fix: correctly handle default value for @Instrument updateMajorVersion annotation. #46

Author: hengyunabc

bytekit-core/src/main/java/com/alibaba/bytekit/asm/instrument/InstrumentTemplate.java

@@ -185,8 +185,10 @@ private void parse(InstrumentParseResult result, byte[] classBytes, boolean trig
         // 清除apm类的行号
         AsmUtils.removeLineNumbers(classNode);
 
-        boolean updateMajorVersion = Boolean.parseBoolean((String) AsmAnnotationUtils.queryAnnotationValue(classNode.visibleAnnotations,
-                Type.getDescriptor(Instrument.class), "updateMajorVersion"));
+        // 注意：注解字段值如果等于默认值，编译到 class 文件时不会写入 values 里，这里需要补齐默认值
+        String updateMajorVersionValue = (String) AsmAnnotationUtils.queryAnnotationValue(classNode.visibleAnnotations,
+                Type.getDescriptor(Instrument.class), "updateMajorVersion");
+        boolean updateMajorVersion = updateMajorVersionValue == null || Boolean.parseBoolean(updateMajorVersionValue);
 
         List<String> matchClassList = AsmAnnotationUtils.queryAnnotationArrayValue(classNode.visibleAnnotations,
                 Type.getDescriptor(Instrument.class), "Class");

bytekit-core/src/test/java/com/alibaba/bytekit/asm/inst/AbstractAutowireCapableBeanFactory_Instrument.java

@@ -0,0 +1,20 @@
+package com.alibaba.bytekit.asm.inst;
+
+import java.util.Comparator;
+
+import org.springframework.beans.factory.BeanCreationException;
+import org.springframework.beans.factory.support.RootBeanDefinition;
+
+import com.alibaba.bytekit.agent.inst.Instrument;
+import com.alibaba.bytekit.agent.inst.InstrumentApi;
+
+@Instrument(Class = "org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory")
+public abstract class AbstractAutowireCapableBeanFactory_Instrument {
+
+    public Object createBean(String beanName, RootBeanDefinition mbd, Object[] args) throws BeanCreationException {
+        // 触发 Java8 接口静态方法调用（invokestatic + InterfaceMethodref），用于覆盖 updateMajorVersion 的默认行为
+        Comparator.naturalOrder();
+        return InstrumentApi.invokeOrigin();
+    }
+}
+

bytekit-core/src/test/java/com/alibaba/bytekit/asm/instrument/UpdateMajorVersionDefaultTest.java

@@ -0,0 +1,55 @@
+package com.alibaba.bytekit.asm.instrument;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.Test;
+import org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory;
+
+import com.alibaba.bytekit.asm.inst.AbstractAutowireCapableBeanFactory_Instrument;
+import com.alibaba.bytekit.utils.AsmUtils;
+import com.alibaba.bytekit.utils.ClassLoaderUtils;
+import com.alibaba.bytekit.utils.VerifyUtils;
+import com.alibaba.deps.org.objectweb.asm.tree.ClassNode;
+
+/**
+ * 覆盖 @Instrument(updateMajorVersion) 的默认值解析逻辑。
+ */
+public class UpdateMajorVersionDefaultTest {
+
+    @Test
+    public void testUpdateMajorVersionDefaultValue() throws Exception {
+        byte[] instrumentBytes = ClassLoaderUtils.readBytecode(AbstractAutowireCapableBeanFactory_Instrument.class);
+        InstrumentTemplate instrumentTemplate = new InstrumentTemplate();
+        instrumentTemplate.addInstrumentClass(instrumentBytes);
+
+        InstrumentParseResult parseResult = instrumentTemplate.build();
+        assertThat(parseResult.getInstrumentConfigs()).hasSize(1);
+
+        InstrumentConfig config = parseResult.getInstrumentConfigs().get(0);
+        assertThat(config.isUpdateMajorVersion()).isTrue();
+
+        Class<?> targetClass = AbstractAutowireCapableBeanFactory.class;
+        byte[] originBytes = ClassLoaderUtils.readBytecode(targetClass);
+
+        ClassNode originNode = AsmUtils.toClassNode(originBytes);
+        int originMajorVersion = AsmUtils.getMajorVersion(originNode.version);
+        assertThat(originMajorVersion).isLessThan(52);
+
+        InstrumentTransformer transformer = new InstrumentTransformer(parseResult);
+        byte[] transformedBytes = transformer.transform(targetClass.getClassLoader(),
+                targetClass.getName().replace('.', '/'), targetClass, targetClass.getProtectionDomain(), originBytes);
+        assertThat(transformedBytes).isNotNull();
+
+        ClassNode transformedNode = AsmUtils.toClassNode(transformedBytes);
+        int transformedMajorVersion = AsmUtils.getMajorVersion(transformedNode.version);
+        assertThat(transformedMajorVersion).isGreaterThanOrEqualTo(52);
+
+        // 触发 JVM 校验，避免出现 VerifyError: Illegal type at constant pool entry
+        java.net.URL[] urls = ClassLoaderUtils.getUrls(ClassLoader.getSystemClassLoader());
+        if (urls != null) {
+            VerifyUtils.ClassbyteClassLoader cl = new VerifyUtils.ClassbyteClassLoader(urls,
+                    ClassLoader.getSystemClassLoader().getParent());
+            cl.addClass(targetClass.getName(), transformedBytes);
+        }
+    }
+}