X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fchown.m4;h=fa46981b2274e8277036e00c1313d6bb1db926df;hb=1bb384c44db25aef8f8b455cef22af32d8401abc;hp=b3c0a7c43c7ab26197da063999afd6a94e0b8cfe;hpb=c281d94c469bec6e34b0ccf74f02f0d3c0c6f7e2;p=gnulib.git diff --git a/m4/chown.m4 b/m4/chown.m4 index b3c0a7c43..fa46981b2 100644 --- a/m4/chown.m4 +++ b/m4/chown.m4 @@ -1,49 +1,135 @@ -#serial 4 - -dnl From Jim Meyering. -dnl Determine whether chown accepts arguments of -1 for uid and gid. -dnl If it doesn't, arrange to use the replacement function. -dnl - -AC_DEFUN(jm_FUNC_CHOWN, -[AC_REQUIRE([AC_TYPE_UID_T])dnl - test -z "$ac_cv_header_unistd_h" \ - && AC_CHECK_HEADERS(unistd.h) - AC_CACHE_CHECK([for working chown], jm_cv_func_working_chown, - [AC_TRY_RUN([ -# include -# include -# include -# ifdef HAVE_UNISTD_H -# include -# endif - - int - main () - { - char *f = "conftestchown"; - struct stat before, after; - - if (creat (f, 0600) < 0) - exit (1); - if (stat (f, &before) < 0) - exit (1); - if (chown (f, (uid_t) -1, (gid_t) -1) == -1) - exit (1); - if (stat (f, &after) < 0) - exit (1); - exit ((before.st_uid == after.st_uid - && before.st_gid == after.st_gid) ? 0 : 1); - } - ], - jm_cv_func_working_chown=yes, - jm_cv_func_working_chown=no, - dnl When crosscompiling, assume chown is broken. - jm_cv_func_working_chown=no) - ]) - if test $jm_cv_func_working_chown = no; then - LIBOBJS="$LIBOBJS chown.o" - AC_DEFINE_UNQUOTED(chown, rpl_chown, - [Define to rpl_chown if the replacement function should be used.]) +# serial 25 +# Determine whether we need the chown wrapper. + +dnl Copyright (C) 1997-2001, 2003-2005, 2007, 2009-2011 Free Software +dnl Foundation, Inc. + +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. + +# chown should accept arguments of -1 for uid and gid, and it should +# dereference symlinks. If it doesn't, arrange to use the replacement +# function. + +# From Jim Meyering. + +AC_DEFUN_ONCE([gl_FUNC_CHOWN], +[ + AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) + AC_REQUIRE([AC_TYPE_UID_T]) + AC_REQUIRE([AC_FUNC_CHOWN]) + AC_REQUIRE([gl_FUNC_CHOWN_FOLLOWS_SYMLINK]) + AC_CHECK_FUNCS_ONCE([chown fchown]) + + dnl mingw lacks chown altogether. + if test $ac_cv_func_chown = no; then + HAVE_CHOWN=0 + else + dnl Some old systems treated chown like lchown. + if test $gl_cv_func_chown_follows_symlink = no; then + REPLACE_CHOWN=1 + fi + + dnl Some old systems tried to use uid/gid -1 literally. + if test $ac_cv_func_chown_works = no; then + AC_DEFINE([CHOWN_FAILS_TO_HONOR_ID_OF_NEGATIVE_ONE], [1], + [Define if chown is not POSIX compliant regarding IDs of -1.]) + REPLACE_CHOWN=1 + fi + + dnl Solaris 9 ignores trailing slash. + dnl FreeBSD 7.2 mishandles trailing slash on symlinks. + dnl Likewise for AIX 7.1. + AC_CACHE_CHECK([whether chown honors trailing slash], + [gl_cv_func_chown_slash_works], + [touch conftest.file && rm -f conftest.link + AC_RUN_IFELSE([AC_LANG_PROGRAM([[ +#include +#include +#include +]], [[ if (symlink ("conftest.file", "conftest.link")) return 1; + if (chown ("conftest.link/", getuid (), getgid ()) == 0) return 2; + ]])], + [gl_cv_func_chown_slash_works=yes], + [gl_cv_func_chown_slash_works=no], + [gl_cv_func_chown_slash_works="guessing no"]) + rm -f conftest.link conftest.file]) + if test "$gl_cv_func_chown_slash_works" != yes; then + AC_DEFINE([CHOWN_TRAILING_SLASH_BUG], [1], + [Define to 1 if chown mishandles trailing slash.]) + REPLACE_CHOWN=1 + fi + + dnl OpenBSD fails to update ctime if ownership does not change. + AC_CACHE_CHECK([whether chown always updates ctime], + [gl_cv_func_chown_ctime_works], + [AC_RUN_IFELSE([AC_LANG_PROGRAM([[ +#include +#include +#include +#include +#include +]], [[ struct stat st1, st2; + if (close (creat ("conftest.file", 0600))) return 1; + if (stat ("conftest.file", &st1)) return 2; + sleep (1); + if (chown ("conftest.file", st1.st_uid, st1.st_gid)) return 3; + if (stat ("conftest.file", &st2)) return 4; + if (st2.st_ctime <= st1.st_ctime) return 5; + ]])], + [gl_cv_func_chown_ctime_works=yes], + [gl_cv_func_chown_ctime_works=no], + [gl_cv_func_chown_ctime_works="guessing no"]) + rm -f conftest.file]) + if test "$gl_cv_func_chown_ctime_works" != yes; then + AC_DEFINE([CHOWN_CHANGE_TIME_BUG], [1], [Define to 1 if chown fails + to change ctime when at least one argument was not -1.]) + REPLACE_CHOWN=1 + fi + fi +]) + +# Determine whether chown follows symlinks (it should). +AC_DEFUN_ONCE([gl_FUNC_CHOWN_FOLLOWS_SYMLINK], +[ + AC_CACHE_CHECK( + [whether chown dereferences symlinks], + [gl_cv_func_chown_follows_symlink], + [ + AC_RUN_IFELSE([AC_LANG_SOURCE([[ +#include +#include +#include + + int + main () + { + int result = 0; + char const *dangling_symlink = "conftest.dangle"; + + unlink (dangling_symlink); + if (symlink ("conftest.no-such", dangling_symlink)) + abort (); + + /* Exit successfully on a conforming system, + i.e., where chown must fail with ENOENT. */ + if (chown (dangling_symlink, getuid (), getgid ()) == 0) + result |= 1; + if (errno != ENOENT) + result |= 2; + return result; + } + ]])], + [gl_cv_func_chown_follows_symlink=yes], + [gl_cv_func_chown_follows_symlink=no], + [gl_cv_func_chown_follows_symlink=yes] + ) + ] + ) + + if test $gl_cv_func_chown_follows_symlink = no; then + AC_DEFINE([CHOWN_MODIFIES_SYMLINK], [1], + [Define if chown modifies symlinks.]) fi ])