Drop KFunctionFromReferenceImpl, make FunctionImpl an interface

23 invokes in KFunctionFromReferenceImpl (and consequently, in FunctionImpl)
were needed before 1576160390: a wrapped function
reference must have had the necessary invoke to be called as an instance of a
specific function type. After 1576160390, this is
not needed anymore because KFunctionFromReferenceImpl is now an internal
implementation detail of reflection, and no invoke is ever called on it.

generators/src/org/jetbrains/kotlin/generators/builtins/functionImpl.kt

@@ -1,80 +0,0 @@
-/*
- * Copyright 2010-2015 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.generators.builtins.functionImpl
-
-import org.jetbrains.kotlin.generators.builtins.functions.MAX_PARAM_COUNT
-import org.jetbrains.kotlin.generators.builtins.generateBuiltIns.BuiltInsSourceGenerator
-import org.jetbrains.kotlin.generators.builtins.generateBuiltIns.BuiltInsSourceGenerator.Language
-import java.io.PrintWriter
-
-class GenerateFunctionImpl(out: PrintWriter) : BuiltInsSourceGenerator(out) {
-    override fun getPackage() = "kotlin.jvm.internal"
-
-    override val language = Language.JAVA
-
-    override fun generateBody() {
-        val n = MAX_PARAM_COUNT
-
-        out.print("""import kotlin.Function;
-import kotlin.jvm.functions.*;
-
-import java.io.Serializable;
-
-public abstract class FunctionImpl
-        implements Function, Serializable,""")
-
-        for (i in 0..n) {
-            if (i % 10 == 0) {
-                // Insert newline sometimes to avoid very long lines
-                out.println()
-                out.print("                   ")
-            }
-            out.print("Function$i")
-            if (i < n) out.print(", ")
-        }
-
-        out.println(" {")
-
-        out.println("""
-    public abstract int getArity();
-
-    public Object invokeVararg(Object... p) {
-        throw new UnsupportedOperationException();
-    }
-
-    private void checkArity(int expected) {
-        if (getArity() != expected) {
-            throwWrongArity(expected);
-        }
-    }
-
-    private void throwWrongArity(int expected) {
-        throw new IllegalStateException("Wrong function arity, expected: " + expected + ", actual: " + getArity());
-    }""")
-
-        for (i in 0..n) {
-            out.println()
-            out.println("    @Override")
-            out.println("    public Object invoke(" + (1..i).joinToString { "Object p$it" } + ") {")
-            out.println("        checkArity($i);")
-            out.println("        return invokeVararg(" + (1..i).joinToString { "p$it" } + ");")
-            out.println("    }")
-        }
-
-        out.println("}")
-    }
-}

generators/src/org/jetbrains/kotlin/generators/builtins/generateBuiltIns.kt

@@ -18,7 +18,6 @@ package org.jetbrains.kotlin.generators.builtins.generateBuiltIns
 
 import org.jetbrains.kotlin.generators.builtins.arrayIterators.GenerateArrayIterators
 import org.jetbrains.kotlin.generators.builtins.arrays.GenerateArrays
-import org.jetbrains.kotlin.generators.builtins.functionImpl.GenerateFunctionImpl
 import org.jetbrains.kotlin.generators.builtins.functions.GenerateFunctions
 import org.jetbrains.kotlin.generators.builtins.iterators.GenerateIterators
 import org.jetbrains.kotlin.generators.builtins.progressionIterators.GenerateProgressionIterators
@@ -41,21 +40,19 @@ abstract class BuiltInsSourceGenerator(val out: PrintWriter) {
 
     protected open fun getPackage(): String = "kotlin"
 
-    protected open val language: Language = Language.KOTLIN
-
     enum class Language {
         KOTLIN,
         JAVA
     }
 
-    final fun generate() {
+    fun generate() {
         out.println(File("license/LICENSE.txt").readText())
         // Don't include generator class name in the message: these are built-in sources,
         // and we don't want to scare users with any internal information about our project
         out.println("// Auto-generated file. DO NOT EDIT!")
         out.println()
         out.print("package ${getPackage()}")
-        if (language == Language.KOTLIN) out.println() else out.println(";")
+        out.println()
         out.println()
 
         generateBody()
@@ -68,7 +65,6 @@ fun generateBuiltIns(generate: (File, (PrintWriter) -> BuiltInsSourceGenerator)
     assertExists(RUNTIME_JVM_DIR)
 
     generate(File(RUNTIME_JVM_DIR, "kotlin/jvm/functions/Functions.kt")) { GenerateFunctions(it) }
-    generate(File(RUNTIME_JVM_DIR, "kotlin/jvm/internal/FunctionImpl.java")) { GenerateFunctionImpl(it) }
     generate(File(BUILT_INS_NATIVE_DIR, "kotlin/Arrays.kt")) { GenerateArrays(it) }
     generate(File(BUILT_INS_NATIVE_DIR, "kotlin/Primitives.kt")) { GeneratePrimitives(it) }
     generate(File(BUILT_INS_SRC_DIR, "kotlin/Iterators.kt")) { GenerateIterators(it) }