Fix bug #4503: mixing universe polymorphic and monomorphic

variables and definitions in sections is unsupported.

library/declare.ml

@@ -158,7 +158,7 @@ let cache_constant ((sp,kn), obj) =
   assert (eq_constant kn' (constant_of_kn kn));
   Nametab.push (Nametab.Until 1) sp (ConstRef (constant_of_kn kn));
   let cst = Global.lookup_constant kn' in
-  add_section_constant (cst.const_proj <> None) kn' cst.const_hyps;
+  add_section_constant cst.const_polymorphic kn' cst.const_hyps;
   Dischargedhypsmap.set_discharged_hyps sp obj.cst_hyps;
   add_constant_kind (constant_of_kn kn) obj.cst_kind
 
@@ -325,7 +325,7 @@ let cache_inductive ((sp,kn),(dhyps,mie)) =
   let kn' = Global.add_mind dir id mie in
   assert (eq_mind kn' (mind_of_kn kn));
   let mind = Global.lookup_mind kn' in
-  add_section_kn kn' mind.mind_hyps;
+  add_section_kn mind.mind_polymorphic kn' mind.mind_hyps;
   Dischargedhypsmap.set_discharged_hyps sp dhyps;
   List.iter (fun (sp, ref) -> Nametab.push (Nametab.Until 1) sp ref) names
 

library/lib.ml

@@ -408,17 +408,24 @@ let add_section () =
   sectab := ([],(Names.Cmap.empty,Names.Mindmap.empty),
                 (Names.Cmap.empty,Names.Mindmap.empty)) :: !sectab
 
+let check_same_poly p vars =
+  let pred = function Context _ -> p = false | Variable (_, _, poly, _) -> p != poly in
+  if List.exists pred vars then
+    error "Cannot mix universe polymorphic and monomorphic declarations in sections."
+
 let add_section_variable id impl poly ctx =
   match !sectab with
     | [] -> () (* because (Co-)Fixpoint temporarily uses local vars *)
     | (vars,repl,abs)::sl ->
-	sectab := (Variable (id,impl,poly,ctx)::vars,repl,abs)::sl
+       check_same_poly poly vars;
+       sectab := (Variable (id,impl,poly,ctx)::vars,repl,abs)::sl
 
 let add_section_context ctx =
   match !sectab with
     | [] -> () (* because (Co-)Fixpoint temporarily uses local vars *)
     | (vars,repl,abs)::sl ->
-	sectab := (Context ctx :: vars,repl,abs)::sl
+       check_same_poly true vars;
+       sectab := (Context ctx :: vars,repl,abs)::sl
 
 let extract_hyps (secs,ohyps) =
   let rec aux = function
@@ -443,24 +450,25 @@ let instance_from_variable_context sign =
 
 let named_of_variable_context ctx = List.map (fun (id,_,b,t) -> (id,b,t)) ctx
 
-let add_section_replacement f g hyps =
+let add_section_replacement f g poly hyps =
   match !sectab with
   | [] -> ()
   | (vars,exps,abs)::sl ->
+    let () = check_same_poly poly vars in
     let sechyps,ctx = extract_hyps (vars,hyps) in
     let ctx = Univ.ContextSet.to_context ctx in
     let subst, ctx = Univ.abstract_universes true ctx in
     let args = instance_from_variable_context (List.rev sechyps) in
     sectab := (vars,f (Univ.UContext.instance ctx,args) exps,
 	      g (sechyps,subst,ctx) abs)::sl
 
-let add_section_kn kn =
+let add_section_kn poly kn =
   let f x (l1,l2) = (l1,Names.Mindmap.add kn x l2) in
-    add_section_replacement f f
+    add_section_replacement f f poly
 
-let add_section_constant is_projection kn =
+let add_section_constant poly kn =
   let f x (l1,l2) = (Names.Cmap.add kn x l1,l2) in
-    add_section_replacement f f
+    add_section_replacement f f poly
 
 let replacement_context () = pi2 (List.hd !sectab)
 

library/lib.mli

@@ -178,9 +178,10 @@ val is_in_section : Globnames.global_reference -> bool
 
 val add_section_variable : Names.Id.t -> Decl_kinds.binding_kind -> Decl_kinds.polymorphic -> Univ.universe_context_set -> unit
 val add_section_context : Univ.universe_context_set -> unit
-val add_section_constant : bool (* is_projection *) -> 
+val add_section_constant : Decl_kinds.polymorphic ->
   Names.constant -> Context.named_context -> unit
-val add_section_kn : Names.mutual_inductive -> Context.named_context -> unit
+val add_section_kn : Decl_kinds.polymorphic ->
+  Names.mutual_inductive -> Context.named_context -> unit
 val replacement_context : unit -> Opaqueproof.work_list
 
 (** {6 Discharge: decrease the section level if in the current section } *)

test-suite/bugs/closed/4503.v

@@ -0,0 +1,37 @@
+Require Coq.Classes.RelationClasses.
+
+Class PreOrder (A : Type) (r : A -> A -> Type) : Type :=
+{ refl : forall x, r x x }.
+
+(* FAILURE 1 *)
+
+Section foo.
+  Polymorphic Universes A.
+  Polymorphic Context {A : Type@{A}} {rA : A -> A -> Prop} {PO : PreOrder A rA}.
+
+  Fail Definition foo := PO.
+End foo.
+
+
+Module ILogic.
+
+Set Universe Polymorphism.
+
+(* Logical connectives *)
+Class ILogic@{L} (A : Type@{L}) : Type := mkILogic
+{
+  lentails: A -> A -> Prop;
+  lentailsPre:> RelationClasses.PreOrder lentails
+}.
+
+
+End ILogic.
+
+Set Printing Universes.
+
+(* There is stil a problem if the class is universe polymorphic *)
+Section Embed_ILogic_Pre.
+  Polymorphic Universes A T.
+  Fail Context {A : Type@{A}} {ILA: ILogic.ILogic@{A} A}.
+
+End Embed_ILogic_Pre.

test-suite/bugs/closed/HoTT_coq_002.v

@@ -9,7 +9,7 @@ Section SpecializedFunctor.
   (* Variable objC : Type. *)
   Context `(C : SpecializedCategory objC).
 
-  Polymorphic Record SpecializedFunctor := {
+  Record SpecializedFunctor := {
     ObjectOf' : objC -> Type;
     ObjectC : Object C
   }.

test-suite/bugs/closed/HoTT_coq_020.v

@@ -59,8 +59,8 @@ Polymorphic Definition FunctorFrom0 objC (C : Category objC) : Functor Cat0 C
   := Build_Functor Cat0 C (fun x => match x with end).
 
 Section Law0.
-  Variable objC : Type.
-  Variable C : Category objC.
+  Polymorphic Variable objC : Type.
+  Polymorphic Variable C : Category objC.
 
   Set Printing All.
   Set Printing Universes.

theories/Logic/Hurkens.v

@@ -631,6 +631,8 @@ End NoRetractFromTypeToProp.
 
 Module TypeNeqSmallType.
 
+Unset Universe Polymorphism.
+
 Section Paradox.
 
 (** ** Universe [U] is equal to one of its elements. *)
@@ -655,7 +657,6 @@ Proof.
   reflexivity.
 Qed.
 
-
 Theorem paradox : False.
 Proof.
   Generic.paradox p.