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   command_line.rpath = NULL;
 167
 168   link_info.callbacks = &link_callbacks;
 169   link_info.relocateable = false;
 170   link_info.shared = false;
 171   link_info.strip = strip_none;
 172   link_info.discard = discard_none;
 173   link_info.lprefix_len = 1;
 174   link_info.lprefix = "L";
 175   link_info.keep_memory = true;
 176   link_info.input_bfds = NULL;
 177   link_info.create_object_symbols_section = NULL;
 178   link_info.hash = NULL;
 179   link_info.keep_hash = NULL;
 180   link_info.notice_hash = NULL;
 181
 182   ldfile_add_arch ("");
 183
 184   config.make_executable = true;
 185   force_make_executable = false;
 186   config.magic_demand_paged = true;
 187   config.text_read_only = true;
 188   config.make_executable = true;
 189
 190   emulation = get_emulation (argc, argv);
 191   ldemul_choose_mode (emulation);
 192   default_target = ldemul_choose_target ();
 193   lang_init ();
 194   ldemul_before_parse ();
 195   lang_has_input_file = false;
 196   parse_args (argc, argv);
 197
 198   if (link_info.relocateable)
 199     {
 200       if (command_line.relax)
 201         einfo ("%P%F: -relax and -r may not be used together\n");
 202       if (config.dynamic_link)
 203         einfo ("%P%F: -r and -call_shared may not be used together\n");
 204       if (link_info.strip == strip_all)
 205         einfo ("%P%F: -r and -s may not be used together\n");
 206       if (link_info.shared)
 207         einfo ("%P%F: -r and -shared may not be used together\n");
 208     }
 209
 210   /* This essentially adds another -L directory so this must be done after
 211      the -L's in argv have been processed.  */
 212   set_scripts_dir ();
 213
 214   if (had_script == false)
 215     {
 216       /* Read the emulation's appropriate default script.  */
 217       int isfile;
 218       char *s = ldemul_get_script (&isfile);
 219
 220       if (isfile)
 221         ldfile_open_command_file (s);
 222       else
 223         lex_redirect (s);
 224       parser_input = input_script;
 225       yyparse ();
 226     }
 227
 228   lang_final ();
 229
 230   if (lang_has_input_file == false)
 231     {
 232       if (version_printed)
 233         xexit (0);
 234       einfo ("%P%F: no input files\n");
 235     }
 236
 237   if (trace_files)
 238     {
 239       info_msg ("%P: mode %s\n", emulation);
 240     }
 241
 242   ldemul_after_parse ();
 243
 244
 245   if (config.map_filename)
 246     {
 247       if (strcmp (config.map_filename, "-") == 0)
 248         {
 249           config.map_file = stdout;
 250         }
 251       else
 252         {
 253           config.map_file = fopen (config.map_filename, FOPEN_WT);
 254           if (config.map_file == (FILE *) NULL)
 255             {
 256               einfo ("%P%F: cannot open map file %s: %E\n",
 257                      config.map_filename);
 258             }
 259         }
 260     }
 261
 262
 263   lang_process ();
 264
 265   /* Print error messages for any missing symbols, for any warning
 266      symbols, and possibly multiple definitions */
 267
 268
 269   if (config.text_read_only)
 270     {
 271       /* Look for a text section and mark the readonly attribute in it */
 272       asection *found = bfd_get_section_by_name (output_bfd, ".text");
 273
 274       if (found != (asection *) NULL)
 275         {
 276           found->flags |= SEC_READONLY;
 277         }
 278     }
 279
 280   if (link_info.relocateable)
 281     output_bfd->flags &= ~EXEC_P;
 282   else
 283     output_bfd->flags |= EXEC_P;
 284
 285   ldwrite ();
 286
 287   /* Even if we're producing relocateable output, some non-fatal errors should
 288      be reported in the exit status.  (What non-fatal errors, if any, do we
 289      want to ignore for relocateable output?)  */
 290
 291   if (config.make_executable == false && force_make_executable == false)
 292     {
 293       if (trace_files == true)
 294         {
 295           einfo ("%P: link errors found, deleting executable `%s'\n",
 296                  output_filename);
 297         }
 298
 299       if (output_bfd->iostream)
 300         fclose ((FILE *) (output_bfd->iostream));
 301
 302       unlink (output_filename);
 303       xexit (1);
 304     }
 305   else
 306     {
 307       if (! bfd_close (output_bfd))
 308         einfo ("%F%B: final close failed: %E\n", output_bfd);
 309     }
 310
 311   if (config.stats)
 312     {
 313       extern char **environ;
 314       char *lim = (char *) sbrk (0);
 315       long run_time = get_run_time () - start_time;
 316
 317       fprintf (stderr, "%s: total time in link: %ld.%06ld\n",
 318                program_name, run_time / 1000000, run_time % 1000000);
 319       fprintf (stderr, "%s: data size %ld\n", program_name,
 320                (long) (lim - (char *) &environ));
 321     }
 322
 323   /* Prevent remove_output from doing anything, after a successful link.  */
 324   output_filename = NULL;
 325
 326   xexit (0);
 327   return 0;
 328 }
 329
 330 /* We need to find any explicitly given emulation in order to initialize the
 331    state that's needed by the lex&yacc argument parser (parse_args).  */
 332
 333 static char *
 334 get_emulation (argc, argv)
 335      int argc;
 336      char **argv;
 337 {
 338   char *emulation;
 339   int i;
 340
 341   emulation = (char *) getenv (EMULATION_ENVIRON);
 342   if (emulation == NULL)
 343     emulation = DEFAULT_EMULATION;
 344
 345   for (i = 1; i < argc; i++)
 346     {
 347       if (!strncmp (argv[i], "-m", 2))
 348         {
 349           if (argv[i][2] == '\0')
 350             {
 351               /* -m EMUL */
 352               if (i < argc - 1)
 353                 {
 354                   emulation = argv[i + 1];
 355                   i++;
 356                 }
 357               else
 358                 {
 359                   einfo("%P%F: missing argument to -m\n");
 360                 }
 361             }
 362           else if (strcmp (argv[i], "-mips1") == 0
 363                    || strcmp (argv[i], "-mips2") == 0
 364                    || strcmp (argv[i], "-mips3") == 0)
 365             {
 366               /* FIXME: The arguments -mips1, -mips2 and -mips3 are
 367                  passed to the linker by some MIPS compilers.  They
 368                  generally tell the linker to use a slightly different
 369                  library path.  Perhaps someday these should be
 370                  implemented as emulations; until then, we just ignore
 371                  the arguments and hope that nobody ever creates
 372                  emulations named ips1, ips2 or ips3.  */
 373             }
 374           else if (strcmp (argv[i], "-m486") == 0)
 375             {
 376               /* FIXME: The argument -m486 is passed to the linker on
 377                  some Linux systems.  Hope that nobody creates an
 378                  emulation named 486.  */
 379             }
 380           else
 381             {
 382               /* -mEMUL */
 383               emulation = &argv[i][2];
 384             }
 385         }
 386     }
 387
 388   return emulation;
 389 }
 390
 391 /* If directory DIR contains an "ldscripts" subdirectory,
 392    add DIR to the library search path and return true,
 393    else return false.  */
 394
 395 static boolean
 396 check_for_scripts_dir (dir)
 397      char *dir;
 398 {
 399   size_t dirlen;
 400   char *buf;
 401   struct stat s;
 402   boolean res;
 403
 404   dirlen = strlen (dir);
 405   /* sizeof counts the terminating NUL.  */
 406   buf = (char *) xmalloc (dirlen + sizeof("/ldscripts"));
 407   sprintf (buf, "%s/ldscripts", dir);
 408
 409   res = stat (buf, &s) == 0 && S_ISDIR (s.st_mode);
 410   free (buf);
 411   if (res)
 412     ldfile_add_library_path (dir, false);
 413   return res;
 414 }
 415
 416 /* Set the default directory for finding script files.
 417    Libraries will be searched for here too, but that's ok.
 418    We look for the "ldscripts" directory in:
 419
 420    SCRIPTDIR (passed from Makefile)
 421    the dir where this program is (for using it from the build tree)
 422    the dir where this program is/../lib (for installing the tool suite elsewhere) */
 423
 424 static void
 425 set_scripts_dir ()
 426 {
 427   char *end, *dir;
 428   size_t dirlen;
 429
 430   if (check_for_scripts_dir (SCRIPTDIR))
 431     return;                     /* We've been installed normally.  */
 432
 433   /* Look for "ldscripts" in the dir where our binary is.  */
 434   end = strrchr (program_name, '/');
 435   if (end)
 436     {
 437       dirlen = end - program_name;
 438       /* Make a copy of program_name in dir.
 439          Leave room for later "/../lib".  */
 440       dir = (char *) xmalloc (dirlen + 8);
 441       strncpy (dir, program_name, dirlen);
 442       dir[dirlen] = '\0';
 443     }
 444   else
 445     {
 446       dirlen = 1;
 447       dir = (char *) xmalloc (dirlen + 8);
 448       strcpy (dir, ".");
 449     }
 450
 451   if (check_for_scripts_dir (dir))
 452     return;                     /* Don't free dir.  */
 453
 454   /* Look for "ldscripts" in <the dir where our binary is>/../lib.  */
 455   strcpy (dir + dirlen, "/../lib");
 456   if (check_for_scripts_dir (dir))
 457     return;
 458
 459   free (dir);                   /* Well, we tried.  */
 460 }
 461
 462 void
 463 add_ysym (name)
 464      const char *name;
 465 {
 466   if (link_info.notice_hash == (struct bfd_hash_table *) NULL)
 467     {
 468       link_info.notice_hash = ((struct bfd_hash_table *)
 469                                xmalloc (sizeof (struct bfd_hash_table)));
 470       if (! bfd_hash_table_init_n (link_info.notice_hash,
 471                                    bfd_hash_newfunc,
 472                                    61))
 473         einfo ("%P%F: bfd_hash_table_init failed: %E\n");
 474     }
 475
 476   if (bfd_hash_lookup (link_info.notice_hash, name, true, true)
 477       == (struct bfd_hash_entry *) NULL)
 478     einfo ("%P%F: bfd_hash_lookup failed: %E\n");
 479 }
 480
 481 /* Handle the -retain-symbols-file option.  */
 482
 483 void
 484 add_keepsyms_file (filename)
 485      const char *filename;
 486 {
 487   FILE *file;
 488   char *buf;
 489   size_t bufsize;
 490   int c;
 491
 492   if (link_info.strip == strip_some)
 493     einfo ("%X%P: error: duplicate retain-symbols-file\n");
 494
 495   file = fopen (filename, "r");
 496   if (file == (FILE *) NULL)
 497     {
 498       bfd_set_error (bfd_error_system_call);
 499       einfo ("%X%P: %s: %E", filename);
 500       return;
 501     }
 502
 503   link_info.keep_hash = ((struct bfd_hash_table *)
 504                          xmalloc (sizeof (struct bfd_hash_table)));
 505   if (! bfd_hash_table_init (link_info.keep_hash, bfd_hash_newfunc))
 506     einfo ("%P%F: bfd_hash_table_init failed: %E\n");
 507
 508   bufsize = 100;
 509   buf = (char *) xmalloc (bufsize);
 510
 511   c = getc (file);
 512   while (c != EOF)
 513     {
 514       while (isspace (c))
 515         c = getc (file);
 516
 517       if (c != EOF)
 518         {
 519           size_t len = 0;
 520
 521           while (! isspace (c) && c != EOF)
 522             {
 523               buf[len] = c;
 524               ++len;
 525               if (len >= bufsize)
 526                 {
 527                   bufsize *= 2;
 528                   buf = xrealloc (buf, bufsize);
 529                 }
 530               c = getc (file);
 531             }
 532
 533           buf[len] = '\0';
 534
 535           if (bfd_hash_lookup (link_info.keep_hash, buf, true, true)
 536               == (struct bfd_hash_entry *) NULL)
 537             einfo ("%P%F: bfd_hash_lookup for insertion failed: %E");
 538         }
 539     }
 540
 541   if (link_info.strip != strip_none)
 542     einfo ("%P: `-retain-symbols-file' overrides `-s' and `-S'\n");
 543
 544   link_info.strip = strip_some;
 545 }
 546 \f
 547 /* Callbacks from the BFD linker routines.  */
 548
 549 /* This is called when BFD has decided to include an archive member in
 550    a link.  */
 551
 552 /*ARGSUSED*/
 553 static boolean
 554 add_archive_element (info, abfd, name)
 555      struct bfd_link_info *info;
 556      bfd *abfd;
 557      const char *name;
 558 {
 559   lang_input_statement_type *input;
 560
 561   input = ((lang_input_statement_type *)
 562            xmalloc ((bfd_size_type) sizeof (lang_input_statement_type)));
 563   input->filename = abfd->filename;
 564   input->local_sym_name = abfd->filename;
 565   input->the_bfd = abfd;
 566   input->asymbols = NULL;
 567   input->next = NULL;
 568   input->just_syms_flag = false;
 569   input->loaded = false;
 570   input->search_dirs_flag = false;
 571
 572   /* FIXME: The following fields are not set: header.next,
 573      header.type, closed, passive_position, symbol_count,
 574      next_real_file, is_archive, target, real, common_section,
 575      common_output_section, complained.  This bit of code is from the
 576      old decode_library_subfile function.  I don't know whether any of
 577      those fields matters.  */
 578
 579   ldlang_add_file (input);
 580
 581   if (config.map_file != (FILE *) NULL)
 582     minfo ("%s needed due to %T\n", abfd->filename, name);
 583
 584   if (trace_files || trace_file_tries)
 585     info_msg ("%I\n", input);
 586
 587   return true;
 588 }
 589
 590 /* This is called when BFD has discovered a symbol which is defined
 591    multiple times.  */
 592
 593 /*ARGSUSED*/
 594 static boolean
 595 multiple_definition (info, name, obfd, osec, oval, nbfd, nsec, nval)
 596      struct bfd_link_info *info;
 597      const char *name;
 598      bfd *obfd;
 599      asection *osec;
 600      bfd_vma oval;
 601      bfd *nbfd;
 602      asection *nsec;
 603      bfd_vma nval;
 604 {
 605   einfo ("%X%C: multiple definition of `%T'\n",
 606          nbfd, nsec, nval, name);
 607   if (obfd != (bfd *) NULL)
 608     einfo ("%D: first defined here\n", obfd, osec, oval);
 609   return true;
 610 }
 611
 612 /* This is called when there is a definition of a common symbol, or
 613    when a common symbol is found for a symbol that is already defined,
 614    or when two common symbols are found.  We only do something if
 615    -warn-common was used.  */
 616
 617 /*ARGSUSED*/
 618 static boolean
 619 multiple_common (info, name, obfd, otype, osize, nbfd, ntype, nsize)
 620      struct bfd_link_info *info;
 621      const char *name;
 622      bfd *obfd;
 623      enum bfd_link_hash_type otype;
 624      bfd_vma osize;
 625      bfd *nbfd;
 626      enum bfd_link_hash_type ntype;
 627      bfd_vma nsize;
 628 {
 629   if (! config.warn_common)
 630     return true;
 631
 632   if (ntype == bfd_link_hash_defined)
 633     {
 634       ASSERT (otype == bfd_link_hash_common);
 635       einfo ("%B: warning: definition of `%T' overriding common\n",
 636              nbfd, name);
 637       einfo ("%B: warning: common is here\n", obfd);
 638     }
 639   else if (otype == bfd_link_hash_defined)
 640     {
 641       ASSERT (ntype == bfd_link_hash_common);
 642       einfo ("%B: warning: common of `%T' overridden by definition\n",
 643              nbfd, name);
 644       einfo ("%B: warning: defined here\n", obfd);
 645     }
 646   else
 647     {
 648       ASSERT (otype == bfd_link_hash_common && ntype == bfd_link_hash_common);
 649       if (osize > nsize)
 650         {
 651           einfo ("%B: warning: common of `%T' overridden by larger common\n",
 652                  nbfd, name);
 653           einfo ("%B: warning: larger common is here\n", obfd);
 654         }
 655       else if (nsize > osize)
 656         {
 657           einfo ("%B: warning: common of `%T' overriding smaller common\n",
 658                  nbfd, name);
 659           einfo ("%B: warning: smaller common is here\n", obfd);
 660         }
 661       else
 662         {
 663           einfo ("%B: warning: multiple common of `%T'\n", nbfd, name);
 664           einfo ("%B: warning: previous common is here\n", obfd);
 665         }
 666     }
 667
 668   return true;
 669 }
 670
 671 /* This is called when BFD has discovered a set element.  H is the
 672    entry in the linker hash table for the set.  SECTION and VALUE
 673    represent a value which should be added to the set.  */
 674
 675 /*ARGSUSED*/
 676 static boolean
 677 add_to_set (info, h, reloc, abfd, section, value)
 678      struct bfd_link_info *info;
 679      struct bfd_link_hash_entry *h;
 680      bfd_reloc_code_real_type reloc;
 681      bfd *abfd;
 682      asection *section;
 683      bfd_vma value;
 684 {
 685   if (! config.build_constructors)
 686     return true;
 687
 688   ldctor_add_set_entry (h, reloc, section, value);
 689
 690   if (h->type == bfd_link_hash_new)
 691     {
 692       h->type = bfd_link_hash_undefined;
 693       h->u.undef.abfd = abfd;
 694       /* We don't call bfd_link_add_undef to add this to the list of
 695          undefined symbols because we are going to define it
 696          ourselves.  */
 697     }
 698
 699   return true;
 700 }
 701
 702 /* This is called when BFD has discovered a constructor.  This is only
 703    called for some object file formats--those which do not handle
 704    constructors in some more clever fashion.  This is similar to
 705    adding an element to a set, but less general.  */
 706
 707 static boolean
 708 constructor_callback (info, constructor, name, abfd, section, value)
 709      struct bfd_link_info *info;
 710      boolean constructor;
 711      const char *name;
 712      bfd *abfd;
 713      asection *section;
 714      bfd_vma value;
 715 {
 716   char *set_name;
 717   char *s;
 718   struct bfd_link_hash_entry *h;
 719
 720   if (! config.build_constructors)
 721     return true;
 722
 723   /* Ensure that BFD_RELOC_CTOR exists now, so that we can give a
 724      useful error message.  */
 725   if (bfd_reloc_type_lookup (output_bfd, BFD_RELOC_CTOR) == NULL)
 726     einfo ("%P%F: BFD backend error: BFD_RELOC_CTOR unsupported");
 727
 728   set_name = (char *) alloca (1 + sizeof "__CTOR_LIST__");
 729   s = set_name;
 730   if (bfd_get_symbol_leading_char (abfd) != '\0')
 731     *s++ = bfd_get_symbol_leading_char (abfd);
 732   if (constructor)
 733     strcpy (s, "__CTOR_LIST__");
 734   else
 735     strcpy (s, "__DTOR_LIST__");
 736
 737   if (config.map_file != (FILE *) NULL)
 738     fprintf (config.map_file,
 739              "Adding %s to constructor/destructor set %s\n", name, set_name);
 740
 741   h = bfd_link_hash_lookup (info->hash, set_name, true, true, true);
 742   if (h == (struct bfd_link_hash_entry *) NULL)
 743     einfo ("%P%F: bfd_link_hash_lookup failed: %E");
 744   if (h->type == bfd_link_hash_new)
 745     {
 746       h->type = bfd_link_hash_undefined;
 747       h->u.undef.abfd = abfd;
 748       /* We don't call bfd_link_add_undef to add this to the list of
 749          undefined symbols because we are going to define it
 750          ourselves.  */
 751     }
 752
 753   ldctor_add_set_entry (h, BFD_RELOC_CTOR, section, value);
 754   return true;
 755 }
 756
 757 /* This is called when there is a reference to a warning symbol.  */
 758
 759 /*ARGSUSED*/
 760 static boolean
 761 warning_callback (info, warning)
 762      struct bfd_link_info *info;
 763      const char *warning;
 764 {
 765   einfo ("%P: %s\n", warning);
 766   return true;
 767 }
 768
 769 /* This is called when an undefined symbol is found.  */
 770
 771 /*ARGSUSED*/
 772 static boolean
 773 undefined_symbol (info, name, abfd, section, address)
 774      struct bfd_link_info *info;
 775      const char *name;
 776      bfd *abfd;
 777      asection *section;
 778      bfd_vma address;
 779 {
 780   static char *error_name;
 781   static unsigned int error_count;
 782
 783 #define MAX_ERRORS_IN_A_ROW 5
 784
 785   if (config.warn_once)
 786     {
 787       static struct bfd_hash_table *hash;
 788
 789       /* Only warn once about a particular undefined symbol.  */
 790
 791       if (hash == NULL)
 792         {
 793           hash = ((struct bfd_hash_table *)
 794                   xmalloc (sizeof (struct bfd_hash_table)));
 795           if (! bfd_hash_table_init (hash, bfd_hash_newfunc))
 796             einfo ("%F%P: bfd_hash_table_init failed: %E\n");
 797         }
 798
 799       if (bfd_hash_lookup (hash, name, false, false) != NULL)
 800         return true;
 801
 802       if (bfd_hash_lookup (hash, name, true, true) == NULL)
 803         einfo ("%F%P: bfd_hash_lookup failed: %E\n");
 804     }
 805
 806   /* We never print more than a reasonable number of errors in a row
 807      for a single symbol.  */
 808   if (error_name != (char *) NULL
 809       && strcmp (name, error_name) == 0)
 810     ++error_count;
 811   else
 812     {
 813       error_count = 0;
 814       if (error_name != (char *) NULL)
 815         free (error_name);
 816       error_name = buystring (name);
 817     }
 818
 819   if (error_count < MAX_ERRORS_IN_A_ROW)
 820     einfo ("%X%C: undefined reference to `%T'\n",
 821            abfd, section, address, name);
 822   else if (error_count == MAX_ERRORS_IN_A_ROW)
 823     einfo ("%D: more undefined references to `%T' follow\n",
 824            abfd, section, address, name);
 825
 826   return true;
 827 }
 828
 829 /* This is called when a reloc overflows.  */
 830
 831 /*ARGSUSED*/
 832 static boolean
 833 reloc_overflow (info, name, reloc_name, addend, abfd, section, address)
 834      struct bfd_link_info *info;
 835      const char *name;
 836      const char *reloc_name;
 837      bfd_vma addend;
 838      bfd *abfd;
 839      asection *section;
 840      bfd_vma address;
 841 {
 842   if (abfd == (bfd *) NULL)
 843     einfo ("%P%X: generated");
 844   else
 845     einfo ("%X%C:", abfd, section, address);
 846   einfo (" relocation truncated to fit: %s %T", reloc_name, name);
 847   if (addend != 0)
 848     einfo ("+%v", addend);
 849   einfo ("\n");
 850   return true;
 851 }
 852
 853 /* This is called when a dangerous relocation is made.  */
 854
 855 /*ARGSUSED*/
 856 static boolean
 857 reloc_dangerous (info, message, abfd, section, address)
 858      struct bfd_link_info *info;
 859      const char *message;
 860      bfd *abfd;
 861      asection *section;
 862      bfd_vma address;
 863 {
 864   if (abfd == (bfd *) NULL)
 865     einfo ("%P%X: generated");
 866   else
 867     einfo ("%X%C:", abfd, section, address);
 868   einfo ("dangerous relocation: %s\n", message);
 869   return true;
 870 }
 871
 872 /* This is called when a reloc is being generated attached to a symbol
 873    that is not being output.  */
 874
 875 /*ARGSUSED*/
 876 static boolean
 877 unattached_reloc (info, name, abfd, section, address)
 878      struct bfd_link_info *info;
 879      const char *name;
 880      bfd *abfd;
 881      asection *section;
 882      bfd_vma address;
 883 {
 884   if (abfd == (bfd *) NULL)
 885     einfo ("%P%X: generated");
 886   else
 887     einfo ("%X%C:", abfd, section, address);
 888   einfo (" reloc refers to symbol `%T' which is not being output\n", name);
 889   return true;
 890 }
 891
 892 /* This is called when a symbol in notice_hash is found.  Symbols are
 893    put in notice_hash using the -y option.  */
 894
 895 /*ARGSUSED*/
 896 static boolean
 897 notice_ysym (info, name, abfd, section, value)
 898      struct bfd_link_info *info;
 899      const char *name;
 900      bfd *abfd;
 901      asection *section;
 902      bfd_vma value;
 903 {
 904   einfo ("%B: %s %s\n", abfd,
 905          bfd_is_und_section (section) ? "reference to" : "definition of",
 906          name);
 907   return true;
 908 }