Generate receivers for callable references in the same way as for calls

Properly handle callable members imported from objects
and other related corner cases.

 #KT-18084 Fixed

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ReflectionReferencesGenerator.kt

@@ -25,8 +25,9 @@ import org.jetbrains.kotlin.psi.KtCallableReferenceExpression
 import org.jetbrains.kotlin.psi.KtClassLiteralExpression
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
 import org.jetbrains.kotlin.psi.psiUtil.startOffset
+import org.jetbrains.kotlin.psi2ir.intermediate.TransientReceiverValue
 import org.jetbrains.kotlin.resolve.BindingContext
-import org.jetbrains.kotlin.resolve.scopes.receivers.TransientReceiver
+import org.jetbrains.kotlin.resolve.ImportedFromObjectCallableDescriptor
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.expressions.DoubleColonLHS
 
@@ -51,24 +52,30 @@ class ReflectionReferencesGenerator(statementGenerator: StatementGenerator) : St
 
     fun generateCallableReference(ktCallableReference: KtCallableReferenceExpression): IrExpression {
         val resolvedCall = getResolvedCall(ktCallableReference.callableReference)!!
-        val irCallableRef = generateCallableReference(
-                ktCallableReference.startOffset, ktCallableReference.endOffset,
-                getInferredTypeWithImplicitCastsOrFail(ktCallableReference),
-                resolvedCall.resultingDescriptor,
-                typeArguments = null
-        )
-        resolvedCall.dispatchReceiver?.let { dispatchReceiver ->
-            if (dispatchReceiver !is TransientReceiver) {
-                irCallableRef.dispatchReceiver = statementGenerator.generateReceiver(ktCallableReference, dispatchReceiver).load()
-            }
-        }
-        resolvedCall.extensionReceiver?.let { extensionReceiver ->
-            if (extensionReceiver !is TransientReceiver) {
-                irCallableRef.extensionReceiver = statementGenerator.generateReceiver(ktCallableReference, extensionReceiver).load()
-            }
-        }
 
-        return irCallableRef
+        val resultingDescriptor = resolvedCall.resultingDescriptor
+        val descriptorImportedFromObject = resultingDescriptor as? ImportedFromObjectCallableDescriptor<*>
+        val referencedDescriptor = descriptorImportedFromObject?.callableFromObject ?: resultingDescriptor
+
+        val startOffset = ktCallableReference.startOffset
+        val endOffset = ktCallableReference.endOffset
+
+        return statementGenerator.generateCallReceiver(
+                ktCallableReference,
+                resultingDescriptor,
+                resolvedCall.dispatchReceiver, resolvedCall.extensionReceiver,
+                isSafe = false
+        ).call { dispatchReceiverValue, extensionReceiverValue ->
+            generateCallableReference(
+                    startOffset, endOffset,
+                    getInferredTypeWithImplicitCastsOrFail(ktCallableReference),
+                    referencedDescriptor,
+                    typeArguments = null
+            ).also { irCallableReference ->
+                irCallableReference.dispatchReceiver = dispatchReceiverValue?.loadIfExists()
+                irCallableReference.extensionReceiver = extensionReceiverValue?.loadIfExists()
+            }
+        }
     }
 
     fun generateCallableReference(

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/intermediate/TransientReceiverValue.kt

@@ -23,4 +23,6 @@ class TransientReceiverValue(override val type: KotlinType): IntermediateValue {
     override fun load(): IrExpression {
         throw AssertionError("Transient receiver should not be instantiated")
     }
+
+    override fun loadIfExists(): IrExpression? = null
 }

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/intermediate/Values.kt

@@ -21,6 +21,7 @@ import org.jetbrains.kotlin.types.KotlinType
 
 interface IntermediateValue {
     fun load(): IrExpression
+    fun loadIfExists(): IrExpression? = load()
     val type: KotlinType
 }
 

compiler/testData/ir/irText/expressions/callableReferenceToImportedFromObject.kt

@@ -0,0 +1,14 @@
+package test
+
+import test.Foo.a
+import test.Foo.foo
+
+object Foo {
+    val a: String = ""
+    fun foo(): String = ""
+}
+
+val test1 = ::a
+val test1a = Foo::a
+val test2 = ::foo
+val test2a = Foo::foo

compiler/testData/ir/irText/expressions/callableReferenceToImportedFromObject.txt

@@ -0,0 +1,65 @@
+FILE /callableReferenceToImportedFromObject.kt
+  CLASS OBJECT Foo
+    $this: VALUE_PARAMETER this@Foo: Foo
+    CONSTRUCTOR private constructor Foo()
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'constructor Any()'
+        INSTANCE_INITIALIZER_CALL classDescriptor='Foo'
+    PROPERTY public final val a: kotlin.String = ""
+      FIELD PROPERTY_BACKING_FIELD public final val a: kotlin.String = ""
+        EXPRESSION_BODY
+          CONST String type=kotlin.String value=''
+      FUN DEFAULT_PROPERTY_ACCESSOR public final fun <get-a>(): kotlin.String
+        $this: VALUE_PARAMETER this@Foo: Foo
+        BLOCK_BODY
+          RETURN type=kotlin.Nothing from='<get-a>(): String'
+            GET_FIELD 'a: String' type=kotlin.String origin=null
+              receiver: GET_VAR 'this@Foo: Foo' type=test.Foo origin=null
+    FUN public final fun foo(): kotlin.String
+      $this: VALUE_PARAMETER this@Foo: Foo
+      BLOCK_BODY
+        RETURN type=kotlin.Nothing from='foo(): String'
+          CONST String type=kotlin.String value=''
+    FUN FAKE_OVERRIDE public open override fun equals(other: kotlin.Any?): kotlin.Boolean
+      $this: VALUE_PARAMETER this@Any: Any
+      VALUE_PARAMETER value-parameter other: kotlin.Any?
+    FUN FAKE_OVERRIDE public open override fun hashCode(): kotlin.Int
+      $this: VALUE_PARAMETER this@Any: Any
+    FUN FAKE_OVERRIDE public open override fun toString(): kotlin.String
+      $this: VALUE_PARAMETER this@Any: Any
+  PROPERTY public val test1: kotlin.reflect.KProperty0<kotlin.String>
+    FIELD PROPERTY_BACKING_FIELD public val test1: kotlin.reflect.KProperty0<kotlin.String>
+      EXPRESSION_BODY
+        PROPERTY_REFERENCE 'a: String' field=null getter='<get-a>(): String' setter=null type=kotlin.reflect.KProperty0<kotlin.String> origin=null
+          $this: GET_OBJECT 'Foo' type=test.Foo
+    FUN DEFAULT_PROPERTY_ACCESSOR public fun <get-test1>(): kotlin.reflect.KProperty0<kotlin.String>
+      BLOCK_BODY
+        RETURN type=kotlin.Nothing from='<get-test1>(): KProperty0<String>'
+          GET_FIELD 'test1: KProperty0<String>' type=kotlin.reflect.KProperty0<kotlin.String> origin=null
+  PROPERTY public val test1a: kotlin.reflect.KProperty0<kotlin.String>
+    FIELD PROPERTY_BACKING_FIELD public val test1a: kotlin.reflect.KProperty0<kotlin.String>
+      EXPRESSION_BODY
+        PROPERTY_REFERENCE 'a: String' field=null getter='<get-a>(): String' setter=null type=kotlin.reflect.KProperty0<kotlin.String> origin=null
+          $this: GET_OBJECT 'Foo' type=test.Foo
+    FUN DEFAULT_PROPERTY_ACCESSOR public fun <get-test1a>(): kotlin.reflect.KProperty0<kotlin.String>
+      BLOCK_BODY
+        RETURN type=kotlin.Nothing from='<get-test1a>(): KProperty0<String>'
+          GET_FIELD 'test1a: KProperty0<String>' type=kotlin.reflect.KProperty0<kotlin.String> origin=null
+  PROPERTY public val test2: kotlin.reflect.KFunction0<kotlin.String>
+    FIELD PROPERTY_BACKING_FIELD public val test2: kotlin.reflect.KFunction0<kotlin.String>
+      EXPRESSION_BODY
+        FUNCTION_REFERENCE 'foo(): String' type=kotlin.reflect.KFunction0<kotlin.String> origin=null
+          $this: GET_OBJECT 'Foo' type=test.Foo
+    FUN DEFAULT_PROPERTY_ACCESSOR public fun <get-test2>(): kotlin.reflect.KFunction0<kotlin.String>
+      BLOCK_BODY
+        RETURN type=kotlin.Nothing from='<get-test2>(): KFunction0<String>'
+          GET_FIELD 'test2: KFunction0<String>' type=kotlin.reflect.KFunction0<kotlin.String> origin=null
+  PROPERTY public val test2a: kotlin.reflect.KFunction0<kotlin.String>
+    FIELD PROPERTY_BACKING_FIELD public val test2a: kotlin.reflect.KFunction0<kotlin.String>
+      EXPRESSION_BODY
+        FUNCTION_REFERENCE 'foo(): String' type=kotlin.reflect.KFunction0<kotlin.String> origin=null
+          $this: GET_OBJECT 'Foo' type=test.Foo
+    FUN DEFAULT_PROPERTY_ACCESSOR public fun <get-test2a>(): kotlin.reflect.KFunction0<kotlin.String>
+      BLOCK_BODY
+        RETURN type=kotlin.Nothing from='<get-test2a>(): KFunction0<String>'
+          GET_FIELD 'test2a: KFunction0<String>' type=kotlin.reflect.KFunction0<kotlin.String> origin=null

compiler/tests/org/jetbrains/kotlin/ir/IrTextTestCaseGenerated.java

@@ -563,6 +563,12 @@ public class IrTextTestCaseGenerated extends AbstractIrTextTestCase {
             doTest(fileName);
         }
 
+        @TestMetadata("callableReferenceToImportedFromObject.kt")
+        public void testCallableReferenceToImportedFromObject() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/ir/irText/expressions/callableReferenceToImportedFromObject.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("calls.kt")
         public void testCalls() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/ir/irText/expressions/calls.kt");