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
|
---|