Fix #4346 1/2: native casts were not inferring universe constraints.

6 files changed, 80 insertions, 82 deletions

diff --git a/kernel/fast_typeops.ml b/kernel/fast_typeops.ml
index d22abff10..063c9cf12 100644
--- a/kernel/fast_typeops.ml
+++ b/kernel/fast_typeops.ml
@@ -227,7 +227,7 @@ let judge_of_cast env c ct k expected_type =
       default_conv ~l2r:true CUMUL env ct expected_type
     | NATIVEcast ->
       let sigma = Nativelambda.empty_evars in
-      native_conv CUMUL sigma env ct expected_type
+      Nativeconv.native_conv CUMUL sigma env ct expected_type
   with NotConvertible ->
     error_actual_type env (make_judge c ct) expected_type
 
diff --git a/kernel/nativeconv.ml b/kernel/nativeconv.ml
index d0aa96fd1..fc68575cd 100644
--- a/kernel/nativeconv.ml
+++ b/kernel/nativeconv.ml
@@ -16,21 +16,21 @@ open Nativecode
 
 (** This module implements the conversion test by compiling to OCaml code *)
 
-let rec conv_val env pb lvl cu v1 v2 = 
-  if v1 == v2 then ()
+let rec conv_val env pb lvl v1 v2 cu =
+  if v1 == v2 then cu
   else
     match kind_of_value v1, kind_of_value v2 with
     | Vfun f1, Vfun f2 ->
 	let v = mk_rel_accu lvl in
-	conv_val env CONV (lvl+1) cu (f1 v) (f2 v)
+	conv_val env CONV (lvl+1) (f1 v) (f2 v) cu
     | Vfun f1, _ ->
-	conv_val env CONV lvl cu v1 (fun x -> v2 x)
+	conv_val env CONV lvl v1 (fun x -> v2 x) cu
     | _, Vfun f2 ->
-	conv_val env CONV lvl cu (fun x -> v1 x) v2
+	conv_val env CONV lvl (fun x -> v1 x) v2 cu
     | Vaccu k1, Vaccu k2 ->
-	conv_accu env pb lvl cu k1 k2
+	conv_accu env pb lvl k1 k2 cu
     | Vconst i1, Vconst i2 -> 
-	if not (Int.equal i1 i2) then raise NotConvertible
+	if Int.equal i1 i2 then cu else raise NotConvertible
     | Vblock b1, Vblock b2 ->
 	let n1 = block_size b1 in
         let n2 = block_size b2 in
@@ -38,76 +38,76 @@ let rec conv_val env pb lvl cu v1 v2 =
 	  raise NotConvertible;
 	let rec aux lvl max b1 b2 i cu =
 	  if Int.equal i max then 
-	    conv_val env CONV lvl cu (block_field b1 i) (block_field b2 i)
+	    conv_val env CONV lvl (block_field b1 i) (block_field b2 i) cu
 	  else
-	      (conv_val env CONV lvl cu (block_field b1 i) (block_field b2 i);
-	    aux lvl max b1 b2 (i+1) cu)
+	    let cu = conv_val env CONV lvl (block_field b1 i) (block_field b2 i) cu in
+	    aux lvl max b1 b2 (i+1) cu
 	in
 	aux lvl (n1-1) b1 b2 0 cu
     | Vaccu _, _ | Vconst _, _ | Vblock _, _ -> raise NotConvertible
 
-and conv_accu env pb lvl cu k1 k2 = 
+and conv_accu env pb lvl k1 k2 cu =
   let n1 = accu_nargs k1 in
   let n2 = accu_nargs k2 in
   if not (Int.equal n1 n2) then raise NotConvertible;
   if Int.equal n1 0 then 
     conv_atom env pb lvl (atom_of_accu k1) (atom_of_accu k2) cu
   else
-    (conv_atom env pb lvl (atom_of_accu k1) (atom_of_accu k2) cu;
-    List.iter2 (conv_val env CONV lvl cu) (args_of_accu k1) (args_of_accu k2))
+    let cu = conv_atom env pb lvl (atom_of_accu k1) (atom_of_accu k2) cu in
+    List.fold_right2 (conv_val env CONV lvl) (args_of_accu k1) (args_of_accu k2) cu
 
 and conv_atom env pb lvl a1 a2 cu =
-  if a1 == a2 then ()
+  if a1 == a2 then cu
   else
     match a1, a2 with
     | Ameta _, _ | _, Ameta _ | Aevar _, _ | _, Aevar _ -> assert false
     | Arel i1, Arel i2 -> 
-	if not (Int.equal i1 i2) then raise NotConvertible
+	if Int.equal i1 i2 then cu else raise NotConvertible
     | Aind ind1, Aind ind2 ->
-	if not (eq_puniverses eq_ind ind1 ind2) then raise NotConvertible
+	if eq_puniverses eq_ind ind1 ind2 then cu else raise NotConvertible
     | Aconstant c1, Aconstant c2 ->
-	if not (eq_puniverses eq_constant c1 c2) then raise NotConvertible
+	if eq_puniverses eq_constant c1 c2 then cu else raise NotConvertible
     | Asort s1, Asort s2 -> 
-        check_sort_cmp_universes env pb s1 s2 cu
+        sort_cmp_universes env pb s1 s2 cu
     | Avar id1, Avar id2 ->
-	if not (Id.equal id1 id2) then raise NotConvertible
+	if Id.equal id1 id2 then cu else raise NotConvertible
     | Acase(a1,ac1,p1,bs1), Acase(a2,ac2,p2,bs2) ->
 	if not (eq_ind a1.asw_ind a2.asw_ind) then raise NotConvertible;
-	conv_accu env CONV lvl cu ac1 ac2;
+	let cu = conv_accu env CONV lvl ac1 ac2 cu in
 	let tbl = a1.asw_reloc in
 	let len = Array.length tbl in
-	if Int.equal len 0 then conv_val env CONV lvl cu p1 p2
+	if Int.equal len 0 then conv_val env CONV lvl p1 p2 cu
 	else begin
-	  conv_val env CONV lvl cu p1 p2;
-	  let max = len - 1 in
-	  let rec aux i =
-	    let tag,arity = tbl.(i) in
-	    let ci = 
-	      if Int.equal arity 0 then mk_const tag
-	      else mk_block tag (mk_rels_accu lvl arity) in
-	    let bi1 = bs1 ci and bi2 = bs2 ci in
-	    if Int.equal i max then conv_val env CONV (lvl + arity) cu bi1 bi2
-	    else (conv_val env CONV (lvl + arity) cu bi1 bi2; aux (i+1)) in
-	  aux 0
+	    let cu = conv_val env CONV lvl p1 p2 cu in
+	    let max = len - 1 in
+	    let rec aux i cu =
+	      let tag,arity = tbl.(i) in
+	      let ci =
+		if Int.equal arity 0 then mk_const tag
+		else mk_block tag (mk_rels_accu lvl arity) in
+	      let bi1 = bs1 ci and bi2 = bs2 ci in
+	      if Int.equal i max then conv_val env CONV (lvl + arity) bi1 bi2 cu
+	      else aux (i+1) (conv_val env CONV (lvl + arity) bi1 bi2 cu) in
+	    aux 0 cu
 	  end
     | Afix(t1,f1,rp1,s1), Afix(t2,f2,rp2,s2) ->
 	if not (Int.equal s1 s2) || not (Array.equal Int.equal rp1 rp2) then raise NotConvertible;
-	if f1 == f2 then ()
+	if f1 == f2 then cu
 	else conv_fix env lvl t1 f1 t2 f2 cu
     | (Acofix(t1,f1,s1,_) | Acofixe(t1,f1,s1,_)),
       (Acofix(t2,f2,s2,_) | Acofixe(t2,f2,s2,_)) ->
 	if not (Int.equal s1 s2) then raise NotConvertible;
-	if f1 == f2 then ()
+	if f1 == f2 then cu
 	else
 	  if not (Int.equal (Array.length f1) (Array.length f2)) then raise NotConvertible
 	  else conv_fix env lvl t1 f1 t2 f2 cu 
     | Aprod(_,d1,c1), Aprod(_,d2,c2) ->
-	conv_val env CONV lvl cu d1 d2;
-	let v = mk_rel_accu lvl in
-	conv_val env pb (lvl + 1) cu (d1 v) (d2 v)
+       let cu = conv_val env CONV lvl d1 d2 cu in
+       let v = mk_rel_accu lvl in
+       conv_val env pb (lvl + 1) (d1 v) (d2 v) cu
     | Aproj(p1,ac1), Aproj(p2,ac2) ->
        if not (Constant.equal p1 p2) then raise NotConvertible
-       else conv_accu env CONV lvl cu ac1 ac2
+       else conv_accu env CONV lvl ac1 ac2 cu
     | Arel _, _ | Aind _, _ | Aconstant _, _ | Asort _, _ | Avar _, _
     | Acase _, _ | Afix _, _ | Acofix _, _ | Acofixe _, _ | Aprod _, _
     | Aproj _, _ -> raise NotConvertible
@@ -118,21 +118,15 @@ and conv_fix env lvl t1 f1 t2 f2 cu =
   let max = len - 1 in
   let fargs = mk_rels_accu lvl len in
   let flvl = lvl + len in
-  let rec aux i =
-    conv_val env CONV lvl cu t1.(i) t2.(i);
+  let rec aux i cu =
+    let cu = conv_val env CONV lvl t1.(i) t2.(i) cu in
     let fi1 = napply f1.(i) fargs in
     let fi2 = napply f2.(i) fargs in
-    if Int.equal i max then conv_val env CONV flvl cu fi1 fi2
-    else (conv_val env CONV flvl cu fi1 fi2; aux (i+1)) in
-  aux 0
+    if Int.equal i max then conv_val env CONV flvl fi1 fi2 cu
+    else aux (i+1) (conv_val env CONV flvl fi1 fi2 cu) in
+  aux 0 cu
 
-let native_conv pb sigma env t1 t2 =
-  if Coq_config.no_native_compiler then begin
-    let msg = "Native compiler is disabled, falling back to VM conversion test." in
-    Pp.msg_warning (Pp.str msg);
-    vm_conv pb env t1 t2
-  end
-  else
+let native_conv_gen pb sigma env univs t1 t2 =
   let penv = Environ.pre_env env in 
   let ml_filename, prefix = get_ml_filename () in
   let code, upds = mk_conv_code penv sigma prefix t1 t2 in
@@ -146,8 +140,26 @@ let native_conv pb sigma env t1 t2 =
         let time_info = Format.sprintf "Evaluation done in %.5f@." (t1 -. t0) in
         if !Flags.debug then Pp.msg_debug (Pp.str time_info);
         (* TODO change 0 when we can have deBruijn *)
-        conv_val env pb 0 (Environ.universes env) !rt1 !rt2
+        fst (conv_val env pb 0 !rt1 !rt2 univs)
       end
   | _ -> anomaly (Pp.str "Compilation failure") 
 
-let _ = set_nat_conv native_conv
+(* Wrapper for [native_conv] above *)
+let native_conv cv_pb sigma env t1 t2 =
+  if Coq_config.no_native_compiler then begin
+    let msg = "Native compiler is disabled, falling back to VM conversion test." in
+    Pp.msg_warning (Pp.str msg);
+    vm_conv cv_pb env t1 t2
+  end
+  else
+  let univs = Environ.universes env in
+  let b =
+    if cv_pb = CUMUL then Constr.leq_constr_univs univs t1 t2
+    else Constr.eq_constr_univs univs t1 t2
+  in
+  let univs = (univs, checked_universes) in
+  if not b then begin
+    let t1 = Term.it_mkLambda_or_LetIn t1 (Environ.rel_context env) in
+    let t2 = Term.it_mkLambda_or_LetIn t2 (Environ.rel_context env) in
+    let _ = native_conv_gen cv_pb sigma env univs t1 t2 in ()
+  end
diff --git a/kernel/nativeconv.mli b/kernel/nativeconv.mli
index 318a7d830..21f0b2e9e 100644
--- a/kernel/nativeconv.mli
+++ b/kernel/nativeconv.mli
@@ -12,3 +12,7 @@ open Nativelambda
 (** This module implements the conversion test by compiling to OCaml code *)
 
 val native_conv : conv_pb -> evars -> types conversion_function
+
+(** A conversion function parametrized by a universe comparator. Used outside of
+    the kernel. *)
+val native_conv_gen : conv_pb -> evars -> (constr, 'a) generic_conversion_function
diff --git a/kernel/reduction.ml b/kernel/reduction.ml
index 0f105b048..b6c97b11d 100644
--- a/kernel/reduction.ml
+++ b/kernel/reduction.ml
@@ -637,7 +637,7 @@ let infer_cmp_universes env pb s0 s1 univs =
 let infer_convert_instances flex u u' (univs,cstrs) =
   (univs, Univ.enforce_eq_instances u u' cstrs)
 
-let infered_universes : (Univ.universes * Univ.Constraint.t) universe_compare = 
+let inferred_universes : (Univ.universes * Univ.Constraint.t) universe_compare =
   { compare = infer_cmp_universes;
     compare_instances = infer_convert_instances }
 
@@ -685,7 +685,7 @@ let conv_leq_vecti ?(l2r=false) ?(evars=fun _->None) env v1 v2 =
     v1
     v2
 
-let generic_conv cv_pb l2r evars reds env univs t1 t2 =
+let generic_conv cv_pb ~l2r evars reds env univs t1 t2 =
   let (s, _) = 
     clos_fconv reds cv_pb l2r evars env univs t1 t2 
   in s
@@ -697,7 +697,7 @@ let infer_conv_universes cv_pb l2r evars reds env univs t1 t2 =
   in
     if b then cstrs
     else
-      let univs = ((univs, Univ.Constraint.empty), infered_universes) in
+      let univs = ((univs, Univ.Constraint.empty), inferred_universes) in
       let ((_,cstrs), _) = clos_fconv reds cv_pb l2r evars env univs t1 t2 in
 	cstrs
 
@@ -716,19 +716,6 @@ let infer_conv_leq ?(l2r=false) ?(evars=fun _ -> None) ?(ts=full_transparent_sta
     env univs t1 t2 = 
   infer_conv_universes CUMUL l2r evars ts env univs t1 t2
 
-(* option for conversion *)
-let nat_conv = ref (fun cv_pb sigma ->
-		    fconv cv_pb false (sigma.Nativelambda.evars_val))
-let set_nat_conv f = nat_conv := f
-
-let native_conv cv_pb sigma env t1 t2 =
-  if eq_constr t1 t2 then ()
-  else begin
-    let t1 = (it_mkLambda_or_LetIn t1 (rel_context env)) in
-    let t2 = (it_mkLambda_or_LetIn t2 (rel_context env)) in
-    !nat_conv cv_pb sigma env t1 t2 
-  end
-
 let vm_conv = ref (fun cv_pb -> fconv cv_pb false (fun _->None))
 let set_vm_conv f = vm_conv := f
 let vm_conv cv_pb env t1 t2 =
diff --git a/kernel/reduction.mli b/kernel/reduction.mli
index 90c008b19..b71356d03 100644
--- a/kernel/reduction.mli
+++ b/kernel/reduction.mli
@@ -49,14 +49,11 @@ type ('a,'b) generic_conversion_function = env -> 'b universe_state -> 'a -> 'a
 
 type 'a infer_conversion_function = env -> Univ.universes -> 'a -> 'a -> Univ.constraints
 
-val check_sort_cmp_universes :
-  env -> conv_pb -> sorts -> sorts -> Univ.universes -> unit
+val sort_cmp_universes : env -> conv_pb -> sorts -> sorts ->
+  'a * 'a universe_compare -> 'a * 'a universe_compare
 
-(* val sort_cmp : *)
-(*     conv_pb -> sorts -> sorts -> Univ.constraints -> Univ.constraints *)
-
-(* val conv_sort      : sorts conversion_function *)
-(* val conv_sort_leq  : sorts conversion_function *)
+val checked_universes : Univ.universes universe_compare
+val inferred_universes : (Univ.universes * Univ.Constraint.t) universe_compare
 
 val trans_conv_cmp       : ?l2r:bool -> conv_pb -> constr trans_conversion_function
 val trans_conv           :
@@ -77,22 +74,20 @@ val conv_leq       :
 val conv_leq_vecti :
   ?l2r:bool -> ?evars:(existential->constr option) -> types array conversion_function
 
+(** These conversion functions are used by module subtyping, which needs to infer
+    universe constraints inside the kernel *)
 val infer_conv : ?l2r:bool -> ?evars:(existential->constr option) -> 
   ?ts:Names.transparent_state -> constr infer_conversion_function
 val infer_conv_leq : ?l2r:bool -> ?evars:(existential->constr option) -> 
   ?ts:Names.transparent_state -> types infer_conversion_function
 
-val generic_conv : conv_pb -> bool -> (existential->constr option) -> 
+val generic_conv : conv_pb -> l2r:bool -> (existential->constr option) ->
   Names.transparent_state -> (constr,'a) generic_conversion_function
 
 (** option for conversion *)
 val set_vm_conv : (conv_pb -> types conversion_function) -> unit
 val vm_conv : conv_pb -> types conversion_function
 
-val set_nat_conv :
-  (conv_pb -> Nativelambda.evars -> types conversion_function) -> unit
-val native_conv : conv_pb -> Nativelambda.evars -> types conversion_function
-
 val default_conv     : conv_pb -> ?l2r:bool -> types conversion_function
 val default_conv_leq : ?l2r:bool -> types conversion_function
 
diff --git a/kernel/typeops.ml b/kernel/typeops.ml
index 8895bae5d..70f6fd803 100644
--- a/kernel/typeops.ml
+++ b/kernel/typeops.ml
@@ -310,7 +310,7 @@ let judge_of_cast env cj k tj =
       | NATIVEcast ->
 	 let sigma = Nativelambda.empty_evars in
          mkCast (cj.uj_val, k, expected_type),
-         native_conv CUMUL sigma env cj.uj_type expected_type
+         Nativeconv.native_conv CUMUL sigma env cj.uj_type expected_type
     in
       { uj_val = c;
 	uj_type = expected_type }