bfd/elf32-sh-symbian.c

   1 /* Renesas / SuperH specific support for Symbian 32-bit ELF files
   2    Copyright (C) 2004-2014 Free Software Foundation, Inc.
   3    Contributed by Red Hat
   4
   5    This file is part of BFD, the Binary File Descriptor library.
   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, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  20    MA 02110-1301, USA.  */
  21
  22
  23 /* Stop elf32-sh.c from defining any target vectors.  */
  24 #define SH_TARGET_ALREADY_DEFINED
  25 #define sh_find_elf_flags           sh_symbian_find_elf_flags
  26 #define sh_elf_get_flags_from_mach  sh_symbian_elf_get_flags_from_mach
  27 #include "elf32-sh.c"
  28
  29
  30 //#define SYMBIAN_DEBUG 1
  31 #define SYMBIAN_DEBUG 0
  32
  33 #define DIRECTIVE_HEADER        "#<SYMEDIT>#\n"
  34 #define DIRECTIVE_IMPORT        "IMPORT "
  35 #define DIRECTIVE_EXPORT        "EXPORT "
  36 #define DIRECTIVE_AS            "AS "
  37
  38 /* Macro to advance 's' until either it reaches 'e' or the
  39    character pointed to by 's' is equal to 'c'.  If 'e' is
  40    reached and SYMBIAN_DEBUG is enabled then the error message 'm'
  41    is displayed.  */
  42 #define SKIP_UNTIL(s,e,c,m)                                     \
  43   do                                                            \
  44     {                                                           \
  45       while (s < e && *s != c)                                  \
  46         ++ s;                                                   \
  47       if (s >= e)                                               \
  48         {                                                       \
  49           if (SYMBIAN_DEBUG)                                    \
  50             fprintf (stderr, "Corrupt directive: %s\n", m);     \
  51           result = FALSE;                                       \
  52         }                                                       \
  53     }                                                           \
  54   while (0);                                                    \
  55   if (!result)                                                  \
  56      break;
  57
  58 /* Like SKIP_UNTIL except there are two terminator characters
  59    c1 and c2.  */
  60 #define SKIP_UNTIL2(s,e,c1,c2,m)                                \
  61   do                                                            \
  62     {                                                           \
  63       while (s < e && *s != c1 && *s != c2)                     \
  64         ++ s;                                                   \
  65       if (s >= e)                                               \
  66         {                                                       \
  67           if (SYMBIAN_DEBUG)                                    \
  68             fprintf (stderr, "Corrupt directive: %s\n", m);     \
  69           result = FALSE;                                       \
  70         }                                                       \
  71     }                                                           \
  72   while (0);                                                    \
  73   if (!result)                                                  \
  74      break;
  75
  76 /* Macro to advance 's' until either it reaches 'e' or the
  77    character pointed to by 's' is not equal to 'c'.  If 'e'
  78    is reached and SYMBIAN_DEBUG is enabled then the error message
  79    'm' is displayed.  */
  80 #define SKIP_WHILE(s,e,c,m)                                     \
  81   do                                                            \
  82     {                                                           \
  83       while (s < e && *s == c)                                  \
  84         ++ s;                                                   \
  85       if (s >= e)                                               \
  86         {                                                       \
  87           if (SYMBIAN_DEBUG)                                    \
  88             fprintf (stderr, "Corrupt directive: %s\n", m);     \
  89           result = FALSE;                                       \
  90         }                                                       \
  91     }                                                           \
  92   while (0);                                                    \
  93   if (!result)                                                  \
  94      break;
  95
  96
  97 typedef struct symbol_rename
  98 {
  99   struct symbol_rename *       next;
 100   char *                       current_name;
 101   char *                       new_name;
 102   struct elf_link_hash_entry * current_hash;
 103   unsigned long                new_symndx;
 104 }
 105 symbol_rename;
 106
 107 static symbol_rename * rename_list = NULL;
 108
 109 /* Accumulate a list of symbols to be renamed.  */
 110
 111 static bfd_boolean
 112 sh_symbian_import_as (struct bfd_link_info *info, bfd * abfd,
 113                       char * current_name, char * new_name)
 114 {
 115   struct elf_link_hash_entry * new_hash;
 116   symbol_rename * node;
 117
 118   if (SYMBIAN_DEBUG)
 119     fprintf (stderr, "IMPORT '%s' AS '%s'\n", current_name, new_name);
 120
 121   for (node = rename_list; node; node = node->next)
 122     if (strcmp (node->current_name, current_name) == 0)
 123       {
 124         if (strcmp (node->new_name, new_name) == 0)
 125           /* Already added to rename list.  */
 126           return TRUE;
 127
 128         bfd_set_error (bfd_error_invalid_operation);
 129         _bfd_error_handler (_("%B: IMPORT AS directive for %s conceals previous IMPORT AS"),
 130                             abfd, current_name);
 131         return FALSE;
 132       }
 133
 134   if ((node = bfd_malloc (sizeof * node)) == NULL)
 135     {
 136       if (SYMBIAN_DEBUG)
 137         fprintf (stderr, "IMPORT AS: No mem for new rename node\n");
 138       return FALSE;
 139     }
 140
 141   if ((node->current_name = bfd_malloc (strlen (current_name) + 1)) == NULL)
 142     {
 143       if (SYMBIAN_DEBUG)
 144         fprintf (stderr, "IMPORT AS: No mem for current name field in rename node\n");
 145       free (node);
 146       return FALSE;
 147     }
 148   else
 149     strcpy (node->current_name, current_name);
 150
 151   if ((node->new_name = bfd_malloc (strlen (new_name) + 1)) == NULL)
 152     {
 153       if (SYMBIAN_DEBUG)
 154         fprintf (stderr, "IMPORT AS: No mem for new name field in rename node\n");
 155       free (node->current_name);
 156       free (node);
 157       return FALSE;
 158     }
 159   else
 160     strcpy (node->new_name, new_name);
 161
 162   node->next = rename_list;
 163   node->current_hash = NULL;
 164   node->new_symndx = 0;
 165   rename_list = node;
 166
 167   new_hash = elf_link_hash_lookup (elf_hash_table (info), node->new_name, TRUE, FALSE, TRUE);
 168   bfd_elf_link_record_dynamic_symbol (info, new_hash);
 169   if (new_hash->root.type == bfd_link_hash_new)
 170     new_hash->root.type = bfd_link_hash_undefined;
 171
 172   return TRUE;
 173 }
 174
 175
 176 static bfd_boolean
 177 sh_symbian_import (bfd * abfd ATTRIBUTE_UNUSED, char * name)
 178 {
 179   if (SYMBIAN_DEBUG)
 180     fprintf (stderr, "IMPORT '%s'\n", name);
 181
 182   /* XXX: Generate an import somehow ?  */
 183
 184   return TRUE;
 185 }
 186
 187 static bfd_boolean
 188 sh_symbian_export (bfd * abfd ATTRIBUTE_UNUSED, char * name)
 189 {
 190   if (SYMBIAN_DEBUG)
 191     fprintf (stderr, "EXPORT '%s'\n", name);
 192
 193   /* XXX: Generate an export somehow ?  */
 194
 195   return TRUE;
 196 }
 197
 198 /* Process any magic embedded commands in the .directive. section.
 199    Returns TRUE upon sucecss, but if it fails it sets bfd_error and
 200    returns FALSE.  */
 201
 202 static bfd_boolean
 203 sh_symbian_process_embedded_commands (struct bfd_link_info *info, bfd * abfd,
 204                                       asection * sec, bfd_byte * contents)
 205 {
 206   char *s;
 207   char *e;
 208   bfd_boolean result = TRUE;
 209   bfd_size_type sz = sec->rawsize ? sec->rawsize : sec->size;
 210
 211   for (s = (char *) contents, e = s + sz; s < e;)
 212     {
 213       char * directive = s;
 214
 215       switch (*s)
 216         {
 217           /* I want to use "case DIRECTIVE_HEADER [0]:" here but gcc won't let me :-(  */
 218         case '#':
 219           if (strcmp (s, DIRECTIVE_HEADER))
 220             result = FALSE;
 221           else
 222             /* Just ignore the header.
 223                XXX: Strictly speaking we ought to check that the header
 224                is present and that it is the first thing in the file.  */
 225             s += strlen (DIRECTIVE_HEADER) + 1;
 226           break;
 227
 228         case 'I':
 229           if (! CONST_STRNEQ (s, DIRECTIVE_IMPORT))
 230             result = FALSE;
 231           else
 232             {
 233               char * new_name;
 234               char * new_name_end;
 235               char   name_end_char;
 236
 237               /* Skip the IMPORT directive.  */
 238               s += strlen (DIRECTIVE_IMPORT);
 239
 240               new_name = s;
 241               /* Find the end of the new name.  */
 242               while (s < e && *s != ' ' && *s != '\n')
 243                 ++ s;
 244               if (s >= e)
 245                 {
 246                   /* We have reached the end of the .directive section
 247                      without encountering a string terminator.  This is
 248                      allowed for IMPORT directives.  */
 249                   new_name_end   = e - 1;
 250                   name_end_char  = * new_name_end;
 251                   * new_name_end = 0;
 252                   result = sh_symbian_import (abfd, new_name);
 253                   * new_name_end = name_end_char;
 254                   break;
 255                 }
 256
 257               /* Remember where the name ends.  */
 258               new_name_end = s;
 259               /* Skip any whitespace before the 'AS'.  */
 260               SKIP_WHILE (s, e, ' ', "IMPORT: Name just followed by spaces");
 261               /* Terminate the new name.  (Do this after skiping...)  */
 262               name_end_char = * new_name_end;
 263               * new_name_end = 0;
 264
 265               /* Check to see if 'AS '... is present.  If so we have an
 266                  IMPORT AS directive, otherwise we have an IMPORT directive.  */
 267               if (! CONST_STRNEQ (s, DIRECTIVE_AS))
 268                 {
 269                   /* Skip the new-line at the end of the name.  */
 270                   if (SYMBIAN_DEBUG && name_end_char != '\n')
 271                     fprintf (stderr, "IMPORT: No newline at end of directive\n");
 272                   else
 273                     s ++;
 274
 275                   result = sh_symbian_import (abfd, new_name);
 276
 277                   /* Skip past the NUL character.  */
 278                   if (* s ++ != 0)
 279                     {
 280                       if (SYMBIAN_DEBUG)
 281                         fprintf (stderr, "IMPORT: No NUL at end of directive\n");
 282                     }
 283                 }
 284               else
 285                 {
 286                   char * current_name;
 287                   char * current_name_end;
 288                   char   current_name_end_char;
 289
 290                   /* Skip the 'AS '.  */
 291                   s += strlen (DIRECTIVE_AS);
 292                   /* Skip any white space after the 'AS '.  */
 293                   SKIP_WHILE (s, e, ' ', "IMPORT AS: Nothing after AS");
 294                   current_name = s;
 295                   /* Find the end of the current name.  */
 296                   SKIP_UNTIL2 (s, e, ' ', '\n', "IMPORT AS: No newline at the end of the current name");
 297                   /* Skip (backwards) over spaces at the end of the current name.  */
 298                   current_name_end = s;
 299                   current_name_end_char = * current_name_end;
 300
 301                   SKIP_WHILE (s, e, ' ', "IMPORT AS: Current name just followed by spaces");
 302                   /* Skip past the newline character.  */
 303                   if (* s ++ != '\n')
 304                     if (SYMBIAN_DEBUG)
 305                       fprintf (stderr, "IMPORT AS: No newline at end of directive\n");
 306
 307                   /* Terminate the current name after having performed the skips.  */
 308                   * current_name_end = 0;
 309
 310                   result = sh_symbian_import_as (info, abfd, current_name, new_name);
 311
 312                   /* The next character should be a NUL.  */
 313                   if (* s != 0)
 314                     {
 315                       if (SYMBIAN_DEBUG)
 316                         fprintf (stderr, "IMPORT AS: Junk at end of directive\n");
 317                       result = FALSE;
 318                     }
 319                   s ++;
 320
 321                   * current_name_end = current_name_end_char;
 322                 }
 323
 324               /* Restore the characters we overwrote, since
 325                  the .directive section will be emitted.  */
 326               * new_name_end = name_end_char;
 327             }
 328           break;
 329
 330         case 'E':
 331           if (! CONST_STRNEQ (s, DIRECTIVE_EXPORT))
 332             result = FALSE;
 333           else
 334             {
 335               char * name;
 336               char * name_end;
 337               char   name_end_char;
 338
 339               /* Skip the directive.  */
 340               s += strlen (DIRECTIVE_EXPORT);
 341               name = s;
 342               /* Find the end of the name to be exported.  */
 343               SKIP_UNTIL (s, e, '\n', "EXPORT: no newline at end of directive");
 344               /* Skip (backwards) over spaces at end of exported name.  */
 345               for (name_end = s; name_end[-1] == ' '; name_end --)
 346                 ;
 347               /* name_end now points at the first character after the
 348                  end of the exported name, so we can termiante it  */
 349               name_end_char = * name_end;
 350               * name_end = 0;
 351               /* Skip passed the newline character.  */
 352               s ++;
 353
 354               result = sh_symbian_export (abfd, name);
 355
 356               /* The next character should be a NUL.  */
 357               if (* s != 0)
 358                 {
 359                   if (SYMBIAN_DEBUG)
 360                     fprintf (stderr, "EXPORT: Junk at end of directive\n");
 361                   result = FALSE;
 362                 }
 363               s++;
 364
 365               /* Restore the character we deleted.  */
 366               * name_end = name_end_char;
 367             }
 368           break;
 369
 370         default:
 371           result = FALSE;
 372           break;
 373         }
 374
 375       if (! result)
 376         {
 377           if (SYMBIAN_DEBUG)
 378             fprintf (stderr, "offset into .directive section: %ld\n",
 379                      (long) (directive - (char *) contents));
 380
 381           bfd_set_error (bfd_error_invalid_operation);
 382           _bfd_error_handler (_("%B: Unrecognised .directive command: %s"),
 383                               abfd, directive);
 384           break;
 385         }
 386     }
 387
 388   return result;
 389 }
 390
 391
 392 /* Scan a bfd for a .directive section, and if found process it.
 393    Returns TRUE upon success, FALSE otherwise.  */
 394
 395 static bfd_boolean
 396 sh_symbian_process_directives (bfd *abfd, struct bfd_link_info *info)
 397 {
 398   bfd_boolean result = FALSE;
 399   bfd_byte *  contents;
 400   asection *  sec = bfd_get_section_by_name (abfd, ".directive");
 401   bfd_size_type sz;
 402
 403   if (!sec)
 404     return TRUE;
 405
 406   sz = sec->rawsize ? sec->rawsize : sec->size;
 407   contents = bfd_malloc (sz);
 408
 409   if (!contents)
 410     bfd_set_error (bfd_error_no_memory);
 411   else
 412     {
 413       if (bfd_get_section_contents (abfd, sec, contents, 0, sz))
 414         result = sh_symbian_process_embedded_commands (info, abfd, sec, contents);
 415       free (contents);
 416     }
 417
 418   return result;
 419 }
 420
 421 /* Intercept the normal sh_relocate_section() function
 422    and magle the relocs to allow for symbol renaming.  */
 423
 424 static bfd_boolean
 425 sh_symbian_relocate_section (bfd *                  output_bfd,
 426                              struct bfd_link_info * info,
 427                              bfd *                  input_bfd,
 428                              asection *             input_section,
 429                              bfd_byte *             contents,
 430                              Elf_Internal_Rela *    relocs,
 431                              Elf_Internal_Sym *     local_syms,
 432                              asection **            local_sections)
 433 {
 434   /* When performing a final link we implement the IMPORT AS directives.  */
 435   if (!info->relocatable)
 436     {
 437       Elf_Internal_Rela *            rel;
 438       Elf_Internal_Rela *            relend;
 439       Elf_Internal_Shdr *            symtab_hdr;
 440       struct elf_link_hash_entry **  sym_hashes;
 441       struct elf_link_hash_entry **  sym_hashes_end;
 442       struct elf_link_hash_table *   hash_table;
 443       symbol_rename *                ptr;
 444       bfd_size_type                  num_global_syms;
 445       unsigned long                  num_local_syms;
 446
 447       BFD_ASSERT (! elf_bad_symtab (input_bfd));
 448
 449       symtab_hdr       = & elf_tdata (input_bfd)->symtab_hdr;
 450       hash_table       = elf_hash_table (info);
 451       num_local_syms   = symtab_hdr->sh_info;
 452       num_global_syms  = symtab_hdr->sh_size / sizeof (Elf32_External_Sym);
 453       num_global_syms -= num_local_syms;
 454       sym_hashes       = elf_sym_hashes (input_bfd);
 455       sym_hashes_end   = sym_hashes + num_global_syms;
 456
 457       /* First scan the rename table, caching the hash entry and the new index.  */
 458       for (ptr = rename_list; ptr; ptr = ptr->next)
 459         {
 460           struct elf_link_hash_entry *   new_hash;
 461           struct elf_link_hash_entry **  h;
 462
 463           ptr->current_hash = elf_link_hash_lookup (hash_table, ptr->current_name, FALSE, FALSE, TRUE);
 464
 465           if (ptr->current_hash == NULL)
 466             {
 467               if (SYMBIAN_DEBUG)
 468                 fprintf (stderr, "IMPORT AS: current symbol '%s' does not exist\n", ptr->current_name);
 469               continue;
 470             }
 471
 472           new_hash = elf_link_hash_lookup (hash_table, ptr->new_name,
 473                                            FALSE, FALSE, TRUE);
 474           /* If we could not find the symbol then it is a new, undefined symbol.
 475              Symbian want this behaviour - ie they want to be able to rename the
 476              reference in a reloc from one undefined symbol to another, new and
 477              undefined symbol.  So we create that symbol here.  */
 478           if (new_hash == NULL)
 479             {
 480               struct bfd_link_hash_entry *bh = NULL;
 481               bfd_boolean collect = get_elf_backend_data (input_bfd)->collect;
 482               if (_bfd_generic_link_add_one_symbol (info, input_bfd,
 483                                                     ptr->new_name, BSF_GLOBAL,
 484                                                     bfd_und_section_ptr, 0,
 485                                                     NULL, FALSE, collect,
 486                                                     &bh))
 487                 {
 488                   new_hash = (struct elf_link_hash_entry *) bh;
 489                   new_hash->type = STT_FUNC;
 490                   new_hash->non_elf = 0;
 491
 492                   if (SYMBIAN_DEBUG)
 493                     fprintf (stderr, "Created new symbol %s\n", ptr->new_name);
 494                 }
 495             }
 496
 497           if (new_hash == NULL)
 498             {
 499               _bfd_error_handler (_("%B: Failed to add renamed symbol %s"),
 500                                   input_bfd, ptr->new_name);
 501               continue;
 502             }
 503
 504           /* Convert the new_hash value into a index into the table of symbol hashes.  */
 505           for (h = sym_hashes; h < sym_hashes_end; h ++)
 506             {
 507               if (* h == new_hash)
 508                 {
 509                   ptr->new_symndx = h - sym_hashes + num_local_syms;
 510                   if (SYMBIAN_DEBUG)
 511                     fprintf (stderr, "Converted new hash to index of %ld\n", ptr->new_symndx);
 512                   break;
 513                 }
 514             }
 515           /* If the new symbol is not in the hash table then it must be
 516              because it is one of the newly created undefined symbols
 517              manufactured above.  So we extend the sym has table here to
 518              include this extra symbol.  */
 519           if (h == sym_hashes_end)
 520             {
 521               struct elf_link_hash_entry **  new_sym_hashes;
 522
 523               /* This is not very efficient, but it works.  */
 524               ++ num_global_syms;
 525               new_sym_hashes = bfd_alloc (input_bfd, num_global_syms * sizeof * sym_hashes);
 526               if (new_sym_hashes == NULL)
 527                 {
 528                   if (SYMBIAN_DEBUG)
 529                     fprintf (stderr, "Out of memory extending hash table\n");
 530                   continue;
 531                 }
 532               memcpy (new_sym_hashes, sym_hashes, (num_global_syms - 1) * sizeof * sym_hashes);
 533               new_sym_hashes[num_global_syms - 1] = new_hash;
 534               elf_sym_hashes (input_bfd) = sym_hashes = new_sym_hashes;
 535               sym_hashes_end = sym_hashes + num_global_syms;
 536               symtab_hdr->sh_size  = (num_global_syms + num_local_syms) * sizeof (Elf32_External_Sym);
 537
 538               ptr->new_symndx = num_global_syms - 1 + num_local_syms;
 539
 540               if (SYMBIAN_DEBUG)
 541                 fprintf (stderr, "Extended symbol hash table to insert new symbol as index %ld\n",
 542                          ptr->new_symndx);
 543             }
 544         }
 545
 546       /* Walk the reloc list looking for references to renamed symbols.
 547          When we find one, we alter the index in the reloc to point to the new symbol.  */
 548       for (rel = relocs, relend = relocs + input_section->reloc_count;
 549            rel < relend;
 550            rel ++)
 551         {
 552           int                          r_type;
 553           unsigned long                r_symndx;
 554           struct elf_link_hash_entry * h;
 555
 556           r_symndx = ELF32_R_SYM (rel->r_info);
 557           r_type = ELF32_R_TYPE (rel->r_info);
 558
 559           /* Ignore unused relocs.  */
 560           if ((r_type >= (int) R_SH_GNU_VTINHERIT
 561                && r_type <= (int) R_SH_LABEL)
 562               || r_type == (int) R_SH_NONE
 563               || r_type < 0
 564               || r_type >= R_SH_max)
 565             continue;
 566
 567           /* Ignore relocs against local symbols.  */
 568           if (r_symndx < num_local_syms)
 569             continue;
 570
 571           BFD_ASSERT (r_symndx < (num_global_syms + num_local_syms));
 572           h = sym_hashes[r_symndx - num_local_syms];
 573           BFD_ASSERT (h != NULL);
 574
 575           while (   h->root.type == bfd_link_hash_indirect
 576                  || h->root.type == bfd_link_hash_warning)
 577             h = (struct elf_link_hash_entry *) h->root.u.i.link;
 578
 579           /* If the symbol is defined there is no need to rename it.
 580              XXX - is this true ?  */
 581           if (   h->root.type == bfd_link_hash_defined
 582               || h->root.type == bfd_link_hash_defweak
 583               || h->root.type == bfd_link_hash_undefweak)
 584             continue;
 585
 586           for (ptr = rename_list; ptr; ptr = ptr->next)
 587             if (h == ptr->current_hash)
 588               {
 589                 BFD_ASSERT (ptr->new_symndx);
 590                 if (SYMBIAN_DEBUG)
 591                   fprintf (stderr, "convert reloc %lx from using index %ld to using index %ld\n",
 592                            (unsigned long) rel->r_info,
 593                            (long) ELF32_R_SYM (rel->r_info), ptr->new_symndx);
 594                 rel->r_info = ELF32_R_INFO (ptr->new_symndx, r_type);
 595                 break;
 596               }
 597         }
 598     }
 599
 600   return sh_elf_relocate_section (output_bfd, info, input_bfd, input_section,
 601                                   contents, relocs, local_syms, local_sections);
 602 }
 603
 604 #define TARGET_LITTLE_SYM       bfd_elf32_shl_symbian_vec
 605 #define TARGET_LITTLE_NAME      "elf32-shl-symbian"
 606
 607 #undef  elf_backend_relocate_section
 608 #define elf_backend_relocate_section    sh_symbian_relocate_section
 609 #undef  elf_backend_check_directives
 610 #define elf_backend_check_directives    sh_symbian_process_directives
 611
 612 #include "elf32-target.h"