Teach the ASN.1 compiler the 'maps' option

When the 'maps' option is given, the SEQUENCE and SET types are
represented as maps instead of as records. Optional and default values
must be not be given as asn1_NOVALUE or asn1_DEFAULT in a map passed
to the M:encode/2 function; they must be omitted from the
map. Similarly, when decoding missing values will be omitted from the
map.

No .hrl files will be generated when the 'maps' options is used.
That means values in an ASN.1 module must be retrieved by calling the
appropriate function in generated module.

Since we one day hope to get rid of the options 'compact_bit_string',
'legacy_bit_string', and 'legacy_erlang_types', we will not allow them
to be combined with the 'maps' option.

1 files changed, 95 insertions, 10 deletions

diff --git a/lib/asn1/test/asn1_test_lib.erl b/lib/asn1/test/asn1_test_lib.erl
index dc614db4f2..a79958d229 100644
--- a/lib/asn1/test/asn1_test_lib.erl
+++ b/lib/asn1/test/asn1_test_lib.erl
@@ -25,7 +25,8 @@
 	 hex_to_bin/1,
 	 match_value/2,
 	 parallel/0,
-	 roundtrip/3,roundtrip/4,roundtrip_enc/3,roundtrip_enc/4]).
+	 roundtrip/3,roundtrip/4,roundtrip_enc/3,roundtrip_enc/4,
+         map_roundtrip/3]).
 
 -include_lib("common_test/include/ct.hrl").
 
@@ -94,15 +95,58 @@ module(F0) ->
     list_to_atom(F).
 %%    filename:join(CaseDir, F ++ ".beam").
 
-compile_file(File, Options) ->
+compile_file(File, Options0) ->
+    Options = [warnings_as_errors|Options0],
     try
-        ok = asn1ct:compile(File, [warnings_as_errors|Options])
+        ok = asn1ct:compile(File, Options),
+        ok = compile_maps(File, Options)
     catch
         _:Reason ->
 	    ct:print("Failed to compile ~s\n~p", [File,Reason]),
             error
     end.
 
+compile_maps(File, Options) ->
+    unload_map_mod(File),
+    Incompat = [abs,compact_bit_string,legacy_bit_string,
+                legacy_erlang_types,maps,asn1_test_lib_no_maps],
+    case lists:any(fun(E) -> lists:member(E, Incompat) end, Options) of
+        true ->
+            ok;
+        false ->
+            compile_maps_1(File, Options)
+    end.
+
+compile_maps_1(File, Options) ->
+    ok = asn1ct:compile(File, [maps,no_ok_wrapper,noobj|Options]),
+    OutDir = proplists:get_value(outdir, Options),
+    Base0 = filename:rootname(filename:basename(File)),
+    Base = case filename:extension(Base0) of
+               ".set" ->
+                   filename:rootname(Base0);
+               _ ->
+                   Base0
+           end,
+    ErlBase = Base ++ ".erl",
+    ErlFile = filename:join(OutDir, ErlBase),
+    {ok,Erl0} = file:read_file(ErlFile),
+    Erl = re:replace(Erl0, <<"-module\\('">>, "&maps_"),
+    MapsErlFile = filename:join(OutDir, "maps_" ++ ErlBase),
+    ok = file:write_file(MapsErlFile, Erl),
+    {ok,_} = compile:file(MapsErlFile, [report,{outdir,OutDir},{i,OutDir}]),
+    ok.
+
+unload_map_mod(File0) ->
+    File1 = filename:basename(File0),
+    File2 = filename:rootname(File1, ".asn"),
+    File3 = filename:rootname(File2, ".asn1"),
+    File4 = filename:rootname(File3, ".py"),
+    File = filename:rootname(File4, ".set"),
+    MapMod = list_to_atom("maps_"++File),
+    code:delete(MapMod),
+    code:purge(MapMod),
+    ok.
+
 compile_erlang(Mod, Config, Options) ->
     DataDir = proplists:get_value(data_dir, Config),
     CaseDir = proplists:get_value(case_dir, Config),
@@ -147,24 +191,60 @@ roundtrip(Mod, Type, Value) ->
     roundtrip(Mod, Type, Value, Value).
 
 roundtrip(Mod, Type, Value, ExpectedValue) ->
-    {ok,Encoded} = Mod:encode(Type, Value),
-    {ok,ExpectedValue} = Mod:decode(Type, Encoded),
-    test_ber_indefinite(Mod, Type, Encoded, ExpectedValue),
-    ok.
+    roundtrip_enc(Mod, Type, Value, ExpectedValue).
 
 roundtrip_enc(Mod, Type, Value) ->
     roundtrip_enc(Mod, Type, Value, Value).
 
 roundtrip_enc(Mod, Type, Value, ExpectedValue) ->
-    {ok,Encoded} = Mod:encode(Type, Value),
-    {ok,ExpectedValue} = Mod:decode(Type, Encoded),
+    case Mod:encode(Type, Value) of
+        {ok,Encoded} ->
+            {ok,ExpectedValue} = Mod:decode(Type, Encoded);
+        Encoded when is_binary(Encoded) ->
+            ExpectedValue = Mod:decode(Type, Encoded)
+    end,
+    map_roundtrip(Mod, Type, Encoded),
     test_ber_indefinite(Mod, Type, Encoded, ExpectedValue),
     Encoded.
 
+map_roundtrip(Mod, Type, Encoded) ->
+    MapMod = list_to_atom("maps_"++atom_to_list(Mod)),
+    try MapMod:maps() of
+        true ->
+            map_roundtrip_1(MapMod, Type, Encoded)
+    catch
+        error:undef ->
+            ok
+    end.
+
 %%%
 %%% Internal functions.
 %%%
 
+map_roundtrip_1(Mod, Type, Encoded) ->
+    Decoded = Mod:decode(Type, Encoded),
+    case Mod:encode(Type, Decoded) of
+        Encoded ->
+            ok;
+        OtherEncoding ->
+            case is_named_bitstring(Decoded) of
+                true ->
+                    %% In BER, named BIT STRINGs with different number of
+                    %% trailing zeroes decode to the same value.
+                    ok;
+                false ->
+                    error({encode_mismatch,Decoded,Encoded,OtherEncoding})
+            end
+    end,
+    ok.
+
+is_named_bitstring([H|T]) ->
+    is_atom(H) andalso is_named_bitstring(T);
+is_named_bitstring([]) ->
+    true;
+is_named_bitstring(_) ->
+    false.
+
 hex2num(C) when $0 =< C, C =< $9 -> C - $0;
 hex2num(C) when $A =< C, C =< $F -> C - $A + 10;
 hex2num(C) when $a =< C, C =< $f -> C - $a + 10.
@@ -179,7 +259,12 @@ test_ber_indefinite(Mod, Type, Encoded, ExpectedValue) ->
     case Mod:encoding_rule() of
 	ber ->
 	    Indefinite = iolist_to_binary(ber_indefinite(Encoded)),
-	    {ok,ExpectedValue} = Mod:decode(Type, Indefinite);
+            case Mod:decode(Type, Indefinite) of
+                {ok,ExpectedValue} ->
+                    ok;
+                ExpectedValue ->
+                    ok
+            end;
 	_ ->
 	    ok
     end.