| /* |
| * Copyright 2015 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| #ifndef GOOGLE_GATEKEEPER_UTILS_H_ |
| #define GOOGLE_GATEKEEPER_UTILS_H_ |
| |
| #include <string.h> |
| |
| namespace gatekeeper { |
| /** |
| * Variant of memset() that uses GCC-specific pragmas to disable optimizations, so effect is not |
| * optimized away. This is important because we often need to wipe blocks of sensitive data from |
| * memory. As an additional convenience, this implementation avoids writing to NULL pointers. |
| */ |
| #ifdef __clang__ |
| #define OPTNONE __attribute__((optnone)) |
| #else // not __clang__ |
| #define OPTNONE __attribute__((optimize("O0"))) |
| #endif // not __clang__ |
| inline OPTNONE void* memset_s(void* s, int c, size_t n) { |
| if (!s) |
| return s; |
| return memset(s, c, n); |
| } |
| #undef OPTNONE |
| |
| /** |
| * Return the number of elements in array \p a. |
| */ |
| template <typename T, size_t N> inline size_t array_length(const T (&)[N]) { |
| return N; |
| } |
| |
| static inline int memcmp_s(const void* p1, const void* p2, size_t length) { |
| const uint8_t* s1 = static_cast<const uint8_t*>(p1); |
| const uint8_t* s2 = static_cast<const uint8_t*>(p2); |
| uint8_t result = 0; |
| for (; length > 0; length--) |
| result |= *s1++ ^ *s2++; |
| return result == 0 ? 0 : 1; |
| } |
| |
| template<typename T> struct remove_reference {typedef T type;}; |
| template<typename T> struct remove_reference<T&> {typedef T type;}; |
| template<typename T> struct remove_reference<T&&> {typedef T type;}; |
| template<typename T> |
| using remove_reference_t = typename remove_reference<T>::type; |
| template<typename T> |
| remove_reference_t<T>&& move(T&& x) { |
| return static_cast<remove_reference_t<T>&&>(x); |
| } |
| |
| template<typename T> |
| constexpr T&& forward(remove_reference_t<T>& x) { |
| return static_cast<T&&>(x); |
| } |
| template<typename T> |
| constexpr T&& forward(remove_reference_t<T>&& x) { |
| return static_cast<T&&>(x); |
| } |
| |
| |
| }; |
| #endif //GOOGLE_GATEKEEPER_UTILS_H_ |