dll/3rdparty/libxslt/attrvt.c

   1 /*
   2  * attrvt.c: Implementation of the XSL Transformation 1.0 engine
   3  *           attribute value template handling part.
   4  *
   5  * References:
   6  *   http://www.w3.org/TR/1999/REC-xslt-19991116
   7  *
   8  *   Michael Kay "XSLT Programmer's Reference" pp 637-643
   9  *   Writing Multiple Output Files
  10  *
  11  * See Copyright for the status of this software.
  12  *
  13  * daniel@veillard.com
  14  */
  15
  16 #define IN_LIBXSLT
  17 #include "libxslt.h"
  18
  19 #include <string.h>
  20
  21 #include <libxml/xmlmemory.h>
  22 #include <libxml/tree.h>
  23 #include <libxml/xpath.h>
  24 #include <libxml/xpathInternals.h>
  25 #include "xslt.h"
  26 #include "xsltutils.h"
  27 #include "xsltInternals.h"
  28 #include "templates.h"
  29
  30 #ifdef WITH_XSLT_DEBUG
  31 #define WITH_XSLT_DEBUG_AVT
  32 #endif
  33
  34 #define MAX_AVT_SEG 10
  35
  36 typedef struct _xsltAttrVT xsltAttrVT;
  37 typedef xsltAttrVT *xsltAttrVTPtr;
  38 struct _xsltAttrVT {
  39     struct _xsltAttrVT *next; /* next xsltAttrVT */
  40     int nb_seg;         /* Number of segments */
  41     int max_seg;        /* max capacity before re-alloc needed */
  42     int strstart;       /* is the start a string */
  43     /*
  44      * the namespaces in scope
  45      */
  46     xmlNsPtr *nsList;
  47     int nsNr;
  48     /*
  49      * the content is an alternate of string and xmlXPathCompExprPtr
  50      */
  51     void *segments[MAX_AVT_SEG];
  52 };
  53
  54 /**
  55  * xsltNewAttrVT:
  56  * @style:  a XSLT process context
  57  *
  58  * Build a new xsltAttrVT structure
  59  *
  60  * Returns the structure or NULL in case of error
  61  */
  62 static xsltAttrVTPtr
  63 xsltNewAttrVT(xsltStylesheetPtr style) {
  64     xsltAttrVTPtr cur;
  65
  66     cur = (xsltAttrVTPtr) xmlMalloc(sizeof(xsltAttrVT));
  67     if (cur == NULL) {
  68         xsltTransformError(NULL, style, NULL,
  69                 "xsltNewAttrVTPtr : malloc failed\n");
  70         if (style != NULL) style->errors++;
  71         return(NULL);
  72     }
  73     memset(cur, 0, sizeof(xsltAttrVT));
  74
  75     cur->nb_seg = 0;
  76     cur->max_seg = MAX_AVT_SEG;
  77     cur->strstart = 0;
  78     cur->next = style->attVTs;
  79     /*
  80      * Note: this pointer may be changed by a re-alloc within xsltCompileAttr,
  81      * so that code may change the stylesheet pointer also!
  82      */
  83     style->attVTs = (xsltAttrVTPtr) cur;
  84
  85     return(cur);
  86 }
  87
  88 /**
  89  * xsltFreeAttrVT:
  90  * @avt: pointer to an xsltAttrVT structure
  91  *
  92  * Free up the memory associated to the attribute value template
  93  */
  94 static void
  95 xsltFreeAttrVT(xsltAttrVTPtr avt) {
  96     int i;
  97
  98     if (avt == NULL) return;
  99
 100     if (avt->strstart == 1) {
 101         for (i = 0;i < avt->nb_seg; i += 2)
 102             if (avt->segments[i] != NULL)
 103                 xmlFree((xmlChar *) avt->segments[i]);
 104         for (i = 1;i < avt->nb_seg; i += 2)
 105             xmlXPathFreeCompExpr((xmlXPathCompExprPtr) avt->segments[i]);
 106     } else {
 107         for (i = 0;i < avt->nb_seg; i += 2)
 108             xmlXPathFreeCompExpr((xmlXPathCompExprPtr) avt->segments[i]);
 109         for (i = 1;i < avt->nb_seg; i += 2)
 110             if (avt->segments[i] != NULL)
 111                 xmlFree((xmlChar *) avt->segments[i]);
 112     }
 113     if (avt->nsList != NULL)
 114         xmlFree(avt->nsList);
 115     xmlFree(avt);
 116 }
 117
 118 /**
 119  * xsltFreeAVTList:
 120  * @avt: pointer to an list of AVT structures
 121  *
 122  * Free up the memory associated to the attribute value templates
 123  */
 124 void
 125 xsltFreeAVTList(void *avt) {
 126     xsltAttrVTPtr cur = (xsltAttrVTPtr) avt, next;
 127
 128     while (cur != NULL) {
 129         next = cur->next;
 130         xsltFreeAttrVT(cur);
 131         cur = next;
 132     }
 133 }
 134 /**
 135  * xsltSetAttrVTsegment:
 136  * @ avt: pointer to an xsltAttrVT structure
 137  * @ val: the value to be set to the next available segment
 138  *
 139  * Within xsltCompileAttr there are several places where a value
 140  * needs to be added to the 'segments' array within the xsltAttrVT
 141  * structure, and at each place the allocated size may have to be
 142  * re-allocated.  This routine takes care of that situation.
 143  *
 144  * Returns the avt pointer, which may have been changed by a re-alloc
 145  */
 146 static xsltAttrVTPtr
 147 xsltSetAttrVTsegment(xsltAttrVTPtr avt, void *val) {
 148     if (avt->nb_seg >= avt->max_seg) {
 149         avt = (xsltAttrVTPtr) xmlRealloc(avt, sizeof(xsltAttrVT) +
 150                         avt->max_seg * sizeof(void *));
 151         if (avt == NULL) {
 152             return NULL;
 153         }
 154         memset(&avt->segments[avt->nb_seg], 0, MAX_AVT_SEG*sizeof(void *));
 155         avt->max_seg += MAX_AVT_SEG;
 156     }
 157     avt->segments[avt->nb_seg++] = val;
 158     return avt;
 159 }
 160
 161 /**
 162  * xsltCompileAttr:
 163  * @style:  a XSLT process context
 164  * @attr: the attribute coming from the stylesheet.
 165  *
 166  * Precompile an attribute in a stylesheet, basically it checks if it is
 167  * an attrubute value template, and if yes establish some structures needed
 168  * to process it at transformation time.
 169  */
 170 void
 171 xsltCompileAttr(xsltStylesheetPtr style, xmlAttrPtr attr) {
 172     const xmlChar *str;
 173     const xmlChar *cur;
 174     xmlChar *ret = NULL;
 175     xmlChar *expr = NULL;
 176     xsltAttrVTPtr avt;
 177     int i = 0, lastavt = 0;
 178
 179     if ((style == NULL) || (attr == NULL) || (attr->children == NULL))
 180         return;
 181     if ((attr->children->type != XML_TEXT_NODE) ||
 182         (attr->children->next != NULL)) {
 183         xsltTransformError(NULL, style, attr->parent,
 184             "Attribute '%s': The content is expected to be a single text "
 185             "node when compiling an AVT.\n", attr->name);
 186         style->errors++;
 187         return;
 188     }
 189     str = attr->children->content;
 190     if ((xmlStrchr(str, '{') == NULL) &&
 191         (xmlStrchr(str, '}') == NULL)) return;
 192
 193 #ifdef WITH_XSLT_DEBUG_AVT
 194     xsltGenericDebug(xsltGenericDebugContext,
 195                     "Found AVT %s: %s\n", attr->name, str);
 196 #endif
 197     if (attr->psvi != NULL) {
 198 #ifdef WITH_XSLT_DEBUG_AVT
 199         xsltGenericDebug(xsltGenericDebugContext,
 200                         "AVT %s: already compiled\n", attr->name);
 201 #endif
 202         return;
 203     }
 204     /*
 205     * Create a new AVT object.
 206     */
 207     avt = xsltNewAttrVT(style);
 208     if (avt == NULL)
 209         return;
 210     attr->psvi = avt;
 211
 212     avt->nsList = xmlGetNsList(attr->doc, attr->parent);
 213     if (avt->nsList != NULL) {
 214         while (avt->nsList[i] != NULL)
 215             i++;
 216     }
 217     avt->nsNr = i;
 218
 219     cur = str;
 220     while (*cur != 0) {
 221         if (*cur == '{') {
 222             if (*(cur+1) == '{') {      /* escaped '{' */
 223                 cur++;
 224                 ret = xmlStrncat(ret, str, cur - str);
 225                 cur++;
 226                 str = cur;
 227                 continue;
 228             }
 229             if (*(cur+1) == '}') {      /* skip empty AVT */
 230                 ret = xmlStrncat(ret, str, cur - str);
 231                 cur += 2;
 232                 str = cur;
 233                 continue;
 234             }
 235             if ((ret != NULL) || (cur - str > 0)) {
 236                 ret = xmlStrncat(ret, str, cur - str);
 237                 str = cur;
 238                 if (avt->nb_seg == 0)
 239                     avt->strstart = 1;
 240                 if ((avt = xsltSetAttrVTsegment(avt, (void *) ret)) == NULL)
 241                     goto error;
 242                 ret = NULL;
 243                 lastavt = 0;
 244             }
 245
 246             cur++;
 247             while ((*cur != 0) && (*cur != '}')) {
 248                 /* Need to check for literal (bug539741) */
 249                 if ((*cur == '\'') || (*cur == '"')) {
 250                     char delim = *(cur++);
 251                     while ((*cur != 0) && (*cur != delim))
 252                         cur++;
 253                     if (*cur != 0)
 254                         cur++;  /* skip the ending delimiter */
 255                 } else
 256                     cur++;
 257             }
 258             if (*cur == 0) {
 259                 xsltTransformError(NULL, style, attr->parent,
 260                      "Attribute '%s': The AVT has an unmatched '{'.\n",
 261                      attr->name);
 262                 style->errors++;
 263                 goto error;
 264             }
 265             str++;
 266             expr = xmlStrndup(str, cur - str);
 267             if (expr == NULL) {
 268                 /*
 269                 * TODO: What needs to be done here?
 270                 */
 271                 XSLT_TODO
 272                 goto error;
 273             } else {
 274                 xmlXPathCompExprPtr comp;
 275
 276                 comp = xsltXPathCompile(style, expr);
 277                 if (comp == NULL) {
 278                     xsltTransformError(NULL, style, attr->parent,
 279                          "Attribute '%s': Failed to compile the expression "
 280                          "'%s' in the AVT.\n", attr->name, expr);
 281                     style->errors++;
 282                     goto error;
 283                 }
 284                 if (avt->nb_seg == 0)
 285                     avt->strstart = 0;
 286                 if (lastavt == 1) {
 287                     if ((avt = xsltSetAttrVTsegment(avt, NULL)) == NULL)
 288                         goto error;
 289                 }
 290                 if ((avt = xsltSetAttrVTsegment(avt, (void *) comp)) == NULL)
 291                     goto error;
 292                 lastavt = 1;
 293                 xmlFree(expr);
 294                 expr = NULL;
 295             }
 296             cur++;
 297             str = cur;
 298         } else if (*cur == '}') {
 299             cur++;
 300             if (*cur == '}') {  /* escaped '}' */
 301                 ret = xmlStrncat(ret, str, cur - str);
 302                 cur++;
 303                 str = cur;
 304                 continue;
 305             } else {
 306                 xsltTransformError(NULL, style, attr->parent,
 307                      "Attribute '%s': The AVT has an unmatched '}'.\n",
 308                      attr->name);
 309                 goto error;
 310             }
 311         } else
 312             cur++;
 313     }
 314     if ((ret != NULL) || (cur - str > 0)) {
 315         ret = xmlStrncat(ret, str, cur - str);
 316         str = cur;
 317         if (avt->nb_seg == 0)
 318             avt->strstart = 1;
 319         if ((avt = xsltSetAttrVTsegment(avt, (void *) ret)) == NULL)
 320             goto error;
 321         ret = NULL;
 322     }
 323
 324 error:
 325     if (avt == NULL) {
 326         xsltTransformError(NULL, style, attr->parent,
 327                 "xsltCompileAttr: malloc problem\n");
 328     } else {
 329         if (attr->psvi != avt) {  /* may have changed from realloc */
 330             attr->psvi = avt;
 331             /*
 332              * This is a "hack", but I can't see any clean method of
 333              * doing it.  If a re-alloc has taken place, then the pointer
 334              * for this AVT may have changed.  style->attVTs was set by
 335              * xsltNewAttrVT, so it needs to be re-set to the new value!
 336              */
 337             style->attVTs = avt;
 338         }
 339     }
 340     if (ret != NULL)
 341         xmlFree(ret);
 342     if (expr != NULL)
 343         xmlFree(expr);
 344 }
 345
 346
 347 /**
 348  * xsltEvalAVT:
 349  * @ctxt: the XSLT transformation context
 350  * @avt: the prevompiled attribute value template info
 351  * @node: the node hosting the attribute
 352  *
 353  * Process the given AVT, and return the new string value.
 354  *
 355  * Returns the computed string value or NULL, must be deallocated by the
 356  *         caller.
 357  */
 358 xmlChar *
 359 xsltEvalAVT(xsltTransformContextPtr ctxt, void *avt, xmlNodePtr node) {
 360     xmlChar *ret = NULL, *tmp;
 361     xmlXPathCompExprPtr comp;
 362     xsltAttrVTPtr cur = (xsltAttrVTPtr) avt;
 363     int i;
 364     int str;
 365
 366     if ((ctxt == NULL) || (avt == NULL) || (node == NULL))
 367         return(NULL);
 368     str = cur->strstart;
 369     for (i = 0;i < cur->nb_seg;i++) {
 370         if (str) {
 371             ret = xmlStrcat(ret, (const xmlChar *) cur->segments[i]);
 372         } else {
 373             comp = (xmlXPathCompExprPtr) cur->segments[i];
 374             tmp = xsltEvalXPathStringNs(ctxt, comp, cur->nsNr, cur->nsList);
 375             if (tmp != NULL) {
 376                 if (ret != NULL) {
 377                     ret = xmlStrcat(ret, tmp);
 378                     xmlFree(tmp);
 379                 } else {
 380                     ret = tmp;
 381                 }
 382             }
 383         }
 384         str = !str;
 385     }
 386     return(ret);
 387 }