[cfe-dev] Choosing the unwinder / C++ low-level libraries in Clang

[David Chisnall]

On 23 Jul 2015, at 13:54, Renato Golin <renato.golin at linaro.org> wrote:
> 
> On 23 July 2015 at 10:40, Renato Golin <renato.golin at linaro.org> wrote:
>> 1. Name. I want it to be short and to look like --rtlib. So I'm
>> looking for a short name matching --rt[a-z]{1,4}. "rtunw" or "rtcpp"
>> would mislead users in thinking it's either one of the other.
>> "rtextra" means very little and is too long. "rtbase", "rtlow",
>> "llrt"?
> 
> What about --rtimpl? Defining the implementation of the low-level
> functions used in the compiler run-time library?

I’m not sure what problem you’re trying to solve here.  These libraries tend to be tightly coupled to the platform, or possibly toolchain, not something that I’d want users to modify (unless they knew what they were doing enough to pass -nostdlib and provide the full set themselves).

On FreeBSD, we don’t explicitly link the C++ ABI library, because libc++.so is a linker script.  We link compiler-rt, but our build of compiler-rt is called libgcc, for compatibility.  On OS X, the libraries that implement these things are also quite specific.  On Windows, they’ll depend a lot on whether you’re using a Cygwin, MinGW, or VS toolchain.

David