IR:

- function with expression bodies are desugared to blocks with return statement;
- property initializers are generated as regular expression bodies.

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/IrDeclarationGenerator.kt

@@ -20,11 +20,9 @@ import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import org.jetbrains.kotlin.descriptors.PropertyGetterDescriptor
 import org.jetbrains.kotlin.descriptors.PropertySetterDescriptor
-import org.jetbrains.kotlin.ir.assertCast
+import org.jetbrains.kotlin.ir.declarations.IrDeclaration
-import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.declarations.IrDummyDeclaration
-import org.jetbrains.kotlin.ir.expressions.IrBody
+import org.jetbrains.kotlin.ir.expressions.*
-import org.jetbrains.kotlin.ir.expressions.IrExpressionBodyImpl
-import org.jetbrains.kotlin.ir.expressions.IrReturnExpressionImpl
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
 import org.jetbrains.kotlin.psi.psiUtil.startOffset
@@ -64,25 +62,25 @@ abstract class IrDeclarationGeneratorBase(
 
     fun generateFunctionDeclaration(ktNamedFunction: KtNamedFunction) {
         val functionDescriptor = getOrFail(BindingContext.FUNCTION, ktNamedFunction)
-        val body = generateExpressionBody(functionDescriptor, ktNamedFunction.bodyExpression ?: TODO("function without body expression"))
+        val body = generateFunctionBody(functionDescriptor, ktNamedFunction.bodyExpression ?: TODO("function without body expression"))
         declarationFactory.createFunction(ktNamedFunction, functionDescriptor, body).register()
     }
 
     fun generatePropertyDeclaration(ktProperty: KtProperty) {
         val propertyDescriptor = getPropertyDescriptor(ktProperty)
         if (ktProperty.hasDelegate()) TODO("handle delegated property")
-        val initializer = ktProperty.initializer?.let { generateExpressionBody(propertyDescriptor, it) }
+        val initializer = ktProperty.initializer?.let { generateInitializerBody(propertyDescriptor, it) }
         val irProperty = declarationFactory.createSimpleProperty(ktProperty, propertyDescriptor, initializer).register()
         ktProperty.getter?.let { ktGetter ->
             val accessorDescriptor = getOrFail(BindingContext.PROPERTY_ACCESSOR, ktGetter)
             val getterDescriptor = accessorDescriptor as? PropertyGetterDescriptor ?: TODO("not a getter?")
-            val getterBody = generateExpressionBody(getterDescriptor, ktGetter.bodyExpression ?: TODO("default getter"))
+            val getterBody = generateFunctionBody(getterDescriptor, ktGetter.bodyExpression ?: TODO("default getter"))
             declarationFactory.createPropertyGetter(ktGetter, irProperty, getterDescriptor, getterBody).register()
         }
         ktProperty.setter?.let { ktSetter ->
             val accessorDescriptor = getOrFail(BindingContext.PROPERTY_ACCESSOR, ktSetter)
             val setterDescriptor = accessorDescriptor as? PropertySetterDescriptor ?: TODO("not a setter?")
-            val setterBody = generateExpressionBody(setterDescriptor, ktSetter.bodyExpression ?: TODO("default setter"))
+            val setterBody = generateFunctionBody(setterDescriptor, ktSetter.bodyExpression ?: TODO("default setter"))
             declarationFactory.createPropertySetter(ktSetter, irProperty, setterDescriptor, setterBody).register()
         }
     }
@@ -93,8 +91,22 @@ abstract class IrDeclarationGeneratorBase(
         return propertyDescriptor
     }
 
-    fun generateExpressionBody(scopeOwner: DeclarationDescriptor, ktBody: KtExpression): IrBody =
+    private fun generateExpressionWithinContext(ktExpression: KtExpression, scopeOwner: DeclarationDescriptor): IrExpression =
-            IrExpressionBodyImpl(ktBody.startOffset, ktBody.endOffset).apply {
+            IrStatementGenerator(context, IrLocalDeclarationsFactory(scopeOwner)).generateExpression(ktExpression)
-                expression = IrStatementGenerator(context, IrLocalDeclarationsFactory(scopeOwner)).generateStatement(ktBody).assertCast()
+
-            }
+    private fun generateFunctionBody(scopeOwner: DeclarationDescriptor, ktBody: KtExpression): IrBody {
+        val irRhs = generateExpressionWithinContext(ktBody, scopeOwner)
+        val irExpressionBody =
+                if (ktBody is KtBlockExpression)
+                    irRhs
+                else
+                    IrBlockExpressionImpl(ktBody.startOffset, ktBody.endOffset, null, hasResult = false, isDesugared = true).apply {
+                        addStatement(IrReturnExpressionImpl(ktBody.startOffset, ktBody.endOffset, null, irRhs))
+                    }
+        return IrExpressionBodyImpl(ktBody.startOffset, ktBody.endOffset, irExpressionBody)
+    }
+
+    private fun generateInitializerBody(scopeOwner: DeclarationDescriptor, ktBody: KtExpression): IrBody =
+            IrExpressionBodyImpl(ktBody.startOffset, ktBody.endOffset,
+                                 generateExpressionWithinContext(ktBody, scopeOwner))
 }

compiler/testData/ir/irText/boxOk.txt

@@ -1,4 +1,6 @@
 IrFile /boxOk.kt
   IrFunction public fun box(): kotlin.String
     IrExpressionBody
-      LITERAL String type=kotlin.String value='OK'
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          LITERAL String type=kotlin.String value='OK'

compiler/testData/ir/irText/callWithReorderedArguments.txt

@@ -4,16 +4,24 @@ IrFile /callWithReorderedArguments.kt
       BLOCK type=kotlin.Unit hasResult=false isDesugared=false
   IrFunction public fun noReorder1(): kotlin.Int
     IrExpressionBody
-      LITERAL Int type=kotlin.Int value='1'
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          LITERAL Int type=kotlin.Int value='1'
   IrFunction public fun noReorder2(): kotlin.Int
     IrExpressionBody
-      LITERAL Int type=kotlin.Int value='2'
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          LITERAL Int type=kotlin.Int value='2'
   IrFunction public fun reordered1(): kotlin.Int
     IrExpressionBody
-      LITERAL Int type=kotlin.Int value='1'
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          LITERAL Int type=kotlin.Int value='1'
   IrFunction public fun reordered2(): kotlin.Int
     IrExpressionBody
-      LITERAL Int type=kotlin.Int value='2'
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          LITERAL Int type=kotlin.Int value='2'
   IrFunction public fun test(): kotlin.Unit
     IrExpressionBody
       BLOCK type=kotlin.Unit hasResult=false isDesugared=false

compiler/testData/ir/irText/calls.kt

@@ -5,3 +5,4 @@ fun qux(x: Int) = foo(foo(x, x), x)
 
 fun Int.ext1() = this
 fun Int.ext2(x: Int) = foo(this, x)
+fun Int.ext3(x: Int) = foo(ext1(), x)

compiler/testData/ir/irText/calls.txt

@@ -1,24 +1,42 @@
 IrFile /calls.kt
   IrFunction public fun foo(/*0*/ x: kotlin.Int, /*1*/ y: kotlin.Int): kotlin.Int
     IrExpressionBody
-      GET_VAR x type=kotlin.Int
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          GET_VAR x type=kotlin.Int
   IrFunction public fun bar(/*0*/ x: kotlin.Int): kotlin.Int
     IrExpressionBody
-      CALL .foo type=kotlin.Int operator=
+      BLOCK type=<no-type> hasResult=false isDesugared=true
-        x: GET_VAR x type=kotlin.Int
+        RETURN type=<no-type>
-        y: LITERAL Int type=kotlin.Int value='1'
+          CALL .foo type=kotlin.Int operator=
+            x: GET_VAR x type=kotlin.Int
+            y: LITERAL Int type=kotlin.Int value='1'
   IrFunction public fun qux(/*0*/ x: kotlin.Int): kotlin.Int
     IrExpressionBody
-      CALL .foo type=kotlin.Int operator=
+      BLOCK type=<no-type> hasResult=false isDesugared=true
-        x: CALL .foo type=kotlin.Int operator=
+        RETURN type=<no-type>
-          x: GET_VAR x type=kotlin.Int
+          CALL .foo type=kotlin.Int operator=
-          y: GET_VAR x type=kotlin.Int
+            x: CALL .foo type=kotlin.Int operator=
-        y: GET_VAR x type=kotlin.Int
+              x: GET_VAR x type=kotlin.Int
+              y: GET_VAR x type=kotlin.Int
+            y: GET_VAR x type=kotlin.Int
   IrFunction public fun kotlin.Int.ext1(): kotlin.Int
     IrExpressionBody
-      $RECEIVER of: ext1 type=kotlin.Int
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          $RECEIVER of: ext1 type=kotlin.Int
   IrFunction public fun kotlin.Int.ext2(/*0*/ x: kotlin.Int): kotlin.Int
     IrExpressionBody
-      CALL .foo type=kotlin.Int operator=
+      BLOCK type=<no-type> hasResult=false isDesugared=true
-        x: $RECEIVER of: ext2 type=kotlin.Int
+        RETURN type=<no-type>
-        y: GET_VAR x type=kotlin.Int
+          CALL .foo type=kotlin.Int operator=
+            x: $RECEIVER of: ext2 type=kotlin.Int
+            y: GET_VAR x type=kotlin.Int
+  IrFunction public fun kotlin.Int.ext3(/*0*/ x: kotlin.Int): kotlin.Int
+    IrExpressionBody
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          CALL .foo type=kotlin.Int operator=
+            x: CALL .ext1 type=kotlin.Int operator=
+              $receiver: $RECEIVER of: ext3 type=kotlin.Int
+            y: GET_VAR x type=kotlin.Int

compiler/testData/ir/irText/dotQualified.txt

@@ -1,9 +1,13 @@
 IrFile /dotQualified.kt
   IrFunction public fun length(/*0*/ s: kotlin.String): kotlin.Int
     IrExpressionBody
-      GET_PROPERTY .length type=kotlin.Int
+      BLOCK type=<no-type> hasResult=false isDesugared=true
-        $this: GET_VAR s type=kotlin.String
+        RETURN type=<no-type>
+          GET_PROPERTY .length type=kotlin.Int
+            $this: GET_VAR s type=kotlin.String
   IrFunction public fun lengthN(/*0*/ s: kotlin.String?): kotlin.Int?
     IrExpressionBody
-      GET_PROPERTY ?.length type=kotlin.Int?
+      BLOCK type=<no-type> hasResult=false isDesugared=true
-        $this: GET_VAR s type=kotlin.String?
+        RETURN type=<no-type>
+          GET_PROPERTY ?.length type=kotlin.Int?
+            $this: GET_VAR s type=kotlin.String?

compiler/testData/ir/irText/extensionPropertyGetterCall.txt

@@ -2,8 +2,12 @@ IrFile /extensionPropertyGetterCall.kt
   IrProperty public val kotlin.String.okext: kotlin.String getter=<get-okext> setter=null
   IrPropertyGetter public fun kotlin.String.<get-okext>(): kotlin.String property=okext
     IrExpressionBody
-      LITERAL String type=kotlin.String value='OK'
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          LITERAL String type=kotlin.String value='OK'
   IrFunction public fun kotlin.String.test5(): kotlin.String
     IrExpressionBody
-      GET_PROPERTY .okext type=kotlin.String
+      BLOCK type=<no-type> hasResult=false isDesugared=true
-        $receiver: $RECEIVER of: test5 type=kotlin.String
+        RETURN type=<no-type>
+          GET_PROPERTY .okext type=kotlin.String
+            $receiver: $RECEIVER of: test5 type=kotlin.String

compiler/testData/ir/irText/references.txt

@@ -8,13 +8,19 @@ IrFile /references.kt
   IrProperty public val ok3: kotlin.String getter=<get-ok3> setter=null
   IrPropertyGetter public fun <get-ok3>(): kotlin.String property=ok3
     IrExpressionBody
-      LITERAL String type=kotlin.String value='OK'
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          LITERAL String type=kotlin.String value='OK'
   IrFunction public fun test1(): kotlin.String
     IrExpressionBody
-      GET_PROPERTY .ok type=kotlin.String
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          GET_PROPERTY .ok type=kotlin.String
   IrFunction public fun test2(/*0*/ x: kotlin.String): kotlin.String
     IrExpressionBody
-      GET_VAR x type=kotlin.String
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          GET_VAR x type=kotlin.String
   IrFunction public fun test3(): kotlin.String
     IrExpressionBody
       BLOCK type=kotlin.Nothing hasResult=false isDesugared=false
@@ -24,12 +30,18 @@ IrFile /references.kt
           GET_VAR x type=kotlin.String
   IrFunction public fun test4(): kotlin.String
     IrExpressionBody
-      GET_PROPERTY .ok3 type=kotlin.String
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          GET_PROPERTY .ok3 type=kotlin.String
   IrProperty public val kotlin.String.okext: kotlin.String getter=<get-okext> setter=null
   IrPropertyGetter public fun kotlin.String.<get-okext>(): kotlin.String property=okext
     IrExpressionBody
-      LITERAL String type=kotlin.String value='OK'
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          LITERAL String type=kotlin.String value='OK'
   IrFunction public fun kotlin.String.test5(): kotlin.String
     IrExpressionBody
-      GET_PROPERTY .okext type=kotlin.String
+      BLOCK type=<no-type> hasResult=false isDesugared=true
-        $receiver: $RECEIVER of: test5 type=kotlin.String
+        RETURN type=<no-type>
+          GET_PROPERTY .okext type=kotlin.String
+            $receiver: $RECEIVER of: test5 type=kotlin.String

compiler/testData/ir/irText/smoke.txt

@@ -10,14 +10,18 @@ IrFile /smoke.kt
   IrProperty public val testValWithGetter: kotlin.Int getter=<get-testValWithGetter> setter=null
   IrPropertyGetter public fun <get-testValWithGetter>(): kotlin.Int property=testValWithGetter
     IrExpressionBody
-      LITERAL Int type=kotlin.Int value='42'
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          LITERAL Int type=kotlin.Int value='42'
   IrProperty public var testSimpleVar: kotlin.Int getter=null setter=null
     IrExpressionBody
       LITERAL Int type=kotlin.Int value='2'
   IrProperty public var testVarWithAccessors: kotlin.Int getter=<get-testVarWithAccessors> setter=<set-testVarWithAccessors>
   IrPropertyGetter public fun <get-testVarWithAccessors>(): kotlin.Int property=testVarWithAccessors
     IrExpressionBody
-      LITERAL Int type=kotlin.Int value='42'
+      BLOCK type=<no-type> hasResult=false isDesugared=true
+        RETURN type=<no-type>
+          LITERAL Int type=kotlin.Int value='42'
   IrPropertySetter public fun <set-testVarWithAccessors>(/*0*/ v: kotlin.Int): kotlin.Unit property=testVarWithAccessors
     IrExpressionBody
       BLOCK type=kotlin.Unit hasResult=false isDesugared=false