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.shared)
 205         einfo ("%P%F: -r and -shared may not be used together\n");
 206     }
 207
 208   /* Treat ld -r -s as ld -r -S -x (i.e., strip all local symbols).  I
 209      don't see how else this can be handled, since in this case we
 210      must preserve all externally visible symbols.  */
 211   if (link_info.relocateable && link_info.strip == strip_all)
 212     {
 213       link_info.strip = strip_debugger;
 214       if (link_info.discard == discard_none)
 215         link_info.discard = discard_all;
 216     }
 217
 218   /* This essentially adds another -L directory so this must be done after
 219      the -L's in argv have been processed.  */
 220   set_scripts_dir ();
 221
 222   if (had_script == false)
 223     {
 224       /* Read the emulation's appropriate default script.  */
 225       int isfile;
 226       char *s = ldemul_get_script (&isfile);
 227
 228       if (isfile)
 229         ldfile_open_command_file (s);
 230       else
 231         {
 232           if (trace_file_tries)
 233             {
 234               info_msg ("using internal linker script:\n");
 235               info_msg ("==================================================\n");
 236               info_msg (s);
 237               info_msg ("\n==================================================\n");
 238             }
 239           lex_redirect (s);
 240         }
 241       parser_input = input_script;
 242       yyparse ();
 243     }
 244
 245   lang_final ();
 246
 247   if (lang_has_input_file == false)
 248     {
 249       if (version_printed)
 250         xexit (0);
 251       einfo ("%P%F: no input files\n");
 252     }
 253
 254   if (trace_files)
 255     {
 256       info_msg ("%P: mode %s\n", emulation);
 257     }
 258
 259   ldemul_after_parse ();
 260
 261
 262   if (config.map_filename)
 263     {
 264       if (strcmp (config.map_filename, "-") == 0)
 265         {
 266           config.map_file = stdout;
 267         }
 268       else
 269         {
 270           config.map_file = fopen (config.map_filename, FOPEN_WT);
 271           if (config.map_file == (FILE *) NULL)
 272             {
 273               einfo ("%P%F: cannot open map file %s: %E\n",
 274                      config.map_filename);
 275             }
 276         }
 277     }
 278
 279
 280   lang_process ();
 281
 282   /* Print error messages for any missing symbols, for any warning
 283      symbols, and possibly multiple definitions */
 284
 285
 286   if (config.text_read_only)
 287     {
 288       /* Look for a text section and mark the readonly attribute in it */
 289       asection *found = bfd_get_section_by_name (output_bfd, ".text");
 290
 291       if (found != (asection *) NULL)
 292         {
 293           found->flags |= SEC_READONLY;
 294         }
 295     }
 296
 297   if (link_info.relocateable || link_info.shared)
 298     output_bfd->flags &= ~EXEC_P;
 299   else
 300     output_bfd->flags |= EXEC_P;
 301
 302   ldwrite ();
 303
 304   /* Even if we're producing relocateable output, some non-fatal errors should
 305      be reported in the exit status.  (What non-fatal errors, if any, do we
 306      want to ignore for relocateable output?)  */
 307
 308   if (config.make_executable == false && force_make_executable == false)
 309     {
 310       if (trace_files == true)
 311         {
 312           einfo ("%P: link errors found, deleting executable `%s'\n",
 313                  output_filename);
 314         }
 315
 316       if (output_bfd->iostream)
 317         fclose ((FILE *) (output_bfd->iostream));
 318
 319       unlink (output_filename);
 320       xexit (1);
 321     }
 322   else
 323     {
 324       if (! bfd_close (output_bfd))
 325         einfo ("%F%B: final close failed: %E\n", output_bfd);
 326     }
 327
 328   if (config.stats)
 329     {
 330       extern char **environ;
 331       char *lim = (char *) sbrk (0);
 332       long run_time = get_run_time () - start_time;
 333
 334       fprintf (stderr, "%s: total time in link: %ld.%06ld\n",
 335                program_name, run_time / 1000000, run_time % 1000000);
 336       fprintf (stderr, "%s: data size %ld\n", program_name,
 337                (long) (lim - (char *) &environ));
 338     }
 339
 340   /* Prevent remove_output from doing anything, after a successful link.  */
 341   output_filename = NULL;
 342
 343   xexit (0);
 344   return 0;
 345 }
 346
 347 /* We need to find any explicitly given emulation in order to initialize the
 348    state that's needed by the lex&yacc argument parser (parse_args).  */
 349
 350 static char *
 351 get_emulation (argc, argv)
 352      int argc;
 353      char **argv;
 354 {
 355   char *emulation;
 356   int i;
 357
 358   emulation = (char *) getenv (EMULATION_ENVIRON);
 359   if (emulation == NULL)
 360     emulation = DEFAULT_EMULATION;
 361
 362   for (i = 1; i < argc; i++)
 363     {
 364       if (!strncmp (argv[i], "-m", 2))
 365         {
 366           if (argv[i][2] == '\0')
 367             {
 368               /* -m EMUL */
 369               if (i < argc - 1)
 370                 {
 371                   emulation = argv[i + 1];
 372                   i++;
 373                 }
 374               else
 375                 {
 376                   einfo("%P%F: missing argument to -m\n");
 377                 }
 378             }
 379           else if (strcmp (argv[i], "-mips1") == 0
 380                    || strcmp (argv[i], "-mips2") == 0
 381                    || strcmp (argv[i], "-mips3") == 0)
 382             {
 383               /* FIXME: The arguments -mips1, -mips2 and -mips3 are
 384                  passed to the linker by some MIPS compilers.  They
 385                  generally tell the linker to use a slightly different
 386                  library path.  Perhaps someday these should be
 387                  implemented as emulations; until then, we just ignore
 388                  the arguments and hope that nobody ever creates
 389                  emulations named ips1, ips2 or ips3.  */
 390             }
 391           else if (strcmp (argv[i], "-m486") == 0)
 392             {
 393               /* FIXME: The argument -m486 is passed to the linker on
 394                  some Linux systems.  Hope that nobody creates an
 395                  emulation named 486.  */
 396             }
 397           else
 398             {
 399               /* -mEMUL */
 400               emulation = &argv[i][2];
 401             }
 402         }
 403     }
 404
 405   return emulation;
 406 }
 407
 408 /* If directory DIR contains an "ldscripts" subdirectory,
 409    add DIR to the library search path and return true,
 410    else return false.  */
 411
 412 static boolean
 413 check_for_scripts_dir (dir)
 414      char *dir;
 415 {
 416   size_t dirlen;
 417   char *buf;
 418   struct stat s;
 419   boolean res;
 420
 421   dirlen = strlen (dir);
 422   /* sizeof counts the terminating NUL.  */
 423   buf = (char *) xmalloc (dirlen + sizeof("/ldscripts"));
 424   sprintf (buf, "%s/ldscripts", dir);
 425
 426   res = stat (buf, &s) == 0 && S_ISDIR (s.st_mode);
 427   free (buf);
 428   if (res)
 429     ldfile_add_library_path (dir, false);
 430   return res;
 431 }
 432
 433 /* Set the default directory for finding script files.
 434    Libraries will be searched for here too, but that's ok.
 435    We look for the "ldscripts" directory in:
 436
 437    SCRIPTDIR (passed from Makefile)
 438    the dir where this program is (for using it from the build tree)
 439    the dir where this program is/../lib (for installing the tool suite elsewhere) */
 440
 441 static void
 442 set_scripts_dir ()
 443 {
 444   char *end, *dir;
 445   size_t dirlen;
 446
 447   if (check_for_scripts_dir (SCRIPTDIR))
 448     return;                     /* We've been installed normally.  */
 449
 450   /* Look for "ldscripts" in the dir where our binary is.  */
 451   end = strrchr (program_name, '/');
 452   if (end)
 453     {
 454       dirlen = end - program_name;
 455       /* Make a copy of program_name in dir.
 456          Leave room for later "/../lib".  */
 457       dir = (char *) xmalloc (dirlen + 8);
 458       strncpy (dir, program_name, dirlen);
 459       dir[dirlen] = '\0';
 460     }
 461   else
 462     {
 463       dirlen = 1;
 464       dir = (char *) xmalloc (dirlen + 8);
 465       strcpy (dir, ".");
 466     }
 467
 468   if (check_for_scripts_dir (dir))
 469     return;                     /* Don't free dir.  */
 470
 471   /* Look for "ldscripts" in <the dir where our binary is>/../lib.  */
 472   strcpy (dir + dirlen, "/../lib");
 473   if (check_for_scripts_dir (dir))
 474     return;
 475
 476   free (dir);                   /* Well, we tried.  */
 477 }
 478
 479 void
 480 add_ysym (name)
 481      const char *name;
 482 {
 483   if (link_info.notice_hash == (struct bfd_hash_table *) NULL)
 484     {
 485       link_info.notice_hash = ((struct bfd_hash_table *)
 486                                xmalloc (sizeof (struct bfd_hash_table)));
 487       if (! bfd_hash_table_init_n (link_info.notice_hash,
 488                                    bfd_hash_newfunc,
 489                                    61))
 490         einfo ("%P%F: bfd_hash_table_init failed: %E\n");
 491     }
 492
 493   if (bfd_hash_lookup (link_info.notice_hash, name, true, true)
 494       == (struct bfd_hash_entry *) NULL)
 495     einfo ("%P%F: bfd_hash_lookup failed: %E\n");
 496 }
 497
 498 /* Handle the -retain-symbols-file option.  */
 499
 500 void
 501 add_keepsyms_file (filename)
 502      const char *filename;
 503 {
 504   FILE *file;
 505   char *buf;
 506   size_t bufsize;
 507   int c;
 508
 509   if (link_info.strip == strip_some)
 510     einfo ("%X%P: error: duplicate retain-symbols-file\n");
 511
 512   file = fopen (filename, "r");
 513   if (file == (FILE *) NULL)
 514     {
 515       bfd_set_error (bfd_error_system_call);
 516       einfo ("%X%P: %s: %E", filename);
 517       return;
 518     }
 519
 520   link_info.keep_hash = ((struct bfd_hash_table *)
 521                          xmalloc (sizeof (struct bfd_hash_table)));
 522   if (! bfd_hash_table_init (link_info.keep_hash, bfd_hash_newfunc))
 523     einfo ("%P%F: bfd_hash_table_init failed: %E\n");
 524
 525   bufsize = 100;
 526   buf = (char *) xmalloc (bufsize);
 527
 528   c = getc (file);
 529   while (c != EOF)
 530     {
 531       while (isspace (c))
 532         c = getc (file);
 533
 534       if (c != EOF)
 535         {
 536           size_t len = 0;
 537
 538           while (! isspace (c) && c != EOF)
 539             {
 540               buf[len] = c;
 541               ++len;
 542               if (len >= bufsize)
 543                 {
 544                   bufsize *= 2;
 545                   buf = xrealloc (buf, bufsize);
 546                 }
 547               c = getc (file);
 548             }
 549
 550           buf[len] = '\0';
 551
 552           if (bfd_hash_lookup (link_info.keep_hash, buf, true, true)
 553               == (struct bfd_hash_entry *) NULL)
 554             einfo ("%P%F: bfd_hash_lookup for insertion failed: %E");
 555         }
 556     }
 557
 558   if (link_info.strip != strip_none)
 559     einfo ("%P: `-retain-symbols-file' overrides `-s' and `-S'\n");
 560
 561   link_info.strip = strip_some;
 562 }
 563 \f
 564 /* Callbacks from the BFD linker routines.  */
 565
 566 /* This is called when BFD has decided to include an archive member in
 567    a link.  */
 568
 569 /*ARGSUSED*/
 570 static boolean
 571 add_archive_element (info, abfd, name)
 572      struct bfd_link_info *info;
 573      bfd *abfd;
 574      const char *name;
 575 {
 576   lang_input_statement_type *input;
 577
 578   input = ((lang_input_statement_type *)
 579            xmalloc ((bfd_size_type) sizeof (lang_input_statement_type)));
 580   input->filename = abfd->filename;
 581   input->local_sym_name = abfd->filename;
 582   input->the_bfd = abfd;
 583   input->asymbols = NULL;
 584   input->next = NULL;
 585   input->just_syms_flag = false;
 586   input->loaded = false;
 587   input->search_dirs_flag = false;
 588
 589   /* FIXME: The following fields are not set: header.next,
 590      header.type, closed, passive_position, symbol_count,
 591      next_real_file, is_archive, target, real, common_section,
 592      common_output_section, complained.  This bit of code is from the
 593      old decode_library_subfile function.  I don't know whether any of
 594      those fields matters.  */
 595
 596   ldlang_add_file (input);
 597
 598   if (config.map_file != (FILE *) NULL)
 599     minfo ("%s needed due to %T\n", abfd->filename, name);
 600
 601   if (trace_files || trace_file_tries)
 602     info_msg ("%I\n", input);
 603
 604   return true;
 605 }
 606
 607 /* This is called when BFD has discovered a symbol which is defined
 608    multiple times.  */
 609
 610 /*ARGSUSED*/
 611 static boolean
 612 multiple_definition (info, name, obfd, osec, oval, nbfd, nsec, nval)
 613      struct bfd_link_info *info;
 614      const char *name;
 615      bfd *obfd;
 616      asection *osec;
 617      bfd_vma oval;
 618      bfd *nbfd;
 619      asection *nsec;
 620      bfd_vma nval;
 621 {
 622   einfo ("%X%C: multiple definition of `%T'\n",
 623          nbfd, nsec, nval, name);
 624   if (obfd != (bfd *) NULL)
 625     einfo ("%D: first defined here\n", obfd, osec, oval);
 626   return true;
 627 }
 628
 629 /* This is called when there is a definition of a common symbol, or
 630    when a common symbol is found for a symbol that is already defined,
 631    or when two common symbols are found.  We only do something if
 632    -warn-common was used.  */
 633
 634 /*ARGSUSED*/
 635 static boolean
 636 multiple_common (info, name, obfd, otype, osize, nbfd, ntype, nsize)
 637      struct bfd_link_info *info;
 638      const char *name;
 639      bfd *obfd;
 640      enum bfd_link_hash_type otype;
 641      bfd_vma osize;
 642      bfd *nbfd;
 643      enum bfd_link_hash_type ntype;
 644      bfd_vma nsize;
 645 {
 646   if (! config.warn_common)
 647     return true;
 648
 649   if (ntype == bfd_link_hash_defined
 650       || ntype == bfd_link_hash_defweak
 651       || ntype == bfd_link_hash_indirect)
 652     {
 653       ASSERT (otype == bfd_link_hash_common);
 654       einfo ("%B: warning: definition of `%T' overriding common\n",
 655              nbfd, name);
 656       if (obfd != NULL)
 657         einfo ("%B: warning: common is here\n", obfd);
 658     }
 659   else if (otype == bfd_link_hash_defined
 660            || otype == bfd_link_hash_defweak
 661            || otype == bfd_link_hash_indirect)
 662     {
 663       ASSERT (ntype == bfd_link_hash_common);
 664       einfo ("%B: warning: common of `%T' overridden by definition\n",
 665              nbfd, name);
 666       if (obfd != NULL)
 667         einfo ("%B: warning: defined here\n", obfd);
 668     }
 669   else
 670     {
 671       ASSERT (otype == bfd_link_hash_common && ntype == bfd_link_hash_common);
 672       if (osize > nsize)
 673         {
 674           einfo ("%B: warning: common of `%T' overridden by larger common\n",
 675                  nbfd, name);
 676           if (obfd != NULL)
 677             einfo ("%B: warning: larger common is here\n", obfd);
 678         }
 679       else if (nsize > osize)
 680         {
 681           einfo ("%B: warning: common of `%T' overriding smaller common\n",
 682                  nbfd, name);
 683           if (obfd != NULL)
 684             einfo ("%B: warning: smaller common is here\n", obfd);
 685         }
 686       else
 687         {
 688           einfo ("%B: warning: multiple common of `%T'\n", nbfd, name);
 689           if (obfd != NULL)
 690             einfo ("%B: warning: previous common is here\n", obfd);
 691         }
 692     }
 693
 694   return true;
 695 }
 696
 697 /* This is called when BFD has discovered a set element.  H is the
 698    entry in the linker hash table for the set.  SECTION and VALUE
 699    represent a value which should be added to the set.  */
 700
 701 /*ARGSUSED*/
 702 static boolean
 703 add_to_set (info, h, reloc, abfd, section, value)
 704      struct bfd_link_info *info;
 705      struct bfd_link_hash_entry *h;
 706      bfd_reloc_code_real_type reloc;
 707      bfd *abfd;
 708      asection *section;
 709      bfd_vma value;
 710 {
 711   if (! config.build_constructors)
 712     return true;
 713
 714   ldctor_add_set_entry (h, reloc, section, value);
 715
 716   if (h->type == bfd_link_hash_new)
 717     {
 718       h->type = bfd_link_hash_undefined;
 719       h->u.undef.abfd = abfd;
 720       /* We don't call bfd_link_add_undef to add this to the list of
 721          undefined symbols because we are going to define it
 722          ourselves.  */
 723     }
 724
 725   return true;
 726 }
 727
 728 /* This is called when BFD has discovered a constructor.  This is only
 729    called for some object file formats--those which do not handle
 730    constructors in some more clever fashion.  This is similar to
 731    adding an element to a set, but less general.  */
 732
 733 static boolean
 734 constructor_callback (info, constructor, name, abfd, section, value)
 735      struct bfd_link_info *info;
 736      boolean constructor;
 737      const char *name;
 738      bfd *abfd;
 739      asection *section;
 740      bfd_vma value;
 741 {
 742   char *set_name;
 743   char *s;
 744   struct bfd_link_hash_entry *h;
 745
 746   if (! config.build_constructors)
 747     return true;
 748
 749   /* Ensure that BFD_RELOC_CTOR exists now, so that we can give a
 750      useful error message.  */
 751   if (bfd_reloc_type_lookup (output_bfd, BFD_RELOC_CTOR) == NULL)
 752     einfo ("%P%F: BFD backend error: BFD_RELOC_CTOR unsupported");
 753
 754   set_name = (char *) alloca (1 + sizeof "__CTOR_LIST__");
 755   s = set_name;
 756   if (bfd_get_symbol_leading_char (abfd) != '\0')
 757     *s++ = bfd_get_symbol_leading_char (abfd);
 758   if (constructor)
 759     strcpy (s, "__CTOR_LIST__");
 760   else
 761     strcpy (s, "__DTOR_LIST__");
 762
 763   if (config.map_file != (FILE *) NULL)
 764     fprintf (config.map_file,
 765              "Adding %s to constructor/destructor set %s\n", name, set_name);
 766
 767   h = bfd_link_hash_lookup (info->hash, set_name, true, true, true);
 768   if (h == (struct bfd_link_hash_entry *) NULL)
 769     einfo ("%P%F: bfd_link_hash_lookup failed: %E");
 770   if (h->type == bfd_link_hash_new)
 771     {
 772       h->type = bfd_link_hash_undefined;
 773       h->u.undef.abfd = abfd;
 774       /* We don't call bfd_link_add_undef to add this to the list of
 775          undefined symbols because we are going to define it
 776          ourselves.  */
 777     }
 778
 779   ldctor_add_set_entry (h, BFD_RELOC_CTOR, section, value);
 780   return true;
 781 }
 782
 783 /* This is called when there is a reference to a warning symbol.  */
 784
 785 /*ARGSUSED*/
 786 static boolean
 787 warning_callback (info, warning)
 788      struct bfd_link_info *info;
 789      const char *warning;
 790 {
 791   einfo ("%P: %s\n", warning);
 792   return true;
 793 }
 794
 795 /* This is called when an undefined symbol is found.  */
 796
 797 /*ARGSUSED*/
 798 static boolean
 799 undefined_symbol (info, name, abfd, section, address)
 800      struct bfd_link_info *info;
 801      const char *name;
 802      bfd *abfd;
 803      asection *section;
 804      bfd_vma address;
 805 {
 806   static char *error_name;
 807   static unsigned int error_count;
 808
 809 #define MAX_ERRORS_IN_A_ROW 5
 810
 811   if (config.warn_once)
 812     {
 813       static struct bfd_hash_table *hash;
 814
 815       /* Only warn once about a particular undefined symbol.  */
 816
 817       if (hash == NULL)
 818         {
 819           hash = ((struct bfd_hash_table *)
 820                   xmalloc (sizeof (struct bfd_hash_table)));
 821           if (! bfd_hash_table_init (hash, bfd_hash_newfunc))
 822             einfo ("%F%P: bfd_hash_table_init failed: %E\n");
 823         }
 824
 825       if (bfd_hash_lookup (hash, name, false, false) != NULL)
 826         return true;
 827
 828       if (bfd_hash_lookup (hash, name, true, true) == NULL)
 829         einfo ("%F%P: bfd_hash_lookup failed: %E\n");
 830     }
 831
 832   /* We never print more than a reasonable number of errors in a row
 833      for a single symbol.  */
 834   if (error_name != (char *) NULL
 835       && strcmp (name, error_name) == 0)
 836     ++error_count;
 837   else
 838     {
 839       error_count = 0;
 840       if (error_name != (char *) NULL)
 841         free (error_name);
 842       error_name = buystring (name);
 843     }
 844
 845   if (section != NULL)
 846     {
 847       if (error_count < MAX_ERRORS_IN_A_ROW)
 848         einfo ("%X%C: undefined reference to `%T'\n",
 849                abfd, section, address, name);
 850       else if (error_count == MAX_ERRORS_IN_A_ROW)
 851         einfo ("%D: more undefined references to `%T' follow\n",
 852                abfd, section, address, name);
 853     }
 854   else
 855     {
 856       if (error_count < MAX_ERRORS_IN_A_ROW)
 857         einfo ("%X%B: undefined reference to `%T'\n",
 858                abfd, name);
 859       else if (error_count == MAX_ERRORS_IN_A_ROW)
 860         einfo ("%B: more undefined references to `%T' follow\n",
 861                abfd, name);
 862     }
 863
 864   return true;
 865 }
 866
 867 /* This is called when a reloc overflows.  */
 868
 869 /*ARGSUSED*/
 870 static boolean
 871 reloc_overflow (info, name, reloc_name, addend, abfd, section, address)
 872      struct bfd_link_info *info;
 873      const char *name;
 874      const char *reloc_name;
 875      bfd_vma addend;
 876      bfd *abfd;
 877      asection *section;
 878      bfd_vma address;
 879 {
 880   if (abfd == (bfd *) NULL)
 881     einfo ("%P%X: generated");
 882   else
 883     einfo ("%X%C:", abfd, section, address);
 884   einfo (" relocation truncated to fit: %s %T", reloc_name, name);
 885   if (addend != 0)
 886     einfo ("+%v", addend);
 887   einfo ("\n");
 888   return true;
 889 }
 890
 891 /* This is called when a dangerous relocation is made.  */
 892
 893 /*ARGSUSED*/
 894 static boolean
 895 reloc_dangerous (info, message, abfd, section, address)
 896      struct bfd_link_info *info;
 897      const char *message;
 898      bfd *abfd;
 899      asection *section;
 900      bfd_vma address;
 901 {
 902   if (abfd == (bfd *) NULL)
 903     einfo ("%P%X: generated");
 904   else
 905     einfo ("%X%C:", abfd, section, address);
 906   einfo ("dangerous relocation: %s\n", message);
 907   return true;
 908 }
 909
 910 /* This is called when a reloc is being generated attached to a symbol
 911    that is not being output.  */
 912
 913 /*ARGSUSED*/
 914 static boolean
 915 unattached_reloc (info, name, abfd, section, address)
 916      struct bfd_link_info *info;
 917      const char *name;
 918      bfd *abfd;
 919      asection *section;
 920      bfd_vma address;
 921 {
 922   if (abfd == (bfd *) NULL)
 923     einfo ("%P%X: generated");
 924   else
 925     einfo ("%X%C:", abfd, section, address);
 926   einfo (" reloc refers to symbol `%T' which is not being output\n", name);
 927   return true;
 928 }
 929
 930 /* This is called when a symbol in notice_hash is found.  Symbols are
 931    put in notice_hash using the -y option.  */
 932
 933 /*ARGSUSED*/
 934 static boolean
 935 notice_ysym (info, name, abfd, section, value)
 936      struct bfd_link_info *info;
 937      const char *name;
 938      bfd *abfd;
 939      asection *section;
 940      bfd_vma value;
 941 {
 942   einfo ("%B: %s %s\n", abfd,
 943          bfd_is_und_section (section) ? "reference to" : "definition of",
 944          name);
 945   return true;
 946 }