struct expr *new_expr_incword(const char *name,
struct expr *skip)
{
i32 word;
i32 offset;
long length;
struct membuf *in;
struct expr *expr;
unsigned char *p;
offset = resolve_expr(skip);
in = get_named_buffer(s->named_buffer, name);
length = membuf_memlen(in);
if(offset < 0)
{
offset += length;
}
if(offset < 0 || offset > length - 2)
{
LOG(LOG_ERROR,
("Can't read word from offset %d in file \"%s\".\n",
offset, name));
exit(-1);
}
p = membuf_get(in);
p += offset;
word = *p++;
word |= *p++ << 8;
expr = new_expr_number(word);
return expr;
}
struct expr *new_expr_inclen(const char *name)
{
long length;
struct membuf *in;
struct expr *expr;
in = get_named_buffer(s->named_buffer, name);
length = membuf_memlen(in);
expr = new_expr_number((i32)length);
return expr;
}
struct expr *pc_get()
{
struct expr *old_pc1;
if(s_pc1 == unset_value)
{
LOG(LOG_ERROR, ("PC must be set by a .org(pc) call.\n"));
exit(-1);
}
if(s_pc1 == NULL || s_pc2 != 0)
{
old_pc1 = s_pc1;
s_pc1 = new_expr_number(s_pc2);
s_pc2 = 0;
if(old_pc1 != NULL)
{
s_pc1 = new_expr_op2(PLUS, s_pc1, old_pc1);
}
}
return s_pc1;
}
void set_initial_symbol(const char *symbol, i32 value)
{
struct expr *e = new_expr_number(value);
map_put(s->initial_symbols, symbol, e);
}
struct expr *new_is_defined(const char *symbol)
{
int expr_val = (map_get(s->sym_table, symbol) != NULL);
return new_expr_number(expr_val);
}