[Native][tests] Keep reflection package name when renaming packages

The test engine renames packages in test files to allow group many tests
into single compilation for performance reasons.

As a result, reflection APIs return different package names. To deal
with this, the test engine uses certain heuristics to detect tests using
reflection APIs, and disables grouping (and thus package renaming) for
them.

This commit provides an alternative solution for the same problem --
now the test engine instructs the compiler to use original package names
for reflection information, by means of the introduced
`ReflectionPackageName` annotation.

native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/group/ExtTestCaseGroupProvider.kt

@@ -152,6 +152,7 @@ private class ExtTestDataFile(
         val args = mutableListOf<String>()
         testDataFileSettings.languageSettings.sorted().mapTo(args) { "-XXLanguage:$it" }
         testDataFileSettings.optInsForCompiler.sorted().mapTo(args) { "-opt-in=$it" }
+        args += "-opt-in=kotlin.native.internal.InternalForKotlinNativeTests" // for ReflectionPackageName
         if (testDataFileSettings.expectActualLinker) args += "-Xexpect-actual-linker"
         return TestCompilerArgs(args)
     }
@@ -281,6 +282,12 @@ private class ExtTestDataFile(
                         file.addAfter(newPackageDirective, file.fileAnnotationList).ensureSurroundedByWhiteSpace()
                     }
 
+                    // Add @ReflectionPackageName annotation to make the compiler use original package name in the reflective information.
+                    val annotationText =
+                        "kotlin.native.internal.ReflectionPackageName(${oldPackageName.asString().quoteAsKotlinStringLiteral()})"
+                    val fileAnnotationList = handler.psiFactory.createFileAnnotationListWithAnnotation(annotationText)
+                    file.addAnnotations(fileAnnotationList)
+
                     visitKtElement(file, file.collectAccessibleDeclarationNames())
                 }
 
@@ -468,23 +475,13 @@ private class ExtTestDataFile(
             filesToTransform.forEach { handler ->
                 handler.accept(object : KtTreeVisitorVoid() {
                     override fun visitKtFile(file: KtFile) {
-                        val oldFileAnnotationList = file.fileAnnotationList
-
                         val newFileAnnotationList = handler.psiFactory.createFile(buildString {
                             testDataFileSettings.optInsForSourceCode.forEach {
                                 appendLine(getAnnotationText(it))
                             }
                         }).fileAnnotationList!!
 
-                        if (oldFileAnnotationList != null) {
-                            // Add new annotations to the old ones.
-                            newFileAnnotationList.annotationEntries.forEach {
-                                oldFileAnnotationList.add(it).ensureSurroundedByWhiteSpace()
-                            }
-                        } else {
-                            // Insert the annotations list immediately before package directive.
-                            file.addBefore(newFileAnnotationList, file.packageDirective).ensureSurroundedByWhiteSpace()
-                        }
+                        file.addAnnotations(newFileAnnotationList)
                     }
                 })
             }
@@ -493,6 +490,19 @@ private class ExtTestDataFile(
         return allFileLevelAnnotationsSorted
     }
 
+    private fun KtFile.addAnnotations(fileAnnotationList: KtFileAnnotationList) {
+        val oldFileAnnotationList = this.fileAnnotationList
+        if (oldFileAnnotationList != null) {
+            // Add new annotations to the old ones.
+            fileAnnotationList.annotationEntries.forEach {
+                oldFileAnnotationList.add(it).ensureSurroundedByWhiteSpace()
+            }
+        } else {
+            // Insert the annotations list immediately before package directive.
+            this.addBefore(fileAnnotationList, packageDirective).ensureSurroundedByWhiteSpace()
+        }
+    }
+
     /** Finds the fully-qualified name of the entry point function (aka `fun box(): String`). */
     private fun findEntryPoint(): String = with(structure) {
         val result = mutableListOf<String>()

native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/util/Names.kt

@@ -31,3 +31,28 @@ internal const val LAUNCHER_MODULE_NAME = "__launcher__" // Used only in KLIB te
 internal const val STATIC_CACHE_DIR_NAME = "__static_cache__"
 
 internal fun prettyHash(hash: Int): String = hash.toUInt().toString(16).padStart(8, '0')
+
+/**
+ * Returns the expression to be parsed by Kotlin as string literal with given contents,
+ * i.e. transforms `foo$bar` to `"foo\$bar"`.
+ */
+internal fun String.quoteAsKotlinStringLiteral(): String = buildString {
+    append('"')
+
+    this@quoteAsKotlinStringLiteral.forEach { c ->
+        when (c) {
+            in charactersAllowedInKotlinStringLiterals -> append(c)
+            '$' -> append("\\$")
+            else -> append("\\u" + "%04X".format(c.code))
+        }
+    }
+
+    append('"')
+}
+
+private val charactersAllowedInKotlinStringLiterals: Set<Char> = mutableSetOf<Char>().apply {
+    addAll('a' .. 'z')
+    addAll('A' .. 'Z')
+    addAll('0' .. '9')
+    addAll(listOf('_', '@', ':', ';', '.', ',', '{', '}', '=', '[', ']', '^', '#', '*', ' ', '(', ')'))
+}