[PATCH] D144179: [Clang] Added functionality to provide config file name via env variable

Fri Mar 3 05:16:37 PST 2023

mgabka added a comment.

In D144179#4146599 <https://reviews.llvm.org/D144179#4146599>, @MaskRay wrote:

> This looks like introducing a footgun (when something behaves differently from an upstream Clang, it would be difficult for toolchain maintainers to know why).
> Why can't your user specify `CLANG_CONFIG_FILE_SYSTEM_DIR`?

hi @MaskRay,
The reason we wanted to suggest use of environment variable is that the CLANG_CONFIG_FILE_SYSTEM_DIR is only defined at compilation time, after discussing it once again we would rather lean towards introducing an environment variable with similar semantics as CLANG_CONFIG_FILE_SYSTEM_DIR or rather ``CLANG_CONFIG_FILE_USER_DIR``, the motivation here is that it will allow to specify the directory to search for config files in a dynamic way, without need to recompile the compiler.
It is for user convenience in situations when they are using a system wide installation in a location where they do not have access right, and the ``CLANG_CONFIG_FILE_SYSTEM_DIR`` and ``CLANG_CONFIG_FILE_USER_DIR`` were not defined at build time.

We realised that environment variables are already used in this area, for example CLANG_NO_DEFAULT_CONFIG, so adding another one is not breaking existing convention.

What do you think about it?

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D144179/new/

https://reviews.llvm.org/D144179