diff --git a/benchtests/strcoll-inputs/filelist#en_US.UTF-8 b/benchtests/strcoll-inputs/filelist#en_US.UTF-8
index 6cee2374f4..bdc61be3b5 100644
--- a/benchtests/strcoll-inputs/filelist#en_US.UTF-8
+++ b/benchtests/strcoll-inputs/filelist#en_US.UTF-8
@@ -1370,7 +1370,6 @@ a.out.h
 semget.c
 posix_fallocate.c
 getpid.c
-_G_config.h
 getsockopt.S
 pthread_setaffinity.c
 setipv4sourcefilter.c
@@ -3407,7 +3406,6 @@ a.out.h
 libBrokenLocale.abilist
 machine-gmon.h
 _itoa.h
-_G_config.h
 local-setxid.h
 dl-osinfo.h
 dl-dtprocnum.h
diff --git a/conform/data/stdio.h-data b/conform/data/stdio.h-data
index f69802cc70..3ef2460661 100644
--- a/conform/data/stdio.h-data
+++ b/conform/data/stdio.h-data
@@ -41,7 +41,7 @@ type fpos_t
 #if !defined ISO && !defined ISO99 && !defined ISO11 && !defined POSIX
 type va_list
 #else
-#define va_list _G_va_list
+#define va_list __gnuc_va_list
 #endif
 type size_t
 #if defined XOPEN2K8 || defined POSIX2008
diff --git a/csu/init.c b/csu/init.c
index bb68386c9b..6da0a9cd47 100644
--- a/csu/init.c
+++ b/csu/init.c
@@ -18,7 +18,7 @@
 
 #if defined __GNUC__ && __GNUC__ >= 2
 
-#include <_G_config.h>
+#include <libio.h>
 
 /* This records which stdio is linked against in the application. */
 const int _IO_stdin_used = _G_IO_IO_FILE_VERSION;
diff --git a/grp/fgetgrent_r.c b/grp/fgetgrent_r.c
index 5a4107ba9c..7bcbdfe539 100644
--- a/grp/fgetgrent_r.c
+++ b/grp/fgetgrent_r.c
@@ -20,10 +20,6 @@
 #include <grp.h>
 #include <stdio.h>
 
-#include <libio/iolibio.h>
-#define flockfile(s) _IO_flockfile (s)
-#define funlockfile(s) _IO_funlockfile (s)
-
 /* Define a line parsing function using the common code
    used in the nss_files module.  */
 
diff --git a/grp/putgrent.c b/grp/putgrent.c
index 5a12c70557..cd3588ded3 100644
--- a/grp/putgrent.c
+++ b/grp/putgrent.c
@@ -21,9 +21,6 @@
 #include <string.h>
 #include <grp.h>
 
-#define flockfile(s) _IO_flockfile (s)
-#define funlockfile(s) _IO_funlockfile (s)
-
 #define _S(x)	x ? x : ""
 
 /* Write an entry to the given stream.
diff --git a/gshadow/fgetsgent_r.c b/gshadow/fgetsgent_r.c
index f1d0650333..95c21e960c 100644
--- a/gshadow/fgetsgent_r.c
+++ b/gshadow/fgetsgent_r.c
@@ -38,21 +38,21 @@ __fgetsgent_r (FILE *stream, struct sgrp *resbuf, char *buffer, size_t buflen,
 {
   char *p;
 
-  _IO_flockfile (stream);
+  flockfile (stream);
   do
     {
       buffer[buflen - 1] = '\xff';
       p = fgets_unlocked (buffer, buflen, stream);
       if (p == NULL && feof_unlocked (stream))
 	{
-	  _IO_funlockfile (stream);
+	  funlockfile (stream);
 	  *result = NULL;
 	  __set_errno (ENOENT);
 	  return errno;
 	}
       if (p == NULL || buffer[buflen - 1] != '\xff')
 	{
-	  _IO_funlockfile (stream);
+	  funlockfile (stream);
 	  *result = NULL;
 	  __set_errno (ERANGE);
 	  return errno;
@@ -67,7 +67,7 @@ __fgetsgent_r (FILE *stream, struct sgrp *resbuf, char *buffer, size_t buflen,
 	     ! parse_line (buffer, (void *) resbuf, (void *) buffer, buflen,
 			   &errno));
 
-  _IO_funlockfile (stream);
+  funlockfile (stream);
 
   *result = resbuf;
   return 0;
diff --git a/gshadow/putsgent.c b/gshadow/putsgent.c
index 4e219c478a..70063d74c2 100644
--- a/gshadow/putsgent.c
+++ b/gshadow/putsgent.c
@@ -40,7 +40,7 @@ putsgent (const struct sgrp *g, FILE *stream)
       return -1;
     }
 
-  _IO_flockfile (stream);
+  flockfile (stream);
 
   if (fprintf (stream, "%s:%s:", g->sg_namp, _S (g->sg_passwd)) < 0)
     ++errors;
@@ -75,7 +75,7 @@ putsgent (const struct sgrp *g, FILE *stream)
   if (putc_unlocked ('\n', stream) == EOF)
     ++errors;
 
-  _IO_funlockfile (stream);
+  funlockfile (stream);
 
   return errors ? -1 : 0;
 }
diff --git a/include/bits/stdio.h b/include/bits/stdio.h
new file mode 100644
index 0000000000..4aebc9edf2
--- /dev/null
+++ b/include/bits/stdio.h
@@ -0,0 +1,9 @@
+#ifndef _BITS_STDIO_H
+# include <libio/bits/stdio.h>
+# ifndef _ISOMAC
+
+libc_hidden_proto (__uflow)
+libc_hidden_proto (__overflow)
+
+# endif
+#endif
diff --git a/include/bits/types/FILE_internals.h b/include/bits/types/FILE_internals.h
new file mode 100644
index 0000000000..a653c8101c
--- /dev/null
+++ b/include/bits/types/FILE_internals.h
@@ -0,0 +1 @@
+#include <libio/bits/types/FILE_internals.h>
diff --git a/include/bits/types/__fpos_t.h b/include/bits/types/__fpos_t.h
new file mode 100644
index 0000000000..2dcdc98d75
--- /dev/null
+++ b/include/bits/types/__fpos_t.h
@@ -0,0 +1 @@
+#include <libio/bits/types/__fpos_t.h>
diff --git a/include/bits/types/cookie_io_functions_t.h b/include/bits/types/cookie_io_functions_t.h
new file mode 100644
index 0000000000..87f7930c6e
--- /dev/null
+++ b/include/bits/types/cookie_io_functions_t.h
@@ -0,0 +1 @@
+#include <libio/bits/types/cookie_io_functions_t.h>
diff --git a/include/libio.h b/include/libio.h
index d2fa796758..54ed704bdd 100644
--- a/include/libio.h
+++ b/include/libio.h
@@ -1,11 +1,9 @@
-#if !defined _ISOMAC && defined _IO_MTSAFE_IO
-# include <stdio-lock.h>
-#endif
-#include <libio/libio.h>
-
-#ifndef _ISOMAC
-#ifndef _LIBC_LIBIO_H
-#define _LIBC_LIBIO_H
+#ifndef _IO_STDIO_H
+# if !defined _ISOMAC && defined _IO_MTSAFE_IO
+#  include <stdio-lock.h>
+# endif
+# include <libio/libio.h>
+# ifndef _ISOMAC
 
 libc_hidden_proto (__overflow)
 libc_hidden_proto (__underflow)
@@ -41,5 +39,5 @@ libc_hidden_proto (_IO_vfscanf)
 # endif
 #endif /* _IO_MTSAFE_IO */
 
-#endif
-#endif
+# endif /* !_ISOMAC */
+#endif /* libio.h */
diff --git a/include/stdio.h b/include/stdio.h
index f68f633bd6..824e970435 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -1,4 +1,7 @@
 #ifndef _STDIO_H
+# if !defined _ISOMAC && defined _IO_MTSAFE_IO
+#  include <stdio-lock.h>
+# endif
 # include <libio/stdio.h>
 # ifndef _ISOMAC
 
@@ -10,44 +13,44 @@ extern int __snprintf (char *__restrict __s, size_t __maxlen,
      __attribute__ ((__format__ (__printf__, 3, 4)));
 libc_hidden_proto (__snprintf)
 extern int __vsnprintf (char *__restrict __s, size_t __maxlen,
-			const char *__restrict __format, _G_va_list __arg)
+			const char *__restrict __format, __gnuc_va_list __arg)
      __attribute__ ((__format__ (__printf__, 3, 0)));
 extern int __vfscanf (FILE *__restrict __s,
 		      const char *__restrict __format,
-		      _G_va_list __arg)
+		      __gnuc_va_list __arg)
      __attribute__ ((__format__ (__scanf__, 2, 0)));
 libc_hidden_proto (__vfscanf)
 extern int __vscanf (const char *__restrict __format,
-		     _G_va_list __arg)
+		     __gnuc_va_list __arg)
      __attribute__ ((__format__ (__scanf__, 1, 0)));
-extern _IO_ssize_t __getline (char **__lineptr, size_t *__n,
+extern __ssize_t __getline (char **__lineptr, size_t *__n,
 			      FILE *__stream);
 extern int __vsscanf (const char *__restrict __s,
 		      const char *__restrict __format,
-		      _G_va_list __arg)
+		      __gnuc_va_list __arg)
      __attribute__ ((__format__ (__scanf__, 2, 0)));
 
 extern int __sprintf_chk (char *, int, size_t, const char *, ...) __THROW;
 extern int __snprintf_chk (char *, size_t, int, size_t, const char *, ...)
      __THROW;
 extern int __vsprintf_chk (char *, int, size_t, const char *,
-			   _G_va_list) __THROW;
+			   __gnuc_va_list) __THROW;
 extern int __vsnprintf_chk (char *, size_t, int, size_t, const char *,
-			    _G_va_list) __THROW;
+			    __gnuc_va_list) __THROW;
 extern int __printf_chk (int, const char *, ...);
 extern int __fprintf_chk (FILE *, int, const char *, ...);
-extern int __vprintf_chk (int, const char *, _G_va_list);
-extern int __vfprintf_chk (FILE *, int, const char *, _G_va_list);
+extern int __vprintf_chk (int, const char *, __gnuc_va_list);
+extern int __vfprintf_chk (FILE *, int, const char *, __gnuc_va_list);
 extern char *__fgets_unlocked_chk (char *buf, size_t size, int n, FILE *fp);
 extern char *__fgets_chk (char *buf, size_t size, int n, FILE *fp);
 extern int __asprintf_chk (char **, int, const char *, ...) __THROW;
-extern int __vasprintf_chk (char **, int, const char *, _G_va_list) __THROW;
+extern int __vasprintf_chk (char **, int, const char *, __gnuc_va_list) __THROW;
 extern int __dprintf_chk (int, int, const char *, ...);
-extern int __vdprintf_chk (int, int, const char *, _G_va_list);
+extern int __vdprintf_chk (int, int, const char *, __gnuc_va_list);
 extern int __obstack_printf_chk (struct obstack *, int, const char *, ...)
      __THROW;
 extern int __obstack_vprintf_chk (struct obstack *, int, const char *,
-				  _G_va_list) __THROW;
+				  __gnuc_va_list) __THROW;
 
 extern int __isoc99_fscanf (FILE *__restrict __stream,
 			    const char *__restrict __format, ...) __wur;
@@ -56,12 +59,12 @@ extern int __isoc99_sscanf (const char *__restrict __s,
 			    const char *__restrict __format, ...) __THROW;
 extern int __isoc99_vfscanf (FILE *__restrict __s,
 			     const char *__restrict __format,
-			     _G_va_list __arg) __wur;
+			     __gnuc_va_list __arg) __wur;
 extern int __isoc99_vscanf (const char *__restrict __format,
-			    _G_va_list __arg) __wur;
+			    __gnuc_va_list __arg) __wur;
 extern int __isoc99_vsscanf (const char *__restrict __s,
 			     const char *__restrict __format,
-			     _G_va_list __arg) __THROW;
+			     __gnuc_va_list __arg) __THROW;
 libc_hidden_proto (__isoc99_vsscanf)
 libc_hidden_proto (__isoc99_vfscanf)
 
@@ -96,9 +99,15 @@ libc_hidden_proto (__fortify_fail)
 
 /* Acquire ownership of STREAM.  */
 extern void __flockfile (FILE *__stream);
+#  if IS_IN (libc)
+#   define flockfile(stream) __flockfile(stream)
+#  endif
 
 /* Relinquish the ownership granted for STREAM.  */
 extern void __funlockfile (FILE *__stream);
+#  if IS_IN (libc)
+#   define funlockfile(stream) __funlockfile(stream)
+#  endif
 
 /* Try to acquire ownership of STREAM but do not block if it is not
    possible.  */
@@ -117,18 +126,18 @@ extern int _sys_nerr_internal attribute_hidden;
 
 libc_hidden_proto (__asprintf)
 #  if IS_IN (libc)
-extern _IO_FILE *_IO_new_fopen (const char*, const char*);
+extern FILE *_IO_new_fopen (const char*, const char*);
 #   define fopen(fname, mode) _IO_new_fopen (fname, mode)
-extern _IO_FILE *_IO_new_fdopen (int, const char*);
+extern FILE *_IO_new_fdopen (int, const char*);
 #   define fdopen(fd, mode) _IO_new_fdopen (fd, mode)
-extern int _IO_new_fclose (_IO_FILE*);
+extern int _IO_new_fclose (FILE*);
 #   define fclose(fp) _IO_new_fclose (fp)
-extern int _IO_fputs (const char*, _IO_FILE*);
+extern int _IO_fputs (const char*, FILE*);
 libc_hidden_proto (_IO_fputs)
 #   define fputs(str, fp) _IO_fputs (str, fp)
-extern int _IO_new_fsetpos (_IO_FILE *, const _IO_fpos_t *);
+extern int _IO_new_fsetpos (FILE *, const __fpos_t *);
 #   define fsetpos(fp, posp) _IO_new_fsetpos (fp, posp)
-extern int _IO_new_fgetpos (_IO_FILE *, _IO_fpos_t *);
+extern int _IO_new_fgetpos (FILE *, __fpos_t *);
 #   define fgetpos(fp, posp) _IO_new_fgetpos (fp, posp)
 #  endif
 
diff --git a/include/stdio_ext.h b/include/stdio_ext.h
index 29c6e68cdb..7f8835211e 100644
--- a/include/stdio_ext.h
+++ b/include/stdio_ext.h
@@ -2,6 +2,7 @@
 #include <stdio-common/stdio_ext.h>
 
 # ifndef _ISOMAC
+# include <libio/bits/types/FILE_internals.h>
 
 libc_hidden_proto (__fsetlocking)
 
diff --git a/libio/Makefile b/libio/Makefile
index a002a3365c..63191f386c 100644
--- a/libio/Makefile
+++ b/libio/Makefile
@@ -22,9 +22,10 @@ subdir	:= libio
 
 include ../Makeconfig
 
-headers	:= stdio.h libio.h _G_config.h bits/stdio.h \
-	   bits/sys_errlist.h bits/stdio2.h bits/stdio-ldbl.h bits/libio-ldbl.h \
-	   bits/types/FILE.h bits/types/__FILE.h
+headers := stdio.h bits/stdio.h bits/stdio2.h bits/sys_errlist.h	      \
+	   bits/stdio-ldbl.h bits/libio-ldbl.h				      \
+	   bits/types/FILE.h bits/types/__FILE.h bits/types/FILE_internals.h  \
+	   bits/types/cookie_io_functions_t.h bits/types/__fpos_t.h
 
 routines	:=							      \
 	filedoalloc iofclose iofdopen iofflush iofgetpos iofgets iofopen      \
diff --git a/libio/__fbufsize.c b/libio/__fbufsize.c
index 74d2ebbe81..8c00ca7658 100644
--- a/libio/__fbufsize.c
+++ b/libio/__fbufsize.c
@@ -16,6 +16,7 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stdio_ext.h>
+#include <libio.h>
 
 size_t
 __fbufsize (FILE *fp)
diff --git a/libio/__flbf.c b/libio/__flbf.c
index 929175df70..dfa68aa2e8 100644
--- a/libio/__flbf.c
+++ b/libio/__flbf.c
@@ -16,6 +16,7 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stdio_ext.h>
+#include <libio.h>
 
 int
 __flbf (FILE *fp)
diff --git a/libio/__fpending.c b/libio/__fpending.c
index e957839985..008cf08fb4 100644
--- a/libio/__fpending.c
+++ b/libio/__fpending.c
@@ -16,6 +16,7 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stdio_ext.h>
+#include <libio.h>
 
 size_t
 __fpending (FILE *fp)
diff --git a/libio/__freadable.c b/libio/__freadable.c
index 3bde42a729..d5535e902b 100644
--- a/libio/__freadable.c
+++ b/libio/__freadable.c
@@ -16,6 +16,7 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stdio_ext.h>
+#include <libio.h>
 
 int
 __freadable (FILE *fp)
diff --git a/libio/__freading.c b/libio/__freading.c
index f16f42679f..32e26f8a6c 100644
--- a/libio/__freading.c
+++ b/libio/__freading.c
@@ -16,6 +16,7 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stdio_ext.h>
+#include <libio.h>
 
 int
 __freading (FILE *fp)
diff --git a/libio/__fwritable.c b/libio/__fwritable.c
index 1584aec68f..328e0b6b5b 100644
--- a/libio/__fwritable.c
+++ b/libio/__fwritable.c
@@ -16,6 +16,7 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stdio_ext.h>
+#include <libio.h>
 
 int
 __fwritable (FILE *fp)
diff --git a/libio/__fwriting.c b/libio/__fwriting.c
index 1769d2107e..2ec8fba1cf 100644
--- a/libio/__fwriting.c
+++ b/libio/__fwriting.c
@@ -16,6 +16,7 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stdio_ext.h>
+#include <libio.h>
 
 int
 __fwriting (FILE *fp)
diff --git a/libio/bits/stdio.h b/libio/bits/stdio.h
index 21ad2fb20c..ad77b04a4f 100644
--- a/libio/bits/stdio.h
+++ b/libio/bits/stdio.h
@@ -16,24 +16,30 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#ifndef _BITS_STDIO_H
+#define _BITS_STDIO_H 1
+
 #ifndef _STDIO_H
 # error "Never include <bits/stdio.h> directly; use <stdio.h> instead."
 #endif
 
+#include <bits/types/FILE_internals.h>
+
+extern int __uflow (FILE *);
+extern int __overflow (FILE *, int);
+
 #ifndef __extern_inline
 # define __STDIO_INLINE inline
 #else
 # define __STDIO_INLINE __extern_inline
 #endif
 
-
-#ifdef __USE_EXTERN_INLINES
 /* For -D_FORTIFY_SOURCE{,=2} bits/stdio2.h will define a different
    inline.  */
 # if !(__USE_FORTIFY_LEVEL > 0 && defined __fortify_function)
 /* Write formatted output to stdout from argument list ARG.  */
 __STDIO_INLINE int
-vprintf (const char *__restrict __fmt, _G_va_list __arg)
+vprintf (const char *__restrict __fmt, __gnuc_va_list __arg)
 {
   return vfprintf (stdout, __fmt, __arg);
 }
@@ -43,33 +49,46 @@ vprintf (const char *__restrict __fmt, _G_va_list __arg)
 __STDIO_INLINE int
 getchar (void)
 {
-  return _IO_getc (stdin);
+  return getc (stdin);
 }
 
+#if defined __USE_MISC || defined __USE_POSIX
+__STDIO_INLINE int
+__getc_unlocked (FILE *__fp)
+{
+  char __c;
+
+  if (__glibc_unlikely (__fp->_IO_read_ptr >= __fp->_IO_read_end))
+    return __uflow (__fp);
+
+  __c = *__fp->_IO_read_ptr++;
+  return (unsigned char) __c;
+}
+#endif
+
 
 # ifdef __USE_MISC
 /* Faster version when locking is not necessary.  */
 __STDIO_INLINE int
 fgetc_unlocked (FILE *__fp)
 {
-  return _IO_getc_unlocked (__fp);
+  return __getc_unlocked (__fp);
 }
 # endif /* misc */
 
-
 # ifdef __USE_POSIX
 /* This is defined in POSIX.1:1996.  */
 __STDIO_INLINE int
 getc_unlocked (FILE *__fp)
 {
-  return _IO_getc_unlocked (__fp);
+  return __getc_unlocked (__fp);
 }
 
 /* This is defined in POSIX.1:1996.  */
 __STDIO_INLINE int
 getchar_unlocked (void)
 {
-  return _IO_getc_unlocked (stdin);
+  return __getc_unlocked (stdin);
 }
 # endif	/* POSIX */
 
@@ -78,16 +97,28 @@ getchar_unlocked (void)
 __STDIO_INLINE int
 putchar (int __c)
 {
-  return _IO_putc (__c, stdout);
+  return putc (__c, stdout);
 }
 
+#if defined __USE_MISC || defined __USE_POSIX
+__STDIO_INLINE int
+__putc_unlocked (int __c, FILE *__stream)
+{
+  unsigned char __cc = __c;
+  if (__glibc_unlikely (__stream->_IO_write_ptr >= __stream->_IO_write_end))
+    return __overflow (__stream, __cc);
+
+  *__stream->_IO_write_ptr++ = __cc;
+  return __cc;
+}
+#endif
 
 # ifdef __USE_MISC
 /* Faster version when locking is not necessary.  */
 __STDIO_INLINE int
 fputc_unlocked (int __c, FILE *__stream)
 {
-  return _IO_putc_unlocked (__c, __stream);
+  return __putc_unlocked (__c, __stream);
 }
 # endif /* misc */
 
@@ -97,21 +128,21 @@ fputc_unlocked (int __c, FILE *__stream)
 __STDIO_INLINE int
 putc_unlocked (int __c, FILE *__stream)
 {
-  return _IO_putc_unlocked (__c, __stream);
+  return __putc_unlocked (__c, __stream);
 }
 
 /* This is defined in POSIX.1:1996.  */
 __STDIO_INLINE int
 putchar_unlocked (int __c)
 {
-  return _IO_putc_unlocked (__c, stdout);
+  return __putc_unlocked (__c, stdout);
 }
 # endif	/* POSIX */
 
 
 # ifdef	__USE_GNU
 /* Like `getdelim', but reads up to a newline.  */
-__STDIO_INLINE _IO_ssize_t
+__STDIO_INLINE __ssize_t
 getline (char **__lineptr, size_t *__n, FILE *__stream)
 {
   return __getdelim (__lineptr, __n, '\n', __stream);
@@ -124,20 +155,17 @@ getline (char **__lineptr, size_t *__n, FILE *__stream)
 __STDIO_INLINE int
 __NTH (feof_unlocked (FILE *__stream))
 {
-  return _IO_feof_unlocked (__stream);
+  return (__stream->_flags & _IO_EOF_SEEN) != 0;
 }
 
 /* Faster versions when locking is not required.  */
 __STDIO_INLINE int
 __NTH (ferror_unlocked (FILE *__stream))
 {
-  return _IO_ferror_unlocked (__stream);
+  return (__stream->_flags & _IO_ERR_SEEN) != 0;
 }
 # endif /* misc */
 
-#endif /* Use extern inlines.  */
-
-
 #if defined __USE_MISC && defined __GNUC__ && defined __OPTIMIZE__ \
     && !defined __cplusplus
 /* Perform some simple optimizations.  */
@@ -151,7 +179,7 @@ __NTH (ferror_unlocked (FILE *__stream))
 		       for (__cnt = (size_t) (size) * (size_t) (n);	      \
 			    __cnt > 0; --__cnt)				      \
 			 {						      \
-			   int __c = _IO_getc_unlocked (__stream);	      \
+			   int __c = __getc_unlocked (__stream);	      \
 			   if (__c == EOF)				      \
 			     break;					      \
 			   *__ptr++ = __c;				      \
@@ -174,7 +202,7 @@ __NTH (ferror_unlocked (FILE *__stream))
 		       size_t __cnt;					      \
 		       for (__cnt = (size_t) (size) * (size_t) (n);	      \
 			    __cnt > 0; --__cnt)				      \
-			 if (_IO_putc_unlocked (*__ptr++, __stream) == EOF)   \
+			 if (__putc_unlocked (*__ptr++, __stream) == EOF)     \
 			   break;					      \
 		       ((size_t) (size) * (size_t) (n) - __cnt)		      \
 			/ (size_t) (size); })				      \
@@ -186,5 +214,6 @@ __NTH (ferror_unlocked (FILE *__stream))
 		     : fwrite_unlocked (ptr, size, n, stream))))
 #endif
 
-/* Define helper macro.  */
 #undef __STDIO_INLINE
+
+#endif /* bits/stdio.h */
diff --git a/libio/bits/stdio2.h b/libio/bits/stdio2.h
index e9f9d6952b..2d5cb5c03d 100644
--- a/libio/bits/stdio2.h
+++ b/libio/bits/stdio2.h
@@ -24,7 +24,7 @@ extern int __sprintf_chk (char *__restrict __s, int __flag, size_t __slen,
 			  const char *__restrict __format, ...) __THROW;
 extern int __vsprintf_chk (char *__restrict __s, int __flag, size_t __slen,
 			   const char *__restrict __format,
-			   _G_va_list __ap) __THROW;
+			   __gnuc_va_list __ap) __THROW;
 
 #ifdef __va_arg_pack
 __fortify_function int
@@ -41,7 +41,7 @@ __NTH (sprintf (char *__restrict __s, const char *__restrict __fmt, ...))
 
 __fortify_function int
 __NTH (vsprintf (char *__restrict __s, const char *__restrict __fmt,
-		 _G_va_list __ap))
+		 __gnuc_va_list __ap))
 {
   return __builtin___vsprintf_chk (__s, __USE_FORTIFY_LEVEL - 1,
 				   __bos (__s), __fmt, __ap);
@@ -54,7 +54,7 @@ extern int __snprintf_chk (char *__restrict __s, size_t __n, int __flag,
 			   ...) __THROW;
 extern int __vsnprintf_chk (char *__restrict __s, size_t __n, int __flag,
 			    size_t __slen, const char *__restrict __format,
-			    _G_va_list __ap) __THROW;
+			    __gnuc_va_list __ap) __THROW;
 
 # ifdef __va_arg_pack
 __fortify_function int
@@ -72,7 +72,7 @@ __NTH (snprintf (char *__restrict __s, size_t __n,
 
 __fortify_function int
 __NTH (vsnprintf (char *__restrict __s, size_t __n,
-		  const char *__restrict __fmt, _G_va_list __ap))
+		  const char *__restrict __fmt, __gnuc_va_list __ap))
 {
   return __builtin___vsnprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
 				    __bos (__s), __fmt, __ap);
@@ -86,9 +86,10 @@ extern int __fprintf_chk (FILE *__restrict __stream, int __flag,
 			  const char *__restrict __format, ...);
 extern int __printf_chk (int __flag, const char *__restrict __format, ...);
 extern int __vfprintf_chk (FILE *__restrict __stream, int __flag,
-			   const char *__restrict __format, _G_va_list __ap);
+			   const char *__restrict __format,
+			   __gnuc_va_list __ap);
 extern int __vprintf_chk (int __flag, const char *__restrict __format,
-			  _G_va_list __ap);
+			  __gnuc_va_list __ap);
 
 # ifdef __va_arg_pack
 __fortify_function int
@@ -111,7 +112,7 @@ printf (const char *__restrict __fmt, ...)
 # endif
 
 __fortify_function int
-vprintf (const char *__restrict __fmt, _G_va_list __ap)
+vprintf (const char *__restrict __fmt, __gnuc_va_list __ap)
 {
 #ifdef __USE_EXTERN_INLINES
   return __vfprintf_chk (stdout, __USE_FORTIFY_LEVEL - 1, __fmt, __ap);
@@ -122,7 +123,7 @@ vprintf (const char *__restrict __fmt, _G_va_list __ap)
 
 __fortify_function int
 vfprintf (FILE *__restrict __stream,
-	  const char *__restrict __fmt, _G_va_list __ap)
+	  const char *__restrict __fmt, __gnuc_va_list __ap)
 {
   return __vfprintf_chk (__stream, __USE_FORTIFY_LEVEL - 1, __fmt, __ap);
 }
@@ -131,7 +132,7 @@ vfprintf (FILE *__restrict __stream,
 extern int __dprintf_chk (int __fd, int __flag, const char *__restrict __fmt,
 			  ...) __attribute__ ((__format__ (__printf__, 3, 4)));
 extern int __vdprintf_chk (int __fd, int __flag,
-			   const char *__restrict __fmt, _G_va_list __arg)
+			   const char *__restrict __fmt, __gnuc_va_list __arg)
      __attribute__ ((__format__ (__printf__, 3, 0)));
 
 #  ifdef __va_arg_pack
@@ -147,7 +148,7 @@ dprintf (int __fd, const char *__restrict __fmt, ...)
 #  endif
 
 __fortify_function int
-vdprintf (int __fd, const char *__restrict __fmt, _G_va_list __ap)
+vdprintf (int __fd, const char *__restrict __fmt, __gnuc_va_list __ap)
 {
   return __vdprintf_chk (__fd, __USE_FORTIFY_LEVEL - 1, __fmt, __ap);
 }
@@ -159,7 +160,7 @@ extern int __asprintf_chk (char **__restrict __ptr, int __flag,
 			   const char *__restrict __fmt, ...)
      __THROW __attribute__ ((__format__ (__printf__, 3, 4))) __wur;
 extern int __vasprintf_chk (char **__restrict __ptr, int __flag,
-			    const char *__restrict __fmt, _G_va_list __arg)
+			    const char *__restrict __fmt, __gnuc_va_list __arg)
      __THROW __attribute__ ((__format__ (__printf__, 3, 0))) __wur;
 extern int __obstack_printf_chk (struct obstack *__restrict __obstack,
 				 int __flag, const char *__restrict __format,
@@ -168,7 +169,7 @@ extern int __obstack_printf_chk (struct obstack *__restrict __obstack,
 extern int __obstack_vprintf_chk (struct obstack *__restrict __obstack,
 				  int __flag,
 				  const char *__restrict __format,
-				  _G_va_list __args)
+				  __gnuc_va_list __args)
      __THROW __attribute__ ((__format__ (__printf__, 3, 0)));
 
 #  ifdef __va_arg_pack
@@ -205,14 +206,14 @@ __NTH (obstack_printf (struct obstack *__restrict __obstack,
 
 __fortify_function int
 __NTH (vasprintf (char **__restrict __ptr, const char *__restrict __fmt,
-		  _G_va_list __ap))
+		  __gnuc_va_list __ap))
 {
   return __vasprintf_chk (__ptr, __USE_FORTIFY_LEVEL - 1, __fmt, __ap);
 }
 
 __fortify_function int
 __NTH (obstack_vprintf (struct obstack *__restrict __obstack,
-			const char *__restrict __fmt, _G_va_list __ap))
+			const char *__restrict __fmt, __gnuc_va_list __ap))
 {
   return __obstack_vprintf_chk (__obstack, __USE_FORTIFY_LEVEL - 1, __fmt,
 				__ap);
@@ -368,7 +369,7 @@ fread_unlocked (void *__restrict __ptr, size_t __size, size_t __n,
 
       for (; __cnt > 0; --__cnt)
 	{
-	  int __c = _IO_getc_unlocked (__stream);
+	  int __c = __getc_unlocked (__stream);
 	  if (__c == EOF)
 	    break;
 	  *__cptr++ = __c;
diff --git a/libio/bits/types/FILE.h b/libio/bits/types/FILE.h
index f268263209..de02a9d75b 100644
--- a/libio/bits/types/FILE.h
+++ b/libio/bits/types/FILE.h
@@ -1,9 +1,12 @@
 #ifndef __FILE_defined
 #define __FILE_defined 1
 
-struct _IO_FILE;
+/* Note: the struct tag is _IO_FILE rather than __FILE for historical
+   reasons.  It potentially appears in C++ mangled names and therefore
+   cannot be changed.  This file must be kept in sync with __FILE.h and
+   FILE_internals.h.  */
 
-/* The opaque type of streams.  This is the definition used elsewhere.  */
+struct _IO_FILE;
 typedef struct _IO_FILE FILE;
 
 #endif
diff --git a/libio/bits/types/FILE_internals.h b/libio/bits/types/FILE_internals.h
new file mode 100644
index 0000000000..5f88b4c6a1
--- /dev/null
+++ b/libio/bits/types/FILE_internals.h
@@ -0,0 +1,110 @@
+/* Internal structure of a FILE object.
+   Copyright (C) 1991-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Written by Per Bothner <bothner@cygnus.com>.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+
+#ifndef _FILE_internals_defined
+#define _FILE_internals_defined 1
+
+/* This file exposes just enough of the internal structure of a FILE
+   object to permit the optimizations in bits/stdio.h.
+
+   Note: the _IO_ prefixes on struct tags and field names are for
+   historical reasons.  The GNU C Library no longer supports the
+   "libio" extension to stdio.
+
+   This file must be kept in sync with __FILE.h, FILE.h, and internal
+   headers.  */
+
+#include <bits/types.h>
+
+/* During the build of glibc itself, _IO_lock_t will already have been
+   defined by internal headers.  */
+#ifndef _IO_lock_t_defined
+typedef void _IO_lock_t;
+#define _IO_lock_t_defined 1
+#endif
+
+struct _IO_marker;
+struct _IO_codecvt;
+struct _IO_wide_data;
+
+struct _IO_FILE
+{
+  int _flags;		/* High-order word is _IO_MAGIC; rest is flags. */
+  /* The following pointers correspond to the C++ streambuf protocol. */
+  char* _IO_read_ptr;	/* Current read pointer */
+  char* _IO_read_end;	/* End of get area. */
+  char* _IO_read_base;	/* Start of putback+get area. */
+  char* _IO_write_base;	/* Start of put area. */
+  char* _IO_write_ptr;	/* Current put pointer. */
+  char* _IO_write_end;	/* End of put area. */
+  char* _IO_buf_base;	/* Start of reserve area. */
+  char* _IO_buf_end;	/* End of reserve area. */
+  /* The following fields are used to support backing up and undo. */
+  char *_IO_save_base; /* Pointer to start of non-current get area. */
+  char *_IO_backup_base;  /* Pointer to first valid character of backup area */
+  char *_IO_save_end; /* Pointer to end of non-current get area. */
+
+  struct _IO_marker *_markers;
+
+  struct _IO_FILE *_chain;
+
+  int _fileno;
+  int _flags2;
+  __off_t _old_offset; /* This used to be _offset but it's too small.  */
+
+  /* 1+column number of pbase(); 0 is unknown. */
+  unsigned short _cur_column;
+  signed char _vtable_offset;
+  char _shortbuf[1];
+  _IO_lock_t *_lock;
+
+  /* Fields below this point are not present in the "old" FILE structure.  */
+  __off64_t _offset;
+  struct _IO_codecvt *_codecvt;
+  struct _IO_wide_data *_wide_data;
+  struct _IO_FILE *_freeres_list;
+  void *_freeres_buf;
+  size_t __pad5;
+  int _mode;
+
+  /* Make sure we don't get into trouble again.  */
+  char _unused2[15 * sizeof (int) - 4 * sizeof (void *) - sizeof (size_t)];
+};
+
+/* Many more flags are defined internally.  */
+#ifndef _IO_EOF_SEEN
+# define _IO_EOF_SEEN 0x10
+#elif _IO_EOF_SEEN != 0x10
+# error "FILE_internals.h out of sync with libio.h (_IO_EOF_SEEN)"
+#endif
+
+#ifndef _IO_ERR_SEEN
+# define _IO_ERR_SEEN 0x20
+#elif _IO_ERR_SEEN != 0x20
+# error "FILE_internals.h out of sync with libio.h (_IO_ERR_SEEN)"
+#endif
+
+#ifndef _IO_USER_LOCK
+# define _IO_USER_LOCK 0x8000
+#elif _IO_USER_LOCK != 0x8000
+# error "FILE_internals.h out of sync with libio.h (_IO_USER_LOCK)"
+#endif
+
+#endif
diff --git a/libio/bits/types/__FILE.h b/libio/bits/types/__FILE.h
index 06dd79bc83..5e8a9096f0 100644
--- a/libio/bits/types/__FILE.h
+++ b/libio/bits/types/__FILE.h
@@ -1,6 +1,11 @@
 #ifndef ____FILE_defined
 #define ____FILE_defined 1
 
+/* Note: the struct tag is _IO_FILE rather than __FILE for historical
+   reasons.  It potentially appears in C++ mangled names and therefore
+   cannot be changed.  This file must be kept in sync with FILE.h and
+   FILE_internals.h.  */
+
 struct _IO_FILE;
 typedef struct _IO_FILE __FILE;
 
diff --git a/libio/bits/types/__fpos_t.h b/libio/bits/types/__fpos_t.h
new file mode 100644
index 0000000000..032a8f12ba
--- /dev/null
+++ b/libio/bits/types/__fpos_t.h
@@ -0,0 +1,19 @@
+#ifndef __fpos_t_defined
+#define __fpos_t_defined 1
+
+#include <bits/types.h>
+#include <bits/types/__mbstate_t.h>
+
+typedef struct
+{
+  __off_t __pos;
+  __mbstate_t __state;
+} __fpos_t;
+
+typedef struct
+{
+  __off64_t __pos;
+  __mbstate_t __state;
+} __fpos64_t;
+
+#endif
diff --git a/libio/bits/types/cookie_io_functions_t.h b/libio/bits/types/cookie_io_functions_t.h
new file mode 100644
index 0000000000..c29a46e019
--- /dev/null
+++ b/libio/bits/types/cookie_io_functions_t.h
@@ -0,0 +1,61 @@
+/* Types for fopencookie.
+   Copyright (C) 1991-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef __cookie_io_functions_t_defined
+#define __cookie_io_functions_t_defined 1
+
+#include <bits/types.h>
+
+#define __need_size_t
+#include <stddef.h>
+
+/* Read NBYTES bytes from COOKIE into a buffer pointed to by BUF.
+   Return number of bytes read.  */
+typedef __ssize_t cookie_read_function_t (void *__cookie, char *__buf,
+					  size_t __nbytes);
+
+/* Write N bytes pointed to by BUF to COOKIE.  Write all N bytes
+   unless there is an error.  Return number of bytes written.  If
+   there is an error, return 0 and do not write anything.  If the file
+   has been opened for append (__mode.__append set), then set the file
+   pointer to the end of the file and then do the write; if not, just
+   write at the current file pointer.  */
+typedef __ssize_t cookie_write_function_t (void *__cookie, const char *__buf,
+					   size_t __n);
+
+/* Move COOKIE's file position to *POS bytes from the
+   beginning of the file (if W is SEEK_SET),
+   the current position (if W is SEEK_CUR),
+   or the end of the file (if W is SEEK_END).
+   Set *POS to the new file position.
+   Returns zero if successful, nonzero if not.  */
+typedef int cookie_seek_function_t (void *__cookie, __off64_t *__pos, int __w);
+
+/* Close COOKIE.  */
+typedef int cookie_close_function_t (void *__cookie);
+
+/* The structure with the cookie function pointers.  */
+typedef struct
+{
+  cookie_read_function_t *read;		/* Read bytes.  */
+  cookie_write_function_t *write;	/* Write bytes.  */
+  cookie_seek_function_t *seek;		/* Seek/tell file position.  */
+  cookie_close_function_t *close;	/* Close file.  */
+} cookie_io_functions_t;
+
+#endif /* cookie_io_functions_t.h */
diff --git a/libio/libio.h b/libio/libio.h
index 518ffd8e44..d7f9d41cbc 100644
--- a/libio/libio.h
+++ b/libio/libio.h
@@ -28,10 +28,54 @@
 #ifndef _IO_STDIO_H
 #define _IO_STDIO_H
 
+#include <features.h>
+
+#if !defined _LIBC || !defined __USE_GNU || defined _ISOMAC
+# error "libio.h is private to the stdio implementation"
+#endif
+
+/* Former configuration parameters for standalone libio.  Most of
+   these are fixed for the GNU C library.  */
+
+#include <bits/types.h>
+
+#define __need_size_t
+#define __need_wchar_t
+#define __need_NULL
+#include <stddef.h>
+
+#define __need___va_list
+#include <stdarg.h>
+
+#include <bits/types/__mbstate_t.h>
+#include <bits/types/__fpos_t.h>
+#include <bits/types/wint_t.h>
+
+#include <gconv.h>
+typedef union
+{
+  struct __gconv_info __cd;
+  struct
+  {
+    struct __gconv_info __cd;
+    struct __gconv_step_data __data;
+  } __combined;
+} _G_iconv_t;
+
+#define _G_HAVE_MMAP 1
+#define _G_IO_IO_FILE_VERSION 0x20001
+
+/* This is defined by <bits/stat.h> if `st_blksize' exists.  */
+#define _G_HAVE_ST_BLKSIZE defined (_STATBUF_ST_BLKSIZE)
+
+/* This must match the definition of BUFSIZ in stdio.h.  */
+#define _G_BUFSIZ 8192
+
+/* Allow ports to override the above if absolutely necessary.   */
 #include <_G_config.h>
-/* ALL of these should be defined in _G_config.h */
-#define _IO_fpos_t _G_fpos_t
-#define _IO_fpos64_t _G_fpos64_t
+
+#define _IO_fpos_t __fpos_t
+#define _IO_fpos64_t __fpos64_t
 #define _IO_size_t size_t
 #define _IO_ssize_t __ssize_t
 #define _IO_off_t __off_t
@@ -41,38 +85,17 @@
 #define _IO_iconv_t _G_iconv_t
 #define _IO_HAVE_ST_BLKSIZE _G_HAVE_ST_BLKSIZE
 #define _IO_BUFSIZ _G_BUFSIZ
-#define _IO_va_list _G_va_list
+#define _IO_va_list __gnuc_va_list
 #define _IO_wint_t wint_t
 
-/* This define avoids name pollution if we're using GNU stdarg.h */
-#define __need___va_list
-#include <stdarg.h>
-#ifdef __GNUC_VA_LIST
-# undef _IO_va_list
-# define _IO_va_list __gnuc_va_list
-#endif /* __GNUC_VA_LIST */
-
-#ifndef __P
-# include <sys/cdefs.h>
-#endif /*!__P*/
-
+/* Backward compatibility */
+#define _STDIO_USES_IOSTREAM 1
 #define _IO_UNIFIED_JUMPTABLES 1
+#define __HAVE_COLUMN 1
 
 #ifndef EOF
 # define EOF (-1)
 #endif
-#ifndef NULL
-# if defined __GNUG__ && \
-    (__GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8))
-#  define NULL (__null)
-# else
-#  if !defined(__cplusplus)
-#   define NULL ((void*)0)
-#  else
-#   define NULL (0)
-#  endif
-# endif
-#endif
 
 #define _IOS_INPUT	1
 #define _IOS_OUTPUT	2
@@ -111,15 +134,11 @@
 
 #define _IO_FLAGS2_MMAP 1
 #define _IO_FLAGS2_NOTCANCEL 2
-#ifdef _LIBC
-# define _IO_FLAGS2_FORTIFY 4
-#endif
+#define _IO_FLAGS2_FORTIFY 4
 #define _IO_FLAGS2_USER_WBUF 8
-#ifdef _LIBC
-# define _IO_FLAGS2_SCANF_STD 16
-# define _IO_FLAGS2_NOCLOSE 32
-# define _IO_FLAGS2_CLOEXEC 64
-#endif
+#define _IO_FLAGS2_SCANF_STD 16
+#define _IO_FLAGS2_NOCLOSE 32
+#define _IO_FLAGS2_CLOEXEC 64
 
 /* These are "formatting flags" matching the iostream fmtflags enum values. */
 #define _IO_SKIPWS 01
@@ -141,34 +160,67 @@
 #define _IO_BOOLALPHA 0200000
 
 
-struct _IO_jump_t;  struct _IO_FILE;
+struct _IO_jump_t;
+struct _IO_FILE;
+struct _IO_FILE_plus;
+typedef struct _IO_FILE _IO_FILE;
 
-/* During the build of glibc itself, _IO_lock_t will already have been
-   defined by internal headers.  */
-#ifndef _IO_lock_t_defined
-typedef void _IO_lock_t;
+#include <bits/types/__FILE.h>
+#include <bits/types/FILE.h>
+#include <bits/types/FILE_internals.h>
+#define _IO_file_flags _flags /* Compatibility. */
+
+#ifdef _IO_USE_OLD_IO_FILE
+/* This structure is a proper prefix of the _IO_FILE structure defined
+   in FILE_internals.h.  */
+struct _IO_FILE_old
+{
+  int _flags;		/* High-order word is _IO_MAGIC; rest is flags. */
+
+  /* The following pointers correspond to the C++ streambuf protocol. */
+  /* Note:  Tk uses the _IO_read_ptr and _IO_read_end fields directly. */
+  char* _IO_read_ptr;	/* Current read pointer */
+  char* _IO_read_end;	/* End of get area. */
+  char* _IO_read_base;	/* Start of putback+get area. */
+  char* _IO_write_base;	/* Start of put area. */
+  char* _IO_write_ptr;	/* Current put pointer. */
+  char* _IO_write_end;	/* End of put area. */
+  char* _IO_buf_base;	/* Start of reserve area. */
+  char* _IO_buf_end;	/* End of reserve area. */
+  /* The following fields are used to support backing up and undo. */
+  char *_IO_save_base; /* Pointer to start of non-current get area. */
+  char *_IO_backup_base;  /* Pointer to first valid character of backup area */
+  char *_IO_save_end; /* Pointer to end of non-current get area. */
+
+  struct _IO_marker *_markers;
+
+  struct _IO_FILE *_chain;
+
+  int _fileno;
+  int _flags2;
+  _IO_off_t _old_offset; /* This used to be _offset but it's too small.  */
+
+  /* 1+column number of pbase(); 0 is unknown. */
+  unsigned short _cur_column;
+  signed char _vtable_offset;
+  char _shortbuf[1];
+
+  /*  char* _save_gptr;  char* _save_egptr; */
+
+  _IO_lock_t *_lock;
+};
 #endif
 
-
 /* A streammarker remembers a position in a buffer. */
 
-struct _IO_marker {
+struct _IO_marker
+{
   struct _IO_marker *_next;
   struct _IO_FILE *_sbuf;
   /* If _pos >= 0
  it points to _buf->Gbase()+_pos. FIXME comment */
   /* if _pos < 0, it points to _buf->eBptr()+_pos. FIXME comment */
   int _pos;
-#if 0
-    void set_streampos(streampos sp) { _spos = sp; }
-    void set_offset(int offset) { _pos = offset; _spos = (streampos)(-2); }
-  public:
-    streammarker(streambuf *sb);
-    ~streammarker();
-    int saving() { return  _spos == -2; }
-    int delta(streammarker&);
-    int delta();
-#endif
 };
 
 /* This is the structure from the libstdc++ codecvt class.  */
@@ -180,7 +232,6 @@ enum __codecvt_result
   __codecvt_noconv
 };
 
-#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
 /* The order of the elements in the following struct must match the order
    of the virtual functions in the libstdc++ codecvt class.  */
 struct _IO_codecvt
@@ -235,166 +286,40 @@ struct _IO_wide_data
 
   const struct _IO_jump_t *_wide_vtable;
 };
-#endif
 
-struct _IO_FILE {
-  int _flags;		/* High-order word is _IO_MAGIC; rest is flags. */
-#define _IO_file_flags _flags
-
-  /* The following pointers correspond to the C++ streambuf protocol. */
-  /* Note:  Tk uses the _IO_read_ptr and _IO_read_end fields directly. */
-  char* _IO_read_ptr;	/* Current read pointer */
-  char* _IO_read_end;	/* End of get area. */
-  char* _IO_read_base;	/* Start of putback+get area. */
-  char* _IO_write_base;	/* Start of put area. */
-  char* _IO_write_ptr;	/* Current put pointer. */
-  char* _IO_write_end;	/* End of put area. */
-  char* _IO_buf_base;	/* Start of reserve area. */
-  char* _IO_buf_end;	/* End of reserve area. */
-  /* The following fields are used to support backing up and undo. */
-  char *_IO_save_base; /* Pointer to start of non-current get area. */
-  char *_IO_backup_base;  /* Pointer to first valid character of backup area */
-  char *_IO_save_end; /* Pointer to end of non-current get area. */
-
-  struct _IO_marker *_markers;
-
-  struct _IO_FILE *_chain;
-
-  int _fileno;
-#if 0
-  int _blksize;
-#else
-  int _flags2;
-#endif
-  _IO_off_t _old_offset; /* This used to be _offset but it's too small.  */
-
-#define __HAVE_COLUMN /* temporary */
-  /* 1+column number of pbase(); 0 is unknown. */
-  unsigned short _cur_column;
-  signed char _vtable_offset;
-  char _shortbuf[1];
-
-  /*  char* _save_gptr;  char* _save_egptr; */
-
-  _IO_lock_t *_lock;
-#ifdef _IO_USE_OLD_IO_FILE
-};
-
-struct _IO_FILE_complete
-{
-  struct _IO_FILE _file;
-#endif
-#if defined _G_IO_IO_FILE_VERSION && _G_IO_IO_FILE_VERSION == 0x20001
-  _IO_off64_t _offset;
-# if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
-  /* Wide character stream stuff.  */
-  struct _IO_codecvt *_codecvt;
-  struct _IO_wide_data *_wide_data;
-  struct _IO_FILE *_freeres_list;
-  void *_freeres_buf;
-# else
-  void *__pad1;
-  void *__pad2;
-  void *__pad3;
-  void *__pad4;
-# endif
-  size_t __pad5;
-  int _mode;
-  /* Make sure we don't get into trouble again.  */
-  char _unused2[15 * sizeof (int) - 4 * sizeof (void *) - sizeof (size_t)];
-#endif
-};
-
-#ifndef __cplusplus
-typedef struct _IO_FILE _IO_FILE;
-#endif
-
-struct _IO_FILE_plus;
 
 extern struct _IO_FILE_plus _IO_2_1_stdin_;
 extern struct _IO_FILE_plus _IO_2_1_stdout_;
 extern struct _IO_FILE_plus _IO_2_1_stderr_;
-#ifndef _LIBC
-#define _IO_stdin ((_IO_FILE*)(&_IO_2_1_stdin_))
-#define _IO_stdout ((_IO_FILE*)(&_IO_2_1_stdout_))
-#define _IO_stderr ((_IO_FILE*)(&_IO_2_1_stderr_))
-#else
 extern _IO_FILE *_IO_stdin attribute_hidden;
 extern _IO_FILE *_IO_stdout attribute_hidden;
 extern _IO_FILE *_IO_stderr attribute_hidden;
-#endif
-
 
 /* Functions to do I/O and file management for a stream.  */
+#include <bits/types/cookie_io_functions_t.h>
 
-/* Read NBYTES bytes from COOKIE into a buffer pointed to by BUF.
-   Return number of bytes read.  */
-typedef __ssize_t __io_read_fn (void *__cookie, char *__buf, size_t __nbytes);
+/* Legacy internal names for cookie I/O types.  */
+typedef cookie_read_function_t __io_read_fn;
+typedef cookie_write_function_t __io_write_fn;
+typedef cookie_seek_function_t __io_seek_fn;
+typedef cookie_close_function_t __io_close_fn;
 
-/* Write N bytes pointed to by BUF to COOKIE.  Write all N bytes
-   unless there is an error.  Return number of bytes written.  If
-   there is an error, return 0 and do not write anything.  If the file
-   has been opened for append (__mode.__append set), then set the file
-   pointer to the end of the file and then do the write; if not, just
-   write at the current file pointer.  */
-typedef __ssize_t __io_write_fn (void *__cookie, const char *__buf,
-				 size_t __n);
-
-/* Move COOKIE's file position to *POS bytes from the
-   beginning of the file (if W is SEEK_SET),
-   the current position (if W is SEEK_CUR),
-   or the end of the file (if W is SEEK_END).
-   Set *POS to the new file position.
-   Returns zero if successful, nonzero if not.  */
-typedef int __io_seek_fn (void *__cookie, _IO_off64_t *__pos, int __w);
-
-/* Close COOKIE.  */
-typedef int __io_close_fn (void *__cookie);
-
-
-#ifdef __USE_GNU
-/* User-visible names for the above.  */
-typedef __io_read_fn cookie_read_function_t;
-typedef __io_write_fn cookie_write_function_t;
-typedef __io_seek_fn cookie_seek_function_t;
-typedef __io_close_fn cookie_close_function_t;
-
-/* The structure with the cookie function pointers.  */
-typedef struct
-{
-  __io_read_fn *read;		/* Read bytes.  */
-  __io_write_fn *write;		/* Write bytes.  */
-  __io_seek_fn *seek;		/* Seek/tell file position.  */
-  __io_close_fn *close;		/* Close file.  */
-} _IO_cookie_io_functions_t;
-typedef _IO_cookie_io_functions_t cookie_io_functions_t;
+typedef cookie_io_functions_t _IO_cookie_io_functions_t;
 
 struct _IO_cookie_file;
 
 /* Initialize one of those.  */
 extern void _IO_cookie_init (struct _IO_cookie_file *__cfile, int __read_write,
 			     void *__cookie, _IO_cookie_io_functions_t __fns);
-#endif
-
-
-#ifdef __cplusplus
-extern "C" {
-#endif
 
 extern int __underflow (_IO_FILE *);
 extern int __uflow (_IO_FILE *);
 extern int __overflow (_IO_FILE *, int);
-#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
 extern _IO_wint_t __wunderflow (_IO_FILE *);
 extern _IO_wint_t __wuflow (_IO_FILE *);
 extern _IO_wint_t __woverflow (_IO_FILE *, _IO_wint_t);
-#endif
 
-#if  __GNUC__ >= 3
-# define _IO_BE(expr, res) __builtin_expect ((expr), res)
-#else
-# define _IO_BE(expr, res) (expr)
-#endif
+#define _IO_BE(expr, res) __builtin_expect ((expr), res)
 
 #define _IO_getc_unlocked(_fp) \
        (_IO_BE ((_fp)->_IO_read_ptr >= (_fp)->_IO_read_end, 0) \
@@ -408,7 +333,6 @@ extern _IO_wint_t __woverflow (_IO_FILE *, _IO_wint_t);
     ? __overflow (_fp, (unsigned char) (_ch)) \
     : (unsigned char) (*(_fp)->_IO_write_ptr++ = (_ch)))
 
-#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
 # define _IO_getwc_unlocked(_fp) \
   (_IO_BE ((_fp)->_wide_data == NULL					\
 	   || ((_fp)->_wide_data->_IO_read_ptr				\
@@ -420,7 +344,6 @@ extern _IO_wint_t __woverflow (_IO_FILE *, _IO_wint_t);
 	       >= (_fp)->_wide_data->_IO_write_end), 0)			\
    ? __woverflow (_fp, _wch)						\
    : (_IO_wint_t) (*(_fp)->_wide_data->_IO_write_ptr++ = (_wch)))
-#endif
 
 #define _IO_feof_unlocked(__fp) (((__fp)->_flags & _IO_EOF_SEEN) != 0)
 #define _IO_ferror_unlocked(__fp) (((__fp)->_flags & _IO_ERR_SEEN) != 0)
@@ -463,28 +386,28 @@ extern _IO_off64_t _IO_seekpos (_IO_FILE *, _IO_off64_t, int);
 
 extern void _IO_free_backup_area (_IO_FILE *) __THROW;
 
-#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
 extern _IO_wint_t _IO_getwc (_IO_FILE *__fp);
 extern _IO_wint_t _IO_putwc (wchar_t __wc, _IO_FILE *__fp);
 extern int _IO_fwide (_IO_FILE *__fp, int __mode) __THROW;
-# if __GNUC__ >= 2
+
 /* While compiling glibc we have to handle compatibility with very old
    versions.  */
-#  if defined _LIBC && defined SHARED
-#   include <shlib-compat.h>
-#   if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
-#    define _IO_fwide_maybe_incompatible \
+#if defined SHARED
+# include <shlib-compat.h>
+# if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
+#  define _IO_fwide_maybe_incompatible \
   (__builtin_expect (&_IO_stdin_used == NULL, 0))
 extern const int _IO_stdin_used;
 weak_extern (_IO_stdin_used);
-#   endif
-#  endif
-#  ifndef _IO_fwide_maybe_incompatible
-#   define _IO_fwide_maybe_incompatible (0)
-#  endif
+# endif
+#endif
+#ifndef _IO_fwide_maybe_incompatible
+# define _IO_fwide_maybe_incompatible (0)
+#endif
+
 /* A special optimized version of the function above.  It optimizes the
    case of initializing an unoriented byte stream.  */
-#  define _IO_fwide(__fp, __mode) \
+#define _IO_fwide(__fp, __mode) \
   ({ int __result = (__mode);						      \
      if (__result < 0 && ! _IO_fwide_maybe_incompatible)		      \
        {								      \
@@ -498,7 +421,6 @@ weak_extern (_IO_stdin_used);
      else								      \
        __result = _IO_fwide (__fp, __result);				      \
      __result; })
-# endif
 
 extern int _IO_vfwscanf (_IO_FILE * __restrict, const wchar_t * __restrict,
 			 _IO_va_list, int *__restrict);
@@ -506,14 +428,9 @@ extern int _IO_vfwprintf (_IO_FILE *__restrict, const wchar_t *__restrict,
 			  _IO_va_list);
 extern _IO_ssize_t _IO_wpadn (_IO_FILE *, wint_t, _IO_ssize_t);
 extern void _IO_free_wbackup_area (_IO_FILE *) __THROW;
-#endif
 
 #ifdef __LDBL_COMPAT
 # include <bits/libio-ldbl.h>
 #endif
 
-#ifdef __cplusplus
-}
-#endif
-
 #endif /* _IO_STDIO_H */
diff --git a/libio/libioP.h b/libio/libioP.h
index eb93418c8d..f537914a71 100644
--- a/libio/libioP.h
+++ b/libio/libioP.h
@@ -347,12 +347,9 @@ struct _IO_FILE_plus
 };
 
 #ifdef _IO_USE_OLD_IO_FILE
-/* This structure is used by the compatibility code as if it were an
-   _IO_FILE_plus, but has enough space to initialize the _mode argument
-   of an _IO_FILE_complete.  */
-struct _IO_FILE_complete_plus
+struct _IO_FILE_old_plus
 {
-  struct _IO_FILE_complete file;
+  struct _IO_FILE_old file;
   const struct _IO_jump_t *vtable;
 };
 #endif
diff --git a/libio/oldfileops.c b/libio/oldfileops.c
index 2eceefa68a..a61a1de87d 100644
--- a/libio/oldfileops.c
+++ b/libio/oldfileops.c
@@ -114,7 +114,7 @@ extern int errno;
 
 void
 attribute_compat_text_section
-_IO_old_file_init_internal (struct _IO_FILE_plus *fp)
+_IO_old_file_init_internal (struct _IO_FILE_old_plus *fp)
 {
   /* POSIX.1 allows another file handle to be used to change the position
      of our file descriptor.  Hence we actually don't know the actual
@@ -123,24 +123,24 @@ _IO_old_file_init_internal (struct _IO_FILE_plus *fp)
   fp->file._IO_file_flags |= CLOSED_FILEBUF_FLAGS;
 
   _IO_link_in (fp);
-  fp->file._vtable_offset = ((int) sizeof (struct _IO_FILE)
-			     - (int) sizeof (struct _IO_FILE_complete));
+  fp->file._vtable_offset = ((int) sizeof (struct _IO_FILE_old)
+			     - (int) sizeof (struct _IO_FILE));
   fp->file._fileno = -1;
 
 #if defined SHARED && defined _LIBC
   if (__builtin_expect (&_IO_stdin_used != NULL, 1)
-      || (fp != (struct _IO_FILE_plus *) _IO_stdin
-	  && fp != (struct _IO_FILE_plus *) _IO_stdout
-	  && fp != (struct _IO_FILE_plus *) _IO_stderr))
+      || (fp != (struct _IO_FILE_old_plus *) _IO_stdin
+	  && fp != (struct _IO_FILE_old_plus *) _IO_stdout
+	  && fp != (struct _IO_FILE_old_plus *) _IO_stderr))
     /* The object is dynamically allocated and large enough.  Initialize
        the _mode element as well.  */
-    ((struct _IO_FILE_complete *) fp)->_mode = -1;
+    ((struct _IO_FILE *) fp)->_mode = -1;
 #endif
 }
 
 void
 attribute_compat_text_section
-_IO_old_file_init (struct _IO_FILE_plus *fp)
+_IO_old_file_init (struct _IO_FILE_old_plus *fp)
 {
   IO_set_accept_foreign_vtables (&_IO_vtable_check);
   _IO_old_file_init_internal (fp);
@@ -148,7 +148,7 @@ _IO_old_file_init (struct _IO_FILE_plus *fp)
 
 int
 attribute_compat_text_section
-_IO_old_file_close_it (_IO_FILE *fp)
+_IO_old_file_close_it (_IO_FILE_old *fp)
 {
   int write_status, close_status;
   if (!_IO_file_is_open (fp))
@@ -166,7 +166,7 @@ _IO_old_file_close_it (_IO_FILE *fp)
   _IO_setg (fp, NULL, NULL, NULL);
   _IO_setp (fp, NULL, NULL);
 
-  _IO_un_link ((struct _IO_FILE_plus *) fp);
+  _IO_un_link ((struct _IO_FILE_old_plus *) fp);
   fp->_flags = _IO_MAGIC|CLOSED_FILEBUF_FLAGS;
   fp->_fileno = -1;
   fp->_old_offset = _IO_pos_BAD;
@@ -176,7 +176,7 @@ _IO_old_file_close_it (_IO_FILE *fp)
 
 void
 attribute_compat_text_section
-_IO_old_file_finish (_IO_FILE *fp, int dummy)
+_IO_old_file_finish (_IO_FILE_old *fp, int dummy)
 {
   if (_IO_file_is_open (fp))
     {
@@ -187,9 +187,9 @@ _IO_old_file_finish (_IO_FILE *fp, int dummy)
   _IO_default_finish (fp, 0);
 }
 
-_IO_FILE *
+_IO_FILE_old *
 attribute_compat_text_section
-_IO_old_file_fopen (_IO_FILE *fp, const char *filename, const char *mode)
+_IO_old_file_fopen (_IO_FILE_old *fp, const char *filename, const char *mode)
 {
   int oflags = 0, omode;
   int read_write, fdesc;
@@ -230,13 +230,13 @@ _IO_old_file_fopen (_IO_FILE *fp, const char *filename, const char *mode)
     if (_IO_SEEKOFF (fp, (_IO_off_t)0, _IO_seek_end, _IOS_INPUT|_IOS_OUTPUT)
 	== _IO_pos_BAD && errno != ESPIPE)
       return NULL;
-  _IO_link_in ((struct _IO_FILE_plus *) fp);
+  _IO_link_in ((struct _IO_FILE_old_plus *) fp);
   return fp;
 }
 
-_IO_FILE *
+_IO_FILE_old *
 attribute_compat_text_section
-_IO_old_file_attach (_IO_FILE *fp, int fd)
+_IO_old_file_attach (_IO_FILE_old *fp, int fd)
 {
   if (_IO_file_is_open (fp))
     return NULL;
@@ -252,9 +252,9 @@ _IO_old_file_attach (_IO_FILE *fp, int fd)
   return fp;
 }
 
-_IO_FILE *
+_IO_FILE_old *
 attribute_compat_text_section
-_IO_old_file_setbuf (_IO_FILE *fp, char *p, _IO_ssize_t len)
+_IO_old_file_setbuf (_IO_FILE_old *fp, char *p, _IO_ssize_t len)
 {
     if (_IO_default_setbuf (fp, p, len) == NULL)
       return NULL;
@@ -266,14 +266,14 @@ _IO_old_file_setbuf (_IO_FILE *fp, char *p, _IO_ssize_t len)
     return fp;
 }
 
-static int old_do_write (_IO_FILE *, const char *, _IO_size_t);
+static int old_do_write (_IO_FILE_old *, const char *, _IO_size_t);
 
 /* Write TO_DO bytes from DATA to FP.
    Then mark FP as having empty buffers. */
 
 int
 attribute_compat_text_section
-_IO_old_do_write (_IO_FILE *fp, const char *data, _IO_size_t to_do)
+_IO_old_do_write (_IO_FILE_old *fp, const char *data, _IO_size_t to_do)
 {
   return (to_do == 0 || (_IO_size_t) old_do_write (fp, data, to_do) == to_do)
 	 ? 0 : EOF;
@@ -281,7 +281,7 @@ _IO_old_do_write (_IO_FILE *fp, const char *data, _IO_size_t to_do)
 
 static int
 attribute_compat_text_section
-old_do_write (_IO_FILE *fp, const char *data, _IO_size_t to_do)
+old_do_write (_IO_FILE_old *fp, const char *data, _IO_size_t to_do)
 {
   _IO_size_t count;
   if (fp->_flags & _IO_IS_APPENDING)
@@ -311,7 +311,7 @@ old_do_write (_IO_FILE *fp, const char *data, _IO_size_t to_do)
 
 int
 attribute_compat_text_section
-_IO_old_file_underflow (_IO_FILE *fp)
+_IO_old_file_underflow (_IO_FILE_old *fp)
 {
   _IO_ssize_t count;
 #if 0
@@ -375,7 +375,7 @@ _IO_old_file_underflow (_IO_FILE *fp)
 
 int
 attribute_compat_text_section
-_IO_old_file_overflow (_IO_FILE *f, int ch)
+_IO_old_file_overflow (_IO_FILE_old *f, int ch)
 {
   if (f->_flags & _IO_NO_WRITES) /* SET ERROR */
     {
@@ -425,7 +425,7 @@ _IO_old_file_overflow (_IO_FILE *f, int ch)
 
 int
 attribute_compat_text_section
-_IO_old_file_sync (_IO_FILE *fp)
+_IO_old_file_sync (_IO_FILE_old *fp)
 {
   _IO_ssize_t delta;
   int retval = 0;
@@ -459,7 +459,7 @@ _IO_old_file_sync (_IO_FILE *fp)
 
 _IO_off64_t
 attribute_compat_text_section
-_IO_old_file_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
+_IO_old_file_seekoff (_IO_FILE_old *fp, _IO_off64_t offset, int dir, int mode)
 {
   _IO_off_t result;
   _IO_off64_t delta, new_offset;
@@ -642,7 +642,7 @@ resync:
 
 _IO_ssize_t
 attribute_compat_text_section
-_IO_old_file_write (_IO_FILE *f, const void *data, _IO_ssize_t n)
+_IO_old_file_write (_IO_FILE_old *f, const void *data, _IO_ssize_t n)
 {
   _IO_ssize_t to_do = n;
   while (to_do > 0)
@@ -664,7 +664,7 @@ _IO_old_file_write (_IO_FILE *f, const void *data, _IO_ssize_t n)
 
 _IO_size_t
 attribute_compat_text_section
-_IO_old_file_xsputn (_IO_FILE *f, const void *data, _IO_size_t n)
+_IO_old_file_xsputn (_IO_FILE_old *f, const void *data, _IO_size_t n)
 {
   const char *s = (char *) data;
   _IO_size_t to_do = n;
diff --git a/libio/stdio.h b/libio/stdio.h
index 47490c8299..7019c1d28f 100644
--- a/libio/stdio.h
+++ b/libio/stdio.h
@@ -32,18 +32,22 @@ __BEGIN_DECLS
 #define __need_NULL
 #include <stddef.h>
 
+#define __need___va_list
+#include <stdarg.h>
+
 #include <bits/types.h>
 #include <bits/types/__FILE.h>
 #include <bits/types/FILE.h>
+#include <bits/types/__fpos_t.h>
 
-#define _STDIO_USES_IOSTREAM
-
-#include <libio.h>
+#ifdef __USE_GNU
+# include <bits/types/cookie_io_functions_t.h>
+#endif
 
 #if defined __USE_XOPEN || defined __USE_XOPEN2K8
 # ifdef __GNUC__
 #  ifndef _VA_LIST_DEFINED
-typedef _G_va_list va_list;
+typedef __gnuc_va_list va_list;
 #   define _VA_LIST_DEFINED
 #  endif
 # else
@@ -75,12 +79,12 @@ typedef __ssize_t ssize_t;
 
 /* The type of the second argument to `fgetpos' and `fsetpos'.  */
 #ifndef __USE_FILE_OFFSET64
-typedef _G_fpos_t fpos_t;
+typedef __fpos_t fpos_t;
 #else
-typedef _G_fpos64_t fpos_t;
+typedef __fpos64_t fpos_t;
 #endif
 #ifdef __USE_LARGEFILE64
-typedef _G_fpos64_t fpos64_t;
+typedef __fpos64_t fpos64_t;
 #endif
 
 /* The possibilities for the third argument to `setvbuf'.  */
@@ -91,7 +95,7 @@ typedef _G_fpos64_t fpos64_t;
 
 /* Default buffer size.  */
 #ifndef BUFSIZ
-# define BUFSIZ _IO_BUFSIZ
+# define BUFSIZ 8192
 #endif
 
 
@@ -132,9 +136,9 @@ typedef _G_fpos64_t fpos64_t;
 
 
 /* Standard streams.  */
-extern struct _IO_FILE *stdin;		/* Standard input stream.  */
-extern struct _IO_FILE *stdout;		/* Standard output stream.  */
-extern struct _IO_FILE *stderr;		/* Standard error output stream.  */
+extern FILE *stdin;		/* Standard input stream.  */
+extern FILE *stdout;		/* Standard output stream.  */
+extern FILE *stderr;		/* Standard error output stream.  */
 /* C89/C99 say they're macros.  Make them happy.  */
 #define stdin stdin
 #define stdout stdout
@@ -270,7 +274,7 @@ extern FILE *fdopen (int __fd, const char *__modes) __THROW __wur;
    and uses the given functions for input and output.  */
 extern FILE *fopencookie (void *__restrict __magic_cookie,
 			  const char *__restrict __modes,
-			  _IO_cookie_io_functions_t __io_funcs) __THROW __wur;
+			  cookie_io_functions_t __io_funcs) __THROW __wur;
 #endif
 
 #if defined __USE_XOPEN2K8 || __GLIBC_USE (LIB_EXT2)
@@ -325,15 +329,15 @@ extern int sprintf (char *__restrict __s,
    This function is a possible cancellation point and therefore not
    marked with __THROW.  */
 extern int vfprintf (FILE *__restrict __s, const char *__restrict __format,
-		     _G_va_list __arg);
+		     __gnuc_va_list __arg);
 /* Write formatted output to stdout from argument list ARG.
 
    This function is a possible cancellation point and therefore not
    marked with __THROW.  */
-extern int vprintf (const char *__restrict __format, _G_va_list __arg);
+extern int vprintf (const char *__restrict __format, __gnuc_va_list __arg);
 /* Write formatted output to S from argument list ARG.  */
 extern int vsprintf (char *__restrict __s, const char *__restrict __format,
-		     _G_va_list __arg) __THROWNL;
+		     __gnuc_va_list __arg) __THROWNL;
 
 #if defined __USE_ISOC99 || defined __USE_UNIX98
 /* Maximum chars of output to write in MAXLEN.  */
@@ -342,7 +346,7 @@ extern int snprintf (char *__restrict __s, size_t __maxlen,
      __THROWNL __attribute__ ((__format__ (__printf__, 3, 4)));
 
 extern int vsnprintf (char *__restrict __s, size_t __maxlen,
-		      const char *__restrict __format, _G_va_list __arg)
+		      const char *__restrict __format, __gnuc_va_list __arg)
      __THROWNL __attribute__ ((__format__ (__printf__, 3, 0)));
 #endif
 
@@ -350,7 +354,7 @@ extern int vsnprintf (char *__restrict __s, size_t __maxlen,
 /* Write formatted output to a string dynamically allocated with `malloc'.
    Store the address of the string in *PTR.  */
 extern int vasprintf (char **__restrict __ptr, const char *__restrict __f,
-		      _G_va_list __arg)
+		      __gnuc_va_list __arg)
      __THROWNL __attribute__ ((__format__ (__printf__, 2, 0))) __wur;
 extern int __asprintf (char **__restrict __ptr,
 		       const char *__restrict __fmt, ...)
@@ -363,7 +367,7 @@ extern int asprintf (char **__restrict __ptr,
 #ifdef __USE_XOPEN2K8
 /* Write formatted output to a file descriptor.  */
 extern int vdprintf (int __fd, const char *__restrict __fmt,
-		     _G_va_list __arg)
+		     __gnuc_va_list __arg)
      __attribute__ ((__format__ (__printf__, 2, 0)));
 extern int dprintf (int __fd, const char *__restrict __fmt, ...)
      __attribute__ ((__format__ (__printf__, 2, 3)));
@@ -418,19 +422,19 @@ extern int __isoc99_sscanf (const char *__restrict __s,
    This function is a possible cancellation point and therefore not
    marked with __THROW.  */
 extern int vfscanf (FILE *__restrict __s, const char *__restrict __format,
-		    _G_va_list __arg)
+		    __gnuc_va_list __arg)
      __attribute__ ((__format__ (__scanf__, 2, 0))) __wur;
 
 /* Read formatted input from stdin into argument list ARG.
 
    This function is a possible cancellation point and therefore not
    marked with __THROW.  */
-extern int vscanf (const char *__restrict __format, _G_va_list __arg)
+extern int vscanf (const char *__restrict __format, __gnuc_va_list __arg)
      __attribute__ ((__format__ (__scanf__, 1, 0))) __wur;
 
 /* Read formatted input from S into argument list ARG.  */
 extern int vsscanf (const char *__restrict __s,
-		    const char *__restrict __format, _G_va_list __arg)
+		    const char *__restrict __format, __gnuc_va_list __arg)
      __THROW __attribute__ ((__format__ (__scanf__, 2, 0)));
 
 # if !defined __USE_GNU \
@@ -442,26 +446,26 @@ extern int vsscanf (const char *__restrict __s,
    s, S or [.  */
 extern int __REDIRECT (vfscanf,
 		       (FILE *__restrict __s,
-			const char *__restrict __format, _G_va_list __arg),
+			const char *__restrict __format, __gnuc_va_list __arg),
 		       __isoc99_vfscanf)
      __attribute__ ((__format__ (__scanf__, 2, 0))) __wur;
 extern int __REDIRECT (vscanf, (const char *__restrict __format,
-				_G_va_list __arg), __isoc99_vscanf)
+				__gnuc_va_list __arg), __isoc99_vscanf)
      __attribute__ ((__format__ (__scanf__, 1, 0))) __wur;
 extern int __REDIRECT_NTH (vsscanf,
 			   (const char *__restrict __s,
 			    const char *__restrict __format,
-			    _G_va_list __arg), __isoc99_vsscanf)
+			    __gnuc_va_list __arg), __isoc99_vsscanf)
      __attribute__ ((__format__ (__scanf__, 2, 0)));
 #  else
 extern int __isoc99_vfscanf (FILE *__restrict __s,
 			     const char *__restrict __format,
-			     _G_va_list __arg) __wur;
+			     __gnuc_va_list __arg) __wur;
 extern int __isoc99_vscanf (const char *__restrict __format,
-			    _G_va_list __arg) __wur;
+			    __gnuc_va_list __arg) __wur;
 extern int __isoc99_vsscanf (const char *__restrict __s,
 			     const char *__restrict __format,
-			     _G_va_list __arg) __THROW;
+			     __gnuc_va_list __arg) __THROW;
 #   define vfscanf __isoc99_vfscanf
 #   define vscanf __isoc99_vscanf
 #   define vsscanf __isoc99_vsscanf
@@ -483,10 +487,6 @@ extern int getc (FILE *__stream);
    marked with __THROW.  */
 extern int getchar (void);
 
-/* The C standard explicitly says this is a macro, so we always do the
-   optimization for it.  */
-#define getc(_fp) _IO_getc (_fp)
-
 #ifdef __USE_POSIX199506
 /* These are defined in POSIX.1:1996.
 
@@ -523,10 +523,6 @@ extern int putc (int __c, FILE *__stream);
    marked with __THROW.  */
 extern int putchar (int __c);
 
-/* The C standard explicitly says this can be a macro,
-   so we always do the optimization for it.  */
-#define putc(_ch, _fp) _IO_putc (_ch, _fp)
-
 #ifdef __USE_MISC
 /* Faster version when locking is not necessary.
 
@@ -600,12 +596,12 @@ extern char *fgets_unlocked (char *__restrict __s, int __n,
    cancellation point.  But due to similarity with an POSIX interface
    or due to the implementation they are cancellation points and
    therefore not marked with __THROW.  */
-extern _IO_ssize_t __getdelim (char **__restrict __lineptr,
-			       size_t *__restrict __n, int __delimiter,
-			       FILE *__restrict __stream) __wur;
-extern _IO_ssize_t getdelim (char **__restrict __lineptr,
+extern __ssize_t __getdelim (char **__restrict __lineptr,
 			     size_t *__restrict __n, int __delimiter,
 			     FILE *__restrict __stream) __wur;
+extern __ssize_t getdelim (char **__restrict __lineptr,
+			   size_t *__restrict __n, int __delimiter,
+			   FILE *__restrict __stream) __wur;
 
 /* Like `getdelim', but reads up to a newline.
 
@@ -613,9 +609,9 @@ extern _IO_ssize_t getdelim (char **__restrict __lineptr,
    cancellation point.  But due to similarity with an POSIX interface
    or due to the implementation it is a cancellation point and
    therefore not marked with __THROW.  */
-extern _IO_ssize_t getline (char **__restrict __lineptr,
-			    size_t *__restrict __n,
-			    FILE *__restrict __stream) __wur;
+extern __ssize_t getline (char **__restrict __lineptr,
+			  size_t *__restrict __n,
+			  FILE *__restrict __stream) __wur;
 #endif
 
 
@@ -828,7 +824,7 @@ extern int obstack_printf (struct obstack *__restrict __obstack,
      __THROWNL __attribute__ ((__format__ (__printf__, 2, 3)));
 extern int obstack_vprintf (struct obstack *__restrict __obstack,
 			    const char *__restrict __format,
-			    _G_va_list __args)
+			    __gnuc_va_list __args)
      __THROWNL __attribute__ ((__format__ (__printf__, 2, 0)));
 #endif /* Use GNU.  */
 
diff --git a/malloc/malloc.c b/malloc/malloc.c
index aa45626093..d3f756b82a 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -222,6 +222,7 @@
 
 #include <unistd.h>
 #include <stdio.h>    /* needed for malloc_stats */
+#include <libio.h>    /* needed for FILE internals in malloc_stats */
 #include <errno.h>
 
 #include <shlib-compat.h>
diff --git a/misc/err.c b/misc/err.c
index 3da4e9d6b0..7b4b7ef814 100644
--- a/misc/err.c
+++ b/misc/err.c
@@ -22,10 +22,8 @@
 #include <errno.h>
 #include <string.h>
 #include <stdio.h>
-
+#include <libio.h>
 #include <wchar.h>
-#define flockfile(s) _IO_flockfile (s)
-#define funlockfile(s) _IO_funlockfile (s)
 
 extern char *__progname;
 
diff --git a/misc/getpass.c b/misc/getpass.c
index 89c783fe20..9d84a7f9cd 100644
--- a/misc/getpass.c
+++ b/misc/getpass.c
@@ -22,8 +22,6 @@
 #include <unistd.h>
 
 #include <wchar.h>
-#define flockfile(s) _IO_flockfile (s)
-#define funlockfile(s) _IO_funlockfile (s)
 #include <libc-lock.h>
 
 /* It is desirable to use this bit on systems that have it.
diff --git a/misc/getttyent.c b/misc/getttyent.c
index 73002f52d1..64a93e9003 100644
--- a/misc/getttyent.c
+++ b/misc/getttyent.c
@@ -37,9 +37,6 @@ static char sccsid[] = "@(#)getttyent.c	8.1 (Berkeley) 6/4/93";
 #include <ctype.h>
 #include <string.h>
 
-#define flockfile(s) _IO_flockfile (s)
-#define funlockfile(s) _IO_funlockfile (s)
-
 static char zapchar;
 static FILE *tf;
 
diff --git a/misc/mntent_r.c b/misc/mntent_r.c
index 30f55212be..02319d152b 100644
--- a/misc/mntent_r.c
+++ b/misc/mntent_r.c
@@ -23,9 +23,6 @@
 #include <string.h>
 #include <sys/types.h>
 
-#define flockfile(s) _IO_flockfile (s)
-#define funlockfile(s) _IO_funlockfile (s)
-
 #undef __setmntent
 #undef __endmntent
 #undef __getmntent_r
diff --git a/posix/getopt.c b/posix/getopt.c
index 543c8e7284..2efdea85dd 100644
--- a/posix/getopt.c
+++ b/posix/getopt.c
@@ -29,17 +29,13 @@
 #include <unistd.h>
 
 #ifdef _LIBC
-/* When used as part of glibc, error printing must be done differently
-   for standards compliance.  getopt is not a cancellation point, so
-   it must not call functions that are, and it is specified by an
-   older standard than stdio locking, so it must not refer to
-   functions in the "user namespace" related to stdio locking.
-   Finally, it must use glibc's internal message translation so that
-   the messages are looked up in the proper text domain.  */
+/* When used as part of glibc, error printing must be done
+   differently: getopt is not a cancellation point, so it must not
+   call functions that are, and it must use glibc's internal message
+   translation so that the messages are looked up in the proper text
+   domain.  */
 # include <libintl.h>
 # define fprintf __fxprintf_nocancel
-# define flockfile(fp) _IO_flockfile (fp)
-# define funlockfile(fp) _IO_funlockfile (fp)
 #else
 # include "gettext.h"
 # define _(msgid) gettext (msgid)
diff --git a/pwd/fgetpwent_r.c b/pwd/fgetpwent_r.c
index 8aa8f69372..044f19b20b 100644
--- a/pwd/fgetpwent_r.c
+++ b/pwd/fgetpwent_r.c
@@ -20,9 +20,6 @@
 #include <stdio.h>
 #include <pwd.h>
 
-#define flockfile(s) _IO_flockfile (s)
-#define funlockfile(s) _IO_funlockfile (s)
-
 /* Define a line parsing function using the common code
    used in the nss_files module.  */
 
diff --git a/shadow/fgetspent_r.c b/shadow/fgetspent_r.c
index 42106302c1..260f59bbc5 100644
--- a/shadow/fgetspent_r.c
+++ b/shadow/fgetspent_r.c
@@ -20,8 +20,6 @@
 #include <shadow.h>
 #include <stdio.h>
 
-#define flockfile(s) _IO_flockfile (s)
-#define funlockfile(s) _IO_funlockfile (s)
 
 /* Define a line parsing function using the common code
    used in the nss_files module.  */
diff --git a/shadow/putspent.c b/shadow/putspent.c
index 5e27340b5d..6dad45f401 100644
--- a/shadow/putspent.c
+++ b/shadow/putspent.c
@@ -20,8 +20,6 @@
 #include <stdio.h>
 #include <shadow.h>
 
-#define flockfile(s) _IO_flockfile (s)
-#define funlockfile(s) _IO_funlockfile (s)
 
 #define _S(x)	x ? x : ""
 
diff --git a/stdio-common/tstgetln.c b/stdio-common/tstgetln.c
index 79ab90c7cc..3b7ecefc0a 100644
--- a/stdio-common/tstgetln.c
+++ b/stdio-common/tstgetln.c
@@ -15,9 +15,8 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#include <sys/types.h>
 #include <stdio.h>
-#undef ssize_t
-#define ssize_t _IO_ssize_t
 
 int
 main (int argc, char *argv[])
diff --git a/sysdeps/generic/_G_config.h b/sysdeps/generic/_G_config.h
index c49eed395b..d98cb3824d 100644
--- a/sysdeps/generic/_G_config.h
+++ b/sysdeps/generic/_G_config.h
@@ -1,58 +1,8 @@
-/* This file is needed by libio to define various configuration parameters.
-   These are always the same in the GNU C library.  */
+/* Configuration parameter overrides for libio - generic version.  */
 
 #ifndef _G_config_h
 #define _G_config_h 1
 
-/* Define types for libio in terms of the standard internal type names.  */
-
-#include <bits/types.h>
-#define __need_size_t
-#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
-# define __need_wchar_t
-#endif
-#define __need_NULL
-#include <stddef.h>
-
-#include <bits/types/__mbstate_t.h>
-#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
-# include <bits/types/wint_t.h>
-#endif
-
-typedef struct
-{
-  __off_t __pos;
-  __mbstate_t __state;
-} _G_fpos_t;
-typedef struct
-{
-  __off64_t __pos;
-  __mbstate_t __state;
-} _G_fpos64_t;
-#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
-# include <gconv.h>
-typedef union
-{
-  struct __gconv_info __cd;
-  struct
-  {
-    struct __gconv_info __cd;
-    struct __gconv_step_data __data;
-  } __combined;
-} _G_iconv_t;
-#endif
-
-
-/* These library features are always available in the GNU C library.  */
-#define _G_va_list __gnuc_va_list
-
-#define _G_HAVE_MMAP 1
-
-#define _G_IO_IO_FILE_VERSION 0x20001
-
-/* This is defined by <bits/stat.h> if `st_blksize' exists.  */
-#define _G_HAVE_ST_BLKSIZE defined (_STATBUF_ST_BLKSIZE)
-
-#define _G_BUFSIZ 8192
+#undef _G_HAVE_MREMAP
 
 #endif	/* _G_config.h */
diff --git a/sysdeps/ieee754/ldbl-opt/nldbl-compat.h b/sysdeps/ieee754/ldbl-opt/nldbl-compat.h
index 72ec0db390..a4f3c37d63 100644
--- a/sysdeps/ieee754/ldbl-opt/nldbl-compat.h
+++ b/sysdeps/ieee754/ldbl-opt/nldbl-compat.h
@@ -82,22 +82,23 @@ extern ssize_t __nldbl___vstrfmon (char *, size_t, const char *, va_list)
 /* These don't use __typeof because they were not declared by the headers,
    since we don't compile with _FORTIFY_SOURCE.  */
 extern int __nldbl___vfprintf_chk (FILE *__restrict, int,
-				   const char *__restrict, _G_va_list);
+				   const char *__restrict, __gnuc_va_list);
 extern int __nldbl___vfwprintf_chk (FILE *__restrict, int,
 				    const wchar_t *__restrict, __gnuc_va_list);
 extern int __nldbl___vsprintf_chk (char *__restrict, int, size_t,
-				   const char *__restrict, _G_va_list) __THROW;
+				   const char *__restrict, __gnuc_va_list)
+  __THROW;
 extern int __nldbl___vsnprintf_chk (char *__restrict, size_t, int, size_t,
-				    const char *__restrict, _G_va_list)
+				    const char *__restrict, __gnuc_va_list)
   __THROW;
 extern int __nldbl___vswprintf_chk (wchar_t *__restrict, size_t, int, size_t,
 				    const wchar_t *__restrict, __gnuc_va_list)
   __THROW;
-extern int __nldbl___vasprintf_chk (char **, int, const char *, _G_va_list)
+extern int __nldbl___vasprintf_chk (char **, int, const char *, __gnuc_va_list)
   __THROW;
-extern int __nldbl___vdprintf_chk (int, int, const char *, _G_va_list);
+extern int __nldbl___vdprintf_chk (int, int, const char *, __gnuc_va_list);
 extern int __nldbl___obstack_vprintf_chk (struct obstack *, int, const char *,
-					  _G_va_list) __THROW;
+					  __gnuc_va_list) __THROW;
 extern void __nldbl___vsyslog_chk (int, int, const char *, va_list);
 
 
diff --git a/sysdeps/unix/sysv/linux/_G_config.h b/sysdeps/unix/sysv/linux/_G_config.h
index 3bc6cfd595..69d5f4694f 100644
--- a/sysdeps/unix/sysv/linux/_G_config.h
+++ b/sysdeps/unix/sysv/linux/_G_config.h
@@ -1,59 +1,8 @@
-/* This file is needed by libio to define various configuration parameters.
-   These are always the same in the GNU C library.  */
+/* Configuration parameter overrides for libio - Linux version.  */
 
 #ifndef _G_config_h
 #define _G_config_h 1
 
-/* Define types for libio in terms of the standard internal type names.  */
-
-#include <bits/types.h>
-#define __need_size_t
-#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
-# define __need_wchar_t
-#endif
-#define __need_NULL
-#include <stddef.h>
-
-#include <bits/types/__mbstate_t.h>
-#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
-# include <bits/types/wint_t.h>
-#endif
-
-typedef struct
-{
-  __off_t __pos;
-  __mbstate_t __state;
-} _G_fpos_t;
-typedef struct
-{
-  __off64_t __pos;
-  __mbstate_t __state;
-} _G_fpos64_t;
-#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
-# include <gconv.h>
-typedef union
-{
-  struct __gconv_info __cd;
-  struct
-  {
-    struct __gconv_info __cd;
-    struct __gconv_step_data __data;
-  } __combined;
-} _G_iconv_t;
-#endif
-
-
-/* These library features are always available in the GNU C library.  */
-#define _G_va_list __gnuc_va_list
-
-#define _G_HAVE_MMAP 1
 #define _G_HAVE_MREMAP 1
 
-#define _G_IO_IO_FILE_VERSION 0x20001
-
-/* This is defined by <bits/stat.h> if `st_blksize' exists.  */
-#define _G_HAVE_ST_BLKSIZE defined (_STATBUF_ST_BLKSIZE)
-
-#define _G_BUFSIZ 8192
-
 #endif	/* _G_config.h */
