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/* Simple expression parser */
%{
#define YYDEBUG 1
#include <stdio.h>
#include "util.h"
#include "util/debug.h"
#include <stdlib.h> // strtod()
#define IN_EXPR_Y 1
#include "expr.h"
#include "smt.h"
#include <string.h>
%}
%define api.pure full
%parse-param { double *final_val }
%parse-param { struct expr_parse_ctx *ctx }
%parse-param {void *scanner}
%lex-param {void* scanner}
%union {
double num;
char *str;
}
%token EXPR_PARSE EXPR_OTHER EXPR_ERROR
%token <num> NUMBER
%token <str> ID
%token MIN MAX IF ELSE SMT_ON
%left MIN MAX IF
%left '|'
%left '^'
%left '&'
%left '-' '+'
%left '*' '/' '%'
%left NEG NOT
%type <num> expr if_expr
%{
static void expr_error(double *final_val __maybe_unused,
struct expr_parse_ctx *ctx __maybe_unused,
void *scanner,
const char *s)
{
pr_debug("%s\n", s);
}
static int lookup_id(struct expr_parse_ctx *ctx, char *id, double *val)
{
int i;
for (i = 0; i < ctx->num_ids; i++) {
if (!strcasecmp(ctx->ids[i].name, id)) {
*val = ctx->ids[i].val;
return 0;
}
}
return -1;
}
%}
%%
start:
EXPR_PARSE all_expr
|
EXPR_OTHER all_other
all_other: all_other other
|
other: ID
{
if (ctx->num_ids + 1 >= EXPR_MAX_OTHER) {
pr_err("failed: way too many variables");
YYABORT;
}
ctx->ids[ctx->num_ids++].name = $1;
}
|
MIN | MAX | IF | ELSE | SMT_ON | NUMBER | '|' | '^' | '&' | '-' | '+' | '*' | '/' | '%' | '(' | ')'
all_expr: if_expr { *final_val = $1; }
;
if_expr:
expr IF expr ELSE expr { $$ = $3 ? $1 : $5; }
| expr
;
expr: NUMBER
| ID { if (lookup_id(ctx, $1, &$$) < 0) {
pr_debug("%s not found\n", $1);
YYABORT;
}
}
| expr '|' expr { $$ = (long)$1 | (long)$3; }
| expr '&' expr { $$ = (long)$1 & (long)$3; }
| expr '^' expr { $$ = (long)$1 ^ (long)$3; }
| expr '+' expr { $$ = $1 + $3; }
| expr '-' expr { $$ = $1 - $3; }
| expr '*' expr { $$ = $1 * $3; }
| expr '/' expr { if ($3 == 0) YYABORT; $$ = $1 / $3; }
| expr '%' expr { if ((long)$3 == 0) YYABORT; $$ = (long)$1 % (long)$3; }
| '-' expr %prec NEG { $$ = -$2; }
| '(' if_expr ')' { $$ = $2; }
| MIN '(' expr ',' expr ')' { $$ = $3 < $5 ? $3 : $5; }
| MAX '(' expr ',' expr ')' { $$ = $3 > $5 ? $3 : $5; }
| SMT_ON { $$ = smt_on() > 0; }
;
%%
|
