dialyzer: Fix pretty printing of binaries

Notice the comment in dialyzer_utils:

%% Copied from core_pp. The function cerl:binary_segments/2 should/could
%% be extended to handle literals, but then the cerl module cannot be
%% HiPE-compiled as of Erlang/OTP 22.0 (due to <<I:N>>).

When at it: simplify some common cases like "/binary-unit:8".

1 files changed, 57 insertions, 8 deletions

diff --git a/lib/dialyzer/src/dialyzer_utils.erl b/lib/dialyzer/src/dialyzer_utils.erl
index 3fe026b096..245c099fef 100644
--- a/lib/dialyzer/src/dialyzer_utils.erl
+++ b/lib/dialyzer/src/dialyzer_utils.erl
@@ -46,6 +46,7 @@
 	]).
 
 -include("dialyzer.hrl").
+-include("../../compiler/src/core_parse.hrl").
 
 %%-define(DEBUG, true).
 
@@ -751,9 +752,13 @@ pp_hook(Node, Ctxt, Cont) ->
     map ->
       pp_map(Node, Ctxt, Cont);
     literal ->
-      case is_map(cerl:concrete(Node)) of
-	true -> pp_map(Node, Ctxt, Cont);
-	false -> Cont(Node, Ctxt)
+      case cerl:concrete(Node) of
+        Map when is_map(Map) ->
+          pp_map(Node, Ctxt, Cont);
+        Bitstr when is_bitstring(Bitstr) ->
+          pp_binary(Node, Ctxt, Cont);
+        _ ->
+          Cont(Node, Ctxt)
       end;
     _ ->
       Cont(Node, Ctxt)
@@ -761,7 +766,7 @@ pp_hook(Node, Ctxt, Cont) ->
 
 pp_binary(Node, Ctxt, Cont) ->
   prettypr:beside(prettypr:text("<<"),
-		  prettypr:beside(pp_segments(cerl:binary_segments(Node),
+		  prettypr:beside(pp_segments(cerl_binary_segments(Node),
 					      Ctxt, Cont),
 				  prettypr:text(">>"))).
 
@@ -780,10 +785,29 @@ pp_segment(Node, Ctxt, Cont) ->
   Unit = cerl:bitstr_unit(Node),
   Type = cerl:bitstr_type(Node),
   Flags = cerl:bitstr_flags(Node),
-  prettypr:beside(Cont(Val, Ctxt),
-		  prettypr:beside(pp_size(Size, Ctxt, Cont),
-				  prettypr:beside(pp_opts(Type, Flags),
-						  pp_unit(Unit, Ctxt, Cont)))).
+  RestPP =
+    case {concrete(Unit), concrete(Type), concrete(Flags)} of
+      {1, integer, [unsigned, big]} -> % Simplify common cases.
+        case concrete(Size) of
+          8 -> prettypr:text("");
+          _ -> pp_size(Size, Ctxt, Cont)
+        end;
+      {8, binary, [unsigned, big]} ->
+        SizePP = pp_size(Size, Ctxt, Cont),
+        prettypr:beside(SizePP,
+                        prettypr:beside(prettypr:text("/"), pp_atom(Type)));
+      _What ->
+        SizePP = pp_size(Size, Ctxt, Cont),
+        UnitPP = pp_unit(Unit, Ctxt, Cont),
+        OptsPP = pp_opts(Type, Flags),
+        prettypr:beside(SizePP, prettypr:beside(OptsPP, UnitPP))
+    end,
+  prettypr:beside(Cont(Val, Ctxt), RestPP).
+
+concrete(Cerl) ->
+  try cerl:concrete(Cerl)
+  catch _:_ -> anything_unexpected
+  end.
 
 pp_size(Size, Ctxt, Cont) ->
   case cerl:is_c_atom(Size) of
@@ -859,6 +883,31 @@ seq([H | T], Separator, Ctxt, Fun) ->
 seq([], _, _, _) ->
   [prettypr:empty()].
 
+cerl_binary_segments(#c_literal{val = B}) when is_bitstring(B) ->
+  segs_from_bitstring(B);
+cerl_binary_segments(CBinary) ->
+  cerl:binary_segments(CBinary).
+
+%% Copied from core_pp. The function cerl:binary_segments/2 should/could
+%% be extended to handle literals, but then the cerl module cannot be
+%% HiPE-compiled as of Erlang/OTP 22.0 (due to <<I:N>>).
+segs_from_bitstring(<<H,T/bitstring>>) ->
+    [#c_bitstr{val=#c_literal{val=H},
+	       size=#c_literal{val=8},
+	       unit=#c_literal{val=1},
+	       type=#c_literal{val=integer},
+	       flags=#c_literal{val=[unsigned,big]}}|segs_from_bitstring(T)];
+segs_from_bitstring(<<>>) ->
+    [];
+segs_from_bitstring(Bitstring) ->
+    N = bit_size(Bitstring),
+    <<I:N>> = Bitstring,
+    [#c_bitstr{val=#c_literal{val=I},
+	      size=#c_literal{val=N},
+	      unit=#c_literal{val=1},
+	      type=#c_literal{val=integer},
+	      flags=#c_literal{val=[unsigned,big]}}].
+
 %%------------------------------------------------------------------------------
 
 -spec refold_pattern(cerl:cerl()) -> cerl:cerl().