[PATCH v3 0/3] kbuild: remove gcc's -Wtype-limits

Vincent Mailhol posted 3 patches 1 month, 2 weeks ago
There is a newer version of this series
drivers/gpu/drm/Makefile |  1 -
fs/btrfs/Makefile        |  1 -
include/linux/overflow.h | 10 ++--------
scripts/Makefile.warn    |  4 +++-
4 files changed, 5 insertions(+), 11 deletions(-)
[PATCH v3 0/3] kbuild: remove gcc's -Wtype-limits
Posted by Vincent Mailhol 1 month, 2 weeks ago
I often read on the mailing list people saying "who cares about W=2
builds anyway?". At least I do. Not that I want to fix all of them,
but on some occasions, such as new driver submissions, I have often
found a couple valid diagnostics in the W=2 output.

That said, the annoying thing is that W=2 is heavily polluted by one
warning: -Wtype-limits. Try a gcc W=2 build on any file and see the
results for yourself. I suspect this to be the reason why so few
people are using W=2.

This series removes gcc's -Wtype-limits in an attempt to make W=2 more
useful. Those who do not use W=2 can continue to not use it if they
want. Those who, like me, use it for time to time will get an improved
experience from the reduced spam.

Patch #1 deactivates -Wtype-limits.  Extra details on statistics, past
attempts and alternatives are given in the description.

Patch #2 clean-ups the local kbuild -Wno-type-limits exceptions, while
patch #3 undoes a local workaround which silenced that warning by
uglifying the code.

Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
Changes in v3:

  - Remove patch #4.

Link to v2: https://lore.kernel.org/r/20251219-remove_wtype-limits-v2-0-2e92b3f566c5@kernel.org

Changes in v2:

  - Add two more patches to clean up some -Wtype-limits workarounds
  - Collect the Reviewed-by tags.

Link to v1: https://lore.kernel.org/r/20251218-remove_wtype-limits-v1-0-735417536787@kernel.org

---
Vincent Mailhol (3):
      kbuild: remove gcc's -Wtype-limits
      kbuild: cleanup local -Wno-type-limits exceptions
      overflow: Remove is_non_negative() and is_negative()

 drivers/gpu/drm/Makefile |  1 -
 fs/btrfs/Makefile        |  1 -
 include/linux/overflow.h | 10 ++--------
 scripts/Makefile.warn    |  4 +++-
 4 files changed, 5 insertions(+), 11 deletions(-)
---
base-commit: 3e7f562e20ee87a25e104ef4fce557d39d62fa85
change-id: 20251205-remove_wtype-limits-c77eb46d09c2

Best regards,
-- 
Vincent Mailhol <mailhol@kernel.org>
Re: [PATCH v3 0/3] kbuild: remove gcc's -Wtype-limits
Posted by Nathan Chancellor 1 month ago
On Sat, 20 Dec 2025 12:02:18 +0100, Vincent Mailhol wrote:
> I often read on the mailing list people saying "who cares about W=2
> builds anyway?". At least I do. Not that I want to fix all of them,
> but on some occasions, such as new driver submissions, I have often
> found a couple valid diagnostics in the W=2 output.
> 
> That said, the annoying thing is that W=2 is heavily polluted by one
> warning: -Wtype-limits. Try a gcc W=2 build on any file and see the
> results for yourself. I suspect this to be the reason why so few
> people are using W=2.
> 
> [...]

Applied to

  https://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux.git kbuild-next

Thanks!

[1/3] kbuild: remove gcc's -Wtype-limits
      https://git.kernel.org/kbuild/c/660e899103e29
[2/3] kbuild: cleanup local -Wno-type-limits exceptions
      https://git.kernel.org/kbuild/c/34a1bd0b6b2c0
[3/3] overflow: Remove is_non_negative() and is_negative()
      https://git.kernel.org/kbuild/c/5ce3218d4f102

Please look out for regression or issue reports or other follow up
comments, as they may result in the patch/series getting dropped or
reverted.

Best regards,
-- 
Nathan Chancellor <nathan@kernel.org>