[heap] Use LiveObjectRange in MarkingVerifier

This removes custom object iteration in MarkingVerifier.

Change-Id: I2e597dab6014ff4443faa60cd3d4be20a2dc1b56
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2438067Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70250}

src/heap/mark-compact-inl.h

@@ -135,8 +135,8 @@ void MainMarkingVisitor<MarkingState>::MarkDescriptorArrayFromWriteBarrier(
 }
 
 template <LiveObjectIterationMode mode>
-LiveObjectRange<mode>::iterator::iterator(MemoryChunk* chunk, Bitmap* bitmap,
-                                          Address start)
+LiveObjectRange<mode>::iterator::iterator(const MemoryChunk* chunk,
+                                          Bitmap* bitmap, Address start)
     : chunk_(chunk),
       one_word_filler_map_(
           ReadOnlyRoots(chunk->heap()).one_pointer_filler_map()),

src/heap/mark-compact.cc

@@ -118,30 +118,28 @@ void MarkingVerifier::VerifyRoots() {
 
 void MarkingVerifier::VerifyMarkingOnPage(const Page* page, Address start,
                                           Address end) {
-  HeapObject object;
   Address next_object_must_be_here_or_later = start;
-  for (Address current = start; current < end;) {
-    object = HeapObject::FromAddress(current);
-    // One word fillers at the end of a black area can be grey.
-    if (IsBlackOrGrey(object) &&
-        object.map() != ReadOnlyRoots(heap_).one_pointer_filler_map()) {
+
+  for (auto object_and_size :
+       LiveObjectRange<kAllLiveObjects>(page, bitmap(page))) {
+    HeapObject object = object_and_size.first;
+    size_t size = object_and_size.second;
+    Address current = object.address();
+    if (current < start) continue;
+    if (current >= end) break;
     CHECK(IsMarked(object));
     CHECK(current >= next_object_must_be_here_or_later);
     object.Iterate(this);
-      next_object_must_be_here_or_later = current + object.Size();
+    next_object_must_be_here_or_later = current + size;
     // The object is either part of a black area of black allocation or a
     // regular black object
-      CHECK(
-          bitmap(page)->AllBitsSetInRange(
+    CHECK(bitmap(page)->AllBitsSetInRange(
               page->AddressToMarkbitIndex(current),
               page->AddressToMarkbitIndex(next_object_must_be_here_or_later)) ||
           bitmap(page)->AllBitsClearInRange(
               page->AddressToMarkbitIndex(current + kTaggedSize * 2),
               page->AddressToMarkbitIndex(next_object_must_be_here_or_later)));
     current = next_object_must_be_here_or_later;
-    } else {
-      current += kTaggedSize;
-    }
   }
 }
 

src/heap/mark-compact.h

@@ -32,7 +32,8 @@ class YoungGenerationMarkingVisitor;
 
 class MarkBitCellIterator {
  public:
-  MarkBitCellIterator(MemoryChunk* chunk, Bitmap* bitmap) : chunk_(chunk) {
+  MarkBitCellIterator(const MemoryChunk* chunk, Bitmap* bitmap)
+      : chunk_(chunk) {
     last_cell_index_ =
         Bitmap::IndexToCell(chunk_->AddressToMarkbitIndex(chunk_->area_end()));
     cell_base_ = chunk_->address();
@@ -83,7 +84,7 @@ class MarkBitCellIterator {
   }
 
  private:
-  MemoryChunk* chunk_;
+  const MemoryChunk* chunk_;
   MarkBit::CellType* cells_;
   unsigned int last_cell_index_;
   unsigned int cell_index_;
@@ -102,7 +103,7 @@ class LiveObjectRange {
     using reference = const value_type&;
     using iterator_category = std::forward_iterator_tag;
 
-    inline iterator(MemoryChunk* chunk, Bitmap* bitmap, Address start);
+    inline iterator(const MemoryChunk* chunk, Bitmap* bitmap, Address start);
 
     inline iterator& operator++();
     inline iterator operator++(int);
@@ -120,7 +121,7 @@ class LiveObjectRange {
    private:
     inline void AdvanceToNextValidObject();
 
-    MemoryChunk* const chunk_;
+    const MemoryChunk* const chunk_;
     Map const one_word_filler_map_;
     Map const two_word_filler_map_;
     Map const free_space_map_;
@@ -131,7 +132,7 @@ class LiveObjectRange {
     int current_size_;
   };
 
-  LiveObjectRange(MemoryChunk* chunk, Bitmap* bitmap)
+  LiveObjectRange(const MemoryChunk* chunk, Bitmap* bitmap)
       : chunk_(chunk),
         bitmap_(bitmap),
         start_(chunk_->area_start()),
@@ -143,7 +144,7 @@ class LiveObjectRange {
   inline iterator end();
 
  private:
-  MemoryChunk* const chunk_;
+  const MemoryChunk* const chunk_;
   Bitmap* bitmap_;
   Address start_;
   Address end_;