blob: 164f5274cf9189d8cbd0f715e6b78c25052c3c56 [file] [log] [blame]
Denis Vlasenko7d219aa2006-10-05 10:17:08 +00001#!/bin/sh
2
3debug=false
4
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +00005# 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
Denis Vlasenko42e41822007-10-09 18:01:13 +000017# -On Not used, maybe useful?
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +000018#
19# List of files to link:
20# $l_list == --start-group -llib1 -llib2 --end-group
21# --start-group $O_FILES $A_FILES --end-group
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +000022#
23# Shared library link:
24# -shared self-explanatory
25# -fPIC position-independent code
Denis Vlasenko724d1962007-10-10 14:41:07 +000026# --enable-new-dtags ?
27# -z,combreloc ?
28# -soname="libbusybox.so.$BB_VER"
Denis Vlasenko9b49a5e2007-10-11 10:05:36 +000029# --undefined=lbb_main Seed name to start pulling from
Denis Vlasenko724d1962007-10-10 14:41:07 +000030# (otherwise we'll need --whole-archive)
31# -static Not used, but may be useful! manpage:
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +000032# "... 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
Denis Vlasenko018e0852007-02-25 00:40:37 +000039try() {
Denis Vlasenko32404742007-10-07 17:05:22 +000040 printf "%s\n" "Output of:" >$EXE.out
41 printf "%s\n" "$*" >>$EXE.out
42 printf "%s\n" "==========" >>$EXE.out
43 $debug && echo "Trying: $*"
Bernhard Reutner-Fischer2dfd2952008-10-23 13:49:21 +000044 $@ >>$EXE.out 2>&1
45 return $?
Denis Vlasenko7d219aa2006-10-05 10:17:08 +000046}
47
Denis Vlasenko130f5592007-11-13 17:36:12 +000048check_cc() {
Denis Vlasenko0a4624a2008-02-13 07:47:37 +000049 local tempname="/tmp/temp.$$.$RANDOM"
50 # Can use "-o /dev/null", but older gcc tend to *unlink it* on failure! :(
51 # "-xc": C language. "/dev/null" is an empty source file.
52 if $CC $1 -shared -xc /dev/null -o "$tempname".o >/dev/null 2>&1; then
Denis Vlasenko3f9c8482007-12-28 17:04:42 +000053 echo "$1";
Denis Vlasenko130f5592007-11-13 17:36:12 +000054 else
Denis Vlasenko3f9c8482007-12-28 17:04:42 +000055 echo "$2";
Denis Vlasenko130f5592007-11-13 17:36:12 +000056 fi
Denis Vlasenko0a4624a2008-02-13 07:47:37 +000057 rm "$tempname".o 2>/dev/null
Denis Vlasenko130f5592007-11-13 17:36:12 +000058}
59
Denis Vlasenko3f9c8482007-12-28 17:04:42 +000060check_libc_is_glibc() {
Denis Vlasenko0a4624a2008-02-13 07:47:37 +000061 local tempname="/tmp/temp.$$.$RANDOM"
Denis Vlasenko3f9c8482007-12-28 17:04:42 +000062 echo "\
63 #include <stdlib.h>
64 /* Apparently uclibc defines __GLIBC__ (compat trick?). Oh well. */
65 #if defined(__GLIBC__) && !defined(__UCLIBC__)
66 syntax error here
67 #endif
Denis Vlasenkoa2dcb502008-04-30 00:15:56 +000068 " >"$tempname".c
Denis Vlasenko0a4624a2008-02-13 07:47:37 +000069 if $CC "$tempname".c -c -o "$tempname".o >/dev/null 2>&1; then
Denis Vlasenko3f9c8482007-12-28 17:04:42 +000070 echo "$2";
71 else
72 echo "$1";
73 fi
Denis Vlasenko0a4624a2008-02-13 07:47:37 +000074 rm "$tempname".c "$tempname".o 2>/dev/null
Denis Vlasenko3f9c8482007-12-28 17:04:42 +000075}
76
Denis Vlasenko32404742007-10-07 17:05:22 +000077EXE="$1"
78CC="$2"
Denis Vlasenkof1d93ec2008-02-14 12:24:14 +000079CFLAGS="$3"
80LDFLAGS="$4"
81O_FILES="$5"
82A_FILES="$6"
83LDLIBS="$7"
Denis Vlasenko32404742007-10-07 17:05:22 +000084
Denis Vlasenkoa2dcb502008-04-30 00:15:56 +000085# The --sort-section option is not supported by older versions of ld
86SORT_SECTION=`check_cc "-Wl,--sort-section,alignment" ""`
Denis Vlasenko130f5592007-11-13 17:36:12 +000087
Bernhard Reutner-Fischera88585a2010-05-21 12:11:34 +020088# gold may not support --sort-common (yet)
89SORT_COMMON=`check_cc "-Wl,--sort-common" ""`
90
Denis Vlasenko3f9c8482007-12-28 17:04:42 +000091# Static linking against glibc produces buggy executables
92# (glibc does not cope well with ld --gc-sections).
93# See sources.redhat.com/bugzilla/show_bug.cgi?id=3400
94# Note that glibc is unsuitable for static linking anyway.
95# We are removing -Wl,--gc-sections from link command line.
Denis Vlasenkoa2dcb502008-04-30 00:15:56 +000096GC_SECTIONS=`(
Denis Vlasenko3f9c8482007-12-28 17:04:42 +000097. ./.config
98if test x"$CONFIG_STATIC" = x"y"; then
99 check_libc_is_glibc "" "-Wl,--gc-sections"
100else
101 echo "-Wl,--gc-sections"
102fi
103)`
104
Denys Vlasenkoeb1cda22009-06-27 00:24:35 +0200105# The --gc-sections option is not supported by older versions of ld
106if test -n "$GC_SECTIONS"; then
107 GC_SECTIONS=`check_cc "$GC_SECTIONS" ""`
108fi
109
Denis Vlasenko150d2fa2007-07-17 20:39:27 +0000110# Sanitize lib list (dups, extra spaces etc)
Denis Vlasenko76a6b232007-10-07 17:05:42 +0000111LDLIBS=`echo "$LDLIBS" | xargs -n1 | sort | uniq | xargs`
Denis Vlasenko150d2fa2007-07-17 20:39:27 +0000112
113# First link with all libs. If it fails, bail out
Denis Vlasenko76a6b232007-10-07 17:05:42 +0000114echo "Trying libraries: $LDLIBS"
Denis Vlasenko32404742007-10-07 17:05:22 +0000115# "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3"
Denis Vlasenko76a6b232007-10-07 17:05:42 +0000116l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
Bernhard Reutner-Fischerd2bb2d32007-09-02 15:28:30 +0000117test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group"
Denis Vlasenkof1d93ec2008-02-14 12:24:14 +0000118try $CC $CFLAGS $LDFLAGS \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000119 -o $EXE \
Bernhard Reutner-Fischera88585a2010-05-21 12:11:34 +0200120 $SORT_COMMON \
Denis Vlasenko130f5592007-11-13 17:36:12 +0000121 $SORT_SECTION \
Denis Vlasenkoa2dcb502008-04-30 00:15:56 +0000122 $GC_SECTIONS \
Denis Vlasenko32404742007-10-07 17:05:22 +0000123 -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
124 $l_list \
Denis Vlasenko150d2fa2007-07-17 20:39:27 +0000125|| {
Denis Vlasenko4824cca2008-03-21 18:29:01 +0000126 echo "Failed: $l_list"
Denis Vlasenko32404742007-10-07 17:05:22 +0000127 cat $EXE.out
Denis Vlasenko150d2fa2007-07-17 20:39:27 +0000128 exit 1
129}
Denis Vlasenko6ca409e2007-08-12 20:58:27 +0000130
Denis Vlasenko8274e062007-08-06 03:41:08 +0000131# Now try to remove each lib and build without it.
Denis Vlasenko150d2fa2007-07-17 20:39:27 +0000132# Stop when no lib can be removed.
Denis Vlasenko76a6b232007-10-07 17:05:42 +0000133while test "$LDLIBS"; do
134 $debug && echo "Trying libraries: $LDLIBS"
Denis Vlasenko150d2fa2007-07-17 20:39:27 +0000135 all_needed=true
Denis Vlasenkodd316dd2008-06-14 15:50:55 +0000136 last_needed=false
Denis Vlasenko76a6b232007-10-07 17:05:42 +0000137 for one in $LDLIBS; do
138 without_one=`echo " $LDLIBS " | sed "s/ $one / /g" | xargs`
Denis Vlasenko32404742007-10-07 17:05:22 +0000139 # "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3"
Bernhard Reutner-Fischerd2bb2d32007-09-02 15:28:30 +0000140 l_list=`echo "$without_one" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
Denis Vlasenkodd316dd2008-06-14 15:50:55 +0000141 test x"$l_list" != x"" && l_list="-Wl,--start-group $l_list -Wl,--end-group"
Bernhard Reutner-Fischer8d91c132007-09-02 14:51:54 +0000142 $debug && echo "Trying -l options: '$l_list'"
Denis Vlasenkof1d93ec2008-02-14 12:24:14 +0000143 try $CC $CFLAGS $LDFLAGS \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000144 -o $EXE \
Bernhard Reutner-Fischera88585a2010-05-21 12:11:34 +0200145 $SORT_COMMON \
Denis Vlasenko130f5592007-11-13 17:36:12 +0000146 $SORT_SECTION \
Denis Vlasenkoa2dcb502008-04-30 00:15:56 +0000147 $GC_SECTIONS \
Denis Vlasenko32404742007-10-07 17:05:22 +0000148 -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
Denis Vlasenkod19b87e2007-10-09 13:08:02 +0000149 $l_list
Denis Vlasenko32404742007-10-07 17:05:22 +0000150 if test $? = 0; then
Denis Vlasenkob522d692008-08-26 20:09:08 +0000151 echo " Library $one is not needed, excluding it"
Denis Vlasenko76a6b232007-10-07 17:05:42 +0000152 LDLIBS="$without_one"
Denis Vlasenko32404742007-10-07 17:05:22 +0000153 all_needed=false
Denis Vlasenkodd316dd2008-06-14 15:50:55 +0000154 last_needed=false
Denis Vlasenko150d2fa2007-07-17 20:39:27 +0000155 else
Denis Vlasenkob522d692008-08-26 20:09:08 +0000156 echo " Library $one is needed, can't exclude it (yet)"
Denis Vlasenkodd316dd2008-06-14 15:50:55 +0000157 last_needed=true
Denis Vlasenko150d2fa2007-07-17 20:39:27 +0000158 fi
159 done
160 # All libs were needed, can't remove any
161 $all_needed && break
Denis Vlasenkodd316dd2008-06-14 15:50:55 +0000162 # Optimization: was the last tried lib needed?
163 if $last_needed; then
164 # Was it the only one lib left? Don't test again then.
165 { echo "$LDLIBS" | grep -q ' '; } || break
166 fi
Denis Vlasenko150d2fa2007-07-17 20:39:27 +0000167done
168
Denis Vlasenko9862e6b2007-09-03 11:28:14 +0000169# Make the binary with final, minimal list of libs
Mike Frysinger49d15892007-11-18 06:42:56 +0000170echo "Final link with: ${LDLIBS:-<none>}"
Denis Vlasenko76a6b232007-10-07 17:05:42 +0000171l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
Denis Vlasenko8d755ad2007-10-09 10:15:41 +0000172test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group"
Denis Vlasenko9862e6b2007-09-03 11:28:14 +0000173# --verbose gives us gobs of info to stdout (e.g. linker script used)
174if ! test -f busybox_ldscript; then
Denis Vlasenkof1d93ec2008-02-14 12:24:14 +0000175 try $CC $CFLAGS $LDFLAGS \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000176 -o $EXE \
Bernhard Reutner-Fischera88585a2010-05-21 12:11:34 +0200177 $SORT_COMMON \
Denis Vlasenko130f5592007-11-13 17:36:12 +0000178 $SORT_SECTION \
Denis Vlasenkoa2dcb502008-04-30 00:15:56 +0000179 $GC_SECTIONS \
Denis Vlasenko32404742007-10-07 17:05:22 +0000180 -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000181 $l_list \
182 -Wl,--warn-common \
Bernhard Reutner-Fischer50dbed92008-05-09 12:43:04 +0000183 -Wl,-Map,$EXE.map \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000184 -Wl,--verbose \
Denis Vlasenkod19b87e2007-10-09 13:08:02 +0000185 || {
186 cat $EXE.out
187 exit 1
188 }
Denis Vlasenko9862e6b2007-09-03 11:28:14 +0000189else
190 echo "Custom linker script 'busybox_ldscript' found, using it"
Denis Vlasenko76a6b232007-10-07 17:05:42 +0000191 # Add SORT_BY_ALIGNMENT to linker script (found in $EXE.out):
Denis Vlasenko9862e6b2007-09-03 11:28:14 +0000192 # .rodata : { *(.rodata SORT_BY_ALIGNMENT(.rodata.*) .gnu.linkonce.r.*) }
193 # *(.data SORT_BY_ALIGNMENT(.data.*) .gnu.linkonce.d.*)
194 # *(.bss SORT_BY_ALIGNMENT(.bss.*) .gnu.linkonce.b.*)
Denis Vlasenko76a6b232007-10-07 17:05:42 +0000195 # This will eliminate most of the padding (~3kb).
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000196 # Hmm, "ld --sort-section alignment" should do it too.
Denis Vlasenkof1d93ec2008-02-14 12:24:14 +0000197 try $CC $CFLAGS $LDFLAGS \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000198 -o $EXE \
Bernhard Reutner-Fischera88585a2010-05-21 12:11:34 +0200199 $SORT_COMMON \
Denis Vlasenko130f5592007-11-13 17:36:12 +0000200 $SORT_SECTION \
Denis Vlasenkoa2dcb502008-04-30 00:15:56 +0000201 $GC_SECTIONS \
Bernhard Reutner-Fischer50dbed92008-05-09 12:43:04 +0000202 -Wl,-T,busybox_ldscript \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000203 -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
204 $l_list \
205 -Wl,--warn-common \
Bernhard Reutner-Fischer50dbed92008-05-09 12:43:04 +0000206 -Wl,-Map,$EXE.map \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000207 -Wl,--verbose \
Denis Vlasenkod19b87e2007-10-09 13:08:02 +0000208 || {
209 cat $EXE.out
210 exit 1
211 }
Denis Vlasenko9862e6b2007-09-03 11:28:14 +0000212fi
Denis Vlasenko32404742007-10-07 17:05:22 +0000213
Denis Vlasenko42e41822007-10-09 18:01:13 +0000214. ./.config
Denis Vlasenko32404742007-10-07 17:05:22 +0000215
Denis Vlasenkodef88982007-10-07 17:06:01 +0000216sharedlib_dir="0_lib"
217
218if test "$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"
Denis Vlasenkof1d93ec2008-02-14 12:24:14 +0000227 try $CC $CFLAGS $LDFLAGS \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000228 -o $EXE \
229 -shared -fPIC \
230 -Wl,--enable-new-dtags \
231 -Wl,-z,combreloc \
232 -Wl,-soname="libbusybox.so.$BB_VER" \
Denis Vlasenko9b49a5e2007-10-11 10:05:36 +0000233 -Wl,--undefined=lbb_main \
Bernhard Reutner-Fischera88585a2010-05-21 12:11:34 +0200234 $SORT_COMMON \
Denis Vlasenko130f5592007-11-13 17:36:12 +0000235 $SORT_SECTION \
Denis Vlasenko724d1962007-10-10 14:41:07 +0000236 -Wl,--start-group $A_FILES -Wl,--end-group \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000237 $l_list \
238 -Wl,--warn-common \
Bernhard Reutner-Fischer50dbed92008-05-09 12:43:04 +0000239 -Wl,-Map,$EXE.map \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000240 -Wl,--verbose \
Denis Vlasenkodef88982007-10-07 17:06:01 +0000241 || {
242 echo "Linking $EXE failed"
243 cat $EXE.out
244 exit 1
245 }
Denis Vlasenko141750e2007-10-10 10:05:35 +0000246 $STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/libbusybox.so.$BB_VER"
Denis Vlasenkod62fd842007-10-07 20:46:34 +0000247 chmod a+x "$sharedlib_dir/libbusybox.so.$BB_VER"
Denis Vlasenkodef88982007-10-07 17:06:01 +0000248 echo "libbusybox: $sharedlib_dir/libbusybox.so.$BB_VER"
249fi
Denis Vlasenko32404742007-10-07 17:05:22 +0000250
Denis Vlasenkodef88982007-10-07 17:06:01 +0000251if test "$CONFIG_FEATURE_SHARED_BUSYBOX" = y; then
252 EXE="$sharedlib_dir/busybox_unstripped"
Denis Vlasenkof1d93ec2008-02-14 12:24:14 +0000253 try $CC $CFLAGS $LDFLAGS \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000254 -o $EXE \
Bernhard Reutner-Fischera88585a2010-05-21 12:11:34 +0200255 $SORT_COMMON \
Denis Vlasenko130f5592007-11-13 17:36:12 +0000256 $SORT_SECTION \
Denis Vlasenkoa2dcb502008-04-30 00:15:56 +0000257 $GC_SECTIONS \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000258 -Wl,--start-group $O_FILES -Wl,--end-group \
259 -L"$sharedlib_dir" -lbusybox \
260 -Wl,--warn-common \
Bernhard Reutner-Fischer50dbed92008-05-09 12:43:04 +0000261 -Wl,-Map,$EXE.map \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000262 -Wl,--verbose \
Denis Vlasenkodef88982007-10-07 17:06:01 +0000263 || {
264 echo "Linking $EXE failed"
265 cat $EXE.out
266 exit 1
267 }
Denis Vlasenko141750e2007-10-10 10:05:35 +0000268 $STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/busybox"
Denis Vlasenkodef88982007-10-07 17:06:01 +0000269 echo "busybox linked against libbusybox: $sharedlib_dir/busybox"
270fi
Denis Vlasenkof545be02007-10-07 17:06:26 +0000271
272if test "$CONFIG_FEATURE_INDIVIDUAL" = y; then
Denis Vlasenkoe9fd69c2007-10-08 22:16:14 +0000273 echo "Linking individual applets against libbusybox (see $sharedlib_dir/*)"
Denis Vlasenkof545be02007-10-07 17:06:26 +0000274 gcc -DNAME_MAIN_CNAME -E -include include/autoconf.h include/applets.h \
275 | grep -v "^#" \
276 | grep -v "^$" \
Denis Vlasenkoe9fd69c2007-10-08 22:16:14 +0000277 > applet_lst.tmp
Denis Vlasenko642a52d2007-10-07 21:00:41 +0000278 while read name main junk; do
Denis Vlasenkof545be02007-10-07 17:06:26 +0000279
280 echo "\
Denis Vlasenko15cb4a42007-10-11 10:06:26 +0000281void lbb_prepare(const char *applet, char **argv);
Denis Vlasenkod62fd842007-10-07 20:46:34 +0000282int $main(int argc, char **argv);
Denis Vlasenkof545be02007-10-07 17:06:26 +0000283
Denis Vlasenkof545be02007-10-07 17:06:26 +0000284int main(int argc, char **argv)
285{
Denis Vlasenko15cb4a42007-10-11 10:06:26 +0000286 lbb_prepare(\"$name\", argv);
Denis Vlasenkod62fd842007-10-07 20:46:34 +0000287 return $main(argc, argv);
Denis Vlasenkof545be02007-10-07 17:06:26 +0000288}
289" >"$sharedlib_dir/applet.c"
290
291 EXE="$sharedlib_dir/$name"
Denis Vlasenkof1d93ec2008-02-14 12:24:14 +0000292 try $CC $CFLAGS $LDFLAGS "$sharedlib_dir/applet.c" \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000293 -o $EXE \
Bernhard Reutner-Fischera88585a2010-05-21 12:11:34 +0200294 $SORT_COMMON \
Denis Vlasenko130f5592007-11-13 17:36:12 +0000295 $SORT_SECTION \
Denis Vlasenkoa2dcb502008-04-30 00:15:56 +0000296 $GC_SECTIONS \
Denis Vlasenko01f3b2c2007-10-09 13:49:26 +0000297 -L"$sharedlib_dir" -lbusybox \
298 -Wl,--warn-common \
Denis Vlasenkof545be02007-10-07 17:06:26 +0000299 || {
300 echo "Linking $EXE failed"
Denis Vlasenko8d755ad2007-10-09 10:15:41 +0000301 cat $EXE.out
Denis Vlasenkof545be02007-10-07 17:06:26 +0000302 exit 1
303 }
304 rm -- "$sharedlib_dir/applet.c" $EXE.out
Denis Vlasenko141750e2007-10-10 10:05:35 +0000305 $STRIP -s --remove-section=.note --remove-section=.comment $EXE
Denis Vlasenkof545be02007-10-07 17:06:26 +0000306
Denis Vlasenkoe9fd69c2007-10-08 22:16:14 +0000307 done <applet_lst.tmp
Denis Vlasenkof545be02007-10-07 17:06:26 +0000308fi
Denis Vlasenkod62fd842007-10-07 20:46:34 +0000309
310# libbusybox.so is needed only for -lbusybox at link time,
311# it is not needed at runtime. Deleting to reduce confusion.
Denis Vlasenko8d755ad2007-10-09 10:15:41 +0000312rm "$sharedlib_dir"/libbusybox.so 2>/dev/null
313exit 0 # or else we may confuse make