# --sort-section alignment reduces padding
# --gc-sections throws out unused sections,
# does not work for shared libs
-# -O Not used, maybe useful?
+# -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
-# or for shlib:
-# --start-group --whole-archive $A_FILES --no-whole-archive --end-group
-# otherwise we don't pull in all parts of *.a files. Now we pull in too much.
-# FIXME: make it work without --whole-archive, or better, with --gc-sections.
#
# Shared library link:
# -shared self-explanatory
# -fPIC position-independent code
-# -Wl,--enable-new-dtags ?
-# -Wl,-z,combreloc ?
-# -Wl,-soname="libbusybox.so.$BB_VER"
-# -static Not used, but may be useful! manpage:
+# --enable-new-dtags ?
+# -z,combreloc ?
+# -soname="libbusybox.so.$BB_VER"
+# --undefined=lbb_main Seed name to start pulling from
+# (otherwise we'll need --whole-archive)
+# -static Not used, but may be useful! manpage:
# "... This option can be used with -shared.
# Doing so means that a shared library
# is being created but that all of the library's
printf "%s\n" "$*" >>$EXE.out
printf "%s\n" "==========" >>$EXE.out
$debug && echo "Trying: $*"
- "$@" >>$EXE.out 2>&1
- exitcode=$?
- return $exitcode
+ $@ >>$EXE.out 2>&1
+ return $?
+}
+
+check_cc() {
+ local tempname="/tmp/temp.$$.$RANDOM"
+ # Can use "-o /dev/null", but older gcc tend to *unlink it* on failure! :(
+ # "-xc": C language. "/dev/null" is an empty source file.
+ if $CC $1 -shared -xc /dev/null -o "$tempname".o >/dev/null 2>&1; then
+ echo "$1";
+ else
+ echo "$2";
+ fi
+ rm "$tempname".o 2>/dev/null
+}
+
+check_libc_is_glibc() {
+ local tempname="/tmp/temp.$$.$RANDOM"
+ echo "\
+ #include <stdlib.h>
+ /* Apparently uclibc defines __GLIBC__ (compat trick?). Oh well. */
+ #if defined(__GLIBC__) && !defined(__UCLIBC__)
+ syntax error here
+ #endif
+ " >"$tempname".c
+ if $CC "$tempname".c -c -o "$tempname".o >/dev/null 2>&1; then
+ echo "$2";
+ else
+ echo "$1";
+ fi
+ rm "$tempname".c "$tempname".o 2>/dev/null
}
EXE="$1"
CC="$2"
-LDFLAGS="$3"
-O_FILES="$4"
-A_FILES="$5"
-LDLIBS="$6"
+CFLAGS="$3"
+LDFLAGS="$4"
+O_FILES="$5"
+A_FILES="$6"
+LDLIBS="$7"
+
+# The --sort-section option is not supported by older versions of ld
+SORT_SECTION=`check_cc "-Wl,--sort-section,alignment" ""`
+
+# Static linking against glibc produces buggy executables
+# (glibc does not cope well with ld --gc-sections).
+# See sources.redhat.com/bugzilla/show_bug.cgi?id=3400
+# Note that glibc is unsuitable for static linking anyway.
+# We are removing -Wl,--gc-sections from link command line.
+GC_SECTIONS=`(
+. ./.config
+if test x"$CONFIG_STATIC" = x"y"; then
+ check_libc_is_glibc "" "-Wl,--gc-sections"
+else
+ echo "-Wl,--gc-sections"
+fi
+)`
+
+# The --gc-sections option is not supported by older versions of ld
+if test -n "$GC_SECTIONS"; then
+ GC_SECTIONS=`check_cc "$GC_SECTIONS" ""`
+fi
# Sanitize lib list (dups, extra spaces etc)
LDLIBS=`echo "$LDLIBS" | xargs -n1 | sort | uniq | xargs`
# "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3"
l_list=`echo "$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 \
+try $CC $CFLAGS $LDFLAGS \
-o $EXE \
-Wl,--sort-common \
- -Wl,--sort-section -Wl,alignment \
- -Wl,--gc-sections \
+ $SORT_SECTION \
+ $GC_SECTIONS \
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
$l_list \
|| {
- echo "Failed: $* $l_list"
+ echo "Failed: $l_list"
cat $EXE.out
exit 1
}
while test "$LDLIBS"; do
$debug && echo "Trying libraries: $LDLIBS"
all_needed=true
+ last_needed=false
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 $l_list -Wl,--end-group"
+ test x"$l_list" != x"" && l_list="-Wl,--start-group $l_list -Wl,--end-group"
$debug && echo "Trying -l options: '$l_list'"
- try $CC $LDFLAGS \
+ try $CC $CFLAGS $LDFLAGS \
-o $EXE \
-Wl,--sort-common \
- -Wl,--sort-section -Wl,alignment \
- -Wl,--gc-sections \
+ $SORT_SECTION \
+ $GC_SECTIONS \
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
$l_list
if test $? = 0; then
- echo "Library $one is not needed"
+ echo " Library $one is not needed, excluding it"
LDLIBS="$without_one"
all_needed=false
+ last_needed=false
else
- echo "Library $one is needed"
+ echo " Library $one is needed, can't exclude it (yet)"
+ last_needed=true
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
+ # Optimization: was the last tried lib needed?
+ if $last_needed; then
+ # Was it the only one lib left? Don't test again then.
+ { echo "$LDLIBS" | grep -q ' '; } || break
+ fi
done
# Make the binary with final, minimal list of libs
-echo "Final link with: $LDLIBS"
+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 \
+ try $CC $CFLAGS $LDFLAGS \
-o $EXE \
-Wl,--sort-common \
- -Wl,--sort-section -Wl,alignment \
- -Wl,--gc-sections \
+ $SORT_SECTION \
+ $GC_SECTIONS \
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
$l_list \
-Wl,--warn-common \
- -Wl,-Map -Wl,$EXE.map \
+ -Wl,-Map,$EXE.map \
-Wl,--verbose \
|| {
cat $EXE.out
# *(.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 \
+ try $CC $CFLAGS $LDFLAGS \
-o $EXE \
-Wl,--sort-common \
- -Wl,--sort-section -Wl,alignment \
- -Wl,--gc-sections \
- -Wl,-T -Wl,busybox_ldscript \
+ $SORT_SECTION \
+ $GC_SECTIONS \
+ -Wl,-T,busybox_ldscript \
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
$l_list \
-Wl,--warn-common \
- -Wl,-Map -Wl,$EXE.map \
+ -Wl,-Map,$EXE.map \
-Wl,--verbose \
|| {
cat $EXE.out
}
fi
-. .config
+. ./.config
sharedlib_dir="0_lib"
ln -s "libbusybox.so.$BB_VER" "$sharedlib_dir"/libbusybox.so 2>/dev/null
EXE="$sharedlib_dir/libbusybox.so.${BB_VER}_unstripped"
- try $CC $LDFLAGS \
+ try $CC $CFLAGS $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 \
- -Wl,--sort-section -Wl,alignment \
- -Wl,--start-group -Wl,--whole-archive $A_FILES -Wl,--no-whole-archive -Wl,--end-group \
+ $SORT_SECTION \
+ -Wl,--start-group $A_FILES -Wl,--end-group \
$l_list \
-Wl,--warn-common \
- -Wl,-Map -Wl,$EXE.map \
+ -Wl,-Map,$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"
+ $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 \
+ try $CC $CFLAGS $LDFLAGS \
-o $EXE \
-Wl,--sort-common \
- -Wl,--sort-section -Wl,alignment \
- -Wl,--gc-sections \
+ $SORT_SECTION \
+ $GC_SECTIONS \
-Wl,--start-group $O_FILES -Wl,--end-group \
-L"$sharedlib_dir" -lbusybox \
-Wl,--warn-common \
- -Wl,-Map -Wl,$EXE.map \
+ -Wl,-Map,$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"
+ $STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/busybox"
echo "busybox linked against libbusybox: $sharedlib_dir/busybox"
fi
while read name main junk; do
echo "\
-void bbox_prepare_main(char **argv);
+void lbb_prepare(const char *applet, char **argv);
int $main(int argc, char **argv);
-const char *applet_name = \"$name\";
-
int main(int argc, char **argv)
{
- bbox_prepare_main(argv);
+ lbb_prepare(\"$name\", argv);
return $main(argc, argv);
}
" >"$sharedlib_dir/applet.c"
EXE="$sharedlib_dir/$name"
- try $CC $LDFLAGS "$sharedlib_dir/applet.c" \
+ try $CC $CFLAGS $LDFLAGS "$sharedlib_dir/applet.c" \
-o $EXE \
-Wl,--sort-common \
- -Wl,--sort-section -Wl,alignment \
- -Wl,--gc-sections \
+ $SORT_SECTION \
+ $GC_SECTIONS \
-L"$sharedlib_dir" -lbusybox \
-Wl,--warn-common \
|| {
exit 1
}
rm -- "$sharedlib_dir/applet.c" $EXE.out
- strip -s --remove-section=.note --remove-section=.comment $EXE
+ $STRIP -s --remove-section=.note --remove-section=.comment $EXE
done <applet_lst.tmp
fi
projects / oweals / busybox.git / blobdiff