Don't install libio.h or _G_config.h.

We shipped 2.27 with libio.h and _G_config.h still installed but
issuing warnings when used.  Let's stop installing them early in 2.28
so that we have plenty of time to think of another plan if there are
problems.

The public stdio.h had a genuine dependency on libio.h for the
complete definitions of FILE and cookie_io_functions_t, and a genuine
dependency on _G_config.h for the complete definitions of fpos_t and
fpos64_t; these are moved to single-type headers.
bits/types/struct_FILE.h also provides a handful of accessor and
bitflags macros so that code is not duplicated between bits/stdio.h
and libio.h.  All the other _IO_ and _G_ names used by the public
stdio.h can be replaced with either public names or __-names.

In order to minimize the risk of breaking our own compatibility code,
bits/types/struct_FILE.h preserves the _IO_USE_OLD_IO_FILE mechanism
exactly as it was in libio.h, but you have to define _LIBC to use it,
or it'll error out.  Similarly, _IO_lock_t_defined is preserved
exactly, but will error out if used without defining _LIBC.

Internally, include/stdio.h continues to include libio.h, and libio.h
scrupulously provides every _IO_* and _G_* name that it always did,
perhaps now defined in terms of the public names.  This is how this
patch avoids touching dozens of files throughout glibc and becoming
entangled with the _IO_MTSAFE_IO mess.  The remaining patches in this
series eliminate most of the _G_ names.

Tested on x86_64-linux; in addition to the test suite, I installed the
library in a sysroot and verified that a simple program that uses
stdio.h could be compiled against the installed library, and I also
verified that installed stripped libraries are unchanged.

	* libio/bits/types/__fpos_t.h, libio/bits/types/__fpos64_t.h:
	New single-type headers split from _G_config.h.
	* libio/bits/types/cookie_io_functions_t.h
	* libio/bits/types/struct_FILE.h
	New single-type headers split from libio.h.

	* libio/Makefile: Install the above new headers.  Don't install
	libio.h, _G_config.h, bits/libio.h, bits/_G_config.h, or
	bits/libio-ldbl.h.
	* libio/_G_config.h, libio/libio.h: Delete file.

	* libio/bits/libio.h: Remove improper-inclusion guard.
	Include stdio.h and don't repeat anything that it does.
	Define _IO_fpos_t as __fpos_t, _IO_fpos64_t as __fpos64_t,
	_IO_BUFSIZ as BUFSIZ, _IO_va_list as __gnuc_va_list,
	__io_read_fn as cookie_read_function_t,
	__io_write_fn as cookie_write_function_t,
	__io_seek_fn as cookie_seek_function_t,
	__io_close_fn as cookie_close_function_t,
	and _IO_cookie_io_functions_t as cookie_io_functions_t.
	Define _STDIO_USES_IOSTREAM, __HAVE_COLUMN, and _IO_file_flags
	here, in the "compatibility defines" section.  Remove an #if 0
	block.  Use the "body" macros from bits/types/struct_FILE.h to
	define _IO_getc_unlocked, _IO_putc_unlocked, _IO_feof_unlocked,
	and _IO_ferror_unlocked.
	Move prototypes of __uflow and __overflow...

	* libio/stdio.h: ...here.  Don't include bits/libio.h.
	Don't define _STDIO_USES_IOSTREAM.  Get __gnuc_va_list
	directly from stdarg.h.  Include bits/types/__fpos_t.h,
	bits/types/__fpos64_t.h, bits/types/struct_FILE.h,
	and, when __USE_GNU, bits/types/cookie_io_functions_t.h.
	Use __gnuc_va_list, not _G_va_list; __fpos_t, not _G_fpos_t;
	__fpos64_t, not _G_fpos64_t; FILE, not struct _IO_FILE;
	cookie_io_functions_t, not _IO_cookie_io_functions_t;
	__ssize_t, not _IO_ssize_t.  Unconditionally define
	BUFSIZ as 8192 and EOF as (-1).

	* libio/bits/stdio.h: Add multiple-include guard.  Use the "body"
	macros from bits/types/struct_FILE.h instead of _IO_* macros
	from libio.h; use __gnuc_va_list instead of va_list and __ssize_t
	instead of _IO_ssize_t.
	* libio/bits/stdio2.h: Similarly.

	* libio/iolibio.h: Add multiple-include guard.
	Include bits/libio.h after stdio.h.
	* libio/libioP.h: Add multiple-include guard.
	Include stdio.h and bits/libio.h before iolibio.h.

        * include/bits/types/__fpos_t.h, include/bits/types/__fpos64_t.h
	* include/bits/types/cookie_io_functions_t.h
	* include/bits/types/struct_FILE.h: New wrappers.

	* bits/_G_config.h, sysdeps/unix/sysv/linux/_G_config.h:
        Get definitions of _G_fpos_t and _G_fpos64_t from
        bits/types/__fpos_t.h and bits/types/__fpos64_t.h
        respectively.  Remove improper-inclusion guards.

        * conform/data/stdio.h-data: Update expectations of va_list.
	* scripts/check-installed-headers.sh: Remove special case for
        libio.h and _G_config.h.

1 files changed, 65 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 66fda89745..d80e9c366e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,68 @@
+2018-02-07  Zack Weinberg  <zackw@panix.com>
+
+	* libio/bits/types/__fpos_t.h, libio/bits/types/__fpos64_t.h:
+	New single-type headers split from _G_config.h.
+	* libio/bits/types/cookie_io_functions_t.h
+	* libio/bits/types/struct_FILE.h
+	New single-type headers split from libio.h.
+
+	* libio/Makefile: Install the above new headers.  Don't install
+	libio.h, _G_config.h, bits/libio.h, bits/_G_config.h, or
+	bits/libio-ldbl.h.
+	* libio/_G_config.h, libio/libio.h: Delete file.
+
+	* libio/bits/libio.h: Remove improper-inclusion guard.
+	Include stdio.h and don't repeat anything that it does.
+	Define _IO_fpos_t as __fpos_t, _IO_fpos64_t as __fpos64_t,
+	_IO_BUFSIZ as BUFSIZ, _IO_va_list as __gnuc_va_list,
+	__io_read_fn as cookie_read_function_t,
+	__io_write_fn as cookie_write_function_t,
+	__io_seek_fn as cookie_seek_function_t,
+	__io_close_fn as cookie_close_function_t,
+	and _IO_cookie_io_functions_t as cookie_io_functions_t.
+	Define _STDIO_USES_IOSTREAM, __HAVE_COLUMN, and _IO_file_flags
+	here, in the "compatibility defines" section.  Remove an #if 0
+	block.  Use the "body" macros from bits/types/struct_FILE.h to
+	define _IO_getc_unlocked, _IO_putc_unlocked, _IO_feof_unlocked,
+	and _IO_ferror_unlocked.
+	Move prototypes of __uflow and __overflow...
+
+	* libio/stdio.h: ...here.  Don't include bits/libio.h.
+	Don't define _STDIO_USES_IOSTREAM.  Get __gnuc_va_list
+	directly from stdarg.h.  Include bits/types/__fpos_t.h,
+	bits/types/__fpos64_t.h, bits/types/struct_FILE.h,
+	and, when __USE_GNU, bits/types/cookie_io_functions_t.h.
+	Use __gnuc_va_list, not _G_va_list; __fpos_t, not _G_fpos_t;
+	__fpos64_t, not _G_fpos64_t; FILE, not struct _IO_FILE;
+	cookie_io_functions_t, not _IO_cookie_io_functions_t;
+	__ssize_t, not _IO_ssize_t.  Unconditionally define
+	BUFSIZ as 8192 and EOF as (-1).
+
+	* libio/bits/stdio.h: Add multiple-include guard.  Use the "body"
+	macros from bits/types/struct_FILE.h instead of _IO_* macros
+	from libio.h; use __gnuc_va_list instead of va_list and __ssize_t
+	instead of _IO_ssize_t.
+	* libio/bits/stdio2.h: Similarly.
+
+	* libio/iolibio.h: Add multiple-include guard.
+	Include bits/libio.h after stdio.h.
+	* libio/libioP.h: Add multiple-include guard.
+	Include stdio.h and bits/libio.h before iolibio.h.
+
+        * include/bits/types/__fpos_t.h, include/bits/types/__fpos64_t.h
+	* include/bits/types/cookie_io_functions_t.h
+	* include/bits/types/struct_FILE.h: New wrappers.
+
+	* bits/_G_config.h, sysdeps/unix/sysv/linux/_G_config.h:
+        Get definitions of _G_fpos_t and _G_fpos64_t from
+        bits/types/__fpos_t.h and bits/types/__fpos64_t.h
+        respectively.  Remove improper-inclusion guards.
+
+        * conform/data/stdio.h-data: Update expectations of va_list.
+	* scripts/check-installed-headers.sh: Remove special case for
+        libio.h and _G_config.h.
+
+
 2018-02-07  Joseph Myers  <joseph@codesourcery.com>
 
 	[BZ #15105]