void VarAssignment(string varName)
{
int type, reg;
Obj obj = tab.Find(varName);
if (obj.kind != var)
{
SemErr("Must assign to a variable");
}
if (tab.typeIsStruct(obj.type.id))
{
SemErr("Can only assign to primitave fields");
}
Expect(35);
Expr(out reg, out type);
if (type != obj.getTypeId())
{
SemErr("Must be equal types, " + obj.getTypeId() + ':' + type);
}
if (obj.level == 0)
{
gen.StoreGlobal(reg, obj.adr, varName);
}
else
{
gen.StoreLocal(reg, tab.curLevel - obj.level, obj.adr, varName);
}
Expect(27);
}
void ConstExpr(out int type, out int value)
{
string name; type = undef; value = -1;
if (la.kind == 1)
{
Get();
type = integer; value = Convert.ToInt32(t.val);
}
else if (la.kind == 5)
{
Get();
Expect(1);
type = integer; value = -(Convert.ToInt32(t.val));
}
else if (la.kind == 20)
{
Get();
type = boolean; value = 1;
}
else if (la.kind == 21)
{
Get();
type = boolean; value = 0;
}
else if (la.kind == 2)
{
Ident(out name);
Obj obj = tab.Find(name);
if (obj.kind == constant)
{
type = obj.getTypeId();
value = obj.compileTimeValue;
}
else
{
SemErr("Must be constant");
}
}
else
{
SynErr(55);
}
}
void SwitchStat()
{
string name; int reg, oReg, cReg; int type;
int caseLabel, statementLabel;
int endLabel = gen.NewLabel();
Expect(43);
Ident(out name);
while (la.kind == 36)
{
StructField(name, out name);
}
Obj obj = tab.Find(name);
tab.OpenSubScope(endLabel);
Expect(29);
while (la.kind == 44)
{
caseLabel = gen.NewLabel();
gen.Label(caseLabel);
Console.WriteLine(";Load in the Case primary");
Get();
Primary(out reg, out type);
Expect(25);
gen.ClearRegisters();
oReg = gen.GetRegister();
cReg = gen.GetRegister();
//move generated primary value to cReg
gen.MoveRegister(cReg, reg);
//load obj value into oReg
Console.WriteLine(";Load in Switch obj ");
if (obj.level == 0)
{
gen.LoadGlobal(oReg, obj.adr, name);
}
else
{
gen.LoadLocal(oReg, tab.curLevel - obj.level, obj.adr, name);
}
if (type != obj.getTypeId())
{
SemErr("Yo, don't mix n' match the types");
}
//Compare oReg to cReg
Console.WriteLine(";Comapare Switch obj with Case primary");
gen.RelOp(Op.EQU, oReg, cReg);
gen.BranchFalse(caseLabel + 2); //jump to next case, +2 to skip statementLabel
//Gen statement labels so optional break can skip the comparisons
statementLabel = gen.NewLabel();
gen.Label(statementLabel);
//....statements
while (StartOf(3))
{
Stat();
}
Console.WriteLine(";Jump to next set of statements");
gen.Branch(statementLabel + 2);
}
Console.WriteLine(";Default labels whether default present or not");
caseLabel = gen.NewLabel();
gen.Label(caseLabel);
statementLabel = gen.NewLabel();
gen.Label(statementLabel);
if (la.kind == 45)
{
Get();
Expect(25);
while (StartOf(3))
{
Stat();
}
}
Expect(30);
gen.Label(endLabel);
tab.CloseSubScope();
}