fix KT-9441 Unable to Access Internal Classes from Test Code within Same Module

#KT-9441 Fixed

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

@@ -47,7 +47,12 @@ class ModuleVisibilityHelperImpl : ModuleVisibilityHelper {
         val whatSource = getSourceElement(what)
         if (whatSource is KotlinSourceElement) return true
 
-        val modules = moduleVisibilityManager.chunk.toList()
+        moduleVisibilityManager.friendPaths.forEach {
+            if (isContainedByCompiledPartOfOurModule(what, File(it))) return true
+        }
+
+        val modules = moduleVisibilityManager.chunk
+
         val outputDirectories = modules.map { File(it.getOutputDirectory()) }
         if (outputDirectories.isEmpty()) return isContainedByCompiledPartOfOurModule(what, null)
 
@@ -56,7 +61,7 @@ class ModuleVisibilityHelperImpl : ModuleVisibilityHelper {
         }
 
         // Hack in order to allow access to internal elements in production code from tests
-        if (modules.size() == 1 && modules[0].getModuleType() == ModuleXmlParser.TYPE_TEST) return true
+        if (modules.singleOrNull()?.getModuleType() == ModuleXmlParser.TYPE_TEST) return true
 
         return false
     }
@@ -68,11 +73,16 @@ class ModuleVisibilityHelperImpl : ModuleVisibilityHelper {
  */
 class CliModuleVisibilityManagerImpl() : ModuleVisibilityManager, Disposable {
     override val chunk: MutableList<Module> = arrayListOf()
+    override val friendPaths: MutableList <String> = arrayListOf()
 
     override fun addModule(module: Module) {
         chunk.add(module)
     }
 
+    override fun addFriendPath(path: String) {
+        friendPaths.add(path)
+    }
+
     override fun dispose() {
         chunk.clear()
     }

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

@@ -21,9 +21,7 @@ import com.intellij.openapi.Disposable
 import org.jetbrains.kotlin.cli.common.CLICompiler
 import org.jetbrains.kotlin.cli.common.CLIConfigurationKeys
 import org.jetbrains.kotlin.cli.common.ExitCode
-import org.jetbrains.kotlin.cli.common.ExitCode.COMPILATION_ERROR
-import org.jetbrains.kotlin.cli.common.ExitCode.INTERNAL_ERROR
-import org.jetbrains.kotlin.cli.common.ExitCode.OK
+import org.jetbrains.kotlin.cli.common.ExitCode.*
 import org.jetbrains.kotlin.cli.common.arguments.K2JVMCompilerArguments
 import org.jetbrains.kotlin.cli.common.messages.*
 import org.jetbrains.kotlin.cli.jvm.compiler.*
@@ -154,6 +152,8 @@ public open class K2JVMCompiler : CLICompiler<K2JVMCompilerArguments>() {
             }
             val environment: KotlinCoreEnvironment
 
+            val friendPaths = arguments.friendPaths?.toList() ?: emptyList<String>()
+
             if (arguments.module != null) {
                 val sanitizedCollector = FilteringMessageCollector(messageSeverityCollector, `in`(CompilerMessageSeverity.VERBOSE))
                 val moduleScript = CompileEnvironmentUtil.loadModuleDescriptions(arguments.module, sanitizedCollector)
@@ -169,7 +169,7 @@ public open class K2JVMCompiler : CLICompiler<K2JVMCompilerArguments>() {
 
                 if (messageSeverityCollector.anyReported(CompilerMessageSeverity.ERROR)) return COMPILATION_ERROR
 
-                KotlinToJVMBytecodeCompiler.compileModules(environment, configuration, moduleScript.getModules(), directory, jar, arguments.includeRuntime)
+                KotlinToJVMBytecodeCompiler.compileModules(environment, configuration, moduleScript.getModules(), directory, jar, friendPaths, arguments.includeRuntime)
             }
             else if (arguments.script) {
                 val scriptArgs = arguments.freeArgs.subList(1, arguments.freeArgs.size())
@@ -189,7 +189,7 @@ public open class K2JVMCompiler : CLICompiler<K2JVMCompilerArguments>() {
                     return COMPILATION_ERROR
                 }
 
-                KotlinToJVMBytecodeCompiler.compileBunchOfSources(environment, jar, outputDir, arguments.includeRuntime)
+                KotlinToJVMBytecodeCompiler.compileBunchOfSources(environment, jar, outputDir, friendPaths, arguments.includeRuntime)
             }
 
             if (arguments.reportPerf) {

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/KotlinToJVMBytecodeCompiler.java

@@ -114,14 +114,21 @@ public class KotlinToJVMBytecodeCompiler {
             @NotNull List<Module> chunk,
             @NotNull File directory,
             @Nullable File jarPath,
+            @NotNull List<String> friendPaths,
             boolean jarRuntime
     ) {
         Map<Module, ClassFileFactory> outputFiles = Maps.newHashMap();
 
         ProgressIndicatorAndCompilationCanceledStatus.checkCanceled();
 
+        ModuleVisibilityManager moduleVisibilityManager = ModuleVisibilityManager.SERVICE.getInstance(environment.getProject());
+
         for (Module module: chunk) {
-            ModuleVisibilityManager.SERVICE.getInstance(environment.getProject()).addModule(module);
+            moduleVisibilityManager.addModule(module);
+        }
+
+        for (String path : friendPaths) {
+            moduleVisibilityManager.addFriendPath(path);
         }
 
         String targetDescription = "in targets [" + Joiner.on(", ").join(Collections2.transform(chunk, new Function<Module, String>() {
@@ -215,9 +222,16 @@ public class KotlinToJVMBytecodeCompiler {
             @NotNull KotlinCoreEnvironment environment,
             @Nullable File jar,
             @Nullable File outputDir,
+            @NotNull List<String> friendPaths,
             boolean includeRuntime
     ) {
 
+        ModuleVisibilityManager moduleVisibilityManager = ModuleVisibilityManager.SERVICE.getInstance(environment.getProject());
+
+        for (String path : friendPaths) {
+            moduleVisibilityManager.addFriendPath(path);
+        }
+
         GenerationState generationState = analyzeAndGenerate(environment);
         if (generationState == null) {
             return false;