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
  86   VEC_safe_push (CORE_ADDR, last->segment_bases, address_p);
  87 }
  88
  89 /* Handle the start of a <library> element.  */
  90
  91 static void
  92 library_list_start_library (struct gdb_xml_parser *parser,
  93                             const struct gdb_xml_element *element,
  94                             void *user_data, VEC(gdb_xml_value_s) *attributes)
  95 {
  96   VEC(lm_info_p) **list = user_data;
  97   struct lm_info *item = XZALLOC (struct lm_info);
  98   const char *name = VEC_index (gdb_xml_value_s, attributes, 0)->value;
  99
 100   item->name = xstrdup (name);
 101   VEC_safe_push (lm_info_p, *list, item);
 102 }
 103
 104 /* Handle the start of a <library-list> element.  */
 105
 106 static void
 107 library_list_start_list (struct gdb_xml_parser *parser,
 108                          const struct gdb_xml_element *element,
 109                          void *user_data, VEC(gdb_xml_value_s) *attributes)
 110 {
 111   char *version = VEC_index (gdb_xml_value_s, attributes, 0)->value;
 112
 113   if (strcmp (version, "1.0") != 0)
 114     gdb_xml_error (parser,
 115                    _("Library list has unsupported version \"%s\""),
 116                    version);
 117 }
 118
 119 /* Discard the constructed library list.  */
 120
 121 static void
 122 solib_target_free_library_list (void *p)
 123 {
 124   VEC(lm_info_p) **result = p;
 125   struct lm_info *info;
 126   int ix;
 127
 128   for (ix = 0; VEC_iterate (lm_info_p, *result, ix, info); ix++)
 129     {
 130       xfree (info->name);
 131       VEC_free (CORE_ADDR, info->segment_bases);
 132       xfree (info);
 133     }
 134   VEC_free (lm_info_p, *result);
 135   *result = NULL;
 136 }
 137
 138 /* The allowed elements and attributes for an XML library list.
 139    The root element is a <library-list>.  */
 140
 141 const struct gdb_xml_attribute segment_attributes[] = {
 142   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 143   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 144 };
 145
 146 const struct gdb_xml_element library_children[] = {
 147   { "segment", segment_attributes, NULL, GDB_XML_EF_REPEATABLE,
 148     library_list_start_segment, NULL },
 149   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 150 };
 151
 152 const struct gdb_xml_attribute library_attributes[] = {
 153   { "name", GDB_XML_AF_NONE, NULL, NULL },
 154   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 155 };
 156
 157 const struct gdb_xml_element library_list_children[] = {
 158   { "library", library_attributes, library_children,
 159     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 160     library_list_start_library, NULL },
 161   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 162 };
 163
 164 const struct gdb_xml_attribute library_list_attributes[] = {
 165   { "version", GDB_XML_AF_NONE, NULL, NULL },
 166   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 167 };
 168
 169 const struct gdb_xml_element library_list_elements[] = {
 170   { "library-list", library_list_attributes, library_list_children,
 171     GDB_XML_EF_NONE, library_list_start_list, NULL },
 172   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 173 };
 174
 175 static VEC(lm_info_p) *
 176 solib_target_parse_libraries (const char *library)
 177 {
 178   struct gdb_xml_parser *parser;
 179   VEC(lm_info_p) *result = NULL;
 180   struct cleanup *before_deleting_result, *back_to;
 181
 182   back_to = make_cleanup (null_cleanup, NULL);
 183   parser = gdb_xml_create_parser_and_cleanup (_("target library list"),
 184                                               library_list_elements, &result);
 185   gdb_xml_use_dtd (parser, "library-list.dtd");
 186
 187   before_deleting_result = make_cleanup (solib_target_free_library_list,
 188                                          &result);
 189
 190   if (gdb_xml_parse (parser, library) == 0)
 191     /* Parsed successfully, don't need to delete the result.  */
 192     discard_cleanups (before_deleting_result);
 193
 194   do_cleanups (back_to);
 195   return result;
 196 }
 197 #endif
 198
 199 static struct so_list *
 200 solib_target_current_sos (void)
 201 {
 202   struct so_list *new_solib, *start = NULL, *last = NULL;
 203   const char *library_document;
 204   VEC(lm_info_p) *library_list;
 205   struct lm_info *info;
 206   int ix;
 207
 208   /* Fetch the list of shared libraries.  */
 209   library_document = target_read_stralloc (&current_target,
 210                                            TARGET_OBJECT_LIBRARIES,
 211                                            NULL);
 212   if (library_document == NULL)
 213     return NULL;
 214
 215   /* Parse the list.  */
 216   library_list = solib_target_parse_libraries (library_document);
 217   if (library_list == NULL)
 218     return NULL;
 219
 220   /* Build a struct so_list for each entry on the list.  */
 221   for (ix = 0; VEC_iterate (lm_info_p, library_list, ix, info); ix++)
 222     {
 223       new_solib = XZALLOC (struct so_list);
 224       strncpy (new_solib->so_name, info->name, SO_NAME_MAX_PATH_SIZE - 1);
 225       new_solib->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 226       strncpy (new_solib->so_original_name, info->name,
 227                SO_NAME_MAX_PATH_SIZE - 1);
 228       new_solib->so_original_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 229       new_solib->lm_info = info;
 230
 231       /* We no longer need this copy of the name.  */
 232       xfree (info->name);
 233       info->name = NULL;
 234
 235       /* Add it to the list.  */
 236       if (!start)
 237         last = start = new_solib;
 238       else
 239         {
 240           last->next = new_solib;
 241           last = new_solib;
 242         }
 243     }
 244
 245   /* Free the library list, but not its members.  */
 246   VEC_free (lm_info_p, library_list);
 247
 248   return start;
 249 }
 250
 251 static void
 252 solib_target_special_symbol_handling (void)
 253 {
 254   /* Nothing needed.  */
 255 }
 256
 257 static void
 258 solib_target_solib_create_inferior_hook (void)
 259 {
 260   /* Nothing needed.  */
 261 }
 262
 263 static void
 264 solib_target_clear_solib (void)
 265 {
 266   /* Nothing needed.  */
 267 }
 268
 269 static void
 270 solib_target_free_so (struct so_list *so)
 271 {
 272   gdb_assert (so->lm_info->name == NULL);
 273   xfree (so->lm_info->offsets);
 274   VEC_free (CORE_ADDR, so->lm_info->segment_bases);
 275   xfree (so->lm_info);
 276 }
 277
 278 static void
 279 solib_target_relocate_section_addresses (struct so_list *so,
 280                                          struct section_table *sec)
 281 {
 282   int flags = bfd_get_section_flags (sec->bfd, sec->the_bfd_section);
 283   CORE_ADDR offset;
 284
 285   /* Build the offset table only once per object file.  We can not do
 286      it any earlier, since we need to open the file first.  */
 287   if (so->lm_info->offsets == NULL)
 288     {
 289       struct symfile_segment_data *data;
 290       int num_sections = bfd_count_sections (so->abfd);
 291
 292       so->lm_info->offsets = xzalloc (SIZEOF_N_SECTION_OFFSETS (num_sections));
 293
 294       data = get_symfile_segment_data (so->abfd);
 295       if (data == NULL)
 296         warning (_("Could not relocate shared library \"%s\": no segments"),
 297                  so->so_name);
 298       else
 299         {
 300           ULONGEST orig_delta;
 301           int i;
 302           int num_bases = VEC_length (CORE_ADDR, so->lm_info->segment_bases);
 303           CORE_ADDR *segment_bases = VEC_address (CORE_ADDR,
 304                                                   so->lm_info->segment_bases);
 305
 306           if (!symfile_map_offsets_to_segments (so->abfd, data,
 307                                                 so->lm_info->offsets,
 308                                                 num_bases, segment_bases))
 309             warning (_("Could not relocate shared library \"%s\": bad offsets"),
 310                      so->so_name);
 311
 312           /* Find the range of addresses to report for this library in
 313              "info sharedlibrary".  Report any consecutive segments
 314              which were relocated as a single unit.  */
 315           gdb_assert (num_bases > 0);
 316           orig_delta = segment_bases[0] - data->segment_bases[0];
 317
 318           for (i = 1; i < data->num_segments; i++)
 319             {
 320               /* If we have run out of offsets, assume all remaining segments
 321                  have the same offset.  */
 322               if (i >= num_bases)
 323                 continue;
 324
 325               /* If this segment does not have the same offset, do not include
 326                  it in the library's range.  */
 327               if (segment_bases[i] - data->segment_bases[i] != orig_delta)
 328                 break;
 329             }
 330
 331           so->addr_low = segment_bases[0];
 332           so->addr_high = (data->segment_bases[i - 1]
 333                            + data->segment_sizes[i - 1]
 334                            /* FIXME this must be needed! + orig_delta */);
 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 static 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
 383   current_target_so_ops = &solib_target_so_ops;
 384 }