Export JRuby jar files (#13)

* Export JRuby jar to avoid pinning a version through maven downstream

* Buildifier

* Create a dummy jar for non-java ruby

Author: mkruskal-google

ruby/private/providers.bzl

@@ -25,6 +25,7 @@ RubyRuntimeToolchainInfo = provider(
         "interpreter": "A label which points the Ruby interpreter",
         "bundler": "A label which points bundler command",
         "runtime": "A list of labels which points runtime libraries",
+        "jars": "A list of labels which points to ruby jars",
         "headers": "A list of labels which points to the ruby headers",
         "rubyopt": "A list of strings which should be passed to the interpreter as command line options",
     },

ruby/private/runtime_alias.bzl

@@ -19,6 +19,30 @@ ruby_runtime_alias = rule(
     toolchains = [TOOLCHAIN_TYPE_NAME],
 )
 
+def _ruby_jars_alias_impl(ctx):
+    runtime = ctx.attr.runtime[RubyRuntimeToolchainInfo]
+    target = runtime.jars
+    infos = [
+        DefaultInfo(
+            files = target.files,
+            runfiles = ctx.runfiles(transitive_files = target.files),
+        ),
+    ]
+    for jar in infos[0].files.to_list():
+        infos.append(JavaInfo(jar, jar))
+
+    return infos
+
+ruby_jars_alias = rule(
+    implementation = _ruby_jars_alias_impl,
+    attrs = {
+        "runtime": attr.label(
+            doc = "The runtime alias to use.",
+            mandatory = True,
+        ),
+    },
+)
+
 def _ruby_headers_alias_impl(ctx):
     runtime = ctx.attr.runtime[RubyRuntimeToolchainInfo]
     target = runtime.headers

ruby/private/toolchain.bzl

@@ -7,6 +7,7 @@ def _ruby_toolchain_impl(ctx):
             ruby_runtime = RubyRuntimeToolchainInfo(
                 interpreter = ctx.attr.interpreter,
                 runtime = ctx.files.runtime,
+                jars = ctx.attr.jars,
                 headers = ctx.attr.headers,
                 rubyopt = ctx.attr.rubyopt,
             ),
@@ -27,6 +28,11 @@ _ruby_toolchain = rule(
             allow_files = True,
             cfg = "target",
         ),
+        "jars": attr.label(
+            mandatory = True,
+            allow_files = True,
+            cfg = "target",
+        ),
         "headers": attr.label(
             mandatory = True,
             allow_files = True,
@@ -42,6 +48,7 @@ def ruby_toolchain(
         name,
         interpreter,
         runtime,
+        jars,
         headers,
         rubyopt = [],
         rules_ruby_workspace = RULES_RUBY_WORKSPACE_NAME,
@@ -51,6 +58,7 @@ def ruby_toolchain(
         name = impl_name,
         interpreter = interpreter,
         runtime = runtime,
+        jars = jars,
         headers = headers,
         rubyopt = rubyopt,
     )

ruby/private/toolchains/ruby_runtime.bzl

@@ -29,6 +29,16 @@ cc_library(
     includes = [],
 )
 
+java_binary(
+    name = "dummy_jar"
+    srcs = ["Dummy.java"],
+)
+
+filegroup(
+    name = "jars",
+    srcs = [":dummy_jar"],
+)
+
 filegroup(
     name = "runtime",
     srcs = [],
@@ -46,6 +56,7 @@ ruby_toolchain(
     interpreter = "//:ruby_bin",
     rules_ruby_workspace = "{rules_ruby_workspace}",
     runtime = "//:runtime",
+    jars = "//:jars",
     headers = "//:headers",
     target_settings = [
         "{rules_ruby_workspace}//ruby/runtime:{setting}"
@@ -74,6 +85,16 @@ cc_library(
     includes = {includes},
 )
 
+java_library(
+    name = "dummy_jar",
+    srcs = ["Dummy.java"],
+)
+
+filegroup(
+    name = "jars",
+    srcs = {jars},
+)
+
 filegroup(
     name = "runtime",
     srcs = glob(
@@ -86,6 +107,13 @@ filegroup(
 )
 """
 
+# Define a dummy java file for creating a no-op jar when JRuby isn't selected.
+_dummy_jar = """
+public class Dummy {
+    public static void main(String[] args) {}
+}
+"""
+
 _bundle_bzl = """
 load("{rules_ruby_workspace}//ruby/private/bundle:def.bzl", "ruby_bundle_impl")
 load("{rules_ruby_workspace}//ruby/private:constants.bzl", "BUNDLE_ATTRS")
@@ -244,6 +272,8 @@ def _ruby_runtime_impl(ctx):
         if not interpreter_path or not interpreter_path.exists:
             fail("Installation of ruby version %s failed")
 
+    ctx.file("Dummy.java", _dummy_jar)
+
     if interpreter_path and interpreter_path.exists:
         ruby = ruby_repository_context(ctx, interpreter_path)
         installed = _install_ruby(ctx, ruby)
@@ -252,6 +282,7 @@ def _ruby_runtime_impl(ctx):
         toolchain = _toolchain.format(
             includes = repr(installed.includedirs),
             hdrs = repr(["%s/**/*.h" % path for path in installed.includedirs]),
+            jars = "glob([\"**/lib/jruby.jar\"])" if ruby_impl == "jruby" else [":dummy_jar"],
             static_library = repr(installed.static_library),
             shared_library = repr(installed.shared_library),
             rules_ruby_workspace = RULES_RUBY_WORKSPACE_NAME,

ruby/runtime/BUILD.bazel

@@ -11,6 +11,7 @@ load(
     "@rules_ruby//ruby/private:runtime_alias.bzl",
     _ruby_headers_alias = "ruby_headers_alias",
     _ruby_interpreter_alias = "ruby_interpreter_alias",
+    _ruby_jars_alias = "ruby_jars_alias",
     _ruby_runtime_alias = "ruby_runtime_alias",
 )
 
@@ -25,6 +26,11 @@ _ruby_runtime_alias(
     name = "runtime",
 )
 
+_ruby_jars_alias(
+    name = "jars",
+    runtime = ":runtime",
+)
+
 _ruby_headers_alias(
     name = "headers",
     runtime = ":runtime",