267 lines
7.7 KiB
Bash
Executable File
267 lines
7.7 KiB
Bash
Executable File
#!/bin/sh
|
|
|
|
debug=false
|
|
|
|
# Linker flags used:
|
|
#
|
|
# Informational:
|
|
# --warn-common
|
|
# -Map $EXE.map
|
|
# --verbose
|
|
#
|
|
# Optimizations:
|
|
# --sort-common reduces padding
|
|
# --sort-section alignment reduces padding
|
|
# --gc-sections throws out unused sections,
|
|
# does not work for shared libs
|
|
# -On Not used, maybe useful?
|
|
#
|
|
# List of files to link:
|
|
# $l_list == --start-group -llib1 -llib2 --end-group
|
|
# --start-group $O_FILES $A_FILES --end-group
|
|
#
|
|
# Shared library link:
|
|
# -shared self-explanatory
|
|
# -fPIC position-independent code
|
|
# --enable-new-dtags ?
|
|
# -z,combreloc ?
|
|
# -soname="libbusybox.so.$BB_VER"
|
|
# --undefined=lbb_main Seed name to start pulling from
|
|
# (otherwise we'll need --whole-archive)
|
|
# -static Not used, but may be useful! manpage:
|
|
# "... This option can be used with -shared.
|
|
# Doing so means that a shared library
|
|
# is being created but that all of the library's
|
|
# external references must be resolved by pulling
|
|
# in entries from static libraries."
|
|
|
|
|
|
try() {
|
|
printf "%s\n" "Output of:" >$EXE.out
|
|
printf "%s\n" "$*" >>$EXE.out
|
|
printf "%s\n" "==========" >>$EXE.out
|
|
$debug && echo "Trying: $*"
|
|
"$@" >>$EXE.out 2>&1
|
|
exitcode=$?
|
|
return $exitcode
|
|
}
|
|
|
|
check_cc() {
|
|
if $CC $1 -shared -o /dev/null -xc /dev/null > /dev/null 2>&1; then
|
|
echo "$1";
|
|
else
|
|
echo "$2";
|
|
fi
|
|
}
|
|
|
|
EXE="$1"
|
|
CC="$2"
|
|
LDFLAGS="$3"
|
|
O_FILES="$4"
|
|
A_FILES="$5"
|
|
LDLIBS="$6"
|
|
|
|
# The -Wl,--sort-section option is not supported by older versions of ld
|
|
SORT_SECTION=`check_cc "-Wl,--sort-section -Wl,alignment" ""`
|
|
|
|
# Sanitize lib list (dups, extra spaces etc)
|
|
LDLIBS=`echo "$LDLIBS" | xargs -n1 | sort | uniq | xargs`
|
|
|
|
# First link with all libs. If it fails, bail out
|
|
echo "Trying libraries: $LDLIBS"
|
|
# "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3"
|
|
l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
|
|
test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group"
|
|
try $CC $LDFLAGS \
|
|
-o $EXE \
|
|
-Wl,--sort-common \
|
|
$SORT_SECTION \
|
|
-Wl,--gc-sections \
|
|
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
|
|
$l_list \
|
|
|| {
|
|
echo "Failed: $* $l_list"
|
|
cat $EXE.out
|
|
exit 1
|
|
}
|
|
|
|
# Now try to remove each lib and build without it.
|
|
# Stop when no lib can be removed.
|
|
while test "$LDLIBS"; do
|
|
$debug && echo "Trying libraries: $LDLIBS"
|
|
all_needed=true
|
|
for one in $LDLIBS; do
|
|
without_one=`echo " $LDLIBS " | sed "s/ $one / /g" | xargs`
|
|
# "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3"
|
|
l_list=`echo "$without_one" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
|
|
test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group"
|
|
$debug && echo "Trying -l options: '$l_list'"
|
|
try $CC $LDFLAGS \
|
|
-o $EXE \
|
|
-Wl,--sort-common \
|
|
$SORT_SECTION \
|
|
-Wl,--gc-sections \
|
|
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
|
|
$l_list
|
|
if test $? = 0; then
|
|
echo " Library $one is not needed"
|
|
LDLIBS="$without_one"
|
|
all_needed=false
|
|
else
|
|
echo " Library $one is needed"
|
|
fi
|
|
done
|
|
# All libs were needed, can't remove any
|
|
$all_needed && break
|
|
# If there is no space char, the list has just one lib.
|
|
# I'm not sure that in this case lib really is 100% needed.
|
|
# Let's try linking without it anyway... thus commented out.
|
|
#{ echo "$LDLIBS" | grep -q ' '; } || break
|
|
done
|
|
|
|
# Make the binary with final, minimal list of libs
|
|
echo "Final link with: ${LDLIBS:-<none>}"
|
|
l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
|
|
test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group"
|
|
# --verbose gives us gobs of info to stdout (e.g. linker script used)
|
|
if ! test -f busybox_ldscript; then
|
|
try $CC $LDFLAGS \
|
|
-o $EXE \
|
|
-Wl,--sort-common \
|
|
$SORT_SECTION \
|
|
-Wl,--gc-sections \
|
|
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
|
|
$l_list \
|
|
-Wl,--warn-common \
|
|
-Wl,-Map -Wl,$EXE.map \
|
|
-Wl,--verbose \
|
|
|| {
|
|
cat $EXE.out
|
|
exit 1
|
|
}
|
|
else
|
|
echo "Custom linker script 'busybox_ldscript' found, using it"
|
|
# Add SORT_BY_ALIGNMENT to linker script (found in $EXE.out):
|
|
# .rodata : { *(.rodata SORT_BY_ALIGNMENT(.rodata.*) .gnu.linkonce.r.*) }
|
|
# *(.data SORT_BY_ALIGNMENT(.data.*) .gnu.linkonce.d.*)
|
|
# *(.bss SORT_BY_ALIGNMENT(.bss.*) .gnu.linkonce.b.*)
|
|
# This will eliminate most of the padding (~3kb).
|
|
# Hmm, "ld --sort-section alignment" should do it too.
|
|
try $CC $LDFLAGS \
|
|
-o $EXE \
|
|
-Wl,--sort-common \
|
|
$SORT_SECTION \
|
|
-Wl,--gc-sections \
|
|
-Wl,-T -Wl,busybox_ldscript \
|
|
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
|
|
$l_list \
|
|
-Wl,--warn-common \
|
|
-Wl,-Map -Wl,$EXE.map \
|
|
-Wl,--verbose \
|
|
|| {
|
|
cat $EXE.out
|
|
exit 1
|
|
}
|
|
fi
|
|
|
|
. ./.config
|
|
|
|
sharedlib_dir="0_lib"
|
|
|
|
if test "$CONFIG_BUILD_LIBBUSYBOX" = y; then
|
|
mkdir "$sharedlib_dir" 2>/dev/null
|
|
test -d "$sharedlib_dir" || {
|
|
echo "Cannot make directory $sharedlib_dir"
|
|
exit 1
|
|
}
|
|
ln -s "libbusybox.so.$BB_VER" "$sharedlib_dir"/libbusybox.so 2>/dev/null
|
|
|
|
EXE="$sharedlib_dir/libbusybox.so.${BB_VER}_unstripped"
|
|
try $CC $LDFLAGS \
|
|
-o $EXE \
|
|
-shared -fPIC \
|
|
-Wl,--enable-new-dtags \
|
|
-Wl,-z,combreloc \
|
|
-Wl,-soname="libbusybox.so.$BB_VER" \
|
|
-Wl,--undefined=lbb_main \
|
|
-Wl,--sort-common \
|
|
$SORT_SECTION \
|
|
-Wl,--start-group $A_FILES -Wl,--end-group \
|
|
$l_list \
|
|
-Wl,--warn-common \
|
|
-Wl,-Map -Wl,$EXE.map \
|
|
-Wl,--verbose \
|
|
|| {
|
|
echo "Linking $EXE failed"
|
|
cat $EXE.out
|
|
exit 1
|
|
}
|
|
$STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/libbusybox.so.$BB_VER"
|
|
chmod a+x "$sharedlib_dir/libbusybox.so.$BB_VER"
|
|
echo "libbusybox: $sharedlib_dir/libbusybox.so.$BB_VER"
|
|
fi
|
|
|
|
if test "$CONFIG_FEATURE_SHARED_BUSYBOX" = y; then
|
|
EXE="$sharedlib_dir/busybox_unstripped"
|
|
try $CC $LDFLAGS \
|
|
-o $EXE \
|
|
-Wl,--sort-common \
|
|
$SORT_SECTION \
|
|
-Wl,--gc-sections \
|
|
-Wl,--start-group $O_FILES -Wl,--end-group \
|
|
-L"$sharedlib_dir" -lbusybox \
|
|
-Wl,--warn-common \
|
|
-Wl,-Map -Wl,$EXE.map \
|
|
-Wl,--verbose \
|
|
|| {
|
|
echo "Linking $EXE failed"
|
|
cat $EXE.out
|
|
exit 1
|
|
}
|
|
$STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/busybox"
|
|
echo "busybox linked against libbusybox: $sharedlib_dir/busybox"
|
|
fi
|
|
|
|
if test "$CONFIG_FEATURE_INDIVIDUAL" = y; then
|
|
echo "Linking individual applets against libbusybox (see $sharedlib_dir/*)"
|
|
gcc -DNAME_MAIN_CNAME -E -include include/autoconf.h include/applets.h \
|
|
| grep -v "^#" \
|
|
| grep -v "^$" \
|
|
> applet_lst.tmp
|
|
while read name main junk; do
|
|
|
|
echo "\
|
|
void lbb_prepare(const char *applet, char **argv);
|
|
int $main(int argc, char **argv);
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
lbb_prepare(\"$name\", argv);
|
|
return $main(argc, argv);
|
|
}
|
|
" >"$sharedlib_dir/applet.c"
|
|
|
|
EXE="$sharedlib_dir/$name"
|
|
try $CC $LDFLAGS "$sharedlib_dir/applet.c" \
|
|
-o $EXE \
|
|
-Wl,--sort-common \
|
|
$SORT_SECTION \
|
|
-Wl,--gc-sections \
|
|
-L"$sharedlib_dir" -lbusybox \
|
|
-Wl,--warn-common \
|
|
|| {
|
|
echo "Linking $EXE failed"
|
|
cat $EXE.out
|
|
exit 1
|
|
}
|
|
rm -- "$sharedlib_dir/applet.c" $EXE.out
|
|
$STRIP -s --remove-section=.note --remove-section=.comment $EXE
|
|
|
|
done <applet_lst.tmp
|
|
fi
|
|
|
|
# libbusybox.so is needed only for -lbusybox at link time,
|
|
# it is not needed at runtime. Deleting to reduce confusion.
|
|
rm "$sharedlib_dir"/libbusybox.so 2>/dev/null
|
|
exit 0 # or else we may confuse make
|