Post-cleanup 1: move libio.h back out of bits/.

We can't go very far with libio cleanups as long as we still have
_IO_MTSAFE_IO, and I am not tackling that in this patch series,
but we can at least make the maze of stdio-related headers a
little less complicated.

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.

        * 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>.

2 files changed, 1 insertions, 46 deletions

diff --git a/include/bits/libio.h b/include/bits/libio.h
deleted file mode 100644
index 572395d5ff..0000000000
--- 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 3b6da17d82..f12b281b4d 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.  */