[LU-16518] Fix Clang build errors

Related — Wed, 29 Nov 2023 23:00:21 +0000

I've been experimenting with using Clang 15.0.6 to compile Lustre. The compiler runs into a number of build issues. Clang seems to be stricter than GCC in a few cases. Lustre can still be compiled by disabling the errors [1], but a first glance the errors seem legitimate. I'm making this ticket because I have a patch to fix some of the failures.

It seems like some Clang-based static analyzers were used in the past [2], although I'm not sure if compiling Lustre with Clang is super common. I think it could be useful to have Clang as an option for development purposes, along the lines of ClangBuiltLinux [3]. It's seems like some kind of plugin [4] was developed at some point. It would be for an old (3.0) Clang, but it could be interesting to look at.

[1] Errors that needed to be disabled:

-Wno-error=enum-conversion
-Wno-error=unused-but-set-variable
-Wno-error=uninitialized
-Wno-error=format
-Wno-error=strncat-size
-Wno-error=switch
-Wno-error=strlcpy-strlcat-size
-Wno-error=unneeded-internal-declaration
-Wno-error=self-assign
-Wno-error=tautological-constant-out-of-range-compare
-Wno-error=constant-logical-operand
-Wno-error=pointer-bool-conversion
-Wno-error=unused-function
-Wno-error=parentheses-equality
-Wno-error=deprecated-non-prototype

[2] Old Clang tickets:

https://jira.whamcloud.com/browse/LU-871

https://jira.whamcloud.com/browse/LU-2675

[3] Clang/Linux: https://clangbuiltlinux.github.io/

[4] Plugin: https://wiki.whamcloud.com/pages/viewpage.action?pageId=18645101

Whamcloud Community JIRA

[LU-16518] Fix Clang build errors