Hi,
On Mon, Nov 18, 2024 at 07:13:31PM +0000, David Laight wrote:
> Use BUILD_BUG_ON_MSG(statically_true(ulo > uhi), ...) for the sanity
> check of the bounds in clamp().
> Gives better error coverage and one less expansion of the arguments.
>
> Signed-off-by: David Laight <david.laight@xxxxxxxxxx>
This patch triggers a build error when trying to build parisc:allmodconfig.
See error message and bisect log below.
I don't think there is anything wrong with the patch. The underlying
problem seems to be that parisc:allmodconfig enables CONFIG_DRM_XE which
tries to build the affected file even though CONFIG_DRM_I915 is not
enabled/supported on parisc.
Copying XE maintainers for feedback/advice.
Thanks,
Guenter
---
Building parisc:allmodconfig ... failed
--------------
Error log:
In file included from <command-line>:
drivers/gpu/drm/i915/display/intel_backlight.c: In function 'scale':
include/linux/compiler_types.h:542:45: error: call to '__compiletime_assert_415' declared with attribute error: clamp() low limit source_min greater than high limit source_max
542 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^
include/linux/compiler_types.h:523:25: note: in definition of macro '__compiletime_assert'
523 | prefix ## suffix(); \
| ^~~~~~
include/linux/compiler_types.h:542:9: note: in expansion of macro '_compiletime_assert'
542 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^~~~~~~~~~~~~~~~~~~
include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert'
39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
| ^~~~~~~~~~~~~~~~~~
include/linux/minmax.h:188:9: note: in expansion of macro 'BUILD_BUG_ON_MSG'
188 | BUILD_BUG_ON_MSG(statically_true(ulo > uhi), \
| ^~~~~~~~~~~~~~~~
include/linux/minmax.h:195:9: note: in expansion of macro '__clamp_once'
195 | __clamp_once(type, val, lo, hi, __UNIQUE_ID(v_), __UNIQUE_ID(l_), __UNIQUE_ID(h_))
| ^~~~~~~~~~~~
include/linux/minmax.h:206:28: note: in expansion of macro '__careful_clamp'
206 | #define clamp(val, lo, hi) __careful_clamp(__auto_type, val, lo, hi)
| ^~~~~~~~~~~~~~~
drivers/gpu/drm/i915/display/intel_backlight.c:48:22: note: in expansion of macro 'clamp'
48 | source_val = clamp(source_val, source_min, source_max);
| ^~~~~
---
# bad: [0907e7fb35756464aa34c35d6abb02998418164b] Add linux-next specific files for 20250117
# good: [5bc55a333a2f7316b58edc7573e8e893f7acb532] Linux 6.13-rc7
git bisect start 'HEAD' 'v6.13-rc7'
# bad: [195cedf4deacf84167c32b866ceac1cf4a16df15] Merge branch 'main' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git
git bisect bad 195cedf4deacf84167c32b866ceac1cf4a16df15
# bad: [e8c0711b153b0db806410d8b31ed23b590f4eab4] Merge branch 'xtensa-for-next' of git://github.com/jcmvbkbc/linux-xtensa.git
git bisect bad e8c0711b153b0db806410d8b31ed23b590f4eab4
# bad: [81d45722d699e594c66c150c8f7a0ec2e2bc9be6] Merge branch 'for-next/perf' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git
git bisect bad 81d45722d699e594c66c150c8f7a0ec2e2bc9be6
# bad: [7acb844a672defb15cf202a501815ec22c68c800] foo
git bisect bad 7acb844a672defb15cf202a501815ec22c68c800
# good: [fb2368075b135f174264071b851330649d55f9d0] mm/damon/core: add damos_filter->allow field
git bisect good fb2368075b135f174264071b851330649d55f9d0
# bad: [fc83c501e385753c90db7316faf9fd4158caaa96] minmax.h: remove some #defines that are only expanded once
git bisect bad fc83c501e385753c90db7316faf9fd4158caaa96
# good: [b04d305df1171448df5e87802c4d1f1022cc5784] ocfs2: use a folio in ocfs2_map_and_dirty_page()
git bisect good b04d305df1171448df5e87802c4d1f1022cc5784
# good: [7e01619507058f90ab603acec482951f3c452aaa] kthread: correct comments before kthread_queue_work()
git bisect good 7e01619507058f90ab603acec482951f3c452aaa
# good: [21b510a64c223707caa6db6176128779f0806a73] nilfs2: correct return value kernel-doc descriptions for ioctl functions
git bisect good 21b510a64c223707caa6db6176128779f0806a73
# good: [6afb87f23458f2d4e4334ee5a4efb8b0d07af68b] nilfs2: handle errors that nilfs_prepare_chunk() may return
git bisect good 6afb87f23458f2d4e4334ee5a4efb8b0d07af68b
# good: [8f6d46fed0bad163e5146fea1fdff150039235b2] minmax.h: reduce the #define expansion of min(), max() and clamp()
git bisect good 8f6d46fed0bad163e5146fea1fdff150039235b2
# bad: [7a70c678548d71e609b95dbddf2d411a02d13b54] minmax.h: move all the clamp() definitions after the min/max() ones
git bisect bad 7a70c678548d71e609b95dbddf2d411a02d13b54
# bad: [37f375aab0c585388b90d1af6968454fc2769cb9] minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()
git bisect bad 37f375aab0c585388b90d1af6968454fc2769cb9
# first bad commit: [37f375aab0c585388b90d1af6968454fc2769cb9] minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()
