gdb/xml-tdesc.c

   1 /* XML target description support for GDB.
   2
   3    Copyright (C) 2006, 2008, 2009 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
  29 #include "filenames.h"
  30
  31 #include "gdb_assert.h"
  32
  33 #if !defined(HAVE_LIBEXPAT)
  34
  35 /* Parse DOCUMENT into a target description.  Or don't, since we don't have
  36    an XML parser.  */
  37
  38 static struct target_desc *
  39 tdesc_parse_xml (const char *document, xml_fetch_another fetcher,
  40                  void *fetcher_baton)
  41 {
  42   static int have_warned;
  43
  44   if (!have_warned)
  45     {
  46       have_warned = 1;
  47       warning (_("Can not parse XML target description; XML support was "
  48                  "disabled at compile time"));
  49     }
  50
  51   return NULL;
  52 }
  53
  54 #else /* HAVE_LIBEXPAT */
  55
  56 /* A record of every XML description we have parsed.  We never discard
  57    old descriptions, because we never discard gdbarches.  As long as we
  58    have a gdbarch referencing this description, we want to have a copy
  59    of it here, so that if we parse the same XML document again we can
  60    return the same "struct target_desc *"; if they are not singletons,
  61    then we will create unnecessary duplicate gdbarches.  See
  62    gdbarch_list_lookup_by_info.  */
  63
  64 struct tdesc_xml_cache
  65 {
  66   const char *xml_document;
  67   struct target_desc *tdesc;
  68 };
  69 typedef struct tdesc_xml_cache tdesc_xml_cache_s;
  70 DEF_VEC_O(tdesc_xml_cache_s);
  71
  72 static VEC(tdesc_xml_cache_s) *xml_cache;
  73
  74 /* Callback data for target description parsing.  */
  75
  76 struct tdesc_parsing_data
  77 {
  78   /* The target description we are building.  */
  79   struct target_desc *tdesc;
  80
  81   /* The target feature we are currently parsing, or last parsed.  */
  82   struct tdesc_feature *current_feature;
  83
  84   /* The register number to use for the next register we see, if
  85      it does not have its own.  This starts at zero.  */
  86   int next_regnum;
  87
  88   /* The union we are currently parsing, or last parsed.  */
  89   struct tdesc_type *current_union;
  90 };
  91
  92 /* Handle the end of an <architecture> element and its value.  */
  93
  94 static void
  95 tdesc_end_arch (struct gdb_xml_parser *parser,
  96                 const struct gdb_xml_element *element,
  97                 void *user_data, const char *body_text)
  98 {
  99   struct tdesc_parsing_data *data = user_data;
 100   const struct bfd_arch_info *arch;
 101
 102   arch = bfd_scan_arch (body_text);
 103   if (arch == NULL)
 104     gdb_xml_error (parser, _("Target description specified unknown "
 105                              "architecture \"%s\""), body_text);
 106   set_tdesc_architecture (data->tdesc, arch);
 107 }
 108
 109 /* Handle the end of an <osabi> element and its value.  */
 110
 111 static void
 112 tdesc_end_osabi (struct gdb_xml_parser *parser,
 113                  const struct gdb_xml_element *element,
 114                  void *user_data, const char *body_text)
 115 {
 116   struct tdesc_parsing_data *data = user_data;
 117   enum gdb_osabi osabi;
 118
 119   osabi = osabi_from_tdesc_string (body_text);
 120   if (osabi == GDB_OSABI_UNKNOWN)
 121     warning (_("Target description specified unknown osabi \"%s\""),
 122              body_text);
 123   else
 124     set_tdesc_osabi (data->tdesc, osabi);
 125 }
 126
 127 /* Handle the end of a <compatible> element and its value.  */
 128
 129 static void
 130 tdesc_end_compatible (struct gdb_xml_parser *parser,
 131                       const struct gdb_xml_element *element,
 132                       void *user_data, const char *body_text)
 133 {
 134   struct tdesc_parsing_data *data = user_data;
 135   const struct bfd_arch_info *arch;
 136
 137   arch = bfd_scan_arch (body_text);
 138   tdesc_add_compatible (data->tdesc, arch);
 139 }
 140
 141 /* Handle the start of a <target> element.  */
 142
 143 static void
 144 tdesc_start_target (struct gdb_xml_parser *parser,
 145                     const struct gdb_xml_element *element,
 146                     void *user_data, VEC(gdb_xml_value_s) *attributes)
 147 {
 148   struct tdesc_parsing_data *data = user_data;
 149   char *version = VEC_index (gdb_xml_value_s, attributes, 0)->value;
 150
 151   if (strcmp (version, "1.0") != 0)
 152     gdb_xml_error (parser,
 153                    _("Target description has unsupported version \"%s\""),
 154                    version);
 155 }
 156
 157 /* Handle the start of a <feature> element.  */
 158
 159 static void
 160 tdesc_start_feature (struct gdb_xml_parser *parser,
 161                      const struct gdb_xml_element *element,
 162                      void *user_data, VEC(gdb_xml_value_s) *attributes)
 163 {
 164   struct tdesc_parsing_data *data = user_data;
 165   char *name = VEC_index (gdb_xml_value_s, attributes, 0)->value;
 166
 167   data->current_feature = tdesc_create_feature (data->tdesc, name);
 168 }
 169
 170 /* Handle the start of a <reg> element.  Fill in the optional
 171    attributes and attach it to the containing feature.  */
 172
 173 static void
 174 tdesc_start_reg (struct gdb_xml_parser *parser,
 175                  const struct gdb_xml_element *element,
 176                  void *user_data, VEC(gdb_xml_value_s) *attributes)
 177 {
 178   struct tdesc_parsing_data *data = user_data;
 179   struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
 180   int ix = 0, length;
 181   char *name, *group, *type;
 182   int bitsize, regnum, save_restore;
 183
 184   length = VEC_length (gdb_xml_value_s, attributes);
 185
 186   name = attrs[ix++].value;
 187   bitsize = * (ULONGEST *) attrs[ix++].value;
 188
 189   if (ix < length && strcmp (attrs[ix].name, "regnum") == 0)
 190     regnum = * (ULONGEST *) attrs[ix++].value;
 191   else
 192     regnum = data->next_regnum;
 193
 194   if (ix < length && strcmp (attrs[ix].name, "type") == 0)
 195     type = attrs[ix++].value;
 196   else
 197     type = "int";
 198
 199   if (ix < length && strcmp (attrs[ix].name, "group") == 0)
 200     group = attrs[ix++].value;
 201   else
 202     group = NULL;
 203
 204   if (ix < length && strcmp (attrs[ix].name, "save-restore") == 0)
 205     save_restore = * (ULONGEST *) attrs[ix++].value;
 206   else
 207     save_restore = 1;
 208
 209   if (strcmp (type, "int") != 0
 210       && strcmp (type, "float") != 0
 211       && tdesc_named_type (data->current_feature, type) == NULL)
 212     gdb_xml_error (parser, _("Register \"%s\" has unknown type \"%s\""),
 213                    name, type);
 214
 215   tdesc_create_reg (data->current_feature, name, regnum, save_restore, group,
 216                     bitsize, type);
 217
 218   data->next_regnum = regnum + 1;
 219 }
 220
 221 /* Handle the start of a <union> element.  Initialize the type and
 222    record it with the current feature.  */
 223
 224 static void
 225 tdesc_start_union (struct gdb_xml_parser *parser,
 226                    const struct gdb_xml_element *element,
 227                    void *user_data, VEC(gdb_xml_value_s) *attributes)
 228 {
 229   struct tdesc_parsing_data *data = user_data;
 230   char *id = VEC_index (gdb_xml_value_s, attributes, 0)->value;
 231
 232   data->current_union = tdesc_create_union (data->current_feature, id);
 233 }
 234
 235 /* Handle the start of a <field> element.  Attach the field to the
 236    current union.  */
 237
 238 static void
 239 tdesc_start_field (struct gdb_xml_parser *parser,
 240                    const struct gdb_xml_element *element,
 241                    void *user_data, VEC(gdb_xml_value_s) *attributes)
 242 {
 243   struct tdesc_parsing_data *data = user_data;
 244   struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
 245   struct tdesc_type *field_type;
 246   char *field_name, *field_type_id;
 247
 248   field_name = attrs[0].value;
 249   field_type_id = attrs[1].value;
 250
 251   field_type = tdesc_named_type (data->current_feature, field_type_id);
 252   if (field_type == NULL)
 253     gdb_xml_error (parser, _("Union field \"%s\" references undefined "
 254                              "type \"%s\""),
 255                    field_name, field_type_id);
 256
 257   tdesc_add_field (data->current_union, field_name, field_type);
 258 }
 259
 260 /* Handle the start of a <vector> element.  Initialize the type and
 261    record it with the current feature.  */
 262
 263 static void
 264 tdesc_start_vector (struct gdb_xml_parser *parser,
 265                     const struct gdb_xml_element *element,
 266                     void *user_data, VEC(gdb_xml_value_s) *attributes)
 267 {
 268   struct tdesc_parsing_data *data = user_data;
 269   struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
 270   struct tdesc_type *field_type;
 271   char *id, *field_type_id;
 272   int count;
 273
 274   id = attrs[0].value;
 275   field_type_id = attrs[1].value;
 276   count = * (ULONGEST *) attrs[2].value;
 277
 278   field_type = tdesc_named_type (data->current_feature, field_type_id);
 279   if (field_type == NULL)
 280     gdb_xml_error (parser, _("Vector \"%s\" references undefined type \"%s\""),
 281                    id, field_type_id);
 282
 283   tdesc_create_vector (data->current_feature, id, field_type, count);
 284 }
 285
 286 /* The elements and attributes of an XML target description.  */
 287
 288 static const struct gdb_xml_attribute field_attributes[] = {
 289   { "name", GDB_XML_AF_NONE, NULL, NULL },
 290   { "type", GDB_XML_AF_NONE, NULL, NULL },
 291   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 292 };
 293
 294 static const struct gdb_xml_element union_children[] = {
 295   { "field", field_attributes, NULL, GDB_XML_EF_REPEATABLE,
 296     tdesc_start_field, NULL },
 297   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 298 };
 299
 300 static const struct gdb_xml_attribute reg_attributes[] = {
 301   { "name", GDB_XML_AF_NONE, NULL, NULL },
 302   { "bitsize", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 303   { "regnum", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
 304   { "type", GDB_XML_AF_OPTIONAL, NULL, NULL },
 305   { "group", GDB_XML_AF_OPTIONAL, NULL, NULL },
 306   { "save-restore", GDB_XML_AF_OPTIONAL,
 307     gdb_xml_parse_attr_enum, gdb_xml_enums_boolean },
 308   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 309 };
 310
 311 static const struct gdb_xml_attribute union_attributes[] = {
 312   { "id", GDB_XML_AF_NONE, NULL, NULL },
 313   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 314 };
 315
 316 static const struct gdb_xml_attribute vector_attributes[] = {
 317   { "id", GDB_XML_AF_NONE, NULL, NULL },
 318   { "type", GDB_XML_AF_NONE, NULL, NULL },
 319   { "count", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 320   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 321 };
 322
 323 static const struct gdb_xml_attribute feature_attributes[] = {
 324   { "name", GDB_XML_AF_NONE, NULL, NULL },
 325   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 326 };
 327
 328 static const struct gdb_xml_element feature_children[] = {
 329   { "reg", reg_attributes, NULL,
 330     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 331     tdesc_start_reg, NULL },
 332   { "union", union_attributes, union_children,
 333     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 334     tdesc_start_union, NULL },
 335   { "vector", vector_attributes, NULL,
 336     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 337     tdesc_start_vector, NULL },
 338   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 339 };
 340
 341 static const struct gdb_xml_attribute target_attributes[] = {
 342   { "version", GDB_XML_AF_NONE, NULL, NULL },
 343   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 344 };
 345
 346 static const struct gdb_xml_element target_children[] = {
 347   { "architecture", NULL, NULL, GDB_XML_EF_OPTIONAL,
 348     NULL, tdesc_end_arch },
 349   { "osabi", NULL, NULL, GDB_XML_EF_OPTIONAL,
 350     NULL, tdesc_end_osabi },
 351   { "compatible", NULL, NULL, GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 352     NULL, tdesc_end_compatible },
 353   { "feature", feature_attributes, feature_children,
 354     GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
 355     tdesc_start_feature, NULL },
 356   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 357 };
 358
 359 static const struct gdb_xml_element tdesc_elements[] = {
 360   { "target", target_attributes, target_children, GDB_XML_EF_NONE,
 361     tdesc_start_target, NULL },
 362   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 363 };
 364
 365 /* Parse DOCUMENT into a target description and return it.  */
 366
 367 static struct target_desc *
 368 tdesc_parse_xml (const char *document, xml_fetch_another fetcher,
 369                  void *fetcher_baton)
 370 {
 371   struct cleanup *back_to, *result_cleanup;
 372   struct gdb_xml_parser *parser;
 373   struct tdesc_parsing_data data;
 374   struct tdesc_xml_cache *cache;
 375   char *expanded_text;
 376   int ix;
 377
 378   /* Expand all XInclude directives.  */
 379   expanded_text = xml_process_xincludes (_("target description"),
 380                                          document, fetcher, fetcher_baton, 0);
 381   if (expanded_text == NULL)
 382     {
 383       warning (_("Could not load XML target description; ignoring"));
 384       return NULL;
 385     }
 386
 387   /* Check for an exact match in the list of descriptions we have
 388      previously parsed.  strcmp is a slightly inefficient way to
 389      do this; an SHA-1 checksum would work as well.  */
 390   for (ix = 0; VEC_iterate (tdesc_xml_cache_s, xml_cache, ix, cache); ix++)
 391     if (strcmp (cache->xml_document, expanded_text) == 0)
 392       {
 393        xfree (expanded_text);
 394        return cache->tdesc;
 395       }
 396
 397   back_to = make_cleanup (null_cleanup, NULL);
 398   parser = gdb_xml_create_parser_and_cleanup (_("target description"),
 399                                               tdesc_elements, &data);
 400   gdb_xml_use_dtd (parser, "gdb-target.dtd");
 401
 402   memset (&data, 0, sizeof (struct tdesc_parsing_data));
 403   data.tdesc = allocate_target_description ();
 404   result_cleanup = make_cleanup_free_target_description (data.tdesc);
 405   make_cleanup (xfree, expanded_text);
 406
 407   if (gdb_xml_parse (parser, expanded_text) == 0)
 408     {
 409       /* Parsed successfully.  */
 410       struct tdesc_xml_cache new_cache;
 411
 412       new_cache.xml_document = expanded_text;
 413       new_cache.tdesc = data.tdesc;
 414       VEC_safe_push (tdesc_xml_cache_s, xml_cache, &new_cache);
 415       discard_cleanups (result_cleanup);
 416       do_cleanups (back_to);
 417       return data.tdesc;
 418     }
 419   else
 420     {
 421       warning (_("Could not load XML target description; ignoring"));
 422       do_cleanups (back_to);
 423       return NULL;
 424     }
 425 }
 426 #endif /* HAVE_LIBEXPAT */
 427 \f
 428
 429 /* Read an XML target description from FILENAME.  Parse it, and return
 430    the parsed description.  */
 431
 432 const struct target_desc *
 433 file_read_description_xml (const char *filename)
 434 {
 435   struct target_desc *tdesc;
 436   char *tdesc_str;
 437   struct cleanup *back_to;
 438   char *dirname;
 439
 440   tdesc_str = xml_fetch_content_from_file (filename, NULL);
 441   if (tdesc_str == NULL)
 442     {
 443       warning (_("Could not open \"%s\""), filename);
 444       return NULL;
 445     }
 446
 447   back_to = make_cleanup (xfree, tdesc_str);
 448
 449   dirname = ldirname (filename);
 450   if (dirname != NULL)
 451     make_cleanup (xfree, dirname);
 452
 453   tdesc = tdesc_parse_xml (tdesc_str, xml_fetch_content_from_file, dirname);
 454   do_cleanups (back_to);
 455
 456   return tdesc;
 457 }
 458
 459 /* Read a string representation of available features from the target,
 460    using TARGET_OBJECT_AVAILABLE_FEATURES.  The returned string is
 461    malloc allocated and NUL-terminated.  NAME should be a non-NULL
 462    string identifying the XML document we want; the top level document
 463    is "target.xml".  Other calls may be performed for the DTD or
 464    for <xi:include>.  */
 465
 466 static char *
 467 fetch_available_features_from_target (const char *name, void *baton_)
 468 {
 469   struct target_ops *ops = baton_;
 470
 471   /* Read this object as a string.  This ensures that a NUL
 472      terminator is added.  */
 473   return target_read_stralloc (ops,
 474                                TARGET_OBJECT_AVAILABLE_FEATURES,
 475                                name);
 476 }
 477 \f
 478
 479 /* Read an XML target description using OPS.  Parse it, and return the
 480    parsed description.  */
 481
 482 const struct target_desc *
 483 target_read_description_xml (struct target_ops *ops)
 484 {
 485   struct target_desc *tdesc;
 486   char *tdesc_str;
 487   struct cleanup *back_to;
 488
 489   tdesc_str = fetch_available_features_from_target ("target.xml", ops);
 490   if (tdesc_str == NULL)
 491     return NULL;
 492
 493   back_to = make_cleanup (xfree, tdesc_str);
 494   tdesc = tdesc_parse_xml (tdesc_str,
 495                            fetch_available_features_from_target,
 496                            ops);
 497   do_cleanups (back_to);
 498
 499   return tdesc;
 500 }