llvm-project

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Benjamin Stott 7ceac4b1af [Lit] Open sub-processes with text=False (#194577 )

This PR is part of a series of patches upgrading Lit's in-process
built-ins to be able to run with piped input/output and full redirection
support, and to allow custom in-process builtns to be provided via the
Lit config. The remaining patches to Lit's test runner can be found here:
https://github.com/BStott6/llvm-project/compare/lit-inproc-builtins.

This is part of the Lit daemonized testing project:
https://discourse.llvm.org/t/88612

This PR makes Lit open all sub-processes with `text=False`, so that the
Python code will be able to read and write binary data to and from their
IO streams. This currently causes no functional change, as when Lit
reads output from the sub-processes, it already handles the case that
the read output is `bytes` by decoding it, but we will need to be able
to read binary data from a sub-process's STDIN if its output, which may
be binary, is piped into an in-process built-in, and we will need to be
able to write binary data to a sub-process's STDOUT if its input is
piped from an in-process builtin.

I have made sure that on Windows, when a sub-process invoked by Lit has
its output redirected to a file by Lit, the `\n -> \r\n` conversion is
performed as usual when writing to the file from the process - this
change only affects how the Python code interacts with the streams.

2026-04-28 16:36:28 +01:00

examples

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lit

[Lit] Open sub-processes with text=False (#194577 )

2026-04-28 16:36:28 +01:00

tests

[Lit] Change processRedirects to open all files in binary mode (#194368 )

2026-04-28 15:50:05 +01:00

utils

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CMakeLists.txt

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LICENSE.TXT

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lit.py

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MANIFEST.in

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pyproject.toml

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README.rst

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setup.py

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README.rst

===============================
 lit - A Software Testing Tool
===============================

About
=====

*lit* is a portable tool for executing LLVM and Clang style test suites,
summarizing their results, and providing indication of failures. *lit* is
designed to be a lightweight testing tool with as simple a user interface as
possible.


Features
========

 * Portable!
 * Flexible test discovery.
 * Parallel test execution.
 * Support for multiple test formats and test suite designs.


Documentation
=============

The official *lit* documentation is in the man page, available online at the LLVM
Command Guide: http://llvm.org/cmds/lit.html.


Source
======

The *lit* source is available as part of LLVM, in the LLVM source repository:
https://github.com/llvm/llvm-project/tree/main/llvm/utils/lit


Contributing to lit
===================

Please browse the issues labeled *tools:llvm-lit* in LLVM's issue tracker for
ideas on what to work on:
https://github.com/llvm/llvm-project/labels/tools%3Allvm-lit

Before submitting patches, run the test suite to ensure nothing has regressed::

    # From within your LLVM source directory.
    utils/lit/lit.py \
        --path /path/to/your/llvm/build/bin \
        utils/lit/tests

Note that lit's tests depend on ``not`` and ``FileCheck``, LLVM utilities.
You will need to have built LLVM tools in order to run lit's test suite
successfully.

You'll also want to confirm that lit continues to work when testing LLVM.
Follow the instructions in http://llvm.org/docs/TestingGuide.html to run the
regression test suite:

    make check-llvm

And be sure to run the llvm-lit wrapper script as well:

    /path/to/your/llvm/build/bin/llvm-lit utils/lit/tests

Finally, make sure lit works when installed via setuptools:

    python utils/lit/setup.py install
    lit --path /path/to/your/llvm/build/bin utils/lit/tests