110 lines
1.5 KiB
C++
110 lines
1.5 KiB
C++
// The symbol table is a simple array of struct U.
|
|
|
|
#include "stdafx.h"
|
|
#include "defs.h"
|
|
|
|
// put symbol at index n
|
|
|
|
void
|
|
std_symbol(char *s, int n)
|
|
{
|
|
U *p;
|
|
p = symtab + n;
|
|
p->u.printname = s;
|
|
}
|
|
|
|
// symbol lookup, create symbol if need be
|
|
|
|
U *
|
|
usr_symbol(char *s)
|
|
{
|
|
int i;
|
|
U *p;
|
|
for (i = 0; i < NSYM; i++) {
|
|
if (symtab[i].u.printname == 0)
|
|
break;
|
|
if (strcmp(s, symtab[i].u.printname) == 0)
|
|
return symtab + i;
|
|
}
|
|
if (i == NSYM)
|
|
stop("symbol table overflow");
|
|
p = symtab + i;
|
|
p->u.printname = (char *)malloc(strlen(s)+1);
|
|
strcpy(p->u.printname,s);
|
|
return p;
|
|
}
|
|
|
|
// get the symbol's printname
|
|
|
|
char *
|
|
get_printname(U *p)
|
|
{
|
|
if (p->k != SYM)
|
|
stop("symbol error");
|
|
return p->u.printname;
|
|
}
|
|
|
|
// clears the arglist too
|
|
|
|
void
|
|
set_binding(U *p, U *q)
|
|
{
|
|
if (p->k != SYM)
|
|
stop("symbol error");
|
|
binding[p - symtab] = q;
|
|
arglist[p - symtab] = symbol(NIL);
|
|
}
|
|
|
|
U *
|
|
get_binding(U *p)
|
|
{
|
|
if (p->k != SYM)
|
|
stop("symbol error");
|
|
return binding[p - symtab];
|
|
}
|
|
|
|
void
|
|
set_binding_and_arglist(U *p, U *q, U *r)
|
|
{
|
|
if (p->k != SYM)
|
|
stop("symbol error");
|
|
binding[p - symtab] = q;
|
|
arglist[p - symtab] = r;
|
|
}
|
|
|
|
U *
|
|
get_arglist(U *p)
|
|
{
|
|
if (p->k != SYM)
|
|
stop("symbol error");
|
|
return arglist[p - symtab];
|
|
}
|
|
|
|
// get symbol's number from ptr
|
|
|
|
int
|
|
symnum(U *p)
|
|
{
|
|
if (p->k != SYM)
|
|
stop("symbol error");
|
|
return (int) (p - symtab);
|
|
}
|
|
|
|
// push indexed symbol
|
|
|
|
void
|
|
push_symbol(int k)
|
|
{
|
|
push(symtab + k);
|
|
}
|
|
|
|
void
|
|
clear_symbols(void)
|
|
{
|
|
int i;
|
|
for (i = 0; i < NSYM; i++) {
|
|
binding[i] = symtab + i;
|
|
arglist[i] = symbol(NIL);
|
|
}
|
|
}
|