The C89 standard and later defines the `<string.h>` header as part of
the standard headers [1] and on current systems it is always present.
Code included also `<strings.h>` header as an alterinative in some
files. This kind of check was relevant on some older systems where the
`<strings.h>` file included definitions for the C89 compliant
`<string.h>`. Today such alternative check is not required anymore. The
`<strings.h>` file is part of the POSIX definition these days.
Also Autoconf suggests doing this and relying on C89 or above [2] and [3].
This patch also cleans few unused `<strings.h>` inclusions in the libmbfl.
[1]: https://port70.net/~nsz/c/c89/c89-draft.html#4.1.2
[2]: http://git.savannah.gnu.org/cgit/autoconf.git/tree/lib/autoconf/headers.m4
[3]: https://www.gnu.org/software/autoconf/manual/autoconf-2.69/autoconf.html
Autoconf 2.50 made several changes to macro calls. These include also
arguments passed to AC_OUTPUT macro. The upgrading chapter in Autoconf
documentation include an example of using AC_OUTPUT with
AC_CONFIG_FILES and AC_CONFIG_COMMANDS:
- https://www.gnu.org/software/autoconf/manual/autoconf-2.69/html_node/Obsolete-Macros.html
PHP 5.4 to 7.1 require Autoconf 2.59+, PHP 7.2+ require Autoconf 2.64+,
and PHP 7.2 phpize script requires Autoconf 2.59+ which are all greater
than above mentioned 2.50 version. Systems out there should well support
this by now.
This patch was created with the help of autoupdate script:
autoupdate <file>
More info on where exactly this got deprecated:
- ftp://ftp.gnu.org/old-gnu/Manuals/autoconf-2.13/html_mono/autoconf.html
- ftp://ftp.auckland.ac.nz/pub/gnu/Manuals/autoconf-2.52/html_chapter/autoconf_15.html
- http://git.savannah.gnu.org/cgit/autoconf.git/tree/NEWS
The $Id$ keywords were used in Subversion where they can be substituted
with filename, last revision number change, last changed date, and last
user who changed it.
In Git this functionality is different and can be done with Git attribute
ident. These need to be defined manually for each file in the
.gitattributes file and are afterwards replaced with 40-character
hexadecimal blob object name which is based only on the particular file
contents.
This patch simplifies handling of $Id$ keywords by removing them since
they are not used anymore.
configure.ac was introduced in 2001 with automake-1.15 and autoconf-2.50
to replace the file named configure.in.
Autotools is preparing to remove configure.in in Automake 2.0.
All new software should be using configure.ac.
This also fixes Bug #69770 where extensions are creating configure.in
Signed-off-by: Brian Evans <grknight@gentoo.org>
