internal static GStack Make(XType[] topCombo, GStack tail)
{
GStackElt tos = tail.tos;
for (int i = topCombo.Length - 1; i >= 0; i--)
{
XTypeSet xts = new XTypeSet();
xts.Add(topCombo[i]);
tos = new GStackElt(tos, xts);
}
return(new GStack(tos));
}
internal DCall(GStack gs, Function f)
{
this.gs = gs;
this.f = f;
}
internal void DoCall(string name)
{
/*
* Make sure the next node exists. We also set its locals
* to the current locals (the called function cannot
* change our locals). Note that the stack is not set;
* this will be done only when (if) one of the called
* functions returns.
*/
if (next == null)
{
next = GetNode(addr + 1);
}
next.MergeLocals(Locals);
/*
* Find all functions registered with the specified name.
* If none is found, then we want a specific error message
* (this is probably a typographic error in the function
* name).
*/
List <FunctionRegistration> r1 = Function.LookupAll(name);
if (r1.Count == 0)
{
throw new Exception(string.Format("no such function: {0}", name));
}
/*
* Find all functions that may match the types on the
* stack.
*/
List <FunctionRegistration> r2 =
new List <FunctionRegistration>();
int maxNum = 0;
foreach (FunctionRegistration fr in r1)
{
if (Stack.MayMatch(fr.types))
{
r2.Add(fr);
maxNum = Math.Max(maxNum, fr.types.Length);
}
}
/*
* For all combinations of types that may occur on the
* stack, try to resolve the call; if any fails, then
* report it as an error.
* While doing so, we accumulate, for each reachable
* function, the types that may appear on entry of
* that function.
*/
CCType[] combo = new CCType[maxNum];
CCTypeSet.ComboEnumerator ce = new CCTypeSet.ComboEnumerator(
Stack.GetTopElements(maxNum));
XType[] xts = new XType[maxNum];
SortedDictionary <Function, CCStack> targets =
new SortedDictionary <Function, CCStack>();
CCStack root = Stack.Pop(maxNum);
GStack gtail = GStack.Make(root);
calls = new List <DCall>();
for (;;)
{
if (!ce.Next(combo))
{
break;
}
for (int i = 0; i < maxNum; i++)
{
xts[i] = combo[i].xType;
}
Function f = Function.Resolve(name, r2, xts);
CCStack nstack = root.Push(combo);
CCStack ostack;
if (targets.TryGetValue(f, out ostack))
{
targets[f] = CCStack.Merge(ostack, nstack);
}
else
{
targets[f] = nstack;
}
calls.Add(new DCall(GStack.Make(xts, gtail), f));
}
/*
* We now have a complete list of reachable functions,
* each with a corresponding entry stack; we know that
* the call will always resolve to a single function. If
* we are updating, we reuse the previous functions from
* the dispatch variable if available. Note that an update
* can only add new functions, not remove existing ones.
*/
if (dispatch == null)
{
dispatch = new SortedDictionary <Function, CCNode>();
}
foreach (Function f in targets.Keys)
{
CCStack stack = targets[f];
CCNode onode;
if (dispatch.TryGetValue(f, out onode))
{
onode.MergeStack(stack);
}
else
{
dispatch[f] = f.Enter(stack, cfi.Entry, next);
}
}
}
