Limit "always null" scope: only for !!, is and dot; senseless comparison rolled back; "smart constant" information for nulls #KT-10029 Fixed

compiler/testData/diagnostics/tests/smartCasts/alwaysNull.kt

@@ -1,11 +1,23 @@
 fun foo(): String {
     var s: String?
     s = null
-    <!ALWAYS_NULL!>s<!>?.length
-    if (<!ALWAYS_NULL!>s<!> == null) s = "z"
+    <!DEBUG_INFO_CONSTANT!>s<!>?.length
+    <!ALWAYS_NULL!>s<!><!UNSAFE_CALL!>.<!>length
+    if (<!SENSELESS_COMPARISON!><!DEBUG_INFO_CONSTANT!>s<!> == null<!>) return <!ALWAYS_NULL!>s<!>!!
     var t: String? = "y"
     if (t == null) t = "x"
     var x: Int? = null
     if (x == null) <!TYPE_MISMATCH!>x += null<!>
     return <!DEBUG_INFO_SMARTCAST!>t<!> + s
+}
+
+fun String?.gav() {}
+
+fun bar(s: String?) {
+    if (s != null) return
+    // Ideally we should have DEBUG_INFO_CONSTANT instead
+    <!ALWAYS_NULL!>s<!>.gav()
+    <!DEBUG_INFO_CONSTANT!>s<!> as? String
+    <!DEBUG_INFO_CONSTANT!>s<!> <!USELESS_CAST!>as String?<!>
+    <!ALWAYS_NULL!>s<!> as String
 }

compiler/testData/diagnostics/tests/smartCasts/alwaysNull.txt

@@ -1,3 +1,5 @@
 package
 
+public fun bar(/*0*/ s: kotlin.String?): kotlin.Unit
 public fun foo(): kotlin.String
+public fun kotlin.String?.gav(): kotlin.Unit

compiler/testData/diagnostics/tests/smartCasts/alwaysNullWithJava.kt

@@ -0,0 +1,16 @@
+// FILE: My.java
+
+public class My {
+    static public My create() { return new My(); }
+    public void foo() {}
+}
+
+// FILE: Test.kt
+
+fun test() {
+    val my = My.create()
+    if (my == null) {
+        <!ALWAYS_NULL!>my<!>.foo()
+    }
+}
+

compiler/testData/diagnostics/tests/smartCasts/alwaysNullWithJava.txt

@@ -0,0 +1,14 @@
+package
+
+public fun test(): kotlin.Unit
+
+public open class My {
+    public constructor My()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    // Static members
+    public open fun create(): My!
+}

compiler/testData/diagnostics/tests/smartCasts/comparisonUnderAnd.kt

@@ -8,7 +8,7 @@ fun foo(x : String?, y : String?) {
         x<!UNSAFE_CALL!>.<!>length
         y<!UNSAFE_CALL!>.<!>length
     }
-    if (y != null || x == <!ALWAYS_NULL!>y<!>) {
+    if (y != null || x == <!DEBUG_INFO_CONSTANT!>y<!>) {
         x<!UNSAFE_CALL!>.<!>length
         y<!UNSAFE_CALL!>.<!>length
     }
@@ -17,7 +17,7 @@ fun foo(x : String?, y : String?) {
         <!DEBUG_INFO_SMARTCAST!>x<!>.length
         <!ALWAYS_NULL!>y<!><!UNSAFE_CALL!>.<!>length
     }
-    if (y == null && x != <!ALWAYS_NULL!>y<!>) {
+    if (y == null && x != <!DEBUG_INFO_CONSTANT!>y<!>) {
         // y == null but x != y
         <!DEBUG_INFO_SMARTCAST!>x<!>.length
         <!ALWAYS_NULL!>y<!><!UNSAFE_CALL!>.<!>length

compiler/testData/diagnostics/tests/smartCasts/complexComparison.kt

@@ -3,7 +3,7 @@ fun foo(x: String?, y: String?, z: String?, w: String?) {
         <!DEBUG_INFO_SMARTCAST!>z<!>.length
     else
         z<!UNSAFE_CALL!>.<!>length
-    if (x != null || y != null || (<!ALWAYS_NULL!>x<!> != z && <!ALWAYS_NULL!>y<!> != z))
+    if (x != null || y != null || (<!DEBUG_INFO_CONSTANT!>x<!> != z && <!DEBUG_INFO_CONSTANT!>y<!> != z))
         z<!UNSAFE_CALL!>.<!>length
     else
         <!ALWAYS_NULL!>z<!><!UNSAFE_CALL!>.<!>length

compiler/testData/diagnostics/tests/smartCasts/notNullorNotNull.kt

@@ -1,6 +1,6 @@
 fun bar(x: Int?): Int {
     if (x != null) return -1
-    if (<!ALWAYS_NULL!>x<!> == null) return -2
+    if (<!SENSELESS_COMPARISON!><!DEBUG_INFO_CONSTANT!>x<!> == null<!>) return -2
     // Should be unreachable
     return 2 + 2
 }

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

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