Add __diagused
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Authored by mjg on Jul 14 2021, 11:52 PM.

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kib
markj

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rGf0d034474236: Add __diagused
rGbc28e9596c59: Add __diagused
rGb9296725cf99: Add __diagused

Summary

This can be used for variables which are only used with either INVARIANTS or WITNESS. Without any annotation they run into dead store warnings from cc --analyze and blindly annotating with __unused may hide bad vars when it should not.

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mjg requested review of this revision.Jul 14 2021, 11:52 PM

mjg created this revision.

The added macro is affected by symbols from the user namespace. This is actually a feature for kernel compilation environment. It should be put e.g. into sys/systm.h, not into the common header that must be usable in all environments. And in sys/systm.h, it should be under #ifdef _KERNEL.

After the move to kernel-only, there might be an issue if any code that is shared between kernel and userspace, starts using __diagused, but lets handle this when it become a real issue.