+# error "stdio is no longer supported as the default base layer -- use perlio."
+#endif
+
+/* -------------------- End of Configure controls ---------------------------- */
+
+/*
+ * Although we may not want stdio to be used including <stdio.h> here
+ * avoids issues where stdio.h has strange side effects
+ */
+#include <stdio.h>
+
+#if defined(USE_64_BIT_STDIO) && defined(HAS_FTELLO) && !defined(USE_FTELL64)
+#define ftell ftello
+#endif
+
+#if defined(USE_64_BIT_STDIO) && defined(HAS_FSEEKO) && !defined(USE_FSEEK64)
+#define fseek fseeko
+#endif
+
+/* BS2000 includes are sometimes a bit non standard :-( */
+#if defined(POSIX_BC) && defined(O_BINARY) && !defined(O_TEXT)
+#undef O_BINARY
+#endif
+
+#ifndef PerlIO
+/* ----------- PerlIO implementation ---------- */
+/* PerlIO not #define-d to something else - define the implementation */
+
+typedef struct _PerlIO PerlIOl;
+typedef struct _PerlIO_funcs PerlIO_funcs;
+typedef PerlIOl *PerlIO;
+#define PerlIO PerlIO
+#define PERLIO_LAYERS 1
+
+/* PERLIO_FUNCS_CONST is now on by default for efficiency, PERLIO_FUNCS_CONST
+ can be removed 1 day once stable & then PerlIO vtables are permanently RO */
+#ifdef PERLIO_FUNCS_CONST
+#define PERLIO_FUNCS_DECL(funcs) const PerlIO_funcs funcs
+#define PERLIO_FUNCS_CAST(funcs) (PerlIO_funcs*)(funcs)
+#else
+#define PERLIO_FUNCS_DECL(funcs) PerlIO_funcs funcs
+#define PERLIO_FUNCS_CAST(funcs) (funcs)
+#endif
+
+PERL_CALLCONV void PerlIO_define_layer(pTHX_ PerlIO_funcs *tab);
+PERL_CALLCONV PerlIO_funcs *PerlIO_find_layer(pTHX_ const char *name,
+ STRLEN len,
+ int load);
+PERL_CALLCONV PerlIO *PerlIO_push(pTHX_ PerlIO *f, PERLIO_FUNCS_DECL(*tab),
+ const char *mode, SV *arg);
+PERL_CALLCONV void PerlIO_pop(pTHX_ PerlIO *f);
+PERL_CALLCONV AV* PerlIO_get_layers(pTHX_ PerlIO *f);
+PERL_CALLCONV void PerlIO_clone(pTHX_ PerlInterpreter *proto,
+ CLONE_PARAMS *param);
+
+#endif /* PerlIO */
+
+/* ----------- End of implementation choices ---------- */
+
+/* We now need to determine what happens if source trys to use stdio.
+ * There are three cases based on PERLIO_NOT_STDIO which XS code
+ * can set how it wants.
+ */
+
+#ifdef PERL_CORE
+/* Make a choice for perl core code
+ - currently this is set to try and catch lingering raw stdio calls.
+ This is a known issue with some non UNIX ports which still use
+ "native" stdio features.
+*/
+# ifndef PERLIO_NOT_STDIO
+# define PERLIO_NOT_STDIO 1