YACC : 使用了符号 **** 但未定义为令牌且没有规则

Question

%{
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "parser.h"
extern int yylval;
%}
%start E
%token number
%%
S   :E  {printf("%s",);}
    ;
E   :E PLUS T   {$$ =  + ;}
    |T  {$$ = ;}
    ;
T   :T STAR F   {$$ =  * ;}
    |F  {$$ = ;}
    ;
F   :LP E RP    {$$ = ;}
    |number {$$ = ;}
    ;
%%

yylex(){
    char ch;
    ch = getchar();

    switch(ch){
        case '+':
            return PLUS;
            break;
        case '*':
            return STAR;
            break;
        case '(':
            return LP;
            break;
        case ')':
            return RP;
            break;
        default:
            if(ch >= '0' && ch <= '9'){
                ch -= '0';
                yylval = ch;;
                return (number);
            }
            else
                return -1;
    }
}

void main(){
    yyparse();
}

下午，我正在做关于如何使用 yacc 的作业，问题是我不知道如何在 .y 文件中正确包含头文件。从我所看到的描述如何编写 .y 文件的各种页面来看，我在编写这个 .y 文件方面没有做错任何事情。所以，请帮助我！

这些是我收到的错误信息

embedded@embedded-P15xEMx:~/Project/Compiler$ yacc parser.y
parser.y:19.10-11: error: symbol LP is used, but is not defined as a token and has no rules
 F  :LP E RP    {$$ = ;}
     ^^
parser.y:13.12-15: error: symbol PLUS is used, but is not defined as a token and has no rules
 E  :E PLUS T   {$$ =  + ;}
       ^^^^
parser.y:19.15-16: error: symbol RP is used, but is not defined as a token and has no rules
 F  :LP E RP    {$$ = ;}
          ^^
parser.y:16.12-15: error: symbol STAR is used, but is not defined as a token and has no rules
 T  :T STAR F   {$$ =  * ;}
       ^^^^

这是我包含的头文件

#ifndef _PARSER_H_
#define _PARSER_H_

    #include <stdio.h>

    #define PLUS 1
    #define STAR 2
    #define LP 3
    #define RP 4
    #define number 5

#endif

Answer 1

token符号不能自己声明，必须用yacc来声明，like

%token PLUS

等等

YACC : 使用了符号 **** 但未定义为令牌且没有规则

YACC : symbol **** is used but, is not defined as a token and has no rules

c

compiler-construction

yacc

lex