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. */
40 /* Somewhere above, sys/stat.h got included . . . . */
41 #if !defined(S_ISDIR) && defined(S_IFDIR)
42 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
47 static char *get_emulation
PARAMS ((int, char **));
48 static void set_scripts_dir
PARAMS ((void));
53 const char *output_filename
= "a.out";
55 /* Name this program was invoked by. */
58 /* The file that we're creating */
61 /* Set by -G argument, for MIPS ECOFF target. */
62 int g_switch_value
= 8;
64 /* Nonzero means print names of input files as processed. */
67 /* Nonzero means same, but note open failures, too. */
68 boolean trace_file_tries
;
70 /* Nonzero means version number was printed, so exit successfully
71 instead of complaining if no input files are given. */
72 boolean version_printed
;
74 /* 1 => write load map. */
77 args_type command_line
;
79 ld_config_type config
;
81 static boolean check_for_scripts_dir
PARAMS ((char *dir
));
82 static boolean add_archive_element
PARAMS ((struct bfd_link_info
*, bfd
*,
84 static boolean multiple_definition
PARAMS ((struct bfd_link_info
*,
86 bfd
*, asection
*, bfd_vma
,
87 bfd
*, asection
*, bfd_vma
));
88 static boolean multiple_common
PARAMS ((struct bfd_link_info
*,
90 enum bfd_link_hash_type
, bfd_vma
,
91 bfd
*, enum bfd_link_hash_type
,
93 static boolean add_to_set
PARAMS ((struct bfd_link_info
*,
94 struct bfd_link_hash_entry
*,
96 bfd
*, asection
*, bfd_vma
));
97 static boolean constructor_callback
PARAMS ((struct bfd_link_info
*,
101 bfd
*, asection
*, bfd_vma
));
102 static boolean warning_callback
PARAMS ((struct bfd_link_info
*,
104 static boolean undefined_symbol
PARAMS ((struct bfd_link_info
*,
106 asection
*, bfd_vma
));
107 static boolean reloc_overflow
PARAMS ((struct bfd_link_info
*, const char *,
108 const char *, bfd_vma
,
109 bfd
*, asection
*, bfd_vma
));
110 static boolean reloc_dangerous
PARAMS ((struct bfd_link_info
*, const char *,
111 bfd
*, asection
*, bfd_vma
));
112 static boolean unattached_reloc
PARAMS ((struct bfd_link_info
*,
113 const char *, bfd
*, asection
*,
115 static boolean notice_ysym
PARAMS ((struct bfd_link_info
*, const char *,
116 bfd
*, asection
*, bfd_vma
));
118 static struct bfd_link_callbacks link_callbacks
=
124 constructor_callback
,
133 struct bfd_link_info link_info
;
140 if (output_bfd
&& output_bfd
->iostream
)
141 fclose((FILE *)(output_bfd
->iostream
));
142 if (delete_output_file_on_failure
)
143 unlink (output_filename
);
153 long start_time
= get_run_time ();
155 program_name
= argv
[0];
159 atexit (remove_output
);
161 /* Initialize the data about options. */
162 trace_files
= trace_file_tries
= version_printed
= false;
164 config
.build_constructors
= true;
165 command_line
.force_common_definition
= false;
167 link_info
.callbacks
= &link_callbacks
;
168 link_info
.relocateable
= false;
169 link_info
.strip
= strip_none
;
170 link_info
.discard
= discard_none
;
171 link_info
.lprefix_len
= 1;
172 link_info
.lprefix
= "L";
173 link_info
.keep_memory
= true;
174 link_info
.input_bfds
= NULL
;
175 link_info
.create_object_symbols_section
= NULL
;
176 link_info
.hash
= NULL
;
177 link_info
.keep_hash
= NULL
;
178 link_info
.notice_hash
= NULL
;
180 ldfile_add_arch ("");
182 config
.make_executable
= true;
183 force_make_executable
= false;
184 config
.magic_demand_paged
= true;
185 config
.text_read_only
= true;
186 config
.make_executable
= true;
188 emulation
= get_emulation (argc
, argv
);
189 ldemul_choose_mode (emulation
);
190 default_target
= ldemul_choose_target ();
192 ldemul_before_parse ();
193 lang_has_input_file
= false;
194 parse_args (argc
, argv
);
196 /* This essentially adds another -L directory so this must be done after
197 the -L's in argv have been processed. */
200 if (had_script
== false)
202 /* Read the emulation's appropriate default script. */
204 char *s
= ldemul_get_script (&isfile
);
208 /* sizeof counts the terminating NUL. */
209 size_t size
= strlen (s
) + sizeof ("-T ");
210 char *buf
= (char *) xmalloc(size
);
211 sprintf (buf
, "-T %s", s
);
219 if (link_info
.relocateable
&& command_line
.relax
)
221 einfo ("%P%F: -relax and -r may not be used together\n");
225 if (lang_has_input_file
== false)
229 einfo ("%P%F: no input files\n");
234 info_msg ("%P: mode %s\n", emulation
);
237 ldemul_after_parse ();
240 if (config
.map_filename
)
242 if (strcmp (config
.map_filename
, "-") == 0)
244 config
.map_file
= stdout
;
248 config
.map_file
= fopen (config
.map_filename
, FOPEN_WT
);
249 if (config
.map_file
== (FILE *) NULL
)
251 einfo ("%P%F: cannot open map file %s: %E\n",
252 config
.map_filename
);
260 /* Print error messages for any missing symbols, for any warning
261 symbols, and possibly multiple definitions */
264 if (config
.text_read_only
)
266 /* Look for a text section and mark the readonly attribute in it */
267 asection
*found
= bfd_get_section_by_name (output_bfd
, ".text");
269 if (found
!= (asection
*) NULL
)
271 found
->flags
|= SEC_READONLY
;
275 if (link_info
.relocateable
)
276 output_bfd
->flags
&= ~EXEC_P
;
278 output_bfd
->flags
|= EXEC_P
;
282 /* Even if we're producing relocateable output, some non-fatal errors should
283 be reported in the exit status. (What non-fatal errors, if any, do we
284 want to ignore for relocateable output?) */
286 if (config
.make_executable
== false && force_make_executable
== false)
288 if (trace_files
== true)
290 einfo ("%P: link errors found, deleting executable `%s'\n",
294 if (output_bfd
->iostream
)
295 fclose ((FILE *) (output_bfd
->iostream
));
297 unlink (output_filename
);
302 bfd_close (output_bfd
);
307 extern char **environ
;
308 char *lim
= (char *) sbrk (0);
309 long run_time
= get_run_time () - start_time
;
311 fprintf (stderr
, "%s: total time in link: %d.%06d\n",
312 program_name
, run_time
/ 1000000, run_time
% 1000000);
313 fprintf (stderr
, "%s: data size %ld\n", program_name
,
314 (long) (lim
- (char *) &environ
));
317 /* Prevent remove_output from doing anything, after a successful link. */
318 output_filename
= NULL
;
324 /* We need to find any explicitly given emulation in order to initialize the
325 state that's needed by the lex&yacc argument parser (parse_args). */
328 get_emulation (argc
, argv
)
335 emulation
= (char *) getenv (EMULATION_ENVIRON
);
336 if (emulation
== NULL
)
337 emulation
= DEFAULT_EMULATION
;
339 for (i
= 1; i
< argc
; i
++)
341 if (!strncmp (argv
[i
], "-m", 2))
343 if (argv
[i
][2] == '\0')
348 emulation
= argv
[i
+ 1];
353 einfo("%P%F: missing argument to -m\n");
356 else if (strcmp (argv
[i
], "-mips1") == 0
357 || strcmp (argv
[i
], "-mips2") == 0
358 || strcmp (argv
[i
], "-mips3") == 0)
360 /* FIXME: The arguments -mips1, -mips2 and -mips3 are
361 passed to the linker by some MIPS compilers. They
362 generally tell the linker to use a slightly different
363 library path. Perhaps someday these should be
364 implemented as emulations; until then, we just ignore
365 the arguments and hope that nobody ever creates
366 emulations named ips1, ips2 or ips3. */
371 emulation
= &argv
[i
][2];
379 /* If directory DIR contains an "ldscripts" subdirectory,
380 add DIR to the library search path and return true,
381 else return false. */
384 check_for_scripts_dir (dir
)
392 dirlen
= strlen (dir
);
393 /* sizeof counts the terminating NUL. */
394 buf
= (char *) xmalloc (dirlen
+ sizeof("/ldscripts"));
395 sprintf (buf
, "%s/ldscripts", dir
);
397 res
= stat (buf
, &s
) == 0 && S_ISDIR (s
.st_mode
);
400 ldfile_add_library_path (dir
);
404 /* Set the default directory for finding script files.
405 Libraries will be searched for here too, but that's ok.
406 We look for the "ldscripts" directory in:
408 SCRIPTDIR (passed from Makefile)
409 the dir where this program is (for using it from the build tree)
410 the dir where this program is/../lib (for installing the tool suite elsewhere) */
418 if (check_for_scripts_dir (SCRIPTDIR
))
419 return; /* We've been installed normally. */
421 /* Look for "ldscripts" in the dir where our binary is. */
422 end
= strrchr (program_name
, '/');
425 dirlen
= end
- program_name
;
426 /* Make a copy of program_name in dir.
427 Leave room for later "/../lib". */
428 dir
= (char *) xmalloc (dirlen
+ 8);
429 strncpy (dir
, program_name
, dirlen
);
435 dir
= (char *) xmalloc (dirlen
+ 8);
439 if (check_for_scripts_dir (dir
))
440 return; /* Don't free dir. */
442 /* Look for "ldscripts" in <the dir where our binary is>/../lib. */
443 strcpy (dir
+ dirlen
, "/../lib");
444 if (check_for_scripts_dir (dir
))
447 free (dir
); /* Well, we tried. */
454 if (link_info
.notice_hash
== (struct bfd_hash_table
*) NULL
)
456 link_info
.notice_hash
= ((struct bfd_hash_table
*)
457 xmalloc (sizeof (struct bfd_hash_table
)));
458 if (! bfd_hash_table_init_n (link_info
.notice_hash
,
461 einfo ("%P%F: bfd_hash_table_init failed: %E\n");
464 if (bfd_hash_lookup (link_info
.notice_hash
, name
, true, true)
465 == (struct bfd_hash_entry
*) NULL
)
466 einfo ("%P%F: bfd_hash_lookup failed: %E\n");
469 /* Handle the -retain-symbols-file option. */
472 add_keepsyms_file (filename
)
473 const char *filename
;
480 if (link_info
.strip
== strip_some
)
481 einfo ("%X%P: error: duplicate retain-symbols-file\n");
483 file
= fopen (filename
, "r");
484 if (file
== (FILE *) NULL
)
486 bfd_error
= system_call_error
;
487 einfo ("%X%P: %s: %E", filename
);
491 link_info
.keep_hash
= ((struct bfd_hash_table
*)
492 xmalloc (sizeof (struct bfd_hash_table
)));
493 if (! bfd_hash_table_init (link_info
.keep_hash
, bfd_hash_newfunc
))
494 einfo ("%P%F: bfd_hash_table_init failed: %E\n");
497 buf
= (char *) xmalloc (bufsize
);
509 while (! isspace (c
) && c
!= EOF
)
516 buf
= xrealloc (buf
, bufsize
);
523 if (bfd_hash_lookup (link_info
.keep_hash
, buf
, true, true)
524 == (struct bfd_hash_entry
*) NULL
)
525 einfo ("%P%F: bfd_hash_lookup for insertion failed: %E");
529 if (link_info
.strip
!= strip_none
)
530 einfo ("%P: `-retain-symbols-file' overrides `-s' and `-S'\n");
532 link_info
.strip
= strip_some
;
535 /* Callbacks from the BFD linker routines. */
537 /* This is called when BFD has decided to include an archive member in
542 add_archive_element (info
, abfd
, name
)
543 struct bfd_link_info
*info
;
547 lang_input_statement_type
*input
;
549 input
= ((lang_input_statement_type
*)
550 xmalloc ((bfd_size_type
) sizeof (lang_input_statement_type
)));
551 input
->filename
= abfd
->filename
;
552 input
->local_sym_name
= abfd
->filename
;
553 input
->the_bfd
= abfd
;
554 input
->asymbols
= NULL
;
555 input
->subfiles
= NULL
;
557 input
->just_syms_flag
= false;
558 input
->loaded
= false;
561 /* FIXME: This is wrong. It should point to an entry for the
562 archive itself. However, it doesn't seem to matter. */
563 input
->superfile
= NULL
;
565 /* FIXME: The following fields are not set: header.next,
566 header.type, closed, passive_position, symbol_count, total_size,
567 next_real_file, is_archive, search_dirs_flag, target, real,
568 common_section, common_output_section, complained. This bit of
569 code is from the old decode_library_subfile function. I don't
570 know whether any of those fields matters. */
572 ldlang_add_file (input
);
575 info_msg ("%s needed due to %T\n", abfd
->filename
, name
);
577 if (trace_files
|| trace_file_tries
)
578 info_msg ("%I\n", input
);
583 /* This is called when BFD has discovered a symbol which is defined
588 multiple_definition (info
, name
, obfd
, osec
, oval
, nbfd
, nsec
, nval
)
589 struct bfd_link_info
*info
;
598 einfo ("%X%C: multiple definition of `%T'\n",
599 nbfd
, nsec
, nval
, name
);
600 if (obfd
!= (bfd
*) NULL
)
601 einfo ("%C: first defined here\n", obfd
, osec
, oval
);
605 /* This is called when there is a definition of a common symbol, or
606 when a common symbol is found for a symbol that is already defined,
607 or when two common symbols are found. We only do something if
608 -warn-common was used. */
612 multiple_common (info
, name
, obfd
, otype
, osize
, nbfd
, ntype
, nsize
)
613 struct bfd_link_info
*info
;
616 enum bfd_link_hash_type otype
;
619 enum bfd_link_hash_type ntype
;
622 if (! config
.warn_common
)
625 if (ntype
== bfd_link_hash_defined
)
627 ASSERT (otype
== bfd_link_hash_common
);
628 einfo ("%B: warning: definition of `%T' overriding common\n",
630 einfo ("%B: warning: common is here\n", obfd
);
632 else if (otype
== bfd_link_hash_defined
)
634 ASSERT (ntype
== bfd_link_hash_common
);
635 einfo ("%B: warning: common of `%T' overridden by definition\n",
637 einfo ("%B: warning: defined here\n", obfd
);
641 ASSERT (otype
== bfd_link_hash_common
&& ntype
== bfd_link_hash_common
);
644 einfo ("%B: warning: common of `%T' overridden by larger common\n",
646 einfo ("%B: warning: larger common is here\n", obfd
);
648 else if (nsize
> osize
)
650 einfo ("%B: warning: common of `%T' overriding smaller common\n",
652 einfo ("%B: warning: smaller common is here\n", obfd
);
656 einfo ("%B: warning: multiple common of `%T'\n", nbfd
, name
);
657 einfo ("%B: warning: previous common is here\n", obfd
);
664 /* This is called when BFD has discovered a set element. H is the
665 entry in the linker hash table for the set. SECTION and VALUE
666 represent a value which should be added to the set. */
670 add_to_set (info
, h
, bitsize
, abfd
, section
, value
)
671 struct bfd_link_info
*info
;
672 struct bfd_link_hash_entry
*h
;
673 unsigned int bitsize
;
678 ldctor_add_set_entry (h
, bitsize
, section
, value
);
682 /* This is called when BFD has discovered a constructor. This is only
683 called for some object file formats--those which do not handle
684 constructors in some more clever fashion. This is similar to
685 adding an element to a set, but less general. */
688 constructor_callback (info
, constructor
, bitsize
, name
, abfd
, section
, value
)
689 struct bfd_link_info
*info
;
691 unsigned int bitsize
;
699 struct bfd_link_hash_entry
*h
;
701 if (! config
.build_constructors
)
704 set_name
= (char *) alloca (1 + sizeof "__CTOR_LIST__");
706 if (bfd_get_symbol_leading_char (abfd
) != '\0')
707 *s
++ = bfd_get_symbol_leading_char (abfd
);
709 strcpy (s
, "__CTOR_LIST__");
711 strcpy (s
, "__DTOR_LIST__");
714 info_msg ("Adding %s to constructor/destructor set %s\n", name
, set_name
);
716 h
= bfd_link_hash_lookup (info
->hash
, set_name
, true, true, true);
717 if (h
== (struct bfd_link_hash_entry
*) NULL
)
718 einfo ("%P%F: bfd_link_hash_lookup failed: %E");
719 if (h
->type
== bfd_link_hash_new
)
721 h
->type
= bfd_link_hash_undefined
;
722 h
->u
.undef
.abfd
= abfd
;
723 /* We don't call bfd_link_add_undef to add this to the list of
724 undefined symbols because we are going to define it
728 ldctor_add_set_entry (h
, bitsize
, section
, value
);
732 /* This is called when there is a reference to a warning symbol. */
736 warning_callback (info
, warning
)
737 struct bfd_link_info
*info
;
740 einfo ("%P: %s\n", warning
);
744 /* This is called when an undefined symbol is found. */
748 undefined_symbol (info
, name
, abfd
, section
, address
)
749 struct bfd_link_info
*info
;
755 static char *error_name
;
756 static unsigned int error_count
;
758 #define MAX_ERRORS_IN_A_ROW 5
760 /* We never print more than a reasonable number of errors in a row
761 for a single symbol. */
762 if (error_name
!= (char *) NULL
763 && strcmp (name
, error_name
) == 0)
768 if (error_name
!= (char *) NULL
)
770 error_name
= buystring (name
);
773 if (error_count
< MAX_ERRORS_IN_A_ROW
)
774 einfo ("%X%C: undefined reference to `%T'\n",
775 abfd
, section
, address
, name
);
776 else if (error_count
== MAX_ERRORS_IN_A_ROW
)
777 einfo ("%C: more undefined references to `%T' follow\n",
778 abfd
, section
, address
, name
);
783 /* This is called when a reloc overflows. */
787 reloc_overflow (info
, name
, reloc_name
, addend
, abfd
, section
, address
)
788 struct bfd_link_info
*info
;
790 const char *reloc_name
;
796 einfo ("%X%C: relocation truncated to fit: %s %T", abfd
, section
,
797 address
, reloc_name
, name
);
799 einfo ("+%v", addend
);
804 /* This is called when a dangerous relocation is made. */
808 reloc_dangerous (info
, message
, abfd
, section
, address
)
809 struct bfd_link_info
*info
;
815 einfo ("%X%C: dangerous relocation: %s\n", abfd
, section
, address
, message
);
819 /* This is called when a reloc is being generated attached to a symbol
820 that is not being output. */
824 unattached_reloc (info
, name
, abfd
, section
, address
)
825 struct bfd_link_info
*info
;
831 einfo ("%X%C: reloc refers to symbol `%T' which is not being output\n",
832 abfd
, section
, address
, name
);
836 /* This is called when a symbol in notice_hash is found. Symbols are
837 put in notice_hash using the -y option. */
841 notice_ysym (info
, name
, abfd
, section
, value
)
842 struct bfd_link_info
*info
;
848 einfo ("%B: %s %s\n", abfd
,
849 section
!= &bfd_und_section
? "definition of" : "reference to",