1 /////////////////////////////////////////////////////////////////////////////// 2 // 3 // Copyright (c) 2015 Microsoft Corporation. All rights reserved. 4 // 5 // This code is licensed under the MIT License (MIT). 6 // 7 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 8 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 9 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 10 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 11 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 12 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 13 // THE SOFTWARE. 14 // 15 /////////////////////////////////////////////////////////////////////////////// 16 17 #pragma once 18 19 #ifndef GSL_CONTRACTS_H 20 #define GSL_CONTRACTS_H 21 22 #include <exception> 23 #include <stdexcept> 24 25 // 26 // There are three configuration options for this GSL implementation's behavior 27 // when pre/post conditions on the GSL types are violated: 28 // 29 // 1. GSL_TERMINATE_ON_CONTRACT_VIOLATION: std::terminate will be called (default) 30 // 2. GSL_THROW_ON_CONTRACT_VIOLATION: a gsl::fail_fast exception will be thrown 31 // 3. GSL_UNENFORCED_ON_CONTRACT_VIOLATION: nothing happens 32 // 33 #if !(defined(GSL_THROW_ON_CONTRACT_VIOLATION) || defined(GSL_TERMINATE_ON_CONTRACT_VIOLATION) || \ 34 defined(GSL_UNENFORCED_ON_CONTRACT_VIOLATION)) 35 #define GSL_TERMINATE_ON_CONTRACT_VIOLATION 36 #endif 37 38 #define GSL_STRINGIFY_DETAIL(x) #x 39 #define GSL_STRINGIFY(x) GSL_STRINGIFY_DETAIL(x) 40 41 #if defined(__clang__) || defined(__GNUC__) 42 #define GSL_LIKELY(x) __builtin_expect(!!(x), 1) 43 #define GSL_UNLIKELY(x) __builtin_expect(!!(x), 0) 44 #else 45 #define GSL_LIKELY(x) (!!(x)) 46 #define GSL_UNLIKELY(x) (!!(x)) 47 #endif 48 49 // 50 // GSL_ASSUME(cond) 51 // 52 // Tell the optimizer that the predicate cond must hold. It is unspecified 53 // whether or not cond is actually evaluated. 54 // 55 #ifdef _MSC_VER 56 #define GSL_ASSUME(cond) __assume(cond) 57 #elif defined(__clang__) 58 #define GSL_ASSUME(cond) __builtin_assume(cond) 59 #elif defined(__GNUC__) 60 #define GSL_ASSUME(cond) ((cond) ? static_cast<void>(0) : __builtin_unreachable()) 61 #else 62 #define GSL_ASSUME(cond) static_cast<void>(!!(cond)) 63 #endif 64 65 // 66 // GSL.assert: assertions 67 // 68 69 namespace gsl 70 { 71 struct fail_fast : public std::logic_error 72 { 73 explicit fail_fast(char const* const message) : std::logic_error(message) {} 74 }; 75 } 76 77 #if defined(GSL_THROW_ON_CONTRACT_VIOLATION) 78 79 #define GSL_CONTRACT_CHECK(type, cond) \ 80 (GSL_LIKELY(cond) ? static_cast<void>(0) \ 81 : throw gsl::fail_fast("GSL: " type " failure at " __FILE__ \ 82 ": " GSL_STRINGIFY(__LINE__))) 83 84 #elif defined(GSL_TERMINATE_ON_CONTRACT_VIOLATION) 85 86 #define GSL_CONTRACT_CHECK(type, cond) (GSL_LIKELY(cond) ? static_cast<void>(0) : std::terminate()) 87 88 #elif defined(GSL_UNENFORCED_ON_CONTRACT_VIOLATION) 89 90 #define GSL_CONTRACT_CHECK(type, cond) GSL_ASSUME(cond) 91 92 #endif 93 94 #define Expects(cond) GSL_CONTRACT_CHECK("Precondition", cond) 95 #define Ensures(cond) GSL_CONTRACT_CHECK("Postcondition", cond) 96 97 #endif // GSL_CONTRACTS_H 98
