// vim: set noet ts=4 sw=4:

/*! \file
 * \brief Contains several macros usable for making assertions
 *
 * Depending on the type of assertion (either static or at runtime), a failing
 * assertion will trigger an error. For static assertion, this error will be
 * shown at compile time and abort compilation. Runtime assertions will trigger
 * a message containing details about the error occurred and will make the CPU
 * die.
 */

/*!
 * \defgroup debug Debugging functions
 */

#pragma once
#include "../types.h"

#ifndef STRINGIFY
/*! \def STRINGIFY(S)
 * \brief Converts a macro parameter into a string
 * \ingroup debug
 * \param S Expression to be converted
 * \return stringified version of S
 */
#define STRINGIFY(S) #S
#endif

/*! \def assert_size(TYPE, SIZE)
 * \brief Statically ensure (at compile time) that a data type (or variable)
 * has the expected size.
 *
 * \ingroup debug
 * \param TYPE The type to be checked
 * \param SIZE Expected size in bytes
 */
#define assert_size(TYPE, SIZE) \
  static_assert(sizeof(TYPE) == (SIZE), "Wrong size for " STRINGIFY(TYPE))

/*! \def assert(EXP)
 * \brief Ensure (at execution time) an expression evaluates to `true`, print
 * an error message and stop the CPU otherwise.
 *
 * \ingroup debug
 * \param EXP The expression to be checked
 */
#ifdef NDEBUG
#define assert(EXP) ((void)0)
#else
#define assert(EXP)                                                   \
  do {                                                                \
    if (__builtin_expect(!(EXP), 0)) {                                \
      assertion_failed(STRINGIFY(EXP), __func__, __FILE__, __LINE__); \
    }                                                                 \
  } while (false)

/*! \brief Handles a failed assertion
 *
 * This function will print a message containing further information about the
 * failed assertion and stops the current CPU permanently.
 *
 * \note This function should never be called directly, but only via the macro
 * `assert`.
 *
 * \todo(11) Implement Remainder of Method (output & CPU stopping)
 *
 * \param exp Expression that did not hold
 * \param func Name of the function in which the assertion failed
 * \param file Name of the file in which the assertion failed
 * \param line Line in which the assertion failed
 */
[[noreturn]] void assertion_failed(const char* exp, const char* func,
                                   const char* file, int line);
#endif