[llvm][docs] Correct description of %t lit substitution

[DavidSpickett]

%t is currently documented as:
temporary file name unique to the test

https://llvm.org/docs/CommandGuide/lit.html#substitutions

Which I take to mean if the path is a/b/c/tempfile, then %t would be tempfile. It is not, it's the whole path.

(which is hinted at by %basename_t, but why would you read that if you didn't need to use it)

As seen in #164396 this can create confusion when people use it as if it were just the file name.

Make it clear in the docs that this is a unique path, which can be used to make files or folders.

[llvmbot]

@llvm/pr-subscribers-testing-tools

Author: David Spickett (DavidSpickett)

Changes

%t is currently documented as:
temporary file name unique to the test

https://llvm.org/docs/CommandGuide/lit.html#substitutions

Which I take to mean if the path is a/b/c/tempfile, then %t would be tempfile. It is not, it's the whole path.

(which is hinted at by %basename_t, but why would you read that if you didn't need to use it)

As seen in #164396 this can create confusion when people use it as if it were just the file name.

Make it clear in the docs that this is the path of a file.

---

Full diff: https://github.com/llvm/llvm-project/pull/164397.diff

1 Files Affected:

• (modified) llvm/docs/CommandGuide/lit.rst (+1-1)

diff --git a/llvm/docs/CommandGuide/lit.rst b/llvm/docs/CommandGuide/lit.rst
index 70daae46170cd..89adb003832ef 100644
--- a/llvm/docs/CommandGuide/lit.rst
+++ b/llvm/docs/CommandGuide/lit.rst
@@ -628,7 +628,7 @@ TestRunner.py:
  %{fs-src-root}          root component of file system paths pointing to the LLVM checkout
  %{fs-tmp-root}          root component of file system paths pointing to the test's temporary directory
  %{fs-sep}               file system path separator
- %t                      temporary file name unique to the test
+ %t                      the path of a temporary file unique to the test
  %basename_t             The last path component of %t but without the ``.tmp`` extension (deprecated, use ``%{t:stem}`` instead)
  %%                      %
  %/s                     %s but ``\`` is replaced by ``/``

[mstorsjo]

LGTM, thanks

[c-rhodes]

Also LGTM cheers, although looks like the description needs updating to drop the mention it's a file (since it's just a path that becomes a file or directory depending on what you do with it):

Make it clear in the docs that this is the path of a file.

[DavidSpickett]

Since this is about wording, I'll leave this open for a day or two and see if anyone else chimes in.