8261098: Add clhsdb "findsym" command

Reviewed-by: amenkov, sspitsyn

Author: plummercj

src/jdk.hotspot.agent/linux/native/libsaproc/LinuxDebuggerLocal.cpp

@@ -68,7 +68,7 @@ class AutoJavaString {
 public:
   // check env->ExceptionOccurred() after ctor
   AutoJavaString(JNIEnv* env, jstring str)
-    : m_env(env), m_str(str), m_buf(env->GetStringUTFChars(str, NULL)) {
+    : m_env(env), m_str(str), m_buf(str == NULL ? NULL : env->GetStringUTFChars(str, NULL)) {
   }
 
   ~AutoJavaString() {
@@ -350,12 +350,14 @@ JNIEXPORT jlong JNICALL Java_sun_jvm_hotspot_debugger_linux_LinuxDebuggerLocal_l
   jlong addr;
   jboolean isCopy;
   struct ps_prochandle* ph = get_proc_handle(env, this_obj);
+  // Note, objectName is ignored, and may in fact be NULL.
+  // lookup_symbol will always search all objects/libs
   AutoJavaString objectName_cstr(env, objectName);
   CHECK_EXCEPTION_(0);
   AutoJavaString symbolName_cstr(env, symbolName);
   CHECK_EXCEPTION_(0);
 
-  addr = (jlong) lookup_symbol(ph, objectName_cstr, symbolName_cstr);
+  addr = (jlong) lookup_symbol(ph, NULL, symbolName_cstr);
   return addr;
 }
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -47,6 +47,8 @@
 import sun.jvm.hotspot.code.CodeBlob;
 import sun.jvm.hotspot.code.CodeCacheVisitor;
 import sun.jvm.hotspot.code.NMethod;
+import sun.jvm.hotspot.debugger.cdbg.CDebugger;
+import sun.jvm.hotspot.debugger.cdbg.LoadObject;
 import sun.jvm.hotspot.debugger.Address;
 import sun.jvm.hotspot.debugger.OopHandle;
 import sun.jvm.hotspot.classfile.ClassLoaderDataGraph;
@@ -607,6 +609,40 @@ public void doit(Tokens t) {
                 }
             }
         },
+        new Command("findsym", "findsym name", false) {
+            public void doit(Tokens t) {
+                if (t.countTokens() != 1) {
+                    usage();
+                } else {
+                    String symbol = t.nextToken();
+                    Address addr = VM.getVM().getDebugger().lookup(null, symbol);
+                    if (addr == null && VM.getVM().getDebugger().getOS().equals("win32")) {
+                        // On win32 symbols are prefixed with the dll name. Do the user
+                        // a favor and see if this is a symbol in jvm.dll or java.dll.
+                        addr = VM.getVM().getDebugger().lookup(null, "jvm!" + symbol);
+                        if (addr == null) {
+                            addr = VM.getVM().getDebugger().lookup(null, "java!" + symbol);
+                        }
+                    }
+                    if (addr == null) {
+                        out.println("Symbol not found");
+                        return;
+                    }
+                    out.print(addr);  // Print the address of the symbol.
+                    CDebugger cdbg = VM.getVM().getDebugger().getCDebugger();
+                    LoadObject loadObject = cdbg.loadObjectContainingPC(addr);
+                    // Print the shared library path and the offset of the symbol.
+                    if (loadObject != null) {
+                        out.print(": " + loadObject.getName());
+                        long diff = addr.minus(loadObject.getBase());
+                        if (diff != 0L) {
+                            out.print(" + 0x" + Long.toHexString(diff));
+                        }
+                    }
+                    out.println();
+                }
+            }
+        },
         new Command("findpc", "findpc address", false) {
             public void doit(Tokens t) {
                 if (t.countTokens() != 1) {
@@ -892,7 +928,7 @@ public void visit(Klass k) {
             }
         },
         new Command("dumpideal", "dumpideal { -a | id }", false) {
-            // Do a full dump of the nodes reachabile from root in each compiler thread.
+            // Do a full dump of the nodes reachable from root in each compiler thread.
             public void doit(Tokens t) {
                 if (t.countTokens() != 1) {
                     usage();

src/jdk.hotspot.agent/windows/native/libsaproc/sawindbg.cpp

@@ -101,7 +101,7 @@ class AutoJavaString {
 public:
   // check env->ExceptionOccurred() after ctor
   AutoJavaString(JNIEnv* env, jstring str)
-    : m_env(env), m_str(str), m_buf(env->GetStringUTFChars(str, nullptr)) {
+    : m_env(env), m_str(str), m_buf(str == nullptr ? nullptr : env->GetStringUTFChars(str, nullptr)) {
   }
 
   ~AutoJavaString() {

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

@@ -82,6 +82,7 @@ public class ClhsdbFindPC {
 
     private static void testFindPC(boolean withXcomp, boolean withCore) throws Exception {
         try {
+            String linesep = System.getProperty("line.separator");
             String segvAddress = null;
             List<String> cmds = null;
             String cmdStr = null;
@@ -218,7 +219,7 @@ private static void testFindPC(boolean withXcomp, boolean withCore) throws Excep
             String examineOutput = runTest(withCore, cmds, null);
             // Extract <value>.
             parts = examineOutput.split(tid + ": ");
-            String value = parts[1];
+            String value = parts[1].split(linesep)[0];
             // Use findpc on <value>. The output should look something like:
             //    Address 0x00007fed86f610b8: vtable for JavaThread + 0x10
             cmdStr = "findpc " + value;
@@ -229,13 +230,49 @@ private static void testFindPC(boolean withXcomp, boolean withCore) throws Excep
             } else if (Platform.isOSX()) {
                 if (withCore) {
                     expStrMap.put(cmdStr, List.of("__ZTV10JavaThread"));
-                } else { // symbol lookups not supported with OSX live process
+                } else { // address -> symbol lookups not supported with OSX live process
                     expStrMap.put(cmdStr, List.of("In unknown location"));
                 }
             } else {
                 expStrMap.put(cmdStr, List.of("vtable for JavaThread"));
             }
-            runTest(withCore, cmds, expStrMap);
+            String findpcOutput = runTest(withCore, cmds, expStrMap);
+
+            // Determine if we have symbol support. Currently we assume yes except on windows.
+            boolean hasSymbols = true;
+            if (Platform.isWindows()) {
+                if (findpcOutput.indexOf("jvm!JavaThread::`vftable'") == -1) {
+                    hasSymbols = false;
+                }
+            }
+
+            // Run "findsym MaxJNILocalCapacity". The output should look something like:
+            //   0x00007eff8e1a0da0: <jdk-dir>/lib/server/libjvm.so + 0x1d81da0
+            String symbol = "MaxJNILocalCapacity";
+            cmds = List.of("findsym " + symbol);
+            expStrMap = new HashMap<>();
+            if (!hasSymbols) {
+                expStrMap.put(cmdStr, List.of("Symbol not found"));
+            }
+            String findsymOutput = runTest(withCore, cmds, expStrMap);
+            // Run findpc on the result of "findsym MaxJNILocalCapacity". The output
+            // should look something like:
+            //   Address 0x00007eff8e1a0da0: MaxJNILocalCapacity
+            if (hasSymbols) {
+                parts = findsymOutput.split("findsym " + symbol + linesep);
+                parts = parts[1].split(":");
+                String findsymAddress = parts[0].split(linesep)[0];
+                cmdStr = "findpc " + findsymAddress;
+                cmds = List.of(cmdStr);
+                expStrMap = new HashMap<>();
+                if (Platform.isOSX() && !withCore) {
+                    // address -> symbol lookups not supported with OSX live process
+                    expStrMap.put(cmdStr, List.of("Address " + findsymAddress + ": In unknown location"));
+                } else {
+                    expStrMap.put(cmdStr, List.of("Address " + findsymAddress + ": .*" + symbol));
+                }
+                runTest(withCore, cmds, expStrMap);
+            }
         } catch (SkippedException se) {
             throw se;
         } catch (Exception ex) {