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 args_type command_line
;
77 ld_config_type config
;
79 static boolean check_for_scripts_dir
PARAMS ((char *dir
));
80 static boolean add_archive_element
PARAMS ((struct bfd_link_info
*, bfd
*,
82 static boolean multiple_definition
PARAMS ((struct bfd_link_info
*,
84 bfd
*, asection
*, bfd_vma
,
85 bfd
*, asection
*, bfd_vma
));
86 static boolean multiple_common
PARAMS ((struct bfd_link_info
*,
88 enum bfd_link_hash_type
, bfd_vma
,
89 bfd
*, enum bfd_link_hash_type
,
91 static boolean add_to_set
PARAMS ((struct bfd_link_info
*,
92 struct bfd_link_hash_entry
*,
93 bfd_reloc_code_real_type
,
94 bfd
*, asection
*, bfd_vma
));
95 static boolean constructor_callback
PARAMS ((struct bfd_link_info
*,
98 bfd
*, asection
*, bfd_vma
));
99 static boolean warning_callback
PARAMS ((struct bfd_link_info
*,
101 static boolean undefined_symbol
PARAMS ((struct bfd_link_info
*,
103 asection
*, bfd_vma
));
104 static boolean reloc_overflow
PARAMS ((struct bfd_link_info
*, const char *,
105 const char *, bfd_vma
,
106 bfd
*, asection
*, bfd_vma
));
107 static boolean reloc_dangerous
PARAMS ((struct bfd_link_info
*, const char *,
108 bfd
*, asection
*, bfd_vma
));
109 static boolean unattached_reloc
PARAMS ((struct bfd_link_info
*,
110 const char *, bfd
*, asection
*,
112 static boolean notice_ysym
PARAMS ((struct bfd_link_info
*, const char *,
113 bfd
*, asection
*, bfd_vma
));
115 static struct bfd_link_callbacks link_callbacks
=
121 constructor_callback
,
130 struct bfd_link_info link_info
;
137 if (output_bfd
&& output_bfd
->iostream
)
138 fclose((FILE *)(output_bfd
->iostream
));
139 if (delete_output_file_on_failure
)
140 unlink (output_filename
);
150 long start_time
= get_run_time ();
152 program_name
= argv
[0];
153 xmalloc_set_program_name (program_name
);
157 xatexit (remove_output
);
159 /* Initialize the data about options. */
160 trace_files
= trace_file_tries
= version_printed
= false;
161 config
.traditional_format
= false;
162 config
.build_constructors
= true;
163 config
.dynamic_link
= false;
164 command_line
.force_common_definition
= false;
165 command_line
.interpreter
= NULL
;
167 link_info
.callbacks
= &link_callbacks
;
168 link_info
.relocateable
= false;
169 link_info
.shared
= false;
170 link_info
.strip
= strip_none
;
171 link_info
.discard
= discard_none
;
172 link_info
.lprefix_len
= 1;
173 link_info
.lprefix
= "L";
174 link_info
.keep_memory
= true;
175 link_info
.input_bfds
= NULL
;
176 link_info
.create_object_symbols_section
= NULL
;
177 link_info
.hash
= NULL
;
178 link_info
.keep_hash
= NULL
;
179 link_info
.notice_hash
= NULL
;
181 ldfile_add_arch ("");
183 config
.make_executable
= true;
184 force_make_executable
= false;
185 config
.magic_demand_paged
= true;
186 config
.text_read_only
= true;
187 config
.make_executable
= true;
189 emulation
= get_emulation (argc
, argv
);
190 ldemul_choose_mode (emulation
);
191 default_target
= ldemul_choose_target ();
193 ldemul_before_parse ();
194 lang_has_input_file
= false;
195 parse_args (argc
, argv
);
197 if (link_info
.relocateable
)
199 if (command_line
.relax
)
200 einfo ("%P%F: -relax and -r may not be used together\n");
201 if (config
.dynamic_link
)
202 einfo ("%P%F: -r and -call_shared may not be used together\n");
203 if (link_info
.strip
== strip_all
)
204 einfo ("%P%F: -r and -s may not be used together\n");
205 if (link_info
.shared
)
206 einfo ("%P%F: -r and -shared may not be used together\n");
209 /* This essentially adds another -L directory so this must be done after
210 the -L's in argv have been processed. */
213 if (had_script
== false)
215 /* Read the emulation's appropriate default script. */
217 char *s
= ldemul_get_script (&isfile
);
220 ldfile_open_command_file (s
);
223 parser_input
= input_script
;
229 if (lang_has_input_file
== false)
233 einfo ("%P%F: no input files\n");
238 info_msg ("%P: mode %s\n", emulation
);
241 ldemul_after_parse ();
244 if (config
.map_filename
)
246 if (strcmp (config
.map_filename
, "-") == 0)
248 config
.map_file
= stdout
;
252 config
.map_file
= fopen (config
.map_filename
, FOPEN_WT
);
253 if (config
.map_file
== (FILE *) NULL
)
255 einfo ("%P%F: cannot open map file %s: %E\n",
256 config
.map_filename
);
264 /* Print error messages for any missing symbols, for any warning
265 symbols, and possibly multiple definitions */
268 if (config
.text_read_only
)
270 /* Look for a text section and mark the readonly attribute in it */
271 asection
*found
= bfd_get_section_by_name (output_bfd
, ".text");
273 if (found
!= (asection
*) NULL
)
275 found
->flags
|= SEC_READONLY
;
279 if (link_info
.relocateable
)
280 output_bfd
->flags
&= ~EXEC_P
;
282 output_bfd
->flags
|= EXEC_P
;
286 /* Even if we're producing relocateable output, some non-fatal errors should
287 be reported in the exit status. (What non-fatal errors, if any, do we
288 want to ignore for relocateable output?) */
290 if (config
.make_executable
== false && force_make_executable
== false)
292 if (trace_files
== true)
294 einfo ("%P: link errors found, deleting executable `%s'\n",
298 if (output_bfd
->iostream
)
299 fclose ((FILE *) (output_bfd
->iostream
));
301 unlink (output_filename
);
306 if (! bfd_close (output_bfd
))
307 einfo ("%F%B: final close failed: %E\n", output_bfd
);
312 extern char **environ
;
313 char *lim
= (char *) sbrk (0);
314 long run_time
= get_run_time () - start_time
;
316 fprintf (stderr
, "%s: total time in link: %ld.%06ld\n",
317 program_name
, run_time
/ 1000000, run_time
% 1000000);
318 fprintf (stderr
, "%s: data size %ld\n", program_name
,
319 (long) (lim
- (char *) &environ
));
322 /* Prevent remove_output from doing anything, after a successful link. */
323 output_filename
= NULL
;
329 /* We need to find any explicitly given emulation in order to initialize the
330 state that's needed by the lex&yacc argument parser (parse_args). */
333 get_emulation (argc
, argv
)
340 emulation
= (char *) getenv (EMULATION_ENVIRON
);
341 if (emulation
== NULL
)
342 emulation
= DEFAULT_EMULATION
;
344 for (i
= 1; i
< argc
; i
++)
346 if (!strncmp (argv
[i
], "-m", 2))
348 if (argv
[i
][2] == '\0')
353 emulation
= argv
[i
+ 1];
358 einfo("%P%F: missing argument to -m\n");
361 else if (strcmp (argv
[i
], "-mips1") == 0
362 || strcmp (argv
[i
], "-mips2") == 0
363 || strcmp (argv
[i
], "-mips3") == 0)
365 /* FIXME: The arguments -mips1, -mips2 and -mips3 are
366 passed to the linker by some MIPS compilers. They
367 generally tell the linker to use a slightly different
368 library path. Perhaps someday these should be
369 implemented as emulations; until then, we just ignore
370 the arguments and hope that nobody ever creates
371 emulations named ips1, ips2 or ips3. */
373 else if (strcmp (argv
[i
], "-m486") == 0)
375 /* FIXME: The argument -m486 is passed to the linker on
376 some Linux systems. Hope that nobody creates an
377 emulation named 486. */
382 emulation
= &argv
[i
][2];
390 /* If directory DIR contains an "ldscripts" subdirectory,
391 add DIR to the library search path and return true,
392 else return false. */
395 check_for_scripts_dir (dir
)
403 dirlen
= strlen (dir
);
404 /* sizeof counts the terminating NUL. */
405 buf
= (char *) xmalloc (dirlen
+ sizeof("/ldscripts"));
406 sprintf (buf
, "%s/ldscripts", dir
);
408 res
= stat (buf
, &s
) == 0 && S_ISDIR (s
.st_mode
);
411 ldfile_add_library_path (dir
, false);
415 /* Set the default directory for finding script files.
416 Libraries will be searched for here too, but that's ok.
417 We look for the "ldscripts" directory in:
419 SCRIPTDIR (passed from Makefile)
420 the dir where this program is (for using it from the build tree)
421 the dir where this program is/../lib (for installing the tool suite elsewhere) */
429 if (check_for_scripts_dir (SCRIPTDIR
))
430 return; /* We've been installed normally. */
432 /* Look for "ldscripts" in the dir where our binary is. */
433 end
= strrchr (program_name
, '/');
436 dirlen
= end
- program_name
;
437 /* Make a copy of program_name in dir.
438 Leave room for later "/../lib". */
439 dir
= (char *) xmalloc (dirlen
+ 8);
440 strncpy (dir
, program_name
, dirlen
);
446 dir
= (char *) xmalloc (dirlen
+ 8);
450 if (check_for_scripts_dir (dir
))
451 return; /* Don't free dir. */
453 /* Look for "ldscripts" in <the dir where our binary is>/../lib. */
454 strcpy (dir
+ dirlen
, "/../lib");
455 if (check_for_scripts_dir (dir
))
458 free (dir
); /* Well, we tried. */
465 if (link_info
.notice_hash
== (struct bfd_hash_table
*) NULL
)
467 link_info
.notice_hash
= ((struct bfd_hash_table
*)
468 xmalloc (sizeof (struct bfd_hash_table
)));
469 if (! bfd_hash_table_init_n (link_info
.notice_hash
,
472 einfo ("%P%F: bfd_hash_table_init failed: %E\n");
475 if (bfd_hash_lookup (link_info
.notice_hash
, name
, true, true)
476 == (struct bfd_hash_entry
*) NULL
)
477 einfo ("%P%F: bfd_hash_lookup failed: %E\n");
480 /* Handle the -retain-symbols-file option. */
483 add_keepsyms_file (filename
)
484 const char *filename
;
491 if (link_info
.strip
== strip_some
)
492 einfo ("%X%P: error: duplicate retain-symbols-file\n");
494 file
= fopen (filename
, "r");
495 if (file
== (FILE *) NULL
)
497 bfd_set_error (bfd_error_system_call
);
498 einfo ("%X%P: %s: %E", filename
);
502 link_info
.keep_hash
= ((struct bfd_hash_table
*)
503 xmalloc (sizeof (struct bfd_hash_table
)));
504 if (! bfd_hash_table_init (link_info
.keep_hash
, bfd_hash_newfunc
))
505 einfo ("%P%F: bfd_hash_table_init failed: %E\n");
508 buf
= (char *) xmalloc (bufsize
);
520 while (! isspace (c
) && c
!= EOF
)
527 buf
= xrealloc (buf
, bufsize
);
534 if (bfd_hash_lookup (link_info
.keep_hash
, buf
, true, true)
535 == (struct bfd_hash_entry
*) NULL
)
536 einfo ("%P%F: bfd_hash_lookup for insertion failed: %E");
540 if (link_info
.strip
!= strip_none
)
541 einfo ("%P: `-retain-symbols-file' overrides `-s' and `-S'\n");
543 link_info
.strip
= strip_some
;
546 /* Callbacks from the BFD linker routines. */
548 /* This is called when BFD has decided to include an archive member in
553 add_archive_element (info
, abfd
, name
)
554 struct bfd_link_info
*info
;
558 lang_input_statement_type
*input
;
560 input
= ((lang_input_statement_type
*)
561 xmalloc ((bfd_size_type
) sizeof (lang_input_statement_type
)));
562 input
->filename
= abfd
->filename
;
563 input
->local_sym_name
= abfd
->filename
;
564 input
->the_bfd
= abfd
;
565 input
->asymbols
= NULL
;
567 input
->just_syms_flag
= false;
568 input
->loaded
= false;
569 input
->search_dirs_flag
= false;
571 /* FIXME: The following fields are not set: header.next,
572 header.type, closed, passive_position, symbol_count,
573 next_real_file, is_archive, target, real, common_section,
574 common_output_section, complained. This bit of code is from the
575 old decode_library_subfile function. I don't know whether any of
576 those fields matters. */
578 ldlang_add_file (input
);
580 if (config
.map_file
!= (FILE *) NULL
)
581 minfo ("%s needed due to %T\n", abfd
->filename
, name
);
583 if (trace_files
|| trace_file_tries
)
584 info_msg ("%I\n", input
);
589 /* This is called when BFD has discovered a symbol which is defined
594 multiple_definition (info
, name
, obfd
, osec
, oval
, nbfd
, nsec
, nval
)
595 struct bfd_link_info
*info
;
604 einfo ("%X%C: multiple definition of `%T'\n",
605 nbfd
, nsec
, nval
, name
);
606 if (obfd
!= (bfd
*) NULL
)
607 einfo ("%C: first defined here\n", obfd
, osec
, oval
);
611 /* This is called when there is a definition of a common symbol, or
612 when a common symbol is found for a symbol that is already defined,
613 or when two common symbols are found. We only do something if
614 -warn-common was used. */
618 multiple_common (info
, name
, obfd
, otype
, osize
, nbfd
, ntype
, nsize
)
619 struct bfd_link_info
*info
;
622 enum bfd_link_hash_type otype
;
625 enum bfd_link_hash_type ntype
;
628 if (! config
.warn_common
)
631 if (ntype
== bfd_link_hash_defined
)
633 ASSERT (otype
== bfd_link_hash_common
);
634 einfo ("%B: warning: definition of `%T' overriding common\n",
636 einfo ("%B: warning: common is here\n", obfd
);
638 else if (otype
== bfd_link_hash_defined
)
640 ASSERT (ntype
== bfd_link_hash_common
);
641 einfo ("%B: warning: common of `%T' overridden by definition\n",
643 einfo ("%B: warning: defined here\n", obfd
);
647 ASSERT (otype
== bfd_link_hash_common
&& ntype
== bfd_link_hash_common
);
650 einfo ("%B: warning: common of `%T' overridden by larger common\n",
652 einfo ("%B: warning: larger common is here\n", obfd
);
654 else if (nsize
> osize
)
656 einfo ("%B: warning: common of `%T' overriding smaller common\n",
658 einfo ("%B: warning: smaller common is here\n", obfd
);
662 einfo ("%B: warning: multiple common of `%T'\n", nbfd
, name
);
663 einfo ("%B: warning: previous common is here\n", obfd
);
670 /* This is called when BFD has discovered a set element. H is the
671 entry in the linker hash table for the set. SECTION and VALUE
672 represent a value which should be added to the set. */
676 add_to_set (info
, h
, reloc
, abfd
, section
, value
)
677 struct bfd_link_info
*info
;
678 struct bfd_link_hash_entry
*h
;
679 bfd_reloc_code_real_type reloc
;
684 if (! config
.build_constructors
)
687 ldctor_add_set_entry (h
, reloc
, section
, value
);
689 if (h
->type
== bfd_link_hash_new
)
691 h
->type
= bfd_link_hash_undefined
;
692 h
->u
.undef
.abfd
= abfd
;
693 /* We don't call bfd_link_add_undef to add this to the list of
694 undefined symbols because we are going to define it
701 /* This is called when BFD has discovered a constructor. This is only
702 called for some object file formats--those which do not handle
703 constructors in some more clever fashion. This is similar to
704 adding an element to a set, but less general. */
707 constructor_callback (info
, constructor
, name
, abfd
, section
, value
)
708 struct bfd_link_info
*info
;
717 struct bfd_link_hash_entry
*h
;
719 if (! config
.build_constructors
)
722 /* Ensure that BFD_RELOC_CTOR exists now, so that we can give a
723 useful error message. */
724 if (bfd_reloc_type_lookup (output_bfd
, BFD_RELOC_CTOR
) == NULL
)
725 einfo ("%P%F: BFD backend error: BFD_RELOC_CTOR unsupported");
727 set_name
= (char *) alloca (1 + sizeof "__CTOR_LIST__");
729 if (bfd_get_symbol_leading_char (abfd
) != '\0')
730 *s
++ = bfd_get_symbol_leading_char (abfd
);
732 strcpy (s
, "__CTOR_LIST__");
734 strcpy (s
, "__DTOR_LIST__");
736 if (config
.map_file
!= (FILE *) NULL
)
737 fprintf (config
.map_file
,
738 "Adding %s to constructor/destructor set %s\n", name
, set_name
);
740 h
= bfd_link_hash_lookup (info
->hash
, set_name
, true, true, true);
741 if (h
== (struct bfd_link_hash_entry
*) NULL
)
742 einfo ("%P%F: bfd_link_hash_lookup failed: %E");
743 if (h
->type
== bfd_link_hash_new
)
745 h
->type
= bfd_link_hash_undefined
;
746 h
->u
.undef
.abfd
= abfd
;
747 /* We don't call bfd_link_add_undef to add this to the list of
748 undefined symbols because we are going to define it
752 ldctor_add_set_entry (h
, BFD_RELOC_CTOR
, section
, value
);
756 /* This is called when there is a reference to a warning symbol. */
760 warning_callback (info
, warning
)
761 struct bfd_link_info
*info
;
764 einfo ("%P: %s\n", warning
);
768 /* This is called when an undefined symbol is found. */
772 undefined_symbol (info
, name
, abfd
, section
, address
)
773 struct bfd_link_info
*info
;
779 static char *error_name
;
780 static unsigned int error_count
;
782 #define MAX_ERRORS_IN_A_ROW 5
784 /* We never print more than a reasonable number of errors in a row
785 for a single symbol. */
786 if (error_name
!= (char *) NULL
787 && strcmp (name
, error_name
) == 0)
792 if (error_name
!= (char *) NULL
)
794 error_name
= buystring (name
);
797 if (error_count
< MAX_ERRORS_IN_A_ROW
)
798 einfo ("%X%C: undefined reference to `%T'\n",
799 abfd
, section
, address
, name
);
800 else if (error_count
== MAX_ERRORS_IN_A_ROW
)
801 einfo ("%C: more undefined references to `%T' follow\n",
802 abfd
, section
, address
, name
);
807 /* This is called when a reloc overflows. */
811 reloc_overflow (info
, name
, reloc_name
, addend
, abfd
, section
, address
)
812 struct bfd_link_info
*info
;
814 const char *reloc_name
;
820 if (abfd
== (bfd
*) NULL
)
821 einfo ("%P%X: generated");
823 einfo ("%X%C:", abfd
, section
, address
);
824 einfo (" relocation truncated to fit: %s %T", reloc_name
, name
);
826 einfo ("+%v", addend
);
831 /* This is called when a dangerous relocation is made. */
835 reloc_dangerous (info
, message
, abfd
, section
, address
)
836 struct bfd_link_info
*info
;
842 if (abfd
== (bfd
*) NULL
)
843 einfo ("%P%X: generated");
845 einfo ("%X%C:", abfd
, section
, address
);
846 einfo ("dangerous relocation: %s\n", message
);
850 /* This is called when a reloc is being generated attached to a symbol
851 that is not being output. */
855 unattached_reloc (info
, name
, abfd
, section
, address
)
856 struct bfd_link_info
*info
;
862 if (abfd
== (bfd
*) NULL
)
863 einfo ("%P%X: generated");
865 einfo ("%X%C:", abfd
, section
, address
);
866 einfo (" reloc refers to symbol `%T' which is not being output\n", name
);
870 /* This is called when a symbol in notice_hash is found. Symbols are
871 put in notice_hash using the -y option. */
875 notice_ysym (info
, name
, abfd
, section
, value
)
876 struct bfd_link_info
*info
;
882 einfo ("%B: %s %s\n", abfd
,
883 section
!= &bfd_und_section
? "definition of" : "reference to",