Support dynamic proxy classes with (and as) predefined classes.

substratevm/src/com.oracle.svm.agent/src/com/oracle/svm/agent/BreakpointInterceptor.java

@@ -75,6 +75,7 @@
 
 import com.oracle.svm.agent.stackaccess.InterceptedState;
 import com.oracle.svm.agent.tracing.core.Tracer;
+import com.oracle.svm.configure.trace.AccessAdvisor;
 import com.oracle.svm.core.c.function.CEntryPointOptions;
 import com.oracle.svm.core.util.VMError;
 import com.oracle.svm.jni.JNIObjectHandles;
@@ -997,6 +998,11 @@ private static void onClassFileLoadHook(@SuppressWarnings("unused") JvmtiEnv jvm
         if (loader.equal(nullHandle())) { // boot class loader
             return;
         }
+        String className = fromCString(name);
+        if (className != null && AccessAdvisor.PROXY_CLASS_NAME_PATTERN.matcher(className).matches()) {
+            // Proxy classes are handled using a different mechanism, so we ignore them here
+            return;
+        }
         for (JNIObjectHandle builtinLoader : builtinClassLoaders) {
             if (jniFunctions().getIsSameObject().invoke(jni, loader, builtinLoader)) {
                 return;
@@ -1007,7 +1013,7 @@ private static void onClassFileLoadHook(@SuppressWarnings("unused") JvmtiEnv jvm
         }
         byte[] data = new byte[classDataLen];
         CTypeConversion.asByteBuffer(classData, classDataLen).get(data);
-        tracer.traceCall("classloading", "onClassFileLoadHook", null, null, null, null, state.getFullStackTraceOrNull(), fromCString(name), data);
+        tracer.traceCall("classloading", "onClassFileLoadHook", null, null, null, null, state.getFullStackTraceOrNull(), className, data);
     }
 
     private static final CEntryPointLiteral<CFunctionPointer> onBreakpointLiteral = CEntryPointLiteral.create(BreakpointInterceptor.class, "onBreakpoint",

substratevm/src/com.oracle.svm.agent/src/com/oracle/svm/agent/tracing/TraceFileWriter.java

@@ -96,10 +96,10 @@ private static void printArray(JsonWriter json, Object[] array) throws IOExcepti
     }
 
     private static void printValue(JsonWriter json, Object value) throws IOException {
-        String s;
+        String s = null;
         if (value instanceof byte[]) {
             s = Base64.getEncoder().encodeToString((byte[]) value);
-        } else {
+        } else if (value != null) {
             s = value.toString();
         }
         json.quote(s);

substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/trace/AccessAdvisor.java

@@ -24,6 +24,8 @@
  */
 package com.oracle.svm.configure.trace;
 
+import java.util.regex.Pattern;
+
 import org.graalvm.compiler.phases.common.LazyValue;
 
 import com.oracle.svm.configure.filters.RuleNode;
@@ -33,6 +35,12 @@
  * {@code AccessVerifier} classes which accesses to ignore when the agent is in restriction mode.
  */
 public final class AccessAdvisor {
+    /**
+     * {@link java.lang.reflect.Proxy} generated classes can be put in arbitrary packages depending
+     * on the visibility and module of the interfaces they implement, so we can only match against
+     * their class name using this pattern (which we hope isn't used by anything else).
+     */
+    public static final Pattern PROXY_CLASS_NAME_PATTERN = Pattern.compile("^(.+[/.])?\\$Proxy[0-9]+$");
 
     /** Filter to ignore accesses that <em>originate in</em> methods of these internal classes. */
     private static final RuleNode internalCallerFilter;
@@ -154,7 +162,10 @@ public boolean shouldIgnore(LazyValue<String> queriedClass, LazyValue<String> ca
         if (callerClass.get() == null && queriedClass.get() != null && !accessWithoutCallerFilter.treeIncludes(queriedClass.get())) {
             return true;
         }
-        return accessFilter != null && queriedClass.get() != null && !accessFilter.treeIncludes(queriedClass.get());
+        if (accessFilter != null && queriedClass.get() != null && !accessFilter.treeIncludes(queriedClass.get())) {
+            return true;
+        }
+        return heuristicsEnabled && queriedClass.get() != null && PROXY_CLASS_NAME_PATTERN.matcher(queriedClass.get()).matches();
     }
 
     public boolean shouldIgnoreJniMethodLookup(LazyValue<String> queriedClass, LazyValue<String> name, LazyValue<String> signature, LazyValue<String> callerClass) {

substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/trace/JniProcessor.java

@@ -71,7 +71,7 @@ void processEntry(Map<String, ?> entry) {
             if (!advisor.shouldIgnore(lazyValue(forNameString), callerClassLazyValue)) {
                 if (function.equals("FindClass")) {
                     configuration.getOrCreateType(forNameString);
-                } else if (!lookupName.startsWith("com/sun/proxy/$Proxy")) { // DefineClass
+                } else if (!AccessAdvisor.PROXY_CLASS_NAME_PATTERN.matcher(lookupName).matches()) { // DefineClass
                     logWarning("Unsupported JNI function DefineClass used to load class " + forNameString);
                 }
             }

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/DynamicHub.java

@@ -100,8 +100,8 @@
 public final class DynamicHub implements JavaKind.FormatWithToString, AnnotatedElement, java.lang.reflect.Type, GenericDeclaration, Serializable,
                 Target_java_lang_invoke_TypeDescriptor_OfField<DynamicHub>, Target_java_lang_constant_Constable {
 
-    /** Marker that a value must be obtained from the companion object. */
-    private static final Object FROM_COMPANION = new Object();
+    /** Marker value for {@link #classLoader}. */
+    static final Object NO_CLASS_LOADER = new Object();
 
     @Substitute //
     @TargetElement(onlyWith = JDK11OrLater.class) //
@@ -362,7 +362,7 @@ public DynamicHub(Class<?> hostedJavaClass, String name, HubType hubType, Refere
         this.componentType = componentHub;
         this.sourceFileName = sourceFileName;
         this.modifiers = modifiers;
-        this.classLoader = PredefinedClassesSupport.isPredefined(hostedJavaClass) ? FROM_COMPANION : classLoader;
+        this.classLoader = PredefinedClassesSupport.isPredefined(hostedJavaClass) ? NO_CLASS_LOADER : classLoader;
         setFlag(IS_HIDDED_FLAG_BIT, isHidden);
         setFlag(IS_RECORD_FLAG_BIT, isRecord);
         this.nestHost = nestHost;
@@ -741,14 +741,14 @@ public InputStream getResourceAsStream(String resourceName) {
 
     @Substitute
     private ClassLoader getClassLoader0() {
-        if (classLoader == FROM_COMPANION) {
+        if (classLoader == NO_CLASS_LOADER) {
             return companion.get().getClassLoader();
         }
         return (ClassLoader) classLoader;
     }
 
     public boolean isLoaded() {
-        return classLoader != FROM_COMPANION || (companion.isPresent() && companion.get().hasClassLoader());
+        return classLoader != NO_CLASS_LOADER || (companion.isPresent() && companion.get().hasClassLoader());
     }
 
     void setClassLoaderAtRuntime(ClassLoader loader) {

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/DynamicHubCompanion.java

@@ -24,6 +24,8 @@
  */
 package com.oracle.svm.core.hub;
 
+import static com.oracle.svm.core.hub.DynamicHub.NO_CLASS_LOADER;
+
 import java.security.ProtectionDomain;
 
 import com.oracle.svm.core.util.VMError;
@@ -33,7 +35,7 @@ public final class DynamicHubCompanion {
     private final DynamicHub hub;
 
     private String packageName;
-    private ClassLoader classLoader;
+    private Object classLoader = NO_CLASS_LOADER;
     private ProtectionDomain protectionDomain;
 
     public DynamicHubCompanion(DynamicHub hub) {
@@ -48,17 +50,17 @@ public String getPackageName() {
     }
 
     boolean hasClassLoader() {
-        return classLoader != null;
+        return classLoader != NO_CLASS_LOADER;
     }
 
     public ClassLoader getClassLoader() {
-        ClassLoader loader = classLoader;
-        VMError.guarantee(loader != null);
-        return loader;
+        Object loader = classLoader;
+        VMError.guarantee(loader != NO_CLASS_LOADER);
+        return (ClassLoader) loader;
     }
 
     public void setClassLoader(ClassLoader loader) {
-        VMError.guarantee(classLoader == null && loader != null);
+        VMError.guarantee(classLoader == NO_CLASS_LOADER && loader != NO_CLASS_LOADER);
         classLoader = loader;
     }
 

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/PredefinedClassesSupport.java

@@ -33,7 +33,6 @@
 import java.util.concurrent.locks.ReentrantLock;
 
 import org.graalvm.collections.EconomicMap;
-import org.graalvm.collections.UnmodifiableEconomicMap;
 import org.graalvm.compiler.api.replacements.Fold;
 import org.graalvm.compiler.options.Option;
 import org.graalvm.nativeimage.ImageSingletons;
@@ -45,6 +44,7 @@
 import com.oracle.svm.core.option.SubstrateOptionsParser;
 import com.oracle.svm.core.util.ImageHeapMap;
 import com.oracle.svm.core.util.VMError;
+import com.oracle.svm.util.ClassUtil;
 
 public final class PredefinedClassesSupport {
     public static final class Options {
@@ -104,6 +104,15 @@ public static void registerClass(String hash, Class<?> clazz) {
         }
     }
 
+    /**
+     * Register a class that cannot be loaded via a byte array of its class data, only with
+     * {@link #loadClass(ClassLoader, ProtectionDomain, Class)} or {@link #loadClassIfNotLoaded}.
+     */
+    @Platforms(Platform.HOSTED_ONLY.class)
+    public static void registerClass(Class<?> clazz) {
+        singleton().predefinedClasses.add(clazz);
+    }
+
     @Platforms(Platform.HOSTED_ONLY.class)
     public static boolean isPredefined(Class<?> clazz) {
         return singleton().predefinedClasses.contains(clazz);
@@ -120,21 +129,37 @@ public static Class<?> loadClass(ClassLoader classLoader, String expectedName, b
             throw VMError.unsupportedFeature("Defining a class from new bytecodes at run time is not supported. Class " + name +
                             " with hash " + hash + " was not provided during the image build. Please see BuildConfiguration.md.");
         }
-        return singleton().load(classLoader, protectionDomain, clazz);
+        loadClass(classLoader, protectionDomain, clazz);
+        return clazz;
+    }
+
+    public static void loadClass(ClassLoader classLoader, ProtectionDomain protectionDomain, Class<?> clazz) {
+        boolean loaded = loadClassIfNotLoaded(classLoader, protectionDomain, clazz);
+        if (!loaded) {
+            if (classLoader == clazz.getClassLoader()) {
+                throw new LinkageError("loader " + classLoader + " attempted duplicate class definition for " + clazz.getName() + " defined by " + clazz.getClassLoader());
+            } else {
+                throw VMError.unsupportedFeature("A predefined class can be loaded (defined) at runtime only once by a single class loader. " +
+                                "Hierarchies of class loaders and distinct sets of classes are not supported. Class " + clazz.getName() + " has already " +
+                                "been loaded by class loader: " + clazz.getClassLoader());
+            }
+        }
+    }
+
+    /**
+     * Load the class if it has not already been loaded. Returns {@code true} if the class has been
+     * loaded as a result of this call, {@code false} otherwise. Throws if an error occurred.
+     */
+    public static boolean loadClassIfNotLoaded(ClassLoader classLoader, ProtectionDomain protectionDomain, Class<?> clazz) {
+        return singleton().loadClass0(classLoader, protectionDomain, clazz);
     }
 
-    private Class<?> load(ClassLoader classLoader, ProtectionDomain protectionDomain, Class<?> clazz) {
+    private boolean loadClass0(ClassLoader classLoader, ProtectionDomain protectionDomain, Class<?> clazz) {
         lock.lock();
         try {
             boolean alreadyLoaded = (loadedClassesByName.get(clazz.getName()) == clazz);
             if (alreadyLoaded) {
-                if (classLoader == clazz.getClassLoader()) {
-                    throw new LinkageError("loader " + classLoader + " attempted duplicate class definition for " + clazz.getName() + " defined by " + clazz.getClassLoader());
-                } else {
-                    throw VMError.unsupportedFeature("A predefined class can be loaded (defined) at runtime only once by a single class loader. " +
-                                    "Hierarchies of class loaders and distinct sets of classes are not supported. Class " + clazz.getName() + " has already " +
-                                    "been loaded by class loader: " + clazz.getClassLoader());
-                }
+                return false;
             }
 
             throwIfUnresolvable(clazz.getSuperclass(), classLoader);
@@ -152,7 +177,7 @@ private Class<?> load(ClassLoader classLoader, ProtectionDomain protectionDomain
                 hub.setProtectionDomainAtRuntime(protectionDomain);
             }
             loadedClassesByName.put(clazz.getName(), clazz);
-            return clazz;
+            return true;
         } finally {
             lock.unlock();
         }
@@ -163,24 +188,18 @@ public static void throwIfUnresolvable(Class<?> clazz, ClassLoader classLoader)
             return;
         }
         DynamicHub hub = DynamicHub.fromClass(clazz);
-        if (!hub.isLoaded()) {
-            throwResolutionError(clazz.getName());
+        if (!hub.isLoaded() || !ClassUtil.isSameOrParentLoader(clazz.getClassLoader(), classLoader)) {
+            String name = clazz.getName();
+            // NoClassDefFoundError with ClassNotFoundException required by Java VM spec, 5.3
+            NoClassDefFoundError error = new NoClassDefFoundError(name.replace('.', '/'));
+            error.initCause(new ClassNotFoundException(name));
+            throw error;
         }
-        if (!isSameOrParent(clazz.getClassLoader(), classLoader)) { // common case: same loader
-            throwResolutionError(clazz.getName());
-        }
-    }
-
-    private static void throwResolutionError(String name) {
-        // NoClassDefFoundError with ClassNotFoundException required by Java VM specification, 5.3
-        NoClassDefFoundError error = new NoClassDefFoundError(name.replace('.', '/'));
-        error.initCause(new ClassNotFoundException(name));
-        throw error;
     }
 
     static Class<?> getLoadedForNameOrNull(String name, ClassLoader classLoader) {
         Class<?> clazz = singleton().getLoaded(name);
-        if (clazz == null || !isSameOrParent(clazz.getClassLoader(), classLoader)) {
+        if (clazz == null || !ClassUtil.isSameOrParentLoader(clazz.getClassLoader(), classLoader)) {
             return null;
         }
         return clazz;
@@ -195,23 +214,14 @@ private Class<?> getLoaded(String name) {
         }
     }
 
-    private static boolean isSameOrParent(ClassLoader parent, ClassLoader child) {
-        if (parent == null) {
-            return true; // boot loader: any loader's parent
-        }
-        ClassLoader c = child;
-        do {
-            if (c == parent) { // common case
-                return true;
-            }
-            c = c.getParent();
-        } while (c != null);
-        return false;
-    }
-
+    @Platforms(Platform.HOSTED_ONLY.class)
     public static class TestingBackdoor {
-        public static UnmodifiableEconomicMap<String, Class<?>> getPredefinedClasses() {
-            return singleton().predefinedClassesByHash;
+        public static Set<Class<?>> getConfigurationPredefinedClasses() {
+            Set<Class<?>> set = new HashSet<>();
+            for (Class<?> clazz : singleton().predefinedClassesByHash.getValues()) {
+                set.add(clazz);
+            }
+            return set; // excludes internal classes such as proxy classes
         }
     }
 }

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/proxy/DynamicProxyRegistry.java

@@ -34,14 +34,8 @@ public interface DynamicProxyRegistry {
     @Platforms(Platform.HOSTED_ONLY.class)
     void addProxyClass(Class<?>... interfaces);
 
-    Class<?> getProxyClass(Class<?>... interfaces);
+    Class<?> getProxyClass(ClassLoader loader, Class<?>... interfaces);
 
     boolean isProxyClass(Class<?> clazz);
 
-    @SuppressWarnings("deprecation")
-    @Platforms(Platform.HOSTED_ONLY.class)
-    static Class<?> getProxyClass(ClassLoader loader, Class<?>... interfaces) {
-        return java.lang.reflect.Proxy.getProxyClass(loader, interfaces);
-    }
-
 }

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/proxy/ProxySubstitutions.java

@@ -37,8 +37,8 @@
 import com.oracle.svm.core.annotate.Substitute;
 import com.oracle.svm.core.annotate.TargetClass;
 import com.oracle.svm.core.annotate.TargetElement;
-import com.oracle.svm.core.jdk.JDK8OrEarlier;
 import com.oracle.svm.core.jdk.JDK11OrLater;
+import com.oracle.svm.core.jdk.JDK8OrEarlier;
 
 @TargetClass(java.lang.reflect.Proxy.class)
 final class Target_java_lang_reflect_Proxy {
@@ -51,7 +51,7 @@ final class Target_java_lang_reflect_Proxy {
     @Substitute
     @TargetElement(onlyWith = JDK8OrEarlier.class) //
     private static Class<?> getProxyClass0(@SuppressWarnings("unused") ClassLoader loader, Class<?>... interfaces) {
-        return ImageSingletons.lookup(DynamicProxyRegistry.class).getProxyClass(interfaces);
+        return ImageSingletons.lookup(DynamicProxyRegistry.class).getProxyClass(loader, interfaces);
     }
 
     /** We have our own proxy cache so mark the original one as deleted. */
@@ -63,7 +63,7 @@ private static Class<?> getProxyClass0(@SuppressWarnings("unused") ClassLoader l
     @TargetElement(onlyWith = JDK11OrLater.class)
     @SuppressWarnings("unused")
     private static Constructor<?> getProxyConstructor(Class<?> caller, ClassLoader loader, Class<?>... interfaces) {
-        final Class<?> cl = ImageSingletons.lookup(DynamicProxyRegistry.class).getProxyClass(interfaces);
+        final Class<?> cl = ImageSingletons.lookup(DynamicProxyRegistry.class).getProxyClass(loader, interfaces);
         try {
             final Constructor<?> cons = cl.getConstructor(InvocationHandler.class);
             if (!Modifier.isPublic(cl.getModifiers())) {

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/ClassPredefinitionFeature.java

@@ -61,6 +61,10 @@ public class ClassPredefinitionFeature implements Feature {
     public void afterRegistration(AfterRegistrationAccess arg) {
         ImageSingletons.add(PredefinedClassesSupport.class, new PredefinedClassesSupport());
 
+        /*
+         * NOTE: loading the class predefinition configuration should be done as early as possible
+         * so that their classes are already known for other configuration (reflection, proxies).
+         */
         AfterRegistrationAccessImpl access = (AfterRegistrationAccessImpl) arg;
         PredefinedClassesRegistry registry = new PredefinedClassesRegistryImpl();
         ImageSingletons.add(PredefinedClassesRegistry.class, registry);