xml-support.c revision 1.5
1/* Helper routines for parsing XML using Expat. 2 3 Copyright (C) 2006-2015 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20#include "defs.h" 21#include "gdbcmd.h" 22#include "xml-support.h" 23#include "filestuff.h" 24#include "safe-ctype.h" 25 26/* Debugging flag. */ 27static int debug_xml; 28 29/* The contents of this file are only useful if XML support is 30 available. */ 31#ifdef HAVE_LIBEXPAT 32 33#include "gdb_expat.h" 34 35/* The maximum depth of <xi:include> nesting. No need to be miserly, 36 we just want to avoid running out of stack on loops. */ 37#define MAX_XINCLUDE_DEPTH 30 38 39/* Simplified XML parser infrastructure. */ 40 41/* A parsing level -- used to keep track of the current element 42 nesting. */ 43struct scope_level 44{ 45 /* Elements we allow at this level. */ 46 const struct gdb_xml_element *elements; 47 48 /* The element which we are within. */ 49 const struct gdb_xml_element *element; 50 51 /* Mask of which elements we've seen at this level (used for 52 optional and repeatable checking). */ 53 unsigned int seen; 54 55 /* Body text accumulation. */ 56 struct obstack *body; 57}; 58typedef struct scope_level scope_level_s; 59DEF_VEC_O(scope_level_s); 60 61/* The parser itself, and our additional state. */ 62struct gdb_xml_parser 63{ 64 XML_Parser expat_parser; /* The underlying expat parser. */ 65 66 const char *name; /* Name of this parser. */ 67 void *user_data; /* The user's callback data, for handlers. */ 68 69 VEC(scope_level_s) *scopes; /* Scoping stack. */ 70 71 struct gdb_exception error; /* A thrown error, if any. */ 72 int last_line; /* The line of the thrown error, or 0. */ 73 74 const char *dtd_name; /* The name of the expected / default DTD, 75 if specified. */ 76 int is_xinclude; /* Are we the special <xi:include> parser? */ 77}; 78 79/* Process some body text. We accumulate the text for later use; it's 80 wrong to do anything with it immediately, because a single block of 81 text might be broken up into multiple calls to this function. */ 82 83static void 84gdb_xml_body_text (void *data, const XML_Char *text, int length) 85{ 86 struct gdb_xml_parser *parser = data; 87 struct scope_level *scope = VEC_last (scope_level_s, parser->scopes); 88 89 if (parser->error.reason < 0) 90 return; 91 92 if (scope->body == NULL) 93 { 94 scope->body = XCNEW (struct obstack); 95 obstack_init (scope->body); 96 } 97 98 obstack_grow (scope->body, text, length); 99} 100 101/* Issue a debugging message from one of PARSER's handlers. */ 102 103void 104gdb_xml_debug (struct gdb_xml_parser *parser, const char *format, ...) 105{ 106 int line = XML_GetCurrentLineNumber (parser->expat_parser); 107 va_list ap; 108 char *message; 109 110 if (!debug_xml) 111 return; 112 113 va_start (ap, format); 114 message = xstrvprintf (format, ap); 115 if (line) 116 fprintf_unfiltered (gdb_stderr, "%s (line %d): %s\n", 117 parser->name, line, message); 118 else 119 fprintf_unfiltered (gdb_stderr, "%s: %s\n", 120 parser->name, message); 121 xfree (message); 122} 123 124/* Issue an error message from one of PARSER's handlers, and stop 125 parsing. */ 126 127void 128gdb_xml_error (struct gdb_xml_parser *parser, const char *format, ...) 129{ 130 int line = XML_GetCurrentLineNumber (parser->expat_parser); 131 va_list ap; 132 133 parser->last_line = line; 134 va_start (ap, format); 135 throw_verror (XML_PARSE_ERROR, format, ap); 136} 137 138/* Find the attribute named NAME in the set of parsed attributes 139 ATTRIBUTES. Returns NULL if not found. */ 140 141struct gdb_xml_value * 142xml_find_attribute (VEC(gdb_xml_value_s) *attributes, const char *name) 143{ 144 struct gdb_xml_value *value; 145 int ix; 146 147 for (ix = 0; VEC_iterate (gdb_xml_value_s, attributes, ix, value); ix++) 148 if (strcmp (value->name, name) == 0) 149 return value; 150 151 return NULL; 152} 153 154/* Clean up a vector of parsed attribute values. */ 155 156static void 157gdb_xml_values_cleanup (void *data) 158{ 159 VEC(gdb_xml_value_s) **values = data; 160 struct gdb_xml_value *value; 161 int ix; 162 163 for (ix = 0; VEC_iterate (gdb_xml_value_s, *values, ix, value); ix++) 164 xfree (value->value); 165 VEC_free (gdb_xml_value_s, *values); 166} 167 168/* Handle the start of an element. DATA is our local XML parser, NAME 169 is the element, and ATTRS are the names and values of this 170 element's attributes. */ 171 172static void 173gdb_xml_start_element (void *data, const XML_Char *name, 174 const XML_Char **attrs) 175{ 176 struct gdb_xml_parser *parser = data; 177 struct scope_level *scope; 178 struct scope_level new_scope; 179 const struct gdb_xml_element *element; 180 const struct gdb_xml_attribute *attribute; 181 VEC(gdb_xml_value_s) *attributes = NULL; 182 unsigned int seen; 183 struct cleanup *back_to; 184 185 /* Push an error scope. If we return or throw an exception before 186 filling this in, it will tell us to ignore children of this 187 element. */ 188 VEC_reserve (scope_level_s, parser->scopes, 1); 189 scope = VEC_last (scope_level_s, parser->scopes); 190 memset (&new_scope, 0, sizeof (new_scope)); 191 VEC_quick_push (scope_level_s, parser->scopes, &new_scope); 192 193 gdb_xml_debug (parser, _("Entering element <%s>"), name); 194 195 /* Find this element in the list of the current scope's allowed 196 children. Record that we've seen it. */ 197 198 seen = 1; 199 for (element = scope->elements; element && element->name; 200 element++, seen <<= 1) 201 if (strcmp (element->name, name) == 0) 202 break; 203 204 if (element == NULL || element->name == NULL) 205 { 206 /* If we're working on XInclude, <xi:include> can be the child 207 of absolutely anything. Copy the previous scope's element 208 list into the new scope even if there was no match. */ 209 if (parser->is_xinclude) 210 { 211 struct scope_level *unknown_scope; 212 213 XML_DefaultCurrent (parser->expat_parser); 214 215 unknown_scope = VEC_last (scope_level_s, parser->scopes); 216 unknown_scope->elements = scope->elements; 217 return; 218 } 219 220 gdb_xml_debug (parser, _("Element <%s> unknown"), name); 221 return; 222 } 223 224 if (!(element->flags & GDB_XML_EF_REPEATABLE) && (seen & scope->seen)) 225 gdb_xml_error (parser, _("Element <%s> only expected once"), name); 226 227 scope->seen |= seen; 228 229 back_to = make_cleanup (gdb_xml_values_cleanup, &attributes); 230 231 for (attribute = element->attributes; 232 attribute != NULL && attribute->name != NULL; 233 attribute++) 234 { 235 const char *val = NULL; 236 const XML_Char **p; 237 void *parsed_value; 238 struct gdb_xml_value new_value; 239 240 for (p = attrs; *p != NULL; p += 2) 241 if (!strcmp (attribute->name, p[0])) 242 { 243 val = p[1]; 244 break; 245 } 246 247 if (*p != NULL && val == NULL) 248 { 249 gdb_xml_debug (parser, _("Attribute \"%s\" missing a value"), 250 attribute->name); 251 continue; 252 } 253 254 if (*p == NULL && !(attribute->flags & GDB_XML_AF_OPTIONAL)) 255 { 256 gdb_xml_error (parser, _("Required attribute \"%s\" of " 257 "<%s> not specified"), 258 attribute->name, element->name); 259 continue; 260 } 261 262 if (*p == NULL) 263 continue; 264 265 gdb_xml_debug (parser, _("Parsing attribute %s=\"%s\""), 266 attribute->name, val); 267 268 if (attribute->handler) 269 parsed_value = attribute->handler (parser, attribute, val); 270 else 271 parsed_value = xstrdup (val); 272 273 new_value.name = attribute->name; 274 new_value.value = parsed_value; 275 VEC_safe_push (gdb_xml_value_s, attributes, &new_value); 276 } 277 278 /* Check for unrecognized attributes. */ 279 if (debug_xml) 280 { 281 const XML_Char **p; 282 283 for (p = attrs; *p != NULL; p += 2) 284 { 285 for (attribute = element->attributes; 286 attribute != NULL && attribute->name != NULL; 287 attribute++) 288 if (strcmp (attribute->name, *p) == 0) 289 break; 290 291 if (attribute == NULL || attribute->name == NULL) 292 gdb_xml_debug (parser, _("Ignoring unknown attribute %s"), *p); 293 } 294 } 295 296 /* Call the element handler if there is one. */ 297 if (element->start_handler) 298 element->start_handler (parser, element, parser->user_data, attributes); 299 300 /* Fill in a new scope level. */ 301 scope = VEC_last (scope_level_s, parser->scopes); 302 scope->element = element; 303 scope->elements = element->children; 304 305 do_cleanups (back_to); 306} 307 308/* Wrapper for gdb_xml_start_element, to prevent throwing exceptions 309 through expat. */ 310 311static void 312gdb_xml_start_element_wrapper (void *data, const XML_Char *name, 313 const XML_Char **attrs) 314{ 315 struct gdb_xml_parser *parser = data; 316 317 if (parser->error.reason < 0) 318 return; 319 320 TRY 321 { 322 gdb_xml_start_element (data, name, attrs); 323 } 324 CATCH (ex, RETURN_MASK_ALL) 325 { 326 parser->error = ex; 327#ifdef HAVE_XML_STOPPARSER 328 XML_StopParser (parser->expat_parser, XML_FALSE); 329#endif 330 } 331 END_CATCH 332} 333 334/* Handle the end of an element. DATA is our local XML parser, and 335 NAME is the current element. */ 336 337static void 338gdb_xml_end_element (void *data, const XML_Char *name) 339{ 340 struct gdb_xml_parser *parser = data; 341 struct scope_level *scope = VEC_last (scope_level_s, parser->scopes); 342 const struct gdb_xml_element *element; 343 unsigned int seen; 344 345 gdb_xml_debug (parser, _("Leaving element <%s>"), name); 346 347 for (element = scope->elements, seen = 1; 348 element != NULL && element->name != NULL; 349 element++, seen <<= 1) 350 if ((scope->seen & seen) == 0 351 && (element->flags & GDB_XML_EF_OPTIONAL) == 0) 352 gdb_xml_error (parser, _("Required element <%s> is missing"), 353 element->name); 354 355 /* Call the element processor. */ 356 if (scope->element != NULL && scope->element->end_handler) 357 { 358 char *body; 359 360 if (scope->body == NULL) 361 body = ""; 362 else 363 { 364 int length; 365 366 length = obstack_object_size (scope->body); 367 obstack_1grow (scope->body, '\0'); 368 body = obstack_finish (scope->body); 369 370 /* Strip leading and trailing whitespace. */ 371 while (length > 0 && ISSPACE (body[length-1])) 372 body[--length] = '\0'; 373 while (*body && ISSPACE (*body)) 374 body++; 375 } 376 377 scope->element->end_handler (parser, scope->element, parser->user_data, 378 body); 379 } 380 else if (scope->element == NULL) 381 XML_DefaultCurrent (parser->expat_parser); 382 383 /* Pop the scope level. */ 384 if (scope->body) 385 { 386 obstack_free (scope->body, NULL); 387 xfree (scope->body); 388 } 389 VEC_pop (scope_level_s, parser->scopes); 390} 391 392/* Wrapper for gdb_xml_end_element, to prevent throwing exceptions 393 through expat. */ 394 395static void 396gdb_xml_end_element_wrapper (void *data, const XML_Char *name) 397{ 398 struct gdb_xml_parser *parser = data; 399 400 if (parser->error.reason < 0) 401 return; 402 403 TRY 404 { 405 gdb_xml_end_element (data, name); 406 } 407 CATCH (ex, RETURN_MASK_ALL) 408 { 409 parser->error = ex; 410#ifdef HAVE_XML_STOPPARSER 411 XML_StopParser (parser->expat_parser, XML_FALSE); 412#endif 413 } 414 END_CATCH 415} 416 417/* Free a parser and all its associated state. */ 418 419static void 420gdb_xml_cleanup (void *arg) 421{ 422 struct gdb_xml_parser *parser = arg; 423 struct scope_level *scope; 424 int ix; 425 426 XML_ParserFree (parser->expat_parser); 427 428 /* Clean up the scopes. */ 429 for (ix = 0; VEC_iterate (scope_level_s, parser->scopes, ix, scope); ix++) 430 if (scope->body) 431 { 432 obstack_free (scope->body, NULL); 433 xfree (scope->body); 434 } 435 VEC_free (scope_level_s, parser->scopes); 436 437 xfree (parser); 438} 439 440/* Initialize a parser and store it to *PARSER_RESULT. Register a 441 cleanup to destroy the parser. */ 442 443static struct cleanup * 444gdb_xml_create_parser_and_cleanup (const char *name, 445 const struct gdb_xml_element *elements, 446 void *user_data, 447 struct gdb_xml_parser **parser_result) 448{ 449 struct gdb_xml_parser *parser; 450 struct scope_level start_scope; 451 struct cleanup *result; 452 453 /* Initialize the parser. */ 454 parser = XCNEW (struct gdb_xml_parser); 455 parser->expat_parser = XML_ParserCreateNS (NULL, '!'); 456 if (parser->expat_parser == NULL) 457 { 458 xfree (parser); 459 malloc_failure (0); 460 } 461 462 parser->name = name; 463 464 parser->user_data = user_data; 465 XML_SetUserData (parser->expat_parser, parser); 466 467 /* Set the callbacks. */ 468 XML_SetElementHandler (parser->expat_parser, gdb_xml_start_element_wrapper, 469 gdb_xml_end_element_wrapper); 470 XML_SetCharacterDataHandler (parser->expat_parser, gdb_xml_body_text); 471 472 /* Initialize the outer scope. */ 473 memset (&start_scope, 0, sizeof (start_scope)); 474 start_scope.elements = elements; 475 VEC_safe_push (scope_level_s, parser->scopes, &start_scope); 476 477 *parser_result = parser; 478 return make_cleanup (gdb_xml_cleanup, parser); 479} 480 481/* External entity handler. The only external entities we support 482 are those compiled into GDB (we do not fetch entities from the 483 target). */ 484 485static int XMLCALL 486gdb_xml_fetch_external_entity (XML_Parser expat_parser, 487 const XML_Char *context, 488 const XML_Char *base, 489 const XML_Char *systemId, 490 const XML_Char *publicId) 491{ 492 struct gdb_xml_parser *parser = XML_GetUserData (expat_parser); 493 XML_Parser entity_parser; 494 const char *text; 495 enum XML_Status status; 496 497 if (systemId == NULL) 498 { 499 text = fetch_xml_builtin (parser->dtd_name); 500 if (text == NULL) 501 internal_error (__FILE__, __LINE__, 502 _("could not locate built-in DTD %s"), 503 parser->dtd_name); 504 } 505 else 506 { 507 text = fetch_xml_builtin (systemId); 508 if (text == NULL) 509 return XML_STATUS_ERROR; 510 } 511 512 entity_parser = XML_ExternalEntityParserCreate (expat_parser, context, NULL); 513 514 /* Don't use our handlers for the contents of the DTD. Just let expat 515 process it. */ 516 XML_SetElementHandler (entity_parser, NULL, NULL); 517 XML_SetDoctypeDeclHandler (entity_parser, NULL, NULL); 518 XML_SetXmlDeclHandler (entity_parser, NULL); 519 XML_SetDefaultHandler (entity_parser, NULL); 520 XML_SetUserData (entity_parser, NULL); 521 522 status = XML_Parse (entity_parser, text, strlen (text), 1); 523 524 XML_ParserFree (entity_parser); 525 return status; 526} 527 528/* Associate DTD_NAME, which must be the name of a compiled-in DTD, 529 with PARSER. */ 530 531void 532gdb_xml_use_dtd (struct gdb_xml_parser *parser, const char *dtd_name) 533{ 534 enum XML_Error err; 535 536 parser->dtd_name = dtd_name; 537 538 XML_SetParamEntityParsing (parser->expat_parser, 539 XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE); 540 XML_SetExternalEntityRefHandler (parser->expat_parser, 541 gdb_xml_fetch_external_entity); 542 543 /* Even if no DTD is provided, use the built-in DTD anyway. */ 544 err = XML_UseForeignDTD (parser->expat_parser, XML_TRUE); 545 if (err != XML_ERROR_NONE) 546 internal_error (__FILE__, __LINE__, 547 _("XML_UseForeignDTD failed: %s"), 548 XML_ErrorString (err)); 549} 550 551/* Invoke PARSER on BUFFER. BUFFER is the data to parse, which 552 should be NUL-terminated. 553 554 The return value is 0 for success or -1 for error. It may throw, 555 but only if something unexpected goes wrong during parsing; parse 556 errors will be caught, warned about, and reported as failure. */ 557 558int 559gdb_xml_parse (struct gdb_xml_parser *parser, const char *buffer) 560{ 561 enum XML_Status status; 562 const char *error_string; 563 564 gdb_xml_debug (parser, _("Starting:\n%s"), buffer); 565 566 status = XML_Parse (parser->expat_parser, buffer, strlen (buffer), 1); 567 568 if (status == XML_STATUS_OK && parser->error.reason == 0) 569 return 0; 570 571 if (parser->error.reason == RETURN_ERROR 572 && parser->error.error == XML_PARSE_ERROR) 573 { 574 gdb_assert (parser->error.message != NULL); 575 error_string = parser->error.message; 576 } 577 else if (status == XML_STATUS_ERROR) 578 { 579 enum XML_Error err = XML_GetErrorCode (parser->expat_parser); 580 581 error_string = XML_ErrorString (err); 582 } 583 else 584 { 585 gdb_assert (parser->error.reason < 0); 586 throw_exception (parser->error); 587 } 588 589 if (parser->last_line != 0) 590 warning (_("while parsing %s (at line %d): %s"), parser->name, 591 parser->last_line, error_string); 592 else 593 warning (_("while parsing %s: %s"), parser->name, error_string); 594 595 return -1; 596} 597 598int 599gdb_xml_parse_quick (const char *name, const char *dtd_name, 600 const struct gdb_xml_element *elements, 601 const char *document, void *user_data) 602{ 603 struct gdb_xml_parser *parser; 604 struct cleanup *back_to; 605 int result; 606 607 back_to = gdb_xml_create_parser_and_cleanup (name, elements, 608 user_data, &parser); 609 if (dtd_name != NULL) 610 gdb_xml_use_dtd (parser, dtd_name); 611 result = gdb_xml_parse (parser, document); 612 613 do_cleanups (back_to); 614 615 return result; 616} 617 618/* Parse a field VALSTR that we expect to contain an integer value. 619 The integer is returned in *VALP. The string is parsed with an 620 equivalent to strtoul. 621 622 Returns 0 for success, -1 for error. */ 623 624static int 625xml_parse_unsigned_integer (const char *valstr, ULONGEST *valp) 626{ 627 const char *endptr; 628 ULONGEST result; 629 630 if (*valstr == '\0') 631 return -1; 632 633 result = strtoulst (valstr, &endptr, 0); 634 if (*endptr != '\0') 635 return -1; 636 637 *valp = result; 638 return 0; 639} 640 641/* Parse an integer string into a ULONGEST and return it, or call 642 gdb_xml_error if it could not be parsed. */ 643 644ULONGEST 645gdb_xml_parse_ulongest (struct gdb_xml_parser *parser, const char *value) 646{ 647 ULONGEST result; 648 649 if (xml_parse_unsigned_integer (value, &result) != 0) 650 gdb_xml_error (parser, _("Can't convert \"%s\" to an integer"), value); 651 652 return result; 653} 654 655/* Parse an integer attribute into a ULONGEST. */ 656 657void * 658gdb_xml_parse_attr_ulongest (struct gdb_xml_parser *parser, 659 const struct gdb_xml_attribute *attribute, 660 const char *value) 661{ 662 ULONGEST result; 663 void *ret; 664 665 if (xml_parse_unsigned_integer (value, &result) != 0) 666 gdb_xml_error (parser, _("Can't convert %s=\"%s\" to an integer"), 667 attribute->name, value); 668 669 ret = xmalloc (sizeof (result)); 670 memcpy (ret, &result, sizeof (result)); 671 return ret; 672} 673 674/* A handler_data for yes/no boolean values. */ 675 676const struct gdb_xml_enum gdb_xml_enums_boolean[] = { 677 { "yes", 1 }, 678 { "no", 0 }, 679 { NULL, 0 } 680}; 681 682/* Map NAME to VALUE. A struct gdb_xml_enum * should be saved as the 683 value of handler_data when using gdb_xml_parse_attr_enum to parse a 684 fixed list of possible strings. The list is terminated by an entry 685 with NAME == NULL. */ 686 687void * 688gdb_xml_parse_attr_enum (struct gdb_xml_parser *parser, 689 const struct gdb_xml_attribute *attribute, 690 const char *value) 691{ 692 const struct gdb_xml_enum *enums = attribute->handler_data; 693 void *ret; 694 695 for (enums = attribute->handler_data; enums->name != NULL; enums++) 696 if (strcasecmp (enums->name, value) == 0) 697 break; 698 699 if (enums->name == NULL) 700 gdb_xml_error (parser, _("Unknown attribute value %s=\"%s\""), 701 attribute->name, value); 702 703 ret = xmalloc (sizeof (enums->value)); 704 memcpy (ret, &enums->value, sizeof (enums->value)); 705 return ret; 706} 707 708 709/* XInclude processing. This is done as a separate step from actually 710 parsing the document, so that we can produce a single combined XML 711 document - e.g. to hand to a front end or to simplify comparing two 712 documents. We make extensive use of XML_DefaultCurrent, to pass 713 input text directly into the output without reformatting or 714 requoting it. 715 716 We output the DOCTYPE declaration for the first document unchanged, 717 if present, and discard DOCTYPEs from included documents. Only the 718 one we pass through here is used when we feed the result back to 719 expat. The XInclude standard explicitly does not discuss 720 validation of the result; we choose to apply the same DTD applied 721 to the outermost document. 722 723 We can not simply include the external DTD subset in the document 724 as an internal subset, because <!IGNORE> and <!INCLUDE> are valid 725 only in external subsets. But if we do not pass the DTD into the 726 output at all, default values will not be filled in. 727 728 We don't pass through any <?xml> declaration because we generate 729 UTF-8, not whatever the input encoding was. */ 730 731struct xinclude_parsing_data 732{ 733 /* The obstack to build the output in. */ 734 struct obstack obstack; 735 736 /* A count indicating whether we are in an element whose 737 children should not be copied to the output, and if so, 738 how deep we are nested. This is used for anything inside 739 an xi:include, and for the DTD. */ 740 int skip_depth; 741 742 /* The number of <xi:include> elements currently being processed, 743 to detect loops. */ 744 int include_depth; 745 746 /* A function to call to obtain additional features, and its 747 baton. */ 748 xml_fetch_another fetcher; 749 void *fetcher_baton; 750}; 751 752static void 753xinclude_start_include (struct gdb_xml_parser *parser, 754 const struct gdb_xml_element *element, 755 void *user_data, VEC(gdb_xml_value_s) *attributes) 756{ 757 struct xinclude_parsing_data *data = user_data; 758 char *href = xml_find_attribute (attributes, "href")->value; 759 struct cleanup *back_to; 760 char *text, *output; 761 762 gdb_xml_debug (parser, _("Processing XInclude of \"%s\""), href); 763 764 if (data->include_depth > MAX_XINCLUDE_DEPTH) 765 gdb_xml_error (parser, _("Maximum XInclude depth (%d) exceeded"), 766 MAX_XINCLUDE_DEPTH); 767 768 text = data->fetcher (href, data->fetcher_baton); 769 if (text == NULL) 770 gdb_xml_error (parser, _("Could not load XML document \"%s\""), href); 771 back_to = make_cleanup (xfree, text); 772 773 output = xml_process_xincludes (parser->name, text, data->fetcher, 774 data->fetcher_baton, 775 data->include_depth + 1); 776 if (output == NULL) 777 gdb_xml_error (parser, _("Parsing \"%s\" failed"), href); 778 779 obstack_grow (&data->obstack, output, strlen (output)); 780 xfree (output); 781 782 do_cleanups (back_to); 783 784 data->skip_depth++; 785} 786 787static void 788xinclude_end_include (struct gdb_xml_parser *parser, 789 const struct gdb_xml_element *element, 790 void *user_data, const char *body_text) 791{ 792 struct xinclude_parsing_data *data = user_data; 793 794 data->skip_depth--; 795} 796 797static void XMLCALL 798xml_xinclude_default (void *data_, const XML_Char *s, int len) 799{ 800 struct gdb_xml_parser *parser = data_; 801 struct xinclude_parsing_data *data = parser->user_data; 802 803 /* If we are inside of e.g. xi:include or the DTD, don't save this 804 string. */ 805 if (data->skip_depth) 806 return; 807 808 /* Otherwise just add it to the end of the document we're building 809 up. */ 810 obstack_grow (&data->obstack, s, len); 811} 812 813static void XMLCALL 814xml_xinclude_start_doctype (void *data_, const XML_Char *doctypeName, 815 const XML_Char *sysid, const XML_Char *pubid, 816 int has_internal_subset) 817{ 818 struct gdb_xml_parser *parser = data_; 819 struct xinclude_parsing_data *data = parser->user_data; 820 821 /* Don't print out the doctype, or the contents of the DTD internal 822 subset, if any. */ 823 data->skip_depth++; 824} 825 826static void XMLCALL 827xml_xinclude_end_doctype (void *data_) 828{ 829 struct gdb_xml_parser *parser = data_; 830 struct xinclude_parsing_data *data = parser->user_data; 831 832 data->skip_depth--; 833} 834 835static void XMLCALL 836xml_xinclude_xml_decl (void *data_, const XML_Char *version, 837 const XML_Char *encoding, int standalone) 838{ 839 /* Do nothing - this function prevents the default handler from 840 being called, thus suppressing the XML declaration from the 841 output. */ 842} 843 844static void 845xml_xinclude_cleanup (void *data_) 846{ 847 struct xinclude_parsing_data *data = data_; 848 849 obstack_free (&data->obstack, NULL); 850 xfree (data); 851} 852 853const struct gdb_xml_attribute xinclude_attributes[] = { 854 { "href", GDB_XML_AF_NONE, NULL, NULL }, 855 { NULL, GDB_XML_AF_NONE, NULL, NULL } 856}; 857 858const struct gdb_xml_element xinclude_elements[] = { 859 { "http://www.w3.org/2001/XInclude!include", xinclude_attributes, NULL, 860 GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE, 861 xinclude_start_include, xinclude_end_include }, 862 { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL } 863}; 864 865/* The main entry point for <xi:include> processing. */ 866 867char * 868xml_process_xincludes (const char *name, const char *text, 869 xml_fetch_another fetcher, void *fetcher_baton, 870 int depth) 871{ 872 struct gdb_xml_parser *parser; 873 struct xinclude_parsing_data *data; 874 struct cleanup *back_to; 875 char *result = NULL; 876 877 data = XCNEW (struct xinclude_parsing_data); 878 obstack_init (&data->obstack); 879 back_to = make_cleanup (xml_xinclude_cleanup, data); 880 881 gdb_xml_create_parser_and_cleanup (name, xinclude_elements, 882 data, &parser); 883 parser->is_xinclude = 1; 884 885 data->include_depth = depth; 886 data->fetcher = fetcher; 887 data->fetcher_baton = fetcher_baton; 888 889 XML_SetCharacterDataHandler (parser->expat_parser, NULL); 890 XML_SetDefaultHandler (parser->expat_parser, xml_xinclude_default); 891 892 /* Always discard the XML version declarations; the only important 893 thing this provides is encoding, and our result will have been 894 converted to UTF-8. */ 895 XML_SetXmlDeclHandler (parser->expat_parser, xml_xinclude_xml_decl); 896 897 if (depth > 0) 898 /* Discard the doctype for included documents. */ 899 XML_SetDoctypeDeclHandler (parser->expat_parser, 900 xml_xinclude_start_doctype, 901 xml_xinclude_end_doctype); 902 903 gdb_xml_use_dtd (parser, "xinclude.dtd"); 904 905 if (gdb_xml_parse (parser, text) == 0) 906 { 907 obstack_1grow (&data->obstack, '\0'); 908 result = xstrdup (obstack_finish (&data->obstack)); 909 910 if (depth == 0) 911 gdb_xml_debug (parser, _("XInclude processing succeeded.")); 912 } 913 else 914 result = NULL; 915 916 do_cleanups (back_to); 917 return result; 918} 919#endif /* HAVE_LIBEXPAT */ 920 921 922/* Return an XML document which was compiled into GDB, from 923 the given FILENAME, or NULL if the file was not compiled in. */ 924 925const char * 926fetch_xml_builtin (const char *filename) 927{ 928 const char *(*p)[2]; 929 930 for (p = xml_builtin; (*p)[0]; p++) 931 if (strcmp ((*p)[0], filename) == 0) 932 return (*p)[1]; 933 934 return NULL; 935} 936 937/* A to_xfer_partial helper function which reads XML files which were 938 compiled into GDB. The target may call this function from its own 939 to_xfer_partial handler, after converting object and annex to the 940 appropriate filename. */ 941 942LONGEST 943xml_builtin_xfer_partial (const char *filename, 944 gdb_byte *readbuf, const gdb_byte *writebuf, 945 ULONGEST offset, LONGEST len) 946{ 947 const char *buf; 948 LONGEST len_avail; 949 950 gdb_assert (readbuf != NULL && writebuf == NULL); 951 gdb_assert (filename != NULL); 952 953 buf = fetch_xml_builtin (filename); 954 if (buf == NULL) 955 return -1; 956 957 len_avail = strlen (buf); 958 if (offset >= len_avail) 959 return 0; 960 961 if (len > len_avail - offset) 962 len = len_avail - offset; 963 memcpy (readbuf, buf + offset, len); 964 return len; 965} 966 967 968static void 969show_debug_xml (struct ui_file *file, int from_tty, 970 struct cmd_list_element *c, const char *value) 971{ 972 fprintf_filtered (file, _("XML debugging is %s.\n"), value); 973} 974 975void 976obstack_xml_printf (struct obstack *obstack, const char *format, ...) 977{ 978 va_list ap; 979 const char *f; 980 const char *prev; 981 int percent = 0; 982 983 va_start (ap, format); 984 985 prev = format; 986 for (f = format; *f; f++) 987 { 988 if (percent) 989 { 990 switch (*f) 991 { 992 case 's': 993 { 994 char *p; 995 char *a = va_arg (ap, char *); 996 997 obstack_grow (obstack, prev, f - prev - 1); 998 p = xml_escape_text (a); 999 obstack_grow_str (obstack, p); 1000 xfree (p); 1001 prev = f + 1; 1002 } 1003 break; 1004 } 1005 percent = 0; 1006 } 1007 else if (*f == '%') 1008 percent = 1; 1009 } 1010 1011 obstack_grow_str (obstack, prev); 1012 va_end (ap); 1013} 1014 1015char * 1016xml_fetch_content_from_file (const char *filename, void *baton) 1017{ 1018 const char *dirname = baton; 1019 FILE *file; 1020 struct cleanup *back_to; 1021 char *text; 1022 size_t len, offset; 1023 1024 if (dirname && *dirname) 1025 { 1026 char *fullname = concat (dirname, "/", filename, (char *) NULL); 1027 1028 if (fullname == NULL) 1029 malloc_failure (0); 1030 file = gdb_fopen_cloexec (fullname, FOPEN_RT); 1031 xfree (fullname); 1032 } 1033 else 1034 file = gdb_fopen_cloexec (filename, FOPEN_RT); 1035 1036 if (file == NULL) 1037 return NULL; 1038 1039 back_to = make_cleanup_fclose (file); 1040 1041 /* Read in the whole file, one chunk at a time. */ 1042 len = 4096; 1043 offset = 0; 1044 text = xmalloc (len); 1045 make_cleanup (free_current_contents, &text); 1046 while (1) 1047 { 1048 size_t bytes_read; 1049 1050 /* Continue reading where the last read left off. Leave at least 1051 one byte so that we can NUL-terminate the result. */ 1052 bytes_read = fread (text + offset, 1, len - offset - 1, file); 1053 if (ferror (file)) 1054 { 1055 warning (_("Read error from \"%s\""), filename); 1056 do_cleanups (back_to); 1057 return NULL; 1058 } 1059 1060 offset += bytes_read; 1061 1062 if (feof (file)) 1063 break; 1064 1065 len = len * 2; 1066 text = xrealloc (text, len); 1067 } 1068 1069 fclose (file); 1070 discard_cleanups (back_to); 1071 1072 text[offset] = '\0'; 1073 return text; 1074} 1075 1076void _initialize_xml_support (void); 1077 1078void 1079_initialize_xml_support (void) 1080{ 1081 add_setshow_boolean_cmd ("xml", class_maintenance, &debug_xml, 1082 _("Set XML parser debugging."), 1083 _("Show XML parser debugging."), 1084 _("When set, debugging messages for XML parsers " 1085 "are displayed."), 1086 NULL, show_debug_xml, 1087 &setdebuglist, &showdebuglist); 1088} 1089