Testing Project Panama in JDK 22

PanamaMain.java

package me.daniel.panama;

import java.lang.foreign.*;
import java.lang.invoke.MethodHandle;

public class PanamaMain {
	public static void main(String[] args) throws Throwable {
		Linker linker = Linker.nativeLinker();
		SymbolLookup libc = linker.defaultLookup();
		
		try(Arena arena = Arena.ofConfined()) {			
			tryPrintf(linker, libc).invoke(arena.allocateFrom("Hello from Panama!\n"));
			
			SymbolLookup user32 = SymbolLookup.libraryLookup("User32", arena);
			var mba = MessageBoxA(linker, user32);
			mba.invoke(
					MemorySegment.NULL,
					arena.allocateFrom("Hello from Panama!\nThis works well!"), 
					arena.allocateFrom("Title!"),
					0
			);
		}
		
	}
	
	private static MethodHandle tryPrintf(Linker linker, SymbolLookup libc) {
		FunctionDescriptor printfDesc = FunctionDescriptor.of(ValueLayout.JAVA_INT, AddressLayout.ADDRESS);
		return libc.find("printf")
				.map(seg -> linker.downcallHandle(seg, printfDesc))
				.orElseThrow();
	}
	
	private static MethodHandle MessageBoxA(Linker linker, SymbolLookup libc) {
		FunctionDescriptor mbaDesc = FunctionDescriptor.of(
				ValueLayout.JAVA_INT,
				AddressLayout.ADDRESS,
				AddressLayout.ADDRESS.withTargetLayout(MemoryLayout.sequenceLayout(1024, ValueLayout.JAVA_BYTE)),
				AddressLayout.ADDRESS.withTargetLayout(MemoryLayout.sequenceLayout(1024, ValueLayout.JAVA_BYTE)),
				AddressLayout.JAVA_INT
		);
		
		return libc.find("MessageBoxA")
				.map(seg -> linker.downcallHandle(seg, mbaDesc))
				.orElseThrow();
	}
}