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
|
/* Copyright (C) 2019 C. McEnroe <june@causal.agency>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
%{
#include <ctype.h>
#include <err.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <sysexits.h>
static void yyerror(const char *str) {
errx(EX_DATAERR, "%s", str);
}
#define YYSTYPE char *
static char *fmt(const char *format, ...) {
char *str = NULL;
va_list ap;
va_start(ap, format);
vasprintf(&str, format, ap);
va_end(ap);
if (!str) err(EX_OSERR, "vasprintf");
return str;
}
static int yylex(void);
%}
%token Var Arr Inc Dec Shl Shr Le Ge Eq Ne And Or
%left ','
%right '?' ':'
%left Or
%left And
%left '|'
%left '^'
%left '&'
%left Eq Ne
%left '<' Le '>' Ge
%left Shl Shr
%left '+' '-'
%left '*' '/' '%'
%right '!' '~' Inc Dec
%left '[' ']' Arr '.'
%%
start:
expr { printf("%s\n", $1); }
;
expr:
Var
| '(' expr ')' { $$ = $2; }
| expr '[' expr ']' { $$ = fmt("(%s[%s])", $1, $3); }
| expr Arr Var { $$ = fmt("(%s->%s)", $1, $3); }
| expr '.' Var { $$ = fmt("(%s.%s)", $1, $3); }
| '!' expr { $$ = fmt("(!%s)", $2); }
| '~' expr { $$ = fmt("(~%s)", $2); }
| Inc expr { $$ = fmt("(++%s)", $2); }
| Dec expr { $$ = fmt("(--%s)", $2); }
| expr Inc { $$ = fmt("(%s++)", $1); }
| expr Dec { $$ = fmt("(%s--)", $1); }
| '-' expr { $$ = fmt("(-%s)", $2); }
| '*' expr { $$ = fmt("(*%s)", $2); }
| '&' expr { $$ = fmt("(&%s)", $2); }
| expr '*' expr { $$ = fmt("(%s * %s)", $1, $3); }
| expr '/' expr { $$ = fmt("(%s / %s)", $1, $3); }
| expr '%' expr { $$ = fmt("(%s %% %s)", $1, $3); }
| expr '+' expr { $$ = fmt("(%s + %s)", $1, $3); }
| expr '-' expr { $$ = fmt("(%s - %s)", $1, $3); }
| expr Shl expr { $$ = fmt("(%s << %s)", $1, $3); }
| expr Shr expr { $$ = fmt("(%s >> %s)", $1, $3); }
| expr '<' expr { $$ = fmt("(%s < %s)", $1, $3); }
| expr Le expr { $$ = fmt("(%s <= %s)", $1, $3); }
| expr '>' expr { $$ = fmt("(%s > %s)", $1, $3); }
| expr Ge expr { $$ = fmt("(%s >= %s)", $1, $3); }
| expr Eq expr { $$ = fmt("(%s == %s)", $1, $3); }
| expr Ne expr { $$ = fmt("(%s != %s)", $1, $3); }
| expr '&' expr { $$ = fmt("(%s & %s)", $1, $3); }
| expr '^' expr { $$ = fmt("(%s ^ %s)", $1, $3); }
| expr '|' expr { $$ = fmt("(%s | %s)", $1, $3); }
| expr And expr { $$ = fmt("(%s && %s)", $1, $3); }
| expr Or expr { $$ = fmt("(%s || %s)", $1, $3); }
| expr '?' expr ':' expr { $$ = fmt("(%s ? %s : %s)", $1, $3, $5); }
| expr ',' expr { $$ = fmt("(%s, %s)", $1, $3); }
;
%%
#define T(a, b) ((int)(a) << 8 | (int)(b))
static const char *input;
static int yylex(void) {
while (isspace(input[0])) input++;
if (!input[0]) return EOF;
int len;
for (len = 0; isalnum(input[len]) || input[len] == '_'; ++len);
if (len) {
yylval = fmt("%.*s", len, input);
input += len;
return Var;
}
int tok = 0;
switch (T(input[0], input[1])) {
break; case T('-', '>'): tok = Arr;
break; case T('+', '+'): tok = Inc;
break; case T('-', '-'): tok = Dec;
break; case T('<', '<'): tok = Shl;
break; case T('>', '>'): tok = Shr;
break; case T('<', '='): tok = Le;
break; case T('>', '='): tok = Ge;
break; case T('=', '='): tok = Eq;
break; case T('!', '='): tok = Ne;
break; case T('&', '&'): tok = And;
break; case T('|', '|'): tok = Or;
}
if (tok) {
input += 2;
return tok;
}
return *input++;
}
int main(int argc, char *argv[]) {
for (int i = 1; i < argc; ++i) {
input = argv[i];
yyparse();
}
}
|