| # serial 35 |
| # Determine whether we need the chown wrapper. |
| |
| dnl Copyright (C) 1997-2001, 2003-2005, 2007, 2009-2021 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. |
| |
| # This is taken from the following Autoconf patch: |
| # https://git.savannah.gnu.org/gitweb/?p=autoconf.git;a=commitdiff;h=7fbb553727ed7e0e689a17594b58559ecf3ea6e9 |
| AC_DEFUN([AC_FUNC_CHOWN], |
| [ |
| AC_REQUIRE([AC_TYPE_UID_T])dnl |
| AC_REQUIRE([AC_CANONICAL_HOST])dnl for cross-compiles |
| AC_CHECK_HEADERS([unistd.h]) |
| AC_CACHE_CHECK([for working chown], |
| [ac_cv_func_chown_works], |
| [AC_RUN_IFELSE( |
| [AC_LANG_PROGRAM( |
| [AC_INCLUDES_DEFAULT |
| [#include <fcntl.h> |
| ]GL_MDA_DEFINES], |
| [[ |
| char *f = "conftest.chown"; |
| struct stat before, after; |
| |
| if (creat (f, 0600) < 0) |
| return 1; |
| if (stat (f, &before) < 0) |
| return 1; |
| if (chown (f, (uid_t) -1, (gid_t) -1) == -1) |
| return 1; |
| if (stat (f, &after) < 0) |
| return 1; |
| return ! (before.st_uid == after.st_uid && before.st_gid == after.st_gid); |
| ]]) |
| ], |
| [ac_cv_func_chown_works=yes], |
| [ac_cv_func_chown_works=no], |
| [case "$host_os" in # (( |
| # Guess yes on Linux systems. |
| linux-* | linux) ac_cv_func_chown_works="guessing yes" ;; |
| # Guess yes on glibc systems. |
| *-gnu* | gnu*) ac_cv_func_chown_works="guessing yes" ;; |
| # Guess no on native Windows. |
| mingw*) ac_cv_func_chown_works="guessing no" ;; |
| # If we don't know, obey --enable-cross-guesses. |
| *) ac_cv_func_chown_works="$gl_cross_guess_normal" ;; |
| esac |
| ]) |
| rm -f conftest.chown |
| ]) |
| case "$ac_cv_func_chown_works" in |
| *yes) |
| AC_DEFINE([HAVE_CHOWN], [1], |
| [Define to 1 if your system has a working `chown' function.]) |
| ;; |
| esac |
| ])# AC_FUNC_CHOWN |
| |
| 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_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles |
| AC_CHECK_FUNCS_ONCE([chown fchown]) |
| |
| dnl mingw lacks chown altogether. |
| if test $ac_cv_func_chown = no; then |
| HAVE_CHOWN=0 |
| else |
| dnl Some old systems treated chown like lchown. |
| case "$gl_cv_func_chown_follows_symlink" in |
| *yes) ;; |
| *) REPLACE_CHOWN=1 ;; |
| esac |
| |
| dnl Some old systems tried to use uid/gid -1 literally. |
| case "$ac_cv_func_chown_works" in |
| *no) |
| AC_DEFINE([CHOWN_FAILS_TO_HONOR_ID_OF_NEGATIVE_ONE], [1], |
| [Define if chown is not POSIX compliant regarding IDs of -1.]) |
| REPLACE_CHOWN=1 |
| ;; |
| esac |
| |
| dnl Solaris 9 ignores trailing slash. |
| dnl FreeBSD 7.2 mishandles trailing slash on symlinks. |
| dnl Likewise for AIX 7.1. |
| AC_CACHE_CHECK([whether chown honors trailing slash], |
| [gl_cv_func_chown_slash_works], |
| [touch conftest.file && rm -f conftest.link |
| AC_RUN_IFELSE([AC_LANG_PROGRAM([[ |
| #include <unistd.h> |
| #include <stdlib.h> |
| #include <errno.h> |
| ]GL_MDA_DEFINES], |
| [[if (symlink ("conftest.file", "conftest.link")) return 1; |
| if (chown ("conftest.link/", getuid (), getgid ()) == 0) return 2; |
| ]])], |
| [gl_cv_func_chown_slash_works=yes], |
| [gl_cv_func_chown_slash_works=no], |
| [case "$host_os" in |
| # Guess yes on glibc systems. |
| *-gnu*) gl_cv_func_chown_slash_works="guessing yes" ;; |
| # Guess yes on musl systems. |
| *-musl*) gl_cv_func_chown_slash_works="guessing yes" ;; |
| # If we don't know, obey --enable-cross-guesses. |
| *) gl_cv_func_chown_slash_works="$gl_cross_guess_normal" ;; |
| esac |
| ]) |
| rm -f conftest.link conftest.file]) |
| case "$gl_cv_func_chown_slash_works" in |
| *yes) ;; |
| *) |
| AC_DEFINE([CHOWN_TRAILING_SLASH_BUG], [1], |
| [Define to 1 if chown mishandles trailing slash.]) |
| REPLACE_CHOWN=1 |
| ;; |
| esac |
| |
| 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 <unistd.h> |
| #include <stdlib.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <sys/stat.h> |
| ]GL_MDA_DEFINES], |
| [[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], |
| [case "$host_os" in |
| # Guess yes on glibc systems. |
| *-gnu*) gl_cv_func_chown_ctime_works="guessing yes" ;; |
| # Guess yes on musl systems. |
| *-musl*) gl_cv_func_chown_ctime_works="guessing yes" ;; |
| # If we don't know, obey --enable-cross-guesses. |
| *) gl_cv_func_chown_ctime_works="$gl_cross_guess_normal" ;; |
| esac |
| ]) |
| rm -f conftest.file]) |
| case "$gl_cv_func_chown_ctime_works" in |
| *yes) ;; |
| *) |
| AC_DEFINE([CHOWN_CHANGE_TIME_BUG], [1], [Define to 1 if chown fails |
| to change ctime when at least one argument was not -1.]) |
| REPLACE_CHOWN=1 |
| ;; |
| esac |
| fi |
| ]) |
| |
| # Determine whether chown follows symlinks (it should). |
| AC_DEFUN_ONCE([gl_FUNC_CHOWN_FOLLOWS_SYMLINK], |
| [ |
| AC_CACHE_CHECK( |
| [whether chown dereferences symlinks], |
| [gl_cv_func_chown_follows_symlink], |
| [ |
| AC_RUN_IFELSE([AC_LANG_SOURCE([[ |
| #include <unistd.h> |
| #include <stdlib.h> |
| #include <errno.h> |
| ]GL_MDA_DEFINES[ |
| int |
| main () |
| { |
| int result = 0; |
| char const *dangling_symlink = "conftest.dangle"; |
| |
| unlink (dangling_symlink); |
| if (symlink ("conftest.no-such", dangling_symlink)) |
| abort (); |
| |
| /* Exit successfully on a conforming system, |
| i.e., where chown must fail with ENOENT. */ |
| if (chown (dangling_symlink, getuid (), getgid ()) == 0) |
| result |= 1; |
| if (errno != ENOENT) |
| result |= 2; |
| return result; |
| } |
| ]])], |
| [gl_cv_func_chown_follows_symlink=yes], |
| [gl_cv_func_chown_follows_symlink=no], |
| [gl_cv_func_chown_follows_symlink="guessing yes"] |
| ) |
| ] |
| ) |
| |
| case "$gl_cv_func_chown_follows_symlink" in |
| *yes) ;; |
| *) |
| AC_DEFINE([CHOWN_MODIFIES_SYMLINK], [1], |
| [Define if chown modifies symlinks.]) |
| ;; |
| esac |
| ]) |
