* configure.ac: Use AC_PROG_CC, not AC_PROG_CC_STDC.
* gl/modules/smack (configure.ac):
* m4/jm-macros.m4 (coreutils_MACROS):
* m4/xattr.m4 (gl_FUNC_XATTR):
Use AS_HELP_STRING, not AC_HELP_STRING.
* m4/check-decl.m4 (gl_CHECK_DECLS):
Do not require AC_HEADER_TIME; we no longer care about it directly.
* m4/jm-macros.m4 (coreutils_MACROS):
Do not require AC_ISC_POSIX, which became obsolete in 2006.
Use AC_LINK_IFELSE instead of AC_TRY_LINK.
Consolidate all smack routines and checks in a module.
We replace and wrap the most commonly used smack routines,
which allows removing ifdefs throughout the code.
* gl/lib/smack.h: A new header containing the implementation
of the wrapped and replacement routines. Note the is_smack_enabled()
routine should be optimized out at compile time when compiled
on a system without libsmack.
* gl/modules/smack: Describe the new module and move the
configure time code here from ...
* m4/jm-macros.m4: ... here.
* bootstrap.conf: Reference the new module.
* src/id.c: Use the routines without ifdefs where possible.
* src/ls.c: Likewise.
* src/mkdir.c: Likewise.
* src/mkfifo.c: Likewise.
* src/mknod.c: Likewise.
Paul Eggert
Pádraig Brady