Split Dagger, Dagger Android, and Hilt Android setup for Bazel users

This allows Dagger users to configure targets without requiring android_sdk repository.

RELNOTES=N/A

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=316989001

4 files changed, 177 insertions, 33 deletions

diff --git a/README.md b/README.md
index 8548c2018..8ee14695a 100644
--- a/README.md
+++ b/README.md
@@ -27,12 +27,8 @@ mailing list.
 
 ### Bazel
 
-If you build with `bazel`, you will need to configure your top-level workspace
-to access Dagger/Hilt targets that export the proper dependencies and plugins.
-
 First, import the Dagger repository into your `WORKSPACE` file using
-[`http_archive`][bazel-external-deps], load the `DAGGER_ARTIFACTS` and
-`DAGGER_REPOSITORIES`, and add them to your list of [`maven_install`] artifacts.
+[`http_archive`][bazel-external-deps].
 
 Note: The `http_archive` must point to a tagged release of Dagger, not just any
 commit. The version of the Dagger artifacts will match the version of the tagged
@@ -45,6 +41,18 @@ http_archive(
     name = "dagger",
     urls = ["https://github.com/google/dagger/archive/dagger-<version>.zip"],
 )
+```
+
+Next you will need to setup targets that export the proper dependencies
+and plugins. Follow the sections below to setup the dependencies you need.
+
+#### Dagger Setup
+
+First, load the Dagger artifacts and repositories, and add them to your list of
+[`maven_install`] artifacts.
+
+```python
+# Top-level WORKSPACE file
 
 load("@dagger//:workspace_defs.bzl", "DAGGER_ARTIFACTS", "DAGGER_REPOSITORIES")
 
@@ -54,7 +62,8 @@ maven_install(
 )
 ```
 
-Next, load and call `dagger_rules` in your top-level `BUILD` file:
+Next, load and call [`dagger_rules`](https://github.com/google/dagger/blob/master/workspace_defs.bzl)
+in your top-level `BUILD` file:
 
 ```python
 # Top-level BUILD file
@@ -64,7 +73,7 @@ load("@dagger//:workspace_defs.bzl", "dagger_rules")
 dagger_rules()
 ```
 
-This will setup Dagger and Hilt build targets of the form `:<artifact_id>`.
+This will add the following Dagger build targets:
 (Note that these targets already export all of the dependencies and processors
 they need).
 
@@ -73,8 +82,88 @@ deps = [
     ":dagger",                  # For Dagger
     ":dagger-spi",              # For Dagger SPI
     ":dagger-producers",        # For Dagger Producers
+]
+```
+
+#### Dagger Android Setup
+
+First, load the Dagger Android artifacts and repositories, and add them to your
+list of [`maven_install`] artifacts.
+
+```python
+# Top-level WORKSPACE file
+
+load(
+    "@dagger//:workspace_defs.bzl",
+    "DAGGER_ANDROID_ARTIFACTS",
+    "DAGGER_ANDROID_REPOSITORIES"
+)
+
+maven_install(
+    artifacts = DAGGER_ANDROID_ARTIFACTS + [...],
+    repositories = DAGGER_ANDROID_REPOSITORIES + [...],
+)
+```
+
+Next, load and call [`dagger_android_rules`](https://github.com/google/dagger/blob/master/workspace_defs.bzl)
+in your top-level `BUILD` file:
+
+```python
+# Top-level BUILD file
+
+load("@dagger//:workspace_defs.bzl", "dagger_android_rules")
+
+dagger_android_rules()
+```
+
+This will add the following Dagger Android build targets:
+(Note that these targets already export all of the dependencies and processors
+they need).
+
+```python
+deps = [
     ":dagger-android",          # For Dagger Android
     ":dagger-android-support",  # For Dagger Android (Support)
+]
+```
+
+#### Hilt Android Setup
+
+First, load the Hilt Android artifacts and repositories, and add them to your
+list of [`maven_install`] artifacts.
+
+```python
+# Top-level WORKSPACE file
+
+load(
+    "@dagger//:workspace_defs.bzl",
+    "HILT_ANDROID_ARTIFACTS",
+    "HILT_ANDROID_REPOSITORIES"
+)
+
+maven_install(
+    artifacts = HILT_ANDROID_ARTIFACTS + [...],
+    repositories = HILT_ANDROID_REPOSITORIES + [...],
+)
+```
+
+Next, load and call [`hilt_android_rules`](https://github.com/google/dagger/blob/master/workspace_defs.bzl)
+in your top-level `BUILD` file:
+
+```python
+# Top-level BUILD file
+
+load("@dagger//:workspace_defs.bzl", "hilt_android_rules")
+
+hilt_android_rules()
+```
+
+This will add the following Hilt Android build targets:
+(Note that these targets already export all of the dependencies and processors
+they need).
+
+```python
+deps = [
     ":hilt-android",            # For Hilt Android
     ":hilt-android-testing",    # For Hilt Android Testing
 ]
diff --git a/examples/bazel/BUILD b/examples/bazel/BUILD
index b3342319f..0f9a621b0 100644
--- a/examples/bazel/BUILD
+++ b/examples/bazel/BUILD
@@ -15,6 +15,8 @@
 # Description:
 #   Dagger Bazel examples
 
-load("@dagger//:workspace_defs.bzl", "dagger_rules")
+load("@dagger//:workspace_defs.bzl", "dagger_rules", "hilt_android_rules")
 
 dagger_rules()
+
+hilt_android_rules()
diff --git a/examples/bazel/WORKSPACE b/examples/bazel/WORKSPACE
index 009f99e10..b5900f4f1 100644
--- a/examples/bazel/WORKSPACE
+++ b/examples/bazel/WORKSPACE
@@ -25,7 +25,13 @@ local_repository(
     path = "../../",
 )
 
-load("@dagger//:workspace_defs.bzl", "DAGGER_ARTIFACTS", "DAGGER_REPOSITORIES")
+load(
+    "@dagger//:workspace_defs.bzl",
+    "DAGGER_ARTIFACTS",
+    "DAGGER_REPOSITORIES",
+    "HILT_ANDROID_ARTIFACTS",
+    "HILT_ANDROID_REPOSITORIES",
+)
 
 #########################
 # Load Android repository
@@ -71,7 +77,7 @@ http_archive(
 load("@rules_jvm_external//:defs.bzl", "maven_install")
 
 maven_install(
-    artifacts = DAGGER_ARTIFACTS + [
+    artifacts = DAGGER_ARTIFACTS + HILT_ANDROID_ARTIFACTS + [
         "androidx.test.ext:junit:1.1.1",
         "androidx.test:runner:1.1.1",
         "com.google.truth:truth:1.0.1",
@@ -79,5 +85,5 @@ maven_install(
         "org.robolectric:robolectric:4.1",
         "org.robolectric:annotations:4.1",
     ],
-    repositories = DAGGER_REPOSITORIES,
+    repositories = DAGGER_REPOSITORIES + HILT_ANDROID_REPOSITORIES,
 )
diff --git a/workspace_defs.bzl b/workspace_defs.bzl
index 7f6ad3280..4a585df69 100644
--- a/workspace_defs.bzl
+++ b/workspace_defs.bzl
@@ -20,16 +20,24 @@ _DAGGER_VERSION = POM_VERSION
 _HILT_VERSION = POM_VERSION_ALPHA
 
 DAGGER_ARTIFACTS = [
-    "androidx.test:core:1.1.0",  # Export for ApplicationProvider
-    "javax.annotation:jsr250-api:1.0",  # Export for @Generated
-    "androidx.annotation:annotation:1.1.0",  # Export for @CallSuper/@Nullable
     "com.google.dagger:dagger:" + _DAGGER_VERSION,
     "com.google.dagger:dagger-compiler:" + _DAGGER_VERSION,
+    "com.google.dagger:dagger-producers:" + _DAGGER_VERSION,
+    "com.google.dagger:dagger-spi:" + _DAGGER_VERSION,
+]
+
+DAGGER_ANDROID_ARTIFACTS = [
     "com.google.dagger:dagger-android-processor:" + _DAGGER_VERSION,
     "com.google.dagger:dagger-android-support:" + _DAGGER_VERSION,
     "com.google.dagger:dagger-android:" + _DAGGER_VERSION,
-    "com.google.dagger:dagger-producers:" + _DAGGER_VERSION,
-    "com.google.dagger:dagger-spi:" + _DAGGER_VERSION,
+]
+
+HILT_ANDROID_ARTIFACTS = [
+    "androidx.test:core:1.1.0",  # Export for ApplicationProvider
+    "javax.annotation:jsr250-api:1.0",  # Export for @Generated
+    "androidx.annotation:annotation:1.1.0",  # Export for @CallSuper/@Nullable
+    "com.google.dagger:dagger:" + _DAGGER_VERSION,
+    "com.google.dagger:dagger-compiler:" + _DAGGER_VERSION,
     "com.google.dagger:hilt-android:" + _HILT_VERSION,
     "com.google.dagger:hilt-android-testing:" + _HILT_VERSION,
     "com.google.dagger:hilt-android-compiler:" + _HILT_VERSION,
@@ -40,6 +48,10 @@ DAGGER_REPOSITORIES = [
     "https://repo1.maven.org/maven2",
 ]
 
+DAGGER_ANDROID_REPOSITORIES = DAGGER_REPOSITORIES
+
+HILT_ANDROID_REPOSITORIES = DAGGER_REPOSITORIES
+
 # https://github.com/bazelbuild/buildtools/blob/master/WARNINGS.md#unnamed-macro
 # buildifier: disable=unnamed-macro
 def dagger_rules(repo_name = "@maven"):
@@ -48,7 +60,7 @@ def dagger_rules(repo_name = "@maven"):
     The targets will be of the form ":<artifact-id>".
 
     Args:
-          repo_name: The name of the dependency repository (default is "@maven").
+      repo_name: The name of the dependency repository (default is "@maven").
     """
     native.java_library(
         name = "dagger",
@@ -69,6 +81,34 @@ def dagger_rules(repo_name = "@maven"):
         ],
     )
 
+    native.java_library(
+        name = "dagger-producers",
+        visibility = ["//visibility:public"],
+        exports = [
+            ":dagger",
+            "%s//:com_google_dagger_dagger_producers" % repo_name,
+        ],
+    )
+
+    native.java_library(
+        name = "dagger-spi",
+        visibility = ["//visibility:public"],
+        exports = [
+            "%s//:com_google_dagger_dagger_spi" % repo_name,
+        ],
+    )
+
+# https://github.com/bazelbuild/buildtools/blob/master/WARNINGS.md#unnamed-macro
+# buildifier: disable=unnamed-macro
+def dagger_android_rules(repo_name = "@maven"):
+    """Defines the Dagger Android targets with proper exported dependencies and plugins.
+
+    The targets will be of the form ":<artifact-id>".
+
+    Args:
+      repo_name: The name of the dependency repository (default is "@maven").
+    """
+
     # https://github.com/bazelbuild/buildtools/blob/master/WARNINGS.md#native-android
     # buildifier: disable=native-android
     native.android_library(
@@ -101,28 +141,23 @@ def dagger_rules(repo_name = "@maven"):
         ],
     )
 
-    native.java_library(
-        name = "dagger-producers",
-        visibility = ["//visibility:public"],
-        exports = [
-            ":dagger",
-            "%s//:com_google_dagger_dagger_producers" % repo_name,
-        ],
-    )
+# https://github.com/bazelbuild/buildtools/blob/master/WARNINGS.md#unnamed-macro
+# buildifier: disable=unnamed-macro
+def hilt_android_rules(repo_name = "@maven"):
+    """Defines the Hilt Android targets with proper exported dependencies and plugins.
 
-    native.java_library(
-        name = "dagger-spi",
-        visibility = ["//visibility:public"],
-        exports = [
-            "%s//:com_google_dagger_dagger_spi" % repo_name,
-        ],
-    )
+    The targets will be of the form ":<artifact-id>".
+
+    Args:
+      repo_name: The name of the dependency repository (default is "@maven").
+    """
 
     # https://github.com/bazelbuild/buildtools/blob/master/WARNINGS.md#native-android
     # buildifier: disable=native-android
     native.android_library(
         name = "hilt-android",
         exported_plugins = [
+            ":hilt_dagger_compiler",
             ":hilt_android_entry_point_processor",
             ":hilt_aggregated_deps_processor",
             ":hilt_alias_of_processor",
@@ -133,13 +168,25 @@ def dagger_rules(repo_name = "@maven"):
         ],
         visibility = ["//visibility:public"],
         exports = [
-            ":dagger",
+            "%s//:com_google_dagger_dagger" % repo_name,  # For Dagger APIs
+            "%s//:javax_inject_javax_inject" % repo_name,  # For @Inject
             "%s//:androidx_annotation_annotation" % repo_name,  # For @CallSuper
             "%s//:com_google_dagger_hilt_android" % repo_name,
             "%s//:javax_annotation_jsr250_api" % repo_name,  # For @Generated
         ],
     )
 
+    # This target is same as dagger-compiler, but we're redefining it here
+    # so that users don't have to call dagger_rules() first.
+    native.java_plugin(
+        name = "hilt_dagger_compiler",
+        generates_api = 1,
+        processor_class = "dagger.internal.codegen.ComponentProcessor",
+        deps = [
+            "%s//:com_google_dagger_dagger_compiler" % repo_name,
+        ],
+    )
+
     native.java_plugin(
         name = "hilt_android_entry_point_processor",
         generates_api = 1,