emo/busybox
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

trylink: reformat link flags for readability

Browse Source 
trylink: add --sort-section alignment:
    text           data     bss     dec     hex filename
-   6557            428    3260   10245    2805 busybox
+   6555            428    3260   10243    2803 busybox
- 909621           1076   12108  922805   e14b5 libbusybox.so.1.8.0.svn
+ 908868           1050   12016  921934   e114e libbusybox.so.1.8.0.svn
This commit is contained in:
Denis Vlasenko 2007-10-09 13:49:26 +00:00
parent d19b87ece4
commit 01f3b2c91a
1 changed files with 89 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

114
scripts/trylink
View File

@ -2,6 +2,42 @@
debug=false 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() { try() {
printf "%s\n" "Output of:" >$EXE.out printf "%s\n" "Output of:" >$EXE.out
printf "%s\n" "$*" >>$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$//'` l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group" test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group"
try $CC $LDFLAGS \ try $CC $LDFLAGS \
-o $EXE -Wl,-Map -Wl,$EXE.map \ -o $EXE \
-Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \ -Wl,--sort-common \
-Wl,--sort-section -Wl,alignment \
-Wl,--gc-sections \
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
$l_list \ $l_list \
|| { || {
@ -50,8 +88,10 @@ while test "$LDLIBS"; do
test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group" test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group"
$debug && echo "Trying -l options: '$l_list'" $debug && echo "Trying -l options: '$l_list'"
try $CC $LDFLAGS \ try $CC $LDFLAGS \
-o $EXE -Wl,-Map -Wl,$EXE.map \ -o $EXE \
-Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \ -Wl,--sort-common \
-Wl,--sort-section -Wl,alignment \
-Wl,--gc-sections \
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
$l_list $l_list
if test $? = 0; then 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) # --verbose gives us gobs of info to stdout (e.g. linker script used)
if ! test -f busybox_ldscript; then if ! test -f busybox_ldscript; then
try $CC $LDFLAGS \ try $CC $LDFLAGS \
-o $EXE -Wl,-Map -Wl,$EXE.map \ -o $EXE \
-Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \ -Wl,--sort-common \
-Wl,--sort-section -Wl,alignment \
-Wl,--gc-sections \
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ -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 cat $EXE.out
exit 1 exit 1
@ -92,12 +137,18 @@ else
# *(.data SORT_BY_ALIGNMENT(.data.*) .gnu.linkonce.d.*) # *(.data SORT_BY_ALIGNMENT(.data.*) .gnu.linkonce.d.*)
# *(.bss SORT_BY_ALIGNMENT(.bss.*) .gnu.linkonce.b.*) # *(.bss SORT_BY_ALIGNMENT(.bss.*) .gnu.linkonce.b.*)
# This will eliminate most of the padding (~3kb). # This will eliminate most of the padding (~3kb).
# Hmm, "ld --sort-section alignment" should do it too.
try $CC $LDFLAGS \ try $CC $LDFLAGS \
-o $EXE -Wl,-Map -Wl,$EXE.map \ -o $EXE \
-Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \ -Wl,--sort-common \
-Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \ -Wl,--sort-section -Wl,alignment \
$l_list -Wl,--verbose \ -Wl,--gc-sections \
-Wl,-T -Wl,busybox_ldscript \ -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 cat $EXE.out
exit 1 exit 1
@ -118,12 +169,18 @@ if test "$CONFIG_BUILD_LIBBUSYBOX" = y; then
EXE="$sharedlib_dir/libbusybox.so.${BB_VER}_unstripped" EXE="$sharedlib_dir/libbusybox.so.${BB_VER}_unstripped"
try $CC $LDFLAGS \ try $CC $LDFLAGS \
-o $EXE -Wl,-Map -Wl,$EXE.map \ -o $EXE \
-shared -fPIC -Wl,--enable-new-dtags \ -shared -fPIC \
-Wl,--start-group -Wl,--whole-archive $A_FILES -Wl,--no-whole-archive -Wl,--end-group \ -Wl,--enable-new-dtags \
$l_list -Wl,--verbose \ -Wl,-z,combreloc \
-Wl,-soname="libbusybox.so.$BB_VER" \ -Wl,-soname="libbusybox.so.$BB_VER" \
-Wl,-z,combreloc \ -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" echo "Linking $EXE failed"
cat $EXE.out cat $EXE.out
@ -137,11 +194,15 @@ fi
if test "$CONFIG_FEATURE_SHARED_BUSYBOX" = y; then if test "$CONFIG_FEATURE_SHARED_BUSYBOX" = y; then
EXE="$sharedlib_dir/busybox_unstripped" EXE="$sharedlib_dir/busybox_unstripped"
try $CC $LDFLAGS \ try $CC $LDFLAGS \
-o $EXE -Wl,-Map -Wl,$EXE.map \ -o $EXE \
-Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \ -Wl,--sort-common \
-Wl,--start-group $O_FILES -Wl,--end-group \ -Wl,--sort-section -Wl,alignment \
-Wl,--verbose \ -Wl,--gc-sections \
-L"$sharedlib_dir" -lbusybox \ -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" echo "Linking $EXE failed"
cat $EXE.out cat $EXE.out
@ -174,9 +235,12 @@ int main(int argc, char **argv)
EXE="$sharedlib_dir/$name" EXE="$sharedlib_dir/$name"
try $CC $LDFLAGS "$sharedlib_dir/applet.c" \ try $CC $LDFLAGS "$sharedlib_dir/applet.c" \
-o $EXE \ -o $EXE \
-Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \ -Wl,--sort-common \
-L"$sharedlib_dir" -lbusybox \ -Wl,--sort-section -Wl,alignment \
-Wl,--gc-sections \
-L"$sharedlib_dir" -lbusybox \
-Wl,--warn-common \
|| { || {
echo "Linking $EXE failed" echo "Linking $EXE failed"
cat $EXE.out cat $EXE.out