Deprecate tailRecursive in favor of tailrec

compiler/testData/builtin-classes.txt

@@ -1249,6 +1249,10 @@ kotlin.annotation.target(allowedTargets = {AnnotationTarget.CLASSIFIER, Annotati
         internal final fun <get-names>(): kotlin.Array<out kotlin.String>
 }
 
+kotlin.annotation.target(allowedTargets = {AnnotationTarget.FUNCTION}) kotlin.annotation.annotation(retention = AnnotationRetention.SOURCE) public final class TailRecursive : kotlin.Annotation {
+    /*primary*/ public constructor TailRecursive()
+}
+
 public open class Throwable {
     /*primary*/ public constructor Throwable(/*0*/ message: kotlin.String? = ..., /*1*/ cause: kotlin.Throwable? = ...)
     public final fun getCause(): kotlin.Throwable?
@@ -1287,6 +1291,3 @@ kotlin.annotation.target(allowedTargets = {AnnotationTarget.VALUE_PARAMETER}) ko
 kotlin.annotation.target(allowedTargets = {AnnotationTarget.VALUE_PARAMETER}) kotlin.annotation.annotation(mustBeDocumented = true, retention = AnnotationRetention.RUNTIME) public final class noinline : kotlin.Annotation {
     /*primary*/ public constructor noinline()
 }
-kotlin.annotation.target(allowedTargets = {AnnotationTarget.FUNCTION}) kotlin.annotation.annotation(retention = AnnotationRetention.SOURCE) public final class tailRecursive : kotlin.Annotation {
-    /*primary*/ public constructor tailRecursive()
-}

compiler/testData/cfg/tailCalls/finally.instructions

@@ -1,5 +1,5 @@
 == test ==
-tailRecursive fun test() : Int {
+tailrec fun test() : Int {
     try {
         // do nothing
     } finally {

compiler/testData/cfg/tailCalls/finally.kt

@@ -1,4 +1,4 @@
-tailRecursive fun test() : Int {
+tailrec fun test() : Int {
     try {
         // do nothing
     } finally {

compiler/testData/cfg/tailCalls/finally.values

@@ -1,5 +1,5 @@
 == test ==
-tailRecursive fun test() : Int {
+tailrec fun test() : Int {
     try {
         // do nothing
     } finally {

compiler/testData/cfg/tailCalls/finallyWithReturn.instructions

@@ -1,5 +1,5 @@
 == test ==
-tailRecursive fun test() : Int {
+tailrec fun test() : Int {
     try {
         // do nothing
     } finally {

compiler/testData/cfg/tailCalls/finallyWithReturn.kt

@@ -1,4 +1,4 @@
-tailRecursive fun test() : Int {
+tailrec fun test() : Int {
     try {
         // do nothing
     } finally {

compiler/testData/cfg/tailCalls/finallyWithReturn.values

@@ -1,5 +1,5 @@
 == test ==
-tailRecursive fun test() : Int {
+tailrec fun test() : Int {
     try {
         // do nothing
     } finally {

compiler/testData/cfg/tailCalls/sum.instructions

@@ -1,5 +1,5 @@
 == sum ==
-tailRecursive fun sum(x: Long, sum: Long): Long {
+tailrec fun sum(x: Long, sum: Long): Long {
     if (x == 0.toLong()) return sum
     return sum(x - 1, sum + x)
 }

compiler/testData/cfg/tailCalls/sum.kt

@@ -1,4 +1,4 @@
-tailRecursive fun sum(x: Long, sum: Long): Long {
+tailrec fun sum(x: Long, sum: Long): Long {
     if (x == 0.toLong()) return sum
     return sum(x - 1, sum + x)
 }

compiler/testData/cfg/tailCalls/sum.values

@@ -1,5 +1,5 @@
 == sum ==
-tailRecursive fun sum(x: Long, sum: Long): Long {
+tailrec fun sum(x: Long, sum: Long): Long {
     if (x == 0.toLong()) return sum
     return sum(x - 1, sum + x)
 }

compiler/testData/cfg/tailCalls/try.instructions

@@ -1,5 +1,5 @@
 == foo ==
-tailRecursive fun foo() {
+tailrec fun foo() {
     try {
         return foo()
     }

compiler/testData/cfg/tailCalls/try.kt

@@ -1,4 +1,4 @@
-tailRecursive fun foo() {
+tailrec fun foo() {
     try {
         return foo()
     }

compiler/testData/cfg/tailCalls/try.values

@@ -1,5 +1,5 @@
 == foo ==
-tailRecursive fun foo() {
+tailrec fun foo() {
     try {
         return foo()
     }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/defaultArgs.kt

@@ -1,4 +1,4 @@
-tailRecursive fun test(x : Int = 0, e : Any = "a") {
+tailrec fun test(x : Int = 0, e : Any = "a") {
     if (!e.equals("a")) {
         throw IllegalArgumentException()
     }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/defaultArgs.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun test(/*0*/ x: kotlin.Int = ..., /*1*/ e: kotlin.Any = ...): kotlin.Unit
+kotlin.tailrec() internal fun test(/*0*/ x: kotlin.Int = ..., /*1*/ e: kotlin.Any = ...): kotlin.Unit

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/extensionTailCall.kt

@@ -1,5 +1,5 @@
 // !DIAGNOSTICS: -UNUSED_PARAMETER
-tailRecursive fun Int.foo(x: Int) {
+tailrec fun Int.foo(x: Int) {
     if (x == 0) return
     return 1.foo(x - 1)
 }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/extensionTailCall.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun kotlin.Int.foo(/*0*/ x: kotlin.Int): kotlin.Unit
+kotlin.tailrec() internal fun kotlin.Int.foo(/*0*/ x: kotlin.Int): kotlin.Unit

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/functionWithNoTails.kt

@@ -1,4 +1,4 @@
-<!NO_TAIL_CALLS_FOUND!>tailRecursive fun noTails()<!> {
+<!NO_TAIL_CALLS_FOUND!>tailrec fun noTails()<!> {
     // nothing here
 }
 

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/functionWithNoTails.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun noTails(): kotlin.Unit
+kotlin.tailrec() internal fun noTails(): kotlin.Unit

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/functionWithNonTailRecursions.kt

@@ -1,4 +1,4 @@
-tailRecursive fun badTails(x : Int) : Int {
+tailrec fun badTails(x : Int) : Int {
     if (x < 50 && x != 10 && x > 0) {
         return 1 + <!NON_TAIL_RECURSIVE_CALL!>badTails<!>(x - 1)
     }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/functionWithNonTailRecursions.txt

@@ -1,4 +1,4 @@
 package
 
-kotlin.tailRecursive() internal fun badTails(/*0*/ x: kotlin.Int): kotlin.Int
+kotlin.tailrec() internal fun badTails(/*0*/ x: kotlin.Int): kotlin.Int
 internal fun box(): kotlin.String

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/infixCall.kt

@@ -1,4 +1,4 @@
-tailRecursive fun Int.test(x : Int) : Int {
+tailrec fun Int.test(x : Int) : Int {
     if (this > 1) {
         return (this - 1) test x
     }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/infixCall.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun kotlin.Int.test(/*0*/ x: kotlin.Int): kotlin.Int
+kotlin.tailrec() internal fun kotlin.Int.test(/*0*/ x: kotlin.Int): kotlin.Int

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/infixRecursiveCall.kt

@@ -1,5 +1,5 @@
 // !DIAGNOSTICS: -UNUSED_PARAMETER
-tailRecursive fun Int.foo(x: Int) {
+tailrec fun Int.foo(x: Int) {
     if (x == 0) return
     val xx = x - 1
     return 1 foo xx

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/infixRecursiveCall.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun kotlin.Int.foo(/*0*/ x: kotlin.Int): kotlin.Unit
+kotlin.tailrec() internal fun kotlin.Int.foo(/*0*/ x: kotlin.Int): kotlin.Unit

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/insideElvis.kt

@@ -1,4 +1,4 @@
-tailRecursive fun test(counter : Int) : Int? {
+tailrec fun test(counter : Int) : Int? {
     if (counter < 0) return null
     if (counter == 0) return 777
 

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/insideElvis.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun test(/*0*/ counter: kotlin.Int): kotlin.Int?
+kotlin.tailrec() internal fun test(/*0*/ counter: kotlin.Int): kotlin.Int?

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/labeledThisReferences.kt

@@ -2,13 +2,13 @@
 
 class B {
     inner class C {
-        tailRecursive fun h(counter : Int) {
+        tailrec fun h(counter : Int) {
             if (counter > 0) {
                 this@C.h(counter - 1)
             }
         }
 
-        <!NO_TAIL_CALLS_FOUND!>tailRecursive fun h2(x : Any)<!> {
+        <!NO_TAIL_CALLS_FOUND!>tailrec fun h2(x : Any)<!> {
             this@B.h2("no recursion") // keep vigilance
         }
 

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/labeledThisReferences.txt

@@ -13,8 +13,8 @@ internal final class B {
     internal final inner class C {
         public constructor C()
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
-        kotlin.tailRecursive() internal final fun h(/*0*/ counter: kotlin.Int): kotlin.Unit
+        kotlin.tailrec() internal final fun h(/*0*/ counter: kotlin.Int): kotlin.Unit
-        kotlin.tailRecursive() internal final fun h2(/*0*/ x: kotlin.Any): kotlin.Unit
+        kotlin.tailrec() internal final fun h2(/*0*/ x: kotlin.Any): kotlin.Unit
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
     }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/loops.kt

@@ -1,4 +1,4 @@
-tailRecursive fun test(x : Int) : Int {
+tailrec fun test(x : Int) : Int {
     var z = if (x > 3) 3 else x
     while (z > 0) {
         if (z > 10) {

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/loops.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun test(/*0*/ x: kotlin.Int): kotlin.Int
+kotlin.tailrec() internal fun test(/*0*/ x: kotlin.Int): kotlin.Int

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/multilevelBlocks.kt

@@ -1,4 +1,4 @@
-tailRecursive fun test(x : Int) : Int {
+tailrec fun test(x : Int) : Int {
     if (x == 1) {
         if (x != 1) {
             <!NON_TAIL_RECURSIVE_CALL!>test<!>(0)

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/multilevelBlocks.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun test(/*0*/ x: kotlin.Int): kotlin.Int
+kotlin.tailrec() internal fun test(/*0*/ x: kotlin.Int): kotlin.Int

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/realIteratorFoldl.kt

@@ -1,4 +1,4 @@
-tailRecursive fun <T, A> Iterator<T>.foldl(acc : A, foldFunction : (e : T, acc : A) -> A) : A =
+tailrec fun <T, A> Iterator<T>.foldl(acc : A, foldFunction : (e : T, acc : A) -> A) : A =
         if (!hasNext()) acc
         else foldl(foldFunction(next(), acc), foldFunction)
 

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/realIteratorFoldl.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun </*0*/ T, /*1*/ A> kotlin.Iterator<T>.foldl(/*0*/ acc: A, /*1*/ foldFunction: (T, A) -> A): A
+kotlin.tailrec() internal fun </*0*/ T, /*1*/ A> kotlin.Iterator<T>.foldl(/*0*/ acc: A, /*1*/ foldFunction: (T, A) -> A): A

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/realStringEscape.kt

@@ -5,7 +5,7 @@ fun escapeChar(c : Char) : String? = when (c) {
     else -> "" + c
 }
 
-tailRecursive fun String.escape(i : Int = 0, result : StringBuilder = StringBuilder()) : String =
+tailrec fun String.escape(i : Int = 0, result : StringBuilder = StringBuilder()) : String =
         if (i == length()) result.toString()
         else escape(i + 1, result.append(escapeChar(get(i))))
 

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/realStringEscape.txt

@@ -2,4 +2,4 @@ package
 
 internal fun box(): kotlin.String
 internal fun escapeChar(/*0*/ c: kotlin.Char): kotlin.String?
-kotlin.tailRecursive() internal fun kotlin.String.escape(/*0*/ i: kotlin.Int = ..., /*1*/ result: java.lang.StringBuilder = ...): kotlin.String
+kotlin.tailrec() internal fun kotlin.String.escape(/*0*/ i: kotlin.Int = ..., /*1*/ result: java.lang.StringBuilder = ...): kotlin.String

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/realStringRepeat.kt

@@ -1,4 +1,4 @@
-tailRecursive fun String.repeat(num : Int, acc : StringBuilder = StringBuilder()) : String =
+tailrec fun String.repeat(num : Int, acc : StringBuilder = StringBuilder()) : String =
         if (num == 0) acc.toString()
         else repeat(num - 1, acc.append(this))
 

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/realStringRepeat.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun kotlin.String.repeat(/*0*/ num: kotlin.Int, /*1*/ acc: java.lang.StringBuilder = ...): kotlin.String
+kotlin.tailrec() internal fun kotlin.String.repeat(/*0*/ num: kotlin.Int, /*1*/ acc: java.lang.StringBuilder = ...): kotlin.String

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/recursiveCallInLambda.kt

@@ -1,5 +1,5 @@
 // !DIAGNOSTICS: -UNUSED_PARAMETER
-<!NO_TAIL_CALLS_FOUND!>tailRecursive fun foo()<!> {
+<!NO_TAIL_CALLS_FOUND!>tailrec fun foo()<!> {
     bar {
         <!NON_TAIL_RECURSIVE_CALL!>foo<!>()
     }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/recursiveCallInLambda.txt

@@ -2,4 +2,4 @@ package
 
 internal fun bar(/*0*/ a: kotlin.Any): kotlin.Unit
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun foo(): kotlin.Unit
+kotlin.tailrec() internal fun foo(): kotlin.Unit

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/recursiveCallInLocalFunction.kt

@@ -1,4 +1,4 @@
-<!NO_TAIL_CALLS_FOUND!>tailRecursive fun foo()<!> {
+<!NO_TAIL_CALLS_FOUND!>tailrec fun foo()<!> {
     fun bar() {
         <!NON_TAIL_RECURSIVE_CALL!>foo<!>()
     }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/recursiveCallInLocalFunction.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun foo(): kotlin.Unit
+kotlin.tailrec() internal fun foo(): kotlin.Unit

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/recursiveInnerFunction.kt

@@ -1,5 +1,5 @@
 fun test() {
-    @tailRecursive fun g3(counter : Int) {
+    @tailrec fun g3(counter : Int) {
         if (counter > 0) { g3(counter - 1) }
     }
     g3(1000000)

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/returnIf.kt

@@ -1,4 +1,4 @@
-tailRecursive fun test(x : Int) : Int {
+tailrec fun test(x : Int) : Int {
     return if (x == 1) {
         <!NON_TAIL_RECURSIVE_CALL!>test<!>(x - 1)
         1 + <!NON_TAIL_RECURSIVE_CALL!>test<!>(x - 1)

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/returnIf.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun test(/*0*/ x: kotlin.Int): kotlin.Int
+kotlin.tailrec() internal fun test(/*0*/ x: kotlin.Int): kotlin.Int

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/returnInCatch.kt

@@ -1,4 +1,4 @@
-<!NO_TAIL_CALLS_FOUND!>tailRecursive fun test(counter : Int) : Int<!> {
+<!NO_TAIL_CALLS_FOUND!>tailrec fun test(counter : Int) : Int<!> {
     if (counter == 0) return 0
 
     try {

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/returnInCatch.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun test(/*0*/ counter: kotlin.Int): kotlin.Int
+kotlin.tailrec() internal fun test(/*0*/ counter: kotlin.Int): kotlin.Int

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/returnInFinally.kt

@@ -1,4 +1,4 @@
-<!NO_TAIL_CALLS_FOUND!>tailRecursive fun test(counter : Int) : Int<!> {
+<!NO_TAIL_CALLS_FOUND!>tailrec fun test(counter : Int) : Int<!> {
     if (counter == 0) return 0
 
     try {

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/returnInFinally.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun test(/*0*/ counter: kotlin.Int): kotlin.Int
+kotlin.tailrec() internal fun test(/*0*/ counter: kotlin.Int): kotlin.Int

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/returnInIfInFinally.kt

@@ -1,4 +1,4 @@
-<!NO_TAIL_CALLS_FOUND!>tailRecursive fun test(counter : Int) : Int<!> {
+<!NO_TAIL_CALLS_FOUND!>tailrec fun test(counter : Int) : Int<!> {
     if (counter == 0) return 0
 
     try {

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/returnInIfInFinally.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun test(/*0*/ counter: kotlin.Int): kotlin.Int
+kotlin.tailrec() internal fun test(/*0*/ counter: kotlin.Int): kotlin.Int

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/returnInParentheses.kt

@@ -1,4 +1,4 @@
-tailRecursive fun foo(x: Int) {
+tailrec fun foo(x: Int) {
     if (x == 0) return
     (return foo(x - 1))
 }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/returnInParentheses.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun foo(/*0*/ x: kotlin.Int): kotlin.Unit
+kotlin.tailrec() internal fun foo(/*0*/ x: kotlin.Int): kotlin.Unit

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/returnInTry.kt

@@ -1,4 +1,4 @@
-<!NO_TAIL_CALLS_FOUND!>tailRecursive fun test(counter : Int) : Int<!> {
+<!NO_TAIL_CALLS_FOUND!>tailrec fun test(counter : Int) : Int<!> {
     if (counter == 0) return 0
 
     try {

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/returnInTry.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun test(/*0*/ counter: kotlin.Int): kotlin.Int
+kotlin.tailrec() internal fun test(/*0*/ counter: kotlin.Int): kotlin.Int

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/simpleBlock.kt

@@ -1,4 +1,4 @@
-tailRecursive fun test(x : Int) : Int =
+tailrec fun test(x : Int) : Int =
     if (x == 1) {
         <!NON_TAIL_RECURSIVE_CALL!>test<!>(x - 1)
         1 + <!NON_TAIL_RECURSIVE_CALL!>test<!>(x - 1)

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/simpleBlock.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun test(/*0*/ x: kotlin.Int): kotlin.Int
+kotlin.tailrec() internal fun test(/*0*/ x: kotlin.Int): kotlin.Int

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/simpleReturn.kt

@@ -1,4 +1,4 @@
-tailRecursive fun test(x : Int) : Int {
+tailrec fun test(x : Int) : Int {
     if (x == 10) {
         return 1 + <!NON_TAIL_RECURSIVE_CALL!>test<!>(x - 1)
     }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/simpleReturn.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun test(/*0*/ x: kotlin.Int): kotlin.Int
+kotlin.tailrec() internal fun test(/*0*/ x: kotlin.Int): kotlin.Int

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/simpleReturnWithElse.kt

@@ -1,4 +1,4 @@
-tailRecursive fun test(x : Int) : Int {
+tailrec fun test(x : Int) : Int {
     if (x == 0) {
         return 0
     } else if (x == 10) {

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/simpleReturnWithElse.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun test(/*0*/ x: kotlin.Int): kotlin.Int
+kotlin.tailrec() internal fun test(/*0*/ x: kotlin.Int): kotlin.Int

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/sum.kt

@@ -1,4 +1,4 @@
-tailRecursive fun sum(x: Long, sum: Long): Long {
+tailrec fun sum(x: Long, sum: Long): Long {
     if (x == 0.toLong()) return sum
     return sum(x - 1, sum + x)
 }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/sum.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun sum(/*0*/ x: kotlin.Long, /*1*/ sum: kotlin.Long): kotlin.Long
+kotlin.tailrec() internal fun sum(/*0*/ x: kotlin.Long, /*1*/ sum: kotlin.Long): kotlin.Long

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/tailCallInBlockInParentheses.kt

@@ -1,4 +1,4 @@
-tailRecursive fun foo(x: Int) {
+tailrec fun foo(x: Int) {
     return if (x > 0) {
         (foo(x - 1))
     }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/tailCallInBlockInParentheses.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun foo(/*0*/ x: kotlin.Int): kotlin.Unit
+kotlin.tailrec() internal fun foo(/*0*/ x: kotlin.Int): kotlin.Unit

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/tailCallInParentheses.kt

@@ -1,4 +1,4 @@
-tailRecursive fun foo(x: Int) {
+tailrec fun foo(x: Int) {
     if (x == 0) return
     return (foo(x - 1))
 }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/tailCallInParentheses.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun foo(/*0*/ x: kotlin.Int): kotlin.Unit
+kotlin.tailrec() internal fun foo(/*0*/ x: kotlin.Int): kotlin.Unit

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/tailRecursionInFinally.kt

@@ -1,4 +1,4 @@
-<!NO_TAIL_CALLS_FOUND!>tailRecursive fun test(go: Boolean) : Unit<!> {
+<!NO_TAIL_CALLS_FOUND!>tailrec fun test(go: Boolean) : Unit<!> {
     if (!go) return
     try {
         <!TAIL_RECURSION_IN_TRY_IS_NOT_SUPPORTED!>test<!>(false)

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/tailRecursionInFinally.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun test(/*0*/ go: kotlin.Boolean): kotlin.Unit
+kotlin.tailrec() internal fun test(/*0*/ go: kotlin.Boolean): kotlin.Unit

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/thisReferences.kt

@@ -1,17 +1,17 @@
 class A {
-    tailRecursive fun f1(c : Int) {
+    tailrec fun f1(c : Int) {
         if (c > 0) {
             this.f1(c - 1)
         }
     }
 
-    tailRecursive fun f2(c : Int) {
+    tailrec fun f2(c : Int) {
         if (c > 0) {
             f2(c - 1)
         }
     }
 
-    <!NO_TAIL_CALLS_FOUND!>tailRecursive fun f3(a : A)<!> {
+    <!NO_TAIL_CALLS_FOUND!>tailrec fun f3(a : A)<!> {
         a.<!NON_TAIL_RECURSIVE_CALL!>f3<!>(a) // non-tail recursion, could be potentially resolved by condition if (a == this) f3() else a.f3()
     }
 }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/thisReferences.txt

@@ -5,9 +5,9 @@ internal fun box(): kotlin.String
 internal final class A {
     public constructor A()
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
-    kotlin.tailRecursive() internal final fun f1(/*0*/ c: kotlin.Int): kotlin.Unit
+    kotlin.tailrec() internal final fun f1(/*0*/ c: kotlin.Int): kotlin.Unit
-    kotlin.tailRecursive() internal final fun f2(/*0*/ c: kotlin.Int): kotlin.Unit
+    kotlin.tailrec() internal final fun f2(/*0*/ c: kotlin.Int): kotlin.Unit
-    kotlin.tailRecursive() internal final fun f3(/*0*/ a: A): kotlin.Unit
+    kotlin.tailrec() internal final fun f3(/*0*/ a: A): kotlin.Unit
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/unitBlocks.kt

@@ -1,4 +1,4 @@
-tailRecursive fun test(x : Int) : Unit {
+tailrec fun test(x : Int) : Unit {
     if (x == 1) {
         test(x - 1)
     } else if (x == 2) {

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/unitBlocks.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun test(/*0*/ x: kotlin.Int): kotlin.Unit
+kotlin.tailrec() internal fun test(/*0*/ x: kotlin.Int): kotlin.Unit

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/whenWithCondition.kt

@@ -1,4 +1,4 @@
-tailRecursive fun withWhen(counter : Int) : Int =
+tailrec fun withWhen(counter : Int) : Int =
         when (counter) {
             0 -> counter
             50 -> 1 + <!NON_TAIL_RECURSIVE_CALL!>withWhen<!>(counter - 1)

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/whenWithCondition.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun withWhen(/*0*/ counter: kotlin.Int): kotlin.Int
+kotlin.tailrec() internal fun withWhen(/*0*/ counter: kotlin.Int): kotlin.Int

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/whenWithInRange.kt

@@ -1,6 +1,6 @@
 // !DIAGNOSTICS: -UNUSED_PARAMETER
 
-tailRecursive fun withWhen(counter : Int, d : Any) : Int =
+tailrec fun withWhen(counter : Int, d : Any) : Int =
         when (counter) {
             0 -> counter
             1, 2 -> withWhen(counter - 1, "1,2")

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/whenWithInRange.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun withWhen(/*0*/ counter: kotlin.Int, /*1*/ d: kotlin.Any): kotlin.Int
+kotlin.tailrec() internal fun withWhen(/*0*/ counter: kotlin.Int, /*1*/ d: kotlin.Any): kotlin.Int

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/whenWithIs.kt

@@ -1,4 +1,4 @@
-tailRecursive fun withWhen(counter : Int, d : Any) : Int =
+tailrec fun withWhen(counter : Int, d : Any) : Int =
     if (counter == 0) {
         0
     }

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/whenWithIs.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun withWhen(/*0*/ counter: kotlin.Int, /*1*/ d: kotlin.Any): kotlin.Int
+kotlin.tailrec() internal fun withWhen(/*0*/ counter: kotlin.Int, /*1*/ d: kotlin.Any): kotlin.Int

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/whenWithoutCondition.kt

@@ -1,4 +1,4 @@
-tailRecursive fun withWhen2(counter : Int) : Int =
+tailrec fun withWhen2(counter : Int) : Int =
         when {
             counter == 0 -> counter
             counter == 50 -> 1 + <!NON_TAIL_RECURSIVE_CALL!>withWhen2<!>(counter - 1)

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/whenWithoutCondition.txt

@@ -1,4 +1,4 @@
 package
 
 internal fun box(): kotlin.String
-kotlin.tailRecursive() internal fun withWhen2(/*0*/ counter: kotlin.Int): kotlin.Int
+kotlin.tailrec() internal fun withWhen2(/*0*/ counter: kotlin.Int): kotlin.Int

core/builtins/src/kotlin/Annotations.kt

@@ -78,6 +78,9 @@ public annotation(retention = SOURCE) class Suppress(vararg val names: String)
 target(FUNCTION)
 public annotation(retention = SOURCE) class tailRecursive
 
+target(FUNCTION)
+public annotation(retention = SOURCE) class tailrec
+
 /**
  * Hides the annotated function, property or constructor from the overload resolution,
  * thus preventing its usages from newly compiled code, but keeps compiling it

core/descriptors/src/org/jetbrains/kotlin/builtins/KotlinBuiltIns.java

@@ -171,7 +171,8 @@ public class KotlinBuiltIns {
 
         public final FqName data = fqName("data");
         public final FqName deprecated = fqName("deprecated");
-        public final FqName tailRecursive = fqName("tailRecursive");
+        public final FqName tailRecursive = fqName("tailrec");
+        public final FqName tailRecursiveDeprecated = fqName("tailRecursive");
         public final FqName inline = fqName("inline");
         public final FqName noinline = fqName("noinline");
         public final FqName inlineOptions = fqName("inlineOptions");
@@ -1031,7 +1032,8 @@ public class KotlinBuiltIns {
     }
 
     public static boolean isTailRecursive(@NotNull DeclarationDescriptor declarationDescriptor) {
-        return containsAnnotation(declarationDescriptor, FQ_NAMES.tailRecursive);
+        return containsAnnotation(declarationDescriptor, FQ_NAMES.tailRecursive)
+               || containsAnnotation(declarationDescriptor, FQ_NAMES.tailRecursiveDeprecated);
     }
 
     /** Checks that the symbol represented by the descriptor is annotated with the {@code kotlin.noinline} annotation */