diff options
Diffstat (limited to 'src/InterpreterBorrows.ml')
| -rw-r--r-- | src/InterpreterBorrows.ml | 59 |
1 files changed, 51 insertions, 8 deletions
diff --git a/src/InterpreterBorrows.ml b/src/InterpreterBorrows.ml index 64e82edd..ecbfdc05 100644 --- a/src/InterpreterBorrows.ml +++ b/src/InterpreterBorrows.ml @@ -423,7 +423,8 @@ let give_back_value (config : C.config) (bid : V.BorrowId.id) (** TODO: *) let give_back_symbolic_value (_config : C.config) (_regions : T.RegionId.set_t) - (_sv : V.symbolic_value) (_ctx : C.eval_ctx) : C.eval_ctx = + (_sv : V.symbolic_value) (_nsv : V.symbolic_value) (_ctx : C.eval_ctx) : + C.eval_ctx = raise Errors.Unimplemented (** Auxiliary function to end borrows. See [give_back]. @@ -1154,22 +1155,64 @@ and end_proj_loans_symbolic (config : C.config) (abs_id : V.AbstractionId.id) C.eval_ctx = (* Find the first proj_borrows which intersects the proj_loans *) let explore_shared = true in - match - lookup_first_intersecting_aproj_borrows_opt explore_shared regions sv ctx - with + match lookup_intersecting_aproj_borrows_opt explore_shared regions sv ctx with | None -> (* We couldn't find any in the context: it means that the symbolic value * is in the concrete environment (or that we dropped it, in which case * it is completely absent) *) (* Update the loans depending on the current symbolic value - it is * left unchanged *) - give_back_symbolic_value config regions sv ctx - | Some (abs_id', proj_ty, mutable_proj) -> + give_back_symbolic_value config regions sv sv ctx + | Some (SharedProjs projs) -> + (* We found projectors over shared values - split between the projectors + * which belong to the current *) + (* TODO: we might want to allow ending shared projectors/borrows in + * abstractions without ending the abstractions themselves, if we end + * those abstractions immediately after: some abstractions may be mutually + * dependent, which is ok when it is about shared values *) + let _owned_projs, external_projs = + List.partition (fun (abs_id', _) -> abs_id' = abs_id) projs + in + if external_projs = [] then + (* There are external projs: end the corresponding abstractions *) + let abs_ids = List.map fst external_projs in + let abs_ids = + List.fold_left + (fun s id -> V.AbstractionId.Set.add id s) + V.AbstractionId.Set.empty abs_ids + in + let ctx = end_abstractions config abs_ids ctx in + (* We could end the owned projections, but it is simpler to simply return + * and let the caller recheck if there are proj_loans to end *) + ctx + else + (* All the proj_borrows are owned: simply erase them *) + let ctx = remove_intersecting_aproj_borrows_shared regions sv ctx in + (* Remove the proj_loans - note that the symbolic value was left unchanged *) + give_back_symbolic_value config regions sv sv ctx + | Some (NonSharedProj (abs_id', _proj_ty)) -> (* We found one in the context: if it comes from this abstraction, we can * end it directly, otherwise we need to end the abstraction where it * came from first *) - if abs_id' = abs_id then raise Errors.Unimplemented - else raise Errors.Unimplemented + if abs_id' = abs_id then + (* Replace the proj_borrows *) + let pb_nv = + { V.value = V.ASymbolic V.AEndedProjBorrows; V.ty = sv.V.sv_ty } + in + let ctx = + update_intersecting_aproj_borrows_non_shared regions sv pb_nv ctx + in + (* Replace the proj_loans - note that the loaned (symbolic) value + * was left unchanged *) + give_back_symbolic_value config regions sv sv ctx + else + (* End the abstraction. + * Don't retry ending the current proj_loans after ending the abstraction: + * it may have been eliminated (if it is a proj over mutable value), + * or maybe not (if it is a proj over shared values): simply return, + * as the caller function will recheck if there are loans to end in the + * current abstraction *) + end_abstraction config abs_id' ctx and end_outer_borrow config = end_borrow config None |