Ensure Crema doesn't load Hybrid types

Author: gilles-duboscq

espresso-shared/src/com.oracle.truffle.espresso.classfile/src/com/oracle/truffle/espresso/classfile/ClassfileParser.java

@@ -1126,7 +1126,10 @@ private static Attribute[] spawnAttributesArray(int attributeCount) {
         return attributeCount == 0 ? Attribute.EMPTY_ARRAY : new Attribute[attributeCount];
     }
 
-    private static int parseAnnotation(ClassfileStream subStream) {
+    /**
+     * Parse one annotation in an annotation attribute and return the annotation type index.
+     */
+    public static int parseAnnotation(ClassfileStream subStream) {
         int typeIndex = subStream.readU2();
         int numElementValuePairs = subStream.readU2();
         for (int k = 0; k < numElementValuePairs; k++) {

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

@@ -486,7 +486,10 @@ public static DynamicHub allocate(String name, DynamicHub superHub, Object inter
         } else {
             // instance class
             assert !"java.lang.Class".equals(name);
-            // @Hybrid is ignored
+            /*
+             * @Hybrid types are not supported. The absence of the annotation is assumed to be
+             * checked by callers. See AbstractRuntimeClassRegistry.checkNotHybrid.
+             */
             if (Modifier.isAbstract(modifiers)) {
                 layoutEncoding = LayoutEncoding.forAbstract();
             } else {

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/registry/AbstractRuntimeClassRegistry.java

@@ -47,6 +47,7 @@
 import com.oracle.svm.core.hub.DynamicHub;
 import com.oracle.svm.core.hub.RuntimeClassLoading;
 import com.oracle.svm.core.hub.RuntimeClassLoading.ClassDefinitionInfo;
+import com.oracle.svm.core.hub.registry.SVMSymbols.SVMTypes;
 import com.oracle.svm.core.jdk.Target_java_lang_ClassLoader;
 import com.oracle.svm.core.util.VMError;
 import com.oracle.svm.espresso.classfile.ClassfileParser;
@@ -56,6 +57,7 @@
 import com.oracle.svm.espresso.classfile.ParserField;
 import com.oracle.svm.espresso.classfile.ParserKlass;
 import com.oracle.svm.espresso.classfile.ParserMethod;
+import com.oracle.svm.espresso.classfile.attributes.Attribute;
 import com.oracle.svm.espresso.classfile.attributes.InnerClassesAttribute;
 import com.oracle.svm.espresso.classfile.attributes.NestHostAttribute;
 import com.oracle.svm.espresso.classfile.attributes.PermittedSubclassesAttribute;
@@ -408,6 +410,8 @@ private Class<?> createClass(ParserKlass parsed, ClassDefinitionInfo info, Symbo
         // GR-62339
         Module module = getClassLoader().getUnnamedModule();
 
+        checkNotHybrid(parsed);
+
         DynamicHub hub = DynamicHub.allocate(externalName, superHub, interfacesEncoding, null,
                         sourceFile, modifiers, flags, getClassLoader(), nestHost, simpleBinaryName, module, enclosingClass, classSignature,
                         typeID, numClassTypes, typeIDDepth, numInterfacesTypes, openTypeWorldTypeCheckSlots, dispatchTableLength, afterFieldsOffset, isValueBased);
@@ -417,6 +421,23 @@ sourceFile, modifiers, flags, getClassLoader(), nestHost, simpleBinaryName, modu
         return DynamicHub.toClass(hub);
     }
 
+    private static void checkNotHybrid(ParserKlass parsed) {
+        Attribute attribute = parsed.getAttribute(ParserNames.RuntimeVisibleAnnotations);
+        if (attribute == null) {
+            return;
+        }
+        ClassfileStream stream = new ClassfileStream(attribute.getData(), null);
+        int count = stream.readU2();
+        for (int j = 0; j < count; j++) {
+            int typeIndex = ClassfileParser.parseAnnotation(stream);
+            Symbol<?> annotType = parsed.getConstantPool().utf8At(typeIndex, "annotation type");
+            if (SVMTypes.com_oracle_svm_core_hub_Hybrid.equals(annotType)) {
+                throw new ClassFormatError("Cannot load @Hybrid classes at runtime");
+            }
+        }
+
+    }
+
     private static boolean declaresDefaultMethods(ParserKlass parsed) {
         for (ParserMethod method : parsed.getMethods()) {
             int flags = method.getFlags();

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/registry/SVMSymbols.java

@@ -0,0 +1,58 @@
+/*
+ * 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.hub.registry;
+
+import com.oracle.svm.espresso.classfile.descriptors.ParserSymbols;
+import com.oracle.svm.espresso.classfile.descriptors.StaticSymbols;
+import com.oracle.svm.espresso.classfile.descriptors.Symbol;
+import com.oracle.svm.espresso.classfile.descriptors.Type;
+
+public final class SVMSymbols {
+    // Pre-allocate enough slots to avoid resizing the underlying map.
+    // But not too much, since these maps will be persisted in the image heap (Native Image).
+    public static final StaticSymbols SYMBOLS = new StaticSymbols(ParserSymbols.SYMBOLS, 1 << 8);
+
+    private SVMSymbols() {
+    }
+
+    static {
+        SVMTypes.ensureInitialized();
+    }
+
+    public static void ensureInitialized() {
+        /* nop */
+    }
+
+    public static final class SVMTypes {
+        public static final Symbol<Type> com_oracle_svm_core_hub_Hybrid = SYMBOLS.putType("Lcom/oracle/svm/core/hub/Hybrid;");
+
+        private SVMTypes() {
+        }
+
+        public static void ensureInitialized() {
+            /* nop */
+        }
+    }
+}

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/registry/SymbolsSupport.java

@@ -30,7 +30,6 @@
 import org.graalvm.nativeimage.Platforms;
 
 import com.oracle.svm.espresso.classfile.descriptors.NameSymbols;
-import com.oracle.svm.espresso.classfile.descriptors.ParserSymbols;
 import com.oracle.svm.espresso.classfile.descriptors.SignatureSymbols;
 import com.oracle.svm.espresso.classfile.descriptors.Symbols;
 import com.oracle.svm.espresso.classfile.descriptors.TypeSymbols;
@@ -49,9 +48,8 @@ public final class SymbolsSupport {
 
     @Platforms(Platform.HOSTED_ONLY.class)
     public SymbolsSupport() {
-        ParserSymbols.ensureInitialized();
         int initialSymbolTableCapacity = 4 * 1024;
-        Symbols symbols = Symbols.fromExisting(ParserSymbols.SYMBOLS.freeze(), initialSymbolTableCapacity, 0);
+        Symbols symbols = Symbols.fromExisting(SVMSymbols.SYMBOLS.freeze(), initialSymbolTableCapacity, 0);
         // let this resize when first used at runtime
         utf8 = new Utf8Symbols(symbols);
         names = new NameSymbols(symbols);