Re: Patch for config.guess for "cross-compiling" x86_64 -> powerpc on Mac OS X <= 10.6

[Mojca Miklavec]

On 27 May 2017 at 13:16, Ben Elliston wrote:
> On Mon, Apr 24, 2017 at 12:26:19PM +0200, Mojca Miklavec wrote:
>
>> In this particular case the compiler has already been consulted once with
>>
>>     if (echo '#ifdef __LP64__'; echo IS_64BIT_ARCH; echo '#endif') | \
>>         (CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) | \
>>         grep IS_64BIT_ARCH >/dev/null
>>
>> to determine that this is not x86_64. Is it a problem to ask it once
>> more? (And why?)
>
> Alright, I give in.

Thank you very much, this helps me a lot :)

>> But in case you *really* want to avoid ever using CC_FOR_BUILD: why
>> is it even called for Darwin?
>
> CC_FOR_BUILD was introduced 15 years ago.  There are 11 instances of
> it that I've been trying to get rid of ever since.  Have a look at the
> lines after the line matching ^set_cc.  It's pure horror.

I agree that the code is basically unreadable :)
I tried to replicate it in my "stripped-down" version of
"find-out-which-platform-we-are-running-on", but gave up.

I still believe that it would be really nice to split this project
into two parts (using the same common base), one calling the compiler
to find more details about the target platform and the other one
trying to avoid that entirely. But of course that's quite a bit of
work.

Thanks again for patching this.
    Mojca