Exclude synthetic methods for WitnessMethod (#504)

CHANGES.md

@@ -5,6 +5,7 @@ Release Notes.
 8.16.0
 ------------------
 
+* Exclude `synthetic` methods for the WitnessMethod mechanism
 
 #### Documentation
 

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/WitnessMethod.java

@@ -18,17 +18,19 @@
 
 package org.apache.skywalking.apm.agent.core.plugin;
 
+import com.google.common.base.Preconditions;
 import lombok.Getter;
-import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 import net.bytebuddy.description.method.MethodDescription;
 import net.bytebuddy.matcher.ElementMatcher;
 
+import static net.bytebuddy.matcher.ElementMatchers.isSynthetic;
+import static net.bytebuddy.matcher.ElementMatchers.not;
+
 /**
  * Witness Method for plugin activation
  */
 @ToString
-@RequiredArgsConstructor
 public class WitnessMethod {
 
     /**
@@ -42,4 +44,8 @@ public class WitnessMethod {
     @Getter
     private final ElementMatcher<? super MethodDescription.InDefinedShape> elementMatcher;
 
+    public WitnessMethod(String declaringClassName, ElementMatcher.Junction<? super MethodDescription.InDefinedShape> elementMatcher) {
+        this.declaringClassName = declaringClassName;
+        this.elementMatcher = Preconditions.checkNotNull(elementMatcher).and(not(isSynthetic()));
+    }
 }

apm-sniffer/apm-agent-core/src/test/java/org/apache/skywalking/apm/agent/core/plugin/witness/WitnessTest.java

@@ -21,6 +21,7 @@ package org.apache.skywalking.apm.agent.core.plugin.witness;
 import net.bytebuddy.description.method.MethodDescription;
 import net.bytebuddy.matcher.ElementMatcher;
 import net.bytebuddy.matcher.ElementMatchers;
+import net.bytebuddy.pool.TypePool;
 import org.apache.skywalking.apm.agent.core.plugin.WitnessFinder;
 import org.apache.skywalking.apm.agent.core.plugin.WitnessMethod;
 import org.junit.Assert;
@@ -60,8 +61,27 @@ public class WitnessTest {
         Assert.assertTrue(finder.exist(witnessMethod, this.getClass().getClassLoader()));
     }
 
+    @Test
+    public void testSyntheticMethods() {
+        // public void org.apache.skywalking.apm.agent.core.plugin.witness.WitnessTest$Child.foo()
+        Assert.assertEquals(Child.class.getDeclaredMethods().length, 1);
+        // with an additional synthetic constructor
+        Assert.assertEquals(TypePool.Default.ofSystemLoader().describe(className + "$Child").resolve().getDeclaredMethods().size(), 2);
+        WitnessMethod witnessMethod = new WitnessMethod(className + "$Child", ElementMatchers.named("foo"));
+        Assert.assertTrue(finder.exist(className + "$Child", this.getClass().getClassLoader()));
+        Assert.assertFalse(finder.exist(witnessMethod, this.getClass().getClassLoader()));
+    }
+
     public List<Map<String, Object>> foo(List<Map<String, Object>> param, String s) {
         return null;
     }
 
+    public static class Child extends Base {
+
+    }
+
+    static class Base {
+        public void foo() {
+        }
+    }
 }

test/plugin/scenarios/shenyu-2.4.x-sofarpc-scenario/pom.xml

@@ -63,6 +63,13 @@
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
+            <dependency>
+                <groupId>io.grpc</groupId>
+                <artifactId>grpc-bom</artifactId>
+                <version>1.28.1</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
             <dependency>
                 <groupId>org.apache.shenyu</groupId>
                 <artifactId>shenyu-spring-boot-starter-gateway</artifactId>
@@ -103,7 +110,6 @@
         </dependencies>
     </dependencyManagement>
 
-
     <build>
         <finalName>shenyu-2.4.x-sofarpc-scenario</finalName>
         <plugins>