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trylink: produce even more info about final link stage

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trylink: explain how to modify link and drastically decrease amount
  of padding (unfortunately, needs hand editing ATM).
*: add ALIGN1 / ALIGN2 to global strings and arrays of bytes and shorts

size saving: 0.5k
This commit is contained in:
Denis Vlasenko
2007-08-12 20:58:27 +00:00
parent 4185548984
commit 6ca409e0e4
119 changed files with 491 additions and 444 deletions
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41
scripts/trylink
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@ -6,7 +6,7 @@ try() {
added="$1"
shift
$debug && echo "Trying: $* $added"
"$@" $added >busybox.map 2>busybox_ld.err
"$@" $added 2>busybox_ld.err
}
# Sanitize lib list (dups, extra spaces etc)
@ -22,14 +22,17 @@ try "-Wl,--start-group $l_list -Wl,--end-group" "$@" \
cat busybox_ld.err
exit 1
}
# Hack: we are not supposed to know executable name,
# but this hack cuts down link time
mv busybox_unstripped busybox_unstripped.tmp
mv busybox.map busybox.map.tmp
#### Hack disabled: conflicts with ld --verbose flag in last link phase
##### Hack: we are not supposed to know executable name,
##### but this hack cuts down link time
####mv busybox_unstripped busybox_unstripped.tmp
####mv busybox.map busybox.map.tmp
# Now try to remove each lib and build without it.
# Stop when no lib can be removed.
ever_discarded=false
####ever_discarded=false
while test "$BBOX_LIB_LIST"; do
$debug && echo "Trying libraries: $BBOX_LIB_LIST"
all_needed=true
@ -41,7 +44,7 @@ while test "$BBOX_LIB_LIST"; do
echo "Library $one is not needed"
BBOX_LIB_LIST="$without_one"
all_needed=false
ever_discarded=true
#### ever_discarded=true
else
echo "Library $one is needed"
fi
@ -54,13 +57,23 @@ while test "$BBOX_LIB_LIST"; do
#{ echo "$BBOX_LIB_LIST" | grep -q ' '; } || break
done
mv busybox_unstripped.tmp busybox_unstripped
mv busybox.map.tmp busybox.map
$ever_discarded && {
####mv busybox_unstripped.tmp busybox_unstripped
####mv busybox.map.tmp busybox.map
####$ever_discarded && {
# 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/'`
try "-Wl,--start-group $l_list -Wl,--end-group" "$@" || exit 1
}
rm busybox_ld.err
exit 0 # Ensure "success" exit code
# --verbose gives us gobs of info to stdout (e.g. linker script used)
try "-Wl,--start-group $l_list -Wl,--end-group -Wl,--verbose" "$@" >busybox_ld.out ####|| exit 1
#
# Add SORT_BY_ALIGNMENT to linker script (found in busybox_ld.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. Use linker script
# by commenting "try" above and uncommenting this one (tested on i386):
#try "-Wl,--start-group $l_list -Wl,--end-group -Wl,--verbose -Wl,-T -Wl,busybox_ldscript" "$@" >busybox_ld.out
#
####}
####rm busybox_ld.err
####exit 0 # Ensure "success" exit code