[PATCH] D75677: [Analyzer] Only add iterator note tags to the operations of the affected iterators

[Balogh, Ádám via Phabricator via cfe-commits]

baloghadamsoftware marked an inline comment as done.
baloghadamsoftware added inline comments.


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Comment at: clang/lib/StaticAnalyzer/Checkers/IteratorModeling.cpp:541-542
+        BR.markInteresting(It1);
+        if (const auto &LCV1 = It1.getAs<nonloc::LazyCompoundVal>()) {
+          BR.markInteresting(LCV1->getRegion());
+        }
----------------
baloghadamsoftware wrote:
> Szelethus wrote:
> > NoQ wrote:
> > > baloghadamsoftware wrote:
> > > > NoQ wrote:
> > > > > I'm opposed to this code for the same reason that i'm opposed to it in the debug checker. Parent region is an undocumented implementation detail of `RegionStore`. It is supposed to be immaterial to the user. You should not rely on its exact value.
> > > > > 
> > > > > @baloghadamsoftware Can we eliminate all such code from iterator checkers and instead identify all iterators by regions in which they're stored? Does my improved C++ support help with this anyhow whenever it kicks in?
> > > > How to find the region where it is stored? I am open to find better solutions, but it was the only one I could find so far. If we ignore `LazyCompoundVal` then everything falls apart, we can remove all the iterator-related checkers.
> > > It's the region from which you loaded it. If you obtained it as `Call.getArgSVal()` then it's the parameter region for the call. If you obtained it as `Call.getReturnValue()` then it's the target region can be obtained by looking at the //construction context// for the call.
> > `LazyCompoundVal` and friends seem to be a constantly emerging headache for almost everyone. For how long I've spent in the analyzer, and have religiously studied conversations and your workbook about it, I still feel anxious whenever it comes up.
> > 
> > It would be great to have this documented in the code sometime.
> Do you mean `CallEvent::getParameterLocation()` for arguments? What is the //construction context// for the call? How can it be obtained?
I do not know exactly how many place `LazyCompoundVal`  appears, but one place for sure is in `MaterializeTemporaryExpr::getSubExpr()`. What to use there instead?


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  https://reviews.llvm.org/D75677/new/

https://reviews.llvm.org/D75677