ASN.1 compiler not supporting AtNotation properly

[sebastiw]

Describe the bug ASN.1 compiler (asn1ct 5.0.16 as well as 5.0.19) has issues compiling modules which contains AtNotation. AtNotation is a way to access the fields within the object it is defined in.

Definition from ITU-T X.682:

10.7 A component relation constraint is applied using the associated table of an information object set and the following production:

ComponentRelationConstraint ::= "{" DefinedObjectSet "}" "{" AtNotation "," + "}"
AtNotation ::= "@" ComponentIdList |
               "@" "." Level ComponentIdList
Level ::= "." Level | empty
ComponentIdList ::= identifier "." +

To Reproduce Example ASN.1 file X682-error.asn1 follows:

X682-error {itu-t(0) recommendation(0) x(24) x682(682) errors(0) otpbug(1)}

-- Definition from ITU-T X.682 (https://www.itu.int/rec/T-REC-X.682-202102-I/en)
-- 10 Table constraints, including component relation constraints

DEFINITIONS
::=
BEGIN

ERROR-CLASS ::= CLASS
{
   &category PrintableString (SIZE(1)),
   &code INTEGER,
   &Type
}
WITH SYNTAX {&category &code &Type}

ErrorSet ERROR-CLASS ::=
{
   {"A" 1 INTEGER} |
   {"A" 2 REAL} |
   {"B" 1 CHARACTER STRING} |
   {"B" 2 GeneralString}
}

ErrorReturn ::= SEQUENCE
{
   errorCategory ERROR-CLASS.&category ({ErrorSet}) OPTIONAL,
   errors SEQUENCE OF SEQUENCE
   {
      errorCode ERROR-CLASS.&code ({ErrorSet}{@errorCategory}),
      errorInfo ERROR-CLASS.&Type ({ErrorSet}{@errorCategory,@.errorCode})
   } OPTIONAL
}

END

1> asn1ct:compile("/home/seba/work/forks/bugs/AtNotation/asn1/X682-error.asn1", [{i,"/home/seba/work/forks/bugs/AtNotation/asngen"},verbose,noobj,ber,{outdir,"/home/seba/work/forks/bugs/AtNotation/asngen"},{i,"."},{i,"/home/seba/work/forks/bugs/AtNotation/asn1"}]).
Erlang ASN.1 compiler 5.0.16
Compiling: "/home/seba/work/forks/bugs/AtNotation/asn1/X682-error.asn1"
Options: [{i,"/home/seba/work/forks/bugs/AtNotation/asngen"},
          verbose,noobj,ber,
          {outdir,"/home/seba/work/forks/bugs/AtNotation/asngen"},
          {i,"."},
          {i,"/home/seba/work/forks/bugs/AtNotation/asn1"}]
Internal error: error:function_clause
[{asn1ct_check,extract_at_notation,
     [[{outermost,[{'Externalvaluereference',32,'X682-error',errorCategory}]},
       {innermost,[{'Externalvaluereference',32,'X682-error',errorCode}]}]],
     [{file,"asn1ct_check.erl"},{line,5277}]},
 {asn1ct_check,any_component_relation,5,
     [{file,"asn1ct_check.erl"},{line,5155}]},
 {asn1ct_check,get_simple_table_if_used,2,
     [{file,"asn1ct_check.erl"},{line,5052}]},
 {asn1ct_check,componentrelation_leadingattr,2,
     [{file,"asn1ct_check.erl"},{line,4954}]},
 {asn1ct_check,check_sequence,3,[{file,"asn1ct_check.erl"},{line,4389}]},
 {asn1ct_check,check_type,3,[{file,"asn1ct_check.erl"},{line,2769}]},
 {asn1ct_check,check_sequenceof,3,[{file,"asn1ct_check.erl"},{line,4513}]},
 {asn1ct_check,check_type,3,[{file,"asn1ct_check.erl"},{line,2777}]}]
{error,{internal_error,{error,function_clause}}}

Expected behavior I expect this module to compile.

Affected versions 24.0.1, 25.0.4

Additional context

The reason I found is was that I was trying to compile an ASN.1 module from ETSI EN 301 140-1 V1.3.4 (1999-06)

This is a minimized real-world example, found in the wild.

IN-CS2-classes {
   ccitt(0) identified-organization(4) etsi(0) inDomain(1) in-network(1) cs2(20)
   modules(0) in-cs2-classes (4) version1(0)}

DEFINITIONS ::=
BEGIN

PARAMETERS-BOUND ::= CLASS
{
   &minFCIbccCS2Length INTEGER,
   &maxFCIbccCS2Length INTEGER
}
WITH SYNTAX
{
   MINIMUM-FOR-FCI-BILLING-CHARGING-CS-TWO &minFCIbccCS2Length
   MAXIMUM-FOR-FCI-BILLING-CHARGING-CS-TWO &maxFCIbccCS2Length
}


SupportedExtensions {PARAMETERS-BOUND : bound} EXTENSION ::=
{
   firstExtension,
   ...
   -- full set of network operator extensions –
}

ExtensionField {PARAMETERS-BOUND : bound} ::= SEQUENCE
{
   type EXTENSION.&id ({SupportedExtensions {bound}}),
   value [1] EXTENSION.&ExtensionType ({SupportedExtensions {bound}}{@type}),
   ...
}

END

I'm not entirely sure it is the same issue, but it seems related. Should I open another bug-report with this issue?

2> asn1ct:compile("/home/seba/work/forks/bugs/asn1-AtNotation/asn1/IN-CS2-classes.asn1", [{i,"/home/seba/work/forks/bugs/asn1-AtNotation/asngen"},verbose,noobj,ber,{outdir,"/home/seba/work/forks/bugs/asn1-AtNotat
ion/asngen"},{i,"."},{i,"/home/seba/work/forks/bugs/asn1-AtNotation/asn1"}]).
Erlang ASN.1 compiler 5.0.16
Compiling: "/home/seba/work/forks/bugs/asn1-AtNotation/asn1/IN-CS2-classes.asn1"
Options: [{i,"/home/seba/work/forks/bugs/asn1-AtNotation/asngen"},
          verbose,noobj,ber,
          {outdir,"/home/seba/work/forks/bugs/asn1-AtNotation/asngen"},
          {i,"."},
          {i,"/home/seba/work/forks/bugs/asn1-AtNotation/asn1"}]
IN-CS2-classes.asn1:30: syntax error before: '{'
{error,[{structured_error,{"IN-CS2-classes.asn1",30},
                          asn1ct_parser2,
                          {syntax_error,'{'}}]}

[KennethL]

I think the second case with the IN-CS2-classes is a different problem and that spec is not complete. EXTENSIONis undefined. Will look at the first problem only. Please report the second problem as a separate issue and try to provide a complete spec with a definition of EXTENSION.