Move the Index annotation for KSP to annotations.

The processor will produce a Index annotated class for each LibraryGlideModule in given compilation unit. If the Index annotation is in the ksp module, it will not be accessible in parent modules, causing a compilation failure. To work around that, we'll follow the same pattern as we did for Java and place the annotation in the annotations package, but with package private visibility.

Any compilation unit that uses our annotation processor must already
have a dependency on annotation, so the Index annotation will be
available.

Fixes bumptech#4911.

annotation/ksp/src/main/kotlin/com/bumptech/glide/annotation/ksp/AppGlideModules.kt

@@ -212,7 +212,8 @@ internal class AppGlideModuleParser(
   }
 
   private fun KSAnnotation.getModuleArgumentValues(): List<String> {
-    val result = arguments.find { it.name?.getShortName().equals("modules") }?.value
+    val result =
+      arguments.find { it.name?.getShortName().equals(IndexGenerator.INDEX_MODULES_NAME) }?.value
     if (result is List<*> && result.all { it is String }) {
       @Suppress("UNCHECKED_CAST") return result as List<String>
     }

annotation/ksp/src/main/kotlin/com/bumptech/glide/annotation/ksp/LibraryGlideModules.kt

@@ -68,7 +68,7 @@ internal class LibraryGlideModulesParser(
  * The output file generated by this class with a single LibraryGlideModule looks like this:
  *
  * ```
- * @com.bumptech.glide.annotation.compiler.Index(
+ * @com.bumptech.glide.annotation.ksp.Index(
  *   ["com.bumptech.glide.integration.okhttp3.OkHttpLibraryGlideModule"]
  * )
  * class Indexer_GlideModule_com_bumptech_glide_integration_okhttp3_OkHttpLibraryGlideModule
@@ -80,15 +80,18 @@ internal object IndexGenerator {
   private const val INDEXER_NAME_PREFIX = "GlideIndexer_"
   private const val MAXIMUM_FILE_NAME_LENGTH = 255
 
-  @OptIn(DelicateKotlinPoetApi::class) // We're using AnnotationSpec.builder
+  // The name of the parameter in the Index annotation that points to the list of modules
+  internal const val INDEX_MODULES_NAME = "modules"
+
+  @OptIn(DelicateKotlinPoetApi::class) // For AnnotationSpec.builder
   fun generate(
     libraryModuleNames: List<LibraryModuleName>,
   ): FileSpec {
     val libraryModuleQualifiedNames: List<String> = libraryModuleNames.map { it.qualifiedName }
 
     val indexAnnotation: AnnotationSpec =
       AnnotationSpec.builder(Index::class.java)
-        .addRepeatedMember(libraryModuleQualifiedNames)
+        .addRepeatedMember(INDEX_MODULES_NAME, libraryModuleQualifiedNames)
         .build()
     val indexName = generateUniqueName(libraryModuleQualifiedNames)
 
@@ -124,6 +127,8 @@ internal object IndexGenerator {
     ) { it.replace(".", "_") }
   }
 
-  private fun AnnotationSpec.Builder.addRepeatedMember(repeatedMember: List<String>) =
-    addMember("[\n" + "%S,\n".repeat(repeatedMember.size) + "]", *repeatedMember.toTypedArray())
+  private fun AnnotationSpec.Builder.addRepeatedMember(name: String, repeatedMember: List<String>) =
+    addMember(
+      "$name = [\n" + "%S,\n".repeat(repeatedMember.size) + "]", *repeatedMember.toTypedArray()
+    )
 }

annotation/ksp/test/src/test/kotlin/com/bumptech/glide/annotation/ksp/LibraryGlideModuleTests.kt

@@ -2,9 +2,12 @@ package com.bumptech.glide.annotation.ksp.test
 
 import com.bumptech.glide.annotation.ksp.AppGlideModuleConstants
 import com.bumptech.glide.annotation.ksp.GlideSymbolProcessorConstants
+import com.bumptech.glide.annotation.ksp.GlideSymbolProcessorProvider
 import com.google.common.truth.Truth.assertThat
 import com.tschuchort.compiletesting.KotlinCompilation
 import com.tschuchort.compiletesting.KotlinCompilation.ExitCode
+import com.tschuchort.compiletesting.SourceFile
+import com.tschuchort.compiletesting.symbolProcessorProviders
 import java.io.FileNotFoundException
 import kotlin.test.assertFailsWith
 import org.intellij.lang.annotations.Language
@@ -598,6 +601,66 @@ class LibraryGlideModuleTests(override val sourceType: SourceType) : PerSourceTy
         .contains(AppGlideModuleConstants.INVALID_EXCLUDES_ANNOTATION_MESSAGE.format("AppModule"))
     }
   }
+
+  @Test
+  fun compile_withLibraryGlideModule_compiledSeparately_includesLibraryGlideModule_2() {
+    val kotlinLibraryModule =
+      KotlinSourceFile(
+        "LibraryModule.kt",
+        """
+        import com.bumptech.glide.annotation.GlideModule
+        import com.bumptech.glide.module.LibraryGlideModule
+
+        @GlideModule class LibraryModule : LibraryGlideModule()
+        """
+      )
+    val javaLibraryModule =
+      JavaSourceFile(
+        "LibraryModule.java",
+        """
+          import com.bumptech.glide.annotation.GlideModule;
+          import com.bumptech.glide.module.LibraryGlideModule;
+          
+          @GlideModule public class LibraryModule extends LibraryGlideModule {}
+        """
+      )
+
+    val libraryCompilationResult = compileCurrentSourceType(kotlinLibraryModule, javaLibraryModule)
+
+    val kotlinAppModule =
+      KotlinSourceFile(
+        "AppModule.kt",
+        """
+        import com.bumptech.glide.annotation.GlideModule
+        import com.bumptech.glide.module.AppGlideModule
+
+        @GlideModule class AppModule : AppGlideModule()
+        """
+      )
+    val javaAppModule =
+      JavaSourceFile(
+        "AppModule.java",
+        """
+          import com.bumptech.glide.annotation.GlideModule;
+          import com.bumptech.glide.module.AppGlideModule;
+          
+          @GlideModule public class AppModule extends AppGlideModule {
+            public AppModule() {}
+          }
+        """
+      )
+
+    val generatedLibrarySources =
+      libraryCompilationResult.allGeneratedFiles()
+        .map { GeneratedSourceFile(it, sourceType) }
+
+    compileCurrentSourceType(
+      *(listOf(kotlinAppModule, javaAppModule) + generatedLibrarySources).toTypedArray(),
+    ) {
+      assertThat(it.generatedAppGlideModuleContents())
+        .hasSourceEqualTo(appGlideModuleWithLibraryModule)
+    }
+  }
 }
 
 @Language("kotlin")

annotation/ksp/test/src/test/kotlin/com/bumptech/glide/annotation/ksp/SourceTestHelpers.kt

@@ -19,14 +19,35 @@ internal class CompilationResult(
 
   fun generatedAppGlideModuleContents() = readFile(findAppGlideModule())
 
-  private fun readFile(file: File) = file.readLines().joinToString("\n")
+  fun allGeneratedFiles(): List<File> {
+    val allFiles = mutableListOf<File>()
+    val parentDir = generatedFilesParentDir()
+    if (parentDir != null) {
+      findAllFilesRecursive(parentDir, allFiles)
+    }
+    return allFiles
+  }
 
-  private fun findAppGlideModule(): File {
+  private fun findAllFilesRecursive(parent: File, allFiles: MutableList<File>) {
+    if (parent.isFile) {
+      allFiles.add(parent)
+      return
+    }
+    parent.listFiles()?.map { findAllFilesRecursive(it, allFiles) }
+  }
+
+  private fun generatedFilesParentDir(): File? {
     var currentDir: File? = compilation.kspSourcesDir
     listOf("kotlin", "com", "bumptech", "glide").forEach { directoryName ->
       currentDir = currentDir?.listFiles()?.find { it.name.equals(directoryName) }
     }
-    return currentDir?.listFiles()?.find { it.name.equals("GeneratedAppGlideModuleImpl.kt") }
+    return currentDir
+  }
+
+  private fun readFile(file: File) = file.readLines().joinToString("\n")
+
+  private fun findAppGlideModule(): File {
+    return generatedFilesParentDir()?.listFiles()?.find { it.name.equals("GeneratedAppGlideModuleImpl.kt") }
       ?: throw FileNotFoundException(
         "GeneratedAppGlideModuleImpl.kt was not generated or not generated in the expected" +
           "location"
@@ -44,6 +65,19 @@ sealed interface TypedSourceFile {
   fun sourceType(): SourceType
 }
 
+internal class GeneratedSourceFile(
+  private val file: File, private val currentSourceType: SourceType,
+) : TypedSourceFile {
+  override fun sourceFile(): SourceFile = SourceFile.fromPath(file)
+
+  // Hack alert: We use this class only for generated output of some previous compilation. We rely
+  // on the type in that previous compilation to select the proper source. The output however is
+  // always Kotlin, regardless of source. But we always want to include whatever the generated
+  // output is in the next step. That means we need our sourceType here to match the
+  //  currentSourceType in the test.
+  override fun sourceType(): SourceType = currentSourceType
+}
+
 internal class KotlinSourceFile(
   val name: String,
   @Language("kotlin") val content: String,
@@ -65,11 +99,12 @@ internal interface PerSourceTypeTest {
 
   fun compileCurrentSourceType(
     vararg sourceFiles: TypedSourceFile,
-    test: (input: CompilationResult) -> Unit,
-  ) {
-    test(
+    test: (input: CompilationResult) -> Unit = {},
+  ) : CompilationResult {
+    val result =
       compile(sourceFiles.filter { it.sourceType() == sourceType }.map { it.sourceFile() }.toList())
-    )
+    test(result)
+    return result
   }
 }
 

annotation/src/main/java/com/bumptech/glide/annotation/ksp/Index.java

@@ -0,0 +1,19 @@
+package com.bumptech.glide.annotation.ksp;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Used to retrieve LibraryGlideModule and GlideExtension classes in our annotation processor from
+ * libraries and applications.
+ *
+ * <p>Part of the internals of Glide's annotation processor and not for public use.
+ */
+@Target(ElementType.TYPE)
+// Needs to be parsed from class files in JAR.
+@Retention(RetentionPolicy.CLASS)
+@interface Index {
+  String[] modules() default {};
+}