From ccc272c49f419fc59ccba80231b72c80a4f79ba7 Mon Sep 17 00:00:00 2001
From: Ivan Gavrilovic <gavra@google.com>
Date: Fri, 20 Nov 2020 19:06:50 +0000
Subject: [PATCH] KT-43489: KGP - Avoid storing build history mapping in a
 property

If tasks are created eagerly, it is possible for this
mapping to be initalized too early. This causes incremental
compilation to fail, as it will contain mappings only for
projects that have been evaluated thus far.

Fixes KT-43489
---
 .../IncrementalCompilationMultiProjectIT.kt   | 38 +++++++++++++++++++
 .../jetbrains/kotlin/gradle/tasks/Tasks.kt    |  6 +--
 2 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/IncrementalCompilationMultiProjectIT.kt b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/IncrementalCompilationMultiProjectIT.kt
index bd4b2728148..2425c7fa4a9 100644
--- a/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/IncrementalCompilationMultiProjectIT.kt
+++ b/libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/IncrementalCompilationMultiProjectIT.kt
@@ -99,6 +99,44 @@ class IncrementalCompilationJvmMultiProjectIT : BaseIncrementalCompilationMultiP
             assertCompiledKotlinSources(relativePaths)
         }
     }
+
+    /** Regression test for KT-43489. Make sure build history mapping is not initialized too early. */
+    @Test
+    fun testBuildHistoryMappingLazilyComputedWithWorkers() {
+        val project = defaultProject()
+        project.setupWorkingDir()
+        project.projectDir.resolve("app/build.gradle").appendText(
+            """
+                // added to force eager configuration
+                tasks.withType(JavaCompile) {
+                    options.encoding = 'UTF-8'
+                }
+            """.trimIndent()
+        )
+        val options = defaultBuildOptions().copy(parallelTasksInProject = true)
+        project.build(options = options, params = arrayOf("build")) {
+            assertSuccessful()
+        }
+
+        val aKt = project.projectDir.getFileByName("A.kt")
+        aKt.writeText(
+            """
+package bar
+
+open class A {
+    fun a() {}
+    fun newA() {}
+}
+"""
+        )
+
+        project.build(options = options, params = arrayOf("build")) {
+            assertSuccessful()
+            val affectedSources = project.projectDir.getFilesByNames("A.kt", "B.kt", "AA.kt", "AAA.kt", "BB.kt")
+            val relativePaths = project.relativize(affectedSources)
+            assertCompiledKotlinSources(relativePaths)
+        }
+    }
 }
 
 abstract class BaseIncrementalCompilationMultiProjectIT : BaseGradleIT() {
diff --git a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/Tasks.kt b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/Tasks.kt
index 6357f14a8a3..86233d75273 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/Tasks.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/Tasks.kt
@@ -323,6 +323,7 @@ abstract class AbstractKotlinCompile<T : CommonCompilerArguments>() : AbstractKo
 
     private val kotlinLogger by lazy { GradleKotlinLogger(logger) }
 
+    /** Keep lazy to avoid computing before all projects are evaluated. */
     @get:Internal
     internal val compilerRunner by lazy { compilerRunner() }
 
@@ -593,10 +594,7 @@ internal open class KotlinCompileWithWorkers @Inject constructor(
     private val workerExecutor: WorkerExecutor
 ) : KotlinCompile() {
 
-    @get:Internal
-    val compilerRunnerValue = GradleCompilerRunnerWithWorkers(GradleCompileTaskProvider(this), workerExecutor)
-
-    override fun compilerRunner() = compilerRunnerValue
+    override fun compilerRunner() = GradleCompilerRunnerWithWorkers(GradleCompileTaskProvider(this), workerExecutor)
 }
 
 @CacheableTask