public override int GenerateCode(int loc, IVirtualMachine vm, CheckerInformation info)
{
int copies = 0;
foreach (ASTParam param in Params)
{
if (param.OptMechmode == MechMode.COPY && (param.FlowMode == FlowMode.INOUT || param.FlowMode == FlowMode.OUT))
{
++copies;
}
}
vm.Enter(loc++, copies + Declarations.Count, 0);
//CopyIn of inout copy parameters
foreach (ASTParam param in Params)
{
if (param.OptMechmode == MechMode.COPY && param.FlowMode == FlowMode.INOUT)
{
vm.CopyIn(loc++, param.AddressLocation.Value, param.Address);
}
}
//Generate body
foreach (ASTCpsCmd cmd in Commands)
{
loc = cmd.GenerateCode(loc, vm, info);
}
//CopyOut of inout copy and out copy parameters
bool omit = IsFunc;
foreach (ASTParam param in Params)
{
if (omit)
{
omit = false;
}
else
{
if (param.OptMechmode == MechMode.COPY && (param.FlowMode == FlowMode.INOUT || param.FlowMode == FlowMode.OUT))
{
vm.CopyOut(loc++, param.Address, param.AddressLocation.Value);
}
}
}
if (IsFunc)
{
//CopyOut return value
//Can't use standard CopyOut, becuase it works with absolute target address and not with top of stack as needed!
var paramIttr = Params.GetEnumerator(); paramIttr.MoveNext();
ASTParam result = paramIttr.Current;
vm.LoadRel(loc++, result.Address);
vm.Deref(loc++);
vm.LoadRel(loc++, result.AddressLocation.Value);
vm.Store(loc++);
}
//Return
vm.Return(loc++, Params.Count - (IsFunc ? 1 : 0)); //For function the return size is one smaller, leaving the function expression result on the stack!
return(loc);
}
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);
}
}
/*
* program intDiv
* global
* proc divide(in copy m:int, in copy n:int, out ref q:int, out ref r:int)
* do
* q init := 0;
* r init := m;
* while r >= n do
* q := q + 1;
* r := r - n
* endwhile
* endproc;
*
* var m:int;
* var n:int;
* var q:int;
* var r:int
* do
* ? m init;
* ? n init;
* call divide(m, n, q init, r init);
* ! q;
* ! r
* endprogram
*/
public static void Test()
{
try {
vm.Alloc(0, 4);
vm.IntLoad(1, 0);
vm.IntInput(2, "m");
vm.IntLoad(3, 1);
vm.IntInput(4, "n");
vm.Alloc(5, 0);
vm.IntLoad(6, 0);
vm.Deref(7);
vm.IntLoad(8, 1);
vm.Deref(9);
vm.IntLoad(10, 2);
vm.IntLoad(11, 3);
vm.Call(12, 20);
vm.IntLoad(13, 2);
vm.Deref(14);
vm.IntOutput(15, "q");
vm.IntLoad(16, 3);
vm.Deref(17);
vm.IntOutput(18, "r");
vm.Stop(19);
vm.Enter(20, 0, 0);
vm.IntLoad(21, 0);
vm.LoadRel(22, (-2));
vm.Deref(23);
vm.Store(24);
vm.LoadRel(25, (-4));
vm.Deref(26);
vm.LoadRel(27, (-1));
vm.Deref(28);
vm.Store(29);
vm.LoadRel(30, (-1));
vm.Deref(31);
vm.Deref(32);
vm.LoadRel(33, (-3));
vm.Deref(34);
vm.IntGE(35);
vm.CondJump(36, 55);
vm.LoadRel(37, (-2));
vm.Deref(38);
vm.Deref(39);
vm.IntLoad(40, 1);
vm.IntAdd(41);
vm.LoadRel(42, (-2));
vm.Deref(43);
vm.Store(44);
vm.LoadRel(45, (-1));
vm.Deref(46);
vm.Deref(47);
vm.LoadRel(48, (-3));
vm.Deref(49);
vm.IntSub(50);
vm.LoadRel(51, (-1));
vm.Deref(52);
vm.Store(53);
vm.UncondJump(54, 30);
vm.Return(55, 4);
} catch (IVirtualMachine.CodeTooSmallError e) {
Console.WriteLine(e.ToString());
return;
}
try {
vm.Execute();
} catch (IVirtualMachine.ExecutionError e) {
Console.WriteLine(e.ToString());
return;
}
}
