Line data    Source code

       1             : #pragma once
       2             : 
       3             : #include <iostream>
       4             : 
       5             : // Based on the standard paper P0627r0 (see
       6             : // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0627r0.pdf)
       7             : #if defined(_MSC_VER)
       8             : #define ELSA_UNREACHABLE() __assume(false);
       9             : #elif defined(__GNUC__) or defined(__clang__)
      10             : // All gcc/clang compilers supporting c++17 have __builtin_unreachable
      11             : #define ELSA_UNREACHABLE() __builtin_unreachable()
      12             : #else
      13             : #include <exception>
      14             : #define ELSA_UNREACHABLE() std::terminate()
      15             : #endif
      16             : 
      17             : namespace elsa::detail
      18             : {
      19             :     void assert_msg(const char* expr_str, bool expr, const char* file, int line, const char* msg);
      20             : } // namespace elsa::detail
      21             : 
      22             : /*
      23             :   implementation of ENSURE - which is like an assert but "extensible"
      24             :   ENSURE(condition)
      25             :   ENSURE(condition, errormessage)
      26             : 
      27             :   currently calls assert_msg above.
      28             :   alternatively we could throw a backtrace capturing elsa-exception here.
      29             : */
      30             : #ifndef ENSURE
      31             : 
      32    57531534 : #define ELSA_EXPRTEXT(expr) #expr
      33             : 
      34             : #define ENSURE(...)                                                                 \
      35    57531534 :     do {                                                                            \
      36    57531534 :         ::elsa::detail::assert_msg(ELSA_EXPRTEXT(ELSA_ENS_FIRST(__VA_ARGS__)),      \
      37    57531534 :                                    ELSA_ENS_FIRST(__VA_ARGS__), __FILE__, __LINE__, \
      38    57531534 :                                    ELSA_ENS_REST(__VA_ARGS__));                     \
      39    57531534 :     } while (0)
      40             : 
      41             : /*
      42             :  * expands to the first argument
      43             :  * Modified for MSVC using the technique by Jeff Walden
      44             :  * https://stackoverflow.com/a/9338429
      45             :  */
      46    57531534 : #define ELSA_PP_GLUE(macro, args) macro args
      47    57531534 : #define ELSA_ENS_FIRST(...) ELSA_PP_GLUE(ELSA_ENS_FIRST_HELPER, (__VA_ARGS__, throwaway))
      48    57531534 : #define ELSA_ENS_FIRST_HELPER(first, ...) (first)
      49             : 
      50             : /*
      51             :  * Standard alternative to GCC's ##__VA_ARGS__ trick (Richard Hansen)
      52             :  * http://stackoverflow.com/a/11172679/4742108
      53             :  *
      54             :  * If there's only one argument, expands to 'nullptr'
      55             :  * If there is more than one argument, expands to everything but
      56             :  * the first argument. Only supports up to 2 arguments but can be trivially expanded.
      57             :  *
      58             :  * We could extend this to support arbitrary assert message formatting, with streams, ...
      59             :  */
      60             : #define ELSA_ENS_REST(...) \
      61    57531534 :     ELSA_PP_GLUE(ELSA_ENS_REST_HELPER(ELSA_ENS_NUM(__VA_ARGS__)), (__VA_ARGS__))
      62             : #define ELSA_ENS_REST_HELPER(qty) ELSA_ENS_REST_HELPER1(qty)
      63             : #define ELSA_ENS_REST_HELPER1(qty) ELSA_ENS_REST_HELPER2(qty)
      64             : #define ELSA_ENS_REST_HELPER2(qty) ELSA_ENS_REST_HELPER_##qty
      65    57531534 : #define ELSA_ENS_REST_HELPER_ONE(first) nullptr
      66             : #define ELSA_ENS_REST_HELPER_TWOORMORE(first, ...) __VA_ARGS__
      67             : #define ELSA_ENS_NUM(...) ELSA_ENS_NUM_IMPL((__VA_ARGS__, TWOORMORE, ONE, throwaway))
      68             : #define ELSA_ENS_NUM_IMPL(args) ELSA_ENS_SELECT_2ND args
      69             : #define ELSA_ENS_SELECT_2ND(a1, a2, a3, ...) a3
      70             : #endif // ENSURE
      71             : 
      72    57531534 : #define ELSA_VERIFY ENSURE
      73             : #define ELSA_TODO() ELSA_VERIFY(false, "TODO")