test/hotspot/jtreg/runtime/exceptionMsgs/NullPointerException/NPEInHiddenTopFrameTest.java

rev 56281 : 8218628: Add detailed message to NullPointerException describing what is null.
Summary: This is the implementation of JEP 358: Helpful NullPointerExceptions.
Reviewed-by: coleenp
rev 56283 : [mq]: fixes_review_of_16.patch

@@ -24,13 +24,14 @@
 
 /**
  * @test
  * @summary Test NullPointerException messages thrown in frames that
  *   are hidden in the backtrace/stackTrace.
+ * @bug 8218628
  * @library /test/lib
  * @compile -g NPEInHiddenTopFrameTest.java
- * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:-ShowHiddenFrames -XX:-ShowCodeDetailsInExceptionMessages NPEInHiddenTopFrameTest hidden
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:-ShowHiddenFrames -XX:+ShowCodeDetailsInExceptionMessages NPEInHiddenTopFrameTest hidden
  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+ShowHiddenFrames -XX:+ShowCodeDetailsInExceptionMessages NPEInHiddenTopFrameTest visible
  */
 
 import jdk.test.lib.Asserts;
 

@@ -66,14 +67,15 @@
                 concatter.someMethod(nullString, "validString");
             }
         } catch (NullPointerException e) {
             checkMessage("concatter.someMethod(nullString, \"validString\");", e.getMessage(),
                          framesAreHidden ?
-                         // This is the message printed if the wrong method/bci are used:
+                         // This is the message that would be printed if the wrong method/bci are used:
                          // "Cannot invoke 'NPEInHiddenTopFrameTest$SomeFunctionalInterface.someMethod(String, String)'" +
                          // " because 'concatter' is null."
-                         // With this fix no message is printed.
+                         // But the NPE message generation now recognizes this situation and skips the 
+                         // message. So we expect null:
                          null :
                          // This is the correct message, but it describes code generated on-the-fly.
                          // You get it if you disable hiding frames (-XX:+ShowHiddenframes).
                          "Cannot invoke 'String.concat(String)' because '<parameter1>' is null." );
             e.printStackTrace();