8318682: SA decoding of scalar replaced objects is broken

Reviewed-by: cjplummer, cslucas

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/asm/Disassembler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2024, 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
@@ -91,6 +91,9 @@ private Disassembler(long startPc, byte[] code) {
                           .get();
 
          String arch = targetSysProps.getProperty("os.arch");
+         if (arch.equals("x86_64")) {
+            arch = "amd64";
+         }
          String libname = "hsdis-" + arch + ext;
 
          List<String> libs = List.of(

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/code/DebugInfoReadStream.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2024, 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
@@ -74,6 +74,22 @@ ScopeValue readObjectValue() {
     return result;
   }
 
+  ScopeValue readObjectMergeValue() {
+    int id = readInt();
+    if (Assert.ASSERTS_ENABLED) {
+      Assert.that(objectPool != null, "object pool does not exist");
+      for (Iterator itr = objectPool.iterator(); itr.hasNext();) {
+        ObjectValue ov = (ObjectValue) itr.next();
+        Assert.that(ov.id() != id, "should not be read twice");
+      }
+    }
+    ObjectValue result = new ObjectMergeValue(id);
+    // Cache the object since an object field could reference it.
+    objectPool.add(result);
+    result.readObject(this);
+    return result;
+  }
+
   ScopeValue getCachedObject() {
     int id = readInt();
     Assert.that(objectPool != null, "object pool does not exist");

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/code/MarkerValue.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2024, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+package sun.jvm.hotspot.code;
+
+import java.io.PrintStream;
+
+/** A placeholder value that has no concrete meaning other than helping constructing
+ * other values.
+ */
+public class MarkerValue extends ScopeValue {
+    public boolean isMarker() { return true; }
+
+    public void printOn(PrintStream tty) {
+        tty.print("marker");
+    }
+}

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/code/NMethod.java

@@ -199,7 +199,7 @@ public int immutableDataSize() {
   public OopHandle getOopAt(int index) {
     if (index == 0) return null;
     if (Assert.ASSERTS_ENABLED) {
-      Assert.that(index > 0 && index <= getOopsLength(), "must be a valid non-zero index");
+      Assert.that(index > 0 && index <= getOopsLength(), "must be a valid non-zero index: " + index);
     }
     return oopsBegin().getOopHandleAt((index - 1) * VM.getVM().getOopSize());
   }
@@ -208,7 +208,7 @@ public OopHandle getOopAt(int index) {
   public Address getMetadataAt(int index) {
     if (index == 0) return null;
     if (Assert.ASSERTS_ENABLED) {
-      Assert.that(index > 0 && index <= getMetadataLength(), "must be a valid non-zero index");
+      Assert.that(index > 0 && index <= getMetadataLength(), "must be a valid non-zero index: " + index);
     }
     return metadataBegin().getAddressAt((index - 1) * VM.getVM().getOopSize());
   }
@@ -298,6 +298,19 @@ public PCDesc getPCDescAt(Address pc) {
     return null;
   }
 
+  /**
+   * Attempt to decode all the debug info in this nmethod.  This is intended purely for testing.
+   */
+  public void decodeAllScopeDescs() {
+    for (Address p = scopesPCsBegin(); p.lessThan(scopesPCsEnd()); p = p.addOffsetTo(pcDescSize)) {
+      PCDesc pd = new PCDesc(p);
+      if (pd.getPCOffset() == -1) {
+        break;
+      }
+      ScopeDesc sd = new ScopeDesc(this, pd.getScopeDecodeOffset(), pd.getObjDecodeOffset(), pd.getReexecute());
+    }
+  }
+
   /** ScopeDesc for an instruction */
   public ScopeDesc getScopeDescAt(Address pc) {
     PCDesc pd = getPCDescAt(pc);

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/code/ObjectMergeValue.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2024, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+package sun.jvm.hotspot.code;
+
+import java.io.PrintStream;
+import java.util.ArrayList;
+import java.util.List;
+
+class ObjectMergeValue extends ObjectValue {
+
+    private ScopeValue selector;
+    private ScopeValue mergePointer;
+    private List<ScopeValue> possibleObjects;
+
+    public ObjectMergeValue(int id) {
+        super(id);
+    }
+
+    public boolean isObjectMerge() { return true; }
+
+    void readObject(DebugInfoReadStream stream) {
+        selector = ScopeValue.readFrom(stream);
+        mergePointer = ScopeValue.readFrom(stream);
+        possibleObjects = new ArrayList<>();
+        int length = stream.readInt();
+        for (int i = 0; i < length; i++) {
+            ScopeValue val = readFrom(stream);
+            possibleObjects.add(val);
+        }
+    }
+
+    @Override
+    public void printOn(PrintStream tty) {
+        tty.print("merge_obj[" + id + "]");
+        tty.print(" selector=\"");
+        selector.printOn(tty);
+        tty.print("\"");
+
+        tty.print(" merge_pointer=\"");
+        mergePointer.printOn(tty);
+        tty.print("\"");
+
+        tty.print(", candidate_objs=[" + ((ObjectValue) possibleObjects.get(0)).id);
+        for (int i = 1; i < possibleObjects.size(); i++) {
+            tty.print("," + ((ObjectValue) possibleObjects.get(i)).id);
+        }
+        tty.print("]");
+    }
+}

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/code/ObjectValue.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2009, 2024, 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
@@ -33,7 +33,8 @@
 /** An ObjectValue describes an object eliminated by escape analysis. */
 
 public class ObjectValue extends ScopeValue {
-  private int              id;
+  protected final int      id;
+  private boolean          isRoot;
   private ScopeValue       klass;
   private List<ScopeValue> fieldsValue;
 
@@ -61,8 +62,9 @@ public ObjectValue(int id) {
   /** Serialization of debugging information */
 
   void readObject(DebugInfoReadStream stream) {
+    isRoot = stream.readBoolean();
     klass = readFrom(stream);
-    Assert.that(klass.isConstantOop(), "should be constant klass oop");
+    Assert.that(klass.isConstantOop(), "should be constant klass oop: " + klass);
     int length = stream.readInt();
     for (int i = 0; i < length; i++) {
       ScopeValue val = readFrom(stream);

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/code/ScopeValue.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2009, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2024, 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
@@ -25,6 +25,7 @@
 package sun.jvm.hotspot.code;
 
 import java.io.*;
+import java.nio.charset.StandardCharsets;
 
 import sun.jvm.hotspot.utilities.*;
 
@@ -51,13 +52,18 @@ public abstract class ScopeValue {
   static final int CONSTANT_DOUBLE_CODE = 4;
   static final int CONSTANT_OBJECT_CODE = 5;
   static final int CONSTANT_OBJECT_ID_CODE = 6;
+  static final int AUTO_BOX_OBJECT_CODE = 7;
+  static final int MARKER_CODE = 8;
+  static final int OBJECT_MERGE_CODE = 9;
 
   public boolean isLocation()       { return false; }
   public boolean isConstantInt()    { return false; }
   public boolean isConstantDouble() { return false; }
   public boolean isConstantLong()   { return false; }
   public boolean isConstantOop()    { return false; }
   public boolean isObject()         { return false; }
+  public boolean isMarker()         { return false; }
+  public boolean isObjectMerge()    { return false; }
 
   public static ScopeValue readFrom(DebugInfoReadStream stream) {
     switch (stream.readInt()) {
@@ -72,14 +78,29 @@ public static ScopeValue readFrom(DebugInfoReadStream stream) {
     case CONSTANT_DOUBLE_CODE:
       return new ConstantDoubleValue(stream);
     case CONSTANT_OBJECT_CODE:
+    case AUTO_BOX_OBJECT_CODE:
+      // The C++ code handles these 2 cases separately because the autobox case needs
+      // some extra state during deoptimization.  That's not required to display the
+      // information so treat it like a normal object value.
       return stream.readObjectValue();
     case CONSTANT_OBJECT_ID_CODE:
       return stream.getCachedObject();
+    case MARKER_CODE:
+      return new MarkerValue();
+    case OBJECT_MERGE_CODE:
+      return stream.readObjectMergeValue();
     default:
       Assert.that(false, "should not reach here");
       return null;
     }
   }
 
   public abstract void printOn(PrintStream tty);
+
+  public String toString() {
+    ByteArrayOutputStream baos = new ByteArrayOutputStream();
+    PrintStream ps = new PrintStream(baos, true, StandardCharsets.UTF_8);
+    printOn(ps);
+    return baos.toString(StandardCharsets.UTF_8);
+  }
 }

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/oops/ConstMethod.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2024, 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
@@ -317,13 +317,9 @@ public int getLineNumberFromBCI(int bci) {
       return -1;
     }
 
-    if (Assert.ASSERTS_ENABLED) {
-        Assert.that(0 <= bci && bci < getCodeSize(),
-                    "illegal bci(" + bci + ") codeSize(" + getCodeSize() + ")");
-    }
     int bestBCI  =  0;
     int bestLine = -1;
-    if (hasLineNumberTable()) {
+    if (0 <= bci && bci < getCodeSize() && hasLineNumberTable()) {
       // The line numbers are a short array of 2-tuples [start_pc, line_number].
       // Not necessarily sorted and not necessarily one-to-one.
       CompressedLineNumberReadStream stream =

test/hotspot/jtreg/ProblemList-generational-zgc.txt

@@ -106,6 +106,7 @@ serviceability/sa/jmap-hprof/JMapHProfLargeHeapProc.java      8307393   generic-
 serviceability/sa/jmap-hprof/JMapHProfLargeHeapTest.java      8307393   generic-all
 serviceability/sa/sadebugd/ClhsdbAttachToDebugServer.java     8307393   generic-all
 serviceability/sa/sadebugd/ClhsdbTestConnectArgument.java     8307393   generic-all
+serviceability/sa/ClhsdbTestAllocationMerge.java              8307393   generic-all
 serviceability/sa/sadebugd/DebugdConnectTest.java             8307393   generic-all
 serviceability/sa/sadebugd/DebugdUtils.java                   8307393   generic-all
 serviceability/sa/sadebugd/DisableRegistryTest.java           8307393   generic-all

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

@@ -149,6 +149,7 @@ private String runCmd(List<String> commands,
         oa.shouldNotMatch("^WARNING in native method:.*$");
         // This will detect most SA failures, including during the attach.
         oa.shouldNotMatch("^sun.jvm.hotspot.debugger.DebuggerException:.*$");
+        oa.shouldNotMatch("sun.jvm.hotspot.utilities.AssertionFailure");
         // This will detect unexpected exceptions, like NPEs and asserts, that are caught
         // by sun.jvm.hotspot.CommandProcessor.
         oa.shouldNotMatch("^Error: .*$");

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

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2024, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.util.List;
+import jdk.test.lib.apps.LingeredApp;
+import jtreg.SkippedException;
+
+/**
+ * @test
+ * @bug 8318682
+ * @summary Test clhsdb that decoding of AllocationMerge objects in debug info works correctly
+ * @requires vm.hasSA
+ * @library /test/lib
+ * @run main/othervm ClhsdbTestAllocationMerge
+ */
+
+public class ClhsdbTestAllocationMerge {
+
+    public static void main(String[] args) throws Exception {
+        System.out.println("Starting ClhsdbTestDebugInfodDecode test");
+
+        LingeredApp theApp = null;
+        try {
+            ClhsdbLauncher test = new ClhsdbLauncher();
+
+            theApp = new LingeredAppWithAllocationMerge();
+            LingeredApp.startApp(theApp);
+            System.out.println("Started LingeredAppWithAllocationMerge with pid " + theApp.getPid());
+
+            List<String> cmds = List.of("jstack -v");
+
+            // sun.jvm.hotspot.utilities.AssertionFailure is caught by the harness so it's not
+            // necessary to include extra filters here.
+            test.run(theApp.getPid(), cmds, null, null);
+        } catch (SkippedException se) {
+            throw se;
+        } catch (Exception ex) {
+            throw new RuntimeException("Test ERROR " + ex, ex);
+        } finally {
+            LingeredApp.stopApp(theApp);
+        }
+        System.out.println("Test PASSED");
+    }
+}