Compiler Construction Programs

LAB MANUALCOMPILER LABVIII SEM BTECH (CSE)+DD(CS+SE AND CS+IC)

CP 452

COMPILER LAB

C(L,T,P) = 2 (0,0,2+2)

1,2 Write a Program to identify data storage statements in an 8086 assembly language program and estimate the size of data segment.1. Write a program to identify macro definitions in an assembly language program.

4,5. Extend the above program to implement simple and recursive macro expansion.

6. Write a program to process include and define macro in C language.

7, 8 Write a program to parse source code string of C-language and identify token in terms of keywords and identifiers.

9. Construct parse tree of arithmetic statements in C language program.

10. Write a program to optimize the source program for operator strength reduction, dead code elimination and frequency reduction transformation.

11, 12 Design a simple high level language containing arithmetic and logic operations pointers, branch and loop instructions. Write its lexical analyzer using lex.

PROGRAM1AIM: Write a program to identify data storage statements in an 8086 assembly language program.

// Source.C

#include

#include

#include

struct source

{

char label[10],instr[10],operand[10];

}src;

struct pseudo

{

char code[10];

}ps;

struct result

{

intaddr;


}rst;

int detect(char search[10])

{

FILE *p;

p=fopen("pseudo.txt","r");

while(!feof(p))

{

fscanf(p,"%s",ps.code);

if(strcmp(search,ps.code)==0)

{

fclose(p);

return 1;

}

}

fclose(p);

return 0;

}

void main()

{

FILE *s,*r;

int d=0,addr;

clrscr();

s=fopen("source.txt","r");

r=fopen("result.txt","w");

while(!feof(s))

{

fscanf(s,"%s%s%s",src.label,src.instr,src.operand);

d=detect(src.instr);

if(d==1)

{

if(strcmp(src.instr,"START")==0)

addr=atoi(src.operand);

else if(strcmp(src.instr,"WORD")==0)

addr=rst.addr+3;

else if(strcmp(src.instr,"RESW")==0)

addr=rst.addr+(atoi(src.operand)*3);

else if(strcmp(src.instr,"RESB")==0)

addr=rst.addr+atoi(src.operand);

else if(strcmp(src.instr,"BYTE")==0)

addr=rst.addr+(strlen(src.operand)-3);

else

addr=rst.addr+3;

strcpy(rst.label,src.label);

strcpy(rst.instr,src.instr);

strcpy(rst.operand,src.operand);

fprintf(r,"%d\t%s\t%s\t%s\n",rst.addr,rst.label,rst.instr,rst.operand);

rst.addr=addr;

}

else

{

printf("Error Encounted");

fclose(s);

fclose(r);

getch();

}

}

fclose(s);

fclose(r);

getch();

}

Output

Input File 1:Pseudo.txt

START

READ

WORD

BYTE

RESW

RESB

END

Input File 2:Source.txt

NULL

START1000

A

RESB

100

LOOP

READ

A

B

BYTE

C"LOOP"

C

WORD100

G

RESW

5

NULL

END

NULL

Output File:result.txt

0NULL

START1000

1000A

RESB

100

1100LOOP

READ

A

1103B

BYTE

C"LOOP"

1107C

WORD100

1110G

RESW

5

1125NULL

END

NULL

PROGRAM 2

AIM: Write a program to identify data storage statements in an 8086 assembly language program and estimate the size of data segment.

// Source.C

#include

#include

#include

struct source

{


}src;

struct pseudo

{

char code[10];

}ps;

struct result

{

intaddr;


}rst;

int detect(char search[10])

{

FILE *p;

p=fopen("pseudo.txt","r");

while(!feof(p))

{

fscanf(p,"%s",ps.code);

if(strcmp(search,ps.code)==0)

{

fclose(p);

return 1;

}

}

fclose(p);

return 0;

}

void main()

{

FILE *s,*r;

int d=0,addr;

clrscr();

s=fopen("source.txt","r");

r=fopen("result.txt","w");

while(!feof(s))

{


d=detect(src.instr);

if(d==1)

{

if(strcmp(src.instr,"START")==0){

addr=atoi(s.operand);

size=0;

}

else if(strcmp(src.instr,"WORD")==0){

addr=rst.addr+3;

size=addr-res.address;

}

else if(strcmp(src.instr,"RESW")==0){

addr=rst.addr+(atoi(src.operand)*3);


}

else if(strcmp(src.instr,"RESB")==0){

addr=rst.addr+atoi(src.operand);


}

else if(strcmp(src.instr,"BYTE")==0){

addr=rst.addr+(strlen(src.operand)-3);


}

else{

addr=rst.addr+3;


}




fprintf(r,"%d\t%s\t%s\t%s\n",rst.addr,rst.label,rst.instr,rst.operand);

rst.addr=addr;

}

else

{

printf("Error Encounted");

fclose(s);

fclose(r);

getch();

}

}

fclose(s);

fclose(r);

getch();

}

Input File 1:Pseudo.txt

START

READ

WORD

BYTE

RESW

RESB

END

Input File 2: Source.txt

NULL

START1000

A

RESB

100

LOOP

READ

A

B

BYTE

C"LOOP"

C

WORD100

G

RESW

5

NULL

END

NULL

Output File :Result.txt

AddrLabel

OperandInstrSize

0NULL

START10000

1000A

RESB100100100

1100LOOP

READA00

1103B

BYTE

C"LOOP"4

1107CWORD1003

1110GRESW51515

1125NULLENDNULL00

PROGRAM 3

AIM: Write a program to identify macro definitions in an assembly language program.

//Macro.C

#include

#include

#include

struct source

{

char label[10], instr[10], operand[20];

}src;

struct result

{

char label[10],instr[10], operand[20];

}rst;

void main()

{

FILE *s,*r;

clrscr();

s=fopen("source1.txt","r");

r=fopen("resultmacro.txt","w");

while(!feof(s))

{


if(strcmp(src.instr,"MACRO")==0)

{

while(strcmp(src.instr,"MEND")!=0)

{

fprintf(r,"%s\t%s\t%s\n",rst.label,rst.instr,rst.operand);





}

}

}

printf("MACRO Completed");

fclose(s);

fclose(r);

getch();

}

Input File: Source.txt

NULLMACRO INCR&A,&B,&REG2=BREG

NULLMOVER &REG2,&A

NULLSUB &REG2,&B

NULLMOVEM &REG2,&A

NULLMEND NULL

NULLSTART100

NULLREADN1

NULLREADN2

NULLINCRN1,N2

NULLEND

Output File: Result.txt

NULLMACROINCR&A,&B,&REG2=BREGNULL

NULLMOVER&REG2,&A

NULLSUB&REG2,&B

PROGRAM 4 and 5AIM: Write a program to extend the third program to implement simple macro expansion.//Source.C

#include

#include

#include

#include

structmnt

{

char name[20];

intmdtindex;

intSkipFlag;

}mnt[10];

structmdt

{

intsrno;

charinst[20];

}mdt[10];

structala

{

int index;

chararg[20];

}ala[10];

intmntc,mdtc,alac;

char *replace_str(char *str, char *orig, char *rep)

{

static char buffer[4096];

char *p;

if(!(p = strstr(str, orig))) // Is 'orig' even in 'str'?

{

returnstr;

}

strncpy(buffer, str, p-str); // Copy characters from 'str' start to 'orig' st$

buffer[p-str] = '\0';

sprintf(buffer+(p-str),"%s%s",rep,p+strlen(orig));

if(!(p = strstr(buffer, orig))) // Is 'orig' even in 'buffer'?

return buffer;

else

replace_str(buffer,orig,rep);

}

voiddispALA()

{

int i;

printf("\nIndex\tArgument");

printf("\n------------------");

for(i=0;ilexptr,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 ;

}

}

}

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(';');

}

}

void 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();

getch();

}

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