ysyx-workbench/nemu/src/monitor/sdb/addrexp.y

37 lines
824 B
Text
Raw Normal View History

%{
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
extern int yylex(void);
void yyerror(uint32_t *result, const char *err) {
// fprintf(stderr, "Error: %s\n", err);
}
%}
%token NUMBER HEX_NUMBER
%start input
%define api.value.type { uint32_t }
%parse-param { uint32_t *result }
%left '-' '+'
%left '*' '/'
%%
input
: expression { *result = $1; }
;
expression
: number { $$ = $1; }
| expression '+' expression { $$ = $1 + $3; }
| expression '-' expression { $$ = $1 - $3; }
| expression '*' expression { $$ = $1 * $3; }
| expression '/' expression { if($3 == 0) { perror("Error: Devide by 0 in expression\n"); YYABORT; }; $$ = $1 / $3;}
| '-' number { $$ = -$2; }
| '(' expression ')' { $$ = $2; }
number
: NUMBER
| HEX_NUMBER
%%