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 if (strcmp (argv[i], "-m486") == 0)
 371             {
 372               /* FIXME: The argument -m486 is passed to the linker on
 373                  some Linux systems.  Hope that nobody creates an
 374                  emulation named 486.  */
 375             }
 376           else
 377             {
 378               /* -mEMUL */
 379               emulation = &argv[i][2];
 380             }
 381         }
 382     }
 383
 384   return emulation;
 385 }
 386
 387 /* If directory DIR contains an "ldscripts" subdirectory,
 388    add DIR to the library search path and return true,
 389    else return false.  */
 390
 391 static boolean
 392 check_for_scripts_dir (dir)
 393      char *dir;
 394 {
 395   size_t dirlen;
 396   char *buf;
 397   struct stat s;
 398   boolean res;
 399
 400   dirlen = strlen (dir);
 401   /* sizeof counts the terminating NUL.  */
 402   buf = (char *) xmalloc (dirlen + sizeof("/ldscripts"));
 403   sprintf (buf, "%s/ldscripts", dir);
 404
 405   res = stat (buf, &s) == 0 && S_ISDIR (s.st_mode);
 406   free (buf);
 407   if (res)
 408     ldfile_add_library_path (dir, false);
 409   return res;
 410 }
 411
 412 /* Set the default directory for finding script files.
 413    Libraries will be searched for here too, but that's ok.
 414    We look for the "ldscripts" directory in:
 415
 416    SCRIPTDIR (passed from Makefile)
 417    the dir where this program is (for using it from the build tree)
 418    the dir where this program is/../lib (for installing the tool suite elsewhere) */
 419
 420 static void
 421 set_scripts_dir ()
 422 {
 423   char *end, *dir;
 424   size_t dirlen;
 425
 426   if (check_for_scripts_dir (SCRIPTDIR))
 427     return;                     /* We've been installed normally.  */
 428
 429   /* Look for "ldscripts" in the dir where our binary is.  */
 430   end = strrchr (program_name, '/');
 431   if (end)
 432     {
 433       dirlen = end - program_name;
 434       /* Make a copy of program_name in dir.
 435          Leave room for later "/../lib".  */
 436       dir = (char *) xmalloc (dirlen + 8);
 437       strncpy (dir, program_name, dirlen);
 438       dir[dirlen] = '\0';
 439     }
 440   else
 441     {
 442       dirlen = 1;
 443       dir = (char *) xmalloc (dirlen + 8);
 444       strcpy (dir, ".");
 445     }
 446
 447   if (check_for_scripts_dir (dir))
 448     return;                     /* Don't free dir.  */
 449
 450   /* Look for "ldscripts" in <the dir where our binary is>/../lib.  */
 451   strcpy (dir + dirlen, "/../lib");
 452   if (check_for_scripts_dir (dir))
 453     return;
 454
 455   free (dir);                   /* Well, we tried.  */
 456 }
 457
 458 void
 459 add_ysym (name)
 460      const char *name;
 461 {
 462   if (link_info.notice_hash == (struct bfd_hash_table *) NULL)
 463     {
 464       link_info.notice_hash = ((struct bfd_hash_table *)
 465                                xmalloc (sizeof (struct bfd_hash_table)));
 466       if (! bfd_hash_table_init_n (link_info.notice_hash,
 467                                    bfd_hash_newfunc,
 468                                    61))
 469         einfo ("%P%F: bfd_hash_table_init failed: %E\n");
 470     }
 471
 472   if (bfd_hash_lookup (link_info.notice_hash, name, true, true)
 473       == (struct bfd_hash_entry *) NULL)
 474     einfo ("%P%F: bfd_hash_lookup failed: %E\n");
 475 }
 476
 477 /* Handle the -retain-symbols-file option.  */
 478
 479 void
 480 add_keepsyms_file (filename)
 481      const char *filename;
 482 {
 483   FILE *file;
 484   char *buf;
 485   size_t bufsize;
 486   int c;
 487
 488   if (link_info.strip == strip_some)
 489     einfo ("%X%P: error: duplicate retain-symbols-file\n");
 490
 491   file = fopen (filename, "r");
 492   if (file == (FILE *) NULL)
 493     {
 494       bfd_set_error (bfd_error_system_call);
 495       einfo ("%X%P: %s: %E", filename);
 496       return;
 497     }
 498
 499   link_info.keep_hash = ((struct bfd_hash_table *)
 500                          xmalloc (sizeof (struct bfd_hash_table)));
 501   if (! bfd_hash_table_init (link_info.keep_hash, bfd_hash_newfunc))
 502     einfo ("%P%F: bfd_hash_table_init failed: %E\n");
 503
 504   bufsize = 100;
 505   buf = (char *) xmalloc (bufsize);
 506
 507   c = getc (file);
 508   while (c != EOF)
 509     {
 510       while (isspace (c))
 511         c = getc (file);
 512
 513       if (c != EOF)
 514         {
 515           size_t len = 0;
 516
 517           while (! isspace (c) && c != EOF)
 518             {
 519               buf[len] = c;
 520               ++len;
 521               if (len >= bufsize)
 522                 {
 523                   bufsize *= 2;
 524                   buf = xrealloc (buf, bufsize);
 525                 }
 526               c = getc (file);
 527             }
 528
 529           buf[len] = '\0';
 530
 531           if (bfd_hash_lookup (link_info.keep_hash, buf, true, true)
 532               == (struct bfd_hash_entry *) NULL)
 533             einfo ("%P%F: bfd_hash_lookup for insertion failed: %E");
 534         }
 535     }
 536
 537   if (link_info.strip != strip_none)
 538     einfo ("%P: `-retain-symbols-file' overrides `-s' and `-S'\n");
 539
 540   link_info.strip = strip_some;
 541 }
 542 \f
 543 /* Callbacks from the BFD linker routines.  */
 544
 545 /* This is called when BFD has decided to include an archive member in
 546    a link.  */
 547
 548 /*ARGSUSED*/
 549 static boolean
 550 add_archive_element (info, abfd, name)
 551      struct bfd_link_info *info;
 552      bfd *abfd;
 553      const char *name;
 554 {
 555   lang_input_statement_type *input;
 556
 557   input = ((lang_input_statement_type *)
 558            xmalloc ((bfd_size_type) sizeof (lang_input_statement_type)));
 559   input->filename = abfd->filename;
 560   input->local_sym_name = abfd->filename;
 561   input->the_bfd = abfd;
 562   input->asymbols = NULL;
 563   input->next = NULL;
 564   input->just_syms_flag = false;
 565   input->loaded = false;
 566   input->search_dirs_flag = false;
 567
 568   /* FIXME: The following fields are not set: header.next,
 569      header.type, closed, passive_position, symbol_count,
 570      next_real_file, is_archive, target, real, common_section,
 571      common_output_section, complained.  This bit of code is from the
 572      old decode_library_subfile function.  I don't know whether any of
 573      those fields matters.  */
 574
 575   ldlang_add_file (input);
 576
 577   if (config.map_file != (FILE *) NULL)
 578     minfo ("%s needed due to %T\n", abfd->filename, name);
 579
 580   if (trace_files || trace_file_tries)
 581     info_msg ("%I\n", input);
 582
 583   return true;
 584 }
 585
 586 /* This is called when BFD has discovered a symbol which is defined
 587    multiple times.  */
 588
 589 /*ARGSUSED*/
 590 static boolean
 591 multiple_definition (info, name, obfd, osec, oval, nbfd, nsec, nval)
 592      struct bfd_link_info *info;
 593      const char *name;
 594      bfd *obfd;
 595      asection *osec;
 596      bfd_vma oval;
 597      bfd *nbfd;
 598      asection *nsec;
 599      bfd_vma nval;
 600 {
 601   einfo ("%X%C: multiple definition of `%T'\n",
 602          nbfd, nsec, nval, name);
 603   if (obfd != (bfd *) NULL)
 604     einfo ("%C: first defined here\n", obfd, osec, oval);
 605   return true;
 606 }
 607
 608 /* This is called when there is a definition of a common symbol, or
 609    when a common symbol is found for a symbol that is already defined,
 610    or when two common symbols are found.  We only do something if
 611    -warn-common was used.  */
 612
 613 /*ARGSUSED*/
 614 static boolean
 615 multiple_common (info, name, obfd, otype, osize, nbfd, ntype, nsize)
 616      struct bfd_link_info *info;
 617      const char *name;
 618      bfd *obfd;
 619      enum bfd_link_hash_type otype;
 620      bfd_vma osize;
 621      bfd *nbfd;
 622      enum bfd_link_hash_type ntype;
 623      bfd_vma nsize;
 624 {
 625   if (! config.warn_common)
 626     return true;
 627
 628   if (ntype == bfd_link_hash_defined)
 629     {
 630       ASSERT (otype == bfd_link_hash_common);
 631       einfo ("%B: warning: definition of `%T' overriding common\n",
 632              nbfd, name);
 633       einfo ("%B: warning: common is here\n", obfd);
 634     }
 635   else if (otype == bfd_link_hash_defined)
 636     {
 637       ASSERT (ntype == bfd_link_hash_common);
 638       einfo ("%B: warning: common of `%T' overridden by definition\n",
 639              nbfd, name);
 640       einfo ("%B: warning: defined here\n", obfd);
 641     }
 642   else
 643     {
 644       ASSERT (otype == bfd_link_hash_common && ntype == bfd_link_hash_common);
 645       if (osize > nsize)
 646         {
 647           einfo ("%B: warning: common of `%T' overridden by larger common\n",
 648                  nbfd, name);
 649           einfo ("%B: warning: larger common is here\n", obfd);
 650         }
 651       else if (nsize > osize)
 652         {
 653           einfo ("%B: warning: common of `%T' overriding smaller common\n",
 654                  nbfd, name);
 655           einfo ("%B: warning: smaller common is here\n", obfd);
 656         }
 657       else
 658         {
 659           einfo ("%B: warning: multiple common of `%T'\n", nbfd, name);
 660           einfo ("%B: warning: previous common is here\n", obfd);
 661         }
 662     }
 663
 664   return true;
 665 }
 666
 667 /* This is called when BFD has discovered a set element.  H is the
 668    entry in the linker hash table for the set.  SECTION and VALUE
 669    represent a value which should be added to the set.  */
 670
 671 /*ARGSUSED*/
 672 static boolean
 673 add_to_set (info, h, reloc, abfd, section, value)
 674      struct bfd_link_info *info;
 675      struct bfd_link_hash_entry *h;
 676      bfd_reloc_code_real_type reloc;
 677      bfd *abfd;
 678      asection *section;
 679      bfd_vma value;
 680 {
 681   if (! config.build_constructors)
 682     return true;
 683
 684   ldctor_add_set_entry (h, reloc, section, value);
 685
 686   if (h->type == bfd_link_hash_new)
 687     {
 688       h->type = bfd_link_hash_undefined;
 689       h->u.undef.abfd = abfd;
 690       /* We don't call bfd_link_add_undef to add this to the list of
 691          undefined symbols because we are going to define it
 692          ourselves.  */
 693     }
 694
 695   return true;
 696 }
 697
 698 /* This is called when BFD has discovered a constructor.  This is only
 699    called for some object file formats--those which do not handle
 700    constructors in some more clever fashion.  This is similar to
 701    adding an element to a set, but less general.  */
 702
 703 static boolean
 704 constructor_callback (info, constructor, name, abfd, section, value)
 705      struct bfd_link_info *info;
 706      boolean constructor;
 707      const char *name;
 708      bfd *abfd;
 709      asection *section;
 710      bfd_vma value;
 711 {
 712   char *set_name;
 713   char *s;
 714   struct bfd_link_hash_entry *h;
 715
 716   if (! config.build_constructors)
 717     return true;
 718
 719   /* Ensure that BFD_RELOC_CTOR exists now, so that we can give a
 720      useful error message.  */
 721   if (bfd_reloc_type_lookup (output_bfd, BFD_RELOC_CTOR) == NULL)
 722     einfo ("%P%F: BFD backend error: BFD_RELOC_CTOR unsupported");
 723
 724   set_name = (char *) alloca (1 + sizeof "__CTOR_LIST__");
 725   s = set_name;
 726   if (bfd_get_symbol_leading_char (abfd) != '\0')
 727     *s++ = bfd_get_symbol_leading_char (abfd);
 728   if (constructor)
 729     strcpy (s, "__CTOR_LIST__");
 730   else
 731     strcpy (s, "__DTOR_LIST__");
 732
 733   if (config.map_file != (FILE *) NULL)
 734     fprintf (config.map_file,
 735              "Adding %s to constructor/destructor set %s\n", name, set_name);
 736
 737   h = bfd_link_hash_lookup (info->hash, set_name, true, true, true);
 738   if (h == (struct bfd_link_hash_entry *) NULL)
 739     einfo ("%P%F: bfd_link_hash_lookup failed: %E");
 740   if (h->type == bfd_link_hash_new)
 741     {
 742       h->type = bfd_link_hash_undefined;
 743       h->u.undef.abfd = abfd;
 744       /* We don't call bfd_link_add_undef to add this to the list of
 745          undefined symbols because we are going to define it
 746          ourselves.  */
 747     }
 748
 749   ldctor_add_set_entry (h, BFD_RELOC_CTOR, section, value);
 750   return true;
 751 }
 752
 753 /* This is called when there is a reference to a warning symbol.  */
 754
 755 /*ARGSUSED*/
 756 static boolean
 757 warning_callback (info, warning)
 758      struct bfd_link_info *info;
 759      const char *warning;
 760 {
 761   einfo ("%P: %s\n", warning);
 762   return true;
 763 }
 764
 765 /* This is called when an undefined symbol is found.  */
 766
 767 /*ARGSUSED*/
 768 static boolean
 769 undefined_symbol (info, name, abfd, section, address)
 770      struct bfd_link_info *info;
 771      const char *name;
 772      bfd *abfd;
 773      asection *section;
 774      bfd_vma address;
 775 {
 776   static char *error_name;
 777   static unsigned int error_count;
 778
 779 #define MAX_ERRORS_IN_A_ROW 5
 780
 781   /* We never print more than a reasonable number of errors in a row
 782      for a single symbol.  */
 783   if (error_name != (char *) NULL
 784       && strcmp (name, error_name) == 0)
 785     ++error_count;
 786   else
 787     {
 788       error_count = 0;
 789       if (error_name != (char *) NULL)
 790         free (error_name);
 791       error_name = buystring (name);
 792     }
 793
 794   if (error_count < MAX_ERRORS_IN_A_ROW)
 795     einfo ("%X%C: undefined reference to `%T'\n",
 796            abfd, section, address, name);
 797   else if (error_count == MAX_ERRORS_IN_A_ROW)
 798     einfo ("%C: more undefined references to `%T' follow\n",
 799            abfd, section, address, name);
 800
 801   return true;
 802 }
 803
 804 /* This is called when a reloc overflows.  */
 805
 806 /*ARGSUSED*/
 807 static boolean
 808 reloc_overflow (info, name, reloc_name, addend, abfd, section, address)
 809      struct bfd_link_info *info;
 810      const char *name;
 811      const char *reloc_name;
 812      bfd_vma addend;
 813      bfd *abfd;
 814      asection *section;
 815      bfd_vma address;
 816 {
 817   if (abfd == (bfd *) NULL)
 818     einfo ("%P%X: generated");
 819   else
 820     einfo ("%X%C:", abfd, section, address);
 821   einfo (" relocation truncated to fit: %s %T", reloc_name, name);
 822   if (addend != 0)
 823     einfo ("+%v", addend);
 824   einfo ("\n");
 825   return true;
 826 }
 827
 828 /* This is called when a dangerous relocation is made.  */
 829
 830 /*ARGSUSED*/
 831 static boolean
 832 reloc_dangerous (info, message, abfd, section, address)
 833      struct bfd_link_info *info;
 834      const char *message;
 835      bfd *abfd;
 836      asection *section;
 837      bfd_vma address;
 838 {
 839   if (abfd == (bfd *) NULL)
 840     einfo ("%P%X: generated");
 841   else
 842     einfo ("%X%C:", abfd, section, address);
 843   einfo ("dangerous relocation: %s\n", message);
 844   return true;
 845 }
 846
 847 /* This is called when a reloc is being generated attached to a symbol
 848    that is not being output.  */
 849
 850 /*ARGSUSED*/
 851 static boolean
 852 unattached_reloc (info, name, abfd, section, address)
 853      struct bfd_link_info *info;
 854      const char *name;
 855      bfd *abfd;
 856      asection *section;
 857      bfd_vma address;
 858 {
 859   if (abfd == (bfd *) NULL)
 860     einfo ("%P%X: generated");
 861   else
 862     einfo ("%X%C:", abfd, section, address);
 863   einfo (" reloc refers to symbol `%T' which is not being output\n", name);
 864   return true;
 865 }
 866
 867 /* This is called when a symbol in notice_hash is found.  Symbols are
 868    put in notice_hash using the -y option.  */
 869
 870 /*ARGSUSED*/
 871 static boolean
 872 notice_ysym (info, name, abfd, section, value)
 873      struct bfd_link_info *info;
 874      const char *name;
 875      bfd *abfd;
 876      asection *section;
 877      bfd_vma value;
 878 {
 879   einfo ("%B: %s %s\n", abfd,
 880          section != &bfd_und_section ? "definition of" : "reference to",
 881          name);
 882   return true;
 883 }