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|
%{
#include <stdio.h>
#include <stdlib.h>
int yylex();
int yyerror(char *);
%}
%token ADD SUB MUL DIV INC DEC
%token LT GT LTE GTE EQ NEQ ASSIGN
%token VOID INT DOUBLE FLOAT CHAR
%token LONG UNSIGNED
%token COMMA LPAREN RPAREN LBRACE RBRACE
%token ENDL
%token FOR RET IF ELSE WHILE
%token NUM ID
%start function_definition
%%
type_modifier: LONG
| UNSIGNED
;
type_specifier: VOID
| CHAR
| INT
| FLOAT
| DOUBLE
| type_modifier type_specifier
;
argument: type_specifier ID
;
argument_list: argument
| argument COMMA argument_list
;
primary_expr: NUM
| ID
;
postfix_expr: postfix_expr INC
| postfix_expr DEC
| primary_expr
;
unary_expr: INC unary_expr
| DEC unary_expr
| postfix_expr
;
boolean_expr: unary_expr LT unary_expr
| unary_expr GT unary_expr
| unary_expr LTE unary_expr
| unary_expr GTE unary_expr
| unary_expr EQ unary_expr
| unary_expr NEQ unary_expr
;
assignment_expr: argument ASSIGN unary_expr
| argument ASSIGN boolean_expr
;
func_call_expr: ID LPAREN expression_list RPAREN
| ID LPAREN RPAREN
;
expression: unary_expr
| boolean_expr
| assignment_expr
| func_call_expr
;
expression_list: expression
| expression COMMA expression_list
;
for_expr: FOR LPAREN statement statement expression RPAREN block
| FOR LPAREN statement statement RPAREN block
;
while_expr: WHILE LPAREN expression RPAREN block
;
if_expr: IF LPAREN expression RPAREN block
| IF LPAREN expression RPAREN block ELSE block
| IF LPAREN expression RPAREN block ELSE if_expr
;
block: LBRACE statement block_cont
;
block_cont: statement block_cont
| RBRACE
;
return_stmt: RET ENDL
| RET primary_expr ENDL
;
statement: expression ENDL
| return_stmt
| block
| for_expr
| if_expr
| while_expr
| ENDL
;
function_definition: argument LPAREN argument_list RPAREN block
| argument LPAREN RPAREN block
;
%%
int main() {
yyparse();
printf("valid expression");
}
int yyerror(char *s) {
printf("error: %s", s);
exit(0);
}
|
