Reuse @com_google_protobuf//:protoc when generating scala from proto

scala_proto/scala_proto.bzl

@@ -28,18 +28,6 @@ def scala_proto_repositories(
         url = "http://central.maven.org/maven2/",
     )
 
-    native.maven_jar(
-        name = "scala_proto_rules_protoc_jar",
-        artifact = "com.github.os72:protoc-jar:3.6.0.1",
-        sha1 = "db8a7cc739f5b332e7f32fd5dfacae68f0062581",
-        server = "scala_proto_deps_maven_server",
-    )
-
-    native.bind(
-        name = "io_bazel_rules_scala/dependency/proto/protoc",
-        actual = "@scala_proto_rules_protoc_jar//jar",
-    )
-
     scala_jar_shas = {
         "2.11": {
             "scalapb_plugin": "b67e563d06f1bbb6ea704a063760a85ec7fb5809828402364d5418dd1c5cab06",
@@ -444,7 +432,7 @@ def _gen_proto_srcjar_impl(ctx):
 
     deps_jars = collect_jars(jvm_deps)
 
-    worker_content = "{output}\n{paths}\n{flags_arg}\n{packages}\n{inputs}".format(
+    worker_content = "{output}\n{paths}\n{flags_arg}\n{packages}\n{inputs}\n{protoc}".format(
         output = ctx.outputs.srcjar.path,
         paths = _colon_paths(acc_imports.to_list()),
         # Command line args to worker cannot be empty so using padding
@@ -453,7 +441,8 @@ def _gen_proto_srcjar_impl(ctx):
         packages = "-" +
                    ":".join(depset(transitive = transitive_proto_paths).to_list()),
         # Pass inputs seprately because they doesn't always match to imports (ie blacklisted protos are excluded)
-        inputs = ":".join(sorted([f.path for f in _retained_protos(acc_imports, ctx.attr.blacklisted_protos)]))
+        inputs = ":".join(sorted([f.path for f in _retained_protos(acc_imports, ctx.attr.blacklisted_protos)])),
+        protoc = ctx.executable._protoc.path
     )
     argfile = ctx.actions.declare_file(
         "%s_worker_input" % ctx.label.name,
@@ -462,7 +451,7 @@ def _gen_proto_srcjar_impl(ctx):
     ctx.actions.write(output = argfile, content = worker_content)
     ctx.actions.run(
         executable = ctx.executable.generator,
-        inputs = depset([argfile], transitive = [acc_imports]),
+        inputs = depset([argfile, ctx.executable._protoc], transitive = [acc_imports]),
         outputs = [ctx.outputs.srcjar],
         mnemonic = "ProtoScalaPBRule",
         progress_message = "creating scalapb files %s" % ctx.label,
@@ -496,6 +485,7 @@ scala_proto_srcjar = rule(
             allow_files = True,
         ),
         "blacklisted_protos" : attr.label_list(providers = [["proto"]]),
+        "_protoc": attr.label(executable = True, cfg = "host", default = "@com_google_protobuf//:protoc")
     },
     outputs = {
         "srcjar": "lib%{name}.srcjar",

src/scala/scripts/BUILD

@@ -37,7 +37,6 @@ scala_library(
     ],
     deps = [
         ":scala_proto_request_extractor",
-        "//external:io_bazel_rules_scala/dependency/proto/protoc",
         "//external:io_bazel_rules_scala/dependency/proto/protoc_bridge",
         "//external:io_bazel_rules_scala/dependency/proto/scalapb_plugin",
         "//external:io_bazel_rules_scala/dependency/proto/scalapbc",

src/scala/scripts/PBGenerateRequest.scala

@@ -2,7 +2,7 @@ package scripts
 
 import java.nio.file.{Files, Path, Paths}
 
-class PBGenerateRequest(val jarOutput: String, val scalaPBOutput: Path, val scalaPBArgs: List[String])
+class PBGenerateRequest(val jarOutput: String, val scalaPBOutput: Path, val scalaPBArgs: List[String], val protoc: Path)
 
 object PBGenerateRequest {
 
@@ -42,7 +42,8 @@ object PBGenerateRequest {
     val scalaPBOutput = Files.createTempDirectory(tmp, "bazelscalapb")
     val flagPrefix = flagOpt.fold("")(_ + ":")
     val scalaPBArgs = s"--scala_out=$flagPrefix$scalaPBOutput" :: (padWithProtoPathPrefix(transitiveProtoPaths) ++ imports ++ protoFiles)
-    new PBGenerateRequest(jarOutput, scalaPBOutput, scalaPBArgs)
+    val protoc = Paths.get(args.get(5))
+    new PBGenerateRequest(jarOutput, scalaPBOutput, scalaPBArgs, protoc)
   }
 
   private def padWithProtoPathPrefix(transitiveProtoPathFlags: List[String]) =

src/scala/scripts/ScalaPBGenerator.scala

@@ -3,13 +3,11 @@ package scripts
 import java.io.PrintStream
 import java.nio.file.Path
 
-import com.trueaccord.scalapb.{ScalaPBC, ScalaPbcException}
 import io.bazel.rulesscala.io_utils.DeleteRecursively
 import io.bazel.rulesscala.jar.JarCreator
 import io.bazel.rulesscala.worker.{GenericWorker, Processor}
 import protocbridge.ProtocBridge
-
-import scalapb.ScalaPbCodeGenerator
+import scalapb.{ScalaPBC, ScalaPbCodeGenerator, ScalaPbcException}
 
 object ScalaPBWorker extends GenericWorker(new ScalaPBGenerator) {
 
@@ -41,7 +39,7 @@ class ScalaPBGenerator extends Processor {
     val extractRequestResult = PBGenerateRequest.from(args)
     val config = ScalaPBC.processArgs(extractRequestResult.scalaPBArgs.toArray)
     val code = ProtocBridge.runWithGenerators(
-      protoc = a => com.github.os72.protocjar.Protoc.runProtoc(a.toArray),
+      protoc = exec(extractRequestResult.protoc),
       namedGenerators = Seq("scala" -> ScalaPbCodeGenerator),
       params = config.args)
 
@@ -57,4 +55,7 @@ class ScalaPBGenerator extends Processor {
       deleteDir(extractRequestResult.scalaPBOutput)
     }
   }
+
+  private def exec(protoc: Path): Seq[String] => Int = (args: Seq[String]) =>
+    new ProcessBuilder(protoc.toString +: args: _*).inheritIO().start().waitFor()
 }