8244670: convert clhsdb "whatis" command from javascript to java

Reviewed-by: sspitsyn, kevinw

Author: plummercj

src/jdk.hotspot.agent/doc/clhsdb.html

@@ -90,7 +90,7 @@ <h3>Annotated output of CLHSDB help command</h3>
   vmstructsdump <font color="red">dump hotspot type library in text</font>
   verbose true | false <font color="red">turn on/off verbose mode</font>
   versioncheck [ true | false ] <font color="red">turn on/off debuggee VM version check</font>
-  whatis address <font color="red">print info about any arbitrary address</font>
+  whatis address <font color="red">print info about any arbitrary address. alias for findpc command</font>
   where { -a | id } <font color="red">print Java stack trace of given Java thread or all Java threads (-a)</font>
 </code>
 </pre>

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/CommandProcessor.java

@@ -608,6 +608,18 @@ public void doit(Tokens t) {
                 }
             }
         },
+        // "whatis" is just an alias for "findpc". It's kept around for compatiblity reasons.
+        new Command("whatis", "whatis address", false) {
+            public void doit(Tokens t) {
+                if (t.countTokens() != 1) {
+                    usage();
+                } else {
+                    Address a = VM.getVM().getDebugger().parseAddress(t.nextToken());
+                    PointerLocation loc = PointerFinder.find(a);
+                    loc.printOn(out);
+                }
+            }
+        },
         new Command("symbol", "symbol address", false) {
             public void doit(Tokens t) {
                 if (t.countTokens() != 1) {

test/hotspot/jtreg/serviceability/sa/ClhsdbFindPC.java

@@ -182,6 +182,15 @@ private static void testFindPC(boolean withXcomp, boolean withCore) throws Excep
                                           methodAddr));
             runTest(withCore, cmds, expStrMap);
 
+            // Rerun above findpc command, but this time using "whatis", which is an alias for "findpc".
+            cmdStr = "whatis " + methodAddr;
+            cmds = List.of(cmdStr);
+            expStrMap = new HashMap<>();
+            expStrMap.put(cmdStr, List.of("Method ",
+                                          "LingeredApp.steadyState",
+                                          methodAddr));
+            runTest(withCore, cmds, expStrMap);
+
             // Run findpc on a JavaThread*. We can find one in the jstack output.
             // The tid for a thread is it's JavaThread*. For example:
             //  "main" #1 prio=5 tid=0x00000080263398f0 nid=0x277e0 ...