unicode: Add utf8-data module

utf8data.h contains a large database table which is an auto-generated
decodification trie for the unicode normalization functions.

Allow building it into a separate module.

Based on a patch from Shreeya Patel <shreeya.patel@collabora.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

unicode: cache the normalization tables in struct unicode_map

Instead of repeatedly looking up the version add pointers to the
NFD and NFD+CF tables to struct unicode_map, and pass a
unicode_map plus index to the functions using the normalization
tables.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

unicode: move utf8cursor to utf8-selftest.c

Only used by the tests, so no need to keep it in the core.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

unicode: simplify utf8len

Just use the utf8nlen implementation with a (size_t)-1 len argument,
similar to utf8_lookup. Also move the function to utf8-selftest.c, as
it isn't used anywhere else.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

unicode: pass a UNICODE_AGE() tripple to utf8_load

Don't bother with pointless string parsing when the caller can just pass
the version in the format that the core expects. Also remove the
fallback to the latest version that none of the callers actually uses.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

unicode: Move static keyword to the front of declarations

Move the static keyword to the front of declarations of nfdi_test_data
and nfdicf_test_data, and resolve the following compiler warnings that
can be seen when building with warnings enabled (W=1):

fs/unicode/utf8-selftest.c:38:1: warning:
‘static’ is not at beginning of declaration [-Wold-style-declaration]

fs/unicode/utf8-selftest.c:92:1: warning:
‘static’ is not at beginning of declaration [-Wold-style-declaration]

Signed-off-by: Krzysztof Wilczynski <kw@linux.com>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282

Based on 1 normalized pattern(s):

this software is licensed under the terms of the gnu general public
license version 2 as published by the free software foundation and
may be copied distributed and modified under those terms this
program 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
general public license for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 285 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

unicode: update unicode database unicode version 12.1.0

Regenerate utf8data.h based on the latest UCD files and run tests
against the latest version.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

unicode: introduce test module for normalized utf8 implementation

This implements a in-kernel sanity test module for the utf8
normalization core. At probe time, it will run basic sequences through
the utf8n core, to identify problems will equivalent sequences and
normalization/casefold code. This is supposed to be useful for
regression testing when adding support for a new version of utf8 to
linux.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>