根据以上C语言代码生成其文法

以下是基于该 C 代码的文法：

program -> declaration_list

declaration_list -> declaration
                  | declaration_list declaration

declaration -> var_declaration
             | fun_declaration

var_declaration -> type_specifier ID ;
                 | type_specifier ID [ NUM ] ;

type_specifier -> int
                | void

fun_declaration -> type_specifier ID ( params ) compound_stmt

params -> param_list
        | void

param_list -> param
            | param_list , param

param -> type_specifier ID
       | type_specifier ID []

compound_stmt -> { local_declarations statement_list }

local_declarations -> local_declarations var_declaration
                    | empty

statement_list -> statement
                 | statement_list statement

statement -> expression_stmt
           | compound_stmt
           | selection_stmt
           | iteration_stmt
           | return_stmt

expression_stmt -> expression ;
                 | ;

selection_stmt -> if ( expression ) statement
                | if ( expression ) statement else statement

iteration_stmt -> while ( expression ) statement

return_stmt -> return ;
             | return expression ;

expression -> var = expression
            | simple_expression

var -> ID
    | ID [ expression ]

simple_expression -> additive_expression relop additive_expression
                   | additive_expression

additive_expression -> additive_expression addop term
                     | term

term -> term mulop factor
      | factor

factor -> ( expression )
        | var
        | call
        | NUM

call -> ID ( args )

args -> arg_list
      | empty

arg_list -> expression
          | arg_list , expression

empty -> ε

其中，大写字母表示非终结符，小写字母表示终结符，ε 表示空串。