database and compiler lab

Ellenki College of Engineering & Technology Databases and Compiler Lab

MTech CSE 2nd Semester

Ellenki College of Engineering & Technology Name : Patelguda (V), Near BHEL, Patancheru (M), Medak (Dist.) Roll No :

Database Programs Index

S NO NAME OF THE PROGRAM DATE

1 Basic DDL Commands

2 DML Commands

3 Querying

4 Triggers

5 Procedures

6 Cursors

MTech CSE 2nd Semester Databases and Compiler lab


Compiler Programs Index

S NO NAME OF THE PROGRAM DATE

1 A Program to Design Lexical Analyzer

2 Implement the Lexical Analyzer Using Lex Tool

3 Implementation of Predictive Parser

4 Design LALR Bottom up Parser

5Convert The BNF rules into Yacc form and write code to generate abstract syntax tree

6 A Program to Generate Machine Code



1.Practicing Basic DDL Commands The basic MySQL DDL Commands such as CREATE, DROP, etc

A.Create tables:

mysql>create table bus(BusNo varchar(10),source varchar(10),Destination varchar(10),Primary Key(BusNo)); Query OK, 0 rows affected (0.31 sec)

mysql> create table passenger(pnr_no numeric(10),ticket_no numeric(10),name varchar(15),age int(3),sex char(10),ppno varchar(15) primary key(pnr_no)); Query OK, 0 rows affected (0.31 sec)

mysql> create table reservation(pnr_no numeric(10),Journey_Data datetime,No_Of_Seats numeric(10),Address Varchar(30),ConTact_No numeric(10),Status Char(2),foreign key (pnr_no) REFERENCES passenger(pnr_no)); Query OK, 0 rows affected (0.31 sec)

mysql> create table cancellation(pnr_no numeric(10),Journey_Data datetime,No_Of_Seats numeric(10),Address Varchar(30),ConTact_No numeric(10),Status char(2),foreign key (pnr_no) REFERENCES passenger(pnr_no)); Query OK, 0 rows affected (0.14 sec)

mysql> create table ticket(ticket_no numeric(10),Journey_Data datetime,ageb int(3),sex char(10),source varchar(15),destination varchar(15),Dep_time varchar(10),primary key(ticket_no)); Query OK, 0 rows affected (0.28 sec)

B. Describe Tables:



2.Practicing DML Commands

A. Insert Command: inserts data into a table

mysql> insert into bus values("ap092356","hyderabad","Gunter"); Query OK, 1 row affected (0.06 sec)

mysql> select * from bus; +--------------+-------------+-------------+ | bus no | source | destination | +---------- +-------------+--------------+ | ap092356 | hyderabad | Gunter | +-------------+-------------+--------------+ 1 row in set (0.00 sec)

mysql> insert into bus values("ap092490","Hyderabad","Gunter"); Query OK, 1 row affected (0.11 sec)

mysql> insert into bus values("ap212356","Hyderabad","Bangalore"); Query OK, 1 row affected (0.13 sec) mysql> insert into passenger values(1001,123,"sam",25,"male",9908233232); Query OK, 1 row affected (0.03 sec)

B. Update Command: Updates existing data within a table

mysql> update bus set destination="Tirupati"; Query OK, 1 row affected (0.06 sec) Rows matched: 1 Changed: 1 Warnings: 0

C. Select Command: Retrieve data from the Data Base mysql> select * from bus;

+-------------+--------------+-------------+ | bus no | source | destination| +-------------+--------------+-------------+ | ap092356 | hyderabad | Tirupati | | ap092490 | Hyderabad | Gunter | | ap212356 | Hyderabad | Bangalore |



+-------------+--------------+--------------+ 3 rows in set (0.00 sec)

3. Querying1.Display unique Pnr_No of all passengers

mysql> select distinct pnr_no from passenger;+--------+| pnr_no |+--------+| 1001 || 1002 || 1005 || 1023 || 1040 || 1435 || 1956 |+--------+7 rows in set (0.02 sec)

2.Display all the names of male passengers. mysql> select name from passenger where sex="male";

+----------+| name |+----------+| sam || prashant|| ranga || subhani |+----------+4 rows in set (0.00 sec)

3.Display the ticket numbers and names of all passengers.



mysql> select ticket_no,name from passenger;+-----------+------------+| ticket_no | name |+-----------+------------+| 123 | sam || 123 | bala || 126 | anitha || 124 | deepti || 127 | prashant || 125 | ranga || 128 | subhani |+-----------+------------+7 rows in set (0.00 sec)

4.Display the source and destination having journey time more than 10 hours.

mysql> select source,destination from ticket where timediff(arr_time,dep_time) > '10:00:00';+-------------+---------------+| source | destination |+-------------+---------------+| Hyderabad | gunter |+--------------+--------------+1 row in set (0.00 sec)

5.Find the ticket numbers of the passengers whose name start with “A” and ends with “H”

mysql> select ticket_no,name from passenger where name like "a%h";+-----------+-------+| ticket_no | name |+-----------+-------+| 129 | alah || 130 | ah |+-----------+-------+2 rows in set (0.00 sec)

6.Find the names of passengers whose age is between 30 and 45



mysql> select name,age from passenger where age between 30 and 45;+-----------+------+ | name | age |+-----------+------+ | bala | 30 | | anitha | 33 | | alah | 30 | | ah | 30 | | subhani | 33 |+-----------+-------+5 rows in set (0.20 sec)

7.Display all the passengers names beginning with ‘A’

mysql> select * from passenger where name like"a%";+---------+------------+--------+------+--------+----------------+| pnr_no | ticket_no | name | age | sex | ppno |+---------+------------+--------+------+--------+-----------------+| 1005 | 126 | anitha | 33 | female| 9441038706 || 1008 | 129 | alah | 30 | male | 9002345122 || 1009 | 130 | ah | 30 | male | 9002345122 |+--------+-------------+--------+------+--------+-----------------+3 rows in set (0.00 sec)

8.Display sorted list of passengers names

mysql> select name from passenger order by name;+----------+| name |+----------+| ah || alah || anitha || bala || deepti || prashant|



| ranga || sam || subhani |+-----------+9 rows in set (0.01 sec)

9.Display the bus numbers that travel on Sunday and Wednesday

mysql> select bus no from bus,ticket where bus.destination=ticket.destination and (dayname(journey_data)='sunday' or dayname(journey_data)='wednesday');+-------------+| bus no |+-------------+| ap092490 || ap092490 |+-------------+2 rows in set (0.00 sec)

10.Write a query to display the information present in the passenger and cancellation tables use UNION Operator

mysql> select pnr_no from passenger union select pnr_no from cancellation;

+---------+| pnr_no |

+---------+| 1001 || 1002 || 1005 || 1008 || 1009 || 1023 || 1040 || 1435 || 1956 |+---------+



9 rows in set (0.01 sec) 11. Display the number of days in a week on which the bus is available.

mysql> select day_travel from bus where bus no="ap092356";

+------------------+| day_travel |+------------------+| sun,tue,thur,sat |+------------------+1 row in set (0.00 sec)

12. Find number of seats booked for each PNR_NO using Group by Clause Hint: Use Group By On PNR_NO mysql> SELECT NO_OF_SEATS FROM RESERVATION GROUP BY PNR_NO;

+--------------------+| NO_OF_SEATS |+--------------------+| 2 |+--------------------+1 row in set (0.00 sec)

13. SELECT Distinct PNR_NO that are present

mysql> SELECT DISTINCT PNR_NO FROM PASSENGER;+----------+| PNR_NO |+----------+| 1001 || 1002 || 1005 || 1008 || 1009 || 1023 || 1040 |



| 1435 || 1956 |+----------+9 rows in set (0.00 sec)

14. Find total number of cancelled seats

mysql> select sum(no_of_seats) from cancellation;+---------------------+| sum(no_of_seats) |+---------------------+| 7 |+---------------------+1 row in set (0.00 sec)

15. Write a query to count the number of tickets booked for the buses, which traveled after the date “2010-07-02”.

mysql> select count(ticket_no) from ticket where date(journey_date) > '2010-07-02';+--------------------+| count(ticket_no) |+--------------------+| 3 |+--------------------+1 row in set (0.00 sec)



4.Triggers: Creation of Insert trigger, Delete Trigger, Update TriggerEX: mysql> delimiter $$; mysql> create trigger updatecheck before update on passenger for each row -> begin

-> if new.ticket_no>60 then -> set new.ticket_no=ticket_no; -> else -> set new.ticket_no=0; -> end if; -> end$$;

Query OK, 0 rows affected (0.08 sec)

mysql> delimiter ;

5.Procedures: In this we will learn creation of stored procedure, Execution of procedure and Modification of procedure.

mysql> delimiter $$; mysql> create procedure p1() -> begin

-> select count(ticket_no) from ticket where ageb>20; -> end$$;Query OK, 0 rows affected (0.00 sec)

mysql> delimiter ;mysql> call p1();+----------------------+| count(ticket_no) |+----------------------+| 3 |+----------------------+1 row in set (0.03 sec)



6.cursors:

We will define a cursor that defines a result set. Open the cursor to establish the Result set. Fetch the data into local variables as needed from the cursor one Row at a time. Then we will close the cursor.

mysql> delimiter $$;mysql> create procedure procd() -> begin -> declare busn varchar(20); -> declare dest varchar(20); -> declare cu5 cursor for select busno,destination from bus where destination="tirupati"; -> open cu5; -> fetch cu5 into busn,dest; -> select * from bus where destination=dest; -> close cu5; -> end$$;Query OK, 0 rows affected (0.00 sec)

mysql> delimiter ;

mysql> call procd();+-------------+-------------+--------------+--------------------+ | bus no | source | destination | day_travel |+-------------+-------------+--------------+--------------------+ | ap092356 | hyderabad | Tirupati | sun,tue,thur,sat |+-------------+-------------+--------------+--------------------+1 row in set (0.08 sec)

Query OK, 0 rows affected (0.08 sec)



1)A Program to Design Lexical Analyzer.

#include<string.h>#include<ctype.h>#include<stdio.h>void keyword(char str[10]){if(strcmp("for",str)==0||strcmp("while",str)==0||strcmp("do",str)==0||

strcmp("int",str)==0||strcmp("float",str)==0||strcmp("char",str)==0||strcmp("double",str)==0||strcmp("static",str)==0||strcmp("switch",str)==0||strcmp("case",str)==0)

printf("\n%s is a keyword",str); else printf("\n%s is an identifier",str); }main()

{FILE *f1,*f2,*f3;char c,str[10],st1[10];int num[100],lineno=0,tokenvalue=0,i=0,j=0,k=0;

printf("\nEnter the c program");/*gets(st1);*/f1=fopen("input","w");while((c=getchar())!=EOF)

putc(c,f1);fclose(f1);f1=fopen("input","r");f2=fopen("identifier","w");f3=fopen("specialchar","w");while((c=getc(f1))!=EOF){

if(isdigit(c))

{tokenvalue=c-'0';c=getc(f1);



while(isdigit(c)){

tokenvalue*=10+c-'0'; c=getc(f1); }num[i++]=tokenvalue; ungetc(c,f1); }else if(isalpha(c))

{putc(c,f2);c=getc(f1);

while(isdigit(c)||isalpha(c)||c=='_'||c=='$')

{putc(c,f2);c=getc(f1);

}putc(' ',f2); ungetc(c,f1); }else if(c==' '||c=='\t') printf(" "); else if(c=='\n') lineno++; else putc(c,f3); }fclose(f2);

fclose(f3);fclose(f1);printf("\nThe no's in the program are");for(j=0;j<i;j++)

printf("%d",num[j]);printf("\n");f2=fopen("identifier","r");k=0;printf("The keywords and identifiersare:");while((c=getc(f2))!=EOF){

if(c!=' ')str[k++]=c;



else { str[k]='\0'; keyword(str); k=0; } }fclose(f2);

f3=fopen("specialchar","r");printf("\nSpecial characters are");while((c=getc(f3))!=EOF)

printf("%c",c);printf("\n");fclose(f3);printf("Total no. of lines are:%d",lineno);

}

Output: Enter the C program

a+b*c

Ctrl-D

The no’s in the program are:

The keywords and identifiers are:

a is an identifier and terminal b is an identifier and terminal c is an identifier and terminal

Special characters are: + * Total no. of lines are: 1 7



2)Implement the Lexical Analyzer Using Lex Tool.

/* program name is lexp.l */ %{ /* program to recognize a c program */

int COMMENT=0;%}identifier [a-zA-Z][a-zA-Z0-9]*

%%

#.* { printf("\n%s is a PREPROCESSOR DIRECTIVE",yytext);}int |float |char |double |while |for |do |if |break |continue |void |switch |case |long |struct |const |typedef |return |else |goto

{printf("\n\t%s is a KEYWORD",yytext);} "/*" {COMMENT = 1;} /*{printf("\n\n\t%s is a COMMENT\n",yytext);}*/ "*/" {COMMENT = 0;} /* printf("\n\n\t%s is a COMMENT\n",yytext);}*/ {identifier}\( {if(!COMMENT)printf("\n\nFUNCTION\n\t%s",yytext);} \{ {if(!COMMENT) printf("\n BLOCK BEGINS");} \} {if(!COMMENT) printf("\n BLOCK ENDS");}



{identifier}(\[[0-9]*\])? {if(!COMMENT) printf("\n %s IDENTIFIER",yytext);}

\".*\" {if(!COMMENT) printf("\n\t%s is a STRING",yytext);}

[0-9]+ {if(!COMMENT) printf("\n\t%s is a NUMBER",yytext);}

\)(\;)? {if(!COMMENT) printf("\n\t");ECHO;printf("\n");}

\(

ECHO; = {if(!COMMENT)printf("\n\t%s is an ASSIGNMENT OPERATOR",yytext);}

\<= |\>= |\< |== |\> {if(!COMMENT) printf("\n\t%s is a RELATIONAL OPERATOR",yytext);}

%% int main(int argc,char **argv) {if (argc > 1) {FILE *file;

file = fopen(argv[1],"r");if(!file){printf("could not open %s \n",argv[1]);

exit(0);

}yyin = file;

}yylex();

printf("\n\n");

return 0; }int yywrap() { return 0;



}

Input: $vi var.c

#include<stdio.h>main(){

int a,b; }

Output:

$lex lex.l$cc lex.yy.c$./a.out var.c

#include<stdio.h> is a PREPROCESSOR DIRECTIVE

FUNCTION main ( ) BLOCK BEGINS int is a KEYWORD

a IDENTIFIER b IDENTIFIER

BLOCK ENDS



3) Implementation of Predictive Parser.

#include<stdio.h>#include<ctype.h>#include<string.h>#include<stdlib.h>#define SIZE 128#define NONE -1#define EOS '\0'#define NUM 257#define KEYWORD 258#define ID 259#define DONE 260#define MAX 999char lexemes[MAX];char buffer[SIZE];int lastchar=-1;int lastentry=0;int tokenval=DONE;int lineno=1;int lookahead;struct entry{

char *lexptr;

int token;}symtable[100];struct entrykeywords[]={"if",KEYWORD,"else",KEYWORD,"for",KEYWORD,"int",KEYWORD,"float",KEYWORD,"double",KEYWORD,"char",KEYWORD,"struct",KEYWORD,"return",KEYWORD,0,0};void Error_Message(char *m){fprintf(stderr,"line %d, %s \n",lineno,m);exit(1);}int look_up(char s[ ])



{int k;for(k=lastentry;k>0;k--)

if(strcmp(symtable[k].lexptr,s)==0) return k; return 0; }int insert(char s[ ],int tok) { int len; len=strlen(s); if(lastentry+1>=MAX) Error_Message("Symbpl table is full"); if(lastchar+len+1>=MAX)

Error_Message("Lexemes array is full");lastentry=lastentry+1;symtable[lastentry].token=tok;symtable[lastentry].lexptr=&lexemes[lastchar+1];lastchar=lastchar+len+1;strcpy(symtable[lastentry].lexptr,s);return lastentry;

}/*void Initialize()

{struct entry *ptr;for(ptr=keywords;ptr->token;ptr+1)

insert(ptr->lexptr,ptr->token);}*/int lexer(){

int t;int val,i=0;while(1)

{t=getchar();if(t==' '||t=='\t');else if(t=='\n')lineno=lineno+1;



else if(isdigit(t)){

ungetc(t,stdin);scanf("%d",&tokenval);return NUM;

}else if(isalpha(t)) { while(isalnum(t))

{buffer[i]=t;t=getchar();i=i+1;if(i>=SIZE)

Error_Message("Compiler error"); }buffer[i]=EOS; if(t!=EOF) ungetc(t,stdin);val=look_up(buffer);if(val==0)

val=insert(buffer,ID);tokenval=val;return symtable[val].token;

}else if(t==EOF)

return DONE;else{

tokenval=NONE; return t; } } }void Match(int t) { if(lookahead==t) lookahead=lexer(); else



Error_Message("Syntax error"); }void display(int t,int tval) { if(t=='+'||t=='-'||t=='*'||t=='/') printf("\nArithmetic Operator: %c",t); else if(t==NUM) printf("\n Number: %d",tval); else if(t==ID) printf("\n Identifier: %s",symtable[tval].lexptr); else printf("\n Token %d tokenval %d",t,tokenval); }void F()

{//void E();switch(lookahead){

case '(' : Match('(');E();Match(')');break;

case NUM : display(NUM,tokenval);Match(NUM);break;

case ID : display(ID,tokenval);Match(ID);break;

default : Error_Message("Syntax error"); } }void T()

{int t;F();while(1){

switch(lookahead) {



case '*' : t=lookahead;Match(lookahead);F();display(t,NONE);continue;

case '/' : t=lookahead;Match(lookahead);display(t,NONE);continue;

default : return; } } }void E()

{int t;T();while(1){

switch(lookahead) {

case '+' : t=lookahead;Match(lookahead);T();display(t,NONE);continue;

case '-' : t=lookahead;Match(lookahead);T();display(t,NONE);continue;

default : return;

} } }void parser()



{lookahead=lexer();while(lookahead!=DONE){

E(); Match(';'); } }main()

{char ans[10];printf("\n Program for recursive decent parsing ");printf("\n Enter the expression ");printf("And place ; at the end\n");printf("Press Ctrl-Z to terminate\n");parser();

}Output:Program for recursive decent parsingEnter the expression And place ; at the endPress Ctrl-Z to terminatea+b*c;Identifier: aIdentifier: bIdentifier: cArithmetic Operator: *Arithmetic Operator: +2*3;Number: 2Number: 3Arithmetic Operator: *+3;line 5,Syntax errorCtrl-Z



4) Design LALR Bottom up Parser . <parser.l> %{ #include<stdio.h>

#include "y.tab.h"%}%%[0-9]+ {yylval.dval=atof(yytext);

return DIGIT; } \n|. return yytext[0]; %% <parser.y> %{ /*This YACC specification file generates the LALR parser for the program considered in experiment 4.*/

#include<stdio.h>%}%union{

double dval; }%token <dval> DIGIT

%type <dval> expr%type <dval> term%type <dval> factor

%% line: expr '\n'

{printf("%g\n",$1);}

; expr: expr '+' term



{$$=$1 + $3 ;}| term;

Ter m: term '*' factor {$$=$1 * $3 ;}| factor;

factor: '(' expr ')' {$$=$2 ;}

| DIGIT ;

%%int main(){

yyparse(); }yyerror(char *s) { printf("%s",s); }Output:

$lex parser.l$yacc –d parser.y$cc lex.yy.c y.tab.c –ll –lm$./a.out2+35.0000



5) Convert The BNF rules into Yacc form and write code to generate abstract syntax tree.

<int.l> %{#include"y.tab.h"

#include<stdio.h>#include<string.h>int LineNo=1;

%} identifier [a-zA-Z][_a-zA-Z0-9]* number [0-9]+|([0-9]*\.[0-9]+)

%%

main return MAIN;

if

return IF; else return ELSE; while return WHILE;

int |char |float

return TYPE; {identifier} {strcpy(yylval.var,yytext); return VAR;} {number} {strcpy(yylval.var,yytext); return NUM;}

\< |\> |\>= |



\<= |==

{strcpy(yylval.var,yytext); return RELOP;} [ \t] ; \n LineNo++; . return yytext[0]; %%

<int.y>

%{#include<string.h>#include<stdio.h>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 Index=0,tIndex=0,StNo,Ind,tInd;extern int LineNo;%}

%union { char var[10];



}%token <var> NUM VAR RELOP

%token MAIN IF ELSE WHILE TYPE

%type <var> EXPR ASSIGNMENT CONDITION IFST ELSEST WHILELOOP

%left '-' '+'

%left '*' '/'

%%

PROGRAM : MAIN BLOCK

;BLOCK: '{' CODE '}' ;CODE: BLOCK | STATEMENT CODE | STATEMENT ;STATEMENT: DESCT ';' | ASSIGNMENT ';'

| CONDST | WHILEST ;DESCT: TYPE VARLIST ;VARLIST: VAR ',' VARLIST | VAR ;ASSIGNMENT: VAR '=' EXPR{

strcpy(QUAD[Index].op,"=");strcpy(QUAD[Index].arg1,$3);strcpy(QUAD[Index].arg2,"");strcpy(QUAD[Index].result,$1);strcpy($$,QUAD[Index++].result);}

;EXPR: EXPR '+' EXPR {AddQuadruple("+",$1,$3,$$);}

| EXPR '-' EXPR {AddQuadruple("-",$1,$3,$$);}| EXPR '*' EXPR {AddQuadruple("*",$1,$3,$$);}| EXPR '/' EXPR {AddQuadruple("/",$1,$3,$$);}| '-' EXPR {AddQuadruple("UMIN",$2,"",$$);}



| '(' EXPR ')' {strcpy($$,$2);}| VAR| NUM

;CONDST: IFST{

Ind=pop();sprintf(QUAD[Ind].result,"%d",Index);Ind=pop();sprintf(QUAD[Ind].result,"%d",Index);}| IFST ELSEST

;IFST: IF '(' CONDITION ')' {

strcpy(QUAD[Index].op,"==");strcpy(QUAD[Index].arg1,$3);strcpy(QUAD[Index].arg2,"FALSE");strcpy(QUAD[Index].result,"-1");push(Index);Index++;

}BLOCK {

strcpy(QUAD[Index].op,"GOTO");strcpy(QUAD[Index].arg1,"");strcpy(QUAD[Index].arg2,"");strcpy(QUAD[Index].result,"-1");push(Index);Index++;};ELSEST: ELSE{

tInd=pop();Ind=pop();push(tInd);sprintf(QUAD[Ind].result,"%d",Index);}BLOCK{

Ind=pop();sprintf(QUAD[Ind].result,"%d",Index);};CONDITION: VAR RELOP VAR {AddQuadruple($2,$1,$3,$$);

StNo=Index-1;



}| VAR | NUM ;

W WHILEST: WHILELOOP{Ind=pop();sprintf(QUAD[Ind].result,"%d",StNo);Ind=pop();sprintf(QUAD[Ind].result,"%d",Index);

} ;WHILELOOP: WHILE '(' CONDITION ')' {

strcpy(QUAD[Index].op,"==");strcpy(QUAD[Index].arg1,$3);strcpy(QUAD[Index].arg2,"FALSE");strcpy(QUAD[Index].result,"-1");push(Index);Index++;}

BLOCK {

strcpy(QUAD[Index].op,"GOTO");strcpy(QUAD[Index].arg1,"");strcpy(QUAD[Index].arg2,"");strcpy(QUAD[Index].result,"-1");push(Index);Index++;}

;%%extern FILE *yyin;int main(int argc,char *argv[]){

FILE *fp;int i;if(argc>1){



fp=fopen(argv[1],"r");if(!fp){

printf("\n File not found"); exit(0);

}yyin=fp;

}yyparse();

printf("\n\n\t\t----------------------------""\n\t\t Pos Operator Arg1 Arg2 Result" "\n\t\t

--------------------");for(i=0;i<Index;i++){

printf("\n\t\t %d\t %s\t %s\t %s\t%s",i,QUAD[i].op,QUAD[i].arg1,QUAD[i].arg2,QUAD[i].result);}printf("\n\t\t-----------------------");

printf("\n\n"); return 0; }void push(int data)

{stk.top++;if(stk.top==100){

printf("\n Stack overflow\n"); exit(0); }stk.items[stk.top]=data; }

int pop()

{int data;if(stk.top==-1){



printf("\n Stack underflow\n"); exit(0); }data=stk.items[stk.top--]; return data; }void AddQuadruple(char op[5],char arg1[10],char arg2[10],char result[10])

{strcpy(QUAD[Index].op,op);strcpy(QUAD[Index].arg1,arg1);strcpy(QUAD[Index].arg2,arg2);sprintf(QUAD[Index].result,"t%d",tIndex++);strcpy(result,QUAD[Index++].result);

}yyerror() { printf("\n Error on line no:%d",LineNo); }

Input: $vi test.c main()

{int a,b,c;if(a<b){

a=a+b; }while(a<b) { a=a+b; }if(a<=b) { c=a-b; }else { c=a+b; }



}

Output:

$lex int.l$yacc –d int.y$gcc lex.yy.c y.tab.c –ll –lm$./a.out test.c

Pos Operator Arg1 Arg2 Result 0 < a b to 1 == to FALSE 5 2 + a b t1 3 = t1 a 4 GOTO 5 5 < a b t2 6 == t2 FALSE 10 7 + a



6) A Program to Generate Machine Code.

#include<stdio.h>#include<stdlib.h>#include<string.h>int label[20];int no=0;int main()

{FILE *fp1,*fp2;char fname[10],op[10],ch;char operand1[8],operand2[8],result[8];int i=0,j=0;printf("\n Enter filename of the intermediate code");scanf("%s",&fname);fp1=fopen(fname,"r");fp2=fopen("target.txt","w");if(fp1==NULL || fp2==NULL){

printf("\n Error opening the file");exit(0);}while(!feof(fp1))

{fprintf(fp2,"\n");fscanf(fp1,"%s",op);i++;if(check_label(i))

fprintf(fp2,"\nlabel#%d",i);if(strcmp(op,"print")==0){

fscanf(fp1,"%s",result); fprintf(fp2,"\n\t OUT %s",result); }if(strcmp(op,"goto")==0)

{fscanf(fp1,"%s %s",operand1,operand2);



fprintf(fp2,"\n\t JMP %s,label#%s",operand1,operand2);label[no++]=atoi(operand2);

}if(strcmp(op,"[]=")==0)

{fscanf(fp1,"%s %s %s",operand1,operand2,result);fprintf(fp2,"\n\t STORE %s[%s],%s",operand1,operand2,result);}if(strcmp(op,"uminus")==0)

{fscanf(fp1,"%s %s",operand1,result);fprintf(fp2,"\n\t LOAD -%s,R1",operand1);fprintf(fp2,"\n\t STORE R1,%s",result);

}switch(op[0]) {

case '*': fscanf(fp1,"%s %s %s",operand1,operand2,result);fprintf(fp2,"\n \t LOAD",operand1);fprintf(fp2,"\n \t LOAD %s,R1",operand2);fprintf(fp2,"\n \t MUL R1,R0");fprintf(fp2,"\n \t STORE R0,%s",result);break;

case '+': fscanf(fp1,"%s %s %s",operand1,operand2,result);fprintf(fp2,"\n \t LOAD %s,R0",operand1);fprintf(fp2,"\n \t LOAD %s,R1",operand2);fprintf(fp2,"\n \t ADD R1,R0");fprintf(fp2,"\n \t STORE R0,%s",result);break;

case '-': fscanf(fp1,"%s %s %s",operand1,operand2,result);fprintf(fp2,"\n \t LOAD %s,R0",operand1);fprintf(fp2,"\n \t LOAD %s,R1",operand2);fprintf(fp2,"\n \t SUB R1,R0");fprintf(fp2,"\n \t STORE R0,%s",result);break;

case '/': fscanf(fp1,"%s %s %s",operand1,operand2,result);fprintf(fp2,"\n \t LOAD %s,R0",operand1);fprintf(fp2,"\n \t LOAD %s,R1",operand2);



fprintf(fp2,"\n \t DIV R1,R0");fprintf(fp2,"\n \t STORE R0,%s",result);break;

case '%': fscanf(fp1,"%s %s %s",operand1,operand2,result);fprintf(fp2,"\n \t LOAD %s,R0",operand1);fprintf(fp2,"\n \t LOAD %s,R1",operand2);fprintf(fp2,"\n \t DIV R1,R0");fprintf(fp2,"\n \t STORE R0,%s",result);break;

case '=': fscanf(fp1,"%s %s",operand1,result);fprintf(fp2,"\n\t STORE %s %s",operand1,result);break;

case '>': j++;

fscanf(fp1,"%s %s %s",operand1,operand2,result);fprintf(fp2,"\n \t LOAD %s,R0",operand1);fprintf(fp2,"\n\t JGT %s,label#%s",operand2,result);label[no++]=atoi(result);break;

case '<': fscanf(fp1,"%s %s %s",operand1,operand2,result);fprintf(fp2,"\n \t LOAD %s,R0",operand1);fprintf(fp2,"\n\t JLT %s,label#%d",operand2,result);label[no++]=atoi(result);break;

} }fclose(fp2);

fclose(fp1);fp2=fopen("target.txt","r");if(fp2==NULL){

printf("Error opening the file\n"); exit(0); }do { ch=fgetc(fp2);



printf("%c",ch);}while(ch!=EOF);fclose(fp1);return 0;

}int check_label(int k)

{int i;for(i=0;i<no;i++){

if(k==label[i]) return 1; }return 0; }Input: $vi int.txt =t1 2

[]=a 0 1 []=a 1 2 []=a 2 3 *t1 6 t2

+a[2] t2 t3

-a[2] t1 t2/t3 t2 t2uminus t2 t2print t2goto t2 t3=t3 99uminus 25 t2*t2 t3 t3uminus t1 t1+t1 t3 t4print t4

Output: Enter filename of the intermediate code: int.txt

STORE t1,2STORE a[0],1STORE a[1],2STORE a[2],3



LOAD t1,R0LOAD 6,R1ADD R1,R0STORE R0,t3

LOAD a[2],R0LOAD t2,R1ADD R1,R0STORE R0,t3

LOAD a[t2],R0LOAD t1,R1SUB R1,R0STORE R0,t2

LOAD t3,R0LOAD t2,R1DIV R1,R0STORE R0,t2

LOAD t2,R1STORE R1,t2LOAD t2,R0JGT 5,label#11

Label#11: OUT t2 JMP t2,label#13

Label#13: STORE t3,99LOAD 25,R1STORE R1,t2

LOAD t2,R0LOAD t3,R1MUL R1,R0STORE R0,t3

LOAD t1,R1 STORE R1,t1

LOAD t1,R0LOAD t3,R1



ADD R1,R0STORE R0,t4OUT t4


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