reggae 0.3.1

Reggae

A build system in D. This is alpha software, only tested on Linux and likely to have breaking changes made.

Features

• Write readable build descriptions in D
• Out-of-tree builds
• Backends for GNU make, ninja and a binary executable backend.
• User-defined variables like CMake in order to choose features before compile-time
• Low-level DAG build descriptions + high-level convenience rules to build C, C++ and D
• Automatic header dependency detection for C, C++ and D
• Automatically runs itself if the build description changes
• Rules for using dub build targets in your own build decription - use dub with ninja, add to it, ...

Usage

Reggae is actually a meta build system and works similarly to CMake or Premake. Those systems require writing configuration files in their own proprietary languages. The configuration files for Reggae are written in D.

From a build directory (usually not the same as the source one), type reggae -b <ninja|make|binary> </path/to/project>. This will create the actual build system depending on the backend chosen, for Ninja, GNU Make, or a runnable executable, respectively. The project path passed must either:

1. Contain a a file named reggaefile.d with the build configuration
2. Be a dub project

Dub projects with no reggaefile.d will have one generated for them in the build directory.

How to write build configurations

The best examples can be found in the features directory. Each reggaefile.d must contain one and only one function with a return value of type Build. This function can be generated automatically with the build template mixin. The Build struct is a container for Target structs, which themselves may depend on other targets.

Arbritrary build rules can be used. Here is an example of a simple D build reggaefile.d:

import reggae;
const mainObj  = Target("main.o",  "dmd -I$project/src -c $in -of$out", Target("src/main.d"));
const mathsObj = Target("maths.o", "dmd -c $in -of$out", Target("src/maths.d"));
const app = Target("myapp", "dmd -of$out $in", [mainObj, mathsObj]);
mixin build!(app);

That was just an example. To build D apps with no external dependencies, this will suffice:

import reggae;
alias app = executable!(App("src/main.d", "myapp"),
                        Flags("-g -debug"),
                        ImportPaths(["/path/to/imports"])
                        );
mixin build!(app);

There are also other functions and pre-built rules for C and C++ objects. There is no HTML documentation yet but the package file contains the relevant DDoc with details. Other subpackages might contain DDoc of their own.

Dub integration

The easiest dub integration is to run reggae with a directory containing a dub project as parameter. That will create a build system that would do the same as "dub build" but probably faster. In all likelihood a user needing reggae will need more than that, and reggae provides an API to use dub build information in a reggaefile.d build description file. A simple example for building production and unittest binaries concurrently is this:

import reggae;
alias main = dubDefaultTarget!("-g -debug");
alias ut = dubConfigurationTarget!(ExeName("ut"), Configuration("unittest"));
mixin build!(main, ut);

Depending on whether or not the dub project in questions uses configurations, reggae's dub support might not work before this pull request is merged.

Building Reggae

Reggae can build itself. To bootstrap, either use dub or the included bootstrap script. Call it without arguments for make or with one to choose another backend, such as ninja. This will create a reggae binary in a bin directory then call itself to generate the "real" build system with the requested backend. The reggae-enabled build includes a unit test binary.

Goals

1. No external dependencies, including on dub
2. Minimal boilerplate for writing build configurations
3. Flexibility for low-level tasks with built-in common tasks