[LU-12923] replace CLASSERT() with BUILD_BUG_ON()

Related — Fri, 31 Jan 2020 10:08:11 +0000

The Lustre-specific compile-time assertion CLASSERT() should be replaced with the standard kernel BUILD_BUG_ON() macro that does the same thing.

NOTE that the logic of CLASSERT() is ensuring that the expression is true while BUILD_BUG_ON() is verifying if the expression is false, so the logic of each check should be reversed.

All of these expressions are evaluated at compile time, so it is possible to mark all patches fixing this with Test-Parameters: trivial.

The first patch in the series should update contrib/scripts/spelling.txt to add CLASSERT||BUILD_BUG_ON() so that new patches get a warning if they are using the old CLASSERT() macro. The last patch in the series should remove the CLASSERT() macro. There are currently 480 instances of CLASSERT() in the master branch, but a majority of them (318) are in the automatically-generated wirecheck.c, pack-generic.c and api-ni.c file, so most could be easily replaced by fixing the wiretest.c scripts.

Whamcloud Community JIRA

[LU-12923] replace CLASSERT() with BUILD_BUG_ON()