/*- * This code is derived from software copyrighted by the Free Software * Foundation. * * Modified 1991 by Donn Seeley at UUNET Technologies, Inc. * * Modified 1993 by Paul Kranenburg, Erasmus University */ #ifndef lint static char sccsid[] = "@(#)ld.c 6.10 (Berkeley) 5/22/91"; #endif /* not lint */ /* Linker `ld' for GNU Copyright (C) 1988 Free Software Foundation, Inc. This program 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. This program 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 this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* Written by Richard Stallman with some help from Eric Albert. Set, indirect, and warning symbol features added by Randy Smith. NOTE: Set and indirect symbols are no longer supported by this version. (pk) */ /* * $Id: ld.c,v 1.8 1993/10/22 21:00:08 pk Exp $ */ /* Define how to initialize system-dependent header fields. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "ld.h" int building_shared_object; /* 1 => write relocation into output file so can re-input it later. */ int relocatable_output; /* Non zero means to create the output executable. */ /* Cleared by nonfatal errors. */ int make_executable; /* Force the executable to be output, even if there are non-fatal errors */ int force_executable; /* 1 => assign space to common symbols even if `relocatable_output'. */ int force_common_definition; /* 1 => assign jmp slots to text symbols in shared objects even if non-PIC */ int force_alias_definition; /* * Which symbols should be stripped (omitted from the output): none, all, or * debugger symbols. */ enum { STRIP_NONE, STRIP_ALL, STRIP_DEBUGGER } strip_symbols; /* * Which local symbols should be omitted: none, all, or those starting with L. * This is irrelevant if STRIP_NONE. */ enum { DISCARD_NONE, DISCARD_ALL, DISCARD_L } discard_locals; /* Nonzero means print names of input files as processed. */ int trace_files; /* Magic number to use for the output file, set by switch. */ int magic; /* * `text-start' address is normally this much plus a page boundary. * This is not a user option; it is fixed for each system. */ int text_start_alignment; /* * Nonzero if -T was specified in the command line. * This prevents text_start from being set later to default values. */ int T_flag_specified; /* * Nonzero if -Tdata was specified in the command line. * This prevents data_start from being set later to default values. */ int Tdata_flag_specified; /* * Size to pad data section up to. * We simply increase the size of the data section, padding with zeros, * and reduce the size of the bss section to match. */ int specified_data_size; int main(argc, argv) char **argv; int argc; { if ((progname = strrchr(argv[0], '/')) == NULL) progname = argv[0]; else progname++; /* Added this to stop ld core-dumping on very large .o files. */ #ifdef RLIMIT_STACK /* Get rid of any avoidable limit on stack size. */ { struct rlimit rlim; /* Set the stack limit huge so that alloca does not fail. */ getrlimit(RLIMIT_STACK, &rlim); rlim.rlim_cur = rlim.rlim_max; setrlimit(RLIMIT_STACK, &rlim); } #endif /* RLIMIT_STACK */ page_size = PAGSIZ; /* Clear the cumulative info on the output file. */ text_size = 0; data_size = 0; bss_size = 0; text_reloc_size = 0; data_reloc_size = 0; data_pad = 0; text_pad = 0; /* Initialize the data about options. */ specified_data_size = 0; strip_symbols = STRIP_NONE; trace_files = 0; discard_locals = DISCARD_NONE; entry_symbol = 0; write_map = 0; relocatable_output = 0; force_common_definition = 0; T_flag_specified = 0; Tdata_flag_specified = 0; magic = DEFAULT_MAGIC; make_executable = 1; force_executable = 0; link_mode = DYNAMIC; soversion = LD_VERSION_BSD; /* Initialize the cumulative counts of symbols. */ local_sym_count = 0; non_L_local_sym_count = 0; debugger_sym_count = 0; undefined_global_sym_count = 0; warning_count = 0; multiple_def_count = 0; common_defined_global_count = 0; /* Keep a list of symbols referenced from the command line */ cl_refs_allocated = 10; cmdline_references = (struct glosym **) xmalloc(cl_refs_allocated * sizeof(struct glosym *)); *cmdline_references = 0; /* Completely decode ARGV. */ decode_command(argc, argv); building_shared_object = (!relocatable_output && !entry_symbol); /* Create the symbols `etext', `edata' and `end'. */ symtab_init(relocatable_output); /* Prepare for the run-time linking support. */ init_rrs(); /* * Determine whether to count the header as part of the text size, * and initialize the text size accordingly. This depends on the kind * of system and on the output format selected. */ md_init_header(&outheader, magic, 0); text_size = sizeof(struct exec); text_size -= N_TXTOFF(outheader); if (text_size < 0) text_size = 0; entry_offset = text_size; if (!T_flag_specified && !relocatable_output) text_start = TEXT_START(outheader); /* The text-start address is normally this far past a page boundary. */ text_start_alignment = text_start % page_size; /* * Load symbols of all input files. Also search all libraries and * decide which library members to load. */ load_symbols(); /* Compute where each file's sections go, and relocate symbols. */ digest_symbols(); /* * Print error messages for any missing symbols, for any warning * symbols, and possibly multiple definitions */ make_executable = do_warnings(stderr); /* Print a map, if requested. */ if (write_map) print_symbols(stdout); /* Write the output file. */ if (make_executable || force_executable) write_output(); exit(!make_executable); } void decode_option(); /* * Analyze a command line argument. Return 0 if the argument is a filename. * Return 1 if the argument is a option complete in itself. Return 2 if the * argument is a option which uses an argument. * * Thus, the value is the number of consecutive arguments that are part of * options. */ int classify_arg(arg) register char *arg; { if (*arg != '-') return 0; switch (arg[1]) { case 'a': if (!strcmp(&arg[2], "ssert")) return 2; case 'A': case 'D': case 'e': case 'L': case 'l': case 'o': case 'u': case 'V': case 'y': if (arg[2]) return 1; return 2; case 'B': if (!strcmp(&arg[2], "static")) return 1; if (!strcmp(&arg[2], "dynamic")) return 1; case 'T': if (arg[2] == 0) return 2; if (!strcmp(&arg[2], "text")) return 2; if (!strcmp(&arg[2], "data")) return 2; return 1; } return 1; } /* * Process the command arguments, setting up file_table with an entry for * each input file, and setting variables according to the options. */ void decode_command(argc, argv) char **argv; int argc; { register int i; register struct file_entry *p; char *cp; number_of_files = 0; output_filename = "a.out"; /* * First compute number_of_files so we know how long to make * file_table. * Also process most options completely. */ for (i = 1; i < argc; i++) { register int code = classify_arg(argv[i]); if (code) { if (i + code > argc) fatal("no argument following %s\n", argv[i]); decode_option(argv[i], argv[i + 1]); if (argv[i][1] == 'l' || argv[i][1] == 'A') number_of_files++; i += code - 1; } else number_of_files++; } if (!number_of_files) fatal("no input files"); p = file_table = (struct file_entry *) xmalloc(number_of_files * sizeof(struct file_entry)); bzero(p, number_of_files * sizeof(struct file_entry)); /* Now scan again and fill in file_table. */ /* All options except -A and -l are ignored here. */ for (i = 1; i < argc; i++) { char *string; register int code = classify_arg(argv[i]); if (code == 0) { p->filename = argv[i]; p->local_sym_name = argv[i]; p++; continue; } if (code == 2) string = argv[i + 1]; else string = &argv[i][2]; if (argv[i][1] == 'B') { if (strcmp(string, "static") == 0) link_mode &= ~DYNAMIC; else if (strcmp(string, "dynamic") == 0) link_mode |= DYNAMIC; else if (strcmp(string, "symbolic") == 0) link_mode |= SYMBOLIC; else if (strcmp(string, "forcearchive") == 0) link_mode |= FORCEARCHIVE; else if (strcmp(string, "shareable") == 0) link_mode |= 0; } if (argv[i][1] == 'A') { if (p != file_table) fatal("-A specified before an input file other than the first"); p->filename = string; p->local_sym_name = string; p->just_syms_flag = 1; p++; } if (argv[i][1] == 'l') { p->filename = string; p->local_sym_name = concat("-l", string, ""); p->search_dirs_flag = 1; if (link_mode & DYNAMIC && !relocatable_output) p->search_dynamic_flag = 1; p++; } i += code - 1; } /* Now check some option settings for consistency. */ if ((magic != OMAGIC) && (text_start - text_start_alignment) & (page_size - 1)) fatal("-T argument not multiple of page size, with sharable output"); /* Append the standard search directories to the user-specified ones. */ std_search_dirs(getenv("LD_LIBRARY_PATH")); } void add_cmdline_ref(sp) struct glosym *sp; { struct glosym **ptr; for (ptr = cmdline_references; ptr < cmdline_references + cl_refs_allocated && *ptr; ptr++); if (ptr >= cmdline_references + cl_refs_allocated - 1) { int diff = ptr - cmdline_references; cl_refs_allocated *= 2; cmdline_references = (struct glosym **) xrealloc(cmdline_references, cl_refs_allocated * sizeof(struct glosym *)); ptr = cmdline_references + diff; } *ptr++ = sp; *ptr = (struct glosym *) 0; } #if 0 int set_element_prefixed_p(name) char *name; { struct string_list_element *p; int i; for (p = set_element_prefixes; p; p = p->next) { for (i = 0; p->str[i] != '\0' && (p->str[i] == name[i]); i++); if (p->str[i] == '\0') return 1; } return 0; } #endif /* * Record an option and arrange to act on it later. ARG should be the * following command argument, which may or may not be used by this option. * * The `l' and `A' options are ignored here since they actually specify input * files. */ void decode_option(swt, arg) register char *swt, *arg; { /* We get Bstatic from gcc on suns. */ if (!strcmp(swt + 1, "Bstatic")) return; if (!strcmp(swt + 1, "Bdynamic")) return; if (!strcmp(swt + 1, "Bsymbolic")) return; if (!strcmp(swt + 1, "Bforcearchive")) return; if (!strcmp(swt + 1, "Bshareable")) return; if (!strcmp(swt + 1, "assert")) return; if (!strcmp(swt + 1, "Ttext")) { text_start = parse(arg, "%x", "invalid argument to -Ttext"); T_flag_specified = 1; return; } if (!strcmp(swt + 1, "Tdata")) { rrs_data_start = parse(arg, "%x", "invalid argument to -Tdata"); Tdata_flag_specified = 1; return; } if (!strcmp(swt + 1, "noinhibit-exec")) { force_executable = 1; return; } if (swt[2] != 0) arg = &swt[2]; switch (swt[1]) { case 'A': return; case 'D': specified_data_size = parse(arg, "%x", "invalid argument to -D"); return; case 'd': if (*arg == 'c') force_common_definition = 1; else if (*arg == 'p') force_alias_definition = 1; else fatal("-d option takes 'c' or 'p' argument"); return; case 'e': entry_symbol = getsym(arg); if (!entry_symbol->defined && !entry_symbol->referenced) undefined_global_sym_count++; entry_symbol->referenced = 1; add_cmdline_ref(entry_symbol); return; case 'l': return; case 'L': add_search_dir(arg); return; case 'M': write_map = 1; return; case 'N': magic = OMAGIC; return; #ifdef NMAGIC case 'n': magic = NMAGIC; return; #endif #ifdef QMAGIC case 'Q': magic = oldmagic = QMAGIC; return; case 'Z': magic = oldmagic = ZMAGIC; return; #endif case 'o': output_filename = arg; return; case 'r': relocatable_output = 1; magic = OMAGIC; text_start = 0; return; case 'S': strip_symbols = STRIP_DEBUGGER; return; case 's': strip_symbols = STRIP_ALL; return; case 'T': text_start = parse(arg, "%x", "invalid argument to -T"); T_flag_specified = 1; return; case 't': trace_files = 1; return; case 'u': { register symbol *sp = getsym(arg); if (!sp->defined && !sp->referenced) undefined_global_sym_count++; sp->referenced = 1; add_cmdline_ref(sp); } return; #if 1 case 'V': soversion = parse(arg, "%d", "invalid argument to -V"); return; #endif case 'X': discard_locals = DISCARD_L; return; case 'x': discard_locals = DISCARD_ALL; return; case 'y': { register symbol *sp = getsym(&swt[2]); sp->trace = 1; } return; case 'z': magic = ZMAGIC; return; default: fatal("invalid command option `%s'", swt); } } /* Convenient functions for operating on one or all files being loaded. */ /* * Call FUNCTION on each input file entry. Do not call for entries for * libraries; instead, call once for each library member that is being * loaded. * * FUNCTION receives two arguments: the entry, and ARG. */ void each_file(function, arg) register void (*function) (); register int arg; { register int i; for (i = 0; i < number_of_files; i++) { register struct file_entry *entry = &file_table[i]; if (entry->library_flag) { register struct file_entry *subentry = entry->subfiles; for (; subentry; subentry = subentry->chain) (*function) (subentry, arg); } else (*function) (entry, arg); } } /* * Call FUNCTION on each input file entry until it returns a non-zero value. * Return this value. Do not call for entries for libraries; instead, call * once for each library member that is being loaded. * * FUNCTION receives two arguments: the entry, and ARG. It must be a function * returning unsigned long (though this can probably be fudged). */ unsigned long check_each_file(function, arg) register unsigned long (*function) (); register int arg; { register int i; register unsigned long return_val; for (i = 0; i < number_of_files; i++) { register struct file_entry *entry = &file_table[i]; if (entry->library_flag) { register struct file_entry *subentry = entry->subfiles; for (; subentry; subentry = subentry->chain) if (return_val = (*function) (subentry, arg)) return return_val; } else if (return_val = (*function) (entry, arg)) return return_val; } return 0; } /* Like `each_file' but ignore files that were just for symbol definitions. */ void each_full_file(function, arg) register void (*function) (); register int arg; { register int i; for (i = 0; i < number_of_files; i++) { register struct file_entry *entry = &file_table[i]; if (entry->just_syms_flag || entry->is_dynamic) continue; if (entry->library_flag) { register struct file_entry *subentry = entry->subfiles; for (; subentry; subentry = subentry->chain) (*function) (subentry, arg); } else (*function) (entry, arg); } } /* Close the input file that is now open. */ void file_close() { close(input_desc); input_desc = 0; input_file = 0; } /* * Open the input file specified by 'entry', and return a descriptor. The * open file is remembered; if the same file is opened twice in a row, a new * open is not actually done. */ int file_open (entry) register struct file_entry *entry; { register int desc; if (entry->superfile) return file_open (entry->superfile); if (entry == input_file) return input_desc; if (input_file) file_close (); if (entry->search_dirs_flag) { desc = findlib(entry); } else desc = open (entry->filename, O_RDONLY, 0); if (desc > 0) { input_file = entry; input_desc = desc; return desc; } perror_file (entry); /* NOTREACHED */ } int text_offset (entry) struct file_entry *entry; { return entry->starting_offset + N_TXTOFF (entry->header); } /* Medium-level input routines for rel files. */ /* * Read a file's header into the proper place in the file_entry. DESC is the * descriptor on which the file is open. ENTRY is the file's entry. */ void read_header (desc, entry) int desc; register struct file_entry *entry; { register int len; struct exec *loc = (struct exec *) &entry->header; if (lseek (desc, entry->starting_offset, L_SET) != entry->starting_offset) fatal_with_file("read_header: lseek failure ", entry); len = read (desc, &entry->header, sizeof (struct exec)); if (len != sizeof (struct exec)) fatal_with_file ("failure reading header of ", entry); md_swapin_exec_hdr(&entry->header); if (N_BADMAG (*loc)) fatal_with_file ("bad magic number in ", entry); entry->header_read_flag = 1; } /* * Read the symbols of file ENTRY into core. Assume it is already open, on * descriptor DESC. Also read the length of the string table, which follows * the symbol table, but don't read the contents of the string table. */ void read_entry_symbols (desc, entry) struct file_entry *entry; int desc; { int str_size; struct nlist *np; int i; if (!entry->header_read_flag) read_header (desc, entry); np = (struct nlist *) alloca (entry->header.a_syms); entry->nsymbols = entry->header.a_syms / sizeof(struct nlist); entry->symbols = (struct localsymbol *) xmalloc(entry->nsymbols * sizeof(struct localsymbol)); if (lseek(desc, N_SYMOFF(entry->header) + entry->starting_offset, L_SET) != N_SYMOFF(entry->header) + entry->starting_offset) fatal_with_file ("read_symbols(h): lseek failure ", entry); if (entry->header.a_syms != read (desc, np, entry->header.a_syms)) fatal_with_file ("premature end of file in symbols of ", entry); md_swapin_symbols(np, entry->header.a_syms / sizeof(struct nlist)); for (i = 0; i < entry->nsymbols; i++) { entry->symbols[i].nzlist.nlist = *np++; entry->symbols[i].nzlist.nz_size = 0; entry->symbols[i].symbol = NULL; entry->symbols[i].next = NULL; entry->symbols[i].gotslot_offset = -1; entry->symbols[i].gotslot_claimed = 0; } entry->strings_offset = N_STROFF(entry->header) + entry->starting_offset; if (lseek(desc, entry->strings_offset, 0) == (off_t)-1) fatal_with_file ("read_symbols(s): lseek failure ", entry); if (sizeof str_size != read (desc, &str_size, sizeof str_size)) fatal_with_file ("bad string table size in ", entry); entry->string_size = md_swap_long(str_size); } /* * Read the string table of file ENTRY into core. Assume it is already open, * on descriptor DESC. */ void read_entry_strings (desc, entry) struct file_entry *entry; int desc; { int buffer; if (!entry->header_read_flag || !entry->strings_offset) fatal("internal error: %s", "cannot read string table"); if (lseek (desc, entry->strings_offset, L_SET) != entry->strings_offset) fatal_with_file ("read_strings: lseek failure ", entry); if (entry->string_size != read (desc, entry->strings, entry->string_size)) fatal_with_file ("premature end of file in strings of ", entry); return; } /* DEAD - Read in all of the relocation information */ void read_relocation () { each_full_file (read_entry_relocation, 0); } /* Read in the relocation sections of ENTRY if necessary */ void read_entry_relocation (desc, entry) int desc; struct file_entry *entry; { register struct relocation_info *reloc; off_t pos; if (!entry->textrel) { reloc = (struct relocation_info *) xmalloc(entry->header.a_trsize); pos = text_offset(entry) + entry->header.a_text + entry->header.a_data; if (lseek(desc, pos, L_SET) != pos) fatal_with_file("read_reloc(t): lseek failure ", entry); if (entry->header.a_trsize != read(desc, reloc, entry->header.a_trsize)) { fatal_with_file ( "premature eof in text relocation of ", entry); } md_swapin_reloc(reloc, entry->header.a_trsize / sizeof(*reloc)); entry->textrel = reloc; entry->ntextrel = entry->header.a_trsize / sizeof(*reloc); } if (!entry->datarel) { reloc = (struct relocation_info *) xmalloc(entry->header.a_drsize); pos = text_offset(entry) + entry->header.a_text + entry->header.a_data + entry->header.a_trsize; if (lseek(desc, pos, L_SET) != pos) fatal_with_file("read_reloc(d): lseek failure ", entry); if (entry->header.a_drsize != read (desc, reloc, entry->header.a_drsize)) { fatal_with_file ( "premature eof in data relocation of ", entry); } md_swapin_reloc(reloc, entry->header.a_drsize / sizeof(*reloc)); entry->datarel = reloc; entry->ndatarel = entry->header.a_drsize / sizeof(*reloc); } } /* Read in the symbols of all input files. */ void read_file_symbols (), read_entry_symbols (), read_entry_strings (); void enter_file_symbols (), enter_global_ref (); void load_symbols () { register int i; if (trace_files) fprintf (stderr, "Loading symbols:\n\n"); for (i = 0; i < number_of_files; i++) { register struct file_entry *entry = &file_table[i]; read_file_symbols (entry); } if (trace_files) fprintf (stderr, "\n"); } /* * If ENTRY is a rel file, read its symbol and string sections into core. If * it is a library, search it and load the appropriate members (which means * calling this function recursively on those members). */ void read_file_symbols (entry) register struct file_entry *entry; { register int desc; register int len; struct exec hdr; desc = file_open (entry); len = read (desc, &hdr, sizeof hdr); if (len != sizeof hdr) fatal_with_file ("failure reading header of ", entry); md_swapin_exec_hdr(&hdr); if (!N_BADMAG (hdr)) { if (N_IS_DYNAMIC(hdr)) { if (relocatable_output) { fatal_with_file( "-r and shared objects currently not supported ", entry); return; } entry->is_dynamic = 1; read_shared_object(desc, entry); rrs_add_shobj(entry); } else { read_entry_symbols (desc, entry); entry->strings = (char *) alloca (entry->string_size); read_entry_strings (desc, entry); read_entry_relocation(desc, entry); enter_file_symbols (entry); entry->strings = 0; } } else { char armag[SARMAG]; lseek (desc, 0, 0); if (SARMAG != read (desc, armag, SARMAG) || strncmp (armag, ARMAG, SARMAG)) fatal_with_file( "malformed input file (not rel or archive) ", entry); entry->library_flag = 1; search_library (desc, entry); } file_close (); } /* Enter the external symbol defs and refs of ENTRY in the hash table. */ void enter_file_symbols (entry) struct file_entry *entry; { struct localsymbol *lsp, *lspend; if (trace_files) prline_file_name (entry, stderr); lspend = entry->symbols + entry->nsymbols; for (lsp = entry->symbols; lsp < lspend; lsp++) { register struct nlist *p = &lsp->nzlist.nlist; if (p->n_type == N_WARNING) { char *name = p->n_un.n_strx + entry->strings; /* Grab the next entry. */ p++; if (p->n_type != (N_UNDF | N_EXT)) { error("Warning symbol found in %s without external reference following.", get_file_name(entry)); make_executable = 0; p--; /* Process normally. */ } else { symbol *sp; char *sname = p->n_un.n_strx + entry->strings; /* Deal with the warning symbol. */ enter_global_ref(lsp, p->n_un.n_strx + entry->strings, entry); sp = getsym (sname); sp->warning = (char *)xmalloc(strlen(name)+1); strcpy (sp->warning, name); warning_count++; } } else if (p->n_type & N_EXT) enter_global_ref(lsp, p->n_un.n_strx + entry->strings, entry); else if (p->n_un.n_strx && !(p->n_type & (N_STAB | N_EXT)) && !entry->is_dynamic) { if ((p->n_un.n_strx + entry->strings)[0] != LPREFIX) non_L_local_sym_count++; local_sym_count++; } else if (!entry->is_dynamic) debugger_sym_count++; } /* * Count one for the local symbol that we generate, * whose name is the file's name (usually) and whose address * is the start of the file's text. */ if (!entry->is_dynamic) { local_sym_count++; non_L_local_sym_count++; } } /* * Enter one global symbol in the hash table. LSP points to the `struct * localsymbol' from the file that describes the global symbol. NAME is the * symbol's name. ENTRY is the file entry for the file the symbol comes from. * * LSP is put on the chain of all such structs that refer to the same symbol. * This chain starts in the `refs' for symbols from relocatable objects. A * backpointer to the global symbol is kept in LSP. * * Symbols from shared objects are linked through `dynref'. For such symbols * that's all we do at this stage, with the exception of the case where the * symbol is a common. The `referenced' bit is only set for references from * relocatable objects. * */ void enter_global_ref (lsp, name, entry) struct localsymbol *lsp; char *name; struct file_entry *entry; { register struct nzlist *nzp = &lsp->nzlist; register symbol *sp = getsym (name); register int type = nzp->nz_type; int oldref = sp->referenced; int olddef = sp->defined; int com = sp->defined && sp->max_common_size; if (entry->is_dynamic) { lsp->next = sp->dynrefs; sp->dynrefs = lsp; /* * Handle commons from shared objects: * 1) If symbol hitherto undefined, turn it into a common. * 2) If symbol already common, update size if necessary. */ /*XXX - look at case where commons are only in shared objects */ if (type == (N_UNDF | N_EXT) && nzp->nz_value) { if (!olddef) { if (oldref) undefined_global_sym_count--; common_defined_global_count++; sp->max_common_size = nzp->nz_value; sp->defined = N_UNDF | N_EXT; } else if (com && sp->max_common_size < nzp->nz_value) { sp->max_common_size = nzp->nz_value; } } /* * Handle size information in shared objects. */ if (nzp->nz_size > sp->size) sp->size = nzp->nz_size; lsp->symbol = sp; return; } lsp->next = sp->refs; sp->refs = lsp; lsp->symbol = sp; sp->referenced = 1; if (sp == dynamic_symbol || sp == got_symbol) { if (type != (N_UNDF | N_EXT) && !entry->just_syms_flag) fatal("Linker reserved symbol %s defined as type %x ", name, type); return; } #ifdef N_SIZE if (type == (N_SIZE | N_EXT)) { if (sp->size < nzp->nz_value) sp->size = nzp->nz_value; } else #endif if (type != (N_UNDF | N_EXT) || nzp->nz_value) { /* * Set `->defined' here, so commons and undefined globals * can be counted correctly. */ if (!sp->defined || sp->defined == (N_UNDF | N_EXT)) sp->defined = type; if (oldref && !olddef) /* * It used to be undefined and we're defining it. */ undefined_global_sym_count--; if (!olddef && type == (N_UNDF | N_EXT) && nzp->nz_value) { /* * First definition and it's common. */ common_defined_global_count++; sp->max_common_size = nzp->nz_value; } else if (com && type != (N_UNDF | N_EXT)) { /* * It used to be common and we're defining * it as something else. */ common_defined_global_count--; sp->max_common_size = 0; } else if (com && type == (N_UNDF | N_EXT) && sp->max_common_size < nzp->nz_value) /* * It used to be common and this is a new common entry * to which we need to pay attention. */ sp->max_common_size = nzp->nz_value; } else if (!oldref) undefined_global_sym_count++; if (sp == end_symbol && entry->just_syms_flag && !T_flag_specified) text_start = nzp->nz_value; if (sp->trace) { register char *reftype; switch (type & N_TYPE) { case N_UNDF: reftype = nzp->nz_value? "defined as common":"referenced"; break; case N_ABS: reftype = "defined as absolute"; break; case N_TEXT: reftype = "defined in text section"; break; case N_DATA: reftype = "defined in data section"; break; case N_BSS: reftype = "defined in BSS section"; break; default: reftype = "I don't know this type"; break; } fprintf (stderr, "symbol %s %s in ", sp->name, reftype); print_file_name (entry, stderr); fprintf (stderr, "\n"); } } /* * This return 0 if the given file entry's symbol table does *not* contain * the nlist point entry, and it returns the files entry pointer (cast to * unsigned long) if it does. */ unsigned long contains_symbol (entry, np) struct file_entry *entry; register struct nlist *np; { if (np >= &entry->symbols->nzlist.nlist && np < &(entry->symbols + entry->nsymbols)->nzlist.nlist) return (unsigned long) entry; return 0; } void consider_file_section_lengths (), relocate_file_addresses (); void consider_relocation(); /* * Having entered all the global symbols and found the sizes of sections of * all files to be linked, make all appropriate deductions from this data. * * We propagate global symbol values from definitions to references. We compute * the layout of the output file and where each input file's contents fit * into it. * * This is now done in several stages. * * 1) All global symbols are examined for definitions in relocatable (.o) * files. The symbols' type is set according to the definition found, * but its value can not yet be determined. In stead, we keep a pointer * to the file entry's localsymbol that bequeathed the global symbol with * its definition. Also, multiple (incompatible) definitions are checked * for in this pass. If no definition comes forward, the set of local * symbols originating from shared objects is searched for a definition. * * 2) Then the relocation information of each relocatable file is examined * for for possible contributions to the RRS section. * * 3) When this is done, the sizes and start addresses are set of all segments * that will appear in the output file (including the RRS segment). * * 4) Finally, all symbols are relocated according according to the start * of the entry they are part of. Then global symbols are assigned their * final values. Also, space for commons and imported data are allocated * during this pass, if the link mode in effect so demands. * */ void digest_pass1(), digest_pass2(); void digest_symbols () { if (trace_files) fprintf(stderr, "Digesting symbol information:\n\n"); /* Pass 1: check and define symbols */ defined_global_sym_count = 0; digest_pass1(); if (!relocatable_output) { each_full_file(consider_relocation, 0); /* Text */ each_full_file(consider_relocation, 1); /* Data */ } /* * Compute total size of sections. * RRS data is the first output data section, RRS text is the last * text section. Thus, DATA_START is calculated from RRS_DATA_START * and RRS_DATA_SIZE, while RRS_TEXT_START is derived from TEXT_START * and TEXT_SIZE. */ consider_rrs_section_lengths(); each_full_file(consider_file_section_lengths, 0); rrs_text_start = text_start + text_size; text_size += rrs_text_size; data_size += rrs_data_size; /* * If necessary, pad text section to full page in the file. Include * the padding in the text segment size. */ if (magic == ZMAGIC) { int text_end = text_size + N_TXTOFF(outheader); text_pad = PALIGN(text_end, page_size) - text_end; text_size += text_pad; } outheader.a_text = text_size; /* * Make the data segment address start in memory on a suitable * boundary. */ if (!Tdata_flag_specified) rrs_data_start = text_start + DATA_START(outheader) - TEXT_START(outheader); data_start = rrs_data_start + rrs_data_size; bss_start = rrs_data_start + data_size; #ifdef DEBUG printf("textstart = %#x, textsize = %#x, rrs_text_start = %#x, rrs_text_size %#x\n", text_start, text_size, rrs_text_start, rrs_text_size); printf("datastart = %#x, datasize = %#x, rrs_data_start %#x, rrs_data_size %#x\n", data_start, data_size, rrs_data_start, rrs_data_size); printf("bssstart = %#x, bsssize = %#x\n", bss_start, bss_size); #endif /* Compute start addresses of each file's sections and symbols. */ each_full_file(relocate_file_addresses, 0); relocate_rrs_addresses(); /* Pass 2: assign values to symbols */ digest_pass2(); if (end_symbol) { /* These are null if -r. */ etext_symbol->value = text_start + text_size - text_pad; edata_symbol->value = rrs_data_start + data_size; end_symbol->value = rrs_data_start + data_size + bss_size; } /* * Figure the data_pad now, so that it overlaps with the bss * addresses. */ if (specified_data_size && specified_data_size > data_size) data_pad = specified_data_size - data_size; if (magic == ZMAGIC) data_pad = PALIGN(data_pad + data_size, page_size) - data_size; bss_size -= data_pad; if (bss_size < 0) bss_size = 0; #if 0 if (magic == ZMAGIC) bss_size = PALIGN(bss_size, page_size); #endif data_size += data_pad; } void digest_pass1() { /* * Now, for each symbol, verify that it is defined globally at most * once within relocatable files (except when building a shared lib). * and set the `defined' field if there is a definition. * * Then check the shared object symbol chain for any remaining * undefined symbols. Set the `so_defined' field for any * definition find this way. */ FOR_EACH_SYMBOL(i, sp) { struct localsymbol *lsp; int defs = 0; if (!sp->referenced) { #if 0 /* Check for undefined symbols in shared objects */ int type; for (lsp = sp->dynrefs; lsp; lsp = lsp->next) { type = lsp->nzlist.nlist.n_type; if ((type & N_EXT) && type != (N_UNDF | N_EXT)) break; } if ((type & N_EXT) && type == (N_UNDF | N_EXT)) undefined_shobj_sym_count++; #endif /* Superfluous symbol from shared object */ continue; } if (sp == got_symbol || sp == dynamic_symbol) continue; for (lsp = sp->refs; lsp; lsp = lsp->next) { register struct nlist *p = &lsp->nzlist.nlist; register int type = p->n_type; if ((type & N_EXT) && type != (N_UNDF | N_EXT) && (type & N_TYPE) != N_FN) { /* non-common definition */ if (defs++ && sp->value != p->n_value && entry_symbol) { sp->multiply_defined = 1; multiple_def_count++; } sp->def_nlist = p; sp->defined = type; #ifdef DEBUG printf("rel: %s gets defined to %x with value %x\n", sp->name, type, sp->value); #endif } } if (sp->defined) { defined_global_sym_count++; continue; } if (relocatable_output) /* We're done */ continue; /* * Still undefined, search the shared object symbols for a * definition. This symbol must go into the RRS. */ /*WHY DID I DO THIS? sp->so_defined = N_UNDF | N_EXT; */ if (building_shared_object) { /* Just punt for now */ undefined_global_sym_count--; continue; } for (lsp = sp->dynrefs; lsp; lsp = lsp->next) { register struct nlist *p = &lsp->nzlist.nlist; register int type = p->n_type; if ((type & N_EXT) && type != (N_UNDF | N_EXT) && (type & N_TYPE) != N_FN) { /* non-common definition */ sp->def_nlist = p; sp->so_defined = type; undefined_global_sym_count--; #ifdef DEBUG printf("shr: %s gets defined to %x with value %x\n", sp->name, type, sp->value); #endif break; } } if (!sp->so_defined) printf("shr: %s did NOT get defined\n", sp->name); } END_EACH_SYMBOL; } void digest_pass2() { /* * Assign each symbol its final value. * If not -r'ing, allocate common symbols in the BSS section. */ FOR_EACH_SYMBOL(i, sp) { int size; int align = sizeof(int); #if 0 if (!sp->referenced) printf("pass2: UNREF symbol %s\n", sp->name); #endif if (!sp->referenced) continue; if (sp->defined && sp->def_nlist) sp->value = sp->def_nlist->n_value; if (building_shared_object && !(link_mode & SYMBOLIC)) /* No common allocation in shared objects */ continue; if ((size = sp->max_common_size) != 0) { /* * It's a common. */ if (sp->defined != (N_UNDF + N_EXT)) fatal("%s: common isn't", sp->name); } else if ((size = sp->size) != 0 && sp->defined == N_SIZE) { /* * It's data from shared object with size info. */ if (sp->so_defined != (N_DATA + N_EXT)) fatal("%s: Bogus N_SIZE item", sp->name); } else /* * It's neither */ continue; if (relocatable_output && !force_common_definition) { sp->defined = 0; undefined_global_sym_count++; defined_global_sym_count--; continue; } /* * Round up to nearest sizeof (int). I don't know whether * this is necessary or not (given that alignment is taken * care of later), but it's traditional, so I'll leave it in. * Note that if this size alignment is ever removed, ALIGN * above will have to be initialized to 1 instead of sizeof * (int). */ size = PALIGN(size, sizeof(int)); while (!(size & align)) align <<= 1; align = align > MAX_ALIGNMENT ? MAX_ALIGNMENT : align; bss_size = PALIGN(bss_size + data_size + rrs_data_start, align) - (data_size + rrs_data_start); sp->value = rrs_data_start + data_size + bss_size; if (sp->defined == (N_UNDF | N_EXT)) sp->defined = N_BSS | N_EXT; else { sp->so_defined = 0; defined_global_sym_count++; } bss_size += size; if (write_map) printf("Allocating %s %s: %x at %x\n", sp->defined==(N_BSS|N_EXT)?"common":"data", sp->name, size, sp->value); } END_EACH_SYMBOL; } /* * Scan relocation info in ENTRY for contributions to the dynamic section of * the output file. */ void consider_relocation (entry, dataseg) struct file_entry *entry; int dataseg; { struct relocation_info *reloc, *end; struct localsymbol *lsp; symbol *sp; if (dataseg == 0) { /* Text relocations */ reloc = entry->textrel; end = entry->textrel + entry->ntextrel; } else { /* Data relocations */ reloc = entry->datarel; end = entry->datarel + entry->ndatarel; } for (; reloc < end; reloc++) { /* * First, do the PIC specific relocs. * r_relative and r_copy should not occur at this point * (we do output them). The others break down to these * combinations: * * jmptab: extern: needs jmp slot * !extern: "intersegment" jump/call, * should get resolved in output * * baserel: extern: need GOT entry * !extern: may need GOT entry, * machine dependent * * baserel's always refer to symbol through `r_symbolnum' * whether extern or not. Internal baserels refer to statics * that must be accessed either *through* the GOT table like * global data, or by means of an offset from the GOT table. * The macro RELOC_STATICS_THROUGH_GOT_P() determines which * applies, since this is a machine (compiler?) dependent * addressing mode. */ if (RELOC_JMPTAB_P(reloc)) { if (!RELOC_EXTERN_P(reloc)) continue; lsp = &entry->symbols[reloc->r_symbolnum]; sp = lsp->symbol; alloc_rrs_jmpslot(sp); } else if (RELOC_BASEREL_P(reloc)) { lsp = &entry->symbols[reloc->r_symbolnum]; alloc_rrs_gotslot(reloc, lsp); } else if (RELOC_EXTERN_P(reloc)) { /* * Non-PIC relocations. * If the definition comes from a shared object * we need a relocation entry in RRS. * * If the .so definition is N_TEXT a jmpslot is * allocated. * * If it is N_DATA we allocate an address in BSS (?) * and arrange for the data to be copied at run-time. * The symbol is temporarily marked with N_SIZE in * the `defined' field, so we know what to do in * pass2() and during actual relocation. We convert * the type back to something real again when writing * out the symbols. * */ lsp = &entry->symbols[reloc->r_symbolnum]; sp = lsp->symbol; if (sp == NULL) fatal_with_file( "internal error, sp==NULL", entry); /* * Skip refs to _GLOBAL_OFFSET_TABLE_ and __DYNAMIC */ if (sp == got_symbol) { if (!CHECK_GOT_RELOC(reloc)) fatal_with_file( "Unexpected relocation type ", entry); continue; } /* * This symbol gives rise to a RRS entry */ if (building_shared_object) { alloc_rrs_reloc(sp); continue; } if (force_alias_definition && sp->so_defined == N_TEXT + N_EXT) { /* Call to shared library procedure */ alloc_rrs_jmpslot(sp); } else if (sp->size && sp->so_defined == N_DATA + N_EXT) { /* Reference to shared library data */ alloc_rrs_cpy_reloc(sp); sp->defined = N_SIZE; } else if (!sp->defined && sp->max_common_size == 0) alloc_rrs_reloc(sp); } else { /* * Segment relocation. * Prepare an RRS relocation as these are load * address dependent. */ if (building_shared_object) { alloc_rrs_segment_reloc(reloc); } } } } /* * Accumulate the section sizes of input file ENTRY into the section sizes of * the output file. */ void consider_file_section_lengths (entry) register struct file_entry *entry; { if (entry->just_syms_flag) return; entry->text_start_address = text_size; /* If there were any vectors, we need to chop them off */ text_size += entry->header.a_text; entry->data_start_address = data_size; data_size += entry->header.a_data; entry->bss_start_address = bss_size; bss_size += entry->header.a_bss; text_reloc_size += entry->header.a_trsize; data_reloc_size += entry->header.a_drsize; } /* * Determine where the sections of ENTRY go into the output file, * whose total section sizes are already known. * Also relocate the addresses of the file's local and debugger symbols. */ void relocate_file_addresses (entry) register struct file_entry *entry; { register struct localsymbol *lsp, *lspend; entry->text_start_address += text_start; /* * Note that `data_start' and `data_size' have not yet been * adjusted for `data_pad'. If they had been, we would get the wrong * results here. */ entry->data_start_address += data_start; entry->bss_start_address += bss_start; #ifdef DEBUG printf("%s: datastart: %#x, bss %#x\n", get_file_name(entry), entry->data_start_address, entry->bss_start_address); #endif lspend = entry->symbols + entry->nsymbols; for (lsp = entry->symbols; lsp < lspend; lsp++) { register struct nlist *p = &lsp->nzlist.nlist; /* * If this belongs to a section, update it * by the section's start address */ register int type = p->n_type & N_TYPE; switch (type) { case N_TEXT: p->n_value += entry->text_start_address; break; case N_DATA: /* * A symbol whose value is in the data section is * present in the input file as if the data section * started at an address equal to the length of the * file's text. */ p->n_value += entry->data_start_address - entry->header.a_text; break; case N_BSS: /* likewise for symbols with value in BSS. */ p->n_value += entry->bss_start_address - entry->header.a_text - entry->header.a_data; break; } } } /* Write the output file */ void write_output () { struct stat statbuf; int filemode; if (lstat(output_filename, &statbuf) != -1) { if (!S_ISDIR(statbuf.st_mode)) (void)unlink(output_filename); } outdesc = open (output_filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); if (outdesc < 0) perror_name (output_filename); if (fstat (outdesc, &statbuf) < 0) perror_name (output_filename); filemode = statbuf.st_mode; chmod (output_filename, filemode & ~0111); /* Output the a.out header. */ write_header (); /* Output the text and data segments, relocating as we go. */ write_text (); write_data (); /* Output the merged relocation info, if requested with `-r'. */ if (relocatable_output) write_rel (); /* Output the symbol table (both globals and locals). */ write_syms (); /* Output the RSS section */ write_rrs (); close (outdesc); if (chmod (output_filename, filemode | 0111) == -1) perror_name (output_filename); } void modify_location (), perform_relocation (), copy_text (), copy_data (); /* Total number of symbols to be written in the output file. */ int nsyms; void write_header () { int flags = (rrs_section_type == RRS_FULL) ? EX_DYNAMIC : 0; N_SET_FLAG (outheader, flags); outheader.a_text = text_size; outheader.a_data = data_size; outheader.a_bss = bss_size; outheader.a_entry = (entry_symbol ? entry_symbol->value : text_start + entry_offset); if (strip_symbols == STRIP_ALL) nsyms = 0; else { nsyms = (defined_global_sym_count + undefined_global_sym_count); if (discard_locals == DISCARD_L) nsyms += non_L_local_sym_count; else if (discard_locals == DISCARD_NONE) nsyms += local_sym_count; if (dynamic_symbol->referenced) nsyms++, special_sym_count++; if (got_symbol->referenced) nsyms++, special_sym_count++; } if (strip_symbols == STRIP_NONE) nsyms += debugger_sym_count; #ifdef DEBUG printf("defined globals: %d, undefined globals %d, locals: %d (non_L: %d), \ debug symbols: %d, special: %d --> nsyms %d\n", defined_global_sym_count, undefined_global_sym_count, local_sym_count, non_L_local_sym_count, debugger_sym_count, special_sym_count, nsyms); #endif outheader.a_syms = nsyms * sizeof (struct nlist); if (relocatable_output) { outheader.a_trsize = text_reloc_size; outheader.a_drsize = data_reloc_size; } else { outheader.a_trsize = 0; outheader.a_drsize = 0; } md_swapout_exec_hdr(&outheader); mywrite (&outheader, sizeof (struct exec), 1, outdesc); md_swapin_exec_hdr(&outheader); /* * Output whatever padding is required in the executable file * between the header and the start of the text. */ #ifndef COFF_ENCAPSULATE padfile (N_TXTOFF(outheader) - sizeof outheader, outdesc); #endif } /* Relocate the text segment of each input file and write to the output file. */ void write_text () { if (trace_files) fprintf (stderr, "Copying and relocating text:\n\n"); each_full_file (copy_text, 0); file_close (); if (trace_files) fprintf (stderr, "\n"); padfile (text_pad, outdesc); } /* * Read the text segment contents of ENTRY, relocate them, and write the * result to the output file. If `-r', save the text relocation for later * reuse. */ void copy_text (entry) struct file_entry *entry; { register char *bytes; register int desc; if (trace_files) prline_file_name (entry, stderr); desc = file_open (entry); /* Allocate space for the file's text section */ bytes = (char *) alloca (entry->header.a_text); /* Deal with relocation information however is appropriate */ if (entry->textrel == NULL) fatal_with_file("no text relocation of ", entry); /* Read the text section into core. */ lseek (desc, text_offset (entry), 0); if (entry->header.a_text != read (desc, bytes, entry->header.a_text)) fatal_with_file ("premature eof in text section of ", entry); /* Relocate the text according to the text relocation. */ perform_relocation (bytes, entry->header.a_text, entry->textrel, entry->ntextrel, entry, 0); /* Write the relocated text to the output file. */ mywrite (bytes, 1, entry->header.a_text, outdesc); } /* Relocate the data segment of each input file and write to the output file. */ void write_data () { long pos; if (trace_files) fprintf (stderr, "Copying and relocating data:\n\n"); pos = N_DATOFF(outheader) + data_start - rrs_data_start; if (lseek(outdesc, pos, L_SET) != pos) fatal("write_data: lseek: cant position data offset"); each_full_file (copy_data, 0); file_close (); /* * Write out the set element vectors. See digest symbols for * description of length of the set vector section. */ if (trace_files) fprintf (stderr, "\n"); padfile (data_pad, outdesc); } /* * Read the data segment contents of ENTRY, relocate them, and write the * result to the output file. If `-r', save the data relocation for later * reuse. See comments in `copy_text'. */ void copy_data (entry) struct file_entry *entry; { register char *bytes; register int desc; if (trace_files) prline_file_name (entry, stderr); desc = file_open (entry); bytes = (char *)alloca(entry->header.a_data); if (entry->datarel == NULL) fatal_with_file("no data relocation of ", entry); lseek (desc, text_offset (entry) + entry->header.a_text, 0); if (entry->header.a_data != read(desc, bytes, entry->header.a_data)) fatal_with_file ("premature eof in data section of ", entry); perform_relocation (bytes, entry->header.a_data, entry->datarel, entry->ndatarel, entry, 1); mywrite (bytes, 1, entry->header.a_data, outdesc); } /* * Relocate ENTRY's text or data section contents. DATA is the address of the * contents, in core. DATA_SIZE is the length of the contents. PC_RELOCATION * is the difference between the address of the contents in the output file * and its address in the input file. RELOC is the address of the * relocation info, in core. NRELOC says how many there are. */ void perform_relocation(data, data_size, reloc, nreloc, entry, dataseg) char *data; int data_size; struct relocation_info *reloc; int nreloc; struct file_entry *entry; int dataseg; { register struct relocation_info *r = reloc; struct relocation_info *end = reloc + nreloc; text_relocation = entry->text_start_address; data_relocation = entry->data_start_address - entry->header.a_text; bss_relocation = entry->bss_start_address - entry->header.a_text - entry->header.a_data; pc_relocation = dataseg? entry->data_start_address - entry->header.a_text: entry->text_start_address; for (; r < end; r++) { int addr = RELOC_ADDRESS(r); long addend = md_get_addend(r, data+addr); long relocation; /* * Loop over the relocations again as we did in * consider_relocation(), claiming the reserved RRS * relocations. */ if (addr >= data_size) fatal_with_file( "relocation address out of range in ", entry); if (RELOC_JMPTAB_P(r)) { int symindex = RELOC_SYMBOL(r); struct localsymbol *lsp = &entry->symbols[symindex]; symbol *sp = lsp->symbol; if (symindex >= entry->nsymbols) fatal_with_file( "relocation symbolnum out of range in ", entry); if (relocatable_output) relocation = addend; else if (!RELOC_EXTERN_P(r)) { relocation = addend + data_relocation - text_relocation; } else relocation = addend + claim_rrs_jmpslot(r, sp, addend); } else if (RELOC_BASEREL_P(r)) { int symindex = RELOC_SYMBOL(r); struct localsymbol *lsp = &entry->symbols[symindex]; if (symindex >= entry->nsymbols) fatal_with_file( "relocation symbolnum out of range in ", entry); if (relocatable_output) relocation = addend; else if (!RELOC_EXTERN_P(r)) relocation = claim_rrs_internal_gotslot(r, lsp, addend); else relocation = claim_rrs_gotslot(r, lsp, addend); } else if (RELOC_EXTERN_P(r)) { int symindex = RELOC_SYMBOL(r); symbol *sp = entry->symbols[symindex].symbol; if (symindex >= entry->nsymbols) fatal_with_file( "relocation symbolnum out of range in ", entry); if (relocatable_output) { relocation = addend + sp->value; } else if (sp->defined) { if (sp == got_symbol) { /* Handle _GOT_ refs */ relocation = addend + sp->value + md_got_reloc(r); } else if (building_shared_object) { /* * Normal (non-PIC) relocation needs * to be converted into an RRS reloc * when building a shared object. */ r->r_address += dataseg? entry->data_start_address: entry->text_start_address; relocation = addend; if (claim_rrs_reloc(r, sp, &relocation)) continue; } else if (sp->defined == N_SIZE) { /* * If size is known, arrange a * run-time copy. */ if (!sp->size) fatal("Copy item isn't: %s", sp->name); relocation = addend + sp->value; r->r_address = sp->value; claim_rrs_cpy_reloc(r, sp); } else /* Plain old relocation */ relocation = addend + sp->value; } else { /* * If the symbol is undefined, we relocate it * in a way similar to -r case. We use an * RRS relocation to resolve the symbol at * run-time. The r_address field is updated * to reflect the changed position in the * output file. * * In case the symbol is defined in a shared * object as N_TEXT or N_DATA, an appropriate * jmpslot or copy relocation is generated. */ switch (sp->so_defined) { case N_TEXT+N_EXT: /* * Claim a jmpslot if one was * allocated (dependent on * `force_alias_flag'). */ if (sp->jmpslot_offset == -1) goto undefined; relocation = addend + claim_rrs_jmpslot(r, sp, addend); break; case N_DATA+N_EXT: #if 0 /* * If size is known, arrange a * run-time copy. */ if (sp->size) { relocation = addend + sp->value; r->r_address += dataseg? entry->data_start_address: entry->text_start_address; claim_rrs_cpy_reloc(r, sp); break; } #endif /*FALLTHROUGH*/ case 0: undefined: r->r_address += dataseg? entry->data_start_address: entry->text_start_address; relocation = addend; if (claim_rrs_reloc(r, sp, &relocation)) continue; break; case N_BSS+N_EXT: printf("%s: BSS found in so_defined\n", sp->name); /*break;*/ default: fatal("%s: shobj symbol with unknown type %#x", sp->name, sp->so_defined); break; } } } else { switch (RELOC_TYPE(r)) { case N_TEXT: case N_TEXT | N_EXT: relocation = addend + text_relocation; break; case N_DATA: case N_DATA | N_EXT: /* * A word that points to beginning of the the * data section initially contains not 0 but * rather the "address" of that section in * the input file, which is the length of the * file's text. */ relocation = addend + data_relocation; break; case N_BSS: case N_BSS | N_EXT: /* * Similarly, an input word pointing to the * beginning of the bss initially contains * the length of text plus data of the file. */ relocation = addend + bss_relocation; break; case N_ABS: case N_ABS | N_EXT: /* * Don't know why this code would occur, but * apparently it does. */ break; default: fatal_with_file( "nonexternal relocation code invalid in ", entry); } /* * When building a shared object, these segment * relocations need a "load address relative" * RRS fixup. */ if (building_shared_object) { r->r_address += dataseg? entry->data_start_address: entry->text_start_address; claim_rrs_segment_reloc(r); } } if (RELOC_PCREL_P(r)) relocation -= pc_relocation; md_relocate(r, relocation, data+addr, relocatable_output); } } /* For relocatable_output only: write out the relocation, relocating the addresses-to-be-relocated. */ void coptxtrel (), copdatrel (); void write_rel () { register int count = 0; if (trace_files) fprintf (stderr, "Writing text relocation:\n\n"); /* * Assign each global symbol a sequence number, giving the order * in which `write_syms' will write it. * This is so we can store the proper symbolnum fields * in relocation entries we write. * /* BLECH - Assign number 0 to __DYNAMIC (!! Sun compatibility) */ if (dynamic_symbol->referenced) dynamic_symbol->symbolnum = count++; FOR_EACH_SYMBOL(i, sp) { if (sp != dynamic_symbol && sp->referenced) { sp->symbolnum = count++; } } END_EACH_SYMBOL; /* Correct, because if (relocatable_output), we will also be writing whatever indirect blocks we have. */ if (count != defined_global_sym_count + undefined_global_sym_count + special_sym_count) fatal ("internal error: write_rel: count = %d", count); /* Write out the relocations of all files, remembered from copy_text. */ each_full_file (coptxtrel, 0); if (trace_files) fprintf (stderr, "\nWriting data relocation:\n\n"); each_full_file (copdatrel, 0); if (trace_files) fprintf (stderr, "\n"); } void coptxtrel(entry) struct file_entry *entry; { register struct relocation_info *r, *end; register int reloc = entry->text_start_address; r = entry->textrel; end = r + entry->ntextrel; for (; r < end; r++) { register int symindex; symbol *symptr; RELOC_ADDRESS(r) += reloc; if (!RELOC_EXTERN_P(r)) continue; symindex = RELOC_SYMBOL(r); symptr = entry->symbols[symindex].symbol; if (symindex >= entry->nsymbols) fatal_with_file( "relocation symbolnum out of range in ", entry); #ifdef N_INDR /* Resolve indirection. */ if ((symptr->defined & ~N_EXT) == N_INDR) symptr = (symbol *) symptr->value; #endif /* * If the symbol is now defined, change the external * relocation to an internal one. */ if (symptr->defined) { RELOC_EXTERN_P(r) = 0; RELOC_SYMBOL(r) = (symptr->defined & N_TYPE); #ifdef RELOC_ADD_EXTRA /* * If we aren't going to be adding in the * value in memory on the next pass of the * loader, then we need to add it in from the * relocation entry. Otherwise the work we * did in this pass is lost. */ if (!RELOC_MEMORY_ADD_P(r)) RELOC_ADD_EXTRA(r) += symptr->value; #endif } else /* * Global symbols come first. */ RELOC_SYMBOL(r) = symptr->symbolnum; } md_swapout_reloc(entry->textrel, entry->ntextrel); mywrite(entry->textrel, entry->ntextrel, sizeof(struct relocation_info), outdesc); } void copdatrel(entry) struct file_entry *entry; { register struct relocation_info *r, *end; /* * Relocate the address of the relocation. Old address is relative to * start of the input file's data section. New address is relative to * start of the output file's data section. */ register int reloc = entry->data_start_address - text_size; r = entry->datarel; end = r + entry->ndatarel; for (; r < end; r++) { register int symindex; symbol *symptr; int symtype; RELOC_ADDRESS(r) += reloc; if (!RELOC_EXTERN_P(r)) continue; symindex = RELOC_SYMBOL(r); symptr = entry->symbols[symindex].symbol; if (symindex >= entry->header.a_syms) fatal_with_file( "relocation symbolnum out of range in ", entry); #ifdef N_INDR /* Resolve indirection. */ if ((symptr->defined & ~N_EXT) == N_INDR) symptr = (symbol *) symptr->value; #endif symtype = symptr->defined & N_TYPE; if (force_common_definition || symtype == N_DATA || symtype == N_TEXT || symtype == N_ABS) { RELOC_EXTERN_P(r) = 0; RELOC_SYMBOL(r) = symtype; } else /* * Global symbols come first. */ RELOC_SYMBOL(r) = entry->symbols[symindex].symbol->symbolnum; } md_swapout_reloc(entry->datarel, entry->ndatarel); mywrite(entry->datarel, entry->ndatarel, sizeof(struct relocation_info), outdesc); } void write_file_syms (); void write_string_table (); /* Offsets and current lengths of symbol and string tables in output file. */ int symbol_table_offset; int symbol_table_len; /* Address in output file where string table starts. */ int string_table_offset; /* Offset within string table where the strings in `strtab_vector' should be written. */ int string_table_len; /* Total size of string table strings allocated so far, including strings in `strtab_vector'. */ int strtab_size; /* Vector whose elements are strings to be added to the string table. */ char **strtab_vector; /* Vector whose elements are the lengths of those strings. */ int *strtab_lens; /* Index in `strtab_vector' at which the next string will be stored. */ int strtab_index; /* * Add the string NAME to the output file string table. Record it in * `strtab_vector' to be output later. Return the index within the string * table that this string will have. */ int assign_string_table_index(name) char *name; { register int index = strtab_size; register int len = strlen(name) + 1; strtab_size += len; strtab_vector[strtab_index] = name; strtab_lens[strtab_index++] = len; return index; } FILE *outstream = (FILE *) 0; /* * Write the contents of `strtab_vector' into the string table. This is done * once for each file's local&debugger symbols and once for the global * symbols. */ void write_string_table () { register int i; lseek (outdesc, string_table_offset + string_table_len, 0); if (!outstream) outstream = fdopen (outdesc, "w"); for (i = 0; i < strtab_index; i++) { fwrite (strtab_vector[i], 1, strtab_lens[i], outstream); string_table_len += strtab_lens[i]; } fflush (outstream); /* Report I/O error such as disk full. */ if (ferror (outstream)) perror_name (output_filename); } /* Write the symbol table and string table of the output file. */ void write_syms() { /* Number of symbols written so far. */ int non_local_syms = defined_global_sym_count + undefined_global_sym_count + special_sym_count; int syms_written = 0; struct nlist nl; /* * Buffer big enough for all the global symbols. One extra struct * for each indirect symbol to hold the extra reference following. */ struct nlist *buf = (struct nlist *)alloca(non_local_syms * sizeof(struct nlist)); /* Pointer for storing into BUF. */ register struct nlist *bufp = buf; /* Size of string table includes the bytes that store the size. */ strtab_size = sizeof strtab_size; symbol_table_offset = N_SYMOFF(outheader); symbol_table_len = 0; string_table_offset = N_STROFF(outheader); string_table_len = strtab_size; if (strip_symbols == STRIP_ALL) return; #if yesterday /* Write the local symbols defined by the various files. */ each_file(write_file_syms, &syms_written); file_close(); /* Now write out the global symbols. */ #endif /* First, write out the global symbols. */ /* * Allocate two vectors that record the data to generate the string * table from the global symbols written so far. This must include * extra space for the references following indirect outputs. */ strtab_vector = (char **) alloca((non_local_syms) * sizeof(char *)); strtab_lens = (int *) alloca((non_local_syms) * sizeof(int)); strtab_index = 0; /* * __DYNAMIC symbol *must* be first for Sun compatibility, as Sun's * ld.so reads the shared object's first symbol. This means that * (Sun's) shared libraries cannot be stripped! (We only assume * that __DYNAMIC is the first item in the data segment) */ if (dynamic_symbol->referenced) { nl.n_other = 0; nl.n_desc = 0; nl.n_type = dynamic_symbol->defined; #ifdef SUN_COMPAT nl.n_type &= ~N_EXT; #endif nl.n_value = dynamic_symbol->value; nl.n_un.n_strx = assign_string_table_index(dynamic_symbol->name); *bufp++ = nl; syms_written++; } /* Scan the symbol hash table, bucket by bucket. */ FOR_EACH_SYMBOL(i, sp) { if (sp == dynamic_symbol) /* Already dealt with above */ continue; if (!sp->referenced) /* Came from shared object but was not used */ continue; if (sp->so_defined) /* * Definition came from shared object, * don't mention it here */ continue; if (!sp->defined && !relocatable_output) { /* * We're building a shared object and there * are still undefined symbols. Don't output * these, symbol was discounted in digest_pass1() * (they are in the RRS symbol table). */ if (!building_shared_object) error("symbol %s remains undefined", sp->name); continue; } /* Construct a `struct nlist' for the symbol. */ nl.n_other = 0; nl.n_desc = 0; /* * common condition needs to be before undefined * condition because unallocated commons are set * undefined in digest_symbols */ if (sp->defined > 1) { /* defined with known type */ if (sp->defined == N_SIZE) nl.n_type = N_DATA | N_EXT; else nl.n_type = sp->defined; nl.n_value = sp->value; } else if (sp->max_common_size) { /* * defined as common but not allocated, * happens only with -r and not -d, write out * a common definition */ nl.n_type = N_UNDF | N_EXT; nl.n_value = sp->max_common_size; } else if (!sp->defined) { /* undefined -- legit only if -r */ nl.n_type = N_UNDF | N_EXT; nl.n_value = 0; } else fatal( "internal error: %s defined in mysterious way", sp->name); /* * Allocate string table space for the symbol name. */ nl.n_un.n_strx = assign_string_table_index(sp->name); /* Output to the buffer and count it. */ if (syms_written >= non_local_syms) fatal( "internal error: number of symbols exceeds allocated %d", non_local_syms); *bufp++ = nl; syms_written++; #ifdef DEBUG printf("writesym(#%d): %s, type %x\n", syms_written, sp->name, sp->defined); #endif } END_EACH_SYMBOL; if (syms_written != strtab_index || strtab_index != non_local_syms) fatal("internal error: wrong number (%d) of global symbols written into output file, should be %d", syms_written, non_local_syms); /* Output the buffer full of `struct nlist's. */ lseek(outdesc, symbol_table_offset + symbol_table_len, 0); md_swapout_symbols(buf, bufp - buf); mywrite(buf, bufp - buf, sizeof(struct nlist), outdesc); symbol_table_len += sizeof(struct nlist) * (bufp - buf); #if yesterday if (syms_written != nsyms) fatal("internal error: wrong number of symbols written into output file", 0); if (symbol_table_offset + symbol_table_len != string_table_offset) fatal("internal error: inconsistent symbol table length", 0); /* * Now the total string table size is known, so write it. We are * already positioned at the right place in the file. */ mywrite(&strtab_size, sizeof(int), 1, outdesc); /* we're at right place */ #endif /* Write the strings for the global symbols. */ write_string_table(); /**MOVED HERE YESTERDAY**/ /* Write the local symbols defined by the various files. */ each_file(write_file_syms, &syms_written); file_close(); if (syms_written != nsyms) fatal("internal error:\ wrong number of symbols (%d) written into output file, should be %d", syms_written, nsyms); if (symbol_table_offset + symbol_table_len != string_table_offset) fatal( "internal error: inconsistent symbol table length: %d vs %s", symbol_table_offset + symbol_table_len, string_table_offset); lseek(outdesc, string_table_offset, 0); strtab_size = md_swap_long(strtab_size); mywrite(&strtab_size, sizeof(int), 1, outdesc); } /* * Write the local and debugger symbols of file ENTRY. Increment * *SYMS_WRITTEN_ADDR for each symbol that is written. */ /* * Note that we do not combine identical names of local symbols. dbx or gdb * would be confused if we did that. */ void write_file_syms(entry, syms_written_addr) struct file_entry *entry; int *syms_written_addr; { struct localsymbol *lsp, *lspend; /* Upper bound on number of syms to be written here. */ int max_syms = entry->nsymbols + 1; /* * Buffer to accumulate all the syms before writing them. It has one * extra slot for the local symbol we generate here. */ struct nlist *buf = (struct nlist *) alloca(max_syms * sizeof(struct nlist)); register struct nlist *bufp = buf; if (entry->is_dynamic) return; /* * Make tables that record, for each symbol, its name and its name's * length. The elements are filled in by `assign_string_table_index'. */ strtab_vector = (char **) alloca(max_syms * sizeof(char *)); strtab_lens = (int *) alloca(max_syms * sizeof(int)); strtab_index = 0; /* Generate a local symbol for the start of this file's text. */ if (discard_locals != DISCARD_ALL) { struct nlist nl; nl.n_type = N_FN | N_EXT; nl.n_un.n_strx = assign_string_table_index(entry->local_sym_name); nl.n_value = entry->text_start_address; nl.n_desc = 0; nl.n_other = 0; *bufp++ = nl; (*syms_written_addr)++; entry->local_syms_offset = *syms_written_addr * sizeof(struct nlist); } /* Read the file's string table. */ entry->strings = (char *) alloca(entry->string_size); read_entry_strings(file_open(entry), entry); lspend = entry->symbols + entry->nsymbols; for (lsp = entry->symbols; lsp < lspend; lsp++) { register struct nlist *p = &lsp->nzlist.nlist; register int type = p->n_type; register int write = 0; /* * WRITE gets 1 for a non-global symbol that should be * written. */ if (!(type & (N_STAB | N_EXT))) /* ordinary local symbol */ write = ((discard_locals != DISCARD_ALL) && !(discard_locals == DISCARD_L && (p->n_un.n_strx + entry->strings)[0] == LPREFIX) && type != N_WARNING); else if (!(type & N_EXT)) /* debugger symbol */ write = (strip_symbols == STRIP_NONE) && !(discard_locals == DISCARD_L && (p->n_un.n_strx + entry->strings)[0] == LPREFIX); if (write) { /* * If this symbol has a name, allocate space for it * in the output string table. */ if (p->n_un.n_strx) p->n_un.n_strx = assign_string_table_index( p->n_un.n_strx + entry->strings); /* Output this symbol to the buffer and count it. */ *bufp++ = *p; (*syms_written_addr)++; } } /* All the symbols are now in BUF; write them. */ lseek(outdesc, symbol_table_offset + symbol_table_len, 0); md_swapout_symbols(buf, bufp - buf); mywrite(buf, bufp - buf, sizeof(struct nlist), outdesc); symbol_table_len += sizeof(struct nlist) * (bufp - buf); /* * Write the string-table data for the symbols just written, using * the data in vectors `strtab_vector' and `strtab_lens'. */ write_string_table(); entry->strings = 0; /* Since it will disappear anyway. */ }