Simplify accesses to Script::line_ends

line_ends is either undefined (if uninitialized) or a fixed array (after
Script::InitLineEnds). All accesses from JS have been removed, therefore
we can skip assigning a COW map and remove the accessor.

Review-Url: https://codereview.chromium.org/2490903002
Cr-Commit-Position: refs/heads/master@{#40876}

src/accessors.cc

@@ -468,40 +468,6 @@ Handle<AccessorInfo> Accessors::ScriptCompilationTypeInfo(
 }
 
 
-//
-// Accessors::ScriptGetLineEnds
-//
-
-
-void Accessors::ScriptLineEndsGetter(
-    v8::Local<v8::Name> name,
-    const v8::PropertyCallbackInfo<v8::Value>& info) {
-  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(info.GetIsolate());
-  HandleScope scope(isolate);
-  Handle<Object> object = Utils::OpenHandle(*info.Holder());
-  Handle<Script> script(
-      Script::cast(Handle<JSValue>::cast(object)->value()), isolate);
-  Script::InitLineEnds(script);
-  DCHECK(script->line_ends()->IsFixedArray());
-  Handle<FixedArray> line_ends(FixedArray::cast(script->line_ends()));
-  // We do not want anyone to modify this array from JS.
-  DCHECK(*line_ends == isolate->heap()->empty_fixed_array() ||
-         line_ends->map() == isolate->heap()->fixed_cow_array_map());
-  Handle<JSArray> js_array =
-      isolate->factory()->NewJSArrayWithElements(line_ends);
-  info.GetReturnValue().Set(Utils::ToLocal(js_array));
-}
-
-
-Handle<AccessorInfo> Accessors::ScriptLineEndsInfo(
-      Isolate* isolate, PropertyAttributes attributes) {
-  Handle<String> name(isolate->factory()->InternalizeOneByteString(
-      STATIC_CHAR_VECTOR("line_ends")));
-  return MakeAccessor(isolate, name, &ScriptLineEndsGetter, nullptr,
-                      attributes);
-}
-
-
 //
 // Accessors::ScriptSourceUrl
 //

src/accessors.h

@@ -37,7 +37,6 @@ class AccessorInfo;
   V(ScriptEvalFromScriptPosition) \
   V(ScriptEvalFromFunctionName)   \
   V(ScriptId)                     \
-  V(ScriptLineEnds)               \
   V(ScriptLineOffset)             \
   V(ScriptName)                   \
   V(ScriptSource)                 \

src/api.cc

@@ -8880,22 +8880,16 @@ int DebugInterface::Script::ColumnOffset() const {
 }
 
 std::vector<int> DebugInterface::Script::LineEnds() const {
-  i::Isolate* isolate = Utils::OpenHandle(this)->GetIsolate();
+  i::Handle<i::Script> script = Utils::OpenHandle(this);
+  i::Isolate* isolate = script->GetIsolate();
   i::HandleScope scope(isolate);
-  i::Script::InitLineEnds(Utils::OpenHandle(this));
-  i::Handle<i::Object> line_ends_obj(Utils::OpenHandle(this)->line_ends(),
-                                     isolate);
-  std::vector<int> result;
-  if (!line_ends_obj->IsFixedArray()) return result;
-  i::Handle<i::FixedArray> line_ends =
-      i::Handle<i::FixedArray>::cast(line_ends_obj);
+  i::Script::InitLineEnds(script);
+  CHECK(script->line_ends()->IsFixedArray());
+  i::Handle<i::FixedArray> line_ends(i::FixedArray::cast(script->line_ends()));
+  std::vector<int> result(line_ends->length());
   for (int i = 0; i < line_ends->length(); ++i) {
-    i::Handle<i::Object> line_end = i::FixedArray::get(*line_ends, i, isolate);
-    if (line_end->IsSmi()) {
-      result.push_back(i::Handle<i::Smi>::cast(line_end)->value());
-    } else {
-      result.push_back(0);
-    }
+    i::Smi* line_end = i::Smi::cast(line_ends->get(i));
+    result[i] = line_end->value();
   }
   return result;
 }

src/bootstrapper.cc

@@ -3030,15 +3030,6 @@ void Bootstrapper::ExportFromRuntime(Isolate* isolate,
       script_map->AppendDescriptor(&d);
     }
 
-    Handle<AccessorInfo> script_line_ends =
-        Accessors::ScriptLineEndsInfo(isolate, attribs);
-    {
-      AccessorConstantDescriptor d(
-          Handle<Name>(Name::cast(script_line_ends->name())), script_line_ends,
-          attribs);
-      script_map->AppendDescriptor(&d);
-    }
-
     Handle<AccessorInfo> script_context_data =
         Accessors::ScriptContextDataInfo(isolate, attribs);
     {

src/inspector/debugger_script_externs.js

@@ -241,7 +241,6 @@ var SourceLocation;
  *    source_mapping_url: (string|undefined),
  *    is_debugger_script: boolean,
  *    source: string,
- *    line_ends: !Array<number>,
  *    line_offset: number,
  *    column_offset: number,
  *    nameOrSourceURL: function():string,

src/objects.cc

@@ -13375,23 +13375,17 @@ void Script::InitLineEnds(Handle<Script> script) {
   Isolate* isolate = script->GetIsolate();
   if (!script->line_ends()->IsUndefined(isolate)) return;
 
-  if (!script->source()->IsString()) {
-    DCHECK(script->source()->IsUndefined(isolate));
-    Handle<FixedArray> empty = isolate->factory()->NewFixedArray(0);
-    script->set_line_ends(*empty);
-    DCHECK(script->line_ends()->IsFixedArray());
-    return;
-  }
-
-  Handle<String> src(String::cast(script->source()), isolate);
-
-  Handle<FixedArray> array = String::CalculateLineEnds(src, true);
-
-  if (*array != isolate->heap()->empty_fixed_array()) {
-    array->set_map(isolate->heap()->fixed_cow_array_map());
+  Object* src_obj = script->source();
+  if (!src_obj->IsString()) {
+    DCHECK(src_obj->IsUndefined(isolate));
+    script->set_line_ends(isolate->heap()->empty_fixed_array());
+  } else {
+    DCHECK(src_obj->IsString());
+    Handle<String> src(String::cast(src_obj), isolate);
+    Handle<FixedArray> array = String::CalculateLineEnds(src, true);
+    script->set_line_ends(*array);
   }
 
-  script->set_line_ends(*array);
   DCHECK(script->line_ends()->IsFixedArray());
 }