introduce and use close_on_exec_on(fd). -50 bytes.

[oweals/busybox.git] / scripts / trylink

diff --git a/scripts/trylink b/scripts/trylink
index ddd7fb1795515057afe9a02f5f3bc154029e2a23..0b8f6c0625523c58ba993575822980a139bd8b5b 100755 (executable)
--- a/scripts/trylink
+++ b/scripts/trylink
@@ -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)
@@ -14,25 +14,27 @@ try() {
 BBOX_LIB_LIST=`echo "$BBOX_LIB_LIST" | xargs -n1 | sort | uniq | xargs`
 
 # First link with all libs. If it fails, bail out
-l_list=`echo "$BBOX_LIB_LIST" | sed -e 's/ / -l/g' -e 's/^/-l/'`
 echo "Trying libraries: $BBOX_LIB_LIST"
-try "-Wl,--start-group $l_list -Wl,--end-group" "$@" \
+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 $l_list -Wl,--end-group"
+try "$l_list" "$@" \
 || {
     echo "Failed: $* -Wl,--start-group $l_list -Wl,--end-group"
     cat busybox_ld.err
     exit 1
 }
 
-# Now try to remove each lib and build without.
+# 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"
     all_needed=true
     for one in $BBOX_LIB_LIST; do
        without_one=`echo " $BBOX_LIB_LIST " | sed "s/ $one / /g" | xargs`
-       l_list=`echo "$without_one" | sed -e 's/ / -l/g' -e 's/^/-l/'`
-       $debug && echo "Trying -l options: $l_list"
-       if try "-Wl,--start-group $l_list -Wl,--end-group" "$@"; then
+       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'"
+       if try "$l_list" "$@"; then
                echo "Library $one is not needed"
                BBOX_LIB_LIST="$without_one"
                all_needed=false
@@ -42,13 +44,25 @@ while test "$BBOX_LIB_LIST"; do
     done
     # All libs were needed, can't remove any
     $all_needed && break
-    # If there is no space, the list has just one lib.
+    # If there is no space char, the list has just one lib.
     # I'm not sure that in this case lib really is 100% needed.
     # Let's try linking without it anyway... thus commented out.
-    #echo "$BBOX_LIB_LIST" | grep -q ' ' || break
+    #{ echo "$BBOX_LIB_LIST" | grep -q ' '; } || break
 done
 
-# Ok, make the binary
+# 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 $l_list -Wl,--end-group" "$@"
+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 $l_list -Wl,--end-group -Wl,--verbose"
+# --verbose gives us gobs of info to stdout (e.g. linker script used)
+if ! test -f busybox_ldscript; then
+    try "$l_list -Wl,--verbose" "$@" >busybox_ld.out
+else
+    echo "Custom linker script 'busybox_ldscript' found, using it"
+    # Add SORT_BY_ALIGNMENT to linker script (found in busybox_ld.out):
+    #  .rodata         : { *(.rodata SORT_BY_ALIGNMENT(.rodata.*) .gnu.linkonce.r.*) }
+    #  *(.data SORT_BY_ALIGNMENT(.data.*) .gnu.linkonce.d.*)
+    #  *(.bss SORT_BY_ALIGNMENT(.bss.*) .gnu.linkonce.b.*)
+    # This will eliminate most of the data padding (~3kb).
+    try "$l_list -Wl,--verbose -Wl,-T -Wl,busybox_ldscript" "$@" >busybox_ld.out
+fi