[PATCH] D54757: [clang-tidy] new check: bugprone-branch-clone

Mon Dec 3 08:31:58 PST 2018

donat.nagy marked 2 inline comments as done.
donat.nagy added a comment.

I applied this check to the llvm + clang codebase, and I was surprised to see that it produced about 600 results (for comparison, the clang-tidy checks which are enabled by default produce approximately 6000 results together). I didn't go through the whole list, but after examining a few dozen random reports it seems that most of these are true positives: relatively short branches (usually one or two lines of code) are repeated for no obvious reason. I would guess that most of these fall into the "correct but too verbose" case, because otherwise the tests would have caught the problem, but I didn't try to understand their context.

I have seen a few false positives related to preprocessor trickery: when an `.inc` file is included to create a huge switch, sometimes it will become a huge switch with lots of identical branches. There were also some situations where the check found identical branches which are annotated with different comments; I don't know if this should be considered a false positive.

If this is acceptable, then I would be grateful if someone would commit this patch for me as I don't have commit rights.

Repository:
  rCTE Clang Tools Extra

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  https://reviews.llvm.org/D54757/new/

https://reviews.llvm.org/D54757