Request to update libc++ related packages for current Clang/LLVM toolchain

Brian Inglis Brian.Inglis@SystematicSW.ab.ca
Sun Jan 18 08:22:32 GMT 2026


On 2026-01-18 00:45, Takashi Yano via Cygwin wrote:
> On Sun, 18 Jan 2026 00:35:37 +0000, kikairoya via Cygwin wrote:
>> 2026年1月15日 21:53:21 (+09:00) で、Takashi Yano via Cygwin さんが書きました:
>>> The resulted a.exe will be free from libgcc_s. Please try.

>> Using compiler-rt instead of libgcc_s requires extra attention in Cygwin,
>> because the emulated TLS functionality implemented in compiler-rt can't
>> share the storage across DLL boundaries.

> Thanks for pointing this out.
> The comment in the emutls.c explains that.
> https://github.com/llvm/llvm-project/blob/main/compiler-rt/lib/builtins/emutls.c#L378-L389
> Do you think this is a defect we should accept?

Is there a reason why llvm/clang/compiler-rt can not use Cygwin TLS and must use 
Emulated TLS?

Should this discussion be moved to -developers as that level of knowledge seems 
to be required?

-- 
Take care. Thanks, Brian Inglis              Calgary, Alberta, Canada

La perfection est atteinte                   Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter  not when there is no more to add
mais lorsqu'il n'y a plus rien à retrancher  but when there is no more to cut
                                 -- Antoine de Saint-Exupéry


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