[Gradle] Deprecate case when commonMain depends on another source set

^KT-55824 Verification Pending

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/mpp/MppDiagnosticsIt.kt

@@ -13,11 +13,11 @@ import kotlin.test.assertFalse
 import kotlin.test.assertTrue
 
 @MppGradlePluginTests
-class MppDeprecatedPropertiesIt : KGPBaseTest() {
+class MppDiagnosticsIt : KGPBaseTest() {
     @GradleTest
-    fun testDeprecations(gradleVersion: GradleVersion) {
+    fun testDeprecatedProperties(gradleVersion: GradleVersion) {
         project("mppDeprecatedProperties", gradleVersion) {
-            checkDeprecations(isDeprecationExpected = false)
+            checkDeprecatedProperties(isDeprecationExpected = false)
 
             this.gradleProperties.appendText(
                 defaultFlags.entries.joinToString(
@@ -26,18 +26,31 @@ class MppDeprecatedPropertiesIt : KGPBaseTest() {
                     separator = System.lineSeparator(),
                 ) { (prop, value) -> "$prop=$value" }
             )
-            checkDeprecations(isDeprecationExpected = true)
+            checkDeprecatedProperties(isDeprecationExpected = true)
 
             // remove the MPP plugin from the top-level project and check the warnings are still reported in subproject
             this.buildGradleKts.writeText("")
-            checkDeprecations(isDeprecationExpected = true)
+            checkDeprecatedProperties(isDeprecationExpected = true)
 
             this.gradleProperties.appendText("kotlin.mpp.deprecatedProperties.nowarn=true${System.lineSeparator()}")
-            checkDeprecations(isDeprecationExpected = false)
+            checkDeprecatedProperties(isDeprecationExpected = false)
         }
     }
 
-    private fun TestProject.checkDeprecations(isDeprecationExpected: Boolean) {
+    @GradleTest
+    fun testCommonMainMustNotDependOnOtherSourceSets(gradleVersion: GradleVersion) {
+        project("commonMainDependsOnAnotherSourceSet", gradleVersion) {
+            build("tasks") {
+                assertOutputContains("w: 'commonMain' source set can't depend on other source sets.")
+            }
+
+            build("tasks", buildOptions = defaultBuildOptions.copy(freeArgs = listOf("-PcommonSourceSetDependsOnNothing"))) {
+                assertOutputDoesNotContain("w: 'commonMain' source set can't depend on other source sets.")
+            }
+        }
+    }
+
+    private fun TestProject.checkDeprecatedProperties(isDeprecationExpected: Boolean) {
         build {
             val assert: (Boolean, String) -> Unit = if (isDeprecationExpected) ::assertTrue else ::assertFalse
             val warnings = output.lines().filter { it.startsWith("w:") }.toSet()

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/commonMainDependsOnAnotherSourceSet/build.gradle.kts

@@ -0,0 +1,16 @@
+plugins {
+    kotlin("multiplatform")
+}
+
+kotlin {
+    jvm()
+    linuxX64()
+
+    sourceSets {
+        val commonMain by getting
+        if (!hasProperty("commonSourceSetDependsOnNothing")) {
+            val grandCommonMain by creating
+            commonMain.dependsOn(grandCommonMain)
+        }
+    }
+}

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/KotlinMultiplatformPlugin.kt

@@ -22,10 +22,7 @@ import org.jetbrains.kotlin.gradle.plugin.ide.kotlinIdeMultiplatformImport
 import org.jetbrains.kotlin.gradle.plugin.ide.locateOrRegisterIdeResolveDependenciesTask
 import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinMultiplatformPlugin.Companion.sourceSetFreeCompilerArgsPropertyName
 import org.jetbrains.kotlin.gradle.plugin.mpp.apple.addBuildListenerForXcode
-import org.jetbrains.kotlin.gradle.plugin.mpp.internal.checkAndReportDeprecatedMppProperties
-import org.jetbrains.kotlin.gradle.plugin.mpp.internal.checkAndReportDeprecatedNativeTargets
-import org.jetbrains.kotlin.gradle.plugin.mpp.internal.handleHierarchicalStructureFlagsMigration
-import org.jetbrains.kotlin.gradle.plugin.mpp.pm20.*
+import org.jetbrains.kotlin.gradle.plugin.mpp.internal.runDeprecationDiagnostics
 import org.jetbrains.kotlin.gradle.plugin.mpp.pm20.util.copyAttributes
 import org.jetbrains.kotlin.gradle.plugin.sources.DefaultLanguageSettingsBuilder
 import org.jetbrains.kotlin.gradle.plugin.sources.checkSourceSetVisibilityRequirements
@@ -49,10 +46,7 @@ class KotlinMultiplatformPlugin : Plugin<Project> {
 
     override fun apply(project: Project) {
         checkGradleCompatibility("the Kotlin Multiplatform plugin", GradleVersion.version("6.0"))
-
-        checkAndReportDeprecatedMppProperties(project)
-        handleHierarchicalStructureFlagsMigration(project)
-        checkAndReportDeprecatedNativeTargets(project)
+        runDeprecationDiagnostics(project)
 
         project.plugins.apply(JavaBasePlugin::class.java)
 

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/internal/deprecationDiagnostics.kt

@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.gradle.plugin.mpp.internal
 
 import org.gradle.api.Project
 import org.jetbrains.kotlin.gradle.dsl.KotlinMultiplatformExtension
+import org.jetbrains.kotlin.gradle.dsl.multiplatformExtensionOrNull
 import org.jetbrains.kotlin.gradle.plugin.PropertiesProvider.Companion.kotlinPropertiesProvider
 import org.jetbrains.kotlin.gradle.plugin.PropertiesProvider.PropertyNames.KOTLIN_MPP_ENABLE_COMPATIBILITY_METADATA_VARIANT
 import org.jetbrains.kotlin.gradle.plugin.PropertiesProvider.PropertyNames.KOTLIN_MPP_ENABLE_GRANULAR_SOURCE_SETS_METADATA
@@ -14,30 +15,35 @@ import org.jetbrains.kotlin.gradle.plugin.PropertiesProvider.PropertyNames.KOTLI
 import org.jetbrains.kotlin.gradle.plugin.PropertiesProvider.PropertyNames.KOTLIN_MPP_HIERARCHICAL_STRUCTURE_SUPPORT
 import org.jetbrains.kotlin.gradle.plugin.PropertiesProvider.PropertyNames.KOTLIN_NATIVE_DEPENDENCY_PROPAGATION
 import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinNativeTarget
-import org.jetbrains.kotlin.gradle.plugin.whenEvaluated
 import org.jetbrains.kotlin.gradle.utils.SingleWarningPerBuild
-import org.jetbrains.kotlin.gradle.utils.runProjectConfigurationHealthCheck
 import org.jetbrains.kotlin.gradle.utils.runProjectConfigurationHealthCheckWhenEvaluated
 import org.jetbrains.kotlin.konan.target.KonanTarget
 import org.jetbrains.kotlin.tooling.core.UnsafeApi
 
-internal fun checkAndReportDeprecatedNativeTargets(project: Project) {
+internal fun runDeprecationDiagnostics(project: Project) {
+    checkAndReportDeprecatedMppProperties(project)
+    handleHierarchicalStructureFlagsMigration(project)
     project.runProjectConfigurationHealthCheckWhenEvaluated {
-        val targets = project.extensions.getByType(KotlinMultiplatformExtension::class.java).targets
-        val usedDeprecatedTargets = targets.filter { it is KotlinNativeTarget && it.konanTarget in KonanTarget.deprecatedTargets }
-        if (usedDeprecatedTargets.isEmpty()) return@runProjectConfigurationHealthCheckWhenEvaluated
-        SingleWarningPerBuild.show(
-            project,
-            "w: The following deprecated kotlin native targets were used in the project: ${usedDeprecatedTargets.joinToString { it.targetName }}"
-        )
+        checkAndReportDeprecatedNativeTargets(project)
+        checkAndReportDeprecatedSourceSetsLayouts(project)
     }
 }
 
+private fun checkAndReportDeprecatedNativeTargets(project: Project) {
+    val targets = project.extensions.getByType(KotlinMultiplatformExtension::class.java).targets
+    val usedDeprecatedTargets = targets.filter { it is KotlinNativeTarget && it.konanTarget in KonanTarget.deprecatedTargets }
+    if (usedDeprecatedTargets.isEmpty()) return
+    SingleWarningPerBuild.show(
+        project,
+        "w: The following deprecated kotlin native targets were used in the project: ${usedDeprecatedTargets.joinToString { it.targetName }}"
+    )
+}
+
 /**
  * Declared properties have to be captured during plugin application phase before the HMPP migration util sets them.
  * Warnings have to be reported only for successfully evaluated projects without errors.
  */
-internal fun checkAndReportDeprecatedMppProperties(project: Project) {
+private fun checkAndReportDeprecatedMppProperties(project: Project) {
     val projectProperties = project.kotlinPropertiesProvider
     if (projectProperties.ignoreHmppDeprecationWarnings == true) return
 
@@ -54,6 +60,20 @@ internal fun checkAndReportDeprecatedMppProperties(project: Project) {
     }
 }
 
+private fun checkAndReportDeprecatedSourceSetsLayouts(project: Project) {
+    project.reportCommonMainDependsOnOtherSourceSets()
+}
+
+private fun Project.reportCommonMainDependsOnOtherSourceSets() {
+    val commonMain = multiplatformExtensionOrNull?.sourceSets?.getByName("commonMain") ?: return
+    if (commonMain.dependsOn.isNotEmpty()) {
+        SingleWarningPerBuild.show(
+            project,
+            "w: 'commonMain' source set can't depend on other source sets."
+        )
+    }
+}
+
 internal val deprecatedMppProperties: List<String> = listOf(
     KOTLIN_MPP_ENABLE_COMPATIBILITY_METADATA_VARIANT,
     KOTLIN_MPP_ENABLE_GRANULAR_SOURCE_SETS_METADATA,