@@ -250,6 +250,14 @@ set_all(){

     done

 }

+set_weak(){

+    value=$1

+    shift

+    for var; do

+        eval : \${$var:=$value}

+    done

+}

+

 pushvar(){

     for var in $*; do

         eval level=\${${var}_level:=0}

@@ -277,6 +285,14 @@ disable(){

     set_all no $*

 }

+enable_weak(){

+    set_weak yes $*

+}

+

+disable_weak(){

+    set_weak no $*

+}

+

 do_enable_deep(){

     for var; do

         enabled $var && continue

@@ -292,6 +308,11 @@ enable_deep(){

     enable $*

 }

+enable_deep_weak(){

+    do_enable_deep $*

+    enable_weak $*

+}

+

 enabled(){

     test "${1#!}" = "$1" && op== || op=!=

     eval test "x\$${1#!}" $op "xyes"