Implement static field base and offset substitutions for Unsafe

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/SunMiscSubstitutions.java

@@ -32,6 +32,7 @@
 import java.security.ProtectionDomain;
 import java.util.function.Function;
 
+import com.oracle.svm.core.StaticFieldsSupport;
 import org.graalvm.compiler.nodes.extended.MembarNode;
 import org.graalvm.compiler.serviceprovider.JavaVersionUtil;
 import org.graalvm.nativeimage.Platform;
@@ -206,14 +207,13 @@ public void ensureClassInitialized(Class<?> c) {
         DynamicHub.fromClass(c).ensureInitialized();
     }
 
-    @Substitute
-    private long staticFieldOffset(Field f) {
-        throw VMError.unsupportedFeature("Unsupported method of Unsafe");
-    }
-
     @Substitute
     private Object staticFieldBase(Field f) {
-        throw VMError.unsupportedFeature("Unsupported method of Unsafe");
+        if (f.getType().isPrimitive()) {
+            return StaticFieldsSupport.getStaticPrimitiveFields();
+        } else {
+            return StaticFieldsSupport.getStaticObjectFields();
+        }
     }
 
     @Substitute

substratevm/src/com.oracle.svm.reflect/src/com/oracle/svm/reflect/target/Target_jdk_internal_misc_Unsafe_Reflection.java

@@ -43,14 +43,7 @@ public final class Target_jdk_internal_misc_Unsafe_Reflection {
 
     @Substitute
     public long objectFieldOffset(Target_java_lang_reflect_Field field) {
-        int offset = field.root == null ? field.offset : field.root.offset;
-        if (offset > 0) {
-            return offset;
-        }
-        throw VMError.unsupportedFeature("The offset of " + field + " is accessed without the field being first registered as unsafe accessed. " +
-                        "Please register the field as unsafe accessed. You can do so with a reflection configuration that " +
-                        "contains an entry for the field with the attribute \"allowUnsafeAccess\": true. Such a configuration " +
-                        "file can be generated for you. Read BuildConfiguration.md and Reflection.md for details.");
+        return FieldUtils.getFieldOffset(field);
     }
 
     @Substitute
@@ -67,4 +60,27 @@ public long objectFieldOffset(Class<?> c, String name) {
             throw new InternalError();
         }
     }
+
+    @Substitute
+    public long staticFieldOffset(Target_java_lang_reflect_Field field) {
+        /*
+         * Since we store the offset in the `offset` field, which is computed through
+         * `FieldOffsetComputer#compute`, the implementation for this is the same as
+         * `objectFieldOffset` method
+         */
+        return FieldUtils.getFieldOffset(field);
+    }
+
+    private static class FieldUtils {
+        private static long getFieldOffset(Target_java_lang_reflect_Field field) {
+            int offset = field.root == null ? field.offset : field.root.offset;
+            if (offset > 0) {
+                return offset;
+            }
+            throw VMError.unsupportedFeature("The offset of " + field + " is accessed without the field being first registered as unsafe accessed. " +
+                            "Please register the field as unsafe accessed. You can do so with a reflection configuration that " +
+                            "contains an entry for the field with the attribute \"allowUnsafeAccess\": true. Such a configuration " +
+                            "file can be generated for you. Read BuildConfiguration.md and Reflection.md for details.");
+        }
+    }
 }