Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
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
13%}
14
15%define api.pure full
16
17%parse-param { double *final_val }
18%parse-param { struct expr_parse_ctx *ctx }
19%parse-param {void *scanner}
20%lex-param {void* scanner}
21
22%union {
23 double num;
24 char *str;
25}
26
27%token EXPR_PARSE EXPR_OTHER EXPR_ERROR
28%token <num> NUMBER
29%token <str> ID
30%destructor { free ($$); } <str>
31%token MIN MAX IF ELSE SMT_ON
32%left MIN MAX IF
33%left '|'
34%left '^'
35%left '&'
36%left '-' '+'
37%left '*' '/' '%'
38%left NEG NOT
39%type <num> expr if_expr
40
41%{
42static void expr_error(double *final_val __maybe_unused,
43 struct expr_parse_ctx *ctx __maybe_unused,
44 void *scanner,
45 const char *s)
46{
47 pr_debug("%s\n", s);
48}
49
50%}
51%%
52
53start:
54EXPR_PARSE all_expr
55|
56EXPR_OTHER all_other
57
58all_other: all_other other
59|
60
61other: ID
62{
63 expr__add_id(ctx, $1, 0.0);
64}
65|
66MIN | MAX | IF | ELSE | SMT_ON | NUMBER | '|' | '^' | '&' | '-' | '+' | '*' | '/' | '%' | '(' | ')' | ','
67
68
69all_expr: if_expr { *final_val = $1; }
70 ;
71
72if_expr:
73 expr IF expr ELSE expr { $$ = $3 ? $1 : $5; }
74 | expr
75 ;
76
77expr: NUMBER
78 | ID { if (expr__get_id(ctx, $1, &$$)) {
79 pr_debug("%s not found\n", $1);
80 free($1);
81 YYABORT;
82 }
83 free($1);
84 }
85 | expr '|' expr { $$ = (long)$1 | (long)$3; }
86 | expr '&' expr { $$ = (long)$1 & (long)$3; }
87 | expr '^' expr { $$ = (long)$1 ^ (long)$3; }
88 | expr '+' expr { $$ = $1 + $3; }
89 | expr '-' expr { $$ = $1 - $3; }
90 | expr '*' expr { $$ = $1 * $3; }
91 | expr '/' expr { if ($3 == 0) {
92 pr_debug("division by zero\n");
93 YYABORT;
94 }
95 $$ = $1 / $3;
96 }
97 | expr '%' expr { if ((long)$3 == 0) {
98 pr_debug("division by zero\n");
99 YYABORT;
100 }
101 $$ = (long)$1 % (long)$3;
102 }
103 | '-' expr %prec NEG { $$ = -$2; }
104 | '(' if_expr ')' { $$ = $2; }
105 | MIN '(' expr ',' expr ')' { $$ = $3 < $5 ? $3 : $5; }
106 | MAX '(' expr ',' expr ')' { $$ = $3 > $5 ? $3 : $5; }
107 | SMT_ON { $$ = smt_on() > 0; }
108 ;
109
110%%