Support for cc -m32

[John Baldwin]

On Wednesday, November 17, 2010 2:57:51 pm Tijl Coosemans wrote:
> cc-m32-3.diff:
>     Modify amd64 headers to include i386 headers when compiling 32 bit code.
>     
>     All amd64 headers follow the following format:
>     
>     #ifndef _AMD64_HEADER_H_
>     #define _AMD64_HEADER_H_
>     
>     #ifdef __i386__
>     #include <i386/header.h>
>     #else
>     
>     /* Amd64 declarations go here. */
>     
>     #endif /* __i386__ */
>     #endif /* !_AMD64_HEADER_H_ */

I find this to be really ugly, and error prone (since it is a manual process).  
I'd prefer something that autogenerated headers in /usr/include/machine that
#include the appropriate version similar to what Warner suggested.

However, one issue with that approach (and this one) are headers that only 
exist for one platform.  The end result would be that that header would now 
exist for both platforms (in that if you do 'if [ -r 
/usr/include/machine/foo.h ]' it will be true).  We can make it #error or 
otherwise fail (by including a non-existing file for example), but if there 
was some way to have cc -m32 "magically" substitute "i386/" for "machine", 
that is what I would most prefer.  (This has problems too in that #include 
<machine/foo.h> would work with -m32 even though /usr/include/machine/foo.h 
doesn't exist, but /usr/include/i386/foo.h does.)

-- 
John Baldwin