Remove signatureOffset from DynamicHubOffsets

The offset was left at 0 and caused the hub to be overwritten. Added some checks to verify that all offsets correspond to existing fields.
oracle · Jan 23, 2025 · 024a51e · 024a51e
1 parent f6e5249
commit 024a51e
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Showing 2 changed files with 30 additions and 26 deletions.
diff --git a/...tratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/graal/meta/DynamicHubOffsets.java b/...tratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/graal/meta/DynamicHubOffsets.java
@@ -27,7 +27,6 @@
 import java.lang.reflect.Field;
 import java.util.Arrays;
 
-import jdk.graal.compiler.word.BarrieredAccess;
 import org.graalvm.nativeimage.AnnotationAccess;
 import org.graalvm.nativeimage.ImageSingletons;
 import org.graalvm.nativeimage.Platform;
@@ -41,54 +40,53 @@
 import com.oracle.svm.util.ReflectionUtil;
 
 import jdk.graal.compiler.api.replacements.Fold;
+import jdk.graal.compiler.word.BarrieredAccess;
 import jdk.vm.ci.meta.MetaAccessProvider;
 import jdk.vm.ci.meta.ResolvedJavaField;
 
 public class DynamicHubOffsets {
+    private static final int UNINITIALIZED = -1;
     /* defining order in DynamicHub */
 
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int nameOffset;
+    private int nameOffset = UNINITIALIZED;
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int hubTypeOffset;
+    private int hubTypeOffset = UNINITIALIZED;
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int referenceTypeOffset;
+    private int referenceTypeOffset = UNINITIALIZED;
 
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int layoutEncodingOffset;
+    private int layoutEncodingOffset = UNINITIALIZED;
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int typeIDOffset;
+    private int typeIDOffset = UNINITIALIZED;
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int typeIDDepthOffset;
+    private int typeIDDepthOffset = UNINITIALIZED;
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int numClassTypesOffset;
+    private int numClassTypesOffset = UNINITIALIZED;
 
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int numInterfaceTypesOffset;
+    private int numInterfaceTypesOffset = UNINITIALIZED;
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int openTypeWorldTypeCheckSlotsOffset;
+    private int openTypeWorldTypeCheckSlotsOffset = UNINITIALIZED;
 
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int monitorOffsetOffset;
+    private int monitorOffsetOffset = UNINITIALIZED;
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int identityHashOffsetOffset;
+    private int identityHashOffsetOffset = UNINITIALIZED;
 
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int flagsOffset;
+    private int flagsOffset = UNINITIALIZED;
 
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int componentTypeOffset;
+    private int componentTypeOffset = UNINITIALIZED;
 
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int referenceMapIndexOffset;
-    @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int layerIdOffset;
-
+    private int referenceMapIndexOffset = UNINITIALIZED;
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int companionOffset;
+    private int layerIdOffset = UNINITIALIZED;
 
     @UnknownPrimitiveField(availability = BuildPhaseProvider.ReadyForCompilation.class) //
-    private int signatureOffset;
+    private int companionOffset = UNINITIALIZED;
 
     @Fold
     public static DynamicHubOffsets singleton() {
@@ -121,6 +119,18 @@ public void initializeOffsets(MetaAccessProvider metaAccess) {
                 throw VMError.shouldNotReachHere(e);
             }
         }
+        // Ensure the expected fields exist
+        for (Field field : DynamicHubOffsets.class.getDeclaredFields()) {
+            String name = field.getName();
+            if (!name.endsWith("Offset")) {
+                continue;
+            }
+            try {
+                DynamicHub.class.getDeclaredField(name.substring(0, name.length() - "Offset".length()));
+            } catch (NoSuchFieldException e) {
+                throw VMError.shouldNotReachHere(e);
+            }
+        }
     }
 
     public int getNameOffset() {
@@ -187,10 +197,6 @@ public int getCompanionOffset() {
         return companionOffset;
     }
 
-    public int getSignatureOffset() {
-        return signatureOffset;
-    }
-
     public static void writeObject(DynamicHub hub, int offset, Object value) {
         if (offset < 0) {
             /* field removed by analysis */

diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/DynamicHub.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/DynamicHub.java
@@ -516,8 +516,6 @@ public static DynamicHub allocate(String name, DynamicHub superHub, DynamicHub c
 
         writeObject(hub, dynamicHubOffsets.getCompanionOffset(), companion);
 
-        writeObject(hub, dynamicHubOffsets.getSignatureOffset(), signature);
-
         FinalFieldBarrierNode.finalFieldBarrier(hub);
 
         return hub;