[cfe-dev] Fwd: [PATCH]: add support for FreeBSD

[Chris Lattner]

bringing back to the mailing list

Begin forwarded message:

> From: Chris Lattner <clattner at apple.com>
> Date: October 10, 2008 8:16:59 AM PDT
> To: Roman Divacky <rdivacky at freebsd.org>
> Subject: Re: [cfe-dev] [PATCH]: add support for FreeBSD
>
>>> I think that wrapping the configuration logic with #ifdef  
>>> __freebsd__
>>> (or whatever is appropriate) would make sense.  Follow the lead of  
>>> the
>>> similar darwin code.
>>
>> thats not the problem :) the problem is that the given header file
>> does not have to be present on the machine we are building at.
>>
>> it's an internal freebsd sources header file.
>
> Ah ok, that won't work then.
>
>>
>>
>>>> I might ignite a discussion on the fbsd mailing list if we can  
>>>> change
>>>> the sources to export these two numbers to be exported in some
>>>> header file.
>>>
>>> On darwin, we autodetect using the "approved system interfaces".   
>>> The
>>> idea is that we want to be able to build a binary on darwin9 and  
>>> have
>>> it run find on darwin10.  The idea is that we want the compiler to
>>> default to generating code for the current OS, but that requires
>>> detecting it (since the build may have been done on a different  
>>> one).
>>>
>>> Make sense?
>>
>> well.. I could parse output of "touch dummy_file.c ; gcc -E -dM  
>> dummy_file.c"
>> to get the two defines. there's no other way to get this on  
>> runtime, is
>> this an acceptable solution?
>
> I'm confused about why that would be useful.  Worst case you could  
> parse the output of 'system("uname -a")' or something, no?   
> Presumably uname is implemented in terms of some library/system  
> call, and that could just be used instead?
>
> -Chris
>