emacs/m4/warnings.m4, branch scratch/kqueue

Merge from gnulib, incorporating:

2015-01-01T19:06:53+00:00

2015-01-01 version-etc: new year

Update copyright year to 2014 by running admin/update-copyright.

2014-01-01T07:43:34+00:00

Merge from gnulib.

2013-09-25T03:44:34+00:00

This incorporates:
2013-09-24 manywarnings: enable nicer gcc warning messages
2013-09-23 warnings: port --enable-gcc-warnings to Solaris Studio 12.3
2013-09-21 timespec: use the new TIMESPEC_RESOLUTION elsewhere
* configure.ac (WERROR_CFLAGS): Omit -fdiagnostics-show-option
and -funit-at-a-time, since manywarnings does that for us now.

Merge from gnulib.

2013-08-19T05:23:05+00:00

This incorporates:
2013-08-15 warnings: minor optimization
2013-08-15 warnings: check -Wfoo rather than -Wno-foo

Merge from gnulib.

2013-05-16T07:10:39+00:00

2013-05-15 manywarnings: update for GCC 4.8.0
2013-05-15 stdio: use __REDIRECT for fwrite, fwrite_unlocked
2013-05-15 sig2str, stdio, warnings: port to clang

Update copyright notices for 2013.

2013-01-01T09:11:05+00:00

Merge from gnulib.

2012-05-26T23:14:36+00:00

Fixes: debbugs:11527

configure: new option --enable-gcc-warnings

2012-04-09T07:45:59+00:00

I have been using this change for many months in my private copy
of Emacs, and have used it to find several bugs.  It's mature
enough to publish now.
* Makefile.in (GNULIB_MODULES): Add warnings, manywarnings.
* configure.in: Support --enable-gcc-warnings, in the style of
other GNU packages such as coreutils.
(C_WARNINGS_SWITCH): Remove, replacing with...
(WARN_CFLAGS, GNULIB_WARN_CFLAGS): New variable.
(PKG_CHECK_MODULES, C_SWITCH_X_SITE): Use -isystem rather than -I,
when including system files with GCC.
* etc/NEWS: Mention --enable-gcc-warnings.
* lib/Makefile.am (AM_CFLAGS): New macro.
* m4/manywarnings.m4, m4/warnings.m4: New files, from gnulib.
* lib-src/Makefile.in (C_WARNINGS_SWITCH): Remove.
(WARN_CFLAGS, WERROR_CFLAGS): New macros.
(BASE_CFLAGS): Use new macros rather than old.
* lwlib/Makefile.in (C_WARNINGS_SWITCH): Remove.
(WARN_CFLAGS, WERROR_CFLAGS): New macros.
(ALL_CFLAGS): Use new macros rather than old.
* oldXMenu/Makefile.in (C_WARNINGS_SWITCH): Remove.
(WARN_CFLAGS, WERROR_CFLAGS): New macros.
(ALL_CFLAGS): Use new macros rather than old.
* src/Makefile.in (C_WARNINGS_SWITCH): Remove.
(WARN_CFLAGS, WERROR_CFLAGS): New macros.
(ALL_CFLAGS): Use new macros rather than old.
* src/process.c: Ignore -Wstrict-overflow to work around GCC bug 52904.
* src/regex.c: Ignore -Wstrict-overflow.  If !emacs, also ignore
-Wunused-but-set-variable, -Wunused-function, -Wunused-macros,
-Wunused-result, -Wunused-variable.  This should go away once
the Emacs and Gnulib regex code is merged.
(xmalloc, xrealloc): Now static.