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