public override int GenerateLValue(int loc, IVirtualMachine vm, CheckerInformation info, bool hasToBeLValue = true)
{
if (IsFuncCall)
{
throw new IVirtualMachine.InternalError("The result of a function can't be an LValue");
}
else
{
//Write address to the top of the stack
if (info.CurrentNamespace != null &&
info.Namespaces.ContainsKey(info.CurrentNamespace) &&
info.Namespaces[info.CurrentNamespace].ContainsIdent(Ident))
{
IASTStoDecl storage = info.Namespaces[info.CurrentNamespace][Ident];
if (hasToBeLValue)
{
AssertNotConstant(storage);
}
if (storage is ASTStoDecl || (storage is ASTParam && ((ASTParam)storage).OptMechmode == MechMode.COPY))
{
//Local Identifier or parameter with mechmode COPY
vm.LoadRel(loc++, storage.Address);
}
else if (storage is ASTParam)
{
//If mechmode is null: default = Mechmode.REF
//Load parameter with mechmode REF
vm.LoadRel(loc++, storage.Address); //Relative Address to fp
vm.Deref(loc++); //Deref to get global Address
//With another Deref the value is loaded
}
else
{
//Should never happen as long as no new type is added
throw new IVirtualMachine.InternalError("Unknown Identifier Type");
}
}
else if (info.Globals.ContainsIdent(Ident))
{
IASTStoDecl storage = info.Globals[Ident];
if (hasToBeLValue)
{
AssertNotConstant(storage);
}
vm.IntLoad(loc++, storage.Address);
}
else
{
throw new IVirtualMachine.InternalError("Access of undeclared Identifier " + Ident);
}
return(loc);
}
}
private void AssertNotConstant(IASTStoDecl sto)
{
if (sto is ASTStoDecl)
{
AssertNotConstant((ASTStoDecl)sto);
}
else if (sto is ASTParam)
{
AssertNotConstant((ASTParam)sto);
}
else
{
//Should never happen as long as no new type is added
throw new IVirtualMachine.InternalError("Unknown Identifier Type");
}
}
