scripts/config: add option to undef a symbol

It is currently possible to enable, disable or modularise
a symbol. Also, an undefined symbol is reported as such.

Add a new command to undefine a symbol, by removing the
corresponding line from the .config file.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>

1 files changed, 10 insertions, 0 deletions

diff --git a/scripts/config b/scripts/config
index 9723c7de07cc..f65a44a7886a 100755
--- a/scripts/config
+++ b/scripts/config
@@ -17,6 +17,7 @@ commands:
                              Set option to "string"
         --set-val option value
                              Set option to value
+        --undefine|-u option Undefine option
         --state|-s option    Print state of option (n,y,m,undef)
 
         --enable-after|-E beforeopt option
@@ -73,6 +74,12 @@ set_var() {
         fi
 }
 
+undef_var() {
+        local name=$1
+
+        sed -ri "/^($name=|# $name is not set)/d" "$FN"
+}
+
 if [ "$1" = "--file" ]; then
         FN="$2"
         if [ "$FN" = "" ] ; then
@@ -134,6 +141,9 @@ while [ "$1" != "" ] ; do
                 set_var "${CONFIG_}$ARG" "${CONFIG_}$ARG=$1"
                 shift
                 ;;
+        --undefine|-u)
+                undef_var "${CONFIG_}$ARG"
+                ;;
 
         --state|-s)
                 if grep -q "# ${CONFIG_}$ARG is not set" $FN ; then