Several headers set #pragma GCC system_header prior to checking
any multiple inclusion guards; maintenance is easiest if all
replacement headers follow the same paradigm.

* lib/ctype.in.h (system_header): Hoist for consistent placement.
* lib/dirent.in.h (system_header): Likewise.
* lib/errno.in.h (system_header): Likewise.
* lib/float.in.h (system_header): Likewise.
* lib/getopt.in.h (system_header): Likewise.
* lib/iconv.in.h (system_header): Likewise.
* lib/inttypes.in.h (system_header): Likewise.
* lib/langinfo.in.h (system_header): Likewise.
* lib/locale.in.h (system_header): Likewise.
* lib/math.in.h (system_header): Likewise.
* lib/netdb.in.h (system_header): Likewise.
* lib/netinet_in.in.h (system_header): Likewise.
* lib/pty.in.h (system_header): Likewise.
* lib/sched.in.h (system_header): Likewise.
* lib/se-selinux.in.h (system_header): Likewise.
* lib/search.in.h (system_header): Likewise.
* lib/spawn.in.h (system_header): Likewise.
* lib/stdarg.in.h (system_header): Likewise.
* lib/stdint.in.h (system_header): Likewise.
* lib/string.in.h (system_header): Likewise.
* lib/strings.in.h (system_header): Likewise.
* lib/sys_file.in.h (system_header): Likewise.
* lib/sys_ioctl.in.h (system_header): Likewise.
* lib/sys_socket.in.h (system_header): Likewise.
* lib/sys_times.in.h (system_header): Likewise.
* lib/sys_utsname.in.h (system_header): Likewise.
* lib/sys_wait.in.h (system_header): Likewise.
* lib/sysexits.in.h (system_header): Likewise.
* lib/unistd.in.h (system_header): Likewise.
* lib/wctype.in.h (system_header): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>

Use the same procedure as for 2009, outlined in
http://thread.gmane.org/gmane.comp.lib.gnulib.bugs/20081

* lib/getopt.in.h (includes): Leave breadcrumbs during system
include.
* lib/unistd.in.h (getopt): Use them to avoid recursive include.
Reported by Ludovic Courtès.
Signed-off-by: Eric Blake <ebb9@byu.net>

* lib/getopt.in.h (_getopt_internal): Override the name.
* lib/getopt_int.h (includes): Pick up any overrides.
Reported by Reuben Thomas.
Signed-off-by: Eric Blake <ebb9@byu.net>

* lib/getopt.in.h (includes): Use different guard than glibc.
Reported by Sergey Poznyakoff.
Signed-off-by: Eric Blake <ebb9@byu.net>

cygwin <unistd.h> includes <getopt.h>, but gnulib <getopt.h> includes
<unistd.h>, so system declarations were happening after gnulib
replacements, leading to multiply-defined rpl_readlink error on
cygwin 1.5.  The solution is to ensure that the system <unistd.h>
is complete prior to any of gnulib's contents, by picking up
system <getopt.h> in preference to a cycle to <unistd.h>.

* modules/getopt-posix (Depends-on): Add include-next.
(Makefile.am): Substitute more items in replacement header.
* m4/getopt.m4 (gl_GETOPT_CHECK_HEADERS): Also check for native
<getopt.h>.
* lib/getopt.in.h (includes): Use split inclusion guard, and
prefer <getopt.h> over include <unistd.h> when one is present.
(option): Also override name of 'struct option'.
Signed-off-by: Eric Blake <ebb9@byu.net>

* .cppi-disable: Add regcomp.c, regex_internal.c, regex_internal.h,
stat-time.h.
* argmatch.h: Include verify.h
(ARGMATCH_VERIFY): Use verify rather than rolling our own.
(ARGMATCH_ASSERT): Remove; unused.
* canonicalize.c: Assume STDC_HEADERS.
* exclude.c: Include "strcase.h".
* regex_internal.h [!defined _LIBC]: Likewise.
* getusershell.c: Include stdio--.h rather than stdio.h
and stdio-safer.h.
(getusershell): Call fopen, not fopen_safer.
* save-cwd.c: Include fcntl--.h rather than fcntl.h.
Do not include unistd-safer.h.
(save_cwd): Don't call fd_safer; no longer needed
now that we include fcntl--.h.

* modules/argmatch (Depends-on): Add verify.
* modules/getloadavg (Depends-on): Depend on fcntl-safer, not
unistd-safer.
* modules/save-cwd (Depends-on): Likewise.

* backupfile.m4, calloc.m4, chown.m4, cloexec.m4, dup2.m4:
* fileblocks.m4, free.m4, ftruncate.m4, getcwd.m4, getpagesize.m4:
* getugroups.m4, group-member.m4, idcache.m4, link-follow.m4:
* mkstemp.m4, mktime.m4, mountlist.m4, nanosleep.m4, pathmax.m4:
* physmem.m4, posixver.m4, putenv.m4, safe-read.m4, same.m4:
* save-cwd.m4, stdio-safer.m4, unistd-safer.m4, unlinkdir.m4:
* userspec.m4, xgetcwd.m4, xreadlink.m4:
Don't bother checking for string.h, stdlib.h, unistd.h.
* fts.m4 (gl_FUNC_FTS_CORE): Don't require
AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK; that's now the lstat
module's job.
* jm-macros.m4 (gl_MACROS): Likewise.
* prereq.m4 (gl_PREREQ): Add gl_FUNC_LSTAT.

* backupfile.c: Use ARGMATCH_VERIFY, just in case.
* posixtm.c (posixtime) [lint]: Initialize *all* of tm0, not just
the .tm_year member, since otherwise gcc-4.0 would now warn about
tm_zone, tm_gmtoff, tm_isdst, tm_yday, tm_wday.
* quotearg.c (quotearg_n_options): Change code to be suboptimal, in
order to avoid an unsuppressible warning from gcc on 64-bit systems.

* lstat.m4 (gl_FUNC_LSTAT):
Use AC_LIBSOURCES to require lstat.c and lstat.h.
Remove obsolete comment.
* xreadlink.m4: Use AC_LIBSOURCES and AC_LIBOBJ.
* xstrtod.m4: Likewise.

redefinition warnings. To avoid them, include the defines
in `#if !defined __need_getopt ... #endif'. The only place
where __getopt_argv_const is used is in definitions
of getopt_long and getopt_long_only below, which are as well
protected by `#ifndef __need_getopt'.
[defined __GETOPT_PREFIX && !defined __need_getopt]: Undef
__need_getopt after including <stdio.h> and <unistd.h> These
headers might have defined it.

(getopt, getopt_long, getopt_long_only, optarg, opterr, optind,
optopt): Use it instead of invoking ## directly; otherwise, the
symbols will be __GETOPT_PREFIXgetopt rather than rpl_getopt.

(getopt_long, getopt_long_only): Use it.

we can stop lying to compilers about the constness of argv when we
are compiled outside glibc.
(getopt, getopt_long, getopt_long_only): Use it.

[defined __GETOPT_PREFIX && !defined __need_getopt]:
Include <stdlib.h> and <stdio.h>, too.

Include <unistd.h> if available.
Then rename getopt to __GETOPT_PREFIX##getopt, and so forth for
the other external symbols.
(getopt) [!defined __GNU_LIBRARY]: Use prototype, not old-style
declaration, since the above renaming now works around collisions.