[PATCH] D35396: [lit] Make %T return a per-test temporary directory

[Dan Liew via Phabricator via llvm-commits]

delcypher added a comment.

In https://reviews.llvm.org/D35396#839504, @george.karpenkov wrote:

> @delcypher I think LIT already does some magic to work with Windows, right? Many tests use `mkdir`, otherwise none of them would run.


The lit  shell tests have two modes. Internal and external. External just invokes bash and the internal shell implements a shell command parser in python.

The `executeScriptInternal()` function in `TestRunner.py` handles running commands using the internal shell. This eventually calls `_executeShCmd()`. If you look at the implementation is has special support of a few shell built-ins (namely `cd`, `echo`, `export` and `env`). I don't see any special support for `mkdir` though. If the command doesn't start with `.` then `lit.util.which()` will be used to find the executable. So AFAICT `mkdir` will just run the `mkdir` command when using the internal shell.

The approach I've used in the past to handle different system tools is to add a substitution that expands to the command appropriate for the platform.

E.g.

https://github.com/symbooglix/symbooglix/blob/master/test_programs/lit.site.cfg#L116


https://reviews.llvm.org/D35396