| /* |
| * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package jdk.nashorn.internal.codegen.types; |
| |
| import jdk.internal.org.objectweb.asm.MethodVisitor; |
| |
| |
| /** |
| * Interface for byte code generation for all runtime types. Each |
| * type implements this interface and provides the type specific |
| * operations to do the generic things described herein. |
| * |
| * The bytecode ops are coupled to a MethodVisitor from ASM for |
| * byte code generation. They know nothing about our MethodGenerator, |
| * which is the abstraction for working with Nashorn JS types |
| * For exmaple, anything like "two or one slots" for a type, which |
| * is represented in bytecode and ASM, is abstracted away in the |
| * MethodGenerator. There you just say "dup" or "store". |
| * |
| * @see Type |
| * @see MethodVisitor |
| */ |
| interface BytecodeOps { |
| |
| /** |
| * Duplicate top entry of stack. If a too large depth is |
| * given, so that there are no possible bytecode instructions |
| * available to generate the dup sequence, null is returned. |
| * |
| * @param method method visitor |
| * @param depth how far should the copy be pushed down |
| * |
| * @return the type at the top of the stack or null |
| */ |
| Type dup(MethodVisitor method, int depth); |
| |
| /** |
| * Pop an entry of this type from the top of the bytecode |
| * stack. This works regardless of what category this type |
| * is |
| * |
| * @param method method visitor |
| * |
| * @return the popped type |
| */ |
| Type pop(MethodVisitor method); |
| |
| /** |
| * Swap this type with the bytecode stack with the one below |
| * Generate appropriate code no matter the categories of the |
| * two types |
| * |
| * @param method method visitor |
| * @param other the type below this one on the stack |
| * |
| * @return the other type |
| */ |
| Type swap(MethodVisitor method, Type other); |
| |
| /** |
| * Pop two values on top of the stack and add the |
| * first to the second, pushing the result on the stack |
| * |
| * @param method method visitor |
| * @param programPoint program point id |
| * @return result type |
| */ |
| Type add(MethodVisitor method, int programPoint); |
| |
| /** |
| * Load a variable from a local slot to the stack |
| * |
| * @param method method visitor |
| * @param slot the slot to load |
| * |
| * @return the type that was loaded |
| */ |
| Type load(MethodVisitor method, int slot); |
| |
| /** |
| * Store a variable from the stack to a local slot |
| * |
| * @param method method visitor |
| * @param slot the slot to store to |
| */ |
| void store(MethodVisitor method, int slot); |
| |
| /** |
| * Load a constant to the stack. |
| * |
| * @param method method visitor |
| * @param c the value of the constant |
| * |
| * @return the type at the top of the stack after load |
| */ |
| Type ldc(MethodVisitor method, Object c); |
| |
| /** |
| * Load the "undefined" value to the stack. Note that |
| * there may be different representations of this for |
| * e.g. doubles and objects. Abstraction removes this |
| * |
| * @param method method visitor. |
| * |
| * @return the undefined type at the top of the stack |
| */ |
| Type loadUndefined(MethodVisitor method); |
| |
| /** |
| * Load the "forced initializer" value to the stack, used to ensure that a local variable has a value when it is |
| * read by the unwarranted optimism catch block. |
| * |
| * @param method method visitor. |
| * |
| * @return the forced initialization type at the top of the stack |
| */ |
| Type loadForcedInitializer(MethodVisitor method); |
| |
| |
| /** |
| * Load the "empty" value to the stack. |
| * |
| * @param method method visitor. |
| * @return the undefined type at the top of the stack |
| */ |
| Type loadEmpty(MethodVisitor method); |
| |
| /** |
| * Generate code that pops and casts the element on top of the |
| * stack to another type, given as parameter |
| * |
| * @param method method visitor |
| * @param to the type to cast to |
| * |
| * @return the to type |
| */ |
| Type convert(MethodVisitor method, Type to); |
| |
| /** |
| * Return the parameter on top of the stack |
| * from a method |
| * |
| * @param method the method visitor |
| */ |
| void _return(MethodVisitor method); |
| |
| } |