# define dTHXx dTHX
#endif
+/* Under PERL_IMPLICIT_SYS (used in Windows for fork emulation)
+ * PerlIO_foo() expands to PL_StdIO->pFOO(PL_StdIO, ...).
+ * dTHXs is therefore needed for all functions using PerlIO_foo(). */
+#ifdef PERL_IMPLICIT_SYS
+# define dTHXs dTHX
+#else
+# define dTHXs dNOOP
+#endif
+
#undef START_EXTERN_C
#undef END_EXTERN_C
#undef EXTERN_C