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"
42 /* Somewhere above, sys/stat.h got included . . . . */
43 #if !defined(S_ISDIR) && defined(S_IFDIR)
44 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
49 static char *get_emulation
PARAMS ((int, char **));
50 static void set_scripts_dir
PARAMS ((void));
55 const char *output_filename
= "a.out";
57 /* Name this program was invoked by. */
60 /* The file that we're creating */
63 /* Set by -G argument, for MIPS ECOFF target. */
64 int g_switch_value
= 8;
66 /* Nonzero means print names of input files as processed. */
69 /* Nonzero means same, but note open failures, too. */
70 boolean trace_file_tries
;
72 /* Nonzero means version number was printed, so exit successfully
73 instead of complaining if no input files are given. */
74 boolean version_printed
;
76 /* Nonzero means link in every member of an archive. */
77 boolean whole_archive
;
79 args_type command_line
;
81 ld_config_type config
;
83 static boolean check_for_scripts_dir
PARAMS ((char *dir
));
84 static boolean add_archive_element
PARAMS ((struct bfd_link_info
*, bfd
*,
86 static boolean multiple_definition
PARAMS ((struct bfd_link_info
*,
88 bfd
*, asection
*, bfd_vma
,
89 bfd
*, asection
*, bfd_vma
));
90 static boolean multiple_common
PARAMS ((struct bfd_link_info
*,
92 enum bfd_link_hash_type
, bfd_vma
,
93 bfd
*, enum bfd_link_hash_type
,
95 static boolean add_to_set
PARAMS ((struct bfd_link_info
*,
96 struct bfd_link_hash_entry
*,
97 bfd_reloc_code_real_type
,
98 bfd
*, asection
*, bfd_vma
));
99 static boolean constructor_callback
PARAMS ((struct bfd_link_info
*,
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
);
159 START_PROGRESS (program_name
, 0);
163 xatexit (remove_output
);
165 /* Initialize the data about options. */
166 trace_files
= trace_file_tries
= version_printed
= false;
167 whole_archive
= false;
168 config
.traditional_format
= false;
169 config
.build_constructors
= true;
170 config
.dynamic_link
= false;
171 command_line
.force_common_definition
= false;
172 command_line
.interpreter
= NULL
;
173 command_line
.rpath
= NULL
;
175 link_info
.callbacks
= &link_callbacks
;
176 link_info
.relocateable
= false;
177 link_info
.shared
= false;
178 link_info
.strip
= strip_none
;
179 link_info
.discard
= discard_none
;
180 link_info
.lprefix_len
= 1;
181 link_info
.lprefix
= "L";
182 link_info
.keep_memory
= true;
183 link_info
.input_bfds
= NULL
;
184 link_info
.create_object_symbols_section
= NULL
;
185 link_info
.hash
= NULL
;
186 link_info
.keep_hash
= NULL
;
187 link_info
.notice_hash
= NULL
;
189 ldfile_add_arch ("");
191 config
.make_executable
= true;
192 force_make_executable
= false;
193 config
.magic_demand_paged
= true;
194 config
.text_read_only
= true;
195 config
.make_executable
= true;
197 emulation
= get_emulation (argc
, argv
);
198 ldemul_choose_mode (emulation
);
199 default_target
= ldemul_choose_target ();
201 ldemul_before_parse ();
202 lang_has_input_file
= false;
203 parse_args (argc
, argv
);
205 if (link_info
.relocateable
)
207 if (command_line
.relax
)
208 einfo ("%P%F: -relax and -r may not be used together\n");
209 if (config
.dynamic_link
)
210 einfo ("%P%F: -r and -call_shared may not be used together\n");
211 if (link_info
.shared
)
212 einfo ("%P%F: -r and -shared may not be used together\n");
215 /* Treat ld -r -s as ld -r -S -x (i.e., strip all local symbols). I
216 don't see how else this can be handled, since in this case we
217 must preserve all externally visible symbols. */
218 if (link_info
.relocateable
&& link_info
.strip
== strip_all
)
220 link_info
.strip
= strip_debugger
;
221 if (link_info
.discard
== discard_none
)
222 link_info
.discard
= discard_all
;
225 /* This essentially adds another -L directory so this must be done after
226 the -L's in argv have been processed. */
229 if (had_script
== false)
231 /* Read the emulation's appropriate default script. */
233 char *s
= ldemul_get_script (&isfile
);
236 ldfile_open_command_file (s
);
239 if (trace_file_tries
)
241 info_msg ("using internal linker script:\n");
242 info_msg ("==================================================\n");
244 info_msg ("\n==================================================\n");
248 parser_input
= input_script
;
254 if (lang_has_input_file
== false)
258 einfo ("%P%F: no input files\n");
263 info_msg ("%P: mode %s\n", emulation
);
266 ldemul_after_parse ();
269 if (config
.map_filename
)
271 if (strcmp (config
.map_filename
, "-") == 0)
273 config
.map_file
= stdout
;
277 config
.map_file
= fopen (config
.map_filename
, FOPEN_WT
);
278 if (config
.map_file
== (FILE *) NULL
)
280 einfo ("%P%F: cannot open map file %s: %E\n",
281 config
.map_filename
);
289 /* Print error messages for any missing symbols, for any warning
290 symbols, and possibly multiple definitions */
293 if (config
.text_read_only
)
295 /* Look for a text section and mark the readonly attribute in it */
296 asection
*found
= bfd_get_section_by_name (output_bfd
, ".text");
298 if (found
!= (asection
*) NULL
)
300 found
->flags
|= SEC_READONLY
;
304 if (link_info
.relocateable
)
305 output_bfd
->flags
&= ~EXEC_P
;
307 output_bfd
->flags
|= EXEC_P
;
311 /* Even if we're producing relocateable output, some non-fatal errors should
312 be reported in the exit status. (What non-fatal errors, if any, do we
313 want to ignore for relocateable output?) */
315 if (config
.make_executable
== false && force_make_executable
== false)
317 if (trace_files
== true)
319 einfo ("%P: link errors found, deleting executable `%s'\n",
323 if (output_bfd
->iostream
)
324 fclose ((FILE *) (output_bfd
->iostream
));
326 unlink (output_filename
);
331 if (! bfd_close (output_bfd
))
332 einfo ("%F%B: final close failed: %E\n", output_bfd
);
335 END_PROGRESS (program_name
);
339 extern char **environ
;
340 char *lim
= (char *) sbrk (0);
341 long run_time
= get_run_time () - start_time
;
343 fprintf (stderr
, "%s: total time in link: %ld.%06ld\n",
344 program_name
, run_time
/ 1000000, run_time
% 1000000);
345 fprintf (stderr
, "%s: data size %ld\n", program_name
,
346 (long) (lim
- (char *) &environ
));
349 /* Prevent remove_output from doing anything, after a successful link. */
350 output_filename
= NULL
;
356 /* We need to find any explicitly given emulation in order to initialize the
357 state that's needed by the lex&yacc argument parser (parse_args). */
360 get_emulation (argc
, argv
)
367 emulation
= (char *) getenv (EMULATION_ENVIRON
);
368 if (emulation
== NULL
)
369 emulation
= DEFAULT_EMULATION
;
371 for (i
= 1; i
< argc
; i
++)
373 if (!strncmp (argv
[i
], "-m", 2))
375 if (argv
[i
][2] == '\0')
380 emulation
= argv
[i
+ 1];
385 einfo("%P%F: missing argument to -m\n");
388 else if (strcmp (argv
[i
], "-mips1") == 0
389 || strcmp (argv
[i
], "-mips2") == 0
390 || strcmp (argv
[i
], "-mips3") == 0)
392 /* FIXME: The arguments -mips1, -mips2 and -mips3 are
393 passed to the linker by some MIPS compilers. They
394 generally tell the linker to use a slightly different
395 library path. Perhaps someday these should be
396 implemented as emulations; until then, we just ignore
397 the arguments and hope that nobody ever creates
398 emulations named ips1, ips2 or ips3. */
400 else if (strcmp (argv
[i
], "-m486") == 0)
402 /* FIXME: The argument -m486 is passed to the linker on
403 some Linux systems. Hope that nobody creates an
404 emulation named 486. */
409 emulation
= &argv
[i
][2];
417 /* If directory DIR contains an "ldscripts" subdirectory,
418 add DIR to the library search path and return true,
419 else return false. */
422 check_for_scripts_dir (dir
)
430 dirlen
= strlen (dir
);
431 /* sizeof counts the terminating NUL. */
432 buf
= (char *) xmalloc (dirlen
+ sizeof("/ldscripts"));
433 sprintf (buf
, "%s/ldscripts", dir
);
435 res
= stat (buf
, &s
) == 0 && S_ISDIR (s
.st_mode
);
438 ldfile_add_library_path (dir
, false);
442 /* Set the default directory for finding script files.
443 Libraries will be searched for here too, but that's ok.
444 We look for the "ldscripts" directory in:
446 SCRIPTDIR (passed from Makefile)
447 the dir where this program is (for using it from the build tree)
448 the dir where this program is/../lib (for installing the tool suite elsewhere) */
456 if (check_for_scripts_dir (SCRIPTDIR
))
457 return; /* We've been installed normally. */
459 /* Look for "ldscripts" in the dir where our binary is. */
460 end
= strrchr (program_name
, '/');
463 dirlen
= end
- program_name
;
464 /* Make a copy of program_name in dir.
465 Leave room for later "/../lib". */
466 dir
= (char *) xmalloc (dirlen
+ 8);
467 strncpy (dir
, program_name
, dirlen
);
473 dir
= (char *) xmalloc (dirlen
+ 8);
477 if (check_for_scripts_dir (dir
))
478 return; /* Don't free dir. */
480 /* Look for "ldscripts" in <the dir where our binary is>/../lib. */
481 strcpy (dir
+ dirlen
, "/../lib");
482 if (check_for_scripts_dir (dir
))
485 free (dir
); /* Well, we tried. */
492 if (link_info
.notice_hash
== (struct bfd_hash_table
*) NULL
)
494 link_info
.notice_hash
= ((struct bfd_hash_table
*)
495 xmalloc (sizeof (struct bfd_hash_table
)));
496 if (! bfd_hash_table_init_n (link_info
.notice_hash
,
499 einfo ("%P%F: bfd_hash_table_init failed: %E\n");
502 if (bfd_hash_lookup (link_info
.notice_hash
, name
, true, true)
503 == (struct bfd_hash_entry
*) NULL
)
504 einfo ("%P%F: bfd_hash_lookup failed: %E\n");
507 /* Handle the -retain-symbols-file option. */
510 add_keepsyms_file (filename
)
511 const char *filename
;
518 if (link_info
.strip
== strip_some
)
519 einfo ("%X%P: error: duplicate retain-symbols-file\n");
521 file
= fopen (filename
, "r");
522 if (file
== (FILE *) NULL
)
524 bfd_set_error (bfd_error_system_call
);
525 einfo ("%X%P: %s: %E", filename
);
529 link_info
.keep_hash
= ((struct bfd_hash_table
*)
530 xmalloc (sizeof (struct bfd_hash_table
)));
531 if (! bfd_hash_table_init (link_info
.keep_hash
, bfd_hash_newfunc
))
532 einfo ("%P%F: bfd_hash_table_init failed: %E\n");
535 buf
= (char *) xmalloc (bufsize
);
547 while (! isspace (c
) && c
!= EOF
)
554 buf
= xrealloc (buf
, bufsize
);
561 if (bfd_hash_lookup (link_info
.keep_hash
, buf
, true, true)
562 == (struct bfd_hash_entry
*) NULL
)
563 einfo ("%P%F: bfd_hash_lookup for insertion failed: %E");
567 if (link_info
.strip
!= strip_none
)
568 einfo ("%P: `-retain-symbols-file' overrides `-s' and `-S'\n");
570 link_info
.strip
= strip_some
;
573 /* Callbacks from the BFD linker routines. */
575 /* This is called when BFD has decided to include an archive member in
580 add_archive_element (info
, abfd
, name
)
581 struct bfd_link_info
*info
;
585 lang_input_statement_type
*input
;
587 input
= ((lang_input_statement_type
*)
588 xmalloc ((bfd_size_type
) sizeof (lang_input_statement_type
)));
589 input
->filename
= abfd
->filename
;
590 input
->local_sym_name
= abfd
->filename
;
591 input
->the_bfd
= abfd
;
592 input
->asymbols
= NULL
;
594 input
->just_syms_flag
= false;
595 input
->loaded
= false;
596 input
->search_dirs_flag
= false;
598 /* FIXME: The following fields are not set: header.next,
599 header.type, closed, passive_position, symbol_count,
600 next_real_file, is_archive, target, real, common_section,
601 common_output_section, complained. This bit of code is from the
602 old decode_library_subfile function. I don't know whether any of
603 those fields matters. */
605 ldlang_add_file (input
);
607 if (config
.map_file
!= (FILE *) NULL
)
608 minfo ("%s needed due to %T\n", abfd
->filename
, name
);
610 if (trace_files
|| trace_file_tries
)
611 info_msg ("%I\n", input
);
616 /* This is called when BFD has discovered a symbol which is defined
621 multiple_definition (info
, name
, obfd
, osec
, oval
, nbfd
, nsec
, nval
)
622 struct bfd_link_info
*info
;
631 einfo ("%X%C: multiple definition of `%T'\n",
632 nbfd
, nsec
, nval
, name
);
633 if (obfd
!= (bfd
*) NULL
)
634 einfo ("%D: first defined here\n", obfd
, osec
, oval
);
638 /* This is called when there is a definition of a common symbol, or
639 when a common symbol is found for a symbol that is already defined,
640 or when two common symbols are found. We only do something if
641 -warn-common was used. */
645 multiple_common (info
, name
, obfd
, otype
, osize
, nbfd
, ntype
, nsize
)
646 struct bfd_link_info
*info
;
649 enum bfd_link_hash_type otype
;
652 enum bfd_link_hash_type ntype
;
655 if (! config
.warn_common
)
658 if (ntype
== bfd_link_hash_defined
659 || ntype
== bfd_link_hash_defweak
660 || ntype
== bfd_link_hash_indirect
)
662 ASSERT (otype
== bfd_link_hash_common
);
663 einfo ("%B: warning: definition of `%T' overriding common\n",
666 einfo ("%B: warning: common is here\n", obfd
);
668 else if (otype
== bfd_link_hash_defined
669 || otype
== bfd_link_hash_defweak
670 || otype
== bfd_link_hash_indirect
)
672 ASSERT (ntype
== bfd_link_hash_common
);
673 einfo ("%B: warning: common of `%T' overridden by definition\n",
676 einfo ("%B: warning: defined here\n", obfd
);
680 ASSERT (otype
== bfd_link_hash_common
&& ntype
== bfd_link_hash_common
);
683 einfo ("%B: warning: common of `%T' overridden by larger common\n",
686 einfo ("%B: warning: larger common is here\n", obfd
);
688 else if (nsize
> osize
)
690 einfo ("%B: warning: common of `%T' overriding smaller common\n",
693 einfo ("%B: warning: smaller common is here\n", obfd
);
697 einfo ("%B: warning: multiple common of `%T'\n", nbfd
, name
);
699 einfo ("%B: warning: previous common is here\n", obfd
);
706 /* This is called when BFD has discovered a set element. H is the
707 entry in the linker hash table for the set. SECTION and VALUE
708 represent a value which should be added to the set. */
712 add_to_set (info
, h
, reloc
, abfd
, section
, value
)
713 struct bfd_link_info
*info
;
714 struct bfd_link_hash_entry
*h
;
715 bfd_reloc_code_real_type reloc
;
720 if (! config
.build_constructors
)
723 ldctor_add_set_entry (h
, reloc
, section
, value
);
725 if (h
->type
== bfd_link_hash_new
)
727 h
->type
= bfd_link_hash_undefined
;
728 h
->u
.undef
.abfd
= abfd
;
729 /* We don't call bfd_link_add_undef to add this to the list of
730 undefined symbols because we are going to define it
737 /* This is called when BFD has discovered a constructor. This is only
738 called for some object file formats--those which do not handle
739 constructors in some more clever fashion. This is similar to
740 adding an element to a set, but less general. */
743 constructor_callback (info
, constructor
, name
, abfd
, section
, value
)
744 struct bfd_link_info
*info
;
753 struct bfd_link_hash_entry
*h
;
755 if (! config
.build_constructors
)
758 /* Ensure that BFD_RELOC_CTOR exists now, so that we can give a
759 useful error message. */
760 if (bfd_reloc_type_lookup (output_bfd
, BFD_RELOC_CTOR
) == NULL
)
761 einfo ("%P%F: BFD backend error: BFD_RELOC_CTOR unsupported");
763 set_name
= (char *) alloca (1 + sizeof "__CTOR_LIST__");
765 if (bfd_get_symbol_leading_char (abfd
) != '\0')
766 *s
++ = bfd_get_symbol_leading_char (abfd
);
768 strcpy (s
, "__CTOR_LIST__");
770 strcpy (s
, "__DTOR_LIST__");
772 if (config
.map_file
!= (FILE *) NULL
)
773 fprintf (config
.map_file
,
774 "Adding %s to constructor/destructor set %s\n", name
, set_name
);
776 h
= bfd_link_hash_lookup (info
->hash
, set_name
, true, true, true);
777 if (h
== (struct bfd_link_hash_entry
*) NULL
)
778 einfo ("%P%F: bfd_link_hash_lookup failed: %E");
779 if (h
->type
== bfd_link_hash_new
)
781 h
->type
= bfd_link_hash_undefined
;
782 h
->u
.undef
.abfd
= abfd
;
783 /* We don't call bfd_link_add_undef to add this to the list of
784 undefined symbols because we are going to define it
788 ldctor_add_set_entry (h
, BFD_RELOC_CTOR
, section
, value
);
792 /* This is called when there is a reference to a warning symbol. */
796 warning_callback (info
, warning
)
797 struct bfd_link_info
*info
;
800 einfo ("%P: %s\n", warning
);
804 /* This is called when an undefined symbol is found. */
808 undefined_symbol (info
, name
, abfd
, section
, address
)
809 struct bfd_link_info
*info
;
815 static char *error_name
;
816 static unsigned int error_count
;
818 #define MAX_ERRORS_IN_A_ROW 5
820 if (config
.warn_once
)
822 static struct bfd_hash_table
*hash
;
824 /* Only warn once about a particular undefined symbol. */
828 hash
= ((struct bfd_hash_table
*)
829 xmalloc (sizeof (struct bfd_hash_table
)));
830 if (! bfd_hash_table_init (hash
, bfd_hash_newfunc
))
831 einfo ("%F%P: bfd_hash_table_init failed: %E\n");
834 if (bfd_hash_lookup (hash
, name
, false, false) != NULL
)
837 if (bfd_hash_lookup (hash
, name
, true, true) == NULL
)
838 einfo ("%F%P: bfd_hash_lookup failed: %E\n");
841 /* We never print more than a reasonable number of errors in a row
842 for a single symbol. */
843 if (error_name
!= (char *) NULL
844 && strcmp (name
, error_name
) == 0)
849 if (error_name
!= (char *) NULL
)
851 error_name
= buystring (name
);
856 if (error_count
< MAX_ERRORS_IN_A_ROW
)
857 einfo ("%X%C: undefined reference to `%T'\n",
858 abfd
, section
, address
, name
);
859 else if (error_count
== MAX_ERRORS_IN_A_ROW
)
860 einfo ("%D: more undefined references to `%T' follow\n",
861 abfd
, section
, address
, name
);
865 if (error_count
< MAX_ERRORS_IN_A_ROW
)
866 einfo ("%X%B: undefined reference to `%T'\n",
868 else if (error_count
== MAX_ERRORS_IN_A_ROW
)
869 einfo ("%B: more undefined references to `%T' follow\n",
876 /* This is called when a reloc overflows. */
880 reloc_overflow (info
, name
, reloc_name
, addend
, abfd
, section
, address
)
881 struct bfd_link_info
*info
;
883 const char *reloc_name
;
889 if (abfd
== (bfd
*) NULL
)
890 einfo ("%P%X: generated");
892 einfo ("%X%C:", abfd
, section
, address
);
893 einfo (" relocation truncated to fit: %s %T", reloc_name
, name
);
895 einfo ("+%v", addend
);
900 /* This is called when a dangerous relocation is made. */
904 reloc_dangerous (info
, message
, abfd
, section
, address
)
905 struct bfd_link_info
*info
;
911 if (abfd
== (bfd
*) NULL
)
912 einfo ("%P%X: generated");
914 einfo ("%X%C:", abfd
, section
, address
);
915 einfo ("dangerous relocation: %s\n", message
);
919 /* This is called when a reloc is being generated attached to a symbol
920 that is not being output. */
924 unattached_reloc (info
, name
, abfd
, section
, address
)
925 struct bfd_link_info
*info
;
931 if (abfd
== (bfd
*) NULL
)
932 einfo ("%P%X: generated");
934 einfo ("%X%C:", abfd
, section
, address
);
935 einfo (" reloc refers to symbol `%T' which is not being output\n", name
);
939 /* This is called when a symbol in notice_hash is found. Symbols are
940 put in notice_hash using the -y option. */
944 notice_ysym (info
, name
, abfd
, section
, value
)
945 struct bfd_link_info
*info
;
951 einfo ("%B: %s %s\n", abfd
,
952 bfd_is_und_section (section
) ? "reference to" : "definition of",