[MPP]: Add support for old Gradle BasePluginConvention

BasePluginConvention was deprecated in favor of BasePluginExtension
which was introduced in 7.1. So it should be supported until 8.0
where it will be removed.

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/CompilationDetails.kt

@@ -11,7 +11,6 @@ import org.gradle.api.UnknownTaskException
 import org.gradle.api.artifacts.Dependency
 import org.gradle.api.file.FileCollection
 import org.gradle.api.file.SourceDirectorySet
-import org.gradle.api.plugins.BasePluginExtension
 import org.gradle.api.tasks.SourceSet
 import org.gradle.api.tasks.TaskProvider
 import org.gradle.api.tasks.bundling.AbstractArchiveTask
@@ -160,7 +159,7 @@ open class DefaultCompilationDetails<T : KotlinCommonOptions>(
 
     override val ownModuleName: String
         get() {
-            val baseName = project.extensions.getByType(BasePluginExtension::class.java)?.archivesName
+            val baseName = project.archivesName
                 ?: project.name
             val suffix = if (isMainCompilationData()) "" else "_$compilationPurpose"
             return filterModuleName("$baseName$suffix")

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/pm20/KotlinJvmVariant.kt

@@ -5,12 +5,7 @@
 
 package org.jetbrains.kotlin.gradle.plugin.mpp.pm20
 
-import groovy.lang.Closure
 import org.gradle.api.artifacts.Configuration
-import org.gradle.api.plugins.BasePluginConvention
-import org.gradle.api.Project
-import org.gradle.api.file.FileCollection
-import org.gradle.api.plugins.BasePluginExtension
 import org.jetbrains.kotlin.gradle.dsl.KotlinJvmOptions
 import org.jetbrains.kotlin.gradle.dsl.KotlinJvmOptionsImpl
 import org.jetbrains.kotlin.gradle.plugin.*
@@ -50,7 +45,7 @@ class KotlinJvmVariantCompilationData(val variant: KotlinJvmVariant) : KotlinVar
 
 internal fun KotlinGradleVariant.ownModuleName(): String {
     val project = containingModule.project
-    val baseName = project.extensions.getByType(BasePluginExtension::class.java).archivesName.orNull
+    val baseName = project.archivesName
         ?: project.name
     val suffix = if (containingModule.moduleClassifier == null) "" else "_${containingModule.moduleClassifier}"
     return filterModuleName("$baseName$suffix")

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/pm20/KotlinMetadataCompilationData.kt

@@ -9,7 +9,6 @@ import org.gradle.api.DefaultTask
 import org.gradle.api.Project
 import org.gradle.api.file.FileCollection
 import org.gradle.api.file.SourceDirectorySet
-import org.gradle.api.plugins.BasePluginExtension
 import org.gradle.api.tasks.TaskProvider
 import org.jetbrains.kotlin.gradle.dsl.*
 import org.jetbrains.kotlin.gradle.dsl.KotlinMultiplatformCommonOptionsImpl
@@ -83,7 +82,7 @@ internal abstract class AbstractKotlinFragmentMetadataCompilationData<T : Kotlin
 
     override val moduleName: String
         get() { // FIXME deduplicate with ownModuleName
-            val baseName = project.extensions.getByType(BasePluginExtension::class.java).archivesName.orNull
+            val baseName = project.archivesName
                 ?: project.name
             val suffix = if (module.moduleClassifier == null) "" else "_${module.moduleClassifier}"
             return filterModuleName("$baseName$suffix")

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/pm20/Utils.kt

@@ -8,11 +8,14 @@ package org.jetbrains.kotlin.gradle.plugin.mpp.pm20
 import org.gradle.api.Project
 import org.gradle.api.artifacts.component.BuildIdentifier
 import org.gradle.api.internal.project.ProjectInternal
+import org.gradle.api.plugins.BasePluginConvention
+import org.gradle.api.plugins.BasePluginExtension
 import org.gradle.internal.build.BuildState
 import org.jetbrains.kotlin.gradle.dsl.KotlinMultiplatformExtension
 import org.jetbrains.kotlin.gradle.dsl.KotlinProjectExtension
 import org.jetbrains.kotlin.gradle.dsl.KotlinSingleTargetExtension
 import org.jetbrains.kotlin.gradle.plugin.KotlinTarget
+import org.jetbrains.kotlin.gradle.utils.isGradleVersionAtLeast
 import org.jetbrains.kotlin.project.model.KotlinModule
 import org.jetbrains.kotlin.project.model.LocalModuleIdentifier
 
@@ -28,4 +31,25 @@ fun KotlinModule.representsProject(project: Project): Boolean =
 
 // FIXME internal API?
 fun Project.currentBuildId(): BuildIdentifier =
-    (project as ProjectInternal).services.get(BuildState::class.java).buildIdentifier
+    (project as ProjectInternal).services.get(BuildState::class.java).buildIdentifier
+
+
+/**
+ * The base name to use for archive files.
+ */
+val Project.archivesName get() = if (isGradleVersionAtLeast(7, 1)) {
+        extensions.getByType(BasePluginExtension::class.java).archivesName.orNull
+    } else {
+        convention.findPlugin(BasePluginConvention::class.java)?.archivesBaseName
+    }
+
+/**
+ * Returns the directory to generate TAR and ZIP archives into.
+ *
+ * @return The directory. Never returns null.
+ */
+val Project.distsDirectory get() = if (isGradleVersionAtLeast(7, 1)) {
+        extensions.getByType(BasePluginExtension::class.java).distsDirectory
+    } else {
+        convention.getPlugin(BasePluginConvention::class.java).distsDirectory
+    }

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/subtargets/DefaultDistribution.kt

@@ -6,7 +6,7 @@
 package org.jetbrains.kotlin.gradle.targets.js.subtargets
 
 import org.gradle.api.Project
-import org.gradle.api.plugins.BasePluginExtension
+import org.jetbrains.kotlin.gradle.plugin.mpp.pm20.distsDirectory
 import org.jetbrains.kotlin.gradle.targets.js.dsl.Distribution
 import org.jetbrains.kotlin.gradle.utils.property
 import java.io.File
@@ -20,7 +20,7 @@ class DefaultDistribution(
         project.buildDir
             .let { buildDir ->
                 name?.let { buildDir.resolve(it) }
-                    ?: project.extensions.getByType(BasePluginExtension::class.java).distsDirectory.asFile.get()
+                    ?: project.distsDirectory.asFile.get()
             }
     }
 }

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/webpack/KotlinWebpack.kt

@@ -11,7 +11,6 @@ import org.gradle.api.file.FileCollection
 import org.gradle.api.file.RegularFileProperty
 import org.gradle.api.internal.file.FileResolver
 import org.gradle.api.model.ObjectFactory
-import org.gradle.api.plugins.BasePluginExtension
 import org.gradle.api.provider.Provider
 import org.gradle.api.tasks.*
 import org.gradle.deployment.internal.Deployment
@@ -21,6 +20,8 @@ import org.gradle.process.internal.ExecHandle
 import org.gradle.process.internal.ExecHandleFactory
 import org.jetbrains.kotlin.gradle.plugin.PropertiesProvider
 import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinJsCompilation
+import org.jetbrains.kotlin.gradle.plugin.mpp.pm20.archivesName
+import org.jetbrains.kotlin.gradle.plugin.mpp.pm20.distsDirectory
 import org.jetbrains.kotlin.gradle.targets.js.RequiredKotlinJsDependency
 import org.jetbrains.kotlin.gradle.targets.js.nodejs.NodeJsRootPlugin
 import org.jetbrains.kotlin.gradle.targets.js.npm.RequiresNpmDependencies
@@ -108,7 +109,7 @@ constructor(
 
     @Nested
     val output: KotlinWebpackOutput = KotlinWebpackOutput(
-        library = project.extensions.getByType(BasePluginExtension::class.java).archivesName.orNull,
+        library = project.archivesName,
         libraryTarget = KotlinWebpackOutput.Target.UMD,
         globalObject = "this"
     )
@@ -122,7 +123,7 @@ constructor(
     internal var _destinationDirectory: File? = null
 
     private val defaultDestinationDirectory by lazy {
-        project.extensions.getByType(BasePluginExtension::class.java).distsDirectory.asFile.get()
+        project.distsDirectory.asFile.get()
     }
 
     @get:Internal
@@ -133,7 +134,7 @@ constructor(
         }
 
     private val defaultOutputFileName by lazy {
-        project.extensions.getByType(BasePluginExtension::class.java).archivesName.orNull + ".js"
+        project.archivesName + ".js"
     }
 
     @get:Internal