Tweak groovy rules to get their dependencies from //external instead of relying

on @ targets.

This makes them easier to use in third-party repos since the user only has to
define bindings in their WORKSPACE to whatever artifacts they want, rather than
having to provide artifacts with an exact name. Related to #409.

--
Change-Id: Ifc17bc5e7205ce5ce23d2ed1a72dd9ad93e42b97
Reviewed-on: https://bazel-review.googlesource.com/1940
MOS_MIGRATED_REVID=102135202

3 files changed, 28 insertions, 24 deletions

diff --git a/tools/build_defs/groovy/README.md b/tools/build_defs/groovy/README.md
index a4d42cef4b..27fb73d31b 100644
--- a/tools/build_defs/groovy/README.md
+++ b/tools/build_defs/groovy/README.md
@@ -16,11 +16,15 @@ libraries and vice-versa.
 <a name="setup"></a>
 ## Setup
 
-To be able to use the Groovy rules, you must make the Groovy libraries and
-binaries available to Bazel. Groovy tests also require JUnit and Hamcrest to be
-available at a known location. The easiest way to do so is by copying the
-content of `groovy.WORKSPACE` to your workspace file and putting `groovy.BUILD`
-at the root of your workspace.
+To be able to use the Groovy rules, you must provide bindings for the following
+targets:
+
+  * `//external:groovy`, pointing at the core Groovy library
+  * `//external:groovyc`, pointing at the Groovy compiler
+  * `//external:junit`, pointing at JUnit (only required if using `groovy_test`)
+
+The easiest way to do so is by copying the content of `groovy.WORKSPACE` to your
+workspace file and putting `groovy.BUILD` at the root of your workspace.
 
 <a name="basic-example"></a>
 ## Basic Example
diff --git a/tools/build_defs/groovy/groovy.WORKSPACE b/tools/build_defs/groovy/groovy.WORKSPACE
index ce196ba013..c1aa147523 100644
--- a/tools/build_defs/groovy/groovy.WORKSPACE
+++ b/tools/build_defs/groovy/groovy.WORKSPACE
@@ -1,27 +1,28 @@
+bind(
+  name = "groovyc",
+  actual = "@groovy-bin//:groovyc",
+)
 new_http_archive(
   name = "groovy-bin",
   url = "http://dl.bintray.com/groovy/maven/apache-groovy-binary-2.4.4.zip",
   sha256 = "a7cc1e5315a14ea38db1b2b9ce0792e35174161141a6a3e2ef49b7b2788c258c",
-  build_file = "tools/build_defs/groovy/groovy.BUILD",
+  build_file = "groovy.BUILD",
 )
 
-maven_jar(
+bind(
   name = "groovy",
-  group_id = "org.codehaus.groovy",
-  artifact_id = "groovy-all",
-  version = "2.3.7",
+  actual = "@groovy-jar//jar",
 )
-
 maven_jar(
-  name = "hamcrest",
-  group_id = "org.hamcrest",
-  artifact_id = "hamcrest-core",
-  version = "1.3",
+  name = "groovy-jar",
+  artifact = "org.codehaus.groovy:groovy-all:2.3.7",
 )
 
-maven_jar(
+bind (
   name = "junit",
-  group_id = "junit",
-  artifact_id = "junit",
-  version = "4.12",
-)
\ No newline at end of file
+  actual = "@junit-jar//jar",
+)
+maven_jar(
+  name = "junit-jar",
+  artifact = "junit:junit:4.12",
+)
diff --git a/tools/build_defs/groovy/groovy.bzl b/tools/build_defs/groovy/groovy.bzl
index 3b65b8d707..c9da7b6ed7 100644
--- a/tools/build_defs/groovy/groovy.bzl
+++ b/tools/build_defs/groovy/groovy.bzl
@@ -70,7 +70,7 @@ _groovy_jar = rule(
             mandatory=False,
             allow_files=FileType([".jar"])),
         "_groovyc": attr.label(
-            default=Label("@groovy-bin//:groovyc"),
+            default=Label("//external:groovyc"),
             single_file=True),
         "_jar": attr.label(
             default=Label("//third_party/ijar:zipper"),
@@ -202,9 +202,8 @@ groovy_test = rule(
       executable=True,
       single_file=True),
     "_implicit_deps": attr.label_list(default=[
-      Label("@groovy//jar"),
-      Label("@hamcrest//jar"),
-      Label("@junit//jar"),
+      Label("//external:groovy"),
+      Label("//external:junit"),
     ]),
   },
   test = True,