Make the back_id field non optional in Values.abs

3 files changed, 10 insertions, 12 deletions

diff --git a/src/InterpreterStatements.ml b/src/InterpreterStatements.ml
index 59d2c4da..83ad13fe 100644
--- a/src/InterpreterStatements.ml
+++ b/src/InterpreterStatements.ml
@@ -672,7 +672,6 @@ let create_empty_abstractions_from_abs_region_groups (call_id : V.FunCallId.id)
   let create_abs (back_id : T.RegionGroupId.id) (rg : A.abs_region_group) :
       V.abs =
     let abs_id = rg.T.id in
-    let back_id = Some back_id in
     let original_parents = rg.parents in
     let parents =
       List.fold_left
diff --git a/src/SymbolicToPure.ml b/src/SymbolicToPure.ml
index 60fc8c7c..06ccf7bf 100644
--- a/src/SymbolicToPure.ml
+++ b/src/SymbolicToPure.ml
@@ -220,7 +220,7 @@ let bs_ctx_register_forward_call (call_id : V.FunCallId.id) (forward : S.call)
 let bs_ctx_register_backward_call (abs : V.abs) (ctx : bs_ctx) : bs_ctx * fun_id
     =
   (* Insert the abstraction in the call informations *)
-  let back_id = Option.get abs.back_id in
+  let back_id = abs.back_id in
   let info = V.FunCallId.Map.find abs.call_id ctx.calls in
   assert (not (T.RegionGroupId.Map.mem back_id info.backwards));
   let backwards = T.RegionGroupId.Map.add back_id abs info.backwards in
@@ -233,7 +233,7 @@ let bs_ctx_register_backward_call (abs : V.abs) (ctx : bs_ctx) : bs_ctx * fun_id
   (* Retrieve the fun_id *)
   let fun_id =
     match info.forward.call_id with
-    | S.Fun (fid, _) -> Regular (fid, Some (Option.get abs.back_id))
+    | S.Fun (fid, _) -> Regular (fid, Some abs.back_id)
     | S.Unop _ | S.Binop _ -> failwith "Unreachable"
   in
   (* Update the context and return *)
@@ -669,9 +669,7 @@ and translate_end_abstraction (abs : V.abs) (e : S.expression) (ctx : bs_ctx) :
        * *)
       (* First, retrieve the list of variables used for the inputs for the
        * backward function *)
-      let inputs =
-        T.RegionGroupId.Map.find (Option.get abs.back_id) ctx.backward_inputs
-      in
+      let inputs = T.RegionGroupId.Map.find abs.back_id ctx.backward_inputs in
       raise Unimplemented
 
 and translate_expansion (sv : V.symbolic_value) (exp : S.expansion)
diff --git a/src/Values.ml b/src/Values.ml
index 95b1bd13..92b9df35 100644
--- a/src/Values.ml
+++ b/src/Values.ml
@@ -736,12 +736,13 @@ type abs = {
           this is only used for pretty-printing and debugging, in the
           symbolic AST, generated by the symbolic execution.
        *)
-  back_id : (RegionGroupId.id option[@opaque]);
-      (** The id of the backward function to which this abstraction is linked,
-          if there is one. Note that it may not be the case, when introducing
-          abstractions to handle the input values for the function we are
-          synthesizing for instance. TODO: actually should never be None.
-          
+  back_id : (RegionGroupId.id[@opaque]);
+      (** The region group id to which this abstraction is linked.
+      
+          In most situations, it gives the id of the backward function (hence
+          the name), but it is a bit more subtle in the case of synth input
+          and synth ret abstractions.
+
           This is not used by the symbolic execution: it is a utility for
           the symbolic AST, generated by the symbolic execution.
        *)