[LLVMdev] unwind's permanent residence

[Jonathan Roelofs]

+Iain

On 2/3/15 5:07 AM, Renato Golin wrote:
> On 30 January 2015 at 20:43, Jonathan Roelofs <jonathan at codesourcery.com> wrote:
>> Last time we brought this up, there was only partial consensus, and then
>> someone arbitrarily declared total consensus (without compelling arguments
>> in any particular direction) that we were going to move it to compiler_rt.
>> Then the discussion fell on the floor because no-one had time to actually do
>> the move. Please, let's not let that happen again this time.
>
> So, do we have a consensus?
>
> AFAICS, the most agree solution (with optionals to be defined):
>
> 1. Move Unwinder to its own repository in the LLVM server
> 2. Make the CMake connections from libc++abi and compiler-rt
>    2.1 OPTIONAL 1: err if libunwinder is not there, clang errs if rtlib=RT
>    2.2 OPTIONAL 2: warns if libunwind is not there, clang errs if rtlib=RT
>    2.3 OPTIONAL 3: nothing, make clang smarter to pick existing unwinder
> 3. Change clang to assume -lunwind when --rtlib=compiler-rt
>    3.1 OPTIONAL 4: allow linker error if no -lunwind / -lgcc_s
>    3.2 OPTIONAL 5: Add option to change unwinder library by not adding
> -lunwind/-lgcc_s, but whatever comes as argument
>
> 1, 2, and 3 must be changed.
>
> I vote for adding { 2.2, 3.1 } for now, { 2.2, 3.1, 3.2 } for later.
>
> My idea for 3.2 is something like --unwinder=libgcc_s / libunwind, or
> something like that.
>
> I personally don't think the front-end scanning existing libraries is
> a good thing to do, but I'm not against the idea, if anyone feels
> strongly about it.
>
> If all of us could agree to a common solution, and make sure all
> interested parties are in, we should do the move before 3.7.
>
> Please, cast your votes.
Out-of-band +1 on this from Iain Sandoe.
>
> cheers,
> --renato
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>

-- 
Jon Roelofs
jonathan at codesourcery.com
CodeSourcery / Mentor Embedded