pcsx2/3rdparty/winwil/include/wil/stl.h

234 lines
7.2 KiB
C++

//*********************************************************
//
// Copyright (c) Microsoft. All rights reserved.
// This code is licensed under the MIT License.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
// ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
// TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
// PARTICULAR PURPOSE AND NONINFRINGEMENT.
//
//*********************************************************
//! @file
//! Windows STL helpers: custom allocators for STL containers
#ifndef __WIL_STL_INCLUDED
#define __WIL_STL_INCLUDED
#include "common.h"
#include "resource.h"
#include <memory>
#include <string>
#include <vector>
#include <utility>
#if _HAS_CXX17
#include <string_view>
#endif
/// @cond
#ifndef WI_STL_FAIL_FAST_IF
#define WI_STL_FAIL_FAST_IF FAIL_FAST_IF
#endif
/// @endcond
#if defined(WIL_ENABLE_EXCEPTIONS)
namespace wil
{
/** Secure allocator for STL containers.
The `wil::secure_allocator` allocator calls `SecureZeroMemory` before deallocating
memory. This provides a mechanism for secure STL containers such as `wil::secure_vector`,
`wil::secure_string`, and `wil::secure_wstring`. */
template <typename T>
struct secure_allocator : public std::allocator<T>
{
template <typename Other>
struct rebind
{
using other = secure_allocator<Other>;
};
secure_allocator() : std::allocator<T>()
{
}
~secure_allocator() = default;
secure_allocator(const secure_allocator& a) : std::allocator<T>(a)
{
}
template <class U>
secure_allocator(const secure_allocator<U>& a) : std::allocator<T>(a)
{
}
T* allocate(size_t n)
{
return std::allocator<T>::allocate(n);
}
void deallocate(T* p, size_t n)
{
SecureZeroMemory(p, sizeof(T) * n);
std::allocator<T>::deallocate(p, n);
}
};
//! `wil::secure_vector` will be securely zeroed before deallocation.
template <typename Type>
using secure_vector = std::vector<Type, secure_allocator<Type>>;
//! `wil::secure_wstring` will be securely zeroed before deallocation.
using secure_wstring = std::basic_string<wchar_t, std::char_traits<wchar_t>, wil::secure_allocator<wchar_t>>;
//! `wil::secure_string` will be securely zeroed before deallocation.
using secure_string = std::basic_string<char, std::char_traits<char>, wil::secure_allocator<char>>;
/// @cond
namespace details
{
template <>
struct string_maker<std::wstring>
{
HRESULT make(_In_reads_opt_(length) PCWSTR source, size_t length) WI_NOEXCEPT
try
{
m_value = source ? std::wstring(source, length) : std::wstring(length, L'\0');
return S_OK;
}
catch (...)
{
return E_OUTOFMEMORY;
}
wchar_t* buffer()
{
return &m_value[0];
}
HRESULT trim_at_existing_null(size_t length)
{
m_value.erase(length);
return S_OK;
}
std::wstring release()
{
return std::wstring(std::move(m_value));
}
static PCWSTR get(const std::wstring& value)
{
return value.c_str();
}
private:
std::wstring m_value;
};
} // namespace details
/// @endcond
// str_raw_ptr is an overloaded function that retrieves a const pointer to the first character in a string's buffer.
// This is the overload for std::wstring. Other overloads available in resource.h.
inline PCWSTR str_raw_ptr(const std::wstring& str)
{
return str.c_str();
}
#if _HAS_CXX17
/**
zstring_view. A zstring_view is identical to a std::string_view except it is always nul-terminated (unless empty).
* zstring_view can be used for storing string literals without "forgetting" the length or that it is nul-terminated.
* A zstring_view can be converted implicitly to a std::string_view because it is always safe to use a nul-terminated
string_view as a plain string view.
* A zstring_view can be constructed from a std::string because the data in std::string is nul-terminated.
*/
template <class TChar>
class basic_zstring_view : public std::basic_string_view<TChar>
{
using size_type = typename std::basic_string_view<TChar>::size_type;
public:
constexpr basic_zstring_view() noexcept = default;
constexpr basic_zstring_view(const basic_zstring_view&) noexcept = default;
constexpr basic_zstring_view& operator=(const basic_zstring_view&) noexcept = default;
constexpr basic_zstring_view(const TChar* pStringData, size_type stringLength) noexcept :
std::basic_string_view<TChar>(pStringData, stringLength)
{
if (pStringData[stringLength] != 0)
{
WI_STL_FAIL_FAST_IF(true);
}
}
template <size_t stringArrayLength>
constexpr basic_zstring_view(const TChar (&stringArray)[stringArrayLength]) noexcept :
std::basic_string_view<TChar>(&stringArray[0], length_n(&stringArray[0], stringArrayLength))
{
}
// Construct from nul-terminated char ptr. To prevent this from overshadowing array construction,
// we disable this constructor if the value is an array (including string literal).
template <typename TPtr, std::enable_if_t<std::is_convertible<TPtr, const TChar*>::value && !std::is_array<TPtr>::value>* = nullptr>
constexpr basic_zstring_view(TPtr&& pStr) noexcept : std::basic_string_view<TChar>(std::forward<TPtr>(pStr))
{
}
constexpr basic_zstring_view(const std::basic_string<TChar>& str) noexcept :
std::basic_string_view<TChar>(&str[0], str.size())
{
}
// basic_string_view [] precondition won't let us read view[view.size()]; so we define our own.
WI_NODISCARD constexpr const TChar& operator[](size_type idx) const noexcept
{
WI_ASSERT(idx <= this->size() && this->data() != nullptr);
return this->data()[idx];
}
WI_NODISCARD constexpr const TChar* c_str() const noexcept
{
WI_ASSERT(this->data() == nullptr || this->data()[this->size()] == 0);
return this->data();
}
private:
// Bounds-checked version of char_traits::length, like strnlen. Requires that the input contains a null terminator.
static constexpr size_type length_n(_In_reads_opt_(buf_size) const TChar* str, size_type buf_size) noexcept
{
const std::basic_string_view<TChar> view(str, buf_size);
auto pos = view.find_first_of(TChar());
if (pos == view.npos)
{
WI_STL_FAIL_FAST_IF(true);
}
return pos;
}
// The following basic_string_view methods must not be allowed because they break the nul-termination.
using std::basic_string_view<TChar>::swap;
using std::basic_string_view<TChar>::remove_suffix;
};
using zstring_view = basic_zstring_view<char>;
using zwstring_view = basic_zstring_view<wchar_t>;
inline namespace literals
{
constexpr zstring_view operator"" _zv(const char* str, std::size_t len) noexcept
{
return zstring_view(str, len);
}
constexpr zwstring_view operator"" _zv(const wchar_t* str, std::size_t len) noexcept
{
return zwstring_view(str, len);
}
} // namespace literals
#endif // _HAS_CXX17
} // namespace wil
#endif // WIL_ENABLE_EXCEPTIONS
#endif // __WIL_STL_INCLUDED