[PATCH] D32346: [clang-tidy] New readability check for strlen argument

[Jonas Toth via Phabricator via cfe-commits]

JonasToth added a comment.

> #include <string.h>
>  void dostuff(const char *P) {
> 
>   if (strncmp(P+2,"xyz",3)==0) {}
> 
> }
> 
>   

Iam not super familiar with C, but the intend of the function is to check the following:

  P = "foxyz", P2 = "abxyz", P3 = "opxyz", ...

And if P matches this kind of string pattern.

> /home/danielm/strlen.c:3:16: warning: strlen() argument has pointer addition, it is recommended to subtract the result instead. [readability-strlen-argument]
> 
>   if (strncmp(P+2,"xyz",3)==0) {}
>                ^
> 
>   

Why is it matched? This is the code transformation from -O2? I dont know a way to surround that, and i think you should not call clang-tidy with optimization.

> I should probably avoid these, I guess skipping all warnings in macro code sounds ok to me.

You can check if the code is a result of macro expansion, i think that would be enough.


Repository:
  rL LLVM

https://reviews.llvm.org/D32346