diff --git a/NEWS b/NEWS
index 3ac57eca4ee..87a3f1d1cd8 100644
--- a/NEWS
+++ b/NEWS
@@ -13,7 +13,16 @@ Major new features:
 
 Deprecated and removed features, and other changes affecting compatibility:
 
-  [Add deprecations, removals and changes affecting compatibility here]
+ * The nonstandard header files <libio.h> and <_G_config.h> are no longer
+   installed.  Software that was using either header should be updated to
+   use standard <stdio.h> interfaces instead.
+
+ * The stdio.h functions 'getc' and 'putc' are no longer defined as macros.
+   This was never required by the C standard, and the macros just expanded
+   to call alternative names for the same functions.  If you hoped getc and
+   putc would provide performance improvements over fgetc and fputc, instead
+   investigate using (f)getc_unlocked and (f)putc_unlocked, and, if
+   necessary, flockfile and funlockfile.
 
 Changes to build and runtime requirements:
 
diff --git a/bits/_G_config.h b/bits/_G_config.h
index 2b60d29f5ff..701430f47e7 100644
--- a/bits/_G_config.h
+++ b/bits/_G_config.h
@@ -19,20 +19,16 @@
 #include <stddef.h>
 
 #include <bits/types/__mbstate_t.h>
+#include <bits/types/__fpos_t.h>
+#include <bits/types/__fpos64_t.h>
+
+#define _G_fpos_t __fpos_t
+#define _G_fpos64_t __fpos64_t
+
 #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
diff --git a/conform/data/stdio.h-data b/conform/data/stdio.h-data
index f69802cc703..3ef24606610 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/include/bits/types/__fpos64_t.h b/include/bits/types/__fpos64_t.h
new file mode 100644
index 00000000000..68cc4e8b66c
--- /dev/null
+++ b/include/bits/types/__fpos64_t.h
@@ -0,0 +1 @@
+#include <libio/bits/types/__fpos64_t.h>
diff --git a/include/bits/types/__fpos_t.h b/include/bits/types/__fpos_t.h
new file mode 100644
index 00000000000..2dcdc98d750
--- /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 00000000000..87f7930c6ec
--- /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/bits/types/struct_FILE.h b/include/bits/types/struct_FILE.h
new file mode 100644
index 00000000000..971407292be
--- /dev/null
+++ b/include/bits/types/struct_FILE.h
@@ -0,0 +1 @@
+#include <libio/bits/types/struct_FILE.h>
diff --git a/include/stdio.h b/include/stdio.h
index f1e987ae5e3..3b6da17d82f 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -1,6 +1,11 @@
 #ifndef _STDIO_H
+# if !defined _ISOMAC && defined _IO_MTSAFE_IO
+#  include <stdio-lock.h>
+# endif
 # include <libio/stdio.h>
 # ifndef _ISOMAC
+#  define _LIBC_STDIO_H 1
+#  include <bits/libio.h>
 
 /* Now define the internal interfaces.  */
 
diff --git a/libio/Makefile b/libio/Makefile
index 918a86bb743..3e08ed0eeb0 100644
--- a/libio/Makefile
+++ b/libio/Makefile
@@ -22,10 +22,11 @@ subdir	:= libio
 
 include ../Makeconfig
 
-headers	:= stdio.h libio.h _G_config.h \
-	   bits/stdio.h bits/libio.h bits/_G_config.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/types/FILE.h bits/types/__FILE.h bits/types/struct_FILE.h \
+	   bits/types/__fpos_t.h bits/types/__fpos64_t.h \
+	   bits/types/cookie_io_functions_t.h
 
 routines	:=							      \
 	filedoalloc iofclose iofdopen iofflush iofgetpos iofgets iofopen      \
diff --git a/libio/_G_config.h b/libio/_G_config.h
deleted file mode 100644
index 68de2fcaa0d..00000000000
--- a/libio/_G_config.h
+++ /dev/null
@@ -1,25 +0,0 @@
-/* Copyright (C) 2017-2018 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 _G_CONFIG_H
-#define _G_CONFIG_H 1
-
-#warning "<_G_config.h> is deprecated; use <stdio.h> instead."
-
-#include <bits/_G_config.h>
-
-#endif
diff --git a/libio/bits/libio.h b/libio/bits/libio.h
index fae5b932a1f..a9dc3e3efcb 100644
--- a/libio/bits/libio.h
+++ b/libio/bits/libio.h
@@ -28,14 +28,13 @@
 #ifndef _BITS_LIBIO_H
 #define _BITS_LIBIO_H 1
 
-#if !defined _STDIO_H && !defined _LIBIO_H
-# error "Never include <bits/libio.h> directly; use <stdio.h> instead."
-#endif
+#include <stdio.h>
+#include <bits/types/struct_FILE.h>
 
 #include <bits/_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
@@ -44,40 +43,17 @@
 #define _IO_uid_t __uid_t
 #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_BUFSIZ BUFSIZ
 #define _IO_wint_t wint_t
+#define _IO_va_list __gnuc_va_list
 
-/* 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*/
-
+/* compatibility defines */
+#define _STDIO_USES_IOSTREAM
 #define _IO_UNIFIED_JUMPTABLES 1
+#define __HAVE_COLUMN
+#define _IO_file_flags _flags
 
-#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
-
+/* open modes */
 #define _IOS_INPUT	1
 #define _IOS_OUTPUT	2
 #define _IOS_ATEND	4
@@ -146,14 +122,7 @@
 #define _IO_BOOLALPHA 0200000
 
 
-struct _IO_jump_t;  struct _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;
-#endif
-
+struct _IO_jump_t;
 
 /* A streammarker remembers a position in a buffer. */
 
@@ -164,16 +133,6 @@ struct _IO_marker {
  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.  */
@@ -242,73 +201,6 @@ struct _IO_wide_data
 };
 #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;
@@ -330,49 +222,13 @@ extern _IO_FILE *_IO_stderr attribute_hidden;
 #endif
 
 
-/* Functions to do I/O and file management for a stream.  */
-
-/* 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);
-
-/* 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);
-
-
+/* Compatibility names for cookie I/O functions.  */
 #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_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;
+typedef cookie_io_functions_t _IO_cookie_io_functions_t;
 
 struct _IO_cookie_file;
 
@@ -387,8 +243,6 @@ 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 *);
@@ -401,17 +255,12 @@ extern _IO_wint_t __woverflow (_IO_FILE *, _IO_wint_t);
 # define _IO_BE(expr, res) (expr)
 #endif
 
-#define _IO_getc_unlocked(_fp) \
-       (_IO_BE ((_fp)->_IO_read_ptr >= (_fp)->_IO_read_end, 0) \
-	? __uflow (_fp) : *(unsigned char *) (_fp)->_IO_read_ptr++)
+#define _IO_getc_unlocked(_fp) __getc_unlocked_body (_fp)
 #define _IO_peekc_unlocked(_fp) \
        (_IO_BE ((_fp)->_IO_read_ptr >= (_fp)->_IO_read_end, 0) \
 	  && __underflow (_fp) == EOF ? EOF \
 	: *(unsigned char *) (_fp)->_IO_read_ptr)
-#define _IO_putc_unlocked(_ch, _fp) \
-   (_IO_BE ((_fp)->_IO_write_ptr >= (_fp)->_IO_write_end, 0) \
-    ? __overflow (_fp, (unsigned char) (_ch)) \
-    : (unsigned char) (*(_fp)->_IO_write_ptr++ = (_ch)))
+#define _IO_putc_unlocked(_ch, _fp) __putc_unlocked_body (_ch, _fp)
 
 #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
 # define _IO_getwc_unlocked(_fp) \
@@ -427,8 +276,8 @@ extern _IO_wint_t __woverflow (_IO_FILE *, _IO_wint_t);
    : (_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)
+#define _IO_feof_unlocked(_fp) __feof_unlocked_body (_fp)
+#define _IO_ferror_unlocked(_fp) __ferror_unlocked_body (_fp)
 
 extern int _IO_getc (_IO_FILE *__fp);
 extern int _IO_putc (int __c, _IO_FILE *__fp);
diff --git a/libio/bits/stdio.h b/libio/bits/stdio.h
index d287083de16..90b523a7beb 100644
--- a/libio/bits/stdio.h
+++ b/libio/bits/stdio.h
@@ -16,10 +16,15 @@
    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/struct_FILE.h>
+
 #ifndef __extern_inline
 # define __STDIO_INLINE inline
 #else
@@ -33,7 +38,7 @@
 # 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);
 }
@@ -43,7 +48,7 @@ vprintf (const char *__restrict __fmt, _G_va_list __arg)
 __STDIO_INLINE int
 getchar (void)
 {
-  return _IO_getc (stdin);
+  return getc (stdin);
 }
 
 
@@ -52,7 +57,7 @@ getchar (void)
 __STDIO_INLINE int
 fgetc_unlocked (FILE *__fp)
 {
-  return _IO_getc_unlocked (__fp);
+  return __getc_unlocked_body (__fp);
 }
 # endif /* misc */
 
@@ -62,14 +67,14 @@ fgetc_unlocked (FILE *__fp)
 __STDIO_INLINE int
 getc_unlocked (FILE *__fp)
 {
-  return _IO_getc_unlocked (__fp);
+  return __getc_unlocked_body (__fp);
 }
 
 /* This is defined in POSIX.1:1996.  */
 __STDIO_INLINE int
 getchar_unlocked (void)
 {
-  return _IO_getc_unlocked (stdin);
+  return __getc_unlocked_body (stdin);
 }
 # endif	/* POSIX */
 
@@ -78,7 +83,7 @@ getchar_unlocked (void)
 __STDIO_INLINE int
 putchar (int __c)
 {
-  return _IO_putc (__c, stdout);
+  return putc (__c, stdout);
 }
 
 
@@ -87,7 +92,7 @@ putchar (int __c)
 __STDIO_INLINE int
 fputc_unlocked (int __c, FILE *__stream)
 {
-  return _IO_putc_unlocked (__c, __stream);
+  return __putc_unlocked_body (__c, __stream);
 }
 # endif /* misc */
 
@@ -97,21 +102,21 @@ fputc_unlocked (int __c, FILE *__stream)
 __STDIO_INLINE int
 putc_unlocked (int __c, FILE *__stream)
 {
-  return _IO_putc_unlocked (__c, __stream);
+  return __putc_unlocked_body (__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_body (__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);
@@ -124,14 +129,14 @@ getline (char **__lineptr, size_t *__n, FILE *__stream)
 __STDIO_INLINE int
 __NTH (feof_unlocked (FILE *__stream))
 {
-  return _IO_feof_unlocked (__stream);
+  return __feof_unlocked_body (__stream);
 }
 
 /* Faster versions when locking is not required.  */
 __STDIO_INLINE int
 __NTH (ferror_unlocked (FILE *__stream))
 {
-  return _IO_ferror_unlocked (__stream);
+  return __ferror_unlocked_body (__stream);
 }
 # endif /* misc */
 
@@ -151,7 +156,7 @@ __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 +179,7 @@ __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); })				      \
@@ -188,3 +193,5 @@ __NTH (ferror_unlocked (FILE *__stream))
 
 /* Define helper macro.  */
 #undef __STDIO_INLINE
+
+#endif /* bits/stdio.h.  */
diff --git a/libio/bits/stdio2.h b/libio/bits/stdio2.h
index 55302e91d0d..11651506a67 100644
--- a/libio/bits/stdio2.h
+++ b/libio/bits/stdio2.h
@@ -16,6 +16,9 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#ifndef _BITS_STDIO2_H
+#define _BITS_STDIO2_H 1
+
 #ifndef _STDIO_H
 # error "Never include <bits/stdio2.h> directly; use <stdio.h> instead."
 #endif
@@ -24,7 +27,7 @@ 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 +44,7 @@ __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 +57,7 @@ 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 +75,7 @@ __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 +89,9 @@ 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 +114,7 @@ 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 +125,7 @@ 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 +134,7 @@ 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 +150,7 @@ 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 +162,7 @@ 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 +171,7 @@ 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 +208,14 @@ __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 +371,7 @@ 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;
@@ -379,3 +382,5 @@ fread_unlocked (void *__restrict __ptr, size_t __size, size_t __n,
   return __fread_unlocked_alias (__ptr, __size, __n, __stream);
 }
 #endif
+
+#endif /* bits/stdio2.h.  */
diff --git a/libio/bits/types/__fpos64_t.h b/libio/bits/types/__fpos64_t.h
new file mode 100644
index 00000000000..06a6891154f
--- /dev/null
+++ b/libio/bits/types/__fpos64_t.h
@@ -0,0 +1,16 @@
+#ifndef _____fpos64_t_defined
+#define _____fpos64_t_defined 1
+
+#include <bits/types.h>
+#include <bits/types/__mbstate_t.h>
+
+/* The tag name of this struct is _G_fpos64_t to preserve historic
+   C++ mangled names for functions taking fpos_t and/or fpos64_t
+   arguments.  That name should not be used in new code.  */
+typedef struct _G_fpos64_t
+{
+  __off64_t __pos;
+  __mbstate_t __state;
+} __fpos64_t;
+
+#endif
diff --git a/libio/bits/types/__fpos_t.h b/libio/bits/types/__fpos_t.h
new file mode 100644
index 00000000000..bb04576651b
--- /dev/null
+++ b/libio/bits/types/__fpos_t.h
@@ -0,0 +1,16 @@
+#ifndef _____fpos_t_defined
+#define _____fpos_t_defined 1
+
+#include <bits/types.h>
+#include <bits/types/__mbstate_t.h>
+
+/* The tag name of this struct is _G_fpos_t to preserve historic
+   C++ mangled names for functions taking fpos_t arguments.
+   That name should not be used in new code.  */
+typedef struct _G_fpos_t
+{
+  __off_t __pos;
+  __mbstate_t __state;
+} __fpos_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 00000000000..cd4c0e19f4c
--- /dev/null
+++ b/libio/bits/types/cookie_io_functions_t.h
@@ -0,0 +1,46 @@
+#ifndef __cookie_io_functions_t_defined
+#define __cookie_io_functions_t_defined 1
+
+#include <bits/types.h>
+
+/* Functions to do I/O and file management for a stream.  */
+
+/* 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 NBYTES bytes pointed to by BUF to COOKIE.  Write all NBYTES 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 __nbytes);
+
+/* 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.
+   The tag name of this struct is _IO_cookie_io_functions_t to
+   preserve historic C++ mangled names for functions taking
+   cookie_io_functions_t arguments.  That name should not be used in
+   new code.  */
+typedef struct _IO_cookie_io_functions_t
+{
+  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
diff --git a/libio/bits/types/struct_FILE.h b/libio/bits/types/struct_FILE.h
new file mode 100644
index 00000000000..a120c762685
--- /dev/null
+++ b/libio/bits/types/struct_FILE.h
@@ -0,0 +1,120 @@
+/* Copyright (C) 1991-2018 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 __struct_FILE_defined
+#define __struct_FILE_defined 1
+
+/* Caution: The contents of this file are not part of the official
+   stdio.h API.  However, much of it is part of the official *binary*
+   interface, and therefore cannot be changed.  */
+
+#if defined _IO_USE_OLD_IO_FILE && !defined _LIBC
+# error "_IO_USE_OLD_IO_FILE should only be defined when building libc itself"
+#endif
+
+#if defined _IO_lock_t_defined && !defined _LIBC
+# error "_IO_lock_t_defined should only be defined when building libc itself"
+#endif
+
+#include <bits/types.h>
+
+struct _IO_FILE;
+struct _IO_marker;
+struct _IO_codecvt;
+struct _IO_wide_data;
+
+/* 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;
+#endif
+
+/* The tag name of this struct is _IO_FILE to preserve historic
+   C++ mangled names for functions taking FILE* arguments.
+   That name should not be used in new code.  */
+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;
+#ifdef _IO_USE_OLD_IO_FILE
+};
+
+struct _IO_FILE_complete
+{
+  struct _IO_FILE _file;
+#endif
+  __off64_t _offset;
+  /* Wide character stream stuff.  */
+  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)];
+};
+
+/* These macros are used by bits/stdio.h and internal headers.  */
+#define __getc_unlocked_body(_fp)					\
+  (__glibc_unlikely ((_fp)->_IO_read_ptr >= (_fp)->_IO_read_end)	\
+   ? __uflow (_fp) : *(unsigned char *) (_fp)->_IO_read_ptr++)
+
+#define __putc_unlocked_body(_ch, _fp)					\
+  (__glibc_unlikely ((_fp)->_IO_write_ptr >= (_fp)->_IO_write_end)	\
+   ? __overflow (_fp, (unsigned char) (_ch))				\
+   : (unsigned char) (*(_fp)->_IO_write_ptr++ = (_ch)))
+
+#define _IO_EOF_SEEN 0x10
+#define __feof_unlocked_body(_fp) (((_fp)->_flags & _IO_EOF_SEEN) != 0)
+
+#define _IO_ERR_SEEN 0x20
+#define __ferror_unlocked_body(_fp) (((_fp)->_flags & _IO_ERR_SEEN) != 0)
+
+#define _IO_USER_LOCK 0x8000
+/* Many more flag bits are defined internally.  */
+
+#endif
diff --git a/libio/iolibio.h b/libio/iolibio.h
index 621b31cff1f..7814b1d4e56 100644
--- a/libio/iolibio.h
+++ b/libio/iolibio.h
@@ -1,4 +1,8 @@
+#ifndef _IOLIBIO_H
+#define _IOLIBIO_H 1
+
 #include <stdio.h>
+#include <bits/libio.h>
 
 /* These emulate stdio functionality, but with a different name
    (_IO_ungetc instead of ungetc), and using _IO_FILE instead of FILE. */
@@ -94,3 +98,5 @@ _IO_FILE *__old_freopen (const char *, const char *, _IO_FILE *) __THROW;
 #ifdef __cplusplus
 }
 #endif
+
+#endif /* iolibio.h.  */
diff --git a/libio/libio.h b/libio/libio.h
deleted file mode 100644
index 47a25083ce3..00000000000
--- a/libio/libio.h
+++ /dev/null
@@ -1,25 +0,0 @@
-/* Copyright (C) 2017-2018 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 _LIBIO_H
-#define _LIBIO_H 1
-
-#warning "<libio.h> is deprecated; use <stdio.h> instead."
-
-#include <bits/libio.h>
-
-#endif
diff --git a/libio/libioP.h b/libio/libioP.h
index 068ceb2615a..ac66f95f8d4 100644
--- a/libio/libioP.h
+++ b/libio/libioP.h
@@ -32,6 +32,9 @@
 
    FIXME: All of the C++ cruft eventually needs to go away.  */
 
+#ifndef _LIBIOP_H
+#define _LIBIOP_H 1
+
 #include <stddef.h>
 
 #include <errno.h>
@@ -39,6 +42,8 @@
 
 #include <math_ldbl_opt.h>
 
+#include <stdio.h>
+#include <bits/libio.h>
 #include "iolibio.h"
 
 #ifdef __cplusplus
@@ -876,3 +881,5 @@ IO_validate_vtable (const struct _IO_jump_t *vtable)
     _IO_vtable_check ();
   return vtable;
 }
+
+#endif /* libioP.h.  */
diff --git a/libio/stdio.h b/libio/stdio.h
index 95bc902a82c..e22e423e4d1 100644
--- a/libio/stdio.h
+++ b/libio/stdio.h
@@ -32,18 +32,23 @@ __BEGIN_DECLS
 #define __need_NULL
 #include <stddef.h>
 
+#define __need___va_list
+#include <stdarg.h>
+
 #include <bits/types.h>
+#include <bits/types/__fpos_t.h>
+#include <bits/types/__fpos64_t.h>
 #include <bits/types/__FILE.h>
 #include <bits/types/FILE.h>
 
-#define _STDIO_USES_IOSTREAM
-
-#include <bits/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 +80,12 @@ 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'.  */
@@ -90,16 +95,12 @@ typedef _G_fpos64_t fpos64_t;
 
 
 /* Default buffer size.  */
-#ifndef BUFSIZ
-# define BUFSIZ _IO_BUFSIZ
-#endif
+#define BUFSIZ 8192
 
 
-/* End of file character.
-   Some things throughout the library rely on this being -1.  */
-#ifndef EOF
-# define EOF (-1)
-#endif
+/* The value returned by fgetc and similar functions to indicate the
+   end of the file.  */
+#define EOF (-1)
 
 
 /* The possibilities for the third argument to `fseek'.
@@ -132,9 +133,9 @@ 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 +271,7 @@ 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 +326,15 @@ 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 +343,7 @@ 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 +351,7 @@ 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 +364,7 @@ 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 +419,19 @@ 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 +443,26 @@ 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 +484,6 @@ 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 +520,6 @@ 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 +593,12 @@ 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,
-			     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;
+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 +606,9 @@ 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 +821,7 @@ 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.  */
 
@@ -853,6 +846,11 @@ extern void funlockfile (FILE *__stream) __THROW;
 # include <bits/getopt_posix.h>
 #endif
 
+/* Slow-path routines used by the optimized inline functions in
+   bits/stdio.h.  */
+extern int __uflow (FILE *);
+extern int __overflow (FILE *, int);
+
 /* If we are compiling with optimizing read this file.  It contains
    several optimizing inline functions and macros.  */
 #ifdef __USE_EXTERN_INLINES
diff --git a/stdio-common/tstgetln.c b/stdio-common/tstgetln.c
index a18f754e354..6960e686200 100644
--- a/stdio-common/tstgetln.c
+++ b/stdio-common/tstgetln.c
@@ -16,8 +16,6 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stdio.h>
-#undef ssize_t
-#define ssize_t _IO_ssize_t
 
 int
 main (int argc, char *argv[])
diff --git a/stdio-common/vfprintf.c b/stdio-common/vfprintf.c
index 3b87740dd99..a2cab306855 100644
--- a/stdio-common/vfprintf.c
+++ b/stdio-common/vfprintf.c
@@ -39,13 +39,8 @@
    Beside this it is also shared between the normal and wide character
    implementation as defined in ISO/IEC 9899:1990/Amendment 1:1995.  */
 
-
 #include <libioP.h>
-#define FILE		_IO_FILE
-#undef va_list
-#define va_list	_IO_va_list
-#undef BUFSIZ
-#define BUFSIZ		_IO_BUFSIZ
+
 /* In some cases we need extra space for all the output which is not
    counted in the width of the string. We assume 32 characters is
    enough.  */
diff --git a/sysdeps/unix/sysv/linux/bits/_G_config.h b/sysdeps/unix/sysv/linux/bits/_G_config.h
index 9994869098b..338150291f7 100644
--- a/sysdeps/unix/sysv/linux/bits/_G_config.h
+++ b/sysdeps/unix/sysv/linux/bits/_G_config.h
@@ -19,20 +19,16 @@
 #include <stddef.h>
 
 #include <bits/types/__mbstate_t.h>
+#include <bits/types/__fpos_t.h>
+#include <bits/types/__fpos64_t.h>
+
+#define _G_fpos_t __fpos_t
+#define _G_fpos64_t __fpos64_t
+
 #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
