Do not require negative queries for impossible class names

loicottet · loicottet · commit 7fc30ab18cbd · 2025-05-22T10:23:37.000+02:00
diff --git a/substratevm/CHANGELOG.md b/substratevm/CHANGELOG.md
@@ -20,6 +20,7 @@ This changelog summarizes major changes to GraalVM Native Image.
 * (GR-64584) Experimental option `-H:+RelativeCodePointers` to significantly reduce relocation entries in position-independent executables and shared libraries.
 * (GR-60238) JNI registration is now included as part of the `"reflection"` section of _reachability-metadata.json_ using the `"jniAccessible"` attribute. Registrations performed through the `"jni"` section of _reachability-metadata.json_ and through _jni-config.json_ will still be accepted and parsed correctly.
 * (GR-65008) Remove the sequential reachability handler. The only remaining variant is the concurrent reachability handler, which has been the default implementation since its introduction. Additionally, remove the `-H:-RunReachabilityHandlersConcurrently` option which was introduced to simplify migration and has been deprecated since Version 24.0.0.
+* (GR-63268) Reflection and JNI queries do not require metadata entries to throw the expected JDK exception when querying a class that doesn't exist under `--exact-reachability-metadata` if the query cannot possibly be a valid class name
 
 ## GraalVM for JDK 24 (Internal Version 24.2.0)
 * (GR-59717) Added `DuringSetupAccess.registerObjectReachabilityHandler` to allow registering a callback that is executed when an object of a specified type is marked as reachable during heap scanning.
diff --git a/substratevm/src/com.oracle.svm.agent/src/com/oracle/svm/agent/JniCallInterceptor.java b/substratevm/src/com.oracle.svm.agent/src/com/oracle/svm/agent/JniCallInterceptor.java
@@ -137,7 +137,10 @@ private static JNIObjectHandle findClass(JNIEnvironment env, CCharPointer name)
             result = nullHandle();
         }
         if (shouldTrace()) {
-            traceCall(env, "FindClass", nullHandle(), nullHandle(), callerClass, name.notEqual(nullHandle()), state, fromCString(name));
+            String className = fromCString(name);
+            if (className != null) {
+                traceCall(env, "FindClass", nullHandle(), nullHandle(), callerClass, name.notEqual(nullHandle()), state, className);
+            }
         }
         return result;
     }
diff --git a/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/ClassNameSupport.java b/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/ClassNameSupport.java
@@ -182,7 +182,13 @@ private static boolean isValidFullyQualifiedClassName(String name, int startInde
                     return false;
                 }
                 lastPackageSeparatorIndex = i;
-            } else if (!Character.isJavaIdentifierPart(current)) {
+            } else if (current == '.' || current == ';' || current == '[' || current == '/') {
+                /*
+                 * Some special characters are allowed in class files while not being permitted as
+                 * code identifiers (e.g. '+', '-', ',').
+                 *
+                 * @see https://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.2.2
+                 */
                 return false;
             }
         }
diff --git a/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/config/ConfigurationSet.java b/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/config/ConfigurationSet.java
@@ -151,7 +151,6 @@ public static List<Path> writeConfigurationToAllPaths(Function<ConfigurationFile
         for (Path path : configFilePathResolver.apply(reachabilityMetadataFile)) {
             writtenFiles.add(path);
             JsonWriter writer = new JsonPrettyWriter(path);
-            writer.appendObjectStart();
             boolean first = true;
             for (ConfigurationFile configFile : ConfigurationFile.agentGeneratedFiles()) {
                 JsonPrintable configuration = configSupplier.apply(configFile);
@@ -172,14 +171,19 @@ public static List<Path> writeConfigurationToAllPaths(Function<ConfigurationFile
                         continue;
                     }
                     if (first) {
+                        writer.appendObjectStart();
                         first = false;
                     } else {
                         writer.appendSeparator();
                     }
                     printConfigurationToCombinedFile(configSupplier.apply(configFile), configFile, writer);
                 }
             }
-            writer.appendObjectEnd();
+            if (first) {
+                writer.append("{}");
+            } else {
+                writer.appendObjectEnd();
+            }
             writer.close();
         }
         return writtenFiles;
diff --git a/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/trace/JniProcessor.java b/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/trace/JniProcessor.java
@@ -66,15 +66,17 @@ void processEntry(EconomicMap<String, Object> entry, ConfigurationSet configurat
         // Special: FindClass and DefineClass take the class in question as a string argument
         if (function.equals("FindClass") || function.equals("DefineClass")) {
             String jniName = singleElement(args);
-            ConfigurationTypeDescriptor type = NamedConfigurationTypeDescriptor.fromJNIName(jniName);
-            LazyValue<String> reflectionName = lazyValue(ClassNameSupport.jniNameToReflectionName(jniName));
-            if (!advisor.shouldIgnore(reflectionName, callerClassLazyValue, entry)) {
-                if (function.equals("FindClass")) {
-                    if (!advisor.shouldIgnoreJniLookup(function, reflectionName, lazyNull(), lazyNull(), callerClassLazyValue, entry)) {
-                        configurationSet.getReflectionConfiguration().getOrCreateType(condition, type).setJniAccessible();
+            if (ClassNameSupport.isValidJNIName(jniName)) {
+                ConfigurationTypeDescriptor type = NamedConfigurationTypeDescriptor.fromJNIName(jniName);
+                LazyValue<String> reflectionName = lazyValue(ClassNameSupport.jniNameToReflectionName(jniName));
+                if (!advisor.shouldIgnore(reflectionName, callerClassLazyValue, entry)) {
+                    if (function.equals("FindClass")) {
+                        if (!advisor.shouldIgnoreJniLookup(function, reflectionName, lazyNull(), lazyNull(), callerClassLazyValue, entry)) {
+                            configurationSet.getReflectionConfiguration().getOrCreateType(condition, type).setJniAccessible();
+                        }
+                    } else if (!AccessAdvisor.PROXY_CLASS_NAME_PATTERN.matcher(jniName).matches()) { // DefineClass
+                        LogUtils.warning("Unsupported JNI function DefineClass used to load class " + jniName);
                     }
-                } else if (!AccessAdvisor.PROXY_CLASS_NAME_PATTERN.matcher(jniName).matches()) { // DefineClass
-                    LogUtils.warning("Unsupported JNI function DefineClass used to load class " + jniName);
                 }
             }
             return;
diff --git a/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/trace/ReflectionProcessor.java b/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/trace/ReflectionProcessor.java
@@ -32,6 +32,7 @@
 
 import org.graalvm.collections.EconomicMap;
 
+import com.oracle.svm.configure.ClassNameSupport;
 import com.oracle.svm.configure.ConfigurationTypeDescriptor;
 import com.oracle.svm.configure.NamedConfigurationTypeDescriptor;
 import com.oracle.svm.configure.ProxyConfigurationTypeDescriptor;
@@ -101,7 +102,8 @@ public void processEntry(EconomicMap<String, Object> entry, ConfigurationSet con
                 name = MetaUtil.internalNameToJava(MetaUtil.toInternalName(name), true, true);
             }
             if (!advisor.shouldIgnore(lazyValue(name), lazyValue(callerClass), entry) &&
-                            !(isLoadClass && advisor.shouldIgnoreLoadClass(lazyValue(name), lazyValue(callerClass), entry))) {
+                            !(isLoadClass && advisor.shouldIgnoreLoadClass(lazyValue(name), lazyValue(callerClass), entry)) &&
+                            ClassNameSupport.isValidReflectionName(name)) {
                 configuration.getOrCreateType(condition, NamedConfigurationTypeDescriptor.fromReflectionName(name));
             }
             return;
diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/ClassForNameSupport.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/ClassForNameSupport.java
@@ -246,18 +246,7 @@ private Object forName0(String className, ClassLoader classLoader) {
             result = PredefinedClassesSupport.getLoadedForNameOrNull(className, classLoader);
         }
         if (result == null && !ClassNameSupport.isValidReflectionName(className)) {
-            if (result == null && ClassNameSupport.isValidJNIName(className)) {
-                var jniAlias = knownClasses.get(ClassNameSupport.jniNameToReflectionName(className));
-                if (jniAlias != null && jniAlias.getValue() != null) {
-                    result = NEGATIVE_QUERY;
-                }
-            }
-            if (result == null && ClassNameSupport.isValidTypeName(className)) {
-                var typeAlias = knownClasses.get(ClassNameSupport.typeNameToReflectionName(className));
-                if (typeAlias != null && typeAlias.getValue() != null) {
-                    result = NEGATIVE_QUERY;
-                }
-            }
+            result = NEGATIVE_QUERY;
         }
         return result == NEGATIVE_QUERY ? new ClassNotFoundException(className) : result;
     }
diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jni/access/JNIReflectionDictionary.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jni/access/JNIReflectionDictionary.java
@@ -180,14 +180,9 @@ public static Class<?> getClassObjectByName(CharSequence name) {
         for (var dictionary : layeredSingletons()) {
             JNIAccessibleClass clazz = dictionary.classesByName.get(name);
             if (clazz == null && !ClassNameSupport.isValidJNIName(name.toString())) {
-                if (clazz == null && ClassNameSupport.isValidReflectionName(name.toString()) && dictionary.classesByName.containsKey(ClassNameSupport.reflectionNameToJNIName(name.toString()))) {
-                    clazz = NEGATIVE_CLASS_LOOKUP;
-                }
-                if (clazz == null && ClassNameSupport.isValidTypeName(name.toString()) && dictionary.classesByName.containsKey(ClassNameSupport.typeNameToJNIName(name.toString()))) {
-                    clazz = NEGATIVE_CLASS_LOOKUP;
-                }
+                clazz = NEGATIVE_CLASS_LOOKUP;
             }
-            clazz = checkClass(clazz, name);
+            clazz = checkClass(clazz, name.toString());
             if (clazz != null) {
                 return clazz.getClassObject();
             }
@@ -196,9 +191,9 @@ public static Class<?> getClassObjectByName(CharSequence name) {
         return null;
     }
 
-    private static JNIAccessibleClass checkClass(JNIAccessibleClass clazz, CharSequence name) {
+    private static JNIAccessibleClass checkClass(JNIAccessibleClass clazz, String name) {
         if (throwMissingRegistrationErrors() && clazz == null) {
-            MissingJNIRegistrationUtils.forClass(name.toString());
+            MissingJNIRegistrationUtils.forClass(name);
         } else if (clazz != null && clazz.isNegative()) {
             return null;
         }
diff --git a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/jni/JNIAccessFeature.java b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/jni/JNIAccessFeature.java
@@ -257,10 +257,11 @@ private void registerFields(boolean finalIsWritable, Field[] fields) {
         }
 
         @Override
-        public void registerClassLookup(ConfigurationCondition condition, String jniName) {
+        public void registerClassLookup(ConfigurationCondition condition, String reflectionName) {
             try {
-                register(condition, false, Class.forName(ClassNameSupport.jniNameToReflectionName(jniName)));
+                register(condition, false, Class.forName(reflectionName));
             } catch (ClassNotFoundException e) {
+                String jniName = ClassNameSupport.reflectionNameToJNIName(reflectionName);
                 newNegativeClassLookups.add(jniName);
             }
         }

Original file line number	Diff line number	Diff line change
`@@ -137,7 +137,10 @@ private static JNIObjectHandle findClass(JNIEnvironment env, CCharPointer name)`
`137`	`137`	`result = nullHandle();`
`138`	`138`	`}`
`139`	`139`	`if (shouldTrace()) {`
`140`		`- traceCall(env, "FindClass", nullHandle(), nullHandle(), callerClass, name.notEqual(nullHandle()), state, fromCString(name));`
	`140`	`+ String className = fromCString(name);`
	`141`	`+ if (className != null) {`
	`142`	`+ traceCall(env, "FindClass", nullHandle(), nullHandle(), callerClass, name.notEqual(nullHandle()), state, className);`
	`143`	`+ }`
`141`	`144`	`}`
`142`	`145`	`return result;`
`143`	`146`	`}`
Original file line number	Diff line number	Diff line change
`@@ -182,7 +182,13 @@ private static boolean isValidFullyQualifiedClassName(String name, int startInde`
`182`	`182`	`return false;`
`183`	`183`	`}`
`184`	`184`	`lastPackageSeparatorIndex = i;`
`185`		`- } else if (!Character.isJavaIdentifierPart(current)) {`
	`185`	`+ } else if (current == '.' \|\| current == ';' \|\| current == '[' \|\| current == '/') {`
	`186`	`+ /*`
	`187`	`+ * Some special characters are allowed in class files while not being permitted as`
	`188`	`+ * code identifiers (e.g. '+', '-', ',').`
	`189`	`+ *`
	`190`	`+ * @see https://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.2.2`
	`191`	`+ */`
`186`	`192`	`return false;`
`187`	`193`	`}`
`188`	`194`	`}`
Original file line number	Diff line number	Diff line change
`@@ -151,7 +151,6 @@ public static List<Path> writeConfigurationToAllPaths(Function<ConfigurationFile`
`151`	`151`	`for (Path path : configFilePathResolver.apply(reachabilityMetadataFile)) {`
`152`	`152`	`writtenFiles.add(path);`
`153`	`153`	`JsonWriter writer = new JsonPrettyWriter(path);`
`154`		`- writer.appendObjectStart();`
`155`	`154`	`boolean first = true;`
`156`	`155`	`for (ConfigurationFile configFile : ConfigurationFile.agentGeneratedFiles()) {`
`157`	`156`	`JsonPrintable configuration = configSupplier.apply(configFile);`
`@@ -172,14 +171,19 @@ public static List<Path> writeConfigurationToAllPaths(Function<ConfigurationFile`
`172`	`171`	`continue;`
`173`	`172`	`}`
`174`	`173`	`if (first) {`
	`174`	`+ writer.appendObjectStart();`
`175`	`175`	`first = false;`
`176`	`176`	`} else {`
`177`	`177`	`writer.appendSeparator();`
`178`	`178`	`}`
`179`	`179`	`printConfigurationToCombinedFile(configSupplier.apply(configFile), configFile, writer);`
`180`	`180`	`}`
`181`	`181`	`}`
`182`		`- writer.appendObjectEnd();`
	`182`	`+ if (first) {`
	`183`	`+ writer.append("{}");`
	`184`	`+ } else {`
	`185`	`+ writer.appendObjectEnd();`
	`186`	`+ }`
`183`	`187`	`writer.close();`
`184`	`188`	`}`
`185`	`189`	`return writtenFiles;`
Original file line number	Diff line number	Diff line change
`@@ -257,10 +257,11 @@ private void registerFields(boolean finalIsWritable, Field[] fields) {`
`257`	`257`	`}`
`258`	`258`
`259`	`259`	`@Override`
`260`		`- public void registerClassLookup(ConfigurationCondition condition, String jniName) {`
	`260`	`+ public void registerClassLookup(ConfigurationCondition condition, String reflectionName) {`
`261`	`261`	`try {`
`262`		`- register(condition, false, Class.forName(ClassNameSupport.jniNameToReflectionName(jniName)));`
	`262`	`+ register(condition, false, Class.forName(reflectionName));`
`263`	`263`	`} catch (ClassNotFoundException e) {`
	`264`	`+ String jniName = ClassNameSupport.reflectionNameToJNIName(reflectionName);`
`264`	`265`	`newNegativeClassLookups.add(jniName);`
`265`	`266`	`}`
`266`	`267`	`}`