K2: introduce "no source files" CLI check

compiler/cli/src/org/jetbrains/kotlin/cli/common/GroupedKtSources.kt

@@ -26,7 +26,9 @@ data class GroupedKtSources(
     val platformSources: Collection<KtSourceFile>,
     val commonSources: Collection<KtSourceFile>,
     val sourcesByModuleName: Map<String, Set<KtSourceFile>>,
-)
+) {
+    fun isEmpty(): Boolean = platformSources.isEmpty() && commonSources.isEmpty()
+}
 
 fun collectSources(
     compilerConfiguration: CompilerConfiguration,

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/K2JVMCompiler.kt

@@ -142,13 +142,15 @@ class K2JVMCompiler : CLICompiler<K2JVMCompilerArguments>() {
             val targetDescription = chunk.map { input -> input.getModuleName() + "-" + input.getModuleType() }.let { names ->
                 names.singleOrNull() ?: names.joinToString()
             }
-            if (configuration.getBoolean(CommonConfigurationKeys.USE_FIR) && configuration.getBoolean(CommonConfigurationKeys.USE_LIGHT_TREE)) {
+            if (configuration.getBoolean(CommonConfigurationKeys.USE_FIR) && configuration.getBoolean(CommonConfigurationKeys.USE_LIGHT_TREE))  {
+                if (messageCollector.hasErrors()) return COMPILATION_ERROR
                 val projectEnvironment =
                     createProjectEnvironment(configuration, rootDisposable, EnvironmentConfigFiles.JVM_CONFIG_FILES, messageCollector)
                 if (messageCollector.hasErrors()) return COMPILATION_ERROR
 
                 compileModulesUsingFrontendIrAndLightTree(
-                    projectEnvironment, configuration, messageCollector, buildFile, chunk, targetDescription
+                    projectEnvironment, configuration, messageCollector, buildFile, chunk, targetDescription,
+                    checkSourceFiles = !arguments.allowNoSourceFiles && !arguments.version
                 )
             } else {
                 val environment = createCoreEnvironment(

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/pipeline/compilerPipeline.kt

@@ -79,7 +79,8 @@ fun compileModulesUsingFrontendIrAndLightTree(
     messageCollector: MessageCollector,
     buildFile: File?,
     chunk: List<Module>,
-    targetDescription: String
+    targetDescription: String,
+    checkSourceFiles: Boolean
 ): Boolean {
     require(projectEnvironment is VfsBasedProjectEnvironment) // TODO: abstract away this requirement
     ProgressIndicatorAndCompilationCanceledStatus.checkCanceled()
@@ -99,6 +100,14 @@ fun compileModulesUsingFrontendIrAndLightTree(
             put(JVMConfigurationKeys.FRIEND_PATHS, module.getFriendPaths())
         }
         val groupedSources = collectSources(compilerConfiguration, projectEnvironment, messageCollector)
+        if (messageCollector.hasErrors()) {
+            return false
+        }
+
+        if (checkSourceFiles && groupedSources.isEmpty() && buildFile == null) {
+            messageCollector.report(CompilerMessageSeverity.ERROR, "No source files")
+            return false
+        }
 
         val compilerInput = ModuleCompilerInput(
             TargetId(module),