From f1e4ec8d890f907ac70c1e312fbdd06834e9f54b Mon Sep 17 00:00:00 2001
From: Peter Hofer <peter.hofer@oracle.com>
Date: Fri, 3 May 2024 19:50:37 +0200
Subject: [PATCH] fixup! Revisit newly added files.

---
 .../RuntimeCodeCacheFixupWalker.java          | 30 +++++--------------
 .../compacting/ObjectMoveInfo.java            |  6 ++--
 .../compacting/PlanningVisitor.java           |  4 ++-
 3 files changed, 14 insertions(+), 26 deletions(-)

diff --git a/substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/RuntimeCodeCacheFixupWalker.java b/substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/RuntimeCodeCacheFixupWalker.java
index cdab58f1063ee..920f2519ae50b 100644
--- a/substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/RuntimeCodeCacheFixupWalker.java
+++ b/substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/RuntimeCodeCacheFixupWalker.java
@@ -28,21 +28,16 @@
 import org.graalvm.nativeimage.Platforms;
 
 import com.oracle.svm.core.code.CodeInfo;
-import com.oracle.svm.core.code.CodeInfoAccess;
 import com.oracle.svm.core.code.RuntimeCodeCache.CodeInfoVisitor;
 import com.oracle.svm.core.code.RuntimeCodeInfoAccess;
-import com.oracle.svm.core.heap.ObjectReferenceVisitor;
+import com.oracle.svm.core.genscavenge.compacting.ObjectRefFixupVisitor;
 
-/**
- * Before compaction, updates the same references that were visited by
- * {@link RuntimeCodeCacheWalker} during the mark phase.
- */
+/** Before compaction, updates references from {@link CodeInfo} structures. */
 final class RuntimeCodeCacheFixupWalker implements CodeInfoVisitor {
-
-    private final ObjectReferenceVisitor visitor;
+    private final ObjectRefFixupVisitor visitor;
 
     @Platforms(Platform.HOSTED_ONLY.class)
-    RuntimeCodeCacheFixupWalker(ObjectReferenceVisitor visitor) {
+    RuntimeCodeCacheFixupWalker(ObjectRefFixupVisitor visitor) {
         this.visitor = visitor;
     }
 
@@ -52,19 +47,10 @@ public boolean visitCode(CodeInfo codeInfo) {
             return true;
         }
 
-        int state = CodeInfoAccess.getState(codeInfo);
-        assert state != CodeInfo.STATE_INVALIDATED : "should not be observable here";
-        if (state == CodeInfo.STATE_UNREACHABLE || state == CodeInfo.STATE_READY_FOR_INVALIDATION) {
-            /*
-             * The code will be freed during this collection, but we need to make sure that all the
-             * objects that are accessed during the invalidation remain accessible. Those objects
-             * can only be collected in a subsequent garbage collection.
-             */
-            RuntimeCodeInfoAccess.walkObjectFields(codeInfo, visitor);
-            return true;
-        }
-
-        /* The CodeInfo remains valid, so we need to fix up all references. */
+        /*
+         * Whether this CodeInfo remains valid or will be invalidated or freed during this GC, we
+         * update all its references, including clearing those to objects that do not survive.
+         */
         RuntimeCodeInfoAccess.walkStrongReferences(codeInfo, visitor);
         RuntimeCodeInfoAccess.walkWeakReferences(codeInfo, visitor);
         return true;
diff --git a/substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/compacting/ObjectMoveInfo.java b/substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/compacting/ObjectMoveInfo.java
index dcfa7d08e857b..33503e44c5588 100644
--- a/substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/compacting/ObjectMoveInfo.java
+++ b/substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/compacting/ObjectMoveInfo.java
@@ -80,9 +80,9 @@ public final class ObjectMoveInfo {
 
     static void setNewAddress(Pointer objSeqStart, Pointer newAddress) {
         if (useCompressedLayout()) {
-            int alignment = ConfigurationValues.getObjectLayout().getAlignment();
-            UnsignedWord offset = newAddress.subtract(objSeqStart).unsignedDivide(alignment);
-            objSeqStart.writeInt(-8, (int) offset.rawValue());
+            long offset = newAddress.subtract(objSeqStart).rawValue();
+            offset /= ConfigurationValues.getObjectLayout().getAlignment();
+            objSeqStart.writeInt(-8, (int) offset);
         } else {
             objSeqStart.writeWord(-16, newAddress);
         }
diff --git a/substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/compacting/PlanningVisitor.java b/substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/compacting/PlanningVisitor.java
index 4473f77c3ed9e..f728c97c04274 100644
--- a/substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/compacting/PlanningVisitor.java
+++ b/substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/compacting/PlanningVisitor.java
@@ -165,8 +165,10 @@ public boolean visitChunk(AlignedHeapChunk.AlignedHeader chunk) {
     private Pointer allocate(UnsignedWord size) {
         Pointer p = allocPointer;
         allocPointer = allocPointer.add(size);
-        if (allocPointer.aboveOrEqual(AlignedHeapChunk.getObjectsEnd(allocChunk))) {
+        if (allocPointer.aboveThan(AlignedHeapChunk.getObjectsEnd(allocChunk))) {
             allocChunk = HeapChunk.getNext(allocChunk);
+            assert allocChunk.isNonNull();
+
             p = AlignedHeapChunk.getObjectsStart(allocChunk);
             allocPointer = p.add(size);
         }