MosheBerman added a comment. In D123352#3439390 <https://reviews.llvm.org/D123352#3439390>, @steakhal wrote:
> tldr; static-analyzer fixits are not completely implemented. Where can I learn more about this? Would it be possible and idiomatically/architecturally sounds to write a clang-tidy that processes output from this checker? > When I passed the `apply-fixits`, it modified the input source file - as I > expected. Did you test this diff, or an existing checker? Would you please share the command you used to test? > Then I tried the `-analyzer-output=text` and suddenly it inserted the fixit 2 > times xD, which is less than ideal and we should fix this. > And I'm expecting many more bugs with this feature. This is why it's gated. xD. > There is a `clang/test/Analysis/check-analyzer-fixit.py` script which could > be invoked by a RUN line like this: > > // RUN: %check-analyzer-fixit %s %t -analyzer-checker=core > > At least, the comment of that script says so. > > --- > > I'm quite skeptical about inserting such fixits in general - regarding > path-sensitive analysis. > For fixits, we should be confident that some property holds, but the static > analyzer might conclude erroneously that a given pointer is null resulting in > a **bad** fixit. > Thus, relying on this might be dangerous. Understood, and I don't disagree (both because of lack of expertise, and because false-positives is a logical concern.) The intention here is to enable us to add `NS_ASSUME` macros to a bunch of files, then use the nullability return checkers to catch the functions/methods which violate the new contract. This assumes that the existing code is the source of truth, as opposed to, say, callsites. > You can read more about false-positive cases regarding null pointers in the > `clang/include/clang/StaticAnalyzer/Core/AnalyzerOptions.def`, namely > `suppress-null-return-paths`, `avoid-suppressing-null-argument-paths`, > `suppress-inlined-defensive-checks`. These options were introduced for > mitigating such false-positive null pointer deref reports. I'll take a look at that, thanks! Would those suppressions interact with the nullability checkers? They seem to have a lot of defenses against false positives. > Let me invite @Szelethus for his expertise in the null pointer checker. Thanks! Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D123352/new/ https://reviews.llvm.org/D123352 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
