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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 /* Use sbrk() except on specific OS types */
50 #if !defined(__amigados__) && !defined(WINDOWS_NT)
54 static char *get_emulation
PARAMS ((int, char **));
55 static void set_scripts_dir
PARAMS ((void));
60 const char *output_filename
= "a.out";
62 /* Name this program was invoked by. */
65 /* The file that we're creating */
68 /* Set by -G argument, for MIPS ECOFF target. */
69 int g_switch_value
= 8;
71 /* Nonzero means print names of input files as processed. */
74 /* Nonzero means same, but note open failures, too. */
75 boolean trace_file_tries
;
77 /* Nonzero means version number was printed, so exit successfully
78 instead of complaining if no input files are given. */
79 boolean version_printed
;
81 /* Nonzero means link in every member of an archive. */
82 boolean whole_archive
;
84 args_type command_line
;
86 ld_config_type config
;
88 static boolean check_for_scripts_dir
PARAMS ((char *dir
));
89 static boolean add_archive_element
PARAMS ((struct bfd_link_info
*, bfd
*,
91 static boolean multiple_definition
PARAMS ((struct bfd_link_info
*,
93 bfd
*, asection
*, bfd_vma
,
94 bfd
*, asection
*, bfd_vma
));
95 static boolean multiple_common
PARAMS ((struct bfd_link_info
*,
97 enum bfd_link_hash_type
, bfd_vma
,
98 bfd
*, enum bfd_link_hash_type
,
100 static boolean add_to_set
PARAMS ((struct bfd_link_info
*,
101 struct bfd_link_hash_entry
*,
102 bfd_reloc_code_real_type
,
103 bfd
*, asection
*, bfd_vma
));
104 static boolean constructor_callback
PARAMS ((struct bfd_link_info
*,
107 bfd
*, asection
*, bfd_vma
));
108 static boolean warning_callback
PARAMS ((struct bfd_link_info
*,
110 static boolean undefined_symbol
PARAMS ((struct bfd_link_info
*,
112 asection
*, bfd_vma
));
113 static boolean reloc_overflow
PARAMS ((struct bfd_link_info
*, const char *,
114 const char *, bfd_vma
,
115 bfd
*, asection
*, bfd_vma
));
116 static boolean reloc_dangerous
PARAMS ((struct bfd_link_info
*, const char *,
117 bfd
*, asection
*, bfd_vma
));
118 static boolean unattached_reloc
PARAMS ((struct bfd_link_info
*,
119 const char *, bfd
*, asection
*,
121 static boolean notice_ysym
PARAMS ((struct bfd_link_info
*, const char *,
122 bfd
*, asection
*, bfd_vma
));
124 static struct bfd_link_callbacks link_callbacks
=
130 constructor_callback
,
139 struct bfd_link_info link_info
;
146 if (output_bfd
&& output_bfd
->iostream
)
147 fclose((FILE *)(output_bfd
->iostream
));
148 if (delete_output_file_on_failure
)
149 unlink (output_filename
);
159 long start_time
= get_run_time ();
161 program_name
= argv
[0];
162 xmalloc_set_program_name (program_name
);
164 START_PROGRESS (program_name
, 0);
168 xatexit (remove_output
);
170 /* Initialize the data about options. */
171 trace_files
= trace_file_tries
= version_printed
= false;
172 whole_archive
= false;
173 config
.traditional_format
= false;
174 config
.build_constructors
= true;
175 config
.dynamic_link
= false;
176 command_line
.force_common_definition
= false;
177 command_line
.interpreter
= NULL
;
178 command_line
.rpath
= NULL
;
180 link_info
.callbacks
= &link_callbacks
;
181 link_info
.relocateable
= false;
182 link_info
.shared
= false;
183 link_info
.symbolic
= false;
184 link_info
.strip
= strip_none
;
185 link_info
.discard
= discard_none
;
186 link_info
.lprefix_len
= 1;
187 link_info
.lprefix
= "L";
188 link_info
.keep_memory
= true;
189 link_info
.input_bfds
= NULL
;
190 link_info
.create_object_symbols_section
= NULL
;
191 link_info
.hash
= NULL
;
192 link_info
.keep_hash
= NULL
;
193 link_info
.notice_hash
= NULL
;
194 link_info
.subsystem
= console
;
195 link_info
.stack_heap_parameters
.stack_defined
= false;
196 link_info
.stack_heap_parameters
.heap_defined
= false;
197 link_info
.stack_heap_parameters
.stack_reserve
= 0;
198 link_info
.stack_heap_parameters
.stack_commit
= 0;
199 link_info
.stack_heap_parameters
.heap_reserve
= 0;
200 link_info
.stack_heap_parameters
.heap_commit
= 0;
203 ldfile_add_arch ("");
205 config
.make_executable
= true;
206 force_make_executable
= false;
207 config
.magic_demand_paged
= true;
208 config
.text_read_only
= true;
209 config
.make_executable
= true;
211 emulation
= get_emulation (argc
, argv
);
212 ldemul_choose_mode (emulation
);
213 default_target
= ldemul_choose_target ();
215 ldemul_before_parse ();
216 lang_has_input_file
= false;
217 parse_args (argc
, argv
);
219 if (link_info
.relocateable
)
221 if (command_line
.relax
)
222 einfo ("%P%F: -relax and -r may not be used together\n");
223 if (config
.dynamic_link
)
224 einfo ("%P%F: -r and -call_shared may not be used together\n");
225 if (link_info
.shared
)
226 einfo ("%P%F: -r and -shared may not be used together\n");
229 /* Treat ld -r -s as ld -r -S -x (i.e., strip all local symbols). I
230 don't see how else this can be handled, since in this case we
231 must preserve all externally visible symbols. */
232 if (link_info
.relocateable
&& link_info
.strip
== strip_all
)
234 link_info
.strip
= strip_debugger
;
235 if (link_info
.discard
== discard_none
)
236 link_info
.discard
= discard_all
;
239 /* This essentially adds another -L directory so this must be done after
240 the -L's in argv have been processed. */
243 if (had_script
== false)
245 /* Read the emulation's appropriate default script. */
247 char *s
= ldemul_get_script (&isfile
);
250 ldfile_open_command_file (s
);
253 if (trace_file_tries
)
255 info_msg ("using internal linker script:\n");
256 info_msg ("==================================================\n");
258 info_msg ("\n==================================================\n");
262 parser_input
= input_script
;
268 if (lang_has_input_file
== false)
272 einfo ("%P%F: no input files\n");
277 info_msg ("%P: mode %s\n", emulation
);
280 ldemul_after_parse ();
283 if (config
.map_filename
)
285 if (strcmp (config
.map_filename
, "-") == 0)
287 config
.map_file
= stdout
;
291 config
.map_file
= fopen (config
.map_filename
, FOPEN_WT
);
292 if (config
.map_file
== (FILE *) NULL
)
294 bfd_set_error (bfd_error_system_call
);
295 einfo ("%P%F: cannot open map file %s: %E\n",
296 config
.map_filename
);
304 /* Print error messages for any missing symbols, for any warning
305 symbols, and possibly multiple definitions */
308 if (config
.text_read_only
)
310 /* Look for a text section and mark the readonly attribute in it */
311 asection
*found
= bfd_get_section_by_name (output_bfd
, ".text");
313 if (found
!= (asection
*) NULL
)
315 found
->flags
|= SEC_READONLY
;
319 if (link_info
.relocateable
)
320 output_bfd
->flags
&= ~EXEC_P
;
322 output_bfd
->flags
|= EXEC_P
;
326 /* Even if we're producing relocateable output, some non-fatal errors should
327 be reported in the exit status. (What non-fatal errors, if any, do we
328 want to ignore for relocateable output?) */
330 if (config
.make_executable
== false && force_make_executable
== false)
332 if (trace_files
== true)
334 einfo ("%P: link errors found, deleting executable `%s'\n",
338 if (output_bfd
->iostream
)
339 fclose ((FILE *) (output_bfd
->iostream
));
341 unlink (output_filename
);
346 if (! bfd_close (output_bfd
))
347 einfo ("%F%B: final close failed: %E\n", output_bfd
);
350 END_PROGRESS (program_name
);
354 extern char **environ
;
356 char *lim
= (char *) sbrk (0);
358 long run_time
= get_run_time () - start_time
;
360 fprintf (stderr
, "%s: total time in link: %ld.%06ld\n",
361 program_name
, run_time
/ 1000000, run_time
% 1000000);
363 fprintf (stderr
, "%s: data size %ld\n", program_name
,
364 (long) (lim
- (char *) &environ
));
368 /* Prevent remove_output from doing anything, after a successful link. */
369 output_filename
= NULL
;
375 /* We need to find any explicitly given emulation in order to initialize the
376 state that's needed by the lex&yacc argument parser (parse_args). */
379 get_emulation (argc
, argv
)
386 emulation
= (char *) getenv (EMULATION_ENVIRON
);
387 if (emulation
== NULL
)
388 emulation
= DEFAULT_EMULATION
;
390 for (i
= 1; i
< argc
; i
++)
392 if (!strncmp (argv
[i
], "-m", 2))
394 if (argv
[i
][2] == '\0')
399 emulation
= argv
[i
+ 1];
404 einfo("%P%F: missing argument to -m\n");
407 else if (strcmp (argv
[i
], "-mips1") == 0
408 || strcmp (argv
[i
], "-mips2") == 0
409 || strcmp (argv
[i
], "-mips3") == 0)
411 /* FIXME: The arguments -mips1, -mips2 and -mips3 are
412 passed to the linker by some MIPS compilers. They
413 generally tell the linker to use a slightly different
414 library path. Perhaps someday these should be
415 implemented as emulations; until then, we just ignore
416 the arguments and hope that nobody ever creates
417 emulations named ips1, ips2 or ips3. */
419 else if (strcmp (argv
[i
], "-m486") == 0)
421 /* FIXME: The argument -m486 is passed to the linker on
422 some Linux systems. Hope that nobody creates an
423 emulation named 486. */
428 emulation
= &argv
[i
][2];
436 /* If directory DIR contains an "ldscripts" subdirectory,
437 add DIR to the library search path and return true,
438 else return false. */
441 check_for_scripts_dir (dir
)
449 dirlen
= strlen (dir
);
450 /* sizeof counts the terminating NUL. */
451 buf
= (char *) xmalloc (dirlen
+ sizeof("/ldscripts"));
452 sprintf (buf
, "%s/ldscripts", dir
);
454 res
= stat (buf
, &s
) == 0 && S_ISDIR (s
.st_mode
);
457 ldfile_add_library_path (dir
, false);
461 /* Set the default directory for finding script files.
462 Libraries will be searched for here too, but that's ok.
463 We look for the "ldscripts" directory in:
465 SCRIPTDIR (passed from Makefile)
466 the dir where this program is (for using it from the build tree)
467 the dir where this program is/../lib (for installing the tool suite elsewhere) */
475 if (check_for_scripts_dir (SCRIPTDIR
))
476 return; /* We've been installed normally. */
478 /* Look for "ldscripts" in the dir where our binary is. */
479 end
= strrchr (program_name
, '/');
482 dirlen
= end
- program_name
;
483 /* Make a copy of program_name in dir.
484 Leave room for later "/../lib". */
485 dir
= (char *) xmalloc (dirlen
+ 8);
486 strncpy (dir
, program_name
, dirlen
);
492 dir
= (char *) xmalloc (dirlen
+ 8);
496 if (check_for_scripts_dir (dir
))
497 return; /* Don't free dir. */
499 /* Look for "ldscripts" in <the dir where our binary is>/../lib. */
500 strcpy (dir
+ dirlen
, "/../lib");
501 if (check_for_scripts_dir (dir
))
504 free (dir
); /* Well, we tried. */
511 if (link_info
.notice_hash
== (struct bfd_hash_table
*) NULL
)
513 link_info
.notice_hash
= ((struct bfd_hash_table
*)
514 xmalloc (sizeof (struct bfd_hash_table
)));
515 if (! bfd_hash_table_init_n (link_info
.notice_hash
,
518 einfo ("%P%F: bfd_hash_table_init failed: %E\n");
521 if (bfd_hash_lookup (link_info
.notice_hash
, name
, true, true)
522 == (struct bfd_hash_entry
*) NULL
)
523 einfo ("%P%F: bfd_hash_lookup failed: %E\n");
526 /* Handle the -retain-symbols-file option. */
529 add_keepsyms_file (filename
)
530 const char *filename
;
537 if (link_info
.strip
== strip_some
)
538 einfo ("%X%P: error: duplicate retain-symbols-file\n");
540 file
= fopen (filename
, "r");
541 if (file
== (FILE *) NULL
)
543 bfd_set_error (bfd_error_system_call
);
544 einfo ("%X%P: %s: %E", filename
);
548 link_info
.keep_hash
= ((struct bfd_hash_table
*)
549 xmalloc (sizeof (struct bfd_hash_table
)));
550 if (! bfd_hash_table_init (link_info
.keep_hash
, bfd_hash_newfunc
))
551 einfo ("%P%F: bfd_hash_table_init failed: %E\n");
554 buf
= (char *) xmalloc (bufsize
);
566 while (! isspace (c
) && c
!= EOF
)
573 buf
= xrealloc (buf
, bufsize
);
580 if (bfd_hash_lookup (link_info
.keep_hash
, buf
, true, true)
581 == (struct bfd_hash_entry
*) NULL
)
582 einfo ("%P%F: bfd_hash_lookup for insertion failed: %E");
586 if (link_info
.strip
!= strip_none
)
587 einfo ("%P: `-retain-symbols-file' overrides `-s' and `-S'\n");
589 link_info
.strip
= strip_some
;
592 /* Callbacks from the BFD linker routines. */
594 /* This is called when BFD has decided to include an archive member in
599 add_archive_element (info
, abfd
, name
)
600 struct bfd_link_info
*info
;
604 lang_input_statement_type
*input
;
606 input
= ((lang_input_statement_type
*)
607 xmalloc ((bfd_size_type
) sizeof (lang_input_statement_type
)));
608 input
->filename
= abfd
->filename
;
609 input
->local_sym_name
= abfd
->filename
;
610 input
->the_bfd
= abfd
;
611 input
->asymbols
= NULL
;
613 input
->just_syms_flag
= false;
614 input
->loaded
= false;
615 input
->search_dirs_flag
= false;
617 /* FIXME: The following fields are not set: header.next,
618 header.type, closed, passive_position, symbol_count,
619 next_real_file, is_archive, target, real, common_section,
620 common_output_section, complained. This bit of code is from the
621 old decode_library_subfile function. I don't know whether any of
622 those fields matters. */
624 ldlang_add_file (input
);
626 if (config
.map_file
!= (FILE *) NULL
)
627 minfo ("%s needed due to %T\n", abfd
->filename
, name
);
629 if (trace_files
|| trace_file_tries
)
630 info_msg ("%I\n", input
);
635 /* This is called when BFD has discovered a symbol which is defined
640 multiple_definition (info
, name
, obfd
, osec
, oval
, nbfd
, nsec
, nval
)
641 struct bfd_link_info
*info
;
650 einfo ("%X%C: multiple definition of `%T'\n",
651 nbfd
, nsec
, nval
, name
);
652 if (obfd
!= (bfd
*) NULL
)
653 einfo ("%D: first defined here\n", obfd
, osec
, oval
);
657 /* This is called when there is a definition of a common symbol, or
658 when a common symbol is found for a symbol that is already defined,
659 or when two common symbols are found. We only do something if
660 -warn-common was used. */
664 multiple_common (info
, name
, obfd
, otype
, osize
, nbfd
, ntype
, nsize
)
665 struct bfd_link_info
*info
;
668 enum bfd_link_hash_type otype
;
671 enum bfd_link_hash_type ntype
;
674 if (! config
.warn_common
)
677 if (ntype
== bfd_link_hash_defined
678 || ntype
== bfd_link_hash_defweak
679 || ntype
== bfd_link_hash_indirect
)
681 ASSERT (otype
== bfd_link_hash_common
);
682 einfo ("%B: warning: definition of `%T' overriding common\n",
685 einfo ("%B: warning: common is here\n", obfd
);
687 else if (otype
== bfd_link_hash_defined
688 || otype
== bfd_link_hash_defweak
689 || otype
== bfd_link_hash_indirect
)
691 ASSERT (ntype
== bfd_link_hash_common
);
692 einfo ("%B: warning: common of `%T' overridden by definition\n",
695 einfo ("%B: warning: defined here\n", obfd
);
699 ASSERT (otype
== bfd_link_hash_common
&& ntype
== bfd_link_hash_common
);
702 einfo ("%B: warning: common of `%T' overridden by larger common\n",
705 einfo ("%B: warning: larger common is here\n", obfd
);
707 else if (nsize
> osize
)
709 einfo ("%B: warning: common of `%T' overriding smaller common\n",
712 einfo ("%B: warning: smaller common is here\n", obfd
);
716 einfo ("%B: warning: multiple common of `%T'\n", nbfd
, name
);
718 einfo ("%B: warning: previous common is here\n", obfd
);
725 /* This is called when BFD has discovered a set element. H is the
726 entry in the linker hash table for the set. SECTION and VALUE
727 represent a value which should be added to the set. */
731 add_to_set (info
, h
, reloc
, abfd
, section
, value
)
732 struct bfd_link_info
*info
;
733 struct bfd_link_hash_entry
*h
;
734 bfd_reloc_code_real_type reloc
;
739 if (! config
.build_constructors
)
742 ldctor_add_set_entry (h
, reloc
, section
, value
);
744 if (h
->type
== bfd_link_hash_new
)
746 h
->type
= bfd_link_hash_undefined
;
747 h
->u
.undef
.abfd
= abfd
;
748 /* We don't call bfd_link_add_undef to add this to the list of
749 undefined symbols because we are going to define it
756 /* This is called when BFD has discovered a constructor. This is only
757 called for some object file formats--those which do not handle
758 constructors in some more clever fashion. This is similar to
759 adding an element to a set, but less general. */
762 constructor_callback (info
, constructor
, name
, abfd
, section
, value
)
763 struct bfd_link_info
*info
;
772 struct bfd_link_hash_entry
*h
;
774 if (! config
.build_constructors
)
777 /* Ensure that BFD_RELOC_CTOR exists now, so that we can give a
778 useful error message. */
779 if (bfd_reloc_type_lookup (output_bfd
, BFD_RELOC_CTOR
) == NULL
)
780 einfo ("%P%F: BFD backend error: BFD_RELOC_CTOR unsupported");
782 set_name
= (char *) alloca (1 + sizeof "__CTOR_LIST__");
784 if (bfd_get_symbol_leading_char (abfd
) != '\0')
785 *s
++ = bfd_get_symbol_leading_char (abfd
);
787 strcpy (s
, "__CTOR_LIST__");
789 strcpy (s
, "__DTOR_LIST__");
791 if (config
.map_file
!= (FILE *) NULL
)
792 fprintf (config
.map_file
,
793 "Adding %s to constructor/destructor set %s\n", name
, set_name
);
795 h
= bfd_link_hash_lookup (info
->hash
, set_name
, true, true, true);
796 if (h
== (struct bfd_link_hash_entry
*) NULL
)
797 einfo ("%P%F: bfd_link_hash_lookup failed: %E");
798 if (h
->type
== bfd_link_hash_new
)
800 h
->type
= bfd_link_hash_undefined
;
801 h
->u
.undef
.abfd
= abfd
;
802 /* We don't call bfd_link_add_undef to add this to the list of
803 undefined symbols because we are going to define it
807 ldctor_add_set_entry (h
, BFD_RELOC_CTOR
, section
, value
);
811 /* This is called when there is a reference to a warning symbol. */
815 warning_callback (info
, warning
)
816 struct bfd_link_info
*info
;
819 einfo ("%P: %s\n", warning
);
823 /* This is called when an undefined symbol is found. */
827 undefined_symbol (info
, name
, abfd
, section
, address
)
828 struct bfd_link_info
*info
;
834 static char *error_name
;
835 static unsigned int error_count
;
837 #define MAX_ERRORS_IN_A_ROW 5
839 if (config
.warn_once
)
841 static struct bfd_hash_table
*hash
;
843 /* Only warn once about a particular undefined symbol. */
847 hash
= ((struct bfd_hash_table
*)
848 xmalloc (sizeof (struct bfd_hash_table
)));
849 if (! bfd_hash_table_init (hash
, bfd_hash_newfunc
))
850 einfo ("%F%P: bfd_hash_table_init failed: %E\n");
853 if (bfd_hash_lookup (hash
, name
, false, false) != NULL
)
856 if (bfd_hash_lookup (hash
, name
, true, true) == NULL
)
857 einfo ("%F%P: bfd_hash_lookup failed: %E\n");
860 /* We never print more than a reasonable number of errors in a row
861 for a single symbol. */
862 if (error_name
!= (char *) NULL
863 && strcmp (name
, error_name
) == 0)
868 if (error_name
!= (char *) NULL
)
870 error_name
= buystring (name
);
875 if (error_count
< MAX_ERRORS_IN_A_ROW
)
876 einfo ("%X%C: undefined reference to `%T'\n",
877 abfd
, section
, address
, name
);
878 else if (error_count
== MAX_ERRORS_IN_A_ROW
)
879 einfo ("%D: more undefined references to `%T' follow\n",
880 abfd
, section
, address
, name
);
884 if (error_count
< MAX_ERRORS_IN_A_ROW
)
885 einfo ("%X%B: undefined reference to `%T'\n",
887 else if (error_count
== MAX_ERRORS_IN_A_ROW
)
888 einfo ("%B: more undefined references to `%T' follow\n",
895 /* This is called when a reloc overflows. */
899 reloc_overflow (info
, name
, reloc_name
, addend
, abfd
, section
, address
)
900 struct bfd_link_info
*info
;
902 const char *reloc_name
;
908 if (abfd
== (bfd
*) NULL
)
909 einfo ("%P%X: generated");
911 einfo ("%X%C:", abfd
, section
, address
);
912 einfo (" relocation truncated to fit: %s %T", reloc_name
, name
);
914 einfo ("+%v", addend
);
919 /* This is called when a dangerous relocation is made. */
923 reloc_dangerous (info
, message
, abfd
, section
, address
)
924 struct bfd_link_info
*info
;
930 if (abfd
== (bfd
*) NULL
)
931 einfo ("%P%X: generated");
933 einfo ("%X%C:", abfd
, section
, address
);
934 einfo ("dangerous relocation: %s\n", message
);
938 /* This is called when a reloc is being generated attached to a symbol
939 that is not being output. */
943 unattached_reloc (info
, name
, abfd
, section
, address
)
944 struct bfd_link_info
*info
;
950 if (abfd
== (bfd
*) NULL
)
951 einfo ("%P%X: generated");
953 einfo ("%X%C:", abfd
, section
, address
);
954 einfo (" reloc refers to symbol `%T' which is not being output\n", name
);
958 /* This is called when a symbol in notice_hash is found. Symbols are
959 put in notice_hash using the -y option. */
963 notice_ysym (info
, name
, abfd
, section
, value
)
964 struct bfd_link_info
*info
;
970 einfo ("%B: %s %s\n", abfd
,
971 bfd_is_und_section (section
) ? "reference to" : "definition of",