xref: /netbsd/external/gpl3/binutils/dist/ld/ldmain.c (revision 6550d01e)
1 /* Main program of GNU linker.
2    Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
3    2002, 2003, 2004, 2005, 2006, 2007, 2008
4    Free Software Foundation, Inc.
5    Written by Steve Chamberlain steve@cygnus.com
6 
7    This file is part of the GNU Binutils.
8 
9    This program is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 3 of the License, or
12    (at your option) any later version.
13 
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18 
19    You should have received a copy of the GNU General Public License
20    along with this program; if not, write to the Free Software
21    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22    MA 02110-1301, USA.  */
23 
24 #include "sysdep.h"
25 #include "bfd.h"
26 #include "safe-ctype.h"
27 #include "libiberty.h"
28 #include "progress.h"
29 #include "bfdlink.h"
30 #include "filenames.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 
44 /* Somewhere above, sys/stat.h got included.  */
45 #if !defined(S_ISDIR) && defined(S_IFDIR)
46 #define	S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
47 #endif
48 
49 #include <string.h>
50 
51 #ifdef HAVE_SBRK
52 #if !HAVE_DECL_SBRK
53 extern void *sbrk ();
54 #endif
55 #endif
56 
57 #ifndef TARGET_SYSTEM_ROOT
58 #define TARGET_SYSTEM_ROOT ""
59 #endif
60 
61 /* EXPORTS */
62 
63 FILE *saved_script_handle = NULL;
64 FILE *previous_script_handle = NULL;
65 bfd_boolean force_make_executable = FALSE;
66 
67 char *default_target;
68 const char *output_filename = "a.out";
69 
70 /* Name this program was invoked by.  */
71 char *program_name;
72 
73 /* The prefix for system library directories.  */
74 const char *ld_sysroot;
75 
76 /* The canonical representation of ld_sysroot.  */
77 char * ld_canon_sysroot;
78 int ld_canon_sysroot_len;
79 
80 /* Set by -G argument, for MIPS ECOFF target.  */
81 int g_switch_value = 8;
82 
83 /* Nonzero means print names of input files as processed.  */
84 bfd_boolean trace_files;
85 
86 /* Nonzero means same, but note open failures, too.  */
87 bfd_boolean trace_file_tries;
88 
89 /* Nonzero means version number was printed, so exit successfully
90    instead of complaining if no input files are given.  */
91 bfd_boolean version_printed;
92 
93 /* Nonzero means link in every member of an archive.  */
94 bfd_boolean whole_archive;
95 
96 /* Nonzero means create DT_NEEDED entries only if a dynamic library
97    actually satisfies some reference in a regular object.  */
98 bfd_boolean as_needed;
99 
100 /* Nonzero means never create DT_NEEDED entries for dynamic libraries
101    in DT_NEEDED tags.  */
102 bfd_boolean add_needed = TRUE;
103 
104 /* TRUE if we should demangle symbol names.  */
105 bfd_boolean demangling;
106 
107 args_type command_line;
108 
109 ld_config_type config;
110 
111 sort_type sort_section;
112 
113 static const char *get_sysroot
114   (int, char **);
115 static char *get_emulation
116   (int, char **);
117 static bfd_boolean add_archive_element
118   (struct bfd_link_info *, bfd *, const char *);
119 static bfd_boolean multiple_definition
120   (struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma,
121    bfd *, asection *, bfd_vma);
122 static bfd_boolean multiple_common
123   (struct bfd_link_info *, const char *, bfd *, enum bfd_link_hash_type,
124    bfd_vma, bfd *, enum bfd_link_hash_type, bfd_vma);
125 static bfd_boolean add_to_set
126   (struct bfd_link_info *, struct bfd_link_hash_entry *,
127    bfd_reloc_code_real_type, bfd *, asection *, bfd_vma);
128 static bfd_boolean constructor_callback
129   (struct bfd_link_info *, bfd_boolean, const char *, bfd *,
130    asection *, bfd_vma);
131 static bfd_boolean warning_callback
132   (struct bfd_link_info *, const char *, const char *, bfd *,
133    asection *, bfd_vma);
134 static void warning_find_reloc
135   (bfd *, asection *, void *);
136 static bfd_boolean undefined_symbol
137   (struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma,
138    bfd_boolean);
139 static bfd_boolean reloc_overflow
140   (struct bfd_link_info *, struct bfd_link_hash_entry *, const char *,
141    const char *, bfd_vma, bfd *, asection *, bfd_vma);
142 static bfd_boolean reloc_dangerous
143   (struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma);
144 static bfd_boolean unattached_reloc
145   (struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma);
146 static bfd_boolean notice
147   (struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma);
148 
149 static struct bfd_link_callbacks link_callbacks =
150 {
151   add_archive_element,
152   multiple_definition,
153   multiple_common,
154   add_to_set,
155   constructor_callback,
156   warning_callback,
157   undefined_symbol,
158   reloc_overflow,
159   reloc_dangerous,
160   unattached_reloc,
161   notice,
162   einfo,
163   info_msg,
164   minfo,
165   ldlang_override_segment_assignment
166 };
167 
168 struct bfd_link_info link_info;
169 
170 static void
171 remove_output (void)
172 {
173   if (output_filename)
174     {
175       if (link_info.output_bfd)
176 	bfd_cache_close (link_info.output_bfd);
177       if (delete_output_file_on_failure)
178 	unlink_if_ordinary (output_filename);
179     }
180 }
181 
182 int
183 main (int argc, char **argv)
184 {
185   char *emulation;
186   long start_time = get_run_time ();
187 
188 #if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
189   setlocale (LC_MESSAGES, "");
190 #endif
191 #if defined (HAVE_SETLOCALE)
192   setlocale (LC_CTYPE, "");
193 #endif
194   bindtextdomain (PACKAGE, LOCALEDIR);
195   textdomain (PACKAGE);
196 
197   program_name = argv[0];
198   xmalloc_set_program_name (program_name);
199 
200   START_PROGRESS (program_name, 0);
201 
202   expandargv (&argc, &argv);
203 
204   bfd_init ();
205 
206   bfd_set_error_program_name (program_name);
207 
208   xatexit (remove_output);
209 
210   /* Set up the sysroot directory.  */
211   ld_sysroot = get_sysroot (argc, argv);
212   if (*ld_sysroot)
213     {
214       if (*TARGET_SYSTEM_ROOT == 0)
215 	{
216 	  einfo ("%P%F: this linker was not configured to use sysroots\n");
217 	  ld_sysroot = "";
218 	}
219       else
220 	ld_canon_sysroot = lrealpath (ld_sysroot);
221     }
222   if (ld_canon_sysroot)
223     ld_canon_sysroot_len = strlen (ld_canon_sysroot);
224   else
225     ld_canon_sysroot_len = -1;
226 
227   /* Set the default BFD target based on the configured target.  Doing
228      this permits the linker to be configured for a particular target,
229      and linked against a shared BFD library which was configured for
230      a different target.  The macro TARGET is defined by Makefile.  */
231   if (! bfd_set_default_target (TARGET))
232     {
233       einfo (_("%X%P: can't set BFD default target to `%s': %E\n"), TARGET);
234       xexit (1);
235     }
236 
237 #if YYDEBUG
238   {
239     extern int yydebug;
240     yydebug = 1;
241   }
242 #endif
243 
244   config.build_constructors = TRUE;
245   config.rpath_separator = ':';
246   config.split_by_reloc = (unsigned) -1;
247   config.split_by_file = (bfd_size_type) -1;
248   config.make_executable = TRUE;
249   config.magic_demand_paged = TRUE;
250   config.text_read_only = TRUE;
251 
252   command_line.warn_mismatch = TRUE;
253   command_line.warn_search_mismatch = TRUE;
254   command_line.check_section_addresses = TRUE;
255 
256   /* We initialize DEMANGLING based on the environment variable
257      COLLECT_NO_DEMANGLE.  The gcc collect2 program will demangle the
258      output of the linker, unless COLLECT_NO_DEMANGLE is set in the
259      environment.  Acting the same way here lets us provide the same
260      interface by default.  */
261   demangling = getenv ("COLLECT_NO_DEMANGLE") == NULL;
262 
263   link_info.allow_undefined_version = TRUE;
264   link_info.keep_memory = TRUE;
265   link_info.combreloc = TRUE;
266   link_info.strip_discarded = TRUE;
267   link_info.emit_hash = TRUE;
268   link_info.callbacks = &link_callbacks;
269   link_info.input_bfds_tail = &link_info.input_bfds;
270   /* SVR4 linkers seem to set DT_INIT and DT_FINI based on magic _init
271      and _fini symbols.  We are compatible.  */
272   link_info.init_function = "_init";
273   link_info.fini_function = "_fini";
274   link_info.relax_pass = 1;
275   link_info.pei386_auto_import = -1;
276   link_info.spare_dynamic_tags = 5;
277   link_info.path_separator = ':';
278 
279   ldfile_add_arch ("");
280   emulation = get_emulation (argc, argv);
281   ldemul_choose_mode (emulation);
282   default_target = ldemul_choose_target (argc, argv);
283   lang_init ();
284   ldemul_before_parse ();
285   lang_has_input_file = FALSE;
286   parse_args (argc, argv);
287 
288   if (config.hash_table_size != 0)
289     bfd_hash_set_default_size (config.hash_table_size);
290 
291   ldemul_set_symbols ();
292 
293   if (link_info.relocatable)
294     {
295       if (command_line.relax)
296 	einfo (_("%P%F: --relax and -r may not be used together\n"));
297       if (link_info.shared)
298 	einfo (_("%P%F: -r and -shared may not be used together\n"));
299     }
300 
301   /* We may have -Bsymbolic, -Bsymbolic-functions, --dynamic-list-data,
302      --dynamic-list-cpp-new, --dynamic-list-cpp-typeinfo and
303      --dynamic-list FILE.  -Bsymbolic and -Bsymbolic-functions are
304      for shared libraries.  -Bsymbolic overrides all others and vice
305      versa.  */
306   switch (command_line.symbolic)
307     {
308     case symbolic_unset:
309       break;
310     case symbolic:
311       /* -Bsymbolic is for shared library only.  */
312       if (link_info.shared)
313 	{
314 	  link_info.symbolic = TRUE;
315 	  /* Should we free the unused memory?  */
316 	  link_info.dynamic_list = NULL;
317 	  command_line.dynamic_list = dynamic_list_unset;
318 	}
319       break;
320     case symbolic_functions:
321       /* -Bsymbolic-functions is for shared library only.  */
322       if (link_info.shared)
323 	command_line.dynamic_list = dynamic_list_data;
324       break;
325     }
326 
327   switch (command_line.dynamic_list)
328     {
329     case dynamic_list_unset:
330       break;
331     case dynamic_list_data:
332       link_info.dynamic_data = TRUE;
333     case dynamic_list:
334       link_info.dynamic = TRUE;
335       break;
336     }
337 
338   if (! link_info.shared)
339     {
340       if (command_line.filter_shlib)
341 	einfo (_("%P%F: -F may not be used without -shared\n"));
342       if (command_line.auxiliary_filters)
343 	einfo (_("%P%F: -f may not be used without -shared\n"));
344     }
345 
346   if (! link_info.shared || link_info.pie)
347     link_info.executable = TRUE;
348 
349   /* Treat ld -r -s as ld -r -S -x (i.e., strip all local symbols).  I
350      don't see how else this can be handled, since in this case we
351      must preserve all externally visible symbols.  */
352   if (link_info.relocatable && link_info.strip == strip_all)
353     {
354       link_info.strip = strip_debugger;
355       if (link_info.discard == discard_sec_merge)
356 	link_info.discard = discard_all;
357     }
358 
359   /* If we have not already opened and parsed a linker script,
360      try the default script from command line first.  */
361   if (saved_script_handle == NULL
362       && command_line.default_script != NULL)
363     {
364       ldfile_open_command_file (command_line.default_script);
365       parser_input = input_script;
366       yyparse ();
367     }
368 
369   /* If we have not already opened and parsed a linker script
370      read the emulation's appropriate default script.  */
371   if (saved_script_handle == NULL)
372     {
373       int isfile;
374       char *s = ldemul_get_script (&isfile);
375 
376       if (isfile)
377 	ldfile_open_command_file (s);
378       else
379 	{
380 	  lex_string = s;
381 	  lex_redirect (s);
382 	}
383       parser_input = input_script;
384       yyparse ();
385       lex_string = NULL;
386     }
387 
388   if (trace_file_tries)
389     {
390       if (saved_script_handle)
391 	info_msg (_("using external linker script:"));
392       else
393 	info_msg (_("using internal linker script:"));
394       info_msg ("\n==================================================\n");
395 
396       if (saved_script_handle)
397 	{
398 	  static const int ld_bufsz = 8193;
399 	  size_t n;
400 	  char *buf = xmalloc (ld_bufsz);
401 
402 	  rewind (saved_script_handle);
403 	  while ((n = fread (buf, 1, ld_bufsz - 1, saved_script_handle)) > 0)
404 	    {
405 	      buf[n] = 0;
406 	      info_msg (buf);
407 	    }
408 	  rewind (saved_script_handle);
409 	  free (buf);
410 	}
411       else
412 	{
413 	  int isfile;
414 
415 	  info_msg (ldemul_get_script (&isfile));
416 	}
417 
418       info_msg ("\n==================================================\n");
419     }
420 
421   lang_final ();
422 
423   if (!lang_has_input_file)
424     {
425       if (version_printed)
426 	xexit (0);
427       einfo (_("%P%F: no input files\n"));
428     }
429 
430   if (trace_files)
431     info_msg (_("%P: mode %s\n"), emulation);
432 
433   ldemul_after_parse ();
434 
435   if (config.map_filename)
436     {
437       if (strcmp (config.map_filename, "-") == 0)
438 	{
439 	  config.map_file = stdout;
440 	}
441       else
442 	{
443 	  config.map_file = fopen (config.map_filename, FOPEN_WT);
444 	  if (config.map_file == (FILE *) NULL)
445 	    {
446 	      bfd_set_error (bfd_error_system_call);
447 	      einfo (_("%P%F: cannot open map file %s: %E\n"),
448 		     config.map_filename);
449 	    }
450 	}
451     }
452 
453   lang_process ();
454 
455   /* Print error messages for any missing symbols, for any warning
456      symbols, and possibly multiple definitions.  */
457   if (link_info.relocatable)
458     link_info.output_bfd->flags &= ~EXEC_P;
459   else
460     link_info.output_bfd->flags |= EXEC_P;
461 
462   ldwrite ();
463 
464   if (config.map_file != NULL)
465     lang_map ();
466   if (command_line.cref)
467     output_cref (config.map_file != NULL ? config.map_file : stdout);
468   if (nocrossref_list != NULL)
469     check_nocrossrefs ();
470 
471   lang_finish ();
472 
473   /* Even if we're producing relocatable output, some non-fatal errors should
474      be reported in the exit status.  (What non-fatal errors, if any, do we
475      want to ignore for relocatable output?)  */
476   if (!config.make_executable && !force_make_executable)
477     {
478       if (trace_files)
479 	einfo (_("%P: link errors found, deleting executable `%s'\n"),
480 	       output_filename);
481 
482       /* The file will be removed by remove_output.  */
483       xexit (1);
484     }
485   else
486     {
487       if (! bfd_close (link_info.output_bfd))
488 	einfo (_("%F%B: final close failed: %E\n"), link_info.output_bfd);
489 
490       /* If the --force-exe-suffix is enabled, and we're making an
491 	 executable file and it doesn't end in .exe, copy it to one
492 	 which does.  */
493       if (! link_info.relocatable && command_line.force_exe_suffix)
494 	{
495 	  int len = strlen (output_filename);
496 
497 	  if (len < 4
498 	      || (strcasecmp (output_filename + len - 4, ".exe") != 0
499 		  && strcasecmp (output_filename + len - 4, ".dll") != 0))
500 	    {
501 	      FILE *src;
502 	      FILE *dst;
503 	      const int bsize = 4096;
504 	      char *buf = xmalloc (bsize);
505 	      int l;
506 	      char *dst_name = xmalloc (len + 5);
507 
508 	      strcpy (dst_name, output_filename);
509 	      strcat (dst_name, ".exe");
510 	      src = fopen (output_filename, FOPEN_RB);
511 	      dst = fopen (dst_name, FOPEN_WB);
512 
513 	      if (!src)
514 		einfo (_("%X%P: unable to open for source of copy `%s'\n"),
515 		       output_filename);
516 	      if (!dst)
517 		einfo (_("%X%P: unable to open for destination of copy `%s'\n"),
518 		       dst_name);
519 	      while ((l = fread (buf, 1, bsize, src)) > 0)
520 		{
521 		  int done = fwrite (buf, 1, l, dst);
522 
523 		  if (done != l)
524 		    einfo (_("%P: Error writing file `%s'\n"), dst_name);
525 		}
526 
527 	      fclose (src);
528 	      if (fclose (dst) == EOF)
529 		einfo (_("%P: Error closing file `%s'\n"), dst_name);
530 	      free (dst_name);
531 	      free (buf);
532 	    }
533 	}
534     }
535 
536   END_PROGRESS (program_name);
537 
538   if (config.stats)
539     {
540 #ifdef HAVE_SBRK
541       char *lim = sbrk (0);
542 #endif
543       long run_time = get_run_time () - start_time;
544 
545       fprintf (stderr, _("%s: total time in link: %ld.%06ld\n"),
546 	       program_name, run_time / 1000000, run_time % 1000000);
547 #ifdef HAVE_SBRK
548       fprintf (stderr, _("%s: data size %ld\n"), program_name,
549 	       (long) (lim - (char *) &environ));
550 #endif
551     }
552 
553   /* Prevent remove_output from doing anything, after a successful link.  */
554   output_filename = NULL;
555 
556   xexit (0);
557   return 0;
558 }
559 
560 /* If the configured sysroot is relocatable, try relocating it based on
561    default prefix FROM.  Return the relocated directory if it exists,
562    otherwise return null.  */
563 
564 static char *
565 get_relative_sysroot (const char *from ATTRIBUTE_UNUSED)
566 {
567 #ifdef TARGET_SYSTEM_ROOT_RELOCATABLE
568   char *path;
569   struct stat s;
570 
571   path = make_relative_prefix (program_name, from, TARGET_SYSTEM_ROOT);
572   if (path)
573     {
574       if (stat (path, &s) == 0 && S_ISDIR (s.st_mode))
575 	return path;
576       free (path);
577     }
578 #endif
579   return 0;
580 }
581 
582 /* Return the sysroot directory.  Return "" if no sysroot is being used.  */
583 
584 static const char *
585 get_sysroot (int argc, char **argv)
586 {
587   int i;
588   const char *path;
589 
590   for (i = 1; i < argc; i++)
591     if (CONST_STRNEQ (argv[i], "--sysroot="))
592       return argv[i] + strlen ("--sysroot=");
593 
594   path = get_relative_sysroot (BINDIR);
595   if (path)
596     return path;
597 
598   path = get_relative_sysroot (TOOLBINDIR);
599   if (path)
600     return path;
601 
602   return TARGET_SYSTEM_ROOT;
603 }
604 
605 /* We need to find any explicitly given emulation in order to initialize the
606    state that's needed by the lex&yacc argument parser (parse_args).  */
607 
608 static char *
609 get_emulation (int argc, char **argv)
610 {
611   char *emulation;
612   int i;
613 
614   emulation = getenv (EMULATION_ENVIRON);
615   if (emulation == NULL)
616     emulation = DEFAULT_EMULATION;
617 
618   for (i = 1; i < argc; i++)
619     {
620       if (CONST_STRNEQ (argv[i], "-m"))
621 	{
622 	  if (argv[i][2] == '\0')
623 	    {
624 	      /* -m EMUL */
625 	      if (i < argc - 1)
626 		{
627 		  emulation = argv[i + 1];
628 		  i++;
629 		}
630 	      else
631 		einfo (_("%P%F: missing argument to -m\n"));
632 	    }
633 	  else if (strcmp (argv[i], "-mips1") == 0
634 		   || strcmp (argv[i], "-mips2") == 0
635 		   || strcmp (argv[i], "-mips3") == 0
636 		   || strcmp (argv[i], "-mips4") == 0
637 		   || strcmp (argv[i], "-mips5") == 0
638 		   || strcmp (argv[i], "-mips32") == 0
639 		   || strcmp (argv[i], "-mips32r2") == 0
640 		   || strcmp (argv[i], "-mips64") == 0
641 		   || strcmp (argv[i], "-mips64r2") == 0)
642 	    {
643 	      /* FIXME: The arguments -mips1, -mips2, -mips3, etc. are
644 		 passed to the linker by some MIPS compilers.  They
645 		 generally tell the linker to use a slightly different
646 		 library path.  Perhaps someday these should be
647 		 implemented as emulations; until then, we just ignore
648 		 the arguments and hope that nobody ever creates
649 		 emulations named ips1, ips2 or ips3.  */
650 	    }
651 	  else if (strcmp (argv[i], "-m486") == 0)
652 	    {
653 	      /* FIXME: The argument -m486 is passed to the linker on
654 		 some Linux systems.  Hope that nobody creates an
655 		 emulation named 486.  */
656 	    }
657 	  else
658 	    {
659 	      /* -mEMUL */
660 	      emulation = &argv[i][2];
661 	    }
662 	}
663     }
664 
665   return emulation;
666 }
667 
668 void
669 add_ysym (const char *name)
670 {
671   if (link_info.notice_hash == NULL)
672     {
673       link_info.notice_hash = xmalloc (sizeof (struct bfd_hash_table));
674       if (!bfd_hash_table_init_n (link_info.notice_hash,
675 				  bfd_hash_newfunc,
676 				  sizeof (struct bfd_hash_entry),
677 				  61))
678 	einfo (_("%P%F: bfd_hash_table_init failed: %E\n"));
679     }
680 
681   if (bfd_hash_lookup (link_info.notice_hash, name, TRUE, TRUE) == NULL)
682     einfo (_("%P%F: bfd_hash_lookup failed: %E\n"));
683 }
684 
685 void
686 add_ignoresym (const char *name)
687 {
688   if (link_info.ignore_hash == NULL)
689     {
690       link_info.ignore_hash = xmalloc (sizeof (struct bfd_hash_table));
691       if (! bfd_hash_table_init_n (link_info.ignore_hash,
692 				   bfd_hash_newfunc,
693 				   sizeof (struct bfd_hash_entry),
694 				   61))
695 	einfo (_("%P%F: bfd_hash_table_init failed: %E\n"));
696     }
697 
698   if (bfd_hash_lookup (link_info.ignore_hash, name, TRUE, TRUE) == NULL)
699     einfo (_("%P%F: bfd_hash_lookup failed: %E\n"));
700 }
701 
702 /* Record a symbol to be wrapped, from the --wrap option.  */
703 
704 void
705 add_wrap (const char *name)
706 {
707   if (link_info.wrap_hash == NULL)
708     {
709       link_info.wrap_hash = xmalloc (sizeof (struct bfd_hash_table));
710       if (!bfd_hash_table_init_n (link_info.wrap_hash,
711 				  bfd_hash_newfunc,
712 				  sizeof (struct bfd_hash_entry),
713 				  61))
714 	einfo (_("%P%F: bfd_hash_table_init failed: %E\n"));
715     }
716 
717   if (bfd_hash_lookup (link_info.wrap_hash, name, TRUE, TRUE) == NULL)
718     einfo (_("%P%F: bfd_hash_lookup failed: %E\n"));
719 }
720 
721 /* Handle the -retain-symbols-file option.  */
722 
723 void
724 add_keepsyms_file (const char *filename)
725 {
726   FILE *file;
727   char *buf;
728   size_t bufsize;
729   int c;
730 
731   if (link_info.strip == strip_some)
732     einfo (_("%X%P: error: duplicate retain-symbols-file\n"));
733 
734   file = fopen (filename, "r");
735   if (file == NULL)
736     {
737       bfd_set_error (bfd_error_system_call);
738       einfo ("%X%P: %s: %E\n", filename);
739       return;
740     }
741 
742   link_info.keep_hash = xmalloc (sizeof (struct bfd_hash_table));
743   if (!bfd_hash_table_init (link_info.keep_hash, bfd_hash_newfunc,
744 			    sizeof (struct bfd_hash_entry)))
745     einfo (_("%P%F: bfd_hash_table_init failed: %E\n"));
746 
747   bufsize = 100;
748   buf = xmalloc (bufsize);
749 
750   c = getc (file);
751   while (c != EOF)
752     {
753       while (ISSPACE (c))
754 	c = getc (file);
755 
756       if (c != EOF)
757 	{
758 	  size_t len = 0;
759 
760 	  while (! ISSPACE (c) && c != EOF)
761 	    {
762 	      buf[len] = c;
763 	      ++len;
764 	      if (len >= bufsize)
765 		{
766 		  bufsize *= 2;
767 		  buf = xrealloc (buf, bufsize);
768 		}
769 	      c = getc (file);
770 	    }
771 
772 	  buf[len] = '\0';
773 
774 	  if (bfd_hash_lookup (link_info.keep_hash, buf, TRUE, TRUE) == NULL)
775 	    einfo (_("%P%F: bfd_hash_lookup for insertion failed: %E\n"));
776 	}
777     }
778 
779   if (link_info.strip != strip_none)
780     einfo (_("%P: `-retain-symbols-file' overrides `-s' and `-S'\n"));
781 
782   free (buf);
783   link_info.strip = strip_some;
784 }
785 
786 /* Callbacks from the BFD linker routines.  */
787 
788 /* This is called when BFD has decided to include an archive member in
789    a link.  */
790 
791 static bfd_boolean
792 add_archive_element (struct bfd_link_info *info,
793 		     bfd *abfd,
794 		     const char *name)
795 {
796   lang_input_statement_type *input;
797 
798   input = xcalloc (1, sizeof (lang_input_statement_type));
799   input->filename = abfd->filename;
800   input->local_sym_name = abfd->filename;
801   input->the_bfd = abfd;
802 
803   ldlang_add_file (input);
804 
805   if (config.map_file != NULL)
806     {
807       static bfd_boolean header_printed;
808       struct bfd_link_hash_entry *h;
809       bfd *from;
810       int len;
811 
812       h = bfd_link_hash_lookup (info->hash, name, FALSE, FALSE, TRUE);
813 
814       if (h == NULL)
815 	from = NULL;
816       else
817 	{
818 	  switch (h->type)
819 	    {
820 	    default:
821 	      from = NULL;
822 	      break;
823 
824 	    case bfd_link_hash_defined:
825 	    case bfd_link_hash_defweak:
826 	      from = h->u.def.section->owner;
827 	      break;
828 
829 	    case bfd_link_hash_undefined:
830 	    case bfd_link_hash_undefweak:
831 	      from = h->u.undef.abfd;
832 	      break;
833 
834 	    case bfd_link_hash_common:
835 	      from = h->u.c.p->section->owner;
836 	      break;
837 	    }
838 	}
839 
840       if (! header_printed)
841 	{
842 	  char buf[100];
843 
844 	  sprintf (buf, _("Archive member included because of file (symbol)\n\n"));
845 	  minfo ("%s", buf);
846 	  header_printed = TRUE;
847 	}
848 
849       if (bfd_my_archive (abfd) == NULL)
850 	{
851 	  minfo ("%s", bfd_get_filename (abfd));
852 	  len = strlen (bfd_get_filename (abfd));
853 	}
854       else
855 	{
856 	  minfo ("%s(%s)", bfd_get_filename (bfd_my_archive (abfd)),
857 		 bfd_get_filename (abfd));
858 	  len = (strlen (bfd_get_filename (bfd_my_archive (abfd)))
859 		 + strlen (bfd_get_filename (abfd))
860 		 + 2);
861 	}
862 
863       if (len >= 29)
864 	{
865 	  print_nl ();
866 	  len = 0;
867 	}
868       while (len < 30)
869 	{
870 	  print_space ();
871 	  ++len;
872 	}
873 
874       if (from != NULL)
875 	minfo ("%B ", from);
876       if (h != NULL)
877 	minfo ("(%T)\n", h->root.string);
878       else
879 	minfo ("(%s)\n", name);
880     }
881 
882   if (trace_files || trace_file_tries)
883     info_msg ("%I\n", input);
884 
885   return TRUE;
886 }
887 
888 /* This is called when BFD has discovered a symbol which is defined
889    multiple times.  */
890 
891 static bfd_boolean
892 multiple_definition (struct bfd_link_info *info ATTRIBUTE_UNUSED,
893 		     const char *name,
894 		     bfd *obfd,
895 		     asection *osec,
896 		     bfd_vma oval,
897 		     bfd *nbfd,
898 		     asection *nsec,
899 		     bfd_vma nval)
900 {
901   /* If either section has the output_section field set to
902      bfd_abs_section_ptr, it means that the section is being
903      discarded, and this is not really a multiple definition at all.
904      FIXME: It would be cleaner to somehow ignore symbols defined in
905      sections which are being discarded.  */
906   if ((osec->output_section != NULL
907        && ! bfd_is_abs_section (osec)
908        && bfd_is_abs_section (osec->output_section))
909       || (nsec->output_section != NULL
910 	  && ! bfd_is_abs_section (nsec)
911 	  && bfd_is_abs_section (nsec->output_section)))
912     return TRUE;
913 
914   einfo (_("%X%C: multiple definition of `%T'\n"),
915 	 nbfd, nsec, nval, name);
916   if (obfd != NULL)
917     einfo (_("%D: first defined here\n"), obfd, osec, oval);
918 
919   if (command_line.relax)
920     {
921       einfo (_("%P: Disabling relaxation: it will not work with multiple definitions\n"));
922       command_line.relax = 0;
923     }
924 
925   return TRUE;
926 }
927 
928 /* This is called when there is a definition of a common symbol, or
929    when a common symbol is found for a symbol that is already defined,
930    or when two common symbols are found.  We only do something if
931    -warn-common was used.  */
932 
933 static bfd_boolean
934 multiple_common (struct bfd_link_info *info ATTRIBUTE_UNUSED,
935 		 const char *name,
936 		 bfd *obfd,
937 		 enum bfd_link_hash_type otype,
938 		 bfd_vma osize,
939 		 bfd *nbfd,
940 		 enum bfd_link_hash_type ntype,
941 		 bfd_vma nsize)
942 {
943   if (! config.warn_common)
944     return TRUE;
945 
946   if (ntype == bfd_link_hash_defined
947       || ntype == bfd_link_hash_defweak
948       || ntype == bfd_link_hash_indirect)
949     {
950       ASSERT (otype == bfd_link_hash_common);
951       einfo (_("%B: warning: definition of `%T' overriding common\n"),
952 	     nbfd, name);
953       if (obfd != NULL)
954 	einfo (_("%B: warning: common is here\n"), obfd);
955     }
956   else if (otype == bfd_link_hash_defined
957 	   || otype == bfd_link_hash_defweak
958 	   || otype == bfd_link_hash_indirect)
959     {
960       ASSERT (ntype == bfd_link_hash_common);
961       einfo (_("%B: warning: common of `%T' overridden by definition\n"),
962 	     nbfd, name);
963       if (obfd != NULL)
964 	einfo (_("%B: warning: defined here\n"), obfd);
965     }
966   else
967     {
968       ASSERT (otype == bfd_link_hash_common && ntype == bfd_link_hash_common);
969       if (osize > nsize)
970 	{
971 	  einfo (_("%B: warning: common of `%T' overridden by larger common\n"),
972 		 nbfd, name);
973 	  if (obfd != NULL)
974 	    einfo (_("%B: warning: larger common is here\n"), obfd);
975 	}
976       else if (nsize > osize)
977 	{
978 	  einfo (_("%B: warning: common of `%T' overriding smaller common\n"),
979 		 nbfd, name);
980 	  if (obfd != NULL)
981 	    einfo (_("%B: warning: smaller common is here\n"), obfd);
982 	}
983       else
984 	{
985 	  einfo (_("%B: warning: multiple common of `%T'\n"), nbfd, name);
986 	  if (obfd != NULL)
987 	    einfo (_("%B: warning: previous common is here\n"), obfd);
988 	}
989     }
990 
991   return TRUE;
992 }
993 
994 /* This is called when BFD has discovered a set element.  H is the
995    entry in the linker hash table for the set.  SECTION and VALUE
996    represent a value which should be added to the set.  */
997 
998 static bfd_boolean
999 add_to_set (struct bfd_link_info *info ATTRIBUTE_UNUSED,
1000 	    struct bfd_link_hash_entry *h,
1001 	    bfd_reloc_code_real_type reloc,
1002 	    bfd *abfd,
1003 	    asection *section,
1004 	    bfd_vma value)
1005 {
1006   if (config.warn_constructors)
1007     einfo (_("%P: warning: global constructor %s used\n"),
1008 	   h->root.string);
1009 
1010   if (! config.build_constructors)
1011     return TRUE;
1012 
1013   ldctor_add_set_entry (h, reloc, NULL, section, value);
1014 
1015   if (h->type == bfd_link_hash_new)
1016     {
1017       h->type = bfd_link_hash_undefined;
1018       h->u.undef.abfd = abfd;
1019       /* We don't call bfd_link_add_undef to add this to the list of
1020 	 undefined symbols because we are going to define it
1021 	 ourselves.  */
1022     }
1023 
1024   return TRUE;
1025 }
1026 
1027 /* This is called when BFD has discovered a constructor.  This is only
1028    called for some object file formats--those which do not handle
1029    constructors in some more clever fashion.  This is similar to
1030    adding an element to a set, but less general.  */
1031 
1032 static bfd_boolean
1033 constructor_callback (struct bfd_link_info *info,
1034 		      bfd_boolean constructor,
1035 		      const char *name,
1036 		      bfd *abfd,
1037 		      asection *section,
1038 		      bfd_vma value)
1039 {
1040   char *s;
1041   struct bfd_link_hash_entry *h;
1042   char set_name[1 + sizeof "__CTOR_LIST__"];
1043 
1044   if (config.warn_constructors)
1045     einfo (_("%P: warning: global constructor %s used\n"), name);
1046 
1047   if (! config.build_constructors)
1048     return TRUE;
1049 
1050   /* Ensure that BFD_RELOC_CTOR exists now, so that we can give a
1051      useful error message.  */
1052   if (bfd_reloc_type_lookup (link_info.output_bfd, BFD_RELOC_CTOR) == NULL
1053       && (info->relocatable
1054 	  || bfd_reloc_type_lookup (abfd, BFD_RELOC_CTOR) == NULL))
1055     einfo (_("%P%F: BFD backend error: BFD_RELOC_CTOR unsupported\n"));
1056 
1057   s = set_name;
1058   if (bfd_get_symbol_leading_char (abfd) != '\0')
1059     *s++ = bfd_get_symbol_leading_char (abfd);
1060   if (constructor)
1061     strcpy (s, "__CTOR_LIST__");
1062   else
1063     strcpy (s, "__DTOR_LIST__");
1064 
1065   h = bfd_link_hash_lookup (info->hash, set_name, TRUE, TRUE, TRUE);
1066   if (h == (struct bfd_link_hash_entry *) NULL)
1067     einfo (_("%P%F: bfd_link_hash_lookup failed: %E\n"));
1068   if (h->type == bfd_link_hash_new)
1069     {
1070       h->type = bfd_link_hash_undefined;
1071       h->u.undef.abfd = abfd;
1072       /* We don't call bfd_link_add_undef to add this to the list of
1073 	 undefined symbols because we are going to define it
1074 	 ourselves.  */
1075     }
1076 
1077   ldctor_add_set_entry (h, BFD_RELOC_CTOR, name, section, value);
1078   return TRUE;
1079 }
1080 
1081 /* A structure used by warning_callback to pass information through
1082    bfd_map_over_sections.  */
1083 
1084 struct warning_callback_info
1085 {
1086   bfd_boolean found;
1087   const char *warning;
1088   const char *symbol;
1089   asymbol **asymbols;
1090 };
1091 
1092 /* This is called when there is a reference to a warning symbol.  */
1093 
1094 static bfd_boolean
1095 warning_callback (struct bfd_link_info *info ATTRIBUTE_UNUSED,
1096 		  const char *warning,
1097 		  const char *symbol,
1098 		  bfd *abfd,
1099 		  asection *section,
1100 		  bfd_vma address)
1101 {
1102   /* This is a hack to support warn_multiple_gp.  FIXME: This should
1103      have a cleaner interface, but what?  */
1104   if (! config.warn_multiple_gp
1105       && strcmp (warning, "using multiple gp values") == 0)
1106     return TRUE;
1107 
1108   if (section != NULL)
1109     einfo ("%C: %s%s\n", abfd, section, address, _("warning: "), warning);
1110   else if (abfd == NULL)
1111     einfo ("%P: %s%s\n", _("warning: "), warning);
1112   else if (symbol == NULL)
1113     einfo ("%B: %s%s\n", abfd, _("warning: "), warning);
1114   else
1115     {
1116       struct warning_callback_info info;
1117 
1118       /* Look through the relocs to see if we can find a plausible
1119 	 address.  */
1120 
1121       if (!bfd_generic_link_read_symbols (abfd))
1122 	einfo (_("%B%F: could not read symbols: %E\n"), abfd);
1123 
1124       info.found = FALSE;
1125       info.warning = warning;
1126       info.symbol = symbol;
1127       info.asymbols = bfd_get_outsymbols (abfd);
1128       bfd_map_over_sections (abfd, warning_find_reloc, &info);
1129 
1130       if (! info.found)
1131 	einfo ("%B: %s%s\n", abfd, _("warning: "), warning);
1132     }
1133 
1134   return TRUE;
1135 }
1136 
1137 /* This is called by warning_callback for each section.  It checks the
1138    relocs of the section to see if it can find a reference to the
1139    symbol which triggered the warning.  If it can, it uses the reloc
1140    to give an error message with a file and line number.  */
1141 
1142 static void
1143 warning_find_reloc (bfd *abfd, asection *sec, void *iarg)
1144 {
1145   struct warning_callback_info *info = iarg;
1146   long relsize;
1147   arelent **relpp;
1148   long relcount;
1149   arelent **p, **pend;
1150 
1151   if (info->found)
1152     return;
1153 
1154   relsize = bfd_get_reloc_upper_bound (abfd, sec);
1155   if (relsize < 0)
1156     einfo (_("%B%F: could not read relocs: %E\n"), abfd);
1157   if (relsize == 0)
1158     return;
1159 
1160   relpp = xmalloc (relsize);
1161   relcount = bfd_canonicalize_reloc (abfd, sec, relpp, info->asymbols);
1162   if (relcount < 0)
1163     einfo (_("%B%F: could not read relocs: %E\n"), abfd);
1164 
1165   p = relpp;
1166   pend = p + relcount;
1167   for (; p < pend && *p != NULL; p++)
1168     {
1169       arelent *q = *p;
1170 
1171       if (q->sym_ptr_ptr != NULL
1172 	  && *q->sym_ptr_ptr != NULL
1173 	  && strcmp (bfd_asymbol_name (*q->sym_ptr_ptr), info->symbol) == 0)
1174 	{
1175 	  /* We found a reloc for the symbol we are looking for.  */
1176 	  einfo ("%C: %s%s\n", abfd, sec, q->address, _("warning: "),
1177 		 info->warning);
1178 	  info->found = TRUE;
1179 	  break;
1180 	}
1181     }
1182 
1183   free (relpp);
1184 }
1185 
1186 /* This is called when an undefined symbol is found.  */
1187 
1188 static bfd_boolean
1189 undefined_symbol (struct bfd_link_info *info,
1190 		  const char *name,
1191 		  bfd *abfd,
1192 		  asection *section,
1193 		  bfd_vma address,
1194 		  bfd_boolean error)
1195 {
1196   static char *error_name;
1197   static unsigned int error_count;
1198 
1199 #define MAX_ERRORS_IN_A_ROW 5
1200 
1201   if (info->ignore_hash != NULL
1202       && bfd_hash_lookup (info->ignore_hash, name, FALSE, FALSE) != NULL)
1203     return TRUE;
1204 
1205   if (config.warn_once)
1206     {
1207       /* Only warn once about a particular undefined symbol.  */
1208       if (info->ignore_hash == NULL)
1209 	{
1210 	  info->ignore_hash = xmalloc (sizeof (struct bfd_hash_table));
1211 	  if (! bfd_hash_table_init (info->ignore_hash, bfd_hash_newfunc,
1212 				    sizeof (struct bfd_hash_entry)))
1213 	    einfo (_("%F%P: bfd_hash_table_init failed: %E\n"));
1214 	}
1215 
1216       if (bfd_hash_lookup (info->ignore_hash, name, FALSE, FALSE) != NULL)
1217 	return TRUE;
1218 
1219       if (bfd_hash_lookup (info->ignore_hash, name, TRUE, TRUE) == NULL)
1220 	einfo (_("%F%P: bfd_hash_lookup failed: %E\n"));
1221     }
1222 
1223   /* We never print more than a reasonable number of errors in a row
1224      for a single symbol.  */
1225   if (error_name != NULL
1226       && strcmp (name, error_name) == 0)
1227     ++error_count;
1228   else
1229     {
1230       error_count = 0;
1231       if (error_name != NULL)
1232 	free (error_name);
1233       error_name = xstrdup (name);
1234     }
1235 
1236   if (section != NULL)
1237     {
1238       if (error_count < MAX_ERRORS_IN_A_ROW)
1239 	{
1240 	  if (error)
1241 	    einfo (_("%X%C: undefined reference to `%T'\n"),
1242 		   abfd, section, address, name);
1243 	  else
1244 	    einfo (_("%C: warning: undefined reference to `%T'\n"),
1245 		   abfd, section, address, name);
1246 	}
1247       else if (error_count == MAX_ERRORS_IN_A_ROW)
1248 	{
1249 	  if (error)
1250 	    einfo (_("%X%D: more undefined references to `%T' follow\n"),
1251 		   abfd, section, address, name);
1252 	  else
1253 	    einfo (_("%D: warning: more undefined references to `%T' follow\n"),
1254 		   abfd, section, address, name);
1255 	}
1256       else if (error)
1257 	einfo ("%X");
1258     }
1259   else
1260     {
1261       if (error_count < MAX_ERRORS_IN_A_ROW)
1262 	{
1263 	  if (error)
1264 	    einfo (_("%X%B: undefined reference to `%T'\n"),
1265 		   abfd, name);
1266 	  else
1267 	    einfo (_("%B: warning: undefined reference to `%T'\n"),
1268 		   abfd, name);
1269 	}
1270       else if (error_count == MAX_ERRORS_IN_A_ROW)
1271 	{
1272 	  if (error)
1273 	    einfo (_("%X%B: more undefined references to `%T' follow\n"),
1274 		   abfd, name);
1275 	  else
1276 	    einfo (_("%B: warning: more undefined references to `%T' follow\n"),
1277 		   abfd, name);
1278 	}
1279       else if (error)
1280 	einfo ("%X");
1281     }
1282 
1283   return TRUE;
1284 }
1285 
1286 /* Counter to limit the number of relocation overflow error messages
1287    to print.  Errors are printed as it is decremented.  When it's
1288    called and the counter is zero, a final message is printed
1289    indicating more relocations were omitted.  When it gets to -1, no
1290    such errors are printed.  If it's initially set to a value less
1291    than -1, all such errors will be printed (--verbose does this).  */
1292 
1293 int overflow_cutoff_limit = 10;
1294 
1295 /* This is called when a reloc overflows.  */
1296 
1297 static bfd_boolean
1298 reloc_overflow (struct bfd_link_info *info ATTRIBUTE_UNUSED,
1299 		struct bfd_link_hash_entry *entry,
1300 		const char *name,
1301 		const char *reloc_name,
1302 		bfd_vma addend,
1303 		bfd *abfd,
1304 		asection *section,
1305 		bfd_vma address)
1306 {
1307   if (overflow_cutoff_limit == -1)
1308     return TRUE;
1309 
1310   einfo ("%X%C:", abfd, section, address);
1311 
1312   if (overflow_cutoff_limit >= 0
1313       && overflow_cutoff_limit-- == 0)
1314     {
1315       einfo (_(" additional relocation overflows omitted from the output\n"));
1316       return TRUE;
1317     }
1318 
1319   if (entry)
1320     {
1321       while (entry->type == bfd_link_hash_indirect
1322 	     || entry->type == bfd_link_hash_warning)
1323 	entry = entry->u.i.link;
1324       switch (entry->type)
1325 	{
1326 	case bfd_link_hash_undefined:
1327 	case bfd_link_hash_undefweak:
1328 	  einfo (_(" relocation truncated to fit: %s against undefined symbol `%T'"),
1329 		 reloc_name, entry->root.string);
1330 	  break;
1331 	case bfd_link_hash_defined:
1332 	case bfd_link_hash_defweak:
1333 	  einfo (_(" relocation truncated to fit: %s against symbol `%T' defined in %A section in %B"),
1334 		 reloc_name, entry->root.string,
1335 		 entry->u.def.section,
1336 		 entry->u.def.section == bfd_abs_section_ptr
1337 		 ? link_info.output_bfd : entry->u.def.section->owner);
1338 	  break;
1339 	default:
1340 	  abort ();
1341 	  break;
1342 	}
1343     }
1344   else
1345     einfo (_(" relocation truncated to fit: %s against `%T'"),
1346 	   reloc_name, name);
1347   if (addend != 0)
1348     einfo ("+%v", addend);
1349   einfo ("\n");
1350   return TRUE;
1351 }
1352 
1353 /* This is called when a dangerous relocation is made.  */
1354 
1355 static bfd_boolean
1356 reloc_dangerous (struct bfd_link_info *info ATTRIBUTE_UNUSED,
1357 		 const char *message,
1358 		 bfd *abfd,
1359 		 asection *section,
1360 		 bfd_vma address)
1361 {
1362   einfo (_("%X%C: dangerous relocation: %s\n"),
1363 	 abfd, section, address, message);
1364   return TRUE;
1365 }
1366 
1367 /* This is called when a reloc is being generated attached to a symbol
1368    that is not being output.  */
1369 
1370 static bfd_boolean
1371 unattached_reloc (struct bfd_link_info *info ATTRIBUTE_UNUSED,
1372 		  const char *name,
1373 		  bfd *abfd,
1374 		  asection *section,
1375 		  bfd_vma address)
1376 {
1377   einfo (_("%X%C: reloc refers to symbol `%T' which is not being output\n"),
1378 	 abfd, section, address, name);
1379   return TRUE;
1380 }
1381 
1382 /* This is called if link_info.notice_all is set, or when a symbol in
1383    link_info.notice_hash is found.  Symbols are put in notice_hash
1384    using the -y option.  */
1385 
1386 static bfd_boolean
1387 notice (struct bfd_link_info *info,
1388 	const char *name,
1389 	bfd *abfd,
1390 	asection *section,
1391 	bfd_vma value)
1392 {
1393   if (name == NULL)
1394     {
1395       if (command_line.cref || nocrossref_list != NULL)
1396 	return handle_asneeded_cref (abfd, value);
1397       return TRUE;
1398     }
1399 
1400   if (! info->notice_all
1401       || (info->notice_hash != NULL
1402 	  && bfd_hash_lookup (info->notice_hash, name, FALSE, FALSE) != NULL))
1403     {
1404       if (bfd_is_und_section (section))
1405 	einfo ("%B: reference to %s\n", abfd, name);
1406       else
1407 	einfo ("%B: definition of %s\n", abfd, name);
1408     }
1409 
1410   if (command_line.cref || nocrossref_list != NULL)
1411     add_cref (name, abfd, section, value);
1412 
1413   return TRUE;
1414 }
1415