关于语法动作的antlr“java.lang.NoSuchFieldError”

I was trying to use rule reference in grammar action.

我试图在语法动作中使用规则引用。

string_decl_list  : (string_decl)+;
string_decl       : ('STRING' id ':=' str ';') 
{//table.currentScope().define(new BaseDescriptor(), id.text, ValueType.STRING);
 System.out.println($str.text);
};
str               : STRINGLITERAL;

My grammar looks like this. The compilation is fine. But when I try to parse my file.

我的语法看起来像这样。汇编很好。但是当我尝试解析我的文件时。

There's an exception coming out.

有一个例外。

Exception in thread "main" java.lang.NoSuchFieldError: str
at MicroParser.string_decl(MicroParser.java:368)
at MicroParser.string_decl_list(MicroParser.java:312)
at MicroParser.decl(MicroParser.java:246)
at MicroParser.pgm_body(MicroParser.java:187)
at MicroParser.program(MicroParser.java:107)
at Compiler.main(Compiler.java:32)
Java Result: 1

I guess I am doing it right for the rule reference, could anyone help me about this? I don't know how to solve it

我想我正在为规则参考做正确的事,有人可以帮我解决这个问题吗?我不知道如何解决它

1 个解决方案

#1

You get the error

你得到错误

 Exception in thread "main" java.lang.NoSuchFieldError: str

because you don't have a return value for the parser rule "str".

因为您没有解析器规则“str”的返回值。

Try something like this:

尝试这样的事情:

 str returns [String str] :  STRINGLITERAL { $str = new String($STRINGLITERAL.text); } ;

#1