util: Tweak kconfig_check for use in the Makefile

Deal with two problems we have in the chroot:

- An old Python requires a workaround for required arguments
- We may not have access to the Zephyr tree and its full Kconfig, so
  need to gracefully fall back to using ad-hoc searching

Note: This was part of a reverted commit. It is being split out to
avoid mixing the switch-over with updates to the script.

BUG=b:181323955
BRANCH=none
TEST=CQ and see if it passes now

Signed-off-by: Simon Glass <sjg@chromium.org>
Change-Id: I4c885cc0661955b3b091c339b61e21cc2af7ac72
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3425449
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>

1 files changed, 14 insertions, 2 deletions

diff --git a/util/kconfig_check.py b/util/kconfig_check.py
index 93f3afd53c..30a798b8f4 100755
--- a/util/kconfig_check.py
+++ b/util/kconfig_check.py
@@ -70,7 +70,12 @@ a corresponding Kconfig option for Zephyr'''
     parser.add_argument('-s', '--srctree', type=str, default='zephyr/',
                         help='Path to source tree to look for Kconfigs')
 
-    subparsers = parser.add_subparsers(dest='cmd', required=True)
+    # TODO(sjg@chromium.org): The chroot uses a very old Python. Once it moves
+    # to 3.7 or later we can use this instead:
+    #    subparsers = parser.add_subparsers(dest='cmd', required=True)
+    subparsers = parser.add_subparsers(dest='cmd')
+    subparsers.required = True
+
     subparsers.add_parser('check', help='Check for new ad-hoc CONFIGs')
 
     return parser.parse_args(argv)
@@ -269,7 +274,14 @@ class KconfigCheck:
                     current state of the Kconfig options
         """
         configs = self.read_configs(configs_file, use_defines)
-        kconfigs = self.scan_kconfigs(srcdir, prefix, search_paths)
+        try:
+            kconfigs = self.scan_kconfigs(srcdir, prefix, search_paths)
+        except kconfiglib.KconfigError:
+            # If we don't actually have access to the full Kconfig then we may
+            # get an error. Fall back to using manual methods.
+            kconfigs = self.scan_kconfigs(srcdir, prefix, search_paths,
+                                          try_kconfiglib=False)
+
         allowed = self.read_allowed(allowed_file)
         new_adhoc = self.find_new_adhoc(configs, kconfigs, allowed)
         unneeded_adhoc = self.find_unneeded_adhoc(kconfigs, allowed)