From c22c215ea548838bc4cf2d400fd34ec409cb82af Mon Sep 17 00:00:00 2001
From: Danjie Wenren <danjie.wenren@gmail.com>
Date: Sat, 12 Oct 2019 19:54:29 -0700
Subject: [PATCH] Move extra dependencies out of WORKSPACE to its own macro.

This could be useful for projects that use gRPC as an external
repository. This could not be done within the same grpc_deps.bzl due to
the problem discussed in
- https://github.com/bazelbuild/bazel/issues/1550
- https://github.com/bazelbuild/bazel/issues/1943
---
 WORKSPACE                 | 24 ++++-------------------
 bazel/grpc_deps.bzl       | 10 +++++++++-
 bazel/grpc_extra_deps.bzl | 40 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+), 21 deletions(-)
 create mode 100644 bazel/grpc_extra_deps.bzl

diff --git a/WORKSPACE b/WORKSPACE
index b48e85017ff..18bf641a6a8 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -8,6 +8,10 @@ grpc_deps()
 
 grpc_test_only_deps()
 
+load("//bazel:grpc_extra_deps.bzl", "grpc_extra_deps")
+
+grpc_extra_deps()
+
 register_execution_platforms(
     "//third_party/toolchains:local",
     "//third_party/toolchains:local_large",
@@ -50,23 +54,3 @@ load("@io_bazel_rules_python//python:pip.bzl", "pip_repositories")
 load("@grpc_python_dependencies//:requirements.bzl", "pip_install")
 pip_repositories()
 pip_install()
-
-load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
-protobuf_deps()
-
-load("@upb//bazel:workspace_deps.bzl", "upb_deps")
-upb_deps()
-
-load("@envoy_api//bazel:repositories.bzl", "api_dependencies")
-api_dependencies()
-
-load("@io_bazel_rules_go//go:deps.bzl", "go_rules_dependencies", "go_register_toolchains")
-go_rules_dependencies()
-go_register_toolchains()
-
-
-load("@build_bazel_rules_apple//apple:repositories.bzl", "apple_rules_dependencies")
-apple_rules_dependencies()
-
-load("@build_bazel_apple_support//lib:repositories.bzl", "apple_support_dependencies")
-apple_support_dependencies()
diff --git a/bazel/grpc_deps.bzl b/bazel/grpc_deps.bzl
index fcc8077c035..69f341ffa9e 100644
--- a/bazel/grpc_deps.bzl
+++ b/bazel/grpc_deps.bzl
@@ -229,8 +229,16 @@ def grpc_deps():
             sha256 = "bdc8e66e70b8a75da23b79f1f8c6207356df07d041d96d2189add7ee0780cf4e",
         )
 
-    grpc_python_deps()
+    if "build_bazel_apple_support" not in native.existing_rules():
+        http_archive(
+            name = "build_bazel_apple_support",
+            urls = [
+                "https://github.com/bazelbuild/apple_support/releases/download/0.7.1/apple_support.0.7.1.tar.gz",
+            ],
+            sha256 = "122ebf7fe7d1c8e938af6aeaee0efe788a3a2449ece5a8d6a428cb18d6f88033",
+        )
 
+    grpc_python_deps()
 
 # TODO: move some dependencies from "grpc_deps" here?
 def grpc_test_only_deps():
diff --git a/bazel/grpc_extra_deps.bzl b/bazel/grpc_extra_deps.bzl
new file mode 100644
index 00000000000..4c1dfad2e86
--- /dev/null
+++ b/bazel/grpc_extra_deps.bzl
@@ -0,0 +1,40 @@
+"""Loads the dependencies necessary for the external repositories defined in grpc_deps.bzl."""
+
+load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
+load("@upb//bazel:workspace_deps.bzl", "upb_deps")
+load("@envoy_api//bazel:repositories.bzl", "api_dependencies")
+load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_dependencies")
+load("@build_bazel_rules_apple//apple:repositories.bzl", "apple_rules_dependencies")
+load("@build_bazel_apple_support//lib:repositories.bzl", "apple_support_dependencies")
+
+def grpc_extra_deps():
+    """Loads the extra dependencies.
+
+    These are necessary for using the external repositories defined in
+    grpc_deps.bzl. Projects that depend on gRPC as an external repository need
+    to call both grpc_deps and grpc_extra_deps, if they have not already loaded
+    the extra dependencies. For example, they can do the following in their
+    WORKSPACE
+    ```
+    load("@com_github_grpc_grpc//bazel:grpc_deps.bzl", "grpc_deps", "grpc_test_only_deps")
+    grpc_deps()
+
+    grpc_test_only_deps()
+
+    load("@com_github_grpc_grpc//bazel:grpc_extra_deps.bzl", "grpc_extra_deps")
+
+    grpc_extra_deps()
+    ```
+    """
+    protobuf_deps()
+
+    upb_deps()
+
+    api_dependencies()
+
+    go_rules_dependencies()
+    go_register_toolchains()
+
+    apple_rules_dependencies()
+
+    apple_support_dependencies()