bfd/elf32-sh-symbian.c

   1 /* Renesas / SuperH specific support for Symbian 32-bit ELF files
   2    Copyright (C) 2004-2017 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         /* xgettext:c-format */
 130         _bfd_error_handler (_("%B: IMPORT AS directive for %s conceals previous IMPORT AS"),
 131                             abfd, current_name);
 132         return FALSE;
 133       }
 134
 135   if ((node = bfd_malloc (sizeof * node)) == NULL)
 136     {
 137       if (SYMBIAN_DEBUG)
 138         fprintf (stderr, "IMPORT AS: No mem for new rename node\n");
 139       return FALSE;
 140     }
 141
 142   if ((node->current_name = bfd_malloc (strlen (current_name) + 1)) == NULL)
 143     {
 144       if (SYMBIAN_DEBUG)
 145         fprintf (stderr, "IMPORT AS: No mem for current name field in rename node\n");
 146       free (node);
 147       return FALSE;
 148     }
 149   else
 150     strcpy (node->current_name, current_name);
 151
 152   if ((node->new_name = bfd_malloc (strlen (new_name) + 1)) == NULL)
 153     {
 154       if (SYMBIAN_DEBUG)
 155         fprintf (stderr, "IMPORT AS: No mem for new name field in rename node\n");
 156       free (node->current_name);
 157       free (node);
 158       return FALSE;
 159     }
 160   else
 161     strcpy (node->new_name, new_name);
 162
 163   node->next = rename_list;
 164   node->current_hash = NULL;
 165   node->new_symndx = 0;
 166   rename_list = node;
 167
 168   new_hash = elf_link_hash_lookup (elf_hash_table (info), node->new_name, TRUE, FALSE, TRUE);
 169   bfd_elf_link_record_dynamic_symbol (info, new_hash);
 170   if (new_hash->root.type == bfd_link_hash_new)
 171     new_hash->root.type = bfd_link_hash_undefined;
 172
 173   return TRUE;
 174 }
 175
 176
 177 static bfd_boolean
 178 sh_symbian_import (bfd * abfd ATTRIBUTE_UNUSED, char * name)
 179 {
 180   if (SYMBIAN_DEBUG)
 181     fprintf (stderr, "IMPORT '%s'\n", name);
 182
 183   /* XXX: Generate an import somehow ?  */
 184
 185   return TRUE;
 186 }
 187
 188 static bfd_boolean
 189 sh_symbian_export (bfd * abfd ATTRIBUTE_UNUSED, char * name)
 190 {
 191   if (SYMBIAN_DEBUG)
 192     fprintf (stderr, "EXPORT '%s'\n", name);
 193
 194   /* XXX: Generate an export somehow ?  */
 195
 196   return TRUE;
 197 }
 198
 199 /* Process any magic embedded commands in the .directive. section.
 200    Returns TRUE upon sucecss, but if it fails it sets bfd_error and
 201    returns FALSE.  */
 202
 203 static bfd_boolean
 204 sh_symbian_process_embedded_commands (struct bfd_link_info *info, bfd * abfd,
 205                                       asection * sec, bfd_byte * contents)
 206 {
 207   char *s;
 208   char *e;
 209   bfd_boolean result = TRUE;
 210   bfd_size_type sz = sec->rawsize ? sec->rawsize : sec->size;
 211
 212   for (s = (char *) contents, e = s + sz; s < e;)
 213     {
 214       char * directive = s;
 215
 216       switch (*s)
 217         {
 218           /* I want to use "case DIRECTIVE_HEADER [0]:" here but gcc won't let me :-(  */
 219         case '#':
 220           if (strcmp (s, DIRECTIVE_HEADER))
 221             result = FALSE;
 222           else
 223             /* Just ignore the header.
 224                XXX: Strictly speaking we ought to check that the header
 225                is present and that it is the first thing in the file.  */
 226             s += strlen (DIRECTIVE_HEADER) + 1;
 227           break;
 228
 229         case 'I':
 230           if (! CONST_STRNEQ (s, DIRECTIVE_IMPORT))
 231             result = FALSE;
 232           else
 233             {
 234               char * new_name;
 235               char * new_name_end;
 236               char   name_end_char;
 237
 238               /* Skip the IMPORT directive.  */
 239               s += strlen (DIRECTIVE_IMPORT);
 240
 241               new_name = s;
 242               /* Find the end of the new name.  */
 243               while (s < e && *s != ' ' && *s != '\n')
 244                 ++ s;
 245               if (s >= e)
 246                 {
 247                   /* We have reached the end of the .directive section
 248                      without encountering a string terminator.  This is
 249                      allowed for IMPORT directives.  */
 250                   new_name_end   = e - 1;
 251                   name_end_char  = * new_name_end;
 252                   * new_name_end = 0;
 253                   result = sh_symbian_import (abfd, new_name);
 254                   * new_name_end = name_end_char;
 255                   break;
 256                 }
 257
 258               /* Remember where the name ends.  */
 259               new_name_end = s;
 260               /* Skip any whitespace before the 'AS'.  */
 261               SKIP_WHILE (s, e, ' ', "IMPORT: Name just followed by spaces");
 262               /* Terminate the new name.  (Do this after skiping...)  */
 263               name_end_char = * new_name_end;
 264               * new_name_end = 0;
 265
 266               /* Check to see if 'AS '... is present.  If so we have an
 267                  IMPORT AS directive, otherwise we have an IMPORT directive.  */
 268               if (! CONST_STRNEQ (s, DIRECTIVE_AS))
 269                 {
 270                   /* Skip the new-line at the end of the name.  */
 271                   if (SYMBIAN_DEBUG && name_end_char != '\n')
 272                     fprintf (stderr, "IMPORT: No newline at end of directive\n");
 273                   else
 274                     s ++;
 275
 276                   result = sh_symbian_import (abfd, new_name);
 277
 278                   /* Skip past the NUL character.  */
 279                   if (* s ++ != 0)
 280                     {
 281                       if (SYMBIAN_DEBUG)
 282                         fprintf (stderr, "IMPORT: No NUL at end of directive\n");
 283                     }
 284                 }
 285               else
 286                 {
 287                   char * current_name;
 288                   char * current_name_end;
 289                   char   current_name_end_char;
 290
 291                   /* Skip the 'AS '.  */
 292                   s += strlen (DIRECTIVE_AS);
 293                   /* Skip any white space after the 'AS '.  */
 294                   SKIP_WHILE (s, e, ' ', "IMPORT AS: Nothing after AS");
 295                   current_name = s;
 296                   /* Find the end of the current name.  */
 297                   SKIP_UNTIL2 (s, e, ' ', '\n', "IMPORT AS: No newline at the end of the current name");
 298                   /* Skip (backwards) over spaces at the end of the current name.  */
 299                   current_name_end = s;
 300                   current_name_end_char = * current_name_end;
 301
 302                   SKIP_WHILE (s, e, ' ', "IMPORT AS: Current name just followed by spaces");
 303                   /* Skip past the newline character.  */
 304                   if (* s ++ != '\n')
 305                     if (SYMBIAN_DEBUG)
 306                       fprintf (stderr, "IMPORT AS: No newline at end of directive\n");
 307
 308                   /* Terminate the current name after having performed the skips.  */
 309                   * current_name_end = 0;
 310
 311                   result = sh_symbian_import_as (info, abfd, current_name, new_name);
 312
 313                   /* The next character should be a NUL.  */
 314                   if (* s != 0)
 315                     {
 316                       if (SYMBIAN_DEBUG)
 317                         fprintf (stderr, "IMPORT AS: Junk at end of directive\n");
 318                       result = FALSE;
 319                     }
 320                   s ++;
 321
 322                   * current_name_end = current_name_end_char;
 323                 }
 324
 325               /* Restore the characters we overwrote, since
 326                  the .directive section will be emitted.  */
 327               * new_name_end = name_end_char;
 328             }
 329           break;
 330
 331         case 'E':
 332           if (! CONST_STRNEQ (s, DIRECTIVE_EXPORT))
 333             result = FALSE;
 334           else
 335             {
 336               char * name;
 337               char * name_end;
 338               char   name_end_char;
 339
 340               /* Skip the directive.  */
 341               s += strlen (DIRECTIVE_EXPORT);
 342               name = s;
 343               /* Find the end of the name to be exported.  */
 344               SKIP_UNTIL (s, e, '\n', "EXPORT: no newline at end of directive");
 345               /* Skip (backwards) over spaces at end of exported name.  */
 346               for (name_end = s; name_end[-1] == ' '; name_end --)
 347                 ;
 348               /* name_end now points at the first character after the
 349                  end of the exported name, so we can termiante it  */
 350               name_end_char = * name_end;
 351               * name_end = 0;
 352               /* Skip passed the newline character.  */
 353               s ++;
 354
 355               result = sh_symbian_export (abfd, name);
 356
 357               /* The next character should be a NUL.  */
 358               if (* s != 0)
 359                 {
 360                   if (SYMBIAN_DEBUG)
 361                     fprintf (stderr, "EXPORT: Junk at end of directive\n");
 362                   result = FALSE;
 363                 }
 364               s++;
 365
 366               /* Restore the character we deleted.  */
 367               * name_end = name_end_char;
 368             }
 369           break;
 370
 371         default:
 372           result = FALSE;
 373           break;
 374         }
 375
 376       if (! result)
 377         {
 378           if (SYMBIAN_DEBUG)
 379             fprintf (stderr, "offset into .directive section: %ld\n",
 380                      (long) (directive - (char *) contents));
 381
 382           bfd_set_error (bfd_error_invalid_operation);
 383           /* xgettext:c-format */
 384           _bfd_error_handler (_("%B: Unrecognised .directive command: %s"),
 385                               abfd, directive);
 386           break;
 387         }
 388     }
 389
 390   return result;
 391 }
 392
 393
 394 /* Scan a bfd for a .directive section, and if found process it.
 395    Returns TRUE upon success, FALSE otherwise.  */
 396
 397 static bfd_boolean
 398 sh_symbian_process_directives (bfd *abfd, struct bfd_link_info *info)
 399 {
 400   bfd_boolean result = FALSE;
 401   bfd_byte *  contents;
 402   asection *  sec = bfd_get_section_by_name (abfd, ".directive");
 403   bfd_size_type sz;
 404
 405   if (!sec)
 406     return TRUE;
 407
 408   sz = sec->rawsize ? sec->rawsize : sec->size;
 409   contents = bfd_malloc (sz);
 410
 411   if (!contents)
 412     bfd_set_error (bfd_error_no_memory);
 413   else
 414     {
 415       if (bfd_get_section_contents (abfd, sec, contents, 0, sz))
 416         result = sh_symbian_process_embedded_commands (info, abfd, sec, contents);
 417       free (contents);
 418     }
 419
 420   return result;
 421 }
 422
 423 /* Intercept the normal sh_relocate_section() function
 424    and magle the relocs to allow for symbol renaming.  */
 425
 426 static bfd_boolean
 427 sh_symbian_relocate_section (bfd *                  output_bfd,
 428                              struct bfd_link_info * info,
 429                              bfd *                  input_bfd,
 430                              asection *             input_section,
 431                              bfd_byte *             contents,
 432                              Elf_Internal_Rela *    relocs,
 433                              Elf_Internal_Sym *     local_syms,
 434                              asection **            local_sections)
 435 {
 436   /* When performing a final link we implement the IMPORT AS directives.  */
 437   if (!bfd_link_relocatable (info))
 438     {
 439       Elf_Internal_Rela *            rel;
 440       Elf_Internal_Rela *            relend;
 441       Elf_Internal_Shdr *            symtab_hdr;
 442       struct elf_link_hash_entry **  sym_hashes;
 443       struct elf_link_hash_entry **  sym_hashes_end;
 444       struct elf_link_hash_table *   hash_table;
 445       symbol_rename *                ptr;
 446       bfd_size_type                  num_global_syms;
 447       unsigned long                  num_local_syms;
 448
 449       BFD_ASSERT (! elf_bad_symtab (input_bfd));
 450
 451       symtab_hdr       = & elf_tdata (input_bfd)->symtab_hdr;
 452       hash_table       = elf_hash_table (info);
 453       num_local_syms   = symtab_hdr->sh_info;
 454       num_global_syms  = symtab_hdr->sh_size / sizeof (Elf32_External_Sym);
 455       num_global_syms -= num_local_syms;
 456       sym_hashes       = elf_sym_hashes (input_bfd);
 457       sym_hashes_end   = sym_hashes + num_global_syms;
 458
 459       /* First scan the rename table, caching the hash entry and the new index.  */
 460       for (ptr = rename_list; ptr; ptr = ptr->next)
 461         {
 462           struct elf_link_hash_entry *   new_hash;
 463           struct elf_link_hash_entry **  h;
 464
 465           ptr->current_hash = elf_link_hash_lookup (hash_table, ptr->current_name, FALSE, FALSE, TRUE);
 466
 467           if (ptr->current_hash == NULL)
 468             {
 469               if (SYMBIAN_DEBUG)
 470                 fprintf (stderr, "IMPORT AS: current symbol '%s' does not exist\n", ptr->current_name);
 471               continue;
 472             }
 473
 474           new_hash = elf_link_hash_lookup (hash_table, ptr->new_name,
 475                                            FALSE, FALSE, TRUE);
 476           /* If we could not find the symbol then it is a new, undefined symbol.
 477              Symbian want this behaviour - ie they want to be able to rename the
 478              reference in a reloc from one undefined symbol to another, new and
 479              undefined symbol.  So we create that symbol here.  */
 480           if (new_hash == NULL)
 481             {
 482               struct bfd_link_hash_entry *bh = NULL;
 483               bfd_boolean collect = get_elf_backend_data (input_bfd)->collect;
 484               if (_bfd_generic_link_add_one_symbol (info, input_bfd,
 485                                                     ptr->new_name, BSF_GLOBAL,
 486                                                     bfd_und_section_ptr, 0,
 487                                                     NULL, FALSE, collect,
 488                                                     &bh))
 489                 {
 490                   new_hash = (struct elf_link_hash_entry *) bh;
 491                   new_hash->type = STT_FUNC;
 492                   new_hash->non_elf = 0;
 493
 494                   if (SYMBIAN_DEBUG)
 495                     fprintf (stderr, "Created new symbol %s\n", ptr->new_name);
 496                 }
 497             }
 498
 499           if (new_hash == NULL)
 500             {
 501               /* xgettext:c-format */
 502               _bfd_error_handler (_("%B: Failed to add renamed symbol %s"),
 503                                   input_bfd, ptr->new_name);
 504               continue;
 505             }
 506
 507           /* Convert the new_hash value into a index into the table of symbol hashes.  */
 508           for (h = sym_hashes; h < sym_hashes_end; h ++)
 509             {
 510               if (* h == new_hash)
 511                 {
 512                   ptr->new_symndx = h - sym_hashes + num_local_syms;
 513                   if (SYMBIAN_DEBUG)
 514                     fprintf (stderr, "Converted new hash to index of %ld\n", ptr->new_symndx);
 515                   break;
 516                 }
 517             }
 518           /* If the new symbol is not in the hash table then it must be
 519              because it is one of the newly created undefined symbols
 520              manufactured above.  So we extend the sym has table here to
 521              include this extra symbol.  */
 522           if (h == sym_hashes_end)
 523             {
 524               struct elf_link_hash_entry **  new_sym_hashes;
 525
 526               /* This is not very efficient, but it works.  */
 527               ++ num_global_syms;
 528               new_sym_hashes = bfd_alloc (input_bfd, num_global_syms * sizeof * sym_hashes);
 529               if (new_sym_hashes == NULL)
 530                 {
 531                   if (SYMBIAN_DEBUG)
 532                     fprintf (stderr, "Out of memory extending hash table\n");
 533                   continue;
 534                 }
 535               memcpy (new_sym_hashes, sym_hashes, (num_global_syms - 1) * sizeof * sym_hashes);
 536               new_sym_hashes[num_global_syms - 1] = new_hash;
 537               elf_sym_hashes (input_bfd) = sym_hashes = new_sym_hashes;
 538               sym_hashes_end = sym_hashes + num_global_syms;
 539               symtab_hdr->sh_size  = (num_global_syms + num_local_syms) * sizeof (Elf32_External_Sym);
 540
 541               ptr->new_symndx = num_global_syms - 1 + num_local_syms;
 542
 543               if (SYMBIAN_DEBUG)
 544                 fprintf (stderr, "Extended symbol hash table to insert new symbol as index %ld\n",
 545                          ptr->new_symndx);
 546             }
 547         }
 548
 549       /* Walk the reloc list looking for references to renamed symbols.
 550          When we find one, we alter the index in the reloc to point to the new symbol.  */
 551       for (rel = relocs, relend = relocs + input_section->reloc_count;
 552            rel < relend;
 553            rel ++)
 554         {
 555           int                          r_type;
 556           unsigned long                r_symndx;
 557           struct elf_link_hash_entry * h;
 558
 559           r_symndx = ELF32_R_SYM (rel->r_info);
 560           r_type = ELF32_R_TYPE (rel->r_info);
 561
 562           /* Ignore unused relocs.  */
 563           if ((r_type >= (int) R_SH_GNU_VTINHERIT
 564                && r_type <= (int) R_SH_LABEL)
 565               || r_type == (int) R_SH_NONE
 566               || r_type < 0
 567               || r_type >= R_SH_max)
 568             continue;
 569
 570           /* Ignore relocs against local symbols.  */
 571           if (r_symndx < num_local_syms)
 572             continue;
 573
 574           BFD_ASSERT (r_symndx < (num_global_syms + num_local_syms));
 575           h = sym_hashes[r_symndx - num_local_syms];
 576           BFD_ASSERT (h != NULL);
 577
 578           while (   h->root.type == bfd_link_hash_indirect
 579                  || h->root.type == bfd_link_hash_warning)
 580             h = (struct elf_link_hash_entry *) h->root.u.i.link;
 581
 582           /* If the symbol is defined there is no need to rename it.
 583              XXX - is this true ?  */
 584           if (   h->root.type == bfd_link_hash_defined
 585               || h->root.type == bfd_link_hash_defweak
 586               || h->root.type == bfd_link_hash_undefweak)
 587             continue;
 588
 589           for (ptr = rename_list; ptr; ptr = ptr->next)
 590             if (h == ptr->current_hash)
 591               {
 592                 BFD_ASSERT (ptr->new_symndx);
 593                 if (SYMBIAN_DEBUG)
 594                   fprintf (stderr, "convert reloc %lx from using index %ld to using index %ld\n",
 595                            (unsigned long) rel->r_info,
 596                            (long) ELF32_R_SYM (rel->r_info), ptr->new_symndx);
 597                 rel->r_info = ELF32_R_INFO (ptr->new_symndx, r_type);
 598                 break;
 599               }
 600         }
 601     }
 602
 603   return sh_elf_relocate_section (output_bfd, info, input_bfd, input_section,
 604                                   contents, relocs, local_syms, local_sections);
 605 }
 606
 607 #define TARGET_LITTLE_SYM       sh_elf32_symbian_le_vec
 608 #define TARGET_LITTLE_NAME      "elf32-shl-symbian"
 609
 610 #undef  elf_backend_relocate_section
 611 #define elf_backend_relocate_section    sh_symbian_relocate_section
 612 #undef  elf_backend_check_directives
 613 #define elf_backend_check_directives    sh_symbian_process_directives
 614
 615 #include "elf32-target.h"