//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17
// UNSUPPORTED: sanitizer-new-delete
// template<class T>
// shared_ptr<T> make_shared_for_overwrite(); // T is not U[]
//
// template<class T>
// shared_ptr<T> make_shared_for_overwrite(size_t N); // T is U[]
#include <cassert>
#include <concepts>
#include <cstdlib>
#include <cstring>
#include <memory>
#include <utility>
#include "test_macros.h"
template <class T, class... Args>
concept HasMakeSharedForOverwrite =
requires(Args&&... args) { std::make_shared_for_overwrite<T>(std::forward<Args>(args)...); };
struct Foo {
int i;
};
// non array
static_assert(HasMakeSharedForOverwrite<int>);
static_assert(HasMakeSharedForOverwrite<Foo>);
static_assert(!HasMakeSharedForOverwrite<int, int>);
static_assert(!HasMakeSharedForOverwrite<Foo, Foo>);
// bounded array
static_assert(HasMakeSharedForOverwrite<int[2]>);
static_assert(!HasMakeSharedForOverwrite<int[2], std::size_t>);
static_assert(!HasMakeSharedForOverwrite<int[2], int>);
static_assert(!HasMakeSharedForOverwrite<int[2], int, int>);
static_assert(HasMakeSharedForOverwrite<Foo[2]>);
static_assert(!HasMakeSharedForOverwrite<Foo[2], std::size_t>);
static_assert(!HasMakeSharedForOverwrite<Foo[2], int>);
static_assert(!HasMakeSharedForOverwrite<Foo[2], int, int>);
// unbounded array
static_assert(HasMakeSharedForOverwrite<int[], std::size_t>);
static_assert(HasMakeSharedForOverwrite<Foo[], std::size_t>);
static_assert(!HasMakeSharedForOverwrite<int[]>);
static_assert(!HasMakeSharedForOverwrite<Foo[]>);
static_assert(!HasMakeSharedForOverwrite<int[], std::size_t, int>);
static_assert(!HasMakeSharedForOverwrite<Foo[], std::size_t, int>);
constexpr char pattern = static_cast<char>(0xDE);
void* operator new(std::size_t count) {
void* ptr = std::malloc(count);
if (!ptr) {
std::abort(); // placate MSVC's unchecked malloc warning (assert() won't silence it)
}
for (std::size_t i = 0; i < count; ++i) {
*(reinterpret_cast<char*>(ptr) + i) = pattern;
}
return ptr;
}
void* operator new[](std::size_t count) { return ::operator new(count); }
void operator delete(void* ptr) noexcept { std::free(ptr); }
void operator delete[](void* ptr) noexcept { ::operator delete(ptr); }
struct WithDefaultConstructor {
int i;
constexpr WithDefaultConstructor() : i(5) {}
};
bool test() {
// single int
{
std::same_as<std::shared_ptr<int>> decltype(auto) ptr = std::make_shared_for_overwrite<int>();
assert(*(reinterpret_cast<char*>(ptr.get())) == pattern);
}
// bounded array int[N]
{
std::same_as<std::shared_ptr<int[2]>> decltype(auto) ptr = std::make_shared_for_overwrite<int[2]>();
assert(*(reinterpret_cast<char*>(&ptr[0])) == pattern);
assert(*(reinterpret_cast<char*>(&ptr[1])) == pattern);
}
// unbounded array int[]
{
std::same_as<std::shared_ptr<int[]>> decltype(auto) ptr = std::make_shared_for_overwrite<int[]>(3);
assert(*(reinterpret_cast<char*>(&ptr[0])) == pattern);
assert(*(reinterpret_cast<char*>(&ptr[1])) == pattern);
assert(*(reinterpret_cast<char*>(&ptr[2])) == pattern);
}
// single with default constructor
{
std::same_as<std::shared_ptr<WithDefaultConstructor>> decltype(auto) ptr =
std::make_shared_for_overwrite<WithDefaultConstructor>();
assert(ptr->i == 5);
}
// bounded array with default constructor
{
std::same_as<std::shared_ptr<WithDefaultConstructor[2]>> decltype(auto) ptr =
std::make_shared_for_overwrite<WithDefaultConstructor[2]>();
assert(ptr[0].i == 5);
assert(ptr[1].i == 5);
}
// unbounded array with default constructor
{
std::same_as<std::shared_ptr<WithDefaultConstructor[]>> decltype(auto) ptrs =
std::make_shared_for_overwrite<WithDefaultConstructor[]>(3);
assert(ptrs[0].i == 5);
assert(ptrs[1].i == 5);
assert(ptrs[2].i == 5);
}
return true;
}
int main(int, char**) {
test();
return 0;
}