Add redirects for proto rules

Redirected rules: proto_library, proto_toolchain, proto_lang_toolchain
Modules and providers: proto_common, ProtoInfo, ProtoLangToolchainInfo

The structure follows proposal: https://docs.google.com/document/d/1L1JFgjpZ7SrBinb24DC_5nTIELeYDacikcme-YcA7xs/edit?usp=drive_open&ouid=102306600948089647787

PiperOrigin-RevId: 610471985

Author: protobuf-github-bot

WORKSPACE

@@ -135,7 +135,7 @@ ruby_bundle(
 
 http_archive(
     name = "lua",
-    build_file = "//bazel:lua.BUILD",
+    build_file = "//python/dist:lua.BUILD",
     sha256 = "b9e2e4aad6789b3b63a056d442f7b39f0ecfca3ae0f1fc0ae4e9614401b69f4b",
     strip_prefix = "lua-5.2.4",
     urls = [
@@ -160,7 +160,7 @@ http_archive(
     patch_cmds = ["find google -type f -name BUILD.bazel -delete"],
 )
 
-load("//bazel:system_python.bzl", "system_python")
+load("//python/dist:system_python.bzl", "system_python")
 
 system_python(
     name = "system_python",

bazel/BUILD

@@ -6,57 +6,13 @@
 # https://developers.google.com/open-source/licenses/bsd
 
 load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
-load("@bazel_skylib//lib:selects.bzl", "selects")
-load("@rules_python//python:defs.bzl", "py_binary")
 
 # begin:google_only
 # package(default_applicable_licenses = ["//upb:license"])
 # end:google_only
 
 licenses(["notice"])
 
-# begin:google_only
-# selects.config_setting_group(
-#     name = "android_opt",
-#     match_all = [
-#         "//tools/cc_target_os:android",
-#         "//tools/compilation_mode:opt",
-#     ],
-# )
-# end:google_only
-
-py_binary(
-    name = "amalgamate",
-    srcs = ["amalgamate.py"],
-    visibility = ["//upb:__pkg__"],
-)
-
-# py_proto_library() is private rule, only intended for internal use by upb.
-# Hopefully py_proto_library() will eventually be available in rules_proto or
-# another upstream package.
-bzl_library(
-    name = "py_proto_library_bzl",
-    srcs = ["py_proto_library.bzl"],
-    deps = [
-        "@rules_python//python:py_info_bzl",
-    ],
-)
-
-bzl_library(
-    name = "upb_proto_library_internal_bzl",
-    srcs = [
-        "upb_proto_library_internal/aspect.bzl",
-        "upb_proto_library_internal/cc_library_func.bzl",
-        "upb_proto_library_internal/copts.bzl",
-        "upb_proto_library_internal/rule.bzl",
-    ],
-    deps = [
-        "@bazel_skylib//lib:paths",
-        "@bazel_tools//tools/cpp:toolchain_utils.bzl",
-        "@rules_proto//proto:defs",
-    ],
-)
-
 bzl_library(
     name = "upb_proto_library_bzl",
     srcs = [
@@ -67,7 +23,7 @@ bzl_library(
     ],
     visibility = ["//visibility:public"],
     deps = [
-        ":upb_proto_library_internal_bzl",
+        "//bazel/private:upb_proto_library_internal_bzl",
         "@rules_proto//proto:defs",
     ],
 )

bazel/common/BUILD.bazel

@@ -0,0 +1,5 @@
+"""proto_common"""
+
+load("//bazel/private:native.bzl", "native_proto_common")
+
+proto_common = native_proto_common

bazel/common/proto_common.bzl

@@ -0,0 +1,5 @@
+"""ProtoInfo"""
+
+load("//bazel/private:native.bzl", "NativeProtoInfo")
+
+ProtoInfo = NativeProtoInfo

bazel/common/proto_info.bzl

@@ -0,0 +1,5 @@
+"""ProtoLangToolchainInfo"""
+
+load("//bazel/common:proto_common.bzl", "proto_common")
+
+ProtoLangToolchainInfo = proto_common.ProtoLangToolchainInfo

bazel/common/proto_lang_toolchain_info.bzl

@@ -0,0 +1,30 @@
+# Copyright (c) 2009-2021, Google LLC
+# All rights reserved.
+#
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
+
+# begin:google_only
+# package(default_applicable_licenses = ["//upb:license"])
+# end:google_only
+
+licenses(["notice"])
+
+bzl_library(
+    name = "upb_proto_library_internal_bzl",
+    srcs = [
+        "upb_proto_library_internal/aspect.bzl",
+        "upb_proto_library_internal/cc_library_func.bzl",
+        "upb_proto_library_internal/copts.bzl",
+        "upb_proto_library_internal/rule.bzl",
+    ],
+    visibility = ["//bazel:__pkg__"],
+    deps = [
+        "@bazel_skylib//lib:paths",
+        "@bazel_tools//tools/cpp:toolchain_utils.bzl",
+        "@rules_proto//proto:defs",
+    ],
+)

bazel/private/BUILD

@@ -0,0 +1 @@
+package(default_applicable_licenses = ["//src/google/protobuf:license"])

bazel/private/BUILD.bazel

@@ -0,0 +1,5 @@
+"""Renames toplevel symbols so they can be exported in Starlark under the same name"""
+
+NativeProtoInfo = ProtoInfo
+
+native_proto_common = proto_common_do_not_use

bazel/private/native.bzl

@@ -0,0 +1,47 @@
+"""A Starlark implementation of the proto_toolchain rule."""
+
+load("//bazel/common:proto_common.bzl", "proto_common")
+load("//bazel/common:proto_lang_toolchain_info.bzl", "ProtoLangToolchainInfo")
+
+def _impl(ctx):
+    kwargs = {}
+    if getattr(proto_common, "INCOMPATIBLE_PASS_TOOLCHAIN_TYPE", False):
+        kwargs["toolchain_type"] = "//third_party/bazel_rules/rules_proto/proto:toolchain_type"
+
+    return [
+        DefaultInfo(
+            files = depset(),
+            runfiles = ctx.runfiles(),
+        ),
+        platform_common.ToolchainInfo(
+            proto = ProtoLangToolchainInfo(
+                out_replacement_format_flag = ctx.attr.command_line,
+                output_files = ctx.attr.output_files,
+                plugin = None,
+                runtime = None,
+                proto_compiler = ctx.attr.proto_compiler.files_to_run,
+                protoc_opts = ctx.fragments.proto.experimental_protoc_opts,
+                progress_message = ctx.attr.progress_message,
+                mnemonic = ctx.attr.mnemonic,
+                **kwargs
+            ),
+        ),
+    ]
+
+proto_toolchain = rule(
+    _impl,
+    attrs =
+        {
+            "progress_message": attr.string(default = "Generating Descriptor Set proto_library %{label}"),
+            "mnemonic": attr.string(default = "GenProtoDescriptorSet"),
+            "command_line": attr.string(default = "--descriptor_set_out=%s"),
+            "output_files": attr.string(values = ["single", "multiple", "legacy"], default = "single"),
+            "proto_compiler": attr.label(
+                cfg = "exec",
+                executable = True,
+                allow_files = True,  # Used by mocks in tests. Consider fixing tests and removing it.
+            ),
+        },
+    provides = [platform_common.ToolchainInfo],
+    fragments = ["proto"],
+)