ld/ldmain.c

   1 /* Main program of GNU linker.
   2    Copyright (C) 1991, 92, 93, 94 Free Software Foundation, Inc.
   3    Written by Steve Chamberlain steve@cygnus.com
   4
   5 This file is part of GLD, the Gnu Linker.
   6
   7 GLD 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 2, or (at your option)
  10 any later version.
  11
  12 GLD 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 GLD; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21
  22 #include "bfd.h"
  23 #include "sysdep.h"
  24 #include <stdio.h>
  25 #include "libiberty.h"
  26 #include "bfdlink.h"
  27
  28 #include "config.h"
  29 #include "ld.h"
  30 #include "ldmain.h"
  31 #include "ldmisc.h"
  32 #include "ldwrite.h"
  33 #include "ldgram.h"
  34 #include "ldexp.h"
  35 #include "ldlang.h"
  36 #include "ldemul.h"
  37 #include "ldlex.h"
  38 #include "ldfile.h"
  39 #include "ldctor.h"
  40
  41 /* Somewhere above, sys/stat.h got included . . . . */
  42 #if !defined(S_ISDIR) && defined(S_IFDIR)
  43 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
  44 #endif
  45
  46 #include <string.h>
  47
  48 static char *get_emulation PARAMS ((int, char **));
  49 static void set_scripts_dir PARAMS ((void));
  50
  51 /* EXPORTS */
  52
  53 char *default_target;
  54 const char *output_filename = "a.out";
  55
  56 /* Name this program was invoked by.  */
  57 char *program_name;
  58
  59 /* The file that we're creating */
  60 bfd *output_bfd = 0;
  61
  62 /* Set by -G argument, for MIPS ECOFF target.  */
  63 int g_switch_value = 8;
  64
  65 /* Nonzero means print names of input files as processed.  */
  66 boolean trace_files;
  67
  68 /* Nonzero means same, but note open failures, too.  */
  69 boolean trace_file_tries;
  70
  71 /* Nonzero means version number was printed, so exit successfully
  72    instead of complaining if no input files are given.  */
  73 boolean version_printed;
  74
  75 args_type command_line;
  76
  77 ld_config_type config;
  78
  79 static boolean check_for_scripts_dir PARAMS ((char *dir));
  80 static boolean add_archive_element PARAMS ((struct bfd_link_info *, bfd *,
  81                                             const char *));
  82 static boolean multiple_definition PARAMS ((struct bfd_link_info *,
  83                                             const char *,
  84                                             bfd *, asection *, bfd_vma,
  85                                             bfd *, asection *, bfd_vma));
  86 static boolean multiple_common PARAMS ((struct bfd_link_info *,
  87                                         const char *, bfd *,
  88                                         enum bfd_link_hash_type, bfd_vma,
  89                                         bfd *, enum bfd_link_hash_type,
  90                                         bfd_vma));
  91 static boolean add_to_set PARAMS ((struct bfd_link_info *,
  92                                    struct bfd_link_hash_entry *,
  93                                    bfd_reloc_code_real_type,
  94                                    bfd *, asection *, bfd_vma));
  95 static boolean constructor_callback PARAMS ((struct bfd_link_info *,
  96                                              boolean constructor,
  97                                              const char *name,
  98                                              bfd *, asection *, bfd_vma));
  99 static boolean warning_callback PARAMS ((struct bfd_link_info *,
 100                                          const char *));
 101 static boolean undefined_symbol PARAMS ((struct bfd_link_info *,
 102                                          const char *, bfd *,
 103                                          asection *, bfd_vma));
 104 static boolean reloc_overflow PARAMS ((struct bfd_link_info *, const char *,
 105                                        const char *, bfd_vma,
 106                                        bfd *, asection *, bfd_vma));
 107 static boolean reloc_dangerous PARAMS ((struct bfd_link_info *, const char *,
 108                                         bfd *, asection *, bfd_vma));
 109 static boolean unattached_reloc PARAMS ((struct bfd_link_info *,
 110                                          const char *, bfd *, asection *,
 111                                          bfd_vma));
 112 static boolean notice_ysym PARAMS ((struct bfd_link_info *, const char *,
 113                                     bfd *, asection *, bfd_vma));
 114
 115 static struct bfd_link_callbacks link_callbacks =
 116 {
 117   add_archive_element,
 118   multiple_definition,
 119   multiple_common,
 120   add_to_set,
 121   constructor_callback,
 122   warning_callback,
 123   undefined_symbol,
 124   reloc_overflow,
 125   reloc_dangerous,
 126   unattached_reloc,
 127   notice_ysym
 128 };
 129
 130 struct bfd_link_info link_info;
 131 \f
 132 static void
 133 remove_output ()
 134 {
 135   if (output_filename)
 136     {
 137       if (output_bfd && output_bfd->iostream)
 138         fclose((FILE *)(output_bfd->iostream));
 139       if (delete_output_file_on_failure)
 140         unlink (output_filename);
 141     }
 142 }
 143
 144 int
 145 main (argc, argv)
 146      int argc;
 147      char **argv;
 148 {
 149   char *emulation;
 150   long start_time = get_run_time ();
 151
 152   program_name = argv[0];
 153   xmalloc_set_program_name (program_name);
 154
 155   bfd_init ();
 156
 157   xatexit (remove_output);
 158
 159   /* Initialize the data about options.  */
 160   trace_files = trace_file_tries = version_printed = false;
 161   config.build_constructors = true;
 162   config.dynamic_link = false;
 163   command_line.force_common_definition = false;
 164
 165   link_info.callbacks = &link_callbacks;
 166   link_info.relocateable = false;
 167   link_info.strip = strip_none;
 168   link_info.discard = discard_none;
 169   link_info.lprefix_len = 1;
 170   link_info.lprefix = "L";
 171   link_info.keep_memory = true;
 172   link_info.input_bfds = NULL;
 173   link_info.create_object_symbols_section = NULL;
 174   link_info.hash = NULL;
 175   link_info.keep_hash = NULL;
 176   link_info.notice_hash = NULL;
 177
 178   ldfile_add_arch ("");
 179
 180   config.make_executable = true;
 181   force_make_executable = false;
 182   config.magic_demand_paged = true;
 183   config.text_read_only = true;
 184   config.make_executable = true;
 185
 186   emulation = get_emulation (argc, argv);
 187   ldemul_choose_mode (emulation);
 188   default_target = ldemul_choose_target ();
 189   lang_init ();
 190   ldemul_before_parse ();
 191   lang_has_input_file = false;
 192   parse_args (argc, argv);
 193
 194   if (link_info.relocateable)
 195     {
 196       if (command_line.relax)
 197         einfo ("%P%F: -relax and -r may not be used together\n");
 198       if (config.dynamic_link)
 199         einfo ("%P%F: -r and -call_shared may not be used together\n");
 200       if (link_info.strip == strip_all)
 201         einfo ("%P%F: -r and -s may not be used together\n");
 202     }
 203
 204   /* This essentially adds another -L directory so this must be done after
 205      the -L's in argv have been processed.  */
 206   set_scripts_dir ();
 207
 208   if (had_script == false)
 209     {
 210       /* Read the emulation's appropriate default script.  */
 211       int isfile;
 212       char *s = ldemul_get_script (&isfile);
 213
 214       if (isfile)
 215         ldfile_open_command_file (s);
 216       else
 217         lex_redirect (s);
 218       parser_input = input_script;
 219       yyparse ();
 220     }
 221
 222   lang_final ();
 223
 224   if (lang_has_input_file == false)
 225     {
 226       if (version_printed)
 227         xexit (0);
 228       einfo ("%P%F: no input files\n");
 229     }
 230
 231   if (trace_files)
 232     {
 233       info_msg ("%P: mode %s\n", emulation);
 234     }
 235
 236   ldemul_after_parse ();
 237
 238
 239   if (config.map_filename)
 240     {
 241       if (strcmp (config.map_filename, "-") == 0)
 242         {
 243           config.map_file = stdout;
 244         }
 245       else
 246         {
 247           config.map_file = fopen (config.map_filename, FOPEN_WT);
 248           if (config.map_file == (FILE *) NULL)
 249             {
 250               einfo ("%P%F: cannot open map file %s: %E\n",
 251                      config.map_filename);
 252             }
 253         }
 254     }
 255
 256
 257   lang_process ();
 258
 259   /* Print error messages for any missing symbols, for any warning
 260      symbols, and possibly multiple definitions */
 261
 262
 263   if (config.text_read_only)
 264     {
 265       /* Look for a text section and mark the readonly attribute in it */
 266       asection *found = bfd_get_section_by_name (output_bfd, ".text");
 267
 268       if (found != (asection *) NULL)
 269         {
 270           found->flags |= SEC_READONLY;
 271         }
 272     }
 273
 274   if (link_info.relocateable)
 275     output_bfd->flags &= ~EXEC_P;
 276   else
 277     output_bfd->flags |= EXEC_P;
 278
 279   ldwrite ();
 280
 281   /* Even if we're producing relocateable output, some non-fatal errors should
 282      be reported in the exit status.  (What non-fatal errors, if any, do we
 283      want to ignore for relocateable output?)  */
 284
 285   if (config.make_executable == false && force_make_executable == false)
 286     {
 287       if (trace_files == true)
 288         {
 289           einfo ("%P: link errors found, deleting executable `%s'\n",
 290                  output_filename);
 291         }
 292
 293       if (output_bfd->iostream)
 294         fclose ((FILE *) (output_bfd->iostream));
 295
 296       unlink (output_filename);
 297       xexit (1);
 298     }
 299   else
 300     {
 301       if (! bfd_close (output_bfd))
 302         einfo ("%F%B: final close failed: %E\n", output_bfd);
 303     }
 304
 305   if (config.stats)
 306     {
 307       extern char **environ;
 308       char *lim = (char *) sbrk (0);
 309       long run_time = get_run_time () - start_time;
 310
 311       fprintf (stderr, "%s: total time in link: %ld.%06ld\n",
 312                program_name, run_time / 1000000, run_time % 1000000);
 313       fprintf (stderr, "%s: data size %ld\n", program_name,
 314                (long) (lim - (char *) &environ));
 315     }
 316
 317   /* Prevent remove_output from doing anything, after a successful link.  */
 318   output_filename = NULL;
 319
 320   xexit (0);
 321   return 0;
 322 }
 323
 324 /* We need to find any explicitly given emulation in order to initialize the
 325    state that's needed by the lex&yacc argument parser (parse_args).  */
 326
 327 static char *
 328 get_emulation (argc, argv)
 329      int argc;
 330      char **argv;
 331 {
 332   char *emulation;
 333   int i;
 334
 335   emulation = (char *) getenv (EMULATION_ENVIRON);
 336   if (emulation == NULL)
 337     emulation = DEFAULT_EMULATION;
 338
 339   for (i = 1; i < argc; i++)
 340     {
 341       if (!strncmp (argv[i], "-m", 2))
 342         {
 343           if (argv[i][2] == '\0')
 344             {
 345               /* -m EMUL */
 346               if (i < argc - 1)
 347                 {
 348                   emulation = argv[i + 1];
 349                   i++;
 350                 }
 351               else
 352                 {
 353                   einfo("%P%F: missing argument to -m\n");
 354                 }
 355             }
 356           else if (strcmp (argv[i], "-mips1") == 0
 357                    || strcmp (argv[i], "-mips2") == 0
 358                    || strcmp (argv[i], "-mips3") == 0)
 359             {
 360               /* FIXME: The arguments -mips1, -mips2 and -mips3 are
 361                  passed to the linker by some MIPS compilers.  They
 362                  generally tell the linker to use a slightly different
 363                  library path.  Perhaps someday these should be
 364                  implemented as emulations; until then, we just ignore
 365                  the arguments and hope that nobody ever creates
 366                  emulations named ips1, ips2 or ips3.  */
 367             }
 368           else
 369             {
 370               /* -mEMUL */
 371               emulation = &argv[i][2];
 372             }
 373         }
 374     }
 375
 376   return emulation;
 377 }
 378
 379 /* If directory DIR contains an "ldscripts" subdirectory,
 380    add DIR to the library search path and return true,
 381    else return false.  */
 382
 383 static boolean
 384 check_for_scripts_dir (dir)
 385      char *dir;
 386 {
 387   size_t dirlen;
 388   char *buf;
 389   struct stat s;
 390   boolean res;
 391
 392   dirlen = strlen (dir);
 393   /* sizeof counts the terminating NUL.  */
 394   buf = (char *) xmalloc (dirlen + sizeof("/ldscripts"));
 395   sprintf (buf, "%s/ldscripts", dir);
 396
 397   res = stat (buf, &s) == 0 && S_ISDIR (s.st_mode);
 398   free (buf);
 399   if (res)
 400     ldfile_add_library_path (dir, false);
 401   return res;
 402 }
 403
 404 /* Set the default directory for finding script files.
 405    Libraries will be searched for here too, but that's ok.
 406    We look for the "ldscripts" directory in:
 407
 408    SCRIPTDIR (passed from Makefile)
 409    the dir where this program is (for using it from the build tree)
 410    the dir where this program is/../lib (for installing the tool suite elsewhere) */
 411
 412 static void
 413 set_scripts_dir ()
 414 {
 415   char *end, *dir;
 416   size_t dirlen;
 417
 418   if (check_for_scripts_dir (SCRIPTDIR))
 419     return;                     /* We've been installed normally.  */
 420
 421   /* Look for "ldscripts" in the dir where our binary is.  */
 422   end = strrchr (program_name, '/');
 423   if (end)
 424     {
 425       dirlen = end - program_name;
 426       /* Make a copy of program_name in dir.
 427          Leave room for later "/../lib".  */
 428       dir = (char *) xmalloc (dirlen + 8);
 429       strncpy (dir, program_name, dirlen);
 430       dir[dirlen] = '\0';
 431     }
 432   else
 433     {
 434       dirlen = 1;
 435       dir = (char *) xmalloc (dirlen + 8);
 436       strcpy (dir, ".");
 437     }
 438
 439   if (check_for_scripts_dir (dir))
 440     return;                     /* Don't free dir.  */
 441
 442   /* Look for "ldscripts" in <the dir where our binary is>/../lib.  */
 443   strcpy (dir + dirlen, "/../lib");
 444   if (check_for_scripts_dir (dir))
 445     return;
 446
 447   free (dir);                   /* Well, we tried.  */
 448 }
 449
 450 void
 451 add_ysym (name)
 452      const char *name;
 453 {
 454   if (link_info.notice_hash == (struct bfd_hash_table *) NULL)
 455     {
 456       link_info.notice_hash = ((struct bfd_hash_table *)
 457                                xmalloc (sizeof (struct bfd_hash_table)));
 458       if (! bfd_hash_table_init_n (link_info.notice_hash,
 459                                    bfd_hash_newfunc,
 460                                    61))
 461         einfo ("%P%F: bfd_hash_table_init failed: %E\n");
 462     }
 463
 464   if (bfd_hash_lookup (link_info.notice_hash, name, true, true)
 465       == (struct bfd_hash_entry *) NULL)
 466     einfo ("%P%F: bfd_hash_lookup failed: %E\n");
 467 }
 468
 469 /* Handle the -retain-symbols-file option.  */
 470
 471 void
 472 add_keepsyms_file (filename)
 473      const char *filename;
 474 {
 475   FILE *file;
 476   char *buf;
 477   size_t bufsize;
 478   int c;
 479
 480   if (link_info.strip == strip_some)
 481     einfo ("%X%P: error: duplicate retain-symbols-file\n");
 482
 483   file = fopen (filename, "r");
 484   if (file == (FILE *) NULL)
 485     {
 486       bfd_set_error (bfd_error_system_call);
 487       einfo ("%X%P: %s: %E", filename);
 488       return;
 489     }
 490
 491   link_info.keep_hash = ((struct bfd_hash_table *)
 492                          xmalloc (sizeof (struct bfd_hash_table)));
 493   if (! bfd_hash_table_init (link_info.keep_hash, bfd_hash_newfunc))
 494     einfo ("%P%F: bfd_hash_table_init failed: %E\n");
 495
 496   bufsize = 100;
 497   buf = (char *) xmalloc (bufsize);
 498
 499   c = getc (file);
 500   while (c != EOF)
 501     {
 502       while (isspace (c))
 503         c = getc (file);
 504
 505       if (c != EOF)
 506         {
 507           size_t len = 0;
 508
 509           while (! isspace (c) && c != EOF)
 510             {
 511               buf[len] = c;
 512               ++len;
 513               if (len >= bufsize)
 514                 {
 515                   bufsize *= 2;
 516                   buf = xrealloc (buf, bufsize);
 517                 }
 518               c = getc (file);
 519             }
 520
 521           buf[len] = '\0';
 522
 523           if (bfd_hash_lookup (link_info.keep_hash, buf, true, true)
 524               == (struct bfd_hash_entry *) NULL)
 525             einfo ("%P%F: bfd_hash_lookup for insertion failed: %E");
 526         }
 527     }
 528
 529   if (link_info.strip != strip_none)
 530     einfo ("%P: `-retain-symbols-file' overrides `-s' and `-S'\n");
 531
 532   link_info.strip = strip_some;
 533 }
 534 \f
 535 /* Callbacks from the BFD linker routines.  */
 536
 537 /* This is called when BFD has decided to include an archive member in
 538    a link.  */
 539
 540 /*ARGSUSED*/
 541 static boolean
 542 add_archive_element (info, abfd, name)
 543      struct bfd_link_info *info;
 544      bfd *abfd;
 545      const char *name;
 546 {
 547   lang_input_statement_type *input;
 548
 549   input = ((lang_input_statement_type *)
 550            xmalloc ((bfd_size_type) sizeof (lang_input_statement_type)));
 551   input->filename = abfd->filename;
 552   input->local_sym_name = abfd->filename;
 553   input->the_bfd = abfd;
 554   input->asymbols = NULL;
 555   input->next = NULL;
 556   input->just_syms_flag = false;
 557   input->loaded = false;
 558   input->search_dirs_flag = false;
 559
 560   /* FIXME: The following fields are not set: header.next,
 561      header.type, closed, passive_position, symbol_count,
 562      next_real_file, is_archive, target, real, common_section,
 563      common_output_section, complained.  This bit of code is from the
 564      old decode_library_subfile function.  I don't know whether any of
 565      those fields matters.  */
 566
 567   ldlang_add_file (input);
 568
 569   if (config.map_file != (FILE *) NULL)
 570     minfo ("%s needed due to %T\n", abfd->filename, name);
 571
 572   if (trace_files || trace_file_tries)
 573     info_msg ("%I\n", input);
 574
 575   return true;
 576 }
 577
 578 /* This is called when BFD has discovered a symbol which is defined
 579    multiple times.  */
 580
 581 /*ARGSUSED*/
 582 static boolean
 583 multiple_definition (info, name, obfd, osec, oval, nbfd, nsec, nval)
 584      struct bfd_link_info *info;
 585      const char *name;
 586      bfd *obfd;
 587      asection *osec;
 588      bfd_vma oval;
 589      bfd *nbfd;
 590      asection *nsec;
 591      bfd_vma nval;
 592 {
 593   einfo ("%X%C: multiple definition of `%T'\n",
 594          nbfd, nsec, nval, name);
 595   if (obfd != (bfd *) NULL)
 596     einfo ("%C: first defined here\n", obfd, osec, oval);
 597   return true;
 598 }
 599
 600 /* This is called when there is a definition of a common symbol, or
 601    when a common symbol is found for a symbol that is already defined,
 602    or when two common symbols are found.  We only do something if
 603    -warn-common was used.  */
 604
 605 /*ARGSUSED*/
 606 static boolean
 607 multiple_common (info, name, obfd, otype, osize, nbfd, ntype, nsize)
 608      struct bfd_link_info *info;
 609      const char *name;
 610      bfd *obfd;
 611      enum bfd_link_hash_type otype;
 612      bfd_vma osize;
 613      bfd *nbfd;
 614      enum bfd_link_hash_type ntype;
 615      bfd_vma nsize;
 616 {
 617   if (! config.warn_common)
 618     return true;
 619
 620   if (ntype == bfd_link_hash_defined)
 621     {
 622       ASSERT (otype == bfd_link_hash_common);
 623       einfo ("%B: warning: definition of `%T' overriding common\n",
 624              nbfd, name);
 625       einfo ("%B: warning: common is here\n", obfd);
 626     }
 627   else if (otype == bfd_link_hash_defined)
 628     {
 629       ASSERT (ntype == bfd_link_hash_common);
 630       einfo ("%B: warning: common of `%T' overridden by definition\n",
 631              nbfd, name);
 632       einfo ("%B: warning: defined here\n", obfd);
 633     }
 634   else
 635     {
 636       ASSERT (otype == bfd_link_hash_common && ntype == bfd_link_hash_common);
 637       if (osize > nsize)
 638         {
 639           einfo ("%B: warning: common of `%T' overridden by larger common\n",
 640                  nbfd, name);
 641           einfo ("%B: warning: larger common is here\n", obfd);
 642         }
 643       else if (nsize > osize)
 644         {
 645           einfo ("%B: warning: common of `%T' overriding smaller common\n",
 646                  nbfd, name);
 647           einfo ("%B: warning: smaller common is here\n", obfd);
 648         }
 649       else
 650         {
 651           einfo ("%B: warning: multiple common of `%T'\n", nbfd, name);
 652           einfo ("%B: warning: previous common is here\n", obfd);
 653         }
 654     }
 655
 656   return true;
 657 }
 658
 659 /* This is called when BFD has discovered a set element.  H is the
 660    entry in the linker hash table for the set.  SECTION and VALUE
 661    represent a value which should be added to the set.  */
 662
 663 /*ARGSUSED*/
 664 static boolean
 665 add_to_set (info, h, reloc, abfd, section, value)
 666      struct bfd_link_info *info;
 667      struct bfd_link_hash_entry *h;
 668      bfd_reloc_code_real_type reloc;
 669      bfd *abfd;
 670      asection *section;
 671      bfd_vma value;
 672 {
 673   if (! config.build_constructors)
 674     return true;
 675
 676   ldctor_add_set_entry (h, reloc, section, value);
 677
 678   if (h->type == bfd_link_hash_new)
 679     {
 680       h->type = bfd_link_hash_undefined;
 681       h->u.undef.abfd = abfd;
 682       /* We don't call bfd_link_add_undef to add this to the list of
 683          undefined symbols because we are going to define it
 684          ourselves.  */
 685     }
 686
 687   return true;
 688 }
 689
 690 /* This is called when BFD has discovered a constructor.  This is only
 691    called for some object file formats--those which do not handle
 692    constructors in some more clever fashion.  This is similar to
 693    adding an element to a set, but less general.  */
 694
 695 static boolean
 696 constructor_callback (info, constructor, name, abfd, section, value)
 697      struct bfd_link_info *info;
 698      boolean constructor;
 699      const char *name;
 700      bfd *abfd;
 701      asection *section;
 702      bfd_vma value;
 703 {
 704   char *set_name;
 705   char *s;
 706   struct bfd_link_hash_entry *h;
 707
 708   if (! config.build_constructors)
 709     return true;
 710
 711   /* Ensure that BFD_RELOC_CTOR exists now, so that we can give a
 712      useful error message.  */
 713   if (bfd_reloc_type_lookup (output_bfd, BFD_RELOC_CTOR) == NULL)
 714     einfo ("%P%F: BFD backend error: BFD_RELOC_CTOR unsupported");
 715
 716   set_name = (char *) alloca (1 + sizeof "__CTOR_LIST__");
 717   s = set_name;
 718   if (bfd_get_symbol_leading_char (abfd) != '\0')
 719     *s++ = bfd_get_symbol_leading_char (abfd);
 720   if (constructor)
 721     strcpy (s, "__CTOR_LIST__");
 722   else
 723     strcpy (s, "__DTOR_LIST__");
 724
 725   if (config.map_file != (FILE *) NULL)
 726     fprintf (config.map_file,
 727              "Adding %s to constructor/destructor set %s\n", name, set_name);
 728
 729   h = bfd_link_hash_lookup (info->hash, set_name, true, true, true);
 730   if (h == (struct bfd_link_hash_entry *) NULL)
 731     einfo ("%P%F: bfd_link_hash_lookup failed: %E");
 732   if (h->type == bfd_link_hash_new)
 733     {
 734       h->type = bfd_link_hash_undefined;
 735       h->u.undef.abfd = abfd;
 736       /* We don't call bfd_link_add_undef to add this to the list of
 737          undefined symbols because we are going to define it
 738          ourselves.  */
 739     }
 740
 741   ldctor_add_set_entry (h, BFD_RELOC_CTOR, section, value);
 742   return true;
 743 }
 744
 745 /* This is called when there is a reference to a warning symbol.  */
 746
 747 /*ARGSUSED*/
 748 static boolean
 749 warning_callback (info, warning)
 750      struct bfd_link_info *info;
 751      const char *warning;
 752 {
 753   einfo ("%P: %s\n", warning);
 754   return true;
 755 }
 756
 757 /* This is called when an undefined symbol is found.  */
 758
 759 /*ARGSUSED*/
 760 static boolean
 761 undefined_symbol (info, name, abfd, section, address)
 762      struct bfd_link_info *info;
 763      const char *name;
 764      bfd *abfd;
 765      asection *section;
 766      bfd_vma address;
 767 {
 768   static char *error_name;
 769   static unsigned int error_count;
 770
 771 #define MAX_ERRORS_IN_A_ROW 5
 772
 773   /* We never print more than a reasonable number of errors in a row
 774      for a single symbol.  */
 775   if (error_name != (char *) NULL
 776       && strcmp (name, error_name) == 0)
 777     ++error_count;
 778   else
 779     {
 780       error_count = 0;
 781       if (error_name != (char *) NULL)
 782         free (error_name);
 783       error_name = buystring (name);
 784     }
 785
 786   if (error_count < MAX_ERRORS_IN_A_ROW)
 787     einfo ("%X%C: undefined reference to `%T'\n",
 788            abfd, section, address, name);
 789   else if (error_count == MAX_ERRORS_IN_A_ROW)
 790     einfo ("%C: more undefined references to `%T' follow\n",
 791            abfd, section, address, name);
 792
 793   return true;
 794 }
 795
 796 /* This is called when a reloc overflows.  */
 797
 798 /*ARGSUSED*/
 799 static boolean
 800 reloc_overflow (info, name, reloc_name, addend, abfd, section, address)
 801      struct bfd_link_info *info;
 802      const char *name;
 803      const char *reloc_name;
 804      bfd_vma addend;
 805      bfd *abfd;
 806      asection *section;
 807      bfd_vma address;
 808 {
 809   if (abfd == (bfd *) NULL)
 810     einfo ("%P%X: generated");
 811   else
 812     einfo ("%X%C:", abfd, section, address);
 813   einfo (" relocation truncated to fit: %s %T", reloc_name, name);
 814   if (addend != 0)
 815     einfo ("+%v", addend);
 816   einfo ("\n");
 817   return true;
 818 }
 819
 820 /* This is called when a dangerous relocation is made.  */
 821
 822 /*ARGSUSED*/
 823 static boolean
 824 reloc_dangerous (info, message, abfd, section, address)
 825      struct bfd_link_info *info;
 826      const char *message;
 827      bfd *abfd;
 828      asection *section;
 829      bfd_vma address;
 830 {
 831   if (abfd == (bfd *) NULL)
 832     einfo ("%P%X: generated");
 833   else
 834     einfo ("%X%C:", abfd, section, address);
 835   einfo ("dangerous relocation: %s\n", message);
 836   return true;
 837 }
 838
 839 /* This is called when a reloc is being generated attached to a symbol
 840    that is not being output.  */
 841
 842 /*ARGSUSED*/
 843 static boolean
 844 unattached_reloc (info, name, abfd, section, address)
 845      struct bfd_link_info *info;
 846      const char *name;
 847      bfd *abfd;
 848      asection *section;
 849      bfd_vma address;
 850 {
 851   if (abfd == (bfd *) NULL)
 852     einfo ("%P%X: generated");
 853   else
 854     einfo ("%X%C:", abfd, section, address);
 855   einfo (" reloc refers to symbol `%T' which is not being output\n", name);
 856   return true;
 857 }
 858
 859 /* This is called when a symbol in notice_hash is found.  Symbols are
 860    put in notice_hash using the -y option.  */
 861
 862 /*ARGSUSED*/
 863 static boolean
 864 notice_ysym (info, name, abfd, section, value)
 865      struct bfd_link_info *info;
 866      const char *name;
 867      bfd *abfd;
 868      asection *section;
 869      bfd_vma value;
 870 {
 871   einfo ("%B: %s %s\n", abfd,
 872          section != &bfd_und_section ? "definition of" : "reference to",
 873          name);
 874   return true;
 875 }