bool token::is_stack_operation(stack_operation operation) const {
if (is_stack_operation()) {
return get_stack_operation() == operation;
}
return false;
}
dcpu16operand parseoperand(list *labels) {
dcpu16operand op = {0};
dcpu16token tok;
op.addressing = IMMEDIATE;
if ((tok = nexttoken()) == T_IDENTIFIER) {
/* label */
op.type = LABEL;
op.label = getnewlabel(labels, cur_tok.string)->label;
} else if (tok == T_NUMBER) {
/* numeric */
op.type = LITERAL;
op.numeric = cur_tok.number;
} else if (is_register(tok) || is_status_register(tok)
|| is_stack_operation(tok)) {
/* register */
/*
* For all intents and purposes, stack operations, registers and
* status registers are equivalent in usage for immediate addressing,
* so we might as well classify them all as REGISTER
*/
op.type = REGISTER;
op.token = tok;
} else if (tok == T_LBRACK) {
/* [reference] */
dcpu16token a = nexttoken();
op.addressing = REFERENCE;
if (a == T_NUMBER) {
/* [numeric] */
op.type = LITERAL;
op.numeric = cur_tok.number;
} else if (is_register(a)) {
/* [register] */
op.type = REGISTER;
op.token = a;
} else if (a == T_IDENTIFIER) {
/* [label] */
op.type = LABEL;
op.label = getnewlabel(labels, cur_tok.string)->label;
} else {
error("Expected numeric, register or label, got %s", toktostr(a));
}
/* First part parsed correctly so far, now either ']' or '+'
* follows */
if (((tok = nexttoken()) != T_RBRACK) && (tok != T_PLUS))
error("Expected '+' or ']', got %s", toktostr(tok));
if (tok == T_RBRACK) {
/* [numeric], [register], [label] checks out */
return op;
} else {
dcpu16token b = nexttoken();
op.type = REGISTER_OFFSET;
if (is_register(a)) {
/* [register + label], [register + numeric] */
if (b == T_IDENTIFIER) {
op.register_offset.type = LABEL;
op.register_offset.register_index = a;
op.register_offset.label =
getnewlabel(labels, cur_tok.string)->label;
} else if (b == T_NUMBER) {
op.register_offset.type = LITERAL;
op.register_offset.register_index = a;
op.register_offset.offset = cur_tok.number;
} else {
error("Expected numeric or label, got %s", toktostr(b));
}
} else {
/* [numeric + register], [label + register] */
if (is_register(b)) {
op.register_offset.register_index = b;
if (a == T_NUMBER) {
op.register_offset.type = LITERAL;
op.register_offset.offset = cur_tok.number;
} else {
op.register_offset.type = LABEL;
op.register_offset.label =
getnewlabel(labels, cur_tok.string)->label;
}
} else {
error("Expected register, got %s", toktostr(b));
}
}
if (nexttoken() != T_RBRACK)
error("Expected ']'");
}
} else {
error("Expected register, label, numeric or '[', got %s",
toktostr(tok));
}
return op;
}
