xref: /linux/tools/net/sunrpc/xdrgen/grammars/xdr.lark (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1// A Lark grammar for the XDR specification language based on
2// https://tools.ietf.org/html/rfc4506 Section 6.3
3
4declaration             : "opaque" identifier "[" value "]"            -> fixed_length_opaque
5                        | "opaque" identifier "<" [ value ] ">"        -> variable_length_opaque
6                        | "string" identifier "<" [ value ] ">"        -> string
7                        | type_specifier identifier "[" value "]"      -> fixed_length_array
8                        | type_specifier identifier "<" [ value ] ">"  -> variable_length_array
9                        | type_specifier "*" identifier                -> optional_data
10                        | type_specifier identifier                    -> basic
11                        | "void"                                       -> void
12
13value                   : decimal_constant
14                        | hexadecimal_constant
15                        | octal_constant
16                        | identifier
17
18constant                : decimal_constant | hexadecimal_constant | octal_constant
19
20type_specifier          : unsigned_hyper
21                        | unsigned_long
22                        | unsigned_int
23                        | hyper
24                        | long
25                        | int
26                        | float
27                        | double
28                        | quadruple
29                        | bool
30                        | enum_type_spec
31                        | struct_type_spec
32                        | union_type_spec
33                        | identifier
34
35unsigned_hyper          : "unsigned" "hyper"
36unsigned_long           : "unsigned" "long"
37unsigned_int            : "unsigned" "int"
38hyper                   : "hyper"
39long                    : "long"
40int                     : "int"
41float                   : "float"
42double                  : "double"
43quadruple               : "quadruple"
44bool                    : "bool"
45
46enum_type_spec          : "enum" enum_body
47
48enum_body               : "{" ( identifier "=" value ) ( "," identifier "=" value )* "}"
49
50struct_type_spec        : "struct" struct_body
51
52struct_body             : "{" ( declaration ";" )+ "}"
53
54union_type_spec         : "union" union_body
55
56union_body              : switch_spec "{" case_spec+ [ default_spec ] "}"
57
58switch_spec             : "switch" "(" declaration ")"
59
60case_spec               : ( "case" value ":" )+ declaration ";"
61
62default_spec            : "default" ":" declaration ";"
63
64constant_def            : "const" identifier "=" value ";"
65
66type_def                : "typedef" declaration ";"                -> typedef
67                        | "enum" identifier enum_body ";"          -> enum
68                        | "struct" identifier struct_body ";"      -> struct
69                        | "union" identifier union_body ";"        -> union
70
71specification           : definition*
72
73definition              : constant_def
74                        | type_def
75                        | program_def
76                        | pragma_def
77
78//
79// RPC program definitions not specified in RFC 4506
80//
81
82program_def             : "program" identifier "{" version_def+ "}" "=" constant ";"
83
84version_def             : "version" identifier "{" procedure_def+ "}" "=" constant ";"
85
86procedure_def           : type_specifier identifier "(" type_specifier ")" "=" constant ";"
87
88pragma_def              : "pragma" directive identifier [ identifier ] ";"
89
90directive               : big_endian_directive
91                        | exclude_directive
92                        | header_directive
93                        | pages_directive
94                        | public_directive
95                        | skip_directive
96
97big_endian_directive    : "big_endian"
98exclude_directive       : "exclude"
99header_directive        : "header"
100pages_directive         : "pages"
101public_directive        : "public"
102skip_directive          : "skip"
103
104//
105// XDR language primitives
106//
107
108identifier              : /([a-z]|[A-Z])(_|[a-z]|[A-Z]|[0-9])*/
109
110decimal_constant        : /[\+-]?(0|[1-9][0-9]*)/
111hexadecimal_constant    : /0x([a-f]|[A-F]|[0-9])+/
112octal_constant          : /0[0-7]+/
113
114PASSTHRU                : "%" | "%" /.+/
115%ignore PASSTHRU
116
117%import common.C_COMMENT
118%ignore C_COMMENT
119
120%import common.WS
121%ignore WS
122