Compiler

1 Subset of c

#include<stdio.h>

int line=0;

char choice;

INTEGER [0-9]+

DELEMETER [\[\]{}();:]

[ \t\n\r]+;

("/"([^\n\r]*)(\n)) {

printf("\n Comment is found : %s ",yytext);

line++;

if(line > 40)

{

line=0;

printf("\n Press Y To Continue.....");

scanf("%c",choice);

}

[+-]?{INTEGER} {

printf("\n Integer is found : %d ",atoi(yytext));

line++;

if(line > 40)

{

line=0;

printf("\n Press Y To Continue.....");

scanf("%c",choice);

}

[+-]?{INTEGER}\.{INTEGER}([eE][+-]?[0-9]+)? {

printf("\n Floating Number is found : %s ",yytext);

line++;

if(line > 40)

{

line=0;

printf("\n Press Y To Continue.....");

scanf("%c",choice);

}

\'.\' {

printf("\n Charater Literal is found : %s ",yytext);

line++;

if(line > 40)

{

line=0;

printf("\n Press Y To Continue.....");

scanf("%c",choice);

}

(\"([^\n]*)\") {

printf("\n String is found : %s ",yytext);

line++;

if(line > 40)

{

line=0;

printf("\n Press Y To Continue.....");

scanf("%c",choice);

}

int |

double |

char |

float |

short |

long |

struct |

union |

void |

return |

if |

else |

for |

do |

case |

switch |

while |

sizeof |

typedef |

signed |

unsigned |

FILE {

printf("\n Keyword is found : %s ",yytext);

line++;

if(line > 40)

{

line=0;

printf("\n Press Y To Continue.....");

scanf("%c",choice);

}

[a-zA-Z]+[a-zA-Z0-9]* {

printf("\n Variable is found : %s ",yytext);

line++;

if(line > 40)

{

line=0;

printf("\n Press Y To Continue.....");

scanf("%c",choice);

}

{DELEMETER} {

printf("\n Delemeter is found : %s ",yytext);

line++;

if(line > 40)

{

line=0;

printf("\n Press Y To Continue.....");

scanf("%c",choice);

}

int main (int argc, char** argv)

{

FILE *file;

if (argc==2)

{

file=fopen(argv[1],"r");

if(!file)

{

printf("\n File Can Not Open ");

exit(1);

}

yyin=file;

yylex();

}

return 0;

}

File for input :

#include<stdio.h>

main()

{

int a,b,c;

printf("Enter the value of a,b,c");

scanf("%d%d%d",&a,&b,&c);

getch();

}

Running commands :

linuxlab1@linuxlab1-Veriton-M200-H81:~$ lex 4subsetc.l

linuxlab1@linuxlab1-Veriton-M200-H81:~$ gcc lex.yy.c -ll

linuxlab1@linuxlab1-Veriton-M200-H81:~$ ./a.out ch.txt

Variable is found : include <

Variable is found : stdio .

Variable is found : h >

Variable is found : main

Delemeter is found : (

Delemeter is found : )

Delemeter is found : {

Keyword is found : int

Variable is found : a ,

Variable is found : b ,

Variable is found : c

Delemeter is found : ;

Variable is found : printf

Delemeter is found : (

String is found : "Enter the value of a,b,c"

Delemeter is found : )

Delemeter is found : ;

Variable is found : scanf

Delemeter is found : (

String is found : "%d%d%d" ,&

Variable is found : a ,&

Variable is found : b ,&

Variable is found : c

Delemeter is found : )

Delemeter is found : ;

Variable is found : getch

Delemeter is found : (

Delemeter is found : )

Delemeter is found : ;

Delemeter is found : }

linuxlab1@linuxlab1-Veriton-M200-H81:~$

File for input :

#include<stdio.h>

main()

{

int a,b,c;

printf("Enter the value of a,b,c");

scanf("%d%d%d",&a,&b,&c);

getch();

}

2 Replace in string

#include<string.h>

char find[10],*replace[10];

[a-zA-z]* { if(strcmp(yytext,find)==0)

fprintf(yyout,"%s",replace);

else

fprintf(yyout,"%s",yytext);

}

main()

{

yyin=fopen("x.txt","r");

yyout=fopen("y.txt","w");

printf("Enter to find: ");

scanf("%s",find);

printf("Enter string to replace: ");

scanf("%s",replace);

yylex();

}

Files required

x.txt

Shyam is Student

y.txt

blank

Commands

linuxlab1@linuxlab1-Veriton-M200-H81:~$ lex 1replace.l

linuxlab1@linuxlab1-Veriton-M200-H81:~$ cc lex.yy.c -ll

1replace.l: In function ‘yylex’:

1replace.l:11:25: warning: format ‘%s’ expects argument of type ‘char *’, but argument 3 has type ‘char **’ [-Wformat=]

fprintf(yyout,"%s",replace);

1replace.l: In function ‘main’:

1replace.l:27:9: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘char **’ [-Wformat=]

yylex();

linuxlab1@linuxlab1-Veriton-M200-H81:~$ ./a.out

Enter to find: is

Enter string to replace: was

linuxlab1@linuxlab1-Veriton-M200-H81:~$

3 Count word character

#include<string.h>

int wo=0,li=0,ch=0,vw=0;

FILE *fp;

vowel "a"|"e"|"i"|"o"|"u"|"A"|"E"|"I"|"O"|"U"

eo1 [\n]

word [ \t]

{vowel} {vw++;ch++;printf("%s",yytext);}

{word} {wo++;ch+=yyleng;}

{eo1} {li++;wo++;}

. {

ch++;printf("%s",yytext);

}

main(int args,char *argv[])

{

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

if(!fp)

{

printf("cant open");

fclose(fp);

exit(0);

}

else

yyin=fp;

while(!feof(fp))

{

yylex();

}

printf("\n No. of lines = %d \n no.of words = %d \n No. of chars = %d \n No. of vowels = %d \n",li,wo,ch,vw);

fclose(fp);

}

Commands

linuxlab1@linuxlab1-Veriton-M200-H81:~$ lex 3count.l

linuxlab1@linuxlab1-Veriton-M200-H81:~$ gcc lex.yy.c -ll

linuxlab1@linuxlab1-Veriton-M200-H81:~$ ./a.out x.txt

ShyamisStudent

No. of lines = 1

no.of words = 3

No. of chars = 16

No. of vowels = 4

linuxlab1@linuxlab1-Veriton-M200-H81:~$

4 Parser for sample language using YACC.

#include<math.h>

#include "y.tab.h"

[0-9]+|[0-9]*\.[0-9]+ { yylval.p = atof(yytext);

return num;

}

sin return SIN ;

cos return COS ;

tan return TAN ;

log return LOG ;

sqrt return SQRT ;

[\t] ;

\n return 0;

. return yytext[0];

commands

//……………………………………..OUTPUT…………………………………………

[softlab@localhost ~]$ yacc -d cal.y

[softlab@localhost ~]$ lex cal.l

[softlab@localhost ~]$ cc lex.yy.c y.tab.c -ll -lm

[softlab@localhost ~]$ ./a.out

3+5

sin(90)

=0.893997

sqrt(100)

=10

// Program to implement the yacc calculator (cal.y)

#include<stdio.h>

#include<math.h>

%union { double p; }

%token <p> num

%token SIN COS TAN LOG SQRT

%left '+','-'

%left '*','/'

%nonassoc uminus

%type <p> exp

ss: exp { printf("=%g\n",$1);}

exp: exp '+' exp { $$ = $1 + $3; }

|exp '-' exp { $$ = $1 - $3; }

|exp '*' exp { $$ = $1 * $3; }

|exp '/' exp {

if($3==0)

{

printf("can't divide");

exit(0);

}

else $$=$1/$3;

}

|'(' exp ')' { $$ = $2; }

|SIN '(' exp ')' { $$ = sin($3); }

|COS '(' exp ')' { $$ = cos($3); }

|TAN '(' exp ')' { $$ = tan($3); }

|LOG '(' exp ')' { $$ = log($3); }

|SQRT '(' exp ')' { $$ = sqrt($3);}

|num;

extern FILE *yyin;

main()

{

yyparse();

}while(!feof(yyin));

}

yyerror(s)

char *s;

{

printf("Error");

}

// Program to implement the calculator (cal.l)

#include<math.h>

#include "y.tab.h"

[0-9]+|[0-9]*\.[0-9]+ { yylval.p = atof(yytext);

return num;

}

sin return SIN ;

cos return COS ;

tan return TAN ;

log return LOG ;

sqrt return SQRT ;

[\t] ;

\n return 0;

. return yytext[0];

//……………………………………..OUTPUT…………………………………………

[softlab@localhost ~]$ yacc -d cal.y

[softlab@localhost ~]$ lex cal.l

[softlab@localhost ~]$ cc lex.yy.c y.tab.c -ll -lm

[softlab@localhost ~]$ ./a.out

3+5

sin(90)

=0.893997

sqrt(100)

=10

//#include "parsing_lab.h"

#include "y.tab.h"

extern int yylval;

[0-9]+ { yylval=(int)(yytext);return NUMBER;}

/*cast pointer to int for compiler warning*/

[\t\n]+ ;

"+" return(PLUS);

"-" return(MINUS);

"*" return(TIMES);

"/" return(DIVIDE);

"^" return(POWER);

"(" return(LEFT_PARENTHESIS);

")" return(RIGHT_PARENTHESIS);

";" return(END);

int yywrap(void) {return 1;}

Commands

linuxlab15@linuxlab15-p2-1401il:~$ yacc -d parser.y

linuxlab15@linuxlab15-p2-1401il:~$ lex lexer.l

linuxlab15@linuxlab15-p2-1401il:~$ gcc y.tab.c lex.yy.c

lexer.l: In function ‘yylex’:

lexer.l:12:10: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]

[0-9]+ { yylval=(int)(yytext);return NUMBER;}

linuxlab15@linuxlab15-p2-1401il:~$ ./a.out

(1+3*7-1^5);

( ^ ( - ( + 1 ( * 3 7 )) 1 ) 5 )

PUSH 1

PUSH 3

PUSH 7

POP A

POP B

MULT A=A*B

PUSH A

POP A

POP B

ADD A=A+B

PUSH A

PUSH 1

POP A

POP B

SUB A=A-B

PUSH A

PUSH 5

POP A

POP B

POWER A=A^B

PUSH A

/*-------------------------------------------------------------

AIM: To implement ICG for arithematic expression

---------------------------------------------------------------

Name: Vaibhav Ghatol

Roll No: B4136

Class: BE comp A

---------------------------------------------------------------*/

/***********LEX FILE*************/

#include<ctype.h>

#include<stdio.h>

#include "y.tab.h"

Digit [0-9]+

Letter [a-zA-Z]+

%% //end of declaration section

{Digit} {yylval.p=(char)yytext[0];return Digit;}

{Letter} {yylval.p=(char)yytext[0];return Letter;}

. {return yytext[0];}

\n {return 0;}

%% //end of rules section

/***********YACC FILE*************/

#include<stdio.h>

#include<string.h>

char addintotable(char,char,char);

int search(char);

struct icode

{

char op1;

char op2;

char op;

char res;

}code[20];

int index1=0;

%union

{

char p;

}

%token <p> Letter Digit

%type <p> expr

%left '-' '+'

%left '*' '/'

%% //end of declaration section

/* ---------------------------------------------------------------- */

stat:Letter '=' expr ';' {addintotable((char)$1,(char)$3,'=');}

|expr ';'

;

expr:expr '+' expr {$$=addintotable((char)$1,(char)$3,'+');}

|expr '-' expr {$$=addintotable((char)$1,(char)$3,'-');}

|expr '*' expr {$$=addintotable((char)$1,(char)$3,'*');}

|expr '/' expr {$$=addintotable((char)$1,(char)$3,'/');}

|'('expr')' {$$=(char)$2;}

|Digit {$$=(char)$1;}

|Letter {$$=(char)$1;}

;

%% //end of rules section

/* --------------------------------------------------------------- */

int yywrap()

{

return 1;

}

yyerror(char *s)

{

printf("hey vaibhav!! error %s",s);

}

/* ---------------------------------------------------------------- */

char temp='A';

/* ---------------------------------------------------------------- */

char addintotable(char op1,char op2,char op)

{

temp++;

code[index1].op1=op1;

code[index1].op2=op2;

code[index1].op=op;

code[index1].res=temp;

index1++;

return temp;

}

/* ---------------------------------------------------------------- */

void threeaddress()

{

int cnt=0;

char temp='A';

temp++;

printf("\nThe three address code is:\n");

printf("");

while(cnt<index1)

{

printf("%c:=\t",temp);

printf("%c\t",code[cnt].op1);

printf("%c\t",code[cnt].op);

printf("%c\t",code[cnt].op2);

temp++;

cnt++;

printf("\n");

}

/* ---------------------------------------------------------------- */

void quadruple()

{

int cnt=0;

char temp='A';

temp++;

printf("\nThe Quadruple format is:\n");

printf("Operator\tArg1\tArg2\tResult\n");

while(cnt<index1)

{

printf("%c\t\t",code[cnt].op);

printf("%c\t",code[cnt].op1);

printf("%c\t",code[cnt].op2);

printf("%c\t",code[cnt].res);

temp++;

cnt++;

printf("\n");

}

/* ---------------------------------------------------------------- */

void triple()

{

int cnt=0;

int flag;

char temp='A';

temp++;

printf("\nThe Triple format is:\n");

printf("Arg1\tArg2\toperator\n");

while(cnt<index1)

{

if(isalpha(code[cnt].op1) && isupper(code[cnt].op1))

{

flag= search(code[cnt].op1);

printf("%d\t",flag);

}

else if(isalpha(code[cnt].op1))

printf("%c\t",code[cnt].op1);

else

printf("%c\t",temp);

if(isalpha(code[cnt].op2) && isupper(code[cnt].op2))

{

flag= search(code[cnt].op2);

printf("%d\t",flag);

}

else if(isalpha(code[cnt].op2))

printf("%c\t",code[cnt].op2);

else

printf("%c\t",temp);

printf("%c\t",code[cnt].op);

printf("\n");

cnt++;

}

/* ----------------------------------------------------------------- */

int search(char find)

{

int i;

for(i=0;i<index1;i++)

{

if(code[i].res==find)

return(i);

}

return 0;

}

/* ---------------------------------------------------------------- */

void main()

{

yyparse();

threeaddress();

quadruple();

triple();

}

/*************output******************/

vaibhav@ubuntu:~$ lex ic.l

vaibhav@ubuntu:~$ yacc -d ic.y

vaibhav@ubuntu:~$ cc lex.yy.c y.tab.c -ll -lm -ly

vaibhav@ubuntu:~$ ./a.out

a=b+c-d*e;

The three address code is:

B:= b + c

C:= d * e

D:= B - C

E:= a = D

The Quadruple format is:

Operator Arg1 Arg2 Result

+ b c B

* d e C

- B C D

= a D E

The Triple format is:

Arg1 Arg2 operator

b c +

d e *

0 1 -

a 2 =

vaibhav@ubuntu:~$

8 code generation dag

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

int label[20];

int no=0;

int main()

{

FILE *fp1,*fp2;

int check_label(int n);

char fname[10],op[10],ch;

char op1[8]="",op2[8]="",result[8]="";

int i=0,j=0;

//clrscr();

printf("\n\tEnter File Name of The Intermediate Code: ");

scanf("%s",&fname);

fp1=fopen(fname,"r");

fp2=fopen("d:\\output.txt","w");

if(fp1==NULL||fp2==NULL)

{

printf("\n\tEroor To Opening File...");

//getch();

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 ",op1,op2);

fprintf(fp2,"\n\t JMP %s,label#%s",op1,op2);

label[no++]=atoi(op2);

}

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

{

fscanf(fp1,"%s %s %s",op1,op2,result);

fprintf(fp2,"\n\tSTORE%s[%s],%s",op1,op2,result);

}

if(strcmp(op,"uminus")==0)

{

fscanf(fp1,"%s %s",op1,result);

fprintf(fp2,"\n\t LOAD -%s,R1",op1);

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

}

if(strcmp(op,"==")==0)

{

fscanf(fp1,"%s %s %s",op1,op2,result);

fprintf(fp2,"\n\t LOAD %s,R0",op1);

fprintf(fp2,"\n\t JEQ %s,label#%s",op2,result);

label[no++]=atoi(result);

}

if(strcmp(op,"<=")==0)

{

fscanf(fp1,"%s %s %s",op1,op2,result);

fprintf(fp2,"\n\t LOAD %s,R0",op1);

fprintf(fp2,"\n\t JLTEQ %s,label#%s",op2,result);

label[no++]=atoi(result);

}

switch(op[0])

{

case '*':

fscanf(fp1,"%s %s %s",op1,op2,result);

fprintf(fp2,"\n\t LOAD %s,R0",op1);

fprintf(fp2,"\n\t LOAD %s,R1",op2);

fprintf(fp2,"\n\t MUL R1,R0");

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

break;

case '+':

fscanf(fp1,"%s %s %s",op1,op2,result);

fprintf(fp2,"\n\t LOAD %s,R0",op1);

fprintf(fp2,"\n\t LOAD %s,R1",op2);

fprintf(fp2,"\n\t ADD R1,R0");

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

break;

case '-':

fscanf(fp1,"%s %s %s",op1,op2,result);

fprintf(fp2,"\n\t LOAD %s,R0",op1);

fprintf(fp2,"\n\t LOAD %s,R1",op2);

fprintf(fp2,"\n\t SUB R1,R0");

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

break;

case '/':

fscanf(fp1,"%s %s %s",op1,op2,result);

fprintf(fp2,"\n\t LOAD %s,R0",op1);

fprintf(fp2,"\n\t LOAD %s,R1",op2);

fprintf(fp2,"\n\t DIV R1,R0");

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

break;

case '%':

fscanf(fp1,"%s %s %s",op1,op2,result);

fprintf(fp2,"\n\t LOAD %s,R0",op1);

fprintf(fp2,"\n\t LOAD %s,R1",op2);

fprintf(fp2,"\n\t DIV R1,R0");

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

break;

case '=':

fscanf(fp1,"%s %s",op1,result);

fprintf(fp2,"\n\t STORE %s,%s",op1,result);

break;

case '>':

j++;

fscanf(fp1,"%s %s %s",op1,op2,result);

fprintf(fp2,"\n\t LOAD %s,R0",op1);

fprintf(fp2,"\n\t JGT %s,label#%s",op2,result);

label[no++]=atoi(result);

break;

case '<':

fscanf(fp1,"%s %s %s",op1,op2,result);

fprintf(fp2,"\n\t LOAD %s,R0",op1);

fprintf(fp2,"\n\t JLT %s,label#%s",op2,result);

label[no++]=atoi(result);

}//end case

}//end while

fclose(fp2);

fclose(fp1);

fp2=fopen("d:\\output.txt","r");

if(fp2==NULL)

{

printf("\n\tEroor To Opening File...");

//getch();

exit(0);

}

{

ch=fgetc(fp2);

printf("%c",ch);

}while(ch!=EOF);

fclose(fp2);

//getch();

return 0;

}

int check_label(int k)

{

int i;

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

{

if(k==label[i])

return 1;

}

return 0;

}

files

interip.txt

< a b 2

+ a b t1

= t1 a

goto t1 5

< a b 6

+ a b t3

= t3 a

goto t3 5

< a b 10

- a b t4

= t4 c

commands

linuxlab1@linuxlab1-Veriton-M200-H81:~$ gcc target.c

target.c: In function ‘main’:

target.c:19:1: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘char (*)[10]’ [-Wformat=]

scanf("%s",&fname);

linuxlab1@linuxlab1-Veriton-M200-H81:~$ ./a.out

Enter File Name of The Intermediate Code: interip.txt

LOAD a,R0

JLT b,label#2

label#2:

LOAD a,R0

LOAD b,R1

ADD R1,R0

STORE R0,t1

STORE t1,a

JMP t1,label#5

label#5:

LOAD a,R0

JLT b,label#6

label#6:

LOAD a,R0

LOAD b,R1

ADD R1,R0

STORE R0,t3

STORE t3,a

JMP t3,label#5

LOAD a,R0

JLT b,label#10

label#10:

LOAD a,R0

LOAD b,R1

SUB R1,R0

STORE R0,t4

STORE t4,c

Compiler

Wednesday, May 18, 2022

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