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LinuxKPI: change BUILD_BUG_ON()
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Authored by bz on May 24 2021, 6:42 PM.

Details

Summary

BUILD_BUG_ON() can be used inside functions where the definition to
CTASSERT() (_Static_assert()) seems to not work.
Go back to an old-style CTASSERT() implementation but also add a
variable dclaration to avoid "unsued typedef" errors and dummy-use
the variable to avoid "unusued variable" errors. Given it is all
self-contained in a block and not used outside this should be
optimised away.

Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Reviewed by:
Differential Revision:

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rG FreeBSD src repository
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Event Timeline

bz requested review of this revision.May 24 2021, 6:42 PM
hselasky added inline comments.
sys/compat/linuxkpi/common/include/linux/kernel.h
100

Should this be enclosed with while (0) and not "do { } while (0) "?

sys/compat/linuxkpi/common/include/linux/kernel.h
100

Would a while (0) { } be optimized out without ever entering the block because it can never happen?

sys/compat/linuxkpi/common/include/linux/kernel.h
100

Yes, with -O2, but after parsing the code. So I believe any asserts will trigger.

Switch to while (0) { } as suggested by @hselasky

This revision is now accepted and ready to land.May 25 2021, 9:42 AM
This revision was automatically updated to reflect the committed changes.