chown: detect Solaris and FreeBSD bug

[gnulib.git] / m4 / openat.m4

diff --git a/m4/openat.m4 b/m4/openat.m4
index 88efc75..6b4f95c 100644 (file)
--- a/m4/openat.m4
+++ b/m4/openat.m4
@@ -1,7 +1,7 @@
-#serial 13
+# serial 25
 # See if we need to use our replacement for Solaris' openat et al functions.
 
-dnl Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
+dnl Copyright (C) 2004-2009 Free Software 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.
@@ -10,21 +10,54 @@ dnl with or without modifications, as long as this notice is preserved.
 
 AC_DEFUN([gl_FUNC_OPENAT],
 [
-  AC_LIBOBJ([openat-die])
+  AC_REQUIRE([gl_FCNTL_H_DEFAULTS])
+  GNULIB_OPENAT=1
+
+  AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS])
+  GNULIB_FCHMODAT=1
+  GNULIB_FSTATAT=1
+  GNULIB_MKDIRAT=1
+
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  GNULIB_FCHOWNAT=1
+  GNULIB_UNLINKAT=1
+
   AC_LIBOBJ([openat-proc])
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
   AC_CHECK_FUNCS_ONCE([lchmod])
-  AC_CHECK_FUNCS_ONCE([fdopendir])
-  AC_REPLACE_FUNCS([fchmodat mkdirat openat])
+  AC_REPLACE_FUNCS([fchmodat fstatat mkdirat openat unlinkat])
+  AC_REQUIRE([AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK])
+  AC_REQUIRE([gl_FUNC_UNLINK])
   case $ac_cv_func_openat+$ac_cv_func_lstat_dereferences_slashed_symlink in
-  yes+yes) ;;
-  yes+*) AC_LIBOBJ([fstatat]);;
+  yes+yes)
+    # GNU/Hurd has unlinkat, but it has the same bug as unlink.
+    if test $REPLACE_UNLINK = 1; then
+      AC_LIBOBJ([unlinkat])
+      REPLACE_UNLINKAT=1
+    fi ;;
+  yes+*)
+    # Solaris 9 has *at functions, but uniformly mishandles trailing
+    # slash in all of them.
+    AC_LIBOBJ([openat])
+    REPLACE_OPENAT=1
+    AC_LIBOBJ([fstatat])
+    REPLACE_FSTATAT=1
+    AC_LIBOBJ([unlinkat])
+    REPLACE_UNLINKAT=1
+    ;;
   *)
-    AC_DEFINE([__OPENAT_PREFIX], [[rpl_]],
-      [Define to rpl_ if the openat replacement function should be used.])
+    HAVE_OPENAT=0
+    HAVE_UNLINKAT=0 # No known system with unlinkat but not openat
+    HAVE_FSTATAT=0 # No known system with fstatat but not openat
     gl_PREREQ_OPENAT;;
   esac
-  AC_REQUIRE([gl_FUNC_FCHOWNAT])
+  if test $ac_cv_func_fchmodat != yes; then
+    HAVE_FCHMODAT=0
+  fi
+  if test $ac_cv_func_mkdirat != yes; then
+    HAVE_MKDIRAT=0
+  fi
+  gl_FUNC_FCHOWNAT
 ])
 
 # gl_FUNC_FCHOWNAT_DEREF_BUG([ACTION-IF-BUGGY[, ACTION-IF-NOT_BUGGY]])
@@ -38,6 +71,7 @@ AC_DEFUN([gl_FUNC_FCHOWNAT_DEREF_BUG],
      rm -f $gl_dangle
      # Arrange for deletion of the temporary file this test creates.
      ac_clean_files="$ac_clean_files $gl_dangle"
+     ln -s conftest.no-such $gl_dangle
      AC_RUN_IFELSE(
        [AC_LANG_SOURCE(
          [[
@@ -53,7 +87,7 @@ main ()
                    AT_SYMLINK_NOFOLLOW) != 0
          && errno == ENOENT);
 }
-          ]])],
+         ]])],
     [gl_cv_func_fchownat_nofollow_works=yes],
     [gl_cv_func_fchownat_nofollow_works=no],
     [gl_cv_func_fchownat_nofollow_works=no],
@@ -68,26 +102,16 @@ main ()
 # Also use the replacement function if fchownat is simply not available.
 AC_DEFUN([gl_FUNC_FCHOWNAT],
 [
-  # Assume we'll use the replacement function.
-  # The only case in which we won't is when we have fchownat, and it works.
-  use_replacement_fchownat=yes
-
-  AC_CHECK_FUNC([fchownat], [have_fchownat=yes], [have_fchownat=no])
-  if test $have_fchownat = yes; then
-    gl_FUNC_FCHOWNAT_DEREF_BUG([have_fchownat_bug=yes])
-    if test $have_fchownat_bug = no; then
-      use_replacement_fchownat=no
-    fi
-  fi
-
-  if test $use_replacement_fchownat = yes; then
-    AC_LIBOBJ(fchownat)
-    AC_DEFINE(fchownat, rpl_fchownat,
-      [Define to rpl_fchownat if the replacement function should be used.])
+  AC_CHECK_FUNC([fchownat],
+    [gl_FUNC_FCHOWNAT_DEREF_BUG([REPLACE_FCHOWNAT=1])],
+    [HAVE_FCHOWNAT=0])
+  if test $HAVE_FCHOWNAT = 0 || test $REPLACE_FCHOWNAT = 1; then
+    AC_LIBOBJ([fchownat])
   fi
 ])
 
 AC_DEFUN([gl_PREREQ_OPENAT],
 [
-  AC_REQUIRE([gl_SAVE_CWD])
+  AC_REQUIRE([gl_PROMOTED_TYPE_MODE_T])
+  :
 ])