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diff --git a/toplevel/assumptions.ml b/toplevel/assumptions.ml new file mode 100644 index 00000000..a6bd968e --- /dev/null +++ b/toplevel/assumptions.ml @@ -0,0 +1,230 @@ +(************************************************************************) +(* v * The Coq Proof Assistant / The Coq Development Team *) +(* <O___,, * INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2015 *) +(* \VV/ **************************************************************) +(* // * This file is distributed under the terms of the *) +(* * GNU Lesser General Public License Version 2.1 *) +(************************************************************************) + +(* The following definitions are used by the function + [assumptions] which gives as an output the set of all + axioms and sections variables on which a given term depends + in a context (expectingly the Global context) *) + +(* Initial author: Arnaud Spiwack + Module-traversing code: Pierre Letouzey *) + +open Pp +open Errors +open Util +open Names +open Term +open Declarations +open Mod_subst +open Globnames +open Printer + +(** For a constant c in a module sealed by an interface (M:T and + not M<:T), [Global.lookup_constant] may return a [constant_body] + without body. We fix this by looking in the implementation + of the module *) + +let modcache = ref (MPmap.empty : structure_body MPmap.t) + +let rec search_mod_label lab = function + | [] -> raise Not_found + | (l, SFBmodule mb) :: _ when Label.equal l lab -> mb + | _ :: fields -> search_mod_label lab fields + +let rec search_cst_label lab = function + | [] -> raise Not_found + | (l, SFBconst cb) :: _ when Label.equal l lab -> cb + | _ :: fields -> search_cst_label lab fields + +(* TODO: using [empty_delta_resolver] below is probably slightly incorrect. But: + a) I don't see currently what should be used instead + b) this shouldn't be critical for Print Assumption. At worse some + constants will have a canonical name which is non-canonical, + leading to failures in [Global.lookup_constant], but our own + [lookup_constant] should work. +*) + +let rec fields_of_functor f subs mp0 args = function + |NoFunctor a -> f subs mp0 args a + |MoreFunctor (mbid,_,e) -> + match args with + | [] -> assert false (* we should only encounter applied functors *) + | mpa :: args -> + let subs = join (map_mbid mbid mpa empty_delta_resolver (*TODO*)) subs in + fields_of_functor f subs mp0 args e + +let rec lookup_module_in_impl mp = + try Global.lookup_module mp + with Not_found -> + (* The module we search might not be exported by its englobing module(s). + We access the upper layer, and then do a manual search *) + match mp with + | MPfile _ -> raise Not_found (* can happen if mp is an open module *) + | MPbound _ -> assert false + | MPdot (mp',lab') -> + let fields = memoize_fields_of_mp mp' in + search_mod_label lab' fields + +and memoize_fields_of_mp mp = + try MPmap.find mp !modcache + with Not_found -> + let l = fields_of_mp mp in + modcache := MPmap.add mp l !modcache; + l + +and fields_of_mp mp = + let mb = lookup_module_in_impl mp in + let fields,inner_mp,subs = fields_of_mb empty_subst mb [] in + let subs = + if mp_eq inner_mp mp then subs + else add_mp inner_mp mp mb.mod_delta subs + in + Modops.subst_structure subs fields + +and fields_of_mb subs mb args = match mb.mod_expr with + |Algebraic expr -> fields_of_expression subs mb.mod_mp args expr + |Struct sign -> fields_of_signature subs mb.mod_mp args sign + |Abstract|FullStruct -> fields_of_signature subs mb.mod_mp args mb.mod_type + +(** The Abstract case above corresponds to [Declare Module] *) + +and fields_of_signature x = + fields_of_functor + (fun subs mp0 args struc -> + assert (List.is_empty args); + (struc, mp0, subs)) x + +and fields_of_expr subs mp0 args = function + |MEident mp -> + let mb = lookup_module_in_impl (subst_mp subs mp) in + fields_of_mb subs mb args + |MEapply (me1,mp2) -> fields_of_expr subs mp0 (mp2::args) me1 + |MEwith _ -> assert false (* no 'with' in [mod_expr] *) + +and fields_of_expression x = fields_of_functor fields_of_expr x + +let lookup_constant_in_impl cst fallback = + try + let mp,dp,lab = repr_kn (canonical_con cst) in + let fields = memoize_fields_of_mp mp in + (* A module found this way is necessarily closed, in particular + our constant cannot be in an opened section : *) + search_cst_label lab fields + with Not_found -> + (* Either: + - The module part of the constant isn't registered yet : + we're still in it, so the [constant_body] found earlier + (if any) was a true axiom. + - The label has not been found in the structure. This is an error *) + match fallback with + | Some cb -> cb + | None -> anomaly (str "Print Assumption: unknown constant " ++ pr_con cst) + +let lookup_constant cst = + try + let cb = Global.lookup_constant cst in + if Declareops.constant_has_body cb then cb + else lookup_constant_in_impl cst (Some cb) + with Not_found -> lookup_constant_in_impl cst None + +(** Graph traversal of an object, collecting on the way the dependencies of + traversed objects *) + +let label_of = function + | ConstRef kn -> pi3 (repr_con kn) + | IndRef (kn,_) + | ConstructRef ((kn,_),_) -> pi3 (repr_mind kn) + | VarRef id -> Label.of_id id + +let push (r : Context.rel_declaration) (ctx : Context.rel_context) = r :: ctx + +let rec traverse current ctx accu t = match kind_of_term t with +| Var id -> + let body () = match Global.lookup_named id with (_, body, _) -> body in + traverse_object accu body (VarRef id) +| Const (kn, _) -> + let body () = Global.body_of_constant_body (lookup_constant kn) in + traverse_object accu body (ConstRef kn) +| Ind (ind, _) -> + traverse_object accu (fun () -> None) (IndRef ind) +| Construct (cst, _) -> + traverse_object accu (fun () -> None) (ConstructRef cst) +| Meta _ | Evar _ -> assert false +| Case (_,oty,c,[||]) -> + (* non dependent match on an inductive with no constructors *) + begin match Constr.(kind oty, kind c) with + | Lambda(Anonymous,_,oty), Const (kn, _) + when Vars.noccurn 1 oty && + not (Declareops.constant_has_body (lookup_constant kn)) -> + let body () = Global.body_of_constant_body (lookup_constant kn) in + traverse_object + ~inhabits:(current,ctx,Vars.subst1 mkProp oty) accu body (ConstRef kn) + | _ -> + Termops.fold_constr_with_full_binders push (traverse current) ctx accu t + end +| _ -> Termops.fold_constr_with_full_binders push (traverse current) ctx accu t + +and traverse_object ?inhabits (curr, data, ax2ty) body obj = + let data, ax2ty = + let already_in = Refmap_env.mem obj data in + match body () with + | None -> + let data = + if not already_in then Refmap_env.add obj Refset_env.empty data else data in + let ax2ty = + if Option.is_empty inhabits then ax2ty else + let ty = Option.get inhabits in + try let l = Refmap_env.find obj ax2ty in Refmap_env.add obj (ty::l) ax2ty + with Not_found -> Refmap_env.add obj [ty] ax2ty in + data, ax2ty + | Some body -> + if already_in then data, ax2ty else + let contents,data,ax2ty = + traverse (label_of obj) [] (Refset_env.empty,data,ax2ty) body in + Refmap_env.add obj contents data, ax2ty + in + (Refset_env.add obj curr, data, ax2ty) + +let traverse current t = + let () = modcache := MPmap.empty in + traverse current [] (Refset_env.empty, Refmap_env.empty, Refmap_env.empty) t + +(** Hopefully bullet-proof function to recover the type of a constant. It just + ignores all the universe stuff. There are many issues that can arise when + considering terms out of any valid environment, so use with caution. *) +let type_of_constant cb = match cb.Declarations.const_type with +| Declarations.RegularArity ty -> ty +| Declarations.TemplateArity (ctx, arity) -> + Term.mkArity (ctx, Sorts.sort_of_univ arity.Declarations.template_level) + +let assumptions ?(add_opaque=false) ?(add_transparent=false) st gr t = + let (idts, knst) = st in + (** Only keep the transitive dependencies *) + let (_, graph, ax2ty) = traverse (label_of gr) t in + let fold obj _ accu = match obj with + | VarRef id -> + let (_, body, t) = Global.lookup_named id in + if Option.is_empty body then ContextObjectMap.add (Variable id) t accu + else accu + | ConstRef kn -> + let cb = lookup_constant kn in + if not (Declareops.constant_has_body cb) then + let t = type_of_constant cb in + let l = try Refmap_env.find obj ax2ty with Not_found -> [] in + ContextObjectMap.add (Axiom (kn,l)) t accu + else if add_opaque && (Declareops.is_opaque cb || not (Cpred.mem kn knst)) then + let t = type_of_constant cb in + ContextObjectMap.add (Opaque kn) t accu + else if add_transparent then + let t = type_of_constant cb in + ContextObjectMap.add (Transparent kn) t accu + else + accu + | IndRef _ | ConstructRef _ -> accu + in + Refmap_env.fold fold graph ContextObjectMap.empty |