Parse a
(vl-parse-par-block atts &key (tokstream 'tokstream) (config 'config)) → (mv errmsg? value new-tokstream)
Verilog-2005:
par_block ::= 'fork' [ ':' identifier { block_item_declaration } ] { statement } 'join'
SystemVerilog-2012 changes this to allow declarations even on unnamed forks, to allow additional kinds of join keywords, and to allow end-block names.
par_block ::= 'fork' [ ':' identifier ] { block_item_declaration } { statement_or_null } join_keyword [ ':' identifier ] join_keyword ::= 'join' | 'join_any' | 'join_none'