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Date:   Wed, 8 Nov 2023 21:03:34 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     linux-sparse@vger.kernel.org
Cc:     linux-xfs@vger.kernel.org
Subject: sparse feature request: nocast integer types
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Hi dear spearse developers,

in a lot of kernel code we have integer types that store offsets and
length in certain units (typically 512 byte disk "sectors", file systems
block sizes, and some weird variations of the same), and we had a fair
amount of bugs beause people get confused about which ones to use.

I wonder if it is possible to add an attribute (say nocast) that works
similar to __attribute__((bitwise)) in that it disallows mixing this
type with other integer types, but unlike __attribute__((bitwise))
allows all the normal arithmetics on it?  That way we could annotate
all the normal conversion helpers with __force overrides and check
where people are otherwise mixing these types.