From 512472ed17f84f636ebc3dfa1e4c1e0c5d8d6644 Mon Sep 17 00:00:00 2001
From: hengyunabc <hengyunabc@gmail.com>
Date: Thu, 24 Sep 2020 20:35:03 +0800
Subject: [PATCH] Fix the problem that when the --enable-preview feature is
 enabled, set the wrong java version in watch/trace. #1526 #1223

---
 .../taobao/arthas/bytekit/utils/AsmUtils.java | 20 ++++++++++++
 .../arthas/bytekit/utils/AsmUtilsTest.java    | 32 +++++++++++++++++++
 .../taobao/arthas/core/advisor/Enhancer.java  |  6 ++--
 3 files changed, 55 insertions(+), 3 deletions(-)

diff --git a/bytekit/src/main/java/com/taobao/arthas/bytekit/utils/AsmUtils.java b/bytekit/src/main/java/com/taobao/arthas/bytekit/utils/AsmUtils.java
index f094d6644..9846d293d 100644
--- a/bytekit/src/main/java/com/taobao/arthas/bytekit/utils/AsmUtils.java
+++ b/bytekit/src/main/java/com/taobao/arthas/bytekit/utils/AsmUtils.java
@@ -561,6 +561,26 @@ public class AsmUtils {
 	    return new String(charArray);
 	}
 
+    /**
+     * Java ClassFile versions (the minor version is stored in the 16 most
+     * significant bits, and the major version in the 16 least significant bits).
+     * @see com.alibaba.arthas.deps.org.objectweb.asm.Opcodes#V_PREVIEW
+     * @param version
+     * @return
+     */
+    public static int getMajorVersion(int version) {
+        return 0x0000FFFF & version;
+    }
 
+    /**
+     * 替换掉完整 version里的 major version
+     * 
+     * @param version
+     * @param majorVersion
+     * @return
+     */
+    public static int setMajorVersion(int version, int majorVersion) {
+        return (version & 0xFFFF0000) | majorVersion;
+    }
 
 }
diff --git a/bytekit/src/test/java/com/taobao/arthas/bytekit/utils/AsmUtilsTest.java b/bytekit/src/test/java/com/taobao/arthas/bytekit/utils/AsmUtilsTest.java
index eef1d9ab4..21c122b16 100644
--- a/bytekit/src/test/java/com/taobao/arthas/bytekit/utils/AsmUtilsTest.java
+++ b/bytekit/src/test/java/com/taobao/arthas/bytekit/utils/AsmUtilsTest.java
@@ -141,4 +141,36 @@ public class AsmUtilsTest {
     	Assertions.assertThat(object.getClass().getName()).isEqualTo("com.test.Test.XXX");
     }
 
+    @Test
+    public void testGetMajorVersion() throws Exception {
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V1_1)).isEqualTo(45);
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V1_2)).isEqualTo(46);
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V1_3)).isEqualTo(47);
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V1_4)).isEqualTo(48);
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V1_5)).isEqualTo(49);
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V1_6)).isEqualTo(50);
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V1_7)).isEqualTo(51);
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V1_8)).isEqualTo(52);
+
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V9)).isEqualTo(53);
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V10)).isEqualTo(54);
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V11)).isEqualTo(55);
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V12)).isEqualTo(56);
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V13)).isEqualTo(57);
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V14)).isEqualTo(58);
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V15)).isEqualTo(59);
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V16)).isEqualTo(60);
+
+        Assertions.assertThat(AsmUtils.getMajorVersion(Opcodes.V16 | Opcodes.V_PREVIEW)).isEqualTo(60);
+    }
+
+    @Test
+    public void testSetMajorVersion() throws Exception {
+        int version = Opcodes.V16 | Opcodes.V_PREVIEW;
+        int newVersion = AsmUtils.setMajorVersion(version, 58);
+
+        AsmUtils.getMajorVersion(newVersion);
+
+        Assertions.assertThat(AsmUtils.getMajorVersion(newVersion)).isEqualTo(58);
+    }
 }
diff --git a/core/src/main/java/com/taobao/arthas/core/advisor/Enhancer.java b/core/src/main/java/com/taobao/arthas/core/advisor/Enhancer.java
index 2bbce18e2..0ff205bad 100644
--- a/core/src/main/java/com/taobao/arthas/core/advisor/Enhancer.java
+++ b/core/src/main/java/com/taobao/arthas/core/advisor/Enhancer.java
@@ -228,9 +228,9 @@ public class Enhancer implements ClassFileTransformer {
                 affect.addMethodAndCount(inClassLoader, className, methodNode.name, methodNode.desc);
             }
 
-            // https://github.com/alibaba/arthas/issues/1223
-            if (classNode.version < Opcodes.V1_5) {
-                classNode.version = Opcodes.V1_5;
+            // https://github.com/alibaba/arthas/issues/1223 , V1_5 的major version是49
+            if (AsmUtils.getMajorVersion(classNode.version) < 49) {
+                classNode.version = AsmUtils.setMajorVersion(classNode.version, 49);
             }
 
             byte[] enhanceClassByteArray = AsmUtils.toBytes(classNode, inClassLoader, classReader);