Refactor code involving calls to get_fieldname_element/3

Refactor and clean up code. While at it, add error handling and
test cases. (Also add test cases for the existing values in
ValueTest.asn while we are it.)

Add support for defining INTEGER constants by extracting
fields from objects. Example:

  int-from-object INTEGER ::= object.&id

When extracting values from objects in constraints, only one
level of extraction would work. That is, the following would
work:

  SomeName ::= INTEGER (object.&int)

but not:

  SomeName ::= INTEGER (object.&obj.&int)

1 files changed, 51 insertions, 0 deletions

diff --git a/lib/asn1/test/asn1_SUITE_data/InfObjExtract.asn1 b/lib/asn1/test/asn1_SUITE_data/InfObjExtract.asn1
new file mode 100644
index 0000000000..4a8889f940
--- /dev/null
+++ b/lib/asn1/test/asn1_SUITE_data/InfObjExtract.asn1
@@ -0,0 +1,51 @@
+InfObjExtract DEFINITIONS AUTOMATIC TAGS ::=
+BEGIN
+
+DATA-CLASS ::= CLASS {
+  &id INTEGER UNIQUE,
+  &Type
+} WITH SYNTAX {
+  ID &id
+  TYPE &Type
+}
+
+data-object-1 DATA-CLASS ::= { ID 1 TYPE BOOLEAN }
+data-object-2 DATA-CLASS ::= { ID 2 TYPE OCTET STRING }
+data-object-3 DATA-CLASS ::= { ID 3 TYPE BIT STRING }
+
+ObjSet DATA-CLASS ::= {
+  holder-object-1.&obj |
+  data-object-2 |
+  data-object-3,
+  ...
+}
+
+holder-object-1 HOLDER-CLASS ::= {
+  OBJ data-object-1
+}
+
+holder-object-2 HOLDER-CLASS ::= {
+  OBJ-SET {data-object-1}
+}
+
+holder-object-3 HOLDER-CLASS ::= {
+  OBJ-SET {holder-object-2.&ObjSet}
+}
+
+HOLDER-CLASS ::= CLASS {
+  &obj DATA-CLASS OPTIONAL,
+  &ObjSet DATA-CLASS OPTIONAL
+} WITH SYNTAX {
+  [OBJ &obj]
+  [OBJ-SET &ObjSet]
+}
+
+TestSeq{DATA-CLASS:ObjectSet} ::= SEQUENCE {
+  id DATA-CLASS.&id ({ObjectSet}),
+  data DATA-CLASS.&Type ({ObjectSet}{@id})
+}
+
+DataSeq-1 ::= TestSeq{ {ObjSet} }
+DataSeq-2 ::= TestSeq{ {holder-object-3.&ObjSet} }
+
+END