summaryrefslogtreecommitdiff
path: root/grammar/grammar.y
blob: 488d332157e0cde1eb6de41015d218b6172bbb59 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
/* Bison file for rsyslog config format v2 (RainerScript).
 * Please note: this file introduces the new config format, but maintains
 * backward compatibility. In order to do so, the grammar is not 100% clean,
 * but IMHO still sufficiently easy both to understand for programmers
 * maitaining the code as well as users writing the config file. Users are,
 * of course, encouraged to use new constructs only. But it needs to be noted
 * that some of the legacy constructs (specifically the in-front-of-action
 * PRI filter) are very hard to beat in ease of use, at least for simpler
 * cases.
 *
 * Copyright 2011-2014 Rainer Gerhards and Adiscon GmbH.
 *
 * This file is part of the rsyslog runtime library.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *       http://www.apache.org/licenses/LICENSE-2.0
 *       -or-
 *       see COPYING.ASL20 in the source distribution
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
%{
#include "config.h"
#include <stdio.h>
#include <libestr.h>
#include "rainerscript.h"
#include "parserif.h"
#define YYDEBUG 1
extern int yylineno;

/* keep compile rule clean of errors */
extern int yylex(void);
extern int yyerror(char*);
%}

%union {
	char *s;
	long long n;
	es_str_t *estr;
	enum cnfobjType objType;
	struct cnfobj *obj;
	struct cnfstmt *stmt;
	struct nvlst *nvlst;
	struct objlst *objlst;
	struct cnfexpr *expr;
	struct cnfarray *arr;
	struct cnffunc *func;
	struct cnffparamlst *fparams;
}

%token <estr> NAME
%token <estr> FUNC
%token <objType> BEGINOBJ
%token ENDOBJ
%token BEGIN_ACTION
%token BEGIN_PROPERTY
%token BEGIN_CONSTANT
%token BEGIN_TPL
%token BEGIN_RULESET
%token STOP
%token SET
%token UNSET
%token CONTINUE
%token <cnfstmt> CALL
%token <s> LEGACY_ACTION
%token <s> LEGACY_RULESET
%token <s> PRIFILT
%token <s> PROPFILT
%token <s> BSD_TAG_SELECTOR
%token <s> BSD_HOST_SELECTOR
%token IF
%token THEN
%token ELSE
%token OR
%token AND
%token NOT
%token <s> VAR
%token <estr> STRING
%token <n> NUMBER
%token CMP_EQ
%token CMP_NE
%token CMP_LE
%token CMP_GE
%token CMP_LT
%token CMP_GT
%token CMP_CONTAINS
%token CMP_CONTAINSI
%token CMP_STARTSWITH
%token CMP_STARTSWITHI

%type <nvlst> nv nvlst value
%type <obj> obj property constant
%type <objlst> propconst
%type <expr> expr
%type <stmt> stmt s_act actlst block script
%type <fparams> fparams
%type <arr> array arrayelt

%left AND OR
%left CMP_EQ CMP_NE CMP_LE CMP_GE CMP_LT CMP_GT CMP_CONTAINS CMP_CONTAINSI CMP_STARTSWITH CMP_STARTSWITHI
%left '+' '-' '&'
%left '*' '/' '%'
%nonassoc UMINUS NOT

%expect 1 /* dangling else */
/* If more erors show up, Use "bison -v grammar.y" if more conflicts arise and
 * check grammar.output for were exactly these conflicts exits.
 */
%%
/* note: we use left recursion below, because that saves stack space AND
 * offers the right sequence so that we can submit the top-layer objects
 * one by one.
 */
conf:	/* empty (to end recursion) */
	| conf obj			{ cnfDoObj($2); }
	| conf stmt			{ cnfDoScript($2); }
	| conf LEGACY_RULESET		{ cnfDoCfsysline($2); }
	| conf BSD_TAG_SELECTOR		{ cnfDoBSDTag($2); }
	| conf BSD_HOST_SELECTOR	{ cnfDoBSDHost($2); }
obj:	  BEGINOBJ nvlst ENDOBJ 	{ $$ = cnfobjNew($1, $2); }
        | BEGIN_TPL nvlst ENDOBJ	{ $$ = cnfobjNew(CNFOBJ_TPL, $2); }
        | BEGIN_TPL nvlst ENDOBJ '{' propconst '}'
					{ $$ = cnfobjNew(CNFOBJ_TPL, $2);
					  $$->subobjs = $5;
					}
        | BEGIN_RULESET nvlst ENDOBJ '{' script '}'
					{ $$ = cnfobjNew(CNFOBJ_RULESET, $2);
					  $$->script = $5;
					}
propconst:				{ $$ = NULL; }
	| propconst property		{ $$ = objlstAdd($1, $2); }
	| propconst constant		{ $$ = objlstAdd($1, $2); }
property: BEGIN_PROPERTY nvlst ENDOBJ	{ $$ = cnfobjNew(CNFOBJ_PROPERTY, $2); }
constant: BEGIN_CONSTANT nvlst ENDOBJ	{ $$ = cnfobjNew(CNFOBJ_CONSTANT, $2); }
nvlst:					{ $$ = NULL; }
	| nvlst nv 			{ $2->next = $1; $$ = $2; }
nv:	NAME '=' value 			{ $$ = nvlstSetName($3, $1); }
value:	  STRING			{ $$ = nvlstNewStr($1); }
	| array				{ $$ = nvlstNewArray($1); }
script:	  stmt				{ $$ = $1; }
	| script stmt			{ $$ = scriptAddStmt($1, $2); }
stmt:	  actlst			{ $$ = $1; }
	| IF expr THEN block 		{ $$ = cnfstmtNew(S_IF);
					  $$->d.s_if.expr = $2;
					  $$->d.s_if.t_then = $4;
					  $$->d.s_if.t_else = NULL; }
	| IF expr THEN block ELSE block	{ $$ = cnfstmtNew(S_IF);
					  $$->d.s_if.expr = $2;
					  $$->d.s_if.t_then = $4;
					  $$->d.s_if.t_else = $6; }
	| SET VAR '=' expr ';'		{ $$ = cnfstmtNewSet($2, $4); }
	| UNSET VAR ';'			{ $$ = cnfstmtNewUnset($2); }
	| PRIFILT block			{ $$ = cnfstmtNewPRIFILT($1, $2); }
	| PROPFILT block		{ $$ = cnfstmtNewPROPFILT($1, $2); }
block:    stmt				{ $$ = $1; }
	| '{' script '}'		{ $$ = $2; }
actlst:	  s_act				{ $$ = $1; }
	| actlst '&' s_act 		{ $$ = scriptAddStmt($1, $3); }
/* s_act are actions and action-like statements */
s_act:	  BEGIN_ACTION nvlst ENDOBJ	{ $$ = cnfstmtNewAct($2); }
	| LEGACY_ACTION			{ $$ = cnfstmtNewLegaAct($1); }
	| STOP				{ $$ = cnfstmtNew(S_STOP); }
	| CALL NAME			{ $$ = cnfstmtNewCall($2); }
	| CONTINUE			{ $$ = cnfstmtNewContinue(); }
expr:	  expr AND expr			{ $$ = cnfexprNew(AND, $1, $3); }
	| expr OR expr			{ $$ = cnfexprNew(OR, $1, $3); }
	| NOT expr			{ $$ = cnfexprNew(NOT, NULL, $2); }
	| expr CMP_EQ expr		{ $$ = cnfexprNew(CMP_EQ, $1, $3); }
	| expr CMP_NE expr		{ $$ = cnfexprNew(CMP_NE, $1, $3); }
	| expr CMP_LE expr		{ $$ = cnfexprNew(CMP_LE, $1, $3); }
	| expr CMP_GE expr		{ $$ = cnfexprNew(CMP_GE, $1, $3); }
	| expr CMP_LT expr		{ $$ = cnfexprNew(CMP_LT, $1, $3); }
	| expr CMP_GT expr		{ $$ = cnfexprNew(CMP_GT, $1, $3); }
	| expr CMP_CONTAINS expr	{ $$ = cnfexprNew(CMP_CONTAINS, $1, $3); }
	| expr CMP_CONTAINSI expr	{ $$ = cnfexprNew(CMP_CONTAINSI, $1, $3); }
	| expr CMP_STARTSWITH expr	{ $$ = cnfexprNew(CMP_STARTSWITH, $1, $3); }
	| expr CMP_STARTSWITHI expr	{ $$ = cnfexprNew(CMP_STARTSWITHI, $1, $3); }
	| expr '&' expr			{ $$ = cnfexprNew('&', $1, $3); }
	| expr '+' expr			{ $$ = cnfexprNew('+', $1, $3); }
	| expr '-' expr			{ $$ = cnfexprNew('-', $1, $3); }
	| expr '*' expr			{ $$ = cnfexprNew('*', $1, $3); }
	| expr '/' expr			{ $$ = cnfexprNew('/', $1, $3); }
	| expr '%' expr			{ $$ = cnfexprNew('%', $1, $3); }
	| '(' expr ')'			{ $$ = $2; }
	| '-' expr %prec UMINUS		{ $$ = cnfexprNew('M', NULL, $2); }
	| FUNC '(' ')'			{ $$ = (struct cnfexpr*) cnffuncNew($1, NULL); }
	| FUNC '(' fparams ')'		{ $$ = (struct cnfexpr*) cnffuncNew($1, $3); }
	| NUMBER			{ $$ = (struct cnfexpr*) cnfnumvalNew($1); }
	| STRING			{ $$ = (struct cnfexpr*) cnfstringvalNew($1); }
	| VAR				{ $$ = (struct cnfexpr*) cnfvarNew($1); }
	| array				{ $$ = (struct cnfexpr*) $1; }
fparams:  expr				{ $$ = cnffparamlstNew($1, NULL); }
	| expr ',' fparams		{ $$ = cnffparamlstNew($1, $3); }
array:	 '[' arrayelt ']'		{ $$ = $2; }
arrayelt: STRING			{ $$ = cnfarrayNew($1); }
	| arrayelt ',' STRING		{ $$ = cnfarrayAdd($1, $3); }

%%
/*
int yyerror(char *s)
{
	printf("parse failure on or before line %d: %s\n", yylineno, s);
	return 0;
}
*/