Trace JNI accesses

Author: DSouzaM

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jni/access/JNIAccessibleMethodDescriptor.java

@@ -98,10 +98,19 @@ public boolean isClassInitializer() {
         return WRAPPED_CSTRING_EQUIVALENCE.equals(name, INITIALIZER_NAME);
     }
 
+    /**
+     * Returns the method name as a String. Can be used if the descriptor is known to be a String
+     * (i.e., it does not come from a JNI call); otherwise, use {@link #getNameConvertToString()}.
+     */
     public String getName() {
         return (String) name;
     }
 
+    /**
+     * Returns the method signature as a String. Can be used if the descriptor is known to be a
+     * String (i.e., it does not come from a JNI call); otherwise, use
+     * {@link #getSignatureConvertToString()}.
+     */
     public String getSignature() {
         return (String) signature;
     }
@@ -113,6 +122,13 @@ public String getNameConvertToString() {
         return name.toString();
     }
 
+    /**
+     * Performs a potentially costly conversion to string, only for slow paths.
+     */
+    public String getSignatureConvertToString() {
+        return signature.toString();
+    }
+
     public String getSignatureWithoutReturnType() {
         String signatureString = signature.toString();
         int parametersEnd = signatureString.lastIndexOf(')');

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jni/access/JNIReflectionDictionary.java

@@ -42,6 +42,8 @@
 import org.graalvm.word.Pointer;
 
 import com.oracle.svm.configure.ClassNameSupport;
+import com.oracle.svm.configure.config.ConfigurationMemberInfo;
+import com.oracle.svm.configure.config.ConfigurationType;
 import com.oracle.svm.core.SubstrateOptions;
 import com.oracle.svm.core.Uninterruptible;
 import com.oracle.svm.core.heap.Heap;
@@ -53,6 +55,7 @@
 import com.oracle.svm.core.layeredimagesingleton.MultiLayeredImageSingleton;
 import com.oracle.svm.core.layeredimagesingleton.UnsavedSingleton;
 import com.oracle.svm.core.log.Log;
+import com.oracle.svm.core.metadata.MetadataTracer;
 import com.oracle.svm.core.snippets.KnownIntrinsics;
 import com.oracle.svm.core.util.ImageHeapMap;
 import com.oracle.svm.core.util.Utf8.WrappedAsciiCString;
@@ -181,6 +184,9 @@ public static Class<?> getClassObjectByName(CharSequence name) {
             JNIAccessibleClass clazz = dictionary.classesByName.get(name);
             if (clazz == null && !ClassNameSupport.isValidJNIName(name.toString())) {
                 clazz = NEGATIVE_CLASS_LOOKUP;
+            } else if (MetadataTracer.Options.MetadataTracingSupport.getValue() && MetadataTracer.singleton().enabled()) {
+                // trace if class exists (positive query) or name is valid (negative query)
+                MetadataTracer.singleton().traceJNIType(ClassNameSupport.jniNameToTypeName(name.toString()));
             }
             clazz = checkClass(clazz, name.toString());
             if (clazz != null) {
@@ -274,6 +280,10 @@ private static JNIAccessibleMethod getDeclaredMethod(Class<?> classObject, JNIAc
                 foundClass = true;
                 JNIAccessibleMethod method = clazz.getMethod(descriptor);
                 if (method != null) {
+                    if (MetadataTracer.Options.MetadataTracingSupport.getValue() && MetadataTracer.singleton().enabled()) {
+                        ConfigurationType clazzType = MetadataTracer.singleton().traceJNIType(classObject.getName());
+                        clazzType.addMethod(descriptor.getNameConvertToString(), descriptor.getSignatureConvertToString(), ConfigurationMemberInfo.ConfigurationMemberDeclaration.DECLARED);
+                    }
                     return method;
                 }
             }
@@ -329,6 +339,10 @@ private static JNIAccessibleField getDeclaredField(Class<?> classObject, CharSeq
                 foundClass = true;
                 JNIAccessibleField field = clazz.getField(name);
                 if (field != null && (field.isStatic() == isStatic || field.isNegative())) {
+                    if (MetadataTracer.Options.MetadataTracingSupport.getValue() && MetadataTracer.singleton().enabled()) {
+                        ConfigurationType clazzType = MetadataTracer.singleton().traceJNIType(classObject.getName());
+                        clazzType.addField(name.toString(), ConfigurationMemberInfo.ConfigurationMemberDeclaration.DECLARED, false);
+                    }
                     return field;
                 }
             }

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/metadata/MetadataTracer.java

@@ -98,6 +98,13 @@ private ConfigurationType traceReflectionTypeImpl(ConfigurationTypeDescriptor ty
         return config.getReflectionConfiguration().getOrCreateType(UnresolvedConfigurationCondition.alwaysTrue(), new NamedConfigurationTypeDescriptor(className));
     }
 
+    public ConfigurationType traceJNIType(String className) {
+        assert enabled();
+        ConfigurationType result = traceReflectionType(className);
+        result.setJniAccessible();
+        return result;
+    }
+
     public void traceResource(String resourceName, String moduleName) {
         assert enabled();
         config.getResourceConfiguration().addGlobPattern(UnresolvedConfigurationCondition.alwaysTrue(), resourceName, moduleName);