static void Branch()
{
int target;
string name;
Label lab;
if (la.kind == brn_Sym)
{
Get();
}
else if (la.kind == bze_Sym)
{
Get();
}
else
{
SynErr(67);
}
string mnemonic = token.val;
IO.Write(token.val);
IO.Write("", 5);
if (la.kind == number_Sym)
{
Number(out target);
CodeGen.TwoWord(mnemonic, target);
}
else if (la.kind == identifier_Sym)
{
Ident(out name);
LabelEntry entry = LabelTable.Find(name);
if (entry == null)
{
lab = new Label(!known);
int lineNumber = token.line;
LabelTable.Insert(new LabelEntry(name, lab, lineNumber));
}
else
{
lab = entry.label;
entry.AddReference(token.line);
}
IO.Write(name);
IO.Write("", 10 - name.Length);
CodeGen.Branch(mnemonic, lab);
}
else
{
SynErr(68);
}
}
static void Label()
{
Expect(label_Sym);
string name = token.val.Substring(0, token.val.Length - 1).ToLower();
int lineNumber = -token.line;
LabelEntry entry = LabelTable.Find(name);
if (entry == null) //new label to be defined
{
LabelTable.Insert(new LabelEntry(name, new Label(known), lineNumber));
}
else if (entry.label.IsDefined())
{
SemError("redefined label");
}
else
{
entry.label.Here();
entry.AddReference(lineNumber); //label was defined here
}
}
static void Assem()
{
Expect(assem_Sym);
Expect(EOL_Sym);
Expect(begin_Sym);
Expect(EOL_Sym);
IO.WriteLine("ASSEM\nBEGIN");
while (StartOf(1))
{
Statement();
}
Expect(end_Sym);
Expect(point_Sym);
while (la.kind == EOL_Sym)
{
Get();
}
LabelTable.CheckLabels();
LabelTable.ListReferences(pretty);
VarTable.ListReferences(pretty);
}