kconfig: introduce nonint_oldconfig and loose_nonint_oldconfig

This patch has been around for a long time in Fedora and Red Hat Enterprise
Linux kernels and it may be useful for others. The nonint_oldconfig target
will fail and print the unset config options while loose_nonint_oldconfig will
simply let the config option unset. They're useful in distro kernel packages
where the config files are built using a combination of smaller config files.

Arjan van de Ven wrote the initial nonint_config and Roland McGrath added the
loose_nonint_oldconfig.

Signed-off-by: Arjan van de Ven <arjan@redhat.com> [defunct email]
Whatevered-by: Kyle McMartin <kyle@redhat.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Aristeu Rozanski <aris@redhat.com>
[mmarek: whitespace fixes]
Signed-off-by: Michal Marek <mmarek@suse.cz>

2 files changed, 54 insertions, 9 deletions

diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile
index 75bdf5ae202c..f8d1ee3a372e 100644
--- a/scripts/kconfig/Makefile
+++ b/scripts/kconfig/Makefile
@@ -62,6 +62,12 @@ localyesconfig: $(obj)/streamline_config.pl $(obj)/conf
         fi
         $(Q)rm -f .tmp.config
 
+nonint_oldconfig: $(obj)/conf
+        $< -b $(Kconfig)
+
+loose_nonint_oldconfig: $(obj)/conf
+        $< -B $(Kconfig)
+
 # Create new linux.pot file
 # Adjust charset to UTF-8 in .po file to accept UTF-8 in Kconfig files
 # The symlink is used to repair a deficiency in arch/um
@@ -126,6 +132,10 @@ help:
         @echo  '  allmodconfig    - New config selecting modules when possible'
         @echo  '  allyesconfig    - New config where all options are accepted with yes'
         @echo  '  allnoconfig     - New config where all options are answered with no'
+        @echo  '  nonint_oldconfig - Checks the current configuration and fails if an option is '
+        @echo  '                    not set'
+        @echo  '  loose_nonint_oldconfig - Same as nonint_oldconfig, but updates the config file with '
+        @echo  '                    missing config options as unset'
 
 # lxdialog stuff
 check-lxdialog  := $(srctree)/$(src)/lxdialog/check-lxdialog.sh
diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c
index 9960d1c303f8..3fa4abf3b084 100644
--- a/scripts/kconfig/conf.c
+++ b/scripts/kconfig/conf.c
@@ -16,6 +16,10 @@
 #define LKC_DIRECT_LINK
 #include "lkc.h"
 
+/* Return codes */
+#define EUNSETOPT       2       /* if -B and -b are used and unset config
+                                 * options were found */
+
 static void conf(struct menu *menu);
 static void check_conf(struct menu *menu);
 
@@ -23,6 +27,8 @@ enum {
         ask_all,
         ask_new,
         ask_silent,
+        dont_ask,
+        dont_ask_dont_tell,
         set_default,
         set_yes,
         set_mod,
@@ -37,6 +43,7 @@ static int sync_kconfig;
 static int conf_cnt;
 static char line[128];
 static struct menu *rootEntry;
+static int unset_variables;
 
 static void print_help(struct menu *menu)
 {
@@ -360,7 +367,10 @@ static void conf(struct menu *menu)
 
                 switch (prop->type) {
                 case P_MENU:
-                        if (input_mode == ask_silent && rootEntry != menu) {
+                        if ((input_mode == ask_silent ||
+                             input_mode == dont_ask ||
+                             input_mode == dont_ask_dont_tell) &&
+                            rootEntry != menu) {
                                 check_conf(menu);
                                 return;
                         }
@@ -418,10 +428,23 @@ static void check_conf(struct menu *menu)
         if (sym && !sym_has_value(sym)) {
                 if (sym_is_changable(sym) ||
                     (sym_is_choice(sym) && sym_get_tristate_value(sym) == yes)) {
-                        if (!conf_cnt++)
-                                printf(_("*\n* Restart config...\n*\n"));
-                        rootEntry = menu_get_parent_menu(menu);
-                        conf(rootEntry);
+                        if (input_mode == dont_ask ||
+                            input_mode == dont_ask_dont_tell) {
+                                if (input_mode == dont_ask &&
+                                    sym->name && !sym_is_choice_value(sym)) {
+                                        if (!unset_variables)
+                                                fprintf(stderr, "The following"
+                                                  " variables are not set:\n");
+                                        fprintf(stderr, "CONFIG_%s\n",
+                                                        sym->name);
+                                        unset_variables++;
+                                }
+                        } else {
+                                if (!conf_cnt++)
+                                        printf(_("*\n* Restart config...\n*\n"));
+                                rootEntry = menu_get_parent_menu(menu);
+                                conf(rootEntry);
+                        }
                 }
         }
 
@@ -439,7 +462,7 @@ int main(int ac, char **av)
         bindtextdomain(PACKAGE, LOCALEDIR);
         textdomain(PACKAGE);
 
-        while ((opt = getopt(ac, av, "osdD:nmyrh")) != -1) {
+        while ((opt = getopt(ac, av, "osbBdD:nmyrh")) != -1) {
                 switch (opt) {
                 case 'o':
                         input_mode = ask_silent;
@@ -448,6 +471,12 @@ int main(int ac, char **av)
                         input_mode = ask_silent;
                         sync_kconfig = 1;
                         break;
+                case 'b':
+                        input_mode = dont_ask;
+                        break;
+                case 'B':
+                        input_mode = dont_ask_dont_tell;
+                        break;
                 case 'd':
                         input_mode = set_default;
                         break;
@@ -525,6 +554,8 @@ int main(int ac, char **av)
         case ask_silent:
         case ask_all:
         case ask_new:
+        case dont_ask:
+        case dont_ask_dont_tell:
                 conf_read(NULL);
                 break;
         case set_no:
@@ -586,12 +617,16 @@ int main(int ac, char **av)
                 conf(&rootmenu);
                 input_mode = ask_silent;
                 /* fall through */
+        case dont_ask:
+        case dont_ask_dont_tell:
         case ask_silent:
                 /* Update until a loop caused no more changes */
                 do {
                         conf_cnt = 0;
                         check_conf(&rootmenu);
-                } while (conf_cnt);
+                } while (conf_cnt &&
+                         (input_mode != dont_ask &&
+                          input_mode != dont_ask_dont_tell));
                 break;
         }
 
@@ -607,11 +642,11 @@ int main(int ac, char **av)
                         fprintf(stderr, _("\n*** Error during update of the kernel configuration.\n\n"));
                         return 1;
                 }
-        } else {
+        } else if (!unset_variables || input_mode != dont_ask) {
                 if (conf_write(NULL)) {
                         fprintf(stderr, _("\n*** Error during writing of the kernel configuration.\n\n"));
                         exit(1);
                 }
         }
-        return 0;
+        return unset_variables ? EUNSETOPT : 0;
 }