erlang.mk

Common Makefile rules for building and testing Erlang applications.

Also features support for dependencies and a package index.

Requirements

erlang.mk requires GNU Make and expects to be ran in a standard unix environment with Erlang installed and in the $PATH.

erlang.mk uses wget for downloading the package index file.

erlang.mk will NOT work if the path contains spaces. This is a limitation of POSIX compatible make build tools.

Usage

Add the file erlang.mk to your project, then use the following base Makefile:

PROJECT = my_project
include erlang.mk

Alternatively you can use the following command to generate a skeleton of an OTP application:

$ make -f erlang.mk bootstrap

To generate a skeleton of an OTP library:

$ make -f erlang.mk bootstrap-lib

Finally if you are going to create a release of this project you may want to also use the bootstrap-rel target.

You can combine targets to perform many operations. For example, the shell command make clean app will have the effect of recompiling the application fully, without touching the dependencies.

A common workflow when editing a file would be to run make regularly to see if it compiles (or less often make clean app if you want to recompile everything), followed by make dialyze to see if there are any type errors and then make tests to run the test suites. The result of the test runs can be browsed from the logs/index.html file.

Getting help

You can use make help to get help about erlang.mk or its plugins.

Packages

A package index functionality is included with erlang.mk.

To use a package, you simply have to add it to the DEPS variable in your Makefile. For example this depends on Cowboy:

PROJECT = my_project
DEPS = cowboy
include erlang.mk

If the project you want is not included in the package index, or if you want a different version, a few options are available. You can edit the package file and contribute to it by opening a pull request. You can use a custom package file, in which case you will probably want to set the PKG_FILE2 variable to its location. Or you can put the project information directly in the Makefile.

In the latter case you need to create a variable dep_* with the asterisk replaced by the project name, for example cowboy. This variable must contain three things: the fetching method used, the URL and the version requested.

The following snippet overrides the Cowboy version required:

DEPS = cowboy
dep_cowboy = git https://github.com/ninenines/cowboy 1.0.0

They will always be compiled using the command make. If the dependency does not feature a Makefile, then erlang.mk will be used for building.

You can also specify test-only dependencies. These dependencies will only be downloaded when running make tests. The format is the same as above, except the variable TEST_DEPS holds the list of test-only dependencies.

TEST_DEPS = ct_helper
dep_ct_helper = git https://github.com/extend/ct_helper.git master

Please note that the test dependencies will only be compiled once when they are fetched, unlike the normal dependencies.

Releases

If a relx.config file is present, erlang.mk will download relx automatically and build the release into the _rel folder. This is the default command when the file exists.

No special configuration is required for this to work.

Customization

A custom erlang.mk may be created by editing the build.config file and then running make. Only the core package handling and erlc support are required.

If you need more functionality out of your Makefile, you can add extra targets after the include line, or create an erlang.mk plugin.

Defining a target before the include line will override the default target all.

The rest of this README starts by listing the core functionality and then details each plugin individually.

Core functionality

The following targets are standard:

all is equivalent to deps app rel.

deps fetches and compiles the dependencies.

app compiles the application.

rel builds the release.

docs generates the documentation.

tests runs the test suites.

clean deletes the output files.

distclean deletes the output files but also any intermediate files that are usually worth keeping around to save time, and any other files needed by plugins (for example the Dialyzer PLT file).

help gives some help about using erlang.mk.

You may add additional operations to them by using the double colons. Make will run all targets sharing the same name when invoked.

clean::
	@rm anotherfile

You can enable verbose mode by calling Make with the variable V set to 1.

$ V=1 make

Core package functionality

The following targets are specific to packages:

pkg-list lists all packages in the index.

pkg-search n=STRING searches the index for STRING.

Packages are downloaded into DEPS_DIR (./deps/ by default).

The package index file is downloaded from PKG_FILE_URL and saved in PKG_FILE2.

Core compiler functionality

erlang.mk will automatically compile the OTP application resource file found in src/$(PROJECT).app.src (do note it requires an empty modules line); Erlang source files found in src/*.erl or any subdirectory; Core Erlang source files found in src/*.core or any subdirectory; Leex source files found in src/*.xrl or any subdirectory; and Yecc source files found in src/*.yrl or any subdirectory.

You can change compilation options by setting the ERLC_OPTS variable. It takes the arguments that will then be passed to erlc. For more information, please see erl -man erlc.

You can specify a list of modules to be compiled first using the COMPILE_FIRST variable.

Bootstrap plugin

This plugin is available by default. It adds the following targets:

bootstrap generates a skeleton of an OTP application.

bootstrap-lib generates a skeleton of an OTP library.

bootstrap-rel generates the files needed to build a release.

new generate a skeleton module based on one of the available templates.

list-templates lists the available templates.

C compiler plugin

This plugin is not included by default. It is meant to simplify the management of projects that include C source code, like NIFs.

If the file $(C_SRC_DIR)/Makefile exists, then the plugin simply calls it when needed. Otherwise it tries to compile it directly.

You can use a different directory than ./c_src by setting the C_SRC_DIR variable.

You can override the output file by setting the C_SRC_OUTPUT variable.

You can override the temporary file containing information about Erlang's environment by setting the C_SRC_ENV variable. This file is automatically generated on first run.

Finally you can add extra compiler options using the C_SRC_OPTS variable. You can also override the defaults CC and CFLAGS if required.

Common_test plugin

This plugin is available by default.

There is nothing to configure to use it, simply create your test suites in the ./test/ directory and erlang.mk will figure everything out automatically.

You can override the list of suites that will run when using make tests by setting the CT_SUITES variable.

You can add extra ct_run options by defining the CT_OPTS variable. For more information please see erl -man ct_run.

You can run an individual test suite by using the special ct-* targets. For example if you have a common_test suite named spdy and you want to run only this suite and not the others, you can use the make ct-spdy command.

Dialyzer plugin

This plugin is available by default. It adds the following targets:

plt builds the PLT file for this application.

dialyze runs Dialyzer.

The PLT file is built in ./$(PROJECT).plt by default. You can override this location by setting the DIALYZER_PLT variable.

The PLT_APPS variable lists the applications that will be included in the PLT file. There is no need to specify erts, kernel, stdlib or the project's dependencies here, as they are automatically added.

Dialyzer options can be modified by defining the DIALYZER_OPTS variable. For more information please see erl -man dialyzer.

EDoc plugin

This plugin is available by default.

EDoc options can be specified in Erlang format by defining the EDOC_OPTS variable. For more information please see erl -man edoc.

ErlyDTL plugin

This plugin is available by default. It adds automatic compilation of ErlyDTL templates found in templates/*.dtl or any subdirectory.

Relx plugin

This plugin is available by default.

You can change the location of the relx executable (downloaded automatically) by defining the RELX variable, and the location of the configuration file by defining the RELX_CONFIG variable.

The URL used to download relx can be overriden by setting the RELX_URL variable.

You can change the generated releases location by setting the RELX_OUTPUT_DIR variable. Any other option should go in the RELX_OPTS variable.

If RELX_OPTS includes the -o option (instead of using RELX_OUTPUT_DIR, then that option must be the first in the list, otherwise erlang.mk will fail to find it and will not be able to clean up the release directory.

Contributing

You can contribute by providing feedback, creating patches, adding packages to the index or new features as plugins.

For packages, you only need to edit the packages.v2.tsv file, adding your package (they are sorted alphabetically), and then running make to update the older files kept for compatibility reasons.

For patches or plugins, you have to edit the core/*.mk or plugins/*.mk files and then run make to create an updated erlang.mk. If you submit a new plugin, you also need to add it to the build.config file.

Make sure to keep the commit title short, to have a single commit per package/feature/fix and you're good to submit a pull request! And again, please don't forget to run make and to commit the updated erlang.mk or index files along with your other changes. Thanks!

Support

• Official IRC Channel: #ninenines on irc.freenode.net
• Mailing Lists