IR text tests: New tests specifically for main functions mangling

^KT-57755

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/ir/FirLightTreeJvmIrTextTestGenerated.java

@@ -540,6 +540,18 @@ public class FirLightTreeJvmIrTextTestGenerated extends AbstractFirLightTreeJvmI
             runTest("compiler/testData/ir/irText/declarations/localVarInDoWhile.kt");
         }
 
+        @Test
+        @TestMetadata("mainFunctionMangling.kt")
+        public void testMainFunctionMangling() throws Exception {
+            runTest("compiler/testData/ir/irText/declarations/mainFunctionMangling.kt");
+        }
+
+        @Test
+        @TestMetadata("mainFunctionManglingInJvm.kt")
+        public void testMainFunctionManglingInJvm() throws Exception {
+            runTest("compiler/testData/ir/irText/declarations/mainFunctionManglingInJvm.kt");
+        }
+
         @Test
         @TestMetadata("packageLevelProperties.kt")
         public void testPackageLevelProperties() throws Exception {

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/ir/FirPsiJvmIrTextTestGenerated.java

@@ -540,6 +540,18 @@ public class FirPsiJvmIrTextTestGenerated extends AbstractFirPsiJvmIrTextTest {
             runTest("compiler/testData/ir/irText/declarations/localVarInDoWhile.kt");
         }
 
+        @Test
+        @TestMetadata("mainFunctionMangling.kt")
+        public void testMainFunctionMangling() throws Exception {
+            runTest("compiler/testData/ir/irText/declarations/mainFunctionMangling.kt");
+        }
+
+        @Test
+        @TestMetadata("mainFunctionManglingInJvm.kt")
+        public void testMainFunctionManglingInJvm() throws Exception {
+            runTest("compiler/testData/ir/irText/declarations/mainFunctionManglingInJvm.kt");
+        }
+
         @Test
         @TestMetadata("packageLevelProperties.kt")
         public void testPackageLevelProperties() throws Exception {

compiler/testData/ir/irText/declarations/mainFunctionMangling.ir.txt

@@ -0,0 +1,158 @@
+FILE fqName:<root> fileName:/a.kt
+  FUN name:main visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+        message: CONST String type=kotlin.String value="main()"
+  FUN name:main visibility:public modality:FINAL <T> (t:T of <root>.main) returnType:T of <root>.main
+    TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?] reified:false
+    VALUE_PARAMETER name:t index:0 type:T of <root>.main
+    BLOCK_BODY
+      CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+        message: CONST String type=kotlin.String value="main(T): T"
+      RETURN type=kotlin.Nothing from='public final fun main <T> (t: T of <root>.main): T of <root>.main declared in <root>'
+        GET_VAR 't: T of <root>.main declared in <root>.main' type=T of <root>.main origin=null
+  CLASS CLASS name:C modality:FINAL visibility:public superTypes:[kotlin.Any]
+    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.C
+    CONSTRUCTOR visibility:public <> () returnType:<root>.C [primary]
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> () declared in kotlin.Any'
+        INSTANCE_INITIALIZER_CALL classDescriptor='CLASS CLASS name:C modality:FINAL visibility:public superTypes:[kotlin.Any]'
+    FUN name:main visibility:public modality:FINAL <> ($this:<root>.C) returnType:kotlin.Unit
+      $this: VALUE_PARAMETER name:<this> type:<root>.C
+      BLOCK_BODY
+        CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+          message: CONST String type=kotlin.String value="C.main()"
+    FUN name:main visibility:public modality:FINAL <T> ($this:<root>.C, t:T of <root>.C.main) returnType:T of <root>.C.main
+      TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?] reified:false
+      $this: VALUE_PARAMETER name:<this> type:<root>.C
+      VALUE_PARAMETER name:t index:0 type:T of <root>.C.main
+      BLOCK_BODY
+        CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+          message: CONST String type=kotlin.String value="C.main(T): T"
+        RETURN type=kotlin.Nothing from='public final fun main <T> (t: T of <root>.C.main): T of <root>.C.main declared in <root>.C'
+          GET_VAR 't: T of <root>.C.main declared in <root>.C.main' type=T of <root>.C.main origin=null
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
+      overridden:
+        public open fun equals (other: kotlin.Any?): kotlin.Boolean declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+      VALUE_PARAMETER name:other index:0 type:kotlin.Any?
+    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.Int [fake_override]
+      overridden:
+        public open fun hashCode (): kotlin.Int declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.String [fake_override]
+      overridden:
+        public open fun toString (): kotlin.String declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+  CLASS OBJECT name:O modality:FINAL visibility:public superTypes:[kotlin.Any]
+    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.O
+    CONSTRUCTOR visibility:private <> () returnType:<root>.O [primary]
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> () declared in kotlin.Any'
+        INSTANCE_INITIALIZER_CALL classDescriptor='CLASS OBJECT name:O modality:FINAL visibility:public superTypes:[kotlin.Any]'
+    FUN name:main visibility:public modality:FINAL <> ($this:<root>.O) returnType:kotlin.Unit
+      $this: VALUE_PARAMETER name:<this> type:<root>.O
+      BLOCK_BODY
+        CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+          message: CONST String type=kotlin.String value="O.main()"
+    FUN name:main visibility:public modality:FINAL <T> ($this:<root>.O, t:T of <root>.O.main) returnType:T of <root>.O.main
+      TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?] reified:false
+      $this: VALUE_PARAMETER name:<this> type:<root>.O
+      VALUE_PARAMETER name:t index:0 type:T of <root>.O.main
+      BLOCK_BODY
+        CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+          message: CONST String type=kotlin.String value="O.main(T): T"
+        RETURN type=kotlin.Nothing from='public final fun main <T> (t: T of <root>.O.main): T of <root>.O.main declared in <root>.O'
+          GET_VAR 't: T of <root>.O.main declared in <root>.O.main' type=T of <root>.O.main origin=null
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
+      overridden:
+        public open fun equals (other: kotlin.Any?): kotlin.Boolean declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+      VALUE_PARAMETER name:other index:0 type:kotlin.Any?
+    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.Int [fake_override]
+      overridden:
+        public open fun hashCode (): kotlin.Int declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.String [fake_override]
+      overridden:
+        public open fun toString (): kotlin.String declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+FILE fqName:foo fileName:/b.kt
+  FUN name:main visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+        message: CONST String type=kotlin.String value="foo.main()"
+  FUN name:main visibility:public modality:FINAL <T> (t:T of foo.main) returnType:T of foo.main
+    TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?] reified:false
+    VALUE_PARAMETER name:t index:0 type:T of foo.main
+    BLOCK_BODY
+      CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+        message: CONST String type=kotlin.String value="foo.main(T): T"
+      RETURN type=kotlin.Nothing from='public final fun main <T> (t: T of foo.main): T of foo.main declared in foo'
+        GET_VAR 't: T of foo.main declared in foo.main' type=T of foo.main origin=null
+  CLASS CLASS name:C modality:FINAL visibility:public superTypes:[kotlin.Any]
+    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:foo.C
+    CONSTRUCTOR visibility:public <> () returnType:foo.C [primary]
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> () declared in kotlin.Any'
+        INSTANCE_INITIALIZER_CALL classDescriptor='CLASS CLASS name:C modality:FINAL visibility:public superTypes:[kotlin.Any]'
+    FUN name:main visibility:public modality:FINAL <> ($this:foo.C) returnType:kotlin.Unit
+      $this: VALUE_PARAMETER name:<this> type:foo.C
+      BLOCK_BODY
+        CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+          message: CONST String type=kotlin.String value="foo.C.main()"
+    FUN name:main visibility:public modality:FINAL <T> ($this:foo.C, t:T of foo.C.main) returnType:T of foo.C.main
+      TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?] reified:false
+      $this: VALUE_PARAMETER name:<this> type:foo.C
+      VALUE_PARAMETER name:t index:0 type:T of foo.C.main
+      BLOCK_BODY
+        CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+          message: CONST String type=kotlin.String value="foo.C.main(T): T"
+        RETURN type=kotlin.Nothing from='public final fun main <T> (t: T of foo.C.main): T of foo.C.main declared in foo.C'
+          GET_VAR 't: T of foo.C.main declared in foo.C.main' type=T of foo.C.main origin=null
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
+      overridden:
+        public open fun equals (other: kotlin.Any?): kotlin.Boolean declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+      VALUE_PARAMETER name:other index:0 type:kotlin.Any?
+    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.Int [fake_override]
+      overridden:
+        public open fun hashCode (): kotlin.Int declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.String [fake_override]
+      overridden:
+        public open fun toString (): kotlin.String declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+  CLASS OBJECT name:O modality:FINAL visibility:public superTypes:[kotlin.Any]
+    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:foo.O
+    CONSTRUCTOR visibility:private <> () returnType:foo.O [primary]
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> () declared in kotlin.Any'
+        INSTANCE_INITIALIZER_CALL classDescriptor='CLASS OBJECT name:O modality:FINAL visibility:public superTypes:[kotlin.Any]'
+    FUN name:main visibility:public modality:FINAL <> ($this:foo.O) returnType:kotlin.Unit
+      $this: VALUE_PARAMETER name:<this> type:foo.O
+      BLOCK_BODY
+        CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+          message: CONST String type=kotlin.String value="foo.O.main()"
+    FUN name:main visibility:public modality:FINAL <T> ($this:foo.O, t:T of foo.O.main) returnType:T of foo.O.main
+      TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?] reified:false
+      $this: VALUE_PARAMETER name:<this> type:foo.O
+      VALUE_PARAMETER name:t index:0 type:T of foo.O.main
+      BLOCK_BODY
+        CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+          message: CONST String type=kotlin.String value="foo.O.main(T): T"
+        RETURN type=kotlin.Nothing from='public final fun main <T> (t: T of foo.O.main): T of foo.O.main declared in foo.O'
+          GET_VAR 't: T of foo.O.main declared in foo.O.main' type=T of foo.O.main origin=null
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
+      overridden:
+        public open fun equals (other: kotlin.Any?): kotlin.Boolean declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+      VALUE_PARAMETER name:other index:0 type:kotlin.Any?
+    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.Int [fake_override]
+      overridden:
+        public open fun hashCode (): kotlin.Int declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.String [fake_override]
+      overridden:
+        public open fun toString (): kotlin.String declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any

compiler/testData/ir/irText/declarations/mainFunctionMangling.kt

@@ -0,0 +1,78 @@
+// FIR_IDENTICAL
+// WITH_STDLIB
+
+// MUTE_SIGNATURE_COMPARISON_K2: JVM_IR
+// ^^^ JVM K2 eagerly mangles all the functions with `main` name, which is not so in JVM K1. That's the difference that, however,
+//     does not cause problems when switching between K1 and K2 compilers, since signatures are not serialized in JARs.
+
+// FILE: a.kt
+fun main() {
+    println("main()")
+}
+
+// Looks like `main` but is not a main function.
+fun <T> main(t: T): T {
+    println("main(T): T")
+    return t
+}
+
+class C {
+    fun main() {
+        println("C.main()")
+    }
+
+    // Looks like `main` but is not a main function.
+    fun <T> main(t: T): T {
+        println("C.main(T): T")
+        return t
+    }
+}
+
+object O {
+    fun main() {
+        println("O.main()")
+    }
+
+    // Looks like `main` but is not a main function.
+    fun <T> main(t: T): T {
+        println("O.main(T): T")
+        return t
+    }
+}
+
+// FILE: b.kt
+package foo
+
+fun main() {
+    println("foo.main()")
+}
+
+// Looks like `main` but is not a main function.
+fun <T> main(t: T): T {
+    println("foo.main(T): T")
+    return t
+}
+
+class C {
+    fun main() {
+        println("foo.C.main()")
+    }
+
+    // Looks like `main` but is not a main function.
+    fun <T> main(t: T): T {
+        println("foo.C.main(T): T")
+        return t
+    }
+}
+
+object O {
+    fun main() {
+        println("foo.O.main()")
+    }
+
+    // Looks like `main` but is not a main function.
+    fun <T> main(t: T): T {
+        println("foo.O.main(T): T")
+        return t
+    }
+}

compiler/testData/ir/irText/declarations/mainFunctionMangling.kt.txt

@@ -0,0 +1,95 @@
+// FILE: a.kt
+
+fun main() {
+  println(message = "main()")
+}
+
+fun <T : Any?> main(t: T): T {
+  println(message = "main(T): T")
+  return t
+}
+
+class C {
+  constructor() /* primary */ {
+    super/*Any*/()
+    /* <init>() */
+
+  }
+
+  fun main() {
+    println(message = "C.main()")
+  }
+
+  fun <T : Any?> main(t: T): T {
+    println(message = "C.main(T): T")
+    return t
+  }
+
+}
+
+object O {
+  private constructor() /* primary */ {
+    super/*Any*/()
+    /* <init>() */
+
+  }
+
+  fun main() {
+    println(message = "O.main()")
+  }
+
+  fun <T : Any?> main(t: T): T {
+    println(message = "O.main(T): T")
+    return t
+  }
+
+}
+
+// FILE: b.kt
+package foo
+
+fun main() {
+  println(message = "foo.main()")
+}
+
+fun <T : Any?> main(t: T): T {
+  println(message = "foo.main(T): T")
+  return t
+}
+
+class C {
+  constructor() /* primary */ {
+    super/*Any*/()
+    /* <init>() */
+
+  }
+
+  fun main() {
+    println(message = "foo.C.main()")
+  }
+
+  fun <T : Any?> main(t: T): T {
+    println(message = "foo.C.main(T): T")
+    return t
+  }
+
+}
+
+object O {
+  private constructor() /* primary */ {
+    super/*Any*/()
+    /* <init>() */
+
+  }
+
+  fun main() {
+    println(message = "foo.O.main()")
+  }
+
+  fun <T : Any?> main(t: T): T {
+    println(message = "foo.O.main(T): T")
+    return t
+  }
+
+}
+

compiler/testData/ir/irText/declarations/mainFunctionMangling.sig.kt.txt

@@ -0,0 +1,165 @@
+// FILE: a.kt
+
+// CHECK:
+//   Mangled name: C
+//   Public signature: /C|null[0]
+class C {
+  // CHECK:
+  //   Mangled name: C#<init>(){}
+  //   Public signature: /C.<init>|-5645683436151566731[0]
+  //   Public signature debug description: <init>(){}
+  constructor() /* primary */
+
+  // CHECK:
+  //   Mangled name: C#main(){}
+  //   Public signature: /C.main|-4284757841571462650[0]
+  //   Public signature debug description: main(){}
+  fun main(): Unit
+
+  // CHECK JVM_IR:
+  //   Mangled name: C#main(0:0){0§<kotlin.Any?>}0:0
+  //   Public signature: /C.main|2157137022584307775[0]
+  //   Public signature debug description: main(0:0){0§<kotlin.Any?>}0:0
+  // CHECK JS_IR NATIVE:
+  //   Mangled name: C#main(0:0){0§<kotlin.Any?>}
+  //   Public signature: /C.main|-6008025846492417520[0]
+  //   Public signature debug description: main(0:0){0§<kotlin.Any?>}
+  fun <T : Any?> main(t: T): T
+
+}
+
+// CHECK:
+//   Mangled name: O
+//   Public signature: /O|null[0]
+object O {
+  // CHECK:
+  //   Mangled name: O#<init>(){}
+  //   Public signature: /O.<init>|-5645683436151566731[0]
+  //   Public signature debug description: <init>(){}
+  private constructor() /* primary */
+
+  // CHECK:
+  //   Mangled name: O#main(){}
+  //   Public signature: /O.main|-4284757841571462650[0]
+  //   Public signature debug description: main(){}
+  fun main(): Unit
+
+  // CHECK JVM_IR:
+  //   Mangled name: O#main(0:0){0§<kotlin.Any?>}0:0
+  //   Public signature: /O.main|2157137022584307775[0]
+  //   Public signature debug description: main(0:0){0§<kotlin.Any?>}0:0
+  // CHECK JS_IR NATIVE:
+  //   Mangled name: O#main(0:0){0§<kotlin.Any?>}
+  //   Public signature: /O.main|-6008025846492417520[0]
+  //   Public signature debug description: main(0:0){0§<kotlin.Any?>}
+  fun <T : Any?> main(t: T): T
+
+}
+
+// CHECK JVM_IR:
+//   Mangled name: #main(){}
+//   Mangled name for the signature by IR:       main(){}
+//   Mangled name for the signature by Frontend: main(){}%a.kt
+//   Public signature by IR: /main|-4284757841571462650[0]
+//   Public signature by IR debug description: main(){}
+//   Public signature by Frontend: /main|2314384220441172254[0]
+//   Public signature by Frontend debug description: main(){}%a.kt
+// CHECK JS_IR NATIVE:
+//   Mangled name: #main(){}
+//   Public signature: /main|-4284757841571462650[0]
+//   Public signature debug description: main(){}
+fun main(): Unit
+
+// CHECK JVM_IR:
+//   Mangled name: #main(0:0){0§<kotlin.Any?>}0:0
+//   Public signature: /main|2157137022584307775[0]
+//   Public signature debug description: main(0:0){0§<kotlin.Any?>}0:0
+// CHECK JS_IR NATIVE:
+//   Mangled name: #main(0:0){0§<kotlin.Any?>}
+//   Public signature: /main|-6008025846492417520[0]
+//   Public signature debug description: main(0:0){0§<kotlin.Any?>}
+fun <T : Any?> main(t: T): T
+
+// FILE: b.kt
+package foo
+
+// CHECK:
+//   Mangled name: foo.C
+//   Public signature: foo/C|null[0]
+class C {
+  // CHECK:
+  //   Mangled name: foo.C#<init>(){}
+  //   Public signature: foo/C.<init>|-5645683436151566731[0]
+  //   Public signature debug description: <init>(){}
+  constructor() /* primary */
+
+  // CHECK:
+  //   Mangled name: foo.C#main(){}
+  //   Public signature: foo/C.main|-4284757841571462650[0]
+  //   Public signature debug description: main(){}
+  fun main(): Unit
+
+  // CHECK JVM_IR:
+  //   Mangled name: foo.C#main(0:0){0§<kotlin.Any?>}0:0
+  //   Public signature: foo/C.main|2157137022584307775[0]
+  //   Public signature debug description: main(0:0){0§<kotlin.Any?>}0:0
+  // CHECK JS_IR NATIVE:
+  //   Mangled name: foo.C#main(0:0){0§<kotlin.Any?>}
+  //   Public signature: foo/C.main|-6008025846492417520[0]
+  //   Public signature debug description: main(0:0){0§<kotlin.Any?>}
+  fun <T : Any?> main(t: T): T
+
+}
+
+// CHECK:
+//   Mangled name: foo.O
+//   Public signature: foo/O|null[0]
+object O {
+  // CHECK:
+  //   Mangled name: foo.O#<init>(){}
+  //   Public signature: foo/O.<init>|-5645683436151566731[0]
+  //   Public signature debug description: <init>(){}
+  private constructor() /* primary */
+
+  // CHECK:
+  //   Mangled name: foo.O#main(){}
+  //   Public signature: foo/O.main|-4284757841571462650[0]
+  //   Public signature debug description: main(){}
+  fun main(): Unit
+
+  // CHECK JVM_IR:
+  //   Mangled name: foo.O#main(0:0){0§<kotlin.Any?>}0:0
+  //   Public signature: foo/O.main|2157137022584307775[0]
+  //   Public signature debug description: main(0:0){0§<kotlin.Any?>}0:0
+  // CHECK JS_IR NATIVE:
+  //   Mangled name: foo.O#main(0:0){0§<kotlin.Any?>}
+  //   Public signature: foo/O.main|-6008025846492417520[0]
+  //   Public signature debug description: main(0:0){0§<kotlin.Any?>}
+  fun <T : Any?> main(t: T): T
+
+}
+
+// CHECK JVM_IR:
+//   Mangled name: foo#main(){}
+//   Mangled name for the signature by IR:       main(){}
+//   Mangled name for the signature by Frontend: main(){}%b.kt
+//   Public signature by IR: foo/main|-4284757841571462650[0]
+//   Public signature by IR debug description: main(){}
+//   Public signature by Frontend: foo/main|8375568780578146760[0]
+//   Public signature by Frontend debug description: main(){}%b.kt
+// CHECK JS_IR NATIVE:
+//   Mangled name: foo#main(){}
+//   Public signature: foo/main|-4284757841571462650[0]
+//   Public signature debug description: main(){}
+fun main(): Unit
+
+// CHECK JVM_IR:
+//   Mangled name: foo#main(0:0){0§<kotlin.Any?>}0:0
+//   Public signature: foo/main|2157137022584307775[0]
+//   Public signature debug description: main(0:0){0§<kotlin.Any?>}0:0
+// CHECK JS_IR NATIVE:
+//   Mangled name: foo#main(0:0){0§<kotlin.Any?>}
+//   Public signature: foo/main|-6008025846492417520[0]
+//   Public signature debug description: main(0:0){0§<kotlin.Any?>}
+fun <T : Any?> main(t: T): T
+

compiler/testData/ir/irText/declarations/mainFunctionManglingInJvm.ir.txt

@@ -0,0 +1,20 @@
+FILE fqName:<root> fileName:/a.kt
+  FUN name:main visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+        message: CONST String type=kotlin.String value="main() in a.kt"
+FILE fqName:<root> fileName:/b.kt
+  FUN name:main visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+        message: CONST String type=kotlin.String value="main() in b.kt"
+FILE fqName:foo fileName:/c.kt
+  FUN name:main visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+        message: CONST String type=kotlin.String value="foo.main() in c.kt"
+FILE fqName:foo fileName:/d.kt
+  FUN name:main visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      CALL 'public final fun println (message: kotlin.Any?): kotlin.Unit declared in kotlin.io' type=kotlin.Unit origin=null
+        message: CONST String type=kotlin.String value="foo.main() in d.kt"

compiler/testData/ir/irText/declarations/mainFunctionManglingInJvm.kt

@@ -0,0 +1,29 @@
+// TARGET_BACKEND: JVM
+// ^^^ Only JVM allows `main` functions in the same package but in different files.
+
+// FIR_IDENTICAL
+// WITH_STDLIB
+
+// FILE: a.kt
+fun main() {
+    println("main() in a.kt")
+}
+
+// FILE: b.kt
+fun main() {
+    println("main() in b.kt")
+}
+
+// FILE: c.kt
+package foo
+
+fun main() {
+    println("foo.main() in c.kt")
+}
+
+// FILE: d.kt
+package foo
+
+fun main() {
+    println("foo.main() in d.kt")
+}

compiler/testData/ir/irText/declarations/mainFunctionManglingInJvm.kt.txt

@@ -0,0 +1,25 @@
+// FILE: a.kt
+
+fun main() {
+  println(message = "main() in a.kt")
+}
+
+// FILE: b.kt
+
+fun main() {
+  println(message = "main() in b.kt")
+}
+
+// FILE: c.kt
+package foo
+
+fun main() {
+  println(message = "foo.main() in c.kt")
+}
+
+// FILE: d.kt
+package foo
+
+fun main() {
+  println(message = "foo.main() in d.kt")
+}

compiler/testData/ir/irText/declarations/mainFunctionManglingInJvm.sig.kt.txt

@@ -0,0 +1,49 @@
+// FILE: a.kt
+
+// CHECK JVM_IR:
+//   Mangled name: #main(){}
+//   Mangled name for the signature by IR:       main(){}
+//   Mangled name for the signature by Frontend: main(){}%a.kt
+//   Public signature by IR: /main|-4284757841571462650[0]
+//   Public signature by IR debug description: main(){}
+//   Public signature by Frontend: /main|2314384220441172254[0]
+//   Public signature by Frontend debug description: main(){}%a.kt
+fun main(): Unit
+
+// FILE: b.kt
+
+// CHECK JVM_IR:
+//   Mangled name: #main(){}
+//   Mangled name for the signature by IR:       main(){}
+//   Mangled name for the signature by Frontend: main(){}%b.kt
+//   Public signature by IR: /main|-4284757841571462650[0]
+//   Public signature by IR debug description: main(){}
+//   Public signature by Frontend: /main|8375568780578146760[0]
+//   Public signature by Frontend debug description: main(){}%b.kt
+fun main(): Unit
+
+// FILE: c.kt
+package foo
+
+// CHECK JVM_IR:
+//   Mangled name: foo#main(){}
+//   Mangled name for the signature by IR:       main(){}
+//   Mangled name for the signature by Frontend: main(){}%c.kt
+//   Public signature by IR: foo/main|-4284757841571462650[0]
+//   Public signature by IR debug description: main(){}
+//   Public signature by Frontend: foo/main|-6421719669605920145[0]
+//   Public signature by Frontend debug description: main(){}%c.kt
+fun main(): Unit
+
+// FILE: d.kt
+package foo
+
+// CHECK JVM_IR:
+//   Mangled name: foo#main(){}
+//   Mangled name for the signature by IR:       main(){}
+//   Mangled name for the signature by Frontend: main(){}%d.kt
+//   Public signature by IR: foo/main|-4284757841571462650[0]
+//   Public signature by IR debug description: main(){}
+//   Public signature by Frontend: foo/main|-405077377165952676[0]
+//   Public signature by Frontend debug description: main(){}%d.kt
+fun main(): Unit

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

@@ -540,6 +540,18 @@ public class ClassicJvmIrTextTestGenerated extends AbstractClassicJvmIrTextTest
             runTest("compiler/testData/ir/irText/declarations/localVarInDoWhile.kt");
         }
 
+        @Test
+        @TestMetadata("mainFunctionMangling.kt")
+        public void testMainFunctionMangling() throws Exception {
+            runTest("compiler/testData/ir/irText/declarations/mainFunctionMangling.kt");
+        }
+
+        @Test
+        @TestMetadata("mainFunctionManglingInJvm.kt")
+        public void testMainFunctionManglingInJvm() throws Exception {
+            runTest("compiler/testData/ir/irText/declarations/mainFunctionManglingInJvm.kt");
+        }
+
         @Test
         @TestMetadata("packageLevelProperties.kt")
         public void testPackageLevelProperties() throws Exception {

compiler/tests-gen/org/jetbrains/kotlin/klib/KlibIrTextTestCaseGenerated.java

@@ -423,6 +423,11 @@ public class KlibIrTextTestCaseGenerated extends AbstractKlibIrTextTestCase {
             runTest("compiler/testData/ir/irText/declarations/localVarInDoWhile.kt");
         }
 
+        @TestMetadata("mainFunctionMangling.kt")
+        public void testMainFunctionMangling() throws Exception {
+            runTest("compiler/testData/ir/irText/declarations/mainFunctionMangling.kt");
+        }
+
         @TestMetadata("packageLevelProperties.kt")
         public void testPackageLevelProperties() throws Exception {
             runTest("compiler/testData/ir/irText/declarations/packageLevelProperties.kt");

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

@@ -480,6 +480,12 @@ public class FirLightTreeJsIrTextTestGenerated extends AbstractFirLightTreeJsIrT
             runTest("compiler/testData/ir/irText/declarations/localVarInDoWhile.kt");
         }
 
+        @Test
+        @TestMetadata("mainFunctionMangling.kt")
+        public void testMainFunctionMangling() throws Exception {
+            runTest("compiler/testData/ir/irText/declarations/mainFunctionMangling.kt");
+        }
+
         @Test
         @TestMetadata("packageLevelProperties.kt")
         public void testPackageLevelProperties() throws Exception {

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

@@ -480,6 +480,12 @@ public class FirPsiJsIrTextTestGenerated extends AbstractFirPsiJsIrTextTest {
             runTest("compiler/testData/ir/irText/declarations/localVarInDoWhile.kt");
         }
 
+        @Test
+        @TestMetadata("mainFunctionMangling.kt")
+        public void testMainFunctionMangling() throws Exception {
+            runTest("compiler/testData/ir/irText/declarations/mainFunctionMangling.kt");
+        }
+
         @Test
         @TestMetadata("packageLevelProperties.kt")
         public void testPackageLevelProperties() throws Exception {

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

@@ -480,6 +480,12 @@ public class ClassicJsIrTextTestGenerated extends AbstractClassicJsIrTextTest {
             runTest("compiler/testData/ir/irText/declarations/localVarInDoWhile.kt");
         }
 
+        @Test
+        @TestMetadata("mainFunctionMangling.kt")
+        public void testMainFunctionMangling() throws Exception {
+            runTest("compiler/testData/ir/irText/declarations/mainFunctionMangling.kt");
+        }
+
         @Test
         @TestMetadata("packageLevelProperties.kt")
         public void testPackageLevelProperties() throws Exception {

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/irtext/ClassicNativeIrTextTestGenerated.java

@@ -480,6 +480,12 @@ public class ClassicNativeIrTextTestGenerated extends AbstractClassicNativeIrTex
             runTest("compiler/testData/ir/irText/declarations/localVarInDoWhile.kt");
         }
 
+        @Test
+        @TestMetadata("mainFunctionMangling.kt")
+        public void testMainFunctionMangling() throws Exception {
+            runTest("compiler/testData/ir/irText/declarations/mainFunctionMangling.kt");
+        }
+
         @Test
         @TestMetadata("packageLevelProperties.kt")
         public void testPackageLevelProperties() throws Exception {

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/irtext/FirLightTreeNativeIrTextTestGenerated.java

@@ -480,6 +480,12 @@ public class FirLightTreeNativeIrTextTestGenerated extends AbstractFirLightTreeN
             runTest("compiler/testData/ir/irText/declarations/localVarInDoWhile.kt");
         }
 
+        @Test
+        @TestMetadata("mainFunctionMangling.kt")
+        public void testMainFunctionMangling() throws Exception {
+            runTest("compiler/testData/ir/irText/declarations/mainFunctionMangling.kt");
+        }
+
         @Test
         @TestMetadata("packageLevelProperties.kt")
         public void testPackageLevelProperties() throws Exception {

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/irtext/FirPsiNativeIrTextTestGenerated.java

@@ -480,6 +480,12 @@ public class FirPsiNativeIrTextTestGenerated extends AbstractFirPsiNativeIrTextT
             runTest("compiler/testData/ir/irText/declarations/localVarInDoWhile.kt");
         }
 
+        @Test
+        @TestMetadata("mainFunctionMangling.kt")
+        public void testMainFunctionMangling() throws Exception {
+            runTest("compiler/testData/ir/irText/declarations/mainFunctionMangling.kt");
+        }
+
         @Test
         @TestMetadata("packageLevelProperties.kt")
         public void testPackageLevelProperties() throws Exception {