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