NoQ added a comment. Mmm, right, i guess you should also skip adding the tag if the notes array is empty.
There might be more complicated use-cases (especially in `ExprEngine` itself) where you may end up adding a tag even if the state doesn't change. For instance, when changing an Environment value from absent to `UnknownVal`, the state doesn't get actually updated. Or making range assumptions over `UnknownVal`. But i'd argue that we do indeed want the note tag in such cases because it is still worth annotating the `ExplodedGraph` with an explanation of what's happening. Eg., a note "Assuming a condition is false" makes sense even if the condition is an `UnknownVal` and no actual constraints are added. Another example: in a recent `StreamChecker` review we've been talking about a peculiar stream function that by design closes a file descriptor if it's open but does nothing if the descriptor is already closed. I believe this event deserves a note "The descriptor remains closed" (possibly prunable) even though there is no change in the state. This is something we couldn't do with our usual visitor-based approach which involves observing changes in the state (we technically could, via pattern-matching over the program point, but that'd directly duplicate a lot more of checker logic than usual). CHANGES SINCE LAST ACTION https://reviews.llvm.org/D70725/new/ https://reviews.llvm.org/D70725 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
