Incremental: Support top level callables in libs

api/api.base

@@ -61,6 +61,8 @@ package com.google.devtools.ksp.processing {
     method public void associate(@NonNull java.util.List<? extends com.google.devtools.ksp.symbol.KSFile> sources, @NonNull String packageName, @NonNull String fileName, @NonNull String extensionName = "kt");
     method public void associateByPath(@NonNull java.util.List<? extends com.google.devtools.ksp.symbol.KSFile> sources, @NonNull String path, @NonNull String extensionName = "kt");
     method public void associateWithClasses(@NonNull java.util.List<? extends com.google.devtools.ksp.symbol.KSClassDeclaration> classes, @NonNull String packageName, @NonNull String fileName, @NonNull String extensionName = "kt");
+    method public void associateWithFunctions(@NonNull java.util.List<? extends com.google.devtools.ksp.symbol.KSFunctionDeclaration> functions, @NonNull String packageName, @NonNull String fileName, @NonNull String extensionName = "kt");
+    method public void associateWithProperties(@NonNull java.util.List<? extends com.google.devtools.ksp.symbol.KSPropertyDeclaration> properties, @NonNull String packageName, @NonNull String fileName, @NonNull String extensionName = "kt");
     method @NonNull public java.io.OutputStream createNewFile(@NonNull com.google.devtools.ksp.processing.Dependencies dependencies, @NonNull String packageName, @NonNull String fileName, @NonNull String extensionName = "kt");
     method @NonNull public java.io.OutputStream createNewFileByPath(@NonNull com.google.devtools.ksp.processing.Dependencies dependencies, @NonNull String path, @NonNull String extensionName = "kt");
     method @NonNull public java.util.Collection<java.io.File> getGeneratedFile();
@@ -83,6 +85,13 @@ package com.google.devtools.ksp.processing {
     property @NonNull public final com.google.devtools.ksp.processing.Dependencies ALL_FILES;
   }
 
+  public enum ExitCode {
+    method @NonNull public static com.google.devtools.ksp.processing.ExitCode valueOf(String value) throws java.lang.IllegalArgumentException, java.lang.NullPointerException;
+    method @NonNull public static com.google.devtools.ksp.processing.ExitCode[] values();
+    enum_constant public static final com.google.devtools.ksp.processing.ExitCode OK;
+    enum_constant public static final com.google.devtools.ksp.processing.ExitCode PROCESSING_ERROR;
+  }
+
   public interface JsPlatformInfo extends com.google.devtools.ksp.processing.PlatformInfo {
   }
 

api/src/main/kotlin/com/google/devtools/ksp/processing/CodeGenerator.kt

@@ -138,6 +138,42 @@ interface CodeGenerator {
     )
 
     val generatedFile: Collection<File>
+
+    /**
+     * Associate [functions] to an output file.
+     *
+     * @param functions are [KSFunctionDeclaration]s from which this output is built. Only those that are obtained
+     *              directly from [Resolver] are required.
+     * @param packageName corresponds to the relative path of the generated file; using either '.'or '/' as separator.
+     * @param fileName file name
+     * @param extensionName If "kt" or "java", this file will participate in subsequent compilation.
+     *                      Otherwise its creation is only considered in incremental processing.
+     * @see [CodeGenerator] for more details.
+     */
+    fun associateWithFunctions(
+        functions: List<KSFunctionDeclaration>,
+        packageName: String,
+        fileName: String,
+        extensionName: String = "kt"
+    )
+
+    /**
+     * Associate [properties] to an output file.
+     *
+     * @param properties are [KSPropertyDeclaration]s from which this output is built. Only those that are obtained
+     *              directly from [Resolver] are required.
+     * @param packageName corresponds to the relative path of the generated file; using either '.'or '/' as separator.
+     * @param fileName file name
+     * @param extensionName If "kt" or "java", this file will participate in subsequent compilation.
+     *                      Otherwise its creation is only considered in incremental processing.
+     * @see [CodeGenerator] for more details.
+     */
+    fun associateWithProperties(
+        properties: List<KSPropertyDeclaration>,
+        packageName: String,
+        fileName: String,
+        extensionName: String = "kt"
+    )
 }
 
 /**

common-util/src/main/kotlin/com/google/devtools/ksp/processing/impl/CodeGeneratorImpl.kt

@@ -22,6 +22,8 @@ import com.google.devtools.ksp.processing.CodeGenerator
 import com.google.devtools.ksp.processing.Dependencies
 import com.google.devtools.ksp.symbol.KSClassDeclaration
 import com.google.devtools.ksp.symbol.KSFile
+import com.google.devtools.ksp.symbol.KSFunctionDeclaration
+import com.google.devtools.ksp.symbol.KSPropertyDeclaration
 import java.io.File
 import java.io.FileOutputStream
 import java.io.IOException
@@ -98,6 +100,42 @@ class CodeGeneratorImpl(
         associate(files, path, extensionToDirectory(extensionName))
     }
 
+    // FIXME: associate with the containing FileKt.
+    // The containing FileKt is unfortunately a backend thing and is not available in Kotlin metadata.
+    // Therefore, the only way to get it seems to be traversing bytecode and find the functions of interest.
+    //
+    // This implementation associates anyChangesWildcard, which is an overkill.
+    override fun associateWithFunctions(
+        functions: List<KSFunctionDeclaration>,
+        packageName: String,
+        fileName: String,
+        extensionName: String
+    ) {
+        val path = pathOf(packageName, fileName, extensionName)
+        val files = functions.map {
+            it.containingFile ?: anyChangesWildcard
+        }
+        associate(files, path, extensionToDirectory(extensionName))
+    }
+
+    // FIXME: associate with the containing FileKt.
+    // The containing FileKt is unfortunately a backend thing and is not available in Kotlin metadata.
+    // Therefore, the only way to get it seems to be traversing bytecode and find the functions of interest.
+    //
+    // This implementation associates anyChangesWildcard, which is an overkill.
+    override fun associateWithProperties(
+        properties: List<KSPropertyDeclaration>,
+        packageName: String,
+        fileName: String,
+        extensionName: String
+    ) {
+        val path = pathOf(packageName, fileName, extensionName)
+        val files = properties.map {
+            it.containingFile ?: anyChangesWildcard
+        }
+        associate(files, path, extensionToDirectory(extensionName))
+    }
+
     private fun extensionToDirectory(extensionName: String): File {
         return when (extensionName) {
             "class" -> classDir

integration-tests/src/test/kotlin/com/google/devtools/ksp/test/IncrementalCPIT.kt

@@ -77,6 +77,98 @@ class IncrementalCPIT(val useKSP2: Boolean) {
         }
     }
 
+    val func2Dirty = listOf(
+        "l1/src/main/kotlin/p1/TopFunc1.kt" to setOf(
+            "w: [ksp] processing done",
+        ),
+    )
+
+    @Test
+    fun testCPChangesForFunctions() {
+        val gradleRunner = GradleRunner.create().withProjectDir(project.root)
+
+        gradleRunner.withArguments("clean", "assemble").build().let { result ->
+            Assert.assertEquals(TaskOutcome.SUCCESS, result.task(":workload:assemble")?.outcome)
+        }
+
+        // Dummy changes
+        func2Dirty.forEach { (src, expectedDirties) ->
+            File(project.root, src).appendText("\n\n")
+            gradleRunner.withArguments("assemble").build().let { result ->
+                // Trivial changes should not result in re-processing.
+                Assert.assertEquals(TaskOutcome.UP_TO_DATE, result.task(":workload:kspKotlin")?.outcome)
+            }
+        }
+
+        // Value changes
+        func2Dirty.forEach { (src, expectedDirties) ->
+            File(project.root, src).writeText("package p1\n\nfun MyTopFunc1(): Int = 1")
+            gradleRunner.withArguments("assemble").withDebug(true).build().let { result ->
+                // Value changes should not result in re-processing.
+                Assert.assertEquals(TaskOutcome.SUCCESS, result.task(":workload:kspKotlin")?.outcome)
+                val dirties = result.output.lines().filter { it.startsWith("w: [ksp]") }.toSet()
+                // Non-signature changes should not affect anything.
+                Assert.assertEquals(emptyMessage, dirties)
+            }
+        }
+
+        // Signature changes
+        func2Dirty.forEach { (src, expectedDirties) ->
+            File(project.root, src).writeText("package p1\n\nfun MyTopFunc1(): Double = 1.0")
+            gradleRunner.withArguments("assemble").build().let { result ->
+                Assert.assertEquals(TaskOutcome.SUCCESS, result.task(":workload:kspKotlin")?.outcome)
+                val dirties = result.output.lines().filter { it.startsWith("w: [ksp]") }.toSet()
+                Assert.assertEquals(expectedDirties, dirties)
+            }
+        }
+    }
+
+    val prop2Dirty = listOf(
+        "l1/src/main/kotlin/p1/TopProp1.kt" to setOf(
+            "w: [ksp] processing done",
+        ),
+    )
+
+    @Test
+    fun testCPChangesForProperties() {
+        val gradleRunner = GradleRunner.create().withProjectDir(project.root)
+
+        gradleRunner.withArguments("clean", "assemble").build().let { result ->
+            Assert.assertEquals(TaskOutcome.SUCCESS, result.task(":workload:assemble")?.outcome)
+        }
+
+        // Dummy changes
+        prop2Dirty.forEach { (src, expectedDirties) ->
+            File(project.root, src).appendText("\n\n")
+            gradleRunner.withArguments("assemble").build().let { result ->
+                // Trivial changes should not result in re-processing.
+                Assert.assertEquals(TaskOutcome.UP_TO_DATE, result.task(":workload:kspKotlin")?.outcome)
+            }
+        }
+
+        // Value changes
+        prop2Dirty.forEach { (src, expectedDirties) ->
+            File(project.root, src).writeText("package p1\n\nval MyTopProp1: Int = 1")
+            gradleRunner.withArguments("assemble").withDebug(true).build().let { result ->
+                // Value changes should not result in re-processing.
+                Assert.assertEquals(TaskOutcome.SUCCESS, result.task(":workload:kspKotlin")?.outcome)
+                val dirties = result.output.lines().filter { it.startsWith("w: [ksp]") }.toSet()
+                // Non-signature changes should not affect anything.
+                Assert.assertEquals(emptyMessage, dirties)
+            }
+        }
+
+        // Signature changes
+        prop2Dirty.forEach { (src, expectedDirties) ->
+            File(project.root, src).writeText("package p1\n\nval MyTopProp1: Double = 1.0")
+            gradleRunner.withArguments("assemble").build().let { result ->
+                Assert.assertEquals(TaskOutcome.SUCCESS, result.task(":workload:kspKotlin")?.outcome)
+                val dirties = result.output.lines().filter { it.startsWith("w: [ksp]") }.toSet()
+                Assert.assertEquals(expectedDirties, dirties)
+            }
+        }
+    }
+
     private fun toggleFlags(vararg extras: String) {
         val gradleRunner = GradleRunner.create().withProjectDir(project.root).withDebug(true)
 

integration-tests/src/test/resources/incremental-classpath/l1/src/main/kotlin/p1/TopFunc1.kt

@@ -0,0 +1,3 @@
+package p1
+
+fun MyTopFunc1(): Int = 0

integration-tests/src/test/resources/incremental-classpath/l1/src/main/kotlin/p1/TopProp1.kt

@@ -0,0 +1,3 @@
+package p1
+
+val MyTopProp1: Int = 0

integration-tests/src/test/resources/incremental-classpath/validator/src/main/kotlin/Validator.kt

@@ -1,4 +1,6 @@
 import com.google.devtools.ksp.getClassDeclarationByName
+import com.google.devtools.ksp.getFunctionDeclarationsByName
+import com.google.devtools.ksp.getPropertyDeclarationByName
 import com.google.devtools.ksp.processing.*
 import com.google.devtools.ksp.symbol.*
 import com.google.devtools.ksp.validate
@@ -61,6 +63,16 @@ class Validator : SymbolProcessor {
         val l5 = resolver.getClassDeclarationByName("p1.L5")!!
         codeGenerator.createNewFile(Dependencies(false), "p1", "l5", "log")
         codeGenerator.associateWithClasses(listOf(l5), "p1", "l5", "log")
+
+        // create an output from MyTopFunc1, declared in TopFunc1.kt
+        val myTopFunc1 = resolver.getFunctionDeclarationsByName("p1.MyTopFunc1", true).single()
+        codeGenerator.createNewFile(Dependencies(false), "p1", "MyTopFunc1", "log")
+        codeGenerator.associateWithFunctions(listOf(myTopFunc1), "p1", "MyTopFunc1", "log")
+
+        // create an output from MyTopProp1, declared in TopFunc1.kt
+        val myTopProp1 = resolver.getPropertyDeclarationByName("p1.MyTopProp1", true)!!
+        codeGenerator.createNewFile(Dependencies(false), "p1", "MyTopProp1", "log")
+        codeGenerator.associateWithProperties(listOf(myTopProp1), "p1", "MyTopProp1", "log")
         logger.warn("processing done")
 
         processed = true