manas added inline comments.
================
Comment at: clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp:1400
+ if (ResultType.isUnsigned()) {
+ LHS.From().uadd_ov(RHS.From(), HasMinOverflowed);
+ LHS.To().uadd_ov(RHS.To(), HasMaxOverflowed);
----------------
vsavchenko wrote:
> manas wrote:
> > vsavchenko wrote:
> > > manas wrote:
> > > > vsavchenko wrote:
> > > > > manas wrote:
> > > > > > Using `uadd_ov` (and `sadd_ov`), we can get the added value as well
> > > > > > as whether overflow occurred or not. A point is that these
> > > > > > functions return `APInt` instead of `APSInt`.
> > > > > >
> > > > > > But when I tried just using:
> > > > > > Min = LHS.From().uadd_ov(RHS.From(), HasMinOverflowed);
> > > > > > Max = LHS.To().uadd_ov(RHS.From(), HasMaxOverflowed);
> > > > > >
> > > > > > instead of
> > > > > > Min = LHS.From() + RHS.From();
> > > > > > Max = LHS.To() + RHS.To();
> > > > > >
> > > > > > just for the added value, then the following tests failed (//these
> > > > > > tests and all other tests pass when I use the latter method to get
> > > > > > Min/Max//):
> > > > > >
> > > > > > Clang :: Analysis/PR3991.m
> > > > > > Clang :: Analysis/global-region-invalidation.c
> > > > > > Clang :: Analysis/malloc-overflow2.c
> > > > > > Clang :: Analysis/out-of-bounds-new.cpp
> > > > > > Clang :: Analysis/taint-generic.c
> > > > > >
> > > > > > I am working on fixing this part.
> > > > > You can easily construct `APSInt` from `APInt` using `APSInt
> > > > > ::APSInt(APInt I, bool isUnsigned)` constructor.
> > > > Okay. I will try with using `uadd_ov` only then. And check whether
> > > > those tests pass or not.
> > > Hmm, why only `uadd_ov`? What about those tests? How do they fail? Try
> > > to look at the reasons and not brute-force by trying different solutions
> > > blindly.
> > > Those tests are your friends, it's much better to get failures right now
> > > then getting them later when you land the patch.
> > I meant related functions as well.
> >
> > Most of them were failing due to `Error evaluating statements`. Although,
> > I have rebased my tree so I will re-check again.
> `Error evaluating statements` just tells you when we crashed (for the context
> and fast insight).
> Below this message is usually the real reason (and the last time I checked,
> it was assertion `From > To` failure).
My bad. I took a look and found, it was signed mismatch!
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D103440/new/
https://reviews.llvm.org/D103440
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