A small Cocoa app written purely in C using the objc runtime (part of a scrapped project)

dpc-game-stub.c

// compile with
// clang main.c -framework Cocoa

#include <ApplicationServices/ApplicationServices.h>
#include <CoreFoundation/CoreFoundation.h>
#include <CoreGraphics/CoreGraphics.h>
#include <objc/runtime.h>
#include <objc/message.h>
#include <stdio.h>

extern id NSApp;

int RunApplication(void) {
	// Create app event loop
	((id (*)(Class, SEL)) objc_msgSend)(objc_getClass("NSApplication"), sel_registerName("sharedApplication"));
	if (NSApp == NULL) {
		fprintf(stderr, "Failed to create NSApplication! Terminating...\n");
		return 2;
	}

	// yay private APIs
	// change process name to "Minecraft 2"
	CFBundleRef launchServicesBundle = CFBundleGetBundleWithIdentifier(CFSTR("com.apple.LaunchServices"));
	CFTypeRef asn = ((CFTypeRef (*)()) CFBundleGetFunctionPointerForName(launchServicesBundle, CFSTR("_LSGetCurrentApplicationASN")))();
	CFStringRef *displayNameKey = CFBundleGetDataPointerForName(launchServicesBundle, CFSTR("_kLSDisplayNameKey"));
	OSStatus setNameResult = ((OSStatus (*)(int, CFTypeRef, CFStringRef, CFStringRef, void*)) CFBundleGetFunctionPointerForName(launchServicesBundle, CFSTR("_LSSetApplicationInformationItem")))(
		-2, // yay magic values
		asn,
		*displayNameKey,
		CFSTR("Minecraft 2"),
		NULL);

	printf("setNameResult: %d\n", setNameResult); // 0 = noErr, https://www.osstatus.com for others

	// Initialize & close dummy window
	id window = class_createInstance(objc_getClass("NSWindow"), 0);
	window = ((id (*)(id, SEL, struct CGRect, int, int, BOOL)) objc_msgSend)(window, sel_registerName("initWithContentRect:styleMask:backing:defer:"), (struct CGRect) {0, 0, 0, 0}, 0, 2, false);
	((id (*)(id, SEL)) objc_msgSend)(window, sel_registerName("close"));

	// Start app event loop (to keep the program running)
	((id (*)(id, SEL)) objc_msgSend)(NSApp, sel_registerName("run"));
	return 0;
}

int main(int argc, char *argv[]) {
	id pool = class_createInstance(objc_getClass("NSAutoreleasePool"), 0);
	pool = ((id (*)(id, SEL)) objc_msgSend)(pool, sel_registerName("init"));
	if (pool == NULL) {
		fprintf(stderr, "Failed to create NSAutoreleasePool! Terminating...\n");
		return 1;
	}

	int code = RunApplication();

	((id (*)(id, SEL)) objc_msgSend)(pool, sel_registerName("drain"));

	return code;
}