Introduction

Depslint is a tool for analyzing and verifying build dependencies. It was written to assist switching a large project build system from an existing complex legacy solution to ninja.

The tool works by running a complete build under 'strace', recording relevant system calls to discover real 'dependencies', and then verifying that dependencies defined in the ninja manifest and the corresponding depfiles are correct.

Purpose

Verify a build manifest for:

• Correctness of the 'first build' (e.g., building following a pristine checkout, before any dep files are available). This is mostly useful for projects with autogenerated headers, to verify that build rules enforce autogenerated files to be created before including source files are compiled.

• Correctness of the 'incremental build' (e.g., rebuild following a modification of any of the files under the build tree when the tree already contains some of the build products and dep files).

• Redundant dependency specifications in the manifest making incremental rebuilds longer than needed.

• More..

Quick usage guide

cd ~/myproject ninja -t clean git clean -fdX

You can substitute the above with a suitable command cleaning your

build tree.

~/depslint/depstrace.py ninja

The above will build your project under 'strace', parse output and

store discovered dependency information in 'deps.lst'. The complete

strace output will also be stored in 'strace_log.txt' for debugging,

if necessary.

~/depslint/depslint.py --stats=all

Parse build.ninja, load depfiles, build dependency graph and

validate it using 'real' dependency information in 'deps.lst'. If

'.depslint' file is available, it can be used to set

'IGNORED_SUFFICES' and 'IMPLICIT_DEPS_MATCHERS' to ignore certain

dependecy issues. Tool output with extra details is stored to

'depslint.log'.

Documentation

The documentation will eventually appear under doc/.

Hacking & Testing

There are unit-tests available under 'tests' directory. You can run these as: 'python -m unittest tests' under project root. If you wish to contribute changes, it would be best if you will add supporting tests as well.