STL/stl/inc/stacktrace

// stacktrace standard header

// Copyright (c) Microsoft Corporation.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

#pragma once
#ifndef _STACKTRACE_
#define _STACKTRACE_
#include <yvals_core.h>
#if _STL_COMPILER_PREPROCESSOR

#if !_HAS_CXX23
_EMIT_STL_WARNING(STL4038, "The contents of <stacktrace> are available only with C++23 or later.");
#else // ^^^ !_HAS_CXX23 / _HAS_CXX23 vvv

#include <cstdint>
#include <string>
#include <type_traits>
#include <vector>

#pragma pack(push, _CRT_PACKING)
#pragma warning(push, _STL_WARNING_LEVEL)
#pragma warning(disable : _STL_DISABLED_WARNINGS)
_STL_DISABLE_CLANG_WARNINGS
#pragma push_macro("new")
#undef new

// The separately compiled part of the <stacktrace> implementation calls a function pointer of _Stacktrace_string_fill
// type to allocate a buffer for string output. The called function does the buffer allocation and calls a function
// pointer of _Stacktrace_string_fill_callback type to fill the buffer. This is needed to type-erase <string> or
// <ostream>, and makes it possible to keep the separately compiled implementation in the import library.
//
// Additionally, _Stacktrace_string_fill can be called with a null _Callback argument to determine the already reserved
// string buffer for cases when the size is not known before an attempt to fill it -- this potentially avoids both an
// extra fill attempt and an extra allocation if the reserved size is enough.

using _Stacktrace_string_fill_callback = size_t(__stdcall*)(char* _Data, size_t _Size, void* _Context) _NOEXCEPT_FNPTR;

using _Stacktrace_string_fill = size_t(__stdcall*)(
    size_t _Size, void* _String, void* _Context, _Stacktrace_string_fill_callback _Callback);

_EXTERN_C
_NODISCARD unsigned short __stdcall __std_stacktrace_capture(unsigned long _Frames_to_skip,
    unsigned long _Frames_to_capture, void** _Back_trace, unsigned long* _Back_trace_hash) noexcept;

// Some of these functions may throw
// (they would propagate bad_alloc potentially thrown from string::resize_and_overwrite)

void __stdcall __std_stacktrace_address_to_string(
    const void* _Address, void* _Str, _Stacktrace_string_fill _Fill) noexcept(false);

void __stdcall __std_stacktrace_description( //
    const void* _Address, void* _Str, _Stacktrace_string_fill _Fill) noexcept(false);

void __stdcall __std_stacktrace_source_file( //
    const void* _Address, void* _Str, _Stacktrace_string_fill _Fill) noexcept(false);

_NODISCARD unsigned int __stdcall __std_stacktrace_source_line(const void* _Address) noexcept;

void __stdcall __std_stacktrace_to_string(
    const void* const* _Addresses, size_t _Size, void* _Str, _Stacktrace_string_fill _Fill) noexcept(false);
_END_EXTERN_C

_STD_BEGIN
inline size_t __stdcall _Stacktrace_string_fill_impl(
    const size_t _Size, void* const _String, void* const _Context, const _Stacktrace_string_fill_callback _Callback) {
    if (_Callback) {
        static_cast<string*>(_String)->resize_and_overwrite(_Size,
            [_Callback, _Context](char* _Data, size_t _Size) noexcept { return _Callback(_Data, _Size, _Context); });
        return static_cast<string*>(_String)->size();
    } else {
        return static_cast<string*>(_String)->capacity();
    }
}

_EXPORT_STD class stacktrace_entry {
public:
    using native_handle_type = void*;

    constexpr stacktrace_entry() noexcept                                   = default;
    constexpr stacktrace_entry(const stacktrace_entry&) noexcept            = default;
    constexpr stacktrace_entry& operator=(const stacktrace_entry&) noexcept = default;

    ~stacktrace_entry() = default;

    _NODISCARD constexpr native_handle_type native_handle() const noexcept {
        return _Address;
    }

    _NODISCARD constexpr explicit operator bool() const noexcept {
        return _Address != nullptr;
    }

    _NODISCARD string description() const {
        string _Result;
        __std_stacktrace_description(_Address, &_Result, _Stacktrace_string_fill_impl);
        return _Result;
    }

    _NODISCARD string source_file() const {
        string _Result;
        __std_stacktrace_source_file(_Address, &_Result, _Stacktrace_string_fill_impl);
        return _Result;
    }

    _NODISCARD uint_least32_t source_line() const noexcept /* strengthened */ {
        return __std_stacktrace_source_line(_Address);
    }

    _NODISCARD_FRIEND constexpr bool operator==(const stacktrace_entry&, const stacktrace_entry&) noexcept = default;

    _NODISCARD_FRIEND constexpr strong_ordering operator<=>(
        const stacktrace_entry&, const stacktrace_entry&) noexcept = default;

private:
    void* _Address = nullptr;
};

_EXPORT_STD template <class _Alloc>
class basic_stacktrace {
private:
    using _Frames_t = vector<stacktrace_entry, _Alloc>;

public:
    using value_type             = stacktrace_entry;
    using const_reference        = const value_type&;
    using reference              = value_type&;
    using const_iterator         = typename _Frames_t::const_iterator;
    using iterator               = const_iterator;
    using reverse_iterator       = _STD reverse_iterator<iterator>;
    using const_reverse_iterator = _STD reverse_iterator<const_iterator>;
    using difference_type        = typename _Frames_t::difference_type;
    using size_type              = typename _Frames_t::size_type;
    using allocator_type         = _Alloc;

    // __declspec(noinline) to make the same behavior for debug and release.
    // We force the current function to be always noinline and add its frame to skipped.

    _NODISCARD __declspec(noinline) static basic_stacktrace
        current(const allocator_type& _Al = allocator_type()) noexcept {
        _TRY_BEGIN
        basic_stacktrace _Result{_Internal_t{}, _Max_frames, _Al};
        const unsigned short _Actual_size = __std_stacktrace_capture(
            1, static_cast<unsigned long>(_Max_frames), _Result._To_voidptr_array(), &_Result._Hash);
        _Result._Frames.resize(_Actual_size);
        return _Result;
        _CATCH_ALL
        return basic_stacktrace{_Al};
        _CATCH_END
    }

    _NODISCARD __declspec(noinline) static basic_stacktrace
        current(const size_type _Skip, const allocator_type& _Al = allocator_type()) noexcept {
        _TRY_BEGIN
        basic_stacktrace _Result{_Internal_t{}, _Max_frames, _Al};
        const unsigned short _Actual_size = __std_stacktrace_capture(
            _Adjust_skip(_Skip), static_cast<unsigned long>(_Max_frames), _Result._To_voidptr_array(), &_Result._Hash);
        _Result._Frames.resize(_Actual_size);
        return _Result;
        _CATCH_ALL
        return basic_stacktrace{_Al};
        _CATCH_END
    }

    _NODISCARD __declspec(noinline) static basic_stacktrace
        current(const size_type _Skip, size_type _Max_depth, const allocator_type& _Al = allocator_type()) noexcept {
        _TRY_BEGIN
        if (_Max_depth > _Max_frames) {
            _Max_depth = _Max_frames;
        }

        basic_stacktrace _Result{_Internal_t{}, _Max_depth, _Al};

        const unsigned short _Actual_size = __std_stacktrace_capture(
            _Adjust_skip(_Skip), static_cast<unsigned long>(_Max_depth), _Result._To_voidptr_array(), &_Result._Hash);
        _Result._Frames.resize(_Actual_size);
        return _Result;
        _CATCH_ALL
        return basic_stacktrace{_Al};
        _CATCH_END
    }

    basic_stacktrace() noexcept(is_nothrow_default_constructible_v<allocator_type>) = default;
    explicit basic_stacktrace(const allocator_type& _Al) noexcept : _Frames(_Al) {}

    basic_stacktrace(const basic_stacktrace&)     = default;
    basic_stacktrace(basic_stacktrace&&) noexcept = default;
    basic_stacktrace(const basic_stacktrace& _Other, const allocator_type& _Al)
        : _Frames(_Other._Frames, _Al), _Hash(_Other._Hash) {}

    basic_stacktrace(basic_stacktrace&& _Other, const allocator_type& _Al)
        : _Frames(_STD move(_Other._Frames), _Al), _Hash(_Other._Hash) {}

    basic_stacktrace& operator=(const basic_stacktrace&)                 = default;
    basic_stacktrace& operator=(basic_stacktrace&&) noexcept(_Noex_move) = default;

    ~basic_stacktrace() = default;

    _NODISCARD allocator_type get_allocator() const noexcept {
        return _Frames.get_allocator();
    }

    _NODISCARD const_iterator begin() const noexcept {
        return _Frames.cbegin();
    }

    _NODISCARD const_iterator end() const noexcept {
        return _Frames.cend();
    }

    _NODISCARD const_reverse_iterator rbegin() const noexcept {
        return _Frames.crbegin();
    }

    _NODISCARD const_reverse_iterator rend() const noexcept {
        return _Frames.crend();
    }

    _NODISCARD const_iterator cbegin() const noexcept {
        return _Frames.cbegin();
    }

    _NODISCARD const_iterator cend() const noexcept {
        return _Frames.cend();
    }

    _NODISCARD const_reverse_iterator crbegin() const noexcept {
        return _Frames.crbegin();
    }

    _NODISCARD const_reverse_iterator crend() const noexcept {
        return _Frames.crend();
    }

    _NODISCARD_EMPTY_STACKTRACE_MEMBER bool empty() const noexcept {
        return _Frames.empty();
    }

    _NODISCARD size_type size() const noexcept {
        return _Frames.size();
    }

    _NODISCARD size_type max_size() const noexcept {
        return _Frames.max_size();
    }

    _NODISCARD const_reference operator[](const size_type _Sx) const noexcept /* strengthened */ {
        return _Frames[_Sx];
    }

    _NODISCARD const_reference at(const size_type _Sx) const {
        return _Frames.at(_Sx);
    }

    template <class _Al2>
    _NODISCARD_FRIEND bool operator==(const basic_stacktrace& _Lhs, const basic_stacktrace<_Al2>& _Rhs) noexcept {
        return _Lhs._Hash == _Rhs._Hash && _STD equal(_Lhs.begin(), _Lhs.end(), _Rhs.begin(), _Rhs.end());
    }

    template <class _Al2>
    _NODISCARD_FRIEND strong_ordering operator<=>(
        const basic_stacktrace& _Lhs, const basic_stacktrace<_Al2>& _Rhs) noexcept {
        const auto _Result = _Lhs._Frames.size() <=> _Rhs._Frames.size();
        if (_Result != strong_ordering::equal) {
            return _Result;
        }

#ifdef __cpp_lib_concepts
        return _STD lexicographical_compare_three_way(_Lhs.begin(), _Lhs.end(), _Rhs.begin(), _Rhs.end());
#else // ^^^ __cpp_lib_concepts / !__cpp_lib_concepts vvv
        for (size_t _Ix = 0, _Mx = _Lhs._Frames.size(); _Ix != _Mx; ++_Ix) {
            if (_Lhs._Frames[_Ix] != _Rhs._Frames[_Ix]) {
                return _Lhs._Frames[_Ix] <=> _Rhs._Frames[_Ix];
            }
        }

        return strong_ordering::equal;
#endif // ^^^ !__cpp_lib_concepts ^^^
    }

    void swap(basic_stacktrace& _Other) noexcept(allocator_traits<_Alloc>::propagate_on_container_swap::value
                                                 || allocator_traits<_Alloc>::is_always_equal::value) {
        _Frames.swap(_Other._Frames);
        _STD swap(_Hash, _Other._Hash);
    }

    _NODISCARD unsigned long _Get_hash() const noexcept {
        return _Hash;
    }

    _STL_INTERNAL_STATIC_ASSERT(sizeof(void*) == sizeof(stacktrace_entry));
    _STL_INTERNAL_STATIC_ASSERT(alignof(void*) == alignof(stacktrace_entry));

    _NODISCARD const void* const* _To_voidptr_array() const noexcept {
        return reinterpret_cast<const void* const*>(_Frames.data());
    }

    _NODISCARD void** _To_voidptr_array() noexcept {
        return reinterpret_cast<void**>(_Frames.data());
    }

private:
    static constexpr size_t _Max_frames = 0xFFFF;

    static constexpr bool _Noex_move = allocator_traits<_Alloc>::propagate_on_container_move_assignment::value
                                    || allocator_traits<_Alloc>::is_always_equal::value;

    struct _Internal_t {
        explicit _Internal_t() noexcept = default;
    };

    basic_stacktrace(_Internal_t, size_type _Max_depth, const allocator_type& _Al) : _Frames(_Max_depth, _Al) {}

    _NODISCARD static unsigned long _Adjust_skip(size_t _Skip) noexcept {
        return _Skip < ULONG_MAX - 1 ? static_cast<unsigned long>(_Skip + 1) : ULONG_MAX;
    }

    _Frames_t _Frames;
    unsigned long _Hash = 0;
};

_EXPORT_STD using stacktrace = basic_stacktrace<allocator<stacktrace_entry>>;

_EXPORT_STD template <class _Alloc>
void swap(basic_stacktrace<_Alloc>& _Ax, basic_stacktrace<_Alloc>& _Bx) noexcept(noexcept(_Ax.swap(_Bx))) {
    _Ax.swap(_Bx);
}

_EXPORT_STD _NODISCARD inline string to_string(const stacktrace_entry& _Fx) {
    string _Result;
    __std_stacktrace_address_to_string(_Fx.native_handle(), &_Result, _Stacktrace_string_fill_impl);
    return _Result;
}

_EXPORT_STD template <class _Alloc>
_NODISCARD string to_string(const basic_stacktrace<_Alloc>& _St) {
    string _Result;
    __std_stacktrace_to_string(_St._To_voidptr_array(), _St.size(), &_Result, _Stacktrace_string_fill_impl);
    return _Result;
}

_EXPORT_STD template <int = 0>
ostream& operator<<(ostream& _Os, const stacktrace_entry& _Fx) {
    return _Os << _STD to_string(_Fx);
}

_EXPORT_STD template <class _Alloc>
ostream& operator<<(ostream& _Os, const basic_stacktrace<_Alloc>& _St) {
    return _Os << _STD to_string(_St);
}

namespace pmr {
    _EXPORT_STD using stacktrace = basic_stacktrace<polymorphic_allocator<stacktrace_entry>>;
}

template <>
struct hash<stacktrace_entry> {
    // This is a C++23 feature, so argument_type and result_type are omitted.

    _NODISCARD size_t operator()(const stacktrace_entry& _Val) const noexcept {
        return _Hash_representation(_Val.native_handle());
    }
};

template <class _Alloc>
struct hash<basic_stacktrace<_Alloc>> {
    // This is a C++23 feature, so argument_type and result_type are omitted.

    _NODISCARD size_t operator()(const basic_stacktrace<_Alloc>& _Val) const noexcept {
        return _Val._Get_hash();
    }
};
_STD_END

#pragma pop_macro("new")
_STL_RESTORE_CLANG_WARNINGS
#pragma warning(pop)
#pragma pack(pop)
#endif // ^^^ _HAS_CXX23 ^^^

#endif // _STL_COMPILER_PREPROCESSOR
#endif // _STACKTRACE_