CODEWITHSUNDEEP
c++cclang
Parker Coates
Parker Coates

Reputation: 9448

Clang: Override all warning and warning-as-error flags specified earlier on the command line

With gcc I can throw a bunch of -Wsome-issue and -Werror=other-issue flags on the command line and the later cancel them all with a single -w flag somewhere near the end.

This doesn't appear to be the case with clang. A trailing -w suppresses some warnings, but not others. See here for an example. I know I can manually disable each warning individually via -Wno-some-issue and -Wno-error=other-issue, but that's a real pain to manage in the long term.

Am I missing something? Is there a way to cancel all earlier warning flags? Is there a reason why -w can suppress some warnings but not others?

Background: My specific use case is a library containing a mix of source files. Some new and some ancient, semi-third-party stuff that we never want to look at, let alone edit. The project has some semi-strict warning flags set globally, but for these few files I'd like to override the global flags and disable all warnings and warnings-as-werrors. In CMake this is done by settings the COMPILE_OPTIONS property for those files, which appends the given flags after the global flags. With gcc this works just fine, but with clang it's proving to be a headache.

(And yes I know I could reorganise the project to force those files to be compiled into a separate target, but I was hoping to avoid that.)

Upvotes: 3

Views: 2520

Answers (1)

valiano
valiano

Reputation: 18661

The flag you need is -Wno-everything.

Godbolt: https://godbolt.org/g/33uABD

Upvotes: 5

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