gdb/solib-target.c

   1 /* Definitions for targets which report shared library events.
   2
   3    Copyright (C) 2007, 2008 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "objfiles.h"
  22 #include "solist.h"
  23 #include "symtab.h"
  24 #include "symfile.h"
  25 #include "target.h"
  26 #include "vec.h"
  27 #include "solib-target.h"
  28
  29 #include "gdb_string.h"
  30
  31 DEF_VEC_O(CORE_ADDR);
  32
  33 /* Private data for each loaded library.  */
  34 struct lm_info
  35 {
  36   /* The library's name.  The name is normally kept in the struct
  37      so_list; it is only here during XML parsing.  */
  38   char *name;
  39
  40   /* The base addresses for each independently relocatable segment of
  41      this shared library.  */
  42   VEC(CORE_ADDR) *segment_bases;
  43
  44   /* The cached offsets for each section of this shared library,
  45      determined from SEGMENT_BASES.  */
  46   struct section_offsets *offsets;
  47 };
  48
  49 typedef struct lm_info *lm_info_p;
  50 DEF_VEC_P(lm_info_p);
  51
  52 #if !defined(HAVE_LIBEXPAT)
  53
  54 static VEC(lm_info_p) *
  55 solib_target_parse_libraries (const char *library)
  56 {
  57   static int have_warned;
  58
  59   if (!have_warned)
  60     {
  61       have_warned = 1;
  62       warning (_("Can not parse XML library list; XML support was disabled "
  63                  "at compile time"));
  64     }
  65
  66   return NULL;
  67 }
  68
  69 #else /* HAVE_LIBEXPAT */
  70
  71 #include "xml-support.h"
  72
  73 /* Handle the start of a <segment> element.  */
  74
  75 static void
  76 library_list_start_segment (struct gdb_xml_parser *parser,
  77                             const struct gdb_xml_element *element,
  78                             void *user_data, VEC(gdb_xml_value_s) *attributes)
  79 {
  80   VEC(lm_info_p) **list = user_data;
  81   struct lm_info *last = VEC_last (lm_info_p, *list);
  82   ULONGEST *address_p = VEC_index (gdb_xml_value_s, attributes, 0)->value;
  83   CORE_ADDR address = (CORE_ADDR) *address_p;
  84
  85   VEC_safe_push (CORE_ADDR, last->segment_bases, &address);
  86 }
  87
  88 /* Handle the start of a <library> element.  */
  89
  90 static void
  91 library_list_start_library (struct gdb_xml_parser *parser,
  92                             const struct gdb_xml_element *element,
  93                             void *user_data, VEC(gdb_xml_value_s) *attributes)
  94 {
  95   VEC(lm_info_p) **list = user_data;
  96   struct lm_info *item = XZALLOC (struct lm_info);
  97   const char *name = VEC_index (gdb_xml_value_s, attributes, 0)->value;
  98
  99   item->name = xstrdup (name);
 100   VEC_safe_push (lm_info_p, *list, item);
 101 }
 102
 103 /* Handle the start of a <library-list> element.  */
 104
 105 static void
 106 library_list_start_list (struct gdb_xml_parser *parser,
 107                          const struct gdb_xml_element *element,
 108                          void *user_data, VEC(gdb_xml_value_s) *attributes)
 109 {
 110   char *version = VEC_index (gdb_xml_value_s, attributes, 0)->value;
 111
 112   if (strcmp (version, "1.0") != 0)
 113     gdb_xml_error (parser,
 114                    _("Library list has unsupported version \"%s\""),
 115                    version);
 116 }
 117
 118 /* Discard the constructed library list.  */
 119
 120 static void
 121 solib_target_free_library_list (void *p)
 122 {
 123   VEC(lm_info_p) **result = p;
 124   struct lm_info *info;
 125   int ix;
 126
 127   for (ix = 0; VEC_iterate (lm_info_p, *result, ix, info); ix++)
 128     {
 129       xfree (info->name);
 130       VEC_free (CORE_ADDR, info->segment_bases);
 131       xfree (info);
 132     }
 133   VEC_free (lm_info_p, *result);
 134   *result = NULL;
 135 }
 136
 137 /* The allowed elements and attributes for an XML library list.
 138    The root element is a <library-list>.  */
 139
 140 const struct gdb_xml_attribute segment_attributes[] = {
 141   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 142   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 143 };
 144
 145 const struct gdb_xml_element library_children[] = {
 146   { "segment", segment_attributes, NULL, GDB_XML_EF_REPEATABLE,
 147     library_list_start_segment, NULL },
 148   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 149 };
 150
 151 const struct gdb_xml_attribute library_attributes[] = {
 152   { "name", GDB_XML_AF_NONE, NULL, NULL },
 153   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 154 };
 155
 156 const struct gdb_xml_element library_list_children[] = {
 157   { "library", library_attributes, library_children,
 158     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 159     library_list_start_library, NULL },
 160   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 161 };
 162
 163 const struct gdb_xml_attribute library_list_attributes[] = {
 164   { "version", GDB_XML_AF_NONE, NULL, NULL },
 165   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 166 };
 167
 168 const struct gdb_xml_element library_list_elements[] = {
 169   { "library-list", library_list_attributes, library_list_children,
 170     GDB_XML_EF_NONE, library_list_start_list, NULL },
 171   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 172 };
 173
 174 static VEC(lm_info_p) *
 175 solib_target_parse_libraries (const char *library)
 176 {
 177   struct gdb_xml_parser *parser;
 178   VEC(lm_info_p) *result = NULL;
 179   struct cleanup *before_deleting_result, *back_to;
 180
 181   back_to = make_cleanup (null_cleanup, NULL);
 182   parser = gdb_xml_create_parser_and_cleanup (_("target library list"),
 183                                               library_list_elements, &result);
 184   gdb_xml_use_dtd (parser, "library-list.dtd");
 185
 186   before_deleting_result = make_cleanup (solib_target_free_library_list,
 187                                          &result);
 188
 189   if (gdb_xml_parse (parser, library) == 0)
 190     /* Parsed successfully, don't need to delete the result.  */
 191     discard_cleanups (before_deleting_result);
 192
 193   do_cleanups (back_to);
 194   return result;
 195 }
 196 #endif
 197
 198 static struct so_list *
 199 solib_target_current_sos (void)
 200 {
 201   struct so_list *new_solib, *start = NULL, *last = NULL;
 202   const char *library_document;
 203   VEC(lm_info_p) *library_list;
 204   struct lm_info *info;
 205   int ix;
 206
 207   /* Fetch the list of shared libraries.  */
 208   library_document = target_read_stralloc (&current_target,
 209                                            TARGET_OBJECT_LIBRARIES,
 210                                            NULL);
 211   if (library_document == NULL)
 212     return NULL;
 213
 214   /* Parse the list.  */
 215   library_list = solib_target_parse_libraries (library_document);
 216   if (library_list == NULL)
 217     return NULL;
 218
 219   /* Build a struct so_list for each entry on the list.  */
 220   for (ix = 0; VEC_iterate (lm_info_p, library_list, ix, info); ix++)
 221     {
 222       new_solib = XZALLOC (struct so_list);
 223       strncpy (new_solib->so_name, info->name, SO_NAME_MAX_PATH_SIZE - 1);
 224       new_solib->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 225       strncpy (new_solib->so_original_name, info->name,
 226                SO_NAME_MAX_PATH_SIZE - 1);
 227       new_solib->so_original_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 228       new_solib->lm_info = info;
 229
 230       /* We no longer need this copy of the name.  */
 231       xfree (info->name);
 232       info->name = NULL;
 233
 234       /* Add it to the list.  */
 235       if (!start)
 236         last = start = new_solib;
 237       else
 238         {
 239           last->next = new_solib;
 240           last = new_solib;
 241         }
 242     }
 243
 244   /* Free the library list, but not its members.  */
 245   VEC_free (lm_info_p, library_list);
 246
 247   return start;
 248 }
 249
 250 static void
 251 solib_target_special_symbol_handling (void)
 252 {
 253   /* Nothing needed.  */
 254 }
 255
 256 static void
 257 solib_target_solib_create_inferior_hook (void)
 258 {
 259   /* Nothing needed.  */
 260 }
 261
 262 static void
 263 solib_target_clear_solib (void)
 264 {
 265   /* Nothing needed.  */
 266 }
 267
 268 static void
 269 solib_target_free_so (struct so_list *so)
 270 {
 271   gdb_assert (so->lm_info->name == NULL);
 272   xfree (so->lm_info->offsets);
 273   VEC_free (CORE_ADDR, so->lm_info->segment_bases);
 274   xfree (so->lm_info);
 275 }
 276
 277 static void
 278 solib_target_relocate_section_addresses (struct so_list *so,
 279                                          struct section_table *sec)
 280 {
 281   int flags = bfd_get_section_flags (sec->bfd, sec->the_bfd_section);
 282   CORE_ADDR offset;
 283
 284   /* Build the offset table only once per object file.  We can not do
 285      it any earlier, since we need to open the file first.  */
 286   if (so->lm_info->offsets == NULL)
 287     {
 288       struct symfile_segment_data *data;
 289       int num_sections = bfd_count_sections (so->abfd);
 290
 291       so->lm_info->offsets = xzalloc (SIZEOF_N_SECTION_OFFSETS (num_sections));
 292
 293       data = get_symfile_segment_data (so->abfd);
 294       if (data == NULL)
 295         warning (_("Could not relocate shared library \"%s\": no segments"),
 296                  so->so_name);
 297       else
 298         {
 299           ULONGEST orig_delta;
 300           int i;
 301           int num_bases = VEC_length (CORE_ADDR, so->lm_info->segment_bases);
 302           CORE_ADDR *segment_bases = VEC_address (CORE_ADDR,
 303                                                   so->lm_info->segment_bases);
 304
 305           if (!symfile_map_offsets_to_segments (so->abfd, data,
 306                                                 so->lm_info->offsets,
 307                                                 num_bases, segment_bases))
 308             warning (_("Could not relocate shared library \"%s\": bad offsets"),
 309                      so->so_name);
 310
 311           /* Find the range of addresses to report for this library in
 312              "info sharedlibrary".  Report any consecutive segments
 313              which were relocated as a single unit.  */
 314           gdb_assert (num_bases > 0);
 315           orig_delta = segment_bases[0] - data->segment_bases[0];
 316
 317           for (i = 1; i < data->num_segments; i++)
 318             {
 319               /* If we have run out of offsets, assume all remaining segments
 320                  have the same offset.  */
 321               if (i >= num_bases)
 322                 continue;
 323
 324               /* If this segment does not have the same offset, do not include
 325                  it in the library's range.  */
 326               if (segment_bases[i] - data->segment_bases[i] != orig_delta)
 327                 break;
 328             }
 329
 330           so->addr_low = segment_bases[0];
 331           so->addr_high = (data->segment_bases[i - 1]
 332                            + data->segment_sizes[i - 1]
 333                            + orig_delta);
 334           gdb_assert (so->addr_low <= so->addr_high);
 335
 336           free_symfile_segment_data (data);
 337         }
 338     }
 339
 340   offset = so->lm_info->offsets->offsets[sec->the_bfd_section->index];
 341   sec->addr += offset;
 342   sec->endaddr += offset;
 343 }
 344
 345 static int
 346 solib_target_open_symbol_file_object (void *from_ttyp)
 347 {
 348   /* We can't locate the main symbol file based on the target's
 349      knowledge; the user has to specify it.  */
 350   return 0;
 351 }
 352
 353 static int
 354 solib_target_in_dynsym_resolve_code (CORE_ADDR pc)
 355 {
 356   /* We don't have a range of addresses for the dynamic linker; there
 357      may not be one in the program's address space.  So only report
 358      PLT entries (which may be import stubs).  */
 359   return in_plt_section (pc, NULL);
 360 }
 361
 362 struct target_so_ops solib_target_so_ops;
 363
 364 extern initialize_file_ftype _initialize_solib_target; /* -Wmissing-prototypes */
 365
 366 void
 367 _initialize_solib_target (void)
 368 {
 369   solib_target_so_ops.relocate_section_addresses
 370     = solib_target_relocate_section_addresses;
 371   solib_target_so_ops.free_so = solib_target_free_so;
 372   solib_target_so_ops.clear_solib = solib_target_clear_solib;
 373   solib_target_so_ops.solib_create_inferior_hook
 374     = solib_target_solib_create_inferior_hook;
 375   solib_target_so_ops.special_symbol_handling
 376     = solib_target_special_symbol_handling;
 377   solib_target_so_ops.current_sos = solib_target_current_sos;
 378   solib_target_so_ops.open_symbol_file_object
 379     = solib_target_open_symbol_file_object;
 380   solib_target_so_ops.in_dynsym_resolve_code
 381     = solib_target_in_dynsym_resolve_code;
 382 }