Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
1/* Simple expression parser */
2%{
3#define YYDEBUG 1
4#include <stdio.h>
5#include "util.h"
6#include "util/debug.h"
7#include <stdlib.h> // strtod()
8#define IN_EXPR_Y 1
9#include "expr.h"
10#include "smt.h"
11#include <string.h>
12
13static double d_ratio(double val0, double val1)
14{
15 if (val1 == 0) {
16 return 0;
17 }
18 return val0 / val1;
19}
20
21%}
22
23%define api.pure full
24
25%parse-param { double *final_val }
26%parse-param { struct expr_parse_ctx *ctx }
27%parse-param {void *scanner}
28%lex-param {void* scanner}
29
30%union {
31 double num;
32 char *str;
33}
34
35%token EXPR_PARSE EXPR_OTHER EXPR_ERROR
36%token <num> NUMBER
37%token <str> ID
38%destructor { free ($$); } <str>
39%token MIN MAX IF ELSE SMT_ON D_RATIO
40%left MIN MAX IF
41%left '|'
42%left '^'
43%left '&'
44%left '<' '>'
45%left '-' '+'
46%left '*' '/' '%'
47%left NEG NOT
48%type <num> expr if_expr
49
50%{
51static void expr_error(double *final_val __maybe_unused,
52 struct expr_parse_ctx *ctx __maybe_unused,
53 void *scanner,
54 const char *s)
55{
56 pr_debug("%s\n", s);
57}
58
59%}
60%%
61
62start:
63EXPR_PARSE all_expr
64|
65EXPR_OTHER all_other
66
67all_other: all_other other
68|
69
70other: ID
71{
72 expr__add_id(ctx, $1);
73}
74|
75MIN | MAX | IF | ELSE | SMT_ON | NUMBER | '|' | '^' | '&' | '-' | '+' | '*' | '/' | '%' | '(' | ')' | ','
76|
77'<' | '>' | D_RATIO
78
79all_expr: if_expr { *final_val = $1; }
80 ;
81
82if_expr:
83 expr IF expr ELSE expr { $$ = $3 ? $1 : $5; }
84 | expr
85 ;
86
87expr: NUMBER
88 | ID {
89 struct expr_id_data *data;
90
91 if (expr__resolve_id(ctx, $1, &data)) {
92 free($1);
93 YYABORT;
94 }
95
96 $$ = expr_id_data__value(data);
97 free($1);
98 }
99 | expr '|' expr { $$ = (long)$1 | (long)$3; }
100 | expr '&' expr { $$ = (long)$1 & (long)$3; }
101 | expr '^' expr { $$ = (long)$1 ^ (long)$3; }
102 | expr '<' expr { $$ = $1 < $3; }
103 | expr '>' expr { $$ = $1 > $3; }
104 | expr '+' expr { $$ = $1 + $3; }
105 | expr '-' expr { $$ = $1 - $3; }
106 | expr '*' expr { $$ = $1 * $3; }
107 | expr '/' expr { if ($3 == 0) {
108 pr_debug("division by zero\n");
109 YYABORT;
110 }
111 $$ = $1 / $3;
112 }
113 | expr '%' expr { if ((long)$3 == 0) {
114 pr_debug("division by zero\n");
115 YYABORT;
116 }
117 $$ = (long)$1 % (long)$3;
118 }
119 | '-' expr %prec NEG { $$ = -$2; }
120 | '(' if_expr ')' { $$ = $2; }
121 | MIN '(' expr ',' expr ')' { $$ = $3 < $5 ? $3 : $5; }
122 | MAX '(' expr ',' expr ')' { $$ = $3 > $5 ? $3 : $5; }
123 | SMT_ON { $$ = smt_on() > 0; }
124 | D_RATIO '(' expr ',' expr ')' { $$ = d_ratio($3,$5); }
125 ;
126
127%%