Hi,
S the syntax checker that I mentioned does the semantic checks as well
:-). I did try with AUTOMATIC TAGS as well and the results are the same. One
mistake from my part is that I did not consider that only the
RootComponentTypeList is sorted, and not the extensions. My point is that in
the book ASN.1 - Communication by Heterogeneous System, in the section on
semantic model of ASN.1 it is mentioned that the ordering of the fields must
be done before the decision on tagging is done so the tags must match is my
understanding is correct.
Let me again explain with an e.g. -
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Junk DEFINITIONS AUTOMATIC TAGS ::=
BEGIN
Choice1 ::= CHOICE
{
f1 INTEGER,
f2 REAL
}
Choice2 ::= CHOICE
{
f2 REAL,
f1 INTEGER
}
choice1 Choice1 ::= f1:10
choice2 Choice2 ::= choice1
ExtChoice1 ::= CHOICE
{
field1 INTEGER,
field2 INTEGER,
...,
field3 REAL,
field4 INTEGER
}
ExtChoice2 ::= CHOICE
{
field1 INTEGER,
field2 INTEGER,
...,
field4 INTEGER,
field3 REAL
}
ExtChoice3 ::= CHOICE
{
field1 INTEGER,
field2 INTEGER,
...,
field3 NumericString,
field4 INTEGER
}
ext-choice1 ExtChoice1 ::= field2:10
ext-choice2 ExtChoice2 ::= ext-choice1
ext-choice3 ExtChoice3 ::= ext-choice1
END
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Now the types Choice1 & Choice2 should be compatible according to the
semantic model of ASN.1. But it says that the stmt 'choice2 Choice2 ::=
choice1' is illegal (type-mismatch). But it does not report this for the
stmt 'ext-choice2 ExtChoice2 ::= ext-choice2'. I do not understand why this
behavious. Kindly advise.
Thanking you.
Yours Sincerely
Ram
