Fixing #5077 (failure on typing a fixpoint with evars in its type).

Typing.type_of was using conversion for types of fixpoints while it
could have used unification.

3 files changed, 17 insertions, 17 deletions

diff --git a/pretyping/pretyping.ml b/pretyping/pretyping.ml
index d6f8f0de5..2e164e540 100644
--- a/pretyping/pretyping.ml
+++ b/pretyping/pretyping.ml
@@ -267,21 +267,6 @@ let process_inference_flags flags env initial_sigma (sigma,c) =
 (* Allow references to syntactically nonexistent variables (i.e., if applied on an inductive) *)
 let allow_anonymous_refs = ref false
 
-(* Utilisé pour inférer le prédicat des Cases *)
-(* Semble exagérement fort *)
-(* Faudra préférer une unification entre les types de toutes les clauses *)
-(* et autoriser des ? à rester dans le résultat de l'unification *)
-
-let evar_type_fixpoint loc env evdref lna lar vdefj =
-  let lt = Array.length vdefj in
-    if Int.equal (Array.length lar) lt then
-      for i = 0 to lt-1 do
-        if not (e_cumul env evdref (vdefj.(i)).uj_type
-		  (lift lt lar.(i))) then
-          error_ill_typed_rec_body_loc loc env !evdref
-            i lna vdefj lar
-      done
-
 (* coerce to tycon if any *)
 let inh_conv_coerce_to_tycon resolve_tc loc env evdref j = function
   | None -> j
@@ -579,7 +564,7 @@ let rec pretype k0 resolve_tc (tycon : type_constraint) env evdref (lvar : ltac_
 	    { uj_val = it_mkLambda_or_LetIn j.uj_val ctxt;
 	      uj_type = it_mkProd_or_LetIn j.uj_type ctxt })
         ctxtv vdef in
-      evar_type_fixpoint loc env evdref names ftys vdefj;
+      Typing.check_type_fixpoint loc env evdref names ftys vdefj;
       let ftys = Array.map (nf_evar !evdref) ftys in
       let fdefs = Array.map (fun x -> nf_evar !evdref (j_val x)) vdefj in
       let fixj = match fixkind with
diff --git a/pretyping/typing.ml b/pretyping/typing.ml
index eb16628b1..bb3f19859 100644
--- a/pretyping/typing.ml
+++ b/pretyping/typing.ml
@@ -126,6 +126,16 @@ let e_judge_of_case env evdref ci pj cj lfj =
   { uj_val  = mkCase (ci, pj.uj_val, cj.uj_val, Array.map j_val lfj);
     uj_type = rslty }
 
+let check_type_fixpoint loc env evdref lna lar vdefj =
+  let lt = Array.length vdefj in
+    if Int.equal (Array.length lar) lt then
+      for i = 0 to lt-1 do
+        if not (Evarconv.e_cumul env evdref (vdefj.(i)).uj_type
+		  (lift lt lar.(i))) then
+          Pretype_errors.error_ill_typed_rec_body_loc loc env !evdref
+            i lna vdefj lar
+      done
+
 (* FIXME: might depend on the level of actual parameters!*)
 let check_allowed_sort env sigma ind c p =
   let pj = Retyping.get_judgment_of env sigma p in
@@ -263,7 +273,7 @@ and execute_recdef env evdref (names,lar,vdef) =
   let env1 = push_rec_types (names,lara,vdef) env in
   let vdefj = execute_array env1 evdref vdef in
   let vdefv = Array.map j_val vdefj in
-  let _ = type_fixpoint env1 names lara vdefj in
+  let _ = check_type_fixpoint Loc.ghost env1 evdref names lara vdefj in
   (names,lara,vdefv)
 
 and execute_array env evdref = Array.map (execute env evdref)
diff --git a/pretyping/typing.mli b/pretyping/typing.mli
index dafd75231..22cb7f3b9 100644
--- a/pretyping/typing.mli
+++ b/pretyping/typing.mli
@@ -39,3 +39,8 @@ val solve_evars : env -> evar_map ref -> constr -> constr
 (** (first constr is term to match, second is return predicate) *)
 val check_allowed_sort : env -> evar_map -> pinductive -> constr -> constr ->
   unit
+
+(** Raise an error message if bodies have types not unifiable with the
+    expected ones *)
+val check_type_fixpoint : Loc.t -> env -> evar_map ref ->
+  Names.Name.t array -> types array -> unsafe_judgment array -> unit