yacc.y

%{
	#include<string.h>
	#include<stdio.h>
	#include<stdlib.h>
	#include<ctype.h>
	#include "symbol.h"
	//int number;
	/*struct quad
	{
		char op[5];
		char arg1[10];
		char arg2[10];
		char result[10];
	}QUAD[30];*/
	/*struct stack 
	{
		int items[100];
		int top;
	}stk;*/
	int index1=0;
	//int tIndex=0; 
	//int StNo;
	//int Ind; 
	//int tInd;
	//int checkIndex = 0;
	extern int line_no; 
	extern int ind;
	//char* toString(int number);
	//void AddQuadruple(char op[5],char arg1[10],char arg2[10],char result[10]);
	int getValue(int , int , char*);
	//int checkSymbolTable(char *);
	int yyerror(char*);
	int yylex();
	//void label();
	//extern int scopeCount;
	//int globalIndex = 0;
	//int labelCount = 0;
%}
%union
{
	char var[10];
	//struct token *symbol_table[100];
}


%token <var> NUM VAR RELOP MAIN TYPE HEADER
%token WHILE IF ELSE FOR
%type <var> EXPR ASSIGNMENT RELEXPR
%left '-' '+'
%left '*' '/'

%%
START: HEADERFILE Main
	|;
HEADERFILE: HEADER HEADERFILE {printf("Header file completed\n");}
	|;
Main : TYPE MAIN '(' ')' '{' PROGRAM '}' ;
PROGRAM : CODE
;
BLOCK : '{' CODE '}' ;
;
CODE : BLOCK | STATEMENT CODE| STATEMENT
;
STATEMENT: VARASSIGN ';'| WHILE '(' RELEXPR ')' BLOCK  | IF '(' RELEXPR ')' BLOCK | ERROR | error ';'
;

ERROR: NUM {printf("Error at line: %d\n",line_no);}
        | VAR {printf("Error at line: %d\n",line_no);}

VARASSIGN: TYPE VAR {
			printf("Inside VARASSIGN\n");
			//print_symbols();
			//printf("$2 = %s\n",$2);
			index1 = getPosition($2);
			//printf("Index1 = %d\n",index1);
			strcpy(symbol_table[index1]->type,$1);
		}
	 |TYPE VAR '=' EXPR {
	 		index1 = getPosition($2);
	 		strcpy(symbol_table[index1]->type,$1);
	 		symbol_table[index1]->value = atoi($4);
	 	}
	 | ASSIGNMENT
	 ;
ASSIGNMENT: VAR '=' EXPR{						
			/*strcpy(QUAD[Index].op,"=");
			strcpy(QUAD[Index].arg1,$3);
			strcpy(QUAD[Index].arg2,"");
			strcpy(QUAD[Index].result,$1);
			checkIndex = checkSymbolTable($3);
			printf("%d ", scopeCount);*/
			printf("Inside Assignment\n");
			int index1 = getPosition($1);	
			//int index2 = getPosition($3);		

			if (index1 != -1) {
				symbol_table[index1]->value = atoi($3);
			}else{
				printf("Error: variable undeclared\n");
			}
					
			//strcpy($$,QUAD[Index++].result);
			
			
			}
			;
EXPR : EXPR '+' EXPR { /*if(isdigit($1[0]) && isdigit($3[0])) {
				strcpy($$, itoa(atoi($1) + atoi($3))); //AddQuadruple("+",$1,$3,$$);
		    	}else{ 
			index = getPosition($3);			
			if(index != -1) {
				strcpy($$, itoa(atoi($1) + symbol_table[index].value)); 
				//AddQuadruple("+",$1,$3,$$);			
			} else {
				index = getPosition($1);
				strcpy($$, itoa(symbol_table[index].value + atoi($3))); 
				AddQuadruple("+",$1,$3,$$);		
			}				
			
		     }*/	//char temp[25];
		     		sprintf($$, "%d",(atoi($1) + atoi($3)));	
			}
			
     | EXPR '-' EXPR { sprintf($$,"%d",(atoi($1) - atoi($3))); }
     | EXPR '*' EXPR { sprintf($$,"%d",(atoi($1) * atoi($3))); }
     | EXPR '/' EXPR { sprintf($$,"%d",(atoi($1) / atoi($3))); }
     
     | VAR	{
     			index1 = getPosition($1);
     			sprintf($$,"%d",(symbol_table[index1]->value));     			
     		}
     | NUM      {
                        printf("Inside Num\n");
                }
     ;

RELEXPR: VAR RELOP RELEXPR {
				index1 = getPosition($1); 
				/*if (isdigit($3[0])) {
					strcpy($$, itoa(getValue(symbol_table[index]->value, atoi($3), $2))); 
				} else {
					int index2 = getPosition($3);
					strcpy($$, itoa(getValue(symbol_table[index]->value, symbol_table[index2]->value, $2))); 
				}*/
				sprintf($$,"%d",(getValue(symbol_table[index1]->value, atoi($3), $2)));
			   }
	   | NUM RELOP RELEXPR { 	/*if (isdigit($3[0])) {
						strcpy($$, itoa(getValue(atoi($1), atoi($3), $2))); 
					} else {
						index = getPosition($3);
						strcpy($$, itoa(getValue(atoi($1), symbol_table[index]->value, $2))); 
					}*/
					sprintf($$,"%d",(getValue(atoi($1), atoi($3), $2)));
			     }
	   | VAR 	{
	   			index1 = getPosition($1);
     				sprintf($$,"%d",(symbol_table[index1]->value));
	   		}
	   | NUM
	   ;

%%

int getValue(int value1, int value2, char* operator){
	if(strcmp(operator, ">") == 0) 
		return value1 > value2;
	else if(strcmp(operator, "<") == 0) 
		return value1 < value2;
	else if(strcmp(operator, ">=") == 0) 
		return value1 >= value2;
	else if(strcmp(operator, "<=") == 0)
		return value1 <= value2;
	else if(strcmp(operator, "==") == 0)
		return value1 == value2;		
	else 
		return value1 != value2;	
}

int yyerror(char *string)
{
	printf("\n Error on line no:%d\n",line_no);
	fprintf(stderr,"%s\n",string);
	yyparse();
	//return 0;
}

int main(int argc,char *argv[])
{
	int i;
	int a;
	if(!(a = yyparse())) {
		printf("Result of parse: %d",a);
		printf("\t\t\t\t Symbol Table \t\t\t\t\n");
		printf("\n\t%s\t|\t%s\t|\t%s\t|\t%s\t","Varibale Name","Value","Type","Scope");
		printf("\n\t-----------------------------------------------------------------------");	
		for (int i = 0; i <= ind; i++) {
					
					
					if (strcmp(symbol_table[i]->variable_name,"") != 0)
						printf("\n\t\t%s\t|\t%d\t|\t%s\t|\t%s\t", symbol_table[i]->variable_name, symbol_table[i]->value, 
						symbol_table[i]->type,symbol_table[i]->scope);
		}
		printf("\n\n");	
		/*printf("\t\t\t\t Quadruples \t\t\t\t\n");
		printf("\n\t%s\t|\t%s\t|\t%s\t|\t%s\t|\t%s","pos","op","arg1","arg2","result");
		printf("\n\t-----------------------------------------------------------------------");
		for(i=0;i<Index;i++)
		{
			printf("\n\t%d\t|\t%s\t|\t%s\t|\t%s\t|\t%s", i,QUAD[i].op, QUAD[i].arg1,QUAD[i].arg2,QUAD[i].result);
		}
		printf("\n\n");*/

	}
	//printf("Error of parse: %d",a);
	return 0;
}