-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
-
-/* AIX requires this to be the first thing in the file. */
-#ifdef __GNUC__
-# define alloca(Size) __builtin_alloca (Size)
-#else
-# if HAVE_ALLOCA_H
-# include <alloca.h>
-# else
-# ifdef _AIX
- #pragma alloca
-# else
-# ifndef alloca /* predefined by HP cc +Olibcalls */
-char *alloca ();
-# endif
-# endif
-# endif
-#endif
-
-#include <stdio.h>
-
-#include <assert.h>
-
-#if HAVE_STDLIB_H
-# include <stdlib.h>
-#endif
-
-/* The following test is to work around the gross typo in
- systems like Sony NEWS-OS Release 4.0C, whereby EXIT_FAILURE
- is defined to 0, not 1. */
-#if !EXIT_FAILURE
-# undef EXIT_FAILURE
-# define EXIT_FAILURE 1
-#endif
-
-#ifndef EXIT_SUCCESS
-# define EXIT_SUCCESS 0
-#endif
-
-#if HAVE_UNISTD_H
-# include <unistd.h>
-#endif
-
-#if defined(STDC_HEADERS) || defined(HAVE_STRING_H)
-# include <string.h>
-/* An ANSI string.h and pre-ANSI memory.h might conflict. */
-# if !defined(STDC_HEADERS) && defined(HAVE_MEMORY_H)
-# include <memory.h>
-# endif /* not STDC_HEADERS and HAVE_MEMORY_H */
-#else /* not STDC_HEADERS and not HAVE_STRING_H */
-# include <strings.h>
-/* memory.h and strings.h conflict on some systems. */
-#endif /* not STDC_HEADERS and not HAVE_STRING_H */
-
-#include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
-
-#ifndef PARAMS
-# if defined PROTOTYPES || defined __STDC__
-# define PARAMS(Args) Args
-# else
-# define PARAMS(Args) ()
-# endif
-#endif
-
-#if HAVE_LIMITS_H
-# include <limits.h>
-#endif
-#ifndef SHRT_MIN
-# define SHRT_MIN (-32768)
-#endif
-#ifndef SHRT_MAX
-# define SHRT_MAX 32767
+/* flex 2.5.31 gratutiously defines macros like INT8_MIN. But this
+ runs afoul of pre-C99 compilers that have <inttypes.h> or
+ <stdint.h>, which are included below if available. It also runs
+ afoul of pre-C99 compilers that define these macros in <limits.h>. */
+#if ! defined __STDC_VERSION__ || __STDC_VERSION__ < 199901
+# undef INT8_MIN
+# undef INT16_MIN
+# undef INT32_MIN
+# undef INT8_MAX
+# undef INT16_MAX
+# undef UINT8_MAX
+# undef INT32_MAX
+# undef UINT16_MAX
+# undef UINT32_MAX