parser.y

%{
#include <stdio.h>
#include <stdlib.h>
#define YYSTYPE char*

extern FILE* yyin;
extern int lineno;
int isConditional=0;
int tupleIndex=0;
int temporaryGenerated=0;
int lineCount=100;
//Structure to hold code generated
struct quadruple
{
int line;
char *op;
char *arg1;
char *arg2;
char *result;
} tuple[1000];
//Temporary variable generater
char* newTemp();
char* newTemp()
{
	temporaryGenerated++;
	char *temp=(char *)malloc(sizeof(2*10));
	sprintf(temp,"t%d",temporaryGenerated);
	return temp;
}
//code Printer
void printCode();
void printCode()
{
int i=0;
for(;i<=tupleIndex-1;i++)
{
printf("%d:\t%s=%s%s%s\n",tuple[i].line,tuple[i].result,tuple[i].arg1,tuple[i].op,tuple[i].arg2);
}
}
//code generator
void codeGenerator(char*,char*,char*,char*);
void codeGenerator(char*op,char*arg1,char*arg2,char*result)
{
	if(!isConditional)
	{
	tuple[tupleIndex].line=lineCount;
	tuple[tupleIndex].op=op;
	tuple[tupleIndex].arg1=arg1;
	tuple[tupleIndex].arg2=arg2;
	tuple[tupleIndex].result=result;
	tupleIndex++;
	lineCount++;
	}


}

%}

%token NUMBER
%token ID
%token PLUS
%token MINUS
%token TIMES
%token DIVIDE
%token INT
%token FLOAT
%token COMMA
%token ASSIGN
%token OR
%token AND
%token NOT
%token RELOP
%token TRUE
%token FALSE
%token LP
%token RP
%token LB
%token RB
%token IF
%token ELSE
%token WHILE
%token DELIMITOR
%token E_O_F

%left PLUS MINUS
%left TIMES DIVIDE
%left OR
%left AND
%right NOT

%start Program

%%

/*Reduction Rule for the whole Program*/
Program:  Declaration Statements E_O_F {
printf("Parsing Successful. The three address code is: \n"); printCode();}
;

/*Reduction rules for Declarations at the beginning of the program*/
Declaration: Declaration Type Identifier DELIMITOR {}
|
;
Type: INT {}
| FLOAT {}
;
Identifier: ID COMMA Identifier {}
| ID {}
;

/*Reduction rule for the set of statements*/
Statements: Statements Statement {}
|
;


/*Reduction rule for arithmetic assignment statements*/
Statement: ID ASSIGN AExp DELIMITOR {codeGenerator("",$3,"",$1);}
;
AExp: ID {}
| NUMBER {}
| AExp PLUS AExp {$$=newTemp(); codeGenerator($2,$1,$3,$$);}
| AExp MINUS AExp {$$=newTemp(); codeGenerator($2,$1,$3,$$); }
| AExp TIMES AExp {$$=newTemp(); codeGenerator($2,$1,$3,$$); }
| AExp DIVIDE AExp {$$=newTemp(); codeGenerator($2,$1,$3,$$); }
| LP AExp RP {$$=$2;}
;

/*Reduction rule for boolean and boolean assignment expressions*/
Statement: ID ASSIGN BExp DELIMITOR {codeGenerator("",$3,"",$1);}
;
BExp: BExp OR BExp {$$=newTemp(); codeGenerator($2,$1,$3,$$);}
| BExp AND BExp {$$=newTemp(); codeGenerator($2,$1,$3,$$);}
| NOT BExp {$$=newTemp(); codeGenerator($1,$1,"",$$);}
| LP BExp RP {$$=$2;}
| AExp RELOP AExp {$$=newTemp(); codeGenerator($2,$1,$3,$$); }
| TRUE
| FALSE
;

/*Reduction rule for if/if-else statements*/
Statement: IF LP BExp RP LB Statements RB {printf("if %s goto ___\n",$3);printf("goto ___\n");}
| IF LP BExp RP LB Statements RB ELSE LB Statements RB {printf("if %s goto __\n",$3);
	printf("goto__\n");}
;

/*Reduction rule for while loop statement*/
Statement: WHILE LP BExp RP LB Statements RB {}
;

%%

int yyerror(char *s) {
  printf("%s\n", s);
}

int main()
{

	FILE* fp=fopen("/home/madeyedexter/Desktop/CompilerTools/CParser/test.txt","r");
	yyin=fp;
  if (yyparse()==0)
     fprintf(stderr, "Successful parsing.\n");
  else
     {
	fprintf(stderr, "Error found.\n");
	printf("%d\n",lineno);
      }
}