src/helper/compiler.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2
   3 /*
   4  * This file contains compiler specific workarounds to handle different
   5  * compilers and different compiler versions.
   6  * Inspired by Linux's include/linux/compiler_attributes.h
   7  * and file sys/cdefs.h in libc and newlib.
   8  */
   9
  10 #ifndef OPENOCD_HELPER_COMPILER_H
  11 #define OPENOCD_HELPER_COMPILER_H
  12
  13 /*
  14  * __has_attribute is supported on gcc >= 5, clang >= 2.9 and icc >= 17.
  15  */
  16 #ifndef __has_attribute
  17 # define __has_attribute(x) 0
  18 #endif
  19
  20 /*
  21  * The __returns_nonnull function attribute marks the return type of the function
  22  * as always being non-null.
  23  */
  24 #ifndef __returns_nonnull
  25 # if __has_attribute(__returns_nonnull__)
  26 #  define __returns_nonnull __attribute__((__returns_nonnull__))
  27 # else
  28 #  define __returns_nonnull
  29 # endif
  30 #endif
  31
  32 /*
  33  * The __nonnull function attribute marks pointer parameters that
  34  * must not be NULL.
  35  *
  36  * clang for Apple defines
  37  * #define __nonnull _Nonnull
  38  * that is a per argument attribute, incompatible with the gcc per function attribute __nonnull__.
  39  * gcc for Apple includes sys/cdefs.h from MacOSX.sdk that defines
  40  * #define __nonnull
  41  * In both cases, undefine __nonnull to keep compatibility among compilers and platforms.
  42  */
  43 #if defined(__APPLE__)
  44 # undef __nonnull
  45 #endif
  46 #ifndef __nonnull
  47 # if __has_attribute(__nonnull__)
  48 #  define __nonnull(params) __attribute__ ((__nonnull__ params))
  49 # else
  50 #  define __nonnull(params)
  51 # endif
  52 #endif
  53
  54 #endif /* OPENOCD_HELPER_COMPILER_H */