Use builder API in increment/decrement desugaring.

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/builders/IrBuilder.kt

@@ -16,10 +16,13 @@
 
 package org.jetbrains.kotlin.psi2ir.builders
 
-import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
+import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
 import org.jetbrains.kotlin.ir.expressions.*
+import org.jetbrains.kotlin.psi.KtElement
+import org.jetbrains.kotlin.psi.psiUtil.endOffset
+import org.jetbrains.kotlin.psi.psiUtil.startOffset
 import org.jetbrains.kotlin.psi2ir.generators.Generator
 import org.jetbrains.kotlin.psi2ir.generators.GeneratorContext
 import org.jetbrains.kotlin.psi2ir.generators.GeneratorWithScope
@@ -81,6 +84,11 @@ class IrBlockBuilder(
 ) : IrStatementsBuilder<IrBlock>(context, scope, startOffset, endOffset) {
     private val statements = ArrayList<IrStatement>()
 
+    inline fun block(body: IrBlockBuilder.() -> Unit): IrBlock {
+        body()
+        return doBuild()
+    }
+
     override fun addStatement(irStatement: IrStatement) {
         statements.add(irStatement)
     }
@@ -100,3 +108,12 @@ fun <T : IrBuilder> T.at(startOffset: Int, endOffset: Int): T {
     this.endOffset = endOffset
     return this
 }
+
+inline fun GeneratorWithScope.irBlock(ktElement: KtElement? = null, operator: IrOperator? = null, resultType: KotlinType? = null,
+                                      body: IrBlockBuilder.() -> Unit
+): IrExpression =
+        IrBlockBuilder(context, scope,
+                       ktElement?.startOffset ?: UNDEFINED_OFFSET,
+                       ktElement?.endOffset ?: UNDEFINED_OFFSET,
+                       operator, resultType
+        ).block(body)

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

@@ -21,13 +21,14 @@ import org.jetbrains.kotlin.descriptors.ConstructorDescriptor
 import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import org.jetbrains.kotlin.descriptors.impl.LocalVariableDescriptor
 import org.jetbrains.kotlin.descriptors.impl.SyntheticFieldDescriptor
-import org.jetbrains.kotlin.ir.expressions.IrBlockImpl
 import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrOperator
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
 import org.jetbrains.kotlin.psi.psiUtil.startOffset
-import org.jetbrains.kotlin.psi2ir.defaultLoad
+import org.jetbrains.kotlin.psi2ir.builders.defineTemporary
+import org.jetbrains.kotlin.psi2ir.builders.irBlock
+import org.jetbrains.kotlin.psi2ir.builders.irGet
 import org.jetbrains.kotlin.psi2ir.intermediate.*
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.calls.callUtil.isSafeCall
@@ -72,22 +73,14 @@ class AssignmentGenerator(statementGenerator: StatementGenerator) : StatementGen
         val irAssignmentReceiver = generateAssignmentReceiver(ktBaseExpression, irOperator)
 
         return irAssignmentReceiver.assign { irLValue ->
-            val irBlock = IrBlockImpl(expression.startOffset, expression.endOffset, irLValue.type, irOperator)
-
-            // VAR tmp = [lhs].inc()
-            val opCall = statementGenerator.pregenerateCall(opResolvedCall)
-            opCall.setExplicitReceiverValue(irLValue)
-            val irOpCall = CallGenerator(statementGenerator).generateCall(expression, opCall, irOperator)
-            val irTmp = statementGenerator.scope.createTemporaryVariable(irOpCall)
-            irBlock.addStatement(irTmp)
-
-            // [lhs] = tmp
-            irBlock.addStatement(irLValue.store(irTmp.defaultLoad()))
-
-            // ^ tmp
-            irBlock.addStatement(irTmp.defaultLoad())
-
-            irBlock
+            irBlock(expression, irOperator, irLValue.type) {
+                val opCall = statementGenerator.pregenerateCall(opResolvedCall)
+                opCall.setExplicitReceiverValue(irLValue)
+                val irOpCall = CallGenerator(statementGenerator).generateCall(expression, opCall, irOperator)
+                val temporary = defineTemporary(irOpCall)
+                +irLValue.store(irGet(temporary))
+                +irGet(temporary)
+            }
         }
     }
 
@@ -97,22 +90,14 @@ class AssignmentGenerator(statementGenerator: StatementGenerator) : StatementGen
         val irAssignmentReceiver = generateAssignmentReceiver(ktBaseExpression, irOperator)
 
         return irAssignmentReceiver.assign { irLValue ->
-            val irBlock = IrBlockImpl(expression.startOffset, expression.endOffset, irLValue.type, irOperator)
-
-            // VAR tmp = [lhs]
-            val irTmp = scope.createTemporaryVariable(irLValue.load())
-            irBlock.addStatement(irTmp)
-
-            // [lhs] = tmp.inc()
-            val opCall = statementGenerator.pregenerateCall(opResolvedCall)
-            opCall.setExplicitReceiverValue(VariableLValue(irTmp))
-            val irOpCall = CallGenerator(statementGenerator).generateCall(expression, opCall, irOperator)
-            irBlock.addStatement(irLValue.store(irOpCall))
-
-            // ^ tmp
-            irBlock.addStatement(irTmp.defaultLoad())
-
-            irBlock
+            irBlock(expression, irOperator, irLValue.type) {
+                val temporary = defineTemporary(irLValue.load())
+                val opCall = statementGenerator.pregenerateCall(opResolvedCall)
+                opCall.setExplicitReceiverValue(VariableLValue(startOffset, endOffset, temporary))
+                val irOpCall = CallGenerator(statementGenerator).generateCall(expression, opCall, irOperator)
+                +irLValue.store(irOpCall)
+                +irGet(temporary)
+            }
         }
     }