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ldmain.c revision 1.10
      1 /* Main program of GNU linker.
      2    Copyright (C) 1991-2022 Free Software Foundation, Inc.
      3    Written by Steve Chamberlain steve (at) cygnus.com
      4 
      5    This file is part of the GNU Binutils.
      6 
      7    This program 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 3 of the License, or
     10    (at your option) any later version.
     11 
     12    This program 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 this program; if not, write to the Free Software
     19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
     20    MA 02110-1301, USA.  */
     21 
     22 #include "sysdep.h"
     23 #include "bfd.h"
     24 #include "safe-ctype.h"
     25 #include "libiberty.h"
     26 #include "progress.h"
     27 #include "bfdlink.h"
     28 #include "ctf-api.h"
     29 #include "filenames.h"
     30 #include "elf/common.h"
     31 
     32 #include "ld.h"
     33 #include "ldmain.h"
     34 #include "ldmisc.h"
     35 #include "ldwrite.h"
     36 #include "ldexp.h"
     37 #include "ldlang.h"
     38 #include <ldgram.h>
     39 #include "ldlex.h"
     40 #include "ldfile.h"
     41 #include "ldemul.h"
     42 #include "ldctor.h"
     43 #if BFD_SUPPORTS_PLUGINS
     44 #include "plugin.h"
     45 #include "plugin-api.h"
     46 #endif /* BFD_SUPPORTS_PLUGINS */
     47 
     48 /* Somewhere above, sys/stat.h got included.  */
     49 #if !defined(S_ISDIR) && defined(S_IFDIR)
     50 #define	S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
     51 #endif
     52 
     53 #include <string.h>
     54 
     55 #ifndef TARGET_SYSTEM_ROOT
     56 #define TARGET_SYSTEM_ROOT ""
     57 #endif
     58 
     59 /* EXPORTS */
     60 
     61 FILE *saved_script_handle = NULL;
     62 FILE *previous_script_handle = NULL;
     63 bool force_make_executable = false;
     64 
     65 char *default_target;
     66 const char *output_filename = "a.out";
     67 
     68 /* Name this program was invoked by.  */
     69 char *program_name;
     70 
     71 /* The prefix for system library directories.  */
     72 const char *ld_sysroot;
     73 
     74 /* The canonical representation of ld_sysroot.  */
     75 char *ld_canon_sysroot;
     76 int ld_canon_sysroot_len;
     77 
     78 /* Set by -G argument, for targets like MIPS ELF.  */
     79 int g_switch_value = 8;
     80 
     81 /* Nonzero means print names of input files as processed.  */
     82 unsigned int trace_files;
     83 
     84 /* Nonzero means report actions taken by the linker, and describe the linker script in use.  */
     85 bool verbose;
     86 
     87 /* Nonzero means version number was printed, so exit successfully
     88    instead of complaining if no input files are given.  */
     89 bool version_printed;
     90 
     91 /* TRUE if we should demangle symbol names.  */
     92 bool demangling;
     93 
     94 args_type command_line;
     95 
     96 ld_config_type config;
     97 
     98 sort_type sort_section;
     99 
    100 static const char *get_sysroot
    101   (int, char **);
    102 static char *get_emulation
    103   (int, char **);
    104 static bool add_archive_element
    105   (struct bfd_link_info *, bfd *, const char *, bfd **);
    106 static void multiple_definition
    107   (struct bfd_link_info *, struct bfd_link_hash_entry *,
    108    bfd *, asection *, bfd_vma);
    109 static void multiple_common
    110   (struct bfd_link_info *, struct bfd_link_hash_entry *,
    111    bfd *, enum bfd_link_hash_type, bfd_vma);
    112 static void add_to_set
    113   (struct bfd_link_info *, struct bfd_link_hash_entry *,
    114    bfd_reloc_code_real_type, bfd *, asection *, bfd_vma);
    115 static void constructor_callback
    116   (struct bfd_link_info *, bool, const char *, bfd *,
    117    asection *, bfd_vma);
    118 static void warning_callback
    119   (struct bfd_link_info *, const char *, const char *, bfd *,
    120    asection *, bfd_vma);
    121 static void warning_find_reloc
    122   (bfd *, asection *, void *);
    123 static void undefined_symbol
    124   (struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma,
    125    bool);
    126 static void reloc_overflow
    127   (struct bfd_link_info *, struct bfd_link_hash_entry *, const char *,
    128    const char *, bfd_vma, bfd *, asection *, bfd_vma);
    129 static void reloc_dangerous
    130   (struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma);
    131 static void unattached_reloc
    132   (struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma);
    133 static bool notice
    134   (struct bfd_link_info *, struct bfd_link_hash_entry *,
    135    struct bfd_link_hash_entry *, bfd *, asection *, bfd_vma, flagword);
    136 
    137 static struct bfd_link_callbacks link_callbacks =
    138 {
    139   add_archive_element,
    140   multiple_definition,
    141   multiple_common,
    142   add_to_set,
    143   constructor_callback,
    144   warning_callback,
    145   undefined_symbol,
    146   reloc_overflow,
    147   reloc_dangerous,
    148   unattached_reloc,
    149   notice,
    150   einfo,
    151   info_msg,
    152   minfo,
    153   ldlang_override_segment_assignment,
    154   ldlang_ctf_acquire_strings,
    155   NULL,
    156   ldlang_ctf_new_dynsym,
    157   ldlang_write_ctf_late
    158 };
    159 
    160 static bfd_assert_handler_type default_bfd_assert_handler;
    161 static bfd_error_handler_type default_bfd_error_handler;
    162 
    163 struct bfd_link_info link_info;
    164 
    165 struct dependency_file
    167 {
    168   struct dependency_file *next;
    169   char *name;
    170 };
    171 
    172 static struct dependency_file *dependency_files, *dependency_files_tail;
    173 
    174 void
    175 track_dependency_files (const char *filename)
    176 {
    177   struct dependency_file *dep
    178     = (struct dependency_file *) xmalloc (sizeof (*dep));
    179   dep->name = xstrdup (filename);
    180   dep->next = NULL;
    181   if (dependency_files == NULL)
    182     dependency_files = dep;
    183   else
    184     dependency_files_tail->next = dep;
    185   dependency_files_tail = dep;
    186 }
    187 
    188 static void
    189 write_dependency_file (void)
    190 {
    191   FILE *out;
    192   struct dependency_file *dep;
    193 
    194   out = fopen (config.dependency_file, FOPEN_WT);
    195   if (out == NULL)
    196     {
    197       einfo (_("%F%P: cannot open dependency file %s: %E\n"),
    198 	     config.dependency_file);
    199     }
    200 
    201   fprintf (out, "%s:", output_filename);
    202 
    203   for (dep = dependency_files; dep != NULL; dep = dep->next)
    204     fprintf (out, " \\\n  %s", dep->name);
    205 
    206   fprintf (out, "\n");
    207   for (dep = dependency_files; dep != NULL; dep = dep->next)
    208     fprintf (out, "\n%s:\n", dep->name);
    209 
    210   fclose (out);
    211 }
    212 
    213 static void
    215 ld_cleanup (void)
    216 {
    217   bfd_cache_close_all ();
    218 #if BFD_SUPPORTS_PLUGINS
    219   plugin_call_cleanup ();
    220 #endif
    221   if (output_filename && delete_output_file_on_failure)
    222     unlink_if_ordinary (output_filename);
    223 }
    224 
    225 /* Hook to notice BFD assertions.  */
    226 
    227 static void
    228 ld_bfd_assert_handler (const char *fmt, const char *bfdver,
    229 		       const char *file, int line)
    230 {
    231   config.make_executable = false;
    232   (*default_bfd_assert_handler) (fmt, bfdver, file, line);
    233 }
    234 
    235 /* Hook the bfd error/warning handler for --fatal-warnings.  */
    236 
    237 static void
    238 ld_bfd_error_handler (const char *fmt, va_list ap)
    239 {
    240   if (config.fatal_warnings)
    241     config.make_executable = false;
    242   (*default_bfd_error_handler) (fmt, ap);
    243 }
    244 
    245 int
    246 main (int argc, char **argv)
    247 {
    248   char *emulation;
    249   long start_time = get_run_time ();
    250 
    251 #ifdef HAVE_LC_MESSAGES
    252   setlocale (LC_MESSAGES, "");
    253 #endif
    254   setlocale (LC_CTYPE, "");
    255   bindtextdomain (PACKAGE, LOCALEDIR);
    256   textdomain (PACKAGE);
    257 
    258   program_name = argv[0];
    259   xmalloc_set_program_name (program_name);
    260 
    261   START_PROGRESS (program_name, 0);
    262 
    263   expandargv (&argc, &argv);
    264 
    265   if (bfd_init () != BFD_INIT_MAGIC)
    266     einfo (_("%F%P: fatal error: libbfd ABI mismatch\n"));
    267 
    268   bfd_set_error_program_name (program_name);
    269 
    270   /* We want to notice and fail on those nasty BFD assertions which are
    271      likely to signal incorrect output being generated but otherwise may
    272      leave no trace.  */
    273   default_bfd_assert_handler = bfd_set_assert_handler (ld_bfd_assert_handler);
    274 
    275   /* Also hook the bfd error/warning handler for --fatal-warnings.  */
    276   default_bfd_error_handler = bfd_set_error_handler (ld_bfd_error_handler);
    277 
    278   xatexit (ld_cleanup);
    279 
    280   /* Set up the sysroot directory.  */
    281   ld_sysroot = get_sysroot (argc, argv);
    282   if (*ld_sysroot)
    283     ld_canon_sysroot = lrealpath (ld_sysroot);
    284   if (ld_canon_sysroot)
    285     {
    286       ld_canon_sysroot_len = strlen (ld_canon_sysroot);
    287 
    288       /* is_sysrooted_pathname() relies on no trailing dirsep.  */
    289       if (ld_canon_sysroot_len > 0
    290 	  && IS_DIR_SEPARATOR (ld_canon_sysroot [ld_canon_sysroot_len - 1]))
    291 	ld_canon_sysroot [--ld_canon_sysroot_len] = '\0';
    292     }
    293   else
    294     ld_canon_sysroot_len = -1;
    295 
    296   /* Set the default BFD target based on the configured target.  Doing
    297      this permits the linker to be configured for a particular target,
    298      and linked against a shared BFD library which was configured for
    299      a different target.  The macro TARGET is defined by Makefile.  */
    300   if (!bfd_set_default_target (TARGET))
    301     {
    302       einfo (_("%X%P: can't set BFD default target to `%s': %E\n"), TARGET);
    303       xexit (1);
    304     }
    305 
    306 #if YYDEBUG
    307   {
    308     extern int yydebug;
    309     yydebug = 1;
    310   }
    311 #endif
    312 
    313   config.build_constructors = true;
    314   config.rpath_separator = ':';
    315   config.split_by_reloc = (unsigned) -1;
    316   config.split_by_file = (bfd_size_type) -1;
    317   config.make_executable = true;
    318   config.magic_demand_paged = true;
    319   config.text_read_only = true;
    320   config.print_map_discarded = true;
    321   link_info.disable_target_specific_optimizations = -1;
    322 
    323   command_line.warn_mismatch = true;
    324   command_line.warn_search_mismatch = true;
    325   command_line.check_section_addresses = -1;
    326 
    327   /* We initialize DEMANGLING based on the environment variable
    328      COLLECT_NO_DEMANGLE.  The gcc collect2 program will demangle the
    329      output of the linker, unless COLLECT_NO_DEMANGLE is set in the
    330      environment.  Acting the same way here lets us provide the same
    331      interface by default.  */
    332   demangling = getenv ("COLLECT_NO_DEMANGLE") == NULL;
    333 
    334   link_info.allow_undefined_version = true;
    335   link_info.keep_memory = true;
    336   link_info.max_cache_size = (bfd_size_type) -1;
    337   link_info.combreloc = true;
    338   link_info.strip_discarded = true;
    339   link_info.prohibit_multiple_definition_absolute = false;
    340   link_info.textrel_check = DEFAULT_LD_TEXTREL_CHECK;
    341   link_info.emit_hash = DEFAULT_EMIT_SYSV_HASH;
    342   link_info.emit_gnu_hash = DEFAULT_EMIT_GNU_HASH;
    343   link_info.callbacks = &link_callbacks;
    344   link_info.input_bfds_tail = &link_info.input_bfds;
    345   /* SVR4 linkers seem to set DT_INIT and DT_FINI based on magic _init
    346      and _fini symbols.  We are compatible.  */
    347   link_info.init_function = "_init";
    348   link_info.fini_function = "_fini";
    349   link_info.relax_pass = 1;
    350   link_info.extern_protected_data = -1;
    351   link_info.dynamic_undefined_weak = -1;
    352   link_info.indirect_extern_access = -1;
    353   link_info.pei386_auto_import = -1;
    354   link_info.spare_dynamic_tags = 5;
    355   link_info.path_separator = ':';
    356 #ifdef DEFAULT_FLAG_COMPRESS_DEBUG
    357   link_info.compress_debug = COMPRESS_DEBUG_GABI_ZLIB;
    358 #endif
    359 #ifdef DEFAULT_NEW_DTAGS
    360   link_info.new_dtags = DEFAULT_NEW_DTAGS;
    361 #endif
    362   link_info.start_stop_gc = false;
    363   link_info.start_stop_visibility = STV_PROTECTED;
    364 
    365   ldfile_add_arch ("");
    366   emulation = get_emulation (argc, argv);
    367   ldemul_choose_mode (emulation);
    368   default_target = ldemul_choose_target (argc, argv);
    369   lang_init ();
    370   ldexp_init ();
    371   ldemul_before_parse ();
    372   lang_has_input_file = false;
    373   parse_args (argc, argv);
    374 
    375   if (config.hash_table_size != 0)
    376     bfd_hash_set_default_size (config.hash_table_size);
    377 
    378 #if BFD_SUPPORTS_PLUGINS
    379   /* Now all the plugin arguments have been gathered, we can load them.  */
    380   plugin_load_plugins ();
    381 #endif /* BFD_SUPPORTS_PLUGINS */
    382 
    383   ldemul_set_symbols ();
    384 
    385   /* If we have not already opened and parsed a linker script,
    386      try the default script from command line first.  */
    387   if (saved_script_handle == NULL
    388       && command_line.default_script != NULL)
    389     {
    390       ldfile_open_script_file (command_line.default_script);
    391       parser_input = input_script;
    392       yyparse ();
    393     }
    394 
    395   /* If we have not already opened and parsed a linker script
    396      read the emulation's appropriate default script.  */
    397   if (saved_script_handle == NULL)
    398     {
    399       int isfile;
    400       char *s = ldemul_get_script (&isfile);
    401 
    402       if (isfile)
    403 	ldfile_open_default_command_file (s);
    404       else
    405 	{
    406 	  lex_string = s;
    407 	  lex_redirect (s, _("built in linker script"), 1);
    408 	}
    409       parser_input = input_script;
    410       yyparse ();
    411       lex_string = NULL;
    412     }
    413 
    414   if (verbose)
    415     {
    416       if (saved_script_handle)
    417 	info_msg (_("using external linker script:"));
    418       else
    419 	info_msg (_("using internal linker script:"));
    420       info_msg ("\n==================================================\n");
    421 
    422       if (saved_script_handle)
    423 	{
    424 	  static const int ld_bufsz = 8193;
    425 	  size_t n;
    426 	  char *buf = (char *) xmalloc (ld_bufsz);
    427 
    428 	  rewind (saved_script_handle);
    429 	  while ((n = fread (buf, 1, ld_bufsz - 1, saved_script_handle)) > 0)
    430 	    {
    431 	      buf[n] = 0;
    432 	      info_msg ("%s", buf);
    433 	    }
    434 	  rewind (saved_script_handle);
    435 	  free (buf);
    436 	}
    437       else
    438 	{
    439 	  int isfile;
    440 
    441 	  info_msg (ldemul_get_script (&isfile));
    442 	}
    443 
    444       info_msg ("\n==================================================\n");
    445     }
    446 
    447   if (command_line.force_group_allocation
    448       || !bfd_link_relocatable (&link_info))
    449     link_info.resolve_section_groups = true;
    450   else
    451     link_info.resolve_section_groups = false;
    452 
    453   if (command_line.print_output_format)
    454     info_msg ("%s\n", lang_get_output_target ());
    455 
    456   lang_final ();
    457 
    458   /* If the only command line argument has been -v or --version or --verbose
    459      then ignore any input files provided by linker scripts and exit now.
    460      We do not want to create an output file when the linker is just invoked
    461      to provide version information.  */
    462   if (argc == 2 && version_printed)
    463     xexit (0);
    464 
    465   if (link_info.inhibit_common_definition && !bfd_link_dll (&link_info))
    466     einfo (_("%F%P: --no-define-common may not be used without -shared\n"));
    467 
    468   if (!lang_has_input_file)
    469     {
    470       if (version_printed || command_line.print_output_format)
    471 	xexit (0);
    472       einfo (_("%F%P: no input files\n"));
    473     }
    474 
    475   if (verbose)
    476     info_msg (_("%P: mode %s\n"), emulation);
    477 
    478   ldemul_after_parse ();
    479 
    480   if (config.map_filename)
    481     {
    482       if (strcmp (config.map_filename, "-") == 0)
    483 	{
    484 	  config.map_file = stdout;
    485 	}
    486       else
    487 	{
    488 	  config.map_file = fopen (config.map_filename, FOPEN_WT);
    489 	  if (config.map_file == (FILE *) NULL)
    490 	    {
    491 	      bfd_set_error (bfd_error_system_call);
    492 	      einfo (_("%F%P: cannot open map file %s: %E\n"),
    493 		     config.map_filename);
    494 	    }
    495 	}
    496       link_info.has_map_file = true;
    497     }
    498 
    499   lang_process ();
    500 
    501   /* Print error messages for any missing symbols, for any warning
    502      symbols, and possibly multiple definitions.  */
    503   if (bfd_link_relocatable (&link_info))
    504     link_info.output_bfd->flags &= ~EXEC_P;
    505   else
    506     link_info.output_bfd->flags |= EXEC_P;
    507 
    508   if ((link_info.compress_debug & COMPRESS_DEBUG))
    509     {
    510       link_info.output_bfd->flags |= BFD_COMPRESS;
    511       if (link_info.compress_debug == COMPRESS_DEBUG_GABI_ZLIB)
    512 	link_info.output_bfd->flags |= BFD_COMPRESS_GABI;
    513     }
    514 
    515   ldwrite ();
    516 
    517   if (config.map_file != NULL)
    518     lang_map ();
    519   if (command_line.cref)
    520     output_cref (config.map_file != NULL ? config.map_file : stdout);
    521   if (nocrossref_list != NULL)
    522     check_nocrossrefs ();
    523   if (command_line.print_memory_usage)
    524     lang_print_memory_usage ();
    525 #if 0
    526   {
    527     struct bfd_link_hash_entry *h;
    528 
    529     h = bfd_link_hash_lookup (link_info.hash, "__image_base__", 0,0,1);
    530     fprintf (stderr, "lookup = %p val %lx\n", h, h ? h->u.def.value : 1);
    531   }
    532 #endif
    533   ldexp_finish ();
    534   lang_finish ();
    535 
    536   if (config.dependency_file != NULL)
    537     write_dependency_file ();
    538 
    539   /* Even if we're producing relocatable output, some non-fatal errors should
    540      be reported in the exit status.  (What non-fatal errors, if any, do we
    541      want to ignore for relocatable output?)  */
    542   if (!config.make_executable && !force_make_executable)
    543     {
    544       if (verbose)
    545 	einfo (_("%P: link errors found, deleting executable `%s'\n"),
    546 	       output_filename);
    547 
    548       /* The file will be removed by ld_cleanup.  */
    549       xexit (1);
    550     }
    551   else
    552     {
    553       if (!bfd_close (link_info.output_bfd))
    554 	einfo (_("%F%P: %pB: final close failed: %E\n"), link_info.output_bfd);
    555 
    556       /* If the --force-exe-suffix is enabled, and we're making an
    557 	 executable file and it doesn't end in .exe, copy it to one
    558 	 which does.  */
    559       if (!bfd_link_relocatable (&link_info)
    560 	  && command_line.force_exe_suffix)
    561 	{
    562 	  int len = strlen (output_filename);
    563 
    564 	  if (len < 4
    565 	      || (strcasecmp (output_filename + len - 4, ".exe") != 0
    566 		  && strcasecmp (output_filename + len - 4, ".dll") != 0))
    567 	    {
    568 	      FILE *src;
    569 	      FILE *dst;
    570 	      const int bsize = 4096;
    571 	      char *buf = (char *) xmalloc (bsize);
    572 	      int l;
    573 	      char *dst_name = (char *) xmalloc (len + 5);
    574 
    575 	      strcpy (dst_name, output_filename);
    576 	      strcat (dst_name, ".exe");
    577 	      src = fopen (output_filename, FOPEN_RB);
    578 	      dst = fopen (dst_name, FOPEN_WB);
    579 
    580 	      if (!src)
    581 		einfo (_("%F%P: unable to open for source of copy `%s'\n"),
    582 		       output_filename);
    583 	      if (!dst)
    584 		einfo (_("%F%P: unable to open for destination of copy `%s'\n"),
    585 		       dst_name);
    586 	      while ((l = fread (buf, 1, bsize, src)) > 0)
    587 		{
    588 		  int done = fwrite (buf, 1, l, dst);
    589 
    590 		  if (done != l)
    591 		    einfo (_("%P: error writing file `%s'\n"), dst_name);
    592 		}
    593 
    594 	      fclose (src);
    595 	      if (fclose (dst) == EOF)
    596 		einfo (_("%P: error closing file `%s'\n"), dst_name);
    597 	      free (dst_name);
    598 	      free (buf);
    599 	    }
    600 	}
    601     }
    602 
    603   END_PROGRESS (program_name);
    604 
    605   if (config.stats)
    606     {
    607       long run_time = get_run_time () - start_time;
    608 
    609       fflush (stdout);
    610       fprintf (stderr, _("%s: total time in link: %ld.%06ld\n"),
    611 	       program_name, run_time / 1000000, run_time % 1000000);
    612       fflush (stderr);
    613     }
    614 
    615   /* Prevent ld_cleanup from doing anything, after a successful link.  */
    616   output_filename = NULL;
    617 
    618   xexit (0);
    619   return 0;
    620 }
    621 
    622 /* If the configured sysroot is relocatable, try relocating it based on
    623    default prefix FROM.  Return the relocated directory if it exists,
    624    otherwise return null.  */
    625 
    626 static char *
    627 get_relative_sysroot (const char *from ATTRIBUTE_UNUSED)
    628 {
    629 #ifdef TARGET_SYSTEM_ROOT_RELOCATABLE
    630   char *path;
    631   struct stat s;
    632 
    633   path = make_relative_prefix (program_name, from, TARGET_SYSTEM_ROOT);
    634   if (path)
    635     {
    636       if (stat (path, &s) == 0 && S_ISDIR (s.st_mode))
    637 	return path;
    638       free (path);
    639     }
    640 #endif
    641   return 0;
    642 }
    643 
    644 /* Return the sysroot directory.  Return "" if no sysroot is being used.  */
    645 
    646 static const char *
    647 get_sysroot (int argc, char **argv)
    648 {
    649   int i;
    650   const char *path = NULL;
    651 
    652   for (i = 1; i < argc; i++)
    653     if (startswith (argv[i], "--sysroot="))
    654       path = argv[i] + strlen ("--sysroot=");
    655 
    656   if (!path)
    657     path = get_relative_sysroot (BINDIR);
    658 
    659   if (!path)
    660     path = get_relative_sysroot (TOOLBINDIR);
    661 
    662   if (!path)
    663     path = TARGET_SYSTEM_ROOT;
    664 
    665   if (IS_DIR_SEPARATOR (*path) && path[1] == 0)
    666     path = "";
    667 
    668   return path;
    669 }
    670 
    671 /* We need to find any explicitly given emulation in order to initialize the
    672    state that's needed by the lex&yacc argument parser (parse_args).  */
    673 
    674 static char *
    675 get_emulation (int argc, char **argv)
    676 {
    677   char *emulation;
    678   int i;
    679 
    680   emulation = getenv (EMULATION_ENVIRON);
    681   if (emulation == NULL)
    682     emulation = DEFAULT_EMULATION;
    683 
    684   for (i = 1; i < argc; i++)
    685     {
    686       if (startswith (argv[i], "-m"))
    687 	{
    688 	  if (argv[i][2] == '\0')
    689 	    {
    690 	      /* -m EMUL */
    691 	      if (i < argc - 1)
    692 		{
    693 		  emulation = argv[i + 1];
    694 		  i++;
    695 		}
    696 	      else
    697 		einfo (_("%F%P: missing argument to -m\n"));
    698 	    }
    699 	  else if (strcmp (argv[i], "-mips1") == 0
    700 		   || strcmp (argv[i], "-mips2") == 0
    701 		   || strcmp (argv[i], "-mips3") == 0
    702 		   || strcmp (argv[i], "-mips4") == 0
    703 		   || strcmp (argv[i], "-mips5") == 0
    704 		   || strcmp (argv[i], "-mips32") == 0
    705 		   || strcmp (argv[i], "-mips32r2") == 0
    706 		   || strcmp (argv[i], "-mips32r3") == 0
    707 		   || strcmp (argv[i], "-mips32r5") == 0
    708 		   || strcmp (argv[i], "-mips32r6") == 0
    709 		   || strcmp (argv[i], "-mips64") == 0
    710 		   || strcmp (argv[i], "-mips64r2") == 0
    711 		   || strcmp (argv[i], "-mips64r3") == 0
    712 		   || strcmp (argv[i], "-mips64r5") == 0
    713 		   || strcmp (argv[i], "-mips64r6") == 0)
    714 	    {
    715 	      /* FIXME: The arguments -mips1, -mips2, -mips3, etc. are
    716 		 passed to the linker by some MIPS compilers.  They
    717 		 generally tell the linker to use a slightly different
    718 		 library path.  Perhaps someday these should be
    719 		 implemented as emulations; until then, we just ignore
    720 		 the arguments and hope that nobody ever creates
    721 		 emulations named ips1, ips2 or ips3.  */
    722 	    }
    723 	  else if (strcmp (argv[i], "-m486") == 0)
    724 	    {
    725 	      /* FIXME: The argument -m486 is passed to the linker on
    726 		 some Linux systems.  Hope that nobody creates an
    727 		 emulation named 486.  */
    728 	    }
    729 	  else
    730 	    {
    731 	      /* -mEMUL */
    732 	      emulation = &argv[i][2];
    733 	    }
    734 	}
    735     }
    736 
    737   return emulation;
    738 }
    739 
    740 void
    741 add_ysym (const char *name)
    742 {
    743   if (link_info.notice_hash == NULL)
    744     {
    745       link_info.notice_hash
    746 	= (struct bfd_hash_table *) xmalloc (sizeof (struct bfd_hash_table));
    747       if (!bfd_hash_table_init_n (link_info.notice_hash,
    748 				  bfd_hash_newfunc,
    749 				  sizeof (struct bfd_hash_entry),
    750 				  61))
    751 	einfo (_("%F%P: bfd_hash_table_init failed: %E\n"));
    752     }
    753 
    754   if (bfd_hash_lookup (link_info.notice_hash, name, true, true) == NULL)
    755     einfo (_("%F%P: bfd_hash_lookup failed: %E\n"));
    756 }
    757 
    758 void
    759 add_ignoresym (struct bfd_link_info *info, const char *name)
    760 {
    761   if (info->ignore_hash == NULL)
    762     {
    763       info->ignore_hash = xmalloc (sizeof (struct bfd_hash_table));
    764       if (!bfd_hash_table_init_n (info->ignore_hash,
    765 				  bfd_hash_newfunc,
    766 				  sizeof (struct bfd_hash_entry),
    767 				  61))
    768 	einfo (_("%F%P: bfd_hash_table_init failed: %E\n"));
    769     }
    770 
    771   if (bfd_hash_lookup (info->ignore_hash, name, true, true) == NULL)
    772     einfo (_("%F%P: bfd_hash_lookup failed: %E\n"));
    773 }
    774 
    775 /* Record a symbol to be wrapped, from the --wrap option.  */
    776 
    777 void
    778 add_wrap (const char *name)
    779 {
    780   if (link_info.wrap_hash == NULL)
    781     {
    782       link_info.wrap_hash
    783 	= (struct bfd_hash_table *) xmalloc (sizeof (struct bfd_hash_table));
    784       if (!bfd_hash_table_init_n (link_info.wrap_hash,
    785 				  bfd_hash_newfunc,
    786 				  sizeof (struct bfd_hash_entry),
    787 				  61))
    788 	einfo (_("%F%P: bfd_hash_table_init failed: %E\n"));
    789     }
    790 
    791   if (bfd_hash_lookup (link_info.wrap_hash, name, true, true) == NULL)
    792     einfo (_("%F%P: bfd_hash_lookup failed: %E\n"));
    793 }
    794 
    795 /* Handle the -retain-symbols-file option.  */
    796 
    797 void
    798 add_keepsyms_file (const char *filename)
    799 {
    800   FILE *file;
    801   char *buf;
    802   size_t bufsize;
    803   int c;
    804 
    805   if (link_info.strip == strip_some)
    806     einfo (_("%X%P: error: duplicate retain-symbols-file\n"));
    807 
    808   file = fopen (filename, "r");
    809   if (file == NULL)
    810     {
    811       bfd_set_error (bfd_error_system_call);
    812       einfo ("%X%P: %s: %E\n", filename);
    813       return;
    814     }
    815 
    816   link_info.keep_hash = (struct bfd_hash_table *)
    817       xmalloc (sizeof (struct bfd_hash_table));
    818   if (!bfd_hash_table_init (link_info.keep_hash, bfd_hash_newfunc,
    819 			    sizeof (struct bfd_hash_entry)))
    820     einfo (_("%F%P: bfd_hash_table_init failed: %E\n"));
    821 
    822   bufsize = 100;
    823   buf = (char *) xmalloc (bufsize);
    824 
    825   c = getc (file);
    826   while (c != EOF)
    827     {
    828       while (ISSPACE (c))
    829 	c = getc (file);
    830 
    831       if (c != EOF)
    832 	{
    833 	  size_t len = 0;
    834 
    835 	  while (!ISSPACE (c) && c != EOF)
    836 	    {
    837 	      buf[len] = c;
    838 	      ++len;
    839 	      if (len >= bufsize)
    840 		{
    841 		  bufsize *= 2;
    842 		  buf = (char *) xrealloc (buf, bufsize);
    843 		}
    844 	      c = getc (file);
    845 	    }
    846 
    847 	  buf[len] = '\0';
    848 
    849 	  if (bfd_hash_lookup (link_info.keep_hash, buf, true, true) == NULL)
    850 	    einfo (_("%F%P: bfd_hash_lookup for insertion failed: %E\n"));
    851 	}
    852     }
    853 
    854   if (link_info.strip != strip_none)
    855     einfo (_("%P: `-retain-symbols-file' overrides `-s' and `-S'\n"));
    856 
    857   free (buf);
    858   link_info.strip = strip_some;
    859   fclose (file);
    860 }
    861 
    862 /* Callbacks from the BFD linker routines.  */
    864 
    865 /* This is called when BFD has decided to include an archive member in
    866    a link.  */
    867 
    868 static bool
    869 add_archive_element (struct bfd_link_info *info,
    870 		     bfd *abfd,
    871 		     const char *name,
    872 		     bfd **subsbfd ATTRIBUTE_UNUSED)
    873 {
    874   lang_input_statement_type *input;
    875   lang_input_statement_type *parent;
    876   lang_input_statement_type orig_input;
    877 
    878   input = (lang_input_statement_type *)
    879       xcalloc (1, sizeof (lang_input_statement_type));
    880   input->header.type = lang_input_statement_enum;
    881   input->filename = bfd_get_filename (abfd);
    882   input->local_sym_name = bfd_get_filename (abfd);
    883   input->the_bfd = abfd;
    884 
    885   /* Save the original data for trace files/tries below, as plugins
    886      (if enabled) may possibly alter it to point to a replacement
    887      BFD, but we still want to output the original BFD filename.  */
    888   orig_input = *input;
    889 #if BFD_SUPPORTS_PLUGINS
    890   if (link_info.lto_plugin_active)
    891     {
    892       /* We must offer this archive member to the plugins to claim.  */
    893       plugin_maybe_claim (input);
    894       if (input->flags.claimed)
    895 	{
    896 	  if (no_more_claiming)
    897 	    {
    898 	      /* Don't claim new IR symbols after all IR symbols have
    899 		 been claimed.  */
    900 	      if (verbose)
    901 		info_msg ("%pI: no new IR symbols to claim\n",
    902 			  &orig_input);
    903 	      input->flags.claimed = 0;
    904 	      return false;
    905 	    }
    906 	  input->flags.claim_archive = true;
    907 	  *subsbfd = input->the_bfd;
    908 	}
    909     }
    910 #endif /* BFD_SUPPORTS_PLUGINS */
    911 
    912   if (link_info.input_bfds_tail == &input->the_bfd->link.next
    913       || input->the_bfd->link.next != NULL)
    914     {
    915       /* We have already loaded this element, and are attempting to
    916 	 load it again.  This can happen when the archive map doesn't
    917 	 match actual symbols defined by the element.  */
    918       free (input);
    919       bfd_set_error (bfd_error_malformed_archive);
    920       return false;
    921     }
    922 
    923   /* Set the file_chain pointer of archives to the last element loaded
    924      from the archive.  See ldlang.c:find_rescan_insertion.  */
    925   parent = bfd_usrdata (abfd->my_archive);
    926   if (parent != NULL && !parent->flags.reload)
    927     parent->next = input;
    928 
    929   ldlang_add_file (input);
    930 
    931   if (config.map_file != NULL)
    932     {
    933       static bool header_printed;
    934       struct bfd_link_hash_entry *h;
    935       bfd *from;
    936       int len;
    937 
    938       h = bfd_link_hash_lookup (info->hash, name, false, false, true);
    939       if (h == NULL
    940 	  && info->pei386_auto_import
    941 	  && startswith (name, "__imp_"))
    942 	h = bfd_link_hash_lookup (info->hash, name + 6, false, false, true);
    943 
    944       if (h == NULL)
    945 	from = NULL;
    946       else
    947 	{
    948 	  switch (h->type)
    949 	    {
    950 	    default:
    951 	      from = NULL;
    952 	      break;
    953 
    954 	    case bfd_link_hash_defined:
    955 	    case bfd_link_hash_defweak:
    956 	      from = h->u.def.section->owner;
    957 	      break;
    958 
    959 	    case bfd_link_hash_undefined:
    960 	    case bfd_link_hash_undefweak:
    961 	      from = h->u.undef.abfd;
    962 	      break;
    963 
    964 	    case bfd_link_hash_common:
    965 	      from = h->u.c.p->section->owner;
    966 	      break;
    967 	    }
    968 	}
    969 
    970       if (!header_printed)
    971 	{
    972 	  minfo (_("Archive member included to satisfy reference by file (symbol)\n\n"));
    973 	  header_printed = true;
    974 	}
    975 
    976       if (abfd->my_archive == NULL
    977 	  || bfd_is_thin_archive (abfd->my_archive))
    978 	{
    979 	  minfo ("%s", bfd_get_filename (abfd));
    980 	  len = strlen (bfd_get_filename (abfd));
    981 	}
    982       else
    983 	{
    984 	  minfo ("%s(%s)", bfd_get_filename (abfd->my_archive),
    985 		 bfd_get_filename (abfd));
    986 	  len = (strlen (bfd_get_filename (abfd->my_archive))
    987 		 + strlen (bfd_get_filename (abfd))
    988 		 + 2);
    989 	}
    990 
    991       if (len >= 29)
    992 	{
    993 	  print_nl ();
    994 	  len = 0;
    995 	}
    996       while (len < 30)
    997 	{
    998 	  print_space ();
    999 	  ++len;
   1000 	}
   1001 
   1002       if (from != NULL)
   1003 	minfo ("%pB ", from);
   1004       if (h != NULL)
   1005 	minfo ("(%pT)\n", h->root.string);
   1006       else
   1007 	minfo ("(%s)\n", name);
   1008     }
   1009 
   1010   if (verbose
   1011       || trace_files > 1
   1012       || (trace_files && bfd_is_thin_archive (orig_input.the_bfd->my_archive)))
   1013     info_msg ("%pI\n", &orig_input);
   1014   return true;
   1015 }
   1016 
   1017 /* This is called when BFD has discovered a symbol which is defined
   1018    multiple times.  */
   1019 
   1020 static void
   1021 multiple_definition (struct bfd_link_info *info,
   1022 		     struct bfd_link_hash_entry *h,
   1023 		     bfd *nbfd,
   1024 		     asection *nsec,
   1025 		     bfd_vma nval)
   1026 {
   1027   const char *name;
   1028   bfd *obfd;
   1029   asection *osec;
   1030   bfd_vma oval;
   1031 
   1032   if (info->allow_multiple_definition)
   1033     return;
   1034 
   1035   switch (h->type)
   1036     {
   1037     case bfd_link_hash_defined:
   1038       osec = h->u.def.section;
   1039       oval = h->u.def.value;
   1040       obfd = h->u.def.section->owner;
   1041       break;
   1042     case bfd_link_hash_indirect:
   1043       osec = bfd_ind_section_ptr;
   1044       oval = 0;
   1045       obfd = NULL;
   1046       break;
   1047     default:
   1048       abort ();
   1049     }
   1050 
   1051   /* Ignore a redefinition of an absolute symbol to the
   1052      same value; it's harmless.  */
   1053   if (h->type == bfd_link_hash_defined
   1054       && bfd_is_abs_section (osec)
   1055       && bfd_is_abs_section (nsec)
   1056       && nval == oval)
   1057     return;
   1058 
   1059   /* If either section has the output_section field set to
   1060      bfd_abs_section_ptr, it means that the section is being
   1061      discarded, and this is not really a multiple definition at all.
   1062      FIXME: It would be cleaner to somehow ignore symbols defined in
   1063      sections which are being discarded.  */
   1064   if (!info->prohibit_multiple_definition_absolute
   1065       && ((osec->output_section != NULL
   1066 	   && ! bfd_is_abs_section (osec)
   1067 	   && bfd_is_abs_section (osec->output_section))
   1068 	  || (nsec->output_section != NULL
   1069 	      && !bfd_is_abs_section (nsec)
   1070 	      && bfd_is_abs_section (nsec->output_section))))
   1071     return;
   1072 
   1073   name = h->root.string;
   1074   if (nbfd == NULL)
   1075     {
   1076       nbfd = obfd;
   1077       nsec = osec;
   1078       nval = oval;
   1079       obfd = NULL;
   1080     }
   1081   if (info->warn_multiple_definition)
   1082     einfo (_("%P: %C: warning: multiple definition of `%pT'"),
   1083 	   nbfd, nsec, nval, name);
   1084   else
   1085     einfo (_("%X%P: %C: multiple definition of `%pT'"),
   1086 	   nbfd, nsec, nval, name);
   1087   if (obfd != NULL)
   1088     einfo (_("; %D: first defined here"), obfd, osec, oval);
   1089   einfo ("\n");
   1090 
   1091   if (RELAXATION_ENABLED_BY_USER)
   1092     {
   1093       einfo (_("%P: disabling relaxation; it will not work with multiple definitions\n"));
   1094       DISABLE_RELAXATION;
   1095     }
   1096 }
   1097 
   1098 /* This is called when there is a definition of a common symbol, or
   1099    when a common symbol is found for a symbol that is already defined,
   1100    or when two common symbols are found.  We only do something if
   1101    -warn-common was used.  */
   1102 
   1103 static void
   1104 multiple_common (struct bfd_link_info *info ATTRIBUTE_UNUSED,
   1105 		 struct bfd_link_hash_entry *h,
   1106 		 bfd *nbfd,
   1107 		 enum bfd_link_hash_type ntype,
   1108 		 bfd_vma nsize)
   1109 {
   1110   const char *name;
   1111   bfd *obfd;
   1112   enum bfd_link_hash_type otype;
   1113   bfd_vma osize;
   1114 
   1115   if (!config.warn_common)
   1116     return;
   1117 
   1118   name = h->root.string;
   1119   otype = h->type;
   1120   if (otype == bfd_link_hash_common)
   1121     {
   1122       obfd = h->u.c.p->section->owner;
   1123       osize = h->u.c.size;
   1124     }
   1125   else if (otype == bfd_link_hash_defined
   1126 	   || otype == bfd_link_hash_defweak)
   1127     {
   1128       obfd = h->u.def.section->owner;
   1129       osize = 0;
   1130     }
   1131   else
   1132     {
   1133       /* FIXME: It would nice if we could report the BFD which defined
   1134 	 an indirect symbol, but we don't have anywhere to store the
   1135 	 information.  */
   1136       obfd = NULL;
   1137       osize = 0;
   1138     }
   1139 
   1140   if (ntype == bfd_link_hash_defined
   1141       || ntype == bfd_link_hash_defweak
   1142       || ntype == bfd_link_hash_indirect)
   1143     {
   1144       ASSERT (otype == bfd_link_hash_common);
   1145       if (obfd != NULL)
   1146 	einfo (_("%P: %pB: warning: definition of `%pT' overriding common"
   1147 		 " from %pB\n"),
   1148 	       nbfd, name, obfd);
   1149       else
   1150 	einfo (_("%P: %pB: warning: definition of `%pT' overriding common\n"),
   1151 	       nbfd, name);
   1152     }
   1153   else if (otype == bfd_link_hash_defined
   1154 	   || otype == bfd_link_hash_defweak
   1155 	   || otype == bfd_link_hash_indirect)
   1156     {
   1157       ASSERT (ntype == bfd_link_hash_common);
   1158       if (obfd != NULL)
   1159 	einfo (_("%P: %pB: warning: common of `%pT' overridden by definition"
   1160 		 " from %pB\n"),
   1161 	       nbfd, name, obfd);
   1162       else
   1163 	einfo (_("%P: %pB: warning: common of `%pT' overridden by definition\n"),
   1164 	       nbfd, name);
   1165     }
   1166   else
   1167     {
   1168       ASSERT (otype == bfd_link_hash_common && ntype == bfd_link_hash_common);
   1169       if (osize > nsize)
   1170 	{
   1171 	  if (obfd != NULL)
   1172 	    einfo (_("%P: %pB: warning: common of `%pT' overridden"
   1173 		     " by larger common from %pB\n"),
   1174 		   nbfd, name, obfd);
   1175 	  else
   1176 	    einfo (_("%P: %pB: warning: common of `%pT' overridden"
   1177 		     " by larger common\n"),
   1178 		   nbfd, name);
   1179 	}
   1180       else if (nsize > osize)
   1181 	{
   1182 	  if (obfd != NULL)
   1183 	    einfo (_("%P: %pB: warning: common of `%pT' overriding"
   1184 		     " smaller common from %pB\n"),
   1185 		   nbfd, name, obfd);
   1186 	  else
   1187 	    einfo (_("%P: %pB: warning: common of `%pT' overriding"
   1188 		     " smaller common\n"),
   1189 		   nbfd, name);
   1190 	}
   1191       else
   1192 	{
   1193 	  if (obfd != NULL)
   1194 	    einfo (_("%P: %pB and %pB: warning: multiple common of `%pT'\n"),
   1195 		   nbfd, obfd, name);
   1196 	  else
   1197 	    einfo (_("%P: %pB: warning: multiple common of `%pT'\n"),
   1198 		   nbfd, name);
   1199 	}
   1200     }
   1201 }
   1202 
   1203 /* This is called when BFD has discovered a set element.  H is the
   1204    entry in the linker hash table for the set.  SECTION and VALUE
   1205    represent a value which should be added to the set.  */
   1206 
   1207 static void
   1208 add_to_set (struct bfd_link_info *info ATTRIBUTE_UNUSED,
   1209 	    struct bfd_link_hash_entry *h,
   1210 	    bfd_reloc_code_real_type reloc,
   1211 	    bfd *abfd,
   1212 	    asection *section,
   1213 	    bfd_vma value)
   1214 {
   1215   if (config.warn_constructors)
   1216     einfo (_("%P: warning: global constructor %s used\n"),
   1217 	   h->root.string);
   1218 
   1219   if (!config.build_constructors)
   1220     return;
   1221 
   1222   ldctor_add_set_entry (h, reloc, NULL, section, value);
   1223 
   1224   if (h->type == bfd_link_hash_new)
   1225     {
   1226       h->type = bfd_link_hash_undefined;
   1227       h->u.undef.abfd = abfd;
   1228       /* We don't call bfd_link_add_undef to add this to the list of
   1229 	 undefined symbols because we are going to define it
   1230 	 ourselves.  */
   1231     }
   1232 }
   1233 
   1234 /* This is called when BFD has discovered a constructor.  This is only
   1235    called for some object file formats--those which do not handle
   1236    constructors in some more clever fashion.  This is similar to
   1237    adding an element to a set, but less general.  */
   1238 
   1239 static void
   1240 constructor_callback (struct bfd_link_info *info,
   1241 		      bool constructor,
   1242 		      const char *name,
   1243 		      bfd *abfd,
   1244 		      asection *section,
   1245 		      bfd_vma value)
   1246 {
   1247   char *s;
   1248   struct bfd_link_hash_entry *h;
   1249   char set_name[1 + sizeof "__CTOR_LIST__"];
   1250 
   1251   if (config.warn_constructors)
   1252     einfo (_("%P: warning: global constructor %s used\n"), name);
   1253 
   1254   if (!config.build_constructors)
   1255     return;
   1256 
   1257   /* Ensure that BFD_RELOC_CTOR exists now, so that we can give a
   1258      useful error message.  */
   1259   if (bfd_reloc_type_lookup (info->output_bfd, BFD_RELOC_CTOR) == NULL
   1260       && (bfd_link_relocatable (info)
   1261 	  || bfd_reloc_type_lookup (abfd, BFD_RELOC_CTOR) == NULL))
   1262     einfo (_("%F%P: BFD backend error: BFD_RELOC_CTOR unsupported\n"));
   1263 
   1264   s = set_name;
   1265   if (bfd_get_symbol_leading_char (abfd) != '\0')
   1266     *s++ = bfd_get_symbol_leading_char (abfd);
   1267   if (constructor)
   1268     strcpy (s, "__CTOR_LIST__");
   1269   else
   1270     strcpy (s, "__DTOR_LIST__");
   1271 
   1272   h = bfd_link_hash_lookup (info->hash, set_name, true, true, true);
   1273   if (h == (struct bfd_link_hash_entry *) NULL)
   1274     einfo (_("%F%P: bfd_link_hash_lookup failed: %E\n"));
   1275   if (h->type == bfd_link_hash_new)
   1276     {
   1277       h->type = bfd_link_hash_undefined;
   1278       h->u.undef.abfd = abfd;
   1279       /* We don't call bfd_link_add_undef to add this to the list of
   1280 	 undefined symbols because we are going to define it
   1281 	 ourselves.  */
   1282     }
   1283 
   1284   ldctor_add_set_entry (h, BFD_RELOC_CTOR, name, section, value);
   1285 }
   1286 
   1287 /* A structure used by warning_callback to pass information through
   1288    bfd_map_over_sections.  */
   1289 
   1290 struct warning_callback_info
   1291 {
   1292   bool found;
   1293   const char *warning;
   1294   const char *symbol;
   1295   asymbol **asymbols;
   1296 };
   1297 
   1298 /* Look through the relocs to see if we can find a plausible address
   1299    for SYMBOL in ABFD.  Return TRUE if found.  Otherwise return FALSE.  */
   1300 
   1301 static bool
   1302 symbol_warning (const char *warning, const char *symbol, bfd *abfd)
   1303 {
   1304   struct warning_callback_info cinfo;
   1305 
   1306   if (!bfd_generic_link_read_symbols (abfd))
   1307     einfo (_("%F%P: %pB: could not read symbols: %E\n"), abfd);
   1308 
   1309   cinfo.found = false;
   1310   cinfo.warning = warning;
   1311   cinfo.symbol = symbol;
   1312   cinfo.asymbols = bfd_get_outsymbols (abfd);
   1313   bfd_map_over_sections (abfd, warning_find_reloc, &cinfo);
   1314   return cinfo.found;
   1315 }
   1316 
   1317 /* This is called when there is a reference to a warning symbol.  */
   1318 
   1319 static void
   1320 warning_callback (struct bfd_link_info *info ATTRIBUTE_UNUSED,
   1321 		  const char *warning,
   1322 		  const char *symbol,
   1323 		  bfd *abfd,
   1324 		  asection *section,
   1325 		  bfd_vma address)
   1326 {
   1327   /* This is a hack to support warn_multiple_gp.  FIXME: This should
   1328      have a cleaner interface, but what?  */
   1329   if (!config.warn_multiple_gp
   1330       && strcmp (warning, "using multiple gp values") == 0)
   1331     return;
   1332 
   1333   if (section != NULL)
   1334     einfo ("%P: %C: %s%s\n", abfd, section, address, _("warning: "), warning);
   1335   else if (abfd == NULL)
   1336     einfo ("%P: %s%s\n", _("warning: "), warning);
   1337   else if (symbol == NULL)
   1338     einfo ("%P: %pB: %s%s\n", abfd, _("warning: "), warning);
   1339   else if (!symbol_warning (warning, symbol, abfd))
   1340     {
   1341       bfd *b;
   1342       /* Search all input files for a reference to SYMBOL.  */
   1343       for (b = info->input_bfds; b; b = b->link.next)
   1344 	if (b != abfd && symbol_warning (warning, symbol, b))
   1345 	  return;
   1346       einfo ("%P: %pB: %s%s\n", abfd, _("warning: "), warning);
   1347     }
   1348 }
   1349 
   1350 /* This is called by warning_callback for each section.  It checks the
   1351    relocs of the section to see if it can find a reference to the
   1352    symbol which triggered the warning.  If it can, it uses the reloc
   1353    to give an error message with a file and line number.  */
   1354 
   1355 static void
   1356 warning_find_reloc (bfd *abfd, asection *sec, void *iarg)
   1357 {
   1358   struct warning_callback_info *info = (struct warning_callback_info *) iarg;
   1359   long relsize;
   1360   arelent **relpp;
   1361   long relcount;
   1362   arelent **p, **pend;
   1363 
   1364   if (info->found)
   1365     return;
   1366 
   1367   relsize = bfd_get_reloc_upper_bound (abfd, sec);
   1368   if (relsize < 0)
   1369     einfo (_("%F%P: %pB: could not read relocs: %E\n"), abfd);
   1370   if (relsize == 0)
   1371     return;
   1372 
   1373   relpp = (arelent **) xmalloc (relsize);
   1374   relcount = bfd_canonicalize_reloc (abfd, sec, relpp, info->asymbols);
   1375   if (relcount < 0)
   1376     einfo (_("%F%P: %pB: could not read relocs: %E\n"), abfd);
   1377 
   1378   p = relpp;
   1379   pend = p + relcount;
   1380   for (; p < pend && *p != NULL; p++)
   1381     {
   1382       arelent *q = *p;
   1383 
   1384       if (q->sym_ptr_ptr != NULL
   1385 	  && *q->sym_ptr_ptr != NULL
   1386 	  && strcmp (bfd_asymbol_name (*q->sym_ptr_ptr), info->symbol) == 0)
   1387 	{
   1388 	  /* We found a reloc for the symbol we are looking for.  */
   1389 	  einfo ("%P: %C: %s%s\n", abfd, sec, q->address, _("warning: "),
   1390 		 info->warning);
   1391 	  info->found = true;
   1392 	  break;
   1393 	}
   1394     }
   1395 
   1396   free (relpp);
   1397 }
   1398 
   1399 #if SUPPORT_ERROR_HANDLING_SCRIPT
   1400 char * error_handling_script = NULL;
   1401 #endif
   1402 
   1403 /* This is called when an undefined symbol is found.  */
   1404 
   1405 static void
   1406 undefined_symbol (struct bfd_link_info *info,
   1407 		  const char *name,
   1408 		  bfd *abfd,
   1409 		  asection *section,
   1410 		  bfd_vma address,
   1411 		  bool error)
   1412 {
   1413   static char *error_name;
   1414   static unsigned int error_count;
   1415 
   1416 #define MAX_ERRORS_IN_A_ROW 5
   1417 
   1418   if (info->ignore_hash != NULL
   1419       && bfd_hash_lookup (info->ignore_hash, name, false, false) != NULL)
   1420     return;
   1421 
   1422   if (config.warn_once)
   1423     {
   1424       /* Only warn once about a particular undefined symbol.  */
   1425       add_ignoresym (info, name);
   1426     }
   1427 
   1428   /* We never print more than a reasonable number of errors in a row
   1429      for a single symbol.  */
   1430   if (error_name != NULL
   1431       && strcmp (name, error_name) == 0)
   1432     ++error_count;
   1433   else
   1434     {
   1435       error_count = 0;
   1436       free (error_name);
   1437       error_name = xstrdup (name);
   1438     }
   1439 
   1440 #if SUPPORT_ERROR_HANDLING_SCRIPT
   1441   if (error_handling_script != NULL
   1442       && error_count < MAX_ERRORS_IN_A_ROW)
   1443     {
   1444       char *        argv[4];
   1445       const char *  res;
   1446       int           status, err;
   1447 
   1448       argv[0] = error_handling_script;
   1449       argv[1] = "undefined-symbol";
   1450       argv[2] = (char *) name;
   1451       argv[3] = NULL;
   1452 
   1453       if (verbose)
   1454 	einfo (_("%P: About to run error handling script '%s' with arguments: '%s' '%s'\n"),
   1455 	       argv[0], argv[1], argv[2]);
   1456 
   1457       res = pex_one (PEX_SEARCH, error_handling_script, argv,
   1458 		     N_("error handling script"),
   1459 		     NULL /* Send stdout to random, temp file.  */,
   1460 		     NULL /* Write to stderr.  */,
   1461 		     &status, &err);
   1462       if (res != NULL)
   1463 	{
   1464 	  einfo (_("%P: Failed to run error handling script '%s', reason: "),
   1465 		 error_handling_script);
   1466 	  /* FIXME: We assume here that errrno == err.  */
   1467 	  perror (res);
   1468 	}
   1469       /* We ignore the return status of the script and
   1470 	 carry on to issue the normal error message.  */
   1471     }
   1472 #endif /* SUPPORT_ERROR_HANDLING_SCRIPT */
   1473 
   1474   if (section != NULL)
   1475     {
   1476       if (error_count < MAX_ERRORS_IN_A_ROW)
   1477 	{
   1478 	  if (error)
   1479 	    einfo (_("%X%P: %C: undefined reference to `%pT'\n"),
   1480 		   abfd, section, address, name);
   1481 	  else
   1482 	    einfo (_("%P: %C: warning: undefined reference to `%pT'\n"),
   1483 		   abfd, section, address, name);
   1484 	}
   1485       else if (error_count == MAX_ERRORS_IN_A_ROW)
   1486 	{
   1487 	  if (error)
   1488 	    einfo (_("%X%P: %D: more undefined references to `%pT' follow\n"),
   1489 		   abfd, section, address, name);
   1490 	  else
   1491 	    einfo (_("%P: %D: warning: more undefined references to `%pT' follow\n"),
   1492 		   abfd, section, address, name);
   1493 	}
   1494       else if (error)
   1495 	einfo ("%X");
   1496     }
   1497   else
   1498     {
   1499       if (error_count < MAX_ERRORS_IN_A_ROW)
   1500 	{
   1501 	  if (error)
   1502 	    einfo (_("%X%P: %pB: undefined reference to `%pT'\n"),
   1503 		   abfd, name);
   1504 	  else
   1505 	    einfo (_("%P: %pB: warning: undefined reference to `%pT'\n"),
   1506 		   abfd, name);
   1507 	}
   1508       else if (error_count == MAX_ERRORS_IN_A_ROW)
   1509 	{
   1510 	  if (error)
   1511 	    einfo (_("%X%P: %pB: more undefined references to `%pT' follow\n"),
   1512 		   abfd, name);
   1513 	  else
   1514 	    einfo (_("%P: %pB: warning: more undefined references to `%pT' follow\n"),
   1515 		   abfd, name);
   1516 	}
   1517       else if (error)
   1518 	einfo ("%X");
   1519     }
   1520 }
   1521 
   1522 /* Counter to limit the number of relocation overflow error messages
   1523    to print.  Errors are printed as it is decremented.  When it's
   1524    called and the counter is zero, a final message is printed
   1525    indicating more relocations were omitted.  When it gets to -1, no
   1526    such errors are printed.  If it's initially set to a value less
   1527    than -1, all such errors will be printed (--verbose does this).  */
   1528 
   1529 int overflow_cutoff_limit = 10;
   1530 
   1531 /* This is called when a reloc overflows.  */
   1532 
   1533 static void
   1534 reloc_overflow (struct bfd_link_info *info,
   1535 		struct bfd_link_hash_entry *entry,
   1536 		const char *name,
   1537 		const char *reloc_name,
   1538 		bfd_vma addend,
   1539 		bfd *abfd,
   1540 		asection *section,
   1541 		bfd_vma address)
   1542 {
   1543   if (overflow_cutoff_limit == -1)
   1544     return;
   1545 
   1546   einfo ("%X%H:", abfd, section, address);
   1547 
   1548   if (overflow_cutoff_limit >= 0
   1549       && overflow_cutoff_limit-- == 0)
   1550     {
   1551       einfo (_(" additional relocation overflows omitted from the output\n"));
   1552       return;
   1553     }
   1554 
   1555   if (entry)
   1556     {
   1557       while (entry->type == bfd_link_hash_indirect
   1558 	     || entry->type == bfd_link_hash_warning)
   1559 	entry = entry->u.i.link;
   1560       switch (entry->type)
   1561 	{
   1562 	case bfd_link_hash_undefined:
   1563 	case bfd_link_hash_undefweak:
   1564 	  einfo (_(" relocation truncated to fit: "
   1565 		   "%s against undefined symbol `%pT'"),
   1566 		 reloc_name, entry->root.string);
   1567 	  break;
   1568 	case bfd_link_hash_defined:
   1569 	case bfd_link_hash_defweak:
   1570 	  einfo (_(" relocation truncated to fit: "
   1571 		   "%s against symbol `%pT' defined in %pA section in %pB"),
   1572 		 reloc_name, entry->root.string,
   1573 		 entry->u.def.section,
   1574 		 entry->u.def.section == bfd_abs_section_ptr
   1575 		 ? info->output_bfd : entry->u.def.section->owner);
   1576 	  break;
   1577 	default:
   1578 	  abort ();
   1579 	  break;
   1580 	}
   1581     }
   1582   else
   1583     einfo (_(" relocation truncated to fit: %s against `%pT'"),
   1584 	   reloc_name, name);
   1585   if (addend != 0)
   1586     einfo ("+%v", addend);
   1587   einfo ("\n");
   1588 }
   1589 
   1590 /* This is called when a dangerous relocation is made.  */
   1591 
   1592 static void
   1593 reloc_dangerous (struct bfd_link_info *info ATTRIBUTE_UNUSED,
   1594 		 const char *message,
   1595 		 bfd *abfd,
   1596 		 asection *section,
   1597 		 bfd_vma address)
   1598 {
   1599   einfo (_("%X%H: dangerous relocation: %s\n"),
   1600 	 abfd, section, address, message);
   1601 }
   1602 
   1603 /* This is called when a reloc is being generated attached to a symbol
   1604    that is not being output.  */
   1605 
   1606 static void
   1607 unattached_reloc (struct bfd_link_info *info ATTRIBUTE_UNUSED,
   1608 		  const char *name,
   1609 		  bfd *abfd,
   1610 		  asection *section,
   1611 		  bfd_vma address)
   1612 {
   1613   einfo (_("%X%H: reloc refers to symbol `%pT' which is not being output\n"),
   1614 	 abfd, section, address, name);
   1615 }
   1616 
   1617 /* This is called if link_info.notice_all is set, or when a symbol in
   1618    link_info.notice_hash is found.  Symbols are put in notice_hash
   1619    using the -y option, while notice_all is set if the --cref option
   1620    has been supplied, or if there are any NOCROSSREFS sections in the
   1621    linker script; and if plugins are active, since they need to monitor
   1622    all references from non-IR files.  */
   1623 
   1624 static bool
   1625 notice (struct bfd_link_info *info,
   1626 	struct bfd_link_hash_entry *h,
   1627 	struct bfd_link_hash_entry *inh ATTRIBUTE_UNUSED,
   1628 	bfd *abfd,
   1629 	asection *section,
   1630 	bfd_vma value,
   1631 	flagword flags ATTRIBUTE_UNUSED)
   1632 {
   1633   const char *name;
   1634 
   1635   if (h == NULL)
   1636     {
   1637       if (command_line.cref || nocrossref_list != NULL)
   1638 	return handle_asneeded_cref (abfd, (enum notice_asneeded_action) value);
   1639       return true;
   1640     }
   1641 
   1642   name = h->root.string;
   1643   if (info->notice_hash != NULL
   1644       && bfd_hash_lookup (info->notice_hash, name, false, false) != NULL)
   1645     {
   1646       if (bfd_is_und_section (section))
   1647 	einfo (_("%P: %pB: reference to %s\n"), abfd, name);
   1648       else
   1649 	einfo (_("%P: %pB: definition of %s\n"), abfd, name);
   1650     }
   1651 
   1652   if (command_line.cref || nocrossref_list != NULL)
   1653     add_cref (name, abfd, section, value);
   1654 
   1655   return true;
   1656 }
   1657