Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1 | // Copyright 2015 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #include <stdlib.h> |
| 6 | #include <utility> |
| 7 | |
| 8 | #include "test/cctest/test-api.h" |
| 9 | |
| 10 | #include "src/v8.h" |
| 11 | |
| 12 | #include "src/compilation-cache.h" |
| 13 | #include "src/execution.h" |
| 14 | #include "src/factory.h" |
| 15 | #include "src/global-handles.h" |
| 16 | #include "src/ic/stub-cache.h" |
| 17 | #include "src/objects.h" |
| 18 | |
| 19 | using namespace v8::internal; |
| 20 | |
| 21 | |
| 22 | // |
| 23 | // Helper functions. |
| 24 | // |
| 25 | |
| 26 | namespace { |
| 27 | |
| 28 | Handle<String> MakeString(const char* str) { |
| 29 | Isolate* isolate = CcTest::i_isolate(); |
| 30 | Factory* factory = isolate->factory(); |
| 31 | return factory->InternalizeUtf8String(str); |
| 32 | } |
| 33 | |
| 34 | |
| 35 | Handle<String> MakeName(const char* str, int suffix) { |
| 36 | EmbeddedVector<char, 128> buffer; |
| 37 | SNPrintF(buffer, "%s%d", str, suffix); |
| 38 | return MakeString(buffer.start()); |
| 39 | } |
| 40 | |
| 41 | |
| 42 | template <typename T, typename M> |
| 43 | bool EQUALS(Handle<T> left, Handle<M> right) { |
| 44 | if (*left == *right) return true; |
| 45 | return JSObject::Equals(Handle<Object>::cast(left), |
| 46 | Handle<Object>::cast(right)) |
| 47 | .FromJust(); |
| 48 | } |
| 49 | |
| 50 | |
| 51 | template <typename T, typename M> |
| 52 | bool EQUALS(Handle<T> left, M right) { |
| 53 | return EQUALS(left, handle(right)); |
| 54 | } |
| 55 | |
| 56 | |
| 57 | template <typename T, typename M> |
| 58 | bool EQUALS(T left, Handle<M> right) { |
| 59 | return EQUALS(handle(left), right); |
| 60 | } |
| 61 | |
| 62 | } // namespace |
| 63 | |
| 64 | |
| 65 | // |
| 66 | // Tests |
| 67 | // |
| 68 | |
| 69 | TEST(JSObjectAddingProperties) { |
| 70 | CcTest::InitializeVM(); |
| 71 | Isolate* isolate = CcTest::i_isolate(); |
| 72 | Factory* factory = isolate->factory(); |
| 73 | v8::HandleScope scope(CcTest::isolate()); |
| 74 | |
| 75 | Handle<FixedArray> empty_fixed_array(factory->empty_fixed_array()); |
| 76 | Handle<JSFunction> function = factory->NewFunction(factory->empty_string()); |
| 77 | Handle<Object> value(Smi::FromInt(42), isolate); |
| 78 | |
| 79 | Handle<JSObject> object = factory->NewJSObject(function); |
| 80 | Handle<Map> previous_map(object->map()); |
| 81 | CHECK_EQ(previous_map->elements_kind(), FAST_HOLEY_ELEMENTS); |
| 82 | CHECK(EQUALS(object->properties(), empty_fixed_array)); |
| 83 | CHECK(EQUALS(object->elements(), empty_fixed_array)); |
| 84 | |
| 85 | // for the default constructor function no in-object properties are reserved |
| 86 | // hence adding a single property will initialize the property-array |
| 87 | Handle<String> name = MakeName("property", 0); |
| 88 | JSObject::DefinePropertyOrElementIgnoreAttributes(object, name, value, NONE) |
| 89 | .Check(); |
| 90 | CHECK_NE(object->map(), *previous_map); |
| 91 | CHECK_EQ(object->map()->elements_kind(), FAST_HOLEY_ELEMENTS); |
| 92 | CHECK_LE(1, object->properties()->length()); |
| 93 | CHECK(EQUALS(object->elements(), empty_fixed_array)); |
| 94 | } |
| 95 | |
| 96 | |
| 97 | TEST(JSObjectInObjectAddingProperties) { |
| 98 | CcTest::InitializeVM(); |
| 99 | Isolate* isolate = CcTest::i_isolate(); |
| 100 | Factory* factory = isolate->factory(); |
| 101 | v8::HandleScope scope(CcTest::isolate()); |
| 102 | |
| 103 | Handle<FixedArray> empty_fixed_array(factory->empty_fixed_array()); |
| 104 | Handle<JSFunction> function = factory->NewFunction(factory->empty_string()); |
| 105 | int nof_inobject_properties = 10; |
| 106 | // force in object properties by changing the expected_nof_properties |
| 107 | function->shared()->set_expected_nof_properties(nof_inobject_properties); |
| 108 | Handle<Object> value(Smi::FromInt(42), isolate); |
| 109 | |
| 110 | Handle<JSObject> object = factory->NewJSObject(function); |
| 111 | Handle<Map> previous_map(object->map()); |
| 112 | CHECK_EQ(previous_map->elements_kind(), FAST_HOLEY_ELEMENTS); |
| 113 | CHECK(EQUALS(object->properties(), empty_fixed_array)); |
| 114 | CHECK(EQUALS(object->elements(), empty_fixed_array)); |
| 115 | |
| 116 | // we have reserved space for in-object properties, hence adding up to |
| 117 | // |nof_inobject_properties| will not create a property store |
| 118 | for (int i = 0; i < nof_inobject_properties; i++) { |
| 119 | Handle<String> name = MakeName("property", i); |
| 120 | JSObject::DefinePropertyOrElementIgnoreAttributes(object, name, value, NONE) |
| 121 | .Check(); |
| 122 | } |
| 123 | CHECK_NE(object->map(), *previous_map); |
| 124 | CHECK_EQ(object->map()->elements_kind(), FAST_HOLEY_ELEMENTS); |
| 125 | CHECK(EQUALS(object->properties(), empty_fixed_array)); |
| 126 | CHECK(EQUALS(object->elements(), empty_fixed_array)); |
| 127 | |
| 128 | // adding one more property will not fit in the in-object properties, thus |
| 129 | // creating a property store |
| 130 | int index = nof_inobject_properties + 1; |
| 131 | Handle<String> name = MakeName("property", index); |
| 132 | JSObject::DefinePropertyOrElementIgnoreAttributes(object, name, value, NONE) |
| 133 | .Check(); |
| 134 | CHECK_NE(object->map(), *previous_map); |
| 135 | CHECK_EQ(object->map()->elements_kind(), FAST_HOLEY_ELEMENTS); |
| 136 | // there must be at least 1 element in the properies store |
| 137 | CHECK_LE(1, object->properties()->length()); |
| 138 | CHECK(EQUALS(object->elements(), empty_fixed_array)); |
| 139 | } |
| 140 | |
| 141 | |
| 142 | TEST(JSObjectAddingElements) { |
| 143 | CcTest::InitializeVM(); |
| 144 | Isolate* isolate = CcTest::i_isolate(); |
| 145 | Factory* factory = isolate->factory(); |
| 146 | v8::HandleScope scope(CcTest::isolate()); |
| 147 | |
| 148 | Handle<String> name; |
| 149 | Handle<FixedArray> empty_fixed_array(factory->empty_fixed_array()); |
| 150 | Handle<JSFunction> function = factory->NewFunction(factory->empty_string()); |
| 151 | Handle<Object> value(Smi::FromInt(42), isolate); |
| 152 | |
| 153 | Handle<JSObject> object = factory->NewJSObject(function); |
| 154 | Handle<Map> previous_map(object->map()); |
| 155 | CHECK_EQ(previous_map->elements_kind(), FAST_HOLEY_ELEMENTS); |
| 156 | CHECK(EQUALS(object->properties(), empty_fixed_array)); |
| 157 | CHECK(EQUALS(object->elements(), empty_fixed_array)); |
| 158 | |
| 159 | // Adding an indexed element initializes the elements array |
| 160 | name = MakeString("0"); |
| 161 | JSObject::DefinePropertyOrElementIgnoreAttributes(object, name, value, NONE) |
| 162 | .Check(); |
| 163 | // no change in elements_kind => no map transition |
| 164 | CHECK_EQ(object->map(), *previous_map); |
| 165 | CHECK_EQ(object->map()->elements_kind(), FAST_HOLEY_ELEMENTS); |
| 166 | CHECK(EQUALS(object->properties(), empty_fixed_array)); |
| 167 | CHECK_LE(1, object->elements()->length()); |
| 168 | |
| 169 | // Adding more consecutive elements without a change in the backing store |
| 170 | int non_dict_backing_store_limit = 100; |
| 171 | for (int i = 1; i < non_dict_backing_store_limit; i++) { |
| 172 | name = MakeName("", i); |
| 173 | JSObject::DefinePropertyOrElementIgnoreAttributes(object, name, value, NONE) |
| 174 | .Check(); |
| 175 | } |
| 176 | // no change in elements_kind => no map transition |
| 177 | CHECK_EQ(object->map(), *previous_map); |
| 178 | CHECK_EQ(object->map()->elements_kind(), FAST_HOLEY_ELEMENTS); |
| 179 | CHECK(EQUALS(object->properties(), empty_fixed_array)); |
| 180 | CHECK_LE(non_dict_backing_store_limit, object->elements()->length()); |
| 181 | |
| 182 | // Adding an element at an very large index causes a change to |
| 183 | // DICTIONARY_ELEMENTS |
| 184 | name = MakeString("100000000"); |
| 185 | JSObject::DefinePropertyOrElementIgnoreAttributes(object, name, value, NONE) |
| 186 | .Check(); |
| 187 | // change in elements_kind => map transition |
| 188 | CHECK_NE(object->map(), *previous_map); |
| 189 | CHECK_EQ(object->map()->elements_kind(), DICTIONARY_ELEMENTS); |
| 190 | CHECK(EQUALS(object->properties(), empty_fixed_array)); |
| 191 | CHECK_LE(non_dict_backing_store_limit, object->elements()->length()); |
| 192 | } |
| 193 | |
| 194 | |
| 195 | TEST(JSArrayAddingProperties) { |
| 196 | CcTest::InitializeVM(); |
| 197 | Isolate* isolate = CcTest::i_isolate(); |
| 198 | Factory* factory = isolate->factory(); |
| 199 | v8::HandleScope scope(CcTest::isolate()); |
| 200 | |
| 201 | Handle<FixedArray> empty_fixed_array(factory->empty_fixed_array()); |
| 202 | Handle<Object> value(Smi::FromInt(42), isolate); |
| 203 | |
| 204 | Handle<JSArray> array = |
| 205 | factory->NewJSArray(ElementsKind::FAST_SMI_ELEMENTS, 0, 0); |
| 206 | Handle<Map> previous_map(array->map()); |
| 207 | CHECK_EQ(previous_map->elements_kind(), FAST_SMI_ELEMENTS); |
| 208 | CHECK(EQUALS(array->properties(), empty_fixed_array)); |
| 209 | CHECK(EQUALS(array->elements(), empty_fixed_array)); |
| 210 | CHECK_EQ(Smi::cast(array->length())->value(), 0); |
| 211 | |
| 212 | // for the default constructor function no in-object properties are reserved |
| 213 | // hence adding a single property will initialize the property-array |
| 214 | Handle<String> name = MakeName("property", 0); |
| 215 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value, NONE) |
| 216 | .Check(); |
| 217 | // No change in elements_kind but added property => new map |
| 218 | CHECK_NE(array->map(), *previous_map); |
| 219 | CHECK_EQ(array->map()->elements_kind(), FAST_SMI_ELEMENTS); |
| 220 | CHECK_LE(1, array->properties()->length()); |
| 221 | CHECK(EQUALS(array->elements(), empty_fixed_array)); |
| 222 | CHECK_EQ(Smi::cast(array->length())->value(), 0); |
| 223 | } |
| 224 | |
| 225 | |
| 226 | TEST(JSArrayAddingElements) { |
| 227 | CcTest::InitializeVM(); |
| 228 | Isolate* isolate = CcTest::i_isolate(); |
| 229 | Factory* factory = isolate->factory(); |
| 230 | v8::HandleScope scope(CcTest::isolate()); |
| 231 | |
| 232 | Handle<String> name; |
| 233 | Handle<FixedArray> empty_fixed_array(factory->empty_fixed_array()); |
| 234 | Handle<Object> value(Smi::FromInt(42), isolate); |
| 235 | |
| 236 | Handle<JSArray> array = |
| 237 | factory->NewJSArray(ElementsKind::FAST_SMI_ELEMENTS, 0, 0); |
| 238 | Handle<Map> previous_map(array->map()); |
| 239 | CHECK_EQ(previous_map->elements_kind(), FAST_SMI_ELEMENTS); |
| 240 | CHECK(EQUALS(array->properties(), empty_fixed_array)); |
| 241 | CHECK(EQUALS(array->elements(), empty_fixed_array)); |
| 242 | CHECK_EQ(Smi::cast(array->length())->value(), 0); |
| 243 | |
| 244 | // Adding an indexed element initializes the elements array |
| 245 | name = MakeString("0"); |
| 246 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value, NONE) |
| 247 | .Check(); |
| 248 | // no change in elements_kind => no map transition |
| 249 | CHECK_EQ(array->map(), *previous_map); |
| 250 | CHECK_EQ(array->map()->elements_kind(), FAST_SMI_ELEMENTS); |
| 251 | CHECK(EQUALS(array->properties(), empty_fixed_array)); |
| 252 | CHECK_LE(1, array->elements()->length()); |
| 253 | CHECK_EQ(1, Smi::cast(array->length())->value()); |
| 254 | |
| 255 | // Adding more consecutive elements without a change in the backing store |
| 256 | int non_dict_backing_store_limit = 100; |
| 257 | for (int i = 1; i < non_dict_backing_store_limit; i++) { |
| 258 | name = MakeName("", i); |
| 259 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value, NONE) |
| 260 | .Check(); |
| 261 | } |
| 262 | // no change in elements_kind => no map transition |
| 263 | CHECK_EQ(array->map(), *previous_map); |
| 264 | CHECK_EQ(array->map()->elements_kind(), FAST_SMI_ELEMENTS); |
| 265 | CHECK(EQUALS(array->properties(), empty_fixed_array)); |
| 266 | CHECK_LE(non_dict_backing_store_limit, array->elements()->length()); |
| 267 | CHECK_EQ(non_dict_backing_store_limit, Smi::cast(array->length())->value()); |
| 268 | |
| 269 | // Adding an element at an very large index causes a change to |
| 270 | // DICTIONARY_ELEMENTS |
| 271 | int index = 100000000; |
| 272 | name = MakeName("", index); |
| 273 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value, NONE) |
| 274 | .Check(); |
| 275 | // change in elements_kind => map transition |
| 276 | CHECK_NE(array->map(), *previous_map); |
| 277 | CHECK_EQ(array->map()->elements_kind(), DICTIONARY_ELEMENTS); |
| 278 | CHECK(EQUALS(array->properties(), empty_fixed_array)); |
| 279 | CHECK_LE(non_dict_backing_store_limit, array->elements()->length()); |
| 280 | CHECK_LE(array->elements()->length(), index); |
| 281 | CHECK_EQ(index + 1, Smi::cast(array->length())->value()); |
| 282 | } |
| 283 | |
| 284 | |
| 285 | TEST(JSArrayAddingElementsGeneralizingiFastSmiElements) { |
| 286 | CcTest::InitializeVM(); |
| 287 | Isolate* isolate = CcTest::i_isolate(); |
| 288 | Factory* factory = isolate->factory(); |
| 289 | v8::HandleScope scope(CcTest::isolate()); |
| 290 | |
| 291 | Handle<String> name; |
| 292 | Handle<Object> value_smi(Smi::FromInt(42), isolate); |
| 293 | Handle<Object> value_string(MakeString("value")); |
| 294 | Handle<Object> value_double = factory->NewNumber(3.1415); |
| 295 | |
| 296 | Handle<JSArray> array = |
| 297 | factory->NewJSArray(ElementsKind::FAST_SMI_ELEMENTS, 0, 0); |
| 298 | Handle<Map> previous_map(array->map()); |
| 299 | CHECK_EQ(previous_map->elements_kind(), FAST_SMI_ELEMENTS); |
| 300 | CHECK_EQ(Smi::cast(array->length())->value(), 0); |
| 301 | |
| 302 | // `array[0] = smi_value` doesn't change the elements_kind |
| 303 | name = MakeString("0"); |
| 304 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value_smi, |
| 305 | NONE) |
| 306 | .Check(); |
| 307 | // no change in elements_kind => no map transition |
| 308 | CHECK_EQ(array->map(), *previous_map); |
| 309 | CHECK_EQ(array->map()->elements_kind(), FAST_SMI_ELEMENTS); |
| 310 | CHECK_EQ(1, Smi::cast(array->length())->value()); |
| 311 | |
| 312 | // `delete array[0]` does not alter length, but changes the elments_kind |
| 313 | name = MakeString("0"); |
| 314 | CHECK(JSReceiver::DeletePropertyOrElement(array, name).FromMaybe(false)); |
| 315 | CHECK_NE(array->map(), *previous_map); |
| 316 | CHECK_EQ(array->map()->elements_kind(), FAST_HOLEY_SMI_ELEMENTS); |
| 317 | CHECK_EQ(1, Smi::cast(array->length())->value()); |
| 318 | previous_map = handle(array->map()); |
| 319 | |
| 320 | // add a couple of elements again |
| 321 | name = MakeString("0"); |
| 322 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value_smi, |
| 323 | NONE) |
| 324 | .Check(); |
| 325 | name = MakeString("1"); |
| 326 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value_smi, |
| 327 | NONE) |
| 328 | .Check(); |
| 329 | CHECK_EQ(array->map(), *previous_map); |
| 330 | CHECK_EQ(array->map()->elements_kind(), FAST_HOLEY_SMI_ELEMENTS); |
| 331 | CHECK_EQ(2, Smi::cast(array->length())->value()); |
| 332 | |
| 333 | // Adding a string to the array changes from FAST_HOLEY_SMI to FAST_HOLEY |
| 334 | name = MakeString("0"); |
| 335 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value_string, |
| 336 | NONE) |
| 337 | .Check(); |
| 338 | CHECK_NE(array->map(), *previous_map); |
| 339 | CHECK_EQ(array->map()->elements_kind(), FAST_HOLEY_ELEMENTS); |
| 340 | CHECK_EQ(2, Smi::cast(array->length())->value()); |
| 341 | previous_map = handle(array->map()); |
| 342 | |
| 343 | // We don't transition back to FAST_SMI even if we remove the string |
| 344 | name = MakeString("0"); |
| 345 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value_smi, |
| 346 | NONE) |
| 347 | .Check(); |
| 348 | CHECK_EQ(array->map(), *previous_map); |
| 349 | |
| 350 | // Adding a double doesn't change the map either |
| 351 | name = MakeString("0"); |
| 352 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value_double, |
| 353 | NONE) |
| 354 | .Check(); |
| 355 | CHECK_EQ(array->map(), *previous_map); |
| 356 | } |
| 357 | |
| 358 | |
| 359 | TEST(JSArrayAddingElementsGeneralizingFastElements) { |
| 360 | CcTest::InitializeVM(); |
| 361 | Isolate* isolate = CcTest::i_isolate(); |
| 362 | Factory* factory = isolate->factory(); |
| 363 | v8::HandleScope scope(CcTest::isolate()); |
| 364 | |
| 365 | Handle<String> name; |
| 366 | Handle<Object> value_smi(Smi::FromInt(42), isolate); |
| 367 | Handle<Object> value_string(MakeString("value")); |
| 368 | |
| 369 | Handle<JSArray> array = |
| 370 | factory->NewJSArray(ElementsKind::FAST_ELEMENTS, 0, 0); |
| 371 | Handle<Map> previous_map(array->map()); |
| 372 | CHECK_EQ(previous_map->elements_kind(), FAST_ELEMENTS); |
| 373 | CHECK_EQ(Smi::cast(array->length())->value(), 0); |
| 374 | |
| 375 | // `array[0] = smi_value` doesn't change the elements_kind |
| 376 | name = MakeString("0"); |
| 377 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value_smi, |
| 378 | NONE) |
| 379 | .Check(); |
| 380 | // no change in elements_kind => no map transition |
| 381 | CHECK_EQ(array->map(), *previous_map); |
| 382 | CHECK_EQ(array->map()->elements_kind(), FAST_ELEMENTS); |
| 383 | CHECK_EQ(1, Smi::cast(array->length())->value()); |
| 384 | |
| 385 | // `delete array[0]` does not alter length, but changes the elments_kind |
| 386 | name = MakeString("0"); |
| 387 | CHECK(JSReceiver::DeletePropertyOrElement(array, name).FromMaybe(false)); |
| 388 | CHECK_NE(array->map(), *previous_map); |
| 389 | CHECK_EQ(array->map()->elements_kind(), FAST_HOLEY_ELEMENTS); |
| 390 | CHECK_EQ(1, Smi::cast(array->length())->value()); |
| 391 | previous_map = handle(array->map()); |
| 392 | |
| 393 | // add a couple of elements, elements_kind stays HOLEY |
| 394 | name = MakeString("0"); |
| 395 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value_string, |
| 396 | NONE) |
| 397 | .Check(); |
| 398 | name = MakeString("1"); |
| 399 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value_smi, |
| 400 | NONE) |
| 401 | .Check(); |
| 402 | CHECK_EQ(array->map(), *previous_map); |
| 403 | CHECK_EQ(array->map()->elements_kind(), FAST_HOLEY_ELEMENTS); |
| 404 | CHECK_EQ(2, Smi::cast(array->length())->value()); |
| 405 | } |
| 406 | |
| 407 | |
| 408 | TEST(JSArrayAddingElementsGeneralizingiFastDoubleElements) { |
| 409 | CcTest::InitializeVM(); |
| 410 | Isolate* isolate = CcTest::i_isolate(); |
| 411 | Factory* factory = isolate->factory(); |
| 412 | v8::HandleScope scope(CcTest::isolate()); |
| 413 | |
| 414 | Handle<String> name; |
| 415 | Handle<Object> value_smi(Smi::FromInt(42), isolate); |
| 416 | Handle<Object> value_string(MakeString("value")); |
| 417 | Handle<Object> value_double = factory->NewNumber(3.1415); |
| 418 | |
| 419 | Handle<JSArray> array = |
| 420 | factory->NewJSArray(ElementsKind::FAST_SMI_ELEMENTS, 0, 0); |
| 421 | Handle<Map> previous_map(array->map()); |
| 422 | |
| 423 | // `array[0] = value_double` changes |elements_kind| to FAST_DOUBLE_ELEMENTS |
| 424 | name = MakeString("0"); |
| 425 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value_double, |
| 426 | NONE) |
| 427 | .Check(); |
| 428 | CHECK_NE(array->map(), *previous_map); |
| 429 | CHECK_EQ(array->map()->elements_kind(), FAST_DOUBLE_ELEMENTS); |
| 430 | CHECK_EQ(1, Smi::cast(array->length())->value()); |
| 431 | previous_map = handle(array->map()); |
| 432 | |
| 433 | // `array[1] = value_smi` doesn't alter the |elements_kind| |
| 434 | name = MakeString("1"); |
| 435 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value_smi, |
| 436 | NONE) |
| 437 | .Check(); |
| 438 | CHECK_EQ(array->map(), *previous_map); |
| 439 | CHECK_EQ(array->map()->elements_kind(), FAST_DOUBLE_ELEMENTS); |
| 440 | CHECK_EQ(2, Smi::cast(array->length())->value()); |
| 441 | |
| 442 | // `delete array[0]` does not alter length, but changes the elments_kind |
| 443 | name = MakeString("0"); |
| 444 | CHECK(JSReceiver::DeletePropertyOrElement(array, name).FromMaybe(false)); |
| 445 | CHECK_NE(array->map(), *previous_map); |
| 446 | CHECK_EQ(array->map()->elements_kind(), FAST_HOLEY_DOUBLE_ELEMENTS); |
| 447 | CHECK_EQ(2, Smi::cast(array->length())->value()); |
| 448 | previous_map = handle(array->map()); |
| 449 | |
| 450 | // filling the hole `array[0] = value_smi` again doesn't transition back |
| 451 | name = MakeString("0"); |
| 452 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value_double, |
| 453 | NONE) |
| 454 | .Check(); |
| 455 | CHECK_EQ(array->map(), *previous_map); |
| 456 | CHECK_EQ(array->map()->elements_kind(), FAST_HOLEY_DOUBLE_ELEMENTS); |
| 457 | CHECK_EQ(2, Smi::cast(array->length())->value()); |
| 458 | |
| 459 | // Adding a string to the array changes to elements_kind FAST_ELEMENTS |
| 460 | name = MakeString("1"); |
| 461 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value_string, |
| 462 | NONE) |
| 463 | .Check(); |
| 464 | CHECK_NE(array->map(), *previous_map); |
| 465 | CHECK_EQ(array->map()->elements_kind(), FAST_HOLEY_ELEMENTS); |
| 466 | CHECK_EQ(2, Smi::cast(array->length())->value()); |
| 467 | previous_map = handle(array->map()); |
| 468 | |
| 469 | // Adding a double doesn't change the map |
| 470 | name = MakeString("0"); |
| 471 | JSObject::DefinePropertyOrElementIgnoreAttributes(array, name, value_double, |
| 472 | NONE) |
| 473 | .Check(); |
| 474 | CHECK_EQ(array->map(), *previous_map); |
| 475 | } |