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#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<ctype.h>
#include<math.h>
#include"symbol-table.h"
#define TABLE_SIZE 256
symtab * hash_table[TABLE_SIZE];
extern int linenumber;
int HASH(char * str){
int idx=0;
while(*str){
idx = idx << 1;
idx+=*str;
str++;
}
return (idx & (TABLE_SIZE-1));
}
/*returns the symbol table entry if found else NULL*/
symtab * lookup(char *name){
int hash_key;
symtab* symptr;
if(!name)
return NULL;
hash_key=HASH(name);
symptr=hash_table[hash_key];
while(symptr){
if(!(strcmp(name,symptr->lexeme)))
return symptr;
symptr=symptr->front;
}
return NULL;
}
void insertID(char *name){
int hash_key;
symtab* ptr;
symtab* symptr=(symtab*)malloc(sizeof(symtab));
hash_key=HASH(name);
ptr=hash_table[hash_key];
if(ptr==NULL){
/*first entry for this hash_key*/
hash_table[hash_key]=symptr;
symptr->front=NULL;
symptr->back=symptr;
}
else{
symptr->front=ptr;
ptr->back=symptr;
symptr->back=symptr;
hash_table[hash_key]=symptr;
}
strcpy(symptr->lexeme,name);
symptr->line=linenumber;
symptr->counter=1;
}
void printSym(symtab* ptr)
{
printf(" Name = %s \n", ptr->lexeme);
printf(" References = %d \n", ptr->counter);
}
void printSymTab(void)
{
int i;
printf("----- Symbol Table ---------\n");
for (i=0; i<TABLE_SIZE; i++)
{
symtab* symptr;
symptr = hash_table[i];
while (symptr != NULL)
{
printf("====> index = %d \n", i);
printSym(symptr);
symptr=symptr->front;
}
}
}
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