gdb/solib-target.c

   1 /* Definitions for targets which report shared library events.
   2
   3    Copyright (C) 2007
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21    Boston, MA 02110-1301, USA.  */
  22
  23 #include "defs.h"
  24 #include "objfiles.h"
  25 #include "solist.h"
  26 #include "symtab.h"
  27 #include "symfile.h"
  28 #include "target.h"
  29 #include "vec.h"
  30
  31 #include "gdb_string.h"
  32
  33 DEF_VEC_O(CORE_ADDR);
  34
  35 /* Private data for each loaded library.  */
  36 struct lm_info
  37 {
  38   /* The library's name.  The name is normally kept in the struct
  39      so_list; it is only here during XML parsing.  */
  40   char *name;
  41
  42   /* The base addresses for each independently relocatable segment of
  43      this shared library.  */
  44   VEC(CORE_ADDR) *segment_bases;
  45
  46   /* The cached offsets for each section of this shared library,
  47      determined from SEGMENT_BASES.  */
  48   struct section_offsets *offsets;
  49 };
  50
  51 typedef struct lm_info *lm_info_p;
  52 DEF_VEC_P(lm_info_p);
  53
  54 #if !defined(HAVE_LIBEXPAT)
  55
  56 static VEC(lm_info_p)
  57 solib_target_parse_libraries (const char *library)
  58 {
  59   static int have_warned;
  60
  61   if (!have_warned)
  62     {
  63       have_warned = 1;
  64       warning (_("Can not parse XML library list; XML support was disabled "
  65                  "at compile time"));
  66     }
  67
  68   return NULL;
  69 }
  70
  71 #else /* HAVE_LIBEXPAT */
  72
  73 #include "xml-support.h"
  74
  75 /* Handle the start of a <segment> element.  */
  76
  77 static void
  78 library_list_start_segment (struct gdb_xml_parser *parser,
  79                             const struct gdb_xml_element *element,
  80                             void *user_data, VEC(gdb_xml_value_s) *attributes)
  81 {
  82   VEC(lm_info_p) **list = user_data;
  83   struct lm_info *last = VEC_last (lm_info_p, *list);
  84   ULONGEST *address_p = VEC_index (gdb_xml_value_s, attributes, 0)->value;
  85   CORE_ADDR address = (CORE_ADDR) *address_p;
  86
  87   VEC_safe_push (CORE_ADDR, last->segment_bases, &address);
  88 }
  89
  90 /* Handle the start of a <library> element.  */
  91
  92 static void
  93 library_list_start_library (struct gdb_xml_parser *parser,
  94                             const struct gdb_xml_element *element,
  95                             void *user_data, VEC(gdb_xml_value_s) *attributes)
  96 {
  97   VEC(lm_info_p) **list = user_data;
  98   struct lm_info *item = XZALLOC (struct lm_info);
  99   const char *name = VEC_index (gdb_xml_value_s, attributes, 0)->value;
 100
 101   item->name = xstrdup (name);
 102   VEC_safe_push (lm_info_p, *list, item);
 103 }
 104
 105 /* Handle the start of a <library-list> element.  */
 106
 107 static void
 108 library_list_start_list (struct gdb_xml_parser *parser,
 109                          const struct gdb_xml_element *element,
 110                          void *user_data, VEC(gdb_xml_value_s) *attributes)
 111 {
 112   char *version = VEC_index (gdb_xml_value_s, attributes, 0)->value;
 113
 114   if (strcmp (version, "1.0") != 0)
 115     gdb_xml_error (parser,
 116                    _("Library list has unsupported version \"%s\""),
 117                    version);
 118 }
 119
 120 /* Discard the constructed library list.  */
 121
 122 static void
 123 solib_target_free_library_list (void *p)
 124 {
 125   VEC(lm_info_p) **result = p;
 126   struct lm_info *info;
 127   int ix;
 128
 129   for (ix = 0; VEC_iterate (lm_info_p, *result, ix, info); ix++)
 130     {
 131       xfree (info->name);
 132       VEC_free (CORE_ADDR, info->segment_bases);
 133       xfree (info);
 134     }
 135   VEC_free (lm_info_p, *result);
 136   *result = NULL;
 137 }
 138
 139 /* The allowed elements and attributes for an XML library list.
 140    The root element is a <library-list>.  */
 141
 142 const struct gdb_xml_attribute segment_attributes[] = {
 143   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 144   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 145 };
 146
 147 const struct gdb_xml_element library_children[] = {
 148   { "segment", segment_attributes, NULL, GDB_XML_EF_REPEATABLE,
 149     library_list_start_segment, NULL },
 150   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 151 };
 152
 153 const struct gdb_xml_attribute library_attributes[] = {
 154   { "name", GDB_XML_AF_NONE, NULL, NULL },
 155   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 156 };
 157
 158 const struct gdb_xml_element library_list_children[] = {
 159   { "library", library_attributes, library_children,
 160     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 161     library_list_start_library, NULL },
 162   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 163 };
 164
 165 const struct gdb_xml_attribute library_list_attributes[] = {
 166   { "version", GDB_XML_AF_NONE, NULL, NULL },
 167   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 168 };
 169
 170 const struct gdb_xml_element library_list_elements[] = {
 171   { "library-list", library_list_attributes, library_list_children,
 172     GDB_XML_EF_NONE, library_list_start_list, NULL },
 173   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 174 };
 175
 176 static VEC(lm_info_p) *
 177 solib_target_parse_libraries (const char *library)
 178 {
 179   struct gdb_xml_parser *parser;
 180   VEC(lm_info_p) *result = NULL;
 181   struct cleanup *before_deleting_result, *back_to;
 182
 183   back_to = make_cleanup (null_cleanup, NULL);
 184   parser = gdb_xml_create_parser_and_cleanup (_("target library list"),
 185                                               library_list_elements, &result);
 186   gdb_xml_use_dtd (parser, "library-list.dtd");
 187
 188   before_deleting_result = make_cleanup (solib_target_free_library_list,
 189                                          &result);
 190
 191   if (gdb_xml_parse (parser, library) == 0)
 192     /* Parsed successfully, don't need to delete the result.  */
 193     discard_cleanups (before_deleting_result);
 194
 195   do_cleanups (back_to);
 196   return result;
 197 }
 198 #endif
 199
 200 static struct so_list *
 201 solib_target_current_sos (void)
 202 {
 203   struct so_list *new_solib, *start = NULL, *last = NULL;
 204   const char *library_document;
 205   VEC(lm_info_p) *library_list;
 206   struct lm_info *info;
 207   int ix;
 208
 209   /* Fetch the list of shared libraries.  */
 210   library_document = target_read_stralloc (&current_target,
 211                                            TARGET_OBJECT_LIBRARIES,
 212                                            NULL);
 213   if (library_document == NULL)
 214     return NULL;
 215
 216   /* Parse the list.  */
 217   library_list = solib_target_parse_libraries (library_document);
 218   if (library_list == NULL)
 219     return NULL;
 220
 221   /* Build a struct so_list for each entry on the list.  */
 222   for (ix = 0; VEC_iterate (lm_info_p, library_list, ix, info); ix++)
 223     {
 224       new_solib = XZALLOC (struct so_list);
 225       strncpy (new_solib->so_name, info->name, SO_NAME_MAX_PATH_SIZE - 1);
 226       new_solib->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 227       strncpy (new_solib->so_original_name, info->name,
 228                SO_NAME_MAX_PATH_SIZE - 1);
 229       new_solib->so_original_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 230       new_solib->lm_info = info;
 231
 232       /* We no longer need this copy of the name.  */
 233       xfree (info->name);
 234       info->name = NULL;
 235
 236       /* Add it to the list.  */
 237       if (!start)
 238         last = start = new_solib;
 239       else
 240         {
 241           last->next = new_solib;
 242           last = new_solib;
 243         }
 244     }
 245
 246   /* Free the library list, but not its members.  */
 247   VEC_free (lm_info_p, library_list);
 248
 249   return start;
 250 }
 251
 252 static void
 253 solib_target_special_symbol_handling (void)
 254 {
 255   /* Nothing needed.  */
 256 }
 257
 258 static void
 259 solib_target_solib_create_inferior_hook (void)
 260 {
 261   /* Nothing needed.  */
 262 }
 263
 264 static void
 265 solib_target_clear_solib (void)
 266 {
 267   /* Nothing needed.  */
 268 }
 269
 270 static void
 271 solib_target_free_so (struct so_list *so)
 272 {
 273   gdb_assert (so->lm_info->name == NULL);
 274   xfree (so->lm_info->offsets);
 275   VEC_free (CORE_ADDR, so->lm_info->segment_bases);
 276   xfree (so->lm_info);
 277 }
 278
 279 static void
 280 solib_target_relocate_section_addresses (struct so_list *so,
 281                                          struct section_table *sec)
 282 {
 283   int flags = bfd_get_section_flags (sec->bfd, sec->the_bfd_section);
 284   CORE_ADDR offset;
 285
 286   /* Build the offset table only once per object file.  We can not do
 287      it any earlier, since we need to open the file first.  */
 288   if (so->lm_info->offsets == NULL)
 289     {
 290       struct symfile_segment_data *data;
 291       int num_sections = bfd_count_sections (so->abfd);
 292
 293       so->lm_info->offsets = xzalloc (SIZEOF_N_SECTION_OFFSETS (num_sections));
 294
 295       data = get_symfile_segment_data (so->abfd);
 296       if (data == NULL)
 297         warning (_("Could not relocate shared library \"%s\": no segments"),
 298                  so->so_name);
 299       else
 300         {
 301           ULONGEST orig_delta;
 302           int i;
 303           int num_bases = VEC_length (CORE_ADDR, so->lm_info->segment_bases);
 304           CORE_ADDR *segment_bases = VEC_address (CORE_ADDR,
 305                                                   so->lm_info->segment_bases);
 306
 307           if (!symfile_map_offsets_to_segments (so->abfd, data,
 308                                                 so->lm_info->offsets,
 309                                                 num_bases, segment_bases))
 310             warning (_("Could not relocate shared library \"%s\": bad offsets"),
 311                      so->so_name);
 312
 313           /* Find the range of addresses to report for this library in
 314              "info sharedlibrary".  Report any consecutive segments
 315              which were relocated as a single unit.  */
 316           gdb_assert (num_bases > 0);
 317           orig_delta = segment_bases[0] - data->segment_bases[0];
 318
 319           for (i = 1; i < data->num_segments; i++)
 320             {
 321               /* If we have run out of offsets, assume all remaining segments
 322                  have the same offset.  */
 323               if (i >= num_bases)
 324                 continue;
 325
 326               /* If this segment does not have the same offset, do not include
 327                  it in the library's range.  */
 328               if (segment_bases[i] - data->segment_bases[i] != orig_delta)
 329                 break;
 330             }
 331
 332           so->addr_low = segment_bases[0];
 333           so->addr_high = (data->segment_bases[i - 1]
 334                            + data->segment_sizes[i - 1]
 335                            + orig_delta);
 336           gdb_assert (so->addr_low <= so->addr_high);
 337
 338           free_symfile_segment_data (data);
 339         }
 340     }
 341
 342   offset = so->lm_info->offsets->offsets[sec->the_bfd_section->index];
 343   sec->addr += offset;
 344   sec->endaddr += offset;
 345 }
 346
 347 static int
 348 solib_target_open_symbol_file_object (void *from_ttyp)
 349 {
 350   /* We can't locate the main symbol file based on the target's
 351      knowledge; the user has to specify it.  */
 352   return 0;
 353 }
 354
 355 static int
 356 solib_target_in_dynsym_resolve_code (CORE_ADDR pc)
 357 {
 358   /* We don't have a range of addresses for the dynamic linker; there
 359      may not be one in the program's address space.  So only report
 360      PLT entries (which may be import stubs).  */
 361   return in_plt_section (pc, NULL);
 362 }
 363
 364 static struct target_so_ops solib_target_so_ops;
 365
 366 extern initialize_file_ftype _initialize_solib_target; /* -Wmissing-prototypes */
 367
 368 void
 369 _initialize_solib_target (void)
 370 {
 371   solib_target_so_ops.relocate_section_addresses
 372     = solib_target_relocate_section_addresses;
 373   solib_target_so_ops.free_so = solib_target_free_so;
 374   solib_target_so_ops.clear_solib = solib_target_clear_solib;
 375   solib_target_so_ops.solib_create_inferior_hook
 376     = solib_target_solib_create_inferior_hook;
 377   solib_target_so_ops.special_symbol_handling
 378     = solib_target_special_symbol_handling;
 379   solib_target_so_ops.current_sos = solib_target_current_sos;
 380   solib_target_so_ops.open_symbol_file_object
 381     = solib_target_open_symbol_file_object;
 382   solib_target_so_ops.in_dynsym_resolve_code
 383     = solib_target_in_dynsym_resolve_code;
 384
 385   current_target_so_ops = &solib_target_so_ops;
 386 }