[PATCH] D89013: [libcxx] Support per-target __config_site in per-target runtime build

[Fangrui Song via Phabricator via cfe-commits]

MaskRay added a comment.

Supplement:
Even if you omit the vendor part in `-DLLVM_DEFAULT_TARGET_TRIPLE` (if unspecified, use `-DLLVM_HOST_TRIPLE`), `x86_64-linux-gnu`, you will see
`Target: x86_64-unknown-linux-gnu` in `clang -v` output (and similarly in `-dumpmachine`/`--print-target-triple`).

The reason is that clang normalizes the target triple quite early in toolchain selection.
(You may need debugging to figure out where.)

It'd probably make sense to honor `-DLLVM_DEFAULT_TARGET_TRIPLE` and don't add the omitted `vendor` part (`unknown` or `pc`), but it requires some work ;-)
Then Debian/Ubuntu and their derivatives will see `x86_64-linux-gnu` everywhere.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D89013/new/

https://reviews.llvm.org/D89013