[PATCH v2 2/2] kbuild: make W=1 warn files that are tracked but ignored by git

From: Masahiro Yamada
Date: Sat Dec 24 2022 - 10:51:53 EST


The top .gitignore comments about how to detect files breaking
.gitignore rules, but people rarely care about it.

Add a new W=1 warning to detect files that are tracked but ignored by
git. If git is not installed or the source tree is not tracked by git
at all, this script does not print anything.

Running it on the v6.1 kernel detected the following:

$ make W=1 misc-check
Documentation/devicetree/bindings/.yamllint: warning: ignored by one of the .gitignore files
drivers/clk/.kunitconfig: warning: ignored by one of the .gitignore files
drivers/gpu/drm/tests/.kunitconfig: warning: ignored by one of the .gitignore files
drivers/hid/.kunitconfig: warning: ignored by one of the .gitignore files
fs/ext4/.kunitconfig: warning: ignored by one of the .gitignore files
fs/fat/.kunitconfig: warning: ignored by one of the .gitignore files
kernel/kcsan/.kunitconfig: warning: ignored by one of the .gitignore files
lib/kunit/.kunitconfig: warning: ignored by one of the .gitignore files
mm/kfence/.kunitconfig: warning: ignored by one of the .gitignore files
tools/testing/selftests/arm64/tags/.gitignore: warning: ignored by one of the .gitignore files
tools/testing/selftests/arm64/tags/Makefile: warning: ignored by one of the .gitignore files
tools/testing/selftests/arm64/tags/run_tags_test.sh: warning: ignored by one of the .gitignore files
tools/testing/selftests/arm64/tags/tags_test.c: warning: ignored by one of the .gitignore files

These are ignored by the '.*' or 'tags' in the top .gitignore, but
there is no rule to negate it.

You might be tempted to do 'git add -f' but I want to have the real
issue fixed (by fixing a .gitignore, or by renaming files, etc.).

Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---

Changes in v2:
- Add $(srctree)/ to make it work with O=

Makefile | 6 ++++++
scripts/misc-check | 19 +++++++++++++++++++
2 files changed, 25 insertions(+)
create mode 100755 scripts/misc-check

diff --git a/Makefile b/Makefile
index 44239352d2bf..f6ff8f77a669 100644
--- a/Makefile
+++ b/Makefile
@@ -1852,6 +1852,12 @@ rust-analyzer:
# Misc
# ---------------------------------------------------------------------------

+PHONY += misc-check
+misc-check:
+ $(Q)$(srctree)/scripts/misc-check
+
+all: misc-check
+
PHONY += scripts_gdb
scripts_gdb: prepare0
$(Q)$(MAKE) $(build)=scripts/gdb
diff --git a/scripts/misc-check b/scripts/misc-check
new file mode 100755
index 000000000000..bf68712d1ac1
--- /dev/null
+++ b/scripts/misc-check
@@ -0,0 +1,19 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-only
+
+set -e
+
+# Detect files that are tracked but ignored by git. This is checked only when
+# ${KBUILD_EXTRA_WARN} contains 1, git is installed, and the source tree is
+# tracked by git.
+check_tracked_ignored_files () {
+ case "${KBUILD_EXTRA_WARN}" in
+ *1*) ;;
+ *) return;;
+ esac
+
+ git ls-files -i -c --exclude-per-directory=.gitignore 2>/dev/null |
+ sed 's/$/: warning: ignored by one of the .gitignore files/' >&2
+}
+
+check_tracked_ignored_files
--
2.34.1