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];
156 xmalloc_set_program_name (program_name);
160 xatexit (remove_output);
162 /* Initialize the data about options. */
163 trace_files = trace_file_tries = version_printed = false;
165 config.build_constructors = true;
166 command_line.force_common_definition = false;
168 link_info.callbacks = &link_callbacks;
169 link_info.relocateable = 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 /* This essentially adds another -L directory so this must be done after
198 the -L's in argv have been processed. */
201 if (had_script == false)
203 /* Read the emulation's appropriate default script. */
205 char *s = ldemul_get_script (&isfile);
209 /* sizeof counts the terminating NUL. */
210 size_t size = strlen (s) + sizeof ("-T ");
211 char *buf = (char *) xmalloc(size);
212 sprintf (buf, "-T %s", s);
220 if (link_info.relocateable && command_line.relax)
222 einfo ("%P%F: -relax and -r may not be used together\n");
226 if (lang_has_input_file == false)
230 einfo ("%P%F: no input files\n");
235 info_msg ("%P: mode %s\n", emulation);
238 ldemul_after_parse ();
241 if (config.map_filename)
243 if (strcmp (config.map_filename, "-") == 0)
245 config.map_file = stdout;
249 config.map_file = fopen (config.map_filename, FOPEN_WT);
250 if (config.map_file == (FILE *) NULL)
252 einfo ("%P%F: cannot open map file %s: %E\n",
253 config.map_filename);
261 /* Print error messages for any missing symbols, for any warning
262 symbols, and possibly multiple definitions */
265 if (config.text_read_only)
267 /* Look for a text section and mark the readonly attribute in it */
268 asection *found = bfd_get_section_by_name (output_bfd, ".text");
270 if (found != (asection *) NULL)
272 found->flags |= SEC_READONLY;
276 if (link_info.relocateable)
277 output_bfd->flags &= ~EXEC_P;
279 output_bfd->flags |= EXEC_P;
283 /* Even if we're producing relocateable output, some non-fatal errors should
284 be reported in the exit status. (What non-fatal errors, if any, do we
285 want to ignore for relocateable output?) */
287 if (config.make_executable == false && force_make_executable == false)
289 if (trace_files == true)
291 einfo ("%P: link errors found, deleting executable `%s'\n",
295 if (output_bfd->iostream)
296 fclose ((FILE *) (output_bfd->iostream));
298 unlink (output_filename);
303 bfd_close (output_bfd);
308 extern char **environ;
309 char *lim = (char *) sbrk (0);
310 long run_time = get_run_time () - start_time;
312 fprintf (stderr, "%s: total time in link: %ld.%06ld\n",
313 program_name, run_time / 1000000, run_time % 1000000);
314 fprintf (stderr, "%s: data size %ld\n", program_name,
315 (long) (lim - (char *) &environ));
318 /* Prevent remove_output from doing anything, after a successful link. */
319 output_filename = NULL;
325 /* We need to find any explicitly given emulation in order to initialize the
326 state that's needed by the lex&yacc argument parser (parse_args). */
329 get_emulation (argc, argv)
336 emulation = (char *) getenv (EMULATION_ENVIRON);
337 if (emulation == NULL)
338 emulation = DEFAULT_EMULATION;
340 for (i = 1; i < argc; i++)
342 if (!strncmp (argv[i], "-m", 2))
344 if (argv[i][2] == '\0')
349 emulation = argv[i + 1];
354 einfo("%P%F: missing argument to -m\n");
357 else if (strcmp (argv[i], "-mips1") == 0
358 || strcmp (argv[i], "-mips2") == 0
359 || strcmp (argv[i], "-mips3") == 0)
361 /* FIXME: The arguments -mips1, -mips2 and -mips3 are
362 passed to the linker by some MIPS compilers. They
363 generally tell the linker to use a slightly different
364 library path. Perhaps someday these should be
365 implemented as emulations; until then, we just ignore
366 the arguments and hope that nobody ever creates
367 emulations named ips1, ips2 or ips3. */
372 emulation = &argv[i][2];
380 /* If directory DIR contains an "ldscripts" subdirectory,
381 add DIR to the library search path and return true,
382 else return false. */
385 check_for_scripts_dir (dir)
393 dirlen = strlen (dir);
394 /* sizeof counts the terminating NUL. */
395 buf = (char *) xmalloc (dirlen + sizeof("/ldscripts"));
396 sprintf (buf, "%s/ldscripts", dir);
398 res = stat (buf, &s) == 0 && S_ISDIR (s.st_mode);
401 ldfile_add_library_path (dir);
405 /* Set the default directory for finding script files.
406 Libraries will be searched for here too, but that's ok.
407 We look for the "ldscripts" directory in:
409 SCRIPTDIR (passed from Makefile)
410 the dir where this program is (for using it from the build tree)
411 the dir where this program is/../lib (for installing the tool suite elsewhere) */
419 if (check_for_scripts_dir (SCRIPTDIR))
420 return; /* We've been installed normally. */
422 /* Look for "ldscripts" in the dir where our binary is. */
423 end = strrchr (program_name, '/');
426 dirlen = end - program_name;
427 /* Make a copy of program_name in dir.
428 Leave room for later "/../lib". */
429 dir = (char *) xmalloc (dirlen + 8);
430 strncpy (dir, program_name, dirlen);
436 dir = (char *) xmalloc (dirlen + 8);
440 if (check_for_scripts_dir (dir))
441 return; /* Don't free dir. */
443 /* Look for "ldscripts" in <the dir where our binary is>/../lib. */
444 strcpy (dir + dirlen, "/../lib");
445 if (check_for_scripts_dir (dir))
448 free (dir); /* Well, we tried. */
455 if (link_info.notice_hash == (struct bfd_hash_table *) NULL)
457 link_info.notice_hash = ((struct bfd_hash_table *)
458 xmalloc (sizeof (struct bfd_hash_table)));
459 if (! bfd_hash_table_init_n (link_info.notice_hash,
462 einfo ("%P%F: bfd_hash_table_init failed: %E\n");
465 if (bfd_hash_lookup (link_info.notice_hash, name, true, true)
466 == (struct bfd_hash_entry *) NULL)
467 einfo ("%P%F: bfd_hash_lookup failed: %E\n");
470 /* Handle the -retain-symbols-file option. */
473 add_keepsyms_file (filename)
474 const char *filename;
481 if (link_info.strip == strip_some)
482 einfo ("%X%P: error: duplicate retain-symbols-file\n");
484 file = fopen (filename, "r");
485 if (file == (FILE *) NULL)
487 bfd_set_error (bfd_error_system_call);
488 einfo ("%X%P: %s: %E", filename);
492 link_info.keep_hash = ((struct bfd_hash_table *)
493 xmalloc (sizeof (struct bfd_hash_table)));
494 if (! bfd_hash_table_init (link_info.keep_hash, bfd_hash_newfunc))
495 einfo ("%P%F: bfd_hash_table_init failed: %E\n");
498 buf = (char *) xmalloc (bufsize);
510 while (! isspace (c) && c != EOF)
517 buf = xrealloc (buf, bufsize);
524 if (bfd_hash_lookup (link_info.keep_hash, buf, true, true)
525 == (struct bfd_hash_entry *) NULL)
526 einfo ("%P%F: bfd_hash_lookup for insertion failed: %E");
530 if (link_info.strip != strip_none)
531 einfo ("%P: `-retain-symbols-file' overrides `-s' and `-S'\n");
533 link_info.strip = strip_some;
536 /* Callbacks from the BFD linker routines. */
538 /* This is called when BFD has decided to include an archive member in
543 add_archive_element (info, abfd, name)
544 struct bfd_link_info *info;
548 lang_input_statement_type *input;
550 input = ((lang_input_statement_type *)
551 xmalloc ((bfd_size_type) sizeof (lang_input_statement_type)));
552 input->filename = abfd->filename;
553 input->local_sym_name = abfd->filename;
554 input->the_bfd = abfd;
555 input->asymbols = NULL;
556 input->subfiles = NULL;
558 input->just_syms_flag = false;
559 input->loaded = false;
562 /* FIXME: This is wrong. It should point to an entry for the
563 archive itself. However, it doesn't seem to matter. */
564 input->superfile = NULL;
566 /* FIXME: The following fields are not set: header.next,
567 header.type, closed, passive_position, symbol_count, total_size,
568 next_real_file, is_archive, search_dirs_flag, target, real,
569 common_section, common_output_section, complained. This bit of
570 code is from the old decode_library_subfile function. I don't
571 know whether any of those fields matters. */
573 ldlang_add_file (input);
576 info_msg ("%s needed due to %T\n", abfd->filename, name);
578 if (trace_files || trace_file_tries)
579 info_msg ("%I\n", input);
584 /* This is called when BFD has discovered a symbol which is defined
589 multiple_definition (info, name, obfd, osec, oval, nbfd, nsec, nval)
590 struct bfd_link_info *info;
599 einfo ("%X%C: multiple definition of `%T'\n",
600 nbfd, nsec, nval, name);
601 if (obfd != (bfd *) NULL)
602 einfo ("%C: first defined here\n", obfd, osec, oval);
606 /* This is called when there is a definition of a common symbol, or
607 when a common symbol is found for a symbol that is already defined,
608 or when two common symbols are found. We only do something if
609 -warn-common was used. */
613 multiple_common (info, name, obfd, otype, osize, nbfd, ntype, nsize)
614 struct bfd_link_info *info;
617 enum bfd_link_hash_type otype;
620 enum bfd_link_hash_type ntype;
623 if (! config.warn_common)
626 if (ntype == bfd_link_hash_defined)
628 ASSERT (otype == bfd_link_hash_common);
629 einfo ("%B: warning: definition of `%T' overriding common\n",
631 einfo ("%B: warning: common is here\n", obfd);
633 else if (otype == bfd_link_hash_defined)
635 ASSERT (ntype == bfd_link_hash_common);
636 einfo ("%B: warning: common of `%T' overridden by definition\n",
638 einfo ("%B: warning: defined here\n", obfd);
642 ASSERT (otype == bfd_link_hash_common && ntype == bfd_link_hash_common);
645 einfo ("%B: warning: common of `%T' overridden by larger common\n",
647 einfo ("%B: warning: larger common is here\n", obfd);
649 else if (nsize > osize)
651 einfo ("%B: warning: common of `%T' overriding smaller common\n",
653 einfo ("%B: warning: smaller common is here\n", obfd);
657 einfo ("%B: warning: multiple common of `%T'\n", nbfd, name);
658 einfo ("%B: warning: previous common is here\n", obfd);
665 /* This is called when BFD has discovered a set element. H is the
666 entry in the linker hash table for the set. SECTION and VALUE
667 represent a value which should be added to the set. */
671 add_to_set (info, h, bitsize, abfd, section, value)
672 struct bfd_link_info *info;
673 struct bfd_link_hash_entry *h;
674 unsigned int bitsize;
679 ldctor_add_set_entry (h, bitsize, section, value);
683 /* This is called when BFD has discovered a constructor. This is only
684 called for some object file formats--those which do not handle
685 constructors in some more clever fashion. This is similar to
686 adding an element to a set, but less general. */
689 constructor_callback (info, constructor, bitsize, name, abfd, section, value)
690 struct bfd_link_info *info;
692 unsigned int bitsize;
700 struct bfd_link_hash_entry *h;
702 if (! config.build_constructors)
705 set_name = (char *) alloca (1 + sizeof "__CTOR_LIST__");
707 if (bfd_get_symbol_leading_char (abfd) != '\0')
708 *s++ = bfd_get_symbol_leading_char (abfd);
710 strcpy (s, "__CTOR_LIST__");
712 strcpy (s, "__DTOR_LIST__");
715 info_msg ("Adding %s to constructor/destructor set %s\n", name, set_name);
717 h = bfd_link_hash_lookup (info->hash, set_name, true, true, true);
718 if (h == (struct bfd_link_hash_entry *) NULL)
719 einfo ("%P%F: bfd_link_hash_lookup failed: %E");
720 if (h->type == bfd_link_hash_new)
722 h->type = bfd_link_hash_undefined;
723 h->u.undef.abfd = abfd;
724 /* We don't call bfd_link_add_undef to add this to the list of
725 undefined symbols because we are going to define it
729 ldctor_add_set_entry (h, bitsize, section, value);
733 /* This is called when there is a reference to a warning symbol. */
737 warning_callback (info, warning)
738 struct bfd_link_info *info;
741 einfo ("%P: %s\n", warning);
745 /* This is called when an undefined symbol is found. */
749 undefined_symbol (info, name, abfd, section, address)
750 struct bfd_link_info *info;
756 static char *error_name;
757 static unsigned int error_count;
759 #define MAX_ERRORS_IN_A_ROW 5
761 /* We never print more than a reasonable number of errors in a row
762 for a single symbol. */
763 if (error_name != (char *) NULL
764 && strcmp (name, error_name) == 0)
769 if (error_name != (char *) NULL)
771 error_name = buystring (name);
774 if (error_count < MAX_ERRORS_IN_A_ROW)
775 einfo ("%X%C: undefined reference to `%T'\n",
776 abfd, section, address, name);
777 else if (error_count == MAX_ERRORS_IN_A_ROW)
778 einfo ("%C: more undefined references to `%T' follow\n",
779 abfd, section, address, name);
784 /* This is called when a reloc overflows. */
788 reloc_overflow (info, name, reloc_name, addend, abfd, section, address)
789 struct bfd_link_info *info;
791 const char *reloc_name;
797 einfo ("%X%C: relocation truncated to fit: %s %T", abfd, section,
798 address, reloc_name, name);
800 einfo ("+%v", addend);
805 /* This is called when a dangerous relocation is made. */
809 reloc_dangerous (info, message, abfd, section, address)
810 struct bfd_link_info *info;
816 einfo ("%X%C: dangerous relocation: %s\n", abfd, section, address, message);
820 /* This is called when a reloc is being generated attached to a symbol
821 that is not being output. */
825 unattached_reloc (info, name, abfd, section, address)
826 struct bfd_link_info *info;
832 einfo ("%X%C: reloc refers to symbol `%T' which is not being output\n",
833 abfd, section, address, name);
837 /* This is called when a symbol in notice_hash is found. Symbols are
838 put in notice_hash using the -y option. */
842 notice_ysym (info, name, abfd, section, value)
843 struct bfd_link_info *info;
849 einfo ("%B: %s %s\n", abfd,
850 section != &bfd_und_section ? "definition of" : "reference to",