[GR-42996] Refactor shadow heap.

substratevm/src/com.oracle.graal.pointsto/src/com/oracle/graal/pointsto/heap/ImageHeapScanner.java

@@ -118,27 +118,27 @@ public void scanEmbeddedRoot(JavaConstant root, BytecodePosition position) {
     public void onFieldRead(AnalysisField field) {
         assert field.isRead();
         /* Check if the value is available before accessing it. */
-        if (isValueAvailable(field)) {
-            FieldScan reason = new FieldScan(field);
-            AnalysisType declaringClass = field.getDeclaringClass();
-            if (field.isStatic()) {
+        FieldScan reason = new FieldScan(field);
+        AnalysisType declaringClass = field.getDeclaringClass();
+        if (field.isStatic()) {
+            if (isValueAvailable(field)) {
                 JavaConstant fieldValue = declaringClass.getOrComputeData().readFieldValue(field);
                 markReachable(fieldValue, reason);
                 notifyAnalysis(field, null, fieldValue, reason);
-            } else {
-                /* Trigger field scanning for the already processed objects. */
-                postTask(() -> onInstanceFieldRead(field, declaringClass, reason));
+            } else if (field.canBeNull()) {
+                notifyAnalysis(field, null, JavaConstant.NULL_POINTER, reason);
             }
+        } else {
+            /* Trigger field scanning for the already processed objects. */
+            postTask(() -> onInstanceFieldRead(field, declaringClass, reason));
         }
     }
 
     private void onInstanceFieldRead(AnalysisField field, AnalysisType type, FieldScan reason) {
         for (AnalysisType subtype : type.getSubTypes()) {
             for (ImageHeapConstant imageHeapConstant : imageHeap.getReachableObjects(subtype)) {
                 ImageHeapInstance imageHeapInstance = (ImageHeapInstance) imageHeapConstant;
-                JavaConstant fieldValue = imageHeapInstance.readFieldValue(field);
-                markReachable(fieldValue, reason);
-                notifyAnalysis(field, imageHeapInstance, fieldValue, reason);
+                updateInstanceField(field, imageHeapInstance, reason, null);
             }
             /* Subtypes include this type itself. */
             if (!subtype.equals(type)) {
@@ -468,17 +468,25 @@ protected void onObjectReachable(ImageHeapConstant imageHeapConstant, ScanReason
         } else if (imageHeapConstant instanceof ImageHeapInstance imageHeapInstance) {
             for (ResolvedJavaField javaField : objectType.getInstanceFields(true)) {
                 AnalysisField field = (AnalysisField) javaField;
-                if (field.isRead() && isValueAvailable(field)) {
-                    JavaConstant fieldValue = imageHeapInstance.readFieldValue(field);
-                    markReachable(fieldValue, reason, onAnalysisModified);
-                    notifyAnalysis(field, imageHeapInstance, fieldValue, reason, onAnalysisModified);
+                if (field.isRead()) {
+                    updateInstanceField(field, imageHeapInstance, reason, onAnalysisModified);
                 }
             }
         }
     }
 
-    public boolean isValueAvailable(@SuppressWarnings("unused") AnalysisField field) {
-        return true;
+    private void updateInstanceField(AnalysisField field, ImageHeapInstance imageHeapInstance, ScanReason reason, Consumer<ScanReason> onAnalysisModified) {
+        if (isValueAvailable(field)) {
+            JavaConstant fieldValue = imageHeapInstance.readFieldValue(field);
+            markReachable(fieldValue, reason, onAnalysisModified);
+            notifyAnalysis(field, imageHeapInstance, fieldValue, reason, onAnalysisModified);
+        } else if (field.canBeNull()) {
+            notifyAnalysis(field, imageHeapInstance, JavaConstant.NULL_POINTER, reason, onAnalysisModified);
+        }
+    }
+
+    public boolean isValueAvailable(AnalysisField field) {
+        return field.isValueAvailable();
     }
 
     protected String formatReason(String message, ScanReason reason) {

substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/ImageHeapInfo.java

@@ -47,29 +47,29 @@ public final class ImageHeapInfo {
     /** Indicates no chunk with {@link #initialize} chunk offset parameters. */
     public static final long NO_CHUNK = -1;
 
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object firstReadOnlyPrimitiveObject;
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object lastReadOnlyPrimitiveObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object firstReadOnlyPrimitiveObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object lastReadOnlyPrimitiveObject;
 
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object firstReadOnlyReferenceObject;
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object lastReadOnlyReferenceObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object firstReadOnlyReferenceObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object lastReadOnlyReferenceObject;
 
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object firstReadOnlyRelocatableObject;
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object lastReadOnlyRelocatableObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object firstReadOnlyRelocatableObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object lastReadOnlyRelocatableObject;
 
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object firstWritablePrimitiveObject;
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object lastWritablePrimitiveObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object firstWritablePrimitiveObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object lastWritablePrimitiveObject;
 
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object firstWritableReferenceObject;
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object lastWritableReferenceObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object firstWritableReferenceObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object lastWritableReferenceObject;
 
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object firstWritableHugeObject;
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object lastWritableHugeObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object firstWritableHugeObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object lastWritableHugeObject;
 
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object firstReadOnlyHugeObject;
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object lastReadOnlyHugeObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object firstReadOnlyHugeObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object lastReadOnlyHugeObject;
 
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object firstObject;
-    @UnknownObjectField(availability = AfterHeapLayout.class) public Object lastObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object firstObject;
+    @UnknownObjectField(availability = AfterHeapLayout.class, canBeNull = true) public Object lastObject;
 
     // All offsets are relative to the heap base.
     @UnknownPrimitiveField(availability = AfterHeapLayout.class) public long offsetOfFirstWritableAlignedChunk;

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/heapdump/HeapDumpUtils.java

@@ -37,6 +37,7 @@
 import org.graalvm.word.UnsignedWord;
 import org.graalvm.word.WordFactory;
 
+import com.oracle.svm.core.BuildPhaseProvider.AfterCompilation;
 import com.oracle.svm.core.NeverInline;
 import com.oracle.svm.core.SubstrateOptions;
 import com.oracle.svm.core.code.CodeInfo;
@@ -64,7 +65,7 @@
  */
 public class HeapDumpUtils {
 
-    @UnknownObjectField private byte[] fieldsMap;
+    @UnknownObjectField(availability = AfterCompilation.class) private byte[] fieldsMap;
 
     /** Extra methods for testing. */
     private final TestingBackDoor testingBackDoor;

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/DynamicHub.java

@@ -314,6 +314,7 @@ public final class DynamicHub implements AnnotatedElement, java.lang.reflect.Typ
      * Back link to the SubstrateType used by the substrate meta access. Only used for the subset of
      * types for which a SubstrateType exists.
      */
+    @UnknownObjectField(fullyQualifiedTypes = "com.oracle.svm.graal.meta.SubstrateType")//
     private SharedType metaType;
 
     /**

substratevm/src/com.oracle.svm.graal/src/com/oracle/svm/graal/GraalSupport.java

@@ -27,7 +27,6 @@
 import static org.graalvm.word.LocationIdentity.ANY_LOCATION;
 
 import java.io.PrintStream;
-import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -73,6 +72,7 @@
 import org.graalvm.word.Pointer;
 import org.graalvm.word.WordFactory;
 
+import com.oracle.graal.pointsto.meta.AnalysisUniverse;
 import com.oracle.svm.core.c.CGlobalData;
 import com.oracle.svm.core.c.CGlobalDataFactory;
 import com.oracle.svm.core.config.ConfigurationValues;
@@ -86,7 +86,6 @@
 import com.oracle.svm.core.util.ImageHeapMap;
 import com.oracle.svm.graal.meta.SubstrateMethod;
 import com.oracle.svm.hosted.FeatureImpl.DuringAnalysisAccessImpl;
-import com.oracle.svm.util.ReflectionUtil;
 
 /**
  * Holds data that is pre-computed during native image generation and accessed at run time during a
@@ -129,11 +128,6 @@ public class GraalSupport {
     protected final DiagnosticsOutputDirectory outputDirectory = new DiagnosticsOutputDirectory(RuntimeOptionValues.singleton());
     protected final Map<ExceptionAction, Integer> compilationProblemsPerAction = new EnumMap<>(ExceptionAction.class);
 
-    private static final Field graphEncodingField = ReflectionUtil.lookupField(GraalSupport.class, "graphEncoding");
-    private static final Field graphObjectsField = ReflectionUtil.lookupField(GraalSupport.class, "graphObjects");
-    private static final Field graphNodeTypesField = ReflectionUtil.lookupField(GraalSupport.class, "graphNodeTypes");
-    private static final Field methodsToCompileField = ReflectionUtil.lookupField(GraalSupport.class, "methodsToCompile");
-
     private static final CGlobalData<Pointer> nextIsolateId = CGlobalDataFactory.createWord((Pointer) WordFactory.unsigned(1L));
 
     private volatile long isolateId = 0;
@@ -234,7 +228,7 @@ public static boolean setMethodsToCompile(DuringAnalysisAccessImpl config, Subst
         GraalSupport support = get();
         if (!Arrays.equals(support.methodsToCompile, methodsToCompile)) {
             support.methodsToCompile = methodsToCompile;
-            GraalSupport.rescan(config, support, methodsToCompileField);
+            GraalSupport.rescan(config, methodsToCompile);
             result = true;
         }
         return result;
@@ -274,28 +268,38 @@ public static boolean setGraphEncoding(FeatureAccess a, byte[] graphEncoding, Ob
         boolean result = false;
         if (!Arrays.equals(support.graphEncoding, graphEncoding)) {
             support.graphEncoding = graphEncoding;
-            GraalSupport.rescan(a, support, graphEncodingField);
             result = true;
         }
         if (!Arrays.deepEquals(support.graphObjects, graphObjects)) {
             support.graphObjects = graphObjects;
-            GraalSupport.rescan(a, support, graphObjectsField);
+            GraalSupport.rescan(a, graphObjects);
             result = true;
         }
         if (!Arrays.equals(support.graphNodeTypes, graphNodeTypes)) {
             support.graphNodeTypes = graphNodeTypes;
-            GraalSupport.rescan(a, support, graphNodeTypesField);
+            GraalSupport.rescan(a, graphNodeTypes);
             result = true;
         }
         return result;
     }
 
-    private static void rescan(FeatureAccess a, GraalSupport support, Field field) {
-        if (a instanceof DuringAnalysisAccessImpl) {
-            ((DuringAnalysisAccessImpl) a).rescanField(support, field);
+    private static void rescan(FeatureAccess a, Object object) {
+        if (a instanceof DuringAnalysisAccessImpl access) {
+            rescan(access.getUniverse(), object);
         }
     }
 
+    /**
+     * Rescan Graal objects during analysis. The fields that point to these objects are annotated
+     * with {@link UnknownObjectField} so their value is not processed during analysis, only their
+     * declared type is injected in the type flow graphs. Their eventual value becomes available
+     * after analysis. Later when the field is read the lazy value supplier scans the final value
+     * and patches the shadow heap.
+     */
+    public static void rescan(AnalysisUniverse universe, Object object) {
+        universe.getHeapScanner().rescanObject(object);
+    }
+
     @Platforms(Platform.HOSTED_ONLY.class)
     public static void registerImmutableObjects(CompilationAccess access) {
         access.registerAsImmutable(get().graphEncoding);

substratevm/src/com.oracle.svm.graal/src/com/oracle/svm/graal/hosted/GraalGraphObjectReplacer.java

@@ -24,7 +24,6 @@
  */
 package com.oracle.svm.graal.hosted;
 
-import java.lang.reflect.Field;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
@@ -56,6 +55,7 @@
 import com.oracle.svm.core.util.HostedStringDeduplication;
 import com.oracle.svm.core.util.ObservableImageHeapMapProvider;
 import com.oracle.svm.core.util.VMError;
+import com.oracle.svm.graal.GraalSupport;
 import com.oracle.svm.graal.SubstrateGraalRuntime;
 import com.oracle.svm.graal.meta.SubstrateField;
 import com.oracle.svm.graal.meta.SubstrateMethod;
@@ -107,11 +107,6 @@ public class GraalGraphObjectReplacer implements Function<Object, Object> {
 
     private final HostedStringDeduplication stringTable;
 
-    private final Field substrateFieldTypeField;
-    private final Field substrateFieldDeclaringClassField;
-    private final Field dynamicHubMetaTypeField;
-    private final Field substrateTypeRawAllInstanceFieldsField;
-
     private final Class<?> jvmciCleanerClass = ReflectionUtil.lookupClass(false, "jdk.vm.ci.hotspot.Cleaner");
 
     /**
@@ -125,10 +120,6 @@ public GraalGraphObjectReplacer(AnalysisUniverse aUniverse, SubstrateProviders s
         this.sProviders = sProviders;
         this.universeFactory = universeFactory;
         this.stringTable = HostedStringDeduplication.singleton();
-        substrateFieldTypeField = ReflectionUtil.lookupField(SubstrateField.class, "type");
-        substrateFieldDeclaringClassField = ReflectionUtil.lookupField(SubstrateField.class, "declaringClass");
-        dynamicHubMetaTypeField = ReflectionUtil.lookupField(DynamicHub.class, "metaType");
-        substrateTypeRawAllInstanceFieldsField = ReflectionUtil.lookupField(SubstrateType.class, "rawAllInstanceFields");
     }
 
     public void setGraalRuntime(SubstrateGraalRuntime sGraalRuntime) {
@@ -289,8 +280,8 @@ public synchronized SubstrateField createField(ResolvedJavaField original) {
                 sField = newField;
 
                 sField.setLinks(createType(aField.getType()), createType(aField.getDeclaringClass()));
-                aUniverse.getHeapScanner().rescanField(sField, substrateFieldTypeField);
-                aUniverse.getHeapScanner().rescanField(sField, substrateFieldDeclaringClassField);
+                GraalSupport.rescan(aUniverse, sField.getType());
+                GraalSupport.rescan(aUniverse, sField.getDeclaringClass());
             }
         }
         return sField;
@@ -338,10 +329,10 @@ public synchronized SubstrateType createType(JavaType original) {
             if (sType == null) {
                 sType = newType;
                 hub.setMetaType(sType);
-                aUniverse.getHeapScanner().rescanField(hub, dynamicHubMetaTypeField);
+                GraalSupport.rescan(aUniverse, hub.getMetaType());
 
                 sType.setRawAllInstanceFields(createAllInstanceFields(aType));
-                aUniverse.getHeapScanner().rescanField(sType, substrateTypeRawAllInstanceFieldsField);
+                GraalSupport.rescan(aUniverse, sType.getRawAllInstanceFields());
                 createType(aType.getSuperclass());
                 createType(aType.getComponentType());
                 for (AnalysisType aInterface : aType.getInterfaces()) {

substratevm/src/com.oracle.svm.graal/src/com/oracle/svm/graal/meta/SubstrateField.java

@@ -50,8 +50,8 @@ public class SubstrateField implements SharedField {
 
     protected static final SubstrateField[] EMPTY_ARRAY = new SubstrateField[0];
 
-    SubstrateType type;
-    SubstrateType declaringClass;
+    @UnknownObjectField SubstrateType type;
+    @UnknownObjectField SubstrateType declaringClass;
     private final String name;
     private final int modifiers;
     private int hashCode;