Fix warnings after KT-48899

All API ToolingModelBuilder is marked as NonNullApi
https://github.com/gradle/gradle/commit/f93bf949486e73655810ab49ad316100b1c2804c#diff-76e89b92025ccef4e2763c5ee8d30bde939c4a9db26bfc913eac88069cbf5d36

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/model/builder/KaptModelBuilder.kt

@@ -23,12 +23,10 @@ class KaptModelBuilder : ToolingModelBuilder {
         return modelName == Kapt::class.java.name
     }
 
-    override fun buildAll(modelName: String, project: Project): Any? {
-        if (modelName == Kapt::class.java.name) {
-            val kaptTasks = project.tasks.withType(KaptTask::class.java)
-            return KaptImpl(project.name, kaptTasks.map { it.createKaptSourceSet() })
-        }
-        return null
+    override fun buildAll(modelName: String, project: Project): Any {
+        require(canBuild(modelName)) { "buildAll(\"$modelName\") has been called while canBeBuild is false" }
+        val kaptTasks = project.tasks.withType(KaptTask::class.java)
+        return KaptImpl(project.name, kaptTasks.map { it.createKaptSourceSet() })
     }
 
     companion object {
@@ -47,4 +45,4 @@ class KaptModelBuilder : ToolingModelBuilder {
             )
         }
     }
-}
+}

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/model/builder/KotlinAndroidExtensionModelBuilder.kt

@@ -21,11 +21,9 @@ class KotlinAndroidExtensionModelBuilder : ToolingModelBuilder {
         return modelName == KotlinAndroidExtension::class.java.name
     }
 
-    override fun buildAll(modelName: String, project: Project): Any? {
-        if (modelName == KotlinAndroidExtension::class.java.name) {
-            val extension = project.extensions.getByType(AndroidExtensionsExtension::class.java)
-            return KotlinAndroidExtensionImpl(project.name, extension.isExperimental, extension.defaultCacheImplementation.optionName)
-        }
-        return null
+    override fun buildAll(modelName: String, project: Project): Any {
+        require(canBuild(modelName)) { "buildAll(\"$modelName\") has been called while canBeBuild is false" }
+        val extension = project.extensions.getByType(AndroidExtensionsExtension::class.java)
+        return KotlinAndroidExtensionImpl(project.name, extension.isExperimental, extension.defaultCacheImplementation.optionName)
     }
-}
+}

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/model/builder/KotlinModelBuilder.kt

@@ -36,22 +36,20 @@ class KotlinModelBuilder(private val kotlinPluginVersion: String, private val an
         return modelName == KotlinProject::class.java.name
     }
 
-    override fun buildAll(modelName: String, project: Project): Any? {
-        if (modelName == KotlinProject::class.java.name) {
-            val kotlinCompileTasks = project.tasks.withType(AbstractKotlinCompile::class.java).toList()
-            val projectType = getProjectType(project)
-            return KotlinProjectImpl(
-                project.name,
-                kotlinPluginVersion,
-                projectType,
-                kotlinCompileTasks.mapNotNull {
-                    if (androidTarget != null) it.createAndroidSourceSet(androidTarget) else it.createSourceSet(project, projectType)
-                },
-                getExpectedByDependencies(project),
-                kotlinCompileTasks.first()!!.createExperimentalFeatures()
-            )
-        }
-        return null
+    override fun buildAll(modelName: String, project: Project): Any {
+        require(canBuild(modelName)) { "buildAll(\"$modelName\") has been called while canBeBuild is false" }
+        val kotlinCompileTasks = project.tasks.withType(AbstractKotlinCompile::class.java).toList()
+        val projectType = getProjectType(project)
+        return KotlinProjectImpl(
+            project.name,
+            kotlinPluginVersion,
+            projectType,
+            kotlinCompileTasks.mapNotNull {
+                if (androidTarget != null) it.createAndroidSourceSet(androidTarget) else it.createSourceSet(project, projectType)
+            },
+            getExpectedByDependencies(project),
+            kotlinCompileTasks.first()!!.createExperimentalFeatures()
+        )
     }
 
     companion object {
@@ -137,4 +135,4 @@ class KotlinModelBuilder(private val kotlinPluginVersion: String, private val an
             return ExperimentalFeaturesImpl(coroutines.get().name)
         }
     }
-}
+}

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

@@ -40,16 +40,16 @@ class HierarchyAttributeContainer(
         attributesMap.contains(key) || getFilteredParentAttribute(key) != null
 
     @Suppress("UNCHECKED_CAST")
-    override fun <T : Any?> getAttribute(key: Attribute<T>?): T? =
+    override fun <T : Any> getAttribute(key: Attribute<T>): T? =
         attributesMap.get(key as Attribute<*>) as T? ?: getFilteredParentAttribute(key) as T?
 
     override fun isEmpty(): Boolean = attributesMap.isEmpty() && (parent?.keySet().orEmpty().filter(filterParentAttributes).isEmpty())
 
     override fun keySet(): Set<Attribute<*>> = attributesMap.keys + parent?.keySet().orEmpty().filter(filterParentAttributes)
 
-    override fun <T : Any?> attribute(key: Attribute<T>?, value: T): AttributeContainer {
+    override fun <T : Any> attribute(key: Attribute<T>, value: T): AttributeContainer {
         val checkedValue = requireNotNull(value as Any?) { "null values for attributes are not supported" }
-        attributesMap[key as Attribute<*>] = checkedValue
+        attributesMap[key] = checkedValue
         return this
     }
 

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

@@ -137,7 +137,8 @@ abstract class AbstractKotlinTarget(
             adhocVariant as SoftwareComponent
 
             object : ComponentWithVariants, ComponentWithCoordinates, SoftwareComponentInternal {
-                override fun getCoordinates() = (kotlinVariant as? ComponentWithCoordinates)?.coordinates
+                override fun getCoordinates() =
+                    (kotlinVariant as? ComponentWithCoordinates)?.coordinates ?: error("kotlinVariant is not ComponentWithCoordinates")
 
                 override fun getVariants(): Set<SoftwareComponent> =
                     (kotlinVariant as? KotlinVariantWithMetadataVariant)?.variants.orEmpty()

libraries/tools/kotlin-gradle-plugin/src/test/kotlin/org/jetbrains/kotlin/gradle/internal/kapt/incremental/ClasspathAnalyzerTest.kt

@@ -171,9 +171,8 @@ class StructureTransformTestAction(val input: File, val projectDir: File) : Stru
 
     override val inputArtifact: Provider<FileSystemLocation> = project.provider { project.objects.fileProperty().fileValue(input).get() }
 
-    override fun getParameters(): TransformParameters.None? {
-        //no need for StructureTransformAction and so for test
-        return null
+    override fun getParameters(): TransformParameters.None {
+        error("Should not be called")
     }
 }
 
@@ -192,4 +191,4 @@ class TransformOutputsMock(val outputDir: File) : TransformOutputs {
         return newDir
     }
 
-}
+}