Contents of /tags/mkinitrd-6_2_1/busybox/scripts/trylink
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Sun May 30 12:16:23 2010 UTC (14 years ago) by niro
File size: 9115 byte(s)
Sun May 30 12:16:23 2010 UTC (14 years ago) by niro
File size: 9115 byte(s)
tagged 'mkinitrd-6_2_1'
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 | # The --gc-sections option is not supported by older versions of ld |
103 | if test -n "$GC_SECTIONS"; then |
104 | GC_SECTIONS=`check_cc "$GC_SECTIONS" ""` |
105 | fi |
106 | |
107 | # Sanitize lib list (dups, extra spaces etc) |
108 | LDLIBS=`echo "$LDLIBS" | xargs -n1 | sort | uniq | xargs` |
109 | |
110 | # First link with all libs. If it fails, bail out |
111 | echo "Trying libraries: $LDLIBS" |
112 | # "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3" |
113 | l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'` |
114 | test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group" |
115 | try $CC $CFLAGS $LDFLAGS \ |
116 | -o $EXE \ |
117 | -Wl,--sort-common \ |
118 | $SORT_SECTION \ |
119 | $GC_SECTIONS \ |
120 | -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ |
121 | $l_list \ |
122 | || { |
123 | echo "Failed: $l_list" |
124 | cat $EXE.out |
125 | exit 1 |
126 | } |
127 | |
128 | # Now try to remove each lib and build without it. |
129 | # Stop when no lib can be removed. |
130 | while test "$LDLIBS"; do |
131 | $debug && echo "Trying libraries: $LDLIBS" |
132 | all_needed=true |
133 | last_needed=false |
134 | for one in $LDLIBS; do |
135 | without_one=`echo " $LDLIBS " | sed "s/ $one / /g" | xargs` |
136 | # "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3" |
137 | l_list=`echo "$without_one" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'` |
138 | test x"$l_list" != x"" && l_list="-Wl,--start-group $l_list -Wl,--end-group" |
139 | $debug && echo "Trying -l options: '$l_list'" |
140 | try $CC $CFLAGS $LDFLAGS \ |
141 | -o $EXE \ |
142 | -Wl,--sort-common \ |
143 | $SORT_SECTION \ |
144 | $GC_SECTIONS \ |
145 | -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ |
146 | $l_list |
147 | if test $? = 0; then |
148 | echo " Library $one is not needed, excluding it" |
149 | LDLIBS="$without_one" |
150 | all_needed=false |
151 | last_needed=false |
152 | else |
153 | echo " Library $one is needed, can't exclude it (yet)" |
154 | last_needed=true |
155 | fi |
156 | done |
157 | # All libs were needed, can't remove any |
158 | $all_needed && break |
159 | # Optimization: was the last tried lib needed? |
160 | if $last_needed; then |
161 | # Was it the only one lib left? Don't test again then. |
162 | { echo "$LDLIBS" | grep -q ' '; } || break |
163 | fi |
164 | done |
165 | |
166 | # Make the binary with final, minimal list of libs |
167 | echo "Final link with: ${LDLIBS:-<none>}" |
168 | l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'` |
169 | test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group" |
170 | # --verbose gives us gobs of info to stdout (e.g. linker script used) |
171 | if ! test -f busybox_ldscript; then |
172 | try $CC $CFLAGS $LDFLAGS \ |
173 | -o $EXE \ |
174 | -Wl,--sort-common \ |
175 | $SORT_SECTION \ |
176 | $GC_SECTIONS \ |
177 | -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ |
178 | $l_list \ |
179 | -Wl,--warn-common \ |
180 | -Wl,-Map,$EXE.map \ |
181 | -Wl,--verbose \ |
182 | || { |
183 | cat $EXE.out |
184 | exit 1 |
185 | } |
186 | else |
187 | echo "Custom linker script 'busybox_ldscript' found, using it" |
188 | # Add SORT_BY_ALIGNMENT to linker script (found in $EXE.out): |
189 | # .rodata : { *(.rodata SORT_BY_ALIGNMENT(.rodata.*) .gnu.linkonce.r.*) } |
190 | # *(.data SORT_BY_ALIGNMENT(.data.*) .gnu.linkonce.d.*) |
191 | # *(.bss SORT_BY_ALIGNMENT(.bss.*) .gnu.linkonce.b.*) |
192 | # This will eliminate most of the padding (~3kb). |
193 | # Hmm, "ld --sort-section alignment" should do it too. |
194 | try $CC $CFLAGS $LDFLAGS \ |
195 | -o $EXE \ |
196 | -Wl,--sort-common \ |
197 | $SORT_SECTION \ |
198 | $GC_SECTIONS \ |
199 | -Wl,-T,busybox_ldscript \ |
200 | -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ |
201 | $l_list \ |
202 | -Wl,--warn-common \ |
203 | -Wl,-Map,$EXE.map \ |
204 | -Wl,--verbose \ |
205 | || { |
206 | cat $EXE.out |
207 | exit 1 |
208 | } |
209 | fi |
210 | |
211 | . ./.config |
212 | |
213 | sharedlib_dir="0_lib" |
214 | |
215 | if test "$CONFIG_BUILD_LIBBUSYBOX" = y; then |
216 | mkdir "$sharedlib_dir" 2>/dev/null |
217 | test -d "$sharedlib_dir" || { |
218 | echo "Cannot make directory $sharedlib_dir" |
219 | exit 1 |
220 | } |
221 | ln -s "libbusybox.so.$BB_VER" "$sharedlib_dir"/libbusybox.so 2>/dev/null |
222 | |
223 | EXE="$sharedlib_dir/libbusybox.so.${BB_VER}_unstripped" |
224 | try $CC $CFLAGS $LDFLAGS \ |
225 | -o $EXE \ |
226 | -shared -fPIC \ |
227 | -Wl,--enable-new-dtags \ |
228 | -Wl,-z,combreloc \ |
229 | -Wl,-soname="libbusybox.so.$BB_VER" \ |
230 | -Wl,--undefined=lbb_main \ |
231 | -Wl,--sort-common \ |
232 | $SORT_SECTION \ |
233 | -Wl,--start-group $A_FILES -Wl,--end-group \ |
234 | $l_list \ |
235 | -Wl,--warn-common \ |
236 | -Wl,-Map,$EXE.map \ |
237 | -Wl,--verbose \ |
238 | || { |
239 | echo "Linking $EXE failed" |
240 | cat $EXE.out |
241 | exit 1 |
242 | } |
243 | $STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/libbusybox.so.$BB_VER" |
244 | chmod a+x "$sharedlib_dir/libbusybox.so.$BB_VER" |
245 | echo "libbusybox: $sharedlib_dir/libbusybox.so.$BB_VER" |
246 | fi |
247 | |
248 | if test "$CONFIG_FEATURE_SHARED_BUSYBOX" = y; then |
249 | EXE="$sharedlib_dir/busybox_unstripped" |
250 | try $CC $CFLAGS $LDFLAGS \ |
251 | -o $EXE \ |
252 | -Wl,--sort-common \ |
253 | $SORT_SECTION \ |
254 | $GC_SECTIONS \ |
255 | -Wl,--start-group $O_FILES -Wl,--end-group \ |
256 | -L"$sharedlib_dir" -lbusybox \ |
257 | -Wl,--warn-common \ |
258 | -Wl,-Map,$EXE.map \ |
259 | -Wl,--verbose \ |
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 | -Wl,--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 |
Properties
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svn:executable | * |