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 "bfdlink.h"
  26
  27 #include "config.h"
  28 #include "ld.h"
  29 #include "ldmain.h"
  30 #include "ldmisc.h"
  31 #include "ldwrite.h"
  32 #include "ldgram.h"
  33 #include "ldexp.h"
  34 #include "ldlang.h"
  35 #include "ldemul.h"
  36 #include "ldlex.h"
  37 #include "ldfile.h"
  38 #include "ldctor.h"
  39
  40 /* Somewhere above, sys/stat.h got included . . . . */
  41 #if !defined(S_ISDIR) && defined(S_IFDIR)
  42 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
  43 #endif
  44
  45 #include <string.h>
  46
  47 static char *get_emulation PARAMS ((int, char **));
  48 static void set_scripts_dir PARAMS ((void));
  49
  50 /* EXPORTS */
  51
  52 char *default_target;
  53 const char *output_filename = "a.out";
  54
  55 /* Name this program was invoked by.  */
  56 char *program_name;
  57
  58 /* The file that we're creating */
  59 bfd *output_bfd = 0;
  60
  61 /* Set by -G argument, for MIPS ECOFF target.  */
  62 int g_switch_value = 8;
  63
  64 /* Nonzero means print names of input files as processed.  */
  65 boolean trace_files;
  66
  67 /* Nonzero means same, but note open failures, too.  */
  68 boolean trace_file_tries;
  69
  70 /* Nonzero means version number was printed, so exit successfully
  71    instead of complaining if no input files are given.  */
  72 boolean version_printed;
  73
  74 /* 1 => write load map.  */
  75 boolean write_map;
  76
  77 args_type command_line;
  78
  79 ld_config_type config;
  80
  81 static boolean check_for_scripts_dir PARAMS ((char *dir));
  82 static boolean add_archive_element PARAMS ((struct bfd_link_info *, bfd *,
  83                                             const char *));
  84 static boolean multiple_definition PARAMS ((struct bfd_link_info *,
  85                                             const char *,
  86                                             bfd *, asection *, bfd_vma,
  87                                             bfd *, asection *, bfd_vma));
  88 static boolean multiple_common PARAMS ((struct bfd_link_info *,
  89                                         const char *, bfd *,
  90                                         enum bfd_link_hash_type, bfd_vma,
  91                                         bfd *, enum bfd_link_hash_type,
  92                                         bfd_vma));
  93 static boolean add_to_set PARAMS ((struct bfd_link_info *,
  94                                    struct bfd_link_hash_entry *,
  95                                    unsigned int bitsize,
  96                                    bfd *, asection *, bfd_vma));
  97 static boolean constructor_callback PARAMS ((struct bfd_link_info *,
  98                                              boolean constructor,
  99                                              unsigned int bitsize,
 100                                              const char *name,
 101                                              bfd *, asection *, bfd_vma));
 102 static boolean warning_callback PARAMS ((struct bfd_link_info *,
 103                                          const char *));
 104 static boolean undefined_symbol PARAMS ((struct bfd_link_info *,
 105                                          const char *, bfd *,
 106                                          asection *, bfd_vma));
 107 static boolean reloc_overflow PARAMS ((struct bfd_link_info *, const char *,
 108                                        const char *, bfd_vma,
 109                                        bfd *, asection *, bfd_vma));
 110 static boolean reloc_dangerous PARAMS ((struct bfd_link_info *, const char *,
 111                                         bfd *, asection *, bfd_vma));
 112 static boolean unattached_reloc PARAMS ((struct bfd_link_info *,
 113                                          const char *, bfd *, asection *,
 114                                          bfd_vma));
 115 static boolean notice_ysym PARAMS ((struct bfd_link_info *, const char *,
 116                                     bfd *, asection *, bfd_vma));
 117
 118 static struct bfd_link_callbacks link_callbacks =
 119 {
 120   add_archive_element,
 121   multiple_definition,
 122   multiple_common,
 123   add_to_set,
 124   constructor_callback,
 125   warning_callback,
 126   undefined_symbol,
 127   reloc_overflow,
 128   reloc_dangerous,
 129   unattached_reloc,
 130   notice_ysym
 131 };
 132
 133 struct bfd_link_info link_info;
 134 \f
 135 static void
 136 remove_output ()
 137 {
 138   if (output_filename)
 139     {
 140       if (output_bfd && output_bfd->iostream)
 141         fclose((FILE *)(output_bfd->iostream));
 142       if (delete_output_file_on_failure)
 143         unlink (output_filename);
 144     }
 145 }
 146
 147 int
 148 main (argc, argv)
 149      int argc;
 150      char **argv;
 151 {
 152   char *emulation;
 153   long start_time = get_run_time ();
 154
 155   program_name = argv[0];
 156
 157   bfd_init ();
 158
 159   atexit (remove_output);
 160
 161   /* Initialize the data about options.  */
 162   trace_files = trace_file_tries = version_printed = false;
 163   write_map = false;
 164   config.build_constructors = true;
 165   command_line.force_common_definition = false;
 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   /* This essentially adds another -L directory so this must be done after
 197      the -L's in argv have been processed.  */
 198   set_scripts_dir ();
 199
 200   if (had_script == false)
 201     {
 202       /* Read the emulation's appropriate default script.  */
 203       int isfile;
 204       char *s = ldemul_get_script (&isfile);
 205
 206       if (isfile)
 207         {
 208           /* sizeof counts the terminating NUL.  */
 209           size_t size = strlen (s) + sizeof ("-T ");
 210           char *buf = (char *) xmalloc(size);
 211           sprintf (buf, "-T %s", s);
 212           parse_line (buf, 0);
 213           free (buf);
 214         }
 215       else
 216         parse_line (s, 1);
 217     }
 218
 219   if (link_info.relocateable && command_line.relax)
 220     {
 221       einfo ("%P%F: -relax and -r may not be used together\n");
 222     }
 223   lang_final ();
 224
 225   if (lang_has_input_file == false)
 226     {
 227       if (version_printed)
 228         xexit (0);
 229       einfo ("%P%F: no input files\n");
 230     }
 231
 232   if (trace_files)
 233     {
 234       info_msg ("%P: mode %s\n", emulation);
 235     }
 236
 237   ldemul_after_parse ();
 238
 239
 240   if (config.map_filename)
 241     {
 242       if (strcmp (config.map_filename, "-") == 0)
 243         {
 244           config.map_file = stdout;
 245         }
 246       else
 247         {
 248           config.map_file = fopen (config.map_filename, FOPEN_WT);
 249           if (config.map_file == (FILE *) NULL)
 250             {
 251               einfo ("%P%F: cannot open map file %s: %E\n",
 252                      config.map_filename);
 253             }
 254         }
 255     }
 256
 257
 258   lang_process ();
 259
 260   /* Print error messages for any missing symbols, for any warning
 261      symbols, and possibly multiple definitions */
 262
 263
 264   if (config.text_read_only)
 265     {
 266       /* Look for a text section and mark the readonly attribute in it */
 267       asection *found = bfd_get_section_by_name (output_bfd, ".text");
 268
 269       if (found != (asection *) NULL)
 270         {
 271           found->flags |= SEC_READONLY;
 272         }
 273     }
 274
 275   if (link_info.relocateable)
 276     output_bfd->flags &= ~EXEC_P;
 277   else
 278     output_bfd->flags |= EXEC_P;
 279
 280   ldwrite ();
 281
 282   /* Even if we're producing relocateable output, some non-fatal errors should
 283      be reported in the exit status.  (What non-fatal errors, if any, do we
 284      want to ignore for relocateable output?)  */
 285
 286   if (config.make_executable == false && force_make_executable == false)
 287     {
 288       if (trace_files == true)
 289         {
 290           einfo ("%P: link errors found, deleting executable `%s'\n",
 291                  output_filename);
 292         }
 293
 294       if (output_bfd->iostream)
 295         fclose ((FILE *) (output_bfd->iostream));
 296
 297       unlink (output_filename);
 298       xexit (1);
 299     }
 300   else
 301     {
 302       bfd_close (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: %d.%06d\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);
 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_error = system_call_error;
 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->subfiles = NULL;
 556   input->next = NULL;
 557   input->just_syms_flag = false;
 558   input->loaded = false;
 559   input->chain = NULL;
 560
 561   /* FIXME: This is wrong.  It should point to an entry for the
 562      archive itself.  However, it doesn't seem to matter.  */
 563   input->superfile = NULL;
 564
 565   /* FIXME: The following fields are not set: header.next,
 566      header.type, closed, passive_position, symbol_count, total_size,
 567      next_real_file, is_archive, search_dirs_flag, target, real,
 568      common_section, common_output_section, complained.  This bit of
 569      code is from the old decode_library_subfile function.  I don't
 570      know whether any of those fields matters.  */
 571
 572   ldlang_add_file (input);
 573
 574   if (write_map)
 575     info_msg ("%s needed due to %T\n", abfd->filename, name);
 576
 577   if (trace_files || trace_file_tries)
 578     info_msg ("%I\n", input);
 579
 580   return true;
 581 }
 582
 583 /* This is called when BFD has discovered a symbol which is defined
 584    multiple times.  */
 585
 586 /*ARGSUSED*/
 587 static boolean
 588 multiple_definition (info, name, obfd, osec, oval, nbfd, nsec, nval)
 589      struct bfd_link_info *info;
 590      const char *name;
 591      bfd *obfd;
 592      asection *osec;
 593      bfd_vma oval;
 594      bfd *nbfd;
 595      asection *nsec;
 596      bfd_vma nval;
 597 {
 598   einfo ("%X%C: multiple definition of `%T'\n",
 599          nbfd, nsec, nval, name);
 600   if (obfd != (bfd *) NULL)
 601     einfo ("%C: first defined here\n", obfd, osec, oval);
 602   return true;
 603 }
 604
 605 /* This is called when there is a definition of a common symbol, or
 606    when a common symbol is found for a symbol that is already defined,
 607    or when two common symbols are found.  We only do something if
 608    -warn-common was used.  */
 609
 610 /*ARGSUSED*/
 611 static boolean
 612 multiple_common (info, name, obfd, otype, osize, nbfd, ntype, nsize)
 613      struct bfd_link_info *info;
 614      const char *name;
 615      bfd *obfd;
 616      enum bfd_link_hash_type otype;
 617      bfd_vma osize;
 618      bfd *nbfd;
 619      enum bfd_link_hash_type ntype;
 620      bfd_vma nsize;
 621 {
 622   if (! config.warn_common)
 623     return true;
 624
 625   if (ntype == bfd_link_hash_defined)
 626     {
 627       ASSERT (otype == bfd_link_hash_common);
 628       einfo ("%B: warning: definition of `%T' overriding common\n",
 629              nbfd, name);
 630       einfo ("%B: warning: common is here\n", obfd);
 631     }
 632   else if (otype == bfd_link_hash_defined)
 633     {
 634       ASSERT (ntype == bfd_link_hash_common);
 635       einfo ("%B: warning: common of `%T' overridden by definition\n",
 636              nbfd, name);
 637       einfo ("%B: warning: defined here\n", obfd);
 638     }
 639   else
 640     {
 641       ASSERT (otype == bfd_link_hash_common && ntype == bfd_link_hash_common);
 642       if (osize > nsize)
 643         {
 644           einfo ("%B: warning: common of `%T' overridden by larger common\n",
 645                  nbfd, name);
 646           einfo ("%B: warning: larger common is here\n", obfd);
 647         }
 648       else if (nsize > osize)
 649         {
 650           einfo ("%B: warning: common of `%T' overriding smaller common\n",
 651                  nbfd, name);
 652           einfo ("%B: warning: smaller common is here\n", obfd);
 653         }
 654       else
 655         {
 656           einfo ("%B: warning: multiple common of `%T'\n", nbfd, name);
 657           einfo ("%B: warning: previous common is here\n", obfd);
 658         }
 659     }
 660
 661   return true;
 662 }
 663
 664 /* This is called when BFD has discovered a set element.  H is the
 665    entry in the linker hash table for the set.  SECTION and VALUE
 666    represent a value which should be added to the set.  */
 667
 668 /*ARGSUSED*/
 669 static boolean
 670 add_to_set (info, h, bitsize, abfd, section, value)
 671      struct bfd_link_info *info;
 672      struct bfd_link_hash_entry *h;
 673      unsigned int bitsize;
 674      bfd *abfd;
 675      asection *section;
 676      bfd_vma value;
 677 {
 678   ldctor_add_set_entry (h, bitsize, section, value);
 679   return true;
 680 }
 681
 682 /* This is called when BFD has discovered a constructor.  This is only
 683    called for some object file formats--those which do not handle
 684    constructors in some more clever fashion.  This is similar to
 685    adding an element to a set, but less general.  */
 686
 687 static boolean
 688 constructor_callback (info, constructor, bitsize, name, abfd, section, value)
 689      struct bfd_link_info *info;
 690      boolean constructor;
 691      unsigned int bitsize;
 692      const char *name;
 693      bfd *abfd;
 694      asection *section;
 695      bfd_vma value;
 696 {
 697   char *set_name;
 698   char *s;
 699   struct bfd_link_hash_entry *h;
 700
 701   if (! config.build_constructors)
 702     return true;
 703
 704   set_name = (char *) alloca (1 + sizeof "__CTOR_LIST__");
 705   s = set_name;
 706   if (bfd_get_symbol_leading_char (abfd) != '\0')
 707     *s++ = bfd_get_symbol_leading_char (abfd);
 708   if (constructor)
 709     strcpy (s, "__CTOR_LIST__");
 710   else
 711     strcpy (s, "__DTOR_LIST__");
 712
 713   if (write_map)
 714     info_msg ("Adding %s to constructor/destructor set %s\n", name, set_name);
 715
 716   h = bfd_link_hash_lookup (info->hash, set_name, true, true, true);
 717   if (h == (struct bfd_link_hash_entry *) NULL)
 718     einfo ("%P%F: bfd_link_hash_lookup failed: %E");
 719   if (h->type == bfd_link_hash_new)
 720     {
 721       h->type = bfd_link_hash_undefined;
 722       h->u.undef.abfd = abfd;
 723       /* We don't call bfd_link_add_undef to add this to the list of
 724          undefined symbols because we are going to define it
 725          ourselves.  */
 726     }
 727
 728   ldctor_add_set_entry (h, bitsize, section, value);
 729   return true;
 730 }
 731
 732 /* This is called when there is a reference to a warning symbol.  */
 733
 734 /*ARGSUSED*/
 735 static boolean
 736 warning_callback (info, warning)
 737      struct bfd_link_info *info;
 738      const char *warning;
 739 {
 740   einfo ("%P: %s\n", warning);
 741   return true;
 742 }
 743
 744 /* This is called when an undefined symbol is found.  */
 745
 746 /*ARGSUSED*/
 747 static boolean
 748 undefined_symbol (info, name, abfd, section, address)
 749      struct bfd_link_info *info;
 750      const char *name;
 751      bfd *abfd;
 752      asection *section;
 753      bfd_vma address;
 754 {
 755   static char *error_name;
 756   static unsigned int error_count;
 757
 758 #define MAX_ERRORS_IN_A_ROW 5
 759
 760   /* We never print more than a reasonable number of errors in a row
 761      for a single symbol.  */
 762   if (error_name != (char *) NULL
 763       && strcmp (name, error_name) == 0)
 764     ++error_count;
 765   else
 766     {
 767       error_count = 0;
 768       if (error_name != (char *) NULL)
 769         free (error_name);
 770       error_name = buystring (name);
 771     }
 772
 773   if (error_count < MAX_ERRORS_IN_A_ROW)
 774     einfo ("%X%C: undefined reference to `%T'\n",
 775            abfd, section, address, name);
 776   else if (error_count == MAX_ERRORS_IN_A_ROW)
 777     einfo ("%C: more undefined references to `%T' follow\n",
 778            abfd, section, address, name);
 779
 780   return true;
 781 }
 782
 783 /* This is called when a reloc overflows.  */
 784
 785 /*ARGSUSED*/
 786 static boolean
 787 reloc_overflow (info, name, reloc_name, addend, abfd, section, address)
 788      struct bfd_link_info *info;
 789      const char *name;
 790      const char *reloc_name;
 791      bfd_vma addend;
 792      bfd *abfd;
 793      asection *section;
 794      bfd_vma address;
 795 {
 796   einfo ("%X%C: relocation truncated to fit: %s %T", abfd, section,
 797          address, reloc_name, name);
 798   if (addend != 0)
 799     einfo ("+%v", addend);
 800   einfo ("\n");
 801   return true;
 802 }
 803
 804 /* This is called when a dangerous relocation is made.  */
 805
 806 /*ARGSUSED*/
 807 static boolean
 808 reloc_dangerous (info, message, abfd, section, address)
 809      struct bfd_link_info *info;
 810      const char *message;
 811      bfd *abfd;
 812      asection *section;
 813      bfd_vma address;
 814 {
 815   einfo ("%X%C: dangerous relocation: %s\n", abfd, section, address, message);
 816   return true;
 817 }
 818
 819 /* This is called when a reloc is being generated attached to a symbol
 820    that is not being output.  */
 821
 822 /*ARGSUSED*/
 823 static boolean
 824 unattached_reloc (info, name, abfd, section, address)
 825      struct bfd_link_info *info;
 826      const char *name;
 827      bfd *abfd;
 828      asection *section;
 829      bfd_vma address;
 830 {
 831   einfo ("%X%C: reloc refers to symbol `%T' which is not being output\n",
 832          abfd, section, address, name);
 833   return true;
 834 }
 835
 836 /* This is called when a symbol in notice_hash is found.  Symbols are
 837    put in notice_hash using the -y option.  */
 838
 839 /*ARGSUSED*/
 840 static boolean
 841 notice_ysym (info, name, abfd, section, value)
 842      struct bfd_link_info *info;
 843      const char *name;
 844      bfd *abfd;
 845      asection *section;
 846      bfd_vma value;
 847 {
 848   einfo ("%B: %s %s\n", abfd,
 849          section != &bfd_und_section ? "definition of" : "reference to",
 850          name);
 851   return true;
 852 }