Patchwork [v2,4/5] Post-cleanup 1: move libio.h back out of bits/.

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Submitter Zack Weinberg
Date Feb. 5, 2018, 11:34 p.m.
Message ID <66d4abc669e9eaa46e128656e686aa0b5eb6aa6c.1517872307.git.zackw@panix.com>
Download mbox | patch
Permalink /patch/25830/
State New
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Comments

Zack Weinberg - Feb. 5, 2018, 11:34 p.m.
In this patch, libio.h moves back out of bits/ into the top level of
the libio subdirectory, and is merged with libio/bits/libio-ldbl.h
(which also used to be installed) and include/libio.h.  Since almost
no files include libio.h directly, this is quite straightforward.

libio.h is now always used with _LIBC defined, so all of the _LIBC ||
_GLIBCPP_USE_WCHAR_T conditionals are unnecessary.  Similarly, the
ifdef nest surrounding the definition of _IO_fwide_maybe_incompatible
can collapse down to a single SHLIB_COMPAT check.  I also took the
opportunity to add some checks for configuration botches to libio.h.

Installed stripped libraries are unchanged by this patch.

The distinction between libio.h and libioP.h should be preserved as
long as include/stdio.h needs to include libio.h, and that's entangled
with _IO_MTSAFE_IO.  It might be feasible to merge iolibio.h into
libioP.h at this point, but I'm not sure whether it's worth the trouble.

        * libio/bits/libio.h: Move back to libio/libio.h and adjust
        multiple-include guard to match.
        Merge contents of libio/bits/libio-ldbl.h and include/libio.h
        into this file.
        Remove preprocessor conditionals that are always true and/or
        redundant to other preprocessor conditionals in the same nest.
        Include shlib-compat.h unconditionally.
        Error out if _LIBC is not defined, or if _ISOMAC is defined,
        or if _IO_MTSAFE_IO is defined but _IO_lock_t_defined is not
        defined after including stdio.h.
        Use __BEGIN_DECLS/__END_DECLS.

        * libio/bits/libio-ldbl.h, include/bits/libio.h: Delete file.
        * include/stdio.h, libio/iolibio.h, libio/libioP.h: Include
        libio.h as <libio/libio.h> rather than as <bits/libio.h>.
---
 include/bits/libio.h     | 45 -----------------------
 include/stdio.h          |  2 +-
 libio/bits/libio-ldbl.h  | 29 ---------------
 libio/iolibio.h          |  2 +-
 libio/{bits => }/libio.h | 96 ++++++++++++++++++++++++++++++++----------------
 libio/libioP.h           |  2 +-
 6 files changed, 67 insertions(+), 109 deletions(-)
 delete mode 100644 include/bits/libio.h
 delete mode 100644 libio/bits/libio-ldbl.h
 rename libio/{bits => }/libio.h (87%)
Adhemerval Zanella Netto - Feb. 6, 2018, 4:57 p.m.
On 05/02/2018 21:34, Zack Weinberg wrote:
> In this patch, libio.h moves back out of bits/ into the top level of
> the libio subdirectory, and is merged with libio/bits/libio-ldbl.h
> (which also used to be installed) and include/libio.h.  Since almost
> no files include libio.h directly, this is quite straightforward.
> 
> libio.h is now always used with _LIBC defined, so all of the _LIBC ||
> _GLIBCPP_USE_WCHAR_T conditionals are unnecessary.  Similarly, the
> ifdef nest surrounding the definition of _IO_fwide_maybe_incompatible
> can collapse down to a single SHLIB_COMPAT check.  I also took the
> opportunity to add some checks for configuration botches to libio.h.
> 
> Installed stripped libraries are unchanged by this patch.
> 
> The distinction between libio.h and libioP.h should be preserved as
> long as include/stdio.h needs to include libio.h, and that's entangled
> with _IO_MTSAFE_IO.  It might be feasible to merge iolibio.h into
> libioP.h at this point, but I'm not sure whether it's worth the trouble.

LGTM with a possible extra cleanups decribed below.

> 
>         * libio/bits/libio.h: Move back to libio/libio.h and adjust
>         multiple-include guard to match.
>         Merge contents of libio/bits/libio-ldbl.h and include/libio.h
>         into this file.
>         Remove preprocessor conditionals that are always true and/or
>         redundant to other preprocessor conditionals in the same nest.
>         Include shlib-compat.h unconditionally.
>         Error out if _LIBC is not defined, or if _ISOMAC is defined,
>         or if _IO_MTSAFE_IO is defined but _IO_lock_t_defined is not
>         defined after including stdio.h.
>         Use __BEGIN_DECLS/__END_DECLS.
> 
>         * libio/bits/libio-ldbl.h, include/bits/libio.h: Delete file.
>         * include/stdio.h, libio/iolibio.h, libio/libioP.h: Include
>         libio.h as <libio/libio.h> rather than as <bits/libio.h>.
> ---
>  include/bits/libio.h     | 45 -----------------------
>  include/stdio.h          |  2 +-
>  libio/bits/libio-ldbl.h  | 29 ---------------
>  libio/iolibio.h          |  2 +-
>  libio/{bits => }/libio.h | 96 ++++++++++++++++++++++++++++++++----------------
>  libio/libioP.h           |  2 +-
>  6 files changed, 67 insertions(+), 109 deletions(-)
>  delete mode 100644 include/bits/libio.h
>  delete mode 100644 libio/bits/libio-ldbl.h
>  rename libio/{bits => }/libio.h (87%)
> 
> diff --git a/include/bits/libio.h b/include/bits/libio.h
> deleted file mode 100644
> index 572395d5ffb..00000000000
> --- a/include/bits/libio.h
> +++ /dev/null
> @@ -1,45 +0,0 @@
> -#if !defined _ISOMAC && defined _IO_MTSAFE_IO
> -# include <stdio-lock.h>
> -#endif
> -#include <libio/bits/libio.h>
> -
> -#ifndef _ISOMAC
> -#ifndef _LIBC_LIBIO_H
> -#define _LIBC_LIBIO_H
> -
> -libc_hidden_proto (__overflow)
> -libc_hidden_proto (__underflow)
> -libc_hidden_proto (__uflow)
> -libc_hidden_proto (__woverflow)
> -libc_hidden_proto (__wunderflow)
> -libc_hidden_proto (__wuflow)
> -libc_hidden_proto (_IO_free_backup_area)
> -libc_hidden_proto (_IO_free_wbackup_area)
> -libc_hidden_proto (_IO_padn)
> -libc_hidden_proto (_IO_putc)
> -libc_hidden_proto (_IO_sgetn)
> -libc_hidden_proto (_IO_vfprintf)
> -libc_hidden_proto (_IO_vfscanf)
> -
> -#ifdef _IO_MTSAFE_IO
> -# undef _IO_peekc
> -# undef _IO_flockfile
> -# undef _IO_funlockfile
> -# undef _IO_ftrylockfile
> -
> -# define _IO_peekc(_fp) _IO_peekc_locked (_fp)
> -# if _IO_lock_inexpensive
> -#  define _IO_flockfile(_fp) \
> -  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_lock_lock (*(_fp)->_lock)
> -#  define _IO_funlockfile(_fp) \
> -  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_lock_unlock (*(_fp)->_lock)
> -# else
> -#  define _IO_flockfile(_fp) \
> -  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_flockfile (_fp)
> -#  define _IO_funlockfile(_fp) \
> -  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_funlockfile (_fp)
> -# endif
> -#endif /* _IO_MTSAFE_IO */
> -
> -#endif
> -#endif

Ok.

> diff --git a/include/stdio.h b/include/stdio.h
> index 3b6da17d82f..f12b281b4d6 100644
> --- a/include/stdio.h
> +++ b/include/stdio.h
> @@ -5,7 +5,7 @@
>  # include <libio/stdio.h>
>  # ifndef _ISOMAC
>  #  define _LIBC_STDIO_H 1
> -#  include <bits/libio.h>
> +#  include <libio/libio.h>
>  
>  /* Now define the internal interfaces.  */
>  

Ok.

> diff --git a/libio/bits/libio-ldbl.h b/libio/bits/libio-ldbl.h
> deleted file mode 100644
> index aa39353ca50..00000000000
> --- a/libio/bits/libio-ldbl.h
> +++ /dev/null
> @@ -1,29 +0,0 @@
> -/* -mlong-double-64 compatibility mode for libio functions.
> -   Copyright (C) 2006-2018 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 _BITS_LIBIO_LDBL_H
> -#define _BITS_LIBIO_LDBL_H 1
> -
> -#ifndef _BITS_LIBIO_H
> -# error "Never include <bits/libio-ldbl.h> directly; use <libio.h> instead."
> -#endif
> -
> -__LDBL_REDIR_DECL (_IO_vfscanf)
> -__LDBL_REDIR_DECL (_IO_vfprintf)
> -
> -#endif

Ok.

> diff --git a/libio/iolibio.h b/libio/iolibio.h
> index 7814b1d4e56..52731b65f91 100644
> --- a/libio/iolibio.h
> +++ b/libio/iolibio.h
> @@ -2,7 +2,7 @@
>  #define _IOLIBIO_H 1
>  
>  #include <stdio.h>
> -#include <bits/libio.h>
> +#include <libio/libio.h>
>  
>  /* These emulate stdio functionality, but with a different name
>     (_IO_ungetc instead of ungetc), and using _IO_FILE instead of FILE. */

Ok.

> diff --git a/libio/bits/libio.h b/libio/libio.h
> similarity index 87%
> rename from libio/bits/libio.h
> rename to libio/libio.h
> index cefc2c855b9..ff67e18c182 100644
> --- a/libio/bits/libio.h
> +++ b/libio/libio.h
> @@ -25,11 +25,22 @@
>     This exception applies to code released by its copyright holders
>     in files containing the exception.  */
>  
> -#ifndef _BITS_LIBIO_H
> -#define _BITS_LIBIO_H 1
> +#ifndef _LIBIO_H
> +#define _LIBIO_H 1
> +
> +#ifndef _LIBC
> +# error "libio.h should only be included when building glibc itself"
> +#endif
> +#ifdef _ISOMAC
> +# error "libio.h should not be included under _ISOMAC"
> +#endif

Ok.

>  
>  #include <stdio.h>
>  
> +#if defined _IO_MTSAFE_IO && !defined _IO_lock_t_defined
> +# error "Someone forgot to include stdio-lock.h"
> +#endif
> +
>  #include <bits/_G_config.h>
>  /* ALL of these should be defined in _G_config.h */
>  #define _IO_fpos_t __fpos_t
> @@ -46,6 +57,10 @@
>  #define _IO_wint_t wint_t
>  #define _IO_va_list __gnuc_va_list
>  
> +#include <shlib-compat.h>
> +
> +__BEGIN_DECLS
> +
>  /* compatibility defines */
>  #define _STDIO_USES_IOSTREAM
>  #define _IO_UNIFIED_JUMPTABLES 1
> @@ -143,7 +158,6 @@ 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
> @@ -198,7 +212,6 @@ struct _IO_wide_data
>  
>    const struct _IO_jump_t *_wide_vtable;
>  };
> -#endif
>  
>  
>  #ifndef __cplusplus
> @@ -236,17 +249,10 @@ 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

I think you can cleanup the __cplusplus guards for _IO_FILE as well.

> -
>  extern int __underflow (_IO_FILE *);
> -#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)
> @@ -261,7 +267,6 @@ extern _IO_wint_t __woverflow (_IO_FILE *, _IO_wint_t);
>  	: *(unsigned char *) (_fp)->_IO_read_ptr)
>  #define _IO_putc_unlocked(_ch, _fp) __putc_unlocked_body (_ch, _fp)
>  
> -#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				\
> @@ -273,7 +278,6 @@ 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) __feof_unlocked_body (_fp)
>  #define _IO_ferror_unlocked(_fp) __ferror_unlocked_body (_fp)
> @@ -319,28 +323,25 @@ 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 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
> +#else
> +# 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)		      \
>         {								      \
> @@ -354,7 +355,6 @@ 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);
> @@ -362,14 +362,46 @@ 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>
> +__LDBL_REDIR_DECL (_IO_vfscanf)
> +__LDBL_REDIR_DECL (_IO_vfprintf)
>  #endif
>  
> -#ifdef __cplusplus
> -}
> -#endif
> +libc_hidden_proto (__overflow)
> +libc_hidden_proto (__underflow)
> +libc_hidden_proto (__uflow)
> +libc_hidden_proto (__woverflow)
> +libc_hidden_proto (__wunderflow)
> +libc_hidden_proto (__wuflow)
> +libc_hidden_proto (_IO_free_backup_area)
> +libc_hidden_proto (_IO_free_wbackup_area)
> +libc_hidden_proto (_IO_padn)
> +libc_hidden_proto (_IO_putc)
> +libc_hidden_proto (_IO_sgetn)
> +libc_hidden_proto (_IO_vfprintf)
> +libc_hidden_proto (_IO_vfscanf)
> +
> +#ifdef _IO_MTSAFE_IO
> +# undef _IO_peekc
> +# undef _IO_flockfile
> +# undef _IO_funlockfile
> +# undef _IO_ftrylockfile
> +
> +# define _IO_peekc(_fp) _IO_peekc_locked (_fp)
> +# if _IO_lock_inexpensive
> +#  define _IO_flockfile(_fp) \
> +  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_lock_lock (*(_fp)->_lock)
> +#  define _IO_funlockfile(_fp) \
> +  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_lock_unlock (*(_fp)->_lock)
> +# else
> +#  define _IO_flockfile(_fp) \
> +  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_flockfile (_fp)
> +#  define _IO_funlockfile(_fp) \
> +  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_funlockfile (_fp)
> +# endif
> +#endif /* _IO_MTSAFE_IO */
> +
> +__END_DECLS
>  
> -#endif /* _BITS_LIBIO_H */
> +#endif /* _LIBIO_H */

As a side note, I think we can cleanup some definitions required to build it
externally:

271 #if  __GNUC__ >= 3
272 # define _IO_BE(expr, res) __builtin_expect ((expr), res)
273 #else
274 # define _IO_BE(expr, res) (expr)
275 #endif

And just use __glibc_{un}likely instead.

Similar for:

122 #ifdef _LIBC
123 # define _IO_FLAGS2_FORTIFY 4
124 #endif
125 #define _IO_FLAGS2_USER_WBUF 8
126 #ifdef _LIBC
127 # define _IO_FLAGS2_SCANF_STD 16
128 # define _IO_FLAGS2_NOCLOSE 32
129 # define _IO_FLAGS2_CLOEXEC 64
130 # define _IO_FLAGS2_NEED_LOCK 128
131 #endif

and

240 #ifndef _LIBC
241 #define _IO_stdin ((_IO_FILE*)(&_IO_2_1_stdin_))
242 #define _IO_stdout ((_IO_FILE*)(&_IO_2_1_stdout_))
243 #define _IO_stderr ((_IO_FILE*)(&_IO_2_1_stderr_))
244 #else
245 extern _IO_FILE *_IO_stdin attribute_hidden;
246 extern _IO_FILE *_IO_stdout attribute_hidden;
247 extern _IO_FILE *_IO_stderr attribute_hidden;
248 #endif

Since there is already a guard for _LIBC definition.

Also:

252 #ifdef __USE_GNU
253 typedef cookie_read_function_t __io_read_fn;
254 typedef cookie_write_function_t __io_write_fn;
255 typedef cookie_seek_function_t __io_seek_fn;
256 typedef cookie_close_function_t __io_close_fn;
257 typedef cookie_io_functions_t _IO_cookie_io_functions_t;
258 
259 struct _IO_cookie_file;
260 
261 /* Initialize one of those.  */
262 extern void _IO_cookie_init (struct _IO_cookie_file *__cfile, int __read_write,
263                              void *__cookie, _IO_cookie_io_functions_t __fns);
264 #endif

Since for glibc build __USE_GNU is implicit.

> diff --git a/libio/libioP.h b/libio/libioP.h
> index ac66f95f8d4..8edc207277e 100644
> --- a/libio/libioP.h
> +++ b/libio/libioP.h
> @@ -43,7 +43,7 @@
>  #include <math_ldbl_opt.h>
>  
>  #include <stdio.h>
> -#include <bits/libio.h>
> +#include <libio/libio.h>
>  #include "iolibio.h"
>  
>  #ifdef __cplusplus
> 

Ok.
Zack Weinberg - Feb. 6, 2018, 8:10 p.m.
On Tue, Feb 6, 2018 at 11:57 AM, Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
> On 05/02/2018 21:34, Zack Weinberg wrote:
>> In this patch, libio.h moves back out of bits/ into the top level of
>> the libio subdirectory, and is merged with libio/bits/libio-ldbl.h
>> (which also used to be installed) and include/libio.h.  Since almost
>> no files include libio.h directly, this is quite straightforward.
>
> LGTM with a possible extra cleanups decribed below.
...
> I think you can cleanup the __cplusplus guards for _IO_FILE as well.
...
> As a side note, I think we can cleanup some definitions required to build it
> externally:

Certainly, but again, I don't want to add yet more stuff to this
patchset and I can't promise to do follow-up work in the near future.

zw
Adhemerval Zanella Netto - Feb. 7, 2018, 12:12 p.m.
On 06/02/2018 18:10, Zack Weinberg wrote:
> On Tue, Feb 6, 2018 at 11:57 AM, Adhemerval Zanella
> <adhemerval.zanella@linaro.org> wrote:
>> On 05/02/2018 21:34, Zack Weinberg wrote:
>>> In this patch, libio.h moves back out of bits/ into the top level of
>>> the libio subdirectory, and is merged with libio/bits/libio-ldbl.h
>>> (which also used to be installed) and include/libio.h.  Since almost
>>> no files include libio.h directly, this is quite straightforward.
>>
>> LGTM with a possible extra cleanups decribed below.
> ...
>> I think you can cleanup the __cplusplus guards for _IO_FILE as well.
> ...
>> As a side note, I think we can cleanup some definitions required to build it
>> externally:
> 
> Certainly, but again, I don't want to add yet more stuff to this
> patchset and I can't promise to do follow-up work in the near future.
> 
> zw
> 

Alright, I don't think these are blockers for the patch itself, but since
you are touching it (and there is a long time since someone work on this
code) I though you could check this out.
Zack Weinberg - Feb. 7, 2018, 3:17 p.m.
On Wed, Feb 7, 2018 at 7:12 AM, Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
> On 06/02/2018 18:10, Zack Weinberg wrote:
>> On Tue, Feb 6, 2018 at 11:57 AM, Adhemerval Zanella
>> <adhemerval.zanella@linaro.org> wrote:
>>> On 05/02/2018 21:34, Zack Weinberg wrote:
>>>> In this patch, libio.h moves back out of bits/ into the top level of
>>>> the libio subdirectory, and is merged with libio/bits/libio-ldbl.h
>>>> (which also used to be installed) and include/libio.h.  Since almost
>>>> no files include libio.h directly, this is quite straightforward.
>>>
>>> LGTM with a possible extra cleanups decribed below.
>> ...
>>> I think you can cleanup the __cplusplus guards for _IO_FILE as well.
>> ...
>>> As a side note, I think we can cleanup some definitions required to build it
>>> externally:
>>
>> Certainly, but again, I don't want to add yet more stuff to this
>> patchset and I can't promise to do follow-up work in the near future.
>
> Alright, I don't think these are blockers for the patch itself, but since
> you are touching it (and there is a long time since someone work on this
> code) I though you could check this out.

Yeah, I understand where you are coming from, it's just that I've
already spent more time on libc this week than I can really afford.
But I may have to wait for computers a lot today and tomorrow, so who
knows.

zw

Patch

diff --git a/include/bits/libio.h b/include/bits/libio.h
deleted file mode 100644
index 572395d5ffb..00000000000
--- a/include/bits/libio.h
+++ /dev/null
@@ -1,45 +0,0 @@ 
-#if !defined _ISOMAC && defined _IO_MTSAFE_IO
-# include <stdio-lock.h>
-#endif
-#include <libio/bits/libio.h>
-
-#ifndef _ISOMAC
-#ifndef _LIBC_LIBIO_H
-#define _LIBC_LIBIO_H
-
-libc_hidden_proto (__overflow)
-libc_hidden_proto (__underflow)
-libc_hidden_proto (__uflow)
-libc_hidden_proto (__woverflow)
-libc_hidden_proto (__wunderflow)
-libc_hidden_proto (__wuflow)
-libc_hidden_proto (_IO_free_backup_area)
-libc_hidden_proto (_IO_free_wbackup_area)
-libc_hidden_proto (_IO_padn)
-libc_hidden_proto (_IO_putc)
-libc_hidden_proto (_IO_sgetn)
-libc_hidden_proto (_IO_vfprintf)
-libc_hidden_proto (_IO_vfscanf)
-
-#ifdef _IO_MTSAFE_IO
-# undef _IO_peekc
-# undef _IO_flockfile
-# undef _IO_funlockfile
-# undef _IO_ftrylockfile
-
-# define _IO_peekc(_fp) _IO_peekc_locked (_fp)
-# if _IO_lock_inexpensive
-#  define _IO_flockfile(_fp) \
-  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_lock_lock (*(_fp)->_lock)
-#  define _IO_funlockfile(_fp) \
-  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_lock_unlock (*(_fp)->_lock)
-# else
-#  define _IO_flockfile(_fp) \
-  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_flockfile (_fp)
-#  define _IO_funlockfile(_fp) \
-  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_funlockfile (_fp)
-# endif
-#endif /* _IO_MTSAFE_IO */
-
-#endif
-#endif
diff --git a/include/stdio.h b/include/stdio.h
index 3b6da17d82f..f12b281b4d6 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -5,7 +5,7 @@ 
 # include <libio/stdio.h>
 # ifndef _ISOMAC
 #  define _LIBC_STDIO_H 1
-#  include <bits/libio.h>
+#  include <libio/libio.h>
 
 /* Now define the internal interfaces.  */
 
diff --git a/libio/bits/libio-ldbl.h b/libio/bits/libio-ldbl.h
deleted file mode 100644
index aa39353ca50..00000000000
--- a/libio/bits/libio-ldbl.h
+++ /dev/null
@@ -1,29 +0,0 @@ 
-/* -mlong-double-64 compatibility mode for libio functions.
-   Copyright (C) 2006-2018 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 _BITS_LIBIO_LDBL_H
-#define _BITS_LIBIO_LDBL_H 1
-
-#ifndef _BITS_LIBIO_H
-# error "Never include <bits/libio-ldbl.h> directly; use <libio.h> instead."
-#endif
-
-__LDBL_REDIR_DECL (_IO_vfscanf)
-__LDBL_REDIR_DECL (_IO_vfprintf)
-
-#endif
diff --git a/libio/iolibio.h b/libio/iolibio.h
index 7814b1d4e56..52731b65f91 100644
--- a/libio/iolibio.h
+++ b/libio/iolibio.h
@@ -2,7 +2,7 @@ 
 #define _IOLIBIO_H 1
 
 #include <stdio.h>
-#include <bits/libio.h>
+#include <libio/libio.h>
 
 /* These emulate stdio functionality, but with a different name
    (_IO_ungetc instead of ungetc), and using _IO_FILE instead of FILE. */
diff --git a/libio/bits/libio.h b/libio/libio.h
similarity index 87%
rename from libio/bits/libio.h
rename to libio/libio.h
index cefc2c855b9..ff67e18c182 100644
--- a/libio/bits/libio.h
+++ b/libio/libio.h
@@ -25,11 +25,22 @@ 
    This exception applies to code released by its copyright holders
    in files containing the exception.  */
 
-#ifndef _BITS_LIBIO_H
-#define _BITS_LIBIO_H 1
+#ifndef _LIBIO_H
+#define _LIBIO_H 1
+
+#ifndef _LIBC
+# error "libio.h should only be included when building glibc itself"
+#endif
+#ifdef _ISOMAC
+# error "libio.h should not be included under _ISOMAC"
+#endif
 
 #include <stdio.h>
 
+#if defined _IO_MTSAFE_IO && !defined _IO_lock_t_defined
+# error "Someone forgot to include stdio-lock.h"
+#endif
+
 #include <bits/_G_config.h>
 /* ALL of these should be defined in _G_config.h */
 #define _IO_fpos_t __fpos_t
@@ -46,6 +57,10 @@ 
 #define _IO_wint_t wint_t
 #define _IO_va_list __gnuc_va_list
 
+#include <shlib-compat.h>
+
+__BEGIN_DECLS
+
 /* compatibility defines */
 #define _STDIO_USES_IOSTREAM
 #define _IO_UNIFIED_JUMPTABLES 1
@@ -143,7 +158,6 @@  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
@@ -198,7 +212,6 @@  struct _IO_wide_data
 
   const struct _IO_jump_t *_wide_vtable;
 };
-#endif
 
 
 #ifndef __cplusplus
@@ -236,17 +249,10 @@  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 *);
-#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)
@@ -261,7 +267,6 @@  extern _IO_wint_t __woverflow (_IO_FILE *, _IO_wint_t);
 	: *(unsigned char *) (_fp)->_IO_read_ptr)
 #define _IO_putc_unlocked(_ch, _fp) __putc_unlocked_body (_ch, _fp)
 
-#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				\
@@ -273,7 +278,6 @@  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) __feof_unlocked_body (_fp)
 #define _IO_ferror_unlocked(_fp) __ferror_unlocked_body (_fp)
@@ -319,28 +323,25 @@  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 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
+#else
+# 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)		      \
        {								      \
@@ -354,7 +355,6 @@  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);
@@ -362,14 +362,46 @@  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>
+__LDBL_REDIR_DECL (_IO_vfscanf)
+__LDBL_REDIR_DECL (_IO_vfprintf)
 #endif
 
-#ifdef __cplusplus
-}
-#endif
+libc_hidden_proto (__overflow)
+libc_hidden_proto (__underflow)
+libc_hidden_proto (__uflow)
+libc_hidden_proto (__woverflow)
+libc_hidden_proto (__wunderflow)
+libc_hidden_proto (__wuflow)
+libc_hidden_proto (_IO_free_backup_area)
+libc_hidden_proto (_IO_free_wbackup_area)
+libc_hidden_proto (_IO_padn)
+libc_hidden_proto (_IO_putc)
+libc_hidden_proto (_IO_sgetn)
+libc_hidden_proto (_IO_vfprintf)
+libc_hidden_proto (_IO_vfscanf)
+
+#ifdef _IO_MTSAFE_IO
+# undef _IO_peekc
+# undef _IO_flockfile
+# undef _IO_funlockfile
+# undef _IO_ftrylockfile
+
+# define _IO_peekc(_fp) _IO_peekc_locked (_fp)
+# if _IO_lock_inexpensive
+#  define _IO_flockfile(_fp) \
+  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_lock_lock (*(_fp)->_lock)
+#  define _IO_funlockfile(_fp) \
+  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_lock_unlock (*(_fp)->_lock)
+# else
+#  define _IO_flockfile(_fp) \
+  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_flockfile (_fp)
+#  define _IO_funlockfile(_fp) \
+  if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_funlockfile (_fp)
+# endif
+#endif /* _IO_MTSAFE_IO */
+
+__END_DECLS
 
-#endif /* _BITS_LIBIO_H */
+#endif /* _LIBIO_H */
diff --git a/libio/libioP.h b/libio/libioP.h
index ac66f95f8d4..8edc207277e 100644
--- a/libio/libioP.h
+++ b/libio/libioP.h
@@ -43,7 +43,7 @@ 
 #include <math_ldbl_opt.h>
 
 #include <stdio.h>
-#include <bits/libio.h>
+#include <libio/libio.h>
 #include "iolibio.h"
 
 #ifdef __cplusplus