Line data    Source code

       1            0 : /*
       2              :  * Copyright (c) 2017 Linaro Limited
       3              :  *
       4              :  * SPDX-License-Identifier: Apache-2.0
       5              :  */
       6              : 
       7              : #ifndef ZEPHYR_INCLUDE_ZEPHYR_TYPES_H_
       8              : #define ZEPHYR_INCLUDE_ZEPHYR_TYPES_H_
       9              : 
      10              : #include <stddef.h>
      11              : #include <stdint.h>
      12              : 
      13              : #ifdef __cplusplus
      14              : extern "C" {
      15              : #endif
      16              : 
      17              : /*
      18              :  * A type with strong alignment requirements, similar to C11 max_align_t. It can
      19              :  * be used to force alignment of data structures allocated on the stack or as
      20              :  * return * type for heap allocators.
      21              :  */
      22              : typedef union {
      23              :         long long       thelonglong;
      24              :         long double     thelongdouble;
      25              :         uintmax_t       theuintmax_t;
      26              :         size_t          thesize_t;
      27              :         uintptr_t       theuintptr_t;
      28              :         void            *thepvoid;
      29              :         void            (*thepfunc)(void);
      30              : } z_max_align_t;
      31              : 
      32              : /*
      33              :  * Thread local variables are declared with different keywords depending on
      34              :  * which C/C++ standard that is used. C++11 and C23 uses "thread_local" whilst
      35              :  * C11 uses "_Thread_local". Previously the GNU "__thread" keyword was used
      36              :  * which is the same in both gcc and g++.
      37              :  */
      38              : #ifndef Z_THREAD_LOCAL
      39              : #if defined(__cplusplus) && (__cplusplus) >= 201103L /* C++11 */
      40              : #define Z_THREAD_LOCAL thread_local
      41              : #elif defined(__STDC_VERSION__) && (__STDC_VERSION__) >= 202311L /* C23 */
      42              : #define Z_THREAD_LOCAL thread_local
      43              : #elif defined(__STDC_VERSION__) && (__STDC_VERSION__) >= 201112L /* C11 */
      44              : #define Z_THREAD_LOCAL _Thread_local
      45              : #else /* Default back to old behavior which used the GNU keyword. */
      46              : #define Z_THREAD_LOCAL __thread
      47              : #endif
      48              : #endif /* Z_THREAD_LOCAL */
      49              : 
      50              : #ifdef __cplusplus
      51              : 
      52              : #if (!__STDC_HOSTED__)
      53              : /*
      54              :  * Zephyr requires an int main(void) signature with C linkage for the
      55              :  * application main if present. gcc, and clang when building in 'hosted' mode
      56              :  * will correctly assume this. But, when building freestanding, clang does not
      57              :  * treat main() specially, and by default name mangles its symbol, which
      58              :  * results in the linker not linking from the kernel init code into this
      59              :  * name mangled app main().
      60              :  *
      61              :  * At the same time, according to the C++ standard Section 6.9.3.1 of
      62              :  * ISO/IEC 14882:2024, main cannot be explicitly declared to have "C" linkage.
      63              :  * This restriction is relaxed for freestanding code, as main is not treated
      64              :  * specially in these circumstances.
      65              :  * Therefore, let's include the prototype when we are not building the code as
      66              :  * freestanding/not-hosted.
      67              :  */
      68              : extern int main(void);
      69              : #endif
      70              : 
      71              : }
      72              : #endif
      73              : 
      74              : #endif /* ZEPHYR_INCLUDE_ZEPHYR_TYPES_H_ */