/* Copyright (C) 1991 Free Software Foundation, Inc. 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 1, 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. */ /* * Written by Steve Chamberlain steve@cygnus.com * * $Id$ * * */ #include "sysdep.h" #include "bfd.h" #include "config.h" #include "ld.h" #include "ldmain.h" #include "ldmisc.h" #include "ldwrite.h" #include "ldgram.h" #include "ldsym.h" #include "ldlang.h" #include "ld-emul.h" #include "ldlex.h" #include "ldfile.h" /* IMPORTS */ extern boolean lang_has_input_file; extern boolean trace_files; /* EXPORTS */ char *default_target; char *output_filename = "a.out"; /* Name this program was invoked by. */ char *program_name; /* The file that we're creating */ bfd *output_bfd = 0; extern boolean option_v; /* The local symbol prefix */ char lprefix = 'L'; /* Count the number of global symbols multiply defined. */ int multiple_def_count; /* Count the number of symbols defined through common declarations. This count is referenced in symdef_library, linear_library, and modified by enter_global_ref. It is incremented when a symbol is created as a common, and decremented when the common declaration is overridden Another way of thinking of it is that this is a count of all ldsym_types with a ->scoms field */ unsigned int commons_pending; /* Count the number of global symbols referenced and not defined. common symbols are not included in this count. */ unsigned int undefined_global_sym_count; /* Count the number of warning symbols encountered. */ int warning_count; /* have we had a load script ? */ extern boolean had_script; /* Nonzero means print names of input files as processed. */ boolean trace_files; /* 1 => write load map. */ boolean write_map; int unix_relocate; /* Force the make_executable to be output, even if there are non-fatal errors */ boolean force_make_executable; /* A count of the total number of local symbols ever seen - by adding the symbol_count field of each newly read afile.*/ unsigned int total_symbols_seen; /* A count of the number of read files - the same as the number of elements in file_chain */ unsigned int total_files_seen; /* IMPORTS */ args_type command_line; ld_config_type config; int main (argc, argv) char **argv; int argc; { char *emulation; program_name = argv[0]; output_filename = "a.out"; #ifdef GNU960 check_v960( argc, argv ); #endif emulation = (char *) getenv(EMULATION_ENVIRON); /* Initialize the data about options. */ trace_files = false; write_map = false; config.relocateable_output = false; unix_relocate = 0; command_line.force_common_definition = false; ldfile_add_arch(""); ldfile_add_library_path("./"); config.make_executable = true; force_make_executable = false; /* Initialize the cumulative counts of symbols. */ undefined_global_sym_count = 0; warning_count = 0; multiple_def_count = 0; commons_pending = 0; config.magic_demand_paged = true ; config.make_executable = true; #ifdef GNU960 ldemul_choose_mode(LNK960_EMULATION_NAME); #else if (emulation == (char *)NULL) { emulation= DEFAULT_EMULATION; } ldemul_choose_mode(emulation); #endif default_target = ldemul_choose_target(); lang_init(); ldemul_before_parse(); lang_has_input_file = false; parse_args(argc, argv); lang_final(); if (trace_files) { info("%P: mode %s\n", emulation); } if (lang_has_input_file == false) { info("%P%F: No input files\n"); } ldemul_after_parse(); lang_process(); /* Print error messages for any missing symbols, for any warning symbols, and possibly multiple definitions */ /* Print a map, if requested. */ if (write_map) { ldsym_print_symbol_table (); lang_map(stdout); } if (config.relocateable_output) { output_bfd->flags &= ~( D_PAGED); output_bfd->flags |= EXEC_P; ldwrite(); bfd_close(output_bfd); } else { output_bfd->flags |= EXEC_P; ldwrite(); bfd_close(output_bfd); if (config.make_executable == false && force_make_executable == false) { unlink(output_filename); } return (!config.make_executable); } return(0); } /* main() */ void Q_read_entry_symbols (desc, entry) bfd *desc; struct lang_input_statement_struct *entry; { if (entry->asymbols == (asymbol **)NULL) { size_t table_size = get_symtab_upper_bound(desc); entry->asymbols = (asymbol **)ldmalloc(table_size); entry->symbol_count = bfd_canonicalize_symtab(desc, entry->asymbols) ; } } /* * turn this item into a reference */ static void refize(sp, nlist_p) ldsym_type *sp; asymbol **nlist_p; { asymbol *sym = *nlist_p; sym->value = 0; sym->flags = BSF_UNDEFINED; sym->section = (asection *)NULL; sym->udata =(PTR)( sp->srefs_chain); sp->srefs_chain = nlist_p; } /* This function is called for each name which is seen which has a global scope. It enters the name into the global symbol table in the correct symbol on the correct chain. Remember that each ldsym_type has three chains attatched, one of all definitions of a symbol, one of all references of a symbol and one of all common definitions of a symbol. When the function is over, the supplied is left connected to the bfd to which is was born, with its udata field pointing to the next member on the chain in which it has been inserted. A certain amount of jigery pokery is necessary since commons come along and upset things, we only keep one item in the common chain; the one with the biggest size seen sofar. When another common comes along it either bumps the previous definition into the ref chain, since it is bigger, or gets turned into a ref on the spot since the one on the common chain is already bigger. If a real definition comes along then the common gets bumped off anyway. Whilst all this is going on we keep a count of the number of multiple definitions seen, undefined global symbols and pending commons. */ void Q_enter_global_ref (nlist_p) asymbol **nlist_p; { asymbol *sym = *nlist_p; CONST char *name = sym->name; ldsym_type *sp = ldsym_get (name); flagword this_symbol_flags = sym->flags; ASSERT(sym->udata == 0); /* Just place onto correct chain */ if (flag_is_common(this_symbol_flags)) { /* If we have a definition of this symbol already then * this common turns into a reference. Also we only * ever point to the largest common, so if we * have a common, but it's bigger that the new symbol * the turn this into a reference too. */ if (sp->sdefs_chain) { /* This is a common symbol, but we already have a definition for it, so just link it into the ref chain as if it were a reference */ refize(sp, nlist_p); } else if (sp->scoms_chain) { /* If we have a previous common, keep only the biggest */ if ( (*(sp->scoms_chain))->value > sym->value) { /* other common is bigger, throw this one away */ refize(sp, nlist_p); } else if (sp->scoms_chain != nlist_p) { /* other common is smaller, throw that away */ refize(sp, sp->scoms_chain); sp->scoms_chain = nlist_p; } } else { /* This is the first time we've seen a common, so * remember it - if it was undefined before, we know it's defined now */ if (sp->srefs_chain) undefined_global_sym_count--; commons_pending++; sp->scoms_chain = nlist_p; } } else if (flag_is_defined(this_symbol_flags)) { /* This is the definition of a symbol, add to def chain */ if (sp->sdefs_chain && (*(sp->sdefs_chain))->section != sym->section) { /* Multiple definition */ asymbol *sy = *(sp->sdefs_chain); lang_input_statement_type *stat = (lang_input_statement_type *) sy->the_bfd->usrdata; lang_input_statement_type *stat1 = (lang_input_statement_type *) sym->the_bfd->usrdata; asymbol ** stat1_symbols = stat1 ? stat1->asymbols: 0; asymbol ** stat_symbols = stat ? stat->asymbols:0; multiple_def_count++; info("%C: multiple definition of `%T'\n", sym->the_bfd, sym->section, stat1_symbols, sym->value, sym); info("%C: first seen here\n", sy->the_bfd, sy->section, stat_symbols, sy->value); } else { sym->udata =(PTR)( sp->sdefs_chain); sp->sdefs_chain = nlist_p; } /* A definition overrides a common symbol */ if (sp->scoms_chain) { refize(sp, sp->scoms_chain); sp->scoms_chain = 0; commons_pending--; } else if (sp->srefs_chain) { /* If previously was undefined, then remember as defined */ undefined_global_sym_count--; } } else { if (sp->scoms_chain == (asymbol **)NULL && sp->srefs_chain == (asymbol **)NULL && sp->sdefs_chain == (asymbol **)NULL) { /* And it's the first time we've seen it */ undefined_global_sym_count++; } refize(sp, nlist_p); } ASSERT(sp->sdefs_chain == 0 || sp->scoms_chain == 0); ASSERT(sp->scoms_chain ==0 || (*(sp->scoms_chain))->udata == 0); } static void Q_enter_file_symbols (entry) lang_input_statement_type *entry; { asymbol **q ; entry->common_section = bfd_make_section(entry->the_bfd, "COMMON"); ldlang_add_file(entry); if (trace_files || option_v) { info("%I\n", entry); } total_symbols_seen += entry->symbol_count; total_files_seen ++; for (q = entry->asymbols; *q; q++) { asymbol *p = *q; if (flag_is_undefined_or_global_or_common(p->flags)) { Q_enter_global_ref(q); } ASSERT(p->flags != 0); } } /* Searching libraries */ struct lang_input_statement_struct *decode_library_subfile (); void linear_library (), symdef_library (); /* Search the library ENTRY, already open on descriptor DESC. This means deciding which library members to load, making a chain of `struct lang_input_statement_struct' for those members, and entering their global symbols in the hash table. */ void search_library (entry) struct lang_input_statement_struct *entry; { /* No need to load a library if no undefined symbols */ if (!undefined_global_sym_count) return; if (bfd_has_map(entry->the_bfd)) symdef_library (entry); else linear_library (entry); } #ifdef GNU960 static boolean gnu960_check_format (abfd, format) bfd *abfd; bfd_format format; { boolean retval; if ((bfd_check_format(abfd,format) == true) && BFD_COFF_FILE_P(abfd)) { return true; } return false; } #endif void ldmain_open_file_read_symbol (entry) struct lang_input_statement_struct *entry; { if (entry->asymbols == (asymbol **)NULL &&entry->real == true && entry->filename != (char *)NULL) { ldfile_open_file (entry); #ifdef GNU960 if (gnu960_check_format(entry->the_bfd, bfd_object)) #else if (bfd_check_format(entry->the_bfd, bfd_object)) #endif { entry->the_bfd->usrdata = (PTR)entry; Q_read_entry_symbols (entry->the_bfd, entry); Q_enter_file_symbols (entry); } #ifdef GNU960 else if (gnu960_check_format(entry->the_bfd, bfd_archive)) #else else if (bfd_check_format(entry->the_bfd, bfd_archive)) #endif { entry->the_bfd->usrdata = (PTR)entry; entry->subfiles = (lang_input_statement_type *)NULL; search_library (entry); } else { info("%F%B: malformed input file (not rel or archive) \n", entry->the_bfd); } } } /* Construct and return a lang_input_statement_struct for a library member. The library's lang_input_statement_struct is library_entry, and the library is open on DESC. SUBFILE_OFFSET is the byte index in the library of this member's header. We store the length of the member into *LENGTH_LOC. */ lang_input_statement_type * decode_library_subfile (library_entry, subfile_offset) struct lang_input_statement_struct *library_entry; bfd *subfile_offset; { register struct lang_input_statement_struct *subentry; subentry = (struct lang_input_statement_struct *) ldmalloc (sizeof (struct lang_input_statement_struct)); subentry->filename = subfile_offset -> filename; subentry->local_sym_name = subfile_offset->filename; subentry->asymbols = 0; subentry->the_bfd = subfile_offset; subentry->subfiles = 0; subentry->next = 0; subentry->superfile = library_entry; subentry->is_archive = false; subentry->just_syms_flag = false; subentry->loaded = false; subentry->chain = 0; return subentry; } boolean subfile_wanted_p (); void clear_syms(entry, offset) struct lang_input_statement_struct *entry; file_ptr offset; { carsym *car; unsigned long indx = bfd_get_next_mapent(entry->the_bfd, BFD_NO_MORE_SYMBOLS, &car); while (indx != BFD_NO_MORE_SYMBOLS) { if (car->file_offset == offset) { car->name = 0; } indx = bfd_get_next_mapent(entry->the_bfd, indx, &car); } } /* Search a library that has a map */ void symdef_library (entry) struct lang_input_statement_struct *entry; { register struct lang_input_statement_struct *prev = 0; boolean not_finished = true; while (not_finished == true) { carsym *exported_library_name; bfd *prev_archive_member_bfd = 0; int idx = bfd_get_next_mapent(entry->the_bfd, BFD_NO_MORE_SYMBOLS, &exported_library_name); not_finished = false; while (idx != BFD_NO_MORE_SYMBOLS && undefined_global_sym_count) { if (exported_library_name->name) { ldsym_type *sp = ldsym_get_soft (exported_library_name->name); /* If we find a symbol that appears to be needed, think carefully about the archive member that the symbol is in. */ /* So - if it exists, and is referenced somewhere and is undefined or */ if (sp && sp->srefs_chain && !sp->sdefs_chain) { bfd *archive_member_bfd = bfd_get_elt_at_index(entry->the_bfd, idx); struct lang_input_statement_struct *archive_member_lang_input_statement_struct; #ifdef GNU960 if (archive_member_bfd && gnu960_check_format(archive_member_bfd, bfd_object)) #else if (archive_member_bfd && bfd_check_format(archive_member_bfd, bfd_object)) #endif { /* Don't think carefully about any archive member more than once in a given pass. */ if (prev_archive_member_bfd != archive_member_bfd) { prev_archive_member_bfd = archive_member_bfd; /* Read the symbol table of the archive member. */ if (archive_member_bfd->usrdata != (PTR)NULL) { archive_member_lang_input_statement_struct =(lang_input_statement_type *) archive_member_bfd->usrdata; } else { archive_member_lang_input_statement_struct = decode_library_subfile (entry, archive_member_bfd); archive_member_bfd->usrdata = (PTR) archive_member_lang_input_statement_struct; } if (archive_member_lang_input_statement_struct == 0) { info ("%F%I contains invalid archive member %s\n", entry, sp->name); } if (archive_member_lang_input_statement_struct->loaded == false) { Q_read_entry_symbols (archive_member_bfd, archive_member_lang_input_statement_struct); /* Now scan the symbol table and decide whether to load. */ if (subfile_wanted_p (archive_member_lang_input_statement_struct) == true) { /* This member is needed; load it. Since we are loading something on this pass, we must make another pass through the symdef data. */ not_finished = true; Q_enter_file_symbols (archive_member_lang_input_statement_struct); if (prev) prev->chain = archive_member_lang_input_statement_struct; else entry->subfiles = archive_member_lang_input_statement_struct; prev = archive_member_lang_input_statement_struct; /* Clear out this member's symbols from the symdef data so that following passes won't waste time on them. */ clear_syms(entry, exported_library_name->file_offset); archive_member_lang_input_statement_struct->loaded = true; } } } } } } idx = bfd_get_next_mapent(entry->the_bfd, idx, &exported_library_name); } } } void linear_library (entry) struct lang_input_statement_struct *entry; { boolean more_to_do = true; register struct lang_input_statement_struct *prev = 0; while (more_to_do) { bfd * archive = bfd_openr_next_archived_file(entry->the_bfd,0); more_to_do = false; while (archive) { #ifdef GNU960 if (gnu960_check_format(archive, bfd_object)) #else if (bfd_check_format(archive, bfd_object)) #endif { register struct lang_input_statement_struct *subentry; subentry = decode_library_subfile (entry, archive); archive->usrdata = (PTR) subentry; if (!subentry) return; if (subentry->loaded == false) { Q_read_entry_symbols (archive, subentry); if (subfile_wanted_p (subentry) == true) { Q_enter_file_symbols (subentry); if (prev) prev->chain = subentry; else entry->subfiles = subentry; prev = subentry; more_to_do = true; subentry->loaded = true; } } } archive = bfd_openr_next_archived_file(entry->the_bfd,archive); } } } /* ENTRY is an entry for a library member. Its symbols have been read into core, but not entered. Return nonzero if we ought to load this member. */ boolean subfile_wanted_p (entry) struct lang_input_statement_struct *entry; { asymbol **q; for (q = entry->asymbols; *q; q++) { asymbol *p = *q; /* If the symbol has an interesting definition, we could potentially want it. */ if (p->flags & BSF_FORT_COMM || p->flags & BSF_GLOBAL) { register ldsym_type *sp = ldsym_get_soft (p->name); /* If this symbol has not been hashed, we can't be looking for it. */ if (sp != (ldsym_type *)NULL && sp->sdefs_chain == (asymbol **)NULL) { if (sp->srefs_chain != (asymbol **)NULL || sp->scoms_chain != (asymbol **)NULL) { /* This is a symbol we are looking for. It is either not yet defined or common. */ if (flag_is_common(p->flags)) { /* This libary member has something to say about this element. We should remember if its a new size */ /* Move something from the ref list to the com list */ if(sp->scoms_chain) { /* Already a common symbol, maybe update it */ if (p->value > (*(sp->scoms_chain))->value) { (*(sp->scoms_chain))->value = p->value; } } else { /* Take a value from the ref chain Here we are moving a symbol from the owning bfd to another bfd. We must set up the common_section portion of the bfd thing */ sp->scoms_chain = sp->srefs_chain; sp->srefs_chain = (asymbol **)((*(sp->srefs_chain))->udata); (*(sp->scoms_chain))->udata = (PTR)NULL; (*( sp->scoms_chain))->flags = BSF_FORT_COMM; /* Remember the size of this item */ sp->scoms_chain[0]->value = p->value; commons_pending++; undefined_global_sym_count--; } { asymbol *com = *(sp->scoms_chain); if (((lang_input_statement_type *) (com->the_bfd->usrdata))->common_section == (asection *)NULL) { ((lang_input_statement_type *) (com->the_bfd->usrdata))->common_section = bfd_make_section(com->the_bfd, "COMMON"); } } ASSERT(p->udata == 0); } else { if (write_map) { info("%I needed due to %s\n",entry, sp->name); } return true; } } } } } return false; }