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-rw-r--r--lib/dialyzer/src/dialyzer_contracts.erl79
1 files changed, 63 insertions, 16 deletions
diff --git a/lib/dialyzer/src/dialyzer_contracts.erl b/lib/dialyzer/src/dialyzer_contracts.erl
index 2b78b736ab..76f23d00b9 100644
--- a/lib/dialyzer/src/dialyzer_contracts.erl
+++ b/lib/dialyzer/src/dialyzer_contracts.erl
@@ -344,7 +344,7 @@ insert_constraints([{subtype, Type1, Type2}|Left], Dict) ->
false ->
%% A lot of things should change to add supertypes
throw({error, io_lib:format("First argument of is_subtype constraint "
- "must be a type variable\n", [])})
+ "must be a type variable: ~p\n", [Type1])})
end;
insert_constraints([], Dict) -> Dict.
@@ -385,9 +385,8 @@ contract_from_form([{type, _L1, bounded_fun,
RecDict, FileLine, TypeAcc, FormAcc) ->
TypeFun =
fun(ExpTypes, AllRecords) ->
- Constr1 = [constraint_from_form(C, RecDict, ExpTypes, AllRecords)
- || C <- Constr],
- VarDict = insert_constraints(Constr1, dict:new()),
+ {Constr1, VarDict} =
+ process_constraints(Constr, RecDict, ExpTypes, AllRecords),
Type = erl_types:t_from_form(Form, RecDict, VarDict),
NewType = erl_types:t_solve_remote(Type, ExpTypes, AllRecords),
{NewType, Constr1}
@@ -398,18 +397,66 @@ contract_from_form([{type, _L1, bounded_fun,
contract_from_form([], _RecDict, _FileLine, TypeAcc, FormAcc) ->
{lists:reverse(TypeAcc), lists:reverse(FormAcc)}.
-constraint_from_form({type, _, constraint, [{atom, _, is_subtype},
- [Type1, Type2]]}, RecDict,
- ExpTypes, AllRecords) ->
- T1 = erl_types:t_from_form(Type1, RecDict),
- T2 = erl_types:t_from_form(Type2, RecDict),
- T3 = erl_types:t_solve_remote(T1, ExpTypes, AllRecords),
- T4 = erl_types:t_solve_remote(T2, ExpTypes, AllRecords),
- {subtype, T3, T4};
-constraint_from_form({type, _, constraint, [{atom,_,Name}, List]}, _RecDict,
- _ExpTypes, _AllRecords) ->
- N = length(List),
- throw({error, io_lib:format("Unsupported type guard ~w/~w\n", [Name, N])}).
+process_constraints(Constrs, RecDict, ExpTypes, AllRecords) ->
+ Init = initialize_constraints(Constrs, RecDict, ExpTypes, AllRecords),
+ constraints_fixpoint(Init, RecDict, ExpTypes, AllRecords).
+
+initialize_constraints(Constrs, RecDict, ExpTypes, AllRecords) ->
+ initialize_constraints(Constrs, RecDict, ExpTypes, AllRecords, []).
+
+initialize_constraints([], _RecDict, _ExpTypes, _AllRecords, Acc) ->
+ Acc;
+initialize_constraints([Constr|Rest], RecDict, ExpTypes, AllRecords, Acc) ->
+ case Constr of
+ {type, _, constraint, [{atom, _, is_subtype}, [Type1, Type2]]} ->
+ T1 = final_form(Type1, RecDict, ExpTypes, AllRecords, dict:new()),
+ Entry = {T1, Type2},
+ initialize_constraints(Rest, RecDict, ExpTypes, AllRecords, [Entry|Acc]);
+ {type, _, constraint, [{atom,_,Name}, List]} ->
+ N = length(List),
+ throw({error,
+ io_lib:format("Unsupported type guard ~w/~w\n", [Name, N])})
+ end.
+
+constraints_fixpoint(Constrs, RecDict, ExpTypes, AllRecords) ->
+ VarDict =
+ constraints_to_dict(Constrs, RecDict, ExpTypes, AllRecords, dict:new()),
+ constraints_fixpoint(VarDict, Constrs, RecDict, ExpTypes, AllRecords).
+
+constraints_fixpoint(OldVarDict, Constrs, RecDict, ExpTypes, AllRecords) ->
+ NewVarDict =
+ constraints_to_dict(Constrs, RecDict, ExpTypes, AllRecords, OldVarDict),
+ case NewVarDict of
+ OldVarDict ->
+ DictFold =
+ fun(Key, Value, Acc) ->
+ [{subtype, erl_types:t_var(Key), Value}|Acc]
+ end,
+ FinalConstrs = dict:fold(DictFold, [], NewVarDict),
+ {FinalConstrs, NewVarDict};
+ _Other ->
+ constraints_fixpoint(NewVarDict, Constrs, RecDict, ExpTypes, AllRecords)
+ end.
+
+-define(TYPE_LIMIT, 4).
+
+final_form(Form, RecDict, ExpTypes, AllRecords, VarDict) ->
+ T1 = erl_types:t_from_form(Form, RecDict, VarDict),
+ T2 = erl_types:t_solve_remote(T1, ExpTypes, AllRecords),
+ erl_types:t_limit(T2, ?TYPE_LIMIT).
+
+constraints_to_dict(Constrs, RecDict, ExpTypes, AllRecords, VarDict) ->
+ Subtypes =
+ constraints_to_subs(Constrs, RecDict, ExpTypes, AllRecords, VarDict, []),
+ insert_constraints(Subtypes, dict:new()).
+
+constraints_to_subs([], _RecDict, _ExpTypes, _AllRecords, _VarDict, Acc) ->
+ Acc;
+constraints_to_subs([C|Rest], RecDict, ExpTypes, AllRecords, VarDict, Acc) ->
+ {T1, Form2} = C,
+ T2 = final_form(Form2, RecDict, ExpTypes, AllRecords, VarDict),
+ NewAcc = [{subtype, T1, T2}|Acc],
+ constraints_to_subs(Rest, RecDict, ExpTypes, AllRecords, VarDict, NewAcc).
%% Gets the most general domain of a list of domains of all
%% the overloaded contracts