lchmod on mingw

[Bruno Haible]

On mingw, the C++ tests give this error:

../gllib/sys/stat.h:659: error: invalid conversion from `int (*)(const char*, 
int)' to `int (*)(const char*, mode_t)'

The reason is that the 'chmod' function in mingw has an 'int' as second
argument type. This fixes it:


2010-04-03  Bruno Haible  <address@hidden>

        sys_stat: Fix C++ test error on mingw.
        * build-aux/c++defs.h (_GL_CXXALIAS_RPL_CAST_1): New macro.
        * lib/sys_stat.in.h (lchmod): Use it instead of _GL_CXXALIAS_RPL_1.

--- build-aux/c++defs.h.orig    Sat Apr  3 12:51:48 2010
+++ build-aux/c++defs.h Sat Apr  3 12:50:14 2010
@@ -126,6 +126,24 @@
     _GL_EXTERN_C int _gl_cxxalias_dummy
 #endif
 
+/* _GL_CXXALIAS_RPL_CAST_1 (func, rpl_func, rettype, parameters);
+   is like  _GL_CXXALIAS_RPL_1 (func, rpl_func, rettype, parameters);
+   except that the C function rpl_func may have a slightly different
+   declaration.  A cast is used to silence the "invalid conversion" error
+   that would otherwise occur.  */
+#if defined __cplusplus && defined GNULIB_NAMESPACE
+# define _GL_CXXALIAS_RPL_CAST_1(func,rpl_func,rettype,parameters) \
+    namespace GNULIB_NAMESPACE                                     \
+    {                                                              \
+      rettype (*const func) parameters =                           \
+        reinterpret_cast<rettype(*)parameters>(::rpl_func);        \
+    }                                                              \
+    _GL_EXTERN_C int _gl_cxxalias_dummy
+#else
+# define _GL_CXXALIAS_RPL_CAST_1(func,rpl_func,rettype,parameters) \
+    _GL_EXTERN_C int _gl_cxxalias_dummy
+#endif
+
 /* _GL_CXXALIAS_SYS (func, rettype, parameters);
    declares a C++ alias called GNULIB_NAMESPACE::func
    that redirects to the system provided function func, if GNULIB_NAMESPACE
--- lib/sys_stat.in.h.orig      Sat Apr  3 12:51:48 2010
+++ lib/sys_stat.in.h   Sat Apr  3 12:51:42 2010
@@ -390,7 +390,10 @@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 #   define lchmod chmod
 #  endif
-_GL_CXXALIAS_RPL_1 (lchmod, chmod, int, (const char *filename, mode_t mode));
+/* Need to cast, because on mingw, the second parameter of chmod is
+                                                int mode.  */
+_GL_CXXALIAS_RPL_CAST_1 (lchmod, chmod, int,
+                         (const char *filename, mode_t mode));
 # else
 #  if 0 /* assume already declared */
 _GL_FUNCDECL_SYS (lchmod, int, (const char *filename, mode_t mode)