| 1 | #!/bin/sh
|
|---|
| 2 |
|
|---|
| 3 | debug=false
|
|---|
| 4 |
|
|---|
| 5 | # Linker flags used:
|
|---|
| 6 | #
|
|---|
| 7 | # Informational:
|
|---|
| 8 | # --warn-common
|
|---|
| 9 | # -Map $EXE.map
|
|---|
| 10 | # --verbose
|
|---|
| 11 | #
|
|---|
| 12 | # Optimizations:
|
|---|
| 13 | # --sort-common reduces padding
|
|---|
| 14 | # --sort-section alignment reduces padding
|
|---|
| 15 | # --gc-sections throws out unused sections,
|
|---|
| 16 | # does not work for shared libs
|
|---|
| 17 | # -On Not used, maybe useful?
|
|---|
| 18 | #
|
|---|
| 19 | # List of files to link:
|
|---|
| 20 | # $l_list == --start-group -llib1 -llib2 --end-group
|
|---|
| 21 | # --start-group $O_FILES $A_FILES --end-group
|
|---|
| 22 | #
|
|---|
| 23 | # Shared library link:
|
|---|
| 24 | # -shared self-explanatory
|
|---|
| 25 | # -fPIC position-independent code
|
|---|
| 26 | # --enable-new-dtags ?
|
|---|
| 27 | # -z,combreloc ?
|
|---|
| 28 | # -soname="libbusybox.so.$BB_VER"
|
|---|
| 29 | # --undefined=lbb_main Seed name to start pulling from
|
|---|
| 30 | # (otherwise we'll need --whole-archive)
|
|---|
| 31 | # -static Not used, but may be useful! manpage:
|
|---|
| 32 | # "... This option can be used with -shared.
|
|---|
| 33 | # Doing so means that a shared library
|
|---|
| 34 | # is being created but that all of the library's
|
|---|
| 35 | # external references must be resolved by pulling
|
|---|
| 36 | # in entries from static libraries."
|
|---|
| 37 |
|
|---|
| 38 |
|
|---|
| 39 | try() {
|
|---|
| 40 | printf "%s\n" "Output of:" >$EXE.out
|
|---|
| 41 | printf "%s\n" "$*" >>$EXE.out
|
|---|
| 42 | printf "%s\n" "==========" >>$EXE.out
|
|---|
| 43 | $debug && echo "Trying: $*"
|
|---|
| 44 | $@ >>$EXE.out 2>&1
|
|---|
| 45 | return $?
|
|---|
| 46 | }
|
|---|
| 47 |
|
|---|
| 48 | check_cc() {
|
|---|
| 49 | local tempname="/tmp/temp.$$.$RANDOM"
|
|---|
| 50 | # Can use "-o /dev/null", but older gcc tend to *unlink it* on failure! :(
|
|---|
| 51 | # "-xc": C language. "/dev/null" is an empty source file.
|
|---|
| 52 | if $CC $1 -shared -xc /dev/null -o "$tempname".o >/dev/null 2>&1; then
|
|---|
| 53 | echo "$1";
|
|---|
| 54 | else
|
|---|
| 55 | echo "$2";
|
|---|
| 56 | fi
|
|---|
| 57 | rm "$tempname".o 2>/dev/null
|
|---|
| 58 | }
|
|---|
| 59 |
|
|---|
| 60 | check_libc_is_glibc() {
|
|---|
| 61 | local tempname="/tmp/temp.$$.$RANDOM"
|
|---|
| 62 | echo "\
|
|---|
| 63 | #include <stdlib.h>
|
|---|
| 64 | /* Apparently uclibc defines __GLIBC__ (compat trick?). Oh well. */
|
|---|
| 65 | #if defined(__GLIBC__) && !defined(__UCLIBC__)
|
|---|
| 66 | syntax error here
|
|---|
| 67 | #endif
|
|---|
| 68 | " >"$tempname".c
|
|---|
| 69 | if $CC "$tempname".c -c -o "$tempname".o >/dev/null 2>&1; then
|
|---|
| 70 | echo "$2";
|
|---|
| 71 | else
|
|---|
| 72 | echo "$1";
|
|---|
| 73 | fi
|
|---|
| 74 | rm "$tempname".c "$tempname".o 2>/dev/null
|
|---|
| 75 | }
|
|---|
| 76 |
|
|---|
| 77 | EXE="$1"
|
|---|
| 78 | CC="$2"
|
|---|
| 79 | CFLAGS="$3"
|
|---|
| 80 | LDFLAGS="$4"
|
|---|
| 81 | O_FILES="$5"
|
|---|
| 82 | A_FILES="$6"
|
|---|
| 83 | LDLIBS="$7"
|
|---|
| 84 |
|
|---|
| 85 | # The --sort-section option is not supported by older versions of ld
|
|---|
| 86 | SORT_SECTION=`check_cc "-Wl,--sort-section,alignment" ""`
|
|---|
| 87 |
|
|---|
| 88 | START_GROUP="-Wl,--start-group"
|
|---|
| 89 | END_GROUP="-Wl,--end-group"
|
|---|
| 90 | INFO_OPTS="-Wl,--warn-common -Wl,-Map,$EXE.map -Wl,--verbose"
|
|---|
| 91 |
|
|---|
| 92 | # gold may not support --sort-common (yet)
|
|---|
| 93 | SORT_COMMON=`check_cc "-Wl,--sort-common" ""`
|
|---|
| 94 |
|
|---|
| 95 | # Static linking against glibc produces buggy executables
|
|---|
| 96 | # (glibc does not cope well with ld --gc-sections).
|
|---|
| 97 | # See sources.redhat.com/bugzilla/show_bug.cgi?id=3400
|
|---|
| 98 | # Note that glibc is unsuitable for static linking anyway.
|
|---|
| 99 | # We are removing -Wl,--gc-sections from link command line.
|
|---|
| 100 | GC_SECTIONS=`(
|
|---|
| 101 | . ./.config
|
|---|
| 102 | if test x"$CONFIG_STATIC" = x"y"; then
|
|---|
| 103 | check_libc_is_glibc "" "-Wl,--gc-sections"
|
|---|
| 104 | else
|
|---|
| 105 | echo "-Wl,--gc-sections"
|
|---|
| 106 | fi
|
|---|
| 107 | )`
|
|---|
| 108 |
|
|---|
| 109 | # The --gc-sections option is not supported by older versions of ld
|
|---|
| 110 | if test -n "$GC_SECTIONS"; then
|
|---|
| 111 | GC_SECTIONS=`check_cc "$GC_SECTIONS" ""`
|
|---|
| 112 | fi
|
|---|
| 113 |
|
|---|
| 114 | # Sanitize lib list (dups, extra spaces etc)
|
|---|
| 115 | LDLIBS=`echo "$LDLIBS" | xargs -n1 | sort | uniq | xargs`
|
|---|
| 116 |
|
|---|
| 117 | # First link with all libs. If it fails, bail out
|
|---|
| 118 | echo "Trying libraries: $LDLIBS"
|
|---|
| 119 | # "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3"
|
|---|
| 120 | l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
|
|---|
| 121 | test "x$l_list" != "x" && l_list="$START_GROUP $l_list $END_GROUP"
|
|---|
| 122 | try $CC $CFLAGS $LDFLAGS \
|
|---|
| 123 | -o $EXE \
|
|---|
| 124 | $SORT_COMMON \
|
|---|
| 125 | $SORT_SECTION \
|
|---|
| 126 | $GC_SECTIONS \
|
|---|
| 127 | $START_GROUP $O_FILES $A_FILES $END_GROUP \
|
|---|
| 128 | $l_list \
|
|---|
| 129 | || {
|
|---|
| 130 | echo "Failed: $l_list"
|
|---|
| 131 | cat $EXE.out
|
|---|
| 132 | exit 1
|
|---|
| 133 | }
|
|---|
| 134 |
|
|---|
| 135 | # Now try to remove each lib and build without it.
|
|---|
| 136 | # Stop when no lib can be removed.
|
|---|
| 137 | while test "$LDLIBS"; do
|
|---|
| 138 | $debug && echo "Trying libraries: $LDLIBS"
|
|---|
| 139 | all_needed=true
|
|---|
| 140 | last_needed=false
|
|---|
| 141 | for one in $LDLIBS; do
|
|---|
| 142 | without_one=`echo " $LDLIBS " | sed "s/ $one / /g" | xargs`
|
|---|
| 143 | # "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3"
|
|---|
| 144 | l_list=`echo "$without_one" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
|
|---|
| 145 | test x"$l_list" != x"" && l_list="$START_GROUP $l_list $END_GROUP"
|
|---|
| 146 | $debug && echo "Trying -l options: '$l_list'"
|
|---|
| 147 | try $CC $CFLAGS $LDFLAGS \
|
|---|
| 148 | -o $EXE \
|
|---|
| 149 | $SORT_COMMON \
|
|---|
| 150 | $SORT_SECTION \
|
|---|
| 151 | $GC_SECTIONS \
|
|---|
| 152 | $START_GROUP $O_FILES $A_FILES $END_GROUP \
|
|---|
| 153 | $l_list
|
|---|
| 154 | if test $? = 0; then
|
|---|
| 155 | echo " Library $one is not needed, excluding it"
|
|---|
| 156 | LDLIBS="$without_one"
|
|---|
| 157 | all_needed=false
|
|---|
| 158 | last_needed=false
|
|---|
| 159 | else
|
|---|
| 160 | echo " Library $one is needed, can't exclude it (yet)"
|
|---|
| 161 | last_needed=true
|
|---|
| 162 | fi
|
|---|
| 163 | done
|
|---|
| 164 | # All libs were needed, can't remove any
|
|---|
| 165 | $all_needed && break
|
|---|
| 166 | # Optimization: was the last tried lib needed?
|
|---|
| 167 | if $last_needed; then
|
|---|
| 168 | # Was it the only one lib left? Don't test again then.
|
|---|
| 169 | { echo "$LDLIBS" | grep -q ' '; } || break
|
|---|
| 170 | fi
|
|---|
| 171 | done
|
|---|
| 172 |
|
|---|
| 173 | # Make the binary with final, minimal list of libs
|
|---|
| 174 | echo "Final link with: ${LDLIBS:-<none>}"
|
|---|
| 175 | l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
|
|---|
| 176 | test "x$l_list" != "x" && l_list="$START_GROUP $l_list $END_GROUP"
|
|---|
| 177 | # --verbose gives us gobs of info to stdout (e.g. linker script used)
|
|---|
| 178 | if ! test -f busybox_ldscript; then
|
|---|
| 179 | try $CC $CFLAGS $LDFLAGS \
|
|---|
| 180 | -o $EXE \
|
|---|
| 181 | $SORT_COMMON \
|
|---|
| 182 | $SORT_SECTION \
|
|---|
| 183 | $GC_SECTIONS \
|
|---|
| 184 | $START_GROUP $O_FILES $A_FILES $END_GROUP \
|
|---|
| 185 | $l_list \
|
|---|
| 186 | $INFO_OPTS \
|
|---|
| 187 | || {
|
|---|
| 188 | cat $EXE.out
|
|---|
| 189 | exit 1
|
|---|
| 190 | }
|
|---|
| 191 | else
|
|---|
| 192 | echo "Custom linker script 'busybox_ldscript' found, using it"
|
|---|
| 193 | # Add SORT_BY_ALIGNMENT to linker script (found in $EXE.out):
|
|---|
| 194 | # .rodata : { *(.rodata SORT_BY_ALIGNMENT(.rodata.*) .gnu.linkonce.r.*) }
|
|---|
| 195 | # *(.data SORT_BY_ALIGNMENT(.data.*) .gnu.linkonce.d.*)
|
|---|
| 196 | # *(.bss SORT_BY_ALIGNMENT(.bss.*) .gnu.linkonce.b.*)
|
|---|
| 197 | # This will eliminate most of the padding (~3kb).
|
|---|
| 198 | # Hmm, "ld --sort-section alignment" should do it too.
|
|---|
| 199 | try $CC $CFLAGS $LDFLAGS \
|
|---|
| 200 | -o $EXE \
|
|---|
| 201 | $SORT_COMMON \
|
|---|
| 202 | $SORT_SECTION \
|
|---|
| 203 | $GC_SECTIONS \
|
|---|
| 204 | -Wl,-T,busybox_ldscript \
|
|---|
| 205 | $START_GROUP $O_FILES $A_FILES $END_GROUP \
|
|---|
| 206 | $l_list \
|
|---|
| 207 | $INFO_OPTS \
|
|---|
| 208 | || {
|
|---|
| 209 | cat $EXE.out
|
|---|
| 210 | exit 1
|
|---|
| 211 | }
|
|---|
| 212 | fi
|
|---|
| 213 |
|
|---|
| 214 | . ./.config
|
|---|
| 215 |
|
|---|
| 216 | sharedlib_dir="0_lib"
|
|---|
| 217 |
|
|---|
| 218 | if test "$CONFIG_BUILD_LIBBUSYBOX" = y; then
|
|---|
| 219 | mkdir "$sharedlib_dir" 2>/dev/null
|
|---|
| 220 | test -d "$sharedlib_dir" || {
|
|---|
| 221 | echo "Cannot make directory $sharedlib_dir"
|
|---|
| 222 | exit 1
|
|---|
| 223 | }
|
|---|
| 224 | ln -s "libbusybox.so.$BB_VER" "$sharedlib_dir"/libbusybox.so 2>/dev/null
|
|---|
| 225 |
|
|---|
| 226 | EXE="$sharedlib_dir/libbusybox.so.${BB_VER}_unstripped"
|
|---|
| 227 | try $CC $CFLAGS $LDFLAGS \
|
|---|
| 228 | -o $EXE \
|
|---|
| 229 | -shared -fPIC \
|
|---|
| 230 | -Wl,--enable-new-dtags \
|
|---|
| 231 | -Wl,-z,combreloc \
|
|---|
| 232 | -Wl,-soname="libbusybox.so.$BB_VER" \
|
|---|
| 233 | -Wl,--undefined=lbb_main \
|
|---|
| 234 | $SORT_COMMON \
|
|---|
| 235 | $SORT_SECTION \
|
|---|
| 236 | $START_GROUP $A_FILES $END_GROUP \
|
|---|
| 237 | $l_list \
|
|---|
| 238 | $INFO_OPTS \
|
|---|
| 239 | || {
|
|---|
| 240 | echo "Linking $EXE failed"
|
|---|
| 241 | cat $EXE.out
|
|---|
| 242 | exit 1
|
|---|
| 243 | }
|
|---|
| 244 | $STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/libbusybox.so.$BB_VER"
|
|---|
| 245 | chmod a+x "$sharedlib_dir/libbusybox.so.$BB_VER"
|
|---|
| 246 | echo "libbusybox: $sharedlib_dir/libbusybox.so.$BB_VER"
|
|---|
| 247 | fi
|
|---|
| 248 |
|
|---|
| 249 | if test "$CONFIG_FEATURE_SHARED_BUSYBOX" = y; then
|
|---|
| 250 | EXE="$sharedlib_dir/busybox_unstripped"
|
|---|
| 251 | try $CC $CFLAGS $LDFLAGS \
|
|---|
| 252 | -o $EXE \
|
|---|
| 253 | $SORT_COMMON \
|
|---|
| 254 | $SORT_SECTION \
|
|---|
| 255 | $GC_SECTIONS \
|
|---|
| 256 | $START_GROUP $O_FILES $END_GROUP \
|
|---|
| 257 | -L"$sharedlib_dir" -lbusybox \
|
|---|
| 258 | $l_list \
|
|---|
| 259 | $INFO_OPTS \
|
|---|
| 260 | || {
|
|---|
| 261 | echo "Linking $EXE failed"
|
|---|
| 262 | cat $EXE.out
|
|---|
| 263 | exit 1
|
|---|
| 264 | }
|
|---|
| 265 | $STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/busybox"
|
|---|
| 266 | echo "busybox linked against libbusybox: $sharedlib_dir/busybox"
|
|---|
| 267 | fi
|
|---|
| 268 |
|
|---|
| 269 | if test "$CONFIG_FEATURE_INDIVIDUAL" = y; then
|
|---|
| 270 | echo "Linking individual applets against libbusybox (see $sharedlib_dir/*)"
|
|---|
| 271 | gcc -DNAME_MAIN_CNAME -E -include include/autoconf.h include/applets.h \
|
|---|
| 272 | | grep -v "^#" \
|
|---|
| 273 | | grep -v "^$" \
|
|---|
| 274 | > applet_lst.tmp
|
|---|
| 275 | while read name main junk; do
|
|---|
| 276 |
|
|---|
| 277 | echo "\
|
|---|
| 278 | void lbb_prepare(const char *applet, char **argv);
|
|---|
| 279 | int $main(int argc, char **argv);
|
|---|
| 280 |
|
|---|
| 281 | int main(int argc, char **argv)
|
|---|
| 282 | {
|
|---|
| 283 | lbb_prepare(\"$name\", argv);
|
|---|
| 284 | return $main(argc, argv);
|
|---|
| 285 | }
|
|---|
| 286 | " >"$sharedlib_dir/applet.c"
|
|---|
| 287 |
|
|---|
| 288 | EXE="$sharedlib_dir/$name"
|
|---|
| 289 | try $CC $CFLAGS $LDFLAGS "$sharedlib_dir/applet.c" \
|
|---|
| 290 | -o $EXE \
|
|---|
| 291 | $SORT_COMMON \
|
|---|
| 292 | $SORT_SECTION \
|
|---|
| 293 | $GC_SECTIONS \
|
|---|
| 294 | -L"$sharedlib_dir" -lbusybox \
|
|---|
| 295 | -Wl,--warn-common \
|
|---|
| 296 | || {
|
|---|
| 297 | echo "Linking $EXE failed"
|
|---|
| 298 | cat $EXE.out
|
|---|
| 299 | exit 1
|
|---|
| 300 | }
|
|---|
| 301 | rm -- "$sharedlib_dir/applet.c" $EXE.out
|
|---|
| 302 | $STRIP -s --remove-section=.note --remove-section=.comment $EXE
|
|---|
| 303 |
|
|---|
| 304 | done <applet_lst.tmp
|
|---|
| 305 | fi
|
|---|
| 306 |
|
|---|
| 307 | # libbusybox.so is needed only for -lbusybox at link time,
|
|---|
| 308 | # it is not needed at runtime. Deleting to reduce confusion.
|
|---|
| 309 | rm "$sharedlib_dir"/libbusybox.so 2>/dev/null
|
|---|
| 310 | exit 0 # or else we may confuse make
|
|---|
