improve support for MSVC 9

[Bruno Haible]

When compiling libiconv for MSVC 9, I'm seeing this error:

/home/bruno/msvc/compile cl -nologo -DHAVE_CONFIG_H -DEXEEXT=\".exe\" -I. -I.. 
-I../lib  -I../intl -DDEPENDS_ON_LIBICONV=1 -DDEPENDS_ON_LIBINTL=1 
-D_WIN32_WINNT=_WIN32_WINNT_WINXP -I/usr/local/msvc/include  -MD -c 
canonicalize-lgpl.c
canonicalize-lgpl.c
C:\Programme\Microsoft Visual Studio 9.0\VC\include\io.h(317) : error C2375: 
'rpl_read': redefinition; different binding
        .\unistd.h(1519): see declaration of 'rpl_read'

Obviously, if <io.h> contains a definition of the read() function, it needs
to be #included before we do a "#define read rpl_read". This fixes it
and a couple of similar situations.


2012-01-15  Bruno Haible  <address@hidden>

        Improve support for MSVC 9.
        * lib/unistd.in.h: Include <io.h> when needed to avoid redefinition
        clashes on MSVC.
        * lib/fcntl.in.h: Likewise.
        * lib/stdlib.in.h: Likewise.
        * lib/sys_stat.in.h: Likewise.

--- lib/fcntl.in.h.orig Sun Jan 15 17:32:52 2012
+++ lib/fcntl.in.h      Sun Jan 15 17:26:28 2012
@@ -62,6 +62,12 @@
 # include <unistd.h>
 #endif
 
+/* Native Windows platforms declare open(), creat() in <io.h>.  */
+#if (@GNULIB_OPEN@ || defined GNULIB_POSIXCHECK) \
+    && ((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__)
+# include <io.h>
+#endif
+
 
 /* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
 
--- lib/stdlib.in.h.orig        Sun Jan 15 17:32:53 2012
+++ lib/stdlib.in.h     Sun Jan 15 17:27:20 2012
@@ -49,6 +49,11 @@
 # include <sys/loadavg.h>
 #endif
 
+/* Native Windows platforms declare mktemp() in <io.h>.  */
+#if 0 && ((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__)
+# include <io.h>
+#endif
+
 #if @GNULIB_RANDOM_R@
 
 /* OSF/1 5.1 declares 'struct random_data' in <random.h>, which is included
--- lib/sys_stat.in.h.orig      Sun Jan 15 17:32:53 2012
+++ lib/sys_stat.in.h   Sun Jan 15 17:23:12 2012
@@ -62,6 +62,11 @@
 # include <direct.h> /* mingw64, MSVC 9 */
 #endif
 
+/* Native Windows platforms declare umask() in <io.h>.  */
+#if 0 && ((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__)
+# include <io.h>
+#endif
+
 #ifndef S_IFIFO
 # ifdef _S_IFIFO
 #  define S_IFIFO _S_IFIFO
--- lib/unistd.in.h.orig        Sun Jan 15 17:32:53 2012
+++ lib/unistd.in.h     Sun Jan 15 17:31:19 2012
@@ -84,12 +84,19 @@
 #endif
 
 /* Native Windows platforms declare chdir, getcwd, rmdir in
-   <io.h> and/or <direct.h>, not in <unistd.h>.  */
+   <io.h> and/or <direct.h>, not in <unistd.h>.
+   They also declare access(), chmod(), close(), dup(), dup2(), isatty(),
+   lseek(), read(), unlink(), write() in <io.h>.  */
 #if ((@GNULIB_CHDIR@ || @GNULIB_GETCWD@ || @GNULIB_RMDIR@ \
       || defined GNULIB_POSIXCHECK) \
      && ((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__))
 # include <io.h>     /* mingw32, mingw64 */
 # include <direct.h> /* mingw64, MSVC 9 */
+#elif (@GNULIB_CLOSE@ || @GNULIB_DUP@ || @GNULIB_DUP2@ || @GNULIB_ISATTY@ \
+       || @GNULIB_LSEEK@ || @GNULIB_READ@ || @GNULIB_UNLINK@ || @GNULIB_WRITE@ 
\
+       || defined GNULIB_POSIXCHECK) \
+      && ((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__)
+# include <io.h>
 #endif
 
 /* AIX and OSF/1 5.1 declare getdomainname in <netdb.h>, not in <unistd.h>.