c--

BNF

1. program -> declaration-list
2. declaration-list -> declaration-list declaration | declaration
3. declaration -> var-declaration | fun-declaration
4. var-declaration -> type-specifier ID;
5. type-specifier -> int | void
6. fun-declaration -> type-specifier ID ( params ) compound-stmt
7. params -> param-list | void
8. param-list -> param-list, param | param
9. param -> type-specifier ID
10. compound-stmt -> { local-declarations statement-list }
11. local-declarations -> local-declarations var-declaration | empty
12. statement-list -> statement-list statement | empty
13. statement -> expression-stmt | compound-stmt | selection-stmt | iteration-stmt | return-stmt
14. selection-stmt -> if ( expression ) statement | if ( expression ) statement else statement
15. iteration-stmt -> while ( expression ) statement
16. return-stmt -> return ; | return expression;
17. expression-stmt -> expression; | ;
18. expression -> var = expression | simple-expression;
19. var -> ID
20. simple-expression -> additive-expression relop additive-expression | additive-expression
21. relop -> <= | < | > | >= | == | !=
22. additive-expression -> additive-expression addop term | term
23. addop -> + | -
24. term -> term mulop factor | factor
25. mulop -> * | /
26. factor -> ( expression ) | var | call | NUM // factor
27. call -> ID ( args )
28. args -> arg-list | empty
29. arg-list -> arg-list, expression | expression