The kernel _must_ check the correctness of the height since the reduction

[helm.git] / helm / software / components / ng_kernel / nCicTypeChecker.ml

diff --git a/helm/software/components/ng_kernel/nCicTypeChecker.ml b/helm/software/components/ng_kernel/nCicTypeChecker.ml
index 0d3fc07d12458267ef78b7addf98d4a393502047..ce16af7d213dc5fbb33f315fdeef49b526689d50 100644 (file)
--- a/helm/software/components/ng_kernel/nCicTypeChecker.ml
+++ b/helm/software/components/ng_kernel/nCicTypeChecker.ml
@@ -1181,9 +1181,52 @@ let typecheck_subst ~metasenv subst =
     ) [] subst)
 ;;
 
+let height_of_term tl =
+ let h = ref 0 in
+ let get_height (NReference.Ref (uri,_)) =
+  let _,height,_,_,_ = NCicEnvironment.get_checked_obj uri in
+   height in
+ let rec aux =
+  function
+     NCic.Meta (_,(_,NCic.Ctx l)) -> List.iter aux l
+   | NCic.Meta _ -> ()
+   | NCic.Rel _
+   | NCic.Sort _ -> ()
+   | NCic.Implicit _ -> assert false
+   | NCic.Const nref -> h := max !h (get_height nref)
+   | NCic.Prod (_,t1,t2)
+   | NCic.Lambda (_,t1,t2) -> aux t1; aux t2
+   | NCic.LetIn (_,s,ty,t) -> aux s; aux ty; aux t
+   | NCic.Appl l -> List.iter aux l
+   | NCic.Match (_,outty,t,pl) -> aux outty; aux t; List.iter aux pl
+ in
+  List.iter aux tl;
+  1 + !h
+;;
+
+let height_of_obj_kind uri =
+ function
+    NCic.Inductive _
+  | NCic.Constant (_,_,None,_,_)
+  | NCic.Fixpoint (false,_,_) -> 0
+  | NCic.Fixpoint (true,ifl,_) ->
+     let iflno = List.length ifl in
+      height_of_term
+       (List.fold_left
+        (fun l (_,_,_,ty,bo) ->
+          let bo = debruijn uri iflno [] bo in
+           ty::bo::l
+       ) [] ifl)
+  | NCic.Constant (_,_,Some bo,ty,_) -> height_of_term [bo;ty]
+;;
 
-let typecheck_obj (uri,_height,metasenv,subst,kind) =
- (* height is not checked since it is only used to implement an optimization *)
+let typecheck_obj (uri,height,metasenv,subst,kind) =
+(*height must be checked since it is not only an optimization during reduction*)
+ let iheight = height_of_obj_kind uri kind in
+ if height <> iheight then
+  raise (TypeCheckerFailure (lazy (Printf.sprintf
+   "the declared object height (%d) is not the inferred one (%d)"
+   height iheight)));
  typecheck_metasenv metasenv;
  typecheck_subst ~metasenv subst;
  match kind with