declare lchmod in sys/stat.h

[Bruno Haible]

glibc and the BSD systems declare lchmod() in <sys/stat.h>. Therefore gnulib
should do the same. Here's a proposed patch to that effect.


2008-10-18  Bruno Haible  <address@hidden>

        * lib/dirchownmod.c: Don't include lchmod.h.

        * lib/lchmod.h: Remove file.
        * lib/sys_stat.in.h: Add placeholder for GL_LINK_WARNING.
        (lchmod): New declaration, moved here from lib/lchown.h.
        * m4/lchmod.m4 (gl_FUNC_LCHMOD): Require gl_SYS_STAT_H_DEFAULTS and
        AC_USE_SYSTEM_EXTENSIONS. Set HAVE_LCHMOD.
        * m4/sys_stat_h.m4 (gl_SYS_STAT_H_DEFAULTS): Initialize GNULIB_LCHMOD
        and HAVE_LCHMOD.
        * modules/lchmod (Files): Remove lib/lchmod.h.
        (Depends-on): Add sys_stat, extensions.
        (configure.ac): Invoke gl_SYS_STAT_MODULE_INDICATOR.
        (Include): Specify <sys/stat.h> instead of lchmod.h.
        * modules/sys_stat (Depends-on): Add link-warning.
        (Makefile.am): Substitute GNULIB_LCHMOD, HAVE_LCHMOD, and the
        definition of GL_LINK_WARNING.
        * NEWS: Mention the change.

--- lib/lchmod.h.orig   2008-10-19 04:11:13.000000000 +0200
+++ lib/lchmod.h        2003-09-23 19:59:22.000000000 +0200
@@ -1,34 +0,0 @@
-/* Provide a replacement for lchmod on hosts that lack it.
-
-   Copyright (C) 2005 Free Software Foundation, Inc.
-
-   This program is free software: you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 3 of the License, or
-   (at your option) any later version.
-
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
-
-/* Written by Paul Eggert.  */
-
-#include <sys/types.h>
-#include <sys/stat.h>
-
-#ifndef HAVE_LCHMOD
-
-/* The lchmod replacement follows symbolic links.  Callers should take
-   this into account; lchmod should be applied only to arguments that
-   are known to not be symbolic links.  On hosts that lack lchmod,
-   this can lead to race conditions between the check and the
-   invocation of lchmod, but we know of no workarounds that are
-   reliable in general.  You might try requesting support for lchmod
-   from your operating system supplier.  */
-
-# define lchmod chmod
-#endif
--- lib/sys_stat.in.h.orig      2008-10-19 04:11:13.000000000 +0200
+++ lib/sys_stat.in.h   2008-10-19 04:10:38.000000000 +0200
@@ -1,5 +1,5 @@
 /* Provide a more complete sys/stat header file.
-   Copyright (C) 2006-2008 Free Software Foundation, Inc.
+   Copyright (C) 2005-2008 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -33,6 +33,8 @@
 #ifndef _GL_SYS_STAT_H
 #define _GL_SYS_STAT_H
 
+/* The definition of GL_LINK_WARNING is copied here.  */
+
 /* Before doing "#define mkdir rpl_mkdir" below, we need to include all
    headers that may declare mkdir().  */
 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
@@ -291,5 +293,32 @@
 # endif
 #endif
 
+
+/* Declare BSD extensions.  */
+
+#if @GNULIB_LCHMOD@
+/* Change the mode of FILENAME to MODE, without dereferencing it if FILENAME
+   denotes a symbolic link.  */
+# if address@hidden@
+/* The lchmod replacement follows symbolic links.  Callers should take
+   this into account; lchmod should be applied only to arguments that
+   are known to not be symbolic links.  On hosts that lack lchmod,
+   this can lead to race conditions between the check and the
+   invocation of lchmod, but we know of no workarounds that are
+   reliable in general.  You might try requesting support for lchmod
+   from your operating system supplier.  */
+#  define lchmod chmod
+# endif
+# if 0 /* assume already declared */
+extern int lchmod (const char *filename, mode_t mode);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef lchmod
+# define lchmod(f,m) \
+    (GL_LINK_WARNING ("lchmod is unportable - " \
+                      "use gnulib module lchmod for portability"), \
+     lchmod (f, m))
+#endif
+
 #endif /* _GL_SYS_STAT_H */
 #endif /* _GL_SYS_STAT_H */
--- m4/lchmod.m4.orig   2008-10-19 04:11:13.000000000 +0200
+++ m4/lchmod.m4        2008-10-19 04:04:44.000000000 +0200
@@ -1,6 +1,6 @@
-#serial 2
+#serial 3
 
-dnl Copyright (C) 2005, 2006 Free Software Foundation, Inc.
+dnl Copyright (C) 2005, 2006, 2008 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.
@@ -10,5 +10,13 @@
 
 AC_DEFUN([gl_FUNC_LCHMOD],
 [
+  AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS])
+
+  dnl Persuade glibc <sys/stat.h> to declare lchmod().
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
   AC_CHECK_FUNCS_ONCE([lchmod])
+  if test $ac_cv_func_lchmod = no; then
+    HAVE_LCHMOD=0
+  fi
 ])
--- m4/sys_stat_h.m4.orig       2008-10-19 04:11:13.000000000 +0200
+++ m4/sys_stat_h.m4    2008-10-19 04:05:26.000000000 +0200
@@ -1,4 +1,4 @@
-# sys_stat_h.m4 serial 8   -*- Autoconf -*-
+# sys_stat_h.m4 serial 9   -*- Autoconf -*-
 dnl Copyright (C) 2006-2008 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -50,6 +50,8 @@
 
 AC_DEFUN([gl_SYS_STAT_H_DEFAULTS],
 [
+  GNULIB_LCHMOD=0; AC_SUBST([GNULIB_LCHMOD])
   dnl Assume proper GNU behavior unless another module says otherwise.
+  HAVE_LCHMOD=1;   AC_SUBST([HAVE_LCHMOD])
   REPLACE_MKDIR=0; AC_SUBST([REPLACE_MKDIR])
 ])
--- modules/lchmod.orig 2008-10-19 04:11:13.000000000 +0200
+++ modules/lchmod      2008-10-19 04:04:50.000000000 +0200
@@ -2,18 +2,20 @@
 lchmod that is actually chmod (!) on hosts lacking lchmod
 
 Files:
-lib/lchmod.h
 m4/lchmod.m4
 
 Depends-on:
+sys_stat
+extensions
 
 configure.ac:
 gl_FUNC_LCHMOD
+gl_SYS_STAT_MODULE_INDICATOR([lchmod])
 
 Makefile.am:
 
 Include:
-"lchmod.h"
+<sys/stat.h>
 
 License:
 GPL
--- modules/sys_stat.orig       2008-10-19 04:11:14.000000000 +0200
+++ modules/sys_stat    2008-10-19 03:59:50.000000000 +0200
@@ -7,6 +7,7 @@
 
 Depends-on:
 include_next
+link-warning
 
 configure.ac:
 gl_HEADER_SYS_STAT_H
@@ -24,8 +25,11 @@
          sed -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
              -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
              -e 's|@''NEXT_SYS_STAT_H''@|$(NEXT_SYS_STAT_H)|g' \
+             -e 's|@''GNULIB_LCHMOD''@|$(GNULIB_LCHMOD)|g' \
+             -e 's|@''HAVE_LCHMOD''@|$(HAVE_LCHMOD)|g' \
              -e 's|@''HAVE_LSTAT''@|$(HAVE_LSTAT)|g' \
              -e 's|@''REPLACE_MKDIR''@|$(REPLACE_MKDIR)|g' \
+             -e '/definition of GL_LINK_WARNING/r $(LINK_WARNING_H)' \
              < $(srcdir)/sys_stat.in.h; \
        } > address@hidden
        mv address@hidden $@
--- NEWS.orig   2008-10-19 04:11:13.000000000 +0200
+++ NEWS        2008-10-19 03:58:48.000000000 +0200
@@ -6,6 +6,9 @@
 
 Date        Modules         Changes
 
+2008-10-18  lchmod          The include file is changed from "lchmod.h" to
+                            <sys/stat.h>.
+
 2008-09-28  sockets         When using this module, you now need to link with
                             $(LIBSOCKET).
 
--- lib/dirchownmod.c.orig      2008-10-19 04:11:13.000000000 +0200
+++ lib/dirchownmod.c   2008-10-19 04:06:26.000000000 +0200
@@ -1,6 +1,6 @@
 /* Change the ownership and mode bits of a directory.
 
-   Copyright (C) 2006, 2007 Free Software Foundation, Inc.
+   Copyright (C) 2006, 2007, 2008 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -26,7 +26,6 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
-#include "lchmod.h"
 #include "stat-macros.h"
 
 #ifndef HAVE_FCHMOD