Re: header file substitutes

[Collin Funk]

On 5/4/24 11:07 PM, Paul Eggert wrote:
>> Since <sys/endian.h> seems resonably portable,
> 
> I assume you mean <endian.h>? There's no <sys/endian.h> on my Ubuntu system.

No, sorry maybe I worded my original email awkwardly. :)

I think all of the BSDs have <sys/endian.h> which define:

    #define LITTLE_ENDIAN 1234
    #define BIG_ENDIAN 4321
    #define BYTE_ORDER /* One of thsoe macros.  */

>From what I can tell, they also had ntohl and friends there. I think
that glibc added the be32toh macros and extended that header, while
also moving it to <endian.h>.

My history might be a bit wrong there. The headers predate me by a few
years. :)

I was trying to say that a macro sequence like this could do most of
the heavy lifting:

    #if HAVE_ENDIAN_H
    #  include <endian.h>
    #elif HAVE_SYS_ENDIAN_H
    #  include <sys/endian.h>
    #endif

Since the BSDs and Solaris should define the same stuff in
<sys/endian.h>.

> Although that's a start, we'll need more of course. Here's what I have so far 
> for my prototype stdbit.in.h, but it needs more work. This sort of thing used 
> to be even trickier (see gl_BIGENDIAN and gl_MULTIARCH) but I hope we can 
> dispense with that complexity nowadays (by using something like the following 
> complexity instead :-).

Looks good to me. You got more of the compiler stuff than I would
have.

Collin