bool Assembler::SetLabels(Assembly& assembly, LabelVector& labels)
{
dword *bytecode = assembly.bytecode;
dword curpos = assembly.curpos;
size_t size = labels.size();
for(dword *cp = bytecode; cp < bytecode + curpos; cp += 2) {
if(IsJumpOp(cp[0])) {
if(cp[1] < size) {
dword pos = labels.at(cp[1]).pos;
if(pos != -1)
cp[1] = pos;
else {
// this is a common error
printf("Label not found: %s\n", labels.at(cp[1]).label.c_str());
labels.clear();
return false;
}
} else {
// if we get here, there's a bug in the assembler ;(
printf("Label index not found: %d\n", cp[1]);
labels.clear();
return false;
}
}
}
labels.clear();
return true;
}
bool Assembler::ParseLine(string& line, int linecount, Assembly& assembly, LabelVector& labels)
{
string op;
int i = NextWord(line, op);
// skip commented and empty lines
if(i == -1 || op == "//" || op == ";") return true;
// this is a a very slow way of doing things, but then this code will only
// be used during development and for debugging
OpDesc *opcode;
int codecount = sizeof(opcodes)/sizeof(OpDesc);
int j = 0;
for(; j < codecount; j ++) {
if(stricmp(opcodes[j].name, op.c_str()) == 0) {
opcode = &opcodes[j];
break;
}
}
// is this a label?
if(j == codecount) {
size_t k = op.length() - 1;
if(op.find_first_of(":") == k) {
string name = op.substr(0, k);
labels.at(AddLabel(name, labels)).pos = assembly.curpos;
return true;
} else
return false;
} else {
assembly.WriteDword(opcode->code);
string param;
i = NextWord(line, param, i);
if(IsJumpOp(opcode->code)) {
// write the label index, we'll later replace this with the code position
assembly.WriteDword(AddLabel(param, labels));
} else {
if(i == -1) {
assembly.WriteDword(0);
if(opcode->paramcount > 0) return false; // if we need more params, bail
} else
assembly.WriteDword(StringToOperand(param, opcode));
}
}
return true;
}