blob: 10b6ddef3ca31868138989ee4ca8cdf9361b297e (
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
|
%{
#include <u.h>
#include <libc.h>
#include <ctype.h>
#include "dat.h"
char *yylp; /* next character to be lex'd */
char *yybuffer;
char *yyend; /* end of buffer to be parsed */
%}
%term LOR
%term LAND
%term WORD
%term NE
%right '!'
%left '|'
%left '&'
%left LOR
%left LAND
%start filter
%%
filter : expr
{ filter = $$; }
;
expr : WORD
{ $$ = $1; }
| WORD '=' WORD
{ $2->l = $1; $2->r = $3; $$ = $2; }
| WORD NE WORD
{ $2->l = newfilter();
$2->l->op = '=';
$2->l->l = $1;
$2->l->r = $3;
$2->op = '!';
$$ = $2;
}
| WORD '(' expr ')'
{ $1->l = $3; free($2); free($4); $$ = $1; }
| '(' expr ')'
{ free($1); free($3); $$ = $2; }
| expr LOR expr
{ $2->l = $1; $2->r = $3; $$ = $2; }
| expr LAND expr
{ $2->l = $1; $2->r = $3; $$ = $2; }
| '!' expr
{ $1->l = $2; $$ = $1; }
;
%%
/*
* Initialize the parsing. Done once for each header field.
*/
void
yyinit(char *p)
{
yylp = p;
}
int
yylex(void)
{
char *p;
int c;
if(yylp == nil || *yylp == 0)
return 0;
while(isspace(*yylp))
yylp++;
yylval = newfilter();
p = strpbrk(yylp, "!|&()= ");
if(p == 0){
yylval->op = WORD;
yylval->s = strdup(yylp);
if(yylval->s == nil)
sysfatal("parsing filter: %r");
yylp = nil;
return WORD;
}
c = *p;
if(p != yylp){
yylval->op = WORD;
*p = 0;
yylval->s = strdup(yylp);
if(yylval->s == nil)
sysfatal("parsing filter: %r");
*p = c;
yylp = p;
return WORD;
}
yylp++;
if(c == '!' && *yylp == '='){
c = NE;
yylp++;
}
else if(c == '&' && *yylp == '&'){
c = LAND;
yylp++;
}
else if(c == '|' && *yylp == '|'){
c = LOR;
yylp++;
}
yylval->op = c;
return c;
}
void
yyerror(char *e)
{
USED(e);
// longjmp(errjmp, 1);
sysfatal("error parsing filter");
}
|