X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=scripts%2Ftrylink;h=48c487bcd30f92f3029bf7f18a704da15a498264;hb=e1603156ff96672375970f460716d37a50c63fae;hp=19b0ba71553e2bb75f492c4b07c6b0687cbbadf1;hpb=3240474c23bf4f47536a854693b4cbacb54b9b04;p=oweals%2Fbusybox.git diff --git a/scripts/trylink b/scripts/trylink index 19b0ba715..48c487bcd 100755 --- a/scripts/trylink +++ b/scripts/trylink @@ -2,132 +2,311 @@ 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:" >$EXE.out printf "%s\n" "$*" >>$EXE.out printf "%s\n" "==========" >>$EXE.out $debug && echo "Trying: $*" - "$@" >>$EXE.out 2>&1 - exitcode=$? - cat $EXE.out - return $exitcode + $@ >>$EXE.out 2>&1 + return $? +} + +check_cc() { + local tempname="$(mktemp)" + # 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 $CPPFLAGS $CFLAGS $1 -shared -xc /dev/null -o "$tempname".o >/dev/null 2>&1; then + echo "$1"; + else + echo "$2"; + fi + rm -f "$tempname" "$tempname".o +} + +check_libc_is_glibc() { + local tempname="$(mktemp)" + echo "\ + #include + /* Apparently uclibc defines __GLIBC__ (compat trick?). Oh well. */ + #if defined(__GLIBC__) && !defined(__UCLIBC__) + syntax error here + #endif + " >"$tempname".c + if $CC $CPPFLAGS $CFLAGS "$tempname".c -c -o "$tempname".o >/dev/null 2>&1; then + echo "$2"; + else + echo "$1"; + fi + rm -f "$tempname" "$tempname".[co] } 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="$7" + +# The --sort-section option is not supported by older versions of ld +SORT_SECTION=`check_cc "-Wl,--sort-section,alignment" ""` + +START_GROUP="-Wl,--start-group" +END_GROUP="-Wl,--end-group" +INFO_OPTS="-Wl,--warn-common -Wl,-Map,$EXE.map -Wl,--verbose" + +# gold may not support --sort-common (yet) +SORT_COMMON=`check_cc "-Wl,--sort-common" ""` + +# 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_SECTIONS=`( +. ./.config +if test x"$CONFIG_STATIC" = x"y"; then + check_libc_is_glibc "" "-Wl,--gc-sections" +else + echo "-Wl,--gc-sections" +fi +)` + +# The --gc-sections option is not supported by older versions of ld +if test -n "$GC_SECTIONS"; then + GC_SECTIONS=`check_cc "$GC_SECTIONS" ""` +fi # Sanitize lib list (dups, extra spaces etc) -BBOX_LIB_LIST=`echo "$BBOX_LIB_LIST" | xargs -n1 | sort | uniq | xargs` +LDLIBS=`echo "$LDLIBS" | xargs -n1 | sort | uniq | xargs` # First link with all libs. If it fails, bail out -echo "Trying libraries: $BBOX_LIB_LIST" +echo "Trying libraries: $LDLIBS" # "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3" -l_list=`echo "$BBOX_LIB_LIST" | 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 \ - -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ +l_list=`echo " $LDLIBS " | sed -e 's: \([^- ][^ ]*\): -l\1:g'` +test "x$l_list" != "x" && l_list="$START_GROUP $l_list $END_GROUP" +try $CC $CFLAGS $LDFLAGS \ + -o $EXE \ + $SORT_COMMON \ + $SORT_SECTION \ + $GC_SECTIONS \ + $START_GROUP $O_FILES $A_FILES $END_GROUP \ $l_list \ - >/dev/null \ || { - echo "Failed: $* $l_list" + echo "Failed: $l_list" cat $EXE.out exit 1 } # Now try to remove each lib and build without it. # Stop when no lib can be removed. -while test "$BBOX_LIB_LIST"; do - $debug && echo "Trying libraries: $BBOX_LIB_LIST" +while test "$LDLIBS"; do + $debug && echo "Trying libraries: $LDLIBS" all_needed=true - for one in $BBOX_LIB_LIST; do - without_one=`echo " $BBOX_LIB_LIST " | sed "s/ $one / /g" | xargs` + last_needed=false + for one in $LDLIBS; do + without_one=`echo " $LDLIBS " | sed "s/ $one / /g" | xargs` # "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3" - l_list=`echo "$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" + l_list=`echo " $without_one " | sed -e 's: \([^- ][^ ]*\): -l\1:g'` + test x"$l_list" != x"" && l_list="$START_GROUP $l_list $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 \ - -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ - $l_list \ - >/dev/null + try $CC $CFLAGS $LDFLAGS \ + -o $EXE \ + $SORT_COMMON \ + $SORT_SECTION \ + $GC_SECTIONS \ + $START_GROUP $O_FILES $A_FILES $END_GROUP \ + $l_list if test $? = 0; then - echo "Library $one is not needed" - BBOX_LIB_LIST="$without_one" + echo " Library $one is not needed, excluding it" + LDLIBS="$without_one" all_needed=false + last_needed=false else - echo "Library $one is needed" + echo " Library $one is needed, can't exclude it (yet)" + last_needed=true fi done # All libs were needed, can't remove any $all_needed && break - # If there is no space char, the list has just one lib. - # I'm not sure that in this case lib really is 100% needed. - # Let's try linking without it anyway... thus commented out. - #{ echo "$BBOX_LIB_LIST" | grep -q ' '; } || break + # Optimization: was the last tried lib needed? + if $last_needed; then + # Was it the only one lib left? Don't test again then. + { echo "$LDLIBS" | grep -q ' '; } || break + fi done # Make the binary with final, minimal list of libs -echo "Final link with: $BBOX_LIB_LIST" -l_list=`echo "$BBOX_LIB_LIST" | 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" +echo "Final link with: ${LDLIBS:-}" +l_list=`echo " $LDLIBS " | sed -e 's: \([^- ][^ ]*\): -l\1:g'` +test "x$l_list" != "x" && l_list="$START_GROUP $l_list $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 \ - -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ - $l_list -Wl,--verbose \ - >/dev/null + try $CC $CFLAGS $LDFLAGS \ + -o $EXE \ + $SORT_COMMON \ + $SORT_SECTION \ + $GC_SECTIONS \ + $START_GROUP $O_FILES $A_FILES $END_GROUP \ + $l_list \ + $INFO_OPTS \ + || { + 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}_ld.out): + # Add SORT_BY_ALIGNMENT to linker script (found in $EXE.out): # .rodata : { *(.rodata SORT_BY_ALIGNMENT(.rodata.*) .gnu.linkonce.r.*) } # *(.data SORT_BY_ALIGNMENT(.data.*) .gnu.linkonce.d.*) # *(.bss SORT_BY_ALIGNMENT(.bss.*) .gnu.linkonce.b.*) - # This will eliminate most of the data 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 \ - -Wl,-T -Wl,busybox_ldscript \ - >/dev/null + # This will eliminate most of the padding (~3kb). + # Hmm, "ld --sort-section alignment" should do it too. + try $CC $CFLAGS $LDFLAGS \ + -o $EXE \ + $SORT_COMMON \ + $SORT_SECTION \ + $GC_SECTIONS \ + -Wl,-T,busybox_ldscript \ + $START_GROUP $O_FILES $A_FILES $END_GROUP \ + $l_list \ + $INFO_OPTS \ + || { + 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 -} +. ./.config -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 $EXE failed" - exit 1 +sharedlib_dir="0_lib" + +if test "$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 \ + $SORT_COMMON \ + $SORT_SECTION \ + $START_GROUP $A_FILES $END_GROUP \ + $l_list \ + $INFO_OPTS \ + || { + 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 \ + $SORT_COMMON \ + $SORT_SECTION \ + $GC_SECTIONS \ + $START_GROUP $O_FILES $END_GROUP \ + -L"$sharedlib_dir" -lbusybox \ + $l_list \ + $INFO_OPTS \ + || { + 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 $sharedlib_dir/*)" + gcc -DNAME_MAIN -E -include include/autoconf.h include/applets.h \ + | grep -v "^#" \ + | grep -v "^$" \ + > 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 $main(argc, argv); } +" >"$sharedlib_dir/applet.c" + + EXE="$sharedlib_dir/$name" + try $CC $CFLAGS $LDFLAGS "$sharedlib_dir/applet.c" \ + -o $EXE \ + $SORT_COMMON \ + $SORT_SECTION \ + $GC_SECTIONS \ + -L"$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 $EXE + # Let user see that we do something - list the names of created binaries: + echo "$EXE" + + done /dev/null +exit 0 # or else we may confuse make