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.traditional_format = false;
 162   config.build_constructors = true;
 163   config.dynamic_link = false;
 164   command_line.force_common_definition = false;
 165   command_line.interpreter = NULL;
 166
 167   link_info.callbacks = &link_callbacks;
 168   link_info.relocateable = false;
 169   link_info.strip = strip_none;
 170   link_info.discard = discard_none;
 171   link_info.lprefix_len = 1;
 172   link_info.lprefix = "L";
 173   link_info.keep_memory = true;
 174   link_info.input_bfds = NULL;
 175   link_info.create_object_symbols_section = NULL;
 176   link_info.hash = NULL;
 177   link_info.keep_hash = NULL;
 178   link_info.notice_hash = NULL;
 179
 180   ldfile_add_arch ("");
 181
 182   config.make_executable = true;
 183   force_make_executable = false;
 184   config.magic_demand_paged = true;
 185   config.text_read_only = true;
 186   config.make_executable = true;
 187
 188   emulation = get_emulation (argc, argv);
 189   ldemul_choose_mode (emulation);
 190   default_target = ldemul_choose_target ();
 191   lang_init ();
 192   ldemul_before_parse ();
 193   lang_has_input_file = false;
 194   parse_args (argc, argv);
 195
 196   if (link_info.relocateable)
 197     {
 198       if (command_line.relax)
 199         einfo ("%P%F: -relax and -r may not be used together\n");
 200       if (config.dynamic_link)
 201         einfo ("%P%F: -r and -call_shared may not be used together\n");
 202       if (link_info.strip == strip_all)
 203         einfo ("%P%F: -r and -s may not be used together\n");
 204     }
 205
 206   /* This essentially adds another -L directory so this must be done after
 207      the -L's in argv have been processed.  */
 208   set_scripts_dir ();
 209
 210   if (had_script == false)
 211     {
 212       /* Read the emulation's appropriate default script.  */
 213       int isfile;
 214       char *s = ldemul_get_script (&isfile);
 215
 216       if (isfile)
 217         ldfile_open_command_file (s);
 218       else
 219         lex_redirect (s);
 220       parser_input = input_script;
 221       yyparse ();
 222     }
 223
 224   lang_final ();
 225
 226   if (lang_has_input_file == false)
 227     {
 228       if (version_printed)
 229         xexit (0);
 230       einfo ("%P%F: no input files\n");
 231     }
 232
 233   if (trace_files)
 234     {
 235       info_msg ("%P: mode %s\n", emulation);
 236     }
 237
 238   ldemul_after_parse ();
 239
 240
 241   if (config.map_filename)
 242     {
 243       if (strcmp (config.map_filename, "-") == 0)
 244         {
 245           config.map_file = stdout;
 246         }
 247       else
 248         {
 249           config.map_file = fopen (config.map_filename, FOPEN_WT);
 250           if (config.map_file == (FILE *) NULL)
 251             {
 252               einfo ("%P%F: cannot open map file %s: %E\n",
 253                      config.map_filename);
 254             }
 255         }
 256     }
 257
 258
 259   lang_process ();
 260
 261   /* Print error messages for any missing symbols, for any warning
 262      symbols, and possibly multiple definitions */
 263
 264
 265   if (config.text_read_only)
 266     {
 267       /* Look for a text section and mark the readonly attribute in it */
 268       asection *found = bfd_get_section_by_name (output_bfd, ".text");
 269
 270       if (found != (asection *) NULL)
 271         {
 272           found->flags |= SEC_READONLY;
 273         }
 274     }
 275
 276   if (link_info.relocateable)
 277     output_bfd->flags &= ~EXEC_P;
 278   else
 279     output_bfd->flags |= EXEC_P;
 280
 281   ldwrite ();
 282
 283   /* Even if we're producing relocateable output, some non-fatal errors should
 284      be reported in the exit status.  (What non-fatal errors, if any, do we
 285      want to ignore for relocateable output?)  */
 286
 287   if (config.make_executable == false && force_make_executable == false)
 288     {
 289       if (trace_files == true)
 290         {
 291           einfo ("%P: link errors found, deleting executable `%s'\n",
 292                  output_filename);
 293         }
 294
 295       if (output_bfd->iostream)
 296         fclose ((FILE *) (output_bfd->iostream));
 297
 298       unlink (output_filename);
 299       xexit (1);
 300     }
 301   else
 302     {
 303       if (! bfd_close (output_bfd))
 304         einfo ("%F%B: final close failed: %E\n", output_bfd);
 305     }
 306
 307   if (config.stats)
 308     {
 309       extern char **environ;
 310       char *lim = (char *) sbrk (0);
 311       long run_time = get_run_time () - start_time;
 312
 313       fprintf (stderr, "%s: total time in link: %ld.%06ld\n",
 314                program_name, run_time / 1000000, run_time % 1000000);
 315       fprintf (stderr, "%s: data size %ld\n", program_name,
 316                (long) (lim - (char *) &environ));
 317     }
 318
 319   /* Prevent remove_output from doing anything, after a successful link.  */
 320   output_filename = NULL;
 321
 322   xexit (0);
 323   return 0;
 324 }
 325
 326 /* We need to find any explicitly given emulation in order to initialize the
 327    state that's needed by the lex&yacc argument parser (parse_args).  */
 328
 329 static char *
 330 get_emulation (argc, argv)
 331      int argc;
 332      char **argv;
 333 {
 334   char *emulation;
 335   int i;
 336
 337   emulation = (char *) getenv (EMULATION_ENVIRON);
 338   if (emulation == NULL)
 339     emulation = DEFAULT_EMULATION;
 340
 341   for (i = 1; i < argc; i++)
 342     {
 343       if (!strncmp (argv[i], "-m", 2))
 344         {
 345           if (argv[i][2] == '\0')
 346             {
 347               /* -m EMUL */
 348               if (i < argc - 1)
 349                 {
 350                   emulation = argv[i + 1];
 351                   i++;
 352                 }
 353               else
 354                 {
 355                   einfo("%P%F: missing argument to -m\n");
 356                 }
 357             }
 358           else if (strcmp (argv[i], "-mips1") == 0
 359                    || strcmp (argv[i], "-mips2") == 0
 360                    || strcmp (argv[i], "-mips3") == 0)
 361             {
 362               /* FIXME: The arguments -mips1, -mips2 and -mips3 are
 363                  passed to the linker by some MIPS compilers.  They
 364                  generally tell the linker to use a slightly different
 365                  library path.  Perhaps someday these should be
 366                  implemented as emulations; until then, we just ignore
 367                  the arguments and hope that nobody ever creates
 368                  emulations named ips1, ips2 or ips3.  */
 369             }
 370           else
 371             {
 372               /* -mEMUL */
 373               emulation = &argv[i][2];
 374             }
 375         }
 376     }
 377
 378   return emulation;
 379 }
 380
 381 /* If directory DIR contains an "ldscripts" subdirectory,
 382    add DIR to the library search path and return true,
 383    else return false.  */
 384
 385 static boolean
 386 check_for_scripts_dir (dir)
 387      char *dir;
 388 {
 389   size_t dirlen;
 390   char *buf;
 391   struct stat s;
 392   boolean res;
 393
 394   dirlen = strlen (dir);
 395   /* sizeof counts the terminating NUL.  */
 396   buf = (char *) xmalloc (dirlen + sizeof("/ldscripts"));
 397   sprintf (buf, "%s/ldscripts", dir);
 398
 399   res = stat (buf, &s) == 0 && S_ISDIR (s.st_mode);
 400   free (buf);
 401   if (res)
 402     ldfile_add_library_path (dir, false);
 403   return res;
 404 }
 405
 406 /* Set the default directory for finding script files.
 407    Libraries will be searched for here too, but that's ok.
 408    We look for the "ldscripts" directory in:
 409
 410    SCRIPTDIR (passed from Makefile)
 411    the dir where this program is (for using it from the build tree)
 412    the dir where this program is/../lib (for installing the tool suite elsewhere) */
 413
 414 static void
 415 set_scripts_dir ()
 416 {
 417   char *end, *dir;
 418   size_t dirlen;
 419
 420   if (check_for_scripts_dir (SCRIPTDIR))
 421     return;                     /* We've been installed normally.  */
 422
 423   /* Look for "ldscripts" in the dir where our binary is.  */
 424   end = strrchr (program_name, '/');
 425   if (end)
 426     {
 427       dirlen = end - program_name;
 428       /* Make a copy of program_name in dir.
 429          Leave room for later "/../lib".  */
 430       dir = (char *) xmalloc (dirlen + 8);
 431       strncpy (dir, program_name, dirlen);
 432       dir[dirlen] = '\0';
 433     }
 434   else
 435     {
 436       dirlen = 1;
 437       dir = (char *) xmalloc (dirlen + 8);
 438       strcpy (dir, ".");
 439     }
 440
 441   if (check_for_scripts_dir (dir))
 442     return;                     /* Don't free dir.  */
 443
 444   /* Look for "ldscripts" in <the dir where our binary is>/../lib.  */
 445   strcpy (dir + dirlen, "/../lib");
 446   if (check_for_scripts_dir (dir))
 447     return;
 448
 449   free (dir);                   /* Well, we tried.  */
 450 }
 451
 452 void
 453 add_ysym (name)
 454      const char *name;
 455 {
 456   if (link_info.notice_hash == (struct bfd_hash_table *) NULL)
 457     {
 458       link_info.notice_hash = ((struct bfd_hash_table *)
 459                                xmalloc (sizeof (struct bfd_hash_table)));
 460       if (! bfd_hash_table_init_n (link_info.notice_hash,
 461                                    bfd_hash_newfunc,
 462                                    61))
 463         einfo ("%P%F: bfd_hash_table_init failed: %E\n");
 464     }
 465
 466   if (bfd_hash_lookup (link_info.notice_hash, name, true, true)
 467       == (struct bfd_hash_entry *) NULL)
 468     einfo ("%P%F: bfd_hash_lookup failed: %E\n");
 469 }
 470
 471 /* Handle the -retain-symbols-file option.  */
 472
 473 void
 474 add_keepsyms_file (filename)
 475      const char *filename;
 476 {
 477   FILE *file;
 478   char *buf;
 479   size_t bufsize;
 480   int c;
 481
 482   if (link_info.strip == strip_some)
 483     einfo ("%X%P: error: duplicate retain-symbols-file\n");
 484
 485   file = fopen (filename, "r");
 486   if (file == (FILE *) NULL)
 487     {
 488       bfd_set_error (bfd_error_system_call);
 489       einfo ("%X%P: %s: %E", filename);
 490       return;
 491     }
 492
 493   link_info.keep_hash = ((struct bfd_hash_table *)
 494                          xmalloc (sizeof (struct bfd_hash_table)));
 495   if (! bfd_hash_table_init (link_info.keep_hash, bfd_hash_newfunc))
 496     einfo ("%P%F: bfd_hash_table_init failed: %E\n");
 497
 498   bufsize = 100;
 499   buf = (char *) xmalloc (bufsize);
 500
 501   c = getc (file);
 502   while (c != EOF)
 503     {
 504       while (isspace (c))
 505         c = getc (file);
 506
 507       if (c != EOF)
 508         {
 509           size_t len = 0;
 510
 511           while (! isspace (c) && c != EOF)
 512             {
 513               buf[len] = c;
 514               ++len;
 515               if (len >= bufsize)
 516                 {
 517                   bufsize *= 2;
 518                   buf = xrealloc (buf, bufsize);
 519                 }
 520               c = getc (file);
 521             }
 522
 523           buf[len] = '\0';
 524
 525           if (bfd_hash_lookup (link_info.keep_hash, buf, true, true)
 526               == (struct bfd_hash_entry *) NULL)
 527             einfo ("%P%F: bfd_hash_lookup for insertion failed: %E");
 528         }
 529     }
 530
 531   if (link_info.strip != strip_none)
 532     einfo ("%P: `-retain-symbols-file' overrides `-s' and `-S'\n");
 533
 534   link_info.strip = strip_some;
 535 }
 536 \f
 537 /* Callbacks from the BFD linker routines.  */
 538
 539 /* This is called when BFD has decided to include an archive member in
 540    a link.  */
 541
 542 /*ARGSUSED*/
 543 static boolean
 544 add_archive_element (info, abfd, name)
 545      struct bfd_link_info *info;
 546      bfd *abfd;
 547      const char *name;
 548 {
 549   lang_input_statement_type *input;
 550
 551   input = ((lang_input_statement_type *)
 552            xmalloc ((bfd_size_type) sizeof (lang_input_statement_type)));
 553   input->filename = abfd->filename;
 554   input->local_sym_name = abfd->filename;
 555   input->the_bfd = abfd;
 556   input->asymbols = NULL;
 557   input->next = NULL;
 558   input->just_syms_flag = false;
 559   input->loaded = false;
 560   input->search_dirs_flag = false;
 561
 562   /* FIXME: The following fields are not set: header.next,
 563      header.type, closed, passive_position, symbol_count,
 564      next_real_file, is_archive, target, real, common_section,
 565      common_output_section, complained.  This bit of code is from the
 566      old decode_library_subfile function.  I don't know whether any of
 567      those fields matters.  */
 568
 569   ldlang_add_file (input);
 570
 571   if (config.map_file != (FILE *) NULL)
 572     minfo ("%s needed due to %T\n", abfd->filename, name);
 573
 574   if (trace_files || trace_file_tries)
 575     info_msg ("%I\n", input);
 576
 577   return true;
 578 }
 579
 580 /* This is called when BFD has discovered a symbol which is defined
 581    multiple times.  */
 582
 583 /*ARGSUSED*/
 584 static boolean
 585 multiple_definition (info, name, obfd, osec, oval, nbfd, nsec, nval)
 586      struct bfd_link_info *info;
 587      const char *name;
 588      bfd *obfd;
 589      asection *osec;
 590      bfd_vma oval;
 591      bfd *nbfd;
 592      asection *nsec;
 593      bfd_vma nval;
 594 {
 595   einfo ("%X%C: multiple definition of `%T'\n",
 596          nbfd, nsec, nval, name);
 597   if (obfd != (bfd *) NULL)
 598     einfo ("%C: first defined here\n", obfd, osec, oval);
 599   return true;
 600 }
 601
 602 /* This is called when there is a definition of a common symbol, or
 603    when a common symbol is found for a symbol that is already defined,
 604    or when two common symbols are found.  We only do something if
 605    -warn-common was used.  */
 606
 607 /*ARGSUSED*/
 608 static boolean
 609 multiple_common (info, name, obfd, otype, osize, nbfd, ntype, nsize)
 610      struct bfd_link_info *info;
 611      const char *name;
 612      bfd *obfd;
 613      enum bfd_link_hash_type otype;
 614      bfd_vma osize;
 615      bfd *nbfd;
 616      enum bfd_link_hash_type ntype;
 617      bfd_vma nsize;
 618 {
 619   if (! config.warn_common)
 620     return true;
 621
 622   if (ntype == bfd_link_hash_defined)
 623     {
 624       ASSERT (otype == bfd_link_hash_common);
 625       einfo ("%B: warning: definition of `%T' overriding common\n",
 626              nbfd, name);
 627       einfo ("%B: warning: common is here\n", obfd);
 628     }
 629   else if (otype == bfd_link_hash_defined)
 630     {
 631       ASSERT (ntype == bfd_link_hash_common);
 632       einfo ("%B: warning: common of `%T' overridden by definition\n",
 633              nbfd, name);
 634       einfo ("%B: warning: defined here\n", obfd);
 635     }
 636   else
 637     {
 638       ASSERT (otype == bfd_link_hash_common && ntype == bfd_link_hash_common);
 639       if (osize > nsize)
 640         {
 641           einfo ("%B: warning: common of `%T' overridden by larger common\n",
 642                  nbfd, name);
 643           einfo ("%B: warning: larger common is here\n", obfd);
 644         }
 645       else if (nsize > osize)
 646         {
 647           einfo ("%B: warning: common of `%T' overriding smaller common\n",
 648                  nbfd, name);
 649           einfo ("%B: warning: smaller common is here\n", obfd);
 650         }
 651       else
 652         {
 653           einfo ("%B: warning: multiple common of `%T'\n", nbfd, name);
 654           einfo ("%B: warning: previous common is here\n", obfd);
 655         }
 656     }
 657
 658   return true;
 659 }
 660
 661 /* This is called when BFD has discovered a set element.  H is the
 662    entry in the linker hash table for the set.  SECTION and VALUE
 663    represent a value which should be added to the set.  */
 664
 665 /*ARGSUSED*/
 666 static boolean
 667 add_to_set (info, h, reloc, abfd, section, value)
 668      struct bfd_link_info *info;
 669      struct bfd_link_hash_entry *h;
 670      bfd_reloc_code_real_type reloc;
 671      bfd *abfd;
 672      asection *section;
 673      bfd_vma value;
 674 {
 675   if (! config.build_constructors)
 676     return true;
 677
 678   ldctor_add_set_entry (h, reloc, section, value);
 679
 680   if (h->type == bfd_link_hash_new)
 681     {
 682       h->type = bfd_link_hash_undefined;
 683       h->u.undef.abfd = abfd;
 684       /* We don't call bfd_link_add_undef to add this to the list of
 685          undefined symbols because we are going to define it
 686          ourselves.  */
 687     }
 688
 689   return true;
 690 }
 691
 692 /* This is called when BFD has discovered a constructor.  This is only
 693    called for some object file formats--those which do not handle
 694    constructors in some more clever fashion.  This is similar to
 695    adding an element to a set, but less general.  */
 696
 697 static boolean
 698 constructor_callback (info, constructor, name, abfd, section, value)
 699      struct bfd_link_info *info;
 700      boolean constructor;
 701      const char *name;
 702      bfd *abfd;
 703      asection *section;
 704      bfd_vma value;
 705 {
 706   char *set_name;
 707   char *s;
 708   struct bfd_link_hash_entry *h;
 709
 710   if (! config.build_constructors)
 711     return true;
 712
 713   /* Ensure that BFD_RELOC_CTOR exists now, so that we can give a
 714      useful error message.  */
 715   if (bfd_reloc_type_lookup (output_bfd, BFD_RELOC_CTOR) == NULL)
 716     einfo ("%P%F: BFD backend error: BFD_RELOC_CTOR unsupported");
 717
 718   set_name = (char *) alloca (1 + sizeof "__CTOR_LIST__");
 719   s = set_name;
 720   if (bfd_get_symbol_leading_char (abfd) != '\0')
 721     *s++ = bfd_get_symbol_leading_char (abfd);
 722   if (constructor)
 723     strcpy (s, "__CTOR_LIST__");
 724   else
 725     strcpy (s, "__DTOR_LIST__");
 726
 727   if (config.map_file != (FILE *) NULL)
 728     fprintf (config.map_file,
 729              "Adding %s to constructor/destructor set %s\n", name, set_name);
 730
 731   h = bfd_link_hash_lookup (info->hash, set_name, true, true, true);
 732   if (h == (struct bfd_link_hash_entry *) NULL)
 733     einfo ("%P%F: bfd_link_hash_lookup failed: %E");
 734   if (h->type == bfd_link_hash_new)
 735     {
 736       h->type = bfd_link_hash_undefined;
 737       h->u.undef.abfd = abfd;
 738       /* We don't call bfd_link_add_undef to add this to the list of
 739          undefined symbols because we are going to define it
 740          ourselves.  */
 741     }
 742
 743   ldctor_add_set_entry (h, BFD_RELOC_CTOR, section, value);
 744   return true;
 745 }
 746
 747 /* This is called when there is a reference to a warning symbol.  */
 748
 749 /*ARGSUSED*/
 750 static boolean
 751 warning_callback (info, warning)
 752      struct bfd_link_info *info;
 753      const char *warning;
 754 {
 755   einfo ("%P: %s\n", warning);
 756   return true;
 757 }
 758
 759 /* This is called when an undefined symbol is found.  */
 760
 761 /*ARGSUSED*/
 762 static boolean
 763 undefined_symbol (info, name, abfd, section, address)
 764      struct bfd_link_info *info;
 765      const char *name;
 766      bfd *abfd;
 767      asection *section;
 768      bfd_vma address;
 769 {
 770   static char *error_name;
 771   static unsigned int error_count;
 772
 773 #define MAX_ERRORS_IN_A_ROW 5
 774
 775   /* We never print more than a reasonable number of errors in a row
 776      for a single symbol.  */
 777   if (error_name != (char *) NULL
 778       && strcmp (name, error_name) == 0)
 779     ++error_count;
 780   else
 781     {
 782       error_count = 0;
 783       if (error_name != (char *) NULL)
 784         free (error_name);
 785       error_name = buystring (name);
 786     }
 787
 788   if (error_count < MAX_ERRORS_IN_A_ROW)
 789     einfo ("%X%C: undefined reference to `%T'\n",
 790            abfd, section, address, name);
 791   else if (error_count == MAX_ERRORS_IN_A_ROW)
 792     einfo ("%C: more undefined references to `%T' follow\n",
 793            abfd, section, address, name);
 794
 795   return true;
 796 }
 797
 798 /* This is called when a reloc overflows.  */
 799
 800 /*ARGSUSED*/
 801 static boolean
 802 reloc_overflow (info, name, reloc_name, addend, abfd, section, address)
 803      struct bfd_link_info *info;
 804      const char *name;
 805      const char *reloc_name;
 806      bfd_vma addend;
 807      bfd *abfd;
 808      asection *section;
 809      bfd_vma address;
 810 {
 811   if (abfd == (bfd *) NULL)
 812     einfo ("%P%X: generated");
 813   else
 814     einfo ("%X%C:", abfd, section, address);
 815   einfo (" relocation truncated to fit: %s %T", reloc_name, name);
 816   if (addend != 0)
 817     einfo ("+%v", addend);
 818   einfo ("\n");
 819   return true;
 820 }
 821
 822 /* This is called when a dangerous relocation is made.  */
 823
 824 /*ARGSUSED*/
 825 static boolean
 826 reloc_dangerous (info, message, abfd, section, address)
 827      struct bfd_link_info *info;
 828      const char *message;
 829      bfd *abfd;
 830      asection *section;
 831      bfd_vma address;
 832 {
 833   if (abfd == (bfd *) NULL)
 834     einfo ("%P%X: generated");
 835   else
 836     einfo ("%X%C:", abfd, section, address);
 837   einfo ("dangerous relocation: %s\n", message);
 838   return true;
 839 }
 840
 841 /* This is called when a reloc is being generated attached to a symbol
 842    that is not being output.  */
 843
 844 /*ARGSUSED*/
 845 static boolean
 846 unattached_reloc (info, name, abfd, section, address)
 847      struct bfd_link_info *info;
 848      const char *name;
 849      bfd *abfd;
 850      asection *section;
 851      bfd_vma address;
 852 {
 853   if (abfd == (bfd *) NULL)
 854     einfo ("%P%X: generated");
 855   else
 856     einfo ("%X%C:", abfd, section, address);
 857   einfo (" reloc refers to symbol `%T' which is not being output\n", name);
 858   return true;
 859 }
 860
 861 /* This is called when a symbol in notice_hash is found.  Symbols are
 862    put in notice_hash using the -y option.  */
 863
 864 /*ARGSUSED*/
 865 static boolean
 866 notice_ysym (info, name, abfd, section, value)
 867      struct bfd_link_info *info;
 868      const char *name;
 869      bfd *abfd;
 870      asection *section;
 871      bfd_vma value;
 872 {
 873   einfo ("%B: %s %s\n", abfd,
 874          section != &bfd_und_section ? "definition of" : "reference to",
 875          name);
 876   return true;
 877 }