PSI2IR: Post-process return expressions based on expected return type

Consider the following example: Java: public class J { public static String foo() { return null; } } Kotlin: fun check(fn: () -> Any) = fn() fun test() = check { J.foo() } When a lambda expression returns a value of platform type ('String!'), corresponding lambda has platform type in its return type, which is approximated to corresponding nullable type ('String?') in IR. However, the lambda itself could occur in position with a functional expected type ('() -> Any'). This implies an extra implicit cast on a return value of lambda expression ('J.foo()'), although it conforms to the return type of lambda.
2019-12-30 19:38:52 +03:00
parent 0e4e5ac287
commit 8054e2960e
7 changed files with 241 additions and 59 deletions
@@ -0,0 +1,60 @@
+FILE fqName:<root> fileName:/nullCheckOnLambdaReturn.kt
+  FUN name:check visibility:public modality:FINAL <> (fn:kotlin.Function0<kotlin.Any>) returnType:kotlin.Any
+    VALUE_PARAMETER name:fn index:0 type:kotlin.Function0<kotlin.Any>
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun check (fn: kotlin.Function0<kotlin.Any>): kotlin.Any declared in <root>'
+        CALL 'public abstract fun invoke (): kotlin.Any [operator] declared in kotlin.Function0' type=kotlin.Any origin=null
+          $this: GET_VAR 'fn: kotlin.Function0<kotlin.Any> declared in <root>.check' type=kotlin.Function0<kotlin.Any> origin=null
+  FUN name:id visibility:public modality:FINAL <T> (x:T of <root>.id) returnType:T of <root>.id
+    TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?]
+    VALUE_PARAMETER name:x index:0 type:T of <root>.id
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun id <T> (x: T of <root>.id): T of <root>.id declared in <root>'
+        GET_VAR 'x: T of <root>.id declared in <root>.id' type=T of <root>.id origin=null
+  FUN name:test1 visibility:public modality:FINAL <> () returnType:kotlin.Any
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun test1 (): kotlin.Any declared in <root>'
+        CALL 'public final fun check (fn: kotlin.Function0<kotlin.Any>): kotlin.Any declared in <root>' type=kotlin.Any origin=null
+          fn: FUN_EXPR type=kotlin.Function0<kotlin.Any> origin=LAMBDA
+            FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:kotlin.Any
+              BLOCK_BODY
+                CALL 'public open fun foo (): kotlin.String? [operator] declared in <root>.J' type=kotlin.String? origin=null
+  PROPERTY name:test2 visibility:public modality:FINAL [val]
+    FIELD PROPERTY_BACKING_FIELD name:test2 type:kotlin.Function0<kotlin.Any> visibility:private [final,static]
+      EXPRESSION_BODY
+        FUN_EXPR type=kotlin.Function0<kotlin.String?> origin=LAMBDA
+          FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:kotlin.String?
+            BLOCK_BODY
+              CALL 'public open fun foo (): kotlin.String? [operator] declared in <root>.J' type=kotlin.String? origin=null
+    FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test2> visibility:public modality:FINAL <> () returnType:kotlin.Function0<kotlin.Any>
+      correspondingProperty: PROPERTY name:test2 visibility:public modality:FINAL [val]
+      BLOCK_BODY
+        RETURN type=kotlin.Nothing from='public final fun <get-test2> (): kotlin.Function0<kotlin.Any> declared in <root>'
+          GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:test2 type:kotlin.Function0<kotlin.Any> visibility:private [final,static]' type=kotlin.Function0<kotlin.Any> origin=null
+  PROPERTY name:test3 visibility:public modality:FINAL [val]
+    FIELD PROPERTY_BACKING_FIELD name:test3 type:kotlin.Function0<kotlin.Any> visibility:private [final,static]
+      EXPRESSION_BODY
+        TYPE_OP type=kotlin.Function0<kotlin.Any> origin=CAST typeOperand=kotlin.Function0<kotlin.Any>
+          FUN_EXPR type=kotlin.Function0<kotlin.String?> origin=LAMBDA
+            FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:kotlin.String?
+              BLOCK_BODY
+                CALL 'public open fun foo (): kotlin.String? [operator] declared in <root>.J' type=kotlin.String? origin=null
+    FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test3> visibility:public modality:FINAL <> () returnType:kotlin.Function0<kotlin.Any>
+      correspondingProperty: PROPERTY name:test3 visibility:public modality:FINAL [val]
+      BLOCK_BODY
+        RETURN type=kotlin.Nothing from='public final fun <get-test3> (): kotlin.Function0<kotlin.Any> declared in <root>'
+          GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:test3 type:kotlin.Function0<kotlin.Any> visibility:private [final,static]' type=kotlin.Function0<kotlin.Any> origin=null
+  PROPERTY name:test4 visibility:public modality:FINAL [val]
+    FIELD PROPERTY_BACKING_FIELD name:test4 type:kotlin.Function0<kotlin.Any> visibility:private [final,static]
+      EXPRESSION_BODY
+        CALL 'public final fun id <T> (x: T of <root>.id): T of <root>.id declared in <root>' type=kotlin.Function0<kotlin.String?> origin=null
+          <T>: kotlin.Function0<kotlin.String?>
+          x: FUN_EXPR type=kotlin.Function0<kotlin.String?> origin=LAMBDA
+            FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:kotlin.String?
+              BLOCK_BODY
+                CALL 'public open fun foo (): kotlin.String? [operator] declared in <root>.J' type=kotlin.String? origin=null
+    FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test4> visibility:public modality:FINAL <> () returnType:kotlin.Function0<kotlin.Any>
+      correspondingProperty: PROPERTY name:test4 visibility:public modality:FINAL [val]
+      BLOCK_BODY
+        RETURN type=kotlin.Nothing from='public final fun <get-test4> (): kotlin.Function0<kotlin.Any> declared in <root>'
+          GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:test4 type:kotlin.Function0<kotlin.Any> visibility:private [final,static]' type=kotlin.Function0<kotlin.Any> origin=null
@@ -0,0 +1,17 @@
+// FILE: nullCheckOnLambdaReturn.kt
+fun check(fn: () -> Any) = fn()
+
+fun <T> id(x: T) = x
+
+fun test1() = check { J.foo() }
+
+val test2: () -> Any = { J.foo() }
+
+val test3: () -> Any = { J.foo() } as () -> Any
+
+val test4: () -> Any = id { J.foo() }
+
+// FILE: J.java
+public class J {
+    public static String foo() { return null; }
+}
@@ -0,0 +1,66 @@
+FILE fqName:<root> fileName:/nullCheckOnLambdaReturn.kt
+  FUN name:check visibility:public modality:FINAL <> (fn:kotlin.Function0<kotlin.Any>) returnType:kotlin.Any
+    VALUE_PARAMETER name:fn index:0 type:kotlin.Function0<kotlin.Any>
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun check (fn: kotlin.Function0<kotlin.Any>): kotlin.Any declared in <root>'
+        CALL 'public abstract fun invoke (): R of kotlin.Function0 [operator] declared in kotlin.Function0' type=kotlin.Any origin=INVOKE
+          $this: GET_VAR 'fn: kotlin.Function0<kotlin.Any> declared in <root>.check' type=kotlin.Function0<kotlin.Any> origin=VARIABLE_AS_FUNCTION
+  FUN name:id visibility:public modality:FINAL <T> (x:T of <root>.id) returnType:T of <root>.id
+    TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?]
+    VALUE_PARAMETER name:x index:0 type:T of <root>.id
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun id <T> (x: T of <root>.id): T of <root>.id declared in <root>'
+        GET_VAR 'x: T of <root>.id declared in <root>.id' type=T of <root>.id origin=null
+  FUN name:test1 visibility:public modality:FINAL <> () returnType:kotlin.Any
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun test1 (): kotlin.Any declared in <root>'
+        CALL 'public final fun check (fn: kotlin.Function0<kotlin.Any>): kotlin.Any declared in <root>' type=kotlin.Any origin=null
+          fn: FUN_EXPR type=kotlin.Function0<kotlin.String?> origin=LAMBDA
+            FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:kotlin.String?
+              BLOCK_BODY
+                RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.String? declared in <root>.test1'
+                  TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+                    CALL 'public open fun foo (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
+  PROPERTY name:test2 visibility:public modality:FINAL [val]
+    FIELD PROPERTY_BACKING_FIELD name:test2 type:kotlin.Function0<kotlin.Any> visibility:private [final,static]
+      EXPRESSION_BODY
+        FUN_EXPR type=kotlin.Function0<kotlin.String?> origin=LAMBDA
+          FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:kotlin.String?
+            BLOCK_BODY
+              RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.String? declared in <root>.test2'
+                TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
+                  CALL 'public open fun foo (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
+    FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test2> visibility:public modality:FINAL <> () returnType:kotlin.Function0<kotlin.Any>
+      correspondingProperty: PROPERTY name:test2 visibility:public modality:FINAL [val]
+      BLOCK_BODY
+        RETURN type=kotlin.Nothing from='public final fun <get-test2> (): kotlin.Function0<kotlin.Any> declared in <root>'
+          GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:test2 type:kotlin.Function0<kotlin.Any> visibility:private [final,static]' type=kotlin.Function0<kotlin.Any> origin=null
+  PROPERTY name:test3 visibility:public modality:FINAL [val]
+    FIELD PROPERTY_BACKING_FIELD name:test3 type:kotlin.Function0<kotlin.Any> visibility:private [final,static]
+      EXPRESSION_BODY
+        TYPE_OP type=kotlin.Function0<kotlin.Any> origin=CAST typeOperand=kotlin.Function0<kotlin.Any>
+          FUN_EXPR type=kotlin.Function0<kotlin.String?> origin=LAMBDA
+            FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:kotlin.String?
+              BLOCK_BODY
+                RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.String? declared in <root>.test3'
+                  CALL 'public open fun foo (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
+    FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test3> visibility:public modality:FINAL <> () returnType:kotlin.Function0<kotlin.Any>
+      correspondingProperty: PROPERTY name:test3 visibility:public modality:FINAL [val]
+      BLOCK_BODY
+        RETURN type=kotlin.Nothing from='public final fun <get-test3> (): kotlin.Function0<kotlin.Any> declared in <root>'
+          GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:test3 type:kotlin.Function0<kotlin.Any> visibility:private [final,static]' type=kotlin.Function0<kotlin.Any> origin=null
+  PROPERTY name:test4 visibility:public modality:FINAL [val]
+    FIELD PROPERTY_BACKING_FIELD name:test4 type:kotlin.Function0<kotlin.Any> visibility:private [final,static]
+      EXPRESSION_BODY
+        CALL 'public final fun id <T> (x: T of <root>.id): T of <root>.id declared in <root>' type=kotlin.Function0<kotlin.String?> origin=null
+          <T>: kotlin.Function0<kotlin.String?>
+          x: FUN_EXPR type=kotlin.Function0<kotlin.String?> origin=LAMBDA
+            FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:kotlin.String?
+              BLOCK_BODY
+                RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.String? declared in <root>.test4'
+                  CALL 'public open fun foo (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
+    FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test4> visibility:public modality:FINAL <> () returnType:kotlin.Function0<kotlin.Any>
+      correspondingProperty: PROPERTY name:test4 visibility:public modality:FINAL [val]
+      BLOCK_BODY
+        RETURN type=kotlin.Nothing from='public final fun <get-test4> (): kotlin.Function0<kotlin.Any> declared in <root>'
+          GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:test4 type:kotlin.Function0<kotlin.Any> visibility:private [final,static]' type=kotlin.Function0<kotlin.Any> origin=null