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, 20 insertions, 2 deletions

diff --git a/lib/asn1/test/asn1_SUITE_data/ValueTest.asn b/lib/asn1/test/asn1_SUITE_data/ValueTest.asn
index 8db2fcf17d..51da9d8afb 100644
--- a/lib/asn1/test/asn1_SUITE_data/ValueTest.asn
+++ b/lib/asn1/test/asn1_SUITE_data/ValueTest.asn
@@ -1,4 +1,4 @@
-ValueTest DEFINITIONS  ::= 
+ValueTest DEFINITIONS AUTOMATIC TAGS ::=
 
 BEGIN
 
@@ -41,7 +41,6 @@ objectdescriptor ObjectDescriptor ::= "ObjectDescriptor"
 graphicstring GraphicString ::= "GraphicString"
 generalstring GeneralString ::= "GeneralString"
 bmpstring1 BMPString ::= "BMPString"
---bmpstring2 BMPString ::= [{0,0,0,66},{0,0,0,77},{0,0,0,80},{0,0,0,115},{0,0,0,116},{0,0,0,114},{0,0,0,105},{0,0,0,110},{0,0,0,103}]
 latinCapitalLetterA UniversalString ::= {0,0,0,65}
 greekCapitalLetterSigma UniversalString ::= {0,0,3,145}
 my-universalstring UniversalString ::= {"This is a capital A: ",
@@ -61,4 +60,23 @@ someInteger INTEGER ::= 42
 integerSeq1 IntegerSeq ::= { a otherInteger }
 otherInteger INTEGER ::= someInteger
 
+--
+-- Values from objects.
+--
+int-from-object-1 INTEGER ::= int-holder-2.&obj.&id
+int-from-object-2 INTEGER ::= int-holder-2.&id
+
+INT-HOLDER ::= CLASS {
+  &id INTEGER UNIQUE,
+  &obj INT-HOLDER OPTIONAL
+} WITH SYNTAX {
+  ID &id
+  [OBJ &obj]
+}
+
+int-holder-1 INT-HOLDER ::= { ID 2 }
+int-holder-2 INT-HOLDER ::= { ID 4 OBJ int-holder-1 }
+
+II ::= INTEGER (int-from-object-1..int-from-object-2)
+
 END