[kotlin] Introduce KotlinBuildSystemFacade to provide access to 'build system' specific information

- Implement findSourceSet, providing 'name' and 'sourceDirectories'
This can be useful for quick-fixes which would like to help
across expect/actual modules

See: FL-28916 K2: Expect/Actual Quick Fix: Create actual for expect

GitOrigin-RevId: 29ba291198ecd1f37bd34acbe7d06d0357e5fc5b

plugins/kotlin/base/external-build-system/kotlin.base.external-build-system.iml

@@ -3,6 +3,7 @@
   <component name="NewModuleRootManager" inherit-compiler-output="true">
     <exclude-output />
     <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/resources" type="java-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
     </content>
     <orderEntry type="inheritedJdk" />

plugins/kotlin/base/external-build-system/resources/kotlin.base.external-build-system.xml

@@ -0,0 +1,10 @@
+<idea-plugin package="org.jetbrains.kotlin.idea.base.externalSystem">
+  <extensionPoints>
+    <extensionPoint
+      qualifiedName="org.jetbrains.kotlin.idea.base.externalSystem.kotlinBuildSystemFacade"
+      interface="org.jetbrains.kotlin.idea.base.externalSystem.KotlinBuildSystemFacade"
+      dynamic="true"
+      />
+
+  </extensionPoints>
+</idea-plugin>

plugins/kotlin/base/external-build-system/src/org/jetbrains/kotlin/idea/base/externalSystem/KotlinBuildSystemFacade.kt

@@ -0,0 +1,35 @@
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package org.jetbrains.kotlin.idea.base.externalSystem
+
+import com.intellij.openapi.extensions.ExtensionPointName
+import com.intellij.openapi.module.Module
+import com.intellij.openapi.util.IntellijInternalApi
+
+/**
+ * Intended to provide build system specific information about a given project, which is not relevant
+ * during regular 'import' and therefore is not present in the project structure.
+ *
+ * For example, The Gradle implementation might reach into external system 'DataNodes'
+ */
+@IntellijInternalApi
+interface KotlinBuildSystemFacade {
+    fun findSourceSet(module: Module): KotlinBuildSystemSourceSet?
+
+    companion object {
+
+        @JvmStatic
+        fun getInstance(): KotlinBuildSystemFacade = KotlinBuildSystemCompositeFacade(EP_NAME.extensionList)
+
+        val EP_NAME = ExtensionPointName.create<KotlinBuildSystemFacade>(
+            "org.jetbrains.kotlin.idea.base.externalSystem.kotlinBuildSystemFacade"
+        )
+    }
+}
+
+private class KotlinBuildSystemCompositeFacade(
+    private val instances: List<KotlinBuildSystemFacade>
+) : KotlinBuildSystemFacade {
+    override fun findSourceSet(module: Module): KotlinBuildSystemSourceSet? {
+        return instances.firstNotNullOfOrNull { instance -> instance.findSourceSet(module) }
+    }
+}

plugins/kotlin/base/external-build-system/src/org/jetbrains/kotlin/idea/base/externalSystem/KotlinBuildSystemSourceSet.kt

@@ -0,0 +1,35 @@
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package org.jetbrains.kotlin.idea.base.externalSystem
+
+import com.intellij.openapi.util.IntellijInternalApi
+import java.nio.file.Path
+
+/**
+ * Represents information about a Kotlin Source Set from the 'Build System'.
+ * Note: Only information which can be available universally in build systems shall be added here.
+ */
+@IntellijInternalApi
+data class KotlinBuildSystemSourceSet(
+    /**
+     * Name of the Source Set as known to the Build System.
+     * Examples:
+     * - "commonMain"
+     * - "appleMain"
+     * - "jvmMain"
+     * - "iosX64Main"
+     * - "commonTest",
+     * - ...
+     */
+    val name: String,
+
+    /**
+     * Actual file paths which are included into this Source Set
+     * Expected to be absolute paths.
+     * Examples:
+     * - {projectPath}/src/commonMain/kotlin
+     * - {projectPath}/src/jvmMain/kotlin
+     * - {projectPath}/src/androidMain/kotlin
+     * - ...
+     */
+    val sourceDirectories: List<Path>,
+)

plugins/kotlin/code-insight/inspections-k2/resources/kotlin.code-insight.inspections.k2.xml

@@ -1,5 +1,6 @@
 <idea-plugin package="org.jetbrains.kotlin.idea.k2.codeinsight.inspections">
   <dependencies>
+    <module name="kotlin.base.external-build-system"/>
     <module name="kotlin.code-insight.intentions.k2"/>
     <module name="kotlin.code-insight.inspections.shared"/>
     <module name="kotlin.searching.k2"/>

plugins/kotlin/gradle/code-insight-groovy/resources/kotlin.gradle.code-insight-groovy.xml

@@ -2,6 +2,7 @@
   <dependencies>
     <plugin id="org.intellij.groovy"/>
     <plugin id="com.intellij.gradle"/>
+    <module name="kotlin.base.external-build-system"/>
     <module name="kotlin.gradle.gradle-tooling"/>
     <module name="kotlin.gradle.gradle"/>
     <module name="kotlin.gradle.code-insight-common"/>

plugins/kotlin/gradle/gradle-java/resources/kotlin.gradle.gradle-java.xml

@@ -5,6 +5,7 @@
     <module name="kotlin.gradle.gradle"/>
     <module name="kotlin.gradle.code-insight-common"/>
     <module name="kotlin.project-wizard.idea"/>
+    <module name="kotlin.base.external-build-system"/>
   </dependencies>
 
   <projectListeners>
@@ -31,6 +32,10 @@
             dynamic="true"/>
   </extensionPoints>
 
+  <extensions defaultExtensionNs="org.jetbrains.kotlin.idea.base.externalSystem">
+    <kotlinBuildSystemFacade implementation="org.jetbrains.kotlin.idea.gradleJava.KotlinGradleBuildSystemFacade"/>
+  </extensions>
+
   <extensions defaultExtensionNs="org.jetbrains.plugins.gradle">
 
     <frameworkSupport implementation="org.jetbrains.kotlin.idea.gradleJava.configuration.GradleKotlinMPPSourceSetsFrameworkSupportProvider"/>

plugins/kotlin/gradle/gradle-java/src/org/jetbrains/kotlin/idea/gradleJava/KotlinGradleBuildSystemFacade.kt

@@ -0,0 +1,26 @@
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package org.jetbrains.kotlin.idea.gradleJava
+
+import com.intellij.openapi.module.Module
+import org.jetbrains.kotlin.idea.base.externalSystem.KotlinBuildSystemFacade
+import org.jetbrains.kotlin.idea.base.externalSystem.KotlinBuildSystemSourceSet
+import org.jetbrains.kotlin.idea.gradle.configuration.kotlinSourceSetData
+import org.jetbrains.kotlin.idea.projectModel.KotlinCompilation
+import org.jetbrains.kotlin.idea.projectModel.KotlinSourceSet
+import org.jetbrains.plugins.gradle.execution.build.CachedModuleDataFinder
+
+internal class KotlinGradleBuildSystemFacade : KotlinBuildSystemFacade {
+    override fun findSourceSet(module: Module): KotlinBuildSystemSourceSet? {
+        val kotlinSourceSetData = CachedModuleDataFinder.findModuleData(module)?.kotlinSourceSetData ?: return null
+
+        val kotlinSourceSet = when (val component = kotlinSourceSetData.sourceSetInfo.kotlinComponent) {
+            is KotlinCompilation -> component.declaredSourceSets.firstOrNull() ?: return null
+            is KotlinSourceSet -> component
+        }
+
+        return KotlinBuildSystemSourceSet(
+            name = kotlinSourceSet.name,
+            sourceDirectories = kotlinSourceSet.sourceDirs.map { file -> file.toPath() }
+        )
+    }
+}

plugins/kotlin/gradle/gradle-java/tests.shared/test/org/jetbrains/kotlin/gradle/KotlinGradleBuildSystemFacadeTest.kt

@@ -0,0 +1,99 @@
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package org.jetbrains.kotlin.gradle
+
+import com.intellij.openapi.module.ModuleManager
+import org.jetbrains.kotlin.gradle.multiplatformTests.testProperties.SimpleProperties
+import org.jetbrains.kotlin.idea.base.externalSystem.KotlinBuildSystemFacade
+import org.jetbrains.kotlin.idea.codeInsight.gradle.KotlinGradleImportingTestCase
+import org.jetbrains.kotlin.idea.codeInsight.gradle.KotlinGradlePluginVersions
+import org.junit.Test
+import org.junit.runners.Parameterized
+
+abstract class KotlinGradleBuildSystemFacadeTest : KotlinGradleImportingTestCase() {
+
+    companion object {
+        /*
+        Running tests against a fixed version of Gradle, expecting latest Kotlin Gradle plugin
+         */
+        @JvmStatic
+        @Suppress("ACCIDENTAL_OVERRIDE")
+        @Parameterized.Parameters(name = "{index}: with Gradle-{0}")
+        fun data(): Collection<Array<Any>> = listOf(arrayOf("8.8"))
+    }
+
+    /*
+    Testing projects from 'multiplatform/smoke'
+     */
+    class MultiplatformSmoke : KotlinGradleBuildSystemFacadeTest() {
+        override fun testDataDirName(): String = "multiplatform/smoke"
+
+        @Test
+        fun testJvmAndNative() {
+            configureByFiles(
+                SimpleProperties(currentGradleVersion, KotlinGradlePluginVersions.latest) +
+                        ("kgp_version" to KotlinGradlePluginVersions.latest.toString())
+            )
+
+            importProject()
+
+            /* Check 'jvmMain' */
+            run {
+                val jvmMain = ModuleManager.getInstance(myProject).findModuleByName("project.jvmMain")
+                    ?: kotlin.test.fail("Missing module jvmMain")
+
+                val jvmMainSourceSet = KotlinBuildSystemFacade.getInstance().findSourceSet(jvmMain)
+                    ?: kotlin.test.fail("Could not find Source Set: jvmMain")
+
+                kotlin.test.assertEquals("jvmMain", jvmMainSourceSet.name)
+
+                val jvmMainSourceDirectories = jvmMainSourceSet.sourceDirectories.filter { sourceDirectory ->
+                    sourceDirectory == myProjectRoot.toNioPath().resolve("src/jvmMain/kotlin")
+                }
+
+                if (jvmMainSourceDirectories.isEmpty()) {
+                    kotlin.test.fail(
+                        "Expected 'src/jvmMain/kotlin' to be present in jvmMainSourceDirectories. " +
+                                "Found: $jvmMainSourceDirectories"
+                    )
+                }
+
+                if (jvmMainSourceDirectories.size > 1) {
+                    kotlin.test.fail(
+                        "Expected 'src/jvmMain/kotlin' to be present only once in jvmMainSourceDirectories. " +
+                                "Found: $jvmMainSourceDirectories"
+                    )
+                }
+            }
+
+            /* Check 'nativeMain' */
+            run {
+                val nativeMain = ModuleManager.getInstance(myProject).findModuleByName("project.nativeMain")
+                    ?: kotlin.test.fail("Missing module nativeMain")
+
+                val nativeMainSourceSet = KotlinBuildSystemFacade.getInstance().findSourceSet(nativeMain)
+                    ?: kotlin.test.fail("Could not find Source Set: nativeMain")
+
+                kotlin.test.assertEquals("nativeMain", nativeMainSourceSet.name)
+
+                val nativeMainSourceDirectories = nativeMainSourceSet.sourceDirectories.filter { sourceDirectory ->
+                    sourceDirectory == myProjectRoot.toNioPath().resolve("src/nativeMain/kotlin")
+                }
+
+                if (nativeMainSourceDirectories.isEmpty()) {
+                    kotlin.test.fail(
+                        "Expected 'src/nativeMain/kotlin' to be present in nativeMainSourceDirectories. " +
+                                "Found: $nativeMainSourceDirectories"
+                    )
+                }
+
+                if (nativeMainSourceDirectories.size > 1) {
+                    kotlin.test.fail(
+                        "Expected 'src/nativeMain/kotlin' to be present only once in nativeMainSourceDirectories. " +
+                                "Found: $nativeMainSourceDirectories"
+                    )
+                }
+            }
+        }
+    }
+}
+

plugins/kotlin/plugin/k1/resources/kotlin.plugin.k1.xml

@@ -44,6 +44,7 @@
 
   <content>
     <module name="kotlin.base.analysis-api-platform"/>
+    <module name="kotlin.base.external-build-system"/>
     <module name="kotlin.base.fe10.plugin"/>
     <module name="kotlin.base.fe10.analysis-api-platform"/>
     <module name="kotlin.base.fe10.project-structure"/>

plugins/kotlin/plugin/k2/resources/kotlin.plugin.k2.xml

@@ -190,6 +190,7 @@
 
   <content>
     <module name="kotlin.base.analysis-api-platform"/>
+    <module name="kotlin.base.external-build-system"/>
     <module name="kotlin.base.fir.analysis-api-platform"/>
     <module name="kotlin.base.fir.code-insight"/>
     <module name="kotlin.base.fir.project-structure"/>

plugins/kotlin/project-wizard/idea/resources/kotlin.project-wizard.idea.xml

@@ -1,6 +1,7 @@
 <idea-plugin package="org.jetbrains.kotlin.tools.projectWizard">
   <dependencies>
     <plugin id="com.intellij.gradle"/>
+    <module name="kotlin.base.external-build-system"/>
   </dependencies>
 
   <extensionPoints>