[heap] Make most Space data members private

Makes all but one data member private instead of protected and replaces
all Space::heap_ accesses with Space::heap().

Also moves Executability down from Space into PagedSpace and remove all
references in SemiSpace since it's always initialized with
NOT_EXECUTABLE.

Bug: v8:7754
Change-Id: Ic03ce35a5f970b3c1e25b32da53e4c9717b2ee1e
Reviewed-on: https://chromium-review.googlesource.com/1055510Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53146}

src/heap/spaces-inl.h

@@ -139,7 +139,7 @@ bool NewSpace::ToSpaceContains(Object* o) { return to_space_.Contains(o); }
 bool NewSpace::FromSpaceContains(Object* o) { return from_space_.Contains(o); }
 
 bool PagedSpace::Contains(Address addr) {
-  if (heap_->lo_space()->FindPage(addr)) return false;
+  if (heap()->lo_space()->FindPage(addr)) return false;
   return MemoryChunk::FromAnyPointerAddress(heap(), addr)->owner() == this;
 }
 

src/heap/spaces.cc

@@ -1464,7 +1464,7 @@ intptr_t Space::GetNextInlineAllocationStepSize() {
 
 PagedSpace::PagedSpace(Heap* heap, AllocationSpace space,
                        Executability executable)
-    : SpaceWithLinearArea(heap, space, executable), anchor_(this) {
+    : SpaceWithLinearArea(heap, space), executable_(executable), anchor_(this) {
   area_size_ = MemoryAllocator::PageAreaSize(space);
   accounting_stats_.Clear();
 }
@@ -1794,7 +1794,7 @@ void PagedSpace::FreeLinearAllocationArea() {
   // The code page of the linear allocation area needs to be unprotected
   // because we are going to write a filler into that memory area below.
   if (identity() == CODE_SPACE) {
-    heap_->UnprotectAndRegisterMemoryChunk(
+    heap()->UnprotectAndRegisterMemoryChunk(
         MemoryChunk::FromAddress(current_top));
   }
   Free(current_top, current_limit - current_top,
@@ -1828,7 +1828,7 @@ void PagedSpace::ReleasePage(Page* page) {
 void PagedSpace::SetReadAndExecutable() {
   DCHECK(identity() == CODE_SPACE);
   for (Page* page : *this) {
-    CHECK(heap_->memory_allocator()->IsMemoryChunkExecutable(page));
+    CHECK(heap()->memory_allocator()->IsMemoryChunkExecutable(page));
     page->SetReadAndExecutable();
   }
 }
@@ -1836,7 +1836,7 @@ void PagedSpace::SetReadAndExecutable() {
 void PagedSpace::SetReadAndWritable() {
   DCHECK(identity() == CODE_SPACE);
   for (Page* page : *this) {
-    CHECK(heap_->memory_allocator()->IsMemoryChunkExecutable(page));
+    CHECK(heap()->memory_allocator()->IsMemoryChunkExecutable(page));
     page->SetReadAndWritable();
   }
 }
@@ -1890,7 +1890,7 @@ bool PagedSpace::RefillLinearAllocationAreaFromFreeList(size_t size_in_bytes) {
   DCHECK_LE(size_in_bytes, limit - start);
   if (limit != end) {
     if (identity() == CODE_SPACE) {
-      heap_->UnprotectAndRegisterMemoryChunk(page);
+      heap()->UnprotectAndRegisterMemoryChunk(page);
     }
     Free(limit, end - limit, SpaceAccountingMode::kSpaceAccounted);
   }
@@ -2124,7 +2124,7 @@ bool SemiSpace::EnsureCurrentCapacity() {
       actual_pages++;
       current_page =
           heap()->memory_allocator()->AllocatePage<MemoryAllocator::kPooled>(
-              Page::kAllocatableMemory, this, executable());
+              Page::kAllocatableMemory, this, NOT_EXECUTABLE);
       if (current_page == nullptr) return false;
       DCHECK_NOT_NULL(current_page);
       current_page->InsertAfter(anchor());
@@ -2440,7 +2440,7 @@ bool SemiSpace::Commit() {
   for (int pages_added = 0; pages_added < num_pages; pages_added++) {
     Page* new_page =
         heap()->memory_allocator()->AllocatePage<MemoryAllocator::kPooled>(
-            Page::kAllocatableMemory, this, executable());
+            Page::kAllocatableMemory, this, NOT_EXECUTABLE);
     if (new_page == nullptr) {
       RewindPages(current, pages_added);
       return false;
@@ -2499,7 +2499,7 @@ bool SemiSpace::GrowTo(size_t new_capacity) {
   for (int pages_added = 0; pages_added < delta_pages; pages_added++) {
     Page* new_page =
         heap()->memory_allocator()->AllocatePage<MemoryAllocator::kPooled>(
-            Page::kAllocatableMemory, this, executable());
+            Page::kAllocatableMemory, this, NOT_EXECUTABLE);
     if (new_page == nullptr) {
       RewindPages(last_page, pages_added);
       return false;
@@ -3272,7 +3272,7 @@ HeapObject* LargeObjectIterator::Next() {
 // LargeObjectSpace
 
 LargeObjectSpace::LargeObjectSpace(Heap* heap, AllocationSpace id)
-    : Space(heap, id, NOT_EXECUTABLE),  // Managed on a per-allocation basis
+    : Space(heap, id),  // Managed on a per-allocation basis
       first_page_(nullptr),
       size_(0),
       page_count_(0),

src/heap/spaces.h

@@ -902,11 +902,10 @@ class LargePage : public MemoryChunk {
 // Space is the abstract superclass for all allocation spaces.
 class Space : public Malloced {
  public:
-  Space(Heap* heap, AllocationSpace id, Executability executable)
+  Space(Heap* heap, AllocationSpace id)
       : allocation_observers_paused_(false),
         heap_(heap),
         id_(id),
-        executable_(executable),
         committed_(0),
         max_committed_(0) {}
 
@@ -914,9 +913,6 @@ class Space : public Malloced {
 
   Heap* heap() const { return heap_; }
 
-  // Does the space need executable memory?
-  Executability executable() { return executable_; }
-
   // Identity used in error reporting.
   AllocationSpace identity() { return id_; }
 
@@ -989,12 +985,11 @@ class Space : public Malloced {
   }
 
   std::vector<AllocationObserver*> allocation_observers_;
-  bool allocation_observers_paused_;
 
- protected:
+ private:
+  bool allocation_observers_paused_;
   Heap* heap_;
   AllocationSpace id_;
-  Executability executable_;
 
   // Keeps track of committed memory in a space.
   size_t committed_;
@@ -1976,8 +1971,8 @@ class LocalAllocationBuffer {
 
 class SpaceWithLinearArea : public Space {
  public:
-  SpaceWithLinearArea(Heap* heap, AllocationSpace id, Executability executable)
-      : Space(heap, id, executable), top_on_previous_step_(0) {
+  SpaceWithLinearArea(Heap* heap, AllocationSpace id)
+      : Space(heap, id), top_on_previous_step_(0) {
     allocation_info_.Reset(kNullAddress, kNullAddress);
   }
 
@@ -2057,6 +2052,9 @@ class V8_EXPORT_PRIVATE PagedSpace
   inline bool Contains(Object* o);
   bool ContainsSlow(Address addr);
 
+  // Does the space need executable memory?
+  Executability executable() { return executable_; }
+
   // During boot the free_space_map is created, and afterwards we may need
   // to write it into the free list nodes that were already created.
   void RepairFreeListsAfterDeserialization();
@@ -2123,8 +2121,8 @@ class V8_EXPORT_PRIVATE PagedSpace
 
   size_t Free(Address start, size_t size_in_bytes, SpaceAccountingMode mode) {
     if (size_in_bytes == 0) return 0;
-    heap_->CreateFillerObjectAt(start, static_cast<int>(size_in_bytes),
-                                ClearRecordedSlots::kNo);
+    heap()->CreateFillerObjectAt(start, static_cast<int>(size_in_bytes),
+                                 ClearRecordedSlots::kNo);
     if (mode == SpaceAccountingMode::kSpaceAccounted) {
       return AccountedFree(start, size_in_bytes);
     } else {
@@ -2318,6 +2316,8 @@ class V8_EXPORT_PRIVATE PagedSpace
   V8_WARN_UNUSED_RESULT bool RawSlowRefillLinearAllocationArea(
       int size_in_bytes);
 
+  Executability executable_;
+
   size_t area_size_;
 
   // Accounting information for this space.
@@ -2354,7 +2354,7 @@ class SemiSpace : public Space {
   static void Swap(SemiSpace* from, SemiSpace* to);
 
   SemiSpace(Heap* heap, SemiSpaceId semispace)
-      : Space(heap, NEW_SPACE, NOT_EXECUTABLE),
+      : Space(heap, NEW_SPACE),
         current_capacity_(0),
         maximum_capacity_(0),
         minimum_capacity_(0),
@@ -2547,7 +2547,7 @@ class NewSpace : public SpaceWithLinearArea {
   typedef PageIterator iterator;
 
   explicit NewSpace(Heap* heap)
-      : SpaceWithLinearArea(heap, NEW_SPACE, NOT_EXECUTABLE),
+      : SpaceWithLinearArea(heap, NEW_SPACE),
         to_space_(heap, kToSpace),
         from_space_(heap, kFromSpace),
         reservation_() {}