diff options
Diffstat (limited to 'scripts')
| -rwxr-xr-x | scripts/trylink | 114 |
1 files changed, 89 insertions, 25 deletions
diff --git a/scripts/trylink b/scripts/trylink index 0829121ab..cbba9000a 100755 --- a/scripts/trylink +++ b/scripts/trylink @@ -2,6 +2,42 @@ 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 +# -O 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 +# or for shlib: +# --start-group --whole-archive $A_FILES --no-whole-archive --end-group +# otherwise we don't pull in all parts of *.a files. Now we pull in too much. +# FIXME: make it work without --whole-archive, or better, with --gc-sections. +# +# Shared library link: +# -shared self-explanatory +# -fPIC position-independent code +# -Wl,--enable-new-dtags ? +# -Wl,-z,combreloc ? +# -Wl,-soname="libbusybox.so.$BB_VER" +# -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 @@ -28,8 +64,10 @@ echo "Trying libraries: $LDLIBS" l_list=`echo "$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" try $CC $LDFLAGS \ - -o $EXE -Wl,-Map -Wl,$EXE.map \ - -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \ + -o $EXE \ + -Wl,--sort-common \ + -Wl,--sort-section -Wl,alignment \ + -Wl,--gc-sections \ -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ $l_list \ || { @@ -50,8 +88,10 @@ while test "$LDLIBS"; do 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 \ + -o $EXE \ + -Wl,--sort-common \ + -Wl,--sort-section -Wl,alignment \ + -Wl,--gc-sections \ -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ $l_list if test $? = 0; then @@ -77,10 +117,15 @@ test "x$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 \ + -o $EXE \ + -Wl,--sort-common \ + -Wl,--sort-section -Wl,alignment \ + -Wl,--gc-sections \ -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ - $l_list -Wl,--verbose \ + $l_list \ + -Wl,--warn-common \ + -Wl,-Map -Wl,$EXE.map \ + -Wl,--verbose \ || { cat $EXE.out exit 1 @@ -92,12 +137,18 @@ 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). + # Hmm, "ld --sort-section alignment" should do it too. 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 \ + -o $EXE \ + -Wl,--sort-common \ + -Wl,--sort-section -Wl,alignment \ + -Wl,--gc-sections \ -Wl,-T -Wl,busybox_ldscript \ + -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ + $l_list \ + -Wl,--warn-common \ + -Wl,-Map -Wl,$EXE.map \ + -Wl,--verbose \ || { cat $EXE.out exit 1 @@ -118,12 +169,18 @@ if test "$CONFIG_BUILD_LIBBUSYBOX" = y; then EXE="$sharedlib_dir/libbusybox.so.${BB_VER}_unstripped" 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 \ - $l_list -Wl,--verbose \ - -Wl,-soname="libbusybox.so.$BB_VER" \ - -Wl,-z,combreloc \ + -o $EXE \ + -shared -fPIC \ + -Wl,--enable-new-dtags \ + -Wl,-z,combreloc \ + -Wl,-soname="libbusybox.so.$BB_VER" \ + -Wl,--sort-common \ + -Wl,--sort-section -Wl,alignment \ + -Wl,--start-group -Wl,--whole-archive $A_FILES -Wl,--no-whole-archive -Wl,--end-group \ + $l_list \ + -Wl,--warn-common \ + -Wl,-Map -Wl,$EXE.map \ + -Wl,--verbose \ || { echo "Linking $EXE failed" cat $EXE.out @@ -137,11 +194,15 @@ fi if test "$CONFIG_FEATURE_SHARED_BUSYBOX" = y; then EXE="$sharedlib_dir/busybox_unstripped" try $CC $LDFLAGS \ - -o $EXE -Wl,-Map -Wl,$EXE.map \ - -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \ - -Wl,--start-group $O_FILES -Wl,--end-group \ - -Wl,--verbose \ - -L"$sharedlib_dir" -lbusybox \ + -o $EXE \ + -Wl,--sort-common \ + -Wl,--sort-section -Wl,alignment \ + -Wl,--gc-sections \ + -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 $EXE.out @@ -174,9 +235,12 @@ int main(int argc, char **argv) EXE="$sharedlib_dir/$name" try $CC $LDFLAGS "$sharedlib_dir/applet.c" \ - -o $EXE \ - -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \ - -L"$sharedlib_dir" -lbusybox \ + -o $EXE \ + -Wl,--sort-common \ + -Wl,--sort-section -Wl,alignment \ + -Wl,--gc-sections \ + -L"$sharedlib_dir" -lbusybox \ + -Wl,--warn-common \ || { echo "Linking $EXE failed" cat $EXE.out |