build: check that the list of supported config options is up to date

Add a script run during 'make check' to verify that all config options
are in the list of supported ones.

Makefile.am

@@ -1486,6 +1486,11 @@ noinst_LTLIBRARIES += \
 	src/libNetworkManager.la \
 	src/libsystemd-nm.la
 
+check-config-options:
+	$(srcdir)/tools/check-config-options.sh "$(srcdir)"
+
+check_local += check-config-options
+
 ###############################################################################
 
 src_libsystemd_nm_la_cppflags = \
@@ -5158,6 +5163,7 @@ EXTRA_DIST += \
 	shared/nm-version-macros.h.in \
 	shared/meson.build \
 	\
+	tools/check-config-options.sh \
 	tools/check-docs.sh \
 	tools/check-exports.sh \
 	tools/create-exports-NetworkManager.sh \

src/meson.build

@@ -309,3 +309,9 @@ if enable_tests
           env: ['LD_BIND_NOW=1', 'LD_PRELOAD=' + plugin.full_path()])
   endforeach
 endif
+
+test(
+  'check-config-options',
+  find_program(join_paths(meson.source_root(), 'tools', 'check-config-options.sh')),
+  args: [meson.source_root()]
+)

src/nm-config.c

@@ -743,6 +743,9 @@ typedef struct {
 	bool is_connection:1;
 } ConfigGroup;
 
+/* The following comment is used by check-config-options.sh, don't remove it. */
+/* START OPTION LIST */
+
 static const ConfigGroup config_groups[] = {
 	{
 		.group = NM_CONFIG_KEYFILE_GROUP_MAIN,
@@ -837,6 +840,9 @@ static const ConfigGroup config_groups[] = {
 	{ } /* sentinel */
 };
 
+/* The following comment is used by check-config-options.sh, don't remove it. */
+/* END OPTION LIST */
+
 static gboolean
 check_config_key (const char *group, const char *key)
 {

src/nm-config.h

@@ -105,8 +105,8 @@
 #define NM_CONFIG_KEYFILE_KEY_MATCH_DEVICE           "match-device"
 #define NM_CONFIG_KEYFILE_KEY_STOP_MATCH             "stop-match"
 
-#define NM_CONFIG_KEYFILE_KEY_ATOMIC_SECTION_WAS            ".was"
-#define NM_CONFIG_KEYFILE_KEY_CONFIG_ENABLE                 "enable"
+#define NM_CONFIG_KEYFILE_KEY_ATOMIC_SECTION_WAS            ".was"   /* check-config-options skip */
+#define NM_CONFIG_KEYFILE_KEY_CONFIG_ENABLE                 "enable" /* check-config-options skip */
 
 #define NM_CONFIG_KEYFILE_KEYPREFIX_WAS                     ".was."
 #define NM_CONFIG_KEYFILE_KEYPREFIX_SET                     ".set."

tools/check-config-options.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+srcdir=${1:-.}
+
+get_supported_options()
+{
+    awk '/START OPTION LIST/{flag=1;next}/END OPTION LIST/{flag=0}flag' "$srcdir/src/nm-config.c" |
+	grep -o 'NM_CONFIG_KEYFILE_KEY_\w*'
+}
+
+get_missing()
+{
+    grep -v '/\* check-config-options skip \*/' "$srcdir/src/nm-config.h" |
+	grep -o 'NM_CONFIG_KEYFILE_KEY_\w*' |
+	grep -v -Fx -f <(get_supported_options)
+}
+
+missing=$(get_missing)
+
+if [ -n "$missing" ]; then
+    echo "***"
+    echo "*** Error: the following configuration options are defined but not present in the list of supported options"
+    echo "***"
+    echo "$missing"
+    exit 1
+fi
+
+exit 0