[cfe-dev] [StaticAnalyser][RFC] New checker, -Wsign-compare without the noise

[Daniel Marjamäki via cfe-dev]

Hello!

I want to implement a new -Wsign-compare checker in the static analyser that is not noisy.

I like the idea of Wsign-compare. However the checker generates lots of noise:

    int x = 10;
    unsigned y = x;  // <- FP

The -Wsign-compare doesn't care that the code is 100% safe and warns anyway.

I only want to see a warning when there can be a real loss of precision or a real loss of sign (when the value can be negative).

I don't plan to remove the -Wsign-compare from Clang. People will have to use -Wno-sign-compare to get rid of the noise.


I attach a simple proof of concept checker. It will just warn if there is an assignment and RHS is a known negative value. Do you have opinions about the design? Should some alternative approach be used?

Best regards,
Daniel Marjamäki

..................................................................................................................
Daniel Marjamäki Senior Engineer
Evidente ES East AB  Warfvinges väg 34  SE-112 51 Stockholm  Sweden

Mobile:                 +46 (0)709 12 42 62
E-mail:                 Daniel.Marjamaki at evidente.se

www.evidente.se
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