static int test_register(char * n, asm86_t * a)
{
int r;
optype_t optype;
/* PSEUDO or JUMP */
if (!a || (a->optype != NONE && a->optype < BYTE))
return isregister(n);
/*
* as we assume that instructions without specified operand size like
* mov use 32bit ones we must make sure that we are not passing
* suchinstruction a register of a different size
*/
if (r = isregister(n)) {
if (IS_REG8(r)) {
optype = BYTE;
} else if (IS_REG16(r)) {
optype = WORD;
} else if (IS_REG32(r)) {
optype = OWORD;
}
}
a->optype = (a->optype > optype ? optype : a->optype);
return r;
}
static expression_t *gnu_get_oplist(asm86_t * a, int *pn, int deref)
/* Get a comma (or colon for jmpf and callf) separated list of instruction
* operands.
*/
{
expression_t *e, *o1, *o2;
token_t *t;
int sreg;
if ((e= gnu_get_operand(a, pn, deref)) == nil) return nil;
t = get_token(*pn);
if (t->symbol == ':' && IS_REGSEG(sreg = isregister(e->name))) {
a->seg = segreg2seg(sreg);
del_expr(e);
(*pn)++;
e = gnu_get_oplist(a, pn, deref);
}
else if (t->symbol == ',' || t->symbol == ':') {
o1= e;
(*pn)++;
if ((o2= gnu_get_oplist(a, pn, deref)) == nil) {
del_expr(o1);
return nil;
}
e= new_expr();
e->operator= ',';
e->left= o2;
e->right= o1;
}
return e;
}
int syms_is_global(const char * n)
{
struct sym *s;
if (!n || is_number(n) || is_local_label_ref(n) || isregister(n))
return 0;
/* if not found, it must be extern -> global */
if (!(s = sym_exists(n)))
return 1;
return s->gl;
}
static expression_t *ack_get_operand(int *pn, int deref)
/* Get something like: (memory), offset(base)(index*scale), or simpler. */
{
expression_t *e, *offset, *base, *index;
token_t *t;
int c;
/* Is it (memory)? */
if (get_token(*pn)->symbol == '('
&& ((t= get_token(*pn + 1))->type != T_WORD
|| !isregister(t->name))
) {
/* A memory dereference. */
(*pn)++;
if ((offset= ack_get_C_expression(pn)) == nil) return nil;
if (get_token(*pn)->symbol != ')') {
parse_err(1, t, "operand syntax error\n");
del_expr(offset);
return nil;
}
(*pn)++;
e= new_expr();
e->operator= '(';
e->middle= offset;
return e;
}
/* #constant? */
if (dialect == NCC && deref
&& ((c= get_token(*pn)->symbol) == '#' || c == '*')) {
/* NCC: mov ax,#constant -> ACK: mov ax,constant */
(*pn)++;
return ack_get_C_expression(pn);
}
/* @address? */
if (dialect == NCC && get_token(*pn)->symbol == '@') {
/* NCC: jmp @address -> ACK: jmp (address) */
(*pn)++;
if ((offset= ack_get_operand(pn, deref)) == nil) return nil;
e= new_expr();
e->operator= '(';
e->middle= offset;
return e;
}
/* Offset? */
if (get_token(*pn)->symbol != '(') {
/* There is an offset. */
if ((offset= ack_get_C_expression(pn)) == nil) return nil;
} else {
/* No offset. */
offset= nil;
}
/* (base)? */
if (get_token(*pn)->symbol == '('
&& (t= get_token(*pn + 1))->type == T_WORD
&& isregister(t->name)
&& get_token(*pn + 2)->symbol == ')'
) {
/* A base register expression. */
base= new_expr();
base->operator= 'B';
base->name= copystr(t->name);
(*pn)+= 3;
} else {
/* No base register expression. */
base= nil;
}
/* (index*scale)? */
if (get_token(*pn)->symbol == '(') {
/* An index most likely. */
token_t *m= nil;
if (!( /* This must be true: */
(t= get_token(*pn + 1))->type == T_WORD
&& isregister(t->name)
&& (get_token(*pn + 2)->symbol == ')' || (
get_token(*pn + 2)->symbol == '*'
&& (m= get_token(*pn + 3))->type == T_WORD
&& strchr("1248", m->name[0]) != nil
&& m->name[1] == 0
&& get_token(*pn + 4)->symbol == ')'
))
)) {
/* Alas it isn't */
parse_err(1, t, "operand syntax error\n");
del_expr(offset);
del_expr(base);
return nil;
}
/* Found an index. */
index= new_expr();
index->operator= m == nil ? '1' : m->name[0];
index->name= copystr(t->name);
(*pn)+= (m == nil ? 3 : 5);
} else {
/* No index. */
index= nil;
}
if (dialect == NCC && deref && base == nil && index == nil
&& !(offset != nil && offset->operator == 'W'
&& isregister(offset->name))
) {
/* NCC: mov ax,thing -> ACK mov ax,(thing) */
e= new_expr();
e->operator= '(';
e->middle= offset;
return e;
}
if (base == nil && index == nil) {
/* Return a lone offset as is. */
e= offset;
} else {
e= new_expr();
e->operator= 'O';
e->left= offset;
e->middle= base;
e->right= index;
}
return e;
}
static expression_t *gnu_get_operand(asm86_t * a, int *pn, int deref)
/* Get something like: $immed, memory, offset(%base,%index,scale), or simpler. */
{
expression_t *e, *offset, *base, *index;
token_t *t;
int c;
if (get_token(*pn)->symbol == '$') {
/* An immediate value. */
(*pn)++;
return gnu_get_C_expression(pn);
}
if (get_token(*pn)->symbol == '*') {
(*pn)++;
deref = 1;
#if 0
if ((offset= gnu_get_operand(a, pn, deref)) == nil) return nil;
#if 0
e= new_expr();
e->operator= '(';
e->middle= offset;
return e;
#endif
return offset;
#endif
}
if ((get_token(*pn)->symbol == '%')
&& (t= get_token(*pn + 1))->type == T_WORD
&& isregister(t->name)
) {
/* A register operand. */
(*pn)+= 2;
e= new_expr();
e->operator= 'W';
e->name= copystr(t->name);
return e;
}
/* Offset? */
if (get_token(*pn)->symbol != '('
|| get_token(*pn + 1)->symbol != '%') {
/* There is an offset. */
if ((offset= gnu_get_C_expression(pn)) == nil) return nil;
} else {
/* No offset. */
offset= nil;
}
/* (%base,%index,scale) ? */
base= index= nil;
if (get_token(*pn)->symbol == '(') {
(*pn)++;
/* %base ? */
if (get_token(*pn)->symbol == '%'
&& (t= get_token(*pn + 1))->type == T_WORD
&& isregister(t->name)
) {
/* A base register expression. */
base= new_expr();
base->operator= 'B';
base->name= copystr(t->name);
(*pn)+= 2;
}
if (get_token(*pn)->symbol == ',') (*pn)++;
/* %index ? */
if (get_token(*pn)->symbol == '%'
&& (t= get_token(*pn + 1))->type == T_WORD
&& isregister(t->name)
) {
/* A index register expression. */
index= new_expr();
index->operator= '1'; /* for now */
index->name= copystr(t->name);
(*pn)+= 2;
}
if (get_token(*pn)->symbol == ',') (*pn)++;
/* scale ? */
if ((base != nil || index != nil)
&& (t= get_token(*pn))->type == T_WORD
&& strchr("1248", t->name[0]) != nil
&& t->name[1] == 0
) {
if (index == nil) {
/* Base is really an index register. */
index= base;
base= nil;
}
index->operator= t->name[0];
(*pn)++;
}
if (get_token(*pn)->symbol == ')') {
/* Ending paren. */
(*pn)++;
} else {
/* Alas. */
parse_err(1, t, "operand syntax error\n");
del_expr(offset);
del_expr(base);
del_expr(index);
return nil;
}
}
if (base == nil && index == nil) {
if (deref) {
/* Return a lone offset as (offset). */
e= new_expr();
e->operator= '(';
e->middle= offset;
} else {
/* Return a lone offset as is. */
e= offset;
}
} else {
e= new_expr();
e->operator= 'O';
e->left= offset;
e->middle= base;
e->right= index;
}
return e;
}
