说明：  PL/0语言编译器的中间代码生成。要求用递归子程序法/或预测分析法实现对表达式、各种说明语句、控制语句进行语法分析。若语法正确，则用语法制导翻译法进行语义翻译：对说明语句，要求将说明的各符号记录到相应符号表中；对可执行语句，应产生出四元式中间代码并填写到三地址码表中； 若语法错误，要求指出出错性质和出错位置（行号）。出错处理应设计成一个出错处理子程序。
(The PL/0 language compiler intermediate code generation. Require the use of recursive subroutine/or forecast and analysis method of expression, statement, control the syntax analysis. If the grammar is correct, then use the grammar-translation method guidance for semantic translation: on the statement, will illustrate the various symbols are recorded onto a corresponding symbol table to executable statements, should produce four yuan intermediate code and fill to the three address code if the grammar mistakes, asked to point out that the error and error location ( nature line number ). Error handling should be designed into an error handling routine.)