[GR-66791] Introduce SingletonTraits annotation.

substratevm/src/com.oracle.svm.core.graal.llvm/src/com/oracle/svm/core/graal/llvm/LLVMFeature.java

@@ -30,7 +30,6 @@
 import org.graalvm.nativeimage.ImageSingletons;
 import org.graalvm.nativeimage.Platform;
 import org.graalvm.nativeimage.Platforms;
-import org.graalvm.nativeimage.hosted.Feature;
 
 import com.oracle.graal.pointsto.BigBang;
 import com.oracle.graal.pointsto.meta.AnalysisMethod;
@@ -52,9 +51,11 @@
 import com.oracle.svm.core.graal.llvm.util.LLVMOptions;
 import com.oracle.svm.core.graal.meta.RuntimeConfiguration;
 import com.oracle.svm.core.graal.snippets.NodeLoweringProvider;
-import com.oracle.svm.core.layeredimagesingleton.UnsupportedLayeredSingleton;
 import com.oracle.svm.core.option.HostedOptionKey;
 import com.oracle.svm.core.snippets.ExceptionUnwind;
+import com.oracle.svm.core.traits.BuiltinTraits;
+import com.oracle.svm.core.traits.SingletonLayeredInstallationKind;
+import com.oracle.svm.core.traits.SingletonTraits;
 import com.oracle.svm.core.util.UserError;
 import com.oracle.svm.hosted.FeatureImpl;
 import com.oracle.svm.hosted.c.codegen.CCompilerInvoker;
@@ -81,7 +82,8 @@
  */
 @AutomaticallyRegisteredFeature
 @Platforms({Platform.LINUX.class, Platform.DARWIN.class})
-public class LLVMFeature implements Feature, InternalFeature, UnsupportedLayeredSingleton {
+@SingletonTraits(access = BuiltinTraits.BuildtimeAccessOnly.class, layeredCallbacks = BuiltinTraits.NoLayeredCallbacks.class, layeredInstallationKind = SingletonLayeredInstallationKind.Disallowed.class)
+public class LLVMFeature implements InternalFeature {
 
     @Override
     public boolean isInConfiguration(IsInConfigurationAccess access) {

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/layeredimagesingleton/LayeredImageSingletonBuilderFlags.java

@@ -41,11 +41,7 @@ public enum LayeredImageSingletonBuilderFlags {
     /**
      * This singleton can be accessed from the buildtime.
      */
-    BUILDTIME_ACCESS,
-    /**
-     * This singleton should not have been created. Throw error if it is created.
-     */
-    UNSUPPORTED;
+    BUILDTIME_ACCESS;
 
     /*
      * Below are some common flag patterns.
@@ -57,15 +53,9 @@ public enum LayeredImageSingletonBuilderFlags {
 
     public static final EnumSet<LayeredImageSingletonBuilderFlags> ALL_ACCESS = EnumSet.of(RUNTIME_ACCESS, BUILDTIME_ACCESS);
 
-    public static boolean verifyImageBuilderFlags(LayeredImageSingleton singleton) {
-        EnumSet<LayeredImageSingletonBuilderFlags> flags = singleton.getImageBuilderFlags();
-
-        if (!(flags.contains(UNSUPPORTED) || flags.contains(BUILDTIME_ACCESS) || flags.contains(RUNTIME_ACCESS))) {
-            assert false : String.format("At least one of the following flags must be set: %s, %s, %s", UNSUPPORTED, BUILDTIME_ACCESS, RUNTIME_ACCESS);
-        }
-
-        if (flags.contains(UNSUPPORTED)) {
-            assert flags.equals(EnumSet.of(UNSUPPORTED)) : "Unsupported should be the only flag set " + flags;
+    public static boolean verifyImageBuilderFlags(Object singleton, EnumSet<LayeredImageSingletonBuilderFlags> flags) {
+        if (!(flags.contains(BUILDTIME_ACCESS) || flags.contains(RUNTIME_ACCESS))) {
+            assert false : String.format("At least one of the following flags must be set: %s, %s", BUILDTIME_ACCESS, RUNTIME_ACCESS);
         }
 
         if (singleton instanceof MultiLayeredImageSingleton || ApplicationLayerOnlyImageSingleton.isSingletonInstanceOf(singleton)) {

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/traits/BuiltinTraits.java

@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2025, 2025, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.svm.core.traits;
+
+import com.oracle.svm.core.layeredimagesingleton.ImageSingletonWriter;
+import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingleton;
+import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingletonBuilderFlags;
+
+/**
+ * Commonly used {@link SingletonTrait}s.
+ */
+public class BuiltinTraits {
+
+    /**
+     * Trait indicating this singleton should only be accessed from code executed at runtime.
+     */
+    public static final SingletonTrait RUNTIME_ONLY = new SingletonTrait(SingletonTraitKind.ACCESS,
+                    (SingletonAccess.Supplier) () -> LayeredImageSingletonBuilderFlags.RUNTIME_ACCESS_ONLY);
+
+    public static final class RuntimeAccessOnly extends SingletonAccessSupplier {
+        @Override
+        public SingletonTrait getAccessTrait() {
+            return RUNTIME_ONLY;
+        }
+    }
+
+    /**
+     * Trait indicating this singleton should only be accessed from the native image generator
+     * process and not at runtime.
+     */
+    public static final SingletonTrait BUILDTIME_ONLY = new SingletonTrait(SingletonTraitKind.ACCESS,
+                    (SingletonAccess.Supplier) () -> LayeredImageSingletonBuilderFlags.BUILDTIME_ACCESS_ONLY);
+
+    public static final class BuildtimeAccessOnly extends SingletonAccessSupplier {
+        @Override
+        public SingletonTrait getAccessTrait() {
+            return BUILDTIME_ONLY;
+        }
+    }
+
+    /**
+     * Trait indicating this singleton can be freely accessed both from the native image generator
+     * process and at runtime.
+     */
+    public static final SingletonTrait ALL_ACCESS = new SingletonTrait(SingletonTraitKind.ACCESS,
+                    (SingletonAccess.Supplier) () -> LayeredImageSingletonBuilderFlags.ALL_ACCESS);
+
+    public static final class AllAccess extends SingletonAccessSupplier {
+        @Override
+        public SingletonTrait getAccessTrait() {
+            return ALL_ACCESS;
+        }
+    }
+
+    /**
+     * Trait indicating this singleton has no special callbacks needed during layered builds.
+     */
+    public static final SingletonTrait NO_LAYERED_CALLBACKS = new SingletonTrait(SingletonTraitKind.LAYERED_CALLBACKS, new SingletonLayeredCallbacks() {
+        @Override
+        public LayeredImageSingleton.PersistFlags doPersist(ImageSingletonWriter writer, Object singleton) {
+            return LayeredImageSingleton.PersistFlags.NOTHING;
+        }
+    });
+
+    public static class NoLayeredCallbacks extends SingletonLayeredCallbacksSupplier {
+        @Override
+        public SingletonTrait getLayeredCallbacksTrait() {
+            return NO_LAYERED_CALLBACKS;
+        }
+    }
+
+    /**
+     * Trait indicating this singleton can be made more layer-aware in the future. See
+     * {@link SingletonTraitKind#DUPLICABLE} for more information.
+     */
+    public static final SingletonTrait DUPLICABLE_TRAIT = new SingletonTrait(SingletonTraitKind.DUPLICABLE, EmptyMetadata.EMPTY);
+
+    @SuppressWarnings("unused")
+    public static class Duplicable extends SingletonTraitsSupplier {
+        @Override
+        public SingletonTrait getTrait() {
+            return DUPLICABLE_TRAIT;
+        }
+    }
+}

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/layeredimagesingleton/RuntimeOnlyWrapper.java → substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/traits/EmptyMetadata.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2024, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2025, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -22,11 +22,15 @@
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
-package com.oracle.svm.core.layeredimagesingleton;
+package com.oracle.svm.core.traits;
 
 /**
- * This is used to wrap singletons which are only allowed to be accessed at runtime. When a
- * singleton wrapped with this is called during image build time an error is thrown.
+ * This metadata class is used for {@link SingletonTrait}s which need to store no additional
+ * content.
  */
-public record RuntimeOnlyWrapper(LayeredImageSingleton wrappedObject) {
+final class EmptyMetadata {
+    static final EmptyMetadata EMPTY = new EmptyMetadata();
+
+    private EmptyMetadata() {
+    }
 }

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/traits/InjectedSingletonLayeredCallbacks.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2025, 2025, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.svm.core.traits;
+
+import com.oracle.svm.core.layeredimagesingleton.ImageSingletonWriter;
+import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingleton;
+
+// GR-66792 remove once no custom persist actions exist
+
+/**
+ * Temporarily used to convert {@link LayeredImageSingleton} callbacks into {@link SingletonTrait}
+ * information.
+ */
+public final class InjectedSingletonLayeredCallbacks extends SingletonLayeredCallbacks {
+    final LayeredImageSingleton singleton;
+
+    public InjectedSingletonLayeredCallbacks(LayeredImageSingleton singleton) {
+        this.singleton = singleton;
+    }
+
+    @Override
+    public LayeredImageSingleton.PersistFlags doPersist(ImageSingletonWriter writer, Object obj) {
+        return singleton.preparePersist(writer);
+    }
+
+    public Class<?> getSingletonClass() {
+        return singleton.getClass();
+    }
+}

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/traits/SingletonAccess.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2025, 2025, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.svm.core.traits;
+
+import java.util.EnumSet;
+
+import com.oracle.svm.core.layeredimagesingleton.LayeredImageSingletonBuilderFlags;
+import com.oracle.svm.core.util.VMError;
+
+/**
+ * Metadata associated with the {@link SingletonTraitKind#ACCESS} trait. Describes when this
+ * singleton can be accessed (e.g., during the native image generator process and/or from within the
+ * generated code at runtime).
+ */
+public class SingletonAccess {
+    interface Supplier {
+        EnumSet<LayeredImageSingletonBuilderFlags> getAccessFlags();
+    }
+
+    public static EnumSet<LayeredImageSingletonBuilderFlags> getAccess(SingletonTrait trait) {
+        VMError.guarantee(trait.kind() == SingletonTraitKind.ACCESS);
+        return ((Supplier) trait.metadata()).getAccessFlags();
+    }
+}

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/traits/SingletonAccessSupplier.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2025, 2025, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.svm.core.traits;
+
+/**
+ * Represents a supplier of the {@link SingletonTraitKind#ACCESS} {@link SingletonTrait}. See
+ * {@link SingletonTraits} and {@link SingletonTraitKind#ACCESS} for more information.
+ */
+public abstract sealed class SingletonAccessSupplier permits BuiltinTraits.BuildtimeAccessOnly, BuiltinTraits.RuntimeAccessOnly, BuiltinTraits.AllAccess {
+    public abstract SingletonTrait getAccessTrait();
+}