The Automake and aclocal were part of the previous PHP build system
where Automake created Makefile from the Makefile.in templates and
aclocal was used to produce the aclocal.m4. They were removed as
dependencies via 9d9d39a0de and
e715fb00f8.
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 2.59d (released in 2006) [1] started promoting several macros
as not relevant for newer systems anymore, including the `AC_HEADER_TIME`.
This macro checks if both `<sys/time.h>` and `<time.h>` can be included
at the same time and defines the `TIME_WITH_SYS_TIME` and
`HAVE_SYS_TIME_H` symbols. On current system such check is not relevant
anymore because in case both headers are present both can be also
included at the same time.
This patch simplifies this checking.
Refs:
[1] http://git.savannah.gnu.org/cgit/autoconf.git/tree/NEWS
[2] https://www.gnu.org/software/autoconf/manual/autoconf-2.69/autoconf.html
Autoconf 2.59d (released in 2006) [1] started promoting several macros
as not relevant for newer systems, including the `AC_C_CONST`.
The `const` keyword is used in C since C89. On old systems some compilers
lacked the `const` and this macro defined it to be empty. This check was
relevant on systems with compilers before C89 and on current systems it
can be omitted. [2]
PHP also requires at least C89 so `const` is always available.
Refs:
[1] http://git.savannah.gnu.org/cgit/autoconf.git/tree/NEWS
[2] https://www.gnu.org/software/autoconf/manual/autoconf-2.69/autoconf.html
