stdapp.mk

Generic Makefile for building Erlang applications. Distributed under the MIT License (see the file LICENSE). Copyright (C) 2014-2017 Klarna AB. Written by Richard Carlsson.

Prerequisites: GNU Make, GNU AWK (gawk).

Use a simple Makefile wrapper like this for local use within an application:

# application-local Makefile
include stdapp.mk

Predefined Make targets:

build
tests
docs
install
clean
distclean
realclean
clean-tests
clean-docs

From a top level directory with a number of applications under a lib/ subdirectory, the following is a minimal example for building all applications:

# Top level Makefile
TOP_DIR = $(CURDIR)
APPS = $(wildcard lib/*)
BUILD_TARGETS = $(APPS:lib/%=build-%)

.PHONY: all $(BUILD_TARGETS)
all: $(BUILD_TARGETS)

$(BUILD_TARGETS):
        $(MAKE) -f $(TOP_DIR)/stdapp.mk -C $(patsubst build-%,lib/%,$@) \
          -I $(TOP_DIR) ERL_DEPS_DIR=$(TOP_DIR)/build/$(@:build-%=%) \
          build

Run make build-foo to build only the application foo. Add similar rules for other targets like tests, docs, clean, etc.

• Run with -jN for parallel builds. Add rules like build-foo: build-bar to control the build order of applications.

• A top level config.mk (e.g., generated via autoconf) will automatically be included if it exists. The file stdapp.local.mk is also included if it exists, for local customizations such as additional targets for all apps. Use the -I flag to tell make to where to look for these files.

• Additional rules and definitions needed for a specific application can be placed in a file apps/$(APPLICATION).mk, or in a file app.mk file in the application directory.

• Header file dependencies are computed using the built-in facilities of erlc. If you don't pass ERL_DEPS_DIR as in the above example, the .d (dependency) files will be placed in the ebin directory of each application.

• Note that the recursive $(MAKE) call runs from within the application directory, so it's best to use absolute paths based on TOP_DIR for the parameters passed from the top Makefile.

• The VPATH feature of GNU Make is used to find source files even if they are located in subdirectories of the src/ directory.

• Dependencies on behaviour or parse transform modules within the same application will be detected automatically. For compile-time module dependencies between applications, add build order rules to the top Makefile.

• VSN will be taken from any existing vsn.mk file, $(APPLICATION).app.src, or $(APPLICATION).app file in the application, or otherwise computed from the git tag (like Rebar does).

• If no $(APPLICATION).app.src file exists, one will be created. (If an $(APPLICATION).app file exists, it will be used to create the $(APPLICATION).app.src. You should keep the $(APPLICATION).app.src file in version control, but not the $(APPLICATION).app file.)

• The $(APPLICATION).app file is checked for readability to prevent nasty surprises.

The following is an example of a complementary app.mk file with additional rules for an application containing a port program in C under c_src:

build: $(PRIV_DIR)/foo_driver

clean: clean_priv

$(PRIV_DIR)/foo_driver: c_src/foo_driver.c | $(PRIV_DIR)
        $(CC) $(CFLAGS) -o $@ $<

$(PRIV_DIR):
        mkdir -p $(PRIV_DIR)

.PHONY: clean_priv
clean_priv:
        rm -f $(PRIV_DIR)/foo_driver