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
$debug && echo "Trying: $*"
"$@" >>$EXE.out 2>&1
exitcode=$?
- cat $EXE.out
return $exitcode
}
+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"
+ 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="$7"
+
+# The -Wl,--sort-section option is not supported by older versions of ld
+SORT_SECTION=`check_cc "-Wl,--sort-section -Wl,alignment" ""`
+
+# Static linking against glibc produces buggy executables
+# (glibc does not cope well with ld --gc-sections).
+# See sources.redhat.com/bugzilla/show_bug.cgi?id=3400
+# Note that glibc is unsuitable for static linking anyway.
+# We are removing -Wl,--gc-sections from link command line.
+GC_SECTION=`(
+. ./.config
+if test x"$CONFIG_STATIC" = x"y"; then
+ check_libc_is_glibc "" "-Wl,--gc-sections"
+else
+ echo "-Wl,--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 \
- -o $EXE -Wl,-Map -Wl,$EXE.map \
- -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \
+try $CC $CFLAGS $LDFLAGS \
+ -o $EXE \
+ -Wl,--sort-common \
+ $SORT_SECTION \
+ $GC_SECTION \
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
$l_list \
- >/dev/null \
|| {
echo "Failed: $* $l_list"
cat $EXE.out
l_list=`echo "$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 $EXE -Wl,-Map -Wl,$EXE.map \
- -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \
+ try $CC $CFLAGS $LDFLAGS \
+ -o $EXE \
+ -Wl,--sort-common \
+ $SORT_SECTION \
+ $GC_SECTION \
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
- $l_list \
- >/dev/null
+ $l_list
if test $? = 0; then
- echo "Library $one is not needed"
+ echo " Library $one is not needed"
LDLIBS="$without_one"
all_needed=false
else
- echo "Library $one is needed"
+ echo " Library $one is needed"
fi
done
# All libs were needed, can't remove any
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 $l_list -Wl,--end-group -Wl,--verbose"
+test "x$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 $EXE -Wl,-Map -Wl,$EXE.map \
- -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \
+ try $CC $CFLAGS $LDFLAGS \
+ -o $EXE \
+ -Wl,--sort-common \
+ $SORT_SECTION \
+ $GC_SECTION \
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
- $l_list -Wl,--verbose \
- >/dev/null
+ $l_list \
+ -Wl,--warn-common \
+ -Wl,-Map -Wl,$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):
# *(.data SORT_BY_ALIGNMENT(.data.*) .gnu.linkonce.d.*)
# *(.bss SORT_BY_ALIGNMENT(.bss.*) .gnu.linkonce.b.*)
# This will eliminate most of the padding (~3kb).
- try $CC $LDFLAGS \
- -o $EXE -Wl,-Map -Wl,$EXE.map \
- -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \
- -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
- $l_list -Wl,--verbose \
+ # Hmm, "ld --sort-section alignment" should do it too.
+ try $CC $CFLAGS $LDFLAGS \
+ -o $EXE \
+ -Wl,--sort-common \
+ $SORT_SECTION \
+ $GC_SECTION \
-Wl,-T -Wl,busybox_ldscript \
- >/dev/null
+ -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
-mkdir 0lib 2>/dev/null
-test -d 0lib || exit 1
-ln -s libbusybox.so.1.8.0 0lib/libbusybox.so 2>/dev/null
-
-EXE="0lib/libbusybox.so.1.8.0"
-try $CC $LDFLAGS \
- -o $EXE -Wl,-Map -Wl,$EXE.map \
- -shared -fPIC -Wl,--enable-new-dtags \
- -Wl,--start-group -Wl,--whole-archive $A_FILES -Wl,--no-whole-archive -Wl,--end-group \
- $l_list -Wl,--verbose \
- -Wl,-soname="libbusybox.so.1.8.0" \
- -Wl,-z,combreloc \
- >/dev/null \
-|| {
- echo "Linking $EXE failed"
- exit 1
-}
-strip -s --remove-section=.note --remove-section=.comment $EXE
-
-EXE="0lib/busybox"
-try $CC $LDFLAGS \
- -o $EXE -Wl,-Map -Wl,$EXE.map \
- -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \
- -Wl,--start-group $O_FILES -Wl,--end-group \
- $l_list -Wl,--verbose \
- -L"0lib" -lbusybox \
- >/dev/null \
-|| {
- echo "Linking $EXE failed"
- exit 1
+. ./.config
+
+sharedlib_dir="0_lib"
+
+if test "$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 $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 \
+ $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 $CFLAGS $LDFLAGS \
+ -o $EXE \
+ -Wl,--sort-common \
+ $SORT_SECTION \
+ $GC_SECTION \
+ -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);
}
-strip -s --remove-section=.note --remove-section=.comment $EXE
+" >"$sharedlib_dir/applet.c"
+
+ EXE="$sharedlib_dir/$name"
+ try $CC $CFLAGS $LDFLAGS "$sharedlib_dir/applet.c" \
+ -o $EXE \
+ -Wl,--sort-common \
+ $SORT_SECTION \
+ $GC_SECTION \
+ -L"$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
projects / oweals / busybox.git / blobdiff