8354949: JFR: Split up the EventInstrumentation class

src/jdk.jfr/share/classes/jdk/jfr/internal/ClassInspector.java

@@ -0,0 +1,361 @@
+/*
+ * Copyright (c) 2016, 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 jdk.jfr.internal;
+
+import static jdk.jfr.internal.util.Bytecode.classDesc;
+
+import java.lang.classfile.Annotation;
+import java.lang.classfile.AnnotationElement;
+import java.lang.classfile.AnnotationValue;
+import java.lang.classfile.Attribute;
+import java.lang.classfile.ClassFile;
+import java.lang.classfile.ClassModel;
+import java.lang.classfile.FieldModel;
+import java.lang.classfile.MethodModel;
+import java.lang.classfile.attribute.RuntimeVisibleAnnotationsAttribute;
+import java.lang.constant.ClassDesc;
+import java.lang.constant.MethodTypeDesc;
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.lang.constant.ConstantDescs;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import jdk.jfr.Enabled;
+import jdk.jfr.Name;
+import jdk.jfr.Registered;
+import jdk.jfr.SettingControl;
+import jdk.jfr.SettingDefinition;
+import jdk.jfr.internal.util.Bytecode;
+import jdk.jfr.internal.util.ImplicitFields;
+import jdk.jfr.internal.util.Bytecode.FieldDesc;
+import jdk.jfr.internal.util.Bytecode.MethodDesc;
+import jdk.jfr.internal.util.Bytecode.SettingDesc;
+import jdk.jfr.internal.util.Utils;
+
+final class ClassInspector {
+    private static final ClassDesc TYPE_SETTING_DEFINITION = Bytecode.classDesc(SettingDefinition.class);
+    private static final ClassDesc ANNOTATION_REGISTERED = classDesc(Registered.class);
+    private static final ClassDesc ANNOTATION_NAME = classDesc(Name.class);
+    private static final ClassDesc ANNOTATION_ENABLED = classDesc(Enabled.class);
+    private static final ClassDesc ANNOTATION_REMOVE_FIELDS = classDesc(RemoveFields.class);
+
+    private final ClassModel classModel;
+    private final Class<?> superClass;
+    private final boolean isJDK;
+    private final ImplicitFields implicitFields;
+    private final List<SettingDesc> settingsDescs = new ArrayList<>();
+    private final List<FieldDesc> fieldDescs = new ArrayList<>();
+    private final String className;
+
+    ClassInspector(Class<?> superClass, byte[] bytes, boolean isJDK) {
+        this.superClass = superClass;
+        this.classModel = ClassFile.of().parse(bytes);
+        this.isJDK = isJDK;
+        this.className = classModel.thisClass().asInternalName().replace("/", ".");
+        this.implicitFields = determineImplicitFields();
+    }
+
+    String getClassName() {
+        return className;
+    }
+
+    MethodDesc findStaticCommitMethod() {
+        if (!isJDK) {
+            return null;
+        }
+        StringBuilder sb = new StringBuilder();
+        sb.append("(");
+        for (FieldDesc field : fieldDescs) {
+            sb.append(field.type().descriptorString());
+        }
+        sb.append(")V");
+        MethodDesc m = MethodDesc.of("commit", sb.toString());
+        for (MethodModel method : classModel.methods()) {
+            if (m.matches(method)) {
+                return m;
+            }
+        }
+        return null;
+    }
+
+    String getEventName() {
+        String name = annotationValue(ANNOTATION_NAME, String.class);
+        return name == null ? getClassName() : name;
+    }
+
+    boolean isRegistered() {
+        Boolean result = annotationValue(ANNOTATION_REGISTERED, Boolean.class);
+        if (result != null) {
+            return result.booleanValue();
+        }
+        if (superClass != null) {
+            Registered r = superClass.getAnnotation(Registered.class);
+            if (r != null) {
+                return r.value();
+            }
+        }
+        return true;
+    }
+
+    boolean isEnabled() {
+        Boolean result = annotationValue(ANNOTATION_ENABLED, Boolean.class);
+        if (result != null) {
+            return result.booleanValue();
+        }
+        if (superClass != null) {
+            Enabled e = superClass.getAnnotation(Enabled.class);
+            if (e != null) {
+                return e.value();
+            }
+        }
+        return true;
+    }
+
+    boolean hasStaticMethod(MethodDesc method) {
+        for (MethodModel m : classModel.methods()) {
+            if (Modifier.isStatic(m.flags().flagsMask())) {
+                return method.matches(m);
+            }
+        }
+        return false;
+    }
+
+    static boolean isValidField(int access, ClassDesc classDesc) {
+        String className = classDesc.packageName();
+        if (!className.isEmpty()) {
+            className = className + ".";
+        }
+        className += classDesc.displayName();
+        return isValidField(access, className);
+    }
+
+    static boolean isValidField(int access, String className) {
+        if (Modifier.isTransient(access) || Modifier.isStatic(access)) {
+            return false;
+        }
+        return Type.isValidJavaFieldType(className);
+    }
+
+    List<SettingDesc> getSettings() {
+        return settingsDescs;
+    }
+
+    List<FieldDesc> getFields() {
+        return fieldDescs;
+    }
+
+    boolean hasDuration() {
+        return implicitFields.hasDuration();
+    }
+
+    boolean hasStackTrace() {
+        return implicitFields.hasStackTrace();
+    }
+
+    boolean hasEventThread() {
+        return implicitFields.hasEventThread();
+    }
+
+    ClassDesc getClassDesc() {
+        return classModel.thisClass().asSymbol();
+    }
+
+    ClassModel getClassModel() {
+        return classModel;
+    }
+
+    boolean isJDK() {
+        return isJDK;
+    }
+
+    private ImplicitFields determineImplicitFields() {
+        if (isJDK) {
+            Class<?> eventClass = MirrorEvents.find(isJDK, getClassName());
+            if (eventClass != null) {
+                return new ImplicitFields(eventClass);
+            }
+        }
+        ImplicitFields ifs = new ImplicitFields(superClass);
+        String[] value = annotationValue(ANNOTATION_REMOVE_FIELDS, String[].class);
+        if (value != null) {
+            ifs.removeFields(value);
+        }
+        return ifs;
+    }
+
+    private List<AnnotationValue> getAnnotationValues(ClassDesc classDesc) {
+        List<AnnotationValue> list = new ArrayList<>();
+        for (Attribute<?> attribute: classModel.attributes()) {
+            if (attribute instanceof RuntimeVisibleAnnotationsAttribute rvaa) {
+                for (Annotation a : rvaa.annotations()) {
+                    if (a.classSymbol().equals(classDesc) && a.elements().size() == 1) {
+                        AnnotationElement ae = a.elements().getFirst();
+                        if (ae.name().equalsString("value")) {
+                            list.add(ae.value());
+                        }
+                    }
+                }
+            }
+        }
+        return list;
+    }
+
+    @SuppressWarnings("unchecked")
+    // Only supports String, String[] and Boolean values
+    private <T> T annotationValue(ClassDesc classDesc, Class<T> type) {
+        for (AnnotationValue a : getAnnotationValues(classDesc)) {
+            if (a instanceof AnnotationValue.OfBoolean ofb && type.equals(Boolean.class)) {
+                Boolean b = ofb.booleanValue();
+                return (T) b;
+            }
+            if (a instanceof AnnotationValue.OfString ofs && type.equals(String.class)) {
+                String s = ofs.stringValue();
+                return (T) s;
+            }
+            if (a instanceof AnnotationValue.OfArray ofa && type.equals(String[].class)) {
+                List<AnnotationValue> list = ofa.values();
+                String[] array = new String[list.size()];
+                int index = 0;
+                for (AnnotationValue av : list) {
+                    var avs = (AnnotationValue.OfString) av;
+                    array[index++] = avs.stringValue();
+                }
+                return (T) array;
+            }
+        }
+        return null;
+    }
+
+    void buildSettings() {
+        Set<String> foundMethods = new HashSet<>();
+        buildClassSettings(foundMethods);
+        buildSuperClassSettings(foundMethods);
+    }
+
+    private void buildClassSettings(Set<String> foundMethods) {
+        for (MethodModel m : classModel.methods()) {
+            for (Attribute<?> attribute : m.attributes()) {
+                if (attribute instanceof RuntimeVisibleAnnotationsAttribute rvaa) {
+                    for (Annotation a : rvaa.annotations()) {
+                        // We can't really validate the method at this
+                        // stage. We would need to check that the parameter
+                        // is an instance of SettingControl.
+                        if (a.classSymbol().equals(TYPE_SETTING_DEFINITION)) {
+                            String name = m.methodName().stringValue();
+                            // Use @Name if it exists
+                            for (Annotation nameCandidate : rvaa.annotations()) {
+                                if (nameCandidate.className().equalsString(ANNOTATION_NAME.descriptorString())) {
+                                    if (nameCandidate.elements().size() == 1) {
+                                        AnnotationElement ae = nameCandidate.elements().getFirst();
+                                        if (ae.name().equalsString("value")) {
+                                            if (ae.value() instanceof AnnotationValue.OfString s) {
+                                                name = Utils.validJavaIdentifier(s.stringValue(), name);
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                            // Add setting if method returns boolean and has one parameter
+                            MethodTypeDesc mtd = m.methodTypeSymbol();
+                            if (ConstantDescs.CD_boolean.equals(mtd.returnType())) {
+                                if (mtd.parameterList().size() == 1) {
+                                    ClassDesc type = mtd.parameterList().getFirst();
+                                    if (type.isClassOrInterface()) {
+                                        String methodName = m.methodName().stringValue();
+                                        foundMethods.add(methodName);
+                                        settingsDescs.add(new SettingDesc(type, methodName));
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    private void buildSuperClassSettings(Set<String> foundMethods) {
+        for (Class<?> c = superClass; jdk.internal.event.Event.class != c; c = c.getSuperclass()) {
+            for (java.lang.reflect.Method method : c.getDeclaredMethods()) {
+                if (!foundMethods.contains(method.getName())) {
+                    buildSettingsMethod(foundMethods, method);
+                }
+            }
+        }
+    }
+
+    private void buildSettingsMethod(Set<String> foundMethods, java.lang.reflect.Method method) {
+        // Skip private methods in base classes
+        if (!Modifier.isPrivate(method.getModifiers())) {
+            if (method.getReturnType().equals(Boolean.TYPE)) {
+                if (method.getParameterCount() == 1) {
+                    Class<?> type = method.getParameters()[0].getType();
+                    if (SettingControl.class.isAssignableFrom(type)) {
+                        ClassDesc paramType = Bytecode.classDesc(type);
+                        foundMethods.add(method.getName());
+                        settingsDescs.add(new SettingDesc(paramType, method.getName()));
+                    }
+                }
+            }
+        }
+    }
+
+    void buildFields() {
+        Set<String> foundFields = new HashSet<>();
+        // These two fields are added by native as 'transient' so they will be
+        // ignored by the loop below.
+        // The benefit of adding them manually is that we can
+        // control in which order they occur and we can add @Name, @Description
+        // in Java, instead of in native. It also means code for adding implicit
+        // fields for native can be reused by Java.
+        fieldDescs.add(ImplicitFields.FIELD_START_TIME);
+        if (implicitFields.hasDuration()) {
+            fieldDescs.add(ImplicitFields.FIELD_DURATION);
+        }
+        for (FieldModel field : classModel.fields()) {
+            if (!foundFields.contains(field.fieldName().stringValue()) && isValidField(field.flags().flagsMask(), field.fieldTypeSymbol())) {
+                fieldDescs.add(FieldDesc.of(field.fieldTypeSymbol(), field.fieldName().stringValue()));
+                foundFields.add(field.fieldName().stringValue());
+            }
+        }
+        for (Class<?> c = superClass; jdk.internal.event.Event.class != c; c = c.getSuperclass()) {
+            for (Field field : c.getDeclaredFields()) {
+                // Skip private fields in base classes
+                if (!Modifier.isPrivate(field.getModifiers())) {
+                    if (isValidField(field.getModifiers(), field.getType().getName())) {
+                        String fieldName = field.getName();
+                        if (!foundFields.contains(fieldName)) {
+                            fieldDescs.add(FieldDesc.of(field.getType(), fieldName));
+                            foundFields.add(fieldName);
+                        }
+                    }
+                }
+            }
+        }
+    }
+}