OpenBSD-4.6/gnu/usr.bin/ld/ld.c
/* $OpenBSD: ld.c,v 1.33 2008/02/12 21:17:53 miod Exp $ */
/* $NetBSD: ld.c,v 1.52 1998/02/20 03:12:51 jonathan Exp $ */
/*-
* 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
#if 0
static char sccsid[] = "@(#)ld.c 6.10 (Berkeley) 5/22/91";
#endif
#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. */
/* Define how to initialize system-dependent header fields. */
#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <err.h>
#include <fcntl.h>
#include <ar.h>
#include <ranlib.h>
#include <a.out.h>
#include <stab.h>
#include <string.h>
#define GNU_BINUTIL_COMPAT /* forwards compatibility with binutils 2.x */
/*#define DEBUG_COMPAT*/
#include "ld.h"
/* Vector of entries for input files specified by arguments.
These are all the input files except for members of specified libraries. */
struct file_entry *file_table;
int number_of_files;
/* 1 => write relocation into output file so can re-input it later. */
int relocatable_output;
/* 1 => building a shared object, set by `-Bshareable'. */
int building_shared_object;
/* 1 => create the output executable. */
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;
/* 1 => some files contain PIC code, affects relocation bits
if `relocatable_output'. */
int pic_code_seen;
/* 1 => segments must be page aligned (ZMAGIC, QMAGIC) */
int page_align_segments;
/* 1 => data segment must be page aligned, even if `-n' or `-N' */
int page_align_data;
/* 1 => do not use standard library search path */
int nostdlib;
/* Version number to put in __DYNAMIC (set by -V) */
int soversion;
int text_size; /* total size of text. */
int text_start; /* start of text */
int text_pad; /* clear space between text and data */
int data_size; /* total size of data. */
int data_start; /* start of data */
int data_pad; /* part of bss segment as part of data */
int bss_size; /* total size of bss. */
int bss_start; /* start of bss */
int text_reloc_size; /* total size of text relocation. */
int data_reloc_size; /* total size of data relocation. */
int rrs_section_type; /* What's in the RRS section */
int rrs_text_size; /* Size of RRS text additions */
int rrs_text_start; /* Location of above */
int rrs_data_size; /* Size of RRS data additions */
int rrs_data_start; /* Location of above */
/* Specifications of start and length of the area reserved at the end
of the data segment for the set vectors. Computed in 'digest_symbols' */
int set_sect_start; /* start of set element vectors */
int set_sect_size; /* size of above */
int link_mode; /* Current link mode */
int pic_type; /* PIC type */
/*
* When loading the text and data, we can avoid doing a close
* and another open between members of the same library.
*
* These two variables remember the file that is currently open.
* Both are zero if no file is open.
*
* See `each_file' and `file_close'.
*/
struct file_entry *input_file;
int input_desc;
/* The name of the file to write; "a.out" by default. */
char *output_filename; /* Output file name. */
FILE *outstream; /* Output file descriptor. */
struct exec outheader; /* Output file header. */
int magic; /* Output file magic. */
int oldmagic;
int relocatable_output; /* `-r'-ed output */
symbol *entry_symbol; /* specified by `-e' */
int entry_offset; /* program entry if no `-e' given */
int page_size; /* Size of a page (machine dependent) */
/*
* Keep a list of any symbols referenced from the command line (so
* that error messages for these guys can be generated). This list is
* zero terminated.
*/
symbol **cmdline_references;
int cl_refs_allocated;
/*
* 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;
int global_sym_count; /* # of nlist entries for global symbols */
int size_sym_count; /* # of N_SIZE nlist entries for output
(relocatable_output only) */
int local_sym_count; /* # of nlist entries for local symbols. */
int non_L_local_sym_count; /* # of nlist entries for non-L symbols */
int debugger_sym_count; /* # of nlist entries for debugger info. */
int undefined_global_sym_count; /* # of global symbols referenced and
not defined. */
int undefined_shobj_sym_count; /* # of undefined symbols referenced
by shared objects */
int multiple_def_count; /* # of multiply defined symbols. */
int defined_global_sym_count; /* # of defined global symbols. */
int common_defined_global_count; /* # of common symbols. */
int undefined_weak_sym_count; /* # of weak symbols referenced and
not defined. */
#if notused
int special_sym_count; /* # of linker defined symbols. */
/* XXX - Currently, only __DYNAMIC and _G_O_T_ go here if required,
* perhaps _etext, _edata and _end should go here too.
*/
#endif
int global_alias_count; /* # of aliased symbols */
int set_symbol_count; /* # of N_SET* symbols. */
int set_vector_count; /* # of set vectors in output. */
int warn_sym_count; /* # of warning symbols encountered. */
int list_warning_symbols; /* 1 => warning symbols referenced */
struct string_list_element *set_element_prefixes;
int trace_files; /* print names of input files as processed (`-t'). */
int write_map; /* write a load map (`-M') */
/*
* `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;
long *set_vectors;
int setv_fill_count;
/*
* Control warnings if we see syntax obsolete in GNU binutils, or if
* our forwards-compatible emulation of binutils flags is not
* completely faithful.
*/
int warn_obsolete_syntax = 0;
#ifdef DEBUG_COMPAT
int warn_forwards_compatible_inexact = 1;
#else
int warn_forwards_compatible_inexact = 0;
#endif
static void decode_option(char *, char *);
static void decode_command(int, char **);
static int classify_arg(char *);
static void load_symbols(void);
static void enter_global_ref(struct localsymbol *,
char *, struct file_entry *);
static void digest_symbols(void);
static void digest_pass1(void), digest_pass2(void);
static void consider_file_section_lengths(struct file_entry *, void *);
static void relocate_file_addresses(struct file_entry *, void *);
static void consider_relocation(struct file_entry *, void *);
static void consider_local_symbols(struct file_entry *, void *);
static void perform_relocation(char *, int,
struct relocation_info *, int,
struct file_entry *, int);
static void copy_text(struct file_entry *, void *);
static void copy_data(struct file_entry *, void *);
static void coptxtrel(struct file_entry *, void *);
static void copdatrel(struct file_entry *, void *);
static void write_output(void);
static void write_header(void);
static void write_text(void);
static void write_data(void);
static void write_rel(void);
static void write_syms(void);
static void assign_symbolnums(struct file_entry *, void *);
static void cleanup(void);
static int parse(char *, char *, char *);
int
main(int argc, char *argv[])
{
if (atexit(cleanup))
err(1, "atexit");
/* 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. */
if (getrlimit(RLIMIT_STACK, &rlim) != 0)
warn("getrlimit");
else {
rlim.rlim_cur = rlim.rlim_max;
if (setrlimit(RLIMIT_STACK, &rlim) != 0)
warn("setrlimit");
}
}
#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;
page_align_segments = 0;
page_align_data = 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;
#ifdef SUNOS4
link_mode |= SILLYARCHIVE;
#endif
soversion = DEFAULT_SOVERSION;
/* 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;
warn_sym_count = 0;
list_warning_symbols = 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 = (symbol **)
xmalloc(cl_refs_allocated * sizeof(symbol *));
*cmdline_references = 0;
/* Completely decode ARGV. */
decode_command(argc, argv);
building_shared_object =
(!relocatable_output && (link_mode & SHAREABLE));
if (building_shared_object && entry_symbol) {
errx(1,"`-Bshareable' and `-e' options are mutually exclusive");
}
/* Create the symbols `etext', `edata' and `end'. */
symtab_init(relocatable_output);
/*
* 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.
*/
if (magic == ZMAGIC || magic == QMAGIC)
page_align_segments = 1;
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);
}
/*
* 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.
*/
static int
classify_arg(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 'R':
case 'l':
case 'o':
case 'u':
case 'V':
case 'y':
if (arg[2])
return 1;
return 2;
case 'E':
/* ignore this option */
return 1;
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;
/* GNU binutils 2.x forward-compatible flags. */
case 'r':
/* Ignore "-rpath" and hope ld.so.conf will cover our sins. */
if (!strcmp(&arg[1], "rpath"))
return 2;
return 1;
case 's':
/* Treat "-shared" and "-soname' like binutils 2.x does. */
if (!strcmp(&arg[1], "shared"))
return 1;
if (!strcmp(&arg[1], "soname"))
return 2;
break;
}
return 1;
}
/*
* Process the command arguments, setting up file_table with an entry for
* each input file, and setting variables according to the options.
*/
static void
decode_command(int argc, char **argv)
{
int i;
struct file_entry *p;
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++) {
int code = classify_arg(argv[i]);
if (code) {
if (i + code > argc)
errx(1, "no argument following %s", 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)
errx(1, "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, -B and -l are ignored here. */
for (i = 1; i < argc; i++) {
char *string;
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 |= SHAREABLE;
#ifdef SUN_COMPAT
else if (strcmp(string, "silly") == 0)
link_mode |= SILLYARCHIVE;
else if (strcmp(string, "~silly") == 0)
link_mode &= ~SILLYARCHIVE;
#endif
}
if (argv[i][1] == 'A') {
if (p != file_table)
errx(1, "-A specified before an input file other than the first");
p->filename = string;
p->local_sym_name = string;
p->flags |= E_JUST_SYMS;
link_mode &= ~DYNAMIC;
p++;
}
if (argv[i][1] == 'l') {
p->filename = string;
p->local_sym_name = concat("-l", string, "");
p->flags |= E_SEARCH_DIRS;
if (link_mode & DYNAMIC && !relocatable_output)
p->flags |= E_SEARCH_DYNAMIC;
p++;
}
i += code - 1;
}
/* Now check some option settings for consistency. */
if (page_align_segments &&
(text_start - text_start_alignment) & (page_size - 1))
errx(1, "incorrect alignment of text start address");
/* Append the standard search directories to the user-specified ones. */
add_search_path(getenv("LD_LIBRARY_PATH"));
if (!nostdlib && getenv("LD_NOSTD_PATH") == NULL)
std_search_path();
}
static void
add_cmdline_ref(symbol *sp)
{
symbol **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 = (symbol **)
xrealloc(cmdline_references,
cl_refs_allocated * sizeof(symbol *));
ptr = cmdline_references + diff;
}
*ptr++ = sp;
*ptr = (symbol *)0;
}
int
set_element_prefixed_p(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;
}
/*
* 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.
*/
static void
decode_option(char *swt, char *arg)
{
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")) {
if (warn_obsolete_syntax)
warnx("-Bshareable: obsolete syntax");
return;
}
if (!strcmp(swt + 1, "assert"))
return;
#ifdef GNU_BINUTIL_COMPAT
if (strcmp(swt + 1, "-whole-archive") == 0) {
/* XXX incomplete emulation */
link_mode |= FORCEARCHIVE;
if (warn_forwards_compatible_inexact)
warnx("-no-whole-archive treated as -Bshareable");
return;
}
if (strcmp(swt + 1, "-no-whole-archive") == 0) {
/* XXX incomplete emulation */
if (warn_forwards_compatible_inexact)
warnx("-no-whole-archive ignored");
return;
}
if (strcmp(swt + 1, "shared") == 0) {
link_mode |= SHAREABLE;
#ifdef DEBUG_COMPAT
warnx("-shared treated as -Bshareable");
#endif
return;
}
if (strcmp(swt + 1, "soname") == 0) {
if (warn_forwards_compatible_inexact)
warnx("-soname %s ignored", arg);
return;
}
if (strcmp(swt + 1, "rpath") == 0) {
if (warn_forwards_compatible_inexact)
warnx("%s %s ignored", swt, arg);
goto do_rpath;
}
#endif /* GNU_BINUTIL_COMPAT */
#ifdef SUN_COMPAT
if (!strcmp(swt + 1, "Bsilly"))
return;
#endif
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 (!strcmp(swt + 1, "nostdlib")) {
nostdlib = 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 (swt[2] == 0 || *arg == 'c')
force_common_definition = 1;
else if (*arg == 'p')
force_alias_definition = 1;
else
errx(1, "-d option takes 'c' or 'p' argument");
return;
case 'e':
entry_symbol = getsym(arg);
if (!entry_symbol->defined &&
!(entry_symbol->flags & GS_REFERENCED))
undefined_global_sym_count++;
entry_symbol->flags |= GS_REFERENCED;
add_cmdline_ref(entry_symbol);
return;
case 'E':
return;
case 'l':
return;
case 'L':
add_search_dir(arg);
return;
case 'R':
do_rpath:
rrs_search_paths = (rrs_search_paths == NULL)
? strdup(arg)
: concat(rrs_search_paths, ":", arg);
return;
case 'M':
write_map = 1;
return;
case 'N':
magic = OMAGIC;
return;
case 'n':
magic = NMAGIC;
return;
case 'o':
output_filename = arg;
return;
case 'p':
page_align_data = 1;
return;
#ifdef QMAGIC
case 'Q':
magic = QMAGIC;
return;
#endif
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':
{
symbol *sp = getsym(arg);
if (!sp->defined && !(sp->flags & GS_REFERENCED))
undefined_global_sym_count++;
sp->flags |= GS_REFERENCED;
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':
{
symbol *sp = getsym(&swt[2]);
sp->flags |= GS_TRACE;
}
return;
case 'z':
magic = ZMAGIC;
oldmagic = 0;
#ifdef FreeBSD
netzmagic = 1;
#endif
return;
case 'Z':
magic = oldmagic = ZMAGIC;
#ifdef FreeBSD
netzmagic = 0;
#endif
return;
default:
errx(1, "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(void (*function)(struct file_entry *, void *), void *arg)
{
int i;
for (i = 0; i < number_of_files; i++) {
struct file_entry *entry = &file_table[i];
struct file_entry *subentry;
if (entry->flags & E_SCRAPPED)
continue;
if (!(entry->flags & E_IS_LIBRARY))
(*function)(entry, arg);
subentry = entry->subfiles;
for (; subentry; subentry = subentry->chain) {
if (subentry->flags & E_SCRAPPED)
continue;
(*function)(subentry, arg);
}
#ifdef SUN_COMPAT
if (entry->silly_archive) {
if (!(entry->flags & E_DYNAMIC))
warnx("Silly");
if (!(entry->silly_archive->flags & E_IS_LIBRARY))
warnx("Sillier");
subentry = entry->silly_archive->subfiles;
for (; subentry; subentry = subentry->chain) {
if (subentry->flags & E_SCRAPPED)
continue;
(*function)(subentry, arg);
}
}
#endif
}
}
/* Like `each_file' but ignore files that were just for symbol definitions. */
void
each_full_file(void (*function)(struct file_entry *, void *), void *arg)
{
int i;
for (i = 0; i < number_of_files; i++) {
struct file_entry *entry = &file_table[i];
struct file_entry *subentry;
if (entry->flags & (E_SCRAPPED | E_JUST_SYMS))
continue;
#ifdef SUN_COMPAT
if (entry->silly_archive) {
if (!(entry->flags & E_DYNAMIC))
warnx("Silly");
if (!(entry->silly_archive->flags & E_IS_LIBRARY))
warnx("Sillier");
subentry = entry->silly_archive->subfiles;
for (; subentry; subentry = subentry->chain) {
if (subentry->flags & E_SCRAPPED)
continue;
(*function)(subentry, arg);
}
}
#endif
if (entry->flags & E_DYNAMIC)
continue;
if (!(entry->flags & E_IS_LIBRARY))
(*function)(entry, arg);
subentry = entry->subfiles;
for (; subentry; subentry = subentry->chain) {
if (subentry->flags & E_SCRAPPED)
continue;
(*function)(subentry, arg);
}
}
}
/* Close the input file that is now open. */
static void
file_close(void)
{
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(struct file_entry *entry)
{
int fd;
if (entry->superfile && (entry->superfile->flags & E_IS_LIBRARY))
return file_open(entry->superfile);
if (entry == input_file)
return input_desc;
if (input_file)
file_close();
if (entry->flags & E_SEARCH_DIRS) {
fd = findlib(entry);
} else
fd = open(entry->filename, O_RDONLY, 0);
if (fd >= 0) {
input_file = entry;
input_desc = fd;
return fd;
}
if (entry->flags & E_SEARCH_DIRS)
errx(1, "%s: no match", entry->local_sym_name);
else
err(1, "%s", entry->filename);
return fd;
}
int
text_offset(struct file_entry *entry)
{
return entry->starting_offset + N_TXTOFF (entry->header);
}
/*---------------------------------------------------------------------------*/
/*
* Read a file's header into the proper place in the file_entry. FD is the
* descriptor on which the file is open. ENTRY is the file's entry.
*/
void
read_header(int fd, struct file_entry *entry)
{
int len;
if (lseek(fd, entry->starting_offset, L_SET) !=
entry->starting_offset)
err(1, "%s: read_header: lseek", get_file_name(entry));
len = read(fd, &entry->header, sizeof(struct exec));
if (len != sizeof (struct exec))
err(1, "%s: read_header: read", get_file_name(entry));
md_swapin_exec_hdr(&entry->header);
if (N_BADMAG (entry->header))
errx(1, "%s: bad magic", get_file_name(entry));
if (N_BADMID(entry->header))
errx(1, "%s: non-native input file", get_file_name(entry));
entry->flags |= E_HEADER_VALID;
}
/*
* Read the symbols of file ENTRY into core. Assume it is already open, on
* descriptor FD. 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(int fd, struct file_entry *entry)
{
int str_size;
struct nlist *np;
int i;
if (!(entry->flags & E_HEADER_VALID))
read_header(fd, entry);
np = (struct nlist *)alloca(entry->header.a_syms);
entry->nsymbols = entry->header.a_syms / sizeof(struct nlist);
if (entry->nsymbols == 0)
return;
entry->symbols = (struct localsymbol *)
xmalloc(entry->nsymbols * sizeof(struct localsymbol));
if (lseek(fd, N_SYMOFF(entry->header) + entry->starting_offset, L_SET)
!= N_SYMOFF(entry->header) + entry->starting_offset)
err(1, "%s: read_symbols: lseek(syms)", get_file_name(entry));
if (entry->header.a_syms != read(fd, np, entry->header.a_syms))
errx(1, "%s: read_symbols: premature end of file in symbols",
get_file_name(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].entry = entry;
entry->symbols[i].gotslot_offset = -1;
entry->symbols[i].flags = 0;
}
entry->strings_offset = N_STROFF(entry->header) +
entry->starting_offset;
if (lseek(fd, entry->strings_offset, 0) == (off_t)-1)
err(1, "%s: read_symbols: lseek(strings)",
get_file_name(entry));
if (sizeof str_size != read(fd, &str_size, sizeof str_size))
errx(1, "%s: read_symbols: cannot read string table size",
get_file_name(entry));
entry->string_size = md_swap_long(str_size);
}
/*
* Read the string table of file ENTRY open on descriptor FD, into core.
*/
void
read_entry_strings(int fd, struct file_entry *entry)
{
if (entry->string_size == 0)
return;
if (!(entry->flags & E_HEADER_VALID) || !entry->strings_offset)
errx(1, "%s: read_strings: string table unavailable",
get_file_name(entry));
if (lseek(fd, entry->strings_offset, L_SET) !=
entry->strings_offset)
err(1, "%s: read_strings: lseek",
get_file_name(entry));
if (read(fd, entry->strings, entry->string_size) !=
entry->string_size)
errx(1, "%s: read_strings: premature end of file in strings",
get_file_name(entry));
return;
}
/* Read in the relocation sections of ENTRY if necessary */
void
read_entry_relocation(int fd, struct file_entry *entry)
{
struct relocation_info *reloc;
off_t pos;
if (!entry->textrel) {
reloc = (struct relocation_info *)
xmalloc(MAX(entry->header.a_trsize, 1));
pos = text_offset(entry) +
entry->header.a_text + entry->header.a_data;
if (lseek(fd, pos, L_SET) != pos)
err(1, "%s: read_reloc(text): lseek",
get_file_name(entry));
if (read(fd, reloc, entry->header.a_trsize) !=
entry->header.a_trsize)
errx(1, "%s: read_reloc(text): premature EOF",
get_file_name(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(MAX(entry->header.a_drsize, 1));
pos = text_offset(entry) + entry->header.a_text +
entry->header.a_data + entry->header.a_trsize;
if (lseek(fd, pos, L_SET) != pos)
err(1, "%s: read_reloc(data): lseek",
get_file_name(entry));
if (read(fd, reloc, entry->header.a_drsize) !=
entry->header.a_drsize)
errx(1, "%s: read_reloc(data): premature EOF",
get_file_name(entry));
md_swapin_reloc(reloc, entry->header.a_drsize / sizeof(*reloc));
entry->datarel = reloc;
entry->ndatarel = entry->header.a_drsize / sizeof(*reloc);
}
}
/*---------------------------------------------------------------------------*/
int current_file;
/*
* Check whether a library name appears in the list of files
* still to link in: used to avoid linking dependent libraries
* that will be pulled in anyways.
*/
int
will_see_later(const char *name)
{
int i;
for (i = current_file+1; i < number_of_files; i++)
if ((file_table[i].flags & E_SEARCH_DIRS) &&
strcmp(name, file_table[i].filename) == 0)
return 1;
return 0;
}
/*
* Read in the symbols of all input files.
*/
static void
load_symbols(void)
{
if (trace_files)
fprintf(stderr, "Loading symbols:\n\n");
for (current_file = 0; current_file < number_of_files; current_file++)
read_file_symbols(&file_table[current_file]);
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(struct file_entry *entry)
{
int fd;
int len;
struct exec hdr;
fd = file_open(entry);
len = read(fd, &hdr, sizeof hdr);
if (len != sizeof hdr)
errx(1, "%s: read_file_symbols(header): premature EOF",
get_file_name(entry));
md_swapin_exec_hdr(&hdr);
if (!N_BADMAG (hdr)) {
if (N_IS_DYNAMIC(hdr) && !(entry->flags & E_JUST_SYMS)) {
if (relocatable_output) {
errx(1,
"%s: -r and shared objects currently not supported",
get_file_name(entry));
return;
}
#if notyet /* Compatibility */
if (!(N_GETFLAG(hdr) & EX_PIC))
warnx("%s: EX_PIC not set",
get_file_name(entry));
#endif
entry->flags |= E_DYNAMIC;
if (entry->superfile || rrs_add_shobj(entry))
read_shared_object(fd, entry);
else
entry->flags |= E_SCRAPPED;
} else {
if (N_GETFLAG(hdr) & EX_PIC)
pic_code_seen = 1;
read_entry_symbols(fd, entry);
entry->strings = (char *)alloca(entry->string_size);
read_entry_strings(fd, entry);
read_entry_relocation(fd, entry);
enter_file_symbols(entry);
entry->strings = 0;
}
} else {
char armag[SARMAG];
lseek (fd, 0, 0);
if (SARMAG != read(fd, armag, SARMAG) ||
strncmp (armag, ARMAG, SARMAG))
errx(1,
"%s: malformed input file (not rel or archive)",
get_file_name(entry));
entry->flags |= E_IS_LIBRARY;
search_library(fd, entry);
}
file_close();
}
/*
* Enter the external symbol defs and refs of ENTRY in the hash table.
*/
void
enter_file_symbols(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++) {
struct nlist *p = &lsp->nzlist.nlist;
if (p->n_type == (N_SETV | N_EXT))
continue;
/*
* Turn magically prefixed symbols into set symbols of
* a corresponding type.
*/
if (set_element_prefixes &&
set_element_prefixed_p(entry->strings+lsp->nzlist.nz_strx))
lsp->nzlist.nz_type += (N_SETA - N_ABS);
if (SET_ELEMENT_P(p->n_type)) {
set_symbol_count++;
if (!relocatable_output)
enter_global_ref(lsp,
p->n_un.n_strx + entry->strings, entry);
} else if (p->n_type == N_WARNING) {
char *msg = p->n_un.n_strx + entry->strings;
/* Grab the next entry. */
lsp++;
p = &lsp->nzlist.nlist;
if (p->n_type != (N_UNDF | N_EXT)) {
warnx(
"%s: Warning symbol without external reference following.",
get_file_name(entry));
make_executable = 0;
lsp--; /* Process normally. */
} else {
symbol *sp;
char *name = p->n_un.n_strx + entry->strings;
/* Deal with the warning symbol. */
lsp->flags |= LS_WARNING;
enter_global_ref(lsp, name, entry);
sp = getsym(name);
if (sp->warning == NULL) {
sp->warning = (char *)xstrdup(msg);
warn_sym_count++;
} else if (strcmp(sp->warning, msg))
warnx(
"%s: multiple definitions for warning symbol `%s'",
get_file_name(entry), sp->name);
}
} 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_un.n_strx + entry->strings)[0] == LPREFIX)
lsp->flags |= LS_L_SYMBOL;
}
}
/*
* 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 `soref'. 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.
*
*/
static void
enter_global_ref(struct localsymbol *lsp, char *name, struct file_entry *entry)
{
struct nzlist *nzp = &lsp->nzlist;
symbol *sp = getsym(name);
int type = nzp->nz_type;
int oldref = (sp->flags & GS_REFERENCED);
int olddef = sp->defined;
int com = sp->defined && sp->common_size;
if (type == (N_INDR | N_EXT) && !olddef) {
sp->alias = getsym(entry->strings + (lsp + 1)->nzlist.nz_strx);
if (sp == sp->alias) {
warnx("%s: %s is alias for itself",
get_file_name(entry), name);
/* Rewrite symbol as global text symbol with value 0 */
lsp->nzlist.nz_type = N_TEXT|N_EXT;
lsp->nzlist.nz_value = 0;
make_executable = 0;
} else {
if ((entry->flags & E_DYNAMIC) == 0)
global_alias_count++;
if (sp->flags & GS_REFERENCED) {
if (!(sp->alias->flags & GS_REFERENCED)) {
sp->alias->flags |= GS_REFERENCED;
if (!sp->alias->defined)
undefined_global_sym_count++;
}
}
}
}
if (entry->flags & E_DYNAMIC) {
lsp->next = sp->sorefs;
sp->sorefs = lsp;
lsp->symbol = sp;
/*
* 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->common_size = nzp->nz_value;
sp->defined = N_UNDF | N_EXT;
} else if (com && sp->common_size < nzp->nz_value) {
sp->common_size = nzp->nz_value;
}
} else if (type != (N_UNDF | N_EXT) && !oldref) {
/*
* This is an ex common...
*/
if (com)
common_defined_global_count--;
sp->common_size = 0;
if (sp != dynamic_symbol && sp != got_symbol)
sp->defined = 0;
}
/*
* Handle size information in shared objects.
*/
if (nzp->nz_size > sp->size)
sp->size = nzp->nz_size;
if ((lsp->flags & LS_WARNING) && (sp->flags & GS_REFERENCED))
/*
* Prevent warning symbols from getting
* gratuitously referenced.
*/
list_warning_symbols = 1;
return;
}
lsp->next = sp->refs;
sp->refs = lsp;
lsp->symbol = sp;
if (lsp->flags & LS_WARNING) {
/*
* Prevent warning symbols from getting
* gratuitously referenced.
*/
if (sp->flags & GS_REFERENCED)
list_warning_symbols = 1;
return;
}
if (sp->warning)
list_warning_symbols = 1;
sp->flags |= GS_REFERENCED;
if (sp == dynamic_symbol || sp == got_symbol) {
if (type != (N_UNDF | N_EXT) && !(entry->flags & E_JUST_SYMS))
errx(1,"Linker reserved symbol %s defined as type %x ",
name, type);
return;
}
if (olddef && N_ISWEAK(&nzp->nlist) && !(sp->flags & GS_WEAK)) {
#ifdef DEBUG
printf("%s: not overridden by weak symbol from %s\n",
sp->name, get_file_name(entry));
#endif
return;
}
if (type == (N_SIZE | N_EXT)) {
if (relocatable_output && nzp->nz_value != 0 && sp->size == 0)
size_sym_count++;
if (sp->size < nzp->nz_value)
sp->size = nzp->nz_value;
} else 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 ((sp->flags & GS_WEAK) && !N_ISWEAK(&nzp->nlist)) {
/*
* Upgrade an existing weak definition.
* We fake it by pretending the symbol is undefined;
* must undo any common fiddling, however.
*/
if (!oldref)
errx(1, "internal error: enter_glob_ref: "
"weak symbol not referenced");
if (!olddef && !com)
undefined_weak_sym_count--;
undefined_global_sym_count++;
sp->defined = type;
sp->flags &= ~GS_WEAK;
olddef = 0;
if (com)
common_defined_global_count--;
com = 0;
sp->common_size = 0;
}
if (oldref && !olddef) {
/*
* It used to be undefined and we're defining it.
*/
undefined_global_sym_count--;
if (sp->flags & GS_WEAK)
/* Used to be a weak reference */
undefined_weak_sym_count--;
if (undefined_global_sym_count < 0 ||
undefined_weak_sym_count < 0)
errx(1, "internal error: enter_glob_ref: "
"undefined_global_sym_count = %d, "
"undefined_weak_sym_count = %d",
undefined_global_sym_count,
undefined_weak_sym_count);
}
if (N_ISWEAK(&nzp->nlist))
/* The definition is weak */
sp->flags |= GS_WEAK;
if (!olddef && type == (N_UNDF | N_EXT) && nzp->nz_value) {
/*
* First definition and it's common.
*/
common_defined_global_count++;
sp->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->common_size = 0;
} else if (com && type == (N_UNDF | N_EXT) &&
sp->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->common_size = nzp->nz_value;
if (SET_ELEMENT_P(type) && (!olddef || com))
set_vector_count++;
} else if (!oldref && !com) {
/*
* An unreferenced symbol can already be defined
* as common by shared objects.
*/
undefined_global_sym_count++;
if (N_ISWEAK(&nzp->nlist)) {
/* The reference is weak */
sp->flags |= GS_WEAK;
undefined_weak_sym_count++;
}
}
if (sp == end_symbol && (entry->flags & E_JUST_SYMS) &&
!T_flag_specified)
text_start = nzp->nz_value;
if (sp->flags & GS_TRACE) {
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;
case N_INDR:
reftype = "alias";
break;
case N_SIZE:
reftype = "size spec";
break;
default:
reftype = "I don't know this type";
break;
}
fprintf(stderr, "symbol %s %s%s in ", sp->name,
(N_ISWEAK(&nzp->nlist))?"weakly ":"", reftype);
print_file_name (entry, stderr);
fprintf(stderr, "\n");
}
}
/*
* 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 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.
*
*/
static void
digest_symbols(void)
{
if (trace_files)
fprintf(stderr, "Digesting symbol information:\n\n");
if (!relocatable_output) {
/*
* The set sector size is the number of set elements + a word
* for each symbol for the length word at the beginning of
* the vector, plus a word for each symbol for a zero at the
* end of the vector (for incremental linking).
*/
set_sect_size = (set_symbol_count + 2 * set_vector_count) *
sizeof (unsigned long);
set_vectors = (long *)xmalloc (set_sect_size);
setv_fill_count = 0;
}
/* Pass 1: check and define symbols */
defined_global_sym_count = 0;
digest_pass1();
each_full_file(consider_relocation, (void *)0); /* Text */
each_full_file(consider_relocation, (void *)1); /* Data */
each_file(consider_local_symbols, (void *)0);
/*
* 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, (void *)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 (page_align_segments || page_align_data) {
text_pad = PALIGN(text_size, page_size) - text_size;
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;
if (!relocatable_output) {
set_sect_start = rrs_data_start + data_size;
data_size += MALIGN(set_sect_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);
printf("set_sect_start = %#x, set_sect_size = %#x\n",
set_sect_start, set_sect_size);
#endif
/* Compute start addresses of each file's sections and symbols. */
each_full_file(relocate_file_addresses, (void*) 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 (page_align_segments)
data_pad = PALIGN(data_pad + data_size, page_size) - data_size;
bss_size -= data_pad;
if (bss_size < 0)
bss_size = 0;
data_size += data_pad;
/*
* Calculate total number of symbols that will go into
* the output symbol table (barring DISCARD_* settings).
*/
global_sym_count = defined_global_sym_count +
undefined_global_sym_count;
if (dynamic_symbol->flags & GS_REFERENCED)
global_sym_count++;
if (got_symbol->flags & GS_REFERENCED)
global_sym_count++;
if (relocatable_output || building_shared_object) {
/* For each alias we write out two struct nlists */
global_sym_count += global_alias_count;
/* Propagate warning symbols; costs two extra struct nlists */
global_sym_count += 2 * warn_sym_count;
}
if (relocatable_output)
/* We write out the original N_SIZE symbols */
global_sym_count += size_sym_count;
#ifdef DEBUG
printf(
"global symbols %d "
"(defined %d, undefined %d, weak %d, aliases %d, warnings 2 * %d, "
"size symbols %d)\ncommons %d, locals: %d, debug symbols: %d, set_symbols %d\n",
global_sym_count,
defined_global_sym_count, undefined_global_sym_count,
undefined_weak_sym_count,
global_alias_count, warn_sym_count, size_sym_count,
common_defined_global_count, local_sym_count,
debugger_sym_count, set_symbol_count);
#endif
}
/*
* Determine the definition of each global symbol.
*/
static void
digest_pass1(void)
{
/*
* 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) {
symbol *spsave;
struct localsymbol *lsp;
struct nlist *q = NULL;
int defs = 0;
if (!(sp->flags & GS_REFERENCED)) {
#if 0
/* Check for undefined symbols in shared objects */
int type;
for (lsp = sp->sorefs; 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->so_defined)
/* Already examined; must have been an alias */
continue;
if (sp == got_symbol || sp == dynamic_symbol)
continue;
for (lsp = sp->refs; lsp; lsp = lsp->next) {
struct nlist *p = &lsp->nzlist.nlist;
int type = p->n_type;
if (SET_ELEMENT_P(type)) {
if (relocatable_output)
errx(1,
"internal error: global ref to set el %s with -r",
sp->name);
if (!defs++) {
sp->defined = N_SETV | N_EXT;
sp->value =
setv_fill_count++ * sizeof(long);
} else if ((sp->defined & N_TYPE) != N_SETV) {
sp->mult_defs = 1;
multiple_def_count++;
}
/* Keep count and remember symbol */
sp->setv_count++;
set_vectors[setv_fill_count++] = (long)p;
if (building_shared_object) {
struct relocation_info reloc;
/*
* Make sure to relocate the contents
* of this set vector.
*/
bzero(&reloc, sizeof(reloc));
RELOC_INIT_SEGMENT_RELOC(&reloc);
RELOC_ADDRESS(&reloc) =
setv_fill_count * sizeof(long);
alloc_rrs_segment_reloc(NULL, &reloc);
}
} else if ((type & N_EXT) && type != (N_UNDF | N_EXT)
&& (type & N_TYPE) != N_FN
&& (type & N_TYPE) != N_SIZE) {
/* non-common definition */
if (!N_ISWEAK(p))
++defs;
if (defs > 1) {
sp->mult_defs = 1;
multiple_def_count++;
} else if (!N_ISWEAK(p) ||
(!sp->def_lsp && !sp->common_size)) {
sp->def_lsp = lsp;
lsp->entry->flags |= E_SYMBOLS_USED;
sp->defined = type;
sp->aux = N_AUX(p);
}
}
}
/*
* If this symbol has acquired final definition, we're done.
* Commons must be allowed to bind to shared object data
* definitions.
*/
if (sp->defined &&
(sp->common_size == 0 ||
relocatable_output || building_shared_object)) {
if ((sp->defined & N_TYPE) == N_SETV)
/* Allocate zero entry in set vector */
setv_fill_count++;
/*
* At this stage, we do not know whether an alias
* is going to be defined for real here, or whether
* it refers to a shared object symbol. The decision
* is deferred until digest_pass2().
*/
if (!sp->alias)
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.
*/
if (building_shared_object) {
/* Just punt for now */
undefined_global_sym_count--;
if (undefined_global_sym_count < 0)
errx(1,
"internal error: digest_pass1,1: %s: undefined_global_sym_count = %d",
sp->name, undefined_global_sym_count);
continue;
}
spsave=sp; /*XXX*/
again:
for (lsp = sp->sorefs; lsp; lsp = lsp->next) {
struct nlist *p = &lsp->nzlist.nlist;
int type = p->n_type;
if ((type & N_EXT) && type != (N_UNDF | N_EXT) &&
(type & N_TYPE) != N_FN) {
/* non-common definition */
if (sp->common_size) {
/*
* This common has an so defn; switch
* to it iff defn is: data, first-class
* and not weak.
*/
if (N_AUX(p) != AUX_OBJECT ||
N_ISWEAK(p) ||
(lsp->entry->flags & E_SECONDCLASS))
continue;
/*
* Change common to so ref. First,
* downgrade common to undefined.
*/
sp->common_size = 0;
sp->defined = 0;
common_defined_global_count--;
undefined_global_sym_count++;
}
/* Let WEAK symbols take precedence over second class */
if (q != NULL && N_ISWEAK(q) &&
(lsp->entry->flags & E_SECONDCLASS))
continue;
q = p;
sp->def_lsp = lsp;
sp->so_defined = type;
sp->aux = N_AUX(p);
if (lsp->entry->flags & E_SECONDCLASS)
/* Keep looking for something better */
continue;
if (N_ISWEAK(p))
/* Keep looking for something better */
continue;
break;
}
}
if (sp->def_lsp) {
#ifdef DEBUG
printf("pass1: SO definition for %s, type %x in %s at %#x\n",
sp->name, sp->so_defined, get_file_name(sp->def_lsp->entry),
sp->def_lsp->nzlist.nz_value);
#endif
sp->def_lsp->entry->flags |= E_SYMBOLS_USED;
if (sp->flags & GS_REFERENCED) {
undefined_global_sym_count--;
} else
sp->flags |= GS_REFERENCED;
if (undefined_global_sym_count < 0)
errx(1, "internal error: digest_pass1,2: "
"%s: undefined_global_sym_count = %d",
sp->name, undefined_global_sym_count);
if (sp->alias &&
!(sp->alias->flags & GS_REFERENCED)) {
sp = sp->alias;
goto again;
}
} else if (sp->defined) {
if (sp->common_size == 0)
errx(1, "internal error: digest_pass1,3: "
"%s: not a common: %x",
sp->name, sp->defined);
/*
* Common not bound to shared object data; treat
* it now like other defined symbols were above.
*/
if (!sp->alias)
defined_global_sym_count++;
}
sp=spsave; /*XXX*/
} END_EACH_SYMBOL;
if (setv_fill_count != set_sect_size/sizeof(long))
errx(1, "internal error: allocated set symbol space (%ld) "
"doesn't match actual (%d)",
set_sect_size/sizeof(long), setv_fill_count);
}
/*
* Scan relocation info in ENTRY for contributions to the RRS section
* of the output file.
*/
static void
consider_relocation( struct file_entry *entry, void *dataseg)
{
struct relocation_info *reloc, *end;
struct localsymbol *lsp;
symbol *sp;
#ifdef ALLOW_SPARC_MIX
static int locked_pic_small = 0;
#endif
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++) {
if (relocatable_output) {
lsp = &entry->symbols[reloc->r_symbolnum];
if (RELOC_BASEREL_P(reloc)) {
pic_code_seen = 1; /* Compatibility */
if (!RELOC_EXTERN_P(reloc))
lsp->flags |= LS_RENAME;
}
continue;
}
/*
* 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;
if (sp->alias)
sp = sp->alias;
if (sp->flags & GS_TRACE) {
fprintf(stderr, "symbol %s has jmpslot in %s\n",
sp->name, get_file_name(entry));
}
alloc_rrs_jmpslot(entry, sp);
} else if (RELOC_BASEREL_P(reloc)) {
lsp = &entry->symbols[reloc->r_symbolnum];
alloc_rrs_gotslot(entry, reloc, lsp);
/* sparc assembler instructions sometimes hold RELOC_22/RELOC_11,
even when using the small -fpic model. This should not yield
an error though. The linker is still thoroughly unsubtle about it
and constrains everything to +/-4096 of the GOT
*/
#ifdef ALLOW_SPARC_MIX
if (!locked_pic_small) {
if (pic_type != PIC_TYPE_NONE &&
RELOC_PIC_TYPE(reloc) != pic_type) {
warnx("%s: reloc type mix, enforcing pic model",
get_file_name(entry));
pic_type = PIC_TYPE_SMALL;
locked_pic_small = 1;
}
else
pic_type = RELOC_PIC_TYPE(reloc);
}
#else
pic_type = RELOC_PIC_TYPE(reloc);
if (pic_type != PIC_TYPE_NONE &&
RELOC_PIC_TYPE(reloc) != pic_type)
errx(1, "%s: illegal reloc type mix",
get_file_name(entry));
pic_type = RELOC_PIC_TYPE(reloc);
#endif
} 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)
errx(1, "%s: bogus relocation record",
get_file_name(entry));
if (sp->alias)
sp = sp->alias;
/*
* Skip refs to _GLOBAL_OFFSET_TABLE_ and __DYNAMIC
*/
if (sp == got_symbol) {
if (!CHECK_GOT_RELOC(reloc))
errx(1,
"%s: Unexpected relocation type for GOT symbol",
get_file_name(entry));
continue;
}
/*
* This symbol gives rise to a RRS entry
*/
if (building_shared_object) {
if (sp->flags & GS_TRACE) {
fprintf(stderr,
"symbol %s RRS entry in %s\n",
sp->name, get_file_name(entry));
}
alloc_rrs_reloc(entry, sp);
continue;
}
if (force_alias_definition && sp->so_defined &&
sp->aux == AUX_FUNC) {
/* Call to shared library procedure */
alloc_rrs_jmpslot(entry, sp);
} else if (sp->size && sp->so_defined &&
sp->aux == AUX_OBJECT) {
/* Reference to shared library data */
alloc_rrs_cpy_reloc(entry, sp);
sp->defined = N_SIZE;
} else if (!sp->defined && sp->common_size == 0 &&
sp->so_defined)
alloc_rrs_reloc(entry, sp);
} else {
/*
* Segment relocation.
* Prepare an RRS relocation as these are load
* address dependent.
*/
if (building_shared_object && !RELOC_PCREL_P(reloc)) {
alloc_rrs_segment_reloc(entry, reloc);
}
}
}
}
/*
* Determine the disposition of each local symbol.
*/
static void
consider_local_symbols(struct file_entry *entry, void *dummy)
{
struct localsymbol *lsp, *lspend;
if (entry->flags & E_DYNAMIC)
return;
lspend = entry->symbols + entry->nsymbols;
/*
* For each symbol determine whether it should go
* in the output symbol table.
*/
for (lsp = entry->symbols; lsp < lspend; lsp++) {
struct nlist *p = &lsp->nzlist.nlist;
int type = p->n_type;
if (type == N_WARNING)
continue;
if (SET_ELEMENT_P (type)) {
/*
* This occurs even if global. These types of
* symbols are never written globally, though
* they are stored globally.
*/
if (relocatable_output)
lsp->flags |= LS_WRITE;
} else if (!(type & (N_STAB | N_EXT))) {
/*
* Ordinary local symbol
*/
if ((lsp->flags & LS_RENAME) || (
discard_locals != DISCARD_ALL &&
!(discard_locals == DISCARD_L &&
(lsp->flags & LS_L_SYMBOL))) ) {
lsp->flags |= LS_WRITE;
local_sym_count++;
}
} else if (!(type & N_EXT)) {
/*
* Debugger symbol
*/
if (strip_symbols == STRIP_NONE) {
lsp->flags |= LS_WRITE;
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 (discard_locals != DISCARD_ALL)
local_sym_count++;
}
/*
* Accumulate the section sizes of input file ENTRY into the section sizes of
* the output file.
*/
static void
consider_file_section_lengths(struct file_entry *entry, void *dummy)
{
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 += MALIGN(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.
*/
static void
relocate_file_addresses(struct file_entry *entry, void *dummy)
{
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++) {
struct nlist *p = &lsp->nzlist.nlist;
int type = p->n_type;
/*
* If this belongs to a section, update it
* by the section's start address
*/
switch (type & N_TYPE) {
case N_TEXT:
case N_SETT:
p->n_value += entry->text_start_address;
break;
case N_DATA:
case N_SETD:
case N_SETV:
/*
* 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:
case N_SETB:
/* likewise for symbols with value in BSS. */
p->n_value += entry->bss_start_address -
(entry->header.a_text +
entry->header.a_data);
break;
}
}
}
/*
* Assign a value to each global symbol.
*/
static void
digest_pass2(void)
{
FOR_EACH_SYMBOL(i, sp) {
int size;
int align = sizeof(int);
if (!(sp->flags & GS_REFERENCED))
continue;
if (sp->alias &&
(relocatable_output || building_shared_object ||
(sp->alias->defined && !sp->alias->so_defined))) {
/*
* The alias points at a defined symbol, so it
* must itself be counted as one too, in order to
* compute the correct number of symbol table entries.
*/
if (!sp->defined) {
if (building_shared_object &&
!sp->alias->defined)
/* Exclude aliases in shared objects */
continue;
/*
* Change aliased symbol's definition too.
* These things happen if shared object commons
* or data is going into our symbol table.
*/
if (sp->so_defined != (N_INDR+N_EXT))
warnx( "pass2: %s: alias isn't",
sp->name);
sp->defined = sp->so_defined;
sp->so_defined = 0;
}
defined_global_sym_count++;
}
if ((sp->defined & N_TYPE) == N_SETV) {
/*
* Set length word at front of vector and zero byte
* at end. Reverse the vector itself to put it in
* file order.
*/
unsigned long i, *p, *q;
unsigned long length_word_index =
sp->value / sizeof(long);
/* Relocate symbol value */
sp->value += set_sect_start;
set_vectors[length_word_index] = sp->setv_count;
/*
* Relocate vector to final address.
*/
for (i = 0; i < sp->setv_count; i++) {
struct nlist *p = (struct nlist *)
set_vectors[1+i+length_word_index];
set_vectors[1+i+length_word_index] = p->n_value;
if (building_shared_object) {
struct relocation_info reloc;
bzero(&reloc, sizeof(reloc));
RELOC_INIT_SEGMENT_RELOC(&reloc);
RELOC_ADDRESS(&reloc) =
(1 + i + length_word_index) *
sizeof(long)
+ set_sect_start;
RELOC_TYPE(&reloc) =
(p->n_type - (N_SETA - N_ABS)) & N_TYPE;
claim_rrs_segment_reloc(NULL, &reloc);
}
}
/*
* Reverse the vector.
*/
p = &set_vectors[length_word_index + 1];
q = &set_vectors[length_word_index + sp->setv_count];
while (p < q) {
unsigned long tmp = *p;
*p++ = *q;
*q-- = tmp;
}
/* Clear terminating entry */
set_vectors[length_word_index + sp->setv_count + 1] = 0;
continue;
}
if (sp->def_lsp) {
if (sp->defined && (sp->defined & ~N_EXT) != N_SETV)
sp->value = sp->def_lsp->nzlist.nz_value;
if (sp->so_defined &&
(sp->def_lsp->entry->flags & E_SECONDCLASS))
/* Flag second-hand definitions */
undefined_global_sym_count++;
if (sp->flags & GS_TRACE)
printf("symbol %s assigned to location %#lx\n",
sp->name, sp->value);
}
/*
* If not -r'ing, allocate common symbols in the BSS section.
*/
if (building_shared_object && !(link_mode & SYMBOLIC))
/* No common allocation in shared objects */
continue;
if ((size = sp->common_size) != 0) {
/*
* It's a common.
*/
if (sp->defined != (N_UNDF + N_EXT))
errx(1, "%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)
errx(1, "%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 (align < MAX_ALIGNMENT && !(size & align))
align <<= 1;
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 %lx\n",
sp->defined==(N_BSS|N_EXT)?"common":"data",
sp->name, size, sp->value);
} END_EACH_SYMBOL;
}
/* -------------------------------------------------------------------*/
/* Write the output file */
void
write_output(void)
{
struct stat statbuf;
int filemode;
mode_t u_mask;
if (lstat(output_filename, &statbuf) == 0) {
if (S_ISREG(statbuf.st_mode))
(void)unlink(output_filename);
}
u_mask = umask(0);
(void)umask(u_mask);
outstream = fopen(output_filename, "w");
if (outstream == NULL)
err(1, "open: %s", output_filename);
if (fstat(fileno(outstream), &statbuf) < 0)
err(1, "fstat: %s", output_filename);
filemode = statbuf.st_mode;
if (S_ISREG(statbuf.st_mode) &&
chmod(output_filename, filemode & ~0111) == -1)
err(1, "chmod: %s", output_filename);
/* 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();
if (chmod (output_filename, filemode | (0111 & ~u_mask)) == -1)
err(1, "chmod: %s", output_filename);
fflush(outstream);
/* Report I/O error such as disk full. */
if (ferror(outstream) || fclose(outstream) != 0)
err(1, "write_output: %s", output_filename);
outstream = 0;
}
/* Total number of symbols to be written in the output file. */
static int nsyms;
void
write_header(void)
{
int flags;
if (link_mode & SHAREABLE)
/* Output is shared object */
flags = EX_DYNAMIC | EX_PIC;
else if (relocatable_output && pic_code_seen)
/* Output is relocatable and contains PIC code */
flags = EX_PIC;
else if (rrs_section_type == RRS_FULL)
/* Output is a dynamic executable */
flags = EX_DYNAMIC;
else
/*
* Output is a static executable
* or a non-PIC relocatable object
*/
flags = 0;
if (oldmagic && (flags & EX_DPMASK))
warnx("Cannot set flag in old magic headers");
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 = global_sym_count + local_sym_count + debugger_sym_count;
if (relocatable_output)
nsyms += set_symbol_count;
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, 1, sizeof(struct exec), outstream);
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, outstream);
#endif
}
/*
* Relocate the text segment of each input file
* and write to the output file.
*/
void
write_text(void)
{
if (trace_files)
fprintf(stderr, "Copying and relocating text:\n\n");
each_full_file(copy_text, (void *)0);
file_close();
if (trace_files)
fprintf(stderr, "\n");
padfile(text_pad, outstream);
}
/*
* 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(struct file_entry *entry, void *dummy)
{
char *bytes;
int fd;
if (trace_files)
prline_file_name(entry, stderr);
fd = 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)
errx(1, "%s: no text relocation", get_file_name(entry));
/* Read the text section into core. */
if (lseek(fd, text_offset(entry), L_SET) == (off_t)-1)
err(1, "%s: copy_text: lseek", get_file_name(entry));
if (entry->header.a_text != read(fd, bytes, entry->header.a_text))
errx(1, "%s: copy_text: premature EOF", get_file_name(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, entry->header.a_text, 1, outstream);
}
/*
* Relocate the data segment of each input file
* and write to the output file.
*/
void
write_data(void)
{
off_t pos;
if (trace_files)
fprintf(stderr, "Copying and relocating data:\n\n");
pos = N_DATOFF(outheader) + data_start - rrs_data_start;
if (fseek(outstream, pos, SEEK_SET) != 0)
errx(1, "write_data: fseek");
each_full_file(copy_data, (void *)0);
file_close();
/*
* Write out the set element vectors. See digest symbols for
* description of length of the set vector section.
*/
if (set_vector_count) {
swap_longs(set_vectors, set_symbol_count + 2*set_vector_count);
mywrite(set_vectors, set_symbol_count + 2*set_vector_count,
sizeof (unsigned long), outstream);
}
if (trace_files)
fprintf(stderr, "\n");
padfile(data_pad, outstream);
}
/*
* 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(struct file_entry *entry, void *dummy)
{
char *bytes;
int fd;
if (trace_files)
prline_file_name (entry, stderr);
fd = file_open(entry);
bytes = (char *)alloca(entry->header.a_data);
if (entry->datarel == NULL)
errx(1, "%s: no data relocation", get_file_name(entry));
if (lseek(fd, text_offset(entry) + entry->header.a_text, L_SET) ==
(off_t)-1)
err(1, "%s: copy_data: lseek", get_file_name(entry));
if (entry->header.a_data != read(fd, bytes, entry->header.a_data))
errx(1, "%s: copy_data: premature EOF", get_file_name(entry));
perform_relocation(bytes, entry->header.a_data,
entry->datarel, entry->ndatarel, entry, 1);
mywrite(bytes, entry->header.a_data, 1, outstream);
}
/*
* 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.
*/
int pc_relocation;
void
perform_relocation(char *data, int data_size, struct relocation_info *reloc,
int nreloc, struct file_entry *entry, int dataseg)
{
struct relocation_info *r = reloc;
struct relocation_info *end = reloc + nreloc;
int text_relocation = entry->text_start_address;
int data_relocation = entry->data_start_address - entry->header.a_text;
int 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)
errx(1, "%s: relocation address out of range",
get_file_name(entry));
if (RELOC_JMPTAB_P(r)) {
int symindex = RELOC_SYMBOL(r);
struct localsymbol *lsp = &entry->symbols[symindex];
symbol *sp;
if (symindex >= entry->nsymbols)
errx(1, "%s: relocation symbolnum out of range",
get_file_name(entry));
sp = lsp->symbol;
if (sp == NULL)
errx(1, "%s: bogus relocation record",
get_file_name(entry));
if (sp->alias)
sp = sp->alias;
if (relocatable_output)
relocation = addend;
else if (!RELOC_EXTERN_P(r)) {
relocation = addend +
data_relocation - text_relocation;
} else
relocation = addend +
claim_rrs_jmpslot(entry, r, sp, addend);
} else if (RELOC_BASEREL_P(r)) {
int symindex = RELOC_SYMBOL(r);
struct localsymbol *lsp = &entry->symbols[symindex];
if (symindex >= entry->nsymbols)
errx(1, "%s: relocation symbolnum out of range",
get_file_name(entry));
if (relocatable_output)
relocation = addend;
else if (!RELOC_EXTERN_P(r))
relocation = claim_rrs_internal_gotslot(
entry, r, lsp, addend);
else
relocation = claim_rrs_gotslot(
entry, r, lsp, addend);
} else if (RELOC_EXTERN_P(r)) {
int symindex = RELOC_SYMBOL(r);
symbol *sp;
if (symindex >= entry->nsymbols)
errx(1, "%s: relocation symbolnum out of range",
get_file_name(entry));
sp = entry->symbols[symindex].symbol;
if (sp == NULL)
errx(1, "%s: bogus relocation record",
get_file_name(entry));
if (sp->alias)
sp = sp->alias;
if (relocatable_output) {
relocation = addend;
/*
* In PIC code, we keep the reference to the
* external symbol, even if defined now.
*/
if (!pic_code_seen)
relocation += sp->value;
} else if (sp->defined) {
if (sp->flags & GS_TRACE) {
fprintf(stderr,
"symbol %s defined as %x in %s\n",
sp->name, sp->defined,
get_file_name(entry) );
}
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(
entry, r, sp, &relocation))
continue;
} else if (sp->defined == N_SIZE) {
/*
* If size is known, arrange a
* run-time copy.
*/
if (!sp->size)
errx(1, "Copy item isn't: %s",
sp->name);
relocation = addend + sp->value;
r->r_address = sp->value;
claim_rrs_cpy_reloc(entry, 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.
*/
if (sp->flags & GS_TRACE) {
fprintf(stderr,
"symbol %s claims RRS in %s%s\n",
sp->name, get_file_name(entry),
(sp->so_defined == (N_TEXT+N_EXT) &&
sp->flags & GS_HASJMPSLOT)?
" (JMPSLOT)":"");
}
if (sp->so_defined == (N_TEXT+N_EXT) &&
sp->flags & GS_HASJMPSLOT) {
/*
* Claim a jmpslot if one was allocated.
*
* At this point, a jmpslot can only
* result from a shared object reference
* while `force_alias' is in effect.
*/
relocation = addend +
claim_rrs_jmpslot(
entry, r, sp, addend);
} else {
r->r_address += dataseg?
entry->data_start_address:
entry->text_start_address;
relocation = addend;
if ((building_shared_object ||
sp->so_defined) &&
claim_rrs_reloc(entry, r, sp,
&relocation))
continue;
}
}
} 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
* 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:
errx(1, "%s: nonexternal relocation invalid",
get_file_name(entry));
}
/*
* When building a shared object, these segment
* relocations need a "load address relative"
* RRS fixup.
*/
if (building_shared_object && !RELOC_PCREL_P(r)) {
r->r_address += dataseg?
entry->data_start_address:
entry->text_start_address;
claim_rrs_segment_reloc(entry, 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
write_rel(void)
{
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->flags & GS_REFERENCED)
dynamic_symbol->symbolnum = count++;
FOR_EACH_SYMBOL(i, sp) {
if (sp == dynamic_symbol)
continue;
if (sp->warning)
count += 2;
if (!(sp->flags & GS_REFERENCED))
continue;
sp->symbolnum = count++;
if (sp->size)
count++;
if (sp->alias)
count++;
} END_EACH_SYMBOL;
if (count != global_sym_count)
errx(1, "internal error: write_rel: count = %d", count);
each_full_file(assign_symbolnums, (void *)&count);
/* Write out the relocations of all files, remembered from copy_text. */
each_full_file(coptxtrel, (void *)0);
if (trace_files)
fprintf(stderr, "\nWriting data relocation:\n\n");
each_full_file(copdatrel, (void *)0);
if (trace_files)
fprintf(stderr, "\n");
}
/*
* Assign symbol ordinal numbers to local symbols in each entry.
*/
static void
assign_symbolnums(struct file_entry *entry, void *arg)
{
struct localsymbol *lsp, *lspend;
int *countp = arg;
int n = *countp;
lspend = entry->symbols + entry->nsymbols;
if (discard_locals != DISCARD_ALL)
/* Count the N_FN symbol for this entry */
n++;
for (lsp = entry->symbols; lsp < lspend; lsp++) {
if (lsp->flags & LS_WRITE)
lsp->symbolnum = n++;
}
*countp = n;
}
static void
coptxtrel(struct file_entry *entry, void *dummy)
{
struct relocation_info *r, *end;
int reloc = entry->text_start_address;
r = entry->textrel;
end = r + entry->ntextrel;
for (; r < end; r++) {
int symindex;
struct localsymbol *lsp;
symbol *sp;
RELOC_ADDRESS(r) += reloc;
symindex = RELOC_SYMBOL(r);
lsp = &entry->symbols[symindex];
if (!RELOC_EXTERN_P(r)) {
if (!pic_code_seen)
continue;
if (RELOC_BASEREL_P(r))
RELOC_SYMBOL(r) = lsp->symbolnum;
continue;
}
if (symindex >= entry->nsymbols)
errx(1, "%s: relocation symbolnum out of range",
get_file_name(entry));
sp = lsp->symbol;
#ifdef N_INDR
/* Resolve indirection. */
if ((sp->defined & ~N_EXT) == N_INDR) {
if (sp->alias == NULL)
errx(1, "internal error: alias in hyperspace");
sp = sp->alias;
}
#endif
/*
* If the symbol is now defined, change the external
* relocation to an internal one.
*/
if (sp->defined) {
if (!pic_code_seen) {
RELOC_EXTERN_P(r) = 0;
RELOC_SYMBOL(r) = (sp->defined & N_TYPE);
} else
RELOC_SYMBOL(r) = sp->symbolnum;
} else
/*
* Global symbols come first.
*/
RELOC_SYMBOL(r) = sp->symbolnum;
}
md_swapout_reloc(entry->textrel, entry->ntextrel);
mywrite(entry->textrel, entry->ntextrel,
sizeof(struct relocation_info), outstream);
}
static void
copdatrel(struct file_entry *entry, void *dummy)
{
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.
*/
int reloc = entry->data_start_address - text_size;
r = entry->datarel;
end = r + entry->ndatarel;
for (; r < end; r++) {
int symindex;
symbol *sp;
int symtype;
RELOC_ADDRESS(r) += reloc;
if (!RELOC_EXTERN_P(r)) {
if (RELOC_BASEREL_P(r))
errx(1, "%s: Unsupported relocation type",
get_file_name(entry));
continue;
}
symindex = RELOC_SYMBOL(r);
sp = entry->symbols[symindex].symbol;
if (symindex >= entry->header.a_syms)
errx(1, "%s: relocation symbolnum out of range",
get_file_name(entry));
#ifdef N_INDR
/* Resolve indirection. */
if ((sp->defined & ~N_EXT) == N_INDR) {
if (sp->alias == NULL)
errx(1, "internal error: alias in hyperspace");
sp = sp->alias;
}
#endif
symtype = sp->defined & N_TYPE;
if (!pic_code_seen && ( symtype == N_BSS ||
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), outstream);
}
void write_file_syms(struct file_entry *, void *);
void write_string_table(void);
/* Offsets and current lengths of symbol and string tables in output file. */
static int symtab_offset;
static int symtab_len;
/* Address in output file where string table starts. */
static int strtab_offset;
/* Offset within string table
where the strings in `strtab_vector' should be written. */
static int strtab_len;
/* Total size of string table strings allocated so far,
including strings in `strtab_vector'. */
static int strtab_size;
/* Vector whose elements are strings to be added to the string table. */
static char **strtab_vector;
/* Vector whose elements are the lengths of those strings. */
static int *strtab_lens;
/* Index in `strtab_vector' at which the next string will be stored. */
static 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.
*/
static int
assign_string_table_index(char *name)
{
int index = strtab_size;
int len = strlen(name) + 1;
strtab_size += len;
strtab_vector[strtab_index] = name;
strtab_lens[strtab_index++] = len;
return index;
}
/*
* 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(void)
{
int i;
if (fseek(outstream, strtab_offset + strtab_len, SEEK_SET) != 0)
err(1, "write_string_table: %s: fseek", output_filename);
for (i = 0; i < strtab_index; i++) {
mywrite(strtab_vector[i], strtab_lens[i], 1, outstream);
strtab_len += strtab_lens[i];
}
}
/* Write the symbol table and string table of the output file. */
void
write_syms(void)
{
/* Number of symbols written so far. */
int strsize, 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(global_sym_count * sizeof(struct nlist));
/* Pointer for storing into BUF. */
struct nlist *bufp = buf;
/* Size of string table includes the bytes that store the size. */
strtab_size = sizeof strtab_size;
symtab_offset = N_SYMOFF(outheader);
symtab_len = 0;
strtab_offset = N_STROFF(outheader);
strtab_len = strtab_size;
if (strip_symbols == STRIP_ALL)
return;
/* 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((global_sym_count) * sizeof(char *));
strtab_lens = (int *)alloca((global_sym_count) * 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 defined (ie. not relocatable_output), make it look
* like an internal symbol.
*/
if (dynamic_symbol->flags & GS_REFERENCED) {
nl.n_other = 0;
nl.n_desc = 0;
nl.n_type = dynamic_symbol->defined;
if (nl.n_type == N_UNDF)
nl.n_type |= N_EXT;
else
nl.n_type &= ~N_EXT;
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;
/*
* Propagate N_WARNING symbols.
*/
if ((relocatable_output || building_shared_object)
&& sp->warning) {
nl.n_type = N_WARNING;
nl.n_un.n_strx = assign_string_table_index(sp->warning);
nl.n_value = 0;
nl.n_other = 0;
nl.n_desc = 0;
*bufp++ = nl;
syms_written++;
nl.n_type = N_UNDF + N_EXT;
nl.n_un.n_strx = assign_string_table_index(sp->name);
nl.n_value = 0;
nl.n_other = 0;
nl.n_desc = 0;
*bufp++ = nl;
syms_written++;
}
if (!(sp->flags & GS_REFERENCED))
/* Came from shared object but was not used */
continue;
if (sp->so_defined || (sp->alias && sp->alias->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)
continue;
if (!(sp->flags & GS_WEAK))
warnx("symbol %s remains undefined", sp->name);
}
if (syms_written >= global_sym_count)
errx(1,
"internal error: number of symbols exceeds alloc'd %d",
global_sym_count);
/*
* Construct a `struct nlist' for the symbol.
*/
nl.n_other = 0;
nl.n_desc = 0;
if (sp->defined > 1) {
/*
* defined with known type
*/
if (!relocatable_output && !building_shared_object &&
sp->alias && sp->alias->defined > 1) {
/*
* If the target of an indirect symbol has
* been defined and we are outputting an
* executable, resolve the indirection; it's
* no longer needed.
*/
nl.n_type = sp->alias->defined;
nl.n_value = sp->alias->value;
nl.n_other = N_OTHER(0, sp->alias->aux);
} else {
int bind = 0;
if (sp->defined == N_SIZE)
nl.n_type = N_DATA | N_EXT;
else
nl.n_type = sp->defined;
if (nl.n_type == (N_INDR|N_EXT) &&
sp->value != 0)
errx(1, "%s: N_INDR has value %#lx",
sp->name, sp->value);
nl.n_value = sp->value;
if (sp->def_lsp)
bind = N_BIND(&sp->def_lsp->nzlist.nlist);
nl.n_other = N_OTHER(bind, sp->aux);
}
} else if (sp->common_size) {
/*
* defined as common but not allocated,
* happens only with -r and not -d, write out
* a common definition.
*
* common condition needs to be before undefined
* condition because unallocated commons are set
* undefined in digest_symbols.
*/
nl.n_type = N_UNDF | N_EXT;
nl.n_value = sp->common_size;
} else if (!sp->defined) {
/* undefined -- legit only if -r */
nl.n_type = N_UNDF | N_EXT;
nl.n_value = 0;
} else
errx(1,
"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. */
*bufp++ = nl;
syms_written++;
/*
* Write second symbol of an alias pair.
*/
if (nl.n_type == N_INDR + N_EXT) {
if (sp->alias == NULL)
errx(1, "internal error: alias in hyperspace");
nl.n_type = N_UNDF + N_EXT;
nl.n_un.n_strx =
assign_string_table_index(sp->alias->name);
nl.n_value = 0;
nl.n_other = 0;
nl.n_desc = 0;
*bufp++ = nl;
syms_written++;
}
/*
* Write N_SIZE symbol for a symbol with a known size.
*/
if (relocatable_output && sp->size) {
nl.n_type = N_SIZE + N_EXT;
nl.n_un.n_strx = assign_string_table_index(sp->name);
nl.n_value = sp->size;
nl.n_other = 0;
nl.n_desc = 0;
*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 != global_sym_count)
errx(1, "internal error: wrong number (%d) of global symbols "
"written into output file, should be %d",
syms_written, global_sym_count);
/* Output the buffer full of `struct nlist's. */
if (fseek(outstream, symtab_offset + symtab_len, SEEK_SET) != 0)
err(1, "write_syms: fseek");
md_swapout_symbols(buf, bufp - buf);
mywrite(buf, bufp - buf, sizeof(struct nlist), outstream);
symtab_len += sizeof(struct nlist) * (bufp - buf);
/* Write the strings for the global symbols. */
write_string_table();
/* Write the local symbols defined by the various files. */
each_file(write_file_syms, (void *)&syms_written);
file_close();
if (syms_written != nsyms)
errx(1, "internal error: wrong number of symbols (%d) "
"written into output file, should be %d",
syms_written, nsyms);
if (symtab_offset + symtab_len != strtab_offset)
errx(1,
"internal error: inconsistent symbol table length: %d vs %d",
symtab_offset + symtab_len, strtab_offset);
if (fseek(outstream, strtab_offset, SEEK_SET) != 0)
err(1, "write_syms: fseek");
strsize = md_swap_long(strtab_size);
mywrite(&strsize, 1, sizeof(int), outstream);
}
/*
* 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(struct file_entry *entry, void *arg)
{
int *syms_written_addr = arg;
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));
struct nlist *bufp = buf;
if (entry->flags & E_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)++;
}
/* 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++) {
struct nlist *p = &lsp->nzlist.nlist;
char *name;
if (!(lsp->flags & LS_WRITE))
continue;
if (p->n_un.n_strx == 0)
name = NULL;
else if (!(lsp->flags & LS_RENAME))
name = p->n_un.n_strx + entry->strings;
else {
char *cp = p->n_un.n_strx + entry->strings;
size_t len = strlen(entry->local_sym_name) + 1 +
strlen(cp) + 1;
name = (char *)alloca(len);
(void)snprintf(name, len, "%s.%s",
entry->local_sym_name, cp);
}
/*
* If this symbol has a name, allocate space for it
* in the output string table.
*/
if (name)
p->n_un.n_strx = assign_string_table_index(name);
/* Output this symbol to the buffer and count it. */
*bufp++ = *p;
(*syms_written_addr)++;
}
/* All the symbols are now in BUF; write them. */
if (fseek(outstream, symtab_offset + symtab_len, SEEK_SET) != 0)
err(1, "write local symbols: fseek");
md_swapout_symbols(buf, bufp - buf);
mywrite(buf, bufp - buf, sizeof(struct nlist), outstream);
symtab_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. */
}
/*
* Parse the string ARG using scanf format FORMAT, and return the result.
* If it does not parse, report fatal error
* generating the error message using format string ERROR and ARG as arg.
*/
static int
parse(char *arg, char *format, char *error)
{
int x;
if (1 != sscanf(arg, format, &x))
errx(1, error, arg);
return x;
}
/*
* Output COUNT*ELTSIZE bytes of data at BUF to the descriptor FD.
*/
void
mywrite(void *buf, int count, int eltsize, FILE *fd)
{
if (fwrite(buf, eltsize, count, fd) != count)
err(1, "write");
}
static void
cleanup(void)
{
struct stat statbuf;
rrs_summarize_warnings();
if (outstream == 0)
return;
if (fstat(fileno(outstream), &statbuf) == 0) {
if (S_ISREG(statbuf.st_mode))
(void)unlink(output_filename);
}
}
/*
* Output PADDING zero-bytes to descriptor FD.
* PADDING may be negative; in that case, do nothing.
*/
void
padfile(int padding, FILE *fd)
{
char *buf;
if (padding <= 0)
return;
buf = (char *)alloca(padding);
bzero(buf, padding);
mywrite(buf, padding, 1, fd);
}