Re: [PATCH 0/2] New target hook TARGET_COMPUTE_MULTILIB and implementation for RISC-V

[Palmer Dabbelt <palmer@dabbelt.com>]

On Thu, 29 Jul 2021 11:44:09 PDT (-0700), gcc-patches@gcc.gnu.org wrote:
> ping
>
> On Wed, Jul 21, 2021 at 5:28 PM Kito Cheng <kito.cheng@sifive.com> wrote:
>>
>> This patch set allow target to use customized multi-lib mechanism rather than the built-in
>> multi-lib mechanism.
>>
>> The motivation of this patch is RISC-V might have very complicated multi-lib re-use
>> rule*, which is hard to maintain and use current multi-lib scripts,
>> we even hit the "argument list too long" error when we tried to add more
>> multi-lib reuse rule.
>>
>> * Here is an example for RISC-V multi-lib rules:
>> https://gist.github.com/kito-cheng/0289cd42d9a756382e5afeb77b42b73b
>>
>> V2 Changes:
>> - NO changes for first patch(TARGET_COMPUTE_MULTILIB part) since first version.
>> - Handle option other than -march and -mabi for riscv_compute_multilib.

This generally LGTM, but I think it's the sort of thing that should be 
looked at by a global reviewer.  There's a bit of a policy decision 
being made here in that this allows external hooks during the build 
process.

I'm fine with this, as it's just the multilib list, those are really 
specific to a specific toolchain distribution, and there's never going 
to be a way to catalog all the interested cases for the embedded 
toolchains.  I'm still not comfortable calling that a review, though, as 
these things are subtle and I don't always have the same bar for 
external bits that the rest of the GCC folks do.