bug#14043: 24.3.50; Compiler warning in cygw32 build on x86_64-cygwin

bug#14043: 24.3.50; Compiler warning in cygw32 build on x86_64-cygwin

[Ken Brown]

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In w32term.c:w32_initialize, the line

   DWORD input_locale_id = (DWORD) GetKeyboardLayout (0);

(line 6666 in the current trunk) generates a "cast from pointer to 
integer of different size" warning in the cygw32 build on 64-bit Cygwin. 
  I think that the warning can be safely ignored in this case, but I 
would prefer to avoid it.

The attached patch fixes this.  I'm wondering, however, whether the same 
warning occurs on 64-bit Windows.  If so, maybe that should be fixed at 
the same time, but I don't know enough about Windows programming to do this.

Ken

In GNU Emacs 24.3.50.2 (x86_64-pc-cygwin)
  of 2013-03-20 on fiona
Bzr revision: 112086 eggert@cs.ucla.edu-20130318210234-bpg2y8i713w6uqhr
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
  `configure --without-makeinfo --with-w32 CFLAGS=-g3 -O0'

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=== modified file 'src/w32term.c'
--- src/w32term.c	2013-03-15 10:07:29 +0000
+++ src/w32term.c	2013-03-23 05:52:28 +0000
@@ -6651,7 +6651,11 @@
   Fset_input_mode (Qnil, Qnil, make_number (2), Qnil);
 
   {
+#ifdef CYGWIN
+    uintptr_t input_locale_id = (uintptr_t) GetKeyboardLayout (0);
+#else
     DWORD input_locale_id = (DWORD) GetKeyboardLayout (0);
+#endif
     w32_keyboard_codepage =
       codepage_for_locale ((LCID) (input_locale_id & 0xffff));
   }

bug#14043: 24.3.50; Compiler warning in cygw32 build on x86_64-cygwin

[Eli Zaretskii]

> Date: Sat, 23 Mar 2013 12:40:38 -0400
> From: Ken Brown <kbrown@cornell.edu>
> 
> In w32term.c:w32_initialize, the line
> 
>    DWORD input_locale_id = (DWORD) GetKeyboardLayout (0);
> 
> (line 6666 in the current trunk) generates a "cast from pointer to 
> integer of different size" warning in the cygw32 build on 64-bit Cygwin. 
>   I think that the warning can be safely ignored in this case, but I 
> would prefer to avoid it.
> 
> The attached patch fixes this.

Does the alternative patch below also work?  I'd like to avoid
ifdef's, if possible.  If you still see a warning, please show the
64-bit Cygwin definitions for DWORD, DWORD_PTR, HANDLE, and HKL.

> I'm wondering, however, whether the same warning occurs on 64-bit
> Windows.

The Microsoft compiler emits much more warnings than even the latest
picky versions of GCC, so I'm quite sure it also warns here, and the
warning is (quite correctly) ignored.

=== modified file 'src/w32term.c'
--- src/w32term.c	2013-03-23 09:01:14 +0000
+++ src/w32term.c	2013-03-23 18:19:24 +0000
@@ -6663,7 +6663,7 @@ w32_initialize (void)
   Fset_input_mode (Qnil, Qnil, make_number (2), Qnil);
 
   {
-    DWORD input_locale_id = (DWORD) GetKeyboardLayout (0);
+    DWORD input_locale_id = ((DWORD_PTR) GetKeyboardLayout (0) & 0xffffffff);
     w32_keyboard_codepage =
       codepage_for_locale ((LCID) (input_locale_id & 0xffff));
   }

bug#14043: 24.3.50; Compiler warning in cygw32 build on x86_64-cygwin

[Ken Brown]

On 3/23/2013 2:25 PM, Eli Zaretskii wrote:
> Does the alternative patch below also work?  I'd like to avoid
> ifdef's, if possible.

Yes, it does.  I too am glad to see a solution that avoids the ifdefs.

Thanks.

Ken

bug#14043: 24.3.50; Compiler warning in cygw32 build on x86_64-cygwin

[Ken Brown]

On 3/23/2013 6:33 PM, Ken Brown wrote:
> On 3/23/2013 2:25 PM, Eli Zaretskii wrote:
>> Does the alternative patch below also work?  I'd like to avoid
>> ifdef's, if possible.
>
> Yes, it does.  I too am glad to see a solution that avoids the ifdefs.

I've committed the change as bzr revision 112120 and am closing the bug 
report.

Ken