Task.java

package com.hol.panama.lab_5_optional;

import com.hol.panama.stdlib.stdio.stdio_h;

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

import static java.lang.foreign.ValueLayout.ADDRESS;
import static java.lang.foreign.ValueLayout.JAVA_INT;

public class Task {
    private static final FunctionDescriptor printfDescriptor =
            FunctionDescriptor.of(JAVA_INT, ADDRESS);
    static final Linker linker = Linker.nativeLinker();
    private static final SymbolLookup linkerLookup = linker.defaultLookup();
    private static final SymbolLookup systemLookup = SymbolLookup.loaderLookup();
    private static final SymbolLookup symbolLookup = name ->
            systemLookup.lookup(name).or(() -> linkerLookup.lookup(name));

    static final MemorySegment printfHandle = symbolLookup.lookup("printf").orElseThrow();

    static MethodHandle specializedPrintf(MemoryLayout... varargLayouts) {
        FunctionDescriptor specialized = printfDescriptor.asVariadic(varargLayouts);
        return linker.downcallHandle(printfHandle, specialized);
    }

    public static final MethodHandle WithInt = specializedPrintf(JAVA_INT);
    public static final MethodHandle WithString = specializedPrintf(ADDRESS);
    public static final MethodHandle WithStringAndInt = specializedPrintf(ADDRESS, JAVA_INT);

    public static void main(String[] args) throws Throwable {
        var one = "My name is %s.\n";
        var two = "Denis";
        var three = "I'm %dyo old.\n";
        var four = 31;
        var five = one + three;

        try (var ms = MemorySession.openConfined()) {
            var oneSegment = ms.allocateUtf8String(one);
            var twoSegment = ms.allocateUtf8String(two);
            var threeSegment = ms.allocateUtf8String(three);
            var fiveSegment = ms.allocateUtf8String(five);

            WithString.invoke(oneSegment.address(), twoSegment);
            WithInt.invoke(threeSegment.address(), four);
            WithStringAndInt.invoke(fiveSegment.address(), twoSegment, four);

            stdio_h.printf(oneSegment.address(), twoSegment.address());
            stdio_h.printf(threeSegment.address(), four);
            stdio_h.printf(fiveSegment.address(), twoSegment.address(), four);

            var allocator = SegmentAllocator.newNativeArena(
                    one.length() + 1 + two.length() + 1 +
                    three.length() + 1 + five.length() + 1,
                    ms
            );
            oneSegment = allocator.allocateUtf8String(one);
            twoSegment = allocator.allocateUtf8String(two);
            threeSegment = allocator.allocateUtf8String(three);
            fiveSegment = allocator.allocateUtf8String(five);

            stdio_h.printf(oneSegment.address(), twoSegment.address());
            stdio_h.printf(threeSegment.address(), four);
            stdio_h.printf(fiveSegment.address(), twoSegment.address(), four);
        }
    }
}