Merge commit 'a39d4083cab589d7cd6a13e8a4b8db8875261d75'

[gnulib.git] / m4 / euidaccess.m4

diff --git a/m4/euidaccess.m4 b/m4/euidaccess.m4
index 18ce475..55393a4 100644 (file)
--- a/m4/euidaccess.m4
+++ b/m4/euidaccess.m4
@@ -1,26 +1,52 @@
-# euidaccess.m4 serial 2
-dnl Copyright (C) 2002, 2003 Free Software Foundation, Inc.
-dnl This file is free software, distributed under the terms of the GNU
-dnl General Public License.  As a special exception to the GNU General
-dnl Public License, this file may be distributed as part of a program
-dnl that contains a configuration script generated by Autoconf, under
-dnl the same distribution terms as the rest of that program.
+# euidaccess.m4 serial 15
+dnl Copyright (C) 2002-2014 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.
+
+AC_DEFUN([gl_FUNC_NONREENTRANT_EUIDACCESS],
+[
+  AC_REQUIRE([gl_FUNC_EUIDACCESS])
+  AC_CHECK_DECLS([setregid])
+  AC_DEFINE([PREFER_NONREENTRANT_EUIDACCESS], [1],
+    [Define this if you prefer euidaccess to return the correct result
+     even if this would make it nonreentrant.  Define this only if your
+     entire application is safe even if the uid or gid might temporarily
+     change.  If your application uses signal handlers or threads it
+     is probably not safe.])
+])
 
 AC_DEFUN([gl_FUNC_EUIDACCESS],
 [
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+
   dnl Persuade glibc <unistd.h> to declare euidaccess().
-  AC_REQUIRE([AC_GNU_SOURCE])
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
 
-  AC_CHECK_DECLS([euidaccess])
-  AC_REPLACE_FUNCS(euidaccess)
+  AC_CHECK_FUNCS([euidaccess])
   if test $ac_cv_func_euidaccess = no; then
-    gl_PREREQ_EUIDACCESS
+    HAVE_EUIDACCESS=0
   fi
 ])
 
 # Prerequisites of lib/euidaccess.c.
 AC_DEFUN([gl_PREREQ_EUIDACCESS], [
-  AC_CHECK_HEADERS_ONCE(unistd.h)
-  AC_REQUIRE([AC_FUNC_GETGROUPS])
-])
+  dnl Prefer POSIX faccessat over non-standard euidaccess.
+  AC_CHECK_FUNCS_ONCE([faccessat])
+  dnl Try various other non-standard fallbacks.
+  AC_CHECK_HEADERS([libgen.h])
+  AC_FUNC_GETGROUPS
 
+  # Solaris 9 and 10 need -lgen to get the eaccess function.
+  # Save and restore LIBS so -lgen isn't added to it.  Otherwise, *all*
+  # programs in the package would end up linked with that potentially-shared
+  # library, inducing unnecessary run-time overhead.
+  LIB_EACCESS=
+  AC_SUBST([LIB_EACCESS])
+  gl_saved_libs=$LIBS
+    AC_SEARCH_LIBS([eaccess], [gen],
+                   [test "$ac_cv_search_eaccess" = "none required" ||
+                    LIB_EACCESS=$ac_cv_search_eaccess])
+    AC_CHECK_FUNCS([eaccess])
+  LIBS=$gl_saved_libs
+])