Eliminate all usage of WIN32 and __WIN32__ macros: Some compilers (e.g. Clang/LLVM) don't define it, and _WIN32 is much more portable anyway.

See: [http://nadeausoftware.com/articles/2012/01/c_c_tip_how_use_compiler_predefined_macros_detect_operating_system#WindowsCygwinnonPOSIXandMinGW]

21 files changed, 79 insertions, 82 deletions

diff --git a/generic/tcl.h b/generic/tcl.h
index b7237bf..b93b3ac 100644
--- a/generic/tcl.h
+++ b/generic/tcl.h
@@ -67,15 +67,12 @@ extern "C" {
  * We use this method because there is no autoconf equivalent.
  */
 
-#ifndef __WIN32__
-#   if defined(_WIN32) || defined(WIN32) || defined(__MINGW32__) || defined(__BORLANDC__) || (defined(__WATCOMC__) && defined(__WINDOWS_386__))
+#ifdef _WIN32
+#   ifndef __WIN32__
 #	define __WIN32__
-#	ifndef WIN32
-#	    define WIN32
-#	endif
-#	ifndef _WIN32
-#	    define _WIN32
-#	endif
+#   endif
+#   ifndef WIN32
+#	define WIN32
 #   endif
 #endif
 
@@ -83,11 +80,11 @@ extern "C" {
  * STRICT: See MSDN Article Q83456
  */
 
-#ifdef __WIN32__
+#ifdef _WIN32
 #   ifndef STRICT
 #	define STRICT
 #   endif
-#endif /* __WIN32__ */
+#endif /* _WIN32 */
 
 /*
  * Utility macros: STRINGIFY takes an argument and wraps it in "" (double
@@ -191,7 +188,7 @@ extern "C" {
  *       MSVCRT.
  */
 
-#if (defined(__WIN32__) && (defined(_MSC_VER) || (defined(__BORLANDC__) && (__BORLANDC__ >= 0x0550)) || defined(__LCC__) || defined(__WATCOMC__) || (defined(__GNUC__) && defined(__declspec))))
+#if (defined(_WIN32) && (defined(_MSC_VER) || (defined(__BORLANDC__) && (__BORLANDC__ >= 0x0550)) || defined(__LCC__) || defined(__WATCOMC__) || (defined(__GNUC__) && defined(__declspec))))
 #   define HAVE_DECLSPEC 1
 #   ifdef STATIC_BUILD
 #       define DLLIMPORT
@@ -315,14 +312,14 @@ extern "C" {
  * VOID. This block is skipped under Cygwin and Mingw.
  */
 
-#if defined(__WIN32__) && !defined(HAVE_WINNT_IGNORE_VOID)
+#if defined(_WIN32) && !defined(HAVE_WINNT_IGNORE_VOID)
 #ifndef VOID
 #define VOID void
 typedef char CHAR;
 typedef short SHORT;
 typedef long LONG;
 #endif
-#endif /* __WIN32__ && !HAVE_WINNT_IGNORE_VOID */
+#endif /* _WIN32 && !HAVE_WINNT_IGNORE_VOID */
 
 /*
  * Macro to use instead of "void" for arguments that must have type "void *"
@@ -390,7 +387,7 @@ typedef long LONG;
  */
 
 #if !defined(TCL_WIDE_INT_TYPE)&&!defined(TCL_WIDE_INT_IS_LONG)
-#   if defined(__WIN32__)
+#   if defined(_WIN32)
 #      define TCL_WIDE_INT_TYPE __int64
 #      ifdef __BORLANDC__
 #         define TCL_LL_MODIFIER	"L"
@@ -400,7 +397,7 @@ typedef long LONG;
 #   elif defined(__GNUC__)
 #      define TCL_WIDE_INT_TYPE long long
 #      define TCL_LL_MODIFIER	"ll"
-#   else /* ! __WIN32__ && ! __GNUC__ */
+#   else /* ! _WIN32 && ! __GNUC__ */
 /*
  * Don't know what platform it is and configure hasn't discovered what is
  * going on for us. Try to guess...
@@ -415,7 +412,7 @@ typedef long LONG;
 #	     define TCL_WIDE_INT_TYPE long long
 #         endif
 #      endif /* NO_LIMITS_H */
-#   endif /* __WIN32__ */
+#   endif /* _WIN32 */
 #endif /* !TCL_WIDE_INT_TYPE & !TCL_WIDE_INT_IS_LONG */
 #ifdef TCL_WIDE_INT_IS_LONG
 #   undef TCL_WIDE_INT_TYPE
@@ -447,7 +444,7 @@ typedef unsigned TCL_WIDE_INT_TYPE	Tcl_WideUInt;
 #   define Tcl_DoubleAsWide(val)	((Tcl_WideInt)((double)(val)))
 #endif /* TCL_WIDE_INT_IS_LONG */
 
-#if defined(__WIN32__)
+#if defined(_WIN32)
 #   ifdef __BORLANDC__
 	typedef struct stati64 Tcl_StatBuf;
 #   elif defined(_WIN64)
@@ -562,7 +559,7 @@ typedef struct Tcl_ZLibStream_ *Tcl_ZlibStream;
  * will be called as the main fuction of the new thread created by that call.
  */
 
-#if defined __WIN32__
+#if defined _WIN32
 typedef unsigned (__stdcall Tcl_ThreadCreateProc) (ClientData clientData);
 #else
 typedef void (Tcl_ThreadCreateProc) (ClientData clientData);
@@ -574,7 +571,7 @@ typedef void (Tcl_ThreadCreateProc) (ClientData clientData);
  * in generic/tclThreadTest.c for it's usage.
  */
 
-#if defined __WIN32__
+#if defined _WIN32
 #   define Tcl_ThreadCreateType		unsigned __stdcall
 #   define TCL_THREAD_CREATE_RETURN	return 0
 #else
diff --git a/generic/tclClock.c b/generic/tclClock.c
index 6d2976d..50d480c 100644
--- a/generic/tclClock.c
+++ b/generic/tclClock.c
@@ -19,7 +19,7 @@
  * Windows has mktime. The configurators do not check.
  */
 
-#ifdef __WIN32__
+#ifdef _WIN32
 #define HAVE_MKTIME 1
 #endif
 
diff --git a/generic/tclCmdAH.c b/generic/tclCmdAH.c
index f90819a..d90a747 100644
--- a/generic/tclCmdAH.c
+++ b/generic/tclCmdAH.c
@@ -1590,7 +1590,7 @@ FileAttrIsOwnedCmd(
 	 * test for equivalence to the current user.
 	 */
 
-#if defined(__WIN32__) || defined(__CYGWIN__)
+#if defined(_WIN32) || defined(__CYGWIN__)
 	value = 1;
 #else
 	value = (geteuid() == buf.st_uid);
diff --git a/generic/tclDecls.h b/generic/tclDecls.h
index 830c998..91c0add 100644..100755
--- a/generic/tclDecls.h
+++ b/generic/tclDecls.h
@@ -63,7 +63,7 @@ EXTERN void		Tcl_DbCkfree(char *ptr, const char *file, int line);
 /* 8 */
 EXTERN char *		Tcl_DbCkrealloc(char *ptr, unsigned int size,
 				const char *file, int line);
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
 /* 9 */
 EXTERN void		Tcl_CreateFileHandler(int fd, int mask,
 				Tcl_FileProc *proc, ClientData clientData);
@@ -73,7 +73,7 @@ EXTERN void		Tcl_CreateFileHandler(int fd, int mask,
 EXTERN void		Tcl_CreateFileHandler(int fd, int mask,
 				Tcl_FileProc *proc, ClientData clientData);
 #endif /* MACOSX */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
 /* 10 */
 EXTERN void		Tcl_DeleteFileHandler(int fd);
 #endif /* UNIX */
@@ -511,7 +511,7 @@ EXTERN Tcl_Interp *	Tcl_GetMaster(Tcl_Interp *interp);
 EXTERN const char *	Tcl_GetNameOfExecutable(void);
 /* 166 */
 EXTERN Tcl_Obj *	Tcl_GetObjResult(Tcl_Interp *interp);
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
 /* 167 */
 EXTERN int		Tcl_GetOpenFile(Tcl_Interp *interp,
 				const char *chanID, int forWriting,
@@ -1835,19 +1835,19 @@ typedef struct TclStubs {
     char * (*tcl_DbCkalloc) (unsigned int size, const char *file, int line); /* 6 */
     void (*tcl_DbCkfree) (char *ptr, const char *file, int line); /* 7 */
     char * (*tcl_DbCkrealloc) (char *ptr, unsigned int size, const char *file, int line); /* 8 */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
     void (*tcl_CreateFileHandler) (int fd, int mask, Tcl_FileProc *proc, ClientData clientData); /* 9 */
 #endif /* UNIX */
-#if defined(__WIN32__) /* WIN */
+#if defined(_WIN32) /* WIN */
     void (*reserved9)(void);
 #endif /* WIN */
 #ifdef MAC_OSX_TCL /* MACOSX */
     void (*tcl_CreateFileHandler) (int fd, int mask, Tcl_FileProc *proc, ClientData clientData); /* 9 */
 #endif /* MACOSX */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
     void (*tcl_DeleteFileHandler) (int fd); /* 10 */
 #endif /* UNIX */
-#if defined(__WIN32__) /* WIN */
+#if defined(_WIN32) /* WIN */
     void (*reserved10)(void);
 #endif /* WIN */
 #ifdef MAC_OSX_TCL /* MACOSX */
@@ -2009,10 +2009,10 @@ typedef struct TclStubs {
     Tcl_Interp * (*tcl_GetMaster) (Tcl_Interp *interp); /* 164 */
     const char * (*tcl_GetNameOfExecutable) (void); /* 165 */
     Tcl_Obj * (*tcl_GetObjResult) (Tcl_Interp *interp); /* 166 */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
     int (*tcl_GetOpenFile) (Tcl_Interp *interp, const char *chanID, int forWriting, int checkUsage, ClientData *filePtr); /* 167 */
 #endif /* UNIX */
-#if defined(__WIN32__) /* WIN */
+#if defined(_WIN32) /* WIN */
     void (*reserved167)(void);
 #endif /* WIN */
 #ifdef MAC_OSX_TCL /* MACOSX */
@@ -2513,7 +2513,7 @@ extern const TclStubs *tclStubsPtr;
 	(tclStubsPtr->tcl_DbCkfree) /* 7 */
 #define Tcl_DbCkrealloc \
 	(tclStubsPtr->tcl_DbCkrealloc) /* 8 */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
 #define Tcl_CreateFileHandler \
 	(tclStubsPtr->tcl_CreateFileHandler) /* 9 */
 #endif /* UNIX */
@@ -2521,7 +2521,7 @@ extern const TclStubs *tclStubsPtr;
 #define Tcl_CreateFileHandler \
 	(tclStubsPtr->tcl_CreateFileHandler) /* 9 */
 #endif /* MACOSX */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
 #define Tcl_DeleteFileHandler \
 	(tclStubsPtr->tcl_DeleteFileHandler) /* 10 */
 #endif /* UNIX */
@@ -2841,7 +2841,7 @@ extern const TclStubs *tclStubsPtr;
 	(tclStubsPtr->tcl_GetNameOfExecutable) /* 165 */
 #define Tcl_GetObjResult \
 	(tclStubsPtr->tcl_GetObjResult) /* 166 */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
 #define Tcl_GetOpenFile \
 	(tclStubsPtr->tcl_GetOpenFile) /* 167 */
 #endif /* UNIX */
diff --git a/generic/tclEnv.c b/generic/tclEnv.c
index 8f51c1b..cd1a954 100644
--- a/generic/tclEnv.c
+++ b/generic/tclEnv.c
@@ -444,7 +444,7 @@ TclUnsetEnv(
      * that no = should be included, and Windows requires it.
      */
 
-#if defined(__WIN32__) || defined(__CYGWIN__)
+#if defined(_WIN32) || defined(__CYGWIN__)
     string = ckalloc(length + 2);
     memcpy(string, name, (size_t) length);
     string[length] = '=';
@@ -453,7 +453,7 @@ TclUnsetEnv(
     string = ckalloc(length + 1);
     memcpy(string, name, (size_t) length);
     string[length] = '\0';
-#endif /* WIN32 */
+#endif /* _WIN32 */
 
     Tcl_UtfToExternalDString(NULL, string, -1, &envString);
     string = ckrealloc(string, Tcl_DStringLength(&envString) + 1);
diff --git a/generic/tclFCmd.c b/generic/tclFCmd.c
index 13377d3..6452fff 100644
--- a/generic/tclFCmd.c
+++ b/generic/tclFCmd.c
@@ -517,7 +517,7 @@ CopyRenameOneFile(
 	 * 16 bits and we get collisions. See bug #2015723.
 	 */
 
-#if !defined(WIN32) && !defined(__CYGWIN__)
+#if !defined(_WIN32) && !defined(__CYGWIN__)
 	if ((sourceStatBuf.st_ino != 0) && (targetStatBuf.st_ino != 0)) {
 	    if ((sourceStatBuf.st_ino == targetStatBuf.st_ino) &&
 		    (sourceStatBuf.st_dev == targetStatBuf.st_dev)) {
diff --git a/generic/tclIOUtil.c b/generic/tclIOUtil.c
index 6259216..f624cb7 100644
--- a/generic/tclIOUtil.c
+++ b/generic/tclIOUtil.c
@@ -19,7 +19,7 @@
  */
 
 #include "tclInt.h"
-#ifdef __WIN32__
+#ifdef _WIN32
 #   include "tclWinInt.h"
 #endif
 #include "tclFileSystem.h"
@@ -792,7 +792,7 @@ TclFinalizeFilesystem(void)
      * filesystem is likely to fail.
      */
 
-#ifdef __WIN32__
+#ifdef _WIN32
     TclWinEncodingsCleanup();
 #endif
 }
@@ -819,7 +819,7 @@ TclResetFilesystem(void)
     filesystemList = &nativeFilesystemRecord;
     theFilesystemEpoch++;
 
-#ifdef __WIN32__
+#ifdef _WIN32
     /*
      * Cleans up the win32 API filesystem proc lookup table. This must happen
      * very late in finalization so that deleting of copied dlls can occur.
@@ -3255,7 +3255,7 @@ Tcl_LoadFile(
 	return TCL_ERROR;
     }
 
-#ifndef __WIN32__
+#ifndef _WIN32
     /*
      * Do we need to set appropriate permissions on the file? This may be
      * required on some systems. On Unix we could loop over the file
diff --git a/generic/tclIntDecls.h b/generic/tclIntDecls.h
index f95f999..f95f999 100644..100755
--- a/generic/tclIntDecls.h
+++ b/generic/tclIntDecls.h
diff --git a/generic/tclIntPlatDecls.h b/generic/tclIntPlatDecls.h
index 72719fe..2c74b5a 100644..100755
--- a/generic/tclIntPlatDecls.h
+++ b/generic/tclIntPlatDecls.h
@@ -13,7 +13,7 @@
 #ifndef _TCLINTPLATDECLS
 #define _TCLINTPLATDECLS
 
-#ifdef __WIN32__
+#ifdef _WIN32
 #   define Tcl_DirEntry void
 #   define DIR void
 #endif
@@ -45,7 +45,7 @@ extern "C" {
  * Exported function declarations:
  */
 
-#if !defined(__WIN32__) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
 /* 0 */
 EXTERN void		TclGetAndDetachPids(Tcl_Interp *interp,
 				Tcl_Channel chan);
@@ -104,7 +104,7 @@ EXTERN int		TclUnixOpenTemporaryFile(Tcl_Obj *dirObj,
 				Tcl_Obj *basenameObj, Tcl_Obj *extensionObj,
 				Tcl_Obj *resultingNameObj);
 #endif /* UNIX */
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
 /* 0 */
 EXTERN void		TclWinConvertError(DWORD errCode);
 /* 1 */
@@ -258,7 +258,7 @@ typedef struct TclIntPlatStubs {
     int magic;
     void *hooks;
 
-#if !defined(__WIN32__) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
     void (*tclGetAndDetachPids) (Tcl_Interp *interp, Tcl_Channel chan); /* 0 */
     int (*tclpCloseFile) (TclFile file); /* 1 */
     Tcl_Channel (*tclpCreateCommandChannel) (TclFile readFile, TclFile writeFile, TclFile errorFile, int numPids, Tcl_Pid *pidPtr); /* 2 */
@@ -291,7 +291,7 @@ typedef struct TclIntPlatStubs {
     int (*tclWinCPUID) (unsigned int index, unsigned int *regs); /* 29 */
     int (*tclUnixOpenTemporaryFile) (Tcl_Obj *dirObj, Tcl_Obj *basenameObj, Tcl_Obj *extensionObj, Tcl_Obj *resultingNameObj); /* 30 */
 #endif /* UNIX */
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
     void (*tclWinConvertError) (DWORD errCode); /* 0 */
     void (*tclWinConvertWSAError) (DWORD errCode); /* 1 */
     struct servent * (*tclWinGetServByName) (const char *nm, const char *proto); /* 2 */
@@ -371,7 +371,7 @@ extern const TclIntPlatStubs *tclIntPlatStubsPtr;
  * Inline function declarations:
  */
 
-#if !defined(__WIN32__) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
 #define TclGetAndDetachPids \
 	(tclIntPlatStubsPtr->tclGetAndDetachPids) /* 0 */
 #define TclpCloseFile \
@@ -420,7 +420,7 @@ extern const TclIntPlatStubs *tclIntPlatStubsPtr;
 #define TclUnixOpenTemporaryFile \
 	(tclIntPlatStubsPtr->tclUnixOpenTemporaryFile) /* 30 */
 #endif /* UNIX */
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
 #define TclWinConvertError \
 	(tclIntPlatStubsPtr->tclWinConvertError) /* 0 */
 #define TclWinConvertWSAError \
@@ -550,7 +550,7 @@ extern const TclIntPlatStubs *tclIntPlatStubsPtr;
 #undef TclpInetNtoa
 #define TclpInetNtoa inet_ntoa
 
-#if defined(__WIN32__) || defined(__CYGWIN__)
+#if defined(_WIN32) || defined(__CYGWIN__)
 #   undef TclWinNToHS
 #   define TclWinNToHS ntohs
 #else
diff --git a/generic/tclLoad.c b/generic/tclLoad.c
index 5cacab1..7c70e03 100644
--- a/generic/tclLoad.c
+++ b/generic/tclLoad.c
@@ -830,7 +830,7 @@ Tcl_UnloadObjCmd(
 	 * Unload the shared library from the application memory...
 	 */
 
-#if defined(TCL_UNLOAD_DLLS) || defined(__WIN32__)
+#if defined(TCL_UNLOAD_DLLS) || defined(_WIN32)
 	/*
 	 * Some Unix dlls are poorly behaved - registering things like atexit
 	 * calls that can't be unregistered. If you unload such dlls, you get
@@ -1151,7 +1151,7 @@ TclFinalizeLoad(void)
 	pkgPtr = firstPackagePtr;
 	firstPackagePtr = pkgPtr->nextPtr;
 
-#if defined(TCL_UNLOAD_DLLS) || defined(__WIN32__)
+#if defined(TCL_UNLOAD_DLLS) || defined(_WIN32)
 	/*
 	 * Some Unix dlls are poorly behaved - registering things like atexit
 	 * calls that can't be unregistered. If you unload such dlls, you get
diff --git a/generic/tclMain.c b/generic/tclMain.c
index faea75a..360f5e9 100644
--- a/generic/tclMain.c
+++ b/generic/tclMain.c
@@ -47,7 +47,7 @@
  * we have to translate that to strcmp here.
  */
 
-#ifndef __WIN32__
+#ifndef _WIN32
 #   define TCHAR char
 #   define TEXT(arg) arg
 #   define _tcscmp strcmp
diff --git a/generic/tclPathObj.c b/generic/tclPathObj.c
index b7f3dcf..fe6063f 100644
--- a/generic/tclPathObj.c
+++ b/generic/tclPathObj.c
@@ -512,7 +512,7 @@ TclFSGetPathType(
 
     if (PATHFLAGS(pathPtr) == 0) {
 	/* The path is not absolute... */
-#ifdef __WIN32__
+#ifdef _WIN32
 	/* ... on Windows we must make another call to determine whether
 	 * it's relative or volumerelative [Bug 2571597]. */
 	return TclGetPathType(pathPtr, filesystemPtrPtr, driveNameLengthPtr,
@@ -1956,7 +1956,7 @@ Tcl_FSGetNormalizedPath(
 		/*
 		 * We have a refCount on the cwd.
 		 */
-#ifdef __WIN32__
+#ifdef _WIN32
 	    } else if (type == TCL_PATH_VOLUME_RELATIVE) {
 		/*
 		 * Only Windows has volume-relative paths.
@@ -1969,7 +1969,7 @@ Tcl_FSGetNormalizedPath(
 		    return NULL;
 		}
 		pureNormalized = 0;
-#endif /* __WIN32__ */
+#endif /* _WIN32 */
 	    }
 	}
 
diff --git a/generic/tclPlatDecls.h b/generic/tclPlatDecls.h
index 681854d..abc8ee8 100644..100755
--- a/generic/tclPlatDecls.h
+++ b/generic/tclPlatDecls.h
@@ -50,7 +50,7 @@ extern "C" {
  * Exported function declarations:
  */
 
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
 /* 0 */
 EXTERN TCHAR *		Tcl_WinUtfToTChar(const char *str, int len,
 				Tcl_DString *dsPtr);
@@ -75,7 +75,7 @@ typedef struct TclPlatStubs {
     int magic;
     void *hooks;
 
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
     TCHAR * (*tcl_WinUtfToTChar) (const char *str, int len, Tcl_DString *dsPtr); /* 0 */
     char * (*tcl_WinTCharToUtf) (const TCHAR *str, int len, Tcl_DString *dsPtr); /* 1 */
 #endif /* WIN */
@@ -97,7 +97,7 @@ extern const TclPlatStubs *tclPlatStubsPtr;
  * Inline function declarations:
  */
 
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
 #define Tcl_WinUtfToTChar \
 	(tclPlatStubsPtr->tcl_WinUtfToTChar) /* 0 */
 #define Tcl_WinTCharToUtf \
diff --git a/generic/tclStubInit.c b/generic/tclStubInit.c
index e1918ef..097269f 100644..100755
--- a/generic/tclStubInit.c
+++ b/generic/tclStubInit.c
@@ -90,7 +90,7 @@ static unsigned short TclWinNToHS(unsigned short ns) {
 }
 #endif
 
-#ifdef __WIN32__
+#ifdef _WIN32
 #   define TclUnixWaitForFile 0
 #   define TclUnixCopyFile 0
 #   define TclUnixOpenTemporaryFile 0
@@ -557,7 +557,7 @@ static const TclIntStubs tclIntStubs = {
 static const TclIntPlatStubs tclIntPlatStubs = {
     TCL_STUB_MAGIC,
     0,
-#if !defined(__WIN32__) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(__CYGWIN__) && !defined(MAC_OSX_TCL) /* UNIX */
     TclGetAndDetachPids, /* 0 */
     TclpCloseFile, /* 1 */
     TclpCreateCommandChannel, /* 2 */
@@ -590,7 +590,7 @@ static const TclIntPlatStubs tclIntPlatStubs = {
     TclWinCPUID, /* 29 */
     TclUnixOpenTemporaryFile, /* 30 */
 #endif /* UNIX */
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
     TclWinConvertError, /* 0 */
     TclWinConvertWSAError, /* 1 */
     TclWinGetServByName, /* 2 */
@@ -661,7 +661,7 @@ static const TclIntPlatStubs tclIntPlatStubs = {
 static const TclPlatStubs tclPlatStubs = {
     TCL_STUB_MAGIC,
     0,
-#if defined(__WIN32__) || defined(__CYGWIN__) /* WIN */
+#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
     Tcl_WinUtfToTChar, /* 0 */
     Tcl_WinTCharToUtf, /* 1 */
 #endif /* WIN */
@@ -758,19 +758,19 @@ const TclStubs tclStubs = {
     Tcl_DbCkalloc, /* 6 */
     Tcl_DbCkfree, /* 7 */
     Tcl_DbCkrealloc, /* 8 */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
     Tcl_CreateFileHandler, /* 9 */
 #endif /* UNIX */
-#if defined(__WIN32__) /* WIN */
+#if defined(_WIN32) /* WIN */
     0, /* 9 */
 #endif /* WIN */
 #ifdef MAC_OSX_TCL /* MACOSX */
     Tcl_CreateFileHandler, /* 9 */
 #endif /* MACOSX */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
     Tcl_DeleteFileHandler, /* 10 */
 #endif /* UNIX */
-#if defined(__WIN32__) /* WIN */
+#if defined(_WIN32) /* WIN */
     0, /* 10 */
 #endif /* WIN */
 #ifdef MAC_OSX_TCL /* MACOSX */
@@ -932,10 +932,10 @@ const TclStubs tclStubs = {
     Tcl_GetMaster, /* 164 */
     Tcl_GetNameOfExecutable, /* 165 */
     Tcl_GetObjResult, /* 166 */
-#if !defined(__WIN32__) && !defined(MAC_OSX_TCL) /* UNIX */
+#if !defined(_WIN32) && !defined(MAC_OSX_TCL) /* UNIX */
     Tcl_GetOpenFile, /* 167 */
 #endif /* UNIX */
-#if defined(__WIN32__) /* WIN */
+#if defined(_WIN32) /* WIN */
     0, /* 167 */
 #endif /* WIN */
 #ifdef MAC_OSX_TCL /* MACOSX */
diff --git a/generic/tclTest.c b/generic/tclTest.c
index f121d0d..a27c95a 100644
--- a/generic/tclTest.c
+++ b/generic/tclTest.c
@@ -414,7 +414,7 @@ static int		TestNRELevels(ClientData clientData,
 static int		TestInterpResolverCmd(ClientData clientData,
 			    Tcl_Interp *interp, int objc,
 			    Tcl_Obj *const objv[]);
-#if defined(HAVE_CPUID) || defined(__WIN32__)
+#if defined(HAVE_CPUID) || defined(_WIN32)
 static int		TestcpuidCmd(ClientData dummy,
 			    Tcl_Interp* interp, int objc,
 			    Tcl_Obj *const objv[]);
@@ -681,7 +681,7 @@ Tcltest_Init(
 	    NULL, NULL);
     Tcl_CreateCommand(interp, "testexitmainloop", TestexitmainloopCmd,
 	    NULL, NULL);
-#if defined(HAVE_CPUID) || defined(__WIN32__)
+#if defined(HAVE_CPUID) || defined(_WIN32)
     Tcl_CreateObjCommand(interp, "testcpuid", TestcpuidCmd,
 	    (ClientData) 0, NULL);
 #endif
@@ -6648,7 +6648,7 @@ TestNumUtfCharsCmd(
     return TCL_OK;
 }
 
-#if defined(HAVE_CPUID) || defined(__WIN32__)
+#if defined(HAVE_CPUID) || defined(_WIN32)
 /*
  *----------------------------------------------------------------------
  *
diff --git a/generic/tclThreadJoin.c b/generic/tclThreadJoin.c
index 4b09e1c..5c70a62 100644
--- a/generic/tclThreadJoin.c
+++ b/generic/tclThreadJoin.c
@@ -14,7 +14,7 @@
 
 #include "tclInt.h"
 
-#ifdef WIN32
+#ifdef _WIN32
 
 /*
  * The information about each joinable thread is remembered in a structure as
@@ -305,7 +305,7 @@ TclSignalExitThread(
 
     Tcl_MutexUnlock(&threadPtr->threadMutex);
 }
-#endif /* WIN32 */
+#endif /* _WIN32 */
 
 /*
  * Local Variables:
diff --git a/tools/genStubs.tcl b/tools/genStubs.tcl
index b45e560..7a75dc6 100644
--- a/tools/genStubs.tcl
+++ b/tools/genStubs.tcl
@@ -283,7 +283,7 @@ proc genStubs::addPlatformGuard {plat iftxt {eltxt {}} {withCygwin 0}} {
     set text ""
     switch $plat {
 	win {
-	    append text "#if defined(__WIN32__)"
+	    append text "#if defined(_WIN32)"
 	    if {$withCygwin} {
 		append text " || defined(__CYGWIN__)"
 	    }
@@ -294,7 +294,7 @@ proc genStubs::addPlatformGuard {plat iftxt {eltxt {}} {withCygwin 0}} {
 	    append text "#endif /* WIN */\n"
 	}
 	unix {
-	    append text "#if !defined(__WIN32__)"
+	    append text "#if !defined(_WIN32)"
 	    if {$withCygwin} {
 		append text " && !defined(__CYGWIN__)"
 	    }
@@ -320,7 +320,7 @@ proc genStubs::addPlatformGuard {plat iftxt {eltxt {}} {withCygwin 0}} {
 	    append text "#endif /* AQUA */\n"
 	}
 	x11 {
-	    append text "#if !(defined(__WIN32__)"
+	    append text "#if !(defined(_WIN32)"
 	    if {$withCygwin} {
 		append text " || defined(__CYGWIN__)"
 	    }
diff --git a/win/configure b/win/configure
index 569172e..2affd38 100755
--- a/win/configure
+++ b/win/configure
@@ -3340,7 +3340,7 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-	    #ifndef __WIN32__
+	    #ifndef _WIN32
 		#error cross-compiler
 	    #endif
 
@@ -3463,7 +3463,7 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
-		#ifdef __WIN32__
+		#ifdef _WIN32
 		    #error win32
 		#endif
 
diff --git a/win/tcl.m4 b/win/tcl.m4
index 625c329..d12ae10 100644
--- a/win/tcl.m4
+++ b/win/tcl.m4
@@ -572,7 +572,7 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
       AC_CACHE_CHECK(for cross-compile version of gcc,
 	ac_cv_cross,
 	AC_TRY_COMPILE([
-	    #ifndef __WIN32__
+	    #ifndef _WIN32
 		#error cross-compiler
 	    #endif
 	], [],
@@ -639,7 +639,7 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	AC_CACHE_CHECK(for mingw32 version of gcc,
 	    ac_cv_win32,
 	    AC_TRY_COMPILE([
-		#ifdef __WIN32__
+		#ifdef _WIN32
 		    #error win32
 		#endif
 	    ], [],
diff --git a/win/tclWin32Dll.c b/win/tclWin32Dll.c
index 634e1d2..688fa8d 100644
--- a/win/tclWin32Dll.c
+++ b/win/tclWin32Dll.c
@@ -69,7 +69,7 @@ TCL_DECLARE_MUTEX(mountPointMap)
  * We will need this below.
  */
 
-#ifdef __WIN32__
+#ifdef _WIN32
 #ifndef STATIC_BUILD
 
 /*
@@ -137,7 +137,7 @@ DllMain(
     return TRUE;
 }
 #endif /* !STATIC_BUILD */
-#endif /* __WIN32__ */
+#endif /* _WIN32 */
 
 /*
  *----------------------------------------------------------------------
diff --git a/win/tclWinTest.c b/win/tclWinTest.c
index b83c0ba..6027e32 100644
--- a/win/tclWinTest.c
+++ b/win/tclWinTest.c
@@ -17,7 +17,7 @@
 /*
  * For TestplatformChmod on Windows
  */
-#ifdef __WIN32__
+#ifdef _WIN32
 #include <aclapi.h>
 #endif