Variable as function calls.

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

@@ -109,8 +109,10 @@ fun StatementGenerator.pregenerateCall(resolvedCall: ResolvedCall<*>): CallBuild
 fun StatementGenerator.pregenerateCallReceivers(resolvedCall: ResolvedCall<*>): CallBuilder {
     val call = CallBuilder(resolvedCall)
 
-    val ktDefaultCallElement = resolvedCall.call.callElement
+    call.callReceiver = generateCallReceiver(resolvedCall.call.callElement,
-    call.callReceiver = generateCallReceiver(ktDefaultCallElement, resolvedCall.dispatchReceiver, resolvedCall.extensionReceiver, resolvedCall.call.isSafeCall())
+                                             resolvedCall.dispatchReceiver,
+                                             resolvedCall.extensionReceiver,
+                                             resolvedCall.call.isSafeCall())
 
     return call
 }

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

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.psi2ir.generators
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor
+import org.jetbrains.kotlin.descriptors.VariableDescriptor
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.psi.KtElement
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
@@ -50,6 +51,10 @@ class CallGenerator(
         return when (descriptor) {
             is PropertyDescriptor ->
                 generatePropertyGetterCall(descriptor, startOffset, endOffset, call)
+            is VariableDescriptor ->
+                call.callReceiver.call { dispatchReceiverValue, extensionReceiverValue ->
+                    IrGetVariableImpl(startOffset, endOffset, descriptor, operator)
+                }
             is FunctionDescriptor ->
                 generateFunctionCall(descriptor, startOffset, endOffset, operator, call)
             else ->

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

@@ -26,9 +26,7 @@ import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
 import org.jetbrains.kotlin.psi.psiUtil.startOffset
 import org.jetbrains.kotlin.psi2ir.deparenthesize
-import org.jetbrains.kotlin.psi2ir.intermediate.Value
+import org.jetbrains.kotlin.psi2ir.intermediate.*
-import org.jetbrains.kotlin.psi2ir.intermediate.createRematerializableOrTemporary
-import org.jetbrains.kotlin.psi2ir.intermediate.setExplicitReceiverValue
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.BindingContextUtils
 import org.jetbrains.kotlin.resolve.DescriptorUtils
@@ -183,7 +181,8 @@ class StatementGenerator(
         val resolvedCall = getResolvedCall(expression) ?: throw AssertionError("No resolved call for ${expression.text}")
 
         if (resolvedCall is VariableAsFunctionResolvedCall) {
-            TODO("Unexpected VariableAsFunctionResolvedCall")
+            val variableCall = pregenerateCall(resolvedCall.variableCall)
+            return CallGenerator(this).generateCall(expression, variableCall, IrOperator.VARIABLE_AS_FUNCTION)
         }
 
         val descriptor = resolvedCall.resultingDescriptor
@@ -222,7 +221,8 @@ class StatementGenerator(
         val resolvedCall = getResolvedCall(expression) ?: TODO("No resolved call for call expression")
 
         if (resolvedCall is VariableAsFunctionResolvedCall) {
-            TODO("VariableAsFunctionResolvedCall = variable call + invoke call")
+            val functionCall = pregenerateCall(resolvedCall.functionCall)
+            return CallGenerator(this).generateCall(expression, functionCall, IrOperator.INVOKE)
         }
 
         return CallGenerator(this).generateCall(expression.startOffset, expression.endOffset, pregenerateCall(resolvedCall))

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

@@ -24,10 +24,10 @@ import org.jetbrains.kotlin.psi2ir.intermediate.CallBuilder
 import org.jetbrains.kotlin.types.KotlinType
 
 class OnceCallValue(
-        val statementGenerator: StatementGenerator,
-        val call: CallBuilder,
         val startOffset: Int,
         val endOffset: Int,
+        val statementGenerator: StatementGenerator,
+        val call: CallBuilder,
         val operator: IrOperator? = null
 ): Value {
     private var instantiated = false

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/expressions/IrOperator.kt

@@ -53,6 +53,7 @@ interface IrOperator {
     object RANGE : IrOperatorImpl("RANGE")
 
     object INVOKE : IrOperatorImpl("INVOKE")
+    object VARIABLE_AS_FUNCTION : IrOperatorImpl("VARIABLE_AS_FUNCTION")
     object GET_ARRAY_ELEMENT : IrOperatorImpl("GET_ARRAY_ELEMENT")
 
     object PREFIX_INCR : IrOperatorImpl("PREFIX_INCR")

compiler/testData/ir/irText/variableAsFunctionCall.kt

@@ -0,0 +1,6 @@
+fun String.k(): () -> String = { -> this }
+
+fun test1(f: () -> Unit) = f()
+fun test2(f: String.() -> Unit) = "hello".f()
+fun test3() = "hello".k()()
+fun test4(ns: String?) = ns?.k()?.invoke()

compiler/testData/ir/irText/variableAsFunctionCall.txt

@@ -0,0 +1,49 @@
+IrFile /variableAsFunctionCall.kt
+  IrFunction public fun kotlin.String.k(): () -> kotlin.String
+    IrExpressionBody
+      BLOCK type=<no-type> hasResult=false operator=null
+        RETURN type=<no-type>
+          DUMMY KtLambdaExpression type=() -> kotlin.String
+  IrFunction public fun test1(/*0*/ f: () -> kotlin.Unit): kotlin.Unit
+    IrExpressionBody
+      BLOCK type=<no-type> hasResult=false operator=null
+        RETURN type=<no-type>
+          CALL .invoke type=kotlin.Unit operator=INVOKE
+            $this: GET_VAR f type=() -> kotlin.Unit operator=VARIABLE_AS_FUNCTION
+  IrFunction public fun test2(/*0*/ f: kotlin.String.() -> kotlin.Unit): kotlin.Unit
+    IrExpressionBody
+      BLOCK type=<no-type> hasResult=false operator=null
+        RETURN type=<no-type>
+          CALL .invoke type=kotlin.Unit operator=INVOKE
+            $this: GET_VAR f type=kotlin.String.() -> kotlin.Unit operator=VARIABLE_AS_FUNCTION
+            $receiver: CONST String type=kotlin.String value='hello'
+  IrFunction public fun test3(): kotlin.String
+    IrExpressionBody
+      BLOCK type=<no-type> hasResult=false operator=null
+        RETURN type=<no-type>
+          CALL .invoke type=kotlin.String operator=null
+            $this: CALL .k type=() -> kotlin.String operator=null
+              $receiver: CONST String type=kotlin.String value='hello'
+  IrFunction public fun test4(/*0*/ ns: kotlin.String?): kotlin.String?
+    IrExpressionBody
+      BLOCK type=<no-type> hasResult=false operator=null
+        RETURN type=<no-type>
+          BLOCK type=kotlin.String? hasResult=true operator=SAFE_CALL
+            VAR val tmp1_safe_receiver: (() -> kotlin.String)?
+              BLOCK type=(() -> kotlin.String)? hasResult=true operator=SAFE_CALL
+                VAR val tmp0_safe_receiver: kotlin.String?
+                  GET_VAR ns type=kotlin.String? operator=null
+                WHEN type=(() -> kotlin.String)? operator=SAFE_CALL
+                  if: CALL .EQEQ type=kotlin.Boolean operator=EQEQ
+                    arg0: GET_VAR tmp0_safe_receiver type=kotlin.String? operator=null
+                    arg1: CONST Null type=kotlin.Nothing? value='null'
+                  then: CONST Null type=kotlin.Nothing? value='null'
+                  else: CALL .k type=() -> kotlin.String operator=null
+                    $this: GET_VAR tmp0_safe_receiver type=kotlin.String? operator=null
+            WHEN type=kotlin.String? operator=SAFE_CALL
+              if: CALL .EQEQ type=kotlin.Boolean operator=EQEQ
+                arg0: GET_VAR tmp1_safe_receiver type=(() -> kotlin.String)? operator=null
+                arg1: CONST Null type=kotlin.Nothing? value='null'
+              then: CONST Null type=kotlin.Nothing? value='null'
+              else: CALL .invoke type=kotlin.String operator=null
+                $this: GET_VAR tmp1_safe_receiver type=(() -> kotlin.String)? operator=null

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

@@ -287,6 +287,12 @@ public class IrTextTestCaseGenerated extends AbstractIrTextTestCase {
         doTest(fileName);
     }
 
+    @TestMetadata("variableAsFunctionCall.kt")
+    public void testVariableAsFunctionCall() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/ir/irText/variableAsFunctionCall.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("when.kt")
     public void testWhen() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/ir/irText/when.kt");