Add Ksp Processor for Dagger Android ProguardProcessor.

RELNOTES=Add Ksp Processor for Dagger Android ProguardProcessor.
PiperOrigin-RevId: 600594616

6 files changed, 198 insertions, 50 deletions

diff --git a/java/dagger/android/internal/proguard/BUILD b/java/dagger/android/internal/proguard/BUILD
index 5a85279fb..7cb2cbc5d 100644
--- a/java/dagger/android/internal/proguard/BUILD
+++ b/java/dagger/android/internal/proguard/BUILD
@@ -22,10 +22,19 @@ package(default_visibility = ["//:src"])
 
 java_library(
     name = "proguard-processor",
-    srcs = ["ProguardProcessor.java"],
+    srcs = [
+        "KspProguardProcessor.java",
+        "ProguardProcessingStep.java",
+        "ProguardProcessor.java",
+    ],
     javacopts = DOCLINT_HTML_AND_SYNTAX + DOCLINT_REFERENCES,
     deps = [
+        "//java/dagger/android/processor:base_processing_step",
+        "//java/dagger/internal/codegen/xprocessing",
         "//third_party/java/auto:service",
+        "//third_party/java/guava/collect",
+        "//third_party/java/javapoet",
+        "@maven//:com_google_devtools_ksp_symbol_processing_api",
     ],
 )
 
diff --git a/java/dagger/android/internal/proguard/KspProguardProcessor.java b/java/dagger/android/internal/proguard/KspProguardProcessor.java
new file mode 100644
index 000000000..e2d4c4c3b
--- /dev/null
+++ b/java/dagger/android/internal/proguard/KspProguardProcessor.java
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2024 The Dagger Authors.
+ *
+ * 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 dagger.android.internal.proguard;
+
+import androidx.room.compiler.processing.XProcessingEnv;
+import androidx.room.compiler.processing.XProcessingEnvConfig;
+import androidx.room.compiler.processing.XProcessingStep;
+import androidx.room.compiler.processing.ksp.KspBasicAnnotationProcessor;
+import com.google.auto.service.AutoService;
+import com.google.common.collect.ImmutableList;
+import com.google.devtools.ksp.processing.SymbolProcessor;
+import com.google.devtools.ksp.processing.SymbolProcessorEnvironment;
+import com.google.devtools.ksp.processing.SymbolProcessorProvider;
+
+/**
+ * An annotation processor to generate dagger-android's specific proguard needs. This is only
+ * intended to run over the dagger-android project itself, as the alternative is to create an
+ * intermediary java_library for proguard rules to be consumed by the project.
+ *
+ * <p>Basic structure looks like this:
+ *
+ * <pre><code>
+ *   resources/META-INF/com.android.tools/proguard/dagger-android.pro
+ *   resources/META-INF/com.android.tools/r8/dagger-android.pro
+ *   resources/META-INF/proguard/dagger-android.pro
+ * </code></pre>
+ */
+public final class KspProguardProcessor extends KspBasicAnnotationProcessor {
+  private static final XProcessingEnvConfig PROCESSING_ENV_CONFIG =
+      new XProcessingEnvConfig.Builder().build();
+  private XProcessingEnv env;
+
+  private KspProguardProcessor(SymbolProcessorEnvironment symbolProcessorEnvironment) {
+    super(symbolProcessorEnvironment, PROCESSING_ENV_CONFIG);
+  }
+
+  @Override
+  public void initialize(XProcessingEnv env) {
+    this.env = env;
+  }
+
+  @Override
+  public Iterable<XProcessingStep> processingSteps() {
+    return ImmutableList.of(new ProguardProcessingStep(env));
+  }
+
+  /** Provides the {@link KspProguardProcessor}. */
+  @AutoService(SymbolProcessorProvider.class)
+  public static final class Provider implements SymbolProcessorProvider {
+    @Override
+    public SymbolProcessor create(SymbolProcessorEnvironment symbolProcessorEnvironment) {
+      return new KspProguardProcessor(symbolProcessorEnvironment);
+    }
+  }
+}
diff --git a/java/dagger/android/internal/proguard/ProguardProcessingStep.java b/java/dagger/android/internal/proguard/ProguardProcessingStep.java
new file mode 100644
index 000000000..c4cc0612d
--- /dev/null
+++ b/java/dagger/android/internal/proguard/ProguardProcessingStep.java
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2024 The Dagger Authors.
+ *
+ * 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 dagger.android.internal.proguard;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import androidx.room.compiler.processing.XElement;
+import androidx.room.compiler.processing.XFiler;
+import androidx.room.compiler.processing.XProcessingEnv;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.squareup.javapoet.ClassName;
+import dagger.android.processor.BaseProcessingStep;
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.nio.file.Path;
+
+/**
+ * A annotation processing step to generate dagger-android's specific proguard needs. This is only
+ * intended to run over the dagger-android project itself, as the alternative is to create an
+ * intermediary java_library for proguard rules to be consumed by the project.
+ *
+ * <p>Basic structure looks like this:
+ *
+ * <pre><code>
+ *   resources/META-INF/com.android.tools/proguard/dagger-android.pro
+ *   resources/META-INF/com.android.tools/r8/dagger-android.pro
+ *   resources/META-INF/proguard/dagger-android.pro
+ * </code></pre>
+ */
+public final class ProguardProcessingStep extends BaseProcessingStep {
+  private final XProcessingEnv processingEnv;
+
+  ProguardProcessingStep(XProcessingEnv processingEnv) {
+    this.processingEnv = processingEnv;
+  }
+
+  static final ClassName GENERATE_RULES_ANNOTATION_NAME =
+      ClassName.get("dagger.android.internal", "GenerateAndroidInjectionProguardRules");
+
+  @Override
+  public ImmutableSet<ClassName> annotationClassNames() {
+    return ImmutableSet.of(GENERATE_RULES_ANNOTATION_NAME);
+  }
+
+  @Override
+  public void process(XElement element, ImmutableSet<ClassName> annotationNames) {
+    XFiler filer = processingEnv.getFiler();
+
+    String errorProneRule = "-dontwarn com.google.errorprone.annotations.**\n";
+    String androidInjectionKeysRule =
+        "-identifiernamestring class dagger.android.internal.AndroidInjectionKeys {\n"
+            + "  java.lang.String of(java.lang.String);\n"
+            + "}\n";
+
+    writeFile(filer, "com.android.tools/proguard", errorProneRule);
+    writeFile(filer, "com.android.tools/r8", errorProneRule + androidInjectionKeysRule);
+    writeFile(filer, "proguard", errorProneRule);
+  }
+
+  private void writeFile(XFiler filer, String intermediatePath, String contents) {
+    try (OutputStream outputStream =
+            filer.writeResource(
+                Path.of("META-INF/" + intermediatePath + "/dagger-android.pro"),
+                ImmutableList.<XElement>of(),
+                XFiler.Mode.Isolating);
+        BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(outputStream, UTF_8))) {
+      writer.write(contents);
+    } catch (IOException e) {
+      throw new IllegalStateException(e);
+    }
+  }
+}
diff --git a/java/dagger/android/internal/proguard/ProguardProcessor.java b/java/dagger/android/internal/proguard/ProguardProcessor.java
index 49274e94f..8677bf179 100644
--- a/java/dagger/android/internal/proguard/ProguardProcessor.java
+++ b/java/dagger/android/internal/proguard/ProguardProcessor.java
@@ -16,19 +16,13 @@
 
 package dagger.android.internal.proguard;
 
-import static javax.tools.StandardLocation.CLASS_OUTPUT;
-
+import androidx.room.compiler.processing.XProcessingEnv;
+import androidx.room.compiler.processing.XProcessingStep;
+import androidx.room.compiler.processing.javac.JavacBasicAnnotationProcessor;
 import com.google.auto.service.AutoService;
-import java.io.IOException;
-import java.io.Writer;
-import java.util.Set;
-import javax.annotation.processing.AbstractProcessor;
-import javax.annotation.processing.Filer;
+import com.google.common.collect.ImmutableList;
 import javax.annotation.processing.Processor;
-import javax.annotation.processing.RoundEnvironment;
-import javax.annotation.processing.SupportedAnnotationTypes;
 import javax.lang.model.SourceVersion;
-import javax.lang.model.element.TypeElement;
 
 /**
  * An {@linkplain Processor annotation processor} to generate dagger-android's specific proguard
@@ -44,46 +38,17 @@ import javax.lang.model.element.TypeElement;
  * </code></pre>
  */
 @AutoService(Processor.class)
-@SupportedAnnotationTypes(ProguardProcessor.GENERATE_RULES_ANNOTATION_NAME)
-public final class ProguardProcessor extends AbstractProcessor {
-
-  static final String GENERATE_RULES_ANNOTATION_NAME =
-      "dagger.android.internal.GenerateAndroidInjectionProguardRules";
+public final class ProguardProcessor extends JavacBasicAnnotationProcessor {
+  private XProcessingEnv env;
 
   @Override
-  public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
-    roundEnv
-        .getElementsAnnotatedWith(
-            processingEnv.getElementUtils().getTypeElement(GENERATE_RULES_ANNOTATION_NAME))
-        .forEach(element -> generate());
-
-    return false;
-  }
-
-  private void generate() {
-    Filer filer = processingEnv.getFiler();
-
-    String errorProneRule = "-dontwarn com.google.errorprone.annotations.**\n";
-    String androidInjectionKeysRule =
-        "-identifiernamestring class dagger.android.internal.AndroidInjectionKeys {\n"
-            + "  java.lang.String of(java.lang.String);\n"
-            + "}\n";
-
-    writeFile(filer, "com.android.tools/proguard", errorProneRule);
-    writeFile(filer, "com.android.tools/r8", errorProneRule + androidInjectionKeysRule);
-    writeFile(filer, "proguard", errorProneRule);
+  public void initialize(XProcessingEnv env) {
+    this.env = env;
   }
 
-  private static void writeFile(Filer filer, String intermediatePath, String contents) {
-    try (Writer writer =
-        filer
-            .createResource(
-                CLASS_OUTPUT, "", "META-INF/" + intermediatePath + "/dagger-android.pro")
-            .openWriter()) {
-      writer.write(contents);
-    } catch (IOException e) {
-      throw new IllegalStateException(e);
-    }
+  @Override
+  public Iterable<XProcessingStep> processingSteps() {
+    return ImmutableList.of(new ProguardProcessingStep(env));
   }
 
   @Override
diff --git a/java/dagger/android/processor/BUILD b/java/dagger/android/processor/BUILD
index eb3fdf643..f70c09102 100644
--- a/java/dagger/android/processor/BUILD
+++ b/java/dagger/android/processor/BUILD
@@ -32,13 +32,28 @@ filegroup(
 )
 
 java_library(
+    name = "base_processing_step",
+    srcs = ["BaseProcessingStep.java"],
+    deps = [
+        "//java/dagger/internal/codegen/extension",
+        "//java/dagger/internal/codegen/xprocessing",
+        "//third_party/java/guava/base",
+        "//third_party/java/guava/collect",
+        "//third_party/java/javapoet",
+    ],
+)
+
+java_library(
     name = "processor",
-    srcs = [":srcs"],
+    srcs = glob(
+        ["*.java"],
+        exclude = ["BaseProcessingStep.java"],
+    ),
     javacopts = DOCLINT_HTML_AND_SYNTAX + DOCLINT_REFERENCES,
     tags = ["maven_coordinates=com.google.dagger:dagger-android-processor:" + POM_VERSION],
     deps = [
+        ":base_processing_step",
         "//java/dagger:core",
-        "//java/dagger/internal/codegen/extension",
         "//java/dagger/internal/codegen/xprocessing",
         "//java/dagger/spi",
         "//third_party/java/auto:service",
@@ -58,6 +73,7 @@ gen_maven_artifact(
     artifact_target = ":processor",
     artifact_target_libs = [
         "//java/dagger/internal/codegen/xprocessing",
+        "//java/dagger/android/processor:base_processing_step",
     ],
     artifact_target_maven_deps = [
         "com.google.dagger:dagger",
diff --git a/java/dagger/android/processor/BaseProcessingStep.java b/java/dagger/android/processor/BaseProcessingStep.java
index 7d51fcad8..100ded0a0 100644
--- a/java/dagger/android/processor/BaseProcessingStep.java
+++ b/java/dagger/android/processor/BaseProcessingStep.java
@@ -36,7 +36,7 @@ import java.util.Set;
  * A {@link XProcessingStep} that processes one element at a time and defers any for which {@link
  * TypeNotPresentException} is thrown.
  */
-abstract class BaseProcessingStep implements XProcessingStep {
+public abstract class BaseProcessingStep implements XProcessingStep {
   @Override
   public final ImmutableSet<String> annotations() {
     return annotationClassNames().stream().map(ClassName::canonicalName).collect(toImmutableSet());