xazax.hun accepted this revision.
xazax.hun added inline comments.
This revision is now accepted and ready to land.


================
Comment at: clang/include/clang/Analysis/FlowSensitive/MapLattice.h:92
+  /// entry as it was in the source map.
+  LatticeJoinEffect join(const MapLattice &Other) {
+    LatticeJoinEffect Effect = LatticeJoinEffect::Unchanged;
----------------
ymandel wrote:
> xazax.hun wrote:
> > It looks like apart from the join operation the rest of the methods are 
> > simply forwarding to DenseMap. I was wondering if it would make more sense 
> > to make the framework support `join` as a free function (possibly using 
> > some custom type traits?) to avoid forcing the user to write wrappers like 
> > this.
> Good point, but I think that these concerns are separable -- that is, how 
> much forwarding we do and whether we should enable `join` an arbitrary types.
> 
> For the first issue, an alternative design here would be to simply expose the 
> container as a public field and drop all the methods except for `join`.  I 
> intentionally left some abstraction in place, though, because I think that 
> `DenseMap` is not the right container, its just "good enough" to get started. 
> I think ultimately we'll want functional data structures, because the current 
> setup forces an absurd amount of copying.
> 
> For the second issue, I'm open to the idea -- it would be like Haskell's type 
> classes in some sense, but I prefer the design where the lattice's operations 
> are grouped together as a unit. I think that we could fit it into the current 
> design with some form of SFINAE-based discrimination on the lattice type 
> parameter of `DataflowAnalysis`.
> 
> Given that, what do you think of just renaming this to `DenseMapLattice` and 
> exposing the container field publicly? When we're ready with a better map 
> lattice, we can add that alongside this one with a different name.
Alternatively, I was wondering if deriving from `llvm::DenseMap<Key, 
ElementLattice>` would reduce the amount of boilerplate this needs.

I'm a big fan of the typeclass approach, so I'd be really happy if the 
framework supported something like that but it is definitely out of scope for 
the PR.

> I think ultimately we'll want functional data structures, because the current 
> setup forces an absurd amount of copying.

+1.

> Given that, what do you think of just renaming this to DenseMapLattice and 
> exposing the container field publicly? When we're ready with a better map 
> lattice, we can add that alongside this one with a different name.

Since we do not consider this to be the final/definitive solution, I'm fine 
with either approach or leaving this as is. 





Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D116369/new/

https://reviews.llvm.org/D116369

_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

Reply via email to