ld/ldfile.c

   1 /* Linker file opening and searching.
   2    Copyright (C) 1991-2015 Free Software Foundation, Inc.
   3
   4    This file is part of the GNU Binutils.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  19    MA 02110-1301, USA.  */
  20
  21 #include "sysdep.h"
  22 #include "bfd.h"
  23 #include "bfdlink.h"
  24 #include "safe-ctype.h"
  25 #include "ld.h"
  26 #include "ldmisc.h"
  27 #include "ldexp.h"
  28 #include "ldlang.h"
  29 #include "ldfile.h"
  30 #include "ldmain.h"
  31 #include <ldgram.h>
  32 #include "ldlex.h"
  33 #include "ldemul.h"
  34 #include "libiberty.h"
  35 #include "filenames.h"
  36 #ifdef ENABLE_PLUGINS
  37 #include "plugin-api.h"
  38 #include "plugin.h"
  39 #endif /* ENABLE_PLUGINS */
  40
  41 bfd_boolean  ldfile_assumed_script = FALSE;
  42 const char * ldfile_output_machine_name = "";
  43 unsigned long ldfile_output_machine;
  44 enum bfd_architecture ldfile_output_architecture;
  45 search_dirs_type * search_head;
  46
  47 #ifdef VMS
  48 static char * slash = "";
  49 #else
  50 #if defined (_WIN32) && ! defined (__CYGWIN32__)
  51 static char * slash = "\\";
  52 #else
  53 static char * slash = "/";
  54 #endif
  55 #endif
  56
  57 typedef struct search_arch
  58 {
  59   char *name;
  60   struct search_arch *next;
  61 } search_arch_type;
  62
  63 static search_dirs_type **search_tail_ptr = &search_head;
  64 static search_arch_type *search_arch_head;
  65 static search_arch_type **search_arch_tail_ptr = &search_arch_head;
  66
  67 /* Test whether a pathname, after canonicalization, is the same or a
  68    sub-directory of the sysroot directory.  */
  69
  70 static bfd_boolean
  71 is_sysrooted_pathname (const char *name)
  72 {
  73   char *realname;
  74   int len;
  75   bfd_boolean result;
  76
  77   if (ld_canon_sysroot == NULL)
  78     return FALSE;
  79
  80   realname = lrealpath (name);
  81   len = strlen (realname);
  82   result = FALSE;
  83   if (len > ld_canon_sysroot_len
  84       && IS_DIR_SEPARATOR (realname[ld_canon_sysroot_len]))
  85     {
  86       realname[ld_canon_sysroot_len] = '\0';
  87       result = FILENAME_CMP (ld_canon_sysroot, realname) == 0;
  88     }
  89
  90   free (realname);
  91   return result;
  92 }
  93
  94 /* Adds NAME to the library search path.
  95    Makes a copy of NAME using xmalloc().  */
  96
  97 void
  98 ldfile_add_library_path (const char *name, bfd_boolean cmdline)
  99 {
 100   search_dirs_type *new_dirs;
 101
 102   if (!cmdline && config.only_cmd_line_lib_dirs)
 103     return;
 104
 105   new_dirs = (search_dirs_type *) xmalloc (sizeof (search_dirs_type));
 106   new_dirs->next = NULL;
 107   new_dirs->cmdline = cmdline;
 108   *search_tail_ptr = new_dirs;
 109   search_tail_ptr = &new_dirs->next;
 110
 111   /* If a directory is marked as honoring sysroot, prepend the sysroot path
 112      now.  */
 113   if (name[0] == '=')
 114     new_dirs->name = concat (ld_sysroot, name + 1, (const char *) NULL);
 115   else
 116     new_dirs->name = xstrdup (name);
 117 }
 118
 119 /* Try to open a BFD for a lang_input_statement.  */
 120
 121 bfd_boolean
 122 ldfile_try_open_bfd (const char *attempt,
 123                      lang_input_statement_type *entry)
 124 {
 125   entry->the_bfd = bfd_openr (attempt, entry->target);
 126
 127   if (verbose)
 128     {
 129       if (entry->the_bfd == NULL)
 130         info_msg (_("attempt to open %s failed\n"), attempt);
 131       else
 132         info_msg (_("attempt to open %s succeeded\n"), attempt);
 133     }
 134
 135   if (entry->the_bfd == NULL)
 136     {
 137       if (bfd_get_error () == bfd_error_invalid_target)
 138         einfo (_("%F%P: invalid BFD target `%s'\n"), entry->target);
 139       return FALSE;
 140     }
 141
 142   /* Linker needs to decompress sections.  */
 143   entry->the_bfd->flags |= BFD_DECOMPRESS;
 144
 145   /* If we are searching for this file, see if the architecture is
 146      compatible with the output file.  If it isn't, keep searching.
 147      If we can't open the file as an object file, stop the search
 148      here.  If we are statically linking, ensure that we don't link
 149      a dynamic object.
 150
 151      In the code below, it's OK to exit early if the check fails,
 152      closing the checked BFD and returning FALSE, but if the BFD
 153      checks out compatible, do not exit early returning TRUE, or
 154      the plugins will not get a chance to claim the file.  */
 155
 156   if (entry->flags.search_dirs || !entry->flags.dynamic)
 157     {
 158       bfd *check;
 159
 160       if (bfd_check_format (entry->the_bfd, bfd_archive))
 161         check = bfd_openr_next_archived_file (entry->the_bfd, NULL);
 162       else
 163         check = entry->the_bfd;
 164
 165       if (check != NULL)
 166         {
 167           if (! bfd_check_format (check, bfd_object))
 168             {
 169               if (check == entry->the_bfd
 170                   && entry->flags.search_dirs
 171                   && bfd_get_error () == bfd_error_file_not_recognized
 172                   && ! ldemul_unrecognized_file (entry))
 173                 {
 174                   int token, skip = 0;
 175                   char *arg, *arg1, *arg2, *arg3;
 176                   extern FILE *yyin;
 177
 178                   /* Try to interpret the file as a linker script.  */
 179                   ldfile_open_command_file (attempt);
 180
 181                   ldfile_assumed_script = TRUE;
 182                   parser_input = input_selected;
 183                   ldlex_both ();
 184                   token = INPUT_SCRIPT;
 185                   while (token != 0)
 186                     {
 187                       switch (token)
 188                         {
 189                         case OUTPUT_FORMAT:
 190                           if ((token = yylex ()) != '(')
 191                             continue;
 192                           if ((token = yylex ()) != NAME)
 193                             continue;
 194                           arg1 = yylval.name;
 195                           arg2 = NULL;
 196                           arg3 = NULL;
 197                           token = yylex ();
 198                           if (token == ',')
 199                             {
 200                               if ((token = yylex ()) != NAME)
 201                                 {
 202                                   free (arg1);
 203                                   continue;
 204                                 }
 205                               arg2 = yylval.name;
 206                               if ((token = yylex ()) != ','
 207                                   || (token = yylex ()) != NAME)
 208                                 {
 209                                   free (arg1);
 210                                   free (arg2);
 211                                   continue;
 212                                 }
 213                               arg3 = yylval.name;
 214                               token = yylex ();
 215                             }
 216                           if (token == ')')
 217                             {
 218                               switch (command_line.endian)
 219                                 {
 220                                 default:
 221                                 case ENDIAN_UNSET:
 222                                   arg = arg1; break;
 223                                 case ENDIAN_BIG:
 224                                   arg = arg2 ? arg2 : arg1; break;
 225                                 case ENDIAN_LITTLE:
 226                                   arg = arg3 ? arg3 : arg1; break;
 227                                 }
 228                               if (strcmp (arg, lang_get_output_target ()) != 0)
 229                                 skip = 1;
 230                             }
 231                           free (arg1);
 232                           if (arg2) free (arg2);
 233                           if (arg3) free (arg3);
 234                           break;
 235                         case NAME:
 236                         case LNAME:
 237                         case VERS_IDENTIFIER:
 238                         case VERS_TAG:
 239                           free (yylval.name);
 240                           break;
 241                         case INT:
 242                           if (yylval.bigint.str)
 243                             free (yylval.bigint.str);
 244                           break;
 245                         }
 246                       token = yylex ();
 247                     }
 248                   ldlex_popstate ();
 249                   ldfile_assumed_script = FALSE;
 250                   fclose (yyin);
 251                   yyin = NULL;
 252                   if (skip)
 253                     {
 254                       if (command_line.warn_search_mismatch)
 255                         einfo (_("%P: skipping incompatible %s "
 256                                  "when searching for %s\n"),
 257                                attempt, entry->local_sym_name);
 258                       bfd_close (entry->the_bfd);
 259                       entry->the_bfd = NULL;
 260                       return FALSE;
 261                     }
 262                 }
 263               goto success;
 264             }
 265
 266           if (!entry->flags.dynamic && (entry->the_bfd->flags & DYNAMIC) != 0)
 267             {
 268               einfo (_("%F%P: attempted static link of dynamic object `%s'\n"),
 269                      attempt);
 270               bfd_close (entry->the_bfd);
 271               entry->the_bfd = NULL;
 272               return FALSE;
 273             }
 274
 275           if (entry->flags.search_dirs
 276               && !bfd_arch_get_compatible (check, link_info.output_bfd,
 277                                            command_line.accept_unknown_input_arch)
 278               /* XCOFF archives can have 32 and 64 bit objects.  */
 279               && ! (bfd_get_flavour (check) == bfd_target_xcoff_flavour
 280                     && bfd_get_flavour (link_info.output_bfd) == bfd_target_xcoff_flavour
 281                     && bfd_check_format (entry->the_bfd, bfd_archive)))
 282             {
 283               if (command_line.warn_search_mismatch)
 284                 einfo (_("%P: skipping incompatible %s "
 285                          "when searching for %s\n"),
 286                        attempt, entry->local_sym_name);
 287               bfd_close (entry->the_bfd);
 288               entry->the_bfd = NULL;
 289               return FALSE;
 290             }
 291         }
 292     }
 293 success:
 294 #ifdef ENABLE_PLUGINS
 295   /* If plugins are active, they get first chance to claim
 296      any successfully-opened input file.  We skip archives
 297      here; the plugin wants us to offer it the individual
 298      members when we enumerate them, not the whole file.  We
 299      also ignore corefiles, because that's just weird.  It is
 300      a needed side-effect of calling  bfd_check_format with
 301      bfd_object that it sets the bfd's arch and mach, which
 302      will be needed when and if we want to bfd_create a new
 303      one using this one as a template.  */
 304   if (bfd_check_format (entry->the_bfd, bfd_object)
 305       && link_info.lto_plugin_active
 306       && !no_more_claiming)
 307     {
 308       int fd = open (attempt, O_RDONLY | O_BINARY);
 309       if (fd >= 0)
 310         {
 311           struct ld_plugin_input_file file;
 312
 313           file.name = attempt;
 314           file.offset = 0;
 315           file.filesize = lseek (fd, 0, SEEK_END);
 316           file.fd = fd;
 317           plugin_maybe_claim (&file, entry);
 318         }
 319     }
 320 #endif /* ENABLE_PLUGINS */
 321
 322   /* It opened OK, the format checked out, and the plugins have had
 323      their chance to claim it, so this is success.  */
 324   return TRUE;
 325 }
 326
 327 /* Search for and open the file specified by ENTRY.  If it is an
 328    archive, use ARCH, LIB and SUFFIX to modify the file name.  */
 329
 330 bfd_boolean
 331 ldfile_open_file_search (const char *arch,
 332                          lang_input_statement_type *entry,
 333                          const char *lib,
 334                          const char *suffix)
 335 {
 336   search_dirs_type *search;
 337
 338   /* If this is not an archive, try to open it in the current
 339      directory first.  */
 340   if (! entry->flags.maybe_archive)
 341     {
 342       if (entry->flags.sysrooted && IS_ABSOLUTE_PATH (entry->filename))
 343         {
 344           char *name = concat (ld_sysroot, entry->filename,
 345                                (const char *) NULL);
 346           if (ldfile_try_open_bfd (name, entry))
 347             {
 348               entry->filename = name;
 349               return TRUE;
 350             }
 351           free (name);
 352         }
 353       else if (ldfile_try_open_bfd (entry->filename, entry))
 354         return TRUE;
 355
 356       if (IS_ABSOLUTE_PATH (entry->filename))
 357         return FALSE;
 358     }
 359
 360   for (search = search_head; search != NULL; search = search->next)
 361     {
 362       char *string;
 363
 364       if (entry->flags.dynamic && ! link_info.relocatable)
 365         {
 366           if (ldemul_open_dynamic_archive (arch, search, entry))
 367             return TRUE;
 368         }
 369
 370       if (entry->flags.maybe_archive && !entry->flags.full_name_provided)
 371         string = concat (search->name, slash, lib, entry->filename,
 372                          arch, suffix, (const char *) NULL);
 373       else
 374         string = concat (search->name, slash, entry->filename,
 375                          (const char *) 0);
 376
 377       if (ldfile_try_open_bfd (string, entry))
 378         {
 379           entry->filename = string;
 380           return TRUE;
 381         }
 382
 383       free (string);
 384     }
 385
 386   return FALSE;
 387 }
 388
 389 /* Open the input file specified by ENTRY.
 390    PR 4437: Do not stop on the first missing file, but
 391    continue processing other input files in case there
 392    are more errors to report.  */
 393
 394 void
 395 ldfile_open_file (lang_input_statement_type *entry)
 396 {
 397   if (entry->the_bfd != NULL)
 398     return;
 399
 400   if (! entry->flags.search_dirs)
 401     {
 402       if (ldfile_try_open_bfd (entry->filename, entry))
 403         return;
 404
 405       if (filename_cmp (entry->filename, entry->local_sym_name) != 0)
 406         einfo (_("%P: cannot find %s (%s): %E\n"),
 407                entry->filename, entry->local_sym_name);
 408       else
 409         einfo (_("%P: cannot find %s: %E\n"), entry->local_sym_name);
 410
 411       entry->flags.missing_file = TRUE;
 412       input_flags.missing_file = TRUE;
 413     }
 414   else
 415     {
 416       search_arch_type *arch;
 417       bfd_boolean found = FALSE;
 418
 419       /* Try to open <filename><suffix> or lib<filename><suffix>.a */
 420       for (arch = search_arch_head; arch != NULL; arch = arch->next)
 421         {
 422           found = ldfile_open_file_search (arch->name, entry, "lib", ".a");
 423           if (found)
 424             break;
 425 #ifdef VMS
 426           found = ldfile_open_file_search (arch->name, entry, ":lib", ".a");
 427           if (found)
 428             break;
 429 #endif
 430           found = ldemul_find_potential_libraries (arch->name, entry);
 431           if (found)
 432             break;
 433         }
 434
 435       /* If we have found the file, we don't need to search directories
 436          again.  */
 437       if (found)
 438         entry->flags.search_dirs = FALSE;
 439       else
 440         {
 441           if (entry->flags.sysrooted
 442                && ld_sysroot
 443                && IS_ABSOLUTE_PATH (entry->local_sym_name))
 444             einfo (_("%P: cannot find %s inside %s\n"),
 445                    entry->local_sym_name, ld_sysroot);
 446           else
 447             einfo (_("%P: cannot find %s\n"), entry->local_sym_name);
 448           entry->flags.missing_file = TRUE;
 449           input_flags.missing_file = TRUE;
 450         }
 451     }
 452 }
 453
 454 /* Try to open NAME.  */
 455
 456 static FILE *
 457 try_open (const char *name, bfd_boolean *sysrooted)
 458 {
 459   FILE *result;
 460
 461   result = fopen (name, "r");
 462
 463   if (result != NULL)
 464     *sysrooted = is_sysrooted_pathname (name);
 465
 466   if (verbose)
 467     {
 468       if (result == NULL)
 469         info_msg (_("cannot find script file %s\n"), name);
 470       else
 471         info_msg (_("opened script file %s\n"), name);
 472     }
 473
 474   return result;
 475 }
 476
 477 /* Return TRUE iff directory DIR contains an "ldscripts" subdirectory.  */
 478
 479 static bfd_boolean
 480 check_for_scripts_dir (char *dir)
 481 {
 482   char *buf;
 483   struct stat s;
 484   bfd_boolean res;
 485
 486   buf = concat (dir, "/ldscripts", (const char *) NULL);
 487   res = stat (buf, &s) == 0 && S_ISDIR (s.st_mode);
 488   free (buf);
 489   return res;
 490 }
 491
 492 /* Return the default directory for finding script files.
 493    We look for the "ldscripts" directory in:
 494
 495    SCRIPTDIR (passed from Makefile)
 496              (adjusted according to the current location of the binary)
 497    the dir where this program is (for using it from the build tree).  */
 498
 499 static char *
 500 find_scripts_dir (void)
 501 {
 502   char *dir;
 503
 504   dir = make_relative_prefix (program_name, BINDIR, SCRIPTDIR);
 505   if (dir)
 506     {
 507       if (check_for_scripts_dir (dir))
 508         return dir;
 509       free (dir);
 510     }
 511
 512   dir = make_relative_prefix (program_name, TOOLBINDIR, SCRIPTDIR);
 513   if (dir)
 514     {
 515       if (check_for_scripts_dir (dir))
 516         return dir;
 517       free (dir);
 518     }
 519
 520   /* Look for "ldscripts" in the dir where our binary is.  */
 521   dir = make_relative_prefix (program_name, ".", ".");
 522   if (dir)
 523     {
 524       if (check_for_scripts_dir (dir))
 525         return dir;
 526       free (dir);
 527     }
 528
 529   return NULL;
 530 }
 531
 532 /* If DEFAULT_ONLY is false, try to open NAME; if that fails, look for
 533    it in directories specified with -L, then in the default script
 534    directory.  If DEFAULT_ONLY is true, the search is restricted to
 535    the default script location.  */
 536
 537 static FILE *
 538 ldfile_find_command_file (const char *name,
 539                           bfd_boolean default_only,
 540                           bfd_boolean *sysrooted)
 541 {
 542   search_dirs_type *search;
 543   FILE *result = NULL;
 544   char *path;
 545   static search_dirs_type *script_search;
 546
 547   if (!default_only)
 548     {
 549       /* First try raw name.  */
 550       result = try_open (name, sysrooted);
 551       if (result != NULL)
 552         return result;
 553     }
 554
 555   if (!script_search)
 556     {
 557       char *script_dir = find_scripts_dir ();
 558       if (script_dir)
 559         {
 560           search_dirs_type **save_tail_ptr = search_tail_ptr;
 561           search_tail_ptr = &script_search;
 562           ldfile_add_library_path (script_dir, TRUE);
 563           search_tail_ptr = save_tail_ptr;
 564         }
 565     }
 566
 567   /* Temporarily append script_search to the path list so that the
 568      paths specified with -L will be searched first.  */
 569   *search_tail_ptr = script_search;
 570
 571   /* Try now prefixes.  */
 572   for (search = default_only ? script_search : search_head;
 573        search != NULL;
 574        search = search->next)
 575     {
 576       path = concat (search->name, slash, name, (const char *) NULL);
 577       result = try_open (path, sysrooted);
 578       free (path);
 579       if (result)
 580         break;
 581     }
 582
 583   /* Restore the original path list.  */
 584   *search_tail_ptr = NULL;
 585
 586   return result;
 587 }
 588
 589 /* Open command file NAME.  */
 590
 591 static void
 592 ldfile_open_command_file_1 (const char *name, bfd_boolean default_only)
 593 {
 594   FILE *ldlex_input_stack;
 595   bfd_boolean sysrooted;
 596
 597   ldlex_input_stack = ldfile_find_command_file (name, default_only, &sysrooted);
 598
 599   if (ldlex_input_stack == NULL)
 600     {
 601       bfd_set_error (bfd_error_system_call);
 602       einfo (_("%P%F: cannot open linker script file %s: %E\n"), name);
 603       return;
 604     }
 605
 606   lex_push_file (ldlex_input_stack, name, sysrooted);
 607
 608   lineno = 1;
 609
 610   saved_script_handle = ldlex_input_stack;
 611 }
 612
 613 /* Open command file NAME in the current directory, -L directories,
 614    the default script location, in that order.  */
 615
 616 void
 617 ldfile_open_command_file (const char *name)
 618 {
 619   ldfile_open_command_file_1 (name, FALSE);
 620 }
 621
 622 /* Open command file NAME at the default script location.  */
 623
 624 void
 625 ldfile_open_default_command_file (const char *name)
 626 {
 627   ldfile_open_command_file_1 (name, TRUE);
 628 }
 629
 630 void
 631 ldfile_add_arch (const char *in_name)
 632 {
 633   char *name = xstrdup (in_name);
 634   search_arch_type *new_arch = (search_arch_type *)
 635       xmalloc (sizeof (search_arch_type));
 636
 637   ldfile_output_machine_name = in_name;
 638
 639   new_arch->name = name;
 640   new_arch->next = NULL;
 641   while (*name)
 642     {
 643       *name = TOLOWER (*name);
 644       name++;
 645     }
 646   *search_arch_tail_ptr = new_arch;
 647   search_arch_tail_ptr = &new_arch->next;
 648
 649 }
 650
 651 /* Set the output architecture.  */
 652
 653 void
 654 ldfile_set_output_arch (const char *string, enum bfd_architecture defarch)
 655 {
 656   const bfd_arch_info_type *arch = bfd_scan_arch (string);
 657
 658   if (arch)
 659     {
 660       ldfile_output_architecture = arch->arch;
 661       ldfile_output_machine = arch->mach;
 662       ldfile_output_machine_name = arch->printable_name;
 663     }
 664   else if (defarch != bfd_arch_unknown)
 665     ldfile_output_architecture = defarch;
 666   else
 667     einfo (_("%P%F: cannot represent machine `%s'\n"), string);
 668 }