Add support for generated Java code with KSP (#1139)

* Add support for generating Java code with KSP

* Add dagger to ksp sample project

* Run java compilation action only when ksp generates java

* Update ksp tests

Author: zalewskise

MODULE.bazel

@@ -63,9 +63,9 @@ maven.install(
         "com.google.auto.service:auto-service-annotations:1.0.1",
         "com.google.auto.value:auto-value:1.10.1",
         "com.google.auto.value:auto-value-annotations:1.10.1",
-        "com.google.dagger:dagger:2.43.2",
-        "com.google.dagger:dagger-compiler:2.43.2",
-        "com.google.dagger:dagger-producers:2.43.2",
+        "com.google.dagger:dagger:2.51",
+        "com.google.dagger:dagger-compiler:2.51",
+        "com.google.dagger:dagger-producers:2.51",
         "javax.annotation:javax.annotation-api:1.3.2",
         "javax.inject:javax.inject:1",
         "org.pantsbuild:jarjar:1.7.2",

docs/kotlin.md

@@ -448,7 +448,7 @@ kt_kotlinc_options(<a href="#kt_kotlinc_options-name">name</a>, <a href="#kt_kot
 
 ## kt_ksp_plugin
 
-kt_ksp_plugin(<a href="#kt_ksp_plugin-name">name</a>, <a href="#kt_ksp_plugin-deps">deps</a>, <a href="#kt_ksp_plugin-processor_class">processor_class</a>)
+kt_ksp_plugin(<a href="#kt_ksp_plugin-name">name</a>, <a href="#kt_ksp_plugin-deps">deps</a>, <a href="#kt_ksp_plugin-generates_java">generates_java</a>, <a href="#kt_ksp_plugin-processor_class">processor_class</a>, <a href="#kt_ksp_plugin-target_embedded_compiler">target_embedded_compiler</a>)
 
 
     Define a KSP plugin for the Kotlin compiler to run. The plugin can then be referenced in the `plugins` attribute
@@ -481,7 +481,9 @@ kt_ksp_plugin(<a href="#kt_ksp_plugin-name">name</a>, <a href="#kt_ksp_plugin-de
 | :------------- | :------------- | :------------- | :------------- | :------------- |
 |<a id="kt_ksp_plugin-name"></a>name |  A unique name for this target.   | <a href="https://bazel.build/concepts/labels#target-names">Name</a> | required |  |
 |<a id="kt_ksp_plugin-deps"></a>deps |  The list of libraries to be added to the compiler's plugin classpath   | <a href="https://bazel.build/concepts/labels">List of labels</a> | optional | [] |
+|<a id="kt_ksp_plugin-generates_java"></a>generates_java |  Runs Java compilation action for plugin generating Java output.   | Boolean | optional | False |
 |<a id="kt_ksp_plugin-processor_class"></a>processor_class |  The fully qualified class name that the Java compiler uses as an entry point to the annotation processor.   | String | required |  |
+|<a id="kt_ksp_plugin-target_embedded_compiler"></a>target_embedded_compiler |  Plugin was compiled against the embeddable kotlin compiler. These plugins expect shaded kotlinc             dependencies, and will fail when running against a non-embeddable compiler.   | Boolean | optional | False |
 
 
 <a id="#kt_plugin_cfg"></a>

examples/ksp/BUILD

@@ -1,5 +1,5 @@
 load("@bazel_skylib//rules:build_test.bzl", "build_test")
-load("@rules_java//java:defs.bzl", "java_binary", "java_plugin")
+load("@rules_java//java:defs.bzl", "java_binary")
 
 # Copyright 2018 The Bazel Authors. All rights reserved.
 #
@@ -14,55 +14,99 @@ load("@rules_java//java:defs.bzl", "java_binary", "java_plugin")
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-load("@rules_kotlin//kotlin:core.bzl", "define_kt_toolchain", "kt_compiler_plugin", "kt_ksp_plugin", "kt_plugin_cfg")
+load("@rules_kotlin//kotlin:core.bzl", "define_kt_toolchain")
 load("@rules_kotlin//kotlin:jvm.bzl", "kt_jvm_library")
 
 package(default_visibility = ["//visibility:public"])
 
 define_kt_toolchain(name = "kotlin_toolchain")
 
-java_plugin(
-    name = "autovalue",
-    generates_api = True,
-    processor_class = "com.google.auto.value.processor.AutoValueProcessor",
-    deps = ["@maven//:com_google_auto_value_auto_value"],
+# Generate a srcjar to validate intellij plugin correctly attaches it.
+genrule(
+    name = "tea_lib_src",
+    outs = ["tea_lib_src.srcjar"],
+    cmd = """
+cat << EOF > TeaPot.kt
+package tea
+object TeaPot {
+    fun isEmpty() = true
+}
+EOF
+$(JAVABASE)/bin/jar -cf $@ TeaPot.kt
+rm TeaPot.kt
+""",
+    toolchains = ["@bazel_tools//tools/jdk:current_host_java_runtime"],
 )
 
-kt_ksp_plugin(
-    name = "moshi-kotlin-codegen",
-    processor_class = "com.squareup.moshi.kotlin.codegen.ksp.JsonClassSymbolProcessorProvider",
-    deps = [
-        "@maven//:com_squareup_moshi_moshi",
-        "@maven//:com_squareup_moshi_moshi_kotlin",
-        "@maven//:com_squareup_moshi_moshi_kotlin_codegen",
-    ],
+genrule(
+    name = "chai_lib_src",
+    outs = ["chai_lib_src.srcjar"],
+    cmd = """
+cat << EOF > ChaiCup.kt
+package chai
+object ChaiCup {
+    fun isEmpty() = true
+}
+EOF
+$(JAVABASE)/bin/jar -cf $@ ChaiCup.kt
+rm ChaiCup.kt
+""",
+    toolchains = ["@bazel_tools//tools/jdk:current_host_java_runtime"],
 )
 
-kt_ksp_plugin(
-    name = "autoservice",
-    processor_class = "dev.zacsweers.autoservice.ksp.AutoServiceSymbolProcessor$Provider",
-    deps = [
-        "@maven//:com_google_auto_service_auto_service_annotations",
-        "@maven//:dev_zacsweers_autoservice_auto_service_ksp",
-    ],
+genrule(
+    name = "genereated_module_src",
+    outs = ["genarated_module_src.srcjar"],
+    cmd = """
+cat << EOF > GeneratedModule.kt
+package generated
+
+import dagger.Provides
+import dagger.Module
+
+@Module
+object GeneratedModule {
+    @Provides
+    fun provideString() = "Hello Coffee"
+}
+EOF
+$(JAVABASE)/bin/jar -cf $@ GeneratedModule.kt
+rm GeneratedModule.kt
+""",
+    toolchains = ["@bazel_tools//tools/jdk:current_host_java_runtime"],
+)
+
+kt_jvm_library(
+    name = "generated_lib",
+    srcs = [":genereated_module_src"],
+    plugins = ["//third_party:dagger_ksp_plugin"],
+    deps = ["@maven//:com_google_dagger_dagger"],
 )
 
 kt_jvm_library(
     name = "coffee_lib",
     srcs = glob([
         "*.kt",
         "*.java",
-    ]),
+    ]) + [
+        # Adding a file ending with .srcjar is how code generation patterns are implemented.
+        ":tea_lib_src",
+        ":chai_lib_src",
+    ],
     plugins = [
-        "//:moshi-kotlin-codegen",
-        "//:autovalue",
-        "//:autoservice",
+        "//third_party:dagger_ksp_plugin",
+        "//third_party:moshi-kotlin-codegen",
+        "//third_party:autovalue",
+        "//third_party:autoservice",
     ],
     deps = [
+        ":generated_lib",
         "@maven//:com_google_auto_service_auto_service_annotations",
         "@maven//:com_google_auto_value_auto_value_annotations",
+        "@maven//:com_google_dagger_dagger",
         "@maven//:com_squareup_moshi_moshi",
         "@maven//:com_squareup_moshi_moshi_kotlin",
+        "@maven//:org_jetbrains_kotlinx_kotlinx_coroutines_core",
     ],
 )
 
@@ -82,60 +126,12 @@ build_test(
     ],
 )
 
-kt_compiler_plugin(
-    name = "ksp",
-    compile_phase = True,
-    id = "com.google.devtools.ksp.symbol-processing",
-    options = {
-        "apclasspath": "{classpath}",
-        # projectBaseDir shouldn't matter because incremental is disabled
-        "projectBaseDir": "{temp}",
-        # Disable incremental mode
-        "incremental": "false",
-        # Directory where class files are written to. Files written to this directory are class
-        # files being written directly from the annotation processor, not Kotlinc
-        "classOutputDir": "{generatedClasses}",
-        # Directory where generated Java sources files are written to
-        "javaOutputDir": "{generatedSources}",
-        # Directory where generated Kotlin sources files are written to
-        "kotlinOutputDir": "{generatedSources}",
-        # Directory where META-INF data is written to. This might not be the most ideal place to
-        # write this. Maybe just directly to the classes directory?
-        "resourceOutputDir": "{generatedSources}",
-        # TODO(bencodes) Not sure what this directory is yet.
-        "kspOutputDir": "{temp}",
-        # Directory to write KSP caches. Shouldn't matter because incremental is disabled
-        "cachesDir": "{temp}",
-        # Include in compilation as an example. This should be processed in the stubs phase.
-        "withCompilation": "true",
-        # Set returnOkOnError to false because we want to fail the build if there are any errors
-        "returnOkOnError": "false",
-        "allWarningsAsErrors": "false",
-    },
-    deps = [
-        "@rules_kotlin//kotlin/compiler:symbol-processing-api",
-        "@rules_kotlin//kotlin/compiler:symbol-processing-cmdline",
-    ],
-)
-
-kt_plugin_cfg(
-    name = "ksp_moshi",
-    options = {
-    },
-    plugin = ":ksp",
-    deps = [
-        "@maven//:com_squareup_moshi_moshi",
-        "@maven//:com_squareup_moshi_moshi_kotlin",
-        "@maven//:com_squareup_moshi_moshi_kotlin_codegen",
-    ],
-)
-
 kt_jvm_library(
     name = "raw_ksp_coffee_app_lib",
     srcs = ["CoffeeAppModel.kt"],
     plugins = [
-        "//:ksp",
-        "//:ksp_moshi",
+        "//third_party:ksp",
+        "//third_party:ksp_moshi",
     ],
     deps = [
         "@maven//:com_google_auto_service_auto_service_annotations",

examples/ksp/CoffeeApp.kt

@@ -16,9 +16,21 @@
 package coffee
 
 import com.squareup.moshi.Moshi
+import generated.GeneratedModule
+import dagger.Component
+import kotlinx.coroutines.runBlocking
+import tea.TeaPot
+import chai.ChaiCup
+import javax.inject.Singleton
 
 class CoffeeApp {
 
+  @Singleton
+  @Component(modules = [DripCoffeeModule::class, GeneratedModule::class])
+  interface CoffeeShop {
+    fun maker(): CoffeeMaker
+  }
+
   companion object {
 
     private val adapter = CoffeeAppModelJsonAdapter(Moshi.Builder().build())
@@ -28,9 +40,14 @@ class CoffeeApp {
 
     @JvmStatic
     fun main(args: Array<String>) {
-      println(
-        adapter.toJson(d.coffeeAppModel())
-      )
+      println("Coffee model: ${adapter.toJson(d.coffeeAppModel())}")
+
+      if (TeaPot.isEmpty() && ChaiCup.isEmpty()) {
+        val coffeeShop = DaggerCoffeeApp_CoffeeShop.builder().build()
+        runBlocking {
+          coffeeShop.maker().brew()
+        }
+      }
     }
   }
 }

examples/ksp/CoffeeMaker.kt

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2018 The Bazel Authors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package coffee
+
+import dagger.Lazy
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import javax.inject.Inject
+
+class CoffeeMaker @Inject internal constructor(
+  // Create a possibly costly heater only when we use it.
+  private val heater: Lazy<Heater>,
+  private val pump: Pump,
+  private val string: String
+) {
+
+  suspend fun brew() {
+    // this function is async to verify intellij support for coroutines.
+    withContext(Dispatchers.Default) {
+      heater.get().on()
+      pump.pump()
+      println(" [_]P coffee! [_]P ")
+      println(string)
+      heater.get().off()
+    }
+  }
+}

examples/ksp/DripCoffeeModule.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2018 The Bazel Authors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package coffee
+
+import dagger.Module
+import dagger.Provides
+import javax.inject.Singleton
+
+@Module(includes = arrayOf(PumpModule::class))
+internal class DripCoffeeModule {
+  @Provides
+  @Singleton
+  fun provideHeater(): Heater {
+    return ElectricHeater()
+  }
+}

examples/ksp/ElectricHeater.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2018 The Bazel Authors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package coffee
+
+internal class ElectricHeater : Heater {
+  override var isHot: Boolean = false
+
+  override fun on() {
+    println("~ ~ ~ heating ~ ~ ~")
+    this.isHot = true
+  }
+
+  override fun off() {
+    this.isHot = false
+  }
+}

examples/ksp/Heater.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2018 The Bazel Authors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package coffee
+
+internal interface Heater {
+  val isHot: Boolean
+  fun on()
+  fun off()
+}