Mark our generated classes and members as synthetic (#3928)

javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/context/FieldBackedProvider.java

@@ -39,6 +39,7 @@ import net.bytebuddy.asm.AsmVisitorWrapper;
 import net.bytebuddy.description.field.FieldDescription;
 import net.bytebuddy.description.field.FieldList;
 import net.bytebuddy.description.method.MethodList;
+import net.bytebuddy.description.modifier.SyntheticState;
 import net.bytebuddy.description.modifier.TypeManifestation;
 import net.bytebuddy.description.modifier.Visibility;
 import net.bytebuddy.description.type.TypeDescription;
@@ -528,7 +529,7 @@ public class FieldBackedProvider implements InstrumentationContextProvider {
             if (!foundField) {
               cv.visitField(
                   // Field should be transient to avoid being serialized with the object.
-                  Opcodes.ACC_PRIVATE | Opcodes.ACC_TRANSIENT,
+                  Opcodes.ACC_PRIVATE | Opcodes.ACC_TRANSIENT | Opcodes.ACC_SYNTHETIC,
                   fieldName,
                   contextType.getDescriptor(),
                   null,
@@ -576,7 +577,7 @@ public class FieldBackedProvider implements InstrumentationContextProvider {
 
           private MethodVisitor getAccessorMethodVisitor(String methodName) {
             return cv.visitMethod(
-                Opcodes.ACC_PUBLIC,
+                Opcodes.ACC_PUBLIC | Opcodes.ACC_SYNTHETIC,
                 methodName,
                 Utils.getMethodDefinition(interfaceType, methodName).getDescriptor(),
                 null,
@@ -622,7 +623,7 @@ public class FieldBackedProvider implements InstrumentationContextProvider {
       String keyClassName, String contextClassName) {
     return byteBuddy
         .rebase(ContextStoreImplementationTemplate.class)
-        .modifiers(Visibility.PUBLIC, TypeManifestation.FINAL)
+        .modifiers(Visibility.PUBLIC, TypeManifestation.FINAL, SyntheticState.SYNTHETIC)
         .name(getContextStoreImplementationClassName(keyClassName, contextClassName))
         .visit(getContextStoreImplementationVisitor(keyClassName, contextClassName))
         .make();
@@ -992,6 +993,7 @@ public class FieldBackedProvider implements InstrumentationContextProvider {
     TypeDescription contextType = new TypeDescription.ForLoadedType(Object.class);
     return byteBuddy
         .makeInterface()
+        .merge(SyntheticState.SYNTHETIC)
         .name(getContextAccessorInterfaceName(keyClassName, contextClassName))
         .defineMethod(getContextGetterName(keyClassName), contextType, Visibility.PUBLIC)
         .withoutCode()

testing-common/integration-tests/build.gradle.kts

@@ -27,7 +27,9 @@ tasks {
   val testFieldInjectionDisabled by registering(Test::class) {
     filter {
       includeTestsMatching("context.FieldInjectionDisabledTest")
+      isFailOnNoMatchingTests = false
     }
+    include("**/FieldInjectionDisabledTest.*")
     jvmArgs("-Dotel.javaagent.experimental.field-injection.enabled=false")
   }
 
@@ -35,6 +37,7 @@ tasks {
     dependsOn(testFieldInjectionDisabled)
     filter {
       excludeTestsMatching("context.FieldInjectionDisabledTest")
+      isFailOnNoMatchingTests = false
     }
     // this is needed for AgentInstrumentationSpecificationTest
     jvmArgs("-Dotel.javaagent.exclude-classes=config.exclude.packagename.*,config.exclude.SomeClass,config.exclude.SomeClass\$NestedClass")

testing-common/integration-tests/src/test/groovy/context/FieldBackedProviderTest.groovy

@@ -42,10 +42,12 @@ class FieldBackedProviderTest extends AgentInstrumentationSpecification {
     boolean hasField = false
     boolean isPrivate = false
     boolean isTransient = false
+    boolean isSynthetic = false
     for (Field field : keyClass.getDeclaredFields()) {
       if (field.getName().startsWith("__opentelemetry")) {
         isPrivate = Modifier.isPrivate(field.getModifiers())
         isTransient = Modifier.isTransient(field.getModifiers())
+        isSynthetic = field.isSynthetic()
         hasField = true
         break
       }
@@ -53,12 +55,14 @@ class FieldBackedProviderTest extends AgentInstrumentationSpecification {
 
     boolean hasMarkerInterface = false
     boolean hasAccessorInterface = false
+    boolean accessorInterfaceIsSynthetic = false
     for (Class inter : keyClass.getInterfaces()) {
       if (inter.getName() == 'io.opentelemetry.javaagent.bootstrap.FieldBackedContextStoreAppliedMarker') {
         hasMarkerInterface = true
       }
       if (inter.getName().startsWith('io.opentelemetry.javaagent.bootstrap.instrumentation.context.FieldBackedProvider$ContextAccessor')) {
         hasAccessorInterface = true
+        accessorInterfaceIsSynthetic = inter.isSynthetic()
       }
     }
 
@@ -66,8 +70,10 @@ class FieldBackedProviderTest extends AgentInstrumentationSpecification {
     hasField == shouldModifyStructure
     isPrivate == shouldModifyStructure
     isTransient == shouldModifyStructure
+    isSynthetic == shouldModifyStructure
     hasMarkerInterface == shouldModifyStructure
     hasAccessorInterface == shouldModifyStructure
+    accessorInterfaceIsSynthetic == shouldModifyStructure
     keyClass.newInstance().isInstrumented() == shouldModifyStructure
 
     where: