Smart casts for local variables not captured in a closure and not changed in a loop, see #KT-3175.

isLocalVariable added. Assignment / initialization analysis.
Control whether a variable is changed in a loop at the beginning and at the end of the loop.
Control whether a variable is captured in a closure. #KT-3175  Fixed. #KT-2266  Fixed.
Tests for variable null safety and for variables is/as operations.
Loop / closure / variable property tests are included.
Old tests changed in accordance with KT-3175. In particular, all three of testSmartcastImpossible were fixed.

compiler/testData/diagnostics/tests/smartCasts/inference/kt4009.kt

@@ -10,10 +10,11 @@ fun foo1(e: PsiElement) {
     var first = true
     while (current != null) {
         if (current is JetExpression && first) {
-            println(current!!.getText()) // error: smart cast not possible. But it's not needed in fact!
+            // Smartcast is possible here
+            println(<!DEBUG_INFO_SMARTCAST!>current<!>.getText())
         }
 
-        current = current?.getParent()
+        current = <!DEBUG_INFO_SMARTCAST!>current<!>.getParent()
     }
 }
 

compiler/testData/diagnostics/tests/smartCasts/variables/assignment.kt

@@ -0,0 +1,10 @@
+fun foo() {
+    var v: Any = 42
+    v.<!UNRESOLVED_REFERENCE!>length<!>()
+    v = "abc"
+    <!DEBUG_INFO_SMARTCAST!>v<!>.length()
+    v = 42
+    v.<!UNRESOLVED_REFERENCE!>length<!>()
+    v = "abc"
+    <!DEBUG_INFO_SMARTCAST!>v<!>.length()
+}

compiler/testData/diagnostics/tests/smartCasts/variables/assignment.txt

@@ -0,0 +1,3 @@
+package
+
+internal fun foo(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/variables/doWhileWithMiddleBreak.kt

@@ -0,0 +1,12 @@
+fun x(): Boolean { return true }
+
+public fun foo(pp: Any): Int {
+    var p = pp
+    do {
+        (p as String).length()
+        if (p == "abc") break
+        p = 42
+    } while (!x())
+    // Smart cast is NOT possible here
+    return p.<!UNRESOLVED_REFERENCE!>length<!>()
+}

compiler/testData/diagnostics/tests/smartCasts/variables/doWhileWithMiddleBreak.txt

@@ -0,0 +1,4 @@
+package
+
+public fun foo(/*0*/ pp: kotlin.Any): kotlin.Int
+internal fun x(): kotlin.Boolean

compiler/testData/diagnostics/tests/smartCasts/variables/ifElseBlockInsideDoWhile.kt

@@ -0,0 +1,15 @@
+public fun foo(xx: Any): Int {
+    var x = xx
+    do {
+        var y: Any
+        // After the check, smart cast should work
+        if (x is String) {
+            y = "xyz"
+        } else {
+            y = "abc"
+        }
+        // y!! in both branches
+        <!DEBUG_INFO_SMARTCAST!>y<!>.length()
+    } while (!(x is String))
+    return <!DEBUG_INFO_SMARTCAST!>x<!>.length()
+}

compiler/testData/diagnostics/tests/smartCasts/variables/ifElseBlockInsideDoWhile.txt

@@ -0,0 +1,3 @@
+package
+
+public fun foo(/*0*/ xx: kotlin.Any): kotlin.Int

compiler/testData/diagnostics/tests/smartCasts/variables/ifElseBlockInsideDoWhileWithBreak.kt

@@ -0,0 +1,16 @@
+public fun foo(xx: Any): Int {
+    var x = xx
+    do {
+        var y: Any
+        // After the check, smart cast should work
+        if (x is String) {
+            break
+        } else {
+            y = "abc"
+        }
+        // y!! in both branches
+        <!DEBUG_INFO_SMARTCAST!>y<!>.length()
+    } while (true)
+    // We could have smart cast here but with break it's hard to detect
+    return x.<!UNRESOLVED_REFERENCE!>length<!>()
+}

compiler/testData/diagnostics/tests/smartCasts/variables/ifElseBlockInsideDoWhileWithBreak.txt

@@ -0,0 +1,3 @@
+package
+
+public fun foo(/*0*/ xx: kotlin.Any): kotlin.Int

compiler/testData/diagnostics/tests/smartCasts/variables/ifVarIs.kt

@@ -0,0 +1,9 @@
+public fun bar(s: String) {
+    System.out.println("Length of $s is ${s.length()}")
+}
+
+public fun foo() {
+    var s: Any = "not null"
+    if (s is String) 
+        bar(<!DEBUG_INFO_SMARTCAST!>s<!>)
+}

compiler/testData/diagnostics/tests/smartCasts/variables/ifVarIs.txt

@@ -0,0 +1,4 @@
+package
+
+public fun bar(/*0*/ s: kotlin.String): kotlin.Unit
+public fun foo(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/variables/ifVarIsAnd.kt

@@ -0,0 +1,13 @@
+// See KT-5737
+fun get(): Any {
+    return "abc"
+}
+
+fun foo(): Int {
+    var ss: Any = get()
+
+    return if (ss is String && <!DEBUG_INFO_SMARTCAST!>ss<!>.length() > 0)
+        1
+    else
+        0
+}

compiler/testData/diagnostics/tests/smartCasts/variables/ifVarIsAnd.txt

@@ -0,0 +1,4 @@
+package
+
+internal fun foo(): kotlin.Int
+internal fun get(): kotlin.Any

compiler/testData/diagnostics/tests/smartCasts/variables/ifVarIsChanged.kt

@@ -0,0 +1,11 @@
+public fun bar(s: String) {
+    System.out.println("Length of $s is ${s.length()}")
+}
+
+public fun foo() {
+    var s: Any = "not null"
+    if (s is String) {
+        s = 42
+        bar(<!TYPE_MISMATCH!>s<!>)
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/variables/ifVarIsChanged.txt

@@ -0,0 +1,4 @@
+package
+
+public fun bar(/*0*/ s: kotlin.String): kotlin.Unit
+public fun foo(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/variables/infix.kt

@@ -0,0 +1,11 @@
+// See KT-774
+fun box() : Int {
+    var a : Any = 1
+    var d = 1
+
+    if (a is Int) {
+        return <!DEBUG_INFO_SMARTCAST!>a<!> + d
+    } else {
+        return 2
+    }
+} 

compiler/testData/diagnostics/tests/smartCasts/variables/infix.txt

@@ -0,0 +1,3 @@
+package
+
+internal fun box(): kotlin.Int

compiler/testData/diagnostics/tests/smartCasts/variables/initialization.kt

@@ -0,0 +1,8 @@
+fun foo() {
+    var v: Any = "xyz"
+    // It is possible in principle to provide smart cast here
+    // but now we decide that v is Any
+    v.<!UNRESOLVED_REFERENCE!>length<!>()
+    v = 42
+    v.<!UNRESOLVED_REFERENCE!>length<!>()
+}

compiler/testData/diagnostics/tests/smartCasts/variables/initialization.txt

@@ -0,0 +1,3 @@
+package
+
+internal fun foo(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/variables/property.kt

@@ -0,0 +1,10 @@
+class MyClass(var p: String?)
+
+fun bar(s: String): Int {
+    return s.length()
+}
+
+fun foo(m: MyClass): Int {
+    m.p = "xyz"
+    return bar(<!SMARTCAST_IMPOSSIBLE!>m.p<!>)
+}

compiler/testData/diagnostics/tests/smartCasts/variables/property.txt

@@ -0,0 +1,12 @@
+package
+
+internal fun bar(/*0*/ s: kotlin.String): kotlin.Int
+internal fun foo(/*0*/ m: MyClass): kotlin.Int
+
+internal final class MyClass {
+    public constructor MyClass(/*0*/ p: kotlin.String?)
+    internal final var p: kotlin.String?
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/variables/propertyNotNeeded.kt

@@ -0,0 +1,10 @@
+class MyClass(var p: String?)
+
+fun bar(s: String?): Int {
+    return s?.length() ?: -1
+}
+
+fun foo(m: MyClass): Int {
+    m.p = "xyz"
+    return bar(m.p)
+}

compiler/testData/diagnostics/tests/smartCasts/variables/propertyNotNeeded.txt

@@ -0,0 +1,12 @@
+package
+
+internal fun bar(/*0*/ s: kotlin.String?): kotlin.Int
+internal fun foo(/*0*/ m: MyClass): kotlin.Int
+
+internal final class MyClass {
+    public constructor MyClass(/*0*/ p: kotlin.String?)
+    internal final var p: kotlin.String?
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/variables/propertySubtype.kt

@@ -0,0 +1,10 @@
+class MyClass(var p: Any)
+
+fun bar(s: Any): Int {
+    return s.hashCode()
+}
+
+fun foo(m: MyClass): Int {
+    m.p = "xyz"
+    return bar(m.p)
+}

compiler/testData/diagnostics/tests/smartCasts/variables/propertySubtype.txt

@@ -0,0 +1,12 @@
+package
+
+internal fun bar(/*0*/ s: kotlin.Any): kotlin.Int
+internal fun foo(/*0*/ m: MyClass): kotlin.Int
+
+internal final class MyClass {
+    public constructor MyClass(/*0*/ p: kotlin.Any)
+    internal final var p: kotlin.Any
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/variables/propertySubtypeInMember.kt

@@ -0,0 +1,10 @@
+fun bar(s: Any): Int {
+    return s.hashCode()
+}
+
+class MyClass(var p: Any) {
+    fun foo(): Int {
+        p = "xyz"
+        return bar(p)
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/variables/propertySubtypeInMember.txt

@@ -0,0 +1,12 @@
+package
+
+internal fun bar(/*0*/ s: kotlin.Any): kotlin.Int
+
+internal final class MyClass {
+    public constructor MyClass(/*0*/ p: kotlin.Any)
+    internal final var p: kotlin.Any
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    internal final fun foo(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/variables/propertySubtypeInMemberCheck.kt

@@ -0,0 +1,13 @@
+fun bar(s: Any): Int {
+    return s.hashCode()
+}
+
+class MyClass(var p: Any) {
+    fun foo(): Int {
+        p = "xyz"
+        if (p is String) {
+            return bar(p)
+        }
+        return -1
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/variables/propertySubtypeInMemberCheck.txt

@@ -0,0 +1,12 @@
+package
+
+internal fun bar(/*0*/ s: kotlin.Any): kotlin.Int
+
+internal final class MyClass {
+    public constructor MyClass(/*0*/ p: kotlin.Any)
+    internal final var p: kotlin.Any
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    internal final fun foo(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/variables/varAsUse.kt

@@ -0,0 +1,9 @@
+fun get(): Any {
+    return ""
+}
+
+fun foo(): Int {
+    var c: Any = get()
+    (c as String).length()
+    return <!DEBUG_INFO_SMARTCAST!>c<!>.length() // Previous line should make as unnecessary here.
+}

compiler/testData/diagnostics/tests/smartCasts/variables/varAsUse.txt

@@ -0,0 +1,4 @@
+package
+
+internal fun foo(): kotlin.Int
+internal fun get(): kotlin.Any

compiler/testData/diagnostics/tests/smartCasts/variables/varChangedInLoop.kt

@@ -0,0 +1,9 @@
+public fun foo() {
+    var i: Any = 1
+    if (i is Int) {
+        while (i != 10) {
+            <!UNUSED_CHANGED_VALUE!>i<!UNRESOLVED_REFERENCE!>++<!><!>      // Here smart cast should not be performed due to a successor
+            i = ""
+        }
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/variables/varChangedInLoop.txt

@@ -0,0 +1,3 @@
+package
+
+public fun foo(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/variables/varNotChangedInLoop.kt

@@ -0,0 +1,8 @@
+public fun foo() {
+    var i: Any = 1
+    if (i is Int) {
+        while (i != 10) {
+            <!DEBUG_INFO_SMARTCAST!>i<!>++
+        }
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/variables/varNotChangedInLoop.txt

@@ -0,0 +1,3 @@
+package
+
+public fun foo(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/variables/whileTrue.kt

@@ -0,0 +1,13 @@
+fun x(): Boolean { return true }
+
+public fun foo(pp: Any): Int {
+    var p = pp
+    while(true) {
+        (p as String).length()
+        if (x()) break
+        p = 42
+    }
+    // Smart cast is NOT possible here
+    // (we could provide it but p = 42 makes it difficult to understand)
+    return p.<!UNRESOLVED_REFERENCE!>length<!>()
+}

compiler/testData/diagnostics/tests/smartCasts/variables/whileTrue.txt

@@ -0,0 +1,4 @@
+package
+
+public fun foo(/*0*/ pp: kotlin.Any): kotlin.Int
+internal fun x(): kotlin.Boolean

compiler/testData/diagnostics/tests/smartCasts/variables/whileWithBreak.kt

@@ -0,0 +1,17 @@
+fun String.next(): String {
+    return "abc"
+}
+
+fun list(start: String) {
+    var e: Any? = start
+    if (e==null) return
+    while (e is String) {
+        // Smart cast due to the loop condition
+        if (<!DEBUG_INFO_SMARTCAST!>e<!>.length() == 0)
+            break
+        // We still have smart cast here despite of a break
+        e = <!DEBUG_INFO_SMARTCAST!>e<!>.next()
+    }
+    // e can never be null but we do not know it
+    e<!UNSAFE_CALL!>.<!>hashCode()
+}

compiler/testData/diagnostics/tests/smartCasts/variables/whileWithBreak.txt

@@ -0,0 +1,4 @@
+package
+
+internal fun list(/*0*/ start: kotlin.String): kotlin.Unit
+internal fun kotlin.String.next(): kotlin.String

compiler/testData/diagnostics/tests/smartCasts/varnotnull/assignment.kt

@@ -0,0 +1,10 @@
+fun foo() {
+    var v: String? = null
+    v<!UNSAFE_CALL!>.<!>length()
+    v = "abc"
+    <!DEBUG_INFO_SMARTCAST!>v<!>.length()
+    v = null
+    v<!UNSAFE_CALL!>.<!>length()
+    v = "abc"
+    <!DEBUG_INFO_SMARTCAST!>v<!>.length()
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/assignment.txt

@@ -0,0 +1,3 @@
+package
+
+internal fun foo(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/varnotnull/doWhileWithBreak.kt

@@ -0,0 +1,21 @@
+data class SomeObject(val n: SomeObject?) {
+    fun doSomething(): Boolean = true
+    fun next(): SomeObject? = n    
+}
+
+
+fun list(start: SomeObject) {
+    var e: SomeObject?
+    e = start
+    do {
+        // In theory smart cast is possible here
+        // But in practice we have a loop with changing e
+        // ?: should we "or" entrance type info with condition type info?
+        if (!e<!UNSAFE_CALL!>.<!>doSomething())
+            break
+        // Smart cast here is still not possible
+        e = e<!UNSAFE_CALL!>.<!>next()
+    } while (e != null)
+    // e can be null because of next()
+    e<!UNSAFE_CALL!>.<!>doSomething()
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/doWhileWithBreak.txt

@@ -0,0 +1,15 @@
+package
+
+internal fun list(/*0*/ start: SomeObject): kotlin.Unit
+
+kotlin.data() internal final class SomeObject {
+    public constructor SomeObject(/*0*/ n: SomeObject?)
+    internal final val n: SomeObject?
+    internal final /*synthesized*/ fun component1(): SomeObject?
+    public final /*synthesized*/ fun copy(/*0*/ n: SomeObject? = ...): SomeObject
+    internal final fun doSomething(): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    internal final fun next(): SomeObject?
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/doWhileWithMiddleBreak.kt

@@ -0,0 +1,12 @@
+fun x(): Boolean { return true }
+
+public fun foo(pp: String?): Int {
+    var p = pp
+    do {
+        p!!.length()
+        if (p == "abc") break
+        p = null
+    } while (!x())
+    // Smart cast is NOT possible here
+    return p<!UNSAFE_CALL!>.<!>length()
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/doWhileWithMiddleBreak.txt

@@ -0,0 +1,4 @@
+package
+
+public fun foo(/*0*/ pp: kotlin.String?): kotlin.Int
+internal fun x(): kotlin.Boolean

compiler/testData/diagnostics/tests/smartCasts/varnotnull/forEach.kt

@@ -0,0 +1,16 @@
+data class SomeObject(val n: SomeObject?) {
+    fun doSomething() {}
+    fun next(): SomeObject? = n    
+}
+
+
+fun list(start: SomeObject): SomeObject {
+    var e: SomeObject? = start
+    for (i in 0..42) {
+        // Unsafe calls because of nullable e at the beginning
+        e<!UNSAFE_CALL!>.<!>doSomething()
+        e = e<!UNSAFE_CALL!>.<!>next()
+    }
+    // Smart cast is not possible here due to next()
+    return <!TYPE_MISMATCH!>e<!>
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/forEach.txt

@@ -0,0 +1,15 @@
+package
+
+internal fun list(/*0*/ start: SomeObject): SomeObject
+
+kotlin.data() internal final class SomeObject {
+    public constructor SomeObject(/*0*/ n: SomeObject?)
+    internal final val n: SomeObject?
+    internal final /*synthesized*/ fun component1(): SomeObject?
+    public final /*synthesized*/ fun copy(/*0*/ n: SomeObject? = ...): SomeObject
+    internal final fun doSomething(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    internal final fun next(): SomeObject?
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/forEachWithBreak.kt

@@ -0,0 +1,17 @@
+data class SomeObject(val n: SomeObject?) {
+    fun doSomething() {}
+    fun next(): SomeObject? = n    
+}
+
+
+fun list(start: SomeObject): SomeObject {
+    var e: SomeObject? = start
+    for (i in 0..42) {
+        if (e == null)
+            break
+        // Smart casts are possible because of the break before
+        <!DEBUG_INFO_SMARTCAST!>e<!>.doSomething()
+        e = <!DEBUG_INFO_SMARTCAST!>e<!>.next()
+    }
+    return <!TYPE_MISMATCH!>e<!>
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/forEachWithBreak.txt

@@ -0,0 +1,15 @@
+package
+
+internal fun list(/*0*/ start: SomeObject): SomeObject
+
+kotlin.data() internal final class SomeObject {
+    public constructor SomeObject(/*0*/ n: SomeObject?)
+    internal final val n: SomeObject?
+    internal final /*synthesized*/ fun component1(): SomeObject?
+    public final /*synthesized*/ fun copy(/*0*/ n: SomeObject? = ...): SomeObject
+    internal final fun doSomething(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    internal final fun next(): SomeObject?
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/forEachWithContinue.kt

@@ -0,0 +1,17 @@
+data class SomeObject(val n: SomeObject?) {
+    fun doSomething() {}
+    fun next(): SomeObject? = n    
+}
+
+
+fun list(start: SomeObject): SomeObject {
+    var e: SomeObject? = start
+    for (i in 0..42) {
+        if (e == null)
+            continue
+        // Smart casts are possible because of the continue before
+        <!DEBUG_INFO_SMARTCAST!>e<!>.doSomething()
+        e = <!DEBUG_INFO_SMARTCAST!>e<!>.next()
+    }
+    return <!TYPE_MISMATCH!>e<!>
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/forEachWithContinue.txt

@@ -0,0 +1,15 @@
+package
+
+internal fun list(/*0*/ start: SomeObject): SomeObject
+
+kotlin.data() internal final class SomeObject {
+    public constructor SomeObject(/*0*/ n: SomeObject?)
+    internal final val n: SomeObject?
+    internal final /*synthesized*/ fun component1(): SomeObject?
+    public final /*synthesized*/ fun copy(/*0*/ n: SomeObject? = ...): SomeObject
+    internal final fun doSomething(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    internal final fun next(): SomeObject?
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/ifVarNotNull.kt

@@ -0,0 +1,9 @@
+public fun fooNotNull(s: String) {
+    System.out.println("Length of $s is ${s.length()}")
+}
+
+public fun foo() {
+    var s: String? = "not null"
+    if (s != null)
+        fooNotNull(<!DEBUG_INFO_SMARTCAST!>s<!>)
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/ifVarNotNull.txt

@@ -0,0 +1,4 @@
+package
+
+public fun foo(): kotlin.Unit
+public fun fooNotNull(/*0*/ s: kotlin.String): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/varnotnull/ifVarNotNullAnd.kt

@@ -0,0 +1,13 @@
+// See KT-5737
+fun get(): String? {
+    return "abc"
+}
+
+fun foo(): Int {
+    var ss:String? = get()
+
+    return if (ss != null && <!DEBUG_INFO_SMARTCAST!>ss<!>.length() > 0)
+        1
+    else
+        0
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/ifVarNotNullAnd.txt

@@ -0,0 +1,4 @@
+package
+
+internal fun foo(): kotlin.Int
+internal fun get(): kotlin.String?

compiler/testData/diagnostics/tests/smartCasts/varnotnull/ifVarNullElse.kt

@@ -0,0 +1,12 @@
+public fun fooNotNull(s: String) {
+    System.out.println("Length of $s is ${s.length()}")
+}
+
+public fun foo() {
+    var s: String? = "not null"
+    if (s == null) {
+        // Coming soon
+    } else {
+        fooNotNull(<!DEBUG_INFO_SMARTCAST!>s<!>)
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/ifVarNullElse.txt

@@ -0,0 +1,4 @@
+package
+
+public fun foo(): kotlin.Unit
+public fun fooNotNull(/*0*/ s: kotlin.String): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/varnotnull/ifVarNullReturn.kt

@@ -0,0 +1,11 @@
+public fun fooNotNull(s: String) {
+    System.out.println("Length of $s is ${s.length()}")
+}
+
+public fun foo() {
+    var s: String? = "not null"
+    if (s == null) {
+        return
+    }
+    fooNotNull(<!DEBUG_INFO_SMARTCAST!>s<!>)
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/ifVarNullReturn.txt

@@ -0,0 +1,4 @@
+package
+
+public fun foo(): kotlin.Unit
+public fun fooNotNull(/*0*/ s: kotlin.String): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/varnotnull/inference.kt

@@ -0,0 +1,21 @@
+// See KT-969
+fun f() {
+  var s: String?
+  s = "a"
+  var s1 = "" // String – ?
+  if (<!SENSELESS_COMPARISON!>s != null<!>) {    // Redundant
+    s1.length()
+    // We can do smartcast here and below
+    s1 = <!DEBUG_INFO_SMARTCAST!>s<!>.toString() // return String?
+    s1.length()
+    s1 = <!DEBUG_INFO_SMARTCAST!>s<!>
+    s1.length()
+    // It's just an assignment without smartcast
+    val s2 = s
+    // But smartcast can be done here
+    <!DEBUG_INFO_SMARTCAST!>s2<!>.length()
+    // And also here
+    val s3 = <!DEBUG_INFO_SMARTCAST!>s<!>.toString()
+    s3.length()
+  }
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/inference.txt

@@ -0,0 +1,3 @@
+package
+
+internal fun f(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/varnotnull/infiniteWhileWithBreak.kt

@@ -0,0 +1,20 @@
+data class SomeObject(val n: SomeObject?) {
+    fun doSomething(): Boolean = true
+    fun next(): SomeObject? = n    
+}
+
+
+fun list(start: SomeObject) {
+    var e: SomeObject?
+    e = start
+    // This comparison is senseless
+    while (e != null) {
+        // Smart cast because of the loop condition
+        if (!<!DEBUG_INFO_SMARTCAST!>e<!>.doSomething())
+            break
+        // We still have smart cast here despite of a break
+        e = <!DEBUG_INFO_SMARTCAST!>e<!>.next()
+    } 
+    // e can be null because of next()
+    e<!UNSAFE_CALL!>.<!>doSomething()
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/infiniteWhileWithBreak.txt

@@ -0,0 +1,15 @@
+package
+
+internal fun list(/*0*/ start: SomeObject): kotlin.Unit
+
+kotlin.data() internal final class SomeObject {
+    public constructor SomeObject(/*0*/ n: SomeObject?)
+    internal final val n: SomeObject?
+    internal final /*synthesized*/ fun component1(): SomeObject?
+    public final /*synthesized*/ fun copy(/*0*/ n: SomeObject? = ...): SomeObject
+    internal final fun doSomething(): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    internal final fun next(): SomeObject?
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/infix.kt

@@ -0,0 +1,11 @@
+// See KT-774
+fun box() : Int {
+    var a : Int? = 1
+    var d = 1
+
+    if (a == null) {
+        return 2
+    } else {
+        return <!DEBUG_INFO_SMARTCAST!>a<!> + d
+    }
+} 

compiler/testData/diagnostics/tests/smartCasts/varnotnull/infix.txt

@@ -0,0 +1,3 @@
+package
+
+internal fun box(): kotlin.Int

compiler/testData/diagnostics/tests/smartCasts/varnotnull/initialization.kt

@@ -0,0 +1,7 @@
+fun foo() {
+    var v: String? = "xyz"
+    // It is possible in principle to provide smart cast here
+    v<!UNSAFE_CALL!>.<!>length()
+    v = null
+    v<!UNSAFE_CALL!>.<!>length()
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/initialization.txt

@@ -0,0 +1,3 @@
+package
+
+internal fun foo(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/varnotnull/iterations.kt

@@ -0,0 +1,14 @@
+data class SomeObject(val n: SomeObject?) {
+    fun doSomething() {}
+    fun next(): SomeObject? = n    
+}
+
+
+fun list(start: SomeObject) {
+    var e: SomeObject? = start
+    while (e != null) {
+        // While condition makes both smart casts possible
+        <!DEBUG_INFO_SMARTCAST!>e<!>.doSomething()
+        e = <!DEBUG_INFO_SMARTCAST!>e<!>.next()
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/iterations.txt

@@ -0,0 +1,15 @@
+package
+
+internal fun list(/*0*/ start: SomeObject): kotlin.Unit
+
+kotlin.data() internal final class SomeObject {
+    public constructor SomeObject(/*0*/ n: SomeObject?)
+    internal final val n: SomeObject?
+    internal final /*synthesized*/ fun component1(): SomeObject?
+    public final /*synthesized*/ fun copy(/*0*/ n: SomeObject? = ...): SomeObject
+    internal final fun doSomething(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    internal final fun next(): SomeObject?
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/nestedDoWhile.kt

@@ -0,0 +1,15 @@
+fun x(): Boolean { return true }
+
+public fun foo(pp: String?, rr: String?): Int {
+    var p = pp
+    var r = rr
+    do {
+        do {
+            p!!.length()
+        } while (r == null)  
+    } while (!x())
+    // Auto cast possible
+    <!DEBUG_INFO_SMARTCAST!>r<!>.length()
+    // Auto cast possible
+    return <!DEBUG_INFO_SMARTCAST!>p<!>.length()
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/nestedDoWhile.txt

@@ -0,0 +1,4 @@
+package
+
+public fun foo(/*0*/ pp: kotlin.String?, /*1*/ rr: kotlin.String?): kotlin.Int
+internal fun x(): kotlin.Boolean

compiler/testData/diagnostics/tests/smartCasts/varnotnull/nestedLoops.kt

@@ -0,0 +1,19 @@
+fun x(): Boolean { return true }
+
+public fun foo(qq: String?): Int {
+    var q = qq
+    while(true) {
+        q!!.length()
+        var r = q
+        do {
+            var p = r
+            do {
+                // p = r, r = q and q is not null
+                <!DEBUG_INFO_SMARTCAST!>p<!>.length()
+            } while (!x())
+        } while (<!SENSELESS_COMPARISON!>r == null<!>) // r = q and q is not null
+        if (!x()) break
+    }
+    // Smart cast is possible
+    return <!DEBUG_INFO_SMARTCAST!>q<!>.length()
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/nestedLoops.txt

@@ -0,0 +1,4 @@
+package
+
+public fun foo(/*0*/ qq: kotlin.String?): kotlin.Int
+internal fun x(): kotlin.Boolean

compiler/testData/diagnostics/tests/smartCasts/varnotnull/nestedWhile.kt

@@ -0,0 +1,27 @@
+class Bar {
+    fun next(): Bar? {
+        if (2 == 4)
+            return this
+        else
+            return null
+    }
+}
+
+fun foo(): Bar {
+    var x: Bar? = Bar()
+    var y: Bar? = Bar()
+    while (x != null) {
+        // Here call is unsafe because of initialization and also inner loop
+        y<!UNSAFE_CALL!>.<!>next()
+        while (y != null) {
+            if (x == y)
+                // x is not null because of outer while
+                return <!DEBUG_INFO_SMARTCAST!>x<!>
+            // y is not null because of inner while
+            y = <!DEBUG_INFO_SMARTCAST!>y<!>.next()
+        }
+        // x is not null because of outer while
+        x = <!DEBUG_INFO_SMARTCAST!>x<!>.next()
+    }
+    return Bar()
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/nestedWhile.txt

@@ -0,0 +1,11 @@
+package
+
+internal fun foo(): Bar
+
+internal final class Bar {
+    public constructor Bar()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    internal final fun next(): Bar?
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/unnecessary.kt

@@ -0,0 +1,12 @@
+fun String?.foo(): String {
+    return this ?: ""
+}
+
+class MyClass {
+    private var s: String? = null
+
+    fun bar(): String {
+        s = "42"
+        return s.foo()
+    }    
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/unnecessary.txt

@@ -0,0 +1,12 @@
+package
+
+internal fun kotlin.String?.foo(): kotlin.String
+
+internal final class MyClass {
+    public constructor MyClass()
+    private final var s: kotlin.String?
+    internal final fun bar(): kotlin.String
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/unnecessaryWithBranch.kt

@@ -0,0 +1,12 @@
+fun String?.foo(): String {
+    return this ?: ""
+}
+
+class MyClass {
+    fun bar(): String {
+        var s: String? = null
+        if (4 < 2)
+            s = "42"
+        return s.foo()
+    }    
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/unnecessaryWithBranch.txt

@@ -0,0 +1,11 @@
+package
+
+internal fun kotlin.String?.foo(): kotlin.String
+
+internal final class MyClass {
+    public constructor MyClass()
+    internal final fun bar(): kotlin.String
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/unnecessaryWithMap.kt

@@ -0,0 +1,19 @@
+fun create(): Map<String, String> = null!!
+
+fun <K, V> Map<K, V>.iterator(): Iterator<Map.Entry<K, V>> = null!!
+
+fun <K, V> Map.Entry<K, V>.component1() = getKey()
+
+fun <K, V> Map.Entry<K, V>.component2() = getValue()
+
+class MyClass {
+    private var m: Map<String, String>? = null
+    fun foo(): Int {
+        var res = 0
+        m = create()
+        // See KT-7428
+        for ((k, v) in <!SMARTCAST_IMPOSSIBLE!>m<!>)
+            res += (k.length() + v.length())
+        return res
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/unnecessaryWithMap.txt

@@ -0,0 +1,15 @@
+package
+
+internal fun create(): kotlin.Map<kotlin.String, kotlin.String>
+internal fun </*0*/ K, /*1*/ V> kotlin.Map.Entry<K, V>.component1(): K
+internal fun </*0*/ K, /*1*/ V> kotlin.Map.Entry<K, V>.component2(): V
+internal fun </*0*/ K, /*1*/ V> kotlin.Map<K, V>.iterator(): kotlin.Iterator<kotlin.Map.Entry<K, V>>
+
+internal final class MyClass {
+    public constructor MyClass()
+    private final var m: kotlin.Map<kotlin.String, kotlin.String>?
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    internal final fun foo(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varCapturedInClosure.kt

@@ -0,0 +1,17 @@
+public fun foo() {
+    var s: String? = ""
+    fun closure(): Int {
+        if (s == "") {
+            s = null
+            return -1
+        } else if (s == null) {
+            return -2
+        } else {
+            return s<!UNSAFE_CALL!>.<!>length() // Here smartcast is possible, at least in principle
+        }
+    }
+    if (s != null) {
+        System.out.println(closure())
+        System.out.println(s<!UNSAFE_CALL!>.<!>length())   // Here smartcast is not possible due to a closure predecessor
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varCapturedInClosure.txt

@@ -0,0 +1,3 @@
+package
+
+public fun foo(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varCapturedInInlineClosure.kt

@@ -0,0 +1,15 @@
+// See also KT-7186
+
+fun IntArray.forEachIndexed( op: (i: Int, value: Int) -> Unit) {
+    for (i in 0..this.size()-1)
+        op(i, this[i])
+}
+
+fun max(a: IntArray): Int? {
+    var maxI: Int? = null
+    a.forEachIndexed { i, value ->
+        if (maxI == null || value >= a[<!TYPE_MISMATCH!>maxI<!>])
+            maxI = i
+    }
+    return maxI
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varCapturedInInlineClosure.txt

@@ -0,0 +1,4 @@
+package
+
+internal fun max(/*0*/ a: kotlin.IntArray): kotlin.Int?
+internal fun kotlin.IntArray.forEachIndexed(/*0*/ op: (kotlin.Int, kotlin.Int) -> kotlin.Unit): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varCapturedInSafeClosure.kt

@@ -0,0 +1,15 @@
+public fun foo() {
+    var s: String? = ""
+    fun closure(): Int {
+        if (s == null) {
+            return -1
+        } else {
+            return 0
+        }
+    }
+    if (s != null) {
+        System.out.println(closure())
+        // Smart cast is possible but closure makes it harder to understand
+        System.out.println(s<!UNSAFE_CALL!>.<!>length())   
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varCapturedInSafeClosure.txt

@@ -0,0 +1,3 @@
+package
+
+public fun foo(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varChangedInLoop.kt

@@ -0,0 +1,9 @@
+public fun foo() {
+    var i: Int? = 1
+    if (i != null) {
+        while (i != 10) {
+            <!UNUSED_CHANGED_VALUE!>i<!UNSAFE_CALL!>++<!><!>      // Here smart cast should not be performed due to a successor
+            i = null
+        }
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varChangedInLoop.txt

@@ -0,0 +1,3 @@
+package
+
+public fun foo(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varCheck.kt

@@ -0,0 +1,9 @@
+fun get(): String? {
+    return ""
+}
+
+fun foo(): Int {
+    var c: String? = get()
+    c!!.length()
+    return <!DEBUG_INFO_SMARTCAST!>c<!>.length() // Previous line should make !! unnecessary here.
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varCheck.txt

@@ -0,0 +1,4 @@
+package
+
+internal fun foo(): kotlin.Int
+internal fun get(): kotlin.String?

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varIntNull.kt

@@ -0,0 +1,5 @@
+fun foo(): Int {
+    var i: Int? = <!VARIABLE_WITH_REDUNDANT_INITIALIZER!>42<!>
+    i = null
+    return i <!UNSAFE_INFIX_CALL!>+<!> 1
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varIntNull.txt

@@ -0,0 +1,3 @@
+package
+
+internal fun foo(): kotlin.Int

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varNotChangedInLoop.kt

@@ -0,0 +1,8 @@
+public fun foo() {
+    var i: Int? = 1
+    if (i != null) {
+        while (i != 10) {
+            <!DEBUG_INFO_SMARTCAST!>i<!>++
+        }
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varNotChangedInLoop.txt

@@ -0,0 +1,3 @@
+package
+
+public fun foo(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varNull.kt

@@ -0,0 +1,5 @@
+fun foo(): Int {
+    var s: String? = <!VARIABLE_WITH_REDUNDANT_INITIALIZER!>"abc"<!>
+    s = null
+    return s<!UNSAFE_CALL!>.<!>length()
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/varNull.txt

@@ -0,0 +1,3 @@
+package
+
+internal fun foo(): kotlin.Int

compiler/testData/diagnostics/tests/smartCasts/varnotnull/whileTrue.kt

@@ -0,0 +1,13 @@
+fun x(): Boolean { return true }
+
+public fun foo(pp: String?): Int {
+    var p = pp
+    while(true) {
+        p!!.length()
+        if (x()) break
+        p = null
+    }
+    // Smart cast is NOT possible here
+    // (we could provide it but p = null makes it much harder)
+    return p<!UNSAFE_CALL!>.<!>length()
+}

compiler/testData/diagnostics/tests/smartCasts/varnotnull/whileTrue.txt

@@ -0,0 +1,4 @@
+package
+
+public fun foo(/*0*/ pp: kotlin.String?): kotlin.Int
+internal fun x(): kotlin.Boolean

compiler/testData/diagnostics/tests/smartCasts/varnotnull/whileWithBreak.kt

@@ -0,0 +1,17 @@
+data class SomeObject(val n: SomeObject?) {
+    fun doSomething(): Boolean = true
+    fun next(): SomeObject? = n    
+}
+
+fun list(start: SomeObject) {
+    var e: SomeObject? = start
+    while (e != null) {
+        // Smart cast due to the loop condition
+        if (!<!DEBUG_INFO_SMARTCAST!>e<!>.doSomething())
+            break
+        // We still have smart cast here despite of a break
+        e = <!DEBUG_INFO_SMARTCAST!>e<!>.next()
+    }
+    // e can be null because of next()
+    e<!UNSAFE_CALL!>.<!>doSomething()
+}