[PATCH] D127898: [clang][dataflow] Find unsafe locs after fixpoint

[Gábor Horváth via Phabricator via cfe-commits]

xazax.hun added inline comments.


================
Comment at: clang-tools-extra/clang-tidy/bugprone/UncheckedOptionalAccessCheck.cpp:66
+  SourceLocations Locs;
+  for (const CFGBlock *Block : Context->getCFG()) {
+    // Skip blocks that were not evaluated.
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While doing yet another iteration after we reached the fixed point is a valid approach, many analyses have a monotonic property when it comes to emitting diagnostics. In this case, when the analysis discovered that an optional access is unsafe in one of the iterations I would not expect it to become safe in subsequent iterations. In most of the cases this makes collecting diagnostics eagerly a viable option and saves us from doing one more traversal of the CFG. On the other hand, we need to be careful to not to emit duplicate diagnostics.

I wonder whether, from a user point of view, not having to do one more iteration is a more ergonomic interface. 


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  https://reviews.llvm.org/D127898/new/

https://reviews.llvm.org/D127898