[K/N] Warn if the inferred main package of a framework is root

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/objcexport/ObjCExport.kt

@@ -14,8 +14,10 @@ import org.jetbrains.kotlin.backend.konan.getExportedDependencies
 import org.jetbrains.kotlin.backend.konan.llvm.CodeGenerator
 import org.jetbrains.kotlin.backend.konan.llvm.objcexport.ObjCExportBlockCodeGenerator
 import org.jetbrains.kotlin.backend.konan.llvm.objcexport.ObjCExportCodeGenerator
+import org.jetbrains.kotlin.cli.common.messages.CompilerMessageSeverity
 import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.descriptors.ModuleDescriptor
 import org.jetbrains.kotlin.descriptors.SourceFile
 import org.jetbrains.kotlin.ir.util.SymbolTable
 import org.jetbrains.kotlin.konan.exec.Command
@@ -158,10 +160,7 @@ internal class ObjCExport(val context: Context, symbolTable: SymbolTable) {
         }
 
         val file = directory.child("Info.plist")
-        // TODO: consider showing warning if the main package is root.
-        val bundleId = context.configuration[BUNDLE_ID]
-                ?: guessMainPackage().child(Name.identifier(name)).asString()
-
+        val bundleId = guessBundleID(name)
         val platform = properties.platformName()
         val minimumOsVersion = properties.osVersionMin
 
@@ -293,8 +292,12 @@ internal class ObjCExport(val context: Context, symbolTable: SymbolTable) {
         }
     }
 
-    private fun guessMainPackage(): FqName {
-        val allPackages = (context.getIncludedLibraryDescriptors() + context.getExportedDependencies() + context.moduleDescriptor).flatMap {
+    private fun guessMainPackage(modules: List<ModuleDescriptor>): FqName? {
+        if (modules.isEmpty()) {
+            return null
+        }
+
+        val allPackages = modules.flatMap {
             it.getPackageFragments() // Includes also all parent packages, e.g. the root one.
         }
 
@@ -305,6 +308,30 @@ internal class ObjCExport(val context: Context, symbolTable: SymbolTable) {
         return allPackages.map { it.fqName }.distinct()
             .filter { candidate -> nonEmptyPackages.all { it.isSubpackageOf(candidate) } }
             // Now there are all common ancestors of non-empty packages. Longest of them is the least common accessor:
-            .maxByOrNull { it.asString().length }!!
+            .maxByOrNull { it.asString().length }
+    }
+
+    private fun guessBundleID(bundleName: String): String {
+        val configuration = context.configuration
+        configuration[BUNDLE_ID]?.let {
+            return it
+        }
+
+        // Consider exported libraries only if we cannot infer the package from sources or included libs.
+        val mainPackage = guessMainPackage(context.getIncludedLibraryDescriptors() + context.moduleDescriptor)
+                ?: guessMainPackage(context.getExportedDependencies())
+                ?: FqName.ROOT
+
+        val bundleID = mainPackage.child(Name.identifier(bundleName)).asString()
+
+        if (mainPackage.isRoot) {
+            configuration.report(
+                    CompilerMessageSeverity.STRONG_WARNING,
+                    "Cannot infer a bundle ID from packages of source files and exported dependencies, " +
+                            "use the bundle name instead: $bundleName. " +
+                            "Please specify the bundle ID explicitly using the -Xbundle-id compiler flag."
+            )
+        }
+        return bundleID
     }
 }

kotlin-native/backend.native/tests/build.gradle

@@ -5486,20 +5486,8 @@ if (isAppleTarget(project)) {
         def currentTarget = project.target.name
         enabled = currentTarget.startsWith("mac")
 
-        konanArtifacts {
-            library("frameworkBundleIdLib", targets: [target.name]) {
-                srcFiles("framework/bundle_id/lib.kt")
-                delegate.getByTarget(target.name).configure{
-                    UtilsKt.dependsOnDist(it)
-                }
-            }
-        }
-
         framework("Foo") {
-            sources = ["framework/bundle_id/main.kt"]
-            library = "frameworkBundleIdLib"
-            def exportedLib = konanArtifacts[library].getArtifactByTarget(target.name)
-            opts = ["-Xexport-library=$exportedLib"]
+            sources = ["framework/bundle_id/main.kt", "framework/bundle_id/lib.kt"]
         }
         swiftSources = []