Remove legacy C++ implementation of Array#slice

Change-Id: Ifdeda00ad55aa937a6a414e7e566e6640ccd83c0
Reviewed-on: https://chromium-review.googlesource.com/980936Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52278}

src/bootstrapper.cc

@@ -1658,12 +1658,8 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     SimpleInstallFunction(proto, "shift", Builtins::kArrayPrototypeShift, 0,
                           false);
     SimpleInstallFunction(proto, "unshift", Builtins::kArrayUnshift, 1, false);
-    if (FLAG_enable_experimental_builtins) {
-      SimpleInstallFunction(proto, "slice", Builtins::kArrayPrototypeSlice, 2,
-                            false);
-    } else {
-      SimpleInstallFunction(proto, "slice", Builtins::kArraySlice, 2, false);
-    }
+    SimpleInstallFunction(proto, "slice", Builtins::kArrayPrototypeSlice, 2,
+                          false);
     SimpleInstallFunction(proto, "splice", Builtins::kArraySplice, 2, false);
     SimpleInstallFunction(proto, "includes", Builtins::kArrayIncludes, 1,
                           false);

src/builtins/builtins-array.cc

@@ -240,75 +240,6 @@ BUILTIN(ArrayUnshift) {
   return Smi::FromInt(new_length);
 }
 
-BUILTIN(ArraySlice) {
-  HandleScope scope(isolate);
-  Handle<Object> receiver = args.receiver();
-  int len = -1;
-  int relative_start = 0;
-  int relative_end = 0;
-
-  if (receiver->IsJSArray()) {
-    DisallowHeapAllocation no_gc;
-    JSArray* array = JSArray::cast(*receiver);
-    if (V8_UNLIKELY(!array->HasFastElements() ||
-                    !IsJSArrayFastElementMovingAllowed(isolate, array) ||
-                    !isolate->IsSpeciesLookupChainIntact() ||
-                    // If this is a subclass of Array, then call out to JS
-                    !array->HasArrayPrototype(isolate))) {
-      AllowHeapAllocation allow_allocation;
-      return CallJsIntrinsic(isolate, isolate->array_slice(), args);
-    }
-    len = Smi::ToInt(array->length());
-  } else if (receiver->IsJSObject() &&
-             JSSloppyArgumentsObject::GetSloppyArgumentsLength(
-                 isolate, Handle<JSObject>::cast(receiver), &len)) {
-    // Array.prototype.slice.call(arguments, ...) is quite a common idiom
-    // (notably more than 50% of invocations in Web apps).
-    // Treat it in C++ as well.
-    DCHECK(JSObject::cast(*receiver)->HasFastElements() ||
-           JSObject::cast(*receiver)->HasFastArgumentsElements());
-  } else {
-    AllowHeapAllocation allow_allocation;
-    return CallJsIntrinsic(isolate, isolate->array_slice(), args);
-  }
-  DCHECK_LE(0, len);
-  int argument_count = args.length() - 1;
-  // Note carefully chosen defaults---if argument is missing,
-  // it's undefined which gets converted to 0 for relative_start
-  // and to len for relative_end.
-  relative_start = 0;
-  relative_end = len;
-  if (argument_count > 0) {
-    DisallowHeapAllocation no_gc;
-    if (!ClampedToInteger(isolate, args[1], &relative_start)) {
-      AllowHeapAllocation allow_allocation;
-      return CallJsIntrinsic(isolate, isolate->array_slice(), args);
-    }
-    if (argument_count > 1) {
-      Object* end_arg = args[2];
-      // slice handles the end_arg specially
-      if (end_arg->IsUndefined(isolate)) {
-        relative_end = len;
-      } else if (!ClampedToInteger(isolate, end_arg, &relative_end)) {
-        AllowHeapAllocation allow_allocation;
-        return CallJsIntrinsic(isolate, isolate->array_slice(), args);
-      }
-    }
-  }
-
-  // ECMAScript 232, 3rd Edition, Section 15.4.4.10, step 6.
-  uint32_t actual_start = (relative_start < 0) ? Max(len + relative_start, 0)
-                                               : Min(relative_start, len);
-
-  // ECMAScript 232, 3rd Edition, Section 15.4.4.10, step 8.
-  uint32_t actual_end =
-      (relative_end < 0) ? Max(len + relative_end, 0) : Min(relative_end, len);
-
-  Handle<JSObject> object = Handle<JSObject>::cast(receiver);
-  ElementsAccessor* accessor = object->GetElementsAccessor();
-  return *accessor->Slice(object, actual_start, actual_end);
-}
-
 BUILTIN(ArraySplice) {
   HandleScope scope(isolate);
   Handle<Object> receiver = args.receiver();

src/builtins/builtins-definitions.h

@@ -269,7 +269,6 @@ namespace internal {
   CPP(ArrayShift)                                                              \
   TFJ(ArrayPrototypeShift, SharedFunctionInfo::kDontAdaptArgumentsSentinel)    \
   /* ES6 #sec-array.prototype.slice */                                         \
-  CPP(ArraySlice)                                                              \
   TFJ(ArrayPrototypeSlice, SharedFunctionInfo::kDontAdaptArgumentsSentinel)    \
   /* ES6 #sec-array.prototype.splice */                                        \
   CPP(ArraySplice)                                                             \

src/contexts.h

@@ -69,7 +69,6 @@ enum ContextLookupFlags {
   V(ARRAY_PUSH_INDEX, JSFunction, array_push)                             \
   V(ARRAY_SHIFT_INDEX, JSFunction, array_shift)                           \
   V(ARRAY_SPLICE_INDEX, JSFunction, array_splice)                         \
-  V(ARRAY_SLICE_INDEX, JSFunction, array_slice)                           \
   V(ARRAY_UNSHIFT_INDEX, JSFunction, array_unshift)                       \
   V(ARRAY_ENTRIES_ITERATOR_INDEX, JSFunction, array_entries_iterator)     \
   V(ARRAY_FOR_EACH_ITERATOR_INDEX, JSFunction, array_for_each_iterator)   \

src/debug/debug-evaluate.cc

@@ -616,7 +616,6 @@ bool BuiltinHasNoSideEffect(Builtins::Name id) {
     case Builtins::kArrayEvery:
     case Builtins::kArraySome:
     case Builtins::kArrayConcat:
-    case Builtins::kArraySlice:
     case Builtins::kArrayFilter:
     case Builtins::kArrayMap:
     case Builtins::kArrayReduce:

src/flag-definitions.h

@@ -832,7 +832,7 @@ DEFINE_BOOL(expose_trigger_failure, false, "expose trigger-failure extension")
 DEFINE_INT(stack_trace_limit, 10, "number of stack frames to capture")
 DEFINE_BOOL(builtins_in_stack_traces, false,
             "show built-in functions in stack traces")
-DEFINE_BOOL(enable_experimental_builtins, true,
+DEFINE_BOOL(enable_experimental_builtins, false,
             "enable new csa-based experimental builtins")
 DEFINE_BOOL(disallow_code_generation_from_strings, false,
             "disallow eval and friends")

src/js/array.js

@@ -578,46 +578,14 @@ function ArrayUnshiftFallback(arg1) {  // length == 1
 }
 
 
+// Oh the humanity... don't remove the following function because js2c for some
+// reason gets symbol minifiation wrong if it's not there. Instead of spending
+// the time fixing js2c (which will go away when all of the internal .js runtime
+// files are gone), just keep this work-around.
 function ArraySliceFallback(start, end) {
-  var array = TO_OBJECT(this);
-  var len = TO_LENGTH(array.length);
-  var start_i = TO_INTEGER(start);
-  var end_i = len;
-
-  if (!IS_UNDEFINED(end)) end_i = TO_INTEGER(end);
-
-  if (start_i < 0) {
-    start_i += len;
-    if (start_i < 0) start_i = 0;
-  } else {
-    if (start_i > len) start_i = len;
-  }
-
-  if (end_i < 0) {
-    end_i += len;
-    if (end_i < 0) end_i = 0;
-  } else {
-    if (end_i > len) end_i = len;
-  }
-
-  var result = ArraySpeciesCreate(array, MathMax(end_i - start_i, 0));
-
-  if (end_i < start_i) return result;
-
-  if (UseSparseVariant(array, len, IS_ARRAY(array), end_i - start_i)) {
-    %NormalizeElements(array);
-    if (IS_ARRAY(result)) %NormalizeElements(result);
-    SparseSlice(array, start_i, end_i - start_i, len, result);
-  } else {
-    SimpleSlice(array, start_i, end_i - start_i, len, result);
-  }
-
-  result.length = end_i - start_i;
-
-  return result;
+  return null;
 }
 
-
 function ComputeSpliceStartIndex(start_i, len) {
   if (start_i < 0) {
     start_i += len;
@@ -1229,7 +1197,6 @@ utils.Export(function(to) {
   "array_push", ArrayPushFallback,
   "array_shift", ArrayShiftFallback,
   "array_splice", ArraySpliceFallback,
-  "array_slice", ArraySliceFallback,
   "array_unshift", ArrayUnshiftFallback,
 ]);