incremental compilation fixes

CHANGELOG.md

@@ -17,6 +17,8 @@
 
 ### Custom Code Generator
 
+- The `GeneratedFile` result type has been deprecated in favor of `GeneratedFileWithSources`.  This new type allows for precise tracking of the generated files, which in turn drastically improves incremental compilation performance (#693).
+
 ### Other Notes & Contributions
 
 

build-logic/conventions/src/main/kotlin/com/squareup/anvil/conventions/BasePlugin.kt

@@ -1,5 +1,6 @@
 package com.squareup.anvil.conventions
 
+import com.rickbusarow.kgx.buildDir
 import com.rickbusarow.kgx.extras
 import com.rickbusarow.kgx.fromInt
 import com.rickbusarow.kgx.javaExtension
@@ -125,6 +126,7 @@ abstract class BasePlugin : Plugin<Project> {
    * so that there is no shared mutable state.
    */
   private fun configureBuildDirs(target: Project) {
+
     when {
       !target.isInAnvilBuild() -> return
 
@@ -136,6 +138,16 @@ abstract class BasePlugin : Plugin<Project> {
         target.layout.buildDirectory.set(target.file("build/included-build"))
       }
     }
+
+    // Set the kase working directory ('<build directory>/kase/<test|gradleTest>') as a System property,
+    // so that it's in the right place for projects with relocated directories.
+    // https://github.com/rickbusarow/kase/blob/255db67f40d5ec83e31755bc9ce81b1a2b08cf11/kase/src/main/kotlin/com/rickbusarow/kase/files/HasWorkingDir.kt#L93-L96
+    target.tasks.withType(Test::class.java).configureEach { task ->
+      task.systemProperty(
+        "kase.baseWorkingDir",
+        target.buildDir().resolve("kase/${task.name}"),
+      )
+    }
   }
 
   /**

compiler-api/api/compiler-api.api

@@ -43,6 +43,7 @@ public abstract interface class com/squareup/anvil/compiler/api/AnvilContext {
 	public abstract fun getGenerateFactories ()Z
 	public abstract fun getGenerateFactoriesOnly ()Z
 	public abstract fun getModule ()Lorg/jetbrains/kotlin/descriptors/ModuleDescriptor;
+	public abstract fun getTrackSourceFiles ()Z
 }
 
 public abstract interface class com/squareup/anvil/compiler/api/CodeGenerator : com/squareup/anvil/compiler/api/AnvilApplicabilityChecker {
@@ -52,17 +53,50 @@ public abstract interface class com/squareup/anvil/compiler/api/CodeGenerator :
 
 public final class com/squareup/anvil/compiler/api/CodeGeneratorKt {
 	public static final fun createGeneratedFile (Lcom/squareup/anvil/compiler/api/CodeGenerator;Ljava/io/File;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Lcom/squareup/anvil/compiler/api/GeneratedFile;
+	public static final fun createGeneratedFile (Lcom/squareup/anvil/compiler/api/CodeGenerator;Ljava/io/File;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/io/File;[Ljava/io/File;)Lcom/squareup/anvil/compiler/api/GeneratedFileWithSources;
+	public static final fun createGeneratedFile (Lcom/squareup/anvil/compiler/api/CodeGenerator;Ljava/io/File;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/util/Set;)Lcom/squareup/anvil/compiler/api/GeneratedFileWithSources;
 }
 
-public final class com/squareup/anvil/compiler/api/GeneratedFile {
+public abstract interface class com/squareup/anvil/compiler/api/FileWithContent : java/lang/Comparable {
+	public abstract fun compareTo (Lcom/squareup/anvil/compiler/api/FileWithContent;)I
+	public abstract fun component1 ()Ljava/io/File;
+	public abstract fun component2 ()Ljava/lang/String;
+	public abstract fun getContent ()Ljava/lang/String;
+	public abstract fun getFile ()Ljava/io/File;
+}
+
+public final class com/squareup/anvil/compiler/api/FileWithContent$DefaultImpls {
+	public static fun compareTo (Lcom/squareup/anvil/compiler/api/FileWithContent;Lcom/squareup/anvil/compiler/api/FileWithContent;)I
+	public static fun component1 (Lcom/squareup/anvil/compiler/api/FileWithContent;)Ljava/io/File;
+	public static fun component2 (Lcom/squareup/anvil/compiler/api/FileWithContent;)Ljava/lang/String;
+}
+
+public final class com/squareup/anvil/compiler/api/GeneratedFile : com/squareup/anvil/compiler/api/FileWithContent {
 	public fun <init> (Ljava/io/File;Ljava/lang/String;)V
+	public fun compareTo (Lcom/squareup/anvil/compiler/api/FileWithContent;)I
+	public synthetic fun compareTo (Ljava/lang/Object;)I
 	public final fun component1 ()Ljava/io/File;
 	public final fun component2 ()Ljava/lang/String;
 	public final fun copy (Ljava/io/File;Ljava/lang/String;)Lcom/squareup/anvil/compiler/api/GeneratedFile;
 	public static synthetic fun copy$default (Lcom/squareup/anvil/compiler/api/GeneratedFile;Ljava/io/File;Ljava/lang/String;ILjava/lang/Object;)Lcom/squareup/anvil/compiler/api/GeneratedFile;
 	public fun equals (Ljava/lang/Object;)Z
-	public final fun getContent ()Ljava/lang/String;
-	public final fun getFile ()Ljava/io/File;
+	public fun getContent ()Ljava/lang/String;
+	public fun getFile ()Ljava/io/File;
+	public fun hashCode ()I
+	public fun toString ()Ljava/lang/String;
+}
+
+public final class com/squareup/anvil/compiler/api/GeneratedFileWithSources : com/squareup/anvil/compiler/api/FileWithContent {
+	public fun <init> (Ljava/io/File;Ljava/lang/String;Ljava/util/Set;)V
+	public fun compareTo (Lcom/squareup/anvil/compiler/api/FileWithContent;)I
+	public synthetic fun compareTo (Ljava/lang/Object;)I
+	public fun component1 ()Ljava/io/File;
+	public fun component2 ()Ljava/lang/String;
+	public final fun component3 ()Ljava/util/Set;
+	public fun equals (Ljava/lang/Object;)Z
+	public fun getContent ()Ljava/lang/String;
+	public fun getFile ()Ljava/io/File;
+	public final fun getSourceFiles ()Ljava/util/Set;
 	public fun hashCode ()I
 	public fun toString ()Ljava/lang/String;
 }

compiler-api/build.gradle.kts

@@ -20,4 +20,9 @@ dependencies {
   api(libs.kotlin.compiler)
 
   implementation(platform(libs.kotlin.bom))
+
+  testImplementation(libs.junit)
+  testImplementation(libs.kase)
+  testImplementation(libs.kotest.assertions.api)
+  testImplementation(libs.kotest.assertions.core.jvm)
 }

compiler-api/src/main/java/com/squareup/anvil/compiler/api/AnvilContext.kt

@@ -43,6 +43,17 @@ public interface AnvilContext {
    */
   public val disableComponentMerging: Boolean
 
+  /**
+   * Enables incremental compilation support.
+   *
+   * This is achieved by tracking the source files for each generated file,
+   * which allows for two new behaviors:
+   * - Generated code is "invalidated" and deleted when the source file is changed or deleted.
+   * - Generated code is cached in a way that Gradle understands,
+   *   and will be restored from cache along with other build artifacts.
+   */
+  public val trackSourceFiles: Boolean
+
   /**
    * The module of the current compilation.
    */

compiler-api/src/main/java/com/squareup/anvil/compiler/api/CodeGenerator.kt

@@ -38,27 +38,81 @@ public interface CodeGenerator : AnvilApplicabilityChecker {
     codeGenDir: File,
     module: ModuleDescriptor,
     projectFiles: Collection<KtFile>,
-  ): Collection<GeneratedFile>
+  ): Collection<FileWithContent>
 }
 
 /**
  * Write [content] into a new file for the given [packageName] and [fileName]. [fileName] usually
  * refers to the class name.
  */
 @ExperimentalAnvilApi
-@Suppress("unused")
+@Deprecated(
+  message = "Use the createGeneratedFile with a `sourceFiles` argument instead.",
+  replaceWith = ReplaceWith(
+    expression = "createGeneratedFile(codeGenDir, packageName, fileName, content, sourceFile = TODO())",
+    imports = ["com.squareup.anvil.compiler.api.createGeneratedFile"],
+  ),
+)
+@Suppress("UnusedReceiverParameter", "unused", "Deprecation")
 public fun CodeGenerator.createGeneratedFile(
   codeGenDir: File,
   packageName: String,
   fileName: String,
   content: String,
-): GeneratedFile {
+): GeneratedFile = GeneratedFile(
+  file = writeFileContent(
+    codeGenDir = codeGenDir,
+    packageName = packageName,
+    fileName = fileName,
+    content = content,
+  ),
+  content = content,
+)
+
+public fun CodeGenerator.createGeneratedFile(
+  codeGenDir: File,
+  packageName: String,
+  fileName: String,
+  content: String,
+  sourceFile: File,
+  vararg additionalSourceFiles: File,
+): GeneratedFileWithSources = createGeneratedFile(
+  codeGenDir = codeGenDir,
+  packageName = packageName,
+  fileName = fileName,
+  content = content,
+  sourceFiles = setOf(sourceFile, *additionalSourceFiles),
+)
+
+@Suppress("UnusedReceiverParameter")
+public fun CodeGenerator.createGeneratedFile(
+  codeGenDir: File,
+  packageName: String,
+  fileName: String,
+  content: String,
+  sourceFiles: Set<File>,
+): GeneratedFileWithSources = GeneratedFileWithSources(
+  file = writeFileContent(
+    codeGenDir = codeGenDir,
+    packageName = packageName,
+    fileName = fileName,
+    content = content,
+  ),
+  content = content,
+  sourceFiles = sourceFiles,
+)
+
+private fun writeFileContent(
+  codeGenDir: File,
+  packageName: String,
+  fileName: String,
+  content: String,
+): File {
   val directory = File(codeGenDir, packageName.replace('.', File.separatorChar))
   val file = File(directory, "$fileName.kt")
   check(file.parentFile.exists() || file.parentFile.mkdirs()) {
     "Could not generate package directory: ${file.parentFile}"
   }
   file.writeText(content)
-
-  return GeneratedFile(file, content)
+  return file
 }

compiler-api/src/main/java/com/squareup/anvil/compiler/api/GeneratedFile.kt

@@ -8,7 +8,32 @@ import java.io.File
  * @property file the [File] to generate.
  * @property content the file contents to write to [file].
  */
-public data class GeneratedFile(
-  val file: File,
-  val content: String,
+@Deprecated(
+  message = "Use GeneratedFileWithSources instead.",
+  replaceWith = ReplaceWith(
+    expression = "GeneratedFileWithSources(file, content, setOf(TODO(\"Add some source files using <somePsiElement>.containingFileAsJavaFile()\")))",
+    imports = [
+      "com.squareup.anvil.compiler.api.GeneratedFileWithSources",
+      "com.squareup.anvil.compiler.internal.containingFileAsJavaFile",
+    ],
+  ),
+  level = DeprecationLevel.WARNING,
 )
+public data class GeneratedFile(
+  override val file: File,
+  override val content: String,
+) : FileWithContent
+
+/** Represents a generated file that Anvil should eventually write. */
+public sealed interface FileWithContent : Comparable<FileWithContent> {
+  /** The file to generate. */
+  public val file: File
+
+  /** The text to write to [file]. */
+  public val content: String
+
+  public operator fun component1(): File = file
+  public operator fun component2(): String = content
+
+  override fun compareTo(other: FileWithContent): Int = file.compareTo(other.file)
+}

compiler-api/src/main/java/com/squareup/anvil/compiler/api/GeneratedFileWithSources.kt

@@ -0,0 +1,113 @@
+package com.squareup.anvil.compiler.api
+
+import java.io.File
+
+/**
+ * Represents a generated file that Anvil should eventually write. The [sourceFiles] are the
+ * files that triggered the generation of this file or are referenced by the generated file.
+ * A modification to any of the [sourceFiles] will invalidate this generated file.
+ *
+ * All source files must be:
+ *   - absolute paths
+ *   - actual files (not directories)
+ *   - existent in the file system
+ *
+ * @property file the [File] to generate.
+ * @property content the file contents to write to [file].
+ * @property sourceFiles the source files used to generate this file.
+ * @throws AnvilCompilationException if a [sourceFiles] is not an absolute file, doesn't exist, or is a directory
+ * @throw AnvilCompilationException if a source file is the same as the generated [file]
+ */
+public class GeneratedFileWithSources(
+  override val file: File,
+  override val content: String,
+  public val sourceFiles: Set<File>,
+) : FileWithContent {
+
+  init {
+    fun require(condition: Boolean, lazyMessage: () -> String) {
+      if (!condition) {
+        throw AnvilCompilationException(
+          """
+          |message:
+          |${lazyMessage()}
+          |
+          |generated file:
+          |$file
+          |
+          """.trimMargin(),
+        )
+      }
+    }
+    require(sourceFiles.none { it == file }) {
+      """
+      |${this::class.simpleName} must not contain the generated file as a source file.
+      |
+      |source files:
+      |${sourceFiles.sorted().joinToString("\n")}
+      """.trimMargin()
+    }
+    require(sourceFiles.all { it.isFile && it.isAbsolute }) {
+
+      val notAbsolute = sourceFiles.filterNot { it.isAbsolute }.sorted()
+      val notFiles = sourceFiles.filterNot { it.isFile }.sorted()
+
+      buildString {
+        appendLine(
+          """
+          All source files must be:
+            - absolute paths
+            - actual files (not directories)
+            - existent in the file system
+          """.trimIndent(),
+        )
+        if (notAbsolute.isNotEmpty()) {
+          append(
+            """
+            |
+            |not absolute:
+            |${notAbsolute.joinToString("\n")}
+            """.trimMargin(),
+          )
+        }
+        if (notFiles.isNotEmpty()) {
+          append(
+            """
+            |
+            |not files:
+            |${notFiles.joinToString("\n")}
+            """.trimMargin(),
+          )
+        }
+      }
+    }
+  }
+
+  public operator fun component3(): Set<File> = sourceFiles
+
+  override fun equals(other: Any?): Boolean {
+    if (this === other) return true
+    if (other !is GeneratedFileWithSources) return false
+
+    if (file != other.file) return false
+    if (content != other.content) return false
+    if (sourceFiles != other.sourceFiles) return false
+
+    return true
+  }
+
+  override fun hashCode(): Int {
+    var result = file.hashCode()
+    result = 31 * result + content.hashCode()
+    result = 31 * result + sourceFiles.hashCode()
+    return result
+  }
+
+  override fun toString(): String = buildString {
+    appendLine("GeneratedFileWithSource(")
+    appendLine("  file: $file")
+    appendLine("  sourceFiles: ${sourceFiles.sorted()}")
+    appendLine("  content: $content")
+    appendLine(")")
+  }
+}