fix reachability metadata drift

build.gradle.kts

@@ -14,6 +14,16 @@ java {
     withSourcesJar()
 }
 
+val graalvmHome = providers.environmentVariable("GRAALVM_HOME")
+    .orElse(providers.systemProperty("java.home"))
+val graalNativeImageJmod = graalvmHome.map {
+    file("$it/jmods/org.graalvm.nativeimage.jmod")
+}
+
+dependencies {
+    compileOnly(files(graalNativeImageJmod))
+}
+
 tasks.withType<JavaCompile>().configureEach {
     options.release.set(22)
 }

flake.nix

@@ -30,6 +30,7 @@
             else if pkgs ? jdk24_headless then pkgs.jdk24_headless
             else if pkgs ? jdk24 then pkgs.jdk24
             else pkgs.jdk;
+          graalvm = pkgs.graalvmPackages.graalvm-ce;
 
           version = "0.1.0-SNAPSHOT";
           groupPath = "dev/jlibghostty";
@@ -79,7 +80,7 @@
               cp "$ghostty_lib" "$bundled_lib"
 
               find src/main/java -name '*.java' | sort > build/sources.txt
-              javac --release 22 -d build/classes @build/sources.txt
+              javac --release 22 --module-path ${graalvm}/jmods -d build/classes @build/sources.txt
 
               jar --create \
                 --file build/${artifactId}-${version}.jar \
@@ -149,14 +150,17 @@ POM
             else if pkgs ? jdk24_headless then pkgs.jdk24_headless
             else if pkgs ? jdk24 then pkgs.jdk24
             else pkgs.jdk;
+          graalvm = pkgs.graalvmPackages.graalvm-ce;
           ghosttyVt = ghostty.packages.${system}.libghostty-vt;
         in
         {
           default = pkgs.mkShell {
             packages =
-              [ jdk pkgs.gradle ]
+              [ jdk pkgs.gradle graalvm ]
               ++ pkgs.lib.optional (pkgs ? jextract) pkgs.jextract;
 
+            GRAALVM_HOME = "${graalvm}";
+
             JLIBGHOSTTY_LIBRARY =
               if pkgs.stdenv.hostPlatform.isDarwin
               then "${ghosttyVt}/lib/libghostty-vt.dylib"

src/main/java/dev/jlibghostty/GhosttyForeignRegistrationFeature.java

@@ -0,0 +1,134 @@
+package dev.jlibghostty;
+
+import org.graalvm.nativeimage.hosted.Feature;
+import org.graalvm.nativeimage.hosted.RuntimeForeignAccess;
+
+import java.lang.foreign.AddressLayout;
+import java.lang.foreign.FunctionDescriptor;
+import java.lang.foreign.GroupLayout;
+import java.lang.foreign.Linker;
+import java.lang.foreign.MemoryLayout;
+import java.lang.foreign.ValueLayout;
+
+/**
+ * Registers FFM descriptors for GraalVM releases that do not consume
+ * foreign.downcalls from reachability-metadata.json.
+ */
+public final class GhosttyForeignRegistrationFeature implements Feature {
+    private static final Linker LINKER = Linker.nativeLinker();
+    private static final AddressLayout C_POINTER = (AddressLayout) LINKER.canonicalLayouts().get("void*");
+    private static final ValueLayout.OfBoolean C_BOOL = (ValueLayout.OfBoolean) LINKER.canonicalLayouts().get("bool");
+    private static final ValueLayout.OfShort C_SHORT = (ValueLayout.OfShort) LINKER.canonicalLayouts().get("short");
+    private static final ValueLayout.OfInt C_INT = (ValueLayout.OfInt) LINKER.canonicalLayouts().get("int");
+    private static final ValueLayout.OfLong C_LONG_LONG = (ValueLayout.OfLong) LINKER.canonicalLayouts().get("long long");
+    private static final ValueLayout.OfLong C_SIZE_T = sizeTLayout();
+
+    private static final GroupLayout TERMINAL_OPTIONS = MemoryLayout.structLayout(
+        C_SHORT.withName("cols"),
+        C_SHORT.withName("rows"),
+        MemoryLayout.paddingLayout(4),
+        C_SIZE_T.withName("max_scrollback")
+    );
+
+    private static final GroupLayout SIZE_REPORT_SIZE = MemoryLayout.structLayout(
+        C_SHORT.withName("rows"),
+        C_SHORT.withName("columns"),
+        C_INT.withName("cell_width"),
+        C_INT.withName("cell_height")
+    );
+
+    private static final GroupLayout SCROLL_VIEWPORT = MemoryLayout.structLayout(
+        C_INT.withName("tag"),
+        MemoryLayout.paddingLayout(4),
+        MemoryLayout.structLayout(
+            C_LONG_LONG.withName("delta"),
+            C_LONG_LONG.withName("padding")
+        ).withName("value")
+    );
+
+    private static final GroupLayout MOUSE_POSITION = MemoryLayout.structLayout(
+        ValueLayout.JAVA_FLOAT.withName("x"),
+        ValueLayout.JAVA_FLOAT.withName("y")
+    );
+
+    private static final GroupLayout FORMATTER_SCREEN_EXTRA = MemoryLayout.structLayout(
+        C_SIZE_T.withName("size"),
+        C_BOOL.withName("cursor"),
+        C_BOOL.withName("style"),
+        C_BOOL.withName("hyperlink"),
+        C_BOOL.withName("protection"),
+        C_BOOL.withName("kitty_keyboard"),
+        C_BOOL.withName("charsets"),
+        MemoryLayout.paddingLayout(2)
+    );
+
+    private static final GroupLayout FORMATTER_TERMINAL_EXTRA = MemoryLayout.structLayout(
+        C_SIZE_T.withName("size"),
+        C_BOOL.withName("palette"),
+        C_BOOL.withName("modes"),
+        C_BOOL.withName("scrolling_region"),
+        C_BOOL.withName("tabstops"),
+        C_BOOL.withName("pwd"),
+        C_BOOL.withName("keyboard"),
+        MemoryLayout.paddingLayout(2),
+        FORMATTER_SCREEN_EXTRA.withName("screen")
+    );
+
+    private static final GroupLayout FORMATTER_TERMINAL_OPTIONS = MemoryLayout.structLayout(
+        C_SIZE_T.withName("size"),
+        C_INT.withName("emit"),
+        C_BOOL.withName("unwrap"),
+        C_BOOL.withName("trim"),
+        MemoryLayout.paddingLayout(2),
+        FORMATTER_TERMINAL_EXTRA.withName("extra"),
+        C_POINTER.withName("selection")
+    );
+
+    @Override
+    public void duringSetup(DuringSetupAccess access) {
+        downcall(FunctionDescriptor.of(C_INT, C_POINTER, C_POINTER, TERMINAL_OPTIONS));
+        downcall(FunctionDescriptor.ofVoid(C_POINTER));
+        downcall(FunctionDescriptor.of(C_INT, C_POINTER, C_SHORT, C_SHORT, C_INT, C_INT));
+        downcall(FunctionDescriptor.ofVoid(C_POINTER, SCROLL_VIEWPORT));
+        downcall(FunctionDescriptor.ofVoid(C_POINTER, C_POINTER, C_SIZE_T));
+        downcall(FunctionDescriptor.of(C_INT, C_POINTER, C_INT, C_POINTER));
+        downcall(FunctionDescriptor.of(C_BOOL, C_POINTER, C_SIZE_T));
+        downcall(FunctionDescriptor.of(C_INT, C_POINTER, C_SIZE_T, C_BOOL, C_POINTER, C_SIZE_T, C_POINTER));
+        downcall(FunctionDescriptor.of(C_INT, C_INT, C_POINTER));
+        downcall(FunctionDescriptor.of(C_POINTER));
+        downcall(FunctionDescriptor.of(C_INT, C_INT, C_POINTER, C_SIZE_T, C_POINTER));
+        downcall(FunctionDescriptor.of(C_INT, C_INT, C_INT, C_POINTER, C_SIZE_T, C_POINTER));
+        downcall(FunctionDescriptor.of(C_INT, C_INT, SIZE_REPORT_SIZE, C_POINTER, C_SIZE_T, C_POINTER));
+        downcall(FunctionDescriptor.of(C_INT, C_POINTER, C_POINTER, C_POINTER, FORMATTER_TERMINAL_OPTIONS));
+        downcall(FunctionDescriptor.of(C_INT, C_POINTER, C_POINTER, C_SIZE_T, C_POINTER));
+        downcall(FunctionDescriptor.of(C_INT, C_POINTER, C_POINTER));
+        downcall(FunctionDescriptor.of(C_BOOL, C_POINTER));
+        downcall(FunctionDescriptor.of(C_INT, C_POINTER, C_POINTER, C_POINTER, C_POINTER));
+        downcall(FunctionDescriptor.ofVoid(C_POINTER, C_INT));
+        downcall(FunctionDescriptor.ofVoid(C_POINTER, C_SHORT));
+        downcall(FunctionDescriptor.ofVoid(C_POINTER, MOUSE_POSITION));
+        downcall(FunctionDescriptor.ofVoid(C_POINTER, C_INT, C_POINTER));
+        downcall(FunctionDescriptor.ofVoid(C_POINTER, C_POINTER));
+        downcall(FunctionDescriptor.of(C_INT, C_POINTER, C_POINTER, C_POINTER, C_SIZE_T, C_POINTER));
+        downcall(FunctionDescriptor.of(C_POINTER, C_POINTER, C_INT));
+
+        upcall(FunctionDescriptor.ofVoid(C_POINTER, C_POINTER, C_POINTER, C_SIZE_T));
+        upcall(FunctionDescriptor.of(C_BOOL, C_POINTER, C_POINTER, C_POINTER));
+    }
+
+    private static void downcall(FunctionDescriptor descriptor) {
+        RuntimeForeignAccess.registerForDowncall(descriptor);
+    }
+
+    private static void upcall(FunctionDescriptor descriptor) {
+        RuntimeForeignAccess.registerForUpcall(descriptor);
+    }
+
+    private static ValueLayout.OfLong sizeTLayout() {
+        ValueLayout layout = (ValueLayout) LINKER.canonicalLayouts().get("size_t");
+        if (layout.byteSize() != Long.BYTES) {
+            throw new UnsupportedOperationException("jlibghostty currently supports 64-bit platforms only");
+        }
+        return (ValueLayout.OfLong) layout;
+    }
+}

src/main/java/module-info.java

@@ -1,3 +1,5 @@
 module dev.jlibghostty {
+    requires static org.graalvm.nativeimage;
+
     exports dev.jlibghostty;
 }

src/main/resources/META-INF/native-image/dev.jlibghostty/jlibghostty/native-image.properties

@@ -0,0 +1,4 @@
+Args = --features=dev.jlibghostty.GhosttyForeignRegistrationFeature \
+       -H:+UnlockExperimentalVMOptions \
+       -H:+ForeignAPISupport \
+       --enable-native-access=ALL-UNNAMED,dev.jlibghostty