xazax.hun added inline comments.
================
Comment at: clang/lib/StaticAnalyzer/Checkers/NullPtrInterferenceChecker.cpp:166
+/// child is a sink node.
+static bool unconditionallyLeadsHere(const ExplodedNode *N) {
+ size_t NonSinkNodeCount = llvm::count_if(
----------------
Szelethus wrote:
> xazax.hun wrote:
> > xazax.hun wrote:
> > > Consider the following code snippet:
> > > ```
> > > void f(int *p, bool b)
> > > {
> > > if (b) {
> > > *p = 4;
> > > }
> > > if (p) {
> > > ...
> > > }
> > > }
> > > ```
> > >
> > > I suspect that we would get a warning for the code above. I think warning
> > > on the code above might be reasonable (the values of `b` and `p` might be
> > > correlated but in some cases the analyzer has no way to know this,
> > > probably some assertions could make the code clearer in that case).
> > >
> > > My problem is with the wording of the error message.
> > > The warning `Pointer is unconditionally non-null here` on the null check
> > > is not true for the code above.
> > Also, if the check would warn for the code snippet above, the note "suggest
> > moving the condition here" would also be incorrect.
> What if we demand that the the `CFGBlock` of the dereference must dominate
> the `CFGBlock` of the condition point?
I think it makes sense to warn both when the dereference dominates the null
check, and when the null check post-dominates the dereference. We just want to
give different error messages in those cases.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D120992/new/
https://reviews.llvm.org/D120992
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
