[PATCH 0/5] hdrtest: hide the disgusting turds

[PATCH 0/5] hdrtest: hide the disgusting turds

[Jani Nikula]

Hide all the disgusting turds in .hdrtest subdirectories in the build
tree, and put the extra drm build-time checks behind a kconfig option.


BR,
Jani.


Cc: linux-kbuild@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: intel-xe@lists.freedesktop.org
Cc: intel-gfx@lists.freedesktop.org
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>

Jani Nikula (5):
  drm: place header test files in .hdrtest subdirectories
  drm/xe: place header test files in .hdrtest subdirectories
  drm/i915: place header test files in .hdrtest subdirectories
  kbuild: hdrtest: place header test files in .hdrtest subdirectories
  drm: add config option for extra build-time checks

 drivers/gpu/drm/Kconfig       | 21 +++++++++++++++++++--
 drivers/gpu/drm/Makefile      |  6 +++---
 drivers/gpu/drm/i915/Makefile |  6 +++---
 drivers/gpu/drm/xe/Makefile   |  6 +++---
 include/drm/Makefile          |  6 +++---
 usr/include/Makefile          |  4 ++--
 6 files changed, 33 insertions(+), 16 deletions(-)

-- 
2.39.5

[PATCH 1/5] drm: 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@linux-foundation.org>
Closes: https://lore.kernel.org/r/CAHk-=wjMrqzuUmH-mFbR_46EWEFS=bB=J7h9ABMVy56Vi81PKQ@mail.gmail.com
Fixes: 62ae45687e43 ("drm: ensure drm headers are self-contained and pass kernel-doc")
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

---

Cc: linux-kbuild@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: intel-xe@lists.freedesktop.org
Cc: intel-gfx@lists.freedesktop.org
---
 drivers/gpu/drm/Makefile | 6 +++---
 include/drm/Makefile     | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index ed54a546bbe2..1666ea55bd24 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -230,14 +230,14 @@ hdrtest-files := \
 	$(shell cd $(src) && find display lib -name '*.h')
 
 always-$(CONFIG_DRM_HEADER_TEST) += \
-	$(patsubst %.h,%.hdrtest, $(hdrtest-files))
+	$(patsubst %.h,.hdrtest/%.hdrtest, $(hdrtest-files))
 
 # Include the header twice to detect missing include guard.
-quiet_cmd_hdrtest = HDRTEST $(patsubst %.hdrtest,%.h,$@)
+quiet_cmd_hdrtest = HDRTEST $<
       cmd_hdrtest = \
 		$(CC) $(c_flags) -fsyntax-only -x c /dev/null -include $< -include $<; \
 		$(srctree)/scripts/kernel-doc -none $(if $(CONFIG_WERROR)$(CONFIG_DRM_WERROR),-Werror) $<; \
 		touch $@
 
-$(obj)/%.hdrtest: $(src)/%.h FORCE
+$(obj)/.hdrtest/%.hdrtest: $(src)/%.h FORCE
 	$(call if_changed_dep,hdrtest)
diff --git a/include/drm/Makefile b/include/drm/Makefile
index a7bd15d2803e..a7593987909b 100644
--- a/include/drm/Makefile
+++ b/include/drm/Makefile
@@ -5,14 +5,14 @@ hdrtest-files := \
 	$(shell cd $(src) && find * -name '*.h' 2>/dev/null)
 
 always-$(CONFIG_DRM_HEADER_TEST) += \
-	$(patsubst %.h,%.hdrtest, $(hdrtest-files))
+	$(patsubst %.h,.hdrtest/%.hdrtest, $(hdrtest-files))
 
 # Include the header twice to detect missing include guard.
-quiet_cmd_hdrtest = HDRTEST $(patsubst %.hdrtest,%.h,$@)
+quiet_cmd_hdrtest = HDRTEST $<
       cmd_hdrtest = \
 		$(CC) $(c_flags) -fsyntax-only -x c /dev/null -include $< -include $<; \
 		$(srctree)/scripts/kernel-doc -none $(if $(CONFIG_WERROR)$(CONFIG_DRM_WERROR),-Werror) $<; \
 		touch $@
 
-$(obj)/%.hdrtest: $(src)/%.h FORCE
+$(obj)/.hdrtest/%.hdrtest: $(src)/%.h FORCE
 	$(call if_changed_dep,hdrtest)
-- 
2.39.5

[PATCH 2/5] drm/xe: 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@linux-foundation.org>
Closes: https://lore.kernel.org/r/CAHk-=wjMrqzuUmH-mFbR_46EWEFS=bB=J7h9ABMVy56Vi81PKQ@mail.gmail.com
Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

---

Cc: linux-kbuild@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: intel-xe@lists.freedesktop.org
Cc: intel-gfx@lists.freedesktop.org
---
 drivers/gpu/drm/xe/Makefile | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
index 9699b08585f7..2029c3b5aa5c 100644
--- a/drivers/gpu/drm/xe/Makefile
+++ b/drivers/gpu/drm/xe/Makefile
@@ -327,12 +327,12 @@ ifneq ($(CONFIG_DRM_XE_DISPLAY),y)
 endif
 
 always-$(CONFIG_DRM_XE_WERROR) += \
-	$(patsubst %.h,%.hdrtest, $(shell cd $(src) && find * -name '*.h' $(hdrtest_find_args)))
+	$(patsubst %.h,.hdrtest/%.hdrtest, $(shell cd $(src) && find * -name '*.h' $(hdrtest_find_args)))
 
-quiet_cmd_hdrtest = HDRTEST $(patsubst %.hdrtest,%.h,$@)
+quiet_cmd_hdrtest = HDRTEST $<
       cmd_hdrtest = $(CC) -DHDRTEST $(filter-out $(CFLAGS_GCOV), $(c_flags)) -S -o /dev/null -x c /dev/null -include $<; touch $@
 
-$(obj)/%.hdrtest: $(src)/%.h FORCE
+$(obj)/.hdrtest/%.hdrtest: $(src)/%.h FORCE
 	$(call if_changed_dep,hdrtest)
 
 uses_generated_oob := $(addprefix $(obj)/, $(xe-y))
-- 
2.39.5

[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@linux-foundation.org>
Closes: https://lore.kernel.org/r/CAHk-=wjMrqzuUmH-mFbR_46EWEFS=bB=J7h9ABMVy56Vi81PKQ@mail.gmail.com
Fixes: c6d4a099a240 ("drm/i915: reimplement header test feature")
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

---

Cc: linux-kbuild@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: intel-xe@lists.freedesktop.org
Cc: intel-gfx@lists.freedesktop.org
---
 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

[PATCH 4/5] kbuild: hdrtest: 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.

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@linux-foundation.org>
Closes: https://lore.kernel.org/r/CAHk-=wjMrqzuUmH-mFbR_46EWEFS=bB=J7h9ABMVy56Vi81PKQ@mail.gmail.com
Fixes: fcbb8461fd23 ("kbuild: remove header compile test")
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

---

Cc: linux-kbuild@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: intel-xe@lists.freedesktop.org
Cc: intel-gfx@lists.freedesktop.org
---
 usr/include/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/usr/include/Makefile b/usr/include/Makefile
index e3d6b03527fe..4fb574fd3fec 100644
--- a/usr/include/Makefile
+++ b/usr/include/Makefile
@@ -71,7 +71,7 @@ endif
 # asm-generic/*.h is used by asm/*.h, and should not be included directly
 no-header-test += asm-generic/%
 
-always-y := $(patsubst $(obj)/%.h,%.hdrtest, $(shell find $(obj) -name '*.h' 2>/dev/null))
+always-y := $(patsubst $(obj)/%.h,.hdrtest/%.hdrtest, $(shell find $(obj) -name '*.h' 2>/dev/null))
 
 # Include the header twice to detect missing include guard.
 quiet_cmd_hdrtest = HDRTEST $<
@@ -81,7 +81,7 @@ quiet_cmd_hdrtest = HDRTEST $<
 		$(PERL) $(src)/headers_check.pl $(obj) $<; \
 		touch $@
 
-$(obj)/%.hdrtest: $(obj)/%.h FORCE
+$(obj)/.hdrtest/%.hdrtest: $(obj)/%.h FORCE
 	$(call if_changed_dep,hdrtest)
 
 # Since GNU Make 4.3, $(patsubst $(obj)/%/,%,$(wildcard $(obj)/*/)) works.
-- 
2.39.5

Re: [PATCH 4/5] kbuild: hdrtest: place header test files in .hdrtest subdirectories

[Masahiro Yamada]

On Tue, Apr 1, 2025 at 9:19 PM Jani Nikula <jani.nikula@intel.com> wrote:
>
> 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.
>
> 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@linux-foundation.org>
> Closes: https://lore.kernel.org/r/CAHk-=wjMrqzuUmH-mFbR_46EWEFS=bB=J7h9ABMVy56Vi81PKQ@mail.gmail.com
> Fixes: fcbb8461fd23 ("kbuild: remove header compile test")
> Cc: Masahiro Yamada <masahiroy@kernel.org>
> Cc: David Airlie <airlied@gmail.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>
> ---


Linus did not mention anything bad for usr/include/.

This crap is unneeded.

NACK.






>
> Cc: linux-kbuild@vger.kernel.org
> Cc: dri-devel@lists.freedesktop.org
> Cc: intel-xe@lists.freedesktop.org
> Cc: intel-gfx@lists.freedesktop.org
> ---
>  usr/include/Makefile | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/usr/include/Makefile b/usr/include/Makefile
> index e3d6b03527fe..4fb574fd3fec 100644
> --- a/usr/include/Makefile
> +++ b/usr/include/Makefile
> @@ -71,7 +71,7 @@ endif
>  # asm-generic/*.h is used by asm/*.h, and should not be included directly
>  no-header-test += asm-generic/%
>
> -always-y := $(patsubst $(obj)/%.h,%.hdrtest, $(shell find $(obj) -name '*.h' 2>/dev/null))
> +always-y := $(patsubst $(obj)/%.h,.hdrtest/%.hdrtest, $(shell find $(obj) -name '*.h' 2>/dev/null))
>
>  # Include the header twice to detect missing include guard.
>  quiet_cmd_hdrtest = HDRTEST $<
> @@ -81,7 +81,7 @@ quiet_cmd_hdrtest = HDRTEST $<
>                 $(PERL) $(src)/headers_check.pl $(obj) $<; \
>                 touch $@
>
> -$(obj)/%.hdrtest: $(obj)/%.h FORCE
> +$(obj)/.hdrtest/%.hdrtest: $(obj)/%.h FORCE
>         $(call if_changed_dep,hdrtest)
>
>  # Since GNU Make 4.3, $(patsubst $(obj)/%/,%,$(wildcard $(obj)/*/)) works.
> --
> 2.39.5
>


--
Best Regards
Masahiro Yamada

[PATCH 5/5] drm: add config option for extra build-time checks

[Jani Nikula]

The DRM subsystem contains additional build-time checks, primarily aimed
at DRM developers and CI systems. The checks may be overzealous. They
may slow down or fail the build altogether. They may create excessive
dependency files in the build tree. They should not be enabled for
regular builds, and certainly not forced on unsuspecting developers
running an allyesconfig or allmodconfig build.

Add config DRM_DISABLE_EXTRA_BUILD_CHECKS, enabled by default as well as
by allyesconfig/allmodconfig, hiding the extra checks from anyone but
people who intentionally opt-in for the checks.

For example, to enable header tests:

$ scripts/config --disable CONFIG_DRM_DISABLE_EXTRA_BUILD_CHECKS --enable CONFIG_DRM_HEADER_TEST
$ make olddefconfig

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Closes: https://lore.kernel.org/r/CAHk-=wjcdfrDTjzm6J6T-3fxtVyBG7a_0BXc2=mgOuM6KPFnCg@mail.gmail.com
Fixes: 62ae45687e43 ("drm: ensure drm headers are self-contained and pass kernel-doc")
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

---

Cc: linux-kbuild@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: intel-xe@lists.freedesktop.org
Cc: intel-gfx@lists.freedesktop.org
---
 drivers/gpu/drm/Kconfig | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 2cba2b6ebe1c..5a3fce9ef998 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -489,9 +489,26 @@ config DRM_PRIVACY_SCREEN
 	bool
 	default n
 
+# Reversed option to disable on allyesconfig/allmodconfig builds
+config DRM_DISABLE_EXTRA_BUILD_CHECKS
+	bool "Disable DRM subsystem extra build-time checks"
+	default y
+	help
+	  The DRM subsystem contains additional build-time checks, primarily
+	  aimed at DRM developers and CI systems. The checks may be
+	  overzealous. They may slow down or fail the build altogether. They may
+	  create excessive dependency files in the tree. They should not be
+	  enabled for regular builds, and thus they are disabled by default.
+
+# Proxy config to allow simple "depends on DRM_EXTRA_BUILD_CHECKS"
+config DRM_EXTRA_BUILD_CHECKS
+	bool
+	depends on DRM && EXPERT && DRM_DISABLE_EXTRA_BUILD_CHECKS=n
+	default !DRM_DISABLE_EXTRA_BUILD_CHECKS
+
 config DRM_WERROR
 	bool "Compile the drm subsystem with warnings as errors"
-	depends on DRM && EXPERT
+	depends on DRM_EXTRA_BUILD_CHECKS
 	depends on !WERROR
 	default n
 	help
@@ -505,7 +522,7 @@ config DRM_WERROR
 
 config DRM_HEADER_TEST
 	bool "Ensure DRM headers are self-contained and pass kernel-doc"
-	depends on DRM && EXPERT && BROKEN
+	depends on DRM_EXTRA_BUILD_CHECKS
 	default n
 	help
 	  Ensure the DRM subsystem headers both under drivers/gpu/drm and
-- 
2.39.5