[Buildroot] [PATCH v2 23/23] toolchain-external: introduce and use external toolchain infra

[Romain Naour <romain.naour@gmail.com>]

Hi Thomas,

Le 01/11/2016 ? 14:23, Thomas Petazzoni a ?crit :
> Hello,
> 
> On Sun, 30 Oct 2016 19:38:20 +0100, Romain Naour wrote:
>>> +source "toolchain/toolchain-external/toolchain-external-blackfin-uclinux/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-arago-armv5te/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-arago-armv7a/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-codescape-mti-mips/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-codescape-img-mips/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-linaro-aarch64/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-linaro-arm/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-linaro-armeb/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-musl-cross/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-codesourcery-aarch64/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-codesourcery-amd64/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-codesourcery-arm/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-codesourcery-mips/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-codesourcery-niosII/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-codesourcery-sh/Config.in"
>>> +source "toolchain/toolchain-external/toolchain-external-codesourcery-x86/Config.in"  
>>
>> The codesourcery toolchains were named sourcery in a previous version of this
>> series, but now it's not sorted alphabetically.
>> Also, for ARM the default toochain choice is arago which is an very old
>> toolchain (2011), do we want to keep the default ARM choice to linaro or
>> codesourcery toolchain ?
> 
> You're talking about Arago vs. Sourcery, and you conclude with a
> question about Linaro vs. Sourcery, so I'm confused.

There are two problem in this patch:
1) The alphabetical order (Sourcery toolchains) which is fixed easily.
2) With toolchains sorted alphabetically, the current default choice is changed
silently with the introduction of the external toolchain infra.

> 
> So:
> 
>  - The Linaro toolchain is EABIhf, the Sourcery toolchain is EABI, so
>    there is never a choice between Linaro and Sourcery for a given
>    target configuration.

Ok for this one but my concern was about Sourcery over Arago ARM toolchains and
Sourcery over Codescape MIPS toolchains. Notice that Linaro provide an EABI
toolchains [1], if someone add this toolchain in Buildroot we will have a choice
between Linaro and Sourcery toolchains.

My understanding is: currently we have a list of "preferred" toolchains with a
fall back to custom toolchains. So even if we want to keep toolchains sorted
alphabetically here, we have to make an exception for toolchain-external-custom
package.

> 
>  - The Arago toolchain is indeed old, and I'd rather not use it for our
>    default on ARM. Maybe we can keep an alphabetic ordering, and add a
>    "default" Config.in clause in the choice...endchoice? Yes, it is
>    weird to have such a default in the generic code, but I don't see
>    another option.

I guess you don't really like the patch 24/24 of the last series (v3):
http://patchwork.ozlabs.org/patch/689378/

Adding a "default" in Config.in may be difficult to maintain over the time.

Thoughts ?

Best regards,
Romain

[1]
https://releases.linaro.org/components/toolchain/binaries/5.3-2016.05/arm-linux-gnueabi

> 
> Thanks,
> 
> Thomas
>