Double throw generated in cpp Reflect.callMethod

[Aidan63]

A few months ago I started updating hxcpp's internal throw functions to use the C++ [[noreturn]] annotation to avoid needing to have return null() peppered around to make C++ compilers happy, but I ran into an issue I forgot about until now.

The generated Reflect.callMethod C++ seems to contain doubled up throws in it.

 ::Dynamic Reflect_obj::callMethod( ::Dynamic o, ::Dynamic func,::cpp::VirtualArray args){
            	HX_STACKFRAME(&_hx_pos_998f5550039526d3_54_callMethod)
HXLINE(  55)		if ((::hx::IsNotNull( func ) && ::hx::IsEq( func->__GetType(),3 ))) {
HXLINE(  56)			if (::hx::IsNull( o )) {
HXLINE(  57)				HX_STACK_DO_THROW(HX_STACK_DO_THROW(HX_INVALID_OBJECT));
            			}
HXLINE(  58)			func = o->__Field(func,::hx::paccDynamic);
            		}
HXLINE(  60)		if (::hx::IsNull( func )) {
HXLINE(  61)			HX_STACK_DO_THROW(HX_STACK_DO_THROW(HX_NULL_FUNCTION_POINTER));
            		}
HXLINE(  62)		func->__SetThis(o);
HXLINE(  63)		return func->__Run(args);
            	}

Initially I thought this might be a bug with gencpp but I don't think it is, looking at the pretty dump of the code the double throws appears there as well.

@:keep @:directlyUsed @:used @:coreApi @:analyzer(ignore)
class Reflect {

	@:has_untyped
	public static function callMethod(o:Dynamic, func:haxe.Function, args:Array<Dynamic>) {
		if ((func != null && func.__GetType() == 3)) {
			if ((o == null)) throw throw cpp.ErrorConstants.HX_INVALID_OBJECT;
			func = o.__Field(func, __cpp__("::hx::paccDynamic"));
		};
		if ((func == null)) throw throw cpp.ErrorConstants.HX_NULL_FUNCTION_POINTER;
		func.__SetThis(o);
		return func.__Run(args);
	}
}

These double throws does not appear in the original Reflect.callMethod and I have not been able to re-create this outside of this function yet.

public static function callMethod(o:Dynamic, func:haxe.Constraints.Function, args:Array<Dynamic>):Dynamic
	untyped {
		if (func != null && func.__GetType() == ObjectType.vtString) {
			if (o == null)
				throw cpp.ErrorConstants.invalidObject;
			func = o.__Field(func, untyped __cpp__("::hx::paccDynamic"));
		}
		if (func == null)
			throw cpp.ErrorConstants.nullFunctionPointer;
		untyped func.__SetThis(o);
		return untyped func.__Run(args);
	
	}

[Simn]

This comes from the @:analyzer(ignore) on hxcpp's Reflect class, and can be easily reproduced:

@:analyzer(ignore)
function main() {
	throw "foo";
}

Dump:

	@:keep @:analyzer(ignore)
	public static function main() {
		throw throw "foo";
	}

Will check where this goes wrong.