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osmo-codegen
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Enhance grammar with AST rewrite rules 

It now generates a pretty meaningful AST representation of the
input data.
This commit is contained in:
Harald Welte 2011-02-19 13:29:34 +01:00
parent 832889c5e7
commit 334493f3b2
1 changed files with 48 additions and 14 deletions
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62
osmo_codegen.g
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@ -1,26 +1,44 @@
grammar osmo_codegen;
//options {
options {
//language = Python;
//}
output = AST;
}
tokens {
PDUFIELD_OPT;
FIELD_VAL;
PDUFIELD_SIZE;
IEFIELD_ENDIAN;
IEFIELD_COND;
IE_SPECS;
IE_ALIASES;
PDU_SPECS;
}
root :
(pdu_spec | ie_spec | ie_alias)*
-> ^(IE_SPECS ie_spec*) ^(IE_ALIASES ie_alias*) ^(PDU_SPECS pdu_spec*)
;
/* INFORMATION ELEMENTS */
/* An alias in the form "ie_alias new_name existing_field" */
ie_alias: 'ie_alias' ie_name ie_name;
ie_alias: 'ie_alias' ie_name ie_name
-> ^(ie_name ie_name)
;
ie_name : ID;
ie_spec : 'ie_spec' ID
ie_field_def*
'end_ie_spec'
-> ^(ID ie_field_def*)
;
ie_field_def
: ie_field_name ie_field_len ie_field_type ie_field_opts
: ie_field_name ie_field_len ie_field_type ie_field_opt*
-> ^(ie_field_name ie_field_type ie_field_len ie_field_opt*)
;
ie_field_name
@ -34,16 +52,22 @@ ie_field_type
| 'bit' | 'bits'
| 'bcd' // BCD digits, always 'lower nibble, upper nibble, lower nibble, ...
);
ie_field_opts
: field_val? ie_field_cond? ie_field_endian?;
ie_field_opt
: (field_val | ie_field_cond | ie_field_endian)
;
ie_field_cond
: 'if (' ie_field_name ('&' ie_field_cond_mask)? COMP_OP ie_field_cond_reference ')';
: 'if (' ie_field_name ('&' ie_field_cond_mask)? COMP_OP ie_field_cond_reference ')'
-> ^(IEFIELD_COND ie_field_name ie_field_cond_mask? COMP_OP ie_field_cond_reference)
;
ie_field_cond_mask
: NUMERIC;
ie_field_cond_reference
: NUMERIC;
ie_field_endian
: ('big' | 'little');
: ( 'big' -> ^(IEFIELD_ENDIAN 'big')
| 'little' -> ^(IEFIELD_ENDIAN 'little')
)
;
/* PDU DEFINITIONS*/
@ -51,20 +75,26 @@ ie_field_endian
pdu_spec
: 'pdu_spec' ID
pdu_field_def*
'end_pdu_spec'
'end_pdu_spec' -> ^(ID pdu_field_def*)
;
pdu_field_mode
: 'mand' | 'opt' | 'cond';
field_val
: ('val'|'value') NUMERIC; // Field always has to have indicated value
: ('val'|'value') NUMERIC // Field always has to have indicated value
-> ^(FIELD_VAL NUMERIC)
;
field_tag
: 'tag' NUMERIC; // for tagged fields
: 'tag' NUMERIC // for tagged fields
-> ^('tag' NUMERIC)
;
pdu_field_size
: NUMERIC ('-' NUMERIC)? ; // fixed length or range
: NUMERIC ('-' NUMERIC)? // fixed length or range
-> ^(PDUFIELD_SIZE NUMERIC*)
;
pdu_field_opts
: pdu_up_downlink | pdu_opt_ie
@ -72,7 +102,9 @@ pdu_field_opts
pdu_up_downlink
: 'uplink_only' | 'downlink_only'; // only valid in uplink or downlink
pdu_opt_ie
: 'ie' ID; // use speciifed IE definition
: 'ie' ID // use speciifed IE definition
-> ^('ie' ID)
;
pdu_field_type
: (
@ -87,7 +119,9 @@ pdu_field_type
) pdu_field_opts*;
pdu_field_def
: ID pdu_field_mode pdu_field_type;
: ID pdu_field_mode pdu_field_type
-> ^(ID pdu_field_mode pdu_field_type)
;
/* LEXER RULES */