Implement xpc_main

However, bundled XPC services still don't work properly.

The problem is that bundled XPC service support needs to be implemented in launchd.
The open-source launchd sources are severely outdated, much like CoreFoundation.
The new launchd is based on libxpc and is closed-source.
We probably don't want to completely rewrite launchd, but at the very least, we do need to add support for new XPC-based features.

CMakeLists.txt

@@ -18,6 +18,7 @@ add_compile_definitions(
 
 add_compile_options(
 	-Wno-extern-initializer
+	-Wno-gnu-folding-constant
 )
 
 add_compile_options(

internal-include/xpc/objects/bundle.h

@@ -32,6 +32,9 @@ struct xpc_bundle_s {
 // this API is modeled after NSBundle
 // (but we've added lots of non-NSBundle extensions)
 
+// NOTE: differs from NSBundle by returning a new bundle every time it's called
+@property(class, readonly, copy) XPC_CLASS(bundle)* mainBundle;
+
 @property(strong) XPC_CLASS(string)* bundlePath;
 @property(strong) XPC_CLASS(string)* executablePath;
 @property(strong) XPC_CLASS(dictionary)* infoDictionary;

src/bundle.m

@@ -20,6 +20,15 @@ OS_OBJECT_NONLAZY_CLASS
 
 XPC_CLASS_HEADER(bundle);
 
++ (XPC_CLASS(bundle)*)mainBundle
+{
+	char* exec_path = xpc_copy_main_executable_path();
+	if (!exec_path) {
+		return NULL;
+	}
+	return [[[[self class] alloc] initWithPath: [XPC_CLASS(string) stringWithUTF8StringNoCopy: exec_path freeWhenDone: YES]] autorelease];
+}
+
 + (BOOL)pathIsBundleRoot: (XPC_CLASS(string)*)path
 {
 	// frameworks are special
@@ -361,11 +370,7 @@ xpc_object_t xpc_bundle_create_from_origin(unsigned int origin, const char* path
 XPC_EXPORT
 xpc_object_t xpc_bundle_create_main(void) {
 	@autoreleasepool {
-		char* exec_path = xpc_copy_main_executable_path();
-		if (!exec_path) {
-			return NULL;
-		}
-		return [[XPC_CLASS(bundle) alloc] initWithPath: [XPC_CLASS(string) stringWithUTF8StringNoCopy: exec_path freeWhenDone: YES]];
+		return [[XPC_CLASS(bundle) mainBundle] retain];
 	}
 };
 

src/runtime.m

@@ -1,6 +1,35 @@
 #import <xpc/xpc.h>
 #import <xpc/util.h>
 
+#import <xpc/private/bundle.h>
+
+#import <xpc/objects/bundle.h>
+#import <xpc/objects/dictionary.h>
+#import <xpc/objects/string.h>
+#import <xpc/objects/connection.h>
+
+#import <objc/runtime.h>
+
+#import <Foundation/NSRunLoop.h>
+#import <dlfcn.h>
+#import <AppKit/NSApplication.h>
+#import <crt_externs.h>
+
+#define INFO_DICT_IDENTIFIER_KEY "CFBundleIdentifier"
+#define INFO_DICT_PACKAGE_TYPE_KEY "CFBundlePackageType"
+
+#define XPC_SERVICE_DICT_RUNLOOP_TYPE_KEY "RunLoopType"
+
+#define XPC_PACKAGE_TYPE "XPC!"
+
+OS_ENUM(xpc_service_runloop_type, uint8_t,
+	xpc_service_runloop_type_invalid,
+	xpc_service_runloop_type_dispatch,
+	xpc_service_runloop_type_nsrunloop,
+	xpc_service_runloop_type_nsapplicationmain,
+	xpc_service_runloop_type_uiapplicationmain,
+);
+
 XPC_EXPORT
 xpc_object_t _xpc_runtime_get_entitlements_data(void) {
 	// returns a data object
@@ -21,10 +50,111 @@ bool _xpc_runtime_is_app_sandboxed(void) {
 	return false;
 };
 
+static xpc_service_runloop_type_t runloop_name_to_type(const char* name) {
+	if (!name) {
+		return xpc_service_runloop_type_dispatch;
+	} else if (strcmp(name, "_UIApplicationMain") == 0) {
+		return xpc_service_runloop_type_uiapplicationmain;
+	} else if (strcmp(name, "_NSApplicationMain") == 0) {
+		return xpc_service_runloop_type_nsapplicationmain;
+	} else if (strcmp(name, "NSRunLoop") == 0 || strcmp(name, "_WebKit") == 0) {
+		return xpc_service_runloop_type_nsrunloop;
+	} else {
+		return xpc_service_runloop_type_dispatch;
+	}
+};
+
 XPC_EXPORT
 void xpc_main(xpc_connection_handler_t handler) {
-	xpc_stub();
-	abort();
+	@autoreleasepool {
+		XPC_CLASS(bundle)* mainBundle = [XPC_CLASS(bundle) mainBundle];
+		XPC_CLASS(string)* identifier = nil;
+		xpc_service_runloop_type_t runloopType = xpc_service_runloop_type_invalid;
+		XPC_CLASS(connection)* server = nil;
+
+		if (!mainBundle) {
+			xpc_abort("failed to retrieve main bundle information");
+		}
+
+		[mainBundle resolve];
+		if (mainBundle.error != 0) {
+			xpc_abort("failed to resolve main bundle information");
+		}
+
+		if (![[mainBundle.infoDictionary stringForKey: INFO_DICT_PACKAGE_TYPE_KEY] isEqualToString: XPC_PACKAGE_TYPE]) {
+			xpc_abort("main bundle was not an XPC service bundle");
+		}
+
+		identifier = [mainBundle.infoDictionary stringForKey: INFO_DICT_IDENTIFIER_KEY];
+		if (!identifier) {
+			xpc_abort("failed to determine main bundle identifier");
+		}
+
+		server = [[XPC_CLASS(connection) alloc] initAsServerForService: identifier.UTF8String queue: NULL];
+		if (!server) {
+			xpc_abort("failed to create server connection");
+		}
+
+		server.eventHandler = ^(xpc_object_t object) {
+			xpc_type_t type = xpc_get_type(object);
+			if (type == (xpc_type_t)XPC_TYPE_CONNECTION) {
+				handler(XPC_CAST(connection, object));
+			} else if (type == (xpc_type_t)XPC_TYPE_ERROR) {
+				if (object == XPC_ERROR_TERMINATION_IMMINENT) {
+					xpc_log(XPC_LOG_WARNING, "someone wants us to terminate");
+				} else {
+					xpc_abort("unexpected error receive in managed server event handler: %s", xpc_copy_description(object));
+				}
+			} else {
+				xpc_abort("invalid object received in managed server event handler: %s", xpc_copy_description(object));
+			}
+		};
+
+		// schedule the connection to be activated once the runloop is kicked off
+		dispatch_async(dispatch_get_main_queue(), ^{
+			[server activate];
+		});
+
+		runloopType = runloop_name_to_type([XPC_CAST(dictionary, xpc_bundle_get_xpcservice_dictionary(mainBundle)) stringForKey: XPC_SERVICE_DICT_RUNLOOP_TYPE_KEY].UTF8String);
+
+		switch (runloopType) {
+			case xpc_service_runloop_type_dispatch: {
+				dispatch_main();
+			} break;
+
+			case xpc_service_runloop_type_nsrunloop: {
+				Class NSRunLoopClass = objc_getClass("NSRunLoop");
+				if (!NSRunLoopClass) {
+					xpc_abort("failed to load NSRunLoop class");
+				}
+				[[NSRunLoopClass currentRunLoop] run];
+			} break;
+
+			case xpc_service_runloop_type_nsapplicationmain: {
+				void* appkit = dlopen("/System/Library/Frameworks/AppKit.framework/AppKit", RTLD_LAZY);
+				if (!appkit) {
+					xpc_abort("failed to load AppKit");
+				}
+
+				__typeof__(NSApplicationMain)* NSApplicationMain_ptr = dlsym(appkit, "NSApplicationMain");
+				if (!NSApplicationMain_ptr) {
+					xpc_abort("failed to load NSApplicationMain from AppKit");
+				}
+
+				NSApplicationMain_ptr(*_NSGetArgc(), (const char**)*_NSGetArgv());
+			} break;
+
+			case xpc_service_runloop_type_uiapplicationmain: {
+				xpc_abort("UIApplicationMain runloop not implemented");
+			} break;
+
+			default: {
+				xpc_abort("failed to determine runloop type");
+			} break;
+		}
+	}
+
+	xpc_abort("runloop returned");
 };
 
 XPC_EXPORT

test/CMakeLists.txt

@@ -1,4 +1,5 @@
 add_subdirectory(launchd-service)
+add_subdirectory(bundled-service)
 
 set(TEST_SOURCES
 	array.m

test/bundled-service/CMakeLists.txt

@@ -0,0 +1,24 @@
+add_darling_executable(libxpc_test_bundled_service service.c)
+
+set_target_properties(libxpc_test_bundled_service PROPERTIES
+	OUTPUT_NAME "XPCBundledService"
+)
+
+target_link_libraries(libxpc_test_bundled_service
+	xpc_static
+	objc
+)
+
+install(
+	TARGETS
+		libxpc_test_bundled_service
+	DESTINATION
+		libexec/darling/usr/libexec/test/xpc/XPCBundledService.xpc/Contents/MacOS
+)
+
+install(
+	FILES
+		Info.plist
+	DESTINATION
+		libexec/darling/usr/libexec/test/xpc/XPCBundledService.xpc/Contents
+)

test/bundled-service/Info.plist

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDisplayName</key>
+	<string>XPC Bundled Service</string>
+	<key>CFBundleExecutable</key>
+	<string>XPCBundledService</string>
+	<key>CFBundleIdentifier</key>
+	<string>org.darlinghq.libxpc.test.bundled-service</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>XPCBundledService</string>
+	<key>CFBundlePackageType</key>
+	<string>XPC!</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>XPCService</key>
+	<dict>
+		<key>ServiceType</key>
+		<string>Application</string>
+	</dict>
+</dict>
+</plist>

test/bundled-service/service.c

@@ -0,0 +1,19 @@
+#include <xpc/xpc.h>
+#include <xpc/connection.h>
+
+static void connection_handler(xpc_connection_t connection) {
+	printf("Got a new connection: %p\n", connection);
+
+	xpc_connection_set_event_handler(connection, ^(xpc_object_t object) {
+		char* desc = xpc_copy_description(object);
+		xpc_type_t type = xpc_get_type(object);
+		printf("Recevied %s from connection %p: %s\n", (type == (xpc_type_t)XPC_TYPE_DICTIONARY) ? "message" : ((type == (xpc_type_t)XPC_TYPE_ERROR) ? "error" : "unexpected object"), connection, desc);
+		free(desc);
+	});
+	xpc_connection_resume(connection);
+};
+
+int main(int argc, char** argv) {
+	xpc_main(connection_handler);
+	return 0;
+};