-/* Some autoconf-unrelated preprocessor magic that needs to be done
- *before* including the system includes and therefore cannot belong
- in sysdep.h.
-
- Everything else related to system tweaking belongs to sysdep.h.
-
- This file is included at the bottom of config.h. */
-
-/* Testing for __sun is not enough because it's also defined on SunOS. */
-#ifdef __sun
-# ifdef __SVR4
-# define solaris
-# endif
-#endif
-
-/* The "namespace tweaks" below attempt to set a friendly "compilation
- environment" under popular operating systems. Default compilation
- environment often means that some functions that are "extensions"
- are not declared -- `strptime' is one example.
-
- But non-default environments can expose bugs in the system header
- files, crippling compilation in _very_ non-obvious ways. Because
- of that, we define them only on well-tested architectures where we
- know they will work. */
-
-#undef NAMESPACE_TWEAKS
-
-#ifdef solaris
-# define NAMESPACE_TWEAKS
-#endif
-
-#ifdef __linux__
-# define NAMESPACE_TWEAKS
-#endif
-
-#ifdef NAMESPACE_TWEAKS
-
-/* Request the "Unix 98 compilation environment". */
-#define _XOPEN_SOURCE 500
-
-/* For Solaris: request everything else that is available and doesn't
- conflict with the above. */
-#define __EXTENSIONS__
-
-/* For Linux: request features of 4.3BSD and SVID (System V Interface
- Definition). */
-#define _SVID_SOURCE
-#define _BSD_SOURCE
-
-/* Under glibc-based systems we want all GNU extensions as well. This
- declares some unnecessary cruft, but also useful functions such as
- timegm, FNM_CASEFOLD extension to fnmatch, memrchr, etc. */
-#define _GNU_SOURCE
-
-#endif /* NAMESPACE_TWEAKS */
-
-
-/* Alloca declaration, based on recommendation in the Autoconf manual.
- These have to be after the above namespace tweaks, but before any
- non-preprocessor code. */
-
-#if HAVE_ALLOCA_H
-# include <alloca.h>
-#elif defined WINDOWS
-# include <malloc.h>
-# ifndef alloca
-# define alloca _alloca
-# endif
-#elif defined __GNUC__
-# define alloca __builtin_alloca
-#elif defined _AIX
-# define alloca __alloca
-#else
-# include <stddef.h>
-# ifdef __cplusplus
-extern "C"
-# endif
-void *alloca (size_t);
-#endif