dialyzer: Prepare erl_types:t_from_form() for a cache

No change of functionality.

1 files changed, 268 insertions, 258 deletions

diff --git a/lib/hipe/cerl/erl_types.erl b/lib/hipe/cerl/erl_types.erl
index 7bfb44c06f..208f439388 100644
--- a/lib/hipe/cerl/erl_types.erl
+++ b/lib/hipe/cerl/erl_types.erl
@@ -4419,6 +4419,7 @@ mod_name(Mod, Name) ->
 -type mta()  :: {module(), atom(), arity()}.
 -type mra()  :: {module(), atom(), arity()}.
 -type site() :: {'type', mta()} | {'spec', mfa()} | {'record', mra()}.
+-type cache() :: #{{module(), parse_form()} => erl_type()}.
 
 -spec t_from_form(parse_form(), sets:set(mfa()),
                   site(), mod_records()) -> erl_type().
@@ -4482,15 +4483,28 @@ t_from_form_loop(Form, TypeNames, ET, Site, MR, V, D, L0) ->
       t_from_form_loop(Form, TypeNames, ET, Site, MR, V, D1, L1)
   end.
 
+-record(from_form, {site   :: site(),
+                    xtypes :: sets:set(mfa()) | 'replace_by_none',
+                    mrecs  :: mod_records(),
+                    vtab   :: var_table(),
+                    tnames :: type_names()}).
+
 t_from_form2(Form, TypeNames, ET, Site, MR, V, D) ->
   L = ?EXPAND_LIMIT,
-  t_from_form(Form, TypeNames, ET, Site, MR, V, D, L).
-
--spec t_from_form(parse_form(), type_names(),
-                  sets:set(mfa()) | 'replace_by_none',
-                  site(), mod_records(), var_table(),
-                  expand_depth(), expand_limit())
-                           -> {erl_type(), expand_limit()}.
+  State = #from_form{site   = Site,
+                     xtypes = ET,
+                     mrecs  = MR,
+                     vtab   = V,
+                     tnames = TypeNames},
+  C = #{},
+  {T, L1, _C1} = from_form(Form, State, D, L, C),
+  {T, L1}.
+
+-spec from_form(parse_form(),
+                #from_form{},
+                expand_depth(),
+                expand_limit(),
+                cache()) -> {erl_type(), expand_limit(), cache()}.
 
 %% If there is something wrong with parse_form()
 %% throw({error, io_lib:chars()} is called;
@@ -4500,218 +4514,213 @@ t_from_form2(Form, TypeNames, ET, Site, MR, V, D) ->
 %%
 %% It is assumed that site_module(S) can be found in MR.
 
-t_from_form(_, _TypeNames, _ET, _S, _MR, _V, D, L) when D =< 0 ; L =< 0 ->
-  {t_any(), L};
-t_from_form({var, _L, '_'}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_any(), L};
-t_from_form({var, _L, Name}, _TypeNames, _ET, _S, _MR, V, _D, L) ->
+from_form(_, _S, D, L, C) when D =< 0 ; L =< 0 ->
+  {t_any(), L, C};
+from_form({var, _L, '_'}, _S, _D, L, C) ->
+  {t_any(), L, C};
+from_form({var, _L, Name}, S, _D, L, C) ->
+  V = S#from_form.vtab,
   case maps:find(Name, V) of
-    error -> {t_var(Name), L};
-    {ok, Val} -> {Val, L}
+    error -> {t_var(Name), L, C};
+    {ok, Val} -> {Val, L, C}
   end;
-t_from_form({ann_type, _L, [_Var, Type]}, TypeNames, ET, S, MR, V, D, L) ->
-  t_from_form(Type, TypeNames, ET, S, MR, V, D, L);
-t_from_form({paren_type, _L, [Type]}, TypeNames, ET, S, MR, V, D, L) ->
-  t_from_form(Type, TypeNames, ET, S, MR, V, D, L);
-t_from_form({remote_type, _L, [{atom, _, Module}, {atom, _, Type}, Args]},
-	    TypeNames, ET, S, MR, V, D, L) ->
-  remote_from_form(Module, Type, Args, TypeNames, ET, S, MR, V, D, L);
-t_from_form({atom, _L, Atom}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_atom(Atom), L};
-t_from_form({integer, _L, Int}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_integer(Int), L};
-t_from_form({op, _L, _Op, _Arg} = Op, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
+from_form({ann_type, _L, [_Var, Type]}, S, D, L, C) ->
+  from_form(Type, S, D, L, C);
+from_form({paren_type, _L, [Type]}, S, D, L, C) ->
+  from_form(Type, S, D, L, C);
+from_form({remote_type, _L, [{atom, _, Module}, {atom, _, Type}, Args]},
+	    S, D, L, C) ->
+  remote_from_form(Module, Type, Args, S, D, L, C);
+from_form({atom, _L, Atom}, _S, _D, L, C) ->
+  {t_atom(Atom), L, C};
+from_form({integer, _L, Int}, _S, _D, L, C) ->
+  {t_integer(Int), L, C};
+from_form({op, _L, _Op, _Arg} = Op, _S, _D, L, C) ->
   case erl_eval:partial_eval(Op) of
     {integer, _, Val} ->
-      {t_integer(Val), L};
+      {t_integer(Val), L, C};
     _ -> throw({error, io_lib:format("Unable to evaluate type ~w\n", [Op])})
   end;
-t_from_form({op, _L, _Op, _Arg1, _Arg2} = Op, _TypeNames,
-            _ET, _S, _MR, _V, _D, L) ->
+from_form({op, _L, _Op, _Arg1, _Arg2} = Op, _S, _D, L, C) ->
   case erl_eval:partial_eval(Op) of
     {integer, _, Val} ->
-      {t_integer(Val), L};
+      {t_integer(Val), L, C};
     _ -> throw({error, io_lib:format("Unable to evaluate type ~w\n", [Op])})
   end;
-t_from_form({type, _L, any, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_any(), L};
-t_from_form({type, _L, arity, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_arity(), L};
-t_from_form({type, _L, atom, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_atom(), L};
-t_from_form({type, _L, binary, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_binary(), L};
-t_from_form({type, _L, binary, [Base, Unit]} = Type,
-	    _TypeNames, _ET, _S, _MR, _V, _D, L) ->
+from_form({type, _L, any, []}, _S, _D, L, C) ->
+  {t_any(), L, C};
+from_form({type, _L, arity, []}, _S, _D, L, C) ->
+  {t_arity(), L, C};
+from_form({type, _L, atom, []}, _S, _D, L, C) ->
+  {t_atom(), L, C};
+from_form({type, _L, binary, []}, _S, _D, L, C) ->
+  {t_binary(), L, C};
+from_form({type, _L, binary, [Base, Unit]} = Type, _S, _D, L, C) ->
   case {erl_eval:partial_eval(Base), erl_eval:partial_eval(Unit)} of
     {{integer, _, B}, {integer, _, U}} when B >= 0, U >= 0 ->
-      {t_bitstr(U, B), L};
+      {t_bitstr(U, B), L, C};
     _ -> throw({error, io_lib:format("Unable to evaluate type ~w\n", [Type])})
   end;
-t_from_form({type, _L, bitstring, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_bitstr(), L};
-t_from_form({type, _L, bool, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_boolean(), L};	% XXX: Temporarily
-t_from_form({type, _L, boolean, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_boolean(), L};
-t_from_form({type, _L, byte, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_byte(), L};
-t_from_form({type, _L, char, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_char(), L};
-t_from_form({type, _L, float, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_float(), L};
-t_from_form({type, _L, function, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_fun(), L};
-t_from_form({type, _L, 'fun', []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_fun(), L};
-t_from_form({type, _L, 'fun', [{type, _, any}, Range]}, TypeNames,
-            ET, S, MR, V, D, L) ->
-  {T, L1} = t_from_form(Range, TypeNames, ET, S, MR, V, D - 1, L - 1),
-  {t_fun(T), L1};
-t_from_form({type, _L, 'fun', [{type, _, product, Domain}, Range]},
-            TypeNames, ET, S, MR, V, D, L) ->
-  {Dom1, L1} = list_from_form(Domain, TypeNames, ET, S, MR, V, D, L),
-  {Ran1, L2} = t_from_form(Range, TypeNames, ET, S, MR, V, D, L1),
-  {t_fun(Dom1, Ran1), L2};
-t_from_form({type, _L, identifier, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_identifier(), L};
-t_from_form({type, _L, integer, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_integer(), L};
-t_from_form({type, _L, iodata, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_iodata(), L};
-t_from_form({type, _L, iolist, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_iolist(), L};
-t_from_form({type, _L, list, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_list(), L};
-t_from_form({type, _L, list, [Type]}, TypeNames, ET, S, MR, V, D, L) ->
-  {T, L1} = t_from_form(Type, TypeNames, ET, S, MR, V, D - 1, L - 1),
-  {t_list(T), L1};
-t_from_form({type, _L, map, any}, TypeNames, ET, S, MR, V, D, L) ->
-  builtin_type(map, t_map(), TypeNames, ET, S, MR, V, D, L);
-t_from_form({type, _L, map, List}, TypeNames, ET, S, MR, V, D, L) ->
-  {Pairs1, L5} =
-    fun PairsFromForm(_, L1) when L1 =< 0 -> {[{?any,?opt,?any}], L1};
-	PairsFromForm([], L1) -> {[], L1};
-	PairsFromForm([{type, _, Oper, [KF, VF]}|T], L1) ->
-	{Key, L2} = t_from_form(KF, TypeNames, ET, S, MR, V, D - 1, L1),
-	{Val, L3} = t_from_form(VF, TypeNames, ET, S, MR, V, D - 1, L2),
-	{Pairs0, L4} = PairsFromForm(T, L3 - 1),
+from_form({type, _L, bitstring, []}, _S, _D, L, C) ->
+  {t_bitstr(), L, C};
+from_form({type, _L, bool, []}, _S, _D, L, C) ->
+  {t_boolean(), L, C};	% XXX: Temporarily
+from_form({type, _L, boolean, []}, _S, _D, L, C) ->
+  {t_boolean(), L, C};
+from_form({type, _L, byte, []}, _S, _D, L, C) ->
+  {t_byte(), L, C};
+from_form({type, _L, char, []}, _S, _D, L, C) ->
+  {t_char(), L, C};
+from_form({type, _L, float, []}, _S, _D, L, C) ->
+  {t_float(), L, C};
+from_form({type, _L, function, []}, _S, _D, L, C) ->
+  {t_fun(), L, C};
+from_form({type, _L, 'fun', []}, _S, _D, L, C) ->
+  {t_fun(), L, C};
+from_form({type, _L, 'fun', [{type, _, any}, Range]}, S, D, L, C) ->
+  {T, L1} = from_form(Range, S, D - 1, L - 1, C),
+  {t_fun(T), L1, C};
+from_form({type, _L, 'fun', [{type, _, product, Domain}, Range]},
+          S, D, L, C) ->
+  {Dom1, L1, C1} = list_from_form(Domain, S, D, L, C),
+  {Ran1, L2, C2} = from_form(Range, S, D, L1, C1),
+  {t_fun(Dom1, Ran1), L2, C2};
+from_form({type, _L, identifier, []}, _S, _D, L, C) ->
+  {t_identifier(), L, C};
+from_form({type, _L, integer, []}, _S, _D, L, C) ->
+  {t_integer(), L, C};
+from_form({type, _L, iodata, []}, _S, _D, L, C) ->
+  {t_iodata(), L, C};
+from_form({type, _L, iolist, []}, _S, _D, L, C) ->
+  {t_iolist(), L, C};
+from_form({type, _L, list, []}, _S, _D, L, C) ->
+  {t_list(), L, C};
+from_form({type, _L, list, [Type]}, S, D, L, C) ->
+  {T, L1, C1} = from_form(Type, S, D - 1, L - 1, C),
+  {t_list(T), L1, C1};
+from_form({type, _L, map, any}, S, D, L, C) ->
+  builtin_type(map, t_map(), S, D, L, C);
+from_form({type, _L, map, List}, S, D0, L, C) ->
+  {Pairs1, L5, C5} =
+    fun PairsFromForm(_, L1, C1) when L1 =< 0 -> {[{?any,?opt,?any}], L1, C1};
+	PairsFromForm([], L1, C1) -> {[], L1, C1};
+	PairsFromForm([{type, _, Oper, [KF, VF]}|T], L1, C1) ->
+        D = D0 - 1,
+	{Key, L2, C2} = from_form(KF, S, D, L1, C1),
+	{Val, L3, C3} = from_form(VF, S, D, L2, C2),
+	{Pairs0, L4, C4} = PairsFromForm(T, L3 - 1, C3),
 	case Oper of
-	  map_field_assoc -> {[{Key,?opt, Val}|Pairs0], L4};
-	  map_field_exact -> {[{Key,?mand,Val}|Pairs0], L4}
+	  map_field_assoc -> {[{Key,?opt, Val}|Pairs0], L4, C4};
+	  map_field_exact -> {[{Key,?mand,Val}|Pairs0], L4, C4}
 	end
-    end(List, L),
+    end(List, L, C),
   try
     {Pairs, DefK, DefV} = map_from_form(Pairs1, [], [], [], ?none, ?none),
-    {t_map(Pairs, DefK, DefV), L5}
-  catch none -> {t_none(), L5}
+    {t_map(Pairs, DefK, DefV), L5, C5}
+  catch none -> {t_none(), L5, C5}
   end;
-t_from_form({type, _L, mfa, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_mfa(), L};
-t_from_form({type, _L, module, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_module(), L};
-t_from_form({type, _L, nil, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_nil(), L};
-t_from_form({type, _L, neg_integer, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_neg_integer(), L};
-t_from_form({type, _L, non_neg_integer, []}, _TypeNames, _ET, _S, _MR,
-               _V, _D, L) ->
-  {t_non_neg_integer(), L};
-t_from_form({type, _L, no_return, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_unit(), L};
-t_from_form({type, _L, node, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_node(), L};
-t_from_form({type, _L, none, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_none(), L};
-t_from_form({type, _L, nonempty_list, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_nonempty_list(), L};
-t_from_form({type, _L, nonempty_list, [Type]}, TypeNames, ET, S, MR, V, D, L) ->
-  {T, L1} = t_from_form(Type, TypeNames, ET, S, MR, V, D, L - 1),
-  {t_nonempty_list(T), L1};
-t_from_form({type, _L, nonempty_improper_list, [Cont, Term]}, TypeNames,
-            ET, S, MR, V, D, L) ->
-  {T1, L1} = t_from_form(Cont, TypeNames, ET, S, MR, V, D, L - 1),
-  {T2, L2} = t_from_form(Term, TypeNames, ET, S, MR, V, D, L1),
-  {t_cons(T1, T2), L2};
-t_from_form({type, _L, nonempty_maybe_improper_list, []}, _TypeNames,
-            _ET, _S, _MR, _V, _D, L) ->
-  {t_cons(?any, ?any), L};
-t_from_form({type, _L, nonempty_maybe_improper_list, [Cont, Term]},
-            TypeNames, ET, S, MR, V, D, L) ->
-  {T1, L1} = t_from_form(Cont, TypeNames, ET, S, MR, V, D, L - 1),
-  {T2, L2} = t_from_form(Term, TypeNames, ET, S, MR, V, D, L1),
-  {t_cons(T1, T2), L2};
-t_from_form({type, _L, nonempty_string, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_nonempty_string(), L};
-t_from_form({type, _L, number, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_number(), L};
-t_from_form({type, _L, pid, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_pid(), L};
-t_from_form({type, _L, port, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_port(), L};
-t_from_form({type, _L, pos_integer, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_pos_integer(), L};
-t_from_form({type, _L, maybe_improper_list, []}, _TypeNames,
-            _ET, _S, _MR, _V, _D, L) ->
-  {t_maybe_improper_list(), L};
-t_from_form({type, _L, maybe_improper_list, [Content, Termination]},
-            TypeNames, ET, S, MR, V, D, L) ->
-  {T1, L1} = t_from_form(Content, TypeNames, ET, S, MR, V, D, L - 1),
-  {T2, L2} = t_from_form(Termination, TypeNames, ET, S, MR, V, D, L1),
-  {t_maybe_improper_list(T1, T2), L2};
-t_from_form({type, _L, product, Elements}, TypeNames, ET, S, MR, V, D, L) ->
-  {Lst, L1} = list_from_form(Elements, TypeNames, ET, S, MR, V, D - 1, L),
-  {t_product(Lst), L1};
-t_from_form({type, _L, range, [From, To]} = Type,
-	    _TypeNames, _ET, _S, _MR, _V, _D, L) ->
+from_form({type, _L, mfa, []}, _S, _D, L, C) ->
+  {t_mfa(), L, C};
+from_form({type, _L, module, []}, _S, _D, L, C) ->
+  {t_module(), L, C};
+from_form({type, _L, nil, []}, _S, _D, L, C) ->
+  {t_nil(), L, C};
+from_form({type, _L, neg_integer, []}, _S, _D, L, C) ->
+  {t_neg_integer(), L, C};
+from_form({type, _L, non_neg_integer, []}, _S, _D, L, C) ->
+  {t_non_neg_integer(), L, C};
+from_form({type, _L, no_return, []}, _S, _D, L, C) ->
+  {t_unit(), L, C};
+from_form({type, _L, node, []}, _S, _D, L, C) ->
+  {t_node(), L, C};
+from_form({type, _L, none, []}, _S, _D, L, C) ->
+  {t_none(), L, C};
+from_form({type, _L, nonempty_list, []}, _S, _D, L, C) ->
+  {t_nonempty_list(), L, C};
+from_form({type, _L, nonempty_list, [Type]}, S, D, L, C) ->
+  {T, L1, C1} = from_form(Type, S, D, L - 1, C),
+  {t_nonempty_list(T), L1, C1};
+from_form({type, _L, nonempty_improper_list, [Cont, Term]}, S, D, L, C) ->
+  {T1, L1, C1} = from_form(Cont, S, D, L - 1, C),
+  {T2, L2, C2} = from_form(Term, S, D, L1, C1),
+  {t_cons(T1, T2), L2, C2};
+from_form({type, _L, nonempty_maybe_improper_list, []}, _S, _D, L, C) ->
+  {t_cons(?any, ?any), L, C};
+from_form({type, _L, nonempty_maybe_improper_list, [Cont, Term]},
+          S, D, L, C) ->
+  {T1, L1, C1} = from_form(Cont, S, D, L - 1, C),
+  {T2, L2, C2} = from_form(Term, S, D, L1, C1),
+  {t_cons(T1, T2), L2, C2};
+from_form({type, _L, nonempty_string, []}, _S, _D, L, C) ->
+  {t_nonempty_string(), L, C};
+from_form({type, _L, number, []}, _S, _D, L, C) ->
+  {t_number(), L, C};
+from_form({type, _L, pid, []}, _S, _D, L, C) ->
+  {t_pid(), L, C};
+from_form({type, _L, port, []}, _S, _D, L, C) ->
+  {t_port(), L, C};
+from_form({type, _L, pos_integer, []}, _S, _D, L, C) ->
+  {t_pos_integer(), L, C};
+from_form({type, _L, maybe_improper_list, []}, _S, _D, L, C) ->
+  {t_maybe_improper_list(), L, C};
+from_form({type, _L, maybe_improper_list, [Content, Termination]},
+          S, D, L, C) ->
+  {T1, L1, C1} = from_form(Content, S, D, L - 1, C),
+  {T2, L2, C2} = from_form(Termination, S, D, L1, C1),
+  {t_maybe_improper_list(T1, T2), L2, C2};
+from_form({type, _L, product, Elements}, S, D, L, C) ->
+  {Lst, L1, C1} = list_from_form(Elements, S, D - 1, L, C),
+  {t_product(Lst), L1, C1};
+from_form({type, _L, range, [From, To]} = Type, _S, _D, L, C) ->
   case {erl_eval:partial_eval(From), erl_eval:partial_eval(To)} of
     {{integer, _, FromVal}, {integer, _, ToVal}} ->
-      {t_from_range(FromVal, ToVal), L};
+      {t_from_range(FromVal, ToVal), L, C};
     _ -> throw({error, io_lib:format("Unable to evaluate type ~w\n", [Type])})
   end;
-t_from_form({type, _L, record, [Name|Fields]}, TypeNames, ET, S, MR, V, D, L) ->
-  record_from_form(Name, Fields, TypeNames, ET, S, MR, V, D, L);
-t_from_form({type, _L, reference, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_reference(), L};
-t_from_form({type, _L, string, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_string(), L};
-t_from_form({type, _L, term, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_any(), L};
-t_from_form({type, _L, timeout, []}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_timeout(), L};
-t_from_form({type, _L, tuple, any}, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {t_tuple(), L};
-t_from_form({type, _L, tuple, Args}, TypeNames, ET, S, MR, V, D, L) ->
-  {Lst, L1} = list_from_form(Args, TypeNames, ET, S, MR, V, D - 1, L),
-  {t_tuple(Lst), L1};
-t_from_form({type, _L, union, Args}, TypeNames, ET, S, MR, V, D, L) ->
-  {Lst, L1} = list_from_form(Args, TypeNames, ET, S, MR, V, D, L),
-  {t_sup(Lst), L1};
-t_from_form({user_type, _L, Name, Args}, TypeNames, ET, S, MR, V, D, L) ->
-  type_from_form(Name, Args, TypeNames, ET, S, MR, V, D, L);
-t_from_form({type, _L, Name, Args}, TypeNames, ET, S, MR, V, D, L) ->
+from_form({type, _L, record, [Name|Fields]}, S, D, L, C) ->
+  record_from_form(Name, Fields, S, D, L, C);
+from_form({type, _L, reference, []}, _S, _D, L, C) ->
+  {t_reference(), L, C};
+from_form({type, _L, string, []}, _S, _D, L, C) ->
+  {t_string(), L, C};
+from_form({type, _L, term, []}, _S, _D, L, C) ->
+  {t_any(), L, C};
+from_form({type, _L, timeout, []}, _S, _D, L, C) ->
+  {t_timeout(), L, C};
+from_form({type, _L, tuple, any}, _S, _D, L, C) ->
+  {t_tuple(), L, C};
+from_form({type, _L, tuple, Args}, S, D, L, C) ->
+  {Lst, L1, C1} = list_from_form(Args, S, D - 1, L, C),
+  {t_tuple(Lst), L1, C1};
+from_form({type, _L, union, Args}, S, D, L, C) ->
+  {Lst, L1, C1} = list_from_form(Args, S, D, L, C),
+  {t_sup(Lst), L1, C1};
+from_form({user_type, _L, Name, Args}, S, D, L, C) ->
+  type_from_form(Name, Args, S, D, L, C);
+from_form({type, _L, Name, Args}, S, D, L, C) ->
   %% Compatibility: modules compiled before Erlang/OTP 18.0.
-  type_from_form(Name, Args, TypeNames, ET, S, MR, V, D, L);
-t_from_form({opaque, _L, Name, {Mod, Args, Rep}}, _TypeNames,
-            _ET, _S, _MR, _V, _D, L) ->
+  type_from_form(Name, Args, S, D, L, C);
+from_form({opaque, _L, Name, {Mod, Args, Rep}}, _S, _D, L, C) ->
   %% XXX. To be removed.
-  {t_opaque(Mod, Name, Args, Rep), L}.
+  {t_opaque(Mod, Name, Args, Rep), L, C}.
 
-builtin_type(Name, Type, TypeNames, ET, Site, MR, V, D, L) ->
+builtin_type(Name, Type, S, D, L, C) ->
+  #from_form{site = Site, mrecs = MR} = S,
   M = site_module(Site),
   case dict:find(M, MR) of
     {ok, R} ->
       case lookup_type(Name, 0, R) of
         {_, {{_M, _FL, _F, _A}, _T}} ->
-          type_from_form(Name, [], TypeNames, ET, Site, MR, V, D, L);
+          type_from_form(Name, [], S, D, L, C);
         error ->
-          {Type, L}
+          {Type, L, C}
       end;
     error ->
-      {Type, L}
+      {Type, L, C}
   end.
 
-type_from_form(Name, Args, TypeNames, ET, Site0, MR, V, D, L) ->
+type_from_form(Name, Args, S, D, L, C) ->
+  #from_form{site = Site0, mrecs = MR, tnames = TypeNames} = S,
   ArgsLen = length(Args),
   Module = site_module(Site0),
   {ok, R} = dict:find(Module, MR),
@@ -4721,26 +4730,26 @@ type_from_form(Name, Args, TypeNames, ET, Site0, MR, V, D, L) ->
       case can_unfold_more(TypeName, TypeNames) of
         true ->
           NewTypeNames = [TypeName|TypeNames],
-          {ArgTypes, L1} =
-            list_from_form(Args, TypeNames, ET, Site0, MR, V, D, L),
+          {ArgTypes, L1, C1} = list_from_form(Args, S, D, L, C),
           List = lists:zip(ArgNames, ArgTypes),
           TmpV = maps:from_list(List),
-          Site = TypeName,
-          t_from_form(Form, NewTypeNames, ET, Site, MR, TmpV, D, L1);
+          S1 = S#from_form{site = TypeName,
+                           tnames = NewTypeNames,
+                           vtab = TmpV},
+          from_form(Form, S1, D, L1, C1);
         false ->
-          {t_any(), L}
+          {t_any(), L, C}
       end;
     {opaque, {{Module, _FileName, Form, ArgNames}, Type}} ->
       case can_unfold_more(TypeName, TypeNames) of
         true ->
           NewTypeNames = [TypeName|TypeNames],
-          {ArgTypes, L1} =
-            list_from_form(Args, NewTypeNames, ET, Site0, MR, V, D, L),
+          S1 = S#from_form{tnames = NewTypeNames},
+          {ArgTypes, L1, C1} = list_from_form(Args, S1, D, L, C),
           List = lists:zip(ArgNames, ArgTypes),
           TmpV = maps:from_list(List),
-          Site = TypeName,
-          {Rep, L2} =
-            t_from_form(Form, NewTypeNames, ET, Site, MR, TmpV, D, L1),
+          S2 = S1#from_form{site = TypeName, vtab = TmpV},
+          {Rep, L2, C2} = from_form(Form, S2, D, L1, C1),
           Rep1 = choose_opaque_type(Rep, Type),
           Rep2 = case cannot_have_opaque(Rep1, TypeName, TypeNames) of
                    true -> Rep1;
@@ -4748,25 +4757,26 @@ type_from_form(Name, Args, TypeNames, ET, Site0, MR, V, D, L) ->
                      ArgTypes2 = subst_all_vars_to_any_list(ArgTypes),
                      t_opaque(Module, Name, ArgTypes2, Rep1)
                  end,
-          {Rep2, L2};
-        false -> {t_any(), L}
+          {Rep2, L2, C2};
+        false -> {t_any(), L, C}
       end;
     error ->
       Msg = io_lib:format("Unable to find type ~w/~w\n", [Name, ArgsLen]),
       throw({error, Msg})
   end.
 
-remote_from_form(RemMod, Name, Args, TypeNames, ET, S, MR, V, D, L) ->
+remote_from_form(RemMod, Name, Args, S, D, L, C) ->
+  #from_form{xtypes = ET, mrecs = MR, tnames = TypeNames} = S,
   if
     ET =:= replace_by_none ->
-      {t_none(), L};
+      {t_none(), L, C};
     true ->
       ArgsLen = length(Args),
       MFA = {RemMod, Name, ArgsLen},
       case dict:find(RemMod, MR) of
         error ->
           self() ! {self(), ext_types, MFA},
-          {t_any(), L};
+          {t_any(), L, C};
         {ok, RemDict} ->
           RemType = {type, MFA},
           case sets:is_element(MFA, ET) of
@@ -4776,28 +4786,25 @@ remote_from_form(RemMod, Name, Args, TypeNames, ET, S, MR, V, D, L) ->
                   case can_unfold_more(RemType, TypeNames) of
                     true ->
                       NewTypeNames = [RemType|TypeNames],
-                      {ArgTypes, L1} = list_from_form(Args, TypeNames,
-                                                      ET, S, MR, V, D, L),
+                      S1 = S#from_form{tnames = NewTypeNames},
+                      {ArgTypes, L1, C1} = list_from_form(Args, S1, D, L, C),
                       List = lists:zip(ArgNames, ArgTypes),
-                      TmpVarDict = maps:from_list(List),
-                      Site = RemType,
-                      t_from_form(Form, NewTypeNames, ET,
-                                  Site, MR, TmpVarDict, D, L1);
+                      TmpVarTab = maps:from_list(List),
+                      S2 = S1#from_form{site = RemType, vtab = TmpVarTab},
+                      from_form(Form, S2, D, L1, C1);
                     false ->
-                      {t_any(), L}
+                      {t_any(), L, C}
                   end;
                 {opaque, {{Mod, _FileLine, Form, ArgNames}, Type}} ->
                   case can_unfold_more(RemType, TypeNames) of
                     true ->
                       NewTypeNames = [RemType|TypeNames],
-                      {ArgTypes, L1} = list_from_form(Args, NewTypeNames,
-                                                      ET, S, MR, V, D, L),
+                      S1 = S#from_form{tnames = NewTypeNames},
+                      {ArgTypes, L1, C1} = list_from_form(Args, S1, D, L, C),
                       List = lists:zip(ArgNames, ArgTypes),
-                      TmpVarDict = maps:from_list(List),
-                      Site = RemType,
-                      {NewRep, L2} =
-                        t_from_form(Form, NewTypeNames, ET, Site, MR,
-                                    TmpVarDict, D, L1),
+                      TmpVarTab = maps:from_list(List),
+                      S2 = S1#from_form{site = RemType, vtab = TmpVarTab},
+                      {NewRep, L2, C2} = from_form(Form, S2, D, L1, C1),
                       NewRep1 = choose_opaque_type(NewRep, Type),
                       NewRep2 =
                         case
@@ -4808,9 +4815,9 @@ remote_from_form(RemMod, Name, Args, TypeNames, ET, S, MR, V, D, L) ->
                             ArgTypes2 = subst_all_vars_to_any_list(ArgTypes),
                             t_opaque(Mod, Name, ArgTypes2, NewRep1)
                         end,
-                      {NewRep2, L2};
+                      {NewRep2, L2, C2};
                     false ->
-                      {t_any(), L}
+                      {t_any(), L, C}
                   end;
                 error ->
                   Msg = io_lib:format("Unable to find remote type ~w:~w()\n",
@@ -4819,7 +4826,7 @@ remote_from_form(RemMod, Name, Args, TypeNames, ET, S, MR, V, D, L) ->
               end;
             false ->
               self() ! {self(), ext_types, {RemMod, Name, ArgsLen}},
-              {t_any(), L}
+              {t_any(), L, C}
           end
       end
   end.
@@ -4846,63 +4853,62 @@ choose_opaque_type(Type, DeclType) ->
     false -> DeclType
   end.
 
-record_from_form({atom, _, Name}, ModFields, TypeNames, ET, S, MR, V, D, L) ->
+record_from_form({atom, _, Name}, ModFields, S, D, L, C) ->
+  #from_form{site = Site, mrecs = MR, tnames = TypeNames} = S,
   case can_unfold_more({record, Name}, TypeNames) of
     true ->
-      M = site_module(S),
+      M = site_module(Site),
       {ok, R} = dict:find(M, MR),
       case lookup_record(Name, R) of
         {ok, DeclFields} ->
           NewTypeNames = [{record, Name}|TypeNames],
-          S1 = {record, {M, Name, length(DeclFields)}},
-          {GetModRec, L1} = get_mod_record(ModFields, DeclFields,
-                                           NewTypeNames, ET, S1, MR, V, D, L),
+          Site1 = {record, {M, Name, length(DeclFields)}},
+          S1 = S#from_form{site = Site1, tnames = NewTypeNames},
+          {GetModRec, L1, C1} =
+            get_mod_record(ModFields, DeclFields, S1, D, L, C),
           case GetModRec of
             {error, FieldName} ->
               throw({error, io_lib:format("Illegal declaration of #~w{~w}\n",
                                           [Name, FieldName])});
             {ok, NewFields} ->
-              {NewFields1, L2} =
-                fields_from_form(NewFields, NewTypeNames, ET, S1, MR,
-                                 var_table__new(), D, L1),
+              S2 = S1#from_form{vtab = var_table__new()},
+              {NewFields1, L2, C2} =
+                fields_from_form(NewFields, S2, D, L1, C1),
               Rec = t_tuple(
                       [t_atom(Name)|[Type
                                      || {_FieldName, Type} <- NewFields1]]),
-              {Rec, L2}
+              {Rec, L2, C2}
           end;
         error ->
           throw({error, io_lib:format("Unknown record #~w{}\n", [Name])})
       end;
     false ->
-       {t_any(), L}
+       {t_any(), L, C}
   end.
 
-get_mod_record([], DeclFields, _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {{ok, DeclFields}, L};
-get_mod_record(ModFields, DeclFields, TypeNames, ET, S, MR, V, D, L) ->
+get_mod_record([], DeclFields, _S, _D, L, C) ->
+  {{ok, DeclFields}, L, C};
+get_mod_record(ModFields, DeclFields, S, D, L, C) ->
   DeclFieldsDict = lists:keysort(1, DeclFields),
-  {ModFieldsDict, L1} =
-    build_field_dict(ModFields, TypeNames, ET, S, MR, V, D, L),
+  {ModFieldsDict, L1, C1} = build_field_dict(ModFields, S, D, L, C),
   case get_mod_record_types(DeclFieldsDict, ModFieldsDict, []) of
-    {error, _FieldName} = Error -> {Error, L1};
+    {error, _FieldName} = Error -> {Error, L1, C1};
     {ok, FinalKeyDict} ->
       Fields = [lists:keyfind(FieldName, 1, FinalKeyDict)
              || {FieldName, _, _} <- DeclFields],
-      {{ok, Fields}, L1}
+      {{ok, Fields}, L1, C1}
   end.
 
-build_field_dict(FieldTypes, TypeNames, ET, S, MR, V, D, L) ->
-  build_field_dict(FieldTypes, TypeNames, ET, S, MR, V, D, L, []).
+build_field_dict(FieldTypes, S, D, L, C) ->
+  build_field_dict(FieldTypes, S, D, L, C, []).
 
 build_field_dict([{type, _, field_type, [{atom, _, Name}, Type]}|Left],
-		 TypeNames, ET, S, MR, V, D, L, Acc) ->
-  {T, L1} = t_from_form(Type, TypeNames, ET, S, MR, V, D, L - 1),
+		 S, D, L, C, Acc) ->
+  {T, L1, C1} = from_form(Type, S, D, L - 1, C),
   NewAcc = [{Name, Type, T}|Acc],
-  {Dict, L2} =
-    build_field_dict(Left, TypeNames, ET, S, MR, V, D, L1, NewAcc),
-  {Dict, L2};
-build_field_dict([], _TypeNames, _ET, _S, _MR, _V, _D, L, Acc) ->
-  {lists:keysort(1, Acc), L}.
+  build_field_dict(Left, S, D, L1, C1, NewAcc);
+build_field_dict([], _S, _D, L, C, Acc) ->
+  {lists:keysort(1, Acc), L, C}.
 
 get_mod_record_types([{FieldName, _Abstr, _DeclType}|Left1],
                      [{FieldName, TypeForm, ModType}|Left2],
@@ -4920,20 +4926,19 @@ get_mod_record_types(_, [{FieldName2, _FormType, _ModType}|_], _Acc) ->
 %% It is important to create a limited version of the record type
 %% since nested record types can otherwise easily result in huge
 %% terms.
-fields_from_form([], _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {[], L};
-fields_from_form([{Name, Abstr, _Type}|Tail], TypeNames, ET, S, MR,
-                 V, D, L) ->
-  {T, L1} = t_from_form(Abstr, TypeNames, ET, S, MR, V, D, L),
-  {F, L2} = fields_from_form(Tail, TypeNames, ET, S, MR, V, D, L1),
-  {[{Name, T}|F], L2}.
-
-list_from_form([], _TypeNames, _ET, _S, _MR, _V, _D, L) ->
-  {[], L};
-list_from_form([H|Tail], TypeNames, ET, S, MR, V, D, L) ->
-  {H1, L1} = t_from_form(H, TypeNames, ET, S, MR, V, D, L - 1),
-  {T1, L2} = list_from_form(Tail, TypeNames, ET, S, MR, V, D, L1),
-  {[H1|T1], L2}.
+fields_from_form([], _S, _D, L, C) ->
+  {[], L, C};
+fields_from_form([{Name, Abstr, _Type}|Tail], S, D, L, C) ->
+  {T, L1, C1} = from_form(Abstr, S, D, L, C),
+  {F, L2, C2} = fields_from_form(Tail, S, D, L1, C1),
+  {[{Name, T}|F], L2, C2}.
+
+list_from_form([], _S, _D, L, C) ->
+  {[], L, C};
+list_from_form([H|Tail], S, D, L, C) ->
+  {H1, L1, C1} = from_form(H, S, D, L - 1, C),
+  {T1, L2, C2} = list_from_form(Tail, S, D, L1, C1),
+  {[H1|T1], L2, C2}.
 
 %% Sorts, combines non-singleton pairs, and applies precendence and
 %% mandatoriness rules.
@@ -5151,10 +5156,15 @@ t_form_to_string({type, _L, Name, []} = T) ->
      M = mod,
      D0 = dict:new(),
      MR = dict:from_list([{M, D0}]),
-     S = {type, {M,Name,0}},
+     Site = {type, {M,Name,0}},
      V = #{},
-     {T1, _} =
-       t_from_form(T, [], sets:new(), S, MR, V, _Deep=1000, _ALot=100000),
+     C = #{},
+     State = #from_form{site   = Site,
+                        xtypes = sets:new(),
+                        mrecs  = MR,
+                        vtab   = V,
+                        tnames = []},
+     {T1, _, _} = from_form(T, State, _Deep=1000, _ALot=1000000, C),
      t_to_string(T1)
   catch throw:{error, _} -> atom_to_string(Name) ++ "()"
   end;