Simplify handling of an empty object definition

When the parser sees:

  something SOMETHING ::= {}

it has no way of knowing whether 'something' is an value or an
object. It depends on how SOMETHING is defined.  For example:

  SOMETHING ::= SEQUENCE {}

or

  SOMETHING ::= CLASS { &id OPTIONAL }

Because of that ambiguity, there is no way to avoid a special case
when we check an object definition. However, there is no need to
invent an entire new checking function for this special case.  It is
much easier to just pretend that the parser gave us
{object,defaultsyntax,[]} and let check_objectdefn/3 check it in the
usual way.

2 files changed, 10 insertions, 25 deletions

diff --git a/lib/asn1/src/asn1ct_check.erl b/lib/asn1/src/asn1ct_check.erl
index 79d55feb9f..aba0e6a9ef 100644
--- a/lib/asn1/src/asn1ct_check.erl
+++ b/lib/asn1/src/asn1ct_check.erl
@@ -796,13 +796,10 @@ check_object(S,_ObjDef,#'Object'{classname=ClassRef,def=ObjectDef}) ->
 		{_,Object} = get_referenced_type(S,ObjectDef),
 		check_object(S, Object, object_to_check(Object));
 	    [] -> 
-		%% An object with no fields. All class fields must be
-		%% optional or default.  Check that all fields in
-		%% class are 'OPTIONAL' or 'DEFAULT'
-		class_fields_optional_check(S,ClassDef),
-		#'Object'{def={object,defaultsyntax,[]}};
-	    _  ->
-		exit({error,{no_object,ObjectDef},S})
+		%% An object with no fields (parsed as a value).
+		Def = {object,defaultsyntax,[]},
+		NewSettingList = check_objectdefn(S, Def, ClassDef),
+		#'Object'{def=NewSettingList}
 	end,
     Gen = gen_incl(S,NewObj#'Object'.def,
 		   (ClassDef#classdef.typespec)#objectclass.fields),
@@ -967,23 +964,6 @@ prepare_objset({#type{}=Type,#type{}=Ext}) ->
 prepare_objset(Ret) ->
     Ret.
 
-class_fields_optional_check(S,#classdef{typespec=ClassSpec}) ->
-    Fields = ClassSpec#objectclass.fields,
-    class_fields_optional_check1(S,Fields).
-
-class_fields_optional_check1(_S,[]) ->
-    ok;
-class_fields_optional_check1(S,[{typefield,_,'OPTIONAL'}|Rest]) ->
-    class_fields_optional_check1(S,Rest);
-class_fields_optional_check1(S,[{fixedtypevaluefield,_,_,_,'OPTIONAL'}|Rest]) ->
-    class_fields_optional_check1(S,Rest);
-class_fields_optional_check1(S,[{fixedtypevaluesetfield,_,_,'OPTIONAL'}|Rest]) ->
-    class_fields_optional_check1(S,Rest);
-class_fields_optional_check1(S,[{objectfield,_,_,_,'OPTIONAL'}|Rest]) ->
-    class_fields_optional_check1(S,Rest);
-class_fields_optional_check1(S,[{objectsetfield,_,_,'OPTIONAL'}|Rest]) ->
-    class_fields_optional_check1(S,Rest).
-
 %% ObjectSetFromObjects functionality
 
 %% The fieldname is a list of field names.They may be objects or
diff --git a/lib/asn1/test/error_SUITE.erl b/lib/asn1/test/error_SUITE.erl
index 630daf75c6..f03c2eab16 100644
--- a/lib/asn1/test/error_SUITE.erl
+++ b/lib/asn1/test/error_SUITE.erl
@@ -227,6 +227,7 @@ objects(Config) ->
 	   "  obj3 CL ::= { &Data OCTET STRING }\n"
 	   "  obj4 SMALL ::= { &code 42 }\n"
 	   "  InvalidSet CL ::= { obj1 }\n"
+	   "  obj5 CL ::= {}\n"
 
 	   "  CL ::= CLASS {\n"
 	   "    &code INTEGER UNIQUE,\n"
@@ -255,7 +256,11 @@ objects(Config) ->
       {structured_error,{M,5},asn1ct_check,
        {missing_mandatory_fields,[i],obj4}},
       {structured_error,{M,6},asn1ct_check,
-       {invalid_fields,[wrong],'InvalidSet'}}
+       {invalid_fields,[wrong],'InvalidSet'}},
+      {structured_error,{M,7},asn1ct_check,
+       {missing_mandatory_fields,
+	['Data','Set','VarTypeValue',code,enum,object,
+	 vartypevalue],obj5}}
      ]
     } = run(P, Config),
     ok.