[cpp] Infinite loop in compiler when inheriting from cpp.Pointer

[tobil4sk]

// MyPointer.hx
class MyPointer extends cpp.Pointer<Int> {}

# build.hxml
MyPointer
--cpp out

This has always generated broken code, however, it has only started triggering an infinite loop since: 145e55f.

Prior to that change, it seems ids didn't get added for extern classes, however, now they are added. Since cpp.ConstPointer and cpp.Pointer both point to the same native type, the same id is added twice, which breaks an assumption made by this dump_classes function and causes the code to loop forever.

haxe/src/generators/cpp/gen/cppGenClassImplementation.ml

Lines 372 to 388 in aa3ecc5

	let rec dump_classes indent classes =
	match classes with
	| [] -> ()
	| [ c ] -> output_cpp (indent ^ "return inClassId==(int)" ^ txt c ^ ";\n")
	| [ c; c1 ] ->
	output_cpp
	(indent ^ "return inClassId==(int)" ^ txt c ^ " || inClassId==(int)" ^ txt c1 ^ ";\n")
	| _ ->
	let len = List.length classes in
	let mid = List.nth classes (len / 2) in
	let low, high = List.partition (fun e -> e <= mid) classes in
	output_cpp (indent ^ "if (inClassId<=(int)" ^ txt mid ^ ") {\n");
	dump_classes (indent ^ "\t") low;
	output_cpp (indent ^ "} else {\n");
	dump_classes (indent ^ "\t") high;
	output_cpp (indent ^ "}\n")
	in

@Aidan63 Do you think we should exclude @:nativeGen and extern classes from the id generation?

[Aidan63]

I think that makes sense, the ids are used for type checking so don't server a purpose for non haxe generated classes.