X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;ds=sidebyside;f=scripts%2Ftrylink;h=ebfe6cee3471bdca8a7138d4add6b41035cb37e9;hb=403a5a298eaa5d1d827ad6ebbf38a7b765ba5b44;hp=c621b7c018f81131d7905ef4857dd1443620d024;hpb=76a6b236a9e2654e8c296c61cf71e0cf8bf4a64c;p=oweals%2Fbusybox.git diff --git a/scripts/trylink b/scripts/trylink index c621b7c01..ebfe6cee3 100755 --- a/scripts/trylink +++ b/scripts/trylink @@ -2,6 +2,40 @@ debug=false +# Linker flags used: +# +# Informational: +# --warn-common +# -Map $EXE.map +# --verbose +# +# Optimizations: +# --sort-common reduces padding +# --sort-section alignment reduces padding +# --gc-sections throws out unused sections, +# does not work for shared libs +# -On Not used, maybe useful? +# +# List of files to link: +# $l_list == --start-group -llib1 -llib2 --end-group +# --start-group $O_FILES $A_FILES --end-group +# +# Shared library link: +# -shared self-explanatory +# -fPIC position-independent code +# --enable-new-dtags ? +# -z,combreloc ? +# -soname="libbusybox.so.$BB_VER" +# --undefined=lbb_main Seed name to start pulling from +# (otherwise we'll need --whole-archive) +# -static Not used, but may be useful! manpage: +# "... This option can be used with -shared. +# Doing so means that a shared library +# is being created but that all of the library's +# external references must be resolved by pulling +# in entries from static libraries." + + try() { printf "%s\n" "Output of:" >$EXE.out printf "%s\n" "$*" >>$EXE.out @@ -9,16 +43,62 @@ try() { $debug && echo "Trying: $*" "$@" >>$EXE.out 2>&1 exitcode=$? - cat $EXE.out return $exitcode } +check_cc() { + local tempname="/tmp/temp.$$.$RANDOM" + # Can use "-o /dev/null", but older gcc tend to *unlink it* on failure! :( + # "-xc": C language. "/dev/null" is an empty source file. + if $CC $1 -shared -xc /dev/null -o "$tempname".o >/dev/null 2>&1; then + echo "$1"; + else + echo "$2"; + fi + rm "$tempname".o 2>/dev/null +} + +check_libc_is_glibc() { + local tempname="/tmp/temp.$$.$RANDOM" + echo "\ + #include + /* Apparently uclibc defines __GLIBC__ (compat trick?). Oh well. */ + #if defined(__GLIBC__) && !defined(__UCLIBC__) + syntax error here + #endif + " >"$tempname" + if $CC "$tempname".c -c -o "$tempname".o >/dev/null 2>&1; then + echo "$2"; + else + echo "$1"; + fi + rm "$tempname".c "$tempname".o 2>/dev/null +} + EXE="$1" CC="$2" -LDFLAGS="$3" -O_FILES="$4" -A_FILES="$5" -LDLIBS="$6" +CFLAGS="$3" +LDFLAGS="$4" +O_FILES="$5" +A_FILES="$6" +LDLIBS="$7" + +# The -Wl,--sort-section option is not supported by older versions of ld +SORT_SECTION=`check_cc "-Wl,--sort-section -Wl,alignment" ""` + +# Static linking against glibc produces buggy executables +# (glibc does not cope well with ld --gc-sections). +# See sources.redhat.com/bugzilla/show_bug.cgi?id=3400 +# Note that glibc is unsuitable for static linking anyway. +# We are removing -Wl,--gc-sections from link command line. +GC_SECTION=`( +. ./.config +if test x"$CONFIG_STATIC" = x"y"; then + check_libc_is_glibc "" "-Wl,--gc-sections" +else + echo "-Wl,--gc-sections" +fi +)` # Sanitize lib list (dups, extra spaces etc) LDLIBS=`echo "$LDLIBS" | xargs -n1 | sort | uniq | xargs` @@ -28,12 +108,13 @@ echo "Trying libraries: $LDLIBS" # "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3" l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'` test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group" -try $CC $LDFLAGS \ - -o $EXE -Wl,-Map -Wl,$EXE.map \ - -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \ +try $CC $CFLAGS $LDFLAGS \ + -o $EXE \ + -Wl,--sort-common \ + $SORT_SECTION \ + $GC_SECTION \ -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ $l_list \ - >/dev/null \ || { echo "Failed: $* $l_list" cat $EXE.out @@ -51,18 +132,19 @@ while test "$LDLIBS"; do l_list=`echo "$without_one" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'` test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group" $debug && echo "Trying -l options: '$l_list'" - try $CC $LDFLAGS \ - -o $EXE -Wl,-Map -Wl,$EXE.map \ - -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \ + try $CC $CFLAGS $LDFLAGS \ + -o $EXE \ + -Wl,--sort-common \ + $SORT_SECTION \ + $GC_SECTION \ -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ - $l_list \ - >/dev/null + $l_list if test $? = 0; then - echo "Library $one is not needed" + echo " Library $one is not needed" LDLIBS="$without_one" all_needed=false else - echo "Library $one is needed" + echo " Library $one is needed" fi done # All libs were needed, can't remove any @@ -74,17 +156,25 @@ while test "$LDLIBS"; do done # Make the binary with final, minimal list of libs -echo "Final link with: $LDLIBS" +echo "Final link with: ${LDLIBS:-}" l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'` -test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group -Wl,--verbose" +test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group" # --verbose gives us gobs of info to stdout (e.g. linker script used) if ! test -f busybox_ldscript; then - try $CC $LDFLAGS \ - -o $EXE -Wl,-Map -Wl,$EXE.map \ - -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \ + try $CC $CFLAGS $LDFLAGS \ + -o $EXE \ + -Wl,--sort-common \ + $SORT_SECTION \ + $GC_SECTION \ -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ - $l_list -Wl,--verbose \ - >/dev/null + $l_list \ + -Wl,--warn-common \ + -Wl,-Map -Wl,$EXE.map \ + -Wl,--verbose \ + || { + cat $EXE.out + exit 1 + } else echo "Custom linker script 'busybox_ldscript' found, using it" # Add SORT_BY_ALIGNMENT to linker script (found in $EXE.out): @@ -92,44 +182,121 @@ else # *(.data SORT_BY_ALIGNMENT(.data.*) .gnu.linkonce.d.*) # *(.bss SORT_BY_ALIGNMENT(.bss.*) .gnu.linkonce.b.*) # This will eliminate most of the padding (~3kb). - try $CC $LDFLAGS \ - -o $EXE -Wl,-Map -Wl,$EXE.map \ - -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \ - -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ - $l_list -Wl,--verbose \ + # Hmm, "ld --sort-section alignment" should do it too. + try $CC $CFLAGS $LDFLAGS \ + -o $EXE \ + -Wl,--sort-common \ + $SORT_SECTION \ + $GC_SECTION \ -Wl,-T -Wl,busybox_ldscript \ - >/dev/null + -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ + $l_list \ + -Wl,--warn-common \ + -Wl,-Map -Wl,$EXE.map \ + -Wl,--verbose \ + || { + cat $EXE.out + exit 1 + } fi -mkdir 0lib 2>/dev/null -test -d 0lib || exit 1 -ln -s libbusybox.so.1.8.0 0lib/libbusybox.so 2>/dev/null - -EXE="0lib/libbusybox.so.1.8.0" -try $CC $LDFLAGS \ - -o $EXE -Wl,-Map -Wl,$EXE.map \ - -shared -fPIC -Wl,--enable-new-dtags \ - -Wl,--start-group -Wl,--whole-archive $A_FILES -Wl,--no-whole-archive -Wl,--end-group \ - $l_list -Wl,--verbose \ - -Wl,-soname="libbusybox.so.1.8.0" \ - -Wl,-z,combreloc \ - >/dev/null \ -|| { - echo "Linking $EXE failed" - exit 1 -} -strip -s --remove-section=.note --remove-section=.comment $EXE - -EXE="0lib/busybox" -try $CC $LDFLAGS \ - -o $EXE -Wl,-Map -Wl,$EXE.map \ - -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \ - -Wl,--start-group $O_FILES -Wl,--end-group \ - $l_list -Wl,--verbose \ - -L"0lib" -lbusybox \ - >/dev/null \ -|| { - echo "Linking $EXE failed" - exit 1 +. ./.config + +sharedlib_dir="0_lib" + +if test "$CONFIG_BUILD_LIBBUSYBOX" = y; then + mkdir "$sharedlib_dir" 2>/dev/null + test -d "$sharedlib_dir" || { + echo "Cannot make directory $sharedlib_dir" + exit 1 + } + ln -s "libbusybox.so.$BB_VER" "$sharedlib_dir"/libbusybox.so 2>/dev/null + + EXE="$sharedlib_dir/libbusybox.so.${BB_VER}_unstripped" + try $CC $CFLAGS $LDFLAGS \ + -o $EXE \ + -shared -fPIC \ + -Wl,--enable-new-dtags \ + -Wl,-z,combreloc \ + -Wl,-soname="libbusybox.so.$BB_VER" \ + -Wl,--undefined=lbb_main \ + -Wl,--sort-common \ + $SORT_SECTION \ + -Wl,--start-group $A_FILES -Wl,--end-group \ + $l_list \ + -Wl,--warn-common \ + -Wl,-Map -Wl,$EXE.map \ + -Wl,--verbose \ + || { + echo "Linking $EXE failed" + cat $EXE.out + exit 1 + } + $STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/libbusybox.so.$BB_VER" + chmod a+x "$sharedlib_dir/libbusybox.so.$BB_VER" + echo "libbusybox: $sharedlib_dir/libbusybox.so.$BB_VER" +fi + +if test "$CONFIG_FEATURE_SHARED_BUSYBOX" = y; then + EXE="$sharedlib_dir/busybox_unstripped" + try $CC $CFLAGS $LDFLAGS \ + -o $EXE \ + -Wl,--sort-common \ + $SORT_SECTION \ + $GC_SECTION \ + -Wl,--start-group $O_FILES -Wl,--end-group \ + -L"$sharedlib_dir" -lbusybox \ + -Wl,--warn-common \ + -Wl,-Map -Wl,$EXE.map \ + -Wl,--verbose \ + || { + echo "Linking $EXE failed" + cat $EXE.out + exit 1 + } + $STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/busybox" + echo "busybox linked against libbusybox: $sharedlib_dir/busybox" +fi + +if test "$CONFIG_FEATURE_INDIVIDUAL" = y; then + echo "Linking individual applets against libbusybox (see $sharedlib_dir/*)" + gcc -DNAME_MAIN_CNAME -E -include include/autoconf.h include/applets.h \ + | grep -v "^#" \ + | grep -v "^$" \ + > applet_lst.tmp + while read name main junk; do + + echo "\ +void lbb_prepare(const char *applet, char **argv); +int $main(int argc, char **argv); + +int main(int argc, char **argv) +{ + lbb_prepare(\"$name\", argv); + return $main(argc, argv); } -strip -s --remove-section=.note --remove-section=.comment $EXE +" >"$sharedlib_dir/applet.c" + + EXE="$sharedlib_dir/$name" + try $CC $CFLAGS $LDFLAGS "$sharedlib_dir/applet.c" \ + -o $EXE \ + -Wl,--sort-common \ + $SORT_SECTION \ + $GC_SECTION \ + -L"$sharedlib_dir" -lbusybox \ + -Wl,--warn-common \ + || { + echo "Linking $EXE failed" + cat $EXE.out + exit 1 + } + rm -- "$sharedlib_dir/applet.c" $EXE.out + $STRIP -s --remove-section=.note --remove-section=.comment $EXE + + done /dev/null +exit 0 # or else we may confuse make