[PATCH] D45517: [analyzer] False positive refutation with Z3

[George Karpenkov via Phabricator via cfe-commits]

george.karpenkov added inline comments.


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Comment at: include/clang/StaticAnalyzer/Core/PathSensitive/ConstraintManager.h:183
+  virtual void reset() {}
+  virtual bool isModelFeasible() { return true; }
+  virtual void addRangeConstraints(ConstraintRangeTy) {}
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mikhail.ramalho wrote:
> george.karpenkov wrote:
> > Making those virtual does not make much sense to me.
> > Returning `true` by default is not correct.
> > When we are using the visitor, we should already know we have a `Z3ConstraintsManager`, why can't we just use methods of that class?
> Z3ConstraintManager is fully contained inside a .cpp file, so we need isModelFeasible and addRangeConstraints to be exposed via its base class.
> 
> Another solution is to split Z3ConstraintManager into a .h and a .cpp file and include the header. We would then be able to use it directly, instead of through a ConstraintManager object.
> 
> I honestly prefer the latter. What do you think?
Yeah, I think we would need a header here.
In general we try to avoid inheritance and virtual functions unless they are very beneficial, and here they are not.


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Comment at: lib/StaticAnalyzer/Core/BugReporterVisitors.cpp:2391
+    if (!RefutationMgr->isModelFeasible())
+      BR.markInvalid("Infeasible constraints", N->getLocationContext());
+  }
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mikhail.ramalho wrote:
> george.karpenkov wrote:
> > That would be checking all constraints in all nodes one by one. I thought the idea was to encode all constraints from the entire path and then check all of it.
> All the constraints are being added in the previous for loop, isModelFeasible only calls check().
Ah right, I see we are inside of the branch when `pred_size() == 0`.
Sorry, I was wrong -- but could we move out this code to a private function (could also simply use static function to avoid polluting the header)?


https://reviews.llvm.org/D45517