extension smoke test to avoid regression with indy

settings.gradle.kts

@@ -156,6 +156,8 @@ include(":smoke-tests:images:servlet")
 include(":smoke-tests:images:servlet:servlet-3.0")
 include(":smoke-tests:images:servlet:servlet-5.0")
 include(":smoke-tests:images:spring-boot")
+include(":smoke-tests:extensions:testapp")
+include(":smoke-tests:extensions:extension")
 
 include(":smoke-tests-otel-starter:spring-smoke-testing")
 include(":smoke-tests-otel-starter:spring-boot-2")

smoke-tests/README.md

@@ -2,5 +2,8 @@
 
 Assert that various applications will start up with the JavaAgent without any obvious ill effects.
 
-Each subproject underneath `smoke-tests` produces one or more docker images containing some application
+Each subproject underneath `smoke-tests/images` produces one or more docker images containing some application
 under the test. Various tests in the main module then use them to run the appropriate tests.
+
+The `smoke-tests/extensions` folder contains a test application and packaged instrumentation(s) extension to
+test compatibility with existing user-built extensions.

smoke-tests/build.gradle.kts

@@ -77,8 +77,20 @@ tasks {
       .withPropertyName("javaagent")
       .withNormalizer(ClasspathNormalizer::class)
 
+    val extensionTask = project(":smoke-tests:extensions:extension").tasks.named<Jar>("jar")
+    val extensionJarPath = extensionTask.flatMap { it.archiveFile }
+
+    val extensionTestAppTask = project(":smoke-tests:extensions:testapp").tasks.named<Jar>("jar")
+    val extensionTestAppJarPath = extensionTestAppTask.flatMap { it.archiveFile }
+
+    dependsOn(shadowTask, extensionTestAppTask, extensionTask)
+
     doFirst {
-      jvmArgs("-Dio.opentelemetry.smoketest.agent.shadowJar.path=${agentJarPath.get()}")
+      jvmArgs(
+        "-Dio.opentelemetry.smoketest.agent.shadowJar.path=${agentJarPath.get()}",
+        "-Dio.opentelemetry.smoketest.extension.path=${extensionJarPath.get()}",
+        "-Dio.opentelemetry.smoketest.extension.testapp.path=${extensionTestAppJarPath.get()}"
+      )
     }
   }
 }

smoke-tests/extensions/extension/build.gradle.kts

@@ -0,0 +1,19 @@
+plugins {
+  id("otel.java-conventions")
+  id("io.opentelemetry.instrumentation.javaagent-instrumentation")
+}
+
+dependencies {
+  compileOnly("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure-spi")
+  compileOnly("io.opentelemetry.instrumentation:opentelemetry-instrumentation-api")
+  compileOnly("io.opentelemetry.instrumentation:opentelemetry-instrumentation-api-incubator")
+  compileOnly("io.opentelemetry.javaagent:opentelemetry-javaagent-extension-api")
+
+  compileOnly("com.google.auto.service:auto-service")
+  compileOnly("com.google.auto.service:auto-service-annotations")
+
+  annotationProcessor("com.google.auto.service:auto-service")
+
+  // Used by byte-buddy but not brought in as a transitive dependency
+  compileOnly("com.google.code.findbugs:annotations")
+}

smoke-tests/extensions/extension/src/main/java/io/opentelemetry/smoketest/extensions/inlined/SmokeInlinedInstrumentation.java

@@ -0,0 +1,104 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.smoketest.extensions.inlined;
+
+import static net.bytebuddy.matcher.ElementMatchers.named;
+import static net.bytebuddy.matcher.ElementMatchers.returns;
+import static net.bytebuddy.matcher.ElementMatchers.takesArgument;
+
+import io.opentelemetry.instrumentation.api.util.VirtualField;
+import io.opentelemetry.javaagent.extension.instrumentation.TypeInstrumentation;
+import io.opentelemetry.javaagent.extension.instrumentation.TypeTransformer;
+import java.util.Arrays;
+import net.bytebuddy.asm.Advice;
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.matcher.ElementMatcher;
+
+public class SmokeInlinedInstrumentation implements TypeInstrumentation {
+
+  @Override
+  public ElementMatcher<TypeDescription> typeMatcher() {
+    return named("io.opentelemetry.smoketest.extensions.app.AppMain");
+  }
+
+  @Override
+  public void transform(TypeTransformer transformer) {
+    transformer.applyAdviceToMethod(
+        named("returnValue").and(takesArgument(0, int.class)),
+        this.getClass().getName() + "$ModifyReturnValueAdvice");
+    transformer.applyAdviceToMethod(
+        named("methodArguments").and(takesArgument(0, int.class)),
+        this.getClass().getName() + "$ModifyArgumentsAdvice");
+    transformer.applyAdviceToMethod(
+        named("setVirtualFieldValue")
+            .and(takesArgument(0, Object.class))
+            .and(takesArgument(1, Integer.class)),
+        this.getClass().getName() + "$VirtualFieldSetAdvice");
+    transformer.applyAdviceToMethod(
+        named("getVirtualFieldValue")
+            .and(takesArgument(0, Object.class))
+            .and(returns(Integer.class)),
+        this.getClass().getName() + "$VirtualFieldGetAdvice");
+    transformer.applyAdviceToMethod(
+        named("localValue").and(takesArgument(0, int[].class)).and(returns(int[].class)),
+        this.getClass().getName() + "$LocalVariableAdvice");
+  }
+
+  @SuppressWarnings("unused")
+  public static class ModifyReturnValueAdvice {
+
+    @Advice.OnMethodExit(suppress = Throwable.class)
+    public static void onExit(@Advice.Return(readOnly = false) int returnValue) {
+      returnValue = returnValue + 1;
+    }
+  }
+
+  @SuppressWarnings("unused")
+  public static class ModifyArgumentsAdvice {
+    @Advice.OnMethodEnter(suppress = Throwable.class)
+    public static void onEnter(@Advice.Argument(value = 0, readOnly = false) int argument) {
+      argument = argument - 1;
+    }
+  }
+
+  public static class VirtualFieldSetAdvice {
+    @Advice.OnMethodEnter(suppress = Throwable.class)
+    public static void onEnter(
+        @Advice.Argument(0) Object target, @Advice.Argument(1) Integer value) {
+      VirtualField<Object, Integer> field = VirtualField.find(Object.class, Integer.class);
+      field.set(target, value);
+    }
+  }
+
+  @SuppressWarnings("unused")
+  public static class VirtualFieldGetAdvice {
+    @SuppressWarnings("UnusedVariable")
+    @Advice.OnMethodExit(suppress = Throwable.class)
+    public static void onExit(
+        @Advice.Argument(0) Object target, @Advice.Return(readOnly = false) Integer returnValue) {
+      VirtualField<Object, Integer> field = VirtualField.find(Object.class, Integer.class);
+      returnValue = field.get(target);
+    }
+  }
+
+  @SuppressWarnings("unused")
+  public static class LocalVariableAdvice {
+
+    @SuppressWarnings("UnusedVariable")
+    @Advice.OnMethodEnter(suppress = Throwable.class)
+    public static void onEnter(
+        @Advice.Argument(0) int[] array, @Advice.Local("backup") int[] backupArray) {
+      backupArray = Arrays.copyOf(array, array.length);
+    }
+
+    @SuppressWarnings("UnusedVariable")
+    @Advice.OnMethodExit(suppress = Throwable.class)
+    public static void onExit(
+        @Advice.Return(readOnly = false) int[] array, @Advice.Local("backup") int[] backupArray) {
+      array = Arrays.copyOf(backupArray, backupArray.length);
+    }
+  }
+}

smoke-tests/extensions/extension/src/main/java/io/opentelemetry/smoketest/extensions/inlined/SmokeInlinedInstrumentationModule.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.smoketest.extensions.inlined;
+
+import com.google.auto.service.AutoService;
+import io.opentelemetry.javaagent.extension.instrumentation.InstrumentationModule;
+import io.opentelemetry.javaagent.extension.instrumentation.TypeInstrumentation;
+import java.util.Collections;
+import java.util.List;
+
+@AutoService(InstrumentationModule.class)
+public class SmokeInlinedInstrumentationModule extends InstrumentationModule {
+
+  public SmokeInlinedInstrumentationModule() {
+    super("smoke-test-extension-inlined");
+  }
+
+  @Override
+  public List<TypeInstrumentation> typeInstrumentations() {
+    return Collections.singletonList(new SmokeInlinedInstrumentation());
+  }
+}

smoke-tests/extensions/testapp/build.gradle.kts

@@ -0,0 +1,19 @@
+plugins {
+  id("otel.java-conventions")
+}
+
+dependencies {
+}
+
+java {
+  sourceCompatibility = JavaVersion.VERSION_1_8
+  targetCompatibility = JavaVersion.VERSION_1_8
+}
+
+tasks {
+  jar {
+    manifest {
+      attributes("Main-Class" to "io.opentelemetry.smoketest.extensions.app.AppMain")
+    }
+  }
+}

smoke-tests/extensions/testapp/src/main/java/io/opentelemetry/smoketest/extensions/app/AppMain.java

@@ -0,0 +1,97 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.smoketest.extensions.app;
+
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
+import java.io.PrintStream;
+import java.util.Arrays;
+
+public class AppMain {
+
+  private AppMain() {}
+
+  public static void main(String[] args) {
+    testReturnValue();
+    testMethodArguments();
+    testVirtualFields();
+    testLocalValue();
+  }
+
+  private static void msg(String msg) {
+    // avoid checkstyle to complain
+    PrintStream out = System.out;
+    out.println(msg);
+  }
+
+  private static void testReturnValue() {
+    int returnValue = returnValue(42);
+    if (returnValue != 42) {
+      msg("return value has been modified");
+    } else {
+      msg("return value not modified");
+    }
+  }
+
+  private static int returnValue(int value) {
+    // method return value should be modified by instrumentation
+    return value;
+  }
+
+  private static void testMethodArguments() {
+    methodArguments(42, 42);
+  }
+
+  private static void methodArguments(int argument, int originalArgument) {
+    // method first argument should be modified by instrumentation
+    if (argument != originalArgument) {
+      msg("argument has been modified");
+    } else {
+      msg("argument not modified");
+    }
+  }
+
+  private static void testVirtualFields() {
+    Object target = new Object();
+    setVirtualFieldValue(target, 42);
+    Integer fieldValue = getVirtualFieldValue(target);
+    if (fieldValue == null || fieldValue != 42) {
+      msg("virtual field not supported");
+    } else {
+      msg("virtual field supported");
+    }
+  }
+
+  public static void setVirtualFieldValue(Object target, Integer value) {
+    // implementation should be provided by instrumentation
+  }
+
+  public static Integer getVirtualFieldValue(Object target) {
+    // implementation should be provided by instrumentation
+    return null;
+  }
+
+  private static void testLocalValue() {
+    int[] input = new int[] {1, 2, 3};
+    int[] result = localValue(input);
+    if (result.length != 3) {
+      throw new IllegalStateException();
+    }
+    // assumption on the instrumentation implementation to use a local value to preserve original
+    // array
+    boolean preserved = result[0] == 1 && result[1] == 2 && result[2] == 3;
+    if (!preserved) {
+      msg("local advice variable not supported");
+    } else {
+      msg("local advice variable supported");
+    }
+  }
+
+  @CanIgnoreReturnValue
+  private static int[] localValue(int[] array) {
+    Arrays.fill(array, 0);
+    return array;
+  }
+}