1 /* Main program of GNU linker.
2 Copyright (C) 1991, 92, 93, 94 Free Software Foundation, Inc.
3 Written by Steve Chamberlain steve@cygnus.com
5 This file is part of GLD, the Gnu Linker.
7 GLD is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GLD is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GLD; see the file COPYING. If not, write to
19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
25 #include "libiberty.h"
41 /* Somewhere above, sys/stat.h got included . . . . */
42 #if !defined(S_ISDIR) && defined(S_IFDIR)
43 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
48 static char *get_emulation
PARAMS ((int, char **));
49 static void set_scripts_dir
PARAMS ((void));
54 const char *output_filename
= "a.out";
56 /* Name this program was invoked by. */
59 /* The file that we're creating */
62 /* Set by -G argument, for MIPS ECOFF target. */
63 int g_switch_value
= 8;
65 /* Nonzero means print names of input files as processed. */
68 /* Nonzero means same, but note open failures, too. */
69 boolean trace_file_tries
;
71 /* Nonzero means version number was printed, so exit successfully
72 instead of complaining if no input files are given. */
73 boolean version_printed
;
75 /* 1 => write load map. */
78 args_type command_line
;
80 ld_config_type config
;
82 static boolean check_for_scripts_dir
PARAMS ((char *dir
));
83 static boolean add_archive_element
PARAMS ((struct bfd_link_info
*, bfd
*,
85 static boolean multiple_definition
PARAMS ((struct bfd_link_info
*,
87 bfd
*, asection
*, bfd_vma
,
88 bfd
*, asection
*, bfd_vma
));
89 static boolean multiple_common
PARAMS ((struct bfd_link_info
*,
91 enum bfd_link_hash_type
, bfd_vma
,
92 bfd
*, enum bfd_link_hash_type
,
94 static boolean add_to_set
PARAMS ((struct bfd_link_info
*,
95 struct bfd_link_hash_entry
*,
97 bfd
*, asection
*, bfd_vma
));
98 static boolean constructor_callback
PARAMS ((struct bfd_link_info
*,
100 unsigned int bitsize
,
102 bfd
*, asection
*, bfd_vma
));
103 static boolean warning_callback
PARAMS ((struct bfd_link_info
*,
105 static boolean undefined_symbol
PARAMS ((struct bfd_link_info
*,
107 asection
*, bfd_vma
));
108 static boolean reloc_overflow
PARAMS ((struct bfd_link_info
*, const char *,
109 const char *, bfd_vma
,
110 bfd
*, asection
*, bfd_vma
));
111 static boolean reloc_dangerous
PARAMS ((struct bfd_link_info
*, const char *,
112 bfd
*, asection
*, bfd_vma
));
113 static boolean unattached_reloc
PARAMS ((struct bfd_link_info
*,
114 const char *, bfd
*, asection
*,
116 static boolean notice_ysym
PARAMS ((struct bfd_link_info
*, const char *,
117 bfd
*, asection
*, bfd_vma
));
119 static struct bfd_link_callbacks link_callbacks
=
125 constructor_callback
,
134 struct bfd_link_info link_info
;
141 if (output_bfd
&& output_bfd
->iostream
)
142 fclose((FILE *)(output_bfd
->iostream
));
143 if (delete_output_file_on_failure
)
144 unlink (output_filename
);
154 long start_time
= get_run_time ();
156 program_name
= argv
[0];
157 xmalloc_set_program_name (program_name
);
161 xatexit (remove_output
);
163 /* Initialize the data about options. */
164 trace_files
= trace_file_tries
= version_printed
= false;
166 config
.build_constructors
= true;
167 command_line
.force_common_definition
= false;
169 link_info
.callbacks
= &link_callbacks
;
170 link_info
.relocateable
= false;
171 link_info
.strip
= strip_none
;
172 link_info
.discard
= discard_none
;
173 link_info
.lprefix_len
= 1;
174 link_info
.lprefix
= "L";
175 link_info
.keep_memory
= true;
176 link_info
.input_bfds
= NULL
;
177 link_info
.create_object_symbols_section
= NULL
;
178 link_info
.hash
= NULL
;
179 link_info
.keep_hash
= NULL
;
180 link_info
.notice_hash
= NULL
;
182 ldfile_add_arch ("");
184 config
.make_executable
= true;
185 force_make_executable
= false;
186 config
.magic_demand_paged
= true;
187 config
.text_read_only
= true;
188 config
.make_executable
= true;
190 emulation
= get_emulation (argc
, argv
);
191 ldemul_choose_mode (emulation
);
192 default_target
= ldemul_choose_target ();
194 ldemul_before_parse ();
195 lang_has_input_file
= false;
196 parse_args (argc
, argv
);
198 /* This essentially adds another -L directory so this must be done after
199 the -L's in argv have been processed. */
202 if (had_script
== false)
204 /* Read the emulation's appropriate default script. */
206 char *s
= ldemul_get_script (&isfile
);
209 ldfile_open_command_file (s
);
212 parser_input
= input_script
;
216 if (link_info
.relocateable
&& command_line
.relax
)
218 einfo ("%P%F: -relax and -r may not be used together\n");
222 if (lang_has_input_file
== false)
226 einfo ("%P%F: no input files\n");
231 info_msg ("%P: mode %s\n", emulation
);
234 ldemul_after_parse ();
237 if (config
.map_filename
)
239 if (strcmp (config
.map_filename
, "-") == 0)
241 config
.map_file
= stdout
;
245 config
.map_file
= fopen (config
.map_filename
, FOPEN_WT
);
246 if (config
.map_file
== (FILE *) NULL
)
248 einfo ("%P%F: cannot open map file %s: %E\n",
249 config
.map_filename
);
257 /* Print error messages for any missing symbols, for any warning
258 symbols, and possibly multiple definitions */
261 if (config
.text_read_only
)
263 /* Look for a text section and mark the readonly attribute in it */
264 asection
*found
= bfd_get_section_by_name (output_bfd
, ".text");
266 if (found
!= (asection
*) NULL
)
268 found
->flags
|= SEC_READONLY
;
272 if (link_info
.relocateable
)
273 output_bfd
->flags
&= ~EXEC_P
;
275 output_bfd
->flags
|= EXEC_P
;
279 /* Even if we're producing relocateable output, some non-fatal errors should
280 be reported in the exit status. (What non-fatal errors, if any, do we
281 want to ignore for relocateable output?) */
283 if (config
.make_executable
== false && force_make_executable
== false)
285 if (trace_files
== true)
287 einfo ("%P: link errors found, deleting executable `%s'\n",
291 if (output_bfd
->iostream
)
292 fclose ((FILE *) (output_bfd
->iostream
));
294 unlink (output_filename
);
299 bfd_close (output_bfd
);
304 extern char **environ
;
305 char *lim
= (char *) sbrk (0);
306 long run_time
= get_run_time () - start_time
;
308 fprintf (stderr
, "%s: total time in link: %ld.%06ld\n",
309 program_name
, run_time
/ 1000000, run_time
% 1000000);
310 fprintf (stderr
, "%s: data size %ld\n", program_name
,
311 (long) (lim
- (char *) &environ
));
314 /* Prevent remove_output from doing anything, after a successful link. */
315 output_filename
= NULL
;
321 /* We need to find any explicitly given emulation in order to initialize the
322 state that's needed by the lex&yacc argument parser (parse_args). */
325 get_emulation (argc
, argv
)
332 emulation
= (char *) getenv (EMULATION_ENVIRON
);
333 if (emulation
== NULL
)
334 emulation
= DEFAULT_EMULATION
;
336 for (i
= 1; i
< argc
; i
++)
338 if (!strncmp (argv
[i
], "-m", 2))
340 if (argv
[i
][2] == '\0')
345 emulation
= argv
[i
+ 1];
350 einfo("%P%F: missing argument to -m\n");
353 else if (strcmp (argv
[i
], "-mips1") == 0
354 || strcmp (argv
[i
], "-mips2") == 0
355 || strcmp (argv
[i
], "-mips3") == 0)
357 /* FIXME: The arguments -mips1, -mips2 and -mips3 are
358 passed to the linker by some MIPS compilers. They
359 generally tell the linker to use a slightly different
360 library path. Perhaps someday these should be
361 implemented as emulations; until then, we just ignore
362 the arguments and hope that nobody ever creates
363 emulations named ips1, ips2 or ips3. */
368 emulation
= &argv
[i
][2];
376 /* If directory DIR contains an "ldscripts" subdirectory,
377 add DIR to the library search path and return true,
378 else return false. */
381 check_for_scripts_dir (dir
)
389 dirlen
= strlen (dir
);
390 /* sizeof counts the terminating NUL. */
391 buf
= (char *) xmalloc (dirlen
+ sizeof("/ldscripts"));
392 sprintf (buf
, "%s/ldscripts", dir
);
394 res
= stat (buf
, &s
) == 0 && S_ISDIR (s
.st_mode
);
397 ldfile_add_library_path (dir
);
401 /* Set the default directory for finding script files.
402 Libraries will be searched for here too, but that's ok.
403 We look for the "ldscripts" directory in:
405 SCRIPTDIR (passed from Makefile)
406 the dir where this program is (for using it from the build tree)
407 the dir where this program is/../lib (for installing the tool suite elsewhere) */
415 if (check_for_scripts_dir (SCRIPTDIR
))
416 return; /* We've been installed normally. */
418 /* Look for "ldscripts" in the dir where our binary is. */
419 end
= strrchr (program_name
, '/');
422 dirlen
= end
- program_name
;
423 /* Make a copy of program_name in dir.
424 Leave room for later "/../lib". */
425 dir
= (char *) xmalloc (dirlen
+ 8);
426 strncpy (dir
, program_name
, dirlen
);
432 dir
= (char *) xmalloc (dirlen
+ 8);
436 if (check_for_scripts_dir (dir
))
437 return; /* Don't free dir. */
439 /* Look for "ldscripts" in <the dir where our binary is>/../lib. */
440 strcpy (dir
+ dirlen
, "/../lib");
441 if (check_for_scripts_dir (dir
))
444 free (dir
); /* Well, we tried. */
451 if (link_info
.notice_hash
== (struct bfd_hash_table
*) NULL
)
453 link_info
.notice_hash
= ((struct bfd_hash_table
*)
454 xmalloc (sizeof (struct bfd_hash_table
)));
455 if (! bfd_hash_table_init_n (link_info
.notice_hash
,
458 einfo ("%P%F: bfd_hash_table_init failed: %E\n");
461 if (bfd_hash_lookup (link_info
.notice_hash
, name
, true, true)
462 == (struct bfd_hash_entry
*) NULL
)
463 einfo ("%P%F: bfd_hash_lookup failed: %E\n");
466 /* Handle the -retain-symbols-file option. */
469 add_keepsyms_file (filename
)
470 const char *filename
;
477 if (link_info
.strip
== strip_some
)
478 einfo ("%X%P: error: duplicate retain-symbols-file\n");
480 file
= fopen (filename
, "r");
481 if (file
== (FILE *) NULL
)
483 bfd_set_error (bfd_error_system_call
);
484 einfo ("%X%P: %s: %E", filename
);
488 link_info
.keep_hash
= ((struct bfd_hash_table
*)
489 xmalloc (sizeof (struct bfd_hash_table
)));
490 if (! bfd_hash_table_init (link_info
.keep_hash
, bfd_hash_newfunc
))
491 einfo ("%P%F: bfd_hash_table_init failed: %E\n");
494 buf
= (char *) xmalloc (bufsize
);
506 while (! isspace (c
) && c
!= EOF
)
513 buf
= xrealloc (buf
, bufsize
);
520 if (bfd_hash_lookup (link_info
.keep_hash
, buf
, true, true)
521 == (struct bfd_hash_entry
*) NULL
)
522 einfo ("%P%F: bfd_hash_lookup for insertion failed: %E");
526 if (link_info
.strip
!= strip_none
)
527 einfo ("%P: `-retain-symbols-file' overrides `-s' and `-S'\n");
529 link_info
.strip
= strip_some
;
532 /* Callbacks from the BFD linker routines. */
534 /* This is called when BFD has decided to include an archive member in
539 add_archive_element (info
, abfd
, name
)
540 struct bfd_link_info
*info
;
544 lang_input_statement_type
*input
;
546 input
= ((lang_input_statement_type
*)
547 xmalloc ((bfd_size_type
) sizeof (lang_input_statement_type
)));
548 input
->filename
= abfd
->filename
;
549 input
->local_sym_name
= abfd
->filename
;
550 input
->the_bfd
= abfd
;
551 input
->asymbols
= NULL
;
552 input
->subfiles
= NULL
;
554 input
->just_syms_flag
= false;
555 input
->loaded
= false;
558 /* FIXME: This is wrong. It should point to an entry for the
559 archive itself. However, it doesn't seem to matter. */
560 input
->superfile
= NULL
;
562 /* FIXME: The following fields are not set: header.next,
563 header.type, closed, passive_position, symbol_count, total_size,
564 next_real_file, is_archive, search_dirs_flag, target, real,
565 common_section, common_output_section, complained. This bit of
566 code is from the old decode_library_subfile function. I don't
567 know whether any of those fields matters. */
569 ldlang_add_file (input
);
572 info_msg ("%s needed due to %T\n", abfd
->filename
, name
);
574 if (trace_files
|| trace_file_tries
)
575 info_msg ("%I\n", input
);
580 /* This is called when BFD has discovered a symbol which is defined
585 multiple_definition (info
, name
, obfd
, osec
, oval
, nbfd
, nsec
, nval
)
586 struct bfd_link_info
*info
;
595 einfo ("%X%C: multiple definition of `%T'\n",
596 nbfd
, nsec
, nval
, name
);
597 if (obfd
!= (bfd
*) NULL
)
598 einfo ("%C: first defined here\n", obfd
, osec
, oval
);
602 /* This is called when there is a definition of a common symbol, or
603 when a common symbol is found for a symbol that is already defined,
604 or when two common symbols are found. We only do something if
605 -warn-common was used. */
609 multiple_common (info
, name
, obfd
, otype
, osize
, nbfd
, ntype
, nsize
)
610 struct bfd_link_info
*info
;
613 enum bfd_link_hash_type otype
;
616 enum bfd_link_hash_type ntype
;
619 if (! config
.warn_common
)
622 if (ntype
== bfd_link_hash_defined
)
624 ASSERT (otype
== bfd_link_hash_common
);
625 einfo ("%B: warning: definition of `%T' overriding common\n",
627 einfo ("%B: warning: common is here\n", obfd
);
629 else if (otype
== bfd_link_hash_defined
)
631 ASSERT (ntype
== bfd_link_hash_common
);
632 einfo ("%B: warning: common of `%T' overridden by definition\n",
634 einfo ("%B: warning: defined here\n", obfd
);
638 ASSERT (otype
== bfd_link_hash_common
&& ntype
== bfd_link_hash_common
);
641 einfo ("%B: warning: common of `%T' overridden by larger common\n",
643 einfo ("%B: warning: larger common is here\n", obfd
);
645 else if (nsize
> osize
)
647 einfo ("%B: warning: common of `%T' overriding smaller common\n",
649 einfo ("%B: warning: smaller common is here\n", obfd
);
653 einfo ("%B: warning: multiple common of `%T'\n", nbfd
, name
);
654 einfo ("%B: warning: previous common is here\n", obfd
);
661 /* This is called when BFD has discovered a set element. H is the
662 entry in the linker hash table for the set. SECTION and VALUE
663 represent a value which should be added to the set. */
667 add_to_set (info
, h
, bitsize
, abfd
, section
, value
)
668 struct bfd_link_info
*info
;
669 struct bfd_link_hash_entry
*h
;
670 unsigned int bitsize
;
675 ldctor_add_set_entry (h
, bitsize
, section
, value
);
679 /* This is called when BFD has discovered a constructor. This is only
680 called for some object file formats--those which do not handle
681 constructors in some more clever fashion. This is similar to
682 adding an element to a set, but less general. */
685 constructor_callback (info
, constructor
, bitsize
, name
, abfd
, section
, value
)
686 struct bfd_link_info
*info
;
688 unsigned int bitsize
;
696 struct bfd_link_hash_entry
*h
;
698 if (! config
.build_constructors
)
701 set_name
= (char *) alloca (1 + sizeof "__CTOR_LIST__");
703 if (bfd_get_symbol_leading_char (abfd
) != '\0')
704 *s
++ = bfd_get_symbol_leading_char (abfd
);
706 strcpy (s
, "__CTOR_LIST__");
708 strcpy (s
, "__DTOR_LIST__");
711 info_msg ("Adding %s to constructor/destructor set %s\n", name
, set_name
);
713 h
= bfd_link_hash_lookup (info
->hash
, set_name
, true, true, true);
714 if (h
== (struct bfd_link_hash_entry
*) NULL
)
715 einfo ("%P%F: bfd_link_hash_lookup failed: %E");
716 if (h
->type
== bfd_link_hash_new
)
718 h
->type
= bfd_link_hash_undefined
;
719 h
->u
.undef
.abfd
= abfd
;
720 /* We don't call bfd_link_add_undef to add this to the list of
721 undefined symbols because we are going to define it
725 ldctor_add_set_entry (h
, bitsize
, section
, value
);
729 /* This is called when there is a reference to a warning symbol. */
733 warning_callback (info
, warning
)
734 struct bfd_link_info
*info
;
737 einfo ("%P: %s\n", warning
);
741 /* This is called when an undefined symbol is found. */
745 undefined_symbol (info
, name
, abfd
, section
, address
)
746 struct bfd_link_info
*info
;
752 static char *error_name
;
753 static unsigned int error_count
;
755 #define MAX_ERRORS_IN_A_ROW 5
757 /* We never print more than a reasonable number of errors in a row
758 for a single symbol. */
759 if (error_name
!= (char *) NULL
760 && strcmp (name
, error_name
) == 0)
765 if (error_name
!= (char *) NULL
)
767 error_name
= buystring (name
);
770 if (error_count
< MAX_ERRORS_IN_A_ROW
)
771 einfo ("%X%C: undefined reference to `%T'\n",
772 abfd
, section
, address
, name
);
773 else if (error_count
== MAX_ERRORS_IN_A_ROW
)
774 einfo ("%C: more undefined references to `%T' follow\n",
775 abfd
, section
, address
, name
);
780 /* This is called when a reloc overflows. */
784 reloc_overflow (info
, name
, reloc_name
, addend
, abfd
, section
, address
)
785 struct bfd_link_info
*info
;
787 const char *reloc_name
;
793 einfo ("%X%C: relocation truncated to fit: %s %T", abfd
, section
,
794 address
, reloc_name
, name
);
796 einfo ("+%v", addend
);
801 /* This is called when a dangerous relocation is made. */
805 reloc_dangerous (info
, message
, abfd
, section
, address
)
806 struct bfd_link_info
*info
;
812 einfo ("%X%C: dangerous relocation: %s\n", abfd
, section
, address
, message
);
816 /* This is called when a reloc is being generated attached to a symbol
817 that is not being output. */
821 unattached_reloc (info
, name
, abfd
, section
, address
)
822 struct bfd_link_info
*info
;
828 einfo ("%X%C: reloc refers to symbol `%T' which is not being output\n",
829 abfd
, section
, address
, name
);
833 /* This is called when a symbol in notice_hash is found. Symbols are
834 put in notice_hash using the -y option. */
838 notice_ysym (info
, name
, abfd
, section
, value
)
839 struct bfd_link_info
*info
;
845 einfo ("%B: %s %s\n", abfd
,
846 section
!= &bfd_und_section
? "definition of" : "reference to",