Experiment No - 01

PROGRAM: Implementation of Symbol Table

#include<stdio.h>

#include<string.h>ruct symboltable

{

int position;

char name[20];

char type[20];

int allst;

}s[20];

int main()

{

int i=0,p=0,n,j,k;

char input[20],type[20];

char dt[5][20]={"int","char","float","double","long"};

FILE *fp;

fp=fopen("input.txt","r");

fscanf(fp,"%s",input);

while(strcmp(input,"EOF")!=0)

{

for(j=0;j<5;j++)

{

if(strcmp(input,dt[j])==0)

{

strcpy(type,input);

fscanf(fp,"%s",input);

while(strcmp(input,";")!=0)

{

if(strcmp(input,",")!=0)

{

p++;

s[p].position=++i;

strcpy(s[p].name,input);

strcpy(s[p].type,type);

fscanf(fp,"%s",input);

}

if(strcmp(input,";")!=0)

fscanf(fp,"%s",input);

}

fscanf(fp,"%s",input);

}

}

fscanf(fp,"%s",input);

}

n=i+1;

for(k=1;k<n;k++)

{

if(strcmp(s[k].type,"int")==0)

s[k].allst=2;

else if((strcmp(s[k].type,"float")==0)||(strcmp(s[k].type,"double")==0))

s[k].allst=4;

else if(strcmp(s[k].type,"char")==0)

s[k].allst=1;

else if(strcmp(s[k].type,"long")==0)

s[k].allst=8;

}

printf("\n SYMBOL TABLE FOR IDENTIFIER");

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

printf("\nPOSITION\tNAME\tTYPE\tALLOCATEDSTORAGE\tADDRESS");

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

for(k=1;k<n;k++)

{

printf("\n%d\t\t\t%s\t%s\t\t%d\t\t%d",s[k].position,s[k].name,s[k].type,s[k].allst,1000+k*s[k].allst);                                        

}

}

INPUT:

void main()

{

int a ;

float b ;

int c ;

c = a + b ;

}

EOF

OUTPUT:

$ ./a.out

 SYMBOL TABLE FOR IDENTIFIER

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

POSITION        NAME    TYPE    ALLOCATEDSTORAGE      ADDRESS

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

1                       a               int                         2                            1002

2                       b              float                      4                            1008

3                       c              int                           2                           1010