| 1 | //===----------------------------------------------------------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | // UNSUPPORTED: c++03, c++11, c++14, c++17 |
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| 10 | // UNSUPPORTED: sanitizer-new-delete |
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| 11 | |
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| 12 | // template<class T> |
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| 13 | // constexpr unique_ptr<T> make_unique_for_overwrite(); // T is not array |
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| 14 | // |
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| 15 | // template<class T> |
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| 16 | // constexpr unique_ptr<T> make_unique_for_overwrite(size_t n); // T is U[] |
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| 17 | |
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| 18 | // Test the object is not value initialized |
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| 19 | |
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| 20 | #include <cassert> |
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| 21 | #include <concepts> |
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| 22 | #include <cstddef> |
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| 23 | #include <cstdlib> |
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| 24 | #include <memory> |
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| 25 | |
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| 26 | constexpr char pattern = static_cast<char>(0xDE); |
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| 27 | |
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| 28 | void* operator new(std::size_t count) { |
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| 29 | void* ptr = std::malloc(size: count); |
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| 30 | if (!ptr) { |
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| 31 | std::abort(); // placate MSVC's unchecked malloc warning (assert() won't silence it) |
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| 32 | } |
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| 33 | for (std::size_t i = 0; i < count; ++i) { |
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| 34 | *(reinterpret_cast<char*>(ptr) + i) = pattern; |
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| 35 | } |
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| 36 | return ptr; |
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| 37 | } |
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| 38 | |
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| 39 | void* operator new[](std::size_t count) { return ::operator new(count); } |
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| 40 | |
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| 41 | void operator delete(void* ptr) noexcept { std::free(ptr: ptr); } |
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| 42 | |
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| 43 | void operator delete[](void* ptr) noexcept { ::operator delete(ptr); } |
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| 44 | |
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| 45 | void test() { |
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| 46 | { |
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| 47 | std::same_as<std::unique_ptr<int>> auto ptr = std::make_unique_for_overwrite<int>(); |
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| 48 | assert(*(reinterpret_cast<char*>(ptr.get())) == pattern); |
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| 49 | } |
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| 50 | { |
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| 51 | std::same_as<std::unique_ptr<int[]>> auto ptr = std::make_unique_for_overwrite<int[]>(3); |
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| 52 | assert(*(reinterpret_cast<char*>(&ptr[0])) == pattern); |
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| 53 | assert(*(reinterpret_cast<char*>(&ptr[1])) == pattern); |
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| 54 | assert(*(reinterpret_cast<char*>(&ptr[2])) == pattern); |
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| 55 | } |
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| 56 | } |
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| 57 | |
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| 58 | int main(int, char**) { |
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| 59 | test(); |
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| 60 | |
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| 61 | return 0; |
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| 62 | } |
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| 63 | |
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