Is "host" the build or the target system?

[David Holmes]

On 25/05/2012 7:13 AM, Fredrik Öhrström wrote:
> Hey guys! You are falling into the old tar pit of "not invented here" mentality that Sun was rather (in)famous for.

Please drop the rhetoric and stick with facts.

> If there is a standard, then we should follow it.

It isn't a "standard" it is a convention adopted by one tool chain by a 
small group of people who had their debates and discussions and chose 
something that "worked" for them (with numerous revisions).

I too have worked on embedded systems in the past, long before Java, or 
autoconf and what you are cross-compiling for has always been the 
TARGET. These cross-compilers are even referred to as re-targetable 
compilers. This is true even today:

http://sdcc.sourceforge.net/

"SDCC is a retargettable, optimizing ANSI - C compiler suite that 
targets the Intel 8051, Maxim 80DS390, Zilog Z80, Z180, Rabbit 2000 and 
the Motorola 68HC08 based MCUs. "

As Magnus explained the autoconf folk had to deal with three different 
platforms and they chose their naming to deal with that. As far as I am 
concerned what they came up with is totally wrong for the simple case of 
cross-compiling general programs. Always doing something the wrong way 
doesn't make it right, it just makes it consistently wrong.

Magnus' compromise is fine with me - more than fine!

David
-----

> Let me quote from the GNU autoconf manual
> "Based on the experience of compiler writers, and after long public debates, many aspects of the cross-compilation chain have changed:" and "The relationship between build, host, and target have been cleaned up:"
>
> Thus, the people responsible for autoconf/configure have already rehashed this several times. This is what they came up with,
> and this is what is described on all pages when you search for cross compile, and this is what is described on wikipedia about
> cross compiling and autoconf, and this is what is used by other projects that use configure and autoconf.
>
> We cannot just change the default behavior of configure, just because it feels better with some other english words....
>
> You are running on i686-unknown-linux-gnu,
> you want to build a cross compiler, then use:
> --target=sparc-sun-solaris2_10 when configuring gcc
>
> Now you want to use your newly created cross compiler (sparc-sun-solaris2_10-gcc in your path)
> to build a binary of application foo, for your sparc:
> --host=sparc-sun-solaris2_10 when configuring foo
>
> To hack configure to alias --target to --host will not make life easier for us and it will introduce
> a use case that we will have to support for ever, and this might be difficult in the future when
> autoconf is upgraded.
>
> At the moment, we cannot compile static binaries from the OpenJDK, we only run within a runtime,
> but it clearly is not farfetched to assume that such a feature would be desirable. gcj has it already.
> Thus --target might be valuable for exactly its specified purpose some time in the future.
>
> Sorry for the quick backout, but I had to back out the change quickly since it affected quite a lot of variables
> and it would be inconvenient if someone managed to do another merge after it.
>
> //Fredrik
>
> ----- kelly.ohair at oracle.com skrev:
>
>> Ok.  You've sold me the bridge. I may need some time and a few glasses
>> of wine, but I think I am with you.
>>
>> I'm still a little shocked at the autoconf terminology.  Seems like
>> they completely complicated things for a situation
>> that was extremely rare and few people would ever need to do or even
>> care about.
>>
>> For the record, I'm in favor of your compromise.  Thanks for the time
>> in explaining it to this autoconf novice, me. ;^)
>>
>> -kto
>>
>> On May 24, 2012, at 1:30 PM, Magnus Ihse Bursie wrote:
>>
>>> On 2012-05-24 17:00, Kelly O'Hair wrote:
>>>> So we should talk about this, and maybe come up with a compromise
>> or alternative terminology.
>>>
>>> Just to be clear: My suggestion was to use "build system" for the
>> platform you are building on, and "target system" for the platform the
>> resulting binary should run on, and that we should stay clear of
>> "host".
>>>
>>> Rationale: "build system" and "target system" seems hard to
>> misunderstand, regardless of your previous experiences.
>>>
>>> "Host" on the other hand, is vague enough to be able to be used in
>> the sense of "build system" (as in the old openjdk makefiles) or as
>> "target system" (as in the autoconf tradition), depending (I guess) if
>> your mindset is centered on the build process or the resulting binary.
>> So I say: don't use it at all.
>>>
>>> This means that:
>>> * The openjdk tradition of calling the target system "target" is
>> kept, but the build system will be renamed from "host" to "build".
>>> * The autoconf tradition of calling the build system "build" is
>> kept, but the target system will be renamed from "host" to "target".
>>>
>>> I think it sounds like a good compromise. :)
>>>
>>> /Magnus