panifex 1.1.1

A make-like DI-based Python build system.

Panifex: A Python Build System

Overview

Panifex is a Python build system that easily allows you to tie together various parts of a multi-stage build and to create reusable recipes. It is a good replacement for make and related tools.

Example Usage

The following example defines a bake.py script that builds a tetris game from its project root directory:

#!/usr/bin/env python
from panifex import build, sh, provide, target, default

sh.env(CC="clang", CFLAGS=("-g", "-I./include"), LDFLAGS=("-lncurses", "-lpanel"))

def compile(src):
    return sh(
        "{CC} -c {CFLAGS} {input} -o {output}",
        input=src,
        output=Path(src).with_suffix(".o"),
    )

def link(executable, objects):
    return sh("{CC} {LDFLAGS} {input} -o {output}", input=objects, output=executable)

@provide
def sources():
    return Path.cwd().glob("**/*.c")

@target
def objects(sources):
    return [compile(src) for src in sources]

@default
def executable(objects):
    return link("ntetris2", objects)

build()

In the above example, the following usage patterns are presented:

• build, sh, provide, target, and default are imported from panifex
  • build is the default build factory that provide, target, and default are bound to, and the functor that we'll need to invoke once we've defined all of our provides and targets.
  • sh is a recipe factory for generating shell-based file recipes.
  • provide indicates that the function provides a resource needed by other resources or targets, but that it is not a targetable build artifact.
  • target indicates that the function provides a resource needed by other resources or targets, and that it is a targetable build artifact.
  • default indicates that this function is the default targetable build artifact, and will be built if no targets are explicitly specified when invoking bake.
• CC, CFLAGS, and LDFLAGS are defined as environment variables through sh.env. sh.env extends the environment of the sh recipe factory with additional variables that are interpolated into the command string and added to the environment of commands run with this factory. In addition to OS environment variables which are added automatically as strings, lists or tuples can be specified in sh.env which will be interpolated correctly into command format strings.
• compile is defined. It is a normal function which calls the sh factory to generate a recipe for creating an .o output file for the given source file. compile is referred to as a "recipe function", because it is a function that generates a recipe from arguments. Calling this function itself does not run any commands, but instead the recipe generated should be returned from a build target, where it can be built in parallel with other dependencies in the overall dependency tree. The input and output parameters to sh are special and essential:
  • output specifies the name of the file that will be generated by the shell recipe. This is used to determine if the recipe actually needs to be run, and identifies the file that should be cleaned up while cleaning.
  • input is optional, and specifies the file(s) that will be used to create the output. If the output already exists but any of the input files are newer, the output will be re-created.
• link is defined as another recipe function for creating the final executable from a list of object files.
• sources is a provider. It defines the list of source files to be built.
• objects is the first target. It depends on sources because it has a parameter named sources which is automatically injected with the result from sources, that being a list of source filenames. It uses compile to create a list of recipes and returns them. Panifex will build these recipes in parallel, spawning at maximum as many simultaneous processes as the system has available processor cores.
• executable is the default target. It depends on objects, and as such won't actually run until all of the object file recipes generated by objects are done building. executable doesn't receive the list of object recipes, rather it receives a list containing all of the outputs specified by each recipe, that being a list of object filenames.

Release Notes

v1.1: 07/16/2020

• Added bake -l to list targets and their docstrings.

v1.0: 07/10/2020

• BACKWARDS INCOMPATIBLE CHANGE: End support for class based build modules.

v0.8: 07/04/2020

• Updated to support Xeno's new function providers, builds no longer have to be modeled as classes, but build() must be called at the end of the script.

v0.1: 01/02/2020

• Initial release.