v8/test/cctest/test-strings.cc
Ulan Degenbaev e423f00403 [api] Add a way to specify the max heap size in ResourceConstraints
The new API function is called ConfigureDefaultsFromHeapSize and
accepts two parameters: the initial and the maximum heap size.
Based on the given limits the function computes the default size
for the young and the old generation.

The patch also cleans up the existing functions to make them
consistent in terms of units and heap structure.

Bug: v8:9306
Change-Id: If2200a9cdb45b0b818a373207efe4e6426f7b688
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1631593
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62017}
2019-06-06 10:22:56 +00:00

1965 lines
69 KiB
C++

// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Check that we can traverse very deep stacks of ConsStrings using
// StringCharacterStram. Check that Get(int) works on very deep stacks
// of ConsStrings. These operations may not be very fast, but they
// should be possible without getting errors due to too deep recursion.
#include <stdlib.h>
#include "src/init/v8.h"
#include "src/api/api-inl.h"
#include "src/base/platform/elapsed-timer.h"
#include "src/execution/messages.h"
#include "src/heap/factory.h"
#include "src/heap/heap-inl.h"
#include "src/objects/objects-inl.h"
#include "src/strings/unicode-decoder.h"
#include "test/cctest/cctest.h"
#include "test/cctest/heap/heap-utils.h"
// Adapted from http://en.wikipedia.org/wiki/Multiply-with-carry
class MyRandomNumberGenerator {
public:
MyRandomNumberGenerator() {
init();
}
void init(uint32_t seed = 0x5688C73E) {
static const uint32_t phi = 0x9E3779B9;
c = 362436;
i = kQSize-1;
Q[0] = seed;
Q[1] = seed + phi;
Q[2] = seed + phi + phi;
for (unsigned j = 3; j < kQSize; j++) {
Q[j] = Q[j - 3] ^ Q[j - 2] ^ phi ^ j;
}
}
uint32_t next() {
uint64_t a = 18782;
uint32_t r = 0xFFFFFFFE;
i = (i + 1) & (kQSize-1);
uint64_t t = a * Q[i] + c;
c = (t >> 32);
uint32_t x = static_cast<uint32_t>(t + c);
if (x < c) {
x++;
c++;
}
return (Q[i] = r - x);
}
uint32_t next(int max) {
return next() % max;
}
bool next(double threshold) {
CHECK(threshold >= 0.0 && threshold <= 1.0);
if (threshold == 1.0) return true;
if (threshold == 0.0) return false;
uint32_t value = next() % 100000;
return threshold > static_cast<double>(value)/100000.0;
}
private:
static const uint32_t kQSize = 4096;
uint32_t Q[kQSize];
uint32_t c;
uint32_t i;
};
namespace v8 {
namespace internal {
namespace test_strings {
static const int DEEP_DEPTH = 8 * 1024;
static const int SUPER_DEEP_DEPTH = 80 * 1024;
class Resource: public v8::String::ExternalStringResource {
public:
Resource(const uc16* data, size_t length): data_(data), length_(length) {}
~Resource() override { i::DeleteArray(data_); }
const uint16_t* data() const override { return data_; }
size_t length() const override { return length_; }
private:
const uc16* data_;
size_t length_;
};
class OneByteResource : public v8::String::ExternalOneByteStringResource {
public:
OneByteResource(const char* data, size_t length)
: data_(data), length_(length) {}
~OneByteResource() override { i::DeleteArray(data_); }
const char* data() const override { return data_; }
size_t length() const override { return length_; }
private:
const char* data_;
size_t length_;
};
static void InitializeBuildingBlocks(Handle<String>* building_blocks,
int bb_length,
bool long_blocks,
MyRandomNumberGenerator* rng) {
// A list of pointers that we don't have any interest in cleaning up.
// If they are reachable from a root then leak detection won't complain.
Isolate* isolate = CcTest::i_isolate();
Factory* factory = isolate->factory();
for (int i = 0; i < bb_length; i++) {
int len = rng->next(16);
int slice_head_chars = 0;
int slice_tail_chars = 0;
int slice_depth = 0;
for (int j = 0; j < 3; j++) {
if (rng->next(0.35)) slice_depth++;
}
// Must truncate something for a slice string. Loop until
// at least one end will be sliced.
while (slice_head_chars == 0 && slice_tail_chars == 0) {
slice_head_chars = rng->next(15);
slice_tail_chars = rng->next(12);
}
if (long_blocks) {
// Generate building blocks which will never be merged
len += ConsString::kMinLength + 1;
} else if (len > 14) {
len += 1234;
}
// Don't slice 0 length strings.
if (len == 0) slice_depth = 0;
int slice_length = slice_depth*(slice_head_chars + slice_tail_chars);
len += slice_length;
switch (rng->next(4)) {
case 0: {
uc16 buf[2000];
for (int j = 0; j < len; j++) {
buf[j] = rng->next(0x10000);
}
building_blocks[i] = factory->NewStringFromTwoByte(
Vector<const uc16>(buf, len)).ToHandleChecked();
for (int j = 0; j < len; j++) {
CHECK_EQ(buf[j], building_blocks[i]->Get(j));
}
break;
}
case 1: {
char buf[2000];
for (int j = 0; j < len; j++) {
buf[j] = rng->next(0x80);
}
building_blocks[i] =
factory->NewStringFromOneByte(OneByteVector(buf, len))
.ToHandleChecked();
for (int j = 0; j < len; j++) {
CHECK_EQ(buf[j], building_blocks[i]->Get(j));
}
break;
}
case 2: {
uc16* buf = NewArray<uc16>(len);
for (int j = 0; j < len; j++) {
buf[j] = rng->next(0x10000);
}
Resource* resource = new Resource(buf, len);
building_blocks[i] = v8::Utils::OpenHandle(
*v8::String::NewExternalTwoByte(CcTest::isolate(), resource)
.ToLocalChecked());
for (int j = 0; j < len; j++) {
CHECK_EQ(buf[j], building_blocks[i]->Get(j));
}
break;
}
case 3: {
char* buf = NewArray<char>(len);
for (int j = 0; j < len; j++) {
buf[j] = rng->next(0x80);
}
OneByteResource* resource = new OneByteResource(buf, len);
building_blocks[i] = v8::Utils::OpenHandle(
*v8::String::NewExternalOneByte(CcTest::isolate(), resource)
.ToLocalChecked());
for (int j = 0; j < len; j++) {
CHECK_EQ(buf[j], building_blocks[i]->Get(j));
}
break;
}
}
for (int j = slice_depth; j > 0; j--) {
building_blocks[i] = factory->NewSubString(
building_blocks[i],
slice_head_chars,
building_blocks[i]->length() - slice_tail_chars);
}
CHECK(len == building_blocks[i]->length() + slice_length);
}
}
class ConsStringStats {
public:
ConsStringStats() {
Reset();
}
void Reset();
void VerifyEqual(const ConsStringStats& that) const;
int leaves_;
int empty_leaves_;
int chars_;
int left_traversals_;
int right_traversals_;
private:
DISALLOW_COPY_AND_ASSIGN(ConsStringStats);
};
void ConsStringStats::Reset() {
leaves_ = 0;
empty_leaves_ = 0;
chars_ = 0;
left_traversals_ = 0;
right_traversals_ = 0;
}
void ConsStringStats::VerifyEqual(const ConsStringStats& that) const {
CHECK_EQ(this->leaves_, that.leaves_);
CHECK_EQ(this->empty_leaves_, that.empty_leaves_);
CHECK_EQ(this->chars_, that.chars_);
CHECK_EQ(this->left_traversals_, that.left_traversals_);
CHECK_EQ(this->right_traversals_, that.right_traversals_);
}
class ConsStringGenerationData {
public:
static const int kNumberOfBuildingBlocks = 256;
explicit ConsStringGenerationData(bool long_blocks);
void Reset();
inline Handle<String> block(int offset);
inline Handle<String> block(uint32_t offset);
// Input variables.
double early_termination_threshold_;
double leftness_;
double rightness_;
double empty_leaf_threshold_;
int max_leaves_;
// Cached data.
Handle<String> building_blocks_[kNumberOfBuildingBlocks];
String empty_string_;
MyRandomNumberGenerator rng_;
// Stats.
ConsStringStats stats_;
int early_terminations_;
private:
DISALLOW_COPY_AND_ASSIGN(ConsStringGenerationData);
};
ConsStringGenerationData::ConsStringGenerationData(bool long_blocks) {
rng_.init();
InitializeBuildingBlocks(
building_blocks_, kNumberOfBuildingBlocks, long_blocks, &rng_);
empty_string_ = ReadOnlyRoots(CcTest::heap()).empty_string();
Reset();
}
Handle<String> ConsStringGenerationData::block(uint32_t offset) {
return building_blocks_[offset % kNumberOfBuildingBlocks ];
}
Handle<String> ConsStringGenerationData::block(int offset) {
CHECK_GE(offset, 0);
return building_blocks_[offset % kNumberOfBuildingBlocks];
}
void ConsStringGenerationData::Reset() {
early_termination_threshold_ = 0.01;
leftness_ = 0.75;
rightness_ = 0.75;
empty_leaf_threshold_ = 0.02;
max_leaves_ = 1000;
stats_.Reset();
early_terminations_ = 0;
rng_.init();
}
void AccumulateStats(ConsString cons_string, ConsStringStats* stats) {
int left_length = cons_string.first().length();
int right_length = cons_string.second().length();
CHECK(cons_string.length() == left_length + right_length);
// Check left side.
bool left_is_cons = cons_string.first().IsConsString();
if (left_is_cons) {
stats->left_traversals_++;
AccumulateStats(ConsString::cast(cons_string.first()), stats);
} else {
CHECK_NE(left_length, 0);
stats->leaves_++;
stats->chars_ += left_length;
}
// Check right side.
if (cons_string.second().IsConsString()) {
stats->right_traversals_++;
AccumulateStats(ConsString::cast(cons_string.second()), stats);
} else {
if (right_length == 0) {
stats->empty_leaves_++;
CHECK(!left_is_cons);
}
stats->leaves_++;
stats->chars_ += right_length;
}
}
void AccumulateStats(Handle<String> cons_string, ConsStringStats* stats) {
DisallowHeapAllocation no_allocation;
if (cons_string->IsConsString()) {
return AccumulateStats(ConsString::cast(*cons_string), stats);
}
// This string got flattened by gc.
stats->chars_ += cons_string->length();
}
void AccumulateStatsWithOperator(ConsString cons_string,
ConsStringStats* stats) {
ConsStringIterator iter(cons_string);
int offset;
for (String string = iter.Next(&offset); !string.is_null();
string = iter.Next(&offset)) {
// Accumulate stats.
CHECK_EQ(0, offset);
stats->leaves_++;
stats->chars_ += string.length();
}
}
void VerifyConsString(Handle<String> root, ConsStringGenerationData* data) {
// Verify basic data.
CHECK(root->IsConsString());
CHECK_EQ(root->length(), data->stats_.chars_);
// Recursive verify.
ConsStringStats stats;
AccumulateStats(ConsString::cast(*root), &stats);
stats.VerifyEqual(data->stats_);
// Iteratively verify.
stats.Reset();
AccumulateStatsWithOperator(ConsString::cast(*root), &stats);
// Don't see these. Must copy over.
stats.empty_leaves_ = data->stats_.empty_leaves_;
stats.left_traversals_ = data->stats_.left_traversals_;
stats.right_traversals_ = data->stats_.right_traversals_;
// Adjust total leaves to compensate.
stats.leaves_ += stats.empty_leaves_;
stats.VerifyEqual(data->stats_);
}
static Handle<String> ConstructRandomString(ConsStringGenerationData* data,
unsigned max_recursion) {
Isolate* isolate = CcTest::i_isolate();
Factory* factory = isolate->factory();
// Compute termination characteristics.
bool terminate = false;
bool flat = data->rng_.next(data->empty_leaf_threshold_);
bool terminate_early = data->rng_.next(data->early_termination_threshold_);
if (terminate_early) data->early_terminations_++;
// The obvious condition.
terminate |= max_recursion == 0;
// Flat cons string terminate by definition.
terminate |= flat;
// Cap for max leaves.
terminate |= data->stats_.leaves_ >= data->max_leaves_;
// Roll the dice.
terminate |= terminate_early;
// Compute termination characteristics for each side.
bool terminate_left = terminate || !data->rng_.next(data->leftness_);
bool terminate_right = terminate || !data->rng_.next(data->rightness_);
// Generate left string.
Handle<String> left;
if (terminate_left) {
left = data->block(data->rng_.next());
data->stats_.leaves_++;
data->stats_.chars_ += left->length();
} else {
data->stats_.left_traversals_++;
}
// Generate right string.
Handle<String> right;
if (terminate_right) {
right = data->block(data->rng_.next());
data->stats_.leaves_++;
data->stats_.chars_ += right->length();
} else {
data->stats_.right_traversals_++;
}
// Generate the necessary sub-nodes recursively.
if (!terminate_right) {
// Need to balance generation fairly.
if (!terminate_left && data->rng_.next(0.5)) {
left = ConstructRandomString(data, max_recursion - 1);
}
right = ConstructRandomString(data, max_recursion - 1);
}
if (!terminate_left && left.is_null()) {
left = ConstructRandomString(data, max_recursion - 1);
}
// Build the cons string.
Handle<String> root = factory->NewConsString(left, right).ToHandleChecked();
CHECK(root->IsConsString() && !root->IsFlat());
// Special work needed for flat string.
if (flat) {
data->stats_.empty_leaves_++;
String::Flatten(isolate, root);
CHECK(root->IsConsString() && root->IsFlat());
}
return root;
}
static Handle<String> ConstructLeft(
ConsStringGenerationData* data,
int depth) {
Factory* factory = CcTest::i_isolate()->factory();
Handle<String> answer = factory->NewStringFromStaticChars("");
data->stats_.leaves_++;
for (int i = 0; i < depth; i++) {
Handle<String> block = data->block(i);
Handle<String> next =
factory->NewConsString(answer, block).ToHandleChecked();
if (next->IsConsString()) data->stats_.leaves_++;
data->stats_.chars_ += block->length();
answer = next;
}
data->stats_.left_traversals_ = data->stats_.leaves_ - 2;
return answer;
}
static Handle<String> ConstructRight(
ConsStringGenerationData* data,
int depth) {
Factory* factory = CcTest::i_isolate()->factory();
Handle<String> answer = factory->NewStringFromStaticChars("");
data->stats_.leaves_++;
for (int i = depth - 1; i >= 0; i--) {
Handle<String> block = data->block(i);
Handle<String> next =
factory->NewConsString(block, answer).ToHandleChecked();
if (next->IsConsString()) data->stats_.leaves_++;
data->stats_.chars_ += block->length();
answer = next;
}
data->stats_.right_traversals_ = data->stats_.leaves_ - 2;
return answer;
}
static Handle<String> ConstructBalancedHelper(
ConsStringGenerationData* data,
int from,
int to) {
Factory* factory = CcTest::i_isolate()->factory();
CHECK(to > from);
if (to - from == 1) {
data->stats_.chars_ += data->block(from)->length();
return data->block(from);
}
if (to - from == 2) {
data->stats_.chars_ += data->block(from)->length();
data->stats_.chars_ += data->block(from+1)->length();
return factory->NewConsString(data->block(from), data->block(from+1))
.ToHandleChecked();
}
Handle<String> part1 =
ConstructBalancedHelper(data, from, from + ((to - from) / 2));
Handle<String> part2 =
ConstructBalancedHelper(data, from + ((to - from) / 2), to);
if (part1->IsConsString()) data->stats_.left_traversals_++;
if (part2->IsConsString()) data->stats_.right_traversals_++;
return factory->NewConsString(part1, part2).ToHandleChecked();
}
static Handle<String> ConstructBalanced(
ConsStringGenerationData* data, int depth = DEEP_DEPTH) {
Handle<String> string = ConstructBalancedHelper(data, 0, depth);
data->stats_.leaves_ =
data->stats_.left_traversals_ + data->stats_.right_traversals_ + 2;
return string;
}
static void Traverse(Handle<String> s1, Handle<String> s2) {
int i = 0;
StringCharacterStream character_stream_1(*s1);
StringCharacterStream character_stream_2(*s2);
while (character_stream_1.HasMore()) {
CHECK(character_stream_2.HasMore());
uint16_t c = character_stream_1.GetNext();
CHECK_EQ(c, character_stream_2.GetNext());
i++;
}
CHECK(!character_stream_1.HasMore());
CHECK(!character_stream_2.HasMore());
CHECK_EQ(s1->length(), i);
CHECK_EQ(s2->length(), i);
}
static void TraverseFirst(Handle<String> s1, Handle<String> s2, int chars) {
int i = 0;
StringCharacterStream character_stream_1(*s1);
StringCharacterStream character_stream_2(*s2);
while (character_stream_1.HasMore() && i < chars) {
CHECK(character_stream_2.HasMore());
uint16_t c = character_stream_1.GetNext();
CHECK_EQ(c, character_stream_2.GetNext());
i++;
}
s1->Get(s1->length() - 1);
s2->Get(s2->length() - 1);
}
TEST(Traverse) {
printf("TestTraverse\n");
CcTest::InitializeVM();
Isolate* isolate = CcTest::i_isolate();
v8::HandleScope scope(CcTest::isolate());
ConsStringGenerationData data(false);
Handle<String> flat = ConstructBalanced(&data);
String::Flatten(isolate, flat);
Handle<String> left_asymmetric = ConstructLeft(&data, DEEP_DEPTH);
Handle<String> right_asymmetric = ConstructRight(&data, DEEP_DEPTH);
Handle<String> symmetric = ConstructBalanced(&data);
printf("1\n");
Traverse(flat, symmetric);
printf("2\n");
Traverse(flat, left_asymmetric);
printf("3\n");
Traverse(flat, right_asymmetric);
printf("4\n");
Handle<String> left_deep_asymmetric =
ConstructLeft(&data, SUPER_DEEP_DEPTH);
Handle<String> right_deep_asymmetric =
ConstructRight(&data, SUPER_DEEP_DEPTH);
printf("5\n");
TraverseFirst(left_asymmetric, left_deep_asymmetric, 1050);
printf("6\n");
TraverseFirst(left_asymmetric, right_deep_asymmetric, 65536);
printf("7\n");
String::Flatten(isolate, left_asymmetric);
printf("10\n");
Traverse(flat, left_asymmetric);
printf("11\n");
String::Flatten(isolate, right_asymmetric);
printf("12\n");
Traverse(flat, right_asymmetric);
printf("14\n");
String::Flatten(isolate, symmetric);
printf("15\n");
Traverse(flat, symmetric);
printf("16\n");
String::Flatten(isolate, left_deep_asymmetric);
printf("18\n");
}
TEST(ConsStringWithEmptyFirstFlatten) {
printf("ConsStringWithEmptyFirstFlatten\n");
CcTest::InitializeVM();
v8::HandleScope scope(CcTest::isolate());
Isolate* isolate = CcTest::i_isolate();
i::Handle<i::String> initial_fst =
isolate->factory()->NewStringFromAsciiChecked("fst012345");
i::Handle<i::String> initial_snd =
isolate->factory()->NewStringFromAsciiChecked("snd012345");
i::Handle<i::String> str = isolate->factory()
->NewConsString(initial_fst, initial_snd)
.ToHandleChecked();
CHECK(str->IsConsString());
auto cons = i::Handle<i::ConsString>::cast(str);
const int initial_length = cons->length();
// set_first / set_second does not update the length (which the heap verifier
// checks), so we need to ensure the length stays the same.
i::Handle<i::String> new_fst = isolate->factory()->empty_string();
i::Handle<i::String> new_snd =
isolate->factory()->NewStringFromAsciiChecked("snd012345012345678");
cons->set_first(isolate, *new_fst);
cons->set_second(isolate, *new_snd);
CHECK(!cons->IsFlat());
CHECK_EQ(initial_length, new_fst->length() + new_snd->length());
CHECK_EQ(initial_length, cons->length());
// Make sure Flatten doesn't alloc a new string.
DisallowHeapAllocation no_alloc;
i::Handle<i::String> flat = i::String::Flatten(isolate, cons);
CHECK(flat->IsFlat());
CHECK_EQ(initial_length, flat->length());
}
static void VerifyCharacterStream(String flat_string, String cons_string) {
// Do not want to test ConString traversal on flat string.
CHECK(flat_string.IsFlat() && !flat_string.IsConsString());
CHECK(cons_string.IsConsString());
// TODO(dcarney) Test stream reset as well.
int length = flat_string.length();
// Iterate start search in multiple places in the string.
int outer_iterations = length > 20 ? 20 : length;
for (int j = 0; j <= outer_iterations; j++) {
int offset = length * j / outer_iterations;
if (offset < 0) offset = 0;
// Want to test the offset == length case.
if (offset > length) offset = length;
StringCharacterStream flat_stream(flat_string, offset);
StringCharacterStream cons_stream(cons_string, offset);
for (int i = offset; i < length; i++) {
uint16_t c = flat_string.Get(i);
CHECK(flat_stream.HasMore());
CHECK(cons_stream.HasMore());
CHECK_EQ(c, flat_stream.GetNext());
CHECK_EQ(c, cons_stream.GetNext());
}
CHECK(!flat_stream.HasMore());
CHECK(!cons_stream.HasMore());
}
}
static inline void PrintStats(const ConsStringGenerationData& data) {
#ifdef DEBUG
printf("%s: [%u], %s: [%u], %s: [%u], %s: [%u], %s: [%u], %s: [%u]\n",
"leaves", data.stats_.leaves_, "empty", data.stats_.empty_leaves_,
"chars", data.stats_.chars_, "lefts", data.stats_.left_traversals_,
"rights", data.stats_.right_traversals_, "early_terminations",
data.early_terminations_);
#endif
}
template<typename BuildString>
void TestStringCharacterStream(BuildString build, int test_cases) {
FLAG_gc_global = true;
CcTest::InitializeVM();
Isolate* isolate = CcTest::i_isolate();
HandleScope outer_scope(isolate);
ConsStringGenerationData data(true);
for (int i = 0; i < test_cases; i++) {
printf("%d\n", i);
HandleScope inner_scope(isolate);
AlwaysAllocateScope always_allocate(isolate);
// Build flat version of cons string.
Handle<String> flat_string = build(i, &data);
ConsStringStats flat_string_stats;
AccumulateStats(flat_string, &flat_string_stats);
// Flatten string.
String::Flatten(isolate, flat_string);
// Build unflattened version of cons string to test.
Handle<String> cons_string = build(i, &data);
ConsStringStats cons_string_stats;
AccumulateStats(cons_string, &cons_string_stats);
DisallowHeapAllocation no_allocation;
PrintStats(data);
// Full verify of cons string.
cons_string_stats.VerifyEqual(flat_string_stats);
cons_string_stats.VerifyEqual(data.stats_);
VerifyConsString(cons_string, &data);
String flat_string_ptr = flat_string->IsConsString()
? ConsString::cast(*flat_string).first()
: *flat_string;
VerifyCharacterStream(flat_string_ptr, *cons_string);
}
}
static const int kCharacterStreamNonRandomCases = 8;
static Handle<String> BuildEdgeCaseConsString(int test_case,
ConsStringGenerationData* data) {
Isolate* isolate = CcTest::i_isolate();
Factory* factory = isolate->factory();
data->Reset();
switch (test_case) {
case 0:
return ConstructBalanced(data, 71);
case 1:
return ConstructLeft(data, 71);
case 2:
return ConstructRight(data, 71);
case 3:
return ConstructLeft(data, 10);
case 4:
return ConstructRight(data, 10);
case 5:
// 2 element balanced tree.
data->stats_.chars_ += data->block(0)->length();
data->stats_.chars_ += data->block(1)->length();
data->stats_.leaves_ += 2;
return factory->NewConsString(data->block(0), data->block(1))
.ToHandleChecked();
case 6:
// Simple flattened tree.
data->stats_.chars_ += data->block(0)->length();
data->stats_.chars_ += data->block(1)->length();
data->stats_.leaves_ += 2;
data->stats_.empty_leaves_ += 1;
{
Handle<String> string =
factory->NewConsString(data->block(0), data->block(1))
.ToHandleChecked();
String::Flatten(isolate, string);
return string;
}
case 7:
// Left node flattened.
data->stats_.chars_ += data->block(0)->length();
data->stats_.chars_ += data->block(1)->length();
data->stats_.chars_ += data->block(2)->length();
data->stats_.leaves_ += 3;
data->stats_.empty_leaves_ += 1;
data->stats_.left_traversals_ += 1;
{
Handle<String> left =
factory->NewConsString(data->block(0), data->block(1))
.ToHandleChecked();
String::Flatten(isolate, left);
return factory->NewConsString(left, data->block(2)).ToHandleChecked();
}
case 8:
// Left node and right node flattened.
data->stats_.chars_ += data->block(0)->length();
data->stats_.chars_ += data->block(1)->length();
data->stats_.chars_ += data->block(2)->length();
data->stats_.chars_ += data->block(3)->length();
data->stats_.leaves_ += 4;
data->stats_.empty_leaves_ += 2;
data->stats_.left_traversals_ += 1;
data->stats_.right_traversals_ += 1;
{
Handle<String> left =
factory->NewConsString(data->block(0), data->block(1))
.ToHandleChecked();
String::Flatten(isolate, left);
Handle<String> right =
factory->NewConsString(data->block(2), data->block(2))
.ToHandleChecked();
String::Flatten(isolate, right);
return factory->NewConsString(left, right).ToHandleChecked();
}
}
UNREACHABLE();
}
TEST(StringCharacterStreamEdgeCases) {
printf("TestStringCharacterStreamEdgeCases\n");
TestStringCharacterStream(
BuildEdgeCaseConsString, kCharacterStreamNonRandomCases);
}
static const int kBalances = 3;
static const int kTreeLengths = 4;
static const int kEmptyLeaves = 4;
static const int kUniqueRandomParameters =
kBalances*kTreeLengths*kEmptyLeaves;
static void InitializeGenerationData(
int test_case, ConsStringGenerationData* data) {
// Clear the settings and reinit the rng.
data->Reset();
// Spin up the rng to a known location that is unique per test.
static const int kPerTestJump = 501;
for (int j = 0; j < test_case*kPerTestJump; j++) {
data->rng_.next();
}
// Choose balanced, left or right heavy trees.
switch (test_case % kBalances) {
case 0:
// Nothing to do. Already balanced.
break;
case 1:
// Left balanced.
data->leftness_ = 0.90;
data->rightness_ = 0.15;
break;
case 2:
// Right balanced.
data->leftness_ = 0.15;
data->rightness_ = 0.90;
break;
default:
UNREACHABLE();
}
// Must remove the influence of the above decision.
test_case /= kBalances;
// Choose tree length.
switch (test_case % kTreeLengths) {
case 0:
data->max_leaves_ = 16;
data->early_termination_threshold_ = 0.2;
break;
case 1:
data->max_leaves_ = 50;
data->early_termination_threshold_ = 0.05;
break;
case 2:
data->max_leaves_ = 500;
data->early_termination_threshold_ = 0.03;
break;
case 3:
data->max_leaves_ = 5000;
data->early_termination_threshold_ = 0.001;
break;
default:
UNREACHABLE();
}
// Must remove the influence of the above decision.
test_case /= kTreeLengths;
// Choose how much we allow empty nodes, including not at all.
data->empty_leaf_threshold_ =
0.03 * static_cast<double>(test_case % kEmptyLeaves);
}
static Handle<String> BuildRandomConsString(
int test_case, ConsStringGenerationData* data) {
InitializeGenerationData(test_case, data);
return ConstructRandomString(data, 200);
}
TEST(StringCharacterStreamRandom) {
printf("StringCharacterStreamRandom\n");
TestStringCharacterStream(BuildRandomConsString, kUniqueRandomParameters*7);
}
static const int kDeepOneByteDepth = 100000;
TEST(DeepOneByte) {
CcTest::InitializeVM();
Isolate* isolate = CcTest::i_isolate();
Factory* factory = isolate->factory();
v8::HandleScope scope(CcTest::isolate());
char* foo = NewArray<char>(kDeepOneByteDepth);
for (int i = 0; i < kDeepOneByteDepth; i++) {
foo[i] = "foo "[i % 4];
}
Handle<String> string =
factory->NewStringFromOneByte(OneByteVector(foo, kDeepOneByteDepth))
.ToHandleChecked();
Handle<String> foo_string = factory->NewStringFromStaticChars("foo");
for (int i = 0; i < kDeepOneByteDepth; i += 10) {
string = factory->NewConsString(string, foo_string).ToHandleChecked();
}
Handle<String> flat_string =
factory->NewConsString(string, foo_string).ToHandleChecked();
String::Flatten(isolate, flat_string);
for (int i = 0; i < 500; i++) {
TraverseFirst(flat_string, string, kDeepOneByteDepth);
}
DeleteArray<char>(foo);
}
TEST(Utf8Conversion) {
// Smoke test for converting strings to utf-8.
CcTest::InitializeVM();
v8::HandleScope handle_scope(CcTest::isolate());
// A simple one-byte string
const char* one_byte_string = "abcdef12345";
int len = v8::String::NewFromUtf8(CcTest::isolate(), one_byte_string,
v8::NewStringType::kNormal,
static_cast<int>(strlen(one_byte_string)))
.ToLocalChecked()
->Utf8Length(CcTest::isolate());
CHECK_EQ(strlen(one_byte_string), len);
// A mixed one-byte and two-byte string
// U+02E4 -> CB A4
// U+0064 -> 64
// U+12E4 -> E1 8B A4
// U+0030 -> 30
// U+3045 -> E3 81 85
const uint16_t mixed_string[] = {0x02E4, 0x0064, 0x12E4, 0x0030, 0x3045};
// The characters we expect to be output
const unsigned char as_utf8[11] = {0xCB, 0xA4, 0x64, 0xE1, 0x8B, 0xA4, 0x30,
0xE3, 0x81, 0x85, 0x00};
// The number of bytes expected to be written for each length
const int lengths[12] = {0, 0, 2, 3, 3, 3, 6, 7, 7, 7, 10, 11};
const int char_lengths[12] = {0, 0, 1, 2, 2, 2, 3, 4, 4, 4, 5, 5};
v8::Local<v8::String> mixed =
v8::String::NewFromTwoByte(CcTest::isolate(), mixed_string,
v8::NewStringType::kNormal, 5)
.ToLocalChecked();
CHECK_EQ(10, mixed->Utf8Length(CcTest::isolate()));
// Try encoding the string with all capacities
char buffer[11];
const char kNoChar = static_cast<char>(-1);
for (int i = 0; i <= 11; i++) {
// Clear the buffer before reusing it
for (int j = 0; j < 11; j++)
buffer[j] = kNoChar;
int chars_written;
int written =
mixed->WriteUtf8(CcTest::isolate(), buffer, i, &chars_written);
CHECK_EQ(lengths[i], written);
CHECK_EQ(char_lengths[i], chars_written);
// Check that the contents are correct
for (int j = 0; j < lengths[i]; j++)
CHECK_EQ(as_utf8[j], static_cast<unsigned char>(buffer[j]));
// Check that the rest of the buffer hasn't been touched
for (int j = lengths[i]; j < 11; j++)
CHECK_EQ(kNoChar, buffer[j]);
}
}
TEST(Utf8ConversionPerf) {
// Smoke test for converting strings to utf-8.
LocalContext context;
v8::HandleScope handle_scope(CcTest::isolate());
v8::Local<v8::String> ascii_string =
CompileRun("'abc'.repeat(1E6)").As<v8::String>();
v8::Local<v8::String> one_byte_string =
CompileRun("'\\u0255\\u0254\\u0253'.repeat(1E6)").As<v8::String>();
v8::Local<v8::String> two_byte_string =
CompileRun("'\\u2255\\u2254\\u2253'.repeat(1E6)").As<v8::String>();
v8::Local<v8::String> surrogate_string =
CompileRun("'\\u{12345}\\u2244'.repeat(1E6)").As<v8::String>();
int size = 1E7;
char* buffer = new char[4 * size];
{
v8::base::ElapsedTimer timer;
timer.Start();
ascii_string->WriteUtf8(CcTest::isolate(), buffer, size, nullptr);
printf("ascii string %0.3f\n", timer.Elapsed().InMillisecondsF());
timer.Stop();
}
{
v8::base::ElapsedTimer timer;
timer.Start();
ascii_string->WriteUtf8(CcTest::isolate(), buffer, size, nullptr);
printf("ascii string %0.3f\n", timer.Elapsed().InMillisecondsF());
timer.Stop();
}
{
v8::base::ElapsedTimer timer;
timer.Start();
ascii_string->WriteUtf8(CcTest::isolate(), buffer, 4 * size, nullptr);
printf("ascii string %0.3f\n", timer.Elapsed().InMillisecondsF());
timer.Stop();
}
{
v8::base::ElapsedTimer timer;
timer.Start();
one_byte_string->WriteUtf8(CcTest::isolate(), buffer, size, nullptr);
printf("one byte string %0.3f\n", timer.Elapsed().InMillisecondsF());
timer.Stop();
}
{
v8::base::ElapsedTimer timer;
timer.Start();
one_byte_string->WriteUtf8(CcTest::isolate(), buffer, size, nullptr);
printf("one byte string %0.3f\n", timer.Elapsed().InMillisecondsF());
timer.Stop();
}
{
v8::base::ElapsedTimer timer;
timer.Start();
one_byte_string->WriteUtf8(CcTest::isolate(), buffer, 4 * size, nullptr);
printf("one byte string %0.3f\n", timer.Elapsed().InMillisecondsF());
timer.Stop();
}
{
v8::base::ElapsedTimer timer;
timer.Start();
two_byte_string->WriteUtf8(CcTest::isolate(), buffer, size, nullptr);
printf("two byte string %0.3f\n", timer.Elapsed().InMillisecondsF());
timer.Stop();
}
{
v8::base::ElapsedTimer timer;
timer.Start();
two_byte_string->WriteUtf8(CcTest::isolate(), buffer, size, nullptr);
printf("two byte string %0.3f\n", timer.Elapsed().InMillisecondsF());
timer.Stop();
}
{
v8::base::ElapsedTimer timer;
timer.Start();
two_byte_string->WriteUtf8(CcTest::isolate(), buffer, 4 * size, nullptr);
printf("two byte string %0.3f\n", timer.Elapsed().InMillisecondsF());
timer.Stop();
}
{
v8::base::ElapsedTimer timer;
timer.Start();
surrogate_string->WriteUtf8(CcTest::isolate(), buffer, size, nullptr);
printf("surrogate string %0.3f\n", timer.Elapsed().InMillisecondsF());
timer.Stop();
}
{
v8::base::ElapsedTimer timer;
timer.Start();
surrogate_string->WriteUtf8(CcTest::isolate(), buffer, size, nullptr);
printf("surrogate string %0.3f\n", timer.Elapsed().InMillisecondsF());
timer.Stop();
}
{
v8::base::ElapsedTimer timer;
timer.Start();
surrogate_string->WriteUtf8(CcTest::isolate(), buffer, 4 * size, nullptr);
printf("surrogate string %0.3f\n", timer.Elapsed().InMillisecondsF());
timer.Stop();
}
delete[] buffer;
}
TEST(ExternalShortStringAdd) {
LocalContext context;
v8::HandleScope handle_scope(CcTest::isolate());
// Make sure we cover all always-flat lengths and at least one above.
static const int kMaxLength = 20;
CHECK_GT(kMaxLength, i::ConsString::kMinLength);
// Allocate two JavaScript arrays for holding short strings.
v8::Local<v8::Array> one_byte_external_strings =
v8::Array::New(CcTest::isolate(), kMaxLength + 1);
v8::Local<v8::Array> non_one_byte_external_strings =
v8::Array::New(CcTest::isolate(), kMaxLength + 1);
// Generate short one-byte and two-byte external strings.
for (int i = 0; i <= kMaxLength; i++) {
char* one_byte = NewArray<char>(i + 1);
for (int j = 0; j < i; j++) {
one_byte[j] = 'a';
}
// Terminating '\0' is left out on purpose. It is not required for external
// string data.
OneByteResource* one_byte_resource = new OneByteResource(one_byte, i);
v8::Local<v8::String> one_byte_external_string =
v8::String::NewExternalOneByte(CcTest::isolate(), one_byte_resource)
.ToLocalChecked();
one_byte_external_strings->Set(context.local(),
v8::Integer::New(CcTest::isolate(), i),
one_byte_external_string)
.FromJust();
uc16* non_one_byte = NewArray<uc16>(i + 1);
for (int j = 0; j < i; j++) {
non_one_byte[j] = 0x1234;
}
// Terminating '\0' is left out on purpose. It is not required for external
// string data.
Resource* resource = new Resource(non_one_byte, i);
v8::Local<v8::String> non_one_byte_external_string =
v8::String::NewExternalTwoByte(CcTest::isolate(), resource)
.ToLocalChecked();
non_one_byte_external_strings->Set(context.local(),
v8::Integer::New(CcTest::isolate(), i),
non_one_byte_external_string)
.FromJust();
}
// Add the arrays with the short external strings in the global object.
v8::Local<v8::Object> global = context->Global();
global->Set(context.local(), v8_str("external_one_byte"),
one_byte_external_strings)
.FromJust();
global->Set(context.local(), v8_str("external_non_one_byte"),
non_one_byte_external_strings)
.FromJust();
global->Set(context.local(), v8_str("max_length"),
v8::Integer::New(CcTest::isolate(), kMaxLength))
.FromJust();
// Add short external one-byte and two-byte strings checking the result.
static const char* source =
"function test() {"
" var one_byte_chars = 'aaaaaaaaaaaaaaaaaaaa';"
" var non_one_byte_chars = "
"'\\u1234\\u1234\\u1234\\u1234\\u1234\\u1234\\u1234\\u1234\\u1234\\u1"
"234\\u1234\\u1234\\u1234\\u1234\\u1234\\u1234\\u1234\\u1234\\u1234\\"
"u1234';" // NOLINT
" if (one_byte_chars.length != max_length) return 1;"
" if (non_one_byte_chars.length != max_length) return 2;"
" var one_byte = Array(max_length + 1);"
" var non_one_byte = Array(max_length + 1);"
" for (var i = 0; i <= max_length; i++) {"
" one_byte[i] = one_byte_chars.substring(0, i);"
" non_one_byte[i] = non_one_byte_chars.substring(0, i);"
" };"
" for (var i = 0; i <= max_length; i++) {"
" if (one_byte[i] != external_one_byte[i]) return 3;"
" if (non_one_byte[i] != external_non_one_byte[i]) return 4;"
" for (var j = 0; j < i; j++) {"
" if (external_one_byte[i] !="
" (external_one_byte[j] + external_one_byte[i - j])) return "
"5;"
" if (external_non_one_byte[i] !="
" (external_non_one_byte[j] + external_non_one_byte[i - "
"j])) return 6;"
" if (non_one_byte[i] != (non_one_byte[j] + non_one_byte[i - "
"j])) return 7;"
" if (one_byte[i] != (one_byte[j] + one_byte[i - j])) return 8;"
" if (one_byte[i] != (external_one_byte[j] + one_byte[i - j])) "
"return 9;"
" if (one_byte[i] != (one_byte[j] + external_one_byte[i - j])) "
"return 10;"
" if (non_one_byte[i] !="
" (external_non_one_byte[j] + non_one_byte[i - j])) return "
"11;"
" if (non_one_byte[i] !="
" (non_one_byte[j] + external_non_one_byte[i - j])) return "
"12;"
" }"
" }"
" return 0;"
"};"
"test()";
CHECK_EQ(0, CompileRun(source)->Int32Value(context.local()).FromJust());
}
TEST(ReplaceInvalidUtf8) {
LocalContext context;
v8::HandleScope handle_scope(CcTest::isolate());
v8::Local<v8::String> string = CompileRun("'ab\\ud800cd'").As<v8::String>();
char buffer[7];
memset(buffer, 0, 7);
int chars_written = 0;
int size = string->WriteUtf8(CcTest::isolate(), buffer, 7, &chars_written,
v8::String::REPLACE_INVALID_UTF8);
CHECK_EQ(7, size);
CHECK_EQ(5, chars_written);
CHECK_EQ(0, memcmp("\x61\x62\xef\xbf\xbd\x63\x64", buffer, 7));
memset(buffer, 0, 7);
chars_written = 0;
size = string->WriteUtf8(CcTest::isolate(), buffer, 6, &chars_written,
v8::String::REPLACE_INVALID_UTF8);
CHECK_EQ(6, size);
CHECK_EQ(4, chars_written);
CHECK_EQ(0, memcmp("\x61\x62\xef\xbf\xbd\x63", buffer, 6));
}
TEST(JSONStringifySliceMadeExternal) {
if (!FLAG_string_slices) return;
CcTest::InitializeVM();
// Create a sliced string from a one-byte string. The latter is turned
// into a two-byte external string. Check that JSON.stringify works.
v8::HandleScope handle_scope(CcTest::isolate());
v8::Local<v8::String> underlying =
CompileRun(
"var underlying = 'abcdefghijklmnopqrstuvwxyz';"
"underlying")
->ToString(CcTest::isolate()->GetCurrentContext())
.ToLocalChecked();
v8::Local<v8::String> slice =
CompileRun(
"var slice = '';"
"slice = underlying.slice(1);"
"slice")
->ToString(CcTest::isolate()->GetCurrentContext())
.ToLocalChecked();
CHECK(v8::Utils::OpenHandle(*slice)->IsSlicedString());
CHECK(v8::Utils::OpenHandle(*underlying)->IsSeqOneByteString());
int length = underlying->Length();
uc16* two_byte = NewArray<uc16>(length + 1);
underlying->Write(CcTest::isolate(), two_byte);
Resource* resource = new Resource(two_byte, length);
CHECK(underlying->MakeExternal(resource));
CHECK(v8::Utils::OpenHandle(*slice)->IsSlicedString());
CHECK(v8::Utils::OpenHandle(*underlying)->IsExternalTwoByteString());
CHECK_EQ(0,
strcmp("\"bcdefghijklmnopqrstuvwxyz\"",
*v8::String::Utf8Value(CcTest::isolate(),
CompileRun("JSON.stringify(slice)"))));
}
TEST(JSONStringifyWellFormed) {
CcTest::InitializeVM();
v8::HandleScope handle_scope(CcTest::isolate());
v8::Local<v8::Context> context = CcTest::isolate()->GetCurrentContext();
// Test some leading surrogates (U+D800 to U+DBFF).
{ // U+D800
CHECK_EQ(
0, strcmp("\"\\ud800\"", *v8::String::Utf8Value(
CcTest::isolate(),
CompileRun("JSON.stringify('\\uD800')"))));
v8::Local<v8::String> json = v8_str("\"\\ud800\"");
v8::Local<v8::Value> parsed =
v8::JSON::Parse(context, json).ToLocalChecked();
CHECK(v8::JSON::Stringify(context, parsed)
.ToLocalChecked()
->Equals(context, json)
.FromJust());
}
{ // U+DAAA
CHECK_EQ(
0, strcmp("\"\\udaaa\"", *v8::String::Utf8Value(
CcTest::isolate(),
CompileRun("JSON.stringify('\\uDAAA')"))));
v8::Local<v8::String> json = v8_str("\"\\udaaa\"");
v8::Local<v8::Value> parsed =
v8::JSON::Parse(context, json).ToLocalChecked();
CHECK(v8::JSON::Stringify(context, parsed)
.ToLocalChecked()
->Equals(context, json)
.FromJust());
}
{ // U+DBFF
CHECK_EQ(
0, strcmp("\"\\udbff\"", *v8::String::Utf8Value(
CcTest::isolate(),
CompileRun("JSON.stringify('\\uDBFF')"))));
v8::Local<v8::String> json = v8_str("\"\\udbff\"");
v8::Local<v8::Value> parsed =
v8::JSON::Parse(context, json).ToLocalChecked();
CHECK(v8::JSON::Stringify(context, parsed)
.ToLocalChecked()
->Equals(context, json)
.FromJust());
}
// Test some trailing surrogates (U+DC00 to U+DFFF).
{ // U+DC00
CHECK_EQ(
0, strcmp("\"\\udc00\"", *v8::String::Utf8Value(
CcTest::isolate(),
CompileRun("JSON.stringify('\\uDC00')"))));
v8::Local<v8::String> json = v8_str("\"\\udc00\"");
v8::Local<v8::Value> parsed =
v8::JSON::Parse(context, json).ToLocalChecked();
CHECK(v8::JSON::Stringify(context, parsed)
.ToLocalChecked()
->Equals(context, json)
.FromJust());
}
{ // U+DDDD
CHECK_EQ(
0, strcmp("\"\\udddd\"", *v8::String::Utf8Value(
CcTest::isolate(),
CompileRun("JSON.stringify('\\uDDDD')"))));
v8::Local<v8::String> json = v8_str("\"\\udddd\"");
v8::Local<v8::Value> parsed =
v8::JSON::Parse(context, json).ToLocalChecked();
CHECK(v8::JSON::Stringify(context, parsed)
.ToLocalChecked()
->Equals(context, json)
.FromJust());
}
{ // U+DFFF
CHECK_EQ(
0, strcmp("\"\\udfff\"", *v8::String::Utf8Value(
CcTest::isolate(),
CompileRun("JSON.stringify('\\uDFFF')"))));
v8::Local<v8::String> json = v8_str("\"\\udfff\"");
v8::Local<v8::Value> parsed =
v8::JSON::Parse(context, json).ToLocalChecked();
CHECK(v8::JSON::Stringify(context, parsed)
.ToLocalChecked()
->Equals(context, json)
.FromJust());
}
}
TEST(CachedHashOverflow) {
CcTest::InitializeVM();
// We incorrectly allowed strings to be tagged as array indices even if their
// values didn't fit in the hash field.
// See http://code.google.com/p/v8/issues/detail?id=728
Isolate* isolate = CcTest::i_isolate();
v8::HandleScope handle_scope(CcTest::isolate());
// Lines must be executed sequentially. Combining them into one script
// makes the bug go away.
const char* lines[] = {"var x = [];", "x[4] = 42;", "var s = \"1073741828\";",
"x[s];", "x[s] = 37;", "x[4];",
"x[s];"};
Handle<Smi> fortytwo(Smi::FromInt(42), isolate);
Handle<Smi> thirtyseven(Smi::FromInt(37), isolate);
Handle<Object> results[] = { isolate->factory()->undefined_value(),
fortytwo,
isolate->factory()->undefined_value(),
isolate->factory()->undefined_value(),
thirtyseven,
fortytwo,
thirtyseven // Bug yielded 42 here.
};
v8::Local<v8::Context> context = CcTest::isolate()->GetCurrentContext();
for (size_t i = 0; i < arraysize(lines); i++) {
const char* line = lines[i];
printf("%s\n", line);
v8::Local<v8::Value> result =
v8::Script::Compile(context,
v8::String::NewFromUtf8(CcTest::isolate(), line,
v8::NewStringType::kNormal)
.ToLocalChecked())
.ToLocalChecked()
->Run(context)
.ToLocalChecked();
CHECK_EQ(results[i]->IsUndefined(CcTest::i_isolate()),
result->IsUndefined());
CHECK_EQ(results[i]->IsNumber(), result->IsNumber());
if (result->IsNumber()) {
int32_t value = 0;
CHECK(results[i]->ToInt32(&value));
CHECK_EQ(value, result->ToInt32(context).ToLocalChecked()->Value());
}
}
}
TEST(SliceFromCons) {
if (!FLAG_string_slices) return;
CcTest::InitializeVM();
Factory* factory = CcTest::i_isolate()->factory();
v8::HandleScope scope(CcTest::isolate());
Handle<String> string =
factory->NewStringFromStaticChars("parentparentparent");
Handle<String> parent =
factory->NewConsString(string, string).ToHandleChecked();
CHECK(parent->IsConsString());
CHECK(!parent->IsFlat());
Handle<String> slice = factory->NewSubString(parent, 1, 25);
// After slicing, the original string becomes a flat cons.
CHECK(parent->IsFlat());
CHECK(slice->IsSlicedString());
CHECK_EQ(
SlicedString::cast(*slice).parent(),
// Parent could have been short-circuited.
parent->IsConsString() ? ConsString::cast(*parent).first() : *parent);
CHECK(SlicedString::cast(*slice).parent().IsSeqString());
CHECK(slice->IsFlat());
}
class OneByteVectorResource : public v8::String::ExternalOneByteStringResource {
public:
explicit OneByteVectorResource(i::Vector<const char> vector)
: data_(vector) {}
~OneByteVectorResource() override = default;
size_t length() const override { return data_.length(); }
const char* data() const override { return data_.begin(); }
private:
i::Vector<const char> data_;
};
TEST(InternalizeExternal) {
#ifdef ENABLE_MINOR_MC
// TODO(mlippautz): Remove once we add support for forwarding ThinStrings in
// minor MC
if (FLAG_minor_mc) return;
#endif // ENABLE_MINOR_MC
FLAG_stress_incremental_marking = false;
FLAG_thin_strings = true;
CcTest::InitializeVM();
i::Isolate* isolate = CcTest::i_isolate();
Factory* factory = isolate->factory();
// This won't leak; the external string mechanism will call Dispose() on it.
OneByteVectorResource* resource =
new OneByteVectorResource(i::Vector<const char>("prop-1234", 9));
{
v8::HandleScope scope(CcTest::isolate());
v8::Local<v8::String> ext_string =
v8::String::NewExternalOneByte(CcTest::isolate(), resource)
.ToLocalChecked();
Handle<String> string = v8::Utils::OpenHandle(*ext_string);
CHECK(string->IsExternalString());
CHECK(!string->IsInternalizedString());
CHECK(!i::Heap::InYoungGeneration(*string));
CHECK_EQ(
isolate->factory()->string_table()->LookupStringIfExists_NoAllocate(
isolate, string->ptr()),
Smi::FromInt(ResultSentinel::kNotFound).ptr());
factory->InternalizeName(string);
CHECK(string->IsExternalString());
CHECK(string->IsInternalizedString());
CHECK(!i::Heap::InYoungGeneration(*string));
}
CcTest::CollectGarbage(i::OLD_SPACE);
CcTest::CollectGarbage(i::OLD_SPACE);
}
TEST(SliceFromExternal) {
if (!FLAG_string_slices) return;
CcTest::InitializeVM();
Factory* factory = CcTest::i_isolate()->factory();
v8::HandleScope scope(CcTest::isolate());
OneByteVectorResource resource(
i::Vector<const char>("abcdefghijklmnopqrstuvwxyz", 26));
Handle<String> string =
factory->NewExternalStringFromOneByte(&resource).ToHandleChecked();
CHECK(string->IsExternalString());
Handle<String> slice = factory->NewSubString(string, 1, 25);
CHECK(slice->IsSlicedString());
CHECK(string->IsExternalString());
CHECK_EQ(SlicedString::cast(*slice).parent(), *string);
CHECK(SlicedString::cast(*slice).parent().IsExternalString());
CHECK(slice->IsFlat());
// This avoids the GC from trying to free stack allocated resources.
i::Handle<i::ExternalOneByteString>::cast(string)->SetResource(
CcTest::i_isolate(), nullptr);
}
TEST(TrivialSlice) {
// This tests whether a slice that contains the entire parent string
// actually creates a new string (it should not).
if (!FLAG_string_slices) return;
CcTest::InitializeVM();
Factory* factory = CcTest::i_isolate()->factory();
v8::HandleScope scope(CcTest::isolate());
v8::Local<v8::Value> result;
Handle<String> string;
const char* init = "var str = 'abcdefghijklmnopqrstuvwxyz';";
const char* check = "str.slice(0,26)";
const char* crosscheck = "str.slice(1,25)";
CompileRun(init);
result = CompileRun(check);
CHECK(result->IsString());
string = v8::Utils::OpenHandle(v8::String::Cast(*result));
CHECK(!string->IsSlicedString());
string = factory->NewSubString(string, 0, 26);
CHECK(!string->IsSlicedString());
result = CompileRun(crosscheck);
CHECK(result->IsString());
string = v8::Utils::OpenHandle(v8::String::Cast(*result));
CHECK(string->IsSlicedString());
CHECK_EQ(0, strcmp("bcdefghijklmnopqrstuvwxy", string->ToCString().get()));
}
TEST(SliceFromSlice) {
// This tests whether a slice that contains the entire parent string
// actually creates a new string (it should not).
if (!FLAG_string_slices) return;
CcTest::InitializeVM();
v8::HandleScope scope(CcTest::isolate());
v8::Local<v8::Value> result;
Handle<String> string;
const char* init = "var str = 'abcdefghijklmnopqrstuvwxyz';";
const char* slice = "var slice = ''; slice = str.slice(1,-1); slice";
const char* slice_from_slice = "slice.slice(1,-1);";
CompileRun(init);
result = CompileRun(slice);
CHECK(result->IsString());
string = v8::Utils::OpenHandle(v8::String::Cast(*result));
CHECK(string->IsSlicedString());
CHECK(SlicedString::cast(*string).parent().IsSeqString());
CHECK_EQ(0, strcmp("bcdefghijklmnopqrstuvwxy", string->ToCString().get()));
result = CompileRun(slice_from_slice);
CHECK(result->IsString());
string = v8::Utils::OpenHandle(v8::String::Cast(*result));
CHECK(string->IsSlicedString());
CHECK(SlicedString::cast(*string).parent().IsSeqString());
CHECK_EQ(0, strcmp("cdefghijklmnopqrstuvwx", string->ToCString().get()));
}
UNINITIALIZED_TEST(OneByteArrayJoin) {
v8::Isolate::CreateParams create_params;
// Set heap limits.
create_params.constraints.set_max_young_generation_size_in_bytes(3 * MB);
#ifdef DEBUG
create_params.constraints.set_max_old_generation_size_in_bytes(20 * MB);
#else
create_params.constraints.set_max_old_generation_size_in_bytes(7 * MB);
#endif
create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
v8::Isolate* isolate = v8::Isolate::New(create_params);
isolate->Enter();
{
// String s is made of 2^17 = 131072 'c' characters and a is an array
// starting with 'bad', followed by 2^14 times the string s. That means the
// total length of the concatenated strings is 2^31 + 3. So on 32bit systems
// summing the lengths of the strings (as Smis) overflows and wraps.
LocalContext context(isolate);
v8::HandleScope scope(isolate);
v8::TryCatch try_catch(isolate);
CHECK(CompileRun(
"var two_14 = Math.pow(2, 14);"
"var two_17 = Math.pow(2, 17);"
"var s = Array(two_17 + 1).join('c');"
"var a = ['bad'];"
"for (var i = 1; i <= two_14; i++) a.push(s);"
"a.join("
");").IsEmpty());
CHECK(try_catch.HasCaught());
}
isolate->Exit();
isolate->Dispose();
}
namespace {
int* global_use_counts = nullptr;
void MockUseCounterCallback(v8::Isolate* isolate,
v8::Isolate::UseCounterFeature feature) {
++global_use_counts[feature];
}
}
TEST(CountBreakIterator) {
CcTest::InitializeVM();
v8::HandleScope scope(CcTest::isolate());
LocalContext context;
int use_counts[v8::Isolate::kUseCounterFeatureCount] = {};
global_use_counts = use_counts;
CcTest::isolate()->SetUseCounterCallback(MockUseCounterCallback);
CHECK_EQ(0, use_counts[v8::Isolate::kBreakIterator]);
v8::Local<v8::Value> result = CompileRun(
"(function() {"
" if (!this.Intl) return 0;"
" var iterator = Intl.v8BreakIterator(['en']);"
" iterator.adoptText('Now is the time');"
" iterator.next();"
" return iterator.next();"
"})();");
CHECK(result->IsNumber());
int uses =
result->ToInt32(context.local()).ToLocalChecked()->Value() == 0 ? 0 : 1;
CHECK_EQ(uses, use_counts[v8::Isolate::kBreakIterator]);
// Make sure GC cleans up the break iterator, so we don't get a memory leak
// reported by ASAN.
CcTest::isolate()->LowMemoryNotification();
}
TEST(StringReplaceAtomTwoByteResult) {
CcTest::InitializeVM();
v8::HandleScope scope(CcTest::isolate());
LocalContext context;
v8::Local<v8::Value> result = CompileRun(
"var subject = 'one_byte~only~string~'; "
"var replace = '\x80'; "
"subject.replace(/~/g, replace); ");
CHECK(result->IsString());
Handle<String> string = v8::Utils::OpenHandle(v8::String::Cast(*result));
CHECK(string->IsTwoByteRepresentation());
v8::Local<v8::String> expected = v8_str("one_byte\x80only\x80string\x80");
CHECK(expected->Equals(context.local(), result).FromJust());
}
TEST(IsAscii) {
CHECK(String::IsAscii(static_cast<char*>(nullptr), 0));
CHECK(String::IsOneByte(static_cast<uc16*>(nullptr), 0));
}
template<typename Op, bool return_first>
static uint16_t ConvertLatin1(uint16_t c) {
uint32_t result[Op::kMaxWidth];
int chars;
chars = Op::Convert(c, 0, result, nullptr);
if (chars == 0) return 0;
CHECK_LE(chars, static_cast<int>(sizeof(result)));
if (!return_first && chars > 1) {
return 0;
}
return result[0];
}
#ifndef V8_INTL_SUPPORT
static void CheckCanonicalEquivalence(uint16_t c, uint16_t test) {
uint16_t expect = ConvertLatin1<unibrow::Ecma262UnCanonicalize, true>(c);
if (expect > unibrow::Latin1::kMaxChar || expect == 0) expect = c;
CHECK_EQ(expect, test);
}
TEST(Latin1IgnoreCase) {
for (uint16_t c = unibrow::Latin1::kMaxChar + 1; c != 0; c++) {
uint16_t lower = ConvertLatin1<unibrow::ToLowercase, false>(c);
uint16_t upper = ConvertLatin1<unibrow::ToUppercase, false>(c);
uint16_t test = unibrow::Latin1::TryConvertToLatin1(c);
// Filter out all character whose upper is not their lower or vice versa.
if (lower == 0 && upper == 0) {
CheckCanonicalEquivalence(c, test);
continue;
}
if (lower > unibrow::Latin1::kMaxChar &&
upper > unibrow::Latin1::kMaxChar) {
CheckCanonicalEquivalence(c, test);
continue;
}
if (lower == 0 && upper != 0) {
lower = ConvertLatin1<unibrow::ToLowercase, false>(upper);
}
if (upper == 0 && lower != c) {
upper = ConvertLatin1<unibrow::ToUppercase, false>(lower);
}
if (lower > unibrow::Latin1::kMaxChar &&
upper > unibrow::Latin1::kMaxChar) {
CheckCanonicalEquivalence(c, test);
continue;
}
if (upper != c && lower != c) {
CheckCanonicalEquivalence(c, test);
continue;
}
CHECK_EQ(Min(upper, lower), test);
}
}
#endif
class DummyResource: public v8::String::ExternalStringResource {
public:
const uint16_t* data() const override { return nullptr; }
size_t length() const override { return 1 << 30; }
};
class DummyOneByteResource: public v8::String::ExternalOneByteStringResource {
public:
const char* data() const override { return nullptr; }
size_t length() const override { return 1 << 30; }
};
TEST(InvalidExternalString) {
CcTest::InitializeVM();
LocalContext context;
Isolate* isolate = CcTest::i_isolate();
{ HandleScope scope(isolate);
DummyOneByteResource r;
CHECK(isolate->factory()->NewExternalStringFromOneByte(&r).is_null());
CHECK(isolate->has_pending_exception());
isolate->clear_pending_exception();
}
{ HandleScope scope(isolate);
DummyResource r;
CHECK(isolate->factory()->NewExternalStringFromTwoByte(&r).is_null());
CHECK(isolate->has_pending_exception());
isolate->clear_pending_exception();
}
}
#define INVALID_STRING_TEST(FUN, TYPE) \
TEST(StringOOM##FUN) { \
CcTest::InitializeVM(); \
LocalContext context; \
Isolate* isolate = CcTest::i_isolate(); \
STATIC_ASSERT(String::kMaxLength < kMaxInt); \
static const int invalid = String::kMaxLength + 1; \
HandleScope scope(isolate); \
Vector<TYPE> dummy = Vector<TYPE>::New(invalid); \
memset(dummy.begin(), 0x0, dummy.length() * sizeof(TYPE)); \
CHECK(isolate->factory()->FUN(Vector<const TYPE>::cast(dummy)).is_null()); \
memset(dummy.begin(), 0x20, dummy.length() * sizeof(TYPE)); \
CHECK(isolate->has_pending_exception()); \
isolate->clear_pending_exception(); \
dummy.Dispose(); \
}
INVALID_STRING_TEST(NewStringFromUtf8, char)
INVALID_STRING_TEST(NewStringFromOneByte, uint8_t)
#undef INVALID_STRING_TEST
TEST(FormatMessage) {
CcTest::InitializeVM();
LocalContext context;
Isolate* isolate = CcTest::i_isolate();
HandleScope scope(isolate);
Handle<String> arg0 = isolate->factory()->NewStringFromAsciiChecked("arg0");
Handle<String> arg1 = isolate->factory()->NewStringFromAsciiChecked("arg1");
Handle<String> arg2 = isolate->factory()->NewStringFromAsciiChecked("arg2");
Handle<String> result =
MessageFormatter::Format(isolate, MessageTemplate::kPropertyNotFunction,
arg0, arg1, arg2)
.ToHandleChecked();
Handle<String> expected = isolate->factory()->NewStringFromAsciiChecked(
"'arg0' returned for property 'arg1' of object 'arg2' is not a function");
CHECK(String::Equals(isolate, result, expected));
}
TEST(Regress609831) {
CcTest::InitializeVM();
LocalContext context;
Isolate* isolate = CcTest::i_isolate();
{
HandleScope scope(isolate);
v8::Local<v8::Value> result = CompileRun(
"String.fromCharCode(32, 32, 32, 32, 32, "
"32, 32, 32, 32, 32, 32, 32, 32, 32, 32, "
"32, 32, 32, 32, 32, 32, 32, 32, 32, 32)");
CHECK(v8::Utils::OpenHandle(*result)->IsSeqOneByteString());
}
{
HandleScope scope(isolate);
v8::Local<v8::Value> result = CompileRun(
"String.fromCharCode(432, 432, 432, 432, 432, "
"432, 432, 432, 432, 432, 432, 432, 432, 432, "
"432, 432, 432, 432, 432, 432, 432, 432, 432)");
CHECK(v8::Utils::OpenHandle(*result)->IsSeqTwoByteString());
}
}
TEST(ExternalStringIndexOf) {
CcTest::InitializeVM();
LocalContext context;
v8::HandleScope scope(CcTest::isolate());
const char* raw_string = "abcdefghijklmnopqrstuvwxyz";
v8::Local<v8::String> string =
v8::String::NewExternalOneByte(CcTest::isolate(),
new StaticOneByteResource(raw_string))
.ToLocalChecked();
v8::Local<v8::Object> global = context->Global();
global->Set(context.local(), v8_str("external"), string).FromJust();
char source[] = "external.indexOf('%')";
for (size_t i = 0; i < strlen(raw_string); i++) {
source[18] = raw_string[i];
int result_position = static_cast<int>(i);
CHECK_EQ(result_position,
CompileRun(source)->Int32Value(context.local()).FromJust());
}
CHECK_EQ(-1,
CompileRun("external.indexOf('abcdefghijklmnopqrstuvwxyz%%%%%%')")
->Int32Value(context.local())
.FromJust());
CHECK_EQ(1, CompileRun("external.indexOf('', 1)")
->Int32Value(context.local())
.FromJust());
CHECK_EQ(-1, CompileRun("external.indexOf('a', 1)")
->Int32Value(context.local())
.FromJust());
CHECK_EQ(-1, CompileRun("external.indexOf('$')")
->Int32Value(context.local())
.FromJust());
}
#define GC_INSIDE_NEW_STRING_FROM_UTF8_SUB_STRING(NAME, STRING) \
TEST(GCInsideNewStringFromUtf8SubStringWith##NAME) { \
CcTest::InitializeVM(); \
LocalContext context; \
v8::HandleScope scope(CcTest::isolate()); \
Factory* factory = CcTest::i_isolate()->factory(); \
/* Length must be bigger than the buffer size of the Utf8Decoder. */ \
const char* buf = STRING; \
size_t len = strlen(buf); \
Handle<String> main_string = \
factory \
->NewStringFromOneByte(Vector<const uint8_t>( \
reinterpret_cast<const uint8_t*>(buf), len)) \
.ToHandleChecked(); \
CHECK(Heap::InYoungGeneration(*main_string)); \
/* Next allocation will cause GC. */ \
heap::SimulateFullSpace(CcTest::i_isolate()->heap()->new_space()); \
/* Offset by two to check substring-ing. */ \
Handle<String> s = factory \
->NewStringFromUtf8SubString( \
Handle<SeqOneByteString>::cast(main_string), 2, \
static_cast<int>(len - 2)) \
.ToHandleChecked(); \
Handle<String> expected_string = \
factory->NewStringFromUtf8(Vector<const char>(buf + 2, len - 2)) \
.ToHandleChecked(); \
CHECK(s->Equals(*expected_string)); \
}
GC_INSIDE_NEW_STRING_FROM_UTF8_SUB_STRING(
OneByte,
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ")
GC_INSIDE_NEW_STRING_FROM_UTF8_SUB_STRING(
TwoByte,
"QQ\xF0\x9F\x98\x8D\xF0\x9F\x98\x8D"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ"
"QQ\xF0\x9F\x98\x8D\xF0\x9F\x98\x8D")
#undef GC_INSIDE_NEW_STRING_FROM_UTF8_SUB_STRING
TEST(HashArrayIndexStrings) {
CcTest::InitializeVM();
LocalContext context;
v8::HandleScope scope(CcTest::isolate());
i::Isolate* isolate = CcTest::i_isolate();
CHECK_EQ(StringHasher::MakeArrayIndexHash(0 /* value */, 1 /* length */) >>
Name::kHashShift,
isolate->factory()->zero_string()->Hash());
CHECK_EQ(StringHasher::MakeArrayIndexHash(1 /* value */, 1 /* length */) >>
Name::kHashShift,
isolate->factory()->one_string()->Hash());
}
TEST(StringEquals) {
v8::V8::Initialize();
v8::Isolate* isolate = CcTest::isolate();
v8::HandleScope scope(isolate);
auto foo_str =
v8::String::NewFromUtf8(isolate, "foo", v8::NewStringType::kNormal)
.ToLocalChecked();
auto bar_str =
v8::String::NewFromUtf8(isolate, "bar", v8::NewStringType::kNormal)
.ToLocalChecked();
auto foo_str2 =
v8::String::NewFromUtf8(isolate, "foo", v8::NewStringType::kNormal)
.ToLocalChecked();
uint16_t* two_byte_source = AsciiToTwoByteString("foo");
auto foo_two_byte_str =
v8::String::NewFromTwoByte(isolate, two_byte_source,
v8::NewStringType::kNormal)
.ToLocalChecked();
i::DeleteArray(two_byte_source);
CHECK(foo_str->StringEquals(foo_str));
CHECK(!foo_str->StringEquals(bar_str));
CHECK(foo_str->StringEquals(foo_str2));
CHECK(foo_str->StringEquals(foo_two_byte_str));
CHECK(!bar_str->StringEquals(foo_str2));
}
class OneByteStringResource : public v8::String::ExternalOneByteStringResource {
public:
// Takes ownership of |data|.
OneByteStringResource(char* data, size_t length)
: data_(data), length_(length) {}
~OneByteStringResource() override { delete[] data_; }
const char* data() const override { return data_; }
size_t length() const override { return length_; }
private:
char* data_;
size_t length_;
};
TEST(Regress876759) {
v8::V8::Initialize();
Isolate* isolate = CcTest::i_isolate();
Factory* factory = isolate->factory();
HandleScope handle_scope(isolate);
const int kLength = 30;
uc16 two_byte_buf[kLength];
char* external_one_byte_buf = new char[kLength];
for (int j = 0; j < kLength; j++) {
char c = '0' + (j % 10);
two_byte_buf[j] = c;
external_one_byte_buf[j] = c;
}
Handle<String> parent;
{
Handle<SeqTwoByteString> raw =
factory->NewRawTwoByteString(kLength).ToHandleChecked();
DisallowHeapAllocation no_gc;
CopyChars(raw->GetChars(no_gc), two_byte_buf, kLength);
parent = raw;
}
CHECK(parent->IsTwoByteRepresentation());
Handle<String> sliced = factory->NewSubString(parent, 1, 20);
CHECK(sliced->IsSlicedString());
factory->InternalizeString(parent);
CHECK(parent->IsThinString());
Handle<String> grandparent =
handle(ThinString::cast(*parent).actual(), isolate);
CHECK_EQ(*parent, SlicedString::cast(*sliced).parent());
OneByteStringResource* resource =
new OneByteStringResource(external_one_byte_buf, kLength);
grandparent->MakeExternal(resource);
// The grandparent string becomes one-byte, but the child strings are still
// two-byte.
CHECK(grandparent->IsOneByteRepresentation());
CHECK(parent->IsTwoByteRepresentation());
CHECK(sliced->IsTwoByteRepresentation());
// The *Underneath version returns the correct representation.
CHECK(String::IsOneByteRepresentationUnderneath(*sliced));
}
} // namespace test_strings
} // namespace internal
} // namespace v8