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-rw-r--r--lib/dialyzer/src/dialyzer_typesig.erl48
-rw-r--r--lib/dialyzer/test/small_SUITE_data/src/bs_constraints.erl32
2 files changed, 61 insertions, 19 deletions
diff --git a/lib/dialyzer/src/dialyzer_typesig.erl b/lib/dialyzer/src/dialyzer_typesig.erl
index 17a292a7d6..af282c689d 100644
--- a/lib/dialyzer/src/dialyzer_typesig.erl
+++ b/lib/dialyzer/src/dialyzer_typesig.erl
@@ -246,18 +246,27 @@ traverse(Tree, DefinedVars, State) ->
Val = cerl:bitstr_val(Tree),
{State1, [SizeType, ValType]} =
traverse_list([Size, Val], DefinedVars, State),
- {State2, TypeConstr} =
+ {State2, TypeConstr, BinValTypeConstr} =
case cerl:bitstr_bitsize(Tree) of
- all -> {State1, t_bitstr(UnitVal, 0)};
- utf -> {State1, t_binary()}; % contains an integer number of bytes
- N when is_integer(N) -> {State1, t_bitstr(0, N)};
+ all ->
+ T = t_bitstr(UnitVal, 0),
+ {State1, T, T};
+ utf ->
+ %% contains an integer number of bytes
+ T = t_binary(),
+ {State1, T, T};
+ N when is_integer(N) ->
+ {State1, t_bitstr(0, N), t_bitstr(1, N)};
any -> % Size is not a literal
+ T1 = ?mk_fun_var(bitstr_constr(SizeType, UnitVal), [SizeType]),
+ T2 =
+ ?mk_fun_var(bitstr_constr(SizeType, UnitVal, match), [SizeType]),
{state__store_conj(SizeType, sub, t_non_neg_integer(), State1),
- ?mk_fun_var(bitstr_constr(SizeType, UnitVal), [SizeType])}
+ T1, T2}
end,
ValTypeConstr =
case cerl:concrete(cerl:bitstr_type(Tree)) of
- binary -> TypeConstr;
+ binary -> BinValTypeConstr;
float ->
case state__is_in_match(State1) of
true -> t_float();
@@ -947,12 +956,20 @@ get_type_test({erlang, is_tuple, 1}) -> {ok, t_tuple()};
get_type_test({M, F, A}) when is_atom(M), is_atom(F), is_integer(A) -> error.
bitstr_constr(SizeType, UnitVal) ->
+ bitstr_constr(SizeType, UnitVal, construct).
+
+bitstr_constr(SizeType, UnitVal, ConstructOrMatch) ->
+ Unit =
+ case ConstructOrMatch of
+ construct -> 0;
+ match -> 1
+ end,
fun(Map) ->
TmpSizeType = lookup_type(SizeType, Map),
case t_is_subtype(TmpSizeType, t_non_neg_integer()) of
true ->
case t_number_vals(TmpSizeType) of
- [OneSize] -> t_bitstr(0, OneSize * UnitVal);
+ [OneSize] -> t_bitstr(Unit, OneSize * UnitVal);
_ ->
MinSize = erl_types:number_min(TmpSizeType),
t_bitstr(UnitVal, MinSize * UnitVal)
@@ -3374,16 +3391,6 @@ pp_constraints([#constraint{}=C], Level, MaxDepth, _State) ->
pp_constraints([#constraint{}=C|Tail], Level, MaxDepth, State) ->
pp_op(C, Level),
pp_constraints(Tail, Level, MaxDepth, State);
-pp_constraints([#constraint_list{type = Type, list = List, id = Id}],
- Level, MaxDepth, State) ->
- pp_indent(Level),
- case Type of
- conj -> io:format("Conj ~w (", [Id]);
- disj -> io:format("Disj ~w (", [Id])
- end,
- NewMaxDepth = pp_constraints(List, Level + 1, MaxDepth, State),
- io:format(")", []),
- NewMaxDepth;
pp_constraints([#constraint_list{type = Type, list = List, id = Id}|Tail],
Level, MaxDepth, State) ->
pp_indent(Level),
@@ -3392,8 +3399,11 @@ pp_constraints([#constraint_list{type = Type, list = List, id = Id}|Tail],
disj -> io:format("Disj ~w (", [Id])
end,
NewMaxDepth = pp_constraints(List, Level+1, MaxDepth, State),
- io:format(")", []),
- pp_constraints(Tail, Level, NewMaxDepth, State).
+ io:format(")"),
+ case Tail =:= [] of
+ true -> NewMaxDepth + 1;
+ false -> pp_constraints(Tail, Level, NewMaxDepth, State)
+ end.
pp_op(#constraint{lhs = Lhs, op = Op, rhs = Rhs}, Level) ->
pp_indent(Level),
diff --git a/lib/dialyzer/test/small_SUITE_data/src/bs_constraints.erl b/lib/dialyzer/test/small_SUITE_data/src/bs_constraints.erl
new file mode 100644
index 0000000000..08dfb0808d
--- /dev/null
+++ b/lib/dialyzer/test/small_SUITE_data/src/bs_constraints.erl
@@ -0,0 +1,32 @@
+%% Program which shows that the handling of binaries was not correct.
+%% The success typing inferred was:
+%% -spec bits1(<<_:3>>) -> <<_:3>>.
+%% while it should be:
+%% -spec bits1(<<_:3,_:_*1>>) -> <<_:3>>.
+%% because the only constraint which exists for the head variable is
+%% that it must be a bitstring of bit size at least 3, not a bitstring
+%% of bit size 3.
+-module(bs_constraints).
+
+-export([bits1/1, bits2/1, bits3/1, bins/1, test/0]).
+
+bits1(B) ->
+ <<B:3/bits>>.
+
+bits2(B) ->
+ <<B:4/bits>>.
+
+bits3(B) ->
+ {bits1(B), bits2(B)}.
+
+%% Same problem with the one below. The success typing should be:
+%% -spec bins(<<_:16,_:_*1>>) -> <<_:16>>.
+bins(B) ->
+ <<B:2/binary>>.
+
+%% Same problem, when unit size is a variable:
+test() ->
+ foo(8, 0, <<42>>).
+
+foo(N, S, A) ->
+ <<A:S/binary-unit:1, A:(N-S)/binary-unit:1>>.