/* Main program of GNU linker. Copyright (C) 1991, 92, 93, 94 Free Software Foundation, Inc. Written by Steve Chamberlain steve@cygnus.com This file is part of GLD, the Gnu Linker. GLD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GLD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GLD; see the file COPYING. If not, write to the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "bfd.h" #include "sysdep.h" #include #include "libiberty.h" #include "bfdlink.h" #include "config.h" #include "ld.h" #include "ldmain.h" #include "ldmisc.h" #include "ldwrite.h" #include "ldgram.h" #include "ldexp.h" #include "ldlang.h" #include "ldemul.h" #include "ldlex.h" #include "ldfile.h" #include "ldctor.h" /* Somewhere above, sys/stat.h got included . . . . */ #if !defined(S_ISDIR) && defined(S_IFDIR) #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR) #endif #include static char *get_emulation PARAMS ((int, char **)); static void set_scripts_dir PARAMS ((void)); /* EXPORTS */ char *default_target; const char *output_filename = "a.out"; /* Name this program was invoked by. */ char *program_name; /* The file that we're creating */ bfd *output_bfd = 0; /* Set by -G argument, for MIPS ECOFF target. */ int g_switch_value = 8; /* Nonzero means print names of input files as processed. */ boolean trace_files; /* Nonzero means same, but note open failures, too. */ boolean trace_file_tries; /* Nonzero means version number was printed, so exit successfully instead of complaining if no input files are given. */ boolean version_printed; /* Nonzero means link in every member of an archive. */ boolean whole_archive; args_type command_line; ld_config_type config; static boolean check_for_scripts_dir PARAMS ((char *dir)); static boolean add_archive_element PARAMS ((struct bfd_link_info *, bfd *, const char *)); static boolean multiple_definition PARAMS ((struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma, bfd *, asection *, bfd_vma)); static boolean multiple_common PARAMS ((struct bfd_link_info *, const char *, bfd *, enum bfd_link_hash_type, bfd_vma, bfd *, enum bfd_link_hash_type, bfd_vma)); static boolean add_to_set PARAMS ((struct bfd_link_info *, struct bfd_link_hash_entry *, bfd_reloc_code_real_type, bfd *, asection *, bfd_vma)); static boolean constructor_callback PARAMS ((struct bfd_link_info *, boolean constructor, const char *name, bfd *, asection *, bfd_vma)); static boolean warning_callback PARAMS ((struct bfd_link_info *, const char *)); static boolean undefined_symbol PARAMS ((struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma)); static boolean reloc_overflow PARAMS ((struct bfd_link_info *, const char *, const char *, bfd_vma, bfd *, asection *, bfd_vma)); static boolean reloc_dangerous PARAMS ((struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma)); static boolean unattached_reloc PARAMS ((struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma)); static boolean notice_ysym PARAMS ((struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma)); static struct bfd_link_callbacks link_callbacks = { add_archive_element, multiple_definition, multiple_common, add_to_set, constructor_callback, warning_callback, undefined_symbol, reloc_overflow, reloc_dangerous, unattached_reloc, notice_ysym }; struct bfd_link_info link_info; static void remove_output () { if (output_filename) { if (output_bfd && output_bfd->iostream) fclose((FILE *)(output_bfd->iostream)); if (delete_output_file_on_failure) unlink (output_filename); } } int main (argc, argv) int argc; char **argv; { char *emulation; long start_time = get_run_time (); program_name = argv[0]; xmalloc_set_program_name (program_name); bfd_init (); xatexit (remove_output); /* Initialize the data about options. */ trace_files = trace_file_tries = version_printed = false; whole_archive = false; config.traditional_format = false; config.build_constructors = true; config.dynamic_link = false; command_line.force_common_definition = false; command_line.interpreter = NULL; command_line.rpath = NULL; link_info.callbacks = &link_callbacks; link_info.relocateable = false; link_info.shared = false; link_info.strip = strip_none; link_info.discard = discard_none; link_info.lprefix_len = 1; link_info.lprefix = "L"; link_info.keep_memory = true; link_info.input_bfds = NULL; link_info.create_object_symbols_section = NULL; link_info.hash = NULL; link_info.keep_hash = NULL; link_info.notice_hash = NULL; ldfile_add_arch (""); config.make_executable = true; force_make_executable = false; config.magic_demand_paged = true; config.text_read_only = true; config.make_executable = true; emulation = get_emulation (argc, argv); ldemul_choose_mode (emulation); default_target = ldemul_choose_target (); lang_init (); ldemul_before_parse (); lang_has_input_file = false; parse_args (argc, argv); if (link_info.relocateable) { if (command_line.relax) einfo ("%P%F: -relax and -r may not be used together\n"); if (config.dynamic_link) einfo ("%P%F: -r and -call_shared may not be used together\n"); if (link_info.shared) einfo ("%P%F: -r and -shared may not be used together\n"); } /* Treat ld -r -s as ld -r -S -x (i.e., strip all local symbols). I don't see how else this can be handled, since in this case we must preserve all externally visible symbols. */ if (link_info.relocateable && link_info.strip == strip_all) { link_info.strip = strip_debugger; if (link_info.discard == discard_none) link_info.discard = discard_all; } /* This essentially adds another -L directory so this must be done after the -L's in argv have been processed. */ set_scripts_dir (); if (had_script == false) { /* Read the emulation's appropriate default script. */ int isfile; char *s = ldemul_get_script (&isfile); if (isfile) ldfile_open_command_file (s); else { if (trace_file_tries) { info_msg ("using internal linker script:\n"); info_msg ("==================================================\n"); info_msg (s); info_msg ("\n==================================================\n"); } lex_redirect (s); } parser_input = input_script; yyparse (); } lang_final (); if (lang_has_input_file == false) { if (version_printed) xexit (0); einfo ("%P%F: no input files\n"); } if (trace_files) { info_msg ("%P: mode %s\n", emulation); } ldemul_after_parse (); if (config.map_filename) { if (strcmp (config.map_filename, "-") == 0) { config.map_file = stdout; } else { config.map_file = fopen (config.map_filename, FOPEN_WT); if (config.map_file == (FILE *) NULL) { einfo ("%P%F: cannot open map file %s: %E\n", config.map_filename); } } } lang_process (); /* Print error messages for any missing symbols, for any warning symbols, and possibly multiple definitions */ if (config.text_read_only) { /* Look for a text section and mark the readonly attribute in it */ asection *found = bfd_get_section_by_name (output_bfd, ".text"); if (found != (asection *) NULL) { found->flags |= SEC_READONLY; } } if (link_info.relocateable || link_info.shared) output_bfd->flags &= ~EXEC_P; else output_bfd->flags |= EXEC_P; ldwrite (); /* Even if we're producing relocateable output, some non-fatal errors should be reported in the exit status. (What non-fatal errors, if any, do we want to ignore for relocateable output?) */ if (config.make_executable == false && force_make_executable == false) { if (trace_files == true) { einfo ("%P: link errors found, deleting executable `%s'\n", output_filename); } if (output_bfd->iostream) fclose ((FILE *) (output_bfd->iostream)); unlink (output_filename); xexit (1); } else { if (! bfd_close (output_bfd)) einfo ("%F%B: final close failed: %E\n", output_bfd); } if (config.stats) { extern char **environ; char *lim = (char *) sbrk (0); long run_time = get_run_time () - start_time; fprintf (stderr, "%s: total time in link: %ld.%06ld\n", program_name, run_time / 1000000, run_time % 1000000); fprintf (stderr, "%s: data size %ld\n", program_name, (long) (lim - (char *) &environ)); } /* Prevent remove_output from doing anything, after a successful link. */ output_filename = NULL; xexit (0); return 0; } /* We need to find any explicitly given emulation in order to initialize the state that's needed by the lex&yacc argument parser (parse_args). */ static char * get_emulation (argc, argv) int argc; char **argv; { char *emulation; int i; emulation = (char *) getenv (EMULATION_ENVIRON); if (emulation == NULL) emulation = DEFAULT_EMULATION; for (i = 1; i < argc; i++) { if (!strncmp (argv[i], "-m", 2)) { if (argv[i][2] == '\0') { /* -m EMUL */ if (i < argc - 1) { emulation = argv[i + 1]; i++; } else { einfo("%P%F: missing argument to -m\n"); } } else if (strcmp (argv[i], "-mips1") == 0 || strcmp (argv[i], "-mips2") == 0 || strcmp (argv[i], "-mips3") == 0) { /* FIXME: The arguments -mips1, -mips2 and -mips3 are passed to the linker by some MIPS compilers. They generally tell the linker to use a slightly different library path. Perhaps someday these should be implemented as emulations; until then, we just ignore the arguments and hope that nobody ever creates emulations named ips1, ips2 or ips3. */ } else if (strcmp (argv[i], "-m486") == 0) { /* FIXME: The argument -m486 is passed to the linker on some Linux systems. Hope that nobody creates an emulation named 486. */ } else { /* -mEMUL */ emulation = &argv[i][2]; } } } return emulation; } /* If directory DIR contains an "ldscripts" subdirectory, add DIR to the library search path and return true, else return false. */ static boolean check_for_scripts_dir (dir) char *dir; { size_t dirlen; char *buf; struct stat s; boolean res; dirlen = strlen (dir); /* sizeof counts the terminating NUL. */ buf = (char *) xmalloc (dirlen + sizeof("/ldscripts")); sprintf (buf, "%s/ldscripts", dir); res = stat (buf, &s) == 0 && S_ISDIR (s.st_mode); free (buf); if (res) ldfile_add_library_path (dir, false); return res; } /* Set the default directory for finding script files. Libraries will be searched for here too, but that's ok. We look for the "ldscripts" directory in: SCRIPTDIR (passed from Makefile) the dir where this program is (for using it from the build tree) the dir where this program is/../lib (for installing the tool suite elsewhere) */ static void set_scripts_dir () { char *end, *dir; size_t dirlen; if (check_for_scripts_dir (SCRIPTDIR)) return; /* We've been installed normally. */ /* Look for "ldscripts" in the dir where our binary is. */ end = strrchr (program_name, '/'); if (end) { dirlen = end - program_name; /* Make a copy of program_name in dir. Leave room for later "/../lib". */ dir = (char *) xmalloc (dirlen + 8); strncpy (dir, program_name, dirlen); dir[dirlen] = '\0'; } else { dirlen = 1; dir = (char *) xmalloc (dirlen + 8); strcpy (dir, "."); } if (check_for_scripts_dir (dir)) return; /* Don't free dir. */ /* Look for "ldscripts" in /../lib. */ strcpy (dir + dirlen, "/../lib"); if (check_for_scripts_dir (dir)) return; free (dir); /* Well, we tried. */ } void add_ysym (name) const char *name; { if (link_info.notice_hash == (struct bfd_hash_table *) NULL) { link_info.notice_hash = ((struct bfd_hash_table *) xmalloc (sizeof (struct bfd_hash_table))); if (! bfd_hash_table_init_n (link_info.notice_hash, bfd_hash_newfunc, 61)) einfo ("%P%F: bfd_hash_table_init failed: %E\n"); } if (bfd_hash_lookup (link_info.notice_hash, name, true, true) == (struct bfd_hash_entry *) NULL) einfo ("%P%F: bfd_hash_lookup failed: %E\n"); } /* Handle the -retain-symbols-file option. */ void add_keepsyms_file (filename) const char *filename; { FILE *file; char *buf; size_t bufsize; int c; if (link_info.strip == strip_some) einfo ("%X%P: error: duplicate retain-symbols-file\n"); file = fopen (filename, "r"); if (file == (FILE *) NULL) { bfd_set_error (bfd_error_system_call); einfo ("%X%P: %s: %E", filename); return; } link_info.keep_hash = ((struct bfd_hash_table *) xmalloc (sizeof (struct bfd_hash_table))); if (! bfd_hash_table_init (link_info.keep_hash, bfd_hash_newfunc)) einfo ("%P%F: bfd_hash_table_init failed: %E\n"); bufsize = 100; buf = (char *) xmalloc (bufsize); c = getc (file); while (c != EOF) { while (isspace (c)) c = getc (file); if (c != EOF) { size_t len = 0; while (! isspace (c) && c != EOF) { buf[len] = c; ++len; if (len >= bufsize) { bufsize *= 2; buf = xrealloc (buf, bufsize); } c = getc (file); } buf[len] = '\0'; if (bfd_hash_lookup (link_info.keep_hash, buf, true, true) == (struct bfd_hash_entry *) NULL) einfo ("%P%F: bfd_hash_lookup for insertion failed: %E"); } } if (link_info.strip != strip_none) einfo ("%P: `-retain-symbols-file' overrides `-s' and `-S'\n"); link_info.strip = strip_some; } /* Callbacks from the BFD linker routines. */ /* This is called when BFD has decided to include an archive member in a link. */ /*ARGSUSED*/ static boolean add_archive_element (info, abfd, name) struct bfd_link_info *info; bfd *abfd; const char *name; { lang_input_statement_type *input; input = ((lang_input_statement_type *) xmalloc ((bfd_size_type) sizeof (lang_input_statement_type))); input->filename = abfd->filename; input->local_sym_name = abfd->filename; input->the_bfd = abfd; input->asymbols = NULL; input->next = NULL; input->just_syms_flag = false; input->loaded = false; input->search_dirs_flag = false; /* FIXME: The following fields are not set: header.next, header.type, closed, passive_position, symbol_count, next_real_file, is_archive, target, real, common_section, common_output_section, complained. This bit of code is from the old decode_library_subfile function. I don't know whether any of those fields matters. */ ldlang_add_file (input); if (config.map_file != (FILE *) NULL) minfo ("%s needed due to %T\n", abfd->filename, name); if (trace_files || trace_file_tries) info_msg ("%I\n", input); return true; } /* This is called when BFD has discovered a symbol which is defined multiple times. */ /*ARGSUSED*/ static boolean multiple_definition (info, name, obfd, osec, oval, nbfd, nsec, nval) struct bfd_link_info *info; const char *name; bfd *obfd; asection *osec; bfd_vma oval; bfd *nbfd; asection *nsec; bfd_vma nval; { einfo ("%X%C: multiple definition of `%T'\n", nbfd, nsec, nval, name); if (obfd != (bfd *) NULL) einfo ("%D: first defined here\n", obfd, osec, oval); return true; } /* This is called when there is a definition of a common symbol, or when a common symbol is found for a symbol that is already defined, or when two common symbols are found. We only do something if -warn-common was used. */ /*ARGSUSED*/ static boolean multiple_common (info, name, obfd, otype, osize, nbfd, ntype, nsize) struct bfd_link_info *info; const char *name; bfd *obfd; enum bfd_link_hash_type otype; bfd_vma osize; bfd *nbfd; enum bfd_link_hash_type ntype; bfd_vma nsize; { if (! config.warn_common) return true; if (ntype == bfd_link_hash_defined || ntype == bfd_link_hash_defweak || ntype == bfd_link_hash_indirect) { ASSERT (otype == bfd_link_hash_common); einfo ("%B: warning: definition of `%T' overriding common\n", nbfd, name); if (obfd != NULL) einfo ("%B: warning: common is here\n", obfd); } else if (otype == bfd_link_hash_defined || otype == bfd_link_hash_defweak || otype == bfd_link_hash_indirect) { ASSERT (ntype == bfd_link_hash_common); einfo ("%B: warning: common of `%T' overridden by definition\n", nbfd, name); if (obfd != NULL) einfo ("%B: warning: defined here\n", obfd); } else { ASSERT (otype == bfd_link_hash_common && ntype == bfd_link_hash_common); if (osize > nsize) { einfo ("%B: warning: common of `%T' overridden by larger common\n", nbfd, name); if (obfd != NULL) einfo ("%B: warning: larger common is here\n", obfd); } else if (nsize > osize) { einfo ("%B: warning: common of `%T' overriding smaller common\n", nbfd, name); if (obfd != NULL) einfo ("%B: warning: smaller common is here\n", obfd); } else { einfo ("%B: warning: multiple common of `%T'\n", nbfd, name); if (obfd != NULL) einfo ("%B: warning: previous common is here\n", obfd); } } return true; } /* This is called when BFD has discovered a set element. H is the entry in the linker hash table for the set. SECTION and VALUE represent a value which should be added to the set. */ /*ARGSUSED*/ static boolean add_to_set (info, h, reloc, abfd, section, value) struct bfd_link_info *info; struct bfd_link_hash_entry *h; bfd_reloc_code_real_type reloc; bfd *abfd; asection *section; bfd_vma value; { if (! config.build_constructors) return true; ldctor_add_set_entry (h, reloc, section, value); if (h->type == bfd_link_hash_new) { h->type = bfd_link_hash_undefined; h->u.undef.abfd = abfd; /* We don't call bfd_link_add_undef to add this to the list of undefined symbols because we are going to define it ourselves. */ } return true; } /* This is called when BFD has discovered a constructor. This is only called for some object file formats--those which do not handle constructors in some more clever fashion. This is similar to adding an element to a set, but less general. */ static boolean constructor_callback (info, constructor, name, abfd, section, value) struct bfd_link_info *info; boolean constructor; const char *name; bfd *abfd; asection *section; bfd_vma value; { char *set_name; char *s; struct bfd_link_hash_entry *h; if (! config.build_constructors) return true; /* Ensure that BFD_RELOC_CTOR exists now, so that we can give a useful error message. */ if (bfd_reloc_type_lookup (output_bfd, BFD_RELOC_CTOR) == NULL) einfo ("%P%F: BFD backend error: BFD_RELOC_CTOR unsupported"); set_name = (char *) alloca (1 + sizeof "__CTOR_LIST__"); s = set_name; if (bfd_get_symbol_leading_char (abfd) != '\0') *s++ = bfd_get_symbol_leading_char (abfd); if (constructor) strcpy (s, "__CTOR_LIST__"); else strcpy (s, "__DTOR_LIST__"); if (config.map_file != (FILE *) NULL) fprintf (config.map_file, "Adding %s to constructor/destructor set %s\n", name, set_name); h = bfd_link_hash_lookup (info->hash, set_name, true, true, true); if (h == (struct bfd_link_hash_entry *) NULL) einfo ("%P%F: bfd_link_hash_lookup failed: %E"); if (h->type == bfd_link_hash_new) { h->type = bfd_link_hash_undefined; h->u.undef.abfd = abfd; /* We don't call bfd_link_add_undef to add this to the list of undefined symbols because we are going to define it ourselves. */ } ldctor_add_set_entry (h, BFD_RELOC_CTOR, section, value); return true; } /* This is called when there is a reference to a warning symbol. */ /*ARGSUSED*/ static boolean warning_callback (info, warning) struct bfd_link_info *info; const char *warning; { einfo ("%P: %s\n", warning); return true; } /* This is called when an undefined symbol is found. */ /*ARGSUSED*/ static boolean undefined_symbol (info, name, abfd, section, address) struct bfd_link_info *info; const char *name; bfd *abfd; asection *section; bfd_vma address; { static char *error_name; static unsigned int error_count; #define MAX_ERRORS_IN_A_ROW 5 if (config.warn_once) { static struct bfd_hash_table *hash; /* Only warn once about a particular undefined symbol. */ if (hash == NULL) { hash = ((struct bfd_hash_table *) xmalloc (sizeof (struct bfd_hash_table))); if (! bfd_hash_table_init (hash, bfd_hash_newfunc)) einfo ("%F%P: bfd_hash_table_init failed: %E\n"); } if (bfd_hash_lookup (hash, name, false, false) != NULL) return true; if (bfd_hash_lookup (hash, name, true, true) == NULL) einfo ("%F%P: bfd_hash_lookup failed: %E\n"); } /* We never print more than a reasonable number of errors in a row for a single symbol. */ if (error_name != (char *) NULL && strcmp (name, error_name) == 0) ++error_count; else { error_count = 0; if (error_name != (char *) NULL) free (error_name); error_name = buystring (name); } if (section != NULL) { if (error_count < MAX_ERRORS_IN_A_ROW) einfo ("%X%C: undefined reference to `%T'\n", abfd, section, address, name); else if (error_count == MAX_ERRORS_IN_A_ROW) einfo ("%D: more undefined references to `%T' follow\n", abfd, section, address, name); } else { if (error_count < MAX_ERRORS_IN_A_ROW) einfo ("%X%B: undefined reference to `%T'\n", abfd, name); else if (error_count == MAX_ERRORS_IN_A_ROW) einfo ("%B: more undefined references to `%T' follow\n", abfd, name); } return true; } /* This is called when a reloc overflows. */ /*ARGSUSED*/ static boolean reloc_overflow (info, name, reloc_name, addend, abfd, section, address) struct bfd_link_info *info; const char *name; const char *reloc_name; bfd_vma addend; bfd *abfd; asection *section; bfd_vma address; { if (abfd == (bfd *) NULL) einfo ("%P%X: generated"); else einfo ("%X%C:", abfd, section, address); einfo (" relocation truncated to fit: %s %T", reloc_name, name); if (addend != 0) einfo ("+%v", addend); einfo ("\n"); return true; } /* This is called when a dangerous relocation is made. */ /*ARGSUSED*/ static boolean reloc_dangerous (info, message, abfd, section, address) struct bfd_link_info *info; const char *message; bfd *abfd; asection *section; bfd_vma address; { if (abfd == (bfd *) NULL) einfo ("%P%X: generated"); else einfo ("%X%C:", abfd, section, address); einfo ("dangerous relocation: %s\n", message); return true; } /* This is called when a reloc is being generated attached to a symbol that is not being output. */ /*ARGSUSED*/ static boolean unattached_reloc (info, name, abfd, section, address) struct bfd_link_info *info; const char *name; bfd *abfd; asection *section; bfd_vma address; { if (abfd == (bfd *) NULL) einfo ("%P%X: generated"); else einfo ("%X%C:", abfd, section, address); einfo (" reloc refers to symbol `%T' which is not being output\n", name); return true; } /* This is called when a symbol in notice_hash is found. Symbols are put in notice_hash using the -y option. */ /*ARGSUSED*/ static boolean notice_ysym (info, name, abfd, section, value) struct bfd_link_info *info; const char *name; bfd *abfd; asection *section; bfd_vma value; { einfo ("%B: %s %s\n", abfd, bfd_is_und_section (section) ? "reference to" : "definition of", name); return true; }