blight

blight is a framework for wrapping and instrumenting build tools.

Usage

$ pip3 install blight
$ eval $(blight-env --guess-wrapped)
$ export BLIGHT_ACTIONS="Record"
$ export BLIGHT_ACTION_RECORD="output=/tmp/demo.jsonl"
$ cd /your/project && make
$ cat /tmp/demo.jsonl

Goals

• Wrapping CC, CXX, CPP, LD, AS, AR, STRIP, and INSTALL.
• Providing a visitor-style API for each of the above, pre- and post-execution.
• Providing a nice set of default actions.
• Being as non-invasive as possible.

Anti-goals

• Using LD_PRELOAD to capture every exec in a build system, a la Bear.
• Supporting cl.exe.
• Detailed support for non C/C++ languages.

Contributing a new action

New blight actions are easy to write. For example, the following prints a message before every ld invocation:

# src/blight/actions/printld.py

from blight.action import LDAction


class PrintLD(LDAction):
    def before_run(self, tool):
        print(f"ld was run with: {tool.args}")

# src/blight/actions/__init__.py

# bring PrintLD into blight.actions so that `BLIGHT_ACTIONS` can find it
from printld import PrintLD  # noqa: F401

$ eval $(blight-env --guess-wrapped)
$ export BLIGHT_ACTIONS="PrintLD"
$ make

Check out blight's API documentation for more details, including the kinds of available actions.

The name?

Build systems and tools that instrument build systems are a blight on my productivity.