ddcc added inline comments.
================
Comment at: lib/StaticAnalyzer/Core/SValBuilder.cpp:364
if (symLHS && symRHS &&
- (symLHS->computeComplexity() + symRHS->computeComplexity()) < MaxComp)
+ (symLHS->computeComplexity() + symRHS->computeComplexity()) < MaxComp)
return makeNonLoc(symLHS, Op, symRHS, ResultTy);
----------------
zaks.anna wrote:
> ddcc wrote:
> > zaks.anna wrote:
> > > As a follow up to the previous version of this patch, I do not think we
> > > should set the default complexity limit to 10000.
> > >
> > > What is the relation between this limit and the limit in
> > > VisitNonLocSymbolVal? If they are related, would it be worthwhile turning
> > > these into an analyzer option?
> > To clarify, the current version of this patch does not modify the `MaxComp`
> > parameter.
> >
> > My understanding is that `MaxComp` is the upper bound for building a new
> > `NonLoc` symbol from two children, based on the sum of the number of child
> > symbols (complexity) across both children.
> >
> > In contrast, the limit in `VisitNonLocSymbolVal` (@NoQ, correct me if I'm
> > wrong), is the upper bound for recursively evaluating and inlining a
> > `NonLoc` symbol, triggered from `simplifySVal` by `evalBinOpNN`. Note that
> > these two latter functions indirectly call each other recursively (through
> > `evalBinOp`), causing the previous runtime blowup. Furthermore, each call
> > to `computeComplexity`will re-iterate through all child symbols of the
> > current symbol, but only the first complexity check at the root symbol is
> > actually necessary, because by definition the complexity of a child symbol
> > at each recursive call is monotonically decreasing.
> >
> > I think it'd be useful to allow both to be configurable, but I don't see a
> > direct relationship between the two.
> > To clarify, the current version of this patch does not modify the MaxComp
> > parameter.
>
> I know. Also, currently, it is only used in the unsupported taint tracking
> mode and only for tainted symbols. I would like a different smaller default
> for all expressions.
Ok. I can make both configurable as part of this patch, with a new default of
10 for `VisitNonLocSymbolVal`. But I've never used the taint tracking mode, so
I don't know what would be a reasonable default for `MaxComp`.
https://reviews.llvm.org/D35450
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