Eliminate Dialyzer crash for ill-typed code

Closes #6419

Author: bjorng

lib/dialyzer/src/dialyzer_dataflow.erl

@@ -1599,7 +1599,8 @@ bind_bin_segs([Seg|Segs], BinType, Acc, Map, State) ->
   Val = cerl:bitstr_val(Seg),
   SegType = cerl:concrete(cerl:bitstr_type(Seg)),
   UnitVal = cerl:concrete(cerl:bitstr_unit(Seg)),
-  case cerl:bitstr_bitsize(Seg) of
+  Size = cerl:bitstr_size(Seg),
+  case bitstr_bitsize_type(Size) of
     all ->
       binary = SegType, [] = Segs, %% just an assert
       T = t_inf(t_bitstr(UnitVal, 0), BinType),
@@ -1613,8 +1614,7 @@ bind_bin_segs([Seg|Segs], BinType, Acc, Map, State) ->
                                      Map, State, false, []),
       Type = t_binary(),
       bind_bin_segs(Segs, BinType, [Type|Acc], Map1, State);
-    BitSz when is_integer(BitSz); BitSz =:= any ->
-      Size = cerl:bitstr_size(Seg),
+    any ->
       {Map1, [SizeType]} = do_bind_pat_vars([Size], [t_non_neg_integer()],
                                             Map, State, false, []),
       Opaques = State#state.opaques,
@@ -1665,6 +1665,18 @@ bind_bin_segs([Seg|Segs], BinType, Acc, Map, State) ->
 bind_bin_segs([], _BinType, Acc, Map, _State) ->
   {Map, lists:reverse(Acc)}.
 
+bitstr_bitsize_type(Size) ->
+  case cerl:is_literal(Size) of
+    true ->
+      case cerl:concrete(Size) of
+        all -> all;
+        undefined -> utf;
+        _ -> any
+      end;
+    false ->
+      any
+  end.
+
 %% Return the infimum (meet) of ExpectedType and Type if is not
 %% t_none(), and raise a bind_error() it is t_none().
 bind_checked_inf(Pat, ExpectedType, Type, Opaques) ->

lib/dialyzer/src/dialyzer_typesig.erl

@@ -255,17 +255,24 @@ traverse(Tree, DefinedVars, State) ->
       {State1, [SizeType, ValType]} =
 	traverse_list([Size, Val], DefinedVars, State),
       {State2, TypeConstr, BinValTypeConstr} =
-	case cerl:bitstr_bitsize(Tree) of
-	  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
+        case cerl:is_literal(Size) of
+          true ->
+            case cerl:concrete(Size) of
+              all ->
+                T = t_bitstr(UnitVal, 0),
+                {State1, T, T};
+              undefined ->      %utf-8/16/32
+                %% contains an integer number of bytes
+                T = t_binary(),
+                {State1, T, T};
+              N0 when is_integer(N0) ->
+                N = N0 * UnitVal,
+                {State1, t_bitstr(0, N), t_bitstr(1, N)};
+              _ ->
+                {State1, t_none(), t_none()}
+            end;
+          false ->
+            %% Size is not a literal
             T1 = ?mk_fun_var(bitstr_constr(SizeType, UnitVal), [SizeType]),
             T2 =
               ?mk_fun_var(bitstr_constr(SizeType, UnitVal, match), [SizeType]),

lib/dialyzer/test/small_SUITE_data/results/bs_fail_constr

@@ -3,6 +3,10 @@ bs_fail_constr.erl:11:1: Function w3/1 has no local return
 bs_fail_constr.erl:12:8: Binary construction will fail since the size field S in segment 42:S has type neg_integer()
 bs_fail_constr.erl:14:1: Function w4/1 has no local return
 bs_fail_constr.erl:15:5: Binary construction will fail since the value field V in segment V/utf32 has type float()
+bs_fail_constr.erl:18:1: Function bad_size_1/1 has no local return
+bs_fail_constr.erl:18:1: The pattern <<X:[]>> can never match the type any()
+bs_fail_constr.erl:21:1: Function bad_size_2/1 has no local return
+bs_fail_constr.erl:24:9: The pattern <<X:Size>> can never match the type any()
 bs_fail_constr.erl:5:1: Function w1/1 has no local return
 bs_fail_constr.erl:6:5: Binary construction will fail since the value field V in segment V has type float()
 bs_fail_constr.erl:8:1: Function w2/1 has no local return

lib/dialyzer/test/small_SUITE_data/src/bs_fail_constr.erl

@@ -1,6 +1,6 @@
 -module(bs_fail_constr).
 
--export([w1/1, w2/1, w3/1, w4/1]).
+-export([w1/1, w2/1, w3/1, w4/1, bad_size_1/1, bad_size_2/1]).
 
 w1(V) when is_float(V) ->
   <<V/integer>>.
@@ -13,3 +13,14 @@ w3(S) when is_integer(S), S < 0 ->
 
 w4(V) when is_float(V) ->
   <<V/utf32>>.
+
+%% GH-6419
+bad_size_1(<<X:[]>>) ->
+    ok.
+
+bad_size_2(Bin) ->
+    Size = [],
+    case Bin of
+        <<X:Size>> ->
+            ok
+    end.