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;
166 command_line.rpath = NULL;
168 link_info.callbacks = &link_callbacks;
169 link_info.relocateable = false;
170 link_info.shared = 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 if (link_info.relocateable)
200 if (command_line.relax)
201 einfo ("%P%F: -relax and -r may not be used together\n");
202 if (config.dynamic_link)
203 einfo ("%P%F: -r and -call_shared may not be used together\n");
204 if (link_info.strip == strip_all)
205 einfo ("%P%F: -r and -s may not be used together\n");
206 if (link_info.shared)
207 einfo ("%P%F: -r and -shared may not be used together\n");
210 /* This essentially adds another -L directory so this must be done after
211 the -L's in argv have been processed. */
214 if (had_script == false)
216 /* Read the emulation's appropriate default script. */
218 char *s = ldemul_get_script (&isfile);
221 ldfile_open_command_file (s);
224 parser_input = input_script;
230 if (lang_has_input_file == false)
234 einfo ("%P%F: no input files\n");
239 info_msg ("%P: mode %s\n", emulation);
242 ldemul_after_parse ();
245 if (config.map_filename)
247 if (strcmp (config.map_filename, "-") == 0)
249 config.map_file = stdout;
253 config.map_file = fopen (config.map_filename, FOPEN_WT);
254 if (config.map_file == (FILE *) NULL)
256 einfo ("%P%F: cannot open map file %s: %E\n",
257 config.map_filename);
265 /* Print error messages for any missing symbols, for any warning
266 symbols, and possibly multiple definitions */
269 if (config.text_read_only)
271 /* Look for a text section and mark the readonly attribute in it */
272 asection *found = bfd_get_section_by_name (output_bfd, ".text");
274 if (found != (asection *) NULL)
276 found->flags |= SEC_READONLY;
280 if (link_info.relocateable)
281 output_bfd->flags &= ~EXEC_P;
283 output_bfd->flags |= EXEC_P;
287 /* Even if we're producing relocateable output, some non-fatal errors should
288 be reported in the exit status. (What non-fatal errors, if any, do we
289 want to ignore for relocateable output?) */
291 if (config.make_executable == false && force_make_executable == false)
293 if (trace_files == true)
295 einfo ("%P: link errors found, deleting executable `%s'\n",
299 if (output_bfd->iostream)
300 fclose ((FILE *) (output_bfd->iostream));
302 unlink (output_filename);
307 if (! bfd_close (output_bfd))
308 einfo ("%F%B: final close failed: %E\n", output_bfd);
313 extern char **environ;
314 char *lim = (char *) sbrk (0);
315 long run_time = get_run_time () - start_time;
317 fprintf (stderr, "%s: total time in link: %ld.%06ld\n",
318 program_name, run_time / 1000000, run_time % 1000000);
319 fprintf (stderr, "%s: data size %ld\n", program_name,
320 (long) (lim - (char *) &environ));
323 /* Prevent remove_output from doing anything, after a successful link. */
324 output_filename = NULL;
330 /* We need to find any explicitly given emulation in order to initialize the
331 state that's needed by the lex&yacc argument parser (parse_args). */
334 get_emulation (argc, argv)
341 emulation = (char *) getenv (EMULATION_ENVIRON);
342 if (emulation == NULL)
343 emulation = DEFAULT_EMULATION;
345 for (i = 1; i < argc; i++)
347 if (!strncmp (argv[i], "-m", 2))
349 if (argv[i][2] == '\0')
354 emulation = argv[i + 1];
359 einfo("%P%F: missing argument to -m\n");
362 else if (strcmp (argv[i], "-mips1") == 0
363 || strcmp (argv[i], "-mips2") == 0
364 || strcmp (argv[i], "-mips3") == 0)
366 /* FIXME: The arguments -mips1, -mips2 and -mips3 are
367 passed to the linker by some MIPS compilers. They
368 generally tell the linker to use a slightly different
369 library path. Perhaps someday these should be
370 implemented as emulations; until then, we just ignore
371 the arguments and hope that nobody ever creates
372 emulations named ips1, ips2 or ips3. */
374 else if (strcmp (argv[i], "-m486") == 0)
376 /* FIXME: The argument -m486 is passed to the linker on
377 some Linux systems. Hope that nobody creates an
378 emulation named 486. */
383 emulation = &argv[i][2];
391 /* If directory DIR contains an "ldscripts" subdirectory,
392 add DIR to the library search path and return true,
393 else return false. */
396 check_for_scripts_dir (dir)
404 dirlen = strlen (dir);
405 /* sizeof counts the terminating NUL. */
406 buf = (char *) xmalloc (dirlen + sizeof("/ldscripts"));
407 sprintf (buf, "%s/ldscripts", dir);
409 res = stat (buf, &s) == 0 && S_ISDIR (s.st_mode);
412 ldfile_add_library_path (dir, false);
416 /* Set the default directory for finding script files.
417 Libraries will be searched for here too, but that's ok.
418 We look for the "ldscripts" directory in:
420 SCRIPTDIR (passed from Makefile)
421 the dir where this program is (for using it from the build tree)
422 the dir where this program is/../lib (for installing the tool suite elsewhere) */
430 if (check_for_scripts_dir (SCRIPTDIR))
431 return; /* We've been installed normally. */
433 /* Look for "ldscripts" in the dir where our binary is. */
434 end = strrchr (program_name, '/');
437 dirlen = end - program_name;
438 /* Make a copy of program_name in dir.
439 Leave room for later "/../lib". */
440 dir = (char *) xmalloc (dirlen + 8);
441 strncpy (dir, program_name, dirlen);
447 dir = (char *) xmalloc (dirlen + 8);
451 if (check_for_scripts_dir (dir))
452 return; /* Don't free dir. */
454 /* Look for "ldscripts" in <the dir where our binary is>/../lib. */
455 strcpy (dir + dirlen, "/../lib");
456 if (check_for_scripts_dir (dir))
459 free (dir); /* Well, we tried. */
466 if (link_info.notice_hash == (struct bfd_hash_table *) NULL)
468 link_info.notice_hash = ((struct bfd_hash_table *)
469 xmalloc (sizeof (struct bfd_hash_table)));
470 if (! bfd_hash_table_init_n (link_info.notice_hash,
473 einfo ("%P%F: bfd_hash_table_init failed: %E\n");
476 if (bfd_hash_lookup (link_info.notice_hash, name, true, true)
477 == (struct bfd_hash_entry *) NULL)
478 einfo ("%P%F: bfd_hash_lookup failed: %E\n");
481 /* Handle the -retain-symbols-file option. */
484 add_keepsyms_file (filename)
485 const char *filename;
492 if (link_info.strip == strip_some)
493 einfo ("%X%P: error: duplicate retain-symbols-file\n");
495 file = fopen (filename, "r");
496 if (file == (FILE *) NULL)
498 bfd_set_error (bfd_error_system_call);
499 einfo ("%X%P: %s: %E", filename);
503 link_info.keep_hash = ((struct bfd_hash_table *)
504 xmalloc (sizeof (struct bfd_hash_table)));
505 if (! bfd_hash_table_init (link_info.keep_hash, bfd_hash_newfunc))
506 einfo ("%P%F: bfd_hash_table_init failed: %E\n");
509 buf = (char *) xmalloc (bufsize);
521 while (! isspace (c) && c != EOF)
528 buf = xrealloc (buf, bufsize);
535 if (bfd_hash_lookup (link_info.keep_hash, buf, true, true)
536 == (struct bfd_hash_entry *) NULL)
537 einfo ("%P%F: bfd_hash_lookup for insertion failed: %E");
541 if (link_info.strip != strip_none)
542 einfo ("%P: `-retain-symbols-file' overrides `-s' and `-S'\n");
544 link_info.strip = strip_some;
547 /* Callbacks from the BFD linker routines. */
549 /* This is called when BFD has decided to include an archive member in
554 add_archive_element (info, abfd, name)
555 struct bfd_link_info *info;
559 lang_input_statement_type *input;
561 input = ((lang_input_statement_type *)
562 xmalloc ((bfd_size_type) sizeof (lang_input_statement_type)));
563 input->filename = abfd->filename;
564 input->local_sym_name = abfd->filename;
565 input->the_bfd = abfd;
566 input->asymbols = NULL;
568 input->just_syms_flag = false;
569 input->loaded = false;
570 input->search_dirs_flag = false;
572 /* FIXME: The following fields are not set: header.next,
573 header.type, closed, passive_position, symbol_count,
574 next_real_file, is_archive, target, real, common_section,
575 common_output_section, complained. This bit of code is from the
576 old decode_library_subfile function. I don't know whether any of
577 those fields matters. */
579 ldlang_add_file (input);
581 if (config.map_file != (FILE *) NULL)
582 minfo ("%s needed due to %T\n", abfd->filename, name);
584 if (trace_files || trace_file_tries)
585 info_msg ("%I\n", input);
590 /* This is called when BFD has discovered a symbol which is defined
595 multiple_definition (info, name, obfd, osec, oval, nbfd, nsec, nval)
596 struct bfd_link_info *info;
605 einfo ("%X%C: multiple definition of `%T'\n",
606 nbfd, nsec, nval, name);
607 if (obfd != (bfd *) NULL)
608 einfo ("%D: first defined here\n", obfd, osec, oval);
612 /* This is called when there is a definition of a common symbol, or
613 when a common symbol is found for a symbol that is already defined,
614 or when two common symbols are found. We only do something if
615 -warn-common was used. */
619 multiple_common (info, name, obfd, otype, osize, nbfd, ntype, nsize)
620 struct bfd_link_info *info;
623 enum bfd_link_hash_type otype;
626 enum bfd_link_hash_type ntype;
629 if (! config.warn_common)
632 if (ntype == bfd_link_hash_defined)
634 ASSERT (otype == bfd_link_hash_common);
635 einfo ("%B: warning: definition of `%T' overriding common\n",
637 einfo ("%B: warning: common is here\n", obfd);
639 else if (otype == bfd_link_hash_defined)
641 ASSERT (ntype == bfd_link_hash_common);
642 einfo ("%B: warning: common of `%T' overridden by definition\n",
644 einfo ("%B: warning: defined here\n", obfd);
648 ASSERT (otype == bfd_link_hash_common && ntype == bfd_link_hash_common);
651 einfo ("%B: warning: common of `%T' overridden by larger common\n",
653 einfo ("%B: warning: larger common is here\n", obfd);
655 else if (nsize > osize)
657 einfo ("%B: warning: common of `%T' overriding smaller common\n",
659 einfo ("%B: warning: smaller common is here\n", obfd);
663 einfo ("%B: warning: multiple common of `%T'\n", nbfd, name);
664 einfo ("%B: warning: previous common is here\n", obfd);
671 /* This is called when BFD has discovered a set element. H is the
672 entry in the linker hash table for the set. SECTION and VALUE
673 represent a value which should be added to the set. */
677 add_to_set (info, h, reloc, abfd, section, value)
678 struct bfd_link_info *info;
679 struct bfd_link_hash_entry *h;
680 bfd_reloc_code_real_type reloc;
685 if (! config.build_constructors)
688 ldctor_add_set_entry (h, reloc, section, value);
690 if (h->type == bfd_link_hash_new)
692 h->type = bfd_link_hash_undefined;
693 h->u.undef.abfd = abfd;
694 /* We don't call bfd_link_add_undef to add this to the list of
695 undefined symbols because we are going to define it
702 /* This is called when BFD has discovered a constructor. This is only
703 called for some object file formats--those which do not handle
704 constructors in some more clever fashion. This is similar to
705 adding an element to a set, but less general. */
708 constructor_callback (info, constructor, name, abfd, section, value)
709 struct bfd_link_info *info;
718 struct bfd_link_hash_entry *h;
720 if (! config.build_constructors)
723 /* Ensure that BFD_RELOC_CTOR exists now, so that we can give a
724 useful error message. */
725 if (bfd_reloc_type_lookup (output_bfd, BFD_RELOC_CTOR) == NULL)
726 einfo ("%P%F: BFD backend error: BFD_RELOC_CTOR unsupported");
728 set_name = (char *) alloca (1 + sizeof "__CTOR_LIST__");
730 if (bfd_get_symbol_leading_char (abfd) != '\0')
731 *s++ = bfd_get_symbol_leading_char (abfd);
733 strcpy (s, "__CTOR_LIST__");
735 strcpy (s, "__DTOR_LIST__");
737 if (config.map_file != (FILE *) NULL)
738 fprintf (config.map_file,
739 "Adding %s to constructor/destructor set %s\n", name, set_name);
741 h = bfd_link_hash_lookup (info->hash, set_name, true, true, true);
742 if (h == (struct bfd_link_hash_entry *) NULL)
743 einfo ("%P%F: bfd_link_hash_lookup failed: %E");
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
753 ldctor_add_set_entry (h, BFD_RELOC_CTOR, section, value);
757 /* This is called when there is a reference to a warning symbol. */
761 warning_callback (info, warning)
762 struct bfd_link_info *info;
765 einfo ("%P: %s\n", warning);
769 /* This is called when an undefined symbol is found. */
773 undefined_symbol (info, name, abfd, section, address)
774 struct bfd_link_info *info;
780 static char *error_name;
781 static unsigned int error_count;
783 #define MAX_ERRORS_IN_A_ROW 5
785 if (config.warn_once)
787 static struct bfd_hash_table *hash;
789 /* Only warn once about a particular undefined symbol. */
793 hash = ((struct bfd_hash_table *)
794 xmalloc (sizeof (struct bfd_hash_table)));
795 if (! bfd_hash_table_init (hash, bfd_hash_newfunc))
796 einfo ("%F%P: bfd_hash_table_init failed: %E\n");
799 if (bfd_hash_lookup (hash, name, false, false) != NULL)
802 if (bfd_hash_lookup (hash, name, true, true) == NULL)
803 einfo ("%F%P: bfd_hash_lookup failed: %E\n");
806 /* We never print more than a reasonable number of errors in a row
807 for a single symbol. */
808 if (error_name != (char *) NULL
809 && strcmp (name, error_name) == 0)
814 if (error_name != (char *) NULL)
816 error_name = buystring (name);
819 if (error_count < MAX_ERRORS_IN_A_ROW)
820 einfo ("%X%C: undefined reference to `%T'\n",
821 abfd, section, address, name);
822 else if (error_count == MAX_ERRORS_IN_A_ROW)
823 einfo ("%D: more undefined references to `%T' follow\n",
824 abfd, section, address, name);
829 /* This is called when a reloc overflows. */
833 reloc_overflow (info, name, reloc_name, addend, abfd, section, address)
834 struct bfd_link_info *info;
836 const char *reloc_name;
842 if (abfd == (bfd *) NULL)
843 einfo ("%P%X: generated");
845 einfo ("%X%C:", abfd, section, address);
846 einfo (" relocation truncated to fit: %s %T", reloc_name, name);
848 einfo ("+%v", addend);
853 /* This is called when a dangerous relocation is made. */
857 reloc_dangerous (info, message, abfd, section, address)
858 struct bfd_link_info *info;
864 if (abfd == (bfd *) NULL)
865 einfo ("%P%X: generated");
867 einfo ("%X%C:", abfd, section, address);
868 einfo ("dangerous relocation: %s\n", message);
872 /* This is called when a reloc is being generated attached to a symbol
873 that is not being output. */
877 unattached_reloc (info, name, abfd, section, address)
878 struct bfd_link_info *info;
884 if (abfd == (bfd *) NULL)
885 einfo ("%P%X: generated");
887 einfo ("%X%C:", abfd, section, address);
888 einfo (" reloc refers to symbol `%T' which is not being output\n", name);
892 /* This is called when a symbol in notice_hash is found. Symbols are
893 put in notice_hash using the -y option. */
897 notice_ysym (info, name, abfd, section, value)
898 struct bfd_link_info *info;
904 einfo ("%B: %s %s\n", abfd,
905 bfd_is_und_section (section) ? "reference to" : "definition of",