Rename root kTop to kStackRoots

IMHO kStackRoots is more descriptive than kTop.

Change-Id: I9eeffa6974ae0188021cb1628c2b21e691ab9490
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2810782Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73834}

src/execution/frames.cc

@@ -518,7 +518,7 @@ void StackFrame::IteratePc(RootVisitor* v, Address* pc_address,
          holder.GetHeap()->GcSafeCodeContains(holder, old_pc));
   unsigned pc_offset = holder.GetOffsetFromInstructionStart(isolate_, old_pc);
   Object code = holder;
-  v->VisitRootPointer(Root::kTop, nullptr, FullObjectSlot(&code));
+  v->VisitRootPointer(Root::kStackRoots, nullptr, FullObjectSlot(&code));
   if (code == holder) return;
   holder = Code::unchecked_cast(code);
   Address pc = holder.InstructionStart(isolate_, old_pc) + pc_offset;
@@ -1055,7 +1055,7 @@ void CommonFrame::IterateCompiledFrame(RootVisitor* v) const {
 
   // Visit the rest of the parameters if they are tagged.
   if (has_tagged_outgoing_params) {
-    v->VisitRootPointers(Root::kTop, nullptr, parameters_base,
+    v->VisitRootPointers(Root::kStackRoots, nullptr, parameters_base,
                          parameters_limit);
   }
 
@@ -1081,7 +1081,7 @@ void CommonFrame::IterateCompiledFrame(RootVisitor* v) const {
             DecompressTaggedPointer(isolate(), compressed_value);
       }
 #endif
-      v->VisitRootPointer(Root::kTop, nullptr, spill_slot);
+      v->VisitRootPointer(Root::kStackRoots, nullptr, spill_slot);
     }
   }
 
@@ -1094,7 +1094,7 @@ void CommonFrame::IterateCompiledFrame(RootVisitor* v) const {
     FullObjectSlot tagged_parameter_limit =
         tagged_parameter_base + tagged_parameter_slots;
 
-    v->VisitRootPointers(Root::kTop, nullptr, tagged_parameter_base,
+    v->VisitRootPointers(Root::kStackRoots, nullptr, tagged_parameter_base,
                          tagged_parameter_limit);
   }
 
@@ -1112,7 +1112,7 @@ void CommonFrame::IterateCompiledFrame(RootVisitor* v) const {
     // untagged, we don't need to visit it.
     frame_header_base += 1;
   }
-  v->VisitRootPointers(Root::kTop, nullptr, frame_header_base,
+  v->VisitRootPointers(Root::kStackRoots, nullptr, frame_header_base,
                        frame_header_limit);
 }
 
@@ -1989,7 +1989,7 @@ void WasmDebugBreakFrame::Iterate(RootVisitor* v) const {
         fp() +
         WasmDebugBreakFrameConstants::GetPushedGpRegisterOffset(reg_code)));
 
-    v->VisitRootPointer(Root::kTop, nullptr, spill_slot);
+    v->VisitRootPointer(Root::kStackRoots, nullptr, spill_slot);
   }
 }
 
@@ -2031,7 +2031,8 @@ void JsToWasmFrame::Iterate(RootVisitor* v) const {
   FullObjectSlot spill_slot_base(&Memory<Address>(sp()));
   FullObjectSlot spill_slot_limit(
       &Memory<Address>(sp() + scan_count * kSystemPointerSize));
-  v->VisitRootPointers(Root::kTop, nullptr, spill_slot_base, spill_slot_limit);
+  v->VisitRootPointers(Root::kStackRoots, nullptr, spill_slot_base,
+                       spill_slot_limit);
 }
 
 WasmInstanceObject WasmCompileLazyFrame::wasm_instance() const {
@@ -2047,8 +2048,8 @@ void WasmCompileLazyFrame::Iterate(RootVisitor* v) const {
   const int header_size = WasmCompileLazyFrameConstants::kFixedFrameSizeFromFp;
   FullObjectSlot base(&Memory<Address>(sp()));
   FullObjectSlot limit(&Memory<Address>(fp() - header_size));
-  v->VisitRootPointers(Root::kTop, nullptr, base, limit);
-  v->VisitRootPointer(Root::kTop, nullptr, wasm_instance_slot());
+  v->VisitRootPointers(Root::kStackRoots, nullptr, base, limit);
+  v->VisitRootPointer(Root::kStackRoots, nullptr, wasm_instance_slot());
 }
 #endif  // V8_ENABLE_WEBASSEMBLY
 
@@ -2192,14 +2193,14 @@ void CommonFrame::IterateExpressions(RootVisitor* v) const {
   FullObjectSlot base(&Memory<Address>(sp()));
   FullObjectSlot limit(&Memory<Address>(fp() + last_object_offset) + 1);
   if (StackFrame::IsTypeMarker(marker)) {
-    v->VisitRootPointers(Root::kTop, nullptr, base, limit);
+    v->VisitRootPointers(Root::kStackRoots, nullptr, base, limit);
   } else {
     // The frame contains the actual argument count (intptr) that should not be
     // visited.
     FullObjectSlot argc(
         &Memory<Address>(fp() + StandardFrameConstants::kArgCOffset));
-    v->VisitRootPointers(Root::kTop, nullptr, base, argc);
-    v->VisitRootPointers(Root::kTop, nullptr, argc + 1, limit);
+    v->VisitRootPointers(Root::kStackRoots, nullptr, base, argc);
+    v->VisitRootPointers(Root::kStackRoots, nullptr, argc + 1, limit);
   }
 }
 

src/execution/isolate.cc

@@ -507,22 +507,23 @@ void Isolate::IterateThread(ThreadVisitor* v, char* t) {
 
 void Isolate::Iterate(RootVisitor* v, ThreadLocalTop* thread) {
   // Visit the roots from the top for a given thread.
-  v->VisitRootPointer(Root::kTop, nullptr,
+  v->VisitRootPointer(Root::kStackRoots, nullptr,
                       FullObjectSlot(&thread->pending_exception_));
-  v->VisitRootPointer(Root::kTop, nullptr,
+  v->VisitRootPointer(Root::kStackRoots, nullptr,
                       FullObjectSlot(&thread->pending_message_obj_));
-  v->VisitRootPointer(Root::kTop, nullptr, FullObjectSlot(&thread->context_));
-  v->VisitRootPointer(Root::kTop, nullptr,
+  v->VisitRootPointer(Root::kStackRoots, nullptr,
+                      FullObjectSlot(&thread->context_));
+  v->VisitRootPointer(Root::kStackRoots, nullptr,
                       FullObjectSlot(&thread->scheduled_exception_));
 
   for (v8::TryCatch* block = thread->try_catch_handler_; block != nullptr;
        block = block->next_) {
     // TODO(3770): Make TryCatch::exception_ an Address (and message_obj_ too).
     v->VisitRootPointer(
-        Root::kTop, nullptr,
+        Root::kStackRoots, nullptr,
         FullObjectSlot(reinterpret_cast<Address>(&(block->exception_))));
     v->VisitRootPointer(
-        Root::kTop, nullptr,
+        Root::kStackRoots, nullptr,
         FullObjectSlot(reinterpret_cast<Address>(&(block->message_obj_))));
   }
 

src/heap/heap.cc

@@ -4485,7 +4485,7 @@ void Heap::IterateRoots(RootVisitor* v, base::EnumSet<SkipRoot> options) {
 
     if (!options.contains(SkipRoot::kStack)) {
       IterateStackRoots(v);
-      v->Synchronize(VisitorSynchronization::kTop);
+      v->Synchronize(VisitorSynchronization::kStackRoots);
     }
 
     // Iterate over local handles in handle scopes.

src/objects/visitors.h

@@ -23,7 +23,7 @@ class CodeDataContainer;
   V(kStrongRootList, "(Strong roots)")                \
   V(kSmiRootList, "(Smi roots)")                      \
   V(kBootstrapper, "(Bootstrapper)")                  \
-  V(kTop, "(Isolate)")                                \
+  V(kStackRoots, "(Stack roots)")                     \
   V(kRelocatable, "(Relocatable)")                    \
   V(kDebug, "(Debugger)")                             \
   V(kCompilationCache, "(Compilation cache)")         \