[duped]

C/C++ compilers are tightly coupled to their runtimes, including their standard libraries. GCC is particularly bad about this.

On MacOS there is only one C standard library, and it is the interface to the operating system.

On Windows, your choice of standard library is tightly coupled to your tool chain.

On Linux, you can kind of mix and match, but it also impacts your loader.

[soulbadguy]

Your comment seems a bit self contradictory to me. You mentioned a strong coupling between runtime and compilers, but then go on giving example of the same compilers runtime with different runtime.

I suspect that the terminology we are using might be the culprit. Thinking of it as compilers, distribution/package and target might be helpful. Both LLVM and GCC are quite flexible in how they can be packaged and distributed to target various platform. A compiler distribution typically would include a (default) runtime, default options, std libraries and supporting tools (linker,debugger etc... etc...) for each supported target in the case of X-compilation.

A distribution is definitely strongly coupled to a host os/configuration. But the compiler proper not really.