Define MINGW_W64 and use it instead of _W64

... for detecting MinGW-w64. _W64 is not specific of MinGW-w64, it is
defined for compatibility with MS VC++.

	* nt/inc/ms-w32.h: Define MINGW_W64.

	* admin/CPP-DEFINES: Mention MINGW_W64.

	* nt/addpm.c: Use it.

	* nt/addsection.c: Use it.

	* nt/preprep.c: Use it.

	* src/w32.c: Use MINGW_W64 instead of _W64

	* src/w32term.c: Likewise.

5 files changed, 27 insertions, 8 deletions

diff --git a/nt/ChangeLog b/nt/ChangeLog
index 5ffab4d0151..cb2f33f947b 100644
--- a/nt/ChangeLog
+++ b/nt/ChangeLog
@@ -1,3 +1,13 @@
+2014-11-17  Oscar Fuentes  <ofv@wanadoo.es>
+
+        * inc/ms-w32.h: Define MINGW_W64.
+
+        * nt/addpm.c: Use it.
+
+        * nt/addsection.c: Use it.
+
+        * nt/preprep.c: Use it.
+
 2014-10-31  Eric S. Raymond  <esr@thyrsus.com>
 
         * Neutralize language specific to a repository type.
diff --git a/nt/addpm.c b/nt/addpm.c
index 18057b58b49..f7cfba39d08 100644
--- a/nt/addpm.c
+++ b/nt/addpm.c
@@ -38,9 +38,8 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <stdio.h>
 #include <malloc.h>
 
-/* MinGW64 defines _W64 and barfs if _WIN32_IE is defined to anything
-   below 0x500.  */
-#ifndef _W64
+/* MinGW64 barfs if _WIN32_IE is defined to anything below 0x500.  */
+#ifndef MINGW_W64
 #define _WIN32_IE 0x400
 #endif
 /* Request C Object macros for COM interfaces.  */
diff --git a/nt/addsection.c b/nt/addsection.c
index a897573480d..832066b68c0 100644
--- a/nt/addsection.c
+++ b/nt/addsection.c
@@ -25,7 +25,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
 #include <stdio.h>
 #include <fcntl.h>
 #include <time.h>
-#if defined(__GNUC__) && !defined(_W64)
+#if defined(__GNUC__) && !defined(MINGW_W64)
 #define _ANONYMOUS_UNION
 #define _ANONYMOUS_STRUCT
 #endif
diff --git a/nt/inc/ms-w32.h b/nt/inc/ms-w32.h
index 8f7c36ab1ee..1d45df743de 100644
--- a/nt/inc/ms-w32.h
+++ b/nt/inc/ms-w32.h
@@ -26,6 +26,16 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <mingw_time.h>
 
+/* MinGW-w64 gcc does not automotically define a macro for
+   differentiating it fom MinGW gcc. We need to test the presence of
+   __MINGW64_VERSION_MAJOR in _mingw.h: */
+#ifdef __MINGW32__
+# include <_mingw.h>
+# ifdef __MINGW64_VERSION_MAJOR
+#  define MINGW_W64
+# endif
+#endif
+
 /* #undef const */
 
 /* Number of chars of output in the buffer of a stdio stream. */
@@ -139,7 +149,7 @@ extern char *getenv ();
    versions we still support.  MinGW64 defines this to a higher value
    in its system headers, and is not really compatible with values
    lower than 0x0500, so leave it alone.  */
-#ifndef _W64
+#ifndef MINGW_W64
 # define _WIN32_WINNT 0x0400
 #endif
 
@@ -165,7 +175,7 @@ extern char *getenv ();
 
 #ifdef emacs
 
-#ifdef _W64
+#ifdef MINGW_W64
 /* MinGW64 specific stuff.  */
 /* Make sure 'struct timespec' and 'struct timezone' are defined.  */
 #include <sys/types.h>
@@ -368,7 +378,7 @@ typedef int sigset_t;
 typedef int ssize_t;
 #endif
 
-#ifdef _W64     /* MinGW64 */
+#ifdef MINGW_W64
 #ifndef _POSIX
 typedef _sigset_t sigset_t;
 #endif
diff --git a/nt/preprep.c b/nt/preprep.c
index fda937df0e0..39a9b70e953 100644
--- a/nt/preprep.c
+++ b/nt/preprep.c
@@ -25,7 +25,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
 #include <stdio.h>
 #include <fcntl.h>
 #include <time.h>
-#if defined(__GNUC__) && !defined(_W64)
+#if defined(__GNUC__) && !defined(MINGW_W64)
 #define _ANONYMOUS_UNION
 #define _ANONYMOUS_STRUCT
 #endif