ASDenysPetrov added inline comments.
================
Comment at: clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp:1618-1627
+ const SymbolRef LHS = Sym->getLHS();
+ const llvm::APSInt &Zero =
+ Builder.getBasicValueFactory().getValue(0, Sym->getType());
+ // a % b != 0 implies that a != 0.
+ if (!Constraint.containsZero()) {
+ State = RCM.assumeSymNE(State, LHS, Zero, Zero);
+ if (!State)
----------------
martong wrote:
> ASDenysPetrov wrote:
> > martong wrote:
> > > ASDenysPetrov wrote:
> > > > How about using the family of `ProgramState::isNonNull` or
> > > > `ProgramState::isNull` or `RangeConstraintManager::checkNull` functoins
> > > > for this stuff?
> > > I've been checking this and turend out that `ProgramState::isNull` does
> > > not modify the State (this is aligned with being a `const` member
> > > function). So, these functions do not "assume" anything, they can be used
> > > only to query some property of an SVal (or Symbol) from the State.
> > >
> > > However, this comment and your other previous comment made me to do
> > > further investigations towards exploiting the "assume" machinery better.
> > > The result is a new child patch, where we can handle "adjustments" as
> > > well.
> > But I don't see you use the modified `State` in any way. Why it's important
> > for you to change the `State`?
> >
> >
> > But I don't see you use the modified `State` in any way.
>
> Actually, we do use it. The `State` we overwrite here is the member of the
> class `ConstraintAssignor`, it is not a local variable.
>
> > Why it's important for you to change the `State`?
>
> It is important, because we'd like to assign new information to the existing
> things we know (i.e. to the State). So, once we see a modulo then we can
> defer some extra constraints and that is done via the `ConstraintAssignor`.
OK. I see. Thanks :)
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D110357/new/
https://reviews.llvm.org/D110357
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
