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

Tue Mar 30 19:46:52 PDT 2021

MaskRay added a comment.

Regarding

  /usr/include/x86_64-unknown-linux-gnu/c++/v1
  /usr/include/c++/v1

With GCC multiarch, some `include` search paths are preceded by machine-os-env specific suffix directories.
Note: 'vendor' is not there. So you may see `.../include/x86_64-linux-gnu` but there is no `.../include/x86_64-{pc,unknown}-linux-gnu`

  /usr/local/include/x86_64-linux-gnu         # affected by sysroot, multiarch, usually nonexistent
  /usr/local/include                          # affected by sysroot
  /tmp/opt/gcc-debug/include
  /tmp/opt/gcc-debug/lib/gcc/x86_64-pc-linux-gnu/11.0.1/include-fixed
  /tmp/opt/gcc-debug/lib/gcc/x86_64-pc-linux-gnu/11.0.1/../../../../x86_64-pc-linux-gnu/include
  /usr/include/x86_64-linux-gnu               # affected by sysroot, multiarch
  /usr/include                                # affected by sysroot

On Debian x86_64, `/usr/include/x86_64-linux-gnu/` exists. Adding `x86_64-pc-linux-gnu` (an possible value of `LLVM_DEFAULT_TARGET_TRIPLE`) may add more confusion.

Repository:
  rG LLVM Github Monorepo

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

https://reviews.llvm.org/D89013