vsavchenko added inline comments.
================
Comment at: clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp:1409-1415
+ if ((LHS.From() > 0 && RHS.From() > 0 && Min < 0) ||
+ (LHS.From() < 0 && RHS.From() < 0 && Min > 0) ||
+ (LHS.To() > 0 && RHS.To() > 0 && Max < 0) ||
+ (LHS.To() < 0 && RHS.To() < 0 && Max > 0)) {
+ // return [Tmin, Tmax]
+ return {RangeFactory, Tmin, Tmax};
+ }
----------------
manas wrote:
> vsavchenko wrote:
> > manas wrote:
> > > vsavchenko wrote:
> > > > I thought we talked quite a lot that there is nothing bad with
> > > > overflows and here we have that if ANY overflow happened, we bail out
> > > > and don't give any result.
> > > Understood! Should I replace it with code returning EmptySet()?
> > Why `EmptySet()`? `EmptySet()` means that this can never happen, this path
> > is infeasible. Is that the case?
> > Let's say we have: `[INT_MAX - 20, INT_MAX - 10] + [30, 40]` what happens
> > in this case?
> Right! That will not be the case.
>
> In this particular case, the range will be `[INT_MIN + 9, INT_MIN + 29]`
> which is far smaller than `[Tmin, Tmax]`.
>
> Also, I think I misunderstood the part of //bailing out and not giving any
> result// as returning empty.
Gotcha!
Because of cases like this, you need to re-think that part about `Min > Max`
and maybe count the number of overflows on each side?
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D103440/new/
https://reviews.llvm.org/D103440
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