5.8 Attribute declaration
(23) attribute ::= "attribute" identifier "(" attribute-parameters
")" opt-properties ";"
(32) attribute-parameters ::= [ { attribute-parameter "," }
attribute-parameter ]
(33) attribute-parameter ::= parameter-dir parameter-variable
opt-initializer
(26) opt-properties ::= [ "{" properties "}" ]
(27) properties ::= { property }
(29) service-property ::= ( "task" identifier | "interrupts"
identifier-list | "before" identifier-list |
"after" identifier-list | "validate" codel )
";"