[PATCH 3/5] drm/i915: place header test files in .hdrtest subdirectories

[Jani Nikula]

The header tests track whether headers have been checked using empty
*.hdrtest files in the build tree. This pollutes the build directories,
as the files live in the same "name space" as the real output files,
messing with TAB completion among other things.

Hide the disgusting turds by placing them in .hdrtest subdirectories.

Change the quiet command output to simply $< instead of trying to decode
roughly the same from the increasingly complicated $@.

Note that it would be somewhat nicer to have the basename of the
.hdrtest files be dot-prefixed instead of using subdirectories. However,
it's challenging to come up with a pattern rule for that, as we can list
headers to test in the subdirectories of $(src) too, without requiring
Makefiles and kbuild to descend to each of them.

Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Closes: https://lore.kernel.org/r/CAHk-=wjMrqzuUmH-mFbR_46EWEFS=bB=J7h9ABMVy56Vi81PKQ@xxxxxxxxxxxxxx
Fixes: c6d4a099a240 ("drm/i915: reimplement header test feature")
Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>

---

Cc: linux-kbuild@xxxxxxxxxxxxxxx
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: intel-xe@xxxxxxxxxxxxxxxxxxxxx
Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
---
 drivers/gpu/drm/i915/Makefile | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index ed05b131ed3a..a8ffe5c74962 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -418,12 +418,12 @@ no-header-test := \
 	display/intel_vbt_defs.h
 
 always-$(CONFIG_DRM_I915_WERROR) += \
-	$(patsubst %.h,%.hdrtest, $(filter-out $(no-header-test), \
+	$(patsubst %.h,.hdrtest/%.hdrtest, $(filter-out $(no-header-test), \
 		$(shell cd $(src) && find * -name '*.h')))
 
-quiet_cmd_hdrtest = HDRTEST $(patsubst %.hdrtest,%.h,$@)
+quiet_cmd_hdrtest = HDRTEST $<
       cmd_hdrtest = $(CC) $(filter-out $(CFLAGS_GCOV), $(c_flags)) -S -o /dev/null -x c /dev/null -include $<; \
 		$(srctree)/scripts/kernel-doc -none -Werror $<; touch $@
 
-$(obj)/%.hdrtest: $(src)/%.h FORCE
+$(obj)/.hdrtest/%.hdrtest: $(src)/%.h FORCE
 	$(call if_changed_dep,hdrtest)
-- 
2.39.5