/*
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <folly/memory/UninitializedMemoryHacks.h>
#include <algorithm>
#include <memory>
#include <string>
#include <vector>
#include <folly/Random.h>
#include <folly/portability/GTest.h>
#include <glog/logging.h>
void describePlatform() {
LOG(INFO) << "sizeof(void*) = " << sizeof(void*);
LOG(INFO) << "sizeof(std::string) = " << sizeof(std::string);
#if defined(_LIBCPP_STRING)
LOG(INFO) << "std::string from libc++";
#elif defined(_STLP_STRING)
LOG(INFO) << "std::string from STLport";
#elif defined(_GLIBCXX_STRING) && _GLIBCXX_USE_CXX11_ABI
LOG(INFO) << "std::string from libstdc++ with SSO";
#elif defined(_GLIBCXX_STRING)
LOG(INFO) << "std::string from old libstdc++";
#elif defined(_MSC_VER)
LOG(INFO) << "std::string from MSVC";
#else
LOG(INFO) << "UNKNOWN std::string implementation";
#endif
LOG(INFO) << "sizeof(std::vector<char>) = " << sizeof(std::vector<char>);
#if defined(_LIBCPP_VECTOR)
LOG(INFO) << "std::vector from libc++";
#elif defined(_STLP_VECTOR)
LOG(INFO) << "std::vector from STLport";
#elif defined(_GLIBCXX_VECTOR)
LOG(INFO) << "std::vector from libstdc++";
#elif defined(_MSC_VER)
LOG(INFO) << "std::vector from MSVC";
#else
LOG(INFO) << "UNKNOWN std::vector implementation";
#endif
}
// Returns a concatenation of target[i] for those i where valid[i]
template <typename T>
T validData(T const& target, std::vector<bool> const& valid) {
EXPECT_EQ(target.size(), valid.size());
T rv;
for (std::size_t i = 0; i < valid.size(); ++i) {
if (valid[i]) {
rv.push_back(target[i]);
}
}
return rv;
}
template <typename T>
void doResizeWithoutInit(
T& target, std::vector<bool>& valid, std::size_t newSize) {
auto oldSize = target.size();
auto before = validData(target, valid);
folly::resizeWithoutInitialization(target, newSize);
valid.resize(newSize);
auto after = validData(target, valid);
if (oldSize <= newSize) {
EXPECT_EQ(before, after);
} else {
EXPECT_GE(before.size(), after.size());
EXPECT_TRUE(std::equal(after.begin(), after.end(), before.begin()));
}
}
template <typename T>
void doOverwrite(
T& target, std::vector<bool>& valid, std::size_t b, std::size_t e) {
for (auto i = b; i < e && i < target.size(); ++i) {
target[i] = '0' + (i % 10);
valid[i] = true;
}
}
template <typename T>
void doResize(T& target, std::vector<bool>& valid, std::size_t newSize) {
auto oldSize = target.size();
auto before = validData(target, valid);
target.resize(newSize);
valid.resize(newSize);
for (auto i = oldSize; i < newSize; ++i) {
valid[i] = true;
}
auto after = validData(target, valid);
if (oldSize == newSize) {
EXPECT_EQ(before, after);
} else if (oldSize < newSize) {
EXPECT_LT(before.size(), after.size());
EXPECT_TRUE(std::equal(before.begin(), before.end(), after.begin()));
} else {
EXPECT_GE(before.size(), after.size());
EXPECT_TRUE(std::equal(after.begin(), after.end(), before.begin()));
}
}
template <typename T>
void doClear(T& target, std::vector<bool>& valid) {
target.clear();
valid.clear();
}
template <typename T>
void doInsert(T& target, std::vector<bool>& valid, std::size_t i) {
target.insert(target.begin() + i, 'I');
valid.insert(valid.begin() + i, true);
}
template <typename T>
void doErase(T& target, std::vector<bool>& valid, std::size_t i) {
target.erase(target.begin() + i);
valid.erase(valid.begin() + i);
}
template <typename T>
void doPushBack(T& target, std::vector<bool>& valid) {
target.push_back('P');
valid.push_back(true);
}
template <typename T>
void genericCheck(T& target) {
EXPECT_LE(target.size(), target.capacity());
EXPECT_EQ(target.size() == 0, target.empty());
EXPECT_EQ(target.size(), target.end() - target.begin());
EXPECT_EQ(target.size(), target.cend() - target.cbegin());
if (!target.empty()) {
EXPECT_EQ(target.data(), &target[0]);
EXPECT_EQ(target.data(), &target.front());
EXPECT_EQ(target.data() + target.size() - 1, &target.back());
}
}
template <typename T>
void check(T& target) {
genericCheck(target);
}
template <>
void check<std::string>(std::string& target) {
genericCheck(target);
EXPECT_EQ(target.c_str(), target.data());
EXPECT_EQ(target.c_str()[target.size()], '\0');
}
template <typename T>
void testSimple() {
describePlatform();
auto sizes = {0, 1, 10, 14, 15, 16, 17, 22, 23, 24, 32, 95, 100, 10000};
for (auto i : sizes) {
for (auto j : sizes) {
{
T target;
std::vector<bool> valid;
doResize(target, valid, i);
doResizeWithoutInit(target, valid, j);
check(target);
}
{
T target;
std::vector<bool> valid;
doResize(target, valid, i);
doResizeWithoutInit(target, valid, j);
doOverwrite(target, valid, i, j);
check(target);
}
{
T target;
std::vector<bool> valid;
doResizeWithoutInit(target, valid, i);
doResize(target, valid, j);
doOverwrite(target, valid, i / 2, i / 2);
check(target);
}
{
T target;
std::vector<bool> valid;
doResizeWithoutInit(target, valid, i);
doResize(target, valid, j);
doOverwrite(target, valid, i, j);
check(target);
}
}
}
}
template <typename T>
void testRandom(size_t numSteps = 10000) {
describePlatform();
auto target = std::make_unique<T>();
std::vector<bool> valid;
for (size_t step = 0; step < numSteps; ++step) {
auto pct = folly::Random::rand32(100);
auto v = folly::Random::rand32(uint32_t{3} << folly::Random::rand32(14));
if (pct < 5) {
doClear(*target, valid);
} else if (pct < 30) {
T copy;
folly::resizeWithoutInitialization(copy, target->size());
for (size_t i = 0; i < copy.size(); ++i) {
if (valid[i]) {
copy[i] = target->at(i);
}
}
if (pct < 10) {
std::swap(copy, *target);
} else if (pct < 15) {
*target = std::move(copy);
} else if (pct < 20) {
*target = copy;
} else if (pct < 25) {
target = std::make_unique<T>(std::move(copy));
} else {
target = std::make_unique<T>(copy);
}
} else if (pct < 35) {
target->reserve(v);
} else if (pct < 40) {
target->shrink_to_fit();
} else if (pct < 45) {
doResize(*target, valid, v);
} else if (pct < 50) {
doInsert(*target, valid, v % (target->size() + 1));
} else if (pct < 55) {
if (!target->empty()) {
doErase(*target, valid, v % target->size());
}
} else if (pct < 60) {
doPushBack(*target, valid);
} else if (pct < 65) {
target = std::make_unique<T>();
valid.clear();
} else if (pct < 80) {
auto v2 = folly::Random::rand32(uint32_t{3} << folly::Random::rand32(14));
doOverwrite(*target, valid, std::min(v, v2), std::max(v, v2));
} else {
doResizeWithoutInit(*target, valid, v);
}
// don't check every time in implementation does lazy work
if (folly::Random::rand32(100) < 50) {
check(*target);
}
}
}
TEST(UninitializedMemoryHacks, simpleString) {
testSimple<std::string>();
}
TEST(UninitializedMemoryHacks, simpleStringWChar) {
testSimple<std::wstring>();
}
TEST(UninitializedMemoryHacks, simpleStringSChar) {
testSimple<std::basic_string<signed char>>();
}
TEST(UninitializedMemoryHacks, simpleVectorChar) {
testSimple<std::vector<char>>();
}
TEST(UninitializedMemoryHacks, simpleVectorByte) {
testSimple<std::vector<uint8_t>>();
}
TEST(UninitializedMemoryHacks, simpleVectorInt) {
testSimple<std::vector<int>>();
}
TEST(UninitializedMemoryHacks, randomString) {
testRandom<std::string>();
}
TEST(UninitializedMemoryHacks, randomStringWChar) {
testRandom<std::wstring>();
}
TEST(UninitializedMemoryHacks, randomStringSChar) {
testRandom<std::basic_string<signed char>>();
}
TEST(UninitializedMemoryHacks, randomVectorChar) {
testRandom<std::vector<char>>();
}
TEST(UninitializedMemoryHacks, randomVectorByte) {
testRandom<std::vector<uint8_t>>();
}
TEST(UninitializedMemoryHacks, randomVectorInt) {
testRandom<std::vector<int>>();
}
// We are deliberately putting this at the bottom to make sure it can follow use
FOLLY_DECLARE_STRING_RESIZE_WITHOUT_INIT(signed char)
FOLLY_DECLARE_VECTOR_RESIZE_WITHOUT_INIT(int)
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