aboutsummaryrefslogtreecommitdiff
path: root/gdb/xml-tdesc.c
blob: a4e1fe9a72e3afe8c60d3f4fd2ed67fb64fdd914 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
/* XML target description support for GDB.

   Copyright (C) 2006
   Free Software Foundation, Inc.

   Contributed by CodeSourcery.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.  */

#include "defs.h"
#include "gdbtypes.h"
#include "target.h"
#include "target-descriptions.h"
#include "xml-support.h"
#include "xml-tdesc.h"

#include "filenames.h"

#include "gdb_assert.h"

#if !defined(HAVE_LIBEXPAT)

/* Parse DOCUMENT into a target description.  Or don't, since we don't have
   an XML parser.  */

static struct target_desc *
tdesc_parse_xml (const char *document, xml_fetch_another fetcher,
		 void *fetcher_baton)
{
  static int have_warned;

  if (!have_warned)
    {
      have_warned = 1;
      warning (_("Can not parse XML target description; XML support was "
		 "disabled at compile time"));
    }

  return NULL;
}

#else /* HAVE_LIBEXPAT */

/* A record of every XML description we have parsed.  We never discard
   old descriptions, because we never discard gdbarches.  As long as we
   have a gdbarch referencing this description, we want to have a copy
   of it here, so that if we parse the same XML document again we can
   return the same "struct target_desc *"; if they are not singletons,
   then we will create unnecessary duplicate gdbarches.  See
   gdbarch_list_lookup_by_info.  */

struct tdesc_xml_cache
{
  const char *xml_document;
  struct target_desc *tdesc;
};
typedef struct tdesc_xml_cache tdesc_xml_cache_s;
DEF_VEC_O(tdesc_xml_cache_s);

static VEC(tdesc_xml_cache_s) *xml_cache;

/* Callback data for target description parsing.  */

struct tdesc_parsing_data
{
  /* The target description we are building.  */
  struct target_desc *tdesc;

  /* The target feature we are currently parsing, or last parsed.  */
  struct tdesc_feature *current_feature;

  /* The register number to use for the next register we see, if
     it does not have its own.  This starts at zero.  */
  int next_regnum;

  /* The union we are currently parsing, or last parsed.  */
  struct type *current_union;
};

/* Handle the end of an <architecture> element and its value.  */

static void
tdesc_end_arch (struct gdb_xml_parser *parser,
		const struct gdb_xml_element *element,
		void *user_data, const char *body_text)
{
  struct tdesc_parsing_data *data = user_data;
  const struct bfd_arch_info *arch;

  arch = bfd_scan_arch (body_text);
  if (arch == NULL)
    gdb_xml_error (parser, _("Target description specified unknown "
			     "architecture \"%s\""), body_text);
  set_tdesc_architecture (data->tdesc, arch);
}

/* Handle the start of a <feature> element.  */

static void
tdesc_start_feature (struct gdb_xml_parser *parser,
		     const struct gdb_xml_element *element,
		     void *user_data, VEC(gdb_xml_value_s) *attributes)
{
  struct tdesc_parsing_data *data = user_data;
  char *name = VEC_index (gdb_xml_value_s, attributes, 0)->value;

  data->current_feature = tdesc_create_feature (data->tdesc, name);
}

/* Handle the start of a <reg> element.  Fill in the optional
   attributes and attach it to the containing feature.  */

static void
tdesc_start_reg (struct gdb_xml_parser *parser,
		 const struct gdb_xml_element *element,
		 void *user_data, VEC(gdb_xml_value_s) *attributes)
{
  struct tdesc_parsing_data *data = user_data;
  struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
  int ix = 0, length;
  char *name, *group, *type;
  int bitsize, regnum, save_restore;

  length = VEC_length (gdb_xml_value_s, attributes);

  name = attrs[ix++].value;
  bitsize = * (ULONGEST *) attrs[ix++].value;

  if (ix < length && strcmp (attrs[ix].name, "regnum") == 0)
    regnum = * (ULONGEST *) attrs[ix++].value;
  else
    regnum = data->next_regnum;

  if (ix < length && strcmp (attrs[ix].name, "type") == 0)
    type = attrs[ix++].value;
  else
    type = "int";

  if (ix < length && strcmp (attrs[ix].name, "group") == 0)
    group = attrs[ix++].value;
  else
    group = NULL;

  if (ix < length && strcmp (attrs[ix].name, "save-restore") == 0)
    save_restore = * (ULONGEST *) attrs[ix++].value;
  else
    save_restore = 1;

  if (strcmp (type, "int") != 0
      && strcmp (type, "float") != 0
      && strcmp (type, "code_ptr") != 0
      && strcmp (type, "data_ptr") != 0
      && tdesc_named_type (data->current_feature, type) == NULL)
    gdb_xml_error (parser, _("Register \"%s\" has unknown type \"%s\""),
		   name, type);

  tdesc_create_reg (data->current_feature, name, regnum, save_restore, group,
		    bitsize, type);

  data->next_regnum = regnum + 1;
}

/* Handle the start of a <union> element.  Initialize the type and
   record it with the current feature.  */

static void
tdesc_start_union (struct gdb_xml_parser *parser,
		   const struct gdb_xml_element *element,
		   void *user_data, VEC(gdb_xml_value_s) *attributes)
{
  struct tdesc_parsing_data *data = user_data;
  char *id = VEC_index (gdb_xml_value_s, attributes, 0)->value;
  struct type *type;

  type = init_composite_type (NULL, TYPE_CODE_UNION);
  TYPE_NAME (type) = xstrdup (id);
  tdesc_record_type (data->current_feature, type);
  data->current_union = type;
}

/* Handle the end of a <union> element.  */

static void
tdesc_end_union (struct gdb_xml_parser *parser,
		 const struct gdb_xml_element *element,
		 void *user_data, const char *body_text)
{
  struct tdesc_parsing_data *data = user_data;
  int i;

  /* If any of the children of this union are vectors, flag the union
     as a vector also.  This allows e.g. a union of two vector types
     to show up automatically in "info vector".  */
  for (i = 0; i < TYPE_NFIELDS (data->current_union); i++)
    if (TYPE_VECTOR (TYPE_FIELD_TYPE (data->current_union, i)))
      {
        TYPE_FLAGS (data->current_union) |= TYPE_FLAG_VECTOR;
        break;
      }
}

/* Handle the start of a <field> element.  Attach the field to the
   current union.  */

static void
tdesc_start_field (struct gdb_xml_parser *parser,
		   const struct gdb_xml_element *element,
		   void *user_data, VEC(gdb_xml_value_s) *attributes)
{
  struct tdesc_parsing_data *data = user_data;
  struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
  struct type *type, *field_type;
  char *field_name, *field_type_id;

  field_name = attrs[0].value;
  field_type_id = attrs[1].value;

  field_type = tdesc_named_type (data->current_feature, field_type_id);
  if (field_type == NULL)
    gdb_xml_error (parser, _("Union field \"%s\" references undefined "
			     "type \"%s\""),
		   field_name, field_type_id);

  append_composite_type_field (data->current_union, xstrdup (field_name),
			       field_type);
}

/* Handle the start of a <vector> element.  Initialize the type and
   record it with the current feature.  */

static void
tdesc_start_vector (struct gdb_xml_parser *parser,
		    const struct gdb_xml_element *element,
		    void *user_data, VEC(gdb_xml_value_s) *attributes)
{
  struct tdesc_parsing_data *data = user_data;
  struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
  struct type *type, *field_type, *range_type;
  char *id, *field_type_id;
  int count;

  id = attrs[0].value;
  field_type_id = attrs[1].value;
  count = * (ULONGEST *) attrs[2].value;

  field_type = tdesc_named_type (data->current_feature, field_type_id);
  if (field_type == NULL)
    gdb_xml_error (parser, _("Vector \"%s\" references undefined type \"%s\""),
		   id, field_type_id);

  /* A vector is just an array plus a special flag.  */
  range_type = create_range_type (NULL, builtin_type_int, 0, count - 1);
  type = create_array_type (NULL, field_type, range_type);
  TYPE_NAME (type) = xstrdup (id);

  TYPE_FLAGS (type) |= TYPE_FLAG_VECTOR;

  tdesc_record_type (data->current_feature, type);
}

/* The elements and attributes of an XML target description.  */

static const struct gdb_xml_attribute field_attributes[] = {
  { "name", GDB_XML_AF_NONE, NULL, NULL },
  { "type", GDB_XML_AF_NONE, NULL, NULL },
  { NULL, GDB_XML_AF_NONE, NULL, NULL }
};

static const struct gdb_xml_element union_children[] = {
  { "field", field_attributes, NULL, GDB_XML_EF_REPEATABLE,
    tdesc_start_field, NULL },
  { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};

static const struct gdb_xml_attribute reg_attributes[] = {
  { "name", GDB_XML_AF_NONE, NULL, NULL },
  { "bitsize", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
  { "regnum", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
  { "type", GDB_XML_AF_OPTIONAL, NULL, NULL },
  { "group", GDB_XML_AF_OPTIONAL, NULL, NULL },
  { "save-restore", GDB_XML_AF_OPTIONAL,
    gdb_xml_parse_attr_enum, gdb_xml_enums_boolean },
  { NULL, GDB_XML_AF_NONE, NULL, NULL }
};

static const struct gdb_xml_attribute union_attributes[] = {
  { "id", GDB_XML_AF_NONE, NULL, NULL },
  { NULL, GDB_XML_AF_NONE, NULL, NULL }
};

static const struct gdb_xml_attribute vector_attributes[] = {
  { "id", GDB_XML_AF_NONE, NULL, NULL },
  { "type", GDB_XML_AF_NONE, NULL, NULL },
  { "count", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
  { NULL, GDB_XML_AF_NONE, NULL, NULL }
};

static const struct gdb_xml_attribute feature_attributes[] = {
  { "name", GDB_XML_AF_NONE, NULL, NULL },
  { NULL, GDB_XML_AF_NONE, NULL, NULL }
};

static const struct gdb_xml_element feature_children[] = {
  { "reg", reg_attributes, NULL,
    GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
    tdesc_start_reg, NULL },
  { "union", union_attributes, union_children,
    GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
    tdesc_start_union, tdesc_end_union },
  { "vector", vector_attributes, NULL,
    GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
    tdesc_start_vector, NULL },
  { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};

static const struct gdb_xml_element target_children[] = {
  { "architecture", NULL, NULL, GDB_XML_EF_OPTIONAL,
    NULL, tdesc_end_arch },
  { "feature", feature_attributes, feature_children,
    GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
    tdesc_start_feature, NULL },
  { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};

static const struct gdb_xml_element tdesc_elements[] = {
  { "target", NULL, target_children, GDB_XML_EF_NONE,
    NULL, NULL },
  { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};

/* Parse DOCUMENT into a target description and return it.  */

static struct target_desc *
tdesc_parse_xml (const char *document, xml_fetch_another fetcher,
		 void *fetcher_baton)
{
  struct cleanup *back_to, *result_cleanup;
  struct gdb_xml_parser *parser;
  struct tdesc_parsing_data data;
  struct tdesc_xml_cache *cache;
  char *expanded_text;
  int ix;

  /* Expand all XInclude directives.  */
  expanded_text = xml_process_xincludes (_("target description"),
					 document, fetcher, fetcher_baton, 0);
  if (expanded_text == NULL)
    {
      warning (_("Could not load XML target description; ignoring"));
      return NULL;
    }

  /* Check for an exact match in the list of descriptions we have
     previously parsed.  strcmp is a slightly inefficient way to
     do this; an SHA-1 checksum would work as well.  */
  for (ix = 0; VEC_iterate (tdesc_xml_cache_s, xml_cache, ix, cache); ix++)
    if (strcmp (cache->xml_document, expanded_text) == 0)
      {
       xfree (expanded_text);
       return cache->tdesc;
      }

  back_to = make_cleanup (null_cleanup, NULL);
  parser = gdb_xml_create_parser_and_cleanup (_("target description"),
					      tdesc_elements, &data);
  gdb_xml_use_dtd (parser, "gdb-target.dtd");

  memset (&data, 0, sizeof (struct tdesc_parsing_data));
  data.tdesc = allocate_target_description ();
  result_cleanup = make_cleanup_free_target_description (data.tdesc);
  make_cleanup (xfree, expanded_text);

  if (gdb_xml_parse (parser, expanded_text) == 0)
    {
      /* Parsed successfully.  */
      struct tdesc_xml_cache new_cache;

      new_cache.xml_document = expanded_text;
      new_cache.tdesc = data.tdesc;
      VEC_safe_push (tdesc_xml_cache_s, xml_cache, &new_cache);
      discard_cleanups (result_cleanup);
      do_cleanups (back_to);
      return data.tdesc;
    }
  else
    {
      warning (_("Could not load XML target description; ignoring"));
      do_cleanups (back_to);
      return NULL;
    }
}
#endif /* HAVE_LIBEXPAT */


/* Close FILE.  */

static void
do_cleanup_fclose (void *file)
{
  fclose (file);
}

/* Open FILENAME, read all its text into memory, close it, and return
   the text.  If something goes wrong, return NULL and warn.  */

static char *
fetch_xml_from_file (const char *filename, void *baton)
{
  const char *dirname = baton;
  FILE *file;
  struct cleanup *back_to;
  char *text;
  size_t len, offset;

  if (dirname && *dirname)
    {
      char *fullname = concat (dirname, "/", filename, NULL);
      if (fullname == NULL)
	nomem (0);
      file = fopen (fullname, FOPEN_RT);
      xfree (fullname);
    }
  else
    file = fopen (filename, FOPEN_RT);

  if (file == NULL)
    return NULL;

  back_to = make_cleanup (do_cleanup_fclose, file);

  /* Read in the whole file, one chunk at a time.  */
  len = 4096;
  offset = 0;
  text = xmalloc (len);
  make_cleanup (free_current_contents, &text);
  while (1)
    {
      size_t bytes_read;

      /* Continue reading where the last read left off.  Leave at least
	 one byte so that we can NUL-terminate the result.  */
      bytes_read = fread (text + offset, 1, len - offset - 1, file);
      if (ferror (file))
	{
	  warning (_("Read error from \"%s\""), filename);
	  do_cleanups (back_to);
	  return NULL;
	}

      offset += bytes_read;

      if (feof (file))
	break;

      len = len * 2;
      text = xrealloc (text, len);
    }

  fclose (file);
  discard_cleanups (back_to);

  text[offset] = '\0';
  return text;
}

/* Read an XML target description from FILENAME.  Parse it, and return
   the parsed description.  */

const struct target_desc *
file_read_description_xml (const char *filename)
{
  struct target_desc *tdesc;
  char *tdesc_str;
  struct cleanup *back_to;
  const char *base;
  char *dirname;

  tdesc_str = fetch_xml_from_file (filename, NULL);
  if (tdesc_str == NULL)
    {
      warning (_("Could not open \"%s\""), filename);
      return NULL;
    }

  back_to = make_cleanup (xfree, tdesc_str);

  /* Simple, portable version of dirname that does not modify its
     argument.  */
  base = lbasename (filename);
  while (base > filename && IS_DIR_SEPARATOR (base[-1]))
    --base;
  if (base > filename)
    {
      dirname = xmalloc (base - filename + 2);
      memcpy (dirname, filename, base - filename);

      /* On DOS based file systems, convert "d:foo" to "d:.", so that
	 we create "d:./bar" later instead of the (different)
	 "d:/bar".  */
      if (base - filename == 2 && IS_ABSOLUTE_PATH (base)
	  && !IS_DIR_SEPARATOR (filename[0]))
	dirname[base++ - filename] = '.';

      dirname[base - filename] = '\0';
      make_cleanup (xfree, dirname);
    }
  else
    dirname = NULL;

  tdesc = tdesc_parse_xml (tdesc_str, fetch_xml_from_file, dirname);
  do_cleanups (back_to);

  return tdesc;
}

/* Read a string representation of available features from the target,
   using TARGET_OBJECT_AVAILABLE_FEATURES.  The returned string is
   malloc allocated and NUL-terminated.  NAME should be a non-NULL
   string identifying the XML document we want; the top level document
   is "target.xml".  Other calls may be performed for the DTD or
   for <xi:include>.  */

static char *
fetch_available_features_from_target (const char *name, void *baton_)
{
  struct target_ops *ops = baton_;

  /* Read this object as a string.  This ensures that a NUL
     terminator is added.  */
  return target_read_stralloc (ops,
			       TARGET_OBJECT_AVAILABLE_FEATURES,
			       name);
}


/* Read an XML target description using OPS.  Parse it, and return the
   parsed description.  */

const struct target_desc *
target_read_description_xml (struct target_ops *ops)
{
  struct target_desc *tdesc;
  char *tdesc_str;
  struct cleanup *back_to;

  tdesc_str = fetch_available_features_from_target ("target.xml", ops);
  if (tdesc_str == NULL)
    return NULL;

  back_to = make_cleanup (xfree, tdesc_str);
  tdesc = tdesc_parse_xml (tdesc_str,
			   fetch_available_features_from_target,
			   ops);
  do_cleanups (back_to);

  return tdesc;
}