settings.h

#if defined(LIBCO_C)

/*[amd64, arm, ppc, x86]:
   by default, co_swap_function is marked as a text (code) section
   if not supported, uncomment the below line to use mprotect instead */
/* #define LIBCO_MPROTECT */

/*[amd64]:
   Win64 only: provides a substantial speed-up, but will thrash XMM regs
   do not use this unless you are certain your application won't use SSE */
/* #define LIBCO_NO_SSE */

#if !defined(thread_local) /* User can override thread_local for obscure compilers */
  #if !defined(LIBCO_MP) /* Running in single-threaded environment */
    #define thread_local
  #else /* Running in multi-threaded environment */
    #if defined(__STDC__) /* Compiling as C Language */
      #if defined(_MSC_VER) /* Don't rely on MSVC's C11 support */
        #define thread_local __declspec(thread)
      #elif __STDC_VERSION__ < 201112L /* If we are on C90/99 */
        #if defined(__clang__) || defined(__GNUC__) /* Clang and GCC */
          #define thread_local __thread
        #else /* Otherwise, we ignore the directive (unless user provides their own) */
          #define thread_local
        #endif
      #else /* C11 and newer define thread_local in threads.h */
        #include <threads.h>
      #endif
    #elif defined(__cplusplus) /* Compiling as C++ Language */
      #if __cplusplus < 201103L /* thread_local is a C++11 feature */
        #if defined(_MSC_VER)
          #define thread_local __declspec(thread)
        #elif defined(__clang__) || defined(__GNUC__)
          #define thread_local __thread
        #else /* Otherwise, we ignore the directive (unless user provides their own) */
          #define thread_local
        #endif
      #else /* In C++ >= 11, thread_local in a builtin keyword */
        /* Don't do anything */
      #endif
    #endif
  #endif
#endif

/* In alignas(a), 'a' should be a power of two that is at least the type's
   alignment and at most the implementation's alignment limit.  This limit is
   2**13 on MSVC. To be portable to MSVC through at least version 10.0,
   'a' should be an integer constant, as MSVC does not support expressions
   such as 1 << 3.

   The following C11 requirements are NOT supported on MSVC:

   - If 'a' is zero, alignas has no effect.
   - alignas can be used multiple times; the strictest one wins.
   - alignas (TYPE) is equivalent to alignas (alignof (TYPE)).
*/
#if !defined(alignas) 
  #if defined(__STDC__) /* C Language */
    #if defined(_MSC_VER) /* Don't rely on MSVC's C11 support */
      #define alignas(bytes) __declspec(align(bytes))
    #elif __STDC_VERSION__ >= 201112L /* C11 and above */
      #include <stdalign.h>
    #elif defined(__clang__) || defined(__GNUC__) /* C90/99 on Clang/GCC */
      #define alignas(bytes) __attribute__ ((aligned (bytes)))
    #else /* Otherwise, we ignore the directive (user should provide their own) */
      #define alignas(bytes)
    #endif
  #elif defined(__cplusplus) /* C++ Language */
    #if __cplusplus < 201103L
      #if defined(_MSC_VER)
        #define alignas(bytes) __declspec(align(bytes))
      #elif defined(__clang__) || defined(__GNUC__) /* C++98/03 on Clang/GCC */
        #define alignas(bytes) __attribute__ ((aligned (bytes)))
      #else /* Otherwise, we ignore the directive (unless user provides their own) */
        #define alignas(bytes)
      #endif
    #else /* C++ >= 11 has alignas keyword */
      /* Do nothing */
    #endif
  #endif /* = !defined(__STDC_VERSION__) && !defined(__cplusplus) */
#endif

#if !defined(LIBCO_ASSERT)
  #include <assert.h>
  #define LIBCO_ASSERT assert
#endif

#if defined (__OpenBSD__)
  #if !defined(LIBCO_MALLOC) || !defined(LIBCO_FREE)
    #include <unistd.h>
    #include <sys/mman.h>

    static void* malloc_obsd(size_t size) {
      long pagesize = sysconf(_SC_PAGESIZE);
      char* memory = (char*)mmap(NULL, size + pagesize, PROT_READ|PROT_WRITE, MAP_STACK|MAP_PRIVATE|MAP_ANON, -1, 0);
      if (memory == MAP_FAILED) return NULL;
      *(size_t*)memory = size + pagesize;
      memory += pagesize;
      return (void*)memory;
    }

    static void free_obsd(void *ptr) {
      char* memory = (char*)ptr - sysconf(_SC_PAGESIZE);
      munmap(memory, *(size_t*)memory);
    }

    #define LIBCO_MALLOC malloc_obsd
    #define LIBCO_FREE   free_obsd
  #endif
#endif

#if !defined(LIBCO_MALLOC) || !defined(LIBCO_FREE)
  #include <stdlib.h>
  #define LIBCO_MALLOC malloc
  #define LIBCO_FREE   free
#endif

#if defined(_MSC_VER)
  /* workaround for msvc preprocessor stringification behavior */
  #define LIBCO_STRINGIFY(x) #x
  #define LIBCO_TOSTRING(x) LIBCO_STRINGIFY(x)
  #define section(name) __pragma(code_seg(LIBCO_TOSTRING("." #name))) __declspec(allocate(LIBCO_TOSTRING("." #name)))
#elif defined(__APPLE__)
  #define section(name) __attribute__((section("__TEXT,__" #name)))
#else
  #define section(name) __attribute__((section("." #name "#")))
#endif


/* if defined(LIBCO_C) */
#endif