Merge PR #10177: Fix #10176: shadowing vs automatic class based generalization + cleanups

Reviewed-by: herbelin

10 files changed, 59 insertions, 42 deletions

diff --git a/dev/ci/user-overlays/10177-SkySkimmer-generalize.sh b/dev/ci/user-overlays/10177-SkySkimmer-generalize.sh
new file mode 100644
index 0000000000..a89f6aca1b
--- /dev/null
+++ b/dev/ci/user-overlays/10177-SkySkimmer-generalize.sh
@@ -0,0 +1,6 @@
+if [ "$CI_PULL_REQUEST" = "10177" ] || [ "$CI_BRANCH" = "generalize" ]; then
+
+    quickchick_CI_REF=generalize
+    quickchick_CI_GITURL=https://github.com/SkySkimmer/QuickChick
+
+fi
diff --git a/interp/constrexpr.ml b/interp/constrexpr.ml
index 9f778d99e9..3ebbbdfb88 100644
--- a/interp/constrexpr.ml
+++ b/interp/constrexpr.ml
@@ -40,8 +40,8 @@ type explicitation =
 
 type binder_kind =
   | Default of binding_kind
-  | Generalized of binding_kind * binding_kind * bool
-      (** Inner binding, outer bindings, typeclass-specific flag
+  | Generalized of binding_kind * bool
+      (** (Inner binding always Implicit) Outer bindings, typeclass-specific flag
 	 for implicit generalization of superclasses *)
 
 type abstraction_kind = AbsLambda | AbsPi
diff --git a/interp/constrexpr_ops.ml b/interp/constrexpr_ops.ml
index 443473d5b6..bcb2f34377 100644
--- a/interp/constrexpr_ops.ml
+++ b/interp/constrexpr_ops.ml
@@ -34,8 +34,8 @@ let abstraction_kind_eq ak1 ak2 = match ak1, ak2 with
 
 let binder_kind_eq b1 b2 = match b1, b2 with
 | Default bk1, Default bk2 -> binding_kind_eq bk1 bk2
-| Generalized (bk1, ck1, b1), Generalized (bk2, ck2, b2) ->
-  binding_kind_eq bk1 bk2 && binding_kind_eq ck1 ck2 &&
+| Generalized (ck1, b1), Generalized (ck2, b2) ->
+  binding_kind_eq ck1 ck2 &&
   (if b1 then b2 else not b2)
 | _ -> false
 
diff --git a/interp/constrintern.ml b/interp/constrintern.ml
index f06493b374..753065b7dd 100644
--- a/interp/constrintern.ml
+++ b/interp/constrintern.ml
@@ -389,7 +389,7 @@ let push_name_env ?(global_level=false) ntnvars implargs env =
       {env with ids = Id.Set.add id env.ids; impls = Id.Map.add id implargs env.impls}
 
 let intern_generalized_binder ?(global_level=false) intern_type ntnvars
-    env {loc;v=na} b b' t ty =
+    env {loc;v=na} b' t ty =
   let ids = (match na with Anonymous -> fun x -> x | Name na -> Id.Set.add na) env.ids in
   let ty, ids' =
     if t then ty, ids else
@@ -403,7 +403,7 @@ let intern_generalized_binder ?(global_level=false) intern_type ntnvars
     env fvs in
   let bl = List.map
     CAst.(map (fun id ->
-      (Name id, b, DAst.make ?loc @@ GHole (Evar_kinds.BinderType (Name id), IntroAnonymous, None))))
+      (Name id, Implicit, DAst.make ?loc @@ GHole (Evar_kinds.BinderType (Name id), IntroAnonymous, None))))
     fvs
   in
   let na = match na with
@@ -433,8 +433,8 @@ let intern_assumption intern ntnvars env nal bk ty =
           (push_name_env ntnvars impls env locna,
            (make ?loc (na,k,locate_if_hole ?loc na ty))::bl))
 	(env, []) nal
-  | Generalized (b,b',t) ->
-     let env, b = intern_generalized_binder intern_type ntnvars env (List.hd nal) b b' t ty in
+  | Generalized (b',t) ->
+     let env, b = intern_generalized_binder intern_type ntnvars env (List.hd nal) b' t ty in
      env, b
 
 let glob_local_binder_of_extended = DAst.with_loc_val (fun ?loc -> function
diff --git a/interp/implicit_quantifiers.ml b/interp/implicit_quantifiers.ml
index 6277d874dd..bac46c2d2f 100644
--- a/interp/implicit_quantifiers.ml
+++ b/interp/implicit_quantifiers.ml
@@ -196,10 +196,9 @@ let combine_params avoid fn applied needed =
 	  user_err ?loc:(Constrexpr_ops.constr_loc x) (str "Typeclass does not expect more arguments")
   in aux [] avoid applied needed
 
-let combine_params_freevar =
-  fun avoid (_, decl) ->
-    let id' = next_name_away_from (RelDecl.get_name decl) avoid in
-      (CAst.make @@ CRef (qualid_of_ident id',None), Id.Set.add id' avoid)
+let combine_params_freevar avoid (_, decl) =
+  let id' = next_name_away_from (RelDecl.get_name decl) avoid in
+  (CAst.make @@ CRef (qualid_of_ident id',None), Id.Set.add id' avoid)
 
 let destClassApp cl =
   let open CAst in
@@ -222,34 +221,34 @@ let implicit_application env ?(allow_partial=true) f ty =
   let is_class =
     try
       let ({CAst.v=(qid, _, _)} as clapp) = destClassAppExpl ty in
-      let gr = Nametab.locate qid in
-	if Typeclasses.is_class gr then Some (clapp, gr) else None
+      if Libnames.idset_mem_qualid qid env then None
+      else
+        let gr = Nametab.locate qid in
+        if Typeclasses.is_class gr then Some (clapp, gr) else None
     with Not_found -> None
   in
-    match is_class with
-    | None -> ty, env
-    | Some ({CAst.loc;v=(id, par, inst)}, gr) ->
-	let avoid = Id.Set.union env (ids_of_list (free_vars_of_constr_expr ty ~bound:env [])) in
-	let c, avoid =
-   let env = Global.env () in
-   let sigma = Evd.from_env env in
-   let c = class_info env sigma gr in
-   let (ci, rd) = c.cl_context in
-   if not allow_partial then
-     begin
-       let opt_succ x n = match x with
-         | None -> succ n
-         | Some _ -> n
-       in
-       let applen = List.fold_left (fun acc (x, y) -> opt_succ y acc) 0 par in
-       let needlen = List.fold_left (fun acc x -> opt_succ x acc) 0 ci in
-       if not (Int.equal needlen applen) then
-         mismatched_ctx_inst_err (Global.env ()) Typeclasses_errors.Parameters (List.map fst par) rd
-     end;
-   let pars = List.rev (List.combine ci rd) in
-   let args, avoid = combine_params avoid f par pars in
-   CAst.make ?loc @@ CAppExpl ((None, id, inst), args), avoid
- in c, avoid
+  match is_class with
+  | None -> ty, env
+  | Some ({CAst.loc;v=(id, par, inst)}, gr) ->
+    let avoid = Id.Set.union env (ids_of_list (free_vars_of_constr_expr ty ~bound:env [])) in
+    let env = Global.env () in
+    let sigma = Evd.from_env env in
+    let c = class_info env sigma gr in
+    let (ci, rd) = c.cl_context in
+    if not allow_partial then
+      begin
+        let opt_succ x n = match x with
+          | None -> succ n
+          | Some _ -> n
+        in
+        let applen = List.fold_left (fun acc (x, y) -> opt_succ y acc) 0 par in
+        let needlen = List.fold_left (fun acc x -> opt_succ x acc) 0 ci in
+        if not (Int.equal needlen applen) then
+          mismatched_ctx_inst_err (Global.env ()) Typeclasses_errors.Parameters (List.map fst par) rd
+      end;
+    let pars = List.rev (List.combine ci rd) in
+    let args, avoid = combine_params avoid f par pars in
+    CAst.make ?loc @@ CAppExpl ((None, id, inst), args), avoid
 
 let warn_ignoring_implicit_status =
   CWarnings.create ~name:"ignoring_implicit_status" ~category:"implicits"
diff --git a/library/libnames.ml b/library/libnames.ml
index 87c4de42e8..41b38e0378 100644
--- a/library/libnames.ml
+++ b/library/libnames.ml
@@ -162,6 +162,9 @@ let qualid_basename qid =
 let qualid_path qid =
   qid.CAst.v.dirpath
 
+let idset_mem_qualid qid s =
+  qualid_is_ident qid && Id.Set.mem (qualid_basename qid) s
+
 (* Default paths *)
 let default_library = Names.DirPath.initial (* = ["Top"] *)
 
diff --git a/library/libnames.mli b/library/libnames.mli
index bbb4d2a058..7d77d95991 100644
--- a/library/libnames.mli
+++ b/library/libnames.mli
@@ -88,6 +88,9 @@ val qualid_is_ident : qualid -> bool
 val qualid_path : qualid -> DirPath.t
 val qualid_basename : qualid -> Id.t
 
+val idset_mem_qualid : qualid -> Id.Set.t -> bool
+(** false when the qualid is not an ident *)
+
 (** {6 ... } *)
 
 (** some preset paths *)
diff --git a/parsing/g_constr.mlg b/parsing/g_constr.mlg
index 4a9190c10a..6df97609f5 100644
--- a/parsing/g_constr.mlg
+++ b/parsing/g_constr.mlg
@@ -500,9 +500,9 @@ GRAMMAR EXTEND Gram
       | "{"; id=name; idl=LIST1 name; "}" ->
           { List.map (fun id -> CLocalAssum ([id],Default Implicit, CAst.make ~loc @@ CHole (None, IntroAnonymous, None))) (id::idl) }
       | "`("; tc = LIST1 typeclass_constraint SEP "," ; ")" ->
-	  { List.map (fun (n, b, t) -> CLocalAssum ([n], Generalized (Implicit, Explicit, b), t)) tc }
+          { List.map (fun (n, b, t) -> CLocalAssum ([n], Generalized (Explicit, b), t)) tc }
       | "`{"; tc = LIST1 typeclass_constraint SEP "," ; "}" ->
-	  { List.map (fun (n, b, t) -> CLocalAssum ([n], Generalized (Implicit, Implicit, b), t)) tc }
+          { List.map (fun (n, b, t) -> CLocalAssum ([n], Generalized (Implicit, b), t)) tc }
       | "'"; p = pattern LEVEL "0" ->
           { let (p, ty) =
             match p.CAst.v with
diff --git a/printing/ppconstr.ml b/printing/ppconstr.ml
index 78733784a7..9d3ed40f6c 100644
--- a/printing/ppconstr.ml
+++ b/printing/ppconstr.ml
@@ -339,8 +339,7 @@ let tag_var = tag Tag.variable
 
   let pr_binder many pr (nal,k,t) =
     match k with
-      | Generalized (b, b', t') ->
-        assert (match b with Implicit -> true | _ -> false);
+      | Generalized (b', t') ->
         begin match nal with
           |[{loc; v=Anonymous}] ->
             hov 1 (str"`" ++ (surround_impl b'
diff --git a/test-suite/bugs/closed/bug_10176.v b/test-suite/bugs/closed/bug_10176.v
new file mode 100644
index 0000000000..fdb0eb87a4
--- /dev/null
+++ b/test-suite/bugs/closed/bug_10176.v
@@ -0,0 +1,7 @@
+Class Foo (xxx:nat) := foo : nat.
+
+Lemma aa `{Foo} : nat. Abort.
+
+Fail Lemma xy (Foo:bool->Type) `{Foo} : nat.
+
+Fail Lemma yx (Fooo:bool->Type) `{Fooo} : nat.