diff --git a/stl/inc/__msvc_sanitizer_annotate_container.hpp b/stl/inc/__msvc_sanitizer_annotate_container.hpp index 53e6f8a388c..dbfd83b311d 100644 --- a/stl/inc/__msvc_sanitizer_annotate_container.hpp +++ b/stl/inc/__msvc_sanitizer_annotate_container.hpp @@ -20,11 +20,13 @@ _STL_DISABLE_CLANG_WARNINGS // (this will be auto-defined on unsupported platforms) // + _DISABLE_STRING_ANNOTATION: same, but for only `basic_string` // + _DISABLE_VECTOR_ANNOTATION: same, but for only `vector` +// + _DISABLE_OPTIONAL_ANNOTATION: same, but for only `optional` // - _ENABLE_STL_ANNOTATION_ON_UNSUPPORTED_PLATFORMS: Don't auto-disable ASan annotations // - _ANNOTATE_STL: Even when ASan annotations are disabled, insert the code for annotating into the STL anyways; // this is useful when building static libraries which may be linked against both ASan and non-ASan binaries. // + _ANNOTATE_STRING: same, but only for `basic_string` // + _ANNOTATE_VECTOR: same, but only for `vector` +// + _ANNOTATE_OPTIONAL: same, but only for `optional` #if !defined(_DISABLE_STL_ANNOTATION) && !defined(_ENABLE_STL_ANNOTATION_ON_UNSUPPORTED_PLATFORMS) @@ -46,6 +48,9 @@ _STL_DISABLE_CLANG_WARNINGS #ifndef _DISABLE_VECTOR_ANNOTATION #define _DISABLE_VECTOR_ANNOTATION #endif // ^^^ !defined(_DISABLE_VECTOR_ANNOTATION) ^^^ +#ifndef _DISABLE_OPTIONAL_ANNOTATION +#define _DISABLE_OPTIONAL_ANNOTATION +#endif // ^^^ !defined(_DISABLE_OPTIONAL_ANNOTATION) ^^^ #endif // ^^^ defined(_DISABLE_STL_ANNOTATION) ^^^ @@ -59,6 +64,10 @@ _STL_DISABLE_CLANG_WARNINGS #define _ANNOTATE_VECTOR #endif // ^^^ !defined(_ANNOTATE_VECTOR) ^^^ +#ifndef _ANNOTATE_OPTIONAL +#define _ANNOTATE_OPTIONAL +#endif // ^^^ !defined(_ANNOTATE_OPTIONAL) ^^^ + #endif // ^^^ defined(_ANNOTATE_STL) ^^^ #ifdef __SANITIZE_ADDRESS__ @@ -67,6 +76,8 @@ _STL_DISABLE_CLANG_WARNINGS #define _INSERT_STRING_ANNOTATION #define _ACTIVATE_VECTOR_ANNOTATION #define _INSERT_VECTOR_ANNOTATION +#define _ACTIVATE_OPTIONAL_ANNOTATION +#define _INSERT_OPTIONAL_ANNOTATION #elif defined(__clang__) // ^^^ defined(__SANITIZE_ADDRESS__) / defined(__clang__) vvv @@ -75,6 +86,8 @@ _STL_DISABLE_CLANG_WARNINGS #define _INSERT_STRING_ANNOTATION #define _ACTIVATE_VECTOR_ANNOTATION #define _INSERT_VECTOR_ANNOTATION +#define _ACTIVATE_OPTIONAL_ANNOTATION +#define _INSERT_OPTIONAL_ANNOTATION #pragma comment(linker, "/INFERASANLIBS") #endif // __has_feature(address_sanitizer) @@ -89,6 +102,10 @@ _STL_DISABLE_CLANG_WARNINGS #undef _ACTIVATE_VECTOR_ANNOTATION #undef _INSERT_VECTOR_ANNOTATION #endif // ^^^ defined(_DISABLE_VECTOR_ANNOTATION) ^^^ +#ifdef _DISABLE_OPTIONAL_ANNOTATION +#undef _ACTIVATE_OPTIONAL_ANNOTATION +#undef _INSERT_OPTIONAL_ANNOTATION +#endif // ^^^ defined(_DISABLE_OPTIONAL_ANNOTATION) ^^^ #ifdef _ANNOTATE_STRING #define _INSERT_STRING_ANNOTATION @@ -96,6 +113,9 @@ _STL_DISABLE_CLANG_WARNINGS #ifdef _ANNOTATE_VECTOR #define _INSERT_VECTOR_ANNOTATION #endif // ^^^ defined(_ANNOTATE_VECTOR) ^^^ +#ifdef _ANNOTATE_OPTIONAL +#define _INSERT_OPTIONAL_ANNOTATION +#endif // ^^^ defined(_ANNOTATE_OPTIONAL) ^^^ #ifndef _INSERT_STRING_ANNOTATION @@ -104,6 +124,9 @@ _STL_DISABLE_CLANG_WARNINGS #ifndef _INSERT_VECTOR_ANNOTATION #pragma detect_mismatch("annotate_vector", "0") #endif // ^^^ !defined(_INSERT_VECTOR_ANNOTATION) ^^^ +#ifndef _INSERT_OPTIONAL_ANNOTATION +#pragma detect_mismatch("annotate_optional", "0") +#endif // ^^^ !defined(_INSERT_OPTIONAL_ANNOTATION) ^^^ #ifdef _ACTIVATE_STRING_ANNOTATION #pragma comment(lib, "stl_asan") @@ -113,9 +136,14 @@ _STL_DISABLE_CLANG_WARNINGS #pragma comment(lib, "stl_asan") #pragma detect_mismatch("annotate_vector", "1") #endif // ^^^ defined(_ACTIVATE_VECTOR_ANNOTATION) ^^^ +#ifdef _ACTIVATE_OPTIONAL_ANNOTATION +#pragma comment(lib, "stl_asan") +#pragma detect_mismatch("annotate_optional", "1") +#endif // ^^^ defined(_ACTIVATE_OPTIONAL_ANNOTATION) ^^^ #undef _ACTIVATE_STRING_ANNOTATION #undef _ACTIVATE_VECTOR_ANNOTATION +#undef _ACTIVATE_OPTIONAL_ANNOTATION extern "C" { #ifdef _INSERT_VECTOR_ANNOTATION @@ -125,16 +153,27 @@ extern const bool _Asan_vector_should_annotate; #ifdef _INSERT_STRING_ANNOTATION extern const bool _Asan_string_should_annotate; #endif + +#ifdef _INSERT_OPTIONAL_ANNOTATION +extern const bool _Asan_optional_should_annotate; +#endif } // extern "C" -#if defined(_INSERT_VECTOR_ANNOTATION) || defined(_INSERT_STRING_ANNOTATION) +#if defined(_INSERT_VECTOR_ANNOTATION) || defined(_INSERT_STRING_ANNOTATION) || defined(_INSERT_OPTIONAL_ANNOTATION) extern "C" { +void __cdecl __asan_poison_memory_region(const volatile void* _Addr, size_t _Size); +void __cdecl __asan_unpoison_memory_region(const volatile void* _Addr, size_t _Size); + // This must match ASan's primary declaration, which isn't marked `noexcept`. void __cdecl __sanitizer_annotate_contiguous_container( const void* _First, const void* _End, const void* _Old_last, const void* _New_last); } // extern "C" #ifdef _M_ARM64EC +#pragma comment(linker, "/alternatename:#__asan_poison_memory_region=#__asan_poison_memory_region_default") +#pragma comment(linker, "/alternatename:__asan_poison_memory_region=__asan_poison_memory_region_default") +#pragma comment(linker, "/alternatename:#__asan_unpoison_memory_region=#__asan_unpoison_memory_region_default") +#pragma comment(linker, "/alternatename:__asan_unpoison_memory_region=__asan_unpoison_memory_region_default") #pragma comment(linker, \ "/alternatename:#__sanitizer_annotate_contiguous_container=#__sanitizer_annotate_contiguous_container_default") #pragma comment(linker, \ @@ -143,7 +182,13 @@ void __cdecl __sanitizer_annotate_contiguous_container( #pragma comment(linker, "/alternatename:_Asan_vector_should_annotate=_Asan_vector_should_annotate_default") #pragma comment(linker, "/alternatename:#_Asan_string_should_annotate=#_Asan_string_should_annotate_default") #pragma comment(linker, "/alternatename:_Asan_string_should_annotate=_Asan_string_should_annotate_default") +#pragma comment(linker, "/alternatename:#_Asan_optional_should_annotate=#_Asan_optional_should_annotate_default") +#pragma comment(linker, "/alternatename:_Asan_optional_should_annotate=_Asan_optional_should_annotate_default") #elif defined(_M_HYBRID) +#pragma comment(linker, "/alternatename:#__asan_poison_memory_region=#__asan_poison_memory_region_default") +#pragma comment(linker, "/alternatename:___asan_poison_memory_region=___asan_poison_memory_region_default") +#pragma comment(linker, "/alternatename:#__asan_unpoison_memory_region=#__asan_unpoison_memory_region_default") +#pragma comment(linker, "/alternatename:___asan_unpoison_memory_region=___asan_unpoison_memory_region_default") #pragma comment(linker, \ "/alternatename:#__sanitizer_annotate_contiguous_container=#__sanitizer_annotate_contiguous_container_default") #pragma comment(linker, \ @@ -152,16 +197,24 @@ void __cdecl __sanitizer_annotate_contiguous_container( #pragma comment(linker, "/alternatename:__Asan_vector_should_annotate=__Asan_vector_should_annotate_default") #pragma comment(linker, "/alternatename:#_Asan_string_should_annotate=#_Asan_string_should_annotate_default") #pragma comment(linker, "/alternatename:__Asan_string_should_annotate=__Asan_string_should_annotate_default") +#pragma comment(linker, "/alternatename:#_Asan_optional_should_annotate=#_Asan_optional_should_annotate_default") +#pragma comment(linker, "/alternatename:__Asan_optional_should_annotate=__Asan_optional_should_annotate_default") #elif defined(_M_IX86) +#pragma comment(linker, "/alternatename:___asan_poison_memory_region=___asan_poison_memory_region_default") +#pragma comment(linker, "/alternatename:___asan_unpoison_memory_region=___asan_unpoison_memory_region_default") #pragma comment(linker, \ "/alternatename:___sanitizer_annotate_contiguous_container=___sanitizer_annotate_contiguous_container_default") #pragma comment(linker, "/alternatename:__Asan_vector_should_annotate=__Asan_vector_should_annotate_default") #pragma comment(linker, "/alternatename:__Asan_string_should_annotate=__Asan_string_should_annotate_default") +#pragma comment(linker, "/alternatename:__Asan_optional_should_annotate=__Asan_optional_should_annotate_default") #elif defined(_M_X64) || defined(_M_ARM64) +#pragma comment(linker, "/alternatename:__asan_poison_memory_region=__asan_poison_memory_region_default") +#pragma comment(linker, "/alternatename:__asan_unpoison_memory_region=__asan_unpoison_memory_region_default") #pragma comment(linker, \ "/alternatename:__sanitizer_annotate_contiguous_container=__sanitizer_annotate_contiguous_container_default") #pragma comment(linker, "/alternatename:_Asan_vector_should_annotate=_Asan_vector_should_annotate_default") #pragma comment(linker, "/alternatename:_Asan_string_should_annotate=_Asan_string_should_annotate_default") +#pragma comment(linker, "/alternatename:_Asan_optional_should_annotate=_Asan_optional_should_annotate_default") #else // ^^^ known architecture / unknown architecture vvv #error Unknown architecture #endif // ^^^ unknown architecture ^^^ diff --git a/stl/inc/optional b/stl/inc/optional index 13cb06bebdc..6b55ea08c4e 100644 --- a/stl/inc/optional +++ b/stl/inc/optional @@ -13,6 +13,7 @@ _EMIT_STL_WARNING(STL4038, "The contents of are available only with C #if _HAS_CXX20 #include #endif // _HAS_CXX20 +#include <__msvc_sanitizer_annotate_container.hpp> #include #include #include @@ -90,6 +91,7 @@ struct _Optional_destruct_base { // either contains a value of _Ty or is empty ( // For the trivially destructible case, we can't add a destructor for _MSVC_STL_DESTRUCTOR_TOMBSTONES, due to // N5001 [optional.dtor]/2: "Remarks: If is_trivially_destructible_v is true, then this destructor is trivial." + // This also prevents ASan annotations from being used. _CONSTEXPR20 void reset() noexcept { _Has_value = false; @@ -114,10 +116,25 @@ struct _Optional_destruct_base<_Ty, false> { // either contains a value of _Ty o // and we don't know whether the object has an invalid representation, much less what it could be. _Has_value = false; #endif + } else { +#ifdef _INSERT_OPTIONAL_ANNOTATION + // Unpoison our storage when the std::optional is destroyed. + // We're giving up control of these bytes, which can be validly reused for something else. + if (!_STD _Is_constant_evaluated() && _Asan_optional_should_annotate) { + __asan_unpoison_memory_region(_STD addressof(_Value), sizeof(_Ty)); + } +#endif // ^^^ defined(_INSERT_OPTIONAL_ANNOTATION) ^^^ } } - constexpr _Optional_destruct_base() noexcept : _Dummy{}, _Has_value{false} {} // initialize an empty optional + constexpr _Optional_destruct_base() noexcept : _Dummy{}, _Has_value{false} { // initialize an empty optional +#ifdef _INSERT_OPTIONAL_ANNOTATION + // Poison our storage when starting empty, until that changes or the std::optional is destroyed. + if (!_STD _Is_constant_evaluated() && _Asan_optional_should_annotate) { + __asan_poison_memory_region(_STD addressof(_Value), sizeof(_Ty)); + } +#endif // ^^^ defined(_INSERT_OPTIONAL_ANNOTATION) ^^^ + } template constexpr explicit _Optional_destruct_base(in_place_t, _Types&&... _Args) @@ -140,6 +157,13 @@ struct _Optional_destruct_base<_Ty, false> { // either contains a value of _Ty o if (_Has_value) { _Value.~_Ty(); _Has_value = false; + +#ifdef _INSERT_OPTIONAL_ANNOTATION + // Poison our storage when becoming empty, until that changes or the std::optional is destroyed. + if (!_STD _Is_constant_evaluated() && _Asan_optional_should_annotate) { + __asan_poison_memory_region(_STD addressof(_Value), sizeof(_Ty)); + } +#endif // ^^^ defined(_INSERT_OPTIONAL_ANNOTATION) ^^^ } } }; @@ -153,6 +177,17 @@ struct _Optional_construct_base : _Optional_destruct_base<_Ty> { _CONSTEXPR20 _Ty& _Construct(_Types&&... _Args) noexcept(is_nothrow_constructible_v<_Ty, _Types...>) { // transition from the empty to the value-containing state _STL_INTERNAL_CHECK(!this->_Has_value); + +#ifdef _INSERT_OPTIONAL_ANNOTATION + // Only the non-trivially destructible case can use ASan annotations, as the destructor is needed to undo them. + if constexpr (!is_trivially_destructible_v<_Ty>) { + // Unpoison our storage when becoming non-empty. + if (!_STD _Is_constant_evaluated() && _Asan_optional_should_annotate) { + __asan_unpoison_memory_region(_STD addressof(this->_Value), sizeof(_Ty)); + } + } +#endif // ^^^ defined(_INSERT_OPTIONAL_ANNOTATION) ^^^ + _STD _Construct_in_place(this->_Value, _STD forward<_Types>(_Args)...); this->_Has_value = true; return this->_Value; diff --git a/stl/src/asan.cpp b/stl/src/asan.cpp index da75de1afcd..e49b05f27f6 100644 --- a/stl/src/asan.cpp +++ b/stl/src/asan.cpp @@ -3,7 +3,8 @@ namespace std { extern "C" { - extern const bool _Asan_string_should_annotate = true; - extern const bool _Asan_vector_should_annotate = true; + extern const bool _Asan_string_should_annotate = true; + extern const bool _Asan_vector_should_annotate = true; + extern const bool _Asan_optional_should_annotate = true; } // extern "C" } // namespace std diff --git a/stl/src/asan_noop.cpp b/stl/src/asan_noop.cpp index fda89488c80..88eca405d5a 100644 --- a/stl/src/asan_noop.cpp +++ b/stl/src/asan_noop.cpp @@ -2,8 +2,12 @@ // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception extern "C" { -extern const bool _Asan_string_should_annotate_default = false; -extern const bool _Asan_vector_should_annotate_default = false; +extern const bool _Asan_string_should_annotate_default = false; +extern const bool _Asan_vector_should_annotate_default = false; +extern const bool _Asan_optional_should_annotate_default = false; + +void __cdecl __asan_poison_memory_region_default(const volatile void*, size_t) {} +void __cdecl __asan_unpoison_memory_region_default(const volatile void*, size_t) {} void __cdecl __sanitizer_annotate_contiguous_container_default( const void*, const void*, const void*, const void*) noexcept {} diff --git a/tests/std/test.lst b/tests/std/test.lst index 90a18318348..db08c537c28 100644 --- a/tests/std/test.lst +++ b/tests/std/test.lst @@ -281,6 +281,7 @@ tests\GH_005780_non_ascii_locales tests\GH_005800_stable_sort_large_alignment tests\GH_005816_numeric_limits_traps tests\GH_005968_headers_provide_begin_end +tests\GH_005974_asan_annotate_optional tests\LWG2381_num_get_floating_point tests\LWG2510_tag_classes tests\LWG2597_complex_branch_cut diff --git a/tests/std/tests/GH_005974_asan_annotate_optional/env.lst b/tests/std/tests/GH_005974_asan_annotate_optional/env.lst new file mode 100644 index 00000000000..d2131f19577 --- /dev/null +++ b/tests/std/tests/GH_005974_asan_annotate_optional/env.lst @@ -0,0 +1,56 @@ +# Copyright (c) Microsoft Corporation. +# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception + +# This test matrix was derived from usual_17_matrix.lst with the same elaborate transformations +# that were used to derive GH_002030_asan_annotate_vector/env.lst from usual_matrix.lst. + +# TRANSITION, google/sanitizers#328: clang-cl does not support /MDd or /MTd with ASan +RUNALL_INCLUDE ..\prefix.lst +RUNALL_CROSSLIST +PM_CL="/Zi /wd4611 /w14640 /Zc:threadSafeInit-" PM_LINK="/debug" +RUNALL_CROSSLIST +PM_CL="-fsanitize=address /BE /c /EHsc /MD /std:c++latest /permissive-" +PM_CL="-fsanitize=address /BE /c /EHsc /MDd /std:c++17 /permissive-" +PM_CL="-fsanitize=address /BE /c /EHsc /MT /std:c++20 /permissive-" +PM_CL="-fsanitize=address /BE /c /EHsc /MTd /std:c++latest /permissive-" +PM_CL="-fsanitize=address /EHsc /MD /std:c++17" +PM_CL="-fsanitize=address /EHsc /MD /std:c++20" +PM_CL="-fsanitize=address /EHsc /MD /std:c++latest /permissive- /Zc:char8_t- /Zc:preprocessor" +PM_CL="-fsanitize=address /EHsc /MD /std:c++latest /permissive- /Zc:noexceptTypes-" +PM_CL="-fsanitize=address /EHsc /MD /std:c++latest /permissive-" +PM_CL="-fsanitize=address /EHsc /MDd /std:c++17 /permissive-" +PM_CL="-fsanitize=address /EHsc /MDd /std:c++20 /permissive-" +PM_CL="-fsanitize=address /EHsc /MDd /std:c++latest /permissive- /fp:except /Zc:preprocessor" +PM_CL="-fsanitize=address /EHsc /MDd /std:c++latest /permissive- /Zc:wchar_t-" +PM_CL="-fsanitize=address /EHsc /MDd /std:c++latest /permissive-" +PM_CL="-fsanitize=address /EHsc /MT /std:c++latest /permissive- /analyze:only /analyze:autolog-" +PM_CL="-fsanitize=address /EHsc /MT /std:c++latest /permissive-" +PM_CL="-fsanitize=address /EHsc /MTd /std:c++latest /permissive" +PM_CL="-fsanitize=address /EHsc /MTd /std:c++latest /permissive- /analyze:only /analyze:autolog-" +PM_CL="-fsanitize=address /EHsc /MTd /std:c++latest /permissive- /fp:strict" +PM_CL="-fsanitize=address /EHsc /MTd /std:c++latest /permissive-" +PM_CL="/D_ANNOTATE_OPTIONAL /BE /c /EHsc /MD /std:c++latest /permissive-" +PM_CL="/D_ANNOTATE_OPTIONAL /BE /c /EHsc /MDd /std:c++17 /permissive-" +PM_CL="/D_ANNOTATE_OPTIONAL /BE /c /EHsc /MT /std:c++20 /permissive-" +PM_CL="/D_ANNOTATE_OPTIONAL /BE /c /EHsc /MTd /std:c++latest /permissive-" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MD /std:c++17" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MD /std:c++20" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MD /std:c++latest /permissive- /Zc:char8_t- /Zc:preprocessor" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MD /std:c++latest /permissive- /Zc:noexceptTypes-" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MD /std:c++latest /permissive-" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MDd /std:c++17 /permissive-" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MDd /std:c++20 /permissive-" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MDd /std:c++latest /permissive- /fp:except /Zc:preprocessor" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MDd /std:c++latest /permissive- /Zc:wchar_t-" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MDd /std:c++latest /permissive-" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MT /std:c++latest /permissive- /analyze:only /analyze:autolog-" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MT /std:c++latest /permissive-" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MTd /std:c++latest /permissive" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MTd /std:c++latest /permissive- /analyze:only /analyze:autolog-" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MTd /std:c++latest /permissive- /fp:strict" +PM_CL="/D_ANNOTATE_OPTIONAL /EHsc /MTd /std:c++latest /permissive-" +# TRANSITION, we don't use /ALTERNATENAME for Clang (see GH-5224) so we cannot test /D_ANNOTATE_OPTIONAL without -fsanitize=address +PM_COMPILER="clang-cl" PM_CL="-fsanitize=address -fno-ms-compatibility -fno-delayed-template-parsing -Wno-unqualified-std-cast-call /EHsc /MD /std:c++latest /permissive-" +PM_COMPILER="clang-cl" PM_CL="-fsanitize=address -fno-ms-compatibility -fno-delayed-template-parsing -Wno-unqualified-std-cast-call /EHsc /MD /std:c++17" +PM_COMPILER="clang-cl" PM_CL="-fsanitize=address -fno-ms-compatibility -fno-delayed-template-parsing -Wno-unqualified-std-cast-call /EHsc /MT /std:c++20 /permissive-" +PM_COMPILER="clang-cl" PM_CL="-fsanitize=address -fno-ms-compatibility -fno-delayed-template-parsing -Wno-unqualified-std-cast-call /EHsc /MT /std:c++latest /permissive- /fp:strict" diff --git a/tests/std/tests/GH_005974_asan_annotate_optional/test.cpp b/tests/std/tests/GH_005974_asan_annotate_optional/test.cpp new file mode 100644 index 00000000000..95d0ed99b2c --- /dev/null +++ b/tests/std/tests/GH_005974_asan_annotate_optional/test.cpp @@ -0,0 +1,129 @@ +// Copyright (c) Microsoft Corporation. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception + +// REQUIRES: x64 || x86 || arm64 + +#if defined(__clang__) && defined(_M_ARM64) // TRANSITION, LLVM-184902, fixed in Clang 23 +#pragma comment(linker, "/INFERASANLIBS") +int main() {} +#else // ^^^ workaround / no workaround vvv + +#include +#include +#include +#include +#include +#include +using namespace std; + +#if _HAS_CXX20 +#define CONSTEXPR20 constexpr +#else // ^^^ _HAS_CXX20 / !_HAS_CXX20 vvv +#define CONSTEXPR20 inline +#endif // ^^^ !_HAS_CXX20 ^^^ + +#ifdef __SANITIZE_ADDRESS__ +extern "C" int __cdecl __asan_address_is_poisoned(const volatile void* addr); +#define ASAN_VERIFY_POISONED(addr) assert(__asan_address_is_poisoned((addr)) != 0) +#define ASAN_VERIFY_UNPOISONED(addr) assert(__asan_address_is_poisoned((addr)) == 0) +#else // ^^^ defined(__SANITIZE_ADDRESS__) / !defined(__SANITIZE_ADDRESS__) vvv +#define ASAN_VERIFY_POISONED(addr) ((void) (addr)) +#define ASAN_VERIFY_UNPOISONED(addr) ((void) (addr)) +#endif // ^^^ !defined(__SANITIZE_ADDRESS__) ^^^ + +template +void test_poisoning() { + // std::optional is ASan-annotated only for non-trivially destructible T. + static_assert(!is_trivially_destructible_v); + { + // Verify layout assumption, specific to our implementation but not a guarantee provided to users. + // This test assumes that a std::optional's contained value is stored at offset 0, so it has the same address. + const optional opt{"cats"}; + assert(static_cast(&opt) == static_cast(&opt.value())); + } + { + // Same layout assumption for std::variant. + const variant, int> var{"cats"}; + assert(static_cast(&var) == static_cast(&get>(var).value())); + } + { + optional opt; + ASAN_VERIFY_POISONED(&opt); + assert(!opt.has_value()); + + opt.emplace("cats"); + ASAN_VERIFY_UNPOISONED(&opt); + assert(opt.value() == "cats"); + } + { + optional opt{"cats"}; + ASAN_VERIFY_UNPOISONED(&opt); + assert(opt.value() == "cats"); + + opt.reset(); + ASAN_VERIFY_POISONED(&opt); + assert(!opt.has_value()); + } + { + // Verify that std::optional's destructor unpoisons its storage, so the bytes can be reused for another object. + variant, int> var{"cats"}; + ASAN_VERIFY_UNPOISONED(&var); + assert(get>(var).value() == "cats"); + + get>(var).reset(); + ASAN_VERIFY_POISONED(&var); + assert(!get>(var).has_value()); + + var = 1729; + ASAN_VERIFY_UNPOISONED(&var); + assert(get(var) == 1729); + } +} + +#if _HAS_CXX20 +template +constexpr bool test_constexpr() { + { + optional opt; + assert(!opt.has_value()); + opt.emplace("cats"); + assert(opt.value() == "cats"); + } + { + optional opt{"cats"}; + assert(opt.value() == "cats"); + opt.reset(); + assert(!opt.has_value()); + } + return true; +} +#endif // _HAS_CXX20 + +class MyString { +public: + constexpr MyString(const char* const ptr) : m_sv{ptr} {} + + CONSTEXPR20 ~MyString() {} // non-trivially destructible + + constexpr bool operator==(const char* const ptr) const { + return m_sv == ptr; + } + +private: + string_view m_sv{}; +}; +static_assert(!is_trivially_destructible_v); + +int main() { + // Test std::optional with both std::string and MyString as value types. + // std::string is the realistic scenario. + // MyString ensures that we're exercising std::optional's ASan annotations instead of std::string's. + test_poisoning(); + test_poisoning(); +#if _HAS_CXX20 + static_assert(test_constexpr()); + static_assert(test_constexpr()); +#endif // _HAS_CXX20 +} + +#endif // ^^^ no workaround ^^^