NoArg: Initialize properties in noarg constructor (KT-16692)

2017-05-04 17:55:35 +03:00
parent eba5baa7ff
commit 254e8156ac
13 changed files with 243 additions and 140 deletions
@@ -0,0 +1,83 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.noarg
+
+import org.jetbrains.kotlin.codegen.*
+import org.jetbrains.kotlin.codegen.context.ConstructorContext
+import org.jetbrains.kotlin.codegen.extensions.ExpressionCodegenExtension
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.annotations.Annotations
+import org.jetbrains.kotlin.descriptors.impl.ClassConstructorDescriptorImpl
+import org.jetbrains.kotlin.psi.KtClass
+import org.jetbrains.kotlin.resolve.descriptorUtil.getSuperClassOrAny
+import org.jetbrains.kotlin.resolve.descriptorUtil.hasDefaultValue
+import org.jetbrains.kotlin.resolve.jvm.AsmTypes
+import org.jetbrains.kotlin.resolve.jvm.annotations.findJvmOverloadsAnnotation
+import org.jetbrains.kotlin.resolve.jvm.diagnostics.JvmDeclarationOrigin
+import org.jetbrains.kotlin.resolve.jvm.jvmSignature.JvmMethodSignature
+import org.jetbrains.kotlin.codegen.FunctionGenerationStrategy.CodegenBased
+import org.jetbrains.kotlin.resolve.descriptorUtil.builtIns
+import org.jetbrains.org.objectweb.asm.Opcodes
+import org.jetbrains.org.objectweb.asm.Type
+
+class NoArgExpressionCodegenExtension : ExpressionCodegenExtension {
+    override fun generateClassSyntheticParts(codegen: ImplementationBodyCodegen) = with(codegen) {
+        if (shouldGenerateNoArgConstructor()) {
+            generateNoArgConstructor()
+        }
+    }
+
+    private fun ImplementationBodyCodegen.generateNoArgConstructor() {
+        val superClassInternalName = typeMapper.mapClass(descriptor.getSuperClassOrAny()).internalName
+
+        val constructorDescriptor = createNoArgConstructorDescriptor(descriptor)
+
+        functionCodegen.generateMethod(JvmDeclarationOrigin.NO_ORIGIN, constructorDescriptor, object: CodegenBased(state) {
+            override fun doGenerateBody(codegen: ExpressionCodegen, signature: JvmMethodSignature) {
+                codegen.v.load(0, AsmTypes.OBJECT_TYPE)
+                codegen.v.visitMethodInsn(Opcodes.INVOKESPECIAL, superClassInternalName, "<init>", "()V", false)
+                generateInitializers(codegen)
+                codegen.v.visitInsn(Opcodes.RETURN)
+            }
+        })
+    }
+
+    private fun createNoArgConstructorDescriptor(containingClass: ClassDescriptor): ConstructorDescriptor {
+        return ClassConstructorDescriptorImpl.createSynthesized(containingClass, Annotations.EMPTY, false, SourceElement.NO_SOURCE).apply {
+            initialize(null, calculateDispatchReceiverParameter(), emptyList(), emptyList(),
+                       containingClass.builtIns.unitType, Modality.OPEN, Visibilities.PUBLIC)
+        }
+    }
+
+    private fun KtClass.isNoArgClass() = this.getUserData(NO_ARG_CLASS_KEY) ?: false
+
+    private fun ImplementationBodyCodegen.shouldGenerateNoArgConstructor(): Boolean {
+        val origin = myClass as? KtClass ?: return false
+
+        if (descriptor.kind != ClassKind.CLASS || !origin.isNoArgClass()) {
+            return false
+        }
+
+        return descriptor.constructors.none { it.isZeroParameterConstructor() }
+    }
+
+    private fun ClassConstructorDescriptor.isZeroParameterConstructor(): Boolean {
+        val parameters = this.valueParameters
+        return parameters.isEmpty()
+               || (parameters.all { it.hasDefaultValue() } && (isPrimary || findJvmOverloadsAnnotation() != null))
+    }
+}