Simplify genproto.bzl.

Generate a srcjar artifact, and use native.java_library to emit the
actual jar file.

Post-review modifications:
  - Formatted genproto.bzl
  - Use //external:jar instead of relying on PATH
  - Make proto library a java_import instead of a filegroup in
    test setup.

--
Change-Id: I005f801f09439bbca43e483ad4a47da4588fea94
Reviewed-on: https://bazel-review.googlesource.com/1362
MOS_MIGRATED_REVID=94914935

6 files changed, 62 insertions, 82 deletions

diff --git a/examples/proto/BUILD b/examples/proto/BUILD
index cae538d877..7ce5659ea6 100644
--- a/examples/proto/BUILD
+++ b/examples/proto/BUILD
@@ -1,8 +1,8 @@
 package(default_visibility = ["//visibility:public"])
 
-load("/tools/build_rules/genproto", "genproto")
+load("/tools/build_rules/genproto", "proto_java_library")
 
-genproto(
+proto_java_library(
     name = "test_proto",
     src = "test.proto",
 )
diff --git a/src/main/protobuf/BUILD b/src/main/protobuf/BUILD
index 717d9bf4fc..c319e34d92 100644
--- a/src/main/protobuf/BUILD
+++ b/src/main/protobuf/BUILD
@@ -1,11 +1,8 @@
 package(default_visibility = ["//visibility:public"])
 
-load("/tools/build_rules/genproto", "genproto")
+load("/tools/build_rules/genproto", "proto_java_library")
 
-[genproto(
-    name = "proto_" + proto_file,
-    src = proto_file + ".proto",
-) for proto_file in [
+FILES = [
     "build",
     "deps",
     "crosstool_config",
@@ -13,7 +10,12 @@ load("/tools/build_rules/genproto", "genproto")
     "test_status",
     "bundlemerge",
     "xcodegen",
-]]
+]
+
+[proto_java_library(
+    name = "proto_" + s,
+    src = s + ".proto",
+) for s in FILES]
 
 filegroup(
     name = "srcs",
diff --git a/src/main/tools/jdk.BUILD b/src/main/tools/jdk.BUILD
index c3c7fd558e..9d0979f254 100644
--- a/src/main/tools/jdk.BUILD
+++ b/src/main/tools/jdk.BUILD
@@ -20,6 +20,11 @@ filegroup(
     srcs = ["bin/java"],
 )
 
+filegroup(
+    name = "jar",
+    srcs = ["bin/jar"],
+)
+
 BOOTCLASS_JARS = [
     "rt.jar",
     "resources.jar",
diff --git a/src/main/tools/jdk.WORKSPACE b/src/main/tools/jdk.WORKSPACE
index d8fb5e5154..c26eaa3133 100644
--- a/src/main/tools/jdk.WORKSPACE
+++ b/src/main/tools/jdk.WORKSPACE
@@ -43,6 +43,11 @@ bind(
 )
 
 bind(
+    name = "jar",
+    actual = "@local-jdk//:jar",
+)
+
+bind(
     name = "jdk-default",
     actual = "@local-jdk//:jdk-default",
 )
diff --git a/src/test/shell/bazel/test-setup.sh b/src/test/shell/bazel/test-setup.sh
index a0fe04aa00..ae134866cc 100755
--- a/src/test/shell/bazel/test-setup.sh
+++ b/src/test/shell/bazel/test-setup.sh
@@ -53,9 +53,9 @@ function setup_protoc_support() {
 cat <<EOF > third_party/BUILD
 package(default_visibility = ["//visibility:public"])
 exports_files(["protoc"])
-filegroup(
+java_import(
   name = "protobuf",
-  srcs = [ "protobuf-java.jar"])
+  jars = ["protobuf-java.jar"])
 
 EOF
 }
diff --git a/tools/build_rules/genproto.bzl b/tools/build_rules/genproto.bzl
index f479027f57..a2e2d735a9 100644
--- a/tools/build_rules/genproto.bzl
+++ b/tools/build_rules/genproto.bzl
@@ -15,82 +15,50 @@
 # This is a quick and dirty rule to make Bazel compile itself.  It
 # only supports Java.
 
-
-jar_filetype = FileType([".jar"])
-
 proto_filetype = FileType([".proto"])
 
-def java_compile_command(ctx, classdir, classpath, output):
-  java = ctx.file._java.path
-  langtools = ctx.file._java_langtools.path
-  javabuilder = ctx.file._javabuilder.path
-  return ("%s -Xbootclasspath/p:%s -jar %s " % (java, langtools, javabuilder) +
-          "--classdir %s --classpath %s " % (classdir, classpath) +
-          "--output %s " % (output) +
-          "--javacopts -source 1.8 -target 1.8 --compress_jar --sources ${JAVA_FILES}")
-
-def genproto_impl(ctx):
-  src = ctx.file.src
+def gensrcjar_impl(ctx):
+  out = ctx.outputs.srcjar
+  proto_output = out.path + ".proto_output"
   proto_compiler = ctx.file._proto_compiler
-  proto_dep = ctx.file._proto_dep
-  class_jar = ctx.outputs.java
-  proto_output = class_jar.path + ".proto_output"
-  build_output = class_jar.path + ".build_output"
-  build_output = class_jar.path + ".build_output"
-
-  inputs = [src, proto_dep, proto_compiler]
-  proto_compiler_path = proto_compiler.path
-
-  javapath = "tools/jdk/jdk/bin/"
-  cmd = ("set -e;" +
-         "rm -rf " + proto_output + ";" +
-         "mkdir " + proto_output + ";" +
-         "rm -rf " + build_output + ";" +
-         "mkdir " + build_output + "\n" +
-         proto_compiler_path + " --java_out=" +
-         proto_output +" " + src.path + "\n" +
-         "JAVA_FILES=$(find " + proto_output + " -name '*.java')\n" +
-         java_compile_command(ctx, build_output, proto_dep.path, class_jar.path))
+  sub_commands = [
+    "rm -rf " + proto_output,
+    "mkdir " + proto_output,
+    ' '.join([proto_compiler.path, "--java_out=" + proto_output,
+              ctx.file.src.path]),
+    "touch -t 198001010000 $(find " + proto_output + ")",
+    ctx.file._jar.path + " cMf " + out.path + " -C " + proto_output + " .",
+  ]
 
   ctx.action(
-      inputs = inputs,
-      outputs = [class_jar],
-      mnemonic = 'CompileProtos',
-      command = cmd,
-      use_default_shell_env = True)
-
-  return struct(compile_time_jars = set([class_jar]),
-                runtime_jars = set([class_jar, proto_dep], order="link"))
+    command=" && ".join(sub_commands),
+    inputs=[ctx.file.src, proto_compiler, ctx.file._jar],
+    outputs=[out],
+    mnemonic="GenProtoSrcJar",
+    use_default_shell_env = True)
 
-
-genproto = rule(genproto_impl,
-   # There should be a flag like gen_java, and only generate the jar if it's
-   # set. Skylark needs a bit of improvement first (concat structs).
-   attrs = {
-       "src": attr.label(allow_files=proto_filetype, single_file=True),
-       # TODO(bazel-team): this should be a hidden attribute with a default
-       # value, but Skylark needs to support select first.
-       "_proto_compiler": attr.label(
-           default=Label("//third_party:protoc"),
-           allow_files=True,
-           single_file=True),
-       "_proto_dep": attr.label(
-           default=Label("//third_party:protobuf"),
-           single_file=True,
-           allow_files=jar_filetype,
-           ),
-       "_javabuilder": attr.label(
-           default=Label("//tools/defaults:javabuilder"),
-           single_file=True,
-           ),
-       "_java_langtools": attr.label(
-           default=Label("//tools/defaults:java_langtools"),
-           single_file=True,
-           ),
-       "_java": attr.label(
-           default=Label("//tools/jdk:java"),
-           single_file=True,
-           ),
-   },
-   outputs = {"java": "lib%{name}.jar"},
+gensrcjar = rule(
+  gensrcjar_impl,
+  attrs={
+        "src": attr.label(allow_files=proto_filetype, single_file=True),
+        # TODO(bazel-team): this should be a hidden attribute with a default
+        # value, but Skylark needs to support select first.
+        "_proto_compiler": attr.label(
+            default=Label("//third_party:protoc"),
+            allow_files=True,
+            single_file=True),
+        "_jar": attr.label(
+            default=Label("//external:jar"),
+            allow_files=True,
+            single_file=True),
+  },
+  outputs={"srcjar": "lib%{name}.srcjar"},
 )
+
+# TODO(bazel-team): support proto => proto dependencies too
+def proto_java_library(name, src):
+  gensrcjar(name=name + "_srcjar", src=src)
+  native.java_library(
+    name=name,
+    srcs=[name + "_srcjar"],
+    deps=["//third_party:protobuf"])