Scala Rules for Bazel

Rules

• scala_library/scala_macro_library
• scala_binary

Overview

This rule is used for building Scala projects with Bazel. There are currently three rules, scala_library, scala_macro_library and scala_binary. More features will be added in the future, e.g. scala_test.

In order to use this build rule, you must add the following to your WORKSPACE file:

new_http_archive(
    name = "scala",
    strip_prefix = "scala-2.11.7",
    sha256 = "ffe4196f13ee98a66cf54baffb0940d29432b2bd820bd0781a8316eec22926d0",
    url = "http://downloads.typesafe.com/scala/2.11.7/scala-2.11.7.tgz",
    build_file = "tools/build_defs/scala/scala.BUILD",
)

scala_library / scala_macro_library

scala_library(name, srcs, deps, data, main_class, resources, scalacopts, jvm_flags)
scala_macro_library(name, srcs, deps, data, main_class, resources, scalacopts, jvm_flags)

scala_library generates a .jar file from .scala source files. This rule also creates an interface jar to avoid recompiling downstream targets unless then interface changes.

scala_macro_library generates a .jar file from .scala source files when they contain macros. For macros, there are no interface jars because the macro code is executed at compile time. For best performance, you want very granular targets until such time as the zinc incremental compiler can be supported.

In order to make a java rule use this jar file, use the java_import rule.

Attributes
name	Name, required A unique name for this target
srcs	List of labels, required List of Scala .scala source files used to build the library
deps	List of labels, optional List of other libraries to linked to this library target
data	List of labels, optional List of files needed by this rule at runtime.
main_class	String, optional Name of class with main() method to use as an entry point The value of this attribute is a class name, not a source file. The class must be available at runtime: it may be compiled by this rule (from srcs) or provided by direct or transitive dependencies (through deps). If the class is unavailable, the binary will fail at runtime; there is no build-time check.
resources	List of labels; optional A list of data files to be included in the JAR.
scalacopts	List of strings; optional Extra compiler options for this library to be passed to scalac. Subject to Make variable substitution and Bourne shell tokenization.
jvm_flags	List of strings; optional List of JVM flags to be passed to scalac after the scalacopts. Subject to Make variable substitution and Bourne shell tokenization.

scala_binary

scala_binary(name, srcs, deps, data, main_class, resources, scalacopts, jvm_flags)

scala_binary generates a Scala executable. It may depend on scala_library, scala_macro_library and java_library rules.

A scala_binary requires a main_class attribute.

Attributes
name	Name, required A unique name for this target
srcs	List of labels, required List of Scala .scala source files used to build the binary
deps	List of labels, optional List of other libraries to linked to this binary target
data	List of labels, optional List of files needed by this rule at runtime.
main_class	String, optional Name of class with main() method to use as an entry point The value of this attribute is a class name, not a source file. The class must be available at runtime: it may be compiled by this rule (from srcs) or provided by direct or transitive dependencies (through deps). If the class is unavailable, the binary will fail at runtime; there is no build-time check.
resources	List of labels; optional A list of data files to be included in the JAR.
scalacopts	List of strings; optional Extra compiler options for this binary to be passed to scalac. Subject to Make variable substitution and Bourne shell tokenization.
jvm_flags	List of strings; optional List of JVM flags to be passed to scalac after the scalacopts. Subject to Make variable substitution and Bourne shell tokenization.