CMake already knows per-compiler specific properties. This would be one of them.

-- Gaby


________________________________
From: SG15 <sg15-bounces_at_[hidden]> on behalf of Daniel Ruoso via SG15 <sg15_at_[hidden]>
Sent: Thursday, December 14, 2023 7:26:59 AM
To: Chuanqi Xu <chuanqi.xcq_at_[hidden]>
Cc: Daniel Ruoso <daniel_at_[hidden]>; SG15 <sg15_at_[hidden]>
Subject: Re: [SG15] What is the outcome of the 12-12 meeting for the initial question: the location of std module units?

On Thu, Dec 14, 2023, 09:58 Chuanqi Xu <chuanqi.xcq_at_[hidden]<mailto:chuanqi.xcq_at_[hidden]>> wrote:
I don't think there is a **default standard library** for a compiler. For example, for clang, clang will find the libstdc++ on linux but libc++ on macos. It is actually highly platform dependent. The compiler just hardcode these things in the driver.

That's only true in the abstract.

In practice the compiler, for the user invoking it, has a default standard library defined at build time.

When you invoke CMake without specifying anything, it will just accept the compiler it finds in the PATH, and it will just trust that it has a baked in standard library when you invoke it.

So, in that scenario, what are the steps that CMake would do to discover the path to the metadata file?

Daniel