This is the grammar for abigen files. The grammar is expressed in a modified BNF format.
A nonterminal symbol matches a sequence of other symbols, delimited by commas.
nonterminal = list , of , symbols ;
Some symbols are terminals, which are either in all caps or are in double quotes.
another-nonterminal = THESE , ARE , TERMINALS , AND , SO , IS , "this" ;
Alternation is expressed with a pipe.
choice = this | that | the-other ;
An option (zero or one) is expressed with parentheses.
optional = ( maybe , these ) , but , definitely , these ;
Repetition (zero or more) is expressed with parentheses and a star.
zero-or-more = ( list-part )* ;
file is the starting symbol.
file = ( declaration )* , EOF ; declaration = syscall-declaration ; syscall-declaration = syscall IDENTIFIER attribute-list "(" parameter-list ")" ( "returns" "(" type ( "," parameter-list ) ")" ) parameter-list = parameter | parameter "," parameter-list parameter = IDENTIFIER ":" type attribute-list ( inout ) attribute-list = ( attribute )* attribute = IDENTIFIER type = IDENTIFIER inout = "IN" | "OUT" | "INOUT"