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;
 188   const char *type;
 189   int bitsize, regnum, save_restore;
 190
 191   length = VEC_length (gdb_xml_value_s, attributes);
 192
 193   name = (char *) attrs[ix++].value;
 194   bitsize = * (ULONGEST *) attrs[ix++].value;
 195
 196   if (ix < length && strcmp (attrs[ix].name, "regnum") == 0)
 197     regnum = * (ULONGEST *) attrs[ix++].value;
 198   else
 199     regnum = data->next_regnum;
 200
 201   if (ix < length && strcmp (attrs[ix].name, "type") == 0)
 202     type = (char *) attrs[ix++].value;
 203   else
 204     type = "int";
 205
 206   if (ix < length && strcmp (attrs[ix].name, "group") == 0)
 207     group = (char *) attrs[ix++].value;
 208   else
 209     group = NULL;
 210
 211   if (ix < length && strcmp (attrs[ix].name, "save-restore") == 0)
 212     save_restore = * (ULONGEST *) attrs[ix++].value;
 213   else
 214     save_restore = 1;
 215
 216   if (strcmp (type, "int") != 0
 217       && strcmp (type, "float") != 0
 218       && tdesc_named_type (data->current_feature, type) == NULL)
 219     gdb_xml_error (parser, _("Register \"%s\" has unknown type \"%s\""),
 220                    name, type);
 221
 222   tdesc_create_reg (data->current_feature, name, regnum, save_restore, group,
 223                     bitsize, type);
 224
 225   data->next_regnum = regnum + 1;
 226 }
 227
 228 /* Handle the start of a <union> element.  Initialize the type and
 229    record it with the current feature.  */
 230
 231 static void
 232 tdesc_start_union (struct gdb_xml_parser *parser,
 233                    const struct gdb_xml_element *element,
 234                    void *user_data, VEC(gdb_xml_value_s) *attributes)
 235 {
 236   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 237   char *id = (char *) xml_find_attribute (attributes, "id")->value;
 238
 239   data->current_type = tdesc_create_union (data->current_feature, id);
 240   data->current_type_size = 0;
 241 }
 242
 243 /* Handle the start of a <struct> element.  Initialize the type and
 244    record it with the current feature.  */
 245
 246 static void
 247 tdesc_start_struct (struct gdb_xml_parser *parser,
 248                    const struct gdb_xml_element *element,
 249                    void *user_data, VEC(gdb_xml_value_s) *attributes)
 250 {
 251   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 252   char *id = (char *) xml_find_attribute (attributes, "id")->value;
 253   struct tdesc_type *type;
 254   struct gdb_xml_value *attr;
 255
 256   type = tdesc_create_struct (data->current_feature, id);
 257   data->current_type = type;
 258   data->current_type_size = 0;
 259
 260   attr = xml_find_attribute (attributes, "size");
 261   if (attr != NULL)
 262     {
 263       ULONGEST size = * (ULONGEST *) attr->value;
 264
 265       if (size > MAX_FIELD_SIZE)
 266         {
 267           gdb_xml_error (parser,
 268                          _("Struct size %s is larger than maximum (%d)"),
 269                          pulongest (size), MAX_FIELD_SIZE);
 270         }
 271       tdesc_set_struct_size (type, size);
 272       data->current_type_size = size;
 273     }
 274 }
 275
 276 static void
 277 tdesc_start_flags (struct gdb_xml_parser *parser,
 278                    const struct gdb_xml_element *element,
 279                    void *user_data, VEC(gdb_xml_value_s) *attributes)
 280 {
 281   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 282   char *id = (char *) xml_find_attribute (attributes, "id")->value;
 283   ULONGEST size = * (ULONGEST *)
 284     xml_find_attribute (attributes, "size")->value;
 285   struct tdesc_type *type;
 286
 287   if (size > MAX_FIELD_SIZE)
 288     {
 289       gdb_xml_error (parser,
 290                      _("Flags size %s is larger than maximum (%d)"),
 291                      pulongest (size), MAX_FIELD_SIZE);
 292     }
 293   type = tdesc_create_flags (data->current_feature, id, size);
 294
 295   data->current_type = type;
 296   data->current_type_size = size;
 297 }
 298
 299 static void
 300 tdesc_start_enum (struct gdb_xml_parser *parser,
 301                   const struct gdb_xml_element *element,
 302                   void *user_data, VEC(gdb_xml_value_s) *attributes)
 303 {
 304   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 305   char *id = (char *) xml_find_attribute (attributes, "id")->value;
 306   int size = * (ULONGEST *)
 307     xml_find_attribute (attributes, "size")->value;
 308   struct tdesc_type *type;
 309
 310   if (size > MAX_FIELD_SIZE)
 311     {
 312       gdb_xml_error (parser,
 313                      _("Enum size %s is larger than maximum (%d)"),
 314                      pulongest (size), MAX_FIELD_SIZE);
 315     }
 316   type = tdesc_create_enum (data->current_feature, id, size);
 317
 318   data->current_type = type;
 319   data->current_type_size = 0;
 320 }
 321
 322 /* Handle the start of a <field> element.  Attach the field to the
 323    current struct, union or flags.  */
 324
 325 static void
 326 tdesc_start_field (struct gdb_xml_parser *parser,
 327                    const struct gdb_xml_element *element,
 328                    void *user_data, VEC(gdb_xml_value_s) *attributes)
 329 {
 330   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 331   struct gdb_xml_value *attr;
 332   struct tdesc_type *field_type;
 333   char *field_name, *field_type_id;
 334   int start, end;
 335
 336   field_name = (char *) xml_find_attribute (attributes, "name")->value;
 337
 338   attr = xml_find_attribute (attributes, "type");
 339   if (attr != NULL)
 340     {
 341       field_type_id = (char *) attr->value;
 342       field_type = tdesc_named_type (data->current_feature, field_type_id);
 343     }
 344   else
 345     {
 346       field_type_id = NULL;
 347       field_type = NULL;
 348     }
 349
 350   attr = xml_find_attribute (attributes, "start");
 351   if (attr != NULL)
 352     {
 353       ULONGEST ul_start = * (ULONGEST *) attr->value;
 354
 355       if (ul_start > MAX_FIELD_BITSIZE)
 356         {
 357           gdb_xml_error (parser,
 358                          _("Field start %s is larger than maximum (%d)"),
 359                          pulongest (ul_start), MAX_FIELD_BITSIZE);
 360         }
 361       start = ul_start;
 362     }
 363   else
 364     start = -1;
 365
 366   attr = xml_find_attribute (attributes, "end");
 367   if (attr != NULL)
 368     {
 369       ULONGEST ul_end = * (ULONGEST *) attr->value;
 370
 371       if (ul_end > MAX_FIELD_BITSIZE)
 372         {
 373           gdb_xml_error (parser,
 374                          _("Field end %s is larger than maximum (%d)"),
 375                          pulongest (ul_end), MAX_FIELD_BITSIZE);
 376         }
 377       end = ul_end;
 378     }
 379   else
 380     end = -1;
 381
 382   if (start != -1)
 383     {
 384       struct tdesc_type *t = data->current_type;
 385
 386       /* Older versions of gdb can't handle elided end values.
 387          Stick with that for now, to help ensure backward compatibility.
 388          E.g., If a newer gdbserver is talking to an older gdb.  */
 389       if (end == -1)
 390         gdb_xml_error (parser, _("Missing end value"));
 391
 392       if (data->current_type_size == 0)
 393         gdb_xml_error (parser,
 394                        _("Bitfields must live in explicitly sized types"));
 395
 396       if (field_type_id != NULL
 397           && strcmp (field_type_id, "bool") == 0
 398           && start != end)
 399         {
 400           gdb_xml_error (parser,
 401                          _("Boolean fields must be one bit in size"));
 402         }
 403
 404       if (end >= 64)
 405         gdb_xml_error (parser,
 406                        _("Bitfield \"%s\" goes past "
 407                          "64 bits (unsupported)"),
 408                        field_name);
 409
 410       /* Assume that the bit numbering in XML is "lsb-zero".  Most
 411          architectures other than PowerPC use this ordering.  In the
 412          future, we can add an XML tag to indicate "msb-zero" numbering.  */
 413       if (start > end)
 414         gdb_xml_error (parser, _("Bitfield \"%s\" has start after end"),
 415                        field_name);
 416       if (end >= data->current_type_size * TARGET_CHAR_BIT)
 417         gdb_xml_error (parser, _("Bitfield \"%s\" does not fit in struct"),
 418                        field_name);
 419
 420       if (field_type != NULL)
 421         tdesc_add_typed_bitfield (t, field_name, start, end, field_type);
 422       else if (start == end)
 423         tdesc_add_flag (t, start, field_name);
 424       else
 425         tdesc_add_bitfield (t, field_name, start, end);
 426     }
 427   else if (start == -1 && end != -1)
 428     gdb_xml_error (parser, _("End specified but not start"));
 429   else if (field_type_id != NULL)
 430     {
 431       /* TDESC_TYPE_FLAGS values are explicitly sized, so the following test
 432          catches adding non-bitfield types to flags as well.  */
 433       if (data->current_type_size != 0)
 434         gdb_xml_error (parser,
 435                        _("Explicitly sized type cannot "
 436                          "contain non-bitfield \"%s\""),
 437                        field_name);
 438
 439       if (field_type == NULL)
 440         gdb_xml_error (parser, _("Field \"%s\" references undefined "
 441                                  "type \"%s\""),
 442                        field_name, field_type_id);
 443
 444       tdesc_add_field (data->current_type, field_name, field_type);
 445     }
 446   else
 447     gdb_xml_error (parser, _("Field \"%s\" has neither type nor bit position"),
 448                    field_name);
 449 }
 450
 451 /* Handle the start of an <evalue> element.  Attach the value to the
 452    current enum.  */
 453
 454 static void
 455 tdesc_start_enum_value (struct gdb_xml_parser *parser,
 456                         const struct gdb_xml_element *element,
 457                         void *user_data, VEC(gdb_xml_value_s) *attributes)
 458 {
 459   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 460   struct gdb_xml_value *attr;
 461   char *field_name;
 462   ULONGEST ul_value;
 463   int value;
 464
 465   field_name = (char *) xml_find_attribute (attributes, "name")->value;
 466
 467   attr = xml_find_attribute (attributes, "value");
 468   ul_value = * (ULONGEST *) attr->value;
 469   if (ul_value > INT_MAX)
 470     {
 471       gdb_xml_error (parser,
 472                      _("Enum value %s is larger than maximum (%d)"),
 473                      pulongest (ul_value), INT_MAX);
 474     }
 475   value = ul_value;
 476
 477   tdesc_add_enum_value (data->current_type, value, field_name);
 478 }
 479
 480 /* Handle the start of a <vector> element.  Initialize the type and
 481    record it with the current feature.  */
 482
 483 static void
 484 tdesc_start_vector (struct gdb_xml_parser *parser,
 485                     const struct gdb_xml_element *element,
 486                     void *user_data, VEC(gdb_xml_value_s) *attributes)
 487 {
 488   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
 489   struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
 490   struct tdesc_type *field_type;
 491   char *id, *field_type_id;
 492   ULONGEST count;
 493
 494   id = (char *) attrs[0].value;
 495   field_type_id = (char *) attrs[1].value;
 496   count = * (ULONGEST *) attrs[2].value;
 497
 498   if (count > MAX_VECTOR_SIZE)
 499     {
 500       gdb_xml_error (parser,
 501                      _("Vector size %s is larger than maximum (%d)"),
 502                      pulongest (count), MAX_VECTOR_SIZE);
 503     }
 504
 505   field_type = tdesc_named_type (data->current_feature, field_type_id);
 506   if (field_type == NULL)
 507     gdb_xml_error (parser, _("Vector \"%s\" references undefined type \"%s\""),
 508                    id, field_type_id);
 509
 510   tdesc_create_vector (data->current_feature, id, field_type, count);
 511 }
 512
 513 /* The elements and attributes of an XML target description.  */
 514
 515 static const struct gdb_xml_attribute field_attributes[] = {
 516   { "name", GDB_XML_AF_NONE, NULL, NULL },
 517   { "type", GDB_XML_AF_OPTIONAL, NULL, NULL },
 518   { "start", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
 519   { "end", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
 520   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 521 };
 522
 523 static const struct gdb_xml_attribute enum_value_attributes[] = {
 524   { "name", GDB_XML_AF_NONE, NULL, NULL },
 525   { "value", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
 526   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 527 };
 528
 529 static const struct gdb_xml_element struct_union_children[] = {
 530   { "field", field_attributes, NULL, GDB_XML_EF_REPEATABLE,
 531     tdesc_start_field, NULL },
 532   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 533 };
 534
 535 static const struct gdb_xml_element enum_children[] = {
 536   { "evalue", enum_value_attributes, NULL, GDB_XML_EF_REPEATABLE,
 537     tdesc_start_enum_value, NULL },
 538   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 539 };
 540
 541 static const struct gdb_xml_attribute reg_attributes[] = {
 542   { "name", GDB_XML_AF_NONE, NULL, NULL },
 543   { "bitsize", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 544   { "regnum", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
 545   { "type", GDB_XML_AF_OPTIONAL, NULL, NULL },
 546   { "group", GDB_XML_AF_OPTIONAL, NULL, NULL },
 547   { "save-restore", GDB_XML_AF_OPTIONAL,
 548     gdb_xml_parse_attr_enum, gdb_xml_enums_boolean },
 549   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 550 };
 551
 552 static const struct gdb_xml_attribute struct_union_attributes[] = {
 553   { "id", GDB_XML_AF_NONE, NULL, NULL },
 554   { "size", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL},
 555   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 556 };
 557
 558 static const struct gdb_xml_attribute flags_attributes[] = {
 559   { "id", GDB_XML_AF_NONE, NULL, NULL },
 560   { "size", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL},
 561   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 562 };
 563
 564 static const struct gdb_xml_attribute enum_attributes[] = {
 565   { "id", GDB_XML_AF_NONE, NULL, NULL },
 566   { "size", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL},
 567   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 568 };
 569
 570 static const struct gdb_xml_attribute vector_attributes[] = {
 571   { "id", GDB_XML_AF_NONE, NULL, NULL },
 572   { "type", GDB_XML_AF_NONE, NULL, NULL },
 573   { "count", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 574   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 575 };
 576
 577 static const struct gdb_xml_attribute feature_attributes[] = {
 578   { "name", GDB_XML_AF_NONE, NULL, NULL },
 579   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 580 };
 581
 582 static const struct gdb_xml_element feature_children[] = {
 583   { "reg", reg_attributes, NULL,
 584     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 585     tdesc_start_reg, NULL },
 586   { "struct", struct_union_attributes, struct_union_children,
 587     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 588     tdesc_start_struct, NULL },
 589   { "union", struct_union_attributes, struct_union_children,
 590     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 591     tdesc_start_union, NULL },
 592   { "flags", flags_attributes, struct_union_children,
 593     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 594     tdesc_start_flags, NULL },
 595   { "enum", enum_attributes, enum_children,
 596     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 597     tdesc_start_enum, NULL },
 598   { "vector", vector_attributes, NULL,
 599     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 600     tdesc_start_vector, NULL },
 601   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 602 };
 603
 604 static const struct gdb_xml_attribute target_attributes[] = {
 605   { "version", GDB_XML_AF_NONE, NULL, NULL },
 606   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 607 };
 608
 609 static const struct gdb_xml_element target_children[] = {
 610   { "architecture", NULL, NULL, GDB_XML_EF_OPTIONAL,
 611     NULL, tdesc_end_arch },
 612   { "osabi", NULL, NULL, GDB_XML_EF_OPTIONAL,
 613     NULL, tdesc_end_osabi },
 614   { "compatible", NULL, NULL, GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 615     NULL, tdesc_end_compatible },
 616   { "feature", feature_attributes, feature_children,
 617     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 618     tdesc_start_feature, NULL },
 619   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 620 };
 621
 622 static const struct gdb_xml_element tdesc_elements[] = {
 623   { "target", target_attributes, target_children, GDB_XML_EF_NONE,
 624     tdesc_start_target, NULL },
 625   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 626 };
 627
 628 /* Parse DOCUMENT into a target description and return it.  */
 629
 630 static struct target_desc *
 631 tdesc_parse_xml (const char *document, xml_fetch_another fetcher,
 632                  void *fetcher_baton)
 633 {
 634   struct cleanup *back_to, *result_cleanup;
 635   struct tdesc_parsing_data data;
 636   struct tdesc_xml_cache *cache;
 637   char *expanded_text;
 638   int ix;
 639
 640   /* Expand all XInclude directives.  */
 641   expanded_text = xml_process_xincludes (_("target description"),
 642                                          document, fetcher, fetcher_baton, 0);
 643   if (expanded_text == NULL)
 644     {
 645       warning (_("Could not load XML target description; ignoring"));
 646       return NULL;
 647     }
 648
 649   /* Check for an exact match in the list of descriptions we have
 650      previously parsed.  strcmp is a slightly inefficient way to
 651      do this; an SHA-1 checksum would work as well.  */
 652   for (ix = 0; VEC_iterate (tdesc_xml_cache_s, xml_cache, ix, cache); ix++)
 653     if (strcmp (cache->xml_document, expanded_text) == 0)
 654       {
 655        xfree (expanded_text);
 656        return cache->tdesc;
 657       }
 658
 659   back_to = make_cleanup (null_cleanup, NULL);
 660
 661   memset (&data, 0, sizeof (struct tdesc_parsing_data));
 662   data.tdesc = allocate_target_description ();
 663   result_cleanup = make_cleanup_free_target_description (data.tdesc);
 664   make_cleanup (xfree, expanded_text);
 665
 666   if (gdb_xml_parse_quick (_("target description"), "gdb-target.dtd",
 667                            tdesc_elements, expanded_text, &data) == 0)
 668     {
 669       /* Parsed successfully.  */
 670       struct tdesc_xml_cache new_cache;
 671
 672       new_cache.xml_document = expanded_text;
 673       new_cache.tdesc = data.tdesc;
 674       VEC_safe_push (tdesc_xml_cache_s, xml_cache, &new_cache);
 675       discard_cleanups (result_cleanup);
 676       do_cleanups (back_to);
 677       return data.tdesc;
 678     }
 679   else
 680     {
 681       warning (_("Could not load XML target description; ignoring"));
 682       do_cleanups (back_to);
 683       return NULL;
 684     }
 685 }
 686 #endif /* HAVE_LIBEXPAT */
 687 \f
 688
 689 /* Read an XML target description from FILENAME.  Parse it, and return
 690    the parsed description.  */
 691
 692 const struct target_desc *
 693 file_read_description_xml (const char *filename)
 694 {
 695   struct target_desc *tdesc;
 696   char *tdesc_str;
 697   struct cleanup *back_to;
 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   tdesc = tdesc_parse_xml (tdesc_str, xml_fetch_content_from_file,
 709                            (void *) ldirname (filename).c_str ());
 710   do_cleanups (back_to);
 711
 712   return tdesc;
 713 }
 714
 715 /* Read a string representation of available features from the target,
 716    using TARGET_OBJECT_AVAILABLE_FEATURES.  The returned string is
 717    malloc allocated and NUL-terminated.  NAME should be a non-NULL
 718    string identifying the XML document we want; the top level document
 719    is "target.xml".  Other calls may be performed for the DTD or
 720    for <xi:include>.  */
 721
 722 static char *
 723 fetch_available_features_from_target (const char *name, void *baton_)
 724 {
 725   struct target_ops *ops = (struct target_ops *) baton_;
 726
 727   /* Read this object as a string.  This ensures that a NUL
 728      terminator is added.  */
 729   return target_read_stralloc (ops,
 730                                TARGET_OBJECT_AVAILABLE_FEATURES,
 731                                name);
 732 }
 733 \f
 734
 735 /* Read an XML target description using OPS.  Parse it, and return the
 736    parsed description.  */
 737
 738 const struct target_desc *
 739 target_read_description_xml (struct target_ops *ops)
 740 {
 741   struct target_desc *tdesc;
 742   char *tdesc_str;
 743   struct cleanup *back_to;
 744
 745   tdesc_str = fetch_available_features_from_target ("target.xml", ops);
 746   if (tdesc_str == NULL)
 747     return NULL;
 748
 749   back_to = make_cleanup (xfree, tdesc_str);
 750   tdesc = tdesc_parse_xml (tdesc_str,
 751                            fetch_available_features_from_target,
 752                            ops);
 753   do_cleanups (back_to);
 754
 755   return tdesc;
 756 }
 757
 758 /* Fetches an XML target description using OPS,  processing
 759    includes, but not parsing it.  Used to dump whole tdesc
 760    as a single XML file.  */
 761
 762 char *
 763 target_fetch_description_xml (struct target_ops *ops)
 764 {
 765 #if !defined(HAVE_LIBEXPAT)
 766   static int have_warned;
 767
 768   if (!have_warned)
 769     {
 770       have_warned = 1;
 771       warning (_("Can not fetch XML target description; XML support was "
 772                  "disabled at compile time"));
 773     }
 774
 775   return NULL;
 776 #else
 777   struct target_desc *tdesc;
 778   char *tdesc_str;
 779   char *expanded_text;
 780   struct cleanup *back_to;
 781
 782   tdesc_str = fetch_available_features_from_target ("target.xml", ops);
 783   if (tdesc_str == NULL)
 784     return NULL;
 785
 786   back_to = make_cleanup (xfree, tdesc_str);
 787   expanded_text = xml_process_xincludes (_("target description"),
 788                                          tdesc_str,
 789                                          fetch_available_features_from_target, ops, 0);
 790   do_cleanups (back_to);
 791   if (expanded_text == NULL)
 792     {
 793       warning (_("Could not load XML target description; ignoring"));
 794       return NULL;
 795     }
 796
 797   return expanded_text;
 798 #endif
 799 }