nilankamanoj/CMinusCompiler

lexical analyzer and the parser for the c- language

CMinusCompiler

lexical analyzer and the parser for the c- language

Installation instructions

1. download javcc from https://javacc.org/download
2. extract archive to the location c:\
3. confirm the availability of C:\javacc-6.0\bin\lib\javacc.jar
4. to generate lexical analyzer, parser and supporting scripts:

java -cp C:\javacc-6.0\bin\lib\javacc.jar javacc exparser.jj 

5. to compile scripts:

javac *.java

6. to parse c- language script:

java CMParser input.txt 

Example program of c- language

/* A program to perform Euclid's
Algorithm to compute gcd.*/
int i;
int gcd (int u, int v)
{
if(v==0) return u ;
else return gcd(v, u-u/v*v);
/* u-u/v*v == u mod v*/
}
void main(void)
{
int x; int y;
x = input(); y = input();
output(gcd(x, y));
}

Syntax rules for c-

1. program -> declaration-list

2. declaration-list -> declaration-list declaration | declaration

3. declaration -> var-declaration | fun-declaration

4. var-declaration-> type-specifier ID ; | type-specifier ID [ NUM ] ;

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 | 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. expression-stmt-> expression ; | ;

15. selection-stmt-> if( expression ) statement | if( expression ) statement else statement

16. iteration-stmt-> while ( expression ) statement

17. return-stmt-> return ; | return expression ;

18. expression-> var = expression | simple-expression

19. var-> ID | ID [ expression ]

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

27. call-> ID ( args )

28. args-> arg-list | empty

29. arg-list-> arg-list , expression | expression