VBA: How to a edit a code to eliminate the out of stack space error? - excel

Question

This code used to work, but recently I am getting an error (out of stack space).
I think the code is failing because I am calling a function too many times without exiting/ending.
If that is the case, how many times can you call a function and is there something I can do to fix this?
I am not the original author of this code.
I included the sub where the error occurs.
Sub CalculatePct(e As Variant)
Dim G As Integer
Dim pct As Double
Dim Owned100Pct As Boolean
If entities(e) < 0 Then
pct = 0
Owned100Pct = True ' Keeps track if the entity exists in the table other than as a parent
For G = 1 To UBound(MainArray, 1)
If MainArray(G, colEntity) = e Then
Owned100Pct = False
If entities(MainArray(G, colParent)) = -1 Then
'If we don't know the parent's ownership percentage, go and calculate it
CalculatePct MainArray(G, colParent)
End If
pct = pct + CDbl(MainArray(G, colPct)) / 100 * entities(MainArray(G, colParent))
End If
Next
If Owned100Pct Then
'Assume 100% owned if we don't know the parentage
'("Outside" entities won't go through here as they are already set to 0%)
entities(e) = 1
Else
'Store the entity's percentage
entities(e) = pct
End If
End If
End Sub

Answer 1

A #TimWilliams noted in the comments - you have an endless recursion loop.
Highlighting the problem area:
Sub CalculatePct(e As Variant)
[...]
If entities(MainArray(G, colParent)) = -1 Then
CalculatePct MainArray(G, colParent)
End If
[...]
End Sub
e is the parameter, and entities(e) is checked. In the code, MainParent(G, colParent) is used in place of e, so the next call to the routine gives e = MainParent(G, colParent).
Up to the point in the code, you do not change the value of G, colParent. entities or MainArray. So if entities(MainArray(G, colParent)) = -1 it will be forever calling itself.
Without knowing anything else about the code (including if recursion is necessary) I cannot suggest any definitive solutions. However, some things to consider:
Rewriting to be a loop instead of a recursive call
Making the recursive call to a subset of MainArray
Doing any amendments to G or colParent prior to the recursive
call

Answer 2

You've offered no indication of what line the error occurs on nor what MainArray represents but I'm guessing that MainArray has grown to a size greater than what can be accessed with a signed short integer.
Change the declaration of your iteration variable to a Signed Long Integer. This raises the functional limit of the variable from 32,767 iterations to 2,147,483,647.
Dim G As Long