[llvm-branch-commits] [clang] [SSAF] Close unsafe-buffer reachability over override families (PR #213319)

[Ziqing Luo via llvm-branch-commits]

ziqingluo-90 wrote:

> > The closure runs after the pointer-flow DFS has converged and does not feed
> > its own output back in, so a flow edge out of a newly discovered EPL is still
> > missed. FamilyClosureDoesNotRerunDFS pins that gap.
> 
> I think the alternative is to weave the override-relation into the graph. Your call that it is level-preserving is correct. Hence, the pointer-level expansion I did in the DFS blocks you from doing so. The good news is that the blocker will be gone (see #218209) and the DFS will be simple again.
> 
> After #218209, an edge `p -> q` in the graph simply means that if the EPL`p` is unsafe, so is `q`. You could encode the override-relation 'x and y are in the same family' into two graph edges `x -> y` and `y -> x`.

you could re-stack this PR to follow #218209.

https://github.com/llvm/llvm-project/pull/213319