gdb/xml-tdesc.c

   1 /* XML target description support for GDB.
   2
   3    Copyright (C) 2006-2017 Free Software Foundation, Inc.
   4
   5    Contributed by CodeSourcery.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include "defs.h"
  23 #include "target.h"
  24 #include "target-descriptions.h"
  25 #include "xml-support.h"
  26 #include "xml-tdesc.h"
  27 #include "osabi.h"
  28 #include "filenames.h"
  29
  30 /* Maximum sizes.
  31    This is just to catch obviously wrong values.  */
  32 #define MAX_FIELD_SIZE 65536
  33 #define MAX_FIELD_BITSIZE (MAX_FIELD_SIZE * TARGET_CHAR_BIT)
  34 #define MAX_VECTOR_SIZE 65536
  35
  36 #if !defined(HAVE_LIBEXPAT)
  37
  38 /* Parse DOCUMENT into a target description.  Or don't, since we don't have
  39    an XML parser.  */
  40
  41 static struct target_desc *
  42 tdesc_parse_xml (const char *document, xml_fetch_another fetcher,
  43                  void *fetcher_baton)
  44 {
  45   static int have_warned;
  46
  47   if (!have_warned)
  48     {
  49       have_warned = 1;
  50       warning (_("Can not parse XML target description; XML support was "
  51                  "disabled at compile time"));
  52     }
  53
  54   return NULL;
  55 }
  56
  57 #else /* HAVE_LIBEXPAT */
  58
  59 /* A record of every XML description we have parsed.  We never discard
  60    old descriptions, because we never discard gdbarches.  As long as we
  61    have a gdbarch referencing this description, we want to have a copy
  62    of it here, so that if we parse the same XML document again we can
  63    return the same "struct target_desc *"; if they are not singletons,
  64    then we will create unnecessary duplicate gdbarches.  See
  65    gdbarch_list_lookup_by_info.  */
  66
  67 struct tdesc_xml_cache
  68 {
  69   const char *xml_document;
  70   struct target_desc *tdesc;
  71 };
  72 typedef struct tdesc_xml_cache tdesc_xml_cache_s;
  73 DEF_VEC_O(tdesc_xml_cache_s);
  74
  75 static VEC(tdesc_xml_cache_s) *xml_cache;
  76
  77 /* Callback data for target description parsing.  */
  78
  79 struct tdesc_parsing_data
  80 {
  81   /* The target description we are building.  */
  82   struct target_desc *tdesc;
  83
  84   /* The target feature we are currently parsing, or last parsed.  */
  85   struct tdesc_feature *current_feature;
  86
  87   /* The register number to use for the next register we see, if
  88      it does not have its own.  This starts at zero.  */
  89   int next_regnum;
  90
  91   /* The struct or union we are currently parsing, or last parsed.  */
  92   struct tdesc_type *current_type;
  93
  94   /* The byte size of the current struct/flags type, if specified.  Zero
  95      if not specified.  Flags values must specify a size.  */
  96   int current_type_size;
  97 };
  98
  99 /* Handle the end of an <architecture> element and its value.  */
 100
 101 static void
 102 tdesc_end_arch (struct gdb_xml_parser *parser,
 103                 const struct gdb_xml_element *element,
 104                 void *user_data, const char *body_text)
 105 {
 106   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 107   const struct bfd_arch_info *arch;
 108
 109   arch = bfd_scan_arch (body_text);
 110   if (arch == NULL)
 111     gdb_xml_error (parser, _("Target description specified unknown "
 112                              "architecture \"%s\""), body_text);
 113   set_tdesc_architecture (data->tdesc, arch);
 114 }
 115
 116 /* Handle the end of an <osabi> element and its value.  */
 117
 118 static void
 119 tdesc_end_osabi (struct gdb_xml_parser *parser,
 120                  const struct gdb_xml_element *element,
 121                  void *user_data, const char *body_text)
 122 {
 123   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 124   enum gdb_osabi osabi;
 125
 126   osabi = osabi_from_tdesc_string (body_text);
 127   if (osabi == GDB_OSABI_UNKNOWN)
 128     warning (_("Target description specified unknown osabi \"%s\""),
 129              body_text);
 130   else
 131     set_tdesc_osabi (data->tdesc, osabi);
 132 }
 133
 134 /* Handle the end of a <compatible> element and its value.  */
 135
 136 static void
 137 tdesc_end_compatible (struct gdb_xml_parser *parser,
 138                       const struct gdb_xml_element *element,
 139                       void *user_data, const char *body_text)
 140 {
 141   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 142   const struct bfd_arch_info *arch;
 143
 144   arch = bfd_scan_arch (body_text);
 145   tdesc_add_compatible (data->tdesc, arch);
 146 }
 147
 148 /* Handle the start of a <target> element.  */
 149
 150 static void
 151 tdesc_start_target (struct gdb_xml_parser *parser,
 152                     const struct gdb_xml_element *element,
 153                     void *user_data, VEC(gdb_xml_value_s) *attributes)
 154 {
 155   char *version = (char *) xml_find_attribute (attributes, "version")->value;
 156
 157   if (strcmp (version, "1.0") != 0)
 158     gdb_xml_error (parser,
 159                    _("Target description has unsupported version \"%s\""),
 160                    version);
 161 }
 162
 163 /* Handle the start of a <feature> element.  */
 164
 165 static void
 166 tdesc_start_feature (struct gdb_xml_parser *parser,
 167                      const struct gdb_xml_element *element,
 168                      void *user_data, VEC(gdb_xml_value_s) *attributes)
 169 {
 170   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 171   char *name = (char *) xml_find_attribute (attributes, "name")->value;
 172
 173   data->current_feature = tdesc_create_feature (data->tdesc, name);
 174 }
 175
 176 /* Handle the start of a <reg> element.  Fill in the optional
 177    attributes and attach it to the containing feature.  */
 178
 179 static void
 180 tdesc_start_reg (struct gdb_xml_parser *parser,
 181                  const struct gdb_xml_element *element,
 182                  void *user_data, VEC(gdb_xml_value_s) *attributes)
 183 {
 184   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 185   struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
 186   int ix = 0, length;
 187   char *name, *group, *type;
 188   int bitsize, regnum, save_restore;
 189
 190   length = VEC_length (gdb_xml_value_s, attributes);
 191
 192   name = (char *) attrs[ix++].value;
 193   bitsize = * (ULONGEST *) attrs[ix++].value;
 194
 195   if (ix < length && strcmp (attrs[ix].name, "regnum") == 0)
 196     regnum = * (ULONGEST *) attrs[ix++].value;
 197   else
 198     regnum = data->next_regnum;
 199
 200   if (ix < length && strcmp (attrs[ix].name, "type") == 0)
 201     type = (char *) attrs[ix++].value;
 202   else
 203     type = "int";
 204
 205   if (ix < length && strcmp (attrs[ix].name, "group") == 0)
 206     group = (char *) attrs[ix++].value;
 207   else
 208     group = NULL;
 209
 210   if (ix < length && strcmp (attrs[ix].name, "save-restore") == 0)
 211     save_restore = * (ULONGEST *) attrs[ix++].value;
 212   else
 213     save_restore = 1;
 214
 215   if (strcmp (type, "int") != 0
 216       && strcmp (type, "float") != 0
 217       && tdesc_named_type (data->current_feature, type) == NULL)
 218     gdb_xml_error (parser, _("Register \"%s\" has unknown type \"%s\""),
 219                    name, type);
 220
 221   tdesc_create_reg (data->current_feature, name, regnum, save_restore, group,
 222                     bitsize, type);
 223
 224   data->next_regnum = regnum + 1;
 225 }
 226
 227 /* Handle the start of a <union> element.  Initialize the type and
 228    record it with the current feature.  */
 229
 230 static void
 231 tdesc_start_union (struct gdb_xml_parser *parser,
 232                    const struct gdb_xml_element *element,
 233                    void *user_data, VEC(gdb_xml_value_s) *attributes)
 234 {
 235   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 236   char *id = (char *) xml_find_attribute (attributes, "id")->value;
 237
 238   data->current_type = tdesc_create_union (data->current_feature, id);
 239   data->current_type_size = 0;
 240 }
 241
 242 /* Handle the start of a <struct> element.  Initialize the type and
 243    record it with the current feature.  */
 244
 245 static void
 246 tdesc_start_struct (struct gdb_xml_parser *parser,
 247                    const struct gdb_xml_element *element,
 248                    void *user_data, VEC(gdb_xml_value_s) *attributes)
 249 {
 250   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 251   char *id = (char *) xml_find_attribute (attributes, "id")->value;
 252   struct tdesc_type *type;
 253   struct gdb_xml_value *attr;
 254
 255   type = tdesc_create_struct (data->current_feature, id);
 256   data->current_type = type;
 257   data->current_type_size = 0;
 258
 259   attr = xml_find_attribute (attributes, "size");
 260   if (attr != NULL)
 261     {
 262       ULONGEST size = * (ULONGEST *) attr->value;
 263
 264       if (size > MAX_FIELD_SIZE)
 265         {
 266           gdb_xml_error (parser,
 267                          _("Struct size %s is larger than maximum (%d)"),
 268                          pulongest (size), MAX_FIELD_SIZE);
 269         }
 270       tdesc_set_struct_size (type, size);
 271       data->current_type_size = size;
 272     }
 273 }
 274
 275 static void
 276 tdesc_start_flags (struct gdb_xml_parser *parser,
 277                    const struct gdb_xml_element *element,
 278                    void *user_data, VEC(gdb_xml_value_s) *attributes)
 279 {
 280   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 281   char *id = (char *) xml_find_attribute (attributes, "id")->value;
 282   ULONGEST size = * (ULONGEST *)
 283     xml_find_attribute (attributes, "size")->value;
 284   struct tdesc_type *type;
 285
 286   if (size > MAX_FIELD_SIZE)
 287     {
 288       gdb_xml_error (parser,
 289                      _("Flags size %s is larger than maximum (%d)"),
 290                      pulongest (size), MAX_FIELD_SIZE);
 291     }
 292   type = tdesc_create_flags (data->current_feature, id, size);
 293
 294   data->current_type = type;
 295   data->current_type_size = size;
 296 }
 297
 298 static void
 299 tdesc_start_enum (struct gdb_xml_parser *parser,
 300                   const struct gdb_xml_element *element,
 301                   void *user_data, VEC(gdb_xml_value_s) *attributes)
 302 {
 303   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 304   char *id = (char *) xml_find_attribute (attributes, "id")->value;
 305   int size = * (ULONGEST *)
 306     xml_find_attribute (attributes, "size")->value;
 307   struct tdesc_type *type;
 308
 309   if (size > MAX_FIELD_SIZE)
 310     {
 311       gdb_xml_error (parser,
 312                      _("Enum size %s is larger than maximum (%d)"),
 313                      pulongest (size), MAX_FIELD_SIZE);
 314     }
 315   type = tdesc_create_enum (data->current_feature, id, size);
 316
 317   data->current_type = type;
 318   data->current_type_size = 0;
 319 }
 320
 321 /* Handle the start of a <field> element.  Attach the field to the
 322    current struct, union or flags.  */
 323
 324 static void
 325 tdesc_start_field (struct gdb_xml_parser *parser,
 326                    const struct gdb_xml_element *element,
 327                    void *user_data, VEC(gdb_xml_value_s) *attributes)
 328 {
 329   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 330   struct gdb_xml_value *attr;
 331   struct tdesc_type *field_type;
 332   char *field_name, *field_type_id;
 333   int start, end;
 334
 335   field_name = (char *) xml_find_attribute (attributes, "name")->value;
 336
 337   attr = xml_find_attribute (attributes, "type");
 338   if (attr != NULL)
 339     {
 340       field_type_id = (char *) attr->value;
 341       field_type = tdesc_named_type (data->current_feature, field_type_id);
 342     }
 343   else
 344     {
 345       field_type_id = NULL;
 346       field_type = NULL;
 347     }
 348
 349   attr = xml_find_attribute (attributes, "start");
 350   if (attr != NULL)
 351     {
 352       ULONGEST ul_start = * (ULONGEST *) attr->value;
 353
 354       if (ul_start > MAX_FIELD_BITSIZE)
 355         {
 356           gdb_xml_error (parser,
 357                          _("Field start %s is larger than maximum (%d)"),
 358                          pulongest (ul_start), MAX_FIELD_BITSIZE);
 359         }
 360       start = ul_start;
 361     }
 362   else
 363     start = -1;
 364
 365   attr = xml_find_attribute (attributes, "end");
 366   if (attr != NULL)
 367     {
 368       ULONGEST ul_end = * (ULONGEST *) attr->value;
 369
 370       if (ul_end > MAX_FIELD_BITSIZE)
 371         {
 372           gdb_xml_error (parser,
 373                          _("Field end %s is larger than maximum (%d)"),
 374                          pulongest (ul_end), MAX_FIELD_BITSIZE);
 375         }
 376       end = ul_end;
 377     }
 378   else
 379     end = -1;
 380
 381   if (start != -1)
 382     {
 383       struct tdesc_type *t = data->current_type;
 384
 385       /* Older versions of gdb can't handle elided end values.
 386          Stick with that for now, to help ensure backward compatibility.
 387          E.g., If a newer gdbserver is talking to an older gdb.  */
 388       if (end == -1)
 389         gdb_xml_error (parser, _("Missing end value"));
 390
 391       if (data->current_type_size == 0)
 392         gdb_xml_error (parser,
 393                        _("Bitfields must live in explicitly sized types"));
 394
 395       if (field_type_id != NULL
 396           && strcmp (field_type_id, "bool") == 0
 397           && start != end)
 398         {
 399           gdb_xml_error (parser,
 400                          _("Boolean fields must be one bit in size"));
 401         }
 402
 403       if (end >= 64)
 404         gdb_xml_error (parser,
 405                        _("Bitfield \"%s\" goes past "
 406                          "64 bits (unsupported)"),
 407                        field_name);
 408
 409       /* Assume that the bit numbering in XML is "lsb-zero".  Most
 410          architectures other than PowerPC use this ordering.  In the
 411          future, we can add an XML tag to indicate "msb-zero" numbering.  */
 412       if (start > end)
 413         gdb_xml_error (parser, _("Bitfield \"%s\" has start after end"),
 414                        field_name);
 415       if (end >= data->current_type_size * TARGET_CHAR_BIT)
 416         gdb_xml_error (parser,
 417                        _("Bitfield \"%s\" does not fit in struct"));
 418
 419       if (field_type != NULL)
 420         tdesc_add_typed_bitfield (t, field_name, start, end, field_type);
 421       else if (start == end)
 422         tdesc_add_flag (t, start, field_name);
 423       else
 424         tdesc_add_bitfield (t, field_name, start, end);
 425     }
 426   else if (start == -1 && end != -1)
 427     gdb_xml_error (parser, _("End specified but not start"));
 428   else if (field_type_id != NULL)
 429     {
 430       /* TDESC_TYPE_FLAGS values are explicitly sized, so the following test
 431          catches adding non-bitfield types to flags as well.  */
 432       if (data->current_type_size != 0)
 433         gdb_xml_error (parser,
 434                        _("Explicitly sized type cannot "
 435                          "contain non-bitfield \"%s\""),
 436                        field_name);
 437
 438       if (field_type == NULL)
 439         gdb_xml_error (parser, _("Field \"%s\" references undefined "
 440                                  "type \"%s\""),
 441                        field_name, field_type_id);
 442
 443       tdesc_add_field (data->current_type, field_name, field_type);
 444     }
 445   else
 446     gdb_xml_error (parser, _("Field \"%s\" has neither type nor bit position"),
 447                    field_name);
 448 }
 449
 450 /* Handle the start of an <evalue> element.  Attach the value to the
 451    current enum.  */
 452
 453 static void
 454 tdesc_start_enum_value (struct gdb_xml_parser *parser,
 455                         const struct gdb_xml_element *element,
 456                         void *user_data, VEC(gdb_xml_value_s) *attributes)
 457 {
 458   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 459   struct gdb_xml_value *attr;
 460   char *field_name;
 461   ULONGEST ul_value;
 462   int value;
 463
 464   field_name = (char *) xml_find_attribute (attributes, "name")->value;
 465
 466   attr = xml_find_attribute (attributes, "value");
 467   ul_value = * (ULONGEST *) attr->value;
 468   if (ul_value > INT_MAX)
 469     {
 470       gdb_xml_error (parser,
 471                      _("Enum value %s is larger than maximum (%d)"),
 472                      pulongest (ul_value), INT_MAX);
 473     }
 474   value = ul_value;
 475
 476   tdesc_add_enum_value (data->current_type, value, field_name);
 477 }
 478
 479 /* Handle the start of a <vector> element.  Initialize the type and
 480    record it with the current feature.  */
 481
 482 static void
 483 tdesc_start_vector (struct gdb_xml_parser *parser,
 484                     const struct gdb_xml_element *element,
 485                     void *user_data, VEC(gdb_xml_value_s) *attributes)
 486 {
 487   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 488   struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
 489   struct tdesc_type *field_type;
 490   char *id, *field_type_id;
 491   ULONGEST count;
 492
 493   id = (char *) attrs[0].value;
 494   field_type_id = (char *) attrs[1].value;
 495   count = * (ULONGEST *) attrs[2].value;
 496
 497   if (count > MAX_VECTOR_SIZE)
 498     {
 499       gdb_xml_error (parser,
 500                      _("Vector size %s is larger than maximum (%d)"),
 501                      pulongest (count), MAX_VECTOR_SIZE);
 502     }
 503
 504   field_type = tdesc_named_type (data->current_feature, field_type_id);
 505   if (field_type == NULL)
 506     gdb_xml_error (parser, _("Vector \"%s\" references undefined type \"%s\""),
 507                    id, field_type_id);
 508
 509   tdesc_create_vector (data->current_feature, id, field_type, count);
 510 }
 511
 512 /* The elements and attributes of an XML target description.  */
 513
 514 static const struct gdb_xml_attribute field_attributes[] = {
 515   { "name", GDB_XML_AF_NONE, NULL, NULL },
 516   { "type", GDB_XML_AF_OPTIONAL, NULL, NULL },
 517   { "start", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
 518   { "end", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
 519   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 520 };
 521
 522 static const struct gdb_xml_attribute enum_value_attributes[] = {
 523   { "name", GDB_XML_AF_NONE, NULL, NULL },
 524   { "value", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
 525   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 526 };
 527
 528 static const struct gdb_xml_element struct_union_children[] = {
 529   { "field", field_attributes, NULL, GDB_XML_EF_REPEATABLE,
 530     tdesc_start_field, NULL },
 531   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 532 };
 533
 534 static const struct gdb_xml_element enum_children[] = {
 535   { "evalue", enum_value_attributes, NULL, GDB_XML_EF_REPEATABLE,
 536     tdesc_start_enum_value, NULL },
 537   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 538 };
 539
 540 static const struct gdb_xml_attribute reg_attributes[] = {
 541   { "name", GDB_XML_AF_NONE, NULL, NULL },
 542   { "bitsize", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 543   { "regnum", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
 544   { "type", GDB_XML_AF_OPTIONAL, NULL, NULL },
 545   { "group", GDB_XML_AF_OPTIONAL, NULL, NULL },
 546   { "save-restore", GDB_XML_AF_OPTIONAL,
 547     gdb_xml_parse_attr_enum, gdb_xml_enums_boolean },
 548   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 549 };
 550
 551 static const struct gdb_xml_attribute struct_union_attributes[] = {
 552   { "id", GDB_XML_AF_NONE, NULL, NULL },
 553   { "size", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL},
 554   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 555 };
 556
 557 static const struct gdb_xml_attribute flags_attributes[] = {
 558   { "id", GDB_XML_AF_NONE, NULL, NULL },
 559   { "size", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL},
 560   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 561 };
 562
 563 static const struct gdb_xml_attribute enum_attributes[] = {
 564   { "id", GDB_XML_AF_NONE, NULL, NULL },
 565   { "size", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL},
 566   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 567 };
 568
 569 static const struct gdb_xml_attribute vector_attributes[] = {
 570   { "id", GDB_XML_AF_NONE, NULL, NULL },
 571   { "type", GDB_XML_AF_NONE, NULL, NULL },
 572   { "count", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 573   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 574 };
 575
 576 static const struct gdb_xml_attribute feature_attributes[] = {
 577   { "name", GDB_XML_AF_NONE, NULL, NULL },
 578   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 579 };
 580
 581 static const struct gdb_xml_element feature_children[] = {
 582   { "reg", reg_attributes, NULL,
 583     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 584     tdesc_start_reg, NULL },
 585   { "struct", struct_union_attributes, struct_union_children,
 586     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 587     tdesc_start_struct, NULL },
 588   { "union", struct_union_attributes, struct_union_children,
 589     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 590     tdesc_start_union, NULL },
 591   { "flags", flags_attributes, struct_union_children,
 592     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 593     tdesc_start_flags, NULL },
 594   { "enum", enum_attributes, enum_children,
 595     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 596     tdesc_start_enum, NULL },
 597   { "vector", vector_attributes, NULL,
 598     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 599     tdesc_start_vector, NULL },
 600   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 601 };
 602
 603 static const struct gdb_xml_attribute target_attributes[] = {
 604   { "version", GDB_XML_AF_NONE, NULL, NULL },
 605   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 606 };
 607
 608 static const struct gdb_xml_element target_children[] = {
 609   { "architecture", NULL, NULL, GDB_XML_EF_OPTIONAL,
 610     NULL, tdesc_end_arch },
 611   { "osabi", NULL, NULL, GDB_XML_EF_OPTIONAL,
 612     NULL, tdesc_end_osabi },
 613   { "compatible", NULL, NULL, GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 614     NULL, tdesc_end_compatible },
 615   { "feature", feature_attributes, feature_children,
 616     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 617     tdesc_start_feature, NULL },
 618   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 619 };
 620
 621 static const struct gdb_xml_element tdesc_elements[] = {
 622   { "target", target_attributes, target_children, GDB_XML_EF_NONE,
 623     tdesc_start_target, NULL },
 624   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 625 };
 626
 627 /* Parse DOCUMENT into a target description and return it.  */
 628
 629 static struct target_desc *
 630 tdesc_parse_xml (const char *document, xml_fetch_another fetcher,
 631                  void *fetcher_baton)
 632 {
 633   struct cleanup *back_to, *result_cleanup;
 634   struct tdesc_parsing_data data;
 635   struct tdesc_xml_cache *cache;
 636   char *expanded_text;
 637   int ix;
 638
 639   /* Expand all XInclude directives.  */
 640   expanded_text = xml_process_xincludes (_("target description"),
 641                                          document, fetcher, fetcher_baton, 0);
 642   if (expanded_text == NULL)
 643     {
 644       warning (_("Could not load XML target description; ignoring"));
 645       return NULL;
 646     }
 647
 648   /* Check for an exact match in the list of descriptions we have
 649      previously parsed.  strcmp is a slightly inefficient way to
 650      do this; an SHA-1 checksum would work as well.  */
 651   for (ix = 0; VEC_iterate (tdesc_xml_cache_s, xml_cache, ix, cache); ix++)
 652     if (strcmp (cache->xml_document, expanded_text) == 0)
 653       {
 654        xfree (expanded_text);
 655        return cache->tdesc;
 656       }
 657
 658   back_to = make_cleanup (null_cleanup, NULL);
 659
 660   memset (&data, 0, sizeof (struct tdesc_parsing_data));
 661   data.tdesc = allocate_target_description ();
 662   result_cleanup = make_cleanup_free_target_description (data.tdesc);
 663   make_cleanup (xfree, expanded_text);
 664
 665   if (gdb_xml_parse_quick (_("target description"), "gdb-target.dtd",
 666                            tdesc_elements, expanded_text, &data) == 0)
 667     {
 668       /* Parsed successfully.  */
 669       struct tdesc_xml_cache new_cache;
 670
 671       new_cache.xml_document = expanded_text;
 672       new_cache.tdesc = data.tdesc;
 673       VEC_safe_push (tdesc_xml_cache_s, xml_cache, &new_cache);
 674       discard_cleanups (result_cleanup);
 675       do_cleanups (back_to);
 676       return data.tdesc;
 677     }
 678   else
 679     {
 680       warning (_("Could not load XML target description; ignoring"));
 681       do_cleanups (back_to);
 682       return NULL;
 683     }
 684 }
 685 #endif /* HAVE_LIBEXPAT */
 686 \f
 687
 688 /* Read an XML target description from FILENAME.  Parse it, and return
 689    the parsed description.  */
 690
 691 const struct target_desc *
 692 file_read_description_xml (const char *filename)
 693 {
 694   struct target_desc *tdesc;
 695   char *tdesc_str;
 696   struct cleanup *back_to;
 697   char *dirname;
 698
 699   tdesc_str = xml_fetch_content_from_file (filename, NULL);
 700   if (tdesc_str == NULL)
 701     {
 702       warning (_("Could not open \"%s\""), filename);
 703       return NULL;
 704     }
 705
 706   back_to = make_cleanup (xfree, tdesc_str);
 707
 708   dirname = ldirname (filename);
 709   if (dirname != NULL)
 710     make_cleanup (xfree, dirname);
 711
 712   tdesc = tdesc_parse_xml (tdesc_str, xml_fetch_content_from_file, dirname);
 713   do_cleanups (back_to);
 714
 715   return tdesc;
 716 }
 717
 718 /* Read a string representation of available features from the target,
 719    using TARGET_OBJECT_AVAILABLE_FEATURES.  The returned string is
 720    malloc allocated and NUL-terminated.  NAME should be a non-NULL
 721    string identifying the XML document we want; the top level document
 722    is "target.xml".  Other calls may be performed for the DTD or
 723    for <xi:include>.  */
 724
 725 static char *
 726 fetch_available_features_from_target (const char *name, void *baton_)
 727 {
 728   struct target_ops *ops = (struct target_ops *) baton_;
 729
 730   /* Read this object as a string.  This ensures that a NUL
 731      terminator is added.  */
 732   return target_read_stralloc (ops,
 733                                TARGET_OBJECT_AVAILABLE_FEATURES,
 734                                name);
 735 }
 736 \f
 737
 738 /* Read an XML target description using OPS.  Parse it, and return the
 739    parsed description.  */
 740
 741 const struct target_desc *
 742 target_read_description_xml (struct target_ops *ops)
 743 {
 744   struct target_desc *tdesc;
 745   char *tdesc_str;
 746   struct cleanup *back_to;
 747
 748   tdesc_str = fetch_available_features_from_target ("target.xml", ops);
 749   if (tdesc_str == NULL)
 750     return NULL;
 751
 752   back_to = make_cleanup (xfree, tdesc_str);
 753   tdesc = tdesc_parse_xml (tdesc_str,
 754                            fetch_available_features_from_target,
 755                            ops);
 756   do_cleanups (back_to);
 757
 758   return tdesc;
 759 }
 760
 761 /* Fetches an XML target description using OPS,  processing
 762    includes, but not parsing it.  Used to dump whole tdesc
 763    as a single XML file.  */
 764
 765 char *
 766 target_fetch_description_xml (struct target_ops *ops)
 767 {
 768 #if !defined(HAVE_LIBEXPAT)
 769   static int have_warned;
 770
 771   if (!have_warned)
 772     {
 773       have_warned = 1;
 774       warning (_("Can not fetch XML target description; XML support was "
 775                  "disabled at compile time"));
 776     }
 777
 778   return NULL;
 779 #else
 780   struct target_desc *tdesc;
 781   char *tdesc_str;
 782   char *expanded_text;
 783   struct cleanup *back_to;
 784
 785   tdesc_str = fetch_available_features_from_target ("target.xml", ops);
 786   if (tdesc_str == NULL)
 787     return NULL;
 788
 789   back_to = make_cleanup (xfree, tdesc_str);
 790   expanded_text = xml_process_xincludes (_("target description"),
 791                                          tdesc_str,
 792                                          fetch_available_features_from_target, ops, 0);
 793   do_cleanups (back_to);
 794   if (expanded_text == NULL)
 795     {
 796       warning (_("Could not load XML target description; ignoring"));
 797       return NULL;
 798     }
 799
 800   return expanded_text;
 801 #endif
 802 }