Restructure rules_proto

Design doc: https://docs.google.com/document/d/1L1JFgjpZ7SrBinb24DC_5nTIELeYDacikcme-YcA7xs/edit

PiperOrigin-RevId: 613220055

Author: A Googler

proto/BUILD

@@ -9,15 +9,13 @@ bzl_library(
     name = "defs",
     srcs = [
         "defs.bzl",
-        "proto_descriptor_set.bzl",
-        "proto_library.bzl",
     ],
     visibility = ["//visibility:public"],
     deps = [
+        ":proto_lang_toolchain",
+        ":proto_toolchain",
         "//proto/private:native",
         "//proto/private/rules:proto_descriptor_set",
-        "//proto/toolchains:proto_lang_toolchain",
-        "//proto/toolchains:proto_toolchain",
     ],
 )
 
@@ -27,6 +25,34 @@ bzl_library(
     visibility = ["//visibility:public"],
 )
 
+bzl_library(
+    name = "proto_lang_toolchain",
+    srcs = [
+        "proto_lang_toolchain.bzl",
+    ],
+    deps = [
+        ":proto_common",
+    ],
+)
+
+bzl_library(
+    name = "proto_common",
+    srcs = [
+        "proto_common.bzl",
+    ],
+)
+
+bzl_library(
+    name = "proto_toolchain",
+    srcs = [
+        "proto_toolchain.bzl",
+    ],
+    visibility = ["//visibility:public"],
+    deps = [
+        "//proto/private/rules:proto_toolchain_bzl",
+    ],
+)
+
 # Toolchain type provided by proto_toolchain rule and used by proto_library
 toolchain_type(
     name = "toolchain_type",

proto/defs.bzl

@@ -14,21 +14,44 @@
 
 """Starlark rules for building protocol buffers."""
 
-load("//proto:proto_descriptor_set.bzl", _proto_descriptor_set = "proto_descriptor_set")
-load("//proto:proto_library.bzl", _proto_library = "proto_library")
-load("//proto/modules:proto_common.bzl", _proto_common = "proto_common")
-load("//proto/modules:proto_info.bzl", _ProtoInfo = "ProtoInfo")
-load("//proto/toolchains:proto_lang_toolchain.bzl", _proto_lang_toolchain = "proto_lang_toolchain")
-load("//proto/toolchains:proto_toolchain.bzl", _proto_toolchain = "proto_toolchain")
-
-# Rules
-proto_library = _proto_library
+load("//proto:proto_lang_toolchain.bzl", _proto_lang_toolchain = "proto_lang_toolchain")
+load("//proto:proto_toolchain.bzl", _proto_toolchain = "proto_toolchain")
+load("//proto/private:native.bzl", "NativeProtoInfo", "native_proto_common")
+load("//proto/private/rules:proto_descriptor_set.bzl", _proto_descriptor_set = "proto_descriptor_set")
+
+_MIGRATION_TAG = "__PROTO_RULES_MIGRATION_DO_NOT_USE_WILL_BREAK__"
+
+def _add_migration_tag(attrs):
+    if "tags" in attrs and attrs["tags"] != None:
+        attrs["tags"] = attrs["tags"] + [_MIGRATION_TAG]
+    else:
+        attrs["tags"] = [_MIGRATION_TAG]
+    return attrs
+
+def proto_library(**attrs):
+    """Bazel proto_library rule.
+
+    https://docs.bazel.build/versions/master/be/protocol-buffer.html#proto_library
+
+    Args:
+      **attrs: Rule attributes
+    """
+
+    # buildifier: disable=native-proto
+    native.proto_library(**_add_migration_tag(attrs))
+
 proto_descriptor_set = _proto_descriptor_set
 
-# Toolchain rules
-proto_toolchain = _proto_toolchain
 proto_lang_toolchain = _proto_lang_toolchain
 
-# Modules
-proto_common = _proto_common
-ProtoInfo = _ProtoInfo
+proto_toolchain = _proto_toolchain
+
+# Encapsulates information provided by `proto_library`.
+#
+# https://docs.bazel.build/versions/master/skylark/lib/ProtoInfo.html
+ProtoInfo = NativeProtoInfo
+
+# Utilities for protocol buffers.
+#
+# https://docs.bazel.build/versions/master/skylark/lib/proto_common.html
+proto_common = native_proto_common

proto/modules/BUILD

@@ -18,7 +18,7 @@ bzl_library(
     srcs = [
         "proto_toolchain.bzl",
         "proto_toolchain_rule.bzl",
-        "@bazel_features//:bzl_files",
+        "@bazel_features//:features",
     ],
     visibility = [
         "//proto:__subpackages__",

proto/modules/proto_info.bzl

@@ -15,8 +15,7 @@
 """A Starlark implementation of the proto_toolchain rule."""
 
 load("@bazel_features//:features.bzl", "bazel_features")
-load("//proto/modules:proto_common.bzl", "proto_common")
-load("//proto/modules:proto_lang_toolchain_info.bzl", "ProtoLangToolchainInfo")
+load("//proto:proto_common.bzl", "ProtoLangToolchainInfo", "proto_common")
 
 def _impl(ctx):
     kwargs = {}

proto/modules/proto_lang_toolchain_info.bzl

@@ -17,11 +17,12 @@
 # https://docs.bazel.build/versions/master/skylark/lib/proto_common.html
 """proto_common module"""
 
-load("//proto/modules:proto_lang_toolchain_info.bzl", "ProtoLangToolchainInfo")
 load("//proto/private:native.bzl", "native_proto_common")
 
 proto_common = native_proto_common
 
+ProtoLangToolchainInfo = proto_common.ProtoLangToolchainInfo
+
 def _incompatible_toolchains_enabled():
     return getattr(proto_common, "INCOMPATIBLE_ENABLE_PROTO_TOOLCHAIN_RESOLUTION", False)
 

proto/private/rules/BUILD

@@ -13,8 +13,35 @@
 # limitations under the License.
 """proto_lang_toolchain rule"""
 
-load("//proto/toolchains:proto_lang_toolchain.bzl", _proto_lang_toolchain = "proto_lang_toolchain")
+load("//proto:proto_common.bzl", "proto_common")
 
-# deprecated: load proto_lang_toolchain from toolchain package
+def proto_lang_toolchain(*, name, toolchain_type = None, exec_compatible_with = [], target_compatible_with = [], **attrs):
+    """Creates a proto_lang_toolchain and corresponding toolchain target.
 
-proto_lang_toolchain = _proto_lang_toolchain
+    Toolchain target is only created when toolchain_type is set.
+
+    https://docs.bazel.build/versions/master/be/protocol-buffer.html#proto_lang_toolchain
+
+    Args:
+
+      name: name of the toolchain
+      toolchain_type: The toolchain type
+      exec_compatible_with: ([constraints]) List of constraints the prebuild binaries is compatible with.
+      target_compatible_with: ([constraints]) List of constraints the target libraries are compatible with.
+      **attrs: Rule attributes
+    """
+
+    if getattr(proto_common, "INCOMPATIBLE_PASS_TOOLCHAIN_TYPE", False):
+        attrs["toolchain_type"] = toolchain_type
+
+    # buildifier: disable=native-proto
+    native.proto_lang_toolchain(name = name, **attrs)
+
+    if toolchain_type:
+        native.toolchain(
+            name = name + "_toolchain",
+            toolchain_type = toolchain_type,
+            exec_compatible_with = exec_compatible_with,
+            target_compatible_with = target_compatible_with,
+            toolchain = name,
+        )

proto/private/rules/proto_toolchain_rule.bzl

@@ -16,6 +16,4 @@
 
 load("//proto/private/rules:proto_toolchain.bzl", _proto_toolchain_macro = "proto_toolchain")
 
-# deprecated: load proto_toolchain from toolchain package
-
 proto_toolchain = _proto_toolchain_macro

proto/modules/proto_common.bzl proto/proto_common.bzl

@@ -1,6 +1,6 @@
 load("@bazel_skylib//rules:common_settings.bzl", "bool_flag")
 load("//proto:defs.bzl", "proto_library")
-load("//proto/modules:proto_common.bzl", "proto_common")
+load("//proto:proto_common.bzl", "proto_common")
 
 config_setting(
     name = "incompatible_enable_proto_toolchain_resolution",