Revert of Preprocess structured stack trace on GC to get rid of code reference. (patchset #5 id:80001 of https://codereview.chromium.org/1103843002/)

Reason for revert:
Broke GCStress

Original issue's description:
> Preprocess structured stack trace on GC to get rid of code reference.
>
> R=verwaest@chromium.org
> BUG=v8:2340
> LOG=N
>
> Committed: https://crrev.com/462ffa1dfa0ab3a851ea0294470d1ed7ed12dd56
> Cr-Commit-Position: refs/heads/master@{#28085}

TBR=verwaest@chromium.org,ulan@chromium.org,hpayer@chromium.org,yurys@chromium.org,yangguo@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:2340

Review URL: https://codereview.chromium.org/1102383002

Cr-Commit-Position: refs/heads/master@{#28086}

src/factory.h

@@ -644,10 +644,6 @@ class Factory final {
     isolate()->heap()->set_string_table(*table);
   }
 
-  inline void set_weak_stack_trace_list(Handle<WeakFixedArray> list) {
-    isolate()->heap()->set_weak_stack_trace_list(*list);
-  }
-
   Handle<String> hidden_string() {
     return Handle<String>(&isolate()->heap()->hidden_string_);
   }

src/heap/heap.cc

@@ -706,26 +706,6 @@ void Heap::GarbageCollectionEpilogue() {
 }
 
 
-void Heap::PreprocessStackTraces() {
-  if (!weak_stack_trace_list()->IsWeakFixedArray()) return;
-  WeakFixedArray* array = WeakFixedArray::cast(weak_stack_trace_list());
-  int length = array->Length();
-  for (int i = 0; i < length; i++) {
-    if (array->IsEmptySlot(i)) continue;
-    FixedArray* elements = FixedArray::cast(array->Get(i));
-    for (int j = 1; j < elements->length(); j += 4) {
-      Code* code = Code::cast(elements->get(j + 2));
-      int offset = Smi::cast(elements->get(j + 3))->value();
-      Address pc = code->address() + offset;
-      int pos = code->SourcePosition(pc);
-      elements->set(j + 2, Smi::FromInt(pos));
-    }
-    array->Clear(i);
-  }
-  array->Compact();
-}
-
-
 void Heap::HandleGCRequest() {
   if (incremental_marking()->request_type() ==
       IncrementalMarking::COMPLETE_MARKING) {
@@ -1292,8 +1272,6 @@ void Heap::MarkCompactEpilogue() {
   isolate_->counters()->objs_since_last_full()->Set(0);
 
   incremental_marking()->Epilogue();
-
-  PreprocessStackTraces();
 }
 
 
@@ -3104,8 +3082,6 @@ void Heap::CreateInitialObjects() {
   cell->set_value(Smi::FromInt(Isolate::kArrayProtectorValid));
   set_array_protector(*cell);
 
-  set_weak_stack_trace_list(Smi::FromInt(0));
-
   set_allocation_sites_scratchpad(
       *factory->NewFixedArray(kAllocationSiteScratchpadSize, TENURED));
   InitializeAllocationSitesScratchpad();
@@ -3142,7 +3118,6 @@ bool Heap::RootCanBeWrittenAfterInitialization(Heap::RootListIndex root_index) {
     case kDetachedContextsRootIndex:
     case kWeakObjectToCodeTableRootIndex:
     case kRetainedMapsRootIndex:
-    case kWeakStackTraceListRootIndex:
 // Smi values
 #define SMI_ENTRY(type, name, Name) case k##Name##RootIndex:
       SMI_ROOT_LIST(SMI_ENTRY)

src/heap/heap.h

@@ -186,8 +186,7 @@ namespace internal {
   V(FixedArray, detached_contexts, DetachedContexts)                           \
   V(ArrayList, retained_maps, RetainedMaps)                                    \
   V(WeakHashTable, weak_object_to_code_table, WeakObjectToCodeTable)           \
-  V(PropertyCell, array_protector, ArrayProtector)                             \
-  V(Object, weak_stack_trace_list, WeakStackTraceList)
+  V(PropertyCell, array_protector, ArrayProtector)
 
 // Entries in this list are limited to Smis and are not visited during GC.
 #define SMI_ROOT_LIST(V)                                                   \
@@ -1743,8 +1742,6 @@ class Heap {
   void GarbageCollectionPrologue();
   void GarbageCollectionEpilogue();
 
-  void PreprocessStackTraces();
-
   // Pretenuring decisions are made based on feedback collected during new
   // space evacuation. Note that between feedback collection and calling this
   // method object in old space must not move.

src/isolate.cc

@@ -407,13 +407,8 @@ Handle<Object> Isolate::CaptureSimpleStackTrace(Handle<JSObject> error_object,
     }
   }
   elements->set(0, Smi::FromInt(sloppy_frames));
-  elements->Shrink(cursor);
   Handle<JSArray> result = factory()->NewJSArrayWithElements(elements);
   result->set_length(Smi::FromInt(cursor));
-  // Queue this structured stack trace for preprocessing on GC.
-  Handle<WeakFixedArray> new_weak_list =
-      WeakFixedArray::Add(factory()->weak_stack_trace_list(), elements);
-  factory()->set_weak_stack_trace_list(new_weak_list);
   return result;
 }
 

src/messages.js

@@ -1009,7 +1009,7 @@ function GetStackFrames(raw_stack) {
     var fun = raw_stack[i + 1];
     var code = raw_stack[i + 2];
     var pc = raw_stack[i + 3];
-    var pos = %_IsSmi(code) ? code : %FunctionGetPositionForOffset(code, pc);
+    var pos = %FunctionGetPositionForOffset(code, pc);
     sloppy_frames--;
     frames.push(new CallSite(recv, fun, pos, (sloppy_frames < 0)));
   }

src/objects-inl.h

@@ -2356,7 +2356,7 @@ bool WeakFixedArray::IsEmptySlot(int index) const {
 }
 
 
-void WeakFixedArray::Clear(int index) {
+void WeakFixedArray::clear(int index) {
   FixedArray::cast(this)->set(index + kFirstIndex, Smi::FromInt(0));
 }
 

src/objects.cc

@@ -8347,7 +8347,7 @@ bool WeakFixedArray::Remove(Handle<HeapObject> value) {
   int first_index = last_used_index();
   for (int i = first_index;;) {
     if (Get(i) == *value) {
-      Clear(i);
+      clear(i);
       // Users of WeakFixedArray should make sure that there are no duplicates,
       // they can use Add(..., kAddIfNotFound) if necessary.
       return true;

src/objects.h

@@ -2632,10 +2632,8 @@ class WeakFixedArray : public FixedArray {
   void Compact();
 
   inline Object* Get(int index) const;
-  inline void Clear(int index);
   inline int Length() const;
 
-  inline bool IsEmptySlot(int index) const;
   static Object* Empty() { return Smi::FromInt(0); }
 
   DECLARE_CAST(WeakFixedArray)
@@ -2650,6 +2648,7 @@ class WeakFixedArray : public FixedArray {
   static void Set(Handle<WeakFixedArray> array, int index,
                   Handle<HeapObject> value);
   inline void clear(int index);
+  inline bool IsEmptySlot(int index) const;
 
   inline int last_used_index() const;
   inline void set_last_used_index(int index);

test/cctest/test-heap.cc

@@ -5379,36 +5379,3 @@ TEST(WeakFixedArray) {
   array->Compact();
   WeakFixedArray::Add(array, number);
 }
-
-
-TEST(PreprocessStackTrace) {
-  // Do not automatically trigger early GC.
-  FLAG_gc_interval = -1;
-  CcTest::InitializeVM();
-  v8::HandleScope scope(CcTest::isolate());
-  v8::TryCatch try_catch;
-  CompileRun("throw new Error();");
-  CHECK(try_catch.HasCaught());
-  Isolate* isolate = CcTest::i_isolate();
-  Handle<Object> exception = v8::Utils::OpenHandle(*try_catch.Exception());
-  Handle<Name> key = isolate->factory()->stack_trace_symbol();
-  Handle<Object> stack_trace =
-      JSObject::GetProperty(exception, key).ToHandleChecked();
-  Handle<Object> code =
-      Object::GetElement(isolate, stack_trace, 3).ToHandleChecked();
-  CHECK(code->IsCode());
-
-  isolate->heap()->CollectAllAvailableGarbage("stack trace preprocessing");
-
-  Handle<Object> pos =
-      Object::GetElement(isolate, stack_trace, 3).ToHandleChecked();
-  CHECK(pos->IsSmi());
-
-  Handle<JSArray> stack_trace_array = Handle<JSArray>::cast(stack_trace);
-  int array_length = Smi::cast(stack_trace_array->length())->value();
-  for (int i = 0; i < array_length; i++) {
-    Handle<Object> element =
-        Object::GetElement(isolate, stack_trace, i).ToHandleChecked();
-    CHECK(!element->IsCode());
-  }
-}