--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 2010-03-07  Bruno Haible  <bruno@clisp.org>
 
+	dirent: Avoid #define replacements in C++ mode.
+	* lib/dirent.in.h: Include c++defs.h.
+	(closedir, fdopendir, opendir, scandir, alphasort): In C++, define a
+	namespaced alias symbol.
+	(dirfd): Update declaration.
+	* modules/dirent (Depends-on): Add c++defs.
+	(Makefile.am): Update dirent.h rule.
+
 	ctype: Make it usable in C++ code.
 	* lib/ctype.in.h: Include c++defs.h.
 	(isblank): Declare as extern "C".

--- a/lib/dirent.in.h
+++ b/lib/dirent.in.h
@@ -29,26 +29,31 @@
 /* Get ino_t.  Needed on some systems, including glibc 2.8.  */
 #include <sys/types.h>
 
+/* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
+
 /* The definition of _GL_ARG_NONNULL is copied here.  */
 
 /* The definition of _GL_WARN_ON_USE is copied here.  */
 
-#ifdef __cplusplus
-extern "C" {
-#endif
 
 /* Declare overridden functions.  */
 
 #if @REPLACE_CLOSEDIR@
-# define closedir rpl_closedir
-extern int closedir (DIR *) _GL_ARG_NONNULL ((1));
+# if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#  define closedir rpl_closedir
+# endif
+_GL_FUNCDECL_RPL (closedir, int, (DIR *) _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (closedir, int, (DIR *));
+#else
+_GL_CXXALIAS_SYS (closedir, int, (DIR *));
 #endif
+_GL_CXXALIASWARN (closedir);
 
 #if @GNULIB_DIRFD@
 # if !@HAVE_DECL_DIRFD@ && !defined dirfd
 /* Return the file descriptor associated with the given directory stream,
    or -1 if none exists.  */
-extern int dirfd (DIR *dir) _GL_ARG_NONNULL ((1));
+_GL_EXTERN_C int dirfd (DIR *dir) _GL_ARG_NONNULL ((1));
 # endif
 #elif defined GNULIB_POSIXCHECK
 # undef dirfd
@@ -59,18 +64,25 @@
 #endif
 
 #if @GNULIB_FDOPENDIR@
-# if @REPLACE_FDOPENDIR@
-#  undef fdopendir
-#  define fdopendir rpl_fdopendir
-# endif
-# if !@HAVE_FDOPENDIR@ || @REPLACE_FDOPENDIR@
 /* Open a directory stream visiting the given directory file
    descriptor.  Return NULL and set errno if fd is not visiting a
    directory.  On success, this function consumes fd (it will be
    implicitly closed either by this function or by a subsequent
    closedir).  */
-extern DIR *fdopendir (int fd);
+# if @REPLACE_FDOPENDIR@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef fdopendir
+#   define fdopendir rpl_fdopendir
+#  endif
+_GL_FUNCDECL_RPL (fdopendir, DIR *, (int fd));
+_GL_CXXALIAS_RPL (fdopendir, DIR *, (int fd));
+# else
+#  if !@HAVE_FDOPENDIR@
+_GL_FUNCDECL_SYS (fdopendir, DIR *, (int fd));
+#  endif
+_GL_CXXALIAS_SYS (fdopendir, DIR *, (int fd));
 # endif
+_GL_CXXALIASWARN (fdopendir);
 #elif defined GNULIB_POSIXCHECK
 # undef fdopendir
 # if HAVE_RAW_DECL_FDOPENDIR
@@ -80,9 +92,15 @@
 #endif
 
 #if @REPLACE_OPENDIR@
-# define opendir rpl_opendir
-extern DIR * opendir (const char *) _GL_ARG_NONNULL ((1));
+# if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#  define opendir rpl_opendir
+# endif
+_GL_FUNCDECL_RPL (opendir, DIR *, (const char *) _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (opendir, DIR *, (const char *));
+#else
+_GL_CXXALIAS_SYS (opendir, DIR *, (const char *));
 #endif
+_GL_CXXALIASWARN (opendir);
 
 #if @GNULIB_SCANDIR@
 /* Scan the directory DIR, calling FILTER on each directory entry.
@@ -90,11 +108,19 @@
    sorted using qsort with CMP, and collected in a malloc'd array in
    *NAMELIST.  Returns the number of entries selected, or -1 on error.  */
 # if !@HAVE_SCANDIR@
-extern int scandir (const char *dir, struct dirent ***namelist,
-                    int (*filter) (const struct dirent *),
-                    int (*cmp) (const struct dirent **, const struct dirent **))
-     _GL_ARG_NONNULL ((1, 2, 4));
+_GL_FUNCDECL_SYS (scandir, int,
+                  (const char *dir, struct dirent ***namelist,
+                   int (*filter) (const struct dirent *),
+                   int (*cmp) (const struct dirent **, const struct dirent **))
+                  _GL_ARG_NONNULL ((1, 2, 4)));
 # endif
+/* Need to cast, because on glibc systems, the fourth parameter is
+                        int (*cmp) (const void *, const void *).  */
+_GL_CXXALIAS_SYS_CAST (scandir, int,
+                       (const char *dir, struct dirent ***namelist,
+                        int (*filter) (const struct dirent *),
+                        int (*cmp) (const struct dirent **, const struct dirent **)));
+_GL_CXXALIASWARN (scandir);
 #elif defined GNULIB_POSIXCHECK
 # undef scandir
 # if HAVE_RAW_DECL_SCANDIR
@@ -106,9 +132,15 @@
 #if @GNULIB_ALPHASORT@
 /* Compare two 'struct dirent' entries alphabetically.  */
 # if !@HAVE_ALPHASORT@
-extern int alphasort (const struct dirent **, const struct dirent **)
-     _GL_ARG_NONNULL ((1, 2));
+_GL_FUNCDECL_SYS (alphasort, int,
+                  (const struct dirent **, const struct dirent **)
+                  _GL_ARG_NONNULL ((1, 2)));
 # endif
+/* Need to cast, because on glibc systems, the parameters are
+                       (const void *, const void *).  */
+_GL_CXXALIAS_SYS_CAST (alphasort, int,
+                       (const struct dirent **, const struct dirent **));
+_GL_CXXALIASWARN (alphasort);
 #elif defined GNULIB_POSIXCHECK
 # undef alphasort
 # if HAVE_RAW_DECL_ALPHASORT
@@ -117,10 +149,6 @@
 # endif
 #endif
 
-#ifdef __cplusplus
-}
-#endif
-
 
 #endif /* _GL_DIRENT_H */
 #endif /* _GL_DIRENT_H */

--- a/modules/dirent
+++ b/modules/dirent
@@ -8,6 +8,7 @@
 
 Depends-on:
 arg-nonnull
+c++defs
 include_next
 warn-on-use
 
@@ -19,7 +20,7 @@
 
 # We need the following in order to create <dirent.h> when the system
 # doesn't have one that works with the given compiler.
-dirent.h: dirent.in.h $(WARN_ON_USE_H) $(ARG_NONNULL_H)
+dirent.h: dirent.in.h $(CXXDEFS_H) $(ARG_NONNULL_H) $(WARN_ON_USE_H)
 	$(AM_V_GEN)rm -f $@-t $@ && \
 	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
 	  sed -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
@@ -36,6 +37,7 @@
 	      -e 's|@''REPLACE_CLOSEDIR''@|$(REPLACE_CLOSEDIR)|g' \
 	      -e 's|@''REPLACE_FDOPENDIR''@|$(REPLACE_FDOPENDIR)|g' \
 	      -e 's|@''REPLACE_OPENDIR''@|$(REPLACE_OPENDIR)|g' \
+	      -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \
 	      -e '/definition of _GL_ARG_NONNULL/r $(ARG_NONNULL_H)' \
 	      -e '/definition of _GL_WARN_ON_USE/r $(WARN_ON_USE_H)' \
 	      < $(srcdir)/dirent.in.h; \