Implement cygw32

Here, we use the generic window-system configuration system we just
implemented to support the w32 window-system in the mainline build
under Cygwin.  (Previously, the w32 window system could only be
compiled as part of the NT-native Emacs build process.)

The changes in this patch need to be applied atomically in order to
avoid breaking Emacs.  The changes include:

  - Changes throughout the Lisp and C code to not assume that
      NT Emacs and the w32 window system are synonymous.

  - Wiring up the regular select(2) event loop to Windows messages

  - Cleaning up the w32 drag-and-drop receiving code.

  - Exposing Cygwin path conversion functions to elisp.

  - Unicode file dialog support when compiling for Cygwin.

  - Splitting the w32 term lisp initialization code into code
    applicable to any w32 window-system and code specific to
    system-type windows-nt.

  - Integrating the old and new w32 code into the build system.

1 files changed, 25 insertions, 1 deletions

diff --git a/src/w32menu.c b/src/w32menu.c
index 3aa4c8bc96d..886fd55bbe9 100644
--- a/src/w32menu.c
+++ b/src/w32menu.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <signal.h>
 #include <stdio.h>
-#include <mbstring.h>
 #include <setjmp.h>
 
 #include "lisp.h"
@@ -41,6 +40,14 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    if this is not done before the other system files.  */
 #include "w32term.h"
 
+/* Cygwin does not support the multibyte string functions declared in
+ * mbstring.h below --- but that's okay: because Cygwin is
+ * UNICODE-only, we don't need to use these functions anyway.  */
+
+#ifndef NTGUI_UNICODE
+#include <mbstring.h>
+#endif /* !NTGUI_UNICODE */
+
 /* Load sys/types.h if not already loaded.
    In some systems loading it twice is suicidal.  */
 #ifndef makedev
@@ -79,10 +86,17 @@ typedef int (WINAPI * MessageBoxW_Proc) (
     IN WCHAR *caption,
     IN UINT type);
 
+#ifdef NTGUI_UNICODE
+#define get_menu_item_info GetMenuItemInfoA
+#define set_menu_item_info SetMenuItemInfoA
+#define unicode_append_menu AppendMenuW
+#define unicode_message_box MessageBoxW
+#else /* !NTGUI_UNICODE */
 GetMenuItemInfoA_Proc get_menu_item_info = NULL;
 SetMenuItemInfoA_Proc set_menu_item_info = NULL;
 AppendMenuW_Proc unicode_append_menu = NULL;
 MessageBoxW_Proc unicode_message_box = NULL;
+#endif /* NTGUI_UNICODE */
 
 Lisp_Object Qdebug_on_next_call;
 
@@ -99,6 +113,7 @@ static void utf8to16 (unsigned char *, int, WCHAR *);
 static int fill_in_menu (HMENU, widget_value *);
 
 void w32_free_menu_strings (HWND);
+
 
 
 /* This is set nonzero after the user activates the menu bar, and set
@@ -1406,6 +1421,7 @@ add_menu_item (HMENU menu, widget_value *wv, HMENU item)
                 nlen++;
             }
         }
+#ifndef NTGUI_UNICODE
       else
         {
           /* If encoded with the system codepage, use multibyte string
@@ -1416,6 +1432,7 @@ add_menu_item (HMENU menu, widget_value *wv, HMENU item)
                 nlen++;
             }
         }
+#endif /* !NTGUI_UNICODE */
 
       if (nlen > orig_len)
         {
@@ -1430,6 +1447,7 @@ add_menu_item (HMENU menu, widget_value *wv, HMENU item)
                     *q++ = *p;
                   *q++ = *p++;
                 }
+#ifndef NTGUI_UNICODE
               else
                 {
                   if (_mbsnextc (p) == '&')
@@ -1441,6 +1459,7 @@ add_menu_item (HMENU menu, widget_value *wv, HMENU item)
                   p = _mbsinc (p);
                   q = _mbsinc (q);
                 }
+#endif /* !NTGUI_UNICODE */
             }
           *q = '\0';
         }
@@ -1487,6 +1506,8 @@ add_menu_item (HMENU menu, widget_value *wv, HMENU item)
 					  item != NULL ? (UINT) item
 					    : (UINT) wv->call_data,
 					  utf16_string);
+
+#ifndef NTGUI_UNICODE /* Fallback does not apply when always UNICODE */
       if (!return_value)
 	{
 	  /* On W9x/ME, Unicode menus are not supported, though AppendMenuW
@@ -1505,6 +1526,7 @@ add_menu_item (HMENU menu, widget_value *wv, HMENU item)
 	  if (osinfo_cache.dwPlatformId != VER_PLATFORM_WIN32_NT)
 	    unicode_append_menu = NULL;
 	}
+#endif /* NTGUI_UNICODE */
 
       if (unicode_append_menu && (fuFlags & MF_OWNERDRAW))
 	local_free (out_string);
@@ -1724,10 +1746,12 @@ syms_of_w32menu (void)
 void
 globals_of_w32menu (void)
 {
+#ifndef NTGUI_UNICODE
   /* See if Get/SetMenuItemInfo functions are available.  */
   HMODULE user32 = GetModuleHandle ("user32.dll");
   get_menu_item_info = (GetMenuItemInfoA_Proc) GetProcAddress (user32, "GetMenuItemInfoA");
   set_menu_item_info = (SetMenuItemInfoA_Proc) GetProcAddress (user32, "SetMenuItemInfoA");
   unicode_append_menu = (AppendMenuW_Proc) GetProcAddress (user32, "AppendMenuW");
   unicode_message_box = (MessageBoxW_Proc) GetProcAddress (user32, "MessageBoxW");
+#endif /* !NTGUI_UNICODE */
 }