a2p
accept
access
acct
addftinfo
addr2line
adjtime
afmtodit
after
aio_cancel
aio_error
aio_read
aio_return
aio_suspend
aio_waitcomplete
aio_write
alias
aliases
alloc
anvil
append
apply
apropos
ar
array
as
asa
asn1parse
at
atq
atrm
attemptckalloc
attemptckrealloc
authlib
authtest
autopoint
awk
b64decode
b64encode
basename
batch
bc
bdes
bell
bg
bgerror
biff
big5
binary
bind
bindkey
bindtags
bindtextdomain
bio
bitmap
blowfish
bn
bootparams
bootptab
bounce
brandelf
break
breaksw
brk
bsdiff
bsdtar
bsnmpd
bspatch
bthost
btsockstat
buffer
builtin
builtins
bunzip2
button
byacc
bzcat
bzegrep
bzfgrep
bzgrep
bzip2
c2ph
c89
c99
ca
cal
calendar
canvas
cap_mkdb
case
cat
catch
catman
cc
cd
cdcontrol
chdir
checkbutton
checknr
chflags
chfn
chgrp
chio
chkey
chmod
chown
chpass
chroot
chsh
ci
ciphers
ckalloc
ckdist
ckfree
ckrealloc
cksum
cleanup
clear
clipboard
clock
clock_getres
clock_gettime
clock_settime
close
cmp
co
col
colcrt
colldef
colors
colrm
column
comm
command
compile_et
complete
compress
concat
config
connect
console
continue
core
courierlogger
couriertcpd
cp
cpan
cpio
cpp
creat
crl
crontab
crunchgen
crunchide
crypt
crypto
csh
csplit
ctags
ctm
ctm_dequeue
ctm_rmail
ctm_smail
cu
cursor
cursors
cut
cvs
date
dbiprof
dbiproxy
dc
dcgettext
dcngettext
dd
dde
default
defer
deliverquota
des
destroy
devfs
df
dgettext
dgst
dh
dhparam
dialog
diff
diff3
dig
dir
dirent
dirname
dirs
discard
disktab
dngettext
do
domainname
done
dprofpp
dsa
dsaparam
dtmfdecode
du
dup
dup2
eaccess
ec
ecdsa
echo
echotc
ecparam
ed
edit
editrc
ee
egrep
elf
elfdump
elif
else
enc
enc2xs
encoding
end
endif
endsw
engine
enigma
entry
env
envsubst
eof
eqn
err
errno
error
errstr
esac
ethers
euc
eui64
eval
event
evp
ex
exec
execve
exit
expand
export
exports
expr
extattr
extattr_delete_fd
extattr_delete_file
extattr_get_fd
extattr_get_file
extattr_set_fd
extattr_set_file
f77
false
famm
famx
fblocked
fbtab
fc
fchdir
fchflags
fchmod
fchown
fcntl
fconfigure
fcopy
fdescfs
fdformat
fdread
fdwrite
fetch
fg
fgrep
fhopen
fhstat
fhstatfs
fi
file
file2c
fileevent
filename
filetest
find
find2perl
finger
flex
flock
flush
fmt
focus
fold
font
fontedit
for
foreach
fork
format
forward
fpathconf
frame
from
fs
fstab
fstat
fstatfs
fsync
ftp
ftpchroot
ftpusers
ftruncate
futimes
g711conv
gb2312
gb18030
gbk
gcc
gcore
gcov
gdb
gencat
gendsa
genrsa
gensnmptree
getconf
getdents
getdirentries
getdtablesize
getegid
geteuid
getfacl
getfh
getfsstat
getgid
getgroups
getitimer
getlogin
getopt
getopts
getpeername
getpgid
getpgrp
getpid
getppid
getpriority
getresgid
getresuid
getrlimit
getrusage
gets
getsid
getsockname
getsockopt
gettext
gettextize
gettimeofday
gettytab
getuid
glob
global
gmake
goto
gperf
gprof
grab
grep
grid
grn
grodvi
groff
groff_font
groff_out
groff_tmac
grog
grolbp
grolj4
grops
grotty
group
groups
gunzip
gzcat
gzexe
gzip
h2ph
h2xs
hash
hashstat
hd
head
help2man
hesinfo
hexdump
history
host
hostname
hosts
hosts_access
hosts_options
hpftodit
http
hup
i386_get_ioperm
i386_get_ldt
i386_set_ioperm
i386_set_ldt
i386_vm86
iconv
id
ident
idprio
if
ifnames253
ifnames259
image
imapd
incr
indent
indxbib
info
infokey
inode
install
instmodsh
interp
intro
introduction
ioctl
ipcrm
ipcs
ipf
ipftest
ipnat
ippool
ipresend
issetugid
jail
jail_attach
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jobs
join
jot
kbdcontrol
kbdmap
kcon
kdestroy
kdump
kenv
kevent
keycap
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keylogout
keymap
keysyms
kgdb
kill
killall
killpg
kinit
kldfind
kldfirstmod
kldload
kldnext
kldstat
kldsym
kldunload
klist
kpasswd
kqueue
kse
kse_create
kse_exit
kse_release
kse_switchin
kse_thr_interrupt
kse_wakeup
ktrace
label
labelframe
lam
lappend
last
lastcomm
lastlog
lchflags
lchmod
lchown
ld
ldap
ldapadd
ldapcompare
ldapdelete
ldapmodify
ldapmodrdn
ldappasswd
ldapsearch
ldapwhoami
ldd
leave
less
lesskey
lex
lgetfh
lhash
libnetcfg
library
limit
limits
lindex
link
linprocfs
linsert
lint
lio_listio
list
listbox
listen
lj4_font
lkbib
llength
lmtp
ln
load
loadfont
local
locale
locate
lock
lockf
log
logger
login
logins
logname
logout
look
lookbib
lorder
lower
lp
lpq
lpr
lprm
lptest
lrange
lreplace
ls
lsearch
lseek
lset
lsort
lstat
lsvfs
lutimes
lynx
m4
madvise
magic
mail
maildiracl
maildirkw
maildirmake
mailq
mailx
make
makeinfo
makewhatis
man
manpath
master
mc
mcedit
mcview
md2
md4
md5
mdc2
memory
menu
menubar
menubutton
merge
mesg
message
mincore
minherit
minigzip
mkdep
mkdir
mkfifo
mkimapdcert
mklocale
mknod
mkpop3dcert
mkstr
mktemp
mlock
mlockall
mmap
mmroff
modfind
modfnext
modnext
modstat
moduli
more
motd
mount
mprotect
mptable
msdos
msdosfs
msgattrib
msgcat
msgcmp
msgcomm
msgconv
msgen
msgexec
msgfilter
msgfmt
msggrep
msginit
msgmerge
msgs
msgunfmt
msguniq
mskanji
msql2mysql
msync
mt
munlock
munlockall
munmap
mv
myisamchk
myisamlog
myisampack
mysql
mysqlaccess
mysqladmin
mysqlbinlog
mysqlcheck
mysqld
mysqldump
mysqld_multi
mysqld_safe
mysqlhotcopy
mysqlimport
mysqlshow
mysql_config
mysql_fix_privilege_tables
mysql_zap
namespace
nanosleep
nawk
nc
ncal
ncplist
ncplogin
ncplogout
neqn
netconfig
netgroup
netid
netstat
networks
newaliases
newgrp
nex
nfsstat
nfssvc
ngettext
nice
nl
nm
nmount
nohup
nologin
notify
nroff
nseq
nslookup
ntp_adjtime
ntp_gettime
nvi
nview
objcopy
objdump
objformat
ocsp
od
onintr
open
openssl
opieaccess
opieinfo
opiekey
opiekeys
opiepasswd
option
options
oqmgr
pack
package
packagens
pagesize
palette
pam_auth
panedwindow
parray
passwd
paste
patch
pathchk
pathconf
pawd
pax
pbm
pcre
pcreapi
pcrebuild
pcrecallout
pcrecompat
pcrecpp
pcregrep
pcrematching
pcrepartial
pcrepattern
pcreperform
pcreposix
pcreprecompile
pcresample
pcretest
perl
perl56delta
perl58delta
perl561delta
perl570delta
perl571delta
perl572delta
perl573delta
perl581delta
perl582delta
perl583delta
perl584delta
perl585delta
perl586delta
perl587delta
perl588delta
perl5004delta
perl5005delta
perlaix
perlamiga
perlapi
perlapio
perlapollo
perlartistic
perlbeos
perlbook
perlboot
perlbot
perlbs2000
perlbug
perlcall
perlcc
perlce
perlcheat
perlclib
perlcn
perlcompile
perlcygwin
perldata
perldbmfilter
perldebguts
perldebtut
perldebug
perldelta
perldgux
perldiag
perldoc
perldos
perldsc
perlebcdic
perlembed
perlepoc
perlfaq
perlfaq1
perlfaq2
perlfaq3
perlfaq4
perlfaq5
perlfaq6
perlfaq7
perlfaq8
perlfaq9
perlfilter
perlfork
perlform
perlfreebsd
perlfunc
perlglossary
perlgpl
perlguts
perlhack
perlhist
perlhpux
perlhurd
perlintern
perlintro
perliol
perlipc
perlirix
perlivp
perljp
perlko
perllexwarn
perllinux
perllocale
perllol
perlmachten
perlmacos
perlmacosx
perlmint
perlmod
perlmodinstall
perlmodlib
perlmodstyle
perlmpeix
perlnetware
perlnewmod
perlnumber
perlobj
perlop
perlopenbsd
perlopentut
perlos2
perlos390
perlos400
perlothrtut
perlpacktut
perlplan9
perlpod
perlpodspec
perlport
perlqnx
perlre
perlref
perlreftut
perlrequick
perlreref
perlretut
perlrun
perlsec
perlsolaris
perlstyle
perlsub
perlsyn
perlthrtut
perltie
perltoc
perltodo
perltooc
perltoot
perltrap
perltru64
perltw
perlunicode
perluniintro
perlutil
perluts
perlvar
perlvmesa
perlvms
perlvos
perlwin32
perlxs
perlxstut
perror
pfbtops
pftp
pgrep
phones
photo
pic
pickup
piconv
pid
pipe
pkcs7
pkcs8
pkcs12
pkg_add
pkg_check
pkg_create
pkg_delete
pkg_info
pkg_sign
pkg_version
pkill
pl2pm
place
pod2html
pod2latex
pod2man
pod2text
pod2usage
podchecker
podselect
poll
popd
popup
posix_madvise
postalias
postcat
postconf
postdrop
postfix
postkick
postlock
postlog
postmap
postqueue
postsuper
pr
pread
preadv
printcap
printenv
printf
proc
procfs
profil
protocols
prove
proxymap
ps
psed
psroff
pstruct
ptrace
publickey
pushd
puts
pwd
pwrite
pwritev
qmgr
qmqpd
quota
quotactl
radiobutton
raise
rand
ranlib
rcp
rcs
rcsclean
rcsdiff
rcsfile
rcsfreeze
rcsintro
rcsmerge
read
readelf
readlink
readonly
readv
realpath
reboot
recv
recvfrom
recvmsg
red
ree
refer
regexp
registry
regsub
rehash
remote
rename
repeat
replace
req
reset
resolver
resource
return
rev
revoke
rfcomm_sppd
rfork
rhosts
ripemd
ripemd160
rlog
rlogin
rm
rmd160
rmdir
rpc
rpcgen
rs
rsa
rsautl
rsh
rtld
rtprio
rup
ruptime
rusers
rwall
rwho
s2p
safe
sasl
sasldblistusers2
saslpasswd2
sbrk
scache
scale
scan
sched
sched_getparam
sched_getscheduler
sched_get_priority_max
sched_get_priority_min
sched_rr_get_interval
sched_setparam
sched_setscheduler
sched_yield
scon
scp
script
scrollbar
sdiff
sed
seek
select
selection
semctl
semget
semop
send
sendbug
sendfile
sendmail
sendmsg
sendto
services
sess_id
set
setegid
setenv
seteuid
setfacl
setgid
setgroups
setitimer
setlogin
setpgid
setpgrp
setpriority
setregid
setresgid
setresuid
setreuid
setrlimit
setsid
setsockopt
settc
settimeofday
setty
setuid
setvar
sftp
sh
sha
sha1
sha256
shar
shells
shift
shmat
shmctl
shmdt
shmget
showq
shutdown
sigaction
sigaltstack
sigblock
sigmask
sigpause
sigpending
sigprocmask
sigreturn
sigsetmask
sigstack
sigsuspend
sigvec
sigwait
size
slapadd
slapcat
slapd
slapdn
slapindex
slappasswd
slaptest
sleep
slogin
slurpd
smbutil
smime
smtp
smtpd
socket
socketpair
sockstat
soelim
sort
source
spawn
speed
spinbox
spkac
splain
split
squid
squid_ldap_auth
squid_ldap_group
squid_unix_group
sscop
ssh
sshd_config
ssh_config
stab
startslip
stat
statfs
stop
string
strings
strip
stty
su
subst
sum
suspend
swapoff
swapon
switch
symlink
sync
sysarch
syscall
sysconftool
sysconftoolcheck
systat
s_client
s_server
s_time
tabs
tail
talk
tar
tbl
tclsh
tcltest
tclvars
tcopy
tcpdump
tcpslice
tcsh
tee
tell
telltc
telnet
term
termcap
terminfo
test
texindex
texinfo
text
textdomain
tfmtodit
tftp
then
threads
time
tip
tk
tkerror
tkvars
tkwait
tlsmgr
tmac
top
toplevel
touch
tput
tr
trace
trafshow
trap
troff
true
truncate
truss
tset
tsort
tty
ttys
type
tzfile
ui
ul
ulimit
umask
unalias
uname
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unhash
unifdef
unifdefall
uniq
units
unknown
unlimit
unlink
unmount
unset
unsetenv
until
unvis
update
uplevel
uptime
upvar
usbhidaction
usbhidctl
users
utf8
utimes
utmp
utrace
uudecode
uuencode
uuidgen
vacation
variable
verify
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vfork
vgrind
vgrindefs
vi
vidcontrol
vidfont
view
virtual
vis
vt220keys
vwait
w
wait
wait3
wait4
waitpid
wall
wc
wget
what
whatis
where
whereis
which
while
who
whoami
whois
window
winfo
wish
wm
write
writev
wtmp
x509
xargs
xgettext
xmlwf
xstr
xsubpp
yacc
yes
ypcat
ypchfn
ypchpass
ypchsh
ypmatch
yppasswd
ypwhich
yyfix
zcat
zcmp
zdiff
zegrep
zfgrep
zforce
zgrep
zmore
znew
_exit
__syscall
 
FreeBSD/Linux/UNIX General Commands Manual
Hypertext Man Pages
ld
 
LD(1)			     GNU Development Tools			 LD(1)



NAME
       ld - Using LD, the GNU linker

SYNOPSIS
       ld [options] objfile ...

DESCRIPTION
       ld  combines a number of object and archive files, relocates their data
       and ties up symbol references. Usually the last	step  in  compiling  a
       program is to run ld.

       ld  accepts  Linker  Command  Language  files  written in a superset of
       AT&T's Link Editor Command Language syntax,  to	provide  explicit  and
       total control over the linking process.

       This  man page does not describe the command language; see the ld entry
       in "info", or the manual ld: the GNU linker, for full  details  on  the
       command language and on other aspects of the GNU linker.

       This version of ld uses the general purpose BFD libraries to operate on
       object files. This allows ld to read, combine, and write  object  files
       in  many  different  formats---for example, COFF or "a.out".  Different
       formats may be linked together to produce any available kind of	object
       file.

       Aside  from  its flexibility, the GNU linker is more helpful than other
       linkers in providing diagnostic information.  Many linkers abandon exe-
       cution  immediately  upon  encountering an error; whenever possible, ld
       continues executing, allowing you to identify other errors (or, in some
       cases, to get an output file in spite of the error).

       The GNU linker ld is meant to cover a broad range of situations, and to
       be as compatible as possible with other linkers.  As a result, you have
       many choices to control its behavior.

OPTIONS
       The  linker  supports a plethora of command-line options, but in actual
       practice few of them are used in any particular context.  For instance,
       a  frequent  use of ld is to link standard Unix object files on a stan-
       dard, supported Unix  system.   On  such  a  system,  to  link  a  file
       "hello.o":

	       ld -o  /lib/crt0.o hello.o -lc

       This  tells ld to produce a file called output as the result of linking
       the file "/lib/crt0.o" with "hello.o" and the library  "libc.a",  which
       will come from the standard search directories.	(See the discussion of
       the -l option below.)

       Some of the command-line options to ld may be specified at any point in
       the command line.  However, options which refer to files, such as -l or
       -T, cause the file to be read at the point at which the option  appears
       in  the	command  line,	relative  to  the  object files and other file
       options.  Repeating non-file options with  a  different	argument  will
       either  have  no  further  effect, or override prior occurrences (those
       further to the left on the command line) of that option.  Options which
       may  be meaningfully specified more than once are noted in the descrip-
       tions below.

       Non-option arguments are object files  or  archives  which  are	to  be
       linked  together.   They  may follow, precede, or be mixed in with com-
       mand-line options, except that an  object  file	argument  may  not  be
       placed between an option and its argument.

       Usually	the  linker  is invoked with at least one object file, but you
       can specify other forms of binary input files using  -l,  -R,  and  the
       script  command	language.   If no binary input files at all are speci-
       fied, the linker does not produce any output, and issues the message No
       input files.

       If  the	linker	cannot recognize the format of an object file, it will
       assume that it is a linker script.  A script specified in this way aug-
       ments  the  main  linker  script  used for the link (either the default
       linker script or the one specified by using -T).  This feature  permits
       the  linker  to link against a file which appears to be an object or an
       archive, but actually  merely  defines  some  symbol  values,  or  uses
       "INPUT"	or  "GROUP"  to  load  other  objects.	Note that specifying a
       script in this way merely augments the main linker script; use  the  -T
       option to replace the default linker script entirely.

       For  options  whose  names  are	a single letter, option arguments must
       either follow the option letter without intervening whitespace,	or  be
       given  as  separate  arguments  immediately  following  the option that
       requires them.

       For options whose names are multiple letters, either one  dash  or  two
       can   precede   the   option   name;  for  example,  -trace-symbol  and
       --trace-symbol are equivalent.  Note---there is one exception  to  this
       rule.   Multiple  letter  options  that start with a lower case 'o' can
       only be preceeded by two dashes.  This is to reduce confusion with  the
       -o  option.   So for example -omagic sets the output file name to magic
       whereas --omagic sets the NMAGIC flag on the output.

       Arguments to multiple-letter options must either be separated from  the
       option  name by an equals sign, or be given as separate arguments imme-
       diately	following  the	option	that  requires	them.	For   example,
       --trace-symbol  foo  and  --trace-symbol=foo  are  equivalent.	Unique
       abbreviations of the names of multiple-letter options are accepted.

       Note---if the linker is being invoked indirectly, via a compiler driver
       (e.g.  gcc) then all the linker command line options should be prefixed
       by -Wl, (or whatever is appropriate for the particular compiler driver)
       like this:

		 gcc -Wl,--startgroup foo.o bar.o -Wl,--endgroup

       This  is  important,  because otherwise the compiler driver program may
       silently drop the linker options, resulting in a bad link.

       Here is a table of the generic command line switches  accepted  by  the
       GNU linker:

       -akeyword
	   This  option  is  supported	for  HP/UX compatibility.  The keyword
	   argument must be one of the strings archive,  shared,  or  default.
	   -aarchive is functionally equivalent to -Bstatic, and the other two
	   keywords are functionally equivalent to -Bdynamic.  This option may
	   be used any number of times.

       -Aarchitecture
       --architecture=architecture
	   In  the  current  release of ld, this option is useful only for the
	   Intel 960 family of architectures.  In that ld  configuration,  the
	   architecture argument identifies the particular architecture in the
	   960 family, enabling some safeguards  and  modifying  the  archive-
	   library search path.

	   Future  releases  of ld may support similar functionality for other
	   architecture families.

       -b input-format
       --format=input-format
	   ld may be configured to support more than one kind of object  file.
	   If  your  ld  is  configured this way, you can use the -b option to
	   specify the binary format for input object files that  follow  this
	   option  on the command line.  Even when ld is configured to support
	   alternative object formats, you don't usually need to specify this,
	   as  ld should be configured to expect as a default input format the
	   most usual format on each machine.  input-format is a text  string,
	   the	name  of  a  particular format supported by the BFD libraries.
	   (You can list the available binary formats with objdump -i.)

	   You may want to use this option if you are linking  files  with  an
	   unusual  binary  format.   You  can	also  use -b to switch formats
	   explicitly (when linking object files  of  different  formats),  by
	   including  -b  input-format	before each group of object files in a
	   particular format.

	   The default format is taken from the environment variable  "GNUTAR-
	   GET".

	   You	can also define the input format from a script, using the com-
	   mand "TARGET";

       -c MRI-commandfile
       --mri-script=MRI-commandfile
	   For compatibility with linkers produced by MRI, ld  accepts	script
	   files   written  in	an  alternate,	restricted  command  language,
	   described in the MRI Compatible Script Files section of GNU ld doc-
	   umentation.	Introduce MRI script files with the option -c; use the
	   -T option to run linker scripts written in the  general-purpose  ld
	   scripting language.	If MRI-cmdfile does not exist, ld looks for it
	   in the directories specified by any -L options.

       -d
       -dc
       -dp These three options are equivalent; multiple  forms	are  supported
	   for	compatibility with other linkers.  They assign space to common
	   symbols even if a relocatable output file is specified  (with  -r).
	   The script command "FORCE_COMMON_ALLOCATION" has the same effect.

       -e entry
       --entry=entry
	   Use	entry  as  the explicit symbol for beginning execution of your
	   program, rather than the default entry point.  If there is no  sym-
	   bol	named  entry,  the linker will try to parse entry as a number,
	   and use that as the entry address (the number will  be  interpreted
	   in  base  10;  you may use a leading 0x for base 16, or a leading 0
	   for base 8).

       -E
       --export-dynamic
	   When creating a dynamically linked executable, add all  symbols  to
	   the	dynamic  symbol table.	The dynamic symbol table is the set of
	   symbols which are visible from dynamic objects at run time.

	   If you do not use this option, the dynamic symbol table  will  nor-
	   mally  contain  only  those	symbols  which	are referenced by some
	   dynamic object mentioned in the link.

	   If you use "dlopen" to load a dynamic object which needs  to  refer
	   back  to the symbols defined by the program, rather than some other
	   dynamic object, then you will probably need to use this option when
	   linking the program itself.

	   You	can also use the version script to control what symbols should
	   be added to the dynamic symbol table if the output format  supports
	   it.	See the description of --version-script in @ref{VERSION}.

       -EB Link big-endian objects.  This affects the default output format.

       -EL Link  little-endian	objects.  This affects the default output for-
	   mat.

       -f
       --auxiliary name
	   When creating an ELF shared object, set the	internal  DT_AUXILIARY
	   field  to  the  specified name.  This tells the dynamic linker that
	   the symbol table of the shared object should be used as  an	auxil-
	   iary filter on the symbol table of the shared object name.

	   If  you later link a program against this filter object, then, when
	   you run the program, the dynamic linker will see  the  DT_AUXILIARY
	   field.   If the dynamic linker resolves any symbols from the filter
	   object, it will first check whether there is a  definition  in  the
	   shared  object  name.   If there is one, it will be used instead of
	   the definition in the filter object.  The shared object  name  need
	   not	exist.	 Thus the shared object name may be used to provide an
	   alternative implementation of certain functions, perhaps for debug-
	   ging or for machine specific performance.

	   This  option  may  be  specified  more than once.  The DT_AUXILIARY
	   entries will be created in the order in which they  appear  on  the
	   command line.

       -F name
       --filter name
	   When  creating  an  ELF  shared  object, set the internal DT_FILTER
	   field to the specified name.  This tells the  dynamic  linker  that
	   the symbol table of the shared object which is being created should
	   be used as a filter on the symbol table of the shared object  name.

	   If  you later link a program against this filter object, then, when
	   you run the program, the dynamic  linker  will  see	the  DT_FILTER
	   field.   The  dynamic  linker will resolve symbols according to the
	   symbol table of the filter object as usual, but  it	will  actually
	   link  to the definitions found in the shared object name.  Thus the
	   filter object can be used to select a subset of  the  symbols  pro-
	   vided by the object name.

	   Some  older	linkers  used  the  -F option throughout a compilation
	   toolchain for specifying object-file format for both input and out-
	   put	object	files.	 The GNU linker uses other mechanisms for this
	   purpose: the -b, --format, --oformat options, the "TARGET"  command
	   in  linker  scripts, and the "GNUTARGET" environment variable.  The
	   GNU linker will ignore the -F  option  when	not  creating  an  ELF
	   shared object.

       -fini name
	   When  creating  an  ELF executable or shared object, call NAME when
	   the executable or shared object is unloaded, by setting DT_FINI  to
	   the	address  of the function.  By default, the linker uses "_fini"
	   as the function to call.

       -g  Ignored.  Provided for compatibility with other tools.

       -Gvalue
       --gpsize=value
	   Set the maximum size of objects to be optimized using the GP regis-
	   ter	to size.  This is only meaningful for object file formats such
	   as MIPS ECOFF which supports putting large and small  objects  into
	   different sections.	This is ignored for other object file formats.

       -hname
       -soname=name
	   When creating an ELF shared	object,  set  the  internal  DT_SONAME
	   field  to  the specified name.  When an executable is linked with a
	   shared object which has a DT_SONAME field, then when the executable
	   is  run  the  dynamic linker will attempt to load the shared object
	   specified by the DT_SONAME field rather than  the  using  the  file
	   name given to the linker.

       -i  Perform an incremental link (same as option -r).

       -init name
	   When  creating  an  ELF executable or shared object, call NAME when
	   the executable or shared object is loaded, by  setting  DT_INIT  to
	   the	address  of the function.  By default, the linker uses "_init"
	   as the function to call.

       -larchive
       --library=archive
	   Add archive file archive to the list of files to link.  This option
	   may	be used any number of times.  ld will search its path-list for
	   occurrences of "libarchive.a" for every archive specified.

	   On systems which support shared libraries, ld may also  search  for
	   libraries  with  extensions	other than ".a".  Specifically, on ELF
	   and SunOS systems, ld will search a directory for a library with an
	   extension  of  ".so"  before searching for one with an extension of
	   ".a".  By convention, a ".so" extension indicates a shared library.

	   The	linker will search an archive only once, at the location where
	   it is specified on the command line.  If the archive defines a sym-
	   bol	which  was  undefined in some object which appeared before the
	   archive on the command line, the linker will include the  appropri-
	   ate	file(s)  from the archive.  However, an undefined symbol in an
	   object appearing later on the  command  line  will  not  cause  the
	   linker to search the archive again.

	   See	the -( option for a way to force the linker to search archives
	   multiple times.

	   You may list the same archive multiple times on the command line.

	   This type of archive searching is standard for Unix linkers.   How-
	   ever,  if  you  are using ld on AIX, note that it is different from
	   the behaviour of the AIX linker.

       -Lsearchdir
       --library-path=searchdir
	   Add path searchdir to the list of paths that ld will search for ar-
	   chive  libraries  and  ld control scripts.  You may use this option
	   any number of times.  The directories are searched in the order  in
	   which  they	are specified on the command line.  Directories speci-
	   fied on the command line are searched before the  default  directo-
	   ries.   All	-L  options apply to all -l options, regardless of the
	   order in which the options appear.

	   If searchdir begins with "=", then the "=" will be replaced by  the
	   sysroot prefix, a path specified when the linker is configured.

	   The default set of paths searched (without being specified with -L)
	   depends on which emulation mode ld is using, and in some cases also
	   on how it was configured.

	   The	paths  can  also  be  specified  in  a	link  script  with the
	   "SEARCH_DIR" command.  Directories specified this way are  searched
	   at  the  point  in  which  the linker script appears in the command
	   line.

       -memulation
	   Emulate the emulation linker.  You can list	the  available	emula-
	   tions with the --verbose or -V options.

	   If  the  -m	option	is  not  used, the emulation is taken from the
	   "LDEMULATION" environment variable, if that is defined.

	   Otherwise, the default emulation depends upon how  the  linker  was
	   configured.

       -M
       --print-map
	   Print  a  link  map	to  the  standard output.  A link map provides
	   information about the link, including the following:

	   *   Where object files and symbols are mapped into memory.

	   *   How common symbols are allocated.

	   *   All archive members included in the link, with a mention of the
	       symbol which caused the archive member to be brought in.

       -n
       --nmagic
	   Turn  off  page  alignment  of  sections,  and  mark  the output as
	   "NMAGIC" if possible.

       -N
       --omagic
	   Set the text and data sections to be readable and writable.	 Also,
	   do  not  page-align	the  data segment, and disable linking against
	   shared libraries.  If the output format supports Unix  style  magic
	   numbers,  mark  the	output	as "OMAGIC". Note: Although a writable
	   text section is allowed for PE-COFF targets, it does not conform to
	   the format specification published by Microsoft.

       --no-omagic
	   This  option negates most of the effects of the -N option.  It sets
	   the text section to be read-only, and forces the data segment to be
	   page-aligned.   Note  - this option does not enable linking against
	   shared libraries.  Use -Bdynamic for this.

       -o output
       --output=output
	   Use output as the name for the program  produced  by  ld;  if  this
	   option  is  not  specified, the name a.out is used by default.  The
	   script command "OUTPUT" can also specify the output file name.

       -O level
	   If level is a numeric values greater than  zero  ld	optimizes  the
	   output.   This might take significantly longer and therefore proba-
	   bly should only be enabled for the final binary.

       -q
       --emit-relocs
	   Leave relocation sections and contents in fully  linked  exececuta-
	   bles.   Post  link  analysis  and  optimization tools may need this
	   information in order to perform correct modifications  of  executa-
	   bles.  This results in larger executables.

	   This option is currently only supported on ELF platforms.

       -r
       --relocatable
	   Generate  relocatable  output---i.e.,  generate an output file that
	   can in turn serve as input to ld.  This  is	often  called  partial
	   linking.   As  a side effect, in environments that support standard
	   Unix magic numbers, this option also sets the output  file's  magic
	   number  to  "OMAGIC".  If this option is not specified, an absolute
	   file is produced.  When linking C++ programs, this option will  not
	   resolve references to constructors; to do that, use -Ur.

	   When  an  input  file  does	not have the same format as the output
	   file, partial linking is only supported if that input file does not
	   contain any relocations.  Different output formats can have further
	   restrictions; for example some "a.out"-based formats do not support
	   partial linking with input files in other formats at all.

	   This option does the same thing as -i.

       -R filename
       --just-symbols=filename
	   Read  symbol  names	and  their addresses from filename, but do not
	   relocate it or include it in the output.  This allows  your	output
	   file  to refer symbolically to absolute locations of memory defined
	   in other programs.  You may use this option more than once.

	   For compatibility with other ELF linkers, if the -R option is  fol-
	   lowed  by  a directory name, rather than a file name, it is treated
	   as the -rpath option.

       -s
       --strip-all
	   Omit all symbol information from the output file.

       -S
       --strip-debug
	   Omit debugger symbol information (but not  all  symbols)  from  the
	   output file.

       -t
       --trace
	   Print the names of the input files as ld processes them.

       -T scriptfile
       --script=scriptfile
	   Use	scriptfile  as	the  linker script.  This script replaces ld's
	   default linker script (rather than adding to  it),  so  commandfile
	   must  specify  everything  necessary  to  describe the output file.
	   If scriptfile does not exist in the current directory,  "ld"  looks
	   for	it  in	the directories specified by any preceding -L options.
	   Multiple -T options accumulate.

       -u symbol
       --undefined=symbol
	   Force symbol to be entered in the output file as an undefined  sym-
	   bol.   Doing  this  may, for example, trigger linking of additional
	   modules from standard libraries.  -u may be repeated with different
	   option  arguments  to  enter  additional  undefined	symbols.  This
	   option is equivalent to the "EXTERN" linker script command.

       -Ur For anything other than C++ programs, this option is equivalent  to
	   -r: it generates relocatable output---i.e., an output file that can
	   in turn serve as input to ld.  When linking C++ programs, -Ur  does
	   resolve references to constructors, unlike -r.  It does not work to
	   use -Ur on files that were themselves linked  with  -Ur;  once  the
	   constructor	table  has been built, it cannot be added to.  Use -Ur
	   only for the last partial link, and -r for the others.

       --unique[=SECTION]
	   Creates a separate output section for every input section  matching
	   SECTION,  or  if the optional wildcard SECTION argument is missing,
	   for every orphan input section.   An  orphan  section  is  one  not
	   specifically mentioned in a linker script.  You may use this option
	   multiple times on the command line;	It prevents the normal merging
	   of  input  sections	with  the same name, overriding output section
	   assignments in a linker script.

       -v
       --version
       -V  Display the version number for ld.  The -V option  also  lists  the
	   supported emulations.

       -x
       --discard-all
	   Delete all local symbols.

       -X
       --discard-locals
	   Delete  all temporary local symbols.  For most targets, this is all
	   local symbols whose names begin with L.

       -y symbol
       --trace-symbol=symbol
	   Print the name of each linked file in which symbol  appears.   This
	   option  may	be  given  any number of times.  On many systems it is
	   necessary to prepend an underscore.

	   This option is useful when you have an  undefined  symbol  in  your
	   link but don't know where the reference is coming from.

       -Y path
	   Add	path  to  the default library search path.  This option exists
	   for Solaris compatibility.

       -z keyword
	   The recognized keywords are:

	   combreloc
	       Combines multiple reloc sections and sorts them to make dynamic
	       symbol lookup caching possible.

	   defs
	       Disallows undefined symbols in object files.  Undefined symbols
	       in shared libraries are still allowed.

	   initfirst
	       This option is only meaningful when building a  shared  object.
	       It  marks  the  object  so that its runtime initialization will
	       occur before the runtime initialization of  any	other  objects
	       brought	into the process at the same time.  Similarly the run-
	       time finalization of the object will occur  after  the  runtime
	       finalization of any other objects.

	   interpose
	       Marks  the  object  that its symbol table interposes before all
	       symbols but the primary executable.

	   loadfltr
	       Marks  the object that its filters be processed immediately  at
	       runtime.

	   muldefs
	       Allows multiple definitions.

	   nocombreloc
	       Disables multiple reloc sections combining.

	   nocopyreloc
	       Disables production of copy relocs.

	   nodefaultlib
	       Marks  the  object  that  the  search  for dependencies of this
	       object will ignore any default library search paths.

	   nodelete
	       Marks the object shouldn't be unloaded at runtime.

	   nodlopen
	       Marks the object not available to "dlopen".

	   nodump
	       Marks the object can not be dumped by "dldump".

	   now When generating an executable or shared	library,  mark	it  to
	       tell the dynamic linker to resolve all symbols when the program
	       is started, or when the	shared	library  is  linked  to  using
	       dlopen,	instead  of  deferring function call resolution to the
	       point when the function is first called.

	   origin
	       Marks the object may contain $ORIGIN.

	   Other keywords are ignored for Solaris compatibility.

       -( archives -)
       --start-group archives --end-group
	   The archives should be a list of archive files.  They may be either
	   explicit file names, or -l options.

	   The	specified  archives are searched repeatedly until no new unde-
	   fined references are created.  Normally,  an  archive  is  searched
	   only  once  in  the order that it is specified on the command line.
	   If a symbol in that archive is needed to resolve an undefined  sym-
	   bol	referred  to  by an object in an archive that appears later on
	   the command line, the linker would not be able to resolve that ref-
	   erence.   By grouping the archives, they all be searched repeatedly
	   until all possible references are resolved.

	   Using this option has a significant performance cost.  It  is  best
	   to  use  it	only  when  there  are unavoidable circular references
	   between two or more archives.

       --accept-unknown-input-arch
       --no-accept-unknown-input-arch
	   Tells the linker to accept input files whose architecture cannot be
	   recognised.	 The  assumption  is that the user knows what they are
	   doing and deliberately wants to link in these unknown input	files.
	   This  was the default behaviour of the linker, before release 2.14.
	   The default behaviour from release 2.14 onwards is to  reject  such
	   input files, and so the --accept-unknown-input-arch option has been
	   added to restore the old behaviour.

       --as-needed
       --no-as-needed
	   This option affects ELF DT_NEEDED tags for dynamic  libraries  men-
	   tioned on the command line after the --as-needed option.  Normally,
	   the linker will add a DT_NEEDED tag for each dynamic  library  men-
	   tioned  on  the  command line, regardless of whether the library is
	   actually needed. --as-needed causes DT_NEEDED tags to only be emit-
	   ted for libraries that satisfy some reference from regular objects.
	   --no-as-needed restores the default behaviour.

       -assert keyword
	   This option is ignored for SunOS compatibility.

       -Bdynamic
       -dy
       -call_shared
	   Link against dynamic libraries.  This is only meaningful  on  plat-
	   forms  for  which  shared  libraries are supported.	This option is
	   normally the default on such platforms.  The different variants  of
	   this  option  are  for compatibility with various systems.  You may
	   use this option multiple times on  the  command  line:  it  affects
	   library searching for -l options which follow it.

       -Bgroup
	   Set	the "DF_1_GROUP" flag in the "DT_FLAGS_1" entry in the dynamic
	   section.  This causes the runtime linker to handle lookups in  this
	   object  and its dependencies to be performed only inside the group.
	   --unresolved-symbols=report-all is implied.	This  option  is  only
	   meaningful on ELF platforms which support shared libraries.

       -Bstatic
       -dn
       -non_shared
       -static
	   Do  not  link against shared libraries.  This is only meaningful on
	   platforms for which shared libraries are supported.	The  different
	   variants of this option are for compatibility with various systems.
	   You may use this option multiple times  on  the  command  line:  it
	   affects  library  searching	for  -l options which follow it.  This
	   option also implies --unresolved-symbols=report-all.

       -Bsymbolic
	   When creating a shared library, bind references to  global  symbols
	   to  the definition within the shared library, if any.  Normally, it
	   is possible for a program linked against a shared library to  over-
	   ride the definition within the shared library.  This option is only
	   meaningful on ELF platforms which support shared libraries.

       --check-sections
       --no-check-sections
	   Asks the linker not to check section addresses after they have been
	   assigned  to  see  if there any overlaps.  Normally the linker will
	   perform this check, and if it finds any overlaps  it  will  produce
	   suitable error messages.  The linker does know about, and does make
	   allowances for sections in overlays.  The default behaviour can  be
	   restored by using the command line switch --check-sections.

       --cref
	   Output a cross reference table.  If a linker map file is being gen-
	   erated, the cross reference table is printed to the map file.  Oth-
	   erwise, it is printed on the standard output.

	   The	format of the table is intentionally simple, so that it may be
	   easily processed by a script if necessary.  The symbols are printed
	   out,  sorted  by  name.   For  each symbol, a list of file names is
	   given.  If the symbol is defined, the  first  file  listed  is  the
	   location of the definition.	The remaining files contain references
	   to the symbol.

       --no-define-common
	   This option inhibits the assignment of addresses to common symbols.
	   The script command "INHIBIT_COMMON_ALLOCATION" has the same effect.

	   The --no-define-common option allows  decoupling  the  decision  to
	   assign  addresses  to  Common symbols from the choice of the output
	   file type; otherwise a non-Relocatable output type forces assigning
	   addresses  to Common symbols.  Using --no-define-common allows Com-
	   mon symbols that  are  referenced  from  a  shared  library	to  be
	   assigned  addresses	only in the main program.  This eliminates the
	   unused duplicate space in the shared library, and also prevents any
	   possible confusion over resolving to the wrong duplicate when there
	   are many dynamic modules with specialized search paths for  runtime
	   symbol resolution.

       --defsym symbol=expression
	   Create  a global symbol in the output file, containing the absolute
	   address given by expression.  You may use this option as many times
	   as  necessary  to  define  multiple symbols in the command line.  A
	   limited form of arithmetic is supported for the expression in  this
	   context:  you  may  give  a	hexadecimal constant or the name of an
	   existing symbol, or use "+" and "-" to add or subtract  hexadecimal
	   constants or symbols.  If you need more elaborate expressions, con-
	   sider using the linker command language from a script.  Note: there
	   should  be  no white space between symbol, the equals sign (``=''),
	   and expression.

       --demangle[=style]
       --no-demangle
	   These options control whether to demangle  symbol  names  in  error
	   messages and other output.  When the linker is told to demangle, it
	   tries to present symbol names in  a	readable  fashion:  it	strips
	   leading underscores if they are used by the object file format, and
	   converts C++ mangled symbol names into user readable  names.   Dif-
	   ferent  compilers  have  different  mangling  styles.  The optional
	   demangling style argument can be  used  to  choose  an  appropriate
	   demangling  style  for  your compiler.  The linker will demangle by
	   default unless the environment variable COLLECT_NO_DEMANGLE is set.
	   These options may be used to override the default.

       --dynamic-linker file
	   Set	the  name of the dynamic linker.  This is only meaningful when
	   generating dynamically linked ELF executables.  The default dynamic
	   linker is normally correct; don't use this unless you know what you
	   are doing.

       --embedded-relocs
	   This option is only meaningful when linking MIPS embedded PIC code,
	   generated  by  the  -membedded-pic  option  to the GNU compiler and
	   assembler.  It causes the linker to create a  table	which  may  be
	   used  at runtime to relocate any data which was statically initial-
	   ized to pointer values.  See the  code  in  testsuite/ld-empic  for
	   details.

       --fatal-warnings
	   Treat all warnings as errors.

       --force-exe-suffix
	   Make sure that an output file has a .exe suffix.

	   If  a  successfully	built fully linked output file does not have a
	   ".exe" or ".dll" suffix, this option forces the linker to copy  the
	   output  file  to  one  of  the same name with a ".exe" suffix. This
	   option  is  useful  when  using  unmodified	Unix  makefiles  on  a
	   Microsoft Windows host, since some versions of Windows won't run an
	   image unless it ends in a ".exe" suffix.

       --no-gc-sections
       --gc-sections
	   Enable garbage collection of unused input sections.	It is  ignored
	   on  targets	that  do  not support this option.  This option is not
	   compatible with -r, nor should it be  used  with  dynamic  linking.
	   The	default  behaviour (of not performing this garbage collection)
	   can be restored by specifying --no-gc-sections on the command line.

       --help
	   Print  a summary of the command-line options on the standard output
	   and exit.

       --target-help
	   Print a summary of all target specific options on the standard out-
	   put and exit.

       -Map mapfile
	   Print  a  link map to the file mapfile.  See the description of the
	   -M option, above.

       --no-keep-memory
	   ld normally optimizes for speed over memory usage  by  caching  the
	   symbol  tables  of  input files in memory.  This option tells ld to
	   instead optimize for memory usage, by rereading the	symbol	tables
	   as  necessary.  This may be required if ld runs out of memory space
	   while linking a large executable.

       --no-undefined
       -z defs
	   Report unresolved symbol  references  from  regular	object	files.
	   This  is  done even if the linker is creating a non-symbolic shared
	   library.  The switch --[no-]allow-shlib-undefined controls the  be-
	   haviour   for  reporting  unresolved  references  found  in	shared
	   libraries being linked in.

       --allow-multiple-definition
       -z muldefs
	   Normally when a symbol is defined multiple times, the  linker  will
	   report  a fatal error. These options allow multiple definitions and
	   the first definition will be used.

       --allow-shlib-undefined
       --no-allow-shlib-undefined
	   Allows (the default)  or  disallows	undefined  symbols  in	shared
	   libraries.  This switch is similar to --no-undefined except that it
	   determines the behaviour when the undefined symbols are in a shared
	   library  rather than a regular object file.	It does not affect how
	   undefined symbols in regular object files are handled.

	   The reason that --allow-shlib-undefined is the default is that  the
	   shared  library being specified at link time may not be the same as
	   the one that is available at load time, so the symbols might  actu-
	   ally  be resolvable at load time.  Plus there are some systems, (eg
	   BeOS) where undefined symbols in shared libraries is normal.   (The
	   kernel  patches  them at load time to select which function is most
	   appropriate for the current architecture.  This is used for example
	   to  dynamically select an appropriate memset function).  Apparently
	   it is also normal for HPPA shared libraries to have undefined  sym-
	   bols.

       --no-undefined-version
	   Normally  when  a  symbol has an undefined version, the linker will
	   ignore it. This option disallows symbols with undefined version and
	   a fatal error will be issued instead.

       --no-warn-mismatch
	   Normally  ld  will  give an error if you try to link together input
	   files that are mismatched for some  reason,	perhaps  because  they
	   have  been compiled for different processors or for different endi-
	   annesses.  This option tells ld that it should silently permit such
	   possible  errors.   This  option  should only be used with care, in
	   cases when you have taken some special action that ensures that the
	   linker errors are inappropriate.

       --no-whole-archive
	   Turn  off  the  effect of the --whole-archive option for subsequent
	   archive files.

       --noinhibit-exec
	   Retain the executable output file  whenever	it  is	still  usable.
	   Normally,  the linker will not produce an output file if it encoun-
	   ters errors during the link process; it exits  without  writing  an
	   output file when it issues any error whatsoever.

       -nostdlib
	   Only search library directories explicitly specified on the command
	   line.  Library directories specified in linker  scripts  (including
	   linker scripts specified on the command line) are ignored.

       --oformat output-format
	   ld  may be configured to support more than one kind of object file.
	   If your ld is configured this way, you can use the --oformat option
	   to specify the binary format for the output object file.  Even when
	   ld is configured to support alternative object formats,  you  don't
	   usually need to specify this, as ld should be configured to produce
	   as a default output format the most usual format on	each  machine.
	   output-format  is  a  text  string, the name of a particular format
	   supported by the BFD libraries.  (You can list the available binary
	   formats  with  objdump -i.)	The script command "OUTPUT_FORMAT" can
	   also specify the output format, but this option overrides it.

       -pie
       --pic-executable
	   Create a position independent executable.  This is  currently  only
	   supported  on  ELF platforms.  Position independent executables are
	   similar to shared libraries in  that  they  are  relocated  by  the
	   dynamic  linker  to	the  virtual  address  the OS chooses for them
	   (which can vary  between  invocations).   Like  normal  dynamically
	   linked  executables they can be executed and symbols defined in the
	   executable cannot be overridden by shared libraries.

       -qmagic
	   This option is ignored for Linux compatibility.

       -Qy This option is ignored for SVR4 compatibility.

       --relax
	   An option with machine dependent effects.  This option is only sup-
	   ported on a few targets.

	   On some platforms, the --relax option performs global optimizations
	   that become possible when the linker  resolves  addressing  in  the
	   program,  such  as  relaxing  address  modes  and  synthesizing new
	   instructions in the output object file.

	   On some platforms these link time  global  optimizations  may  make
	   symbolic debugging of the resulting executable impossible.  This is
	   known to be the case for the Matsushita MN10200 and MN10300	family
	   of processors.

	   On  platforms where this is not supported, --relax is accepted, but
	   ignored.

       --retain-symbols-file filename
	   Retain only the symbols listed in the file filename, discarding all
	   others.   filename  is simply a flat file, with one symbol name per
	   line.  This option is especially useful in  environments  (such  as
	   VxWorks)  where  a  large global symbol table is accumulated gradu-
	   ally, to conserve run-time memory.

	   --retain-symbols-file does not discard undefined symbols,  or  sym-
	   bols needed for relocations.

	   You	may  only  specify  --retain-symbols-file  once in the command
	   line.  It overrides -s and -S.

       -rpath dir
	   Add a directory to the runtime library search path.	This  is  used
	   when  linking  an  ELF  executable with shared objects.  All -rpath
	   arguments are concatenated and passed to the runtime linker,  which
	   uses  them  to locate shared objects at runtime.  The -rpath option
	   is also used when locating  shared  objects	which  are  needed  by
	   shared objects explicitly included in the link; see the description
	   of the -rpath-link option.  If -rpath is not used when  linking  an
	   ELF	 executable,   the   contents	of  the  environment  variable
	   "LD_RUN_PATH" will be used if it is defined.

	   The -rpath option may also be used on SunOS.  By default, on SunOS,
	   the	linker	will  form  a  runtime	search patch out of all the -L
	   options it is given.  If a  -rpath  option  is  used,  the  runtime
	   search  path  will  be formed exclusively using the -rpath options,
	   ignoring the -L options.  This can be useful when using gcc,  which
	   adds many -L options which may be on NFS mounted filesystems.

	   For	compatibility with other ELF linkers, if the -R option is fol-
	   lowed by a directory name, rather than a file name, it  is  treated
	   as the -rpath option.

       -rpath-link DIR
	   When  using	ELF  or SunOS, one shared library may require another.
	   This happens when an "ld -shared" link includes a shared library as
	   one of the input files.

	   When   the  linker  encounters  such  a  dependency	when  doing  a
	   non-shared, non-relocatable link,  it  will	automatically  try  to
	   locate  the	required shared library and include it in the link, if
	   it is not included explicitly.  In such  a  case,  the  -rpath-link
	   option  specifies  the  first  set  of  directories to search.  The
	   -rpath-link option may specify a sequence of directory names either
	   by  specifying a list of names separated by colons, or by appearing
	   multiple times.

	   This option should be used with caution as it overrides the	search
	   path  that  may  have  been hard compiled into a shared library. In
	   such a case it is  possible	to  use  unintentionally  a  different
	   search path than the runtime linker would do.

	   The	linker	uses  the  following  search  paths to locate required
	   shared libraries.

	   1.  Any directories specified by -rpath-link options.

	   2.  Any directories specified by -rpath  options.   The  difference
	       between -rpath and -rpath-link is that directories specified by
	       -rpath options are included in the executable and used at  run-
	       time,  whereas the -rpath-link option is only effective at link
	       time. It is for the native linker only.

	   3.  On an ELF system, if the -rpath and "rpath-link"  options  were
	       not  used,  search  the	contents  of  the environment variable
	       "LD_RUN_PATH". It is for the native linker only.

	   4.  On SunOS, if the -rpath option was not used, search any	direc-
	       tories specified using -L options.

	   5.  For  a  native linker, the contents of the environment variable
	       "LD_LIBRARY_PATH".

	   6.  For a native ELF linker, the  directories  in  "DT_RUNPATH"  or
	       "DT_RPATH"   of	a  shared  library  are  searched  for	shared
	       libraries needed by it. The "DT_RPATH" entries are  ignored  if
	       "DT_RUNPATH" entries exist.

	   7.  The default directories, normally /lib and /usr/lib.

	   8.  For   a	 native   linker   on  an  ELF	system,  if  the  file
	       /etc/ld.so.conf exists, the list of directories found  in  that
	       file.

	   If  the required shared library is not found, the linker will issue
	   a warning and continue with the link.

       -shared
       -Bshareable
	   Create a shared library.  This is currently only supported on  ELF,
	   XCOFF and SunOS platforms.  On SunOS, the linker will automatically
	   create a shared library if the -e option is not used and there  are
	   undefined symbols in the link.

       --sort-common
	   This  option  tells	ld  to sort the common symbols by size when it
	   places them in the appropriate output sections.  First come all the
	   one	byte  symbols,	then all the two byte, then all the four byte,
	   and then everything else.  This is to prevent gaps between  symbols
	   due to alignment constraints.

       --split-by-file [size]
	   Similar  to	--split-by-reloc  but creates a new output section for
	   each input file when size is reached.  size defaults to a size of 1
	   if not given.

       --split-by-reloc [count]
	   Tries  to creates extra sections in the output file so that no sin-
	   gle output section in the file contains  more  than	count  reloca-
	   tions.   This  is useful when generating huge relocatable files for
	   downloading into certain real time kernels  with  the  COFF	object
	   file  format;  since  COFF cannot represent more than 65535 reloca-
	   tions in a single section.  Note that this will fail to  work  with
	   object  file  formats which do not support arbitrary sections.  The
	   linker will not split up individual input sections for  redistribu-
	   tion, so if a single input section contains more than count reloca-
	   tions one output section will contain that many relocations.  count
	   defaults to a value of 32768.

       --stats
	   Compute  and  display statistics about the operation of the linker,
	   such as execution time and memory usage.

       --traditional-format
	   For some targets, the output of ld is different in some  ways  from
	   the output of some existing linker.	This switch requests ld to use
	   the traditional format instead.

	   For example, on SunOS, ld combines duplicate entries in the	symbol
	   string table.  This can reduce the size of an output file with full
	   debugging information by over 30 percent.  Unfortunately, the SunOS
	   "dbx"  program  can	not  read  the resulting program ("gdb" has no
	   trouble).  The --traditional-format switch tells ld to not  combine
	   duplicate entries.

       --section-start sectionname=org
	   Locate  a  section in the output file at the absolute address given
	   by org.  You may use this option as	many  times  as  necessary  to
	   locate multiple sections in the command line.  org must be a single
	   hexadecimal integer; for compatibility with other linkers, you  may
	   omit  the  leading  0x  usually associated with hexadecimal values.
	   Note: there should be  no  white  space  between  sectionname,  the
	   equals sign (``=''), and org.

       -Tbss org
       -Tdata org
       -Ttext org
	   Same  as  --section-start,  with  ".bss", ".data" or ".text" as the
	   sectionname.

       --unresolved-symbols=method
	   Determine how to handle unresolved symbols.	There are four	possi-
	   ble values for method:

	   ignore-all
	       Do not report any unresolved symbols.

	   report-all
	       Report all unresolved symbols.  This is the default.

	   ignore-in-object-files
	       Report	unresolved   symbols  that  are  contained  in	shared
	       libraries, but ignore them if they  come  from  regular	object
	       files.

	   ignore-in-shared-libs
	       Report  unresolved symbols that come from regular object files,
	       but ignore them if they come from shared libraries.   This  can
	       be  useful  when creating a dynamic binary and it is known that
	       all the shared libraries that  it  should  be  referencing  are
	       included on the linker's command line.

	   The	behaviour  for	shared libraries on their own can also be con-
	   trolled by the --[no-]allow-shlib-undefined option.

	   Normally the  linker  will  generate  an  error  message  for  each
	   reported unresolved symbol but the option --warn-unresolved-symbols
	   can change this to a warning.

       --dll-verbose
       --verbose
	   Display the version number for ld and list  the  linker  emulations
	   supported.	Display  which	input  files can and cannot be opened.
	   Display the linker script being used by the linker.

       --version-script=version-scriptfile
	   Specify the name of a version script to the linker.	This is  typi-
	   cally  used	when  creating	shared libraries to specify additional
	   information about the version hierarchy for the library being  cre-
	   ated.   This  option is only meaningful on ELF platforms which sup-
	   port shared libraries.

       --warn-common
	   Warn when a common symbol is combined with another common symbol or
	   with  a symbol definition.  Unix linkers allow this somewhat sloppy
	   practise, but linkers on some other operating systems do not.  This
	   option  allows you to find potential problems from combining global
	   symbols.  Unfortunately, some C libraries use this practise, so you
	   may	get some warnings about symbols in the libraries as well as in
	   your programs.

	   There are three kinds of global  symbols,  illustrated  here  by  C
	   examples:

	   int i = 1;
	       A definition, which goes in the initialized data section of the
	       output file.

	   extern int i;
	       An undefined reference, which does not allocate	space.	 There
	       must be either a definition or a common symbol for the variable
	       somewhere.

	   int i;
	       A common symbol.  If there are only (one or more)  common  sym-
	       bols  for a variable, it goes in the uninitialized data area of
	       the output file.  The linker merges multiple common symbols for
	       the same variable into a single symbol.	If they are of differ-
	       ent sizes, it picks the largest size.  The linker turns a  com-
	       mon  symbol into a declaration, if there is a definition of the
	       same variable.

	   The --warn-common option can produce five kinds of warnings.   Each
	   warning consists of a pair of lines: the first describes the symbol
	   just encountered, and the  second  describes  the  previous	symbol
	   encountered	with  the  same  name.	One or both of the two symbols
	   will be a common symbol.

	   1.  Turning a common symbol into  a	reference,  because  there  is
	       already a definition for the symbol.

		       (
): warning: common of `' overridden by definition (
): warning: defined here 2. Turning a common symbol into a reference, because a later defi- nition for the symbol is encountered. This is the same as the previous case, except that the symbols are encountered in a different order. (
): warning: definition of `' overriding common (
): warning: common is here 3. Merging a common symbol with a previous same-sized common sym- bol. (
): warning: multiple common of `' (
): warning: previous common is here 4. Merging a common symbol with a previous larger common symbol. (
): warning: common of `' overridden by larger common (
): warning: larger common is here 5. Merging a common symbol with a previous smaller common symbol. This is the same as the previous case, except that the symbols are encountered in a different order. (
): warning: common of `' overriding smaller common (
): warning: smaller common is here --warn-constructors Warn if any global constructors are used. This is only useful for a few object file formats. For formats like COFF or ELF, the linker can not detect the use of global constructors. --warn-multiple-gp Warn if multiple global pointer values are required in the output file. This is only meaningful for certain processors, such as the Alpha. Specifically, some processors put large-valued constants in a special section. A special register (the global pointer) points into the middle of this section, so that constants can be loaded efficiently via a base-register relative addressing mode. Since the offset in base-register relative mode is fixed and relatively small (e.g., 16 bits), this limits the maximum size of the constant pool. Thus, in large programs, it is often necessary to use multi- ple global pointer values in order to be able to address all possi- ble constants. This option causes a warning to be issued whenever this case occurs. --warn-once Only warn once for each undefined symbol, rather than once per mod- ule which refers to it. --warn-section-align Warn if the address of an output section is changed because of alignment. Typically, the alignment will be set by an input sec- tion. The address will only be changed if it not explicitly speci- fied; that is, if the "SECTIONS" command does not specify a start address for the section. --warn-unresolved-symbols If the linker is going to report an unresolved symbol (see the option --unresolved-symbols) it will normally generate an error. This option makes it generate a warning instead. --error-unresolved-symbols This restores the linker's default behaviour of generating errors when it is reporting unresolved symbols. --whole-archive For each archive mentioned on the command line after the --whole-archive option, include every object file in the archive in the link, rather than searching the archive for the required object files. This is normally used to turn an archive file into a shared library, forcing every object to be included in the resulting shared library. This option may be used more than once. Two notes when using this option from gcc: First, gcc doesn't know about this option, so you have to use -Wl,-whole-archive. Second, don't forget to use -Wl,-no-whole-archive after your list of ar- chives, because gcc will add its own list of archives to your link and you may not want this flag to affect those as well. --wrap symbol Use a wrapper function for symbol. Any undefined reference to sym- bol will be resolved to "__wrap_symbol". Any undefined reference to "__real_symbol" will be resolved to symbol. This can be used to provide a wrapper for a system function. The wrapper function should be called "__wrap_symbol". If it wishes to call the system function, it should call "__real_symbol". Here is a trivial example: void * __wrap_malloc (size_t c) { printf ("malloc called with %zu\n", c); return __real_malloc (c); } If you link other code with this file using --wrap malloc, then all calls to "malloc" will call the function "__wrap_malloc" instead. The call to "__real_malloc" in "__wrap_malloc" will call the real "malloc" function. You may wish to provide a "__real_malloc" function as well, so that links without the --wrap option will succeed. If you do this, you should not put the definition of "__real_malloc" in the same file as "__wrap_malloc"; if you do, the assembler may resolve the call before the linker has a chance to wrap it to "malloc". --enable-new-dtags --disable-new-dtags This linker can create the new dynamic tags in ELF. But the older ELF systems may not understand them. If you specify --enable-new-dtags, the dynamic tags will be created as needed. If you specify --disable-new-dtags, no new dynamic tags will be cre- ated. By default, the new dynamic tags are not created. Note that those options are only available for ELF systems. The i386 PE linker supports the -shared option, which causes the output to be a dynamically linked library (DLL) instead of a normal exe- cutable. You should name the output "*.dll" when you use this option. In addition, the linker fully supports the standard "*.def" files, which may be specified on the linker command line like an object file (in fact, it should precede archives it exports symbols from, to ensure that they get linked in, just like a normal object file). In addition to the options common to all targets, the i386 PE linker support additional command line options that are specific to the i386 PE target. Options that take values may be separated from their values by either a space or an equals sign. --add-stdcall-alias If given, symbols with a stdcall suffix (@nn) will be exported as- is and also with the suffix stripped. [This option is specific to the i386 PE targeted port of the linker] --base-file file Use file as the name of a file in which to save the base addresses of all the relocations needed for generating DLLs with dlltool. [This is an i386 PE specific option] --dll Create a DLL instead of a regular executable. You may also use -shared or specify a "LIBRARY" in a given ".def" file. [This option is specific to the i386 PE targeted port of the linker] --enable-stdcall-fixup --disable-stdcall-fixup If the link finds a symbol that it cannot resolve, it will attempt to do ``fuzzy linking'' by looking for another defined symbol that differs only in the format of the symbol name (cdecl vs stdcall) and will resolve that symbol by linking to the match. For example, the undefined symbol "_foo" might be linked to the function "_foo@12", or the undefined symbol "_bar@16" might be linked to the function "_bar". When the linker does this, it prints a warning, since it normally should have failed to link, but sometimes import libraries generated from third-party dlls may need this feature to be usable. If you specify --enable-stdcall-fixup, this feature is fully enabled and warnings are not printed. If you specify --dis- able-stdcall-fixup, this feature is disabled and such mismatches are considered to be errors. [This option is specific to the i386 PE targeted port of the linker] --export-all-symbols If given, all global symbols in the objects used to build a DLL will be exported by the DLL. Note that this is the default if there otherwise wouldn't be any exported symbols. When symbols are explicitly exported via DEF files or implicitly exported via func- tion attributes, the default is to not export anything else unless this option is given. Note that the symbols "DllMain@12", "DllEn- tryPoint@0", "DllMainCRTStartup@12", and "impure_ptr" will not be automatically exported. Also, symbols imported from other DLLs will not be re-exported, nor will symbols specifying the DLL's internal layout such as those beginning with "_head_" or ending with "_iname". In addition, no symbols from "libgcc", "libstd++", "libmingw32", or "crtX.o" will be exported. Symbols whose names begin with "__rtti_" or "__builtin_" will not be exported, to help with C++ DLLs. Finally, there is an extensive list of cygwin-pri- vate symbols that are not exported (obviously, this applies on when building DLLs for cygwin targets). These cygwin-excludes are: "_cygwin_dll_entry@12", "_cygwin_crt0_common@8", "_cygwin_noncyg- win_dll_entry@12", "_fmode", "_impure_ptr", "cygwin_attach_dll", "cygwin_premain0", "cygwin_premain1", "cygwin_premain2", "cyg- win_premain3", and "environ". [This option is specific to the i386 PE targeted port of the linker] --exclude-symbols symbol,symbol,... Specifies a list of symbols which should not be automatically exported. The symbol names may be delimited by commas or colons. [This option is specific to the i386 PE targeted port of the linker] --exclude-libs lib,lib,... Specifies a list of archive libraries from which symbols should not be automatically exported. The library names may be delimited by commas or colons. Specifying "--exclude-libs ALL" excludes symbols in all archive libraries from automatic export. Symbols explicitly listed in a .def file are still exported, regardless of this option. [This option is specific to the i386 PE targeted port of the linker] --file-alignment Specify the file alignment. Sections in the file will always begin at file offsets which are multiples of this number. This defaults to 512. [This option is specific to the i386 PE targeted port of the linker] --heap reserve --heap reserve,commit Specify the amount of memory to reserve (and optionally commit) to be used as heap for this program. The default is 1Mb reserved, 4K committed. [This option is specific to the i386 PE targeted port of the linker] --image-base value Use value as the base address of your program or dll. This is the lowest memory location that will be used when your program or dll is loaded. To reduce the need to relocate and improve performance of your dlls, each should have a unique base address and not over- lap any other dlls. The default is 0x400000 for executables, and 0x10000000 for dlls. [This option is specific to the i386 PE tar- geted port of the linker] --kill-at If given, the stdcall suffixes (@nn) will be stripped from symbols before they are exported. [This option is specific to the i386 PE targeted port of the linker] --major-image-version value Sets the major number of the ``image version''. Defaults to 1. [This option is specific to the i386 PE targeted port of the linker] --major-os-version value Sets the major number of the ``os version''. Defaults to 4. [This option is specific to the i386 PE targeted port of the linker] --major-subsystem-version value Sets the major number of the ``subsystem version''. Defaults to 4. [This option is specific to the i386 PE targeted port of the linker] --minor-image-version value Sets the minor number of the ``image version''. Defaults to 0. [This option is specific to the i386 PE targeted port of the linker] --minor-os-version value Sets the minor number of the ``os version''. Defaults to 0. [This option is specific to the i386 PE targeted port of the linker] --minor-subsystem-version value Sets the minor number of the ``subsystem version''. Defaults to 0. [This option is specific to the i386 PE targeted port of the linker] --output-def file The linker will create the file file which will contain a DEF file corresponding to the DLL the linker is generating. This DEF file (which should be called "*.def") may be used to create an import library with "dlltool" or may be used as a reference to automati- cally or implicitly exported symbols. [This option is specific to the i386 PE targeted port of the linker] --out-implib file The linker will create the file file which will contain an import lib corresponding to the DLL the linker is generating. This import lib (which should be called "*.dll.a" or "*.a" may be used to link clients against the generated DLL; this behaviour makes it possible to skip a separate "dlltool" import library creation step. [This option is specific to the i386 PE targeted port of the linker] --enable-auto-image-base Automatically choose the image base for DLLs, unless one is speci- fied using the "--image-base" argument. By using a hash generated from the dllname to create unique image bases for each DLL, in-mem- ory collisions and relocations which can delay program execution are avoided. [This option is specific to the i386 PE targeted port of the linker] --disable-auto-image-base Do not automatically generate a unique image base. If there is no user-specified image base ("--image-base") then use the platform default. [This option is specific to the i386 PE targeted port of the linker] --dll-search-prefix string When linking dynamically to a dll without an import library, search for ".dll" in preference to "lib.dll". This behaviour allows easy distinction between DLLs built for the various "subplatforms": native, cygwin, uwin, pw, etc. For instance, cygwin DLLs typically use "--dll-search-prefix=cyg". [This option is specific to the i386 PE targeted port of the linker] --enable-auto-import Do sophisticated linking of "_symbol" to "__imp__symbol" for DATA imports from DLLs, and create the necessary thunking symbols when building the import libraries with those DATA exports. Note: Use of the 'auto-import' extension will cause the text section of the image file to be made writable. This does not conform to the PE- COFF format specification published by Microsoft. Using 'auto-import' generally will 'just work' -- but sometimes you may see this message: "variable '' can't be auto-imported. Please read the documen- tation for ld's "--enable-auto-import" for details." This message occurs when some (sub)expression accesses an address ultimately given by the sum of two constants (Win32 import tables only allow one). Instances where this may occur include accesses to member fields of struct variables imported from a DLL, as well as using a constant index into an array variable imported from a DLL. Any multiword variable (arrays, structs, long long, etc) may trigger this error condition. However, regardless of the exact data type of the offending exported variable, ld will always detect it, issue the warning, and exit. There are several ways to address this difficulty, regardless of the data type of the exported variable: One way is to use --enable-runtime-pseudo-reloc switch. This leaves the task of adjusting references in your client code for runtime environment, so this method works only when runtime environment supports this feature. A second solution is to force one of the 'constants' to be a vari- able -- that is, unknown and un-optimizable at compile time. For arrays, there are two possibilities: a) make the indexee (the array's address) a variable, or b) make the 'constant' index a variable. Thus: extern type extern_array[]; extern_array[1] --> { volatile type *t=extern_array; t[1] } or extern type extern_array[]; extern_array[1] --> { volatile int t=1; extern_array[t] } For structs (and most other multiword data types) the only option is to make the struct itself (or the long long, or the ...) vari- able: extern struct s extern_struct; extern_struct.field --> { volatile struct s *t=&extern_struct; t->field } or extern long long extern_ll; extern_ll --> { volatile long long * local_ll=&extern_ll; *local_ll } A third method of dealing with this difficulty is to abandon 'auto-import' for the offending symbol and mark it with "__declspec(dllimport)". However, in practise that requires using compile-time #defines to indicate whether you are building a DLL, building client code that will link to the DLL, or merely build- ing/linking to a static library. In making the choice between the various methods of resolving the 'direct address with constant off- set' problem, you should consider typical real-world usage: Original: --foo.h extern int arr[]; --foo.c #include "foo.h" void main(int argc, char **argv){ printf("%d\n",arr[1]); } Solution 1: --foo.h extern int arr[]; --foo.c #include "foo.h" void main(int argc, char **argv){ /* This workaround is for win32 and cygwin; do not "optimize" */ volatile int *parr = arr; printf("%d\n",parr[1]); } Solution 2: --foo.h /* Note: auto-export is assumed (no __declspec(dllexport)) */ #if (defined(_WIN32) || defined(__CYGWIN__)) && \ !(defined(FOO_BUILD_DLL) || defined(FOO_STATIC)) #define FOO_IMPORT __declspec(dllimport) #else #define FOO_IMPORT #endif extern FOO_IMPORT int arr[]; --foo.c #include "foo.h" void main(int argc, char **argv){ printf("%d\n",arr[1]); } A fourth way to avoid this problem is to re-code your library to use a functional interface rather than a data interface for the offending variables (e.g. set_foo() and get_foo() accessor func- tions). [This option is specific to the i386 PE targeted port of the linker] --disable-auto-import Do not attempt to do sophisticated linking of "_symbol" to "__imp__symbol" for DATA imports from DLLs. [This option is spe- cific to the i386 PE targeted port of the linker] --enable-runtime-pseudo-reloc If your code contains expressions described in --enable-auto-import section, that is, DATA imports from DLL with non-zero offset, this switch will create a vector of 'runtime pseudo relocations' which can be used by runtime environment to adjust references to such data in your client code. [This option is specific to the i386 PE targeted port of the linker] --disable-runtime-pseudo-reloc Do not create pseudo relocations for non-zero offset DATA imports from DLLs. This is the default. [This option is specific to the i386 PE targeted port of the linker] --enable-extra-pe-debug Show additional debug info related to auto-import symbol thunking. [This option is specific to the i386 PE targeted port of the linker] --section-alignment Sets the section alignment. Sections in memory will always begin at addresses which are a multiple of this number. Defaults to 0x1000. [This option is specific to the i386 PE targeted port of the linker] --stack reserve --stack reserve,commit Specify the amount of memory to reserve (and optionally commit) to be used as stack for this program. The default is 2Mb reserved, 4K committed. [This option is specific to the i386 PE targeted port of the linker] --subsystem which --subsystem which:major --subsystem which:major.minor Specifies the subsystem under which your program will execute. The legal values for which are "native", "windows", "console", and "posix". You may optionally set the subsystem version also. [This option is specific to the i386 PE targeted port of the linker] ENVIRONMENT You can change the behaviour of ld with the environment variables "GNU- TARGET", "LDEMULATION" and "COLLECT_NO_DEMANGLE". "GNUTARGET" determines the input-file object format if you don't use -b (or its synonym --format). Its value should be one of the BFD names for an input format. If there is no "GNUTARGET" in the environment, ld uses the natural format of the target. If "GNUTARGET" is set to "default" then BFD attempts to discover the input format by examining binary input files; this method often succeeds, but there are potential ambiguities, since there is no method of ensuring that the magic number used to specify object-file formats is unique. However, the configura- tion procedure for BFD on each system places the conventional format for that system first in the search-list, so ambiguities are resolved in favor of convention. "LDEMULATION" determines the default emulation if you don't use the -m option. The emulation can affect various aspects of linker behaviour, particularly the default linker script. You can list the available emulations with the --verbose or -V options. If the -m option is not used, and the "LDEMULATION" environment variable is not defined, the default emulation depends upon how the linker was configured. Normally, the linker will default to demangling symbols. However, if "COLLECT_NO_DEMANGLE" is set in the environment, then it will default to not demangling symbols. This environment variable is used in a sim- ilar fashion by the "gcc" linker wrapper program. The default may be overridden by the --demangle and --no-demangle options. SEE ALSO ar(1), nm(1), objcopy(1), objdump(1), readelf(1) and the Info entries for binutils and ld. COPYRIGHT Copyright (c) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled ``GNU Free Documentation License''. binutils-2.15 2004-05-17 LD(1)
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