bug#722: More Visual Studio 6.0 compiler errors on Windows XP

bug#722: More Visual Studio 6.0 compiler errors on Windows XP

[Francis Litterio]

I found these additional compiler errors when building CVS Emacs with
Visual Studio 6.0 on Windows XP:

    dired.c(964) : error C2520: conversion from unsigned __int64 to double not implemented, use signed __int64

and:

    w32fns.c(250) : error C2143: syntax error : missing ')' before '__stdcall'
    w32fns.c(250) : error C2143: syntax error : missing '{' before '__stdcall'
    w32fns.c(250) : error C2059: syntax error : ')'
    w32fns.c(250) : error C2165: 'left-side modifier' : cannot modify pointers to data

The latter appears to be caused by the absense of a definition for the
symbol "HMONITOR".  The following patches fix both of the above errors.
--
Fran



--- dired.c~	2008-08-14 17:09:53.759788900 -0400
+++ dired.c	2008-08-14 17:13:16.585787100 -0400
@@ -961,7 +961,7 @@
   values[7] = make_number (s.st_size);
   /* If the size is out of range for an integer, return a float.  */
   if (XINT (values[7]) != s.st_size)
-    values[7] = make_float ((double)s.st_size);
+    values[7] = make_float ((signed __int64)s.st_size);
   /* If the size is negative, and its type is long, convert it back to
      positive.  */
   if (s.st_size < 0 && sizeof (s.st_size) == sizeof (long))


--- w32fns.c~	2008-08-14 17:23:58.614906000 -0400
+++ w32fns.c	2008-08-14 17:10:41.266229700 -0400
@@ -67,6 +67,8 @@
 #define FOF_NO_CONNECTED_ELEMENTS 0x2000
 #endif
 
+#define HMONITOR HANDLE
+
 void syms_of_w32fns ();
 void globals_of_w32fns ();
 

bug#722: More Visual Studio 6.0 compiler errors on Windows XP

[Andreas Schwab]

Francis Litterio <flitterio@gmail.com> writes:

> --- dired.c~	2008-08-14 17:09:53.759788900 -0400
> +++ dired.c	2008-08-14 17:13:16.585787100 -0400
> @@ -961,7 +961,7 @@
>    values[7] = make_number (s.st_size);
>    /* If the size is out of range for an integer, return a float.  */
>    if (XINT (values[7]) != s.st_size)
> -    values[7] = make_float ((double)s.st_size);
> +    values[7] = make_float ((signed __int64)s.st_size);

Tell Microsoft to fix their compiler, you are changeing perfectly valid
C into unportable junk.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

bug#722: More Visual Studio 6.0 compiler errors on Windows XP

[Eli Zaretskii]

> Date: Thu, 14 Aug 2008 17:11:12 -0400
> From: Francis Litterio <flitterio@gmail.com>
> Cc: 
> 
> --- w32fns.c~	2008-08-14 17:23:58.614906000 -0400
> +++ w32fns.c	2008-08-14 17:10:41.266229700 -0400
> @@ -67,6 +67,8 @@
>  #define FOF_NO_CONNECTED_ELEMENTS 0x2000
>  #endif
>  
> +#define HMONITOR HANDLE
> +

Does it work to replace this #define with the following line?

  DECLARE_HANDLE(HMONITOR);

bug#722: More Visual Studio 6.0 compiler errors on Windows XP

[Francis Litterio]

Andreas Schwab wrote:

> Francis Litterio writes:
>
>> --- dired.c~	2008-08-14 17:09:53.759788900 -0400
>> +++ dired.c	2008-08-14 17:13:16.585787100 -0400
>> @@ -961,7 +961,7 @@
>>    values[7] = make_number (s.st_size);
>>    /* If the size is out of range for an integer, return a float.  */
>>    if (XINT (values[7]) != s.st_size)
>> -    values[7] = make_float ((double)s.st_size);
>> +    values[7] = make_float ((signed __int64)s.st_size);
>
> Tell Microsoft to fix their compiler, you are changeing perfectly valid
> C into unportable junk.

You are preaching to the choir. :) I just want a clean build on Windows.
Emacs has always compiled using VC++ 6.0 in the past, so some change
must have introduced this problem.

I forgot that dired.c is not Windows-only code, so this patch is more
correct:

--- dired.c~	31 Jul 2008 05:33:51 -0000	1.153
+++ dired.c	15 Aug 2008 14:04:04 -0000
@@ -961,7 +961,11 @@
   values[7] = make_number (s.st_size);
   /* If the size is out of range for an integer, return a float.  */
   if (XINT (values[7]) != s.st_size)
+#if defined(WINDOWSNT)
+    values[7] = make_float ((signed __int64)s.st_size);
+#else
     values[7] = make_float ((double)s.st_size);
+#endif
   /* If the size is negative, and its type is long, convert it back to
      positive.  */
   if (s.st_size < 0 && sizeof (s.st_size) == sizeof (long))

Also, a 64-bit integer (signed or unsigned) cannot safely be cast to
double without loss of data.  An IEEE 754 64-bit floating value only has
52-bits of mantissa.  So the non-Windows implementation is not 100%
correct either.
--
Fran

bug#722: More Visual Studio 6.0 compiler errors on Windows XP

[Francis Litterio]

Eli Zaretskii wrote:

>> From: Francis Litterio
>> 
>> --- w32fns.c~	2008-08-14 17:23:58.614906000 -0400
>> +++ w32fns.c	2008-08-14 17:10:41.266229700 -0400
>> @@ -67,6 +67,8 @@
>>  #define FOF_NO_CONNECTED_ELEMENTS 0x2000
>>  #endif
>>  
>> +#define HMONITOR HANDLE
>> +
>
> Does it work to replace this #define with the following line?
>
>   DECLARE_HANDLE(HMONITOR);

Yes, that compiles.
--
Fran

bug#722: More Visual Studio 6.0 compiler errors on Windows XP

[Eli Zaretskii]

> Date: Fri, 15 Aug 2008 09:35:11 -0400
> From: Francis Litterio <flitterio@gmail.com>
> Cc: 
> 
> >> -    values[7] = make_float ((double)s.st_size);
> >> +    values[7] = make_float ((signed __int64)s.st_size);
> >
> > Tell Microsoft to fix their compiler, you are changeing perfectly valid
> > C into unportable junk.
> 
> You are preaching to the choir. :) I just want a clean build on Windows.
> Emacs has always compiled using VC++ 6.0 in the past, so some change
> must have introduced this problem.

The problems in w32.c are due to a recent change I did to impement two
new primitives, but the change in dired.c that made st_size be
unsigned 64-bit type is fairly old.  When did you last build the CVS
code?

> Also, a 64-bit integer (signed or unsigned) cannot safely be cast to
> double without loss of data.

Yes, when file sizes will start hitting 64-bits, we will start losing
precision here.  But I hope till then all compilers will have long
double data type, and then this code could be fixed.

bug#722: More Visual Studio 6.0 compiler errors on Windows XP

[Fran Litterio]

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Eli wrote:

> From: Francis Litterio

> Emacs has always compiled using VC++ 6.0 in the past, so some change
> > must have introduced this problem.
>
> The problems in w32.c are due to a recent change I did to impement two
> new primitives, but the change in dired.c that made st_size be
> unsigned 64-bit type is fairly old.  When did you last build the CVS
> code?
>

Some timestamp sleuthing leads me to believe it was Jan 19th, 2008.

> Also, a 64-bit integer (signed or unsigned) cannot safely be cast to
> > double without loss of data.
>
> Yes, when file sizes will start hitting 64-bits, we will start losing
> precision here.  But I hope till then all compilers will have long
> double data type, and then this code could be fixed.


Good point!
--
Fran

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bug#722: More Visual Studio 6.0 compiler errors on Windows XP

[Eli Zaretskii]

> Date: Fri, 15 Aug 2008 12:39:27 -0400
> From: "Fran Litterio" <flitterio@gmail.com>
> Cc: 722@emacsbugs.donarmstrong.com, schwab@suse.de, 
> 	bug-submit-list@donarmstrong.com, bug-gnu-emacs@gnu.org, 
> 	don@donarmstrong.com
> 
> > Emacs has always compiled using VC++ 6.0 in the past, so some change
> > > must have introduced this problem.
> >
> > The problems in w32.c are due to a recent change I did to impement two
> > new primitives, but the change in dired.c that made st_size be
> > unsigned 64-bit type is fairly old.  When did you last build the CVS
> > code?
> >
> 
> Some timestamp sleuthing leads me to believe it was Jan 19th, 2008.

In that case, it is quite probable that you didn't see those changes
then.

> > Also, a 64-bit integer (signed or unsigned) cannot safely be cast to
> > > double without loss of data.
> >
> > Yes, when file sizes will start hitting 64-bits, we will start losing
> > precision here.  But I hope till then all compilers will have long
> > double data type, and then this code could be fixed.
> 
> 
> Good point!

Maybe I should simply make st_size be a signed 64-bit type.  Does
anyone see any problems with that?

bug#722: More Visual Studio 6.0 compiler errors on Windows XP

[Eli Zaretskii]

> Cc: 722@emacsbugs.donarmstrong.com
> Date: Fri, 15 Aug 2008 10:20:54 -0400
> From: Francis Litterio <flitterio@gmail.com>
> 
> Eli Zaretskii wrote:
> 
> >> From: Francis Litterio
> >> 
> >> --- w32fns.c~	2008-08-14 17:23:58.614906000 -0400
> >> +++ w32fns.c	2008-08-14 17:10:41.266229700 -0400
> >> @@ -67,6 +67,8 @@
> >>  #define FOF_NO_CONNECTED_ELEMENTS 0x2000
> >>  #endif
> >>  
> >> +#define HMONITOR HANDLE
> >> +
> >
> > Does it work to replace this #define with the following line?
> >
> >   DECLARE_HANDLE(HMONITOR);
> 
> Yes, that compiles.

Thanks, installed.

bug#722: More Visual Studio 6.0 compiler errors on Windows XP

[Stefan Monnier]

> I found these additional compiler errors when building CVS Emacs with
> Visual Studio 6.0 on Windows XP:

Let's not spend any time trying to support this compiler.


        Stefan