Require Java 8 (#240)

9 files changed, 19 insertions, 24 deletions

diff --git a/README.md b/README.md
index b7747ba..ecb2ded 100644
--- a/README.md
+++ b/README.md
@@ -22,11 +22,6 @@ tracing function calls to their code to see how long each part takes.
     dependencies making it easy to include in other projects.  If no backend for recording the trace
     is present, the library safely disables itself.
 
-*   **Multiple Java Versions**: The PerfMark API supports Java 6, making it easy to include on 
-    older or constrained environments.  Additionally, PerfMark includes optimized backends for 
-    Java 6, Java 7, and Java 9.  Each of these backends is automatically loaded at runtime 
-    (if possible) and uses advanced JVM features for maximum speed. 
-
 *   **Chrome Trace Viewer Integration**: PerfMark can export to the Chrome Trace Event Format, 
     making it easy to view in your Web Browser.
     
diff --git a/api/build.gradle.kts b/api/build.gradle.kts
index dfaff24..d576f90 100644
--- a/api/build.gradle.kts
+++ b/api/build.gradle.kts
@@ -12,7 +12,7 @@ buildscript {
 }
 
 
-val jdkVersion = JavaVersion.VERSION_1_6
+val jdkVersion = JavaVersion.VERSION_1_8
 
 description = "PerfMark API"
 
diff --git a/impl/build.gradle.kts b/impl/build.gradle.kts
index ae79f59..5716d20 100644
--- a/impl/build.gradle.kts
+++ b/impl/build.gradle.kts
@@ -9,7 +9,7 @@ buildscript {
     }
 }
 
-val jdkVersion = JavaVersion.VERSION_1_6
+val jdkVersion = JavaVersion.VERSION_1_8
 
 description = "PerfMark Implementation API"
 
diff --git a/java6/build.gradle b/java6/build.gradle
index 8ea17d4..ad982a5 100644
--- a/java6/build.gradle
+++ b/java6/build.gradle
@@ -1,6 +1,6 @@
 description = "PerfMark Java6 API"
 ext.moduleName = "io.perfmark.javasix"
-ext.jdkVersion = JavaVersion.VERSION_1_6
+ext.jdkVersion = JavaVersion.VERSION_1_8
 
 java {
     toolchain {
diff --git a/java6/src/test/java/io/perfmark/java6/VersionTest.java b/java6/src/test/java/io/perfmark/java6/VersionTest.java
index 1744298..654b146 100644
--- a/java6/src/test/java/io/perfmark/java6/VersionTest.java
+++ b/java6/src/test/java/io/perfmark/java6/VersionTest.java
@@ -27,7 +27,7 @@ import org.junit.runners.JUnit4;
 @RunWith(JUnit4.class)
 public class VersionTest {
 
-  private static final short JAVA_VERSION_6 = 50;
+  private static final short JAVA_VERSION_6 = 52; // Java 8, now.
 
   @Test
   public void checkVersion() throws Exception {
diff --git a/java7/build.gradle b/java7/build.gradle
index a342af3..51764b5 100644
--- a/java7/build.gradle
+++ b/java7/build.gradle
@@ -1,7 +1,7 @@
 
 description = "PerfMark Java7 API"
 ext.moduleName = "io.perfmark.javaseven"
-ext.jdkVersion = JavaVersion.VERSION_1_7
+ext.jdkVersion = JavaVersion.VERSION_1_8
 
 compileJava {
     sourceCompatibility = jdkVersion
diff --git a/java7/src/test/java/io/perfmark/java7/VersionTest.java b/java7/src/test/java/io/perfmark/java7/VersionTest.java
index 843917a..c33f222 100644
--- a/java7/src/test/java/io/perfmark/java7/VersionTest.java
+++ b/java7/src/test/java/io/perfmark/java7/VersionTest.java
@@ -27,7 +27,7 @@ import org.junit.runners.JUnit4;
 @RunWith(JUnit4.class)
 public class VersionTest {
 
-  private static final short JAVA_VERSION_7 = 51;
+  private static final short JAVA_VERSION_7 = 52; // Java 8, now
 
   @Test
   public void blah() throws Exception {
diff --git a/tracewriter/build.gradle.kts b/tracewriter/build.gradle.kts
index 7aac239..14a6d77 100644
--- a/tracewriter/build.gradle.kts
+++ b/tracewriter/build.gradle.kts
@@ -11,7 +11,7 @@ plugins {
 
 description = "PerfMark Tracer Output"
 
-val jdkVersion = JavaVersion.VERSION_1_7
+val jdkVersion = JavaVersion.VERSION_1_8
 
 dependencies {
     api(project(":perfmark-impl"))
diff --git a/tracewriter/src/main/java/io/perfmark/tracewriter/TraceEventWriter.java b/tracewriter/src/main/java/io/perfmark/tracewriter/TraceEventWriter.java
index 1f75394..e888d79 100644
--- a/tracewriter/src/main/java/io/perfmark/tracewriter/TraceEventWriter.java
+++ b/tracewriter/src/main/java/io/perfmark/tracewriter/TraceEventWriter.java
@@ -466,29 +466,28 @@ public final class TraceEventWriter {
       TaskStart taskStart = taskStack.peekLast();
       TraceEvent taskEvent = traceEvents.get(taskStart.traceEventIdx);
       TraceEvent.TagMap args = taskEvent.args();
-      out:
       {
         switch (mark.getOperation()) {
           case TAG_N0S1:
             args = args.withUnkeyed(mark.getTagStringValue(), Mark.NO_TAG_ID);
-            break out;
+            break;
           case TAG_N1S0:
             args = args.withUnkeyed(Mark.NO_TAG_NAME, mark.getTagFirstNumeric());
-            break out;
+            break;
           case TAG_N1S1:
             args = args.withUnkeyed(mark.getTagStringValue(), mark.getTagFirstNumeric());
-            break out;
+            break;
           case TAG_KEYED_N0S2:
             args = args.withKeyed(mark.getTagKey(), mark.getTagStringValue());
-            break out;
+            break;
           case TAG_KEYED_N1S1:
             args = args.withKeyed(mark.getTagKey(), mark.getTagFirstNumeric());
-            break out;
+            break;
           case TAG_KEYED_N2S1:
             args =
                 args.withKeyed(
                     mark.getTagKey(), mark.getTagFirstNumeric(), mark.getTagSecondNumeric());
-            break out;
+            break;
           case NONE:
           case TASK_START_N1S1:
           case TASK_START_N1S2:
@@ -501,8 +500,9 @@ public final class TraceEventWriter {
           case EVENT_N2S3:
           case LINK:
             break;
+          default:
+            throw new AssertionError(mark.getOperation());
         }
-        throw new AssertionError(mark.getOperation());
       }
       traceEvents.set(taskStart.traceEventIdx, taskEvent.args(args));
     }
@@ -510,16 +510,15 @@ public final class TraceEventWriter {
     @Override
     protected void onEvent(Mark mark) {
       TraceEvent.TagMap tagMap = TraceEvent.TagMap.EMPTY;
-      out:
       {
         switch (mark.getOperation()) {
           case EVENT_N1S1:
           case EVENT_N1S2:
-            break out;
+            break;
           case EVENT_N2S2:
           case EVENT_N2S3:
             tagMap = tagMap.withUnkeyed(mark.getTagStringValue(), mark.getTagFirstNumeric());
-            break out;
+            break;
           case NONE:
           case TASK_START_N1S1:
           case TASK_START_N1S2:
@@ -534,8 +533,9 @@ public final class TraceEventWriter {
           case TAG_KEYED_N1S1:
           case TAG_KEYED_N2S1:
             break;
+          default:
+            throw new AssertionError(mark.getOperation());
         }
-        throw new AssertionError(mark.getOperation());
       }
       TraceEvent traceEvent =
           TraceEvent.EVENT