Instrument DefaultSpan.create to return a bridged span. (#947)

gradle/dependencies.gradle

@@ -9,9 +9,10 @@ configurations.all {
 ext {
   versions = [
     // Check https://oss.jfrog.org/libs-snapshot/io/opentelemetry/ for latest snapshot version.
-    opentelemetry     : '0.7.0',
-    // Snapshot versions are getting split into two suffixes
-    opentelemetryOther: '0.7.0',
+    opentelemetry     : '0.8.0-20200811.154243-20',
+    // Snapshot versions are often split into two suffixes based on jfrog's whims, best to keep
+    // these separate until GA
+    opentelemetryOther: '0.8.0-20200811.154243-20',
 
     slf4j             : "1.7.30",
     guava             : "20.0", // Last version to support Java 7

instrumentation/opentelemetry-api-beta/src/main/java/io/opentelemetry/auto/instrumentation/opentelemetryapi/DefaultSpanInstrumentation.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.opentelemetry.auto.instrumentation.opentelemetryapi;
+
+import static net.bytebuddy.matcher.ElementMatchers.isMethod;
+import static net.bytebuddy.matcher.ElementMatchers.isPublic;
+import static net.bytebuddy.matcher.ElementMatchers.isStatic;
+import static net.bytebuddy.matcher.ElementMatchers.named;
+
+import com.google.auto.service.AutoService;
+import io.opentelemetry.auto.instrumentation.opentelemetryapi.trace.Bridging;
+import io.opentelemetry.auto.tooling.Instrumenter;
+import io.opentelemetry.trace.DefaultSpan;
+import java.util.Collections;
+import java.util.Map;
+import net.bytebuddy.asm.Advice;
+import net.bytebuddy.description.method.MethodDescription;
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.matcher.ElementMatcher;
+
+@AutoService(Instrumenter.class)
+public class DefaultSpanInstrumentation extends AbstractInstrumentation {
+  @Override
+  public ElementMatcher<? super TypeDescription> typeMatcher() {
+    return named("unshaded.io.opentelemetry.trace.DefaultSpan");
+  }
+
+  @Override
+  public Map<? extends ElementMatcher<? super MethodDescription>, String> transformers() {
+    return Collections.singletonMap(
+        isMethod().and(isPublic()).and(isStatic()).and(named("create")),
+        DefaultSpanInstrumentation.class.getName() + "$CreateAdvice");
+  }
+
+  public static class CreateAdvice {
+    @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
+    public static void methodExit(
+        @Advice.Return(readOnly = false) unshaded.io.opentelemetry.trace.Span span) {
+      span = Bridging.toUnshaded(DefaultSpan.create(Bridging.toShaded(span.getContext())));
+    }
+  }
+}

instrumentation/opentelemetry-api-beta/src/test/groovy/TracerTest.groovy

@@ -19,6 +19,7 @@ import io.opentelemetry.trace.attributes.SemanticAttributes
 import unshaded.io.grpc.Context
 import unshaded.io.opentelemetry.OpenTelemetry
 import unshaded.io.opentelemetry.context.Scope
+import unshaded.io.opentelemetry.trace.DefaultSpan
 import unshaded.io.opentelemetry.trace.Span
 import unshaded.io.opentelemetry.trace.Status
 
@@ -357,4 +358,18 @@ class TracerTest extends AgentTestRunner {
       }
     }
   }
+
+  def "add DefaultSpan to context"() {
+    when:
+    // Lazy way to get a span context
+    def tracer = OpenTelemetry.getTracerProvider().get("test")
+    def testSpan = tracer.spanBuilder("test").setSpanKind(PRODUCER).startSpan()
+    testSpan.end()
+
+    def span = DefaultSpan.create(testSpan.getContext())
+    def context = withSpan(span, Context.current())
+
+    then:
+    getSpan(context).getContext().getSpanId() == span.getContext().getSpanId()
+  }
 }