    goto error;
1158 			}
1159 		    }
1160 		    XML_PAT_FREE_STRING(ctxt, prefix);
1161 		    name = NULL;
1162 		    if (token == NULL) {
1163 			if (CUR == '*') {
1164 			    NEXT;
1165 			    PUSH(XML_OP_NS, URL, NULL);
1166 			} else {
1167 			    ERROR(NULL, NULL, NULL,
1168 				"xmlCompileStepPattern : Name expected\n");
1169 			    ctxt->error = 1;
1170 			    goto error;
1171 			}
1172 		    } else {
1173 			PUSH(XML_OP_CHILD, token, URL);
1174 		    }
1175 		} else
1176 		    PUSH(XML_OP_CHILD, name, NULL);
1177 		return;
1178 	    } else if (xmlStrEqual(name, (const xmlChar *) "attribute")) {
1179 		XML_PAT_FREE_STRING(ctxt, name)
1180 		name = NULL;
1181 		if (XML_STREAM_XS_IDC_SEL(ctxt->comp)) {
1182 		    ERROR5(NULL, NULL, NULL,
1183 			"Unexpected attribute axis in '%s'.\n", ctxt->base);
1184 		    ctxt->error = 1;
1185 		    goto error;
1186 		}
1187 		xmlCompileAttributeTest(ctxt);
1188 		if (ctxt->error != 0)
1189 		    goto error;
1190 		return;
1191 	    } else {
1192 		ERROR5(NULL, NULL, NULL,
1193 		    "The 'element' or 'attribute' axis is expected.\n", NULL);
1194 		ctxt->error = 1;
1195 		goto error;
1196 	    }
1197 	}
1198     } else if (CUR == '*') {
1199         if (name != NULL) {
1200 	    ctxt->error = 1;
1201 	    goto error;
1202 	}
1203 	NEXT;
1204 	PUSH(XML_OP_ALL, token, NULL);
1205     } else {
1206 	PUSH(XML_OP_ELEM, name, NULL);
1207     }
1208     return;
1209 error:
1210     if (URL != NULL)
1211 	XML_PAT_FREE_STRING(ctxt, URL)
1212     if (token != NULL)
1213 	XML_PAT_FREE_STRING(ctxt, token)
1214     if (name != NULL)
1215 	XML_PAT_FREE_STRING(ctxt, name)
1216 }
1217 
1218 /**
1219  * xmlCompilePathPattern:
1220  * @ctxt:  the compilation context
1221  *
1222  * Compile the Path Pattern and generates a precompiled
1223  * form suitable for fast matching.
1224  *
1225  * [5]    Path    ::=    ('.//')? ( Step '/' )* ( Step | '@' NameTest )
1226  */
1227 static void
xmlCompilePathPattern(xmlPatParserContextPtr ctxt)1228 xmlCompilePathPattern(xmlPatParserContextPtr ctxt) {
1229     SKIP_BLANKS;
1230     if (CUR == '/') {
1231         ctxt->comp->flags |= PAT_FROM_ROOT;
1232     } else if ((CUR == '.') || (ctxt->comp->flags & XML_PATTERN_NOTPATTERN)) {
1233         ctxt->comp->flags |= PAT_FROM_CUR;
1234     }
1235 
1236     if ((CUR == '/') && (NXT(1) == '/')) {
1237 	PUSH(XML_OP_ANCESTOR, NULL, NULL);
1238 	NEXT;
1239 	NEXT;
1240     } else if ((CUR == '.') && (NXT(1) == '/') && (NXT(2) == '/')) {
1241 	PUSH(XML_OP_ANCESTOR, NULL, NULL);
1242 	NEXT;
1243 	NEXT;
1244 	NEXT;
1245 	/* Check for incompleteness. */
1246 	SKIP_BLANKS;
1247 	if (CUR == 0) {
1248 	    ERROR5(NULL, NULL, NULL,
1249 	       "Incomplete expression '%s'.\n", ctxt->base);
1250 	    ctxt->error = 1;
1251 	    goto error;
1252 	}
1253     }
1254     if (CUR == '@') {
1255 	NEXT;
1256 	xmlCompileAttributeTest(ctxt);
1257 	SKIP_BLANKS;
1258 	/* TODO: check for incompleteness */
1259 	if (CUR != 0) {
1260 	    xmlCompileStepPattern(ctxt);
1261 	    if (ctxt->error != 0)
1262 		goto error;
1263 	}
1264     } else {
1265         if (CUR == '/') {
1266 	    PUSH(XML_OP_ROOT, NULL, NULL);
1267 	    NEXT;
1268 	    /* Check for incompleteness. */
1269 	    SKIP_BLANKS;
1270 	    if (CUR == 0) {
1271 		ERROR5(NULL, NULL, NULL,
1272 		    "Incomplete expression '%s'.\n", ctxt->base);
1273 		ctxt->error = 1;
1274 		goto error;
1275 	    }
1276 	}
1277 	xmlCompileStepPattern(ctxt);
1278 	if (ctxt->error != 0)
1279 	    goto error;
1280 	SKIP_BLANKS;
1281 	while (CUR == '/') {
1282 	    if (NXT(1) == '/') {
1283 	        PUSH(XML_OP_ANCESTOR, NULL, NULL);
1284 		NEXT;
1285 		NEXT;
1286 		SKIP_BLANKS;
1287 		xmlCompileStepPattern(ctxt);
1288 		if (ctxt->error != 0)
1289 		    goto error;
1290 	    } else {
1291 	        PUSH(XML_OP_PARENT, NULL, NULL);
1292 		NEXT;
1293 		SKIP_BLANKS;
1294 		if (CUR == 0) {
1295 		    ERROR5(NULL, NULL, NULL,
1296 		    "Incomplete expression '%s'.\n", ctxt->base);
1297 		    ctxt->error = 1;
1298 		    goto error;
1299 		}
1300 		xmlCompileStepPattern(ctxt);
1301 		if (ctxt->error != 0)
1302 		    goto error;
1303 	    }
1304 	}
1305     }
1306     if (CUR != 0) {
1307 	ERROR5(NULL, NULL, NULL,
1308 	       "Failed to compile pattern %s\n", ctxt->base);
1309 	ctxt->error = 1;
1310     }
1311 error:
1312     return;
1313 }
1314 
1315 /**
1316  * xmlCompileIDCXPathPath:
1317  * @ctxt:  the compilation context
1318  *
1319  * Compile the Path Pattern and generates a precompiled
1320  * form suitable for fast matching.
1321  *
1322  * [5]    Path    ::=    ('.//')? ( Step '/' )* ( Step | '@' NameTest )
1323  */
1324 static void
xmlCompileIDCXPathPath(xmlPatParserContextPtr ctxt)1325 xmlCompileIDCXPathPath(xmlPatParserContextPtr ctxt) {
1326     SKIP_BLANKS;
1327     if (CUR == '/') {
1328 	ERROR5(NULL, NULL, NULL,
1329 	    "Unexpected selection of the document root in '%s'.\n",
1330 	    ctxt->base);
1331 	goto error;
1332     }
1333     ctxt->comp->flags |= PAT_FROM_CUR;
1334 
1335     if (CUR == '.') {
1336 	/* "." - "self::node()" */
1337 	NEXT;
1338 	SKIP_BLANKS;
1339 	if (CUR == 0) {
1340 	    /*
1341 	    * Selection of the context node.
1342 	    */
1343 	    PUSH(XML_OP_ELEM, NULL, NULL);
1344 	    return;
1345 	}
1346 	if (CUR != '/') {
1347 	    /* TODO: A more meaningful error message. */
1348 	    ERROR5(NULL, NULL, NULL,
1349 	    "Unexpected token after '.' in '%s'.\n", ctxt->base);
1350 	    goto error;
1351 	}
1352 	/* "./" - "self::node()/" */
1353 	NEXT;
1354 	SKIP_BLANKS;
1355 	if (CUR == '/') {
1356 	    if (IS_BLANK_CH(PEEKPREV(1))) {
1357 		/*
1358 		* Disallow "./ /"
1359 		*/
1360 		ERROR5(NULL, NULL, NULL,
1361 		    "Unexpected '/' token in '%s'.\n", ctxt->base);
1362 		goto error;
1363 	    }
1364 	    /* ".//" - "self:node()/descendant-or-self::node()/" */
1365 	    PUSH(XML_OP_ANCESTOR, NULL, NULL);
1366 	    NEXT;
1367 	    SKIP_BLANKS;
1368 	}
1369 	if (CUR == 0)
1370 	    goto error_unfinished;
1371     }
1372     /*
1373     * Process steps.
1374     */
1375     do {
1376 	xmlCompileStepPattern(ctxt);
1377 	if (ctxt->error != 0)
1378 	    goto error;
1379 	SKIP_BLANKS;
1380 	if (CUR != '/')
1381 	    break;
1382 	PUSH(XML_OP_PARENT, NULL, NULL);
1383 	NEXT;
1384 	SKIP_BLANKS;
1385 	if (CUR == '/') {
1386 	    /*
1387 	    * Disallow subsequent '//'.
1388 	    */
1389 	    ERROR5(NULL, NULL, NULL,
1390 		"Unexpected subsequent '//' in '%s'.\n",
1391 		ctxt->base);
1392 	    goto error;
1393 	}
1394 	if (CUR == 0)
1395 	    goto error_unfinished;
1396 
1397     } while (CUR != 0);
1398 
1399     if (CUR != 0) {
1400 	ERROR5(NULL, NULL, NULL,
1401 	    "Failed to compile expression '%s'.\n", ctxt->base);
1402 	ctxt->error = 1;
1403     }
1404     return;
1405 error:
1406     ctxt->error = 1;
1407     return;
1408 
1409 error_unfinished:
1410     ctxt->error = 1;
1411     ERROR5(NULL, NULL, NULL,
1412 	"Unfinished expression '%s'.\n", ctxt->base);
1413     return;
1414 }
1415 
1416 /************************************************************************
1417  *									*
1418  *			The streaming code				*
1419  *									*
1420  ************************************************************************/
1421 
1422 #ifdef DEBUG_STREAMING
1423 static void
xmlDebugStreamComp(xmlStreamCompPtr stream)1424 xmlDebugStreamComp(xmlStreamCompPtr stream) {
1425     int i;
1426 
1427     if (stream == NULL) {
1428         printf("Stream: NULL\n");
1429 	return;
1430     }
1431     printf("Stream: %d steps\n", stream->nbStep);
1432     for (i = 0;i < stream->nbStep;i++) {
1433 	if (stream->steps[i].ns != NULL) {
1434 	    printf("{%s}", stream->steps[i].ns);
1435 	}
1436         if (stream->steps[i].name == NULL) {
1437 	    printf("* ");
1438 	} else {
1439 	    printf("%s ", stream->steps[i].name);
1440 	}
1441 	if (stream->steps[i].flags & XML_STREAM_STEP_ROOT)
1442 	    printf("root ");
1443 	if (stream->steps[i].flags & XML_STREAM_STEP_DESC)
1444 	    printf("// ");
1445 	if (stream->steps[i].flags & XML_STREAM_STEP_FINAL)
1446 	    printf("final ");
1447 	printf("\n");
1448     }
1449 }
1450 static void
xmlDebugStreamCtxt(xmlStreamCtxtPtr ctxt,int match)1451 xmlDebugStreamCtxt(xmlStreamCtxtPtr ctxt, int match) {
1452     int i;
1453 
1454     if (ctxt == NULL) {
1455         printf("Stream: NULL\n");
1456 	return;
1457     }
1458     printf("Stream: level %d, %d states: ", ctxt->level, ctxt->nbState);
1459     if (match)
1460         printf("matches\n");
1461     else
1462         printf("\n");
1463     for (i = 0;i < ctxt->nbState;i++) {
1464         if (ctxt->states[2 * i] < 0)
1465 	    printf(" %d: free\n", i);
1466 	else {
1467 	    printf(" %d: step %d, level %d", i, ctxt->states[2 * i],
1468 	           ctxt->states[(2 * i) + 1]);
1469             if (ctxt->comp->steps[ctxt->states[2 * i]].flags &
1470 	        XML_STREAM_STEP_DESC)
1471 	        printf(" //\n");
1472 	    else
1473 	        printf("\n");
1474 	}
1475     }
1476 }
1477 #endif
1478 /**
1479  * xmlNewStreamComp:
1480  * @size: the number of expected steps
1481  *
1482  * build a new compiled pattern for streaming
1483  *
1484  * Returns the new structure or NULL in case of error.
1485  */
1486 static xmlStreamCompPtr
xmlNewStreamComp(int size)1487 xmlNewStreamComp(int size) {
1488     xmlStreamCompPtr cur;
1489 
1490     if (size < 4)
1491         size  = 4;
1492 
1493     cur = (xmlStreamCompPtr) xmlMalloc(sizeof(xmlStreamComp));
1494     if (cur == NULL) {
1495 	ERROR(NULL, NULL, NULL,
1496 		"xmlNewStreamComp: malloc failed\n");
1497 	return(NULL);
1498     }
1499     memset(cur, 0, sizeof(xmlStreamComp));
1500     cur->steps = (xmlStreamStepPtr) xmlMalloc(size * sizeof(xmlStreamStep));
1501     if (cur->steps == NULL) {
1502 	xmlFree(cur);
1503 	ERROR(NULL, NULL, NULL,
1504 	      "xmlNewStreamComp: malloc failed\n");
1505 	return(NULL);
1506     }
1507     cur->nbStep = 0;
1508     cur->maxStep = size;
1509     return(cur);
1510 }
1511 
1512 /**
1513  * xmlFreeStreamComp:
1514  * @comp: the compiled pattern for streaming
1515  *
1516  * Free the compiled pattern for streaming
1517  */
1518 static void
xmlFreeStreamComp(xmlStreamCompPtr comp)1519 xmlFreeStreamComp(xmlStreamCompPtr comp) {
1520     if (comp != NULL) {
1521         if (comp->steps != NULL)
1522 	    xmlFree(comp->steps);
1523 	if (comp->dict != NULL)
1524 	    xmlDictFree(comp->dict);
1525         xmlFree(comp);
1526     }
1527 }
1528 
1529 /**
1530  * xmlStreamCompAddStep:
1531  * @comp: the compiled pattern for streaming
1532  * @name: the first string, the name, or NULL for *
1533  * @ns: the second step, the namespace name
1534  * @flags: the flags for that step
1535  *
1536  * Add a new step to the compiled pattern
1537  *
1538  * Returns -1 in case of error or the step index if successful
1539  */
1540 static int
xmlStreamCompAddStep(xmlStreamCompPtr comp,const xmlChar * name,const xmlChar * ns,int nodeType,int flags)1541 xmlStreamCompAddStep(xmlStreamCompPtr comp, const xmlChar *name,
1542                      const xmlChar *ns, int nodeType, int flags) {
1543     xmlStreamStepPtr cur;
1544 
1545     if (comp->nbStep >= comp->maxStep) {
1546 	cur = (xmlStreamStepPtr) xmlRealloc(comp->steps,
1547 				 comp->maxStep * 2 * sizeof(xmlStreamStep));
1548 	if (cur == NULL) {
1549 	    ERROR(NULL, NULL, NULL,
1550 		  "xmlNewStreamComp: malloc failed\n");
1551 	    return(-1);
1552 	}
1553 	comp->steps = cur;
1554         comp->maxStep *= 2;
1555     }
1556     cur = &comp->steps[comp->nbStep++];
1557     cur->flags = flags;
1558     cur->name = name;
1559     cur->ns = ns;
1560     cur->nodeType = nodeType;
1561     return(comp->nbStep - 1);
1562 }
1563 
1564 /**
1565  * xmlStreamCompile:
1566  * @comp: the precompiled pattern
1567  *
1568  * Tries to stream compile a pattern
1569  *
1570  * Returns -1 in case of failure and 0 in case of success.
1571  */
1572 static int
xmlStreamCompile(xmlPatternPtr comp)1573 xmlStreamCompile(xmlPatternPtr comp) {
1574     xmlStreamCompPtr stream;
1575     int i, s = 0, root = 0, flags = 0, prevs = -1;
1576     xmlStepOp step;
1577 
1578     if ((comp == NULL) || (comp->steps == NULL))
1579         return(-1);
1580     /*
1581      * special case for .
1582      */
1583     if ((comp->nbStep == 1) &&
1584         (comp->steps[0].op == XML_OP_ELEM) &&
1585 	(comp->steps[0].value == NULL) &&
1586 	(comp->steps[0].value2 == NULL)) {
1587 	stream = xmlNewStreamComp(0);
1588 	if (stream == NULL)
1589 	    return(-1);
1590 	/* Note that the stream will have no steps in this case. */
1591 	stream->flags |= XML_STREAM_FINAL_IS_ANY_NODE;
1592 	comp->stream = stream;
1593 	return(0);
1594     }
1595 
1596     stream = xmlNewStreamComp((comp->nbStep / 2) + 1);
1597     if (stream == NULL)
1598         return(-1);
1599     if (comp->dict != NULL) {
1600         stream->dict = comp->dict;
1601 	xmlDictReference(stream->dict);
1602     }
1603 
1604     i = 0;
1605     if (comp->flags & PAT_FROM_ROOT)
1606 	stream->flags |= XML_STREAM_FROM_ROOT;
1607 
1608     for (;i < comp->nbStep;i++) {
1609 	step = comp->steps[i];
1610         switch (step.op) {
1611 	    case XML_OP_END:
1612 	        break;
1613 	    case XML_OP_ROOT:
1614 	        if (i != 0)
1615 		    goto error;
1616 		root = 1;
1617 		break;
1618 	    case XML_OP_NS:
1619 		s = xmlStreamCompAddStep(stream, NULL, step.value,
1620 		    XML_ELEMENT_NODE, flags);
1621 		if (s < 0)
1622 		    goto error;
1623 		prevs = s;
1624 		flags = 0;
1625 		break;
1626 	    case XML_OP_ATTR:
1627 		flags |= XML_STREAM_STEP_ATTR;
1628 		prevs = -1;
1629 		s = xmlStreamCompAddStep(stream,
1630 		    step.value, step.value2, XML_ATTRIBUTE_NODE, flags);
1631 		flags = 0;
1632 		if (s < 0)
1633 		    goto error;
1634 		break;
1635 	    case XML_OP_ELEM:
1636 	        if ((step.value == NULL) && (step.value2 == NULL)) {
1637 		    /*
1638 		    * We have a "." or "self::node()" here.
1639 		    * Eliminate redundant self::node() tests like in "/./."
1640 		    * or "//./"
1641 		    * The only case we won't eliminate is "//.", i.e. if
1642 		    * self::node() is the last node test and we had
1643 		    * continuation somewhere beforehand.
1644 		    */
1645 		    if ((comp->nbStep == i + 1) &&
1646 			(flags & XML_STREAM_STEP_DESC)) {
1647 			/*
1648 			* Mark the special case where the expression resolves
1649 			* to any type of node.
1650 			*/
1651 			if (comp->nbStep == i + 1) {
1652 			    stream->flags |= XML_STREAM_FINAL_IS_ANY_NODE;
1653 			}
1654 			flags |= XML_STREAM_STEP_NODE;
1655 			s = xmlStreamCompAddStep(stream, NULL, NULL,
1656 			    XML_STREAM_ANY_NODE, flags);
1657 			if (s < 0)
1658 			    goto error;
1659 			flags = 0;
1660 			/*
1661 			* If there was a previous step, mark it to be added to
1662 			* the result node-set; this is needed since only
1663 			* the last step will be marked as "final" and only
1664 			* "final" nodes are added to the resulting set.
1665 			*/
1666 			if (prevs != -1) {
1667 			    stream->steps[prevs].flags |= XML_STREAM_STEP_IN_SET;
1668 			    prevs = -1;
1669 			}
1670 			break;
1671 
1672 		    } else {
1673 			/* Just skip this one. */
1674 			continue;
1675 		    }
1676 		}
1677 		/* An element node. */
1678 	        s = xmlStreamCompAddStep(stream, step.value, step.value2,
1679 		    XML_ELEMENT_NODE, flags);
1680 		if (s < 0)
1681 		    goto error;
1682 		prevs = s;
1683 		flags = 0;
1684 		break;
1685 	    case XML_OP_CHILD:
1686 		/* An element node child. */
1687 	        s = xmlStreamCompAddStep(stream, step.value, step.value2,
1688 		    XML_ELEMENT_NODE, flags);
1689 		if (s < 0)
1690 		    goto error;
1691 		prevs = s;
1692 		flags = 0;
1693 		break;
1694 	    case XML_OP_ALL:
1695 	        s = xmlStreamCompAddStep(stream, NULL, NULL,
1696 		    XML_ELEMENT_NODE, flags);
1697 		if (s < 0)
1698 		    goto error;
1699 		prevs = s;
1700 		flags = 0;
1701 		break;
1702 	    case XML_OP_PARENT:
1703 	        break;
1704 	    case XML_OP_ANCESTOR:
1705 		/* Skip redundant continuations. */
1706 		if (flags & XML_STREAM_STEP_DESC)
1707 		    break;
1708 	        flags |= XML_STREAM_STEP_DESC;
1709 		/*
1710 		* Mark the expression as having "//".
1711 		*/
1712 		if ((stream->flags & XML_STREAM_DESC) == 0)
1713 		    stream->flags |= XML_STREAM_DESC;
1714 		break;
1715 	}
1716     }
1717     if ((! root) && (comp->flags & XML_PATTERN_NOTPATTERN) == 0) {
1718 	/*
1719 	* If this should behave like a real pattern, we will mark
1720 	* the first step as having "//", to be reentrant on every
1721 	* tree level.
1722 	*/
1723 	if ((stream->flags & XML_STREAM_DESC) == 0)
1724 	    stream->flags |= XML_STREAM_DESC;
1725 
1726 	if (stream->nbStep > 0) {
1727 	    if ((stream->steps[0].flags & XML_STREAM_STEP_DESC) == 0)
1728 		stream->steps[0].flags |= XML_STREAM_STEP_DESC;
1729 	}
1730     }
1731     if (stream->nbStep <= s)
1732 	goto error;
1733     stream->steps[s].flags |= XML_STREAM_STEP_FINAL;
1734     if (root)
1735 	stream->steps[0].flags |= XML_STREAM_STEP_ROOT;
1736 #ifdef DEBUG_STREAMING
1737     xmlDebugStreamComp(stream);
1738 #endif
1739     comp->stream = stream;
1740     return(0);
1741 error:
1742     xmlFreeStreamComp(stream);
1743     return(0);
1744 }
1745 
1746 /**
1747  * xmlNewStreamCtxt:
1748  * @size: the number of expected states
1749  *
1750  * build a new stream context
1751  *
1752  * Returns the new structure or NULL in case of error.
1753  */
1754 static xmlStreamCtxtPtr
xmlNewStreamCtxt(xmlStreamCompPtr stream)1755 xmlNewStreamCtxt(xmlStreamCompPtr stream) {
1756     xmlStreamCtxtPtr cur;
1757 
1758     cur = (xmlStreamCtxtPtr) xmlMalloc(sizeof(xmlStreamCtxt));
1759     if (cur == NULL) {
1760 	ERROR(NULL, NULL, NULL,
1761 		"xmlNewStreamCtxt: malloc failed\n");
1762 	return(NULL);
1763     }
1764     memset(cur, 0, sizeof(xmlStreamCtxt));
1765     cur->states = (int *) xmlMalloc(4 * 2 * sizeof(int));
1766     if (cur->states == NULL) {
1767 	xmlFree(cur);
1768 	ERROR(NULL, NULL, NULL,
1769 	      "xmlNewStreamCtxt: malloc failed\n");
1770 	return(NULL);
1771     }
1772     cur->nbState = 0;
1773     cur->maxState = 4;
1774     cur->level = 0;
1775     cur->comp = stream;
1776     cur->blockLevel = -1;
1777     return(cur);
1778 }
1779 
1780 /**
1781  * xmlFreeStreamCtxt:
1782  * @stream: the stream context
1783  *
1784  * Free the stream context
1785  */
1786 void
xmlFreeStreamCtxt(xmlStreamCtxtPtr stream)1787 xmlFreeStreamCtxt(xmlStreamCtxtPtr stream) {
1788     xmlStreamCtxtPtr next;
1789 
1790     while (stream != NULL) {
1791         next = stream->next;
1792         if (stream->states != NULL)
1793 	    xmlFree(stream->states);
1794         xmlFree(stream);
1795 	stream = next;
1796     }
1797 }
1798 
1799 /**
1800  * xmlStreamCtxtAddState:
1801  * @comp: the stream context
1802  * @idx: the step index for that streaming state
1803  *
1804  * Add a new state to the stream context
1805  *
1806  * Returns -1 in case of error or the state index if successful
1807  */
1808 static int
xmlStreamCtxtAddState(xmlStreamCtxtPtr comp,int idx,int level)1809 xmlStreamCtxtAddState(xmlStreamCtxtPtr comp, int idx, int level) {
1810     int i;
1811     for (i = 0;i < comp->nbState;i++) {
1812         if (comp->states[2 * i] < 0) {
1813 	    comp->states[2 * i] = idx;
1814 	    comp->states[2 * i + 1] = level;
1815 	    return(i);
1816 	}
1817     }
1818     if (comp->nbState >= comp->maxState) {
1819         int *cur;
1820 
1821 	cur = (int *) xmlRealloc(comp->states,
1822 				 comp->maxState * 4 * sizeof(int));
1823 	if (cur == NULL) {
1824 	    ERROR(NULL, NULL, NULL,
1825 		  "xmlNewStreamCtxt: malloc failed\n");
1826 	    return(-1);
1827 	}
1828 	comp->states = cur;
1829         comp->maxState *= 2;
1830     }
1831     comp->states[2 * comp->nbState] = idx;
1832     comp->states[2 * comp->nbState++ + 1] = level;
1833     return(comp->nbState - 1);
1834 }
1835 
1836 /**
1837  * xmlStreamPushInternal:
1838  * @stream: the stream context
1839  * @name: the current name
1840  * @ns: the namespace name
1841  * @nodeType: the type of the node
1842  *
1843  * Push new data onto the stream. NOTE: if the call xmlPatterncompile()
1844  * indicated a dictionary, then strings for name and ns will be expected
1845  * to come from the dictionary.
1846  * Both @name and @ns being NULL means the / i.e. the root of the document.
1847  * This can also act as a reset.
1848  *
1849  * Returns: -1 in case of error, 1 if the current state in the stream is a
1850  *    match and 0 otherwise.
1851  */
1852 static int
xmlStreamPushInternal(xmlStreamCtxtPtr stream,const xmlChar * name,const xmlChar * ns,int nodeType)1853 xmlStreamPushInternal(xmlStreamCtxtPtr stream,
1854 		      const xmlChar *name, const xmlChar *ns,
1855 		      int nodeType) {
1856     int ret = 0, err = 0, final = 0, tmp, i, m, match, stepNr, desc;
1857     xmlStreamCompPtr comp;
1858     xmlStreamStep step;
1859 #ifdef DEBUG_STREAMING
1860     xmlStreamCtxtPtr orig = stream;
1861 #endif
1862 
1863     if ((stream == NULL) || (stream->nbState < 0))
1864         return(-1);
1865 
1866     while (stream != NULL) {
1867 	comp = stream->comp;
1868 
1869 	if ((nodeType == XML_ELEMENT_NODE) &&
1870 	    (name == NULL) && (ns == NULL)) {
1871 	    /* We have a document node here (or a reset). */
1872 	    stream->nbState = 0;
1873 	    stream->level = 0;
1874 	    stream->blockLevel = -1;
1875 	    if (comp->flags & XML_STREAM_FROM_ROOT) {
1876 		if (comp->nbStep == 0) {
1877 		    /* TODO: We have a "/." here? */
1878 		    ret = 1;
1879 		} else {
1880 		    if ((comp->nbStep == 1) &&
1881 			(comp->steps[0].nodeType == XML_STREAM_ANY_NODE) &&
1882 			(comp->steps[0].flags & XML_STREAM_STEP_DESC))
1883 		    {
1884 			/*
1885 			* In the case of "//." the document node will match
1886 			* as well.
1887 			*/
1888 			ret = 1;
1889 		    } else if (comp->steps[0].flags & XML_STREAM_STEP_ROOT) {
1890 			/* TODO: Do we need this ? */
1891 			tmp = xmlStreamCtxtAddState(stream, 0, 0);
1892 			if (tmp < 0)
1893 			    err++;
1894 		    }
1895 		}
1896 	    }
1897 	    stream = stream->next;
1898 	    continue; /* while */
1899 	}
1900 
1901 	/*
1902 	* Fast check for ".".
1903 	*/
1904 	if (comp->nbStep == 0) {
1905 	    /*
1906 	     * / and . are handled at the XPath node set creation
1907 	     * level by checking min depth
1908 	     */
1909 	    if (stream->flags & XML_PATTERN_XPATH) {
1910 		stream = stream->next;
1911 		continue; /* while */
1912 	    }
1913 	    /*
1914 	    * For non-pattern like evaluation like XML Schema IDCs
1915 	    * or traditional XPath expressions, this will match if
1916 	    * we are at the first level only, otherwise on every level.
1917 	    */
1918 	    if ((nodeType != XML_ATTRIBUTE_NODE) &&
1919 		(((stream->flags & XML_PATTERN_NOTPATTERN) == 0) ||
1920 		(stream->level == 0))) {
1921 		    ret = 1;
1922 	    }
1923 	    stream->level++;
1924 	    goto stream_next;
1925 	}
1926 	if (stream->blockLevel != -1) {
1927 	    /*
1928 	    * Skip blocked expressions.
1929 	    */
1930     	    stream->level++;
1931 	    goto stream_next;
1932 	}
1933 
1934 	if ((nodeType != XML_ELEMENT_NODE) &&
1935 	    (nodeType != XML_ATTRIBUTE_NODE) &&
1936 	    ((comp->flags & XML_STREAM_FINAL_IS_ANY_NODE) == 0)) {
1937 	    /*
1938 	    * No need to process nodes of other types if we don't
1939 	    * resolve to those types.
1940 	    * TODO: Do we need to block the context here?
1941 	    */
1942 	    stream->level++;
1943 	    goto stream_next;
1944 	}
1945 
1946 	/*
1947 	 * Check evolution of existing states
1948 	 */
1949 	i = 0;
1950 	m = stream->nbState;
1951 	while (i < m) {
1952 	    if ((comp->flags & XML_STREAM_DESC) == 0) {
1953 		/*
1954 		* If there is no "//", then only the last
1955 		* added state is of interest.
1956 		*/
1957 		stepNr = stream->states[2 * (stream->nbState -1)];
1958 		/*
1959 		* TODO: Security check, should not happen, remove it.
1960 		*/
1961 		if (stream->states[(2 * (stream->nbState -1)) + 1] <
1962 		    stream->level) {
1963 		    return (-1);
1964 		}
1965 		desc = 0;
1966 		/* loop-stopper */
1967 		i = m;
1968 	    } else {
1969 		/*
1970 		* If there are "//", then we need to process every "//"
1971 		* occuring in the states, plus any other state for this
1972 		* level.
1973 		*/
1974 		stepNr = stream->states[2 * i];
1975 
1976 		/* TODO: should not happen anymore: dead states */
1977 		if (stepNr < 0)
1978 		    goto next_state;
1979 
1980 		tmp = stream->states[(2 * i) + 1];
1981 
1982 		/* skip new states just added */
1983 		if (tmp > stream->level)
1984 		    goto next_state;
1985 
1986 		/* skip states at ancestor levels, except if "//" */
1987 		desc = comp->steps[stepNr].flags & XML_STREAM_STEP_DESC;
1988 		if ((tmp < stream->level) && (!desc))
1989 		    goto next_state;
1990 	    }
1991 	    /*
1992 	    * Check for correct node-type.
1993 	    */
1994 	    step = comp->steps[stepNr];
1995 	    if (step.nodeType != nodeType) {
1996 		if (step.nodeType == XML_ATTRIBUTE_NODE) {
1997 		    /*
1998 		    * Block this expression for deeper evaluation.
1999 		    */
2000 		    if ((comp->flags & XML_STREAM_DESC) == 0)
2001 			stream->blockLevel = stream->level +1;
2002 		    goto next_state;
2003 		} else if (step.nodeType != XML_STREAM_ANY_NODE)
2004 		    goto next_state;
2005 	    }
2006 	    /*
2007 	    * Compare local/namespace-name.
2008 	    */
2009 	    match = 0;
2010 	    if (step.nodeType == XML_STREAM_ANY_NODE) {
2011 		match = 1;
2012 	    } else if (step.name == NULL) {
2013 		if (step.ns == NULL) {
2014 		    /*
2015 		    * This lets through all elements/attributes.
2016 		    */
2017 		    match = 1;
2018 		} else if (ns != NULL)
2019 		    match = xmlStrEqual(step.ns, ns);
2020 	    } else if (((step.ns != NULL) == (ns != NULL)) &&
2021 		(name != NULL) &&
2022 		(step.name[0] == name[0]) &&
2023 		xmlStrEqual(step.name, name) &&
2024 		((step.ns == ns) || xmlStrEqual(step.ns, ns)))
2025 	    {
2026 		match = 1;
2027 	    }
2028 #if 0
2029 /*
2030 * TODO: Pointer comparison won't work, since not guaranteed that the given
2031 *  values are in the same dict; especially if it's the namespace name,
2032 *  normally coming from ns->href. We need a namespace dict mechanism !
2033 */
2034 	    } else if (comp->dict) {
2035 		if (step.name == NULL) {
2036 		    if (step.ns == NULL)
2037 			match = 1;
2038 		    else
2039 			match = (step.ns == ns);
2040 		} else {
2041 		    match = ((step.name == name) && (step.ns == ns));
2042 		}
2043 #endif /* if 0 ------------------------------------------------------- */
2044 	    if (match) {
2045 		final = step.flags & XML_STREAM_STEP_FINAL;
2046 		if (desc) {
2047 		    if (final) {
2048 			ret = 1;
2049 		    } else {
2050 			/* descending match create a new state */
2051 			xmlStreamCtxtAddState(stream, stepNr + 1,
2052 			                      stream->level + 1);
2053 		    }
2054 		} else {
2055 		    if (final) {
2056 			ret = 1;
2057 		    } else {
2058 			xmlStreamCtxtAddState(stream, stepNr + 1,
2059 			                      stream->level + 1);
2060 		    }
2061 		}
2062 		if ((ret != 1) && (step.flags & XML_STREAM_STEP_IN_SET)) {
2063 		    /*
2064 		    * Check if we have a special case like "foo/bar//.", where
2065 		    * "foo" is selected as well.
2066 		    */
2067 		    ret = 1;
2068 		}
2069 	    }
2070 	    if (((comp->flags & XML_STREAM_DESC) == 0) &&
2071 		((! match) || final))  {
2072 		/*
2073 		* Mark this expression as blocked for any evaluation at
2074 		* deeper levels. Note that this includes "/foo"
2075 		* expressions if the *pattern* behaviour is used.
2076 		*/
2077 		stream->blockLevel = stream->level +1;
2078 	    }
2079 next_state:
2080 	    i++;
2081 	}
2082 
2083 	stream->level++;
2084 
2085 	/*
2086 	* Re/enter the expression.
2087 	* Don't reenter if it's an absolute expression like "/foo",
2088 	*   except "//foo".
2089 	*/
2090 	step = comp->steps[0];
2091 	if (step.flags & XML_STREAM_STEP_ROOT)
2092 	    goto stream_next;
2093 
2094 	desc = step.flags & XML_STREAM_STEP_DESC;
2095 	if (stream->flags & XML_PATTERN_NOTPATTERN) {
2096 	    /*
2097 	    * Re/enter the expression if it is a "descendant" one,
2098 	    * or if we are at the 1st level of evaluation.
2099 	    */
2100 
2101 	    if (stream->level == 1) {
2102 		if (XML_STREAM_XS_IDC(stream)) {
2103 		    /*
2104 		    * XS-IDC: The missing "self::node()" will always
2105 		    * match the first given node.
2106 		    */
2107 		    goto stream_next;
2108 		} else
2109 		    goto compare;
2110 	    }
2111 	    /*
2112 	    * A "//" is always reentrant.
2113 	    */
2114 	    if (desc)
2115 		goto compare;
2116 
2117 	    /*
2118 	    * XS-IDC: Process the 2nd level, since the missing
2119 	    * "self::node()" is responsible for the 2nd level being
2120 	    * the real start level.
2121 	    */
2122 	    if ((stream->level == 2) && XML_STREAM_XS_IDC(stream))
2123 		goto compare;
2124 
2125 	    goto stream_next;
2126 	}
2127 
2128 compare:
2129 	/*
2130 	* Check expected node-type.
2131 	*/
2132 	if (step.nodeType != nodeType) {
2133 	    if (nodeType == XML_ATTRIBUTE_NODE)
2134 		goto stream_next;
2135 	    else if (step.nodeType != XML_STREAM_ANY_NODE)
2136 		goto stream_next;
2137 	}
2138 	/*
2139 	* Compare local/namespace-name.
2140 	*/
2141 	match = 0;
2142 	if (step.nodeType == XML_STREAM_ANY_NODE) {
2143 	    match = 1;
2144 	} else if (step.name == NULL) {
2145 	    if (step.ns == NULL) {
2146 		/*
2147 		* This lets through all elements/attributes.
2148 		*/
2149 		match = 1;
2150 	    } else if (ns != NULL)
2151 		match = xmlStrEqual(step.ns, ns);
2152 	} else if (((step.ns != NULL) == (ns != NULL)) &&
2153 	    (name != NULL) &&
2154 	    (step.name[0] == name[0]) &&
2155 	    xmlStrEqual(step.name, name) &&
2156 	    ((step.ns == ns) || xmlStrEqual(step.ns, ns)))
2157 	{
2158 	    match = 1;
2159 	}
2160 	final = step.flags & XML_STREAM_STEP_FINAL;
2161 	if (match) {
2162 	    if (final)
2163 		ret = 1;
2164 	    else
2165 		xmlStreamCtxtAddState(stream, 1, stream->level);
2166 	    if ((ret != 1) && (step.flags & XML_STREAM_STEP_IN_SET)) {
2167 		/*
2168 		* Check if we have a special case like "foo//.", where
2169 		* "foo" is selected as well.
2170 		*/
2171 		ret = 1;
2172 	    }
2173 	}
2174 	if (((comp->flags & XML_STREAM_DESC) == 0) &&
2175 	    ((! match) || final))  {
2176 	    /*
2177 	    * Mark this expression as blocked for any evaluation at
2178 	    * deeper levels.
2179 	    */
2180 	    stream->blockLevel = stream->level;
2181 	}
2182 
2183 stream_next:
2184         stream = stream->next;
2185     } /* while stream != NULL */
2186 
2187     if (err > 0)
2188         ret = -1;
2189 #ifdef DEBUG_STREAMING
2190     xmlDebugStreamCtxt(orig, ret);
2191 #endif
2192     return(ret);
2193 }
2194 
2195 /**
2196  * xmlStreamPush:
2197  * @stream: the stream context
2198  * @name: the current name
2199  * @ns: the namespace name
2200  *
2201  * Push new data onto the stream. NOTE: if the call xmlPatterncompile()
2202  * indicated a dictionary, then strings for name and ns will be expected
2203  * to come from the dictionary.
2204  * Both @name and @ns being NULL means the / i.e. the root of the document.
2205  * This can also act as a reset.
2206  * Otherwise the function will act as if it has been given an element-node.
2207  *
2208  * Returns: -1 in case of error, 1 if the current state in the stream is a
2209  *    match and 0 otherwise.
2210  */
2211 int
xmlStreamPush(xmlStreamCtxtPtr stream,const xmlChar * name,const xmlChar * ns)2212 xmlStreamPush(xmlStreamCtxtPtr stream,
2213               const xmlChar *name, const xmlChar *ns) {
2214     return (xmlStreamPushInternal(stream, name, ns, (int) XML_ELEMENT_NODE));
2215 }
2216 
2217 /**
2218  * xmlStreamPushNode:
2219  * @stream: the stream context
2220  * @name: the current name
2221  * @ns: the namespace name
2222  * @nodeType: the type of the node being pushed
2223  *
2224  * Push new data onto the stream. NOTE: if the call xmlPatterncompile()
2225  * indicated a dictionary, then strings for name and ns will be expected
2226  * to come from the dictionary.
2227  * Both @name and @ns being NULL means the / i.e. the root of the document.
2228  * This can also act as a reset.
2229  * Different from xmlStreamPush() this function can be fed with nodes of type:
2230  * element-, attribute-, text-, cdata-section-, comment- and
2231  * processing-instruction-node.
2232  *
2233  * Returns: -1 in case of error, 1 if the current state in the stream is a
2234  *    match and 0 otherwise.
2235  */
2236 int
xmlStreamPushNode(xmlStreamCtxtPtr stream,const xmlChar * name,const xmlChar * ns,int nodeType)2237 xmlStreamPushNode(xmlStreamCtxtPtr stream,
2238 		  const xmlChar *name, const xmlChar *ns,
2239 		  int nodeType)
2240 {
2241     return (xmlStreamPushInternal(stream, name, ns,
2242 	nodeType));
2243 }
2244 
2245 /**
2246 * xmlStreamPushAttr:
2247 * @stream: the stream context
2248 * @name: the current name
2249 * @ns: the namespace name
2250 *
2251 * Push new attribute data onto the stream. NOTE: if the call xmlPatterncompile()
2252 * indicated a dictionary, then strings for name and ns will be expected
2253 * to come from the dictionary.
2254 * Both @name and @ns being NULL means the / i.e. the root of the document.
2255 * This can also act as a reset.
2256 * Otherwise the function will act as if it has been given an attribute-node.
2257 *
2258 * Returns: -1 in case of error, 1 if the current state in the stream is a
2259 *    match and 0 otherwise.
2260 */
2261 int
xmlStreamPushAttr(xmlStreamCtxtPtr stream,const xmlChar * name,const xmlChar * ns)2262 xmlStreamPushAttr(xmlStreamCtxtPtr stream,
2263 		  const xmlChar *name, const xmlChar *ns) {
2264     return (xmlStreamPushInternal(stream, name, ns, (int) XML_ATTRIBUTE_NODE));
2265 }
2266 
2267 /**
2268  * xmlStreamPop:
2269  * @stream: the stream context
2270  *
2271  * push one level from the stream.
2272  *
2273  * Returns: -1 in case of error, 0 otherwise.
2274  */
2275 int
xmlStreamPop(xmlStreamCtxtPtr stream)2276 xmlStreamPop(xmlStreamCtxtPtr stream) {
2277     int i, lev;
2278 
2279     if (stream == NULL)
2280         return(-1);
2281     while (stream != NULL) {
2282 	/*
2283 	* Reset block-level.
2284 	*/
2285 	if (stream->blockLevel == stream->level)
2286 	    stream->blockLevel = -1;
2287 
2288 	/*
2289 	 *  stream->level can be zero when XML_FINAL_IS_ANY_NODE is set
2290 	 *  (see the thread at
2291 	 *  http://mail.gnome.org/archives/xslt/2008-July/msg00027.html)
2292 	 */
2293 	if (stream->level)
2294 	    stream->level--;
2295 	/*
2296 	 * Check evolution of existing states
2297 	 */
2298 	for (i = stream->nbState -1; i >= 0; i--) {
2299 	    /* discard obsoleted states */
2300 	    lev = stream->states[(2 * i) + 1];
2301 	    if (lev > stream->level)
2302 		stream->nbState--;
2303 	    if (lev <= stream->level)
2304 		break;
2305 	}
2306 	stream = stream->next;
2307     }
2308     return(0);
2309 }
2310 
2311 /**
2312  * xmlStreamWantsAnyNode:
2313  * @streamCtxt: the stream context
2314  *
2315  * Query if the streaming pattern additionally needs to be fed with
2316  * text-, cdata-section-, comment- and processing-instruction-nodes.
2317  * If the result is 0 then only element-nodes and attribute-nodes
2318  * need to be pushed.
2319  *
2320  * Returns: 1 in case of need of nodes of the above described types,
2321  *          0 otherwise. -1 on API errors.
2322  */
2323 int
xmlStreamWantsAnyNode(xmlStreamCtxtPtr streamCtxt)2324 xmlStreamWantsAnyNode(xmlStreamCtxtPtr streamCtxt)
2325 {
2326     if (streamCtxt == NULL)
2327 	return(-1);
2328     while (streamCtxt != NULL) {
2329 	if (streamCtxt->comp->flags & XML_STREAM_FINAL_IS_ANY_NODE)
2330 	    return(1);
2331 	streamCtxt = streamCtxt->next;
2332     }
2333     return(0);
2334 }
2335 
2336 /************************************************************************
2337  *									*
2338  *			The public interfaces				*
2339  *									*
2340  ************************************************************************/
2341 
2342 /**
2343  * xmlPatterncompile:
2344  * @pattern: the pattern to compile
2345  * @dict: an optional dictionary for interned strings
2346  * @flags: compilation flags, see xmlPatternFlags
2347  * @namespaces: the prefix definitions, array of [URI, prefix] or NULL
2348  *
2349  * Compile a pattern.
2350  *
2351  * Returns the compiled form of the pattern or NULL in case of error
2352  */
2353 xmlPatternPtr
xmlPatterncompile(const xmlChar * pattern,xmlDict * dict,int flags,const xmlChar ** namespaces)2354 xmlPatterncompile(const xmlChar *pattern, xmlDict *dict, int flags,
2355                   const xmlChar **namespaces) {
2356     xmlPatternPtr ret = NULL, cur;
2357     xmlPatParserContextPtr ctxt = NULL;
2358     const xmlChar *or, *start;
2359     xmlChar *tmp = NULL;
2360     int type = 0;
2361     int streamable = 1;
2362 
2363     if (pattern == NULL)
2364         return(NULL);
2365 
2366     start = pattern;
2367     or = start;
2368     while (*or != 0) {
2369 	tmp = NULL;
2370 	while ((*or != 0) && (*or != '|')) or++;
2371         if (*or == 0)
2372 	    ctxt = xmlNewPatParserContext(start, dict, namespaces);
2373 	else {
2374 	    tmp = xmlStrndup(start, or - start);
2375 	    if (tmp != NULL) {
2376 		ctxt = xmlNewPatParserContext(tmp, dict, namespaces);
2377 	    }
2378 	    or++;
2379 	}
2380 	if (ctxt == NULL) goto error;
2381 	cur = xmlNewPattern();
2382 	if (cur == NULL) goto error;
2383 	/*
2384 	* Assign string dict.
2385 	*/
2386 	if (dict) {
2387 	    cur->dict = dict;
2388 	    xmlDictReference(dict);
2389 	}
2390 	if (ret == NULL)
2391 	    ret = cur;
2392 	else {
2393 	    cur->next = ret->next;
2394 	    ret->next = cur;
2395 	}
2396 	cur->flags = flags;
2397 	ctxt->comp = cur;
2398 
2399 	if (XML_STREAM_XS_IDC(cur))
2400 	    xmlCompileIDCXPathPath(ctxt);
2401 	else
2402 	    xmlCompilePathPattern(ctxt);
2403 	if (ctxt->error != 0)
2404 	    goto error;
2405 	xmlFreePatParserContext(ctxt);
2406 	ctxt = NULL;
2407 
2408 
2409         if (streamable) {
2410 	    if (type == 0) {
2411 	        type = cur->flags & (PAT_FROM_ROOT | PAT_FROM_CUR);
2412 	    } else if (type == PAT_FROM_ROOT) {
2413 	        if (cur->flags & PAT_FROM_CUR)
2414 		    streamable = 0;
2415 	    } else if (type == PAT_FROM_CUR) {
2416 	        if (cur->flags & PAT_FROM_ROOT)
2417 		    streamable = 0;
2418 	    }
2419 	}
2420 	if (streamable)
2421 	    xmlStreamCompile(cur);
2422 	if (xmlReversePattern(cur) < 0)
2423 	    goto error;
2424 	if (tmp != NULL) {
2425 	    xmlFree(tmp);
2426 	    tmp = NULL;
2427 	}
2428 	start = or;
2429     }
2430     if (streamable == 0) {
2431         cur = ret;
2432 	while (cur != NULL) {
2433 	    if (cur->stream != NULL) {
2434 		xmlFreeStreamComp(cur->stream);
2435 		cur->stream = NULL;
2436 	    }
2437 	    cur = cur->next;
2438 	}
2439     }
2440 
2441     return(ret);
2442 error:
2443     if (ctxt != NULL) xmlFreePatParserContext(ctxt);
2444     if (ret != NULL) xmlFreePattern(ret);
2445     if (tmp != NULL) xmlFree(tmp);
2446     return(NULL);
2447 }
2448 
2449 /**
2450  * xmlPatternMatch:
2451  * @comp: the precompiled pattern
2452  * @node: a node
2453  *
2454  * Test whether the node matches the pattern
2455  *
2456  * Returns 1 if it matches, 0 if it doesn't and -1 in case of failure
2457  */
2458 int
xmlPatternMatch(xmlPatternPtr comp,xmlNodePtr node)2459 xmlPatternMatch(xmlPatternPtr comp, xmlNodePtr node)
2460 {
2461     int ret = 0;
2462 
2463     if ((comp == NULL) || (node == NULL))
2464         return(-1);
2465 
2466     while (comp != NULL) {
2467         ret = xmlPatMatch(comp, node);
2468 	if (ret != 0)
2469 	    return(ret);
2470 	comp = comp->next;
2471     }
2472     return(ret);
2473 }
2474 
2475 /**
2476  * xmlPatternGetStreamCtxt:
2477  * @comp: the precompiled pattern
2478  *
2479  * Get a streaming context for that pattern
2480  * Use xmlFreeStreamCtxt to free the context.
2481  *
2482  * Returns a pointer to the context or NULL in case of failure
2483  */
2484 xmlStreamCtxtPtr
xmlPatternGetStreamCtxt(xmlPatternPtr comp)2485 xmlPatternGetStreamCtxt(xmlPatternPtr comp)
2486 {
2487     xmlStreamCtxtPtr ret = NULL, cur;
2488 
2489     if ((comp == NULL) || (comp->stream == NULL))
2490         return(NULL);
2491 
2492     while (comp != NULL) {
2493         if (comp->stream == NULL)
2494 	    goto failed;
2495 	cur = xmlNewStreamCtxt(comp->stream);
2496 	if (cur == NULL)
2497 	    goto failed;
2498 	if (ret == NULL)
2499 	    ret = cur;
2500 	else {
2501 	    cur->next = ret->next;
2502 	    ret->next = cur;
2503 	}
2504 	cur->flags = comp->flags;
2505 	comp = comp->next;
2506     }
2507     return(ret);
2508 failed:
2509     xmlFreeStreamCtxt(ret);
2510     return(NULL);
2511 }
2512 
2513 /**
2514  * xmlPatternStreamable:
2515  * @comp: the precompiled pattern
2516  *
2517  * Check if the pattern is streamable i.e. xmlPatternGetStreamCtxt()
2518  * should work.
2519  *
2520  * Returns 1 if streamable, 0 if not and -1 in case of error.
2521  */
2522 int
xmlPatternStreamable(xmlPatternPtr comp)2523 xmlPatternStreamable(xmlPatternPtr comp) {
2524     if (comp == NULL)
2525         return(-1);
2526     while (comp != NULL) {
2527         if (comp->stream == NULL)
2528 	    return(0);
2529 	comp = comp->next;
2530     }
2531     return(1);
2532 }
2533 
2534 /**
2535  * xmlPatternMaxDepth:
2536  * @comp: the precompiled pattern
2537  *
2538  * Check the maximum depth reachable by a pattern
2539  *
2540  * Returns -2 if no limit (using //), otherwise the depth,
2541  *         and -1 in case of error
2542  */
2543 int
xmlPatternMaxDepth(xmlPatternPtr comp)2544 xmlPatternMaxDepth(xmlPatternPtr comp) {
2545     int ret = 0, i;
2546     if (comp == NULL)
2547         return(-1);
2548     while (comp != NULL) {
2549         if (comp->stream == NULL)
2550 	    return(-1);
2551 	for (i = 0;i < comp->stream->nbStep;i++)
2552 	    if (comp->stream->steps[i].flags & XML_STREAM_STEP_DESC)
2553 	        return(-2);
2554 	if (comp->stream->nbStep > ret)
2555 	    ret = comp->stream->nbStep;
2556 	comp = comp->next;
2557     }
2558     return(ret);
2559 }
2560 
2561 /**
2562  * xmlPatternMinDepth:
2563  * @comp: the precompiled pattern
2564  *
2565  * Check the minimum depth reachable by a pattern, 0 mean the / or . are
2566  * part of the set.
2567  *
2568  * Returns -1 in case of error otherwise the depth,
2569  *
2570  */
2571 int
xmlPatternMinDepth(xmlPatternPtr comp)2572 xmlPatternMinDepth(xmlPatternPtr comp) {
2573     int ret = 12345678;
2574     if (comp == NULL)
2575         return(-1);
2576     while (comp != NULL) {
2577         if (comp->stream == NULL)
2578 	    return(-1);
2579 	if (comp->stream->nbStep < ret)
2580 	    ret = comp->stream->nbStep;
2581 	if (ret == 0)
2582 	    return(0);
2583 	comp = comp->next;
2584     }
2585     return(ret);
2586 }
2587 
2588 /**
2589  * xmlPatternFromRoot:
2590  * @comp: the precompiled pattern
2591  *
2592  * Check if the pattern must be looked at from the root.
2593  *
2594  * Returns 1 if true, 0 if false and -1 in case of error
2595  */
2596 int
xmlPatternFromRoot(xmlPatternPtr comp)2597 xmlPatternFromRoot(xmlPatternPtr comp) {
2598     if (comp == NULL)
2599         return(-1);
2600     while (comp != NULL) {
2601         if (comp->stream == NULL)
2602 	    return(-1);
2603 	if (comp->flags & PAT_FROM_ROOT)
2604 	    return(1);
2605 	comp = comp->next;
2606     }
2607     return(0);
2608 
2609 }
2610 
2611 #define bottom_pattern
2612 #include "elfgcchack.h"
2613 #endif /* LIBXML_PATTERN_ENABLED */
2614