Introduce 'dkms unbuild' command

Add an action "unbuild" to align with the existing "build" one.

This provides for a complete symmetry - add/remove, build/unbuild and
install/uninstall.

Apart from the seeming cosmetic affect, this function is required when
the binary kernel module(s) produced with "dkms build" must be pruned.

Without this command that is not possible since using:
 - "dkms uninstall" will remove the symlinks/copies produced with
"dkms install", while
 - "dkms remove" will erase all references of the dkms module. Hence
"dkms status" will have no references about the module.

This allows for a proper fix for #20
while avoiding regressions like #77

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>

dkms

@@ -1935,6 +1935,28 @@ do_unbuild()
     [[ $(find $dkms_tree/$module/$module_version/$1/* -maxdepth 0 -type d 2>/dev/null) ]] || \
         rm -rf "$dkms_tree/$module/$module_version/$1"
 }
+
+# Remove the build module, w/o removing/unregistering it.
+# This uninstalls any installed modules along the way
+unbuild_module()
+{
+    # Check that the right arguments were passed
+    check_module_args unbuild
+
+    # Check that $module is in the dkms tree
+    module_is_added_or_die
+
+    local i
+    for ((i=0; i < ${#kernelver[@]}; i++)); do
+        # Only do stuff if module/module version is currently built
+        module_is_built_or_die "${kernelver[$i]}" "${arch[$i]}"
+
+        do_uninstall "${kernelver[$i]}" "${arch[$i]}"
+
+        do_unbuild "${kernelver[$i]}" "${arch[$i]}"
+    done
+}
+
 # Unregister a DKMS module.  This uninstalls any installed modules along the way.
 remove_module()
 {
@@ -3650,7 +3672,7 @@ die_is_fatal="yes"
 [ -x /usr/lib/module-init-tools/weak-modules ] && weak_modules='/usr/lib/module-init-tools/weak-modules'
 no_depmod=""
 
-action_re='^(remove|(auto|un)?install|match|mk(driverdisk|tarball|rpm|deb|bmdeb|dsc|kmp)|build|add|status|ldtarball)$'
+action_re='^(remove|(auto|un)?install|match|mk(driverdisk|tarball|rpm|deb|bmdeb|dsc|kmp)|(un)?build|add|status|ldtarball)$'
 
 # Parse command line arguments
 while (($# > 0)); do
@@ -3846,6 +3868,9 @@ for action_to_run in $action; do
     remove)
         check_root && remove_module
         ;;
+    unbuild)
+        check_root && unbuild_module
+        ;;
     install)
         check_root && check_all_is_banned "install" && install_modules
         ;;

dkms.8

@@ -108,6 +108,18 @@ case
 can take the same arguments that
 .B add
 can.
+.SY unbuild
+.OP module/module\-version
+.OP -k kernel/arch
+.OP \-\-all
+.YS
+.IP "" 4
+Undoes the build for a module/version or module/version/kernel/arch combination from the
+tree.  If the module is currently installed, it first uninstalls it
+and if applicable, will replace it with its original_module. Finally all binary
+kernel modules are removed. Use the
+.B \-\-all
+option in order to remove all instances for every kernel at once.
 .SY install
 .OP module/module\-version
 .OP -k kernel/arch

dkms.bash-completion

@@ -29,7 +29,7 @@ _dkms()
 	cur=${COMP_WORDS[COMP_CWORD]}
 
 	if [[ $COMP_CWORD -eq 1 ]] ; then
-		COMPREPLY=( $( compgen -W "add autoinstall remove build install uninstall \
+		COMPREPLY=( $( compgen -W "add autoinstall remove build unbuild install uninstall \
 			match mkdriverdisk mktarball ldtarball mkrpm mkdeb mkdsc mkkmp \
 			status" -- $cur ) )
 	else