Contents of /tags/mkinitrd-6_1_3/busybox/scripts/trylink
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Mon May 4 18:51:23 2009 UTC (15 years, 4 months ago) by niro
File size: 8966 byte(s)
Mon May 4 18:51:23 2009 UTC (15 years, 4 months ago) by niro
File size: 8966 byte(s)
tagged 'mkinitrd-6_1_3'
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="$7" |
84 | |
85 | # The --sort-section option is not supported by older versions of ld |
86 | SORT_SECTION=`check_cc "-Wl,--sort-section,alignment" ""` |
87 | |
88 | # Static linking against glibc produces buggy executables |
89 | # (glibc does not cope well with ld --gc-sections). |
90 | # See sources.redhat.com/bugzilla/show_bug.cgi?id=3400 |
91 | # Note that glibc is unsuitable for static linking anyway. |
92 | # We are removing -Wl,--gc-sections from link command line. |
93 | GC_SECTIONS=`( |
94 | . ./.config |
95 | if test x"$CONFIG_STATIC" = x"y"; then |
96 | check_libc_is_glibc "" "-Wl,--gc-sections" |
97 | else |
98 | echo "-Wl,--gc-sections" |
99 | fi |
100 | )` |
101 | |
102 | # Sanitize lib list (dups, extra spaces etc) |
103 | LDLIBS=`echo "$LDLIBS" | xargs -n1 | sort | uniq | xargs` |
104 | |
105 | # First link with all libs. If it fails, bail out |
106 | echo "Trying libraries: $LDLIBS" |
107 | # "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3" |
108 | l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'` |
109 | test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group" |
110 | try $CC $CFLAGS $LDFLAGS \ |
111 | -o $EXE \ |
112 | -Wl,--sort-common \ |
113 | $SORT_SECTION \ |
114 | $GC_SECTIONS \ |
115 | -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ |
116 | $l_list \ |
117 | || { |
118 | echo "Failed: $l_list" |
119 | cat $EXE.out |
120 | exit 1 |
121 | } |
122 | |
123 | # Now try to remove each lib and build without it. |
124 | # Stop when no lib can be removed. |
125 | while test "$LDLIBS"; do |
126 | $debug && echo "Trying libraries: $LDLIBS" |
127 | all_needed=true |
128 | last_needed=false |
129 | for one in $LDLIBS; do |
130 | without_one=`echo " $LDLIBS " | sed "s/ $one / /g" | xargs` |
131 | # "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3" |
132 | l_list=`echo "$without_one" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'` |
133 | test x"$l_list" != x"" && l_list="-Wl,--start-group $l_list -Wl,--end-group" |
134 | $debug && echo "Trying -l options: '$l_list'" |
135 | try $CC $CFLAGS $LDFLAGS \ |
136 | -o $EXE \ |
137 | -Wl,--sort-common \ |
138 | $SORT_SECTION \ |
139 | $GC_SECTIONS \ |
140 | -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ |
141 | $l_list |
142 | if test $? = 0; then |
143 | echo " Library $one is not needed, excluding it" |
144 | LDLIBS="$without_one" |
145 | all_needed=false |
146 | last_needed=false |
147 | else |
148 | echo " Library $one is needed, can't exclude it (yet)" |
149 | last_needed=true |
150 | fi |
151 | done |
152 | # All libs were needed, can't remove any |
153 | $all_needed && break |
154 | # Optimization: was the last tried lib needed? |
155 | if $last_needed; then |
156 | # Was it the only one lib left? Don't test again then. |
157 | { echo "$LDLIBS" | grep -q ' '; } || break |
158 | fi |
159 | done |
160 | |
161 | # Make the binary with final, minimal list of libs |
162 | echo "Final link with: ${LDLIBS:-<none>}" |
163 | l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'` |
164 | test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group" |
165 | # --verbose gives us gobs of info to stdout (e.g. linker script used) |
166 | if ! test -f busybox_ldscript; then |
167 | try $CC $CFLAGS $LDFLAGS \ |
168 | -o $EXE \ |
169 | -Wl,--sort-common \ |
170 | $SORT_SECTION \ |
171 | $GC_SECTIONS \ |
172 | -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ |
173 | $l_list \ |
174 | -Wl,--warn-common \ |
175 | -Wl,-Map,$EXE.map \ |
176 | -Wl,--verbose \ |
177 | || { |
178 | cat $EXE.out |
179 | exit 1 |
180 | } |
181 | else |
182 | echo "Custom linker script 'busybox_ldscript' found, using it" |
183 | # Add SORT_BY_ALIGNMENT to linker script (found in $EXE.out): |
184 | # .rodata : { *(.rodata SORT_BY_ALIGNMENT(.rodata.*) .gnu.linkonce.r.*) } |
185 | # *(.data SORT_BY_ALIGNMENT(.data.*) .gnu.linkonce.d.*) |
186 | # *(.bss SORT_BY_ALIGNMENT(.bss.*) .gnu.linkonce.b.*) |
187 | # This will eliminate most of the padding (~3kb). |
188 | # Hmm, "ld --sort-section alignment" should do it too. |
189 | try $CC $CFLAGS $LDFLAGS \ |
190 | -o $EXE \ |
191 | -Wl,--sort-common \ |
192 | $SORT_SECTION \ |
193 | $GC_SECTIONS \ |
194 | -Wl,-T,busybox_ldscript \ |
195 | -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ |
196 | $l_list \ |
197 | -Wl,--warn-common \ |
198 | -Wl,-Map,$EXE.map \ |
199 | -Wl,--verbose \ |
200 | || { |
201 | cat $EXE.out |
202 | exit 1 |
203 | } |
204 | fi |
205 | |
206 | . ./.config |
207 | |
208 | sharedlib_dir="0_lib" |
209 | |
210 | if test "$CONFIG_BUILD_LIBBUSYBOX" = y; then |
211 | mkdir "$sharedlib_dir" 2>/dev/null |
212 | test -d "$sharedlib_dir" || { |
213 | echo "Cannot make directory $sharedlib_dir" |
214 | exit 1 |
215 | } |
216 | ln -s "libbusybox.so.$BB_VER" "$sharedlib_dir"/libbusybox.so 2>/dev/null |
217 | |
218 | EXE="$sharedlib_dir/libbusybox.so.${BB_VER}_unstripped" |
219 | try $CC $CFLAGS $LDFLAGS \ |
220 | -o $EXE \ |
221 | -shared -fPIC \ |
222 | -Wl,--enable-new-dtags \ |
223 | -Wl,-z,combreloc \ |
224 | -Wl,-soname="libbusybox.so.$BB_VER" \ |
225 | -Wl,--undefined=lbb_main \ |
226 | -Wl,--sort-common \ |
227 | $SORT_SECTION \ |
228 | -Wl,--start-group $A_FILES -Wl,--end-group \ |
229 | $l_list \ |
230 | -Wl,--warn-common \ |
231 | -Wl,-Map,$EXE.map \ |
232 | -Wl,--verbose \ |
233 | || { |
234 | echo "Linking $EXE failed" |
235 | cat $EXE.out |
236 | exit 1 |
237 | } |
238 | $STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/libbusybox.so.$BB_VER" |
239 | chmod a+x "$sharedlib_dir/libbusybox.so.$BB_VER" |
240 | echo "libbusybox: $sharedlib_dir/libbusybox.so.$BB_VER" |
241 | fi |
242 | |
243 | if test "$CONFIG_FEATURE_SHARED_BUSYBOX" = y; then |
244 | EXE="$sharedlib_dir/busybox_unstripped" |
245 | try $CC $CFLAGS $LDFLAGS \ |
246 | -o $EXE \ |
247 | -Wl,--sort-common \ |
248 | $SORT_SECTION \ |
249 | $GC_SECTIONS \ |
250 | -Wl,--start-group $O_FILES -Wl,--end-group \ |
251 | -L"$sharedlib_dir" -lbusybox \ |
252 | -Wl,--warn-common \ |
253 | -Wl,-Map,$EXE.map \ |
254 | -Wl,--verbose \ |
255 | || { |
256 | echo "Linking $EXE failed" |
257 | cat $EXE.out |
258 | exit 1 |
259 | } |
260 | $STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/busybox" |
261 | echo "busybox linked against libbusybox: $sharedlib_dir/busybox" |
262 | fi |
263 | |
264 | if test "$CONFIG_FEATURE_INDIVIDUAL" = y; then |
265 | echo "Linking individual applets against libbusybox (see $sharedlib_dir/*)" |
266 | gcc -DNAME_MAIN_CNAME -E -include include/autoconf.h include/applets.h \ |
267 | | grep -v "^#" \ |
268 | | grep -v "^$" \ |
269 | > applet_lst.tmp |
270 | while read name main junk; do |
271 | |
272 | echo "\ |
273 | void lbb_prepare(const char *applet, char **argv); |
274 | int $main(int argc, char **argv); |
275 | |
276 | int main(int argc, char **argv) |
277 | { |
278 | lbb_prepare(\"$name\", argv); |
279 | return $main(argc, argv); |
280 | } |
281 | " >"$sharedlib_dir/applet.c" |
282 | |
283 | EXE="$sharedlib_dir/$name" |
284 | try $CC $CFLAGS $LDFLAGS "$sharedlib_dir/applet.c" \ |
285 | -o $EXE \ |
286 | -Wl,--sort-common \ |
287 | $SORT_SECTION \ |
288 | $GC_SECTIONS \ |
289 | -L"$sharedlib_dir" -lbusybox \ |
290 | -Wl,--warn-common \ |
291 | || { |
292 | echo "Linking $EXE failed" |
293 | cat $EXE.out |
294 | exit 1 |
295 | } |
296 | rm -- "$sharedlib_dir/applet.c" $EXE.out |
297 | $STRIP -s --remove-section=.note --remove-section=.comment $EXE |
298 | |
299 | done <applet_lst.tmp |
300 | fi |
301 | |
302 | # libbusybox.so is needed only for -lbusybox at link time, |
303 | # it is not needed at runtime. Deleting to reduce confusion. |
304 | rm "$sharedlib_dir"/libbusybox.so 2>/dev/null |
305 | exit 0 # or else we may confuse make |
Properties
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svn:executable | * |