[K/N][Tests] Patch package names also for .def files

To separate interop modules to different packages,
.def files should be treated similarly to .kt files:
1) package directive should be prepended with test-specific synthetic package,
or, if, absent, package directive with synthetic package should be added.
2) in .kt files, import directives and fully-qualified import from interop modules
should be prepended with same test-specific synthetic package.

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenTestGenerated.java

@@ -6292,6 +6292,16 @@ public class FirLightTreeBlackBoxCodegenTestGenerated extends AbstractFirLightTr
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/exceptions"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
             }
         }
+
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Packages {
+            @Test
+            public void testAllFilesPresentInPackages() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+            }
+        }
     }
 
     @Nested

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenWithIrFakeOverrideGeneratorTestGenerated.java

@@ -6292,6 +6292,16 @@ public class FirLightTreeBlackBoxCodegenWithIrFakeOverrideGeneratorTestGenerated
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/exceptions"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
             }
         }
+
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Packages {
+            @Test
+            public void testAllFilesPresentInPackages() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+            }
+        }
     }
 
     @Nested

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirPsiBlackBoxCodegenTestGenerated.java

@@ -6292,6 +6292,16 @@ public class FirPsiBlackBoxCodegenTestGenerated extends AbstractFirPsiBlackBoxCo
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/exceptions"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
             }
         }
+
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Packages {
+            @Test
+            public void testAllFilesPresentInPackages() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+            }
+        }
     }
 
     @Nested

compiler/testData/codegen/box/cinterop/basics/3.kt

@@ -4,14 +4,14 @@
  */
 // TARGET_BACKEND: NATIVE
 // MODULE: cinterop
-// FILE: cstdlib_3.def
+// FILE: cstdlib.def
 headers = stdlib.h
 
 // MODULE: main(cinterop)
 // FILE: main.kt
 @file:OptIn(kotlinx.cinterop.ExperimentalForeignApi::class)
 
-import cstdlib_3.*
+import cstdlib.*
 import kotlinx.cinterop.*
 import kotlin.test.*
 

compiler/testData/codegen/box/cinterop/packages/dotFnameNested1.kt

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2010-2024 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+// TARGET_BACKEND: NATIVE
+// MODULE: cinterop
+// FILE: part1.part2.def
+package package1
+---
+#define OK_STRING "OK"
+
+// MODULE: main(cinterop)
+// FILE: main.kt
+@file:OptIn(kotlinx.cinterop.ExperimentalForeignApi::class)
+import package1.*
+
+fun box(): String = OK_STRING

compiler/testData/codegen/box/cinterop/packages/dotFnameNested2.kt

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2010-2024 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+// TARGET_BACKEND: NATIVE
+// MODULE: cinterop
+// FILE: filename1.filename2.def
+package package1.package2
+---
+#define OK_STRING "OK"
+
+// MODULE: main(cinterop)
+// FILE: main.kt
+@file:OptIn(kotlinx.cinterop.ExperimentalForeignApi::class)
+import package1.package2.*
+
+fun box(): String = OK_STRING

compiler/testData/codegen/box/cinterop/packages/dotFnameRoot.kt

@@ -0,0 +1,16 @@
+/*
+ * Copyright 2010-2024 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+// TARGET_BACKEND: NATIVE
+// MODULE: cinterop
+// FILE: root1.root2.def
+---
+#define OK_STRING "OK"
+
+// MODULE: main(cinterop)
+// FILE: main.kt
+@file:OptIn(kotlinx.cinterop.ExperimentalForeignApi::class)
+import root2.root1.*
+
+fun box(): String = OK_STRING

compiler/testData/codegen/box/cinterop/packages/nested1.kt

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2010-2024 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+// TARGET_BACKEND: NATIVE
+// MODULE: cinterop
+// FILE: packages.def
+package package1
+---
+#define OK_STRING "OK"
+
+// MODULE: main(cinterop)
+// FILE: main.kt
+@file:OptIn(kotlinx.cinterop.ExperimentalForeignApi::class)
+import package1.*
+
+fun box(): String = OK_STRING

compiler/testData/codegen/box/cinterop/packages/nested2.kt

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2010-2024 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+// TARGET_BACKEND: NATIVE
+// MODULE: cinterop
+// FILE: packages.def
+package package1.package2
+---
+#define OK_STRING "OK"
+
+// MODULE: main(cinterop)
+// FILE: main.kt
+@file:OptIn(kotlinx.cinterop.ExperimentalForeignApi::class)
+import package1.package2.*
+
+fun box(): String = OK_STRING

compiler/testData/codegen/box/cinterop/packages/root.kt

@@ -0,0 +1,16 @@
+/*
+ * Copyright 2010-2024 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+// TARGET_BACKEND: NATIVE
+// MODULE: cinterop
+// FILE: root1.def
+---
+#define OK_STRING "OK"
+
+// MODULE: main(cinterop)
+// FILE: main.kt
+@file:OptIn(kotlinx.cinterop.ExperimentalForeignApi::class)
+import root1.*
+
+fun box(): String = OK_STRING

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/JvmAbiConsistencyTestBoxGenerated.java

@@ -6292,6 +6292,16 @@ public class JvmAbiConsistencyTestBoxGenerated extends AbstractJvmAbiConsistency
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/exceptions"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
             }
         }
+
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Packages {
+            @Test
+            public void testAllFilesPresentInPackages() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+            }
+        }
     }
 
     @Nested

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java

@@ -6058,6 +6058,16 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/exceptions"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM, true);
             }
         }
+
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Packages {
+            @Test
+            public void testAllFilesPresentInPackages() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM, true);
+            }
+        }
     }
 
     @Nested

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java

@@ -6292,6 +6292,16 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/exceptions"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
             }
         }
+
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Packages {
+            @Test
+            public void testAllFilesPresentInPackages() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+            }
+        }
     }
 
     @Nested

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenWithIrInlinerTestGenerated.java

@@ -6292,6 +6292,16 @@ public class IrBlackBoxCodegenWithIrInlinerTestGenerated extends AbstractIrBlack
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/exceptions"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
             }
         }
+
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Packages {
+            @Test
+            public void testAllFilesPresentInPackages() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+            }
+        }
     }
 
     @Nested

compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -5509,6 +5509,19 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/exceptions"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
             }
         }
+
+        @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class Packages extends AbstractLightAnalysisModeTest {
+            private void runTest(String testDataFilePath) throws Exception {
+                KotlinTestUtils.runTest(this::doTest, TargetBackend.JVM_IR, testDataFilePath);
+            }
+
+            public void testAllFilesPresentInPackages() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+            }
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/box/classLiteral")

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/fir/FirJsCodegenBoxTestGenerated.java

@@ -4630,6 +4630,16 @@ public class FirJsCodegenBoxTestGenerated extends AbstractFirJsCodegenBoxTest {
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/exceptions"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR, true);
             }
         }
+
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Packages {
+            @Test
+            public void testAllFilesPresentInPackages() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR, true);
+            }
+        }
     }
 
     @Nested

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/fir/FirJsES6CodegenBoxTestGenerated.java

@@ -4630,6 +4630,16 @@ public class FirJsES6CodegenBoxTestGenerated extends AbstractFirJsES6CodegenBoxT
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/exceptions"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR_ES6, true);
             }
         }
+
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Packages {
+            @Test
+            public void testAllFilesPresentInPackages() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR_ES6, true);
+            }
+        }
     }
 
     @Nested

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsCodegenBoxTestGenerated.java

@@ -4630,6 +4630,16 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/exceptions"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR, true);
             }
         }
+
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Packages {
+            @Test
+            public void testAllFilesPresentInPackages() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR, true);
+            }
+        }
     }
 
     @Nested

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsES6CodegenBoxTestGenerated.java

@@ -4630,6 +4630,16 @@ public class IrJsES6CodegenBoxTestGenerated extends AbstractIrJsES6CodegenBoxTes
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/exceptions"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR_ES6, true);
             }
         }
+
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Packages {
+            @Test
+            public void testAllFilesPresentInPackages() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR_ES6, true);
+            }
+        }
     }
 
     @Nested

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/FirNativeCodegenBoxTestGenerated.java

@@ -4989,6 +4989,55 @@ public class FirNativeCodegenBoxTestGenerated extends AbstractNativeCodegenBoxTe
                     runTest("compiler/testData/codegen/box/cinterop/exceptions/cCallback.kt");
                 }
             }
+
+            @Nested
+            @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+            @TestDataPath("$PROJECT_ROOT")
+            @Tag("frontend-fir")
+            @FirPipeline()
+            @UseExtTestCaseGroupProvider()
+            public class Packages {
+                @Test
+                public void testAllFilesPresentInPackages() throws Exception {
+                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.NATIVE, true);
+                }
+
+                @Test
+                @TestMetadata("dotFnameNested1.kt")
+                public void testDotFnameNested1() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/dotFnameNested1.kt");
+                }
+
+                @Test
+                @TestMetadata("dotFnameNested2.kt")
+                public void testDotFnameNested2() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/dotFnameNested2.kt");
+                }
+
+                @Test
+                @TestMetadata("dotFnameRoot.kt")
+                public void testDotFnameRoot() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/dotFnameRoot.kt");
+                }
+
+                @Test
+                @TestMetadata("nested1.kt")
+                public void testNested1() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/nested1.kt");
+                }
+
+                @Test
+                @TestMetadata("nested2.kt")
+                public void testNested2() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/nested2.kt");
+                }
+
+                @Test
+                @TestMetadata("root.kt")
+                public void testRoot() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/root.kt");
+                }
+            }
         }
 
         @Nested

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/FirNativeCodegenBoxTestNoPLGenerated.java

@@ -5103,6 +5103,57 @@ public class FirNativeCodegenBoxTestNoPLGenerated extends AbstractNativeCodegenB
                     runTest("compiler/testData/codegen/box/cinterop/exceptions/cCallback.kt");
                 }
             }
+
+            @Nested
+            @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+            @TestDataPath("$PROJECT_ROOT")
+            @Tag("frontend-fir")
+            @FirPipeline()
+            @UseExtTestCaseGroupProvider()
+            @UsePartialLinkage(mode = Mode.DISABLED)
+            @Tag("no-partial-linkage-may-be-skipped")
+            public class Packages {
+                @Test
+                public void testAllFilesPresentInPackages() throws Exception {
+                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.NATIVE, true);
+                }
+
+                @Test
+                @TestMetadata("dotFnameNested1.kt")
+                public void testDotFnameNested1() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/dotFnameNested1.kt");
+                }
+
+                @Test
+                @TestMetadata("dotFnameNested2.kt")
+                public void testDotFnameNested2() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/dotFnameNested2.kt");
+                }
+
+                @Test
+                @TestMetadata("dotFnameRoot.kt")
+                public void testDotFnameRoot() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/dotFnameRoot.kt");
+                }
+
+                @Test
+                @TestMetadata("nested1.kt")
+                public void testNested1() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/nested1.kt");
+                }
+
+                @Test
+                @TestMetadata("nested2.kt")
+                public void testNested2() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/nested2.kt");
+                }
+
+                @Test
+                @TestMetadata("root.kt")
+                public void testRoot() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/root.kt");
+                }
+            }
         }
 
         @Nested

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/NativeCodegenBoxTestGenerated.java

@@ -4875,6 +4875,53 @@ public class NativeCodegenBoxTestGenerated extends AbstractNativeCodegenBoxTest
                     runTest("compiler/testData/codegen/box/cinterop/exceptions/cCallback.kt");
                 }
             }
+
+            @Nested
+            @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+            @TestDataPath("$PROJECT_ROOT")
+            @UseExtTestCaseGroupProvider()
+            public class Packages {
+                @Test
+                public void testAllFilesPresentInPackages() throws Exception {
+                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.NATIVE, true);
+                }
+
+                @Test
+                @TestMetadata("dotFnameNested1.kt")
+                public void testDotFnameNested1() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/dotFnameNested1.kt");
+                }
+
+                @Test
+                @TestMetadata("dotFnameNested2.kt")
+                public void testDotFnameNested2() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/dotFnameNested2.kt");
+                }
+
+                @Test
+                @TestMetadata("dotFnameRoot.kt")
+                public void testDotFnameRoot() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/dotFnameRoot.kt");
+                }
+
+                @Test
+                @TestMetadata("nested1.kt")
+                public void testNested1() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/nested1.kt");
+                }
+
+                @Test
+                @TestMetadata("nested2.kt")
+                public void testNested2() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/nested2.kt");
+                }
+
+                @Test
+                @TestMetadata("root.kt")
+                public void testRoot() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/root.kt");
+                }
+            }
         }
 
         @Nested

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/NativeCodegenBoxTestNoPLGenerated.java

@@ -4990,6 +4990,55 @@ public class NativeCodegenBoxTestNoPLGenerated extends AbstractNativeCodegenBoxT
                     runTest("compiler/testData/codegen/box/cinterop/exceptions/cCallback.kt");
                 }
             }
+
+            @Nested
+            @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+            @TestDataPath("$PROJECT_ROOT")
+            @UseExtTestCaseGroupProvider()
+            @UsePartialLinkage(mode = Mode.DISABLED)
+            @Tag("no-partial-linkage-may-be-skipped")
+            public class Packages {
+                @Test
+                public void testAllFilesPresentInPackages() throws Exception {
+                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.NATIVE, true);
+                }
+
+                @Test
+                @TestMetadata("dotFnameNested1.kt")
+                public void testDotFnameNested1() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/dotFnameNested1.kt");
+                }
+
+                @Test
+                @TestMetadata("dotFnameNested2.kt")
+                public void testDotFnameNested2() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/dotFnameNested2.kt");
+                }
+
+                @Test
+                @TestMetadata("dotFnameRoot.kt")
+                public void testDotFnameRoot() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/dotFnameRoot.kt");
+                }
+
+                @Test
+                @TestMetadata("nested1.kt")
+                public void testNested1() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/nested1.kt");
+                }
+
+                @Test
+                @TestMetadata("nested2.kt")
+                public void testNested2() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/nested2.kt");
+                }
+
+                @Test
+                @TestMetadata("root.kt")
+                public void testRoot() throws Exception {
+                    runTest("compiler/testData/codegen/box/cinterop/packages/root.kt");
+                }
+            }
         }
 
         @Nested

native/native.tests/tests/org/jetbrains/kotlin/konan/test/blackbox/CinteropPackagesTest.kt

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.konan.test.blackbox
+
+import org.jetbrains.kotlin.konan.test.blackbox.support.TestCase
+import org.jetbrains.kotlin.konan.test.blackbox.support.TestCompilerArgs
+import org.jetbrains.kotlin.konan.test.blackbox.support.TestDirectives
+import org.jetbrains.kotlin.konan.test.blackbox.support.TestKind
+import org.jetbrains.kotlin.konan.test.blackbox.support.compilation.TestCompilationResult.Companion.assertSuccess
+import org.junit.jupiter.api.Test
+import java.io.File
+import kotlin.test.assertNotNull
+import kotlin.test.assertNull
+import kotlin.test.assertTrue
+
+// Compile .def and .kt files in most straightforward way to check the structure of packages created by `cinterop` tool into interop klib.
+// Same test sources are also checked with new native test infra using its package renaming feature.
+class CInteropPackagesTest : AbstractNativeSimpleTest() {
+    @Test
+    fun testAllTestSourcesInCinteropPackages() {
+        val testSources = File(TEST_DATA_DIR).listFiles()
+        assertTrue(testSources.isNotEmpty())
+
+        testSources.forEach { testSource ->
+            val lines = testSource.readLines()
+            val testCaseBuildDir = buildDir.resolve(testSource.name)
+            testCaseBuildDir.mkdirs()
+            var output_file: File? = null
+            val generatedFilesByExtension = mutableMapOf<String, File>()
+            lines.forEach { line ->
+                val prefix = "// ${TestDirectives.FILE}: "
+                if (line.startsWith(prefix)) {
+                    output_file = testCaseBuildDir.resolve(line.removePrefix(prefix))
+                    val extension = line.substringAfterLast(".")
+                    assertNull(
+                        generatedFilesByExtension[extension],
+                        "Test source ${testSource.absolutePath} must contain only one directive `// ${TestDirectives.FILE}: <SOMEFILE.$extension>`"
+                    )
+                    generatedFilesByExtension[extension] = output_file!!
+                } else {
+                    output_file?.appendText("$line\n")
+                }
+            }
+            val defFile = generatedFilesByExtension["def"]
+            assertNotNull(
+                defFile,
+                "Test source ${testSource.absolutePath} must contain directive `// ${TestDirectives.FILE}: <SOMEFILE.def>`"
+            )
+            val ktFile = generatedFilesByExtension["kt"]
+            assertNotNull(
+                ktFile,
+                "Test source ${testSource.absolutePath} must contain directive `// ${TestDirectives.FILE}: <SOMEFILE.kt>`"
+            )
+            ktFile.appendText("fun main() { box() }")
+
+            val library = cinteropToLibrary(
+                targets = targets,
+                defFile = defFile,
+                outputDir = buildDir,
+                freeCompilerArgs = TestCompilerArgs.EMPTY
+            ).assertSuccess().resultingArtifact
+
+            compileToExecutable(
+                generateTestCaseWithSingleFile(
+                    sourceFile = ktFile,
+                    testKind = TestKind.STANDALONE_NO_TR,
+                    extras = TestCase.NoTestRunnerExtras("main")
+                ),
+                library.asLibraryDependency()
+            ).assertSuccess()
+        }
+    }
+
+    companion object {
+        private const val TEST_DATA_DIR = "compiler/testData/codegen/box/cinterop/packages"
+    }
+}

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

@@ -258,8 +258,6 @@ private class ExtTestDataFile(
             basePackageName.child(oldPackageName)
         }
 
-        val packagesOfDefFiles = defFiles.map { Name.identifier(it.name.removeSuffix(".def")) }
-
         filesToTransform.forEach { handler ->
             handler.accept(object : KtVisitor<Unit, Set<Name>>() {
                 override fun visitKtElement(element: KtElement, parentAccessibleDeclarationNames: Set<Name>) {
@@ -273,24 +271,26 @@ private class ExtTestDataFile(
                     val oldPackageDirective = file.packageDirective
                     val oldPackageName = oldPackageDirective?.fqName ?: FqName.ROOT
 
-                    val newPackageName = oldToNewPackageNameMapping.getValue(oldPackageName)
+                    val newPackageName = oldToNewPackageNameMapping.getValue(file.packageFqNameForKLib)
                     val newPackageDirective = handler.psiFactory.createPackageDirective(newPackageName)
 
                     if (oldPackageDirective != null) {
                         // Replace old package directive by the new one.
-                        oldPackageDirective.replace(newPackageDirective).ensureSurroundedByWhiteSpace()
+                        oldPackageDirective.replace(newPackageDirective).ensureSurroundedByNewLines()
                     } else {
                         // Insert the package directive immediately after file-level annotations.
-                        file.addAfter(newPackageDirective, file.fileAnnotationList).ensureSurroundedByWhiteSpace()
+                        file.addAfter(newPackageDirective, file.fileAnnotationList).ensureSurroundedByNewLines()
                     }
 
-                    // Add @ReflectionPackageName annotation to make the compiler use original package name in the reflective information.
-                    val annotationText =
-                        "kotlin.native.internal.ReflectionPackageName(${oldPackageName.asString().quoteAsKotlinStringLiteral()})"
-                    val fileAnnotationList = handler.psiFactory.createFileAnnotationListWithAnnotation(annotationText)
-                    file.addAnnotations(fileAnnotationList)
+                    if (!file.name.endsWith(".def")) { // don't process .def file contents after package directive
+                        // Add @ReflectionPackageName annotation to make the compiler use original package name in the reflective information.
+                        val annotationText =
+                            "kotlin.native.internal.ReflectionPackageName(${oldPackageName.asString().quoteAsKotlinStringLiteral()})"
+                        val fileAnnotationList = handler.psiFactory.createFileAnnotationListWithAnnotation(annotationText)
+                        file.addAnnotations(fileAnnotationList)
 
-                    visitKtElement(file, file.collectAccessibleDeclarationNames())
+                        visitKtElement(file, file.collectAccessibleDeclarationNames())
+                    }
                 }
 
                 override fun visitPackageDirective(directive: KtPackageDirective, unused: Set<Name>) = Unit
@@ -303,7 +303,6 @@ private class ExtTestDataFile(
                         || importedFqName.startsWith(KOTLINX_PACKAGE_NAME)
                         || importedFqName.startsWith(HELPERS_PACKAGE_NAME)
                         || importedFqName.startsWith(CNAMES_PACKAGE_NAME)
-                        || packagesOfDefFiles.any { importedFqName.startsWith(it) }
                     ) {
                         return
                     }
@@ -457,11 +456,11 @@ private class ExtTestDataFile(
         if (oldFileAnnotationList != null) {
             // Add new annotations to the old ones.
             fileAnnotationList.annotationEntries.forEach {
-                oldFileAnnotationList.add(it).ensureSurroundedByWhiteSpace()
+                oldFileAnnotationList.add(it).ensureSurroundedByNewLines()
             }
         } else {
             // Insert the annotations list immediately before package directive.
-            this.addBefore(fileAnnotationList, packageDirective).ensureSurroundedByWhiteSpace()
+            this.addBefore(fileAnnotationList, packageDirective).ensureSurroundedByNewLines()
         }
     }
 
@@ -626,12 +625,11 @@ private class ExtTestDataFileStructureFactory(parentDisposable: Disposable) : Te
 
         val directives: Directives get() = filesAndModules.directives
 
-        val defFiles: List<KtFile> = filesAndModules.parsedFiles.filter { it.key.name.endsWith(".def") }.map { it.value }
         val filesToTransform: Iterable<CurrentFileHandler>
-            get() = filesAndModules.parsedFiles.filter { it.key.name.endsWith(".kt") }
+            get() = filesAndModules.parsedFiles.filter { it.key.name.endsWith(".kt") || it.key.name.endsWith(".def") }
                 .map { (extTestFile, psiFile) ->
                     object : CurrentFileHandler {
-                        override val packageFqName get() = psiFile.packageFqName
+                        override val packageFqName get() = psiFile.packageFqNameForKLib
                         override val module = object : CurrentFileHandler.ModuleHandler {
                             override fun markAsMain() {
                                 extTestFile.module.isMain = true
@@ -974,3 +972,15 @@ private fun Settings.isIgnoredWithIGNORE_NATIVE(
     }
     return false
 }
+
+private val KtFile.packageFqNameForKLib: FqName
+    get() = when (name.substringAfterLast(".")) {
+        "kt" -> packageFqName
+        "def" -> {
+            // Without package directive, CInterop tool puts declarations to a package with kinda odd name, as such:
+            // name of .def file without extension, splitted by dot-separated parts, and reversed.
+            if (packageFqName != FqName.ROOT) packageFqName
+            else FqName.fromSegments(name.removeSuffix(".def").split(".").reversed())
+        }
+        else -> TODO("File extension is not yet supported: $name")
+    }

native/native.tests/tests/org/jetbrains/kotlin/konan/test/blackbox/support/util/PsiTransformation.kt

@@ -11,21 +11,21 @@ import org.jetbrains.kotlin.psi.KtPsiFactory
 import org.jetbrains.kotlin.psi.psiUtil.nextLeaf
 import org.jetbrains.kotlin.psi.psiUtil.prevLeaf
 
-internal fun PsiElement.ensureSurroundedByWhiteSpace(): PsiElement =
-    ensureHasWhiteSpaceBefore().ensureHasWhiteSpaceAfter()
+internal fun PsiElement.ensureSurroundedByNewLines(): PsiElement =
+    ensureHasNewLineBefore().ensureHasNewLineAfter()
 
-private fun PsiElement.ensureHasWhiteSpaceBefore(): PsiElement {
+private fun PsiElement.ensureHasNewLineBefore(): PsiElement {
     val (fileBoundaryReached, whiteSpaceBefore) = whiteSpaceBefore()
-    if (!fileBoundaryReached and !whiteSpaceBefore.endsWith(" ")) {
-        parent.addBefore(KtPsiFactory(project).createWhiteSpace(" "), this)
+    if (!fileBoundaryReached and !whiteSpaceBefore.endsWith("\n")) {
+        parent.addBefore(KtPsiFactory(project).createWhiteSpace("\n"), this)
     }
     return this
 }
 
-private fun PsiElement.ensureHasWhiteSpaceAfter(): PsiElement {
+private fun PsiElement.ensureHasNewLineAfter(): PsiElement {
     val (fileBoundaryReached, whiteSpaceAfter) = whiteSpaceAfter()
-    if (!fileBoundaryReached and !whiteSpaceAfter.startsWith(" ")) {
-        parent.addAfter(KtPsiFactory(project).createWhiteSpace(" "), this)
+    if (!fileBoundaryReached and !whiteSpaceAfter.startsWith("\n")) {
+        parent.addAfter(KtPsiFactory(project).createWhiteSpace("\n"), this)
     }
     return this
 }

wasm/wasm.tests/tests-gen/org/jetbrains/kotlin/wasm/test/FirWasmCodegenBoxTestGenerated.java

@@ -4612,6 +4612,16 @@ public class FirWasmCodegenBoxTestGenerated extends AbstractFirWasmCodegenBoxTes
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/exceptions"), Pattern.compile("^([^_](.+))\\.kt$"), null, TargetBackend.WASM, true);
             }
         }
+
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Packages {
+            @Test
+            public void testAllFilesPresentInPackages() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^([^_](.+))\\.kt$"), null, TargetBackend.WASM, true);
+            }
+        }
     }
 
     @Nested

wasm/wasm.tests/tests-gen/org/jetbrains/kotlin/wasm/test/K1WasmCodegenBoxTestGenerated.java

@@ -4612,6 +4612,16 @@ public class K1WasmCodegenBoxTestGenerated extends AbstractK1WasmCodegenBoxTest
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/exceptions"), Pattern.compile("^([^_](.+))\\.kt$"), null, TargetBackend.WASM, true);
             }
         }
+
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/cinterop/packages")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Packages {
+            @Test
+            public void testAllFilesPresentInPackages() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/cinterop/packages"), Pattern.compile("^([^_](.+))\\.kt$"), null, TargetBackend.WASM, true);
+            }
+        }
     }
 
     @Nested