RFC: Cygwin 64 bit?

[Corinna Vinschen]

On Jan 19 10:41, Andy Koppe wrote:
> On 19 January 2012 10:25, Corinna Vinschen wrote:
> > On Jan 18 15:54, Corinna Vinschen wrote:
> >> On Jan 18 14:23, Pedro Alves wrote:
> >> > I was looking for a technical reason that's worse, other then the
> >> > amount of mechanical work, which I'm sure could also be easily
> >> > scripted, with the long/int hidden behind a #define,
> >> > from the perspective of code that uses the headers. Â  It's obvious
> >> > the pragma is less intrusive to the headers.
> >>
> >> I can't think of any. Â In both cases you will get the type mismatches in
> >> certain circumstances within the LP64 code of the application.
> >>
> >> Hmm. Â The only other problem I could see with the #pragma approach is a
> >> potential clash of debug information within the same CU. Â If you use
> >> Windows headers you would potentially have two entries for long in
> >> .debug_info:
> >>
> >> Â From the LLP64 code:
> >>
> >> Â  Â <1><d0>: Abbrev Number: 2 (DW_TAG_base_type)
> >>       <d1>   DW_AT_byte_size   : 4
> >>       <d2>   DW_AT_encoding    : 5        (signed)
> >>       <d3>   DW_AT_name        : long int
> >>
> >> Â From the LP64 code in the same CU:
> >>
> >> Â  Â <1><dc>: Abbrev Number: 2 (DW_TAG_base_type)
> >>       <dd>   DW_AT_byte_size   : 8
> >>       <de>   DW_AT_encoding    : 5        (signed)
> >>       <df>   DW_AT_name        : long int
> >
> > That won't be the case, fortunately. Â A collegue has created a POC patch
> > which would result in only one entry for long, the "right" one with
> > DW_AT_byte_size 8, while the LLP64 usage of long would be converted to
> > the type int internally.
> 
> Great. Does that also avoid nonsensical error messages along the lines
> of "Cannot assign 'long *' to 'long *'"?

I don't know.  It was just a tiny patch to see if it works.  I guess
there would still be some polishing required.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
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