1 /*
   2  * Copyright (c) 2010, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.nashorn.internal.codegen.types;
  27 
  28 import static jdk.internal.org.objectweb.asm.Opcodes.I2D;
  29 import static jdk.internal.org.objectweb.asm.Opcodes.I2L;
  30 import static jdk.internal.org.objectweb.asm.Opcodes.ICONST_0;
  31 import static jdk.internal.org.objectweb.asm.Opcodes.ICONST_1;
  32 import static jdk.internal.org.objectweb.asm.Opcodes.ILOAD;
  33 import static jdk.internal.org.objectweb.asm.Opcodes.IRETURN;
  34 import static jdk.internal.org.objectweb.asm.Opcodes.ISTORE;
  35 import static jdk.nashorn.internal.codegen.CompilerConstants.staticCallNoLookup;
  36 import static jdk.nashorn.internal.runtime.JSType.UNDEFINED_INT;
  37 
  38 import jdk.internal.org.objectweb.asm.MethodVisitor;
  39 import jdk.nashorn.internal.codegen.CompilerConstants;
  40 
  41 /**
  42  * The boolean type class
  43  */
  44 public final class BooleanType extends Type {
  45     private static final long serialVersionUID = 1L;
  46 
  47     private static final CompilerConstants.Call VALUE_OF = staticCallNoLookup(Boolean.class, "valueOf", Boolean.class, boolean.class);
  48     private static final CompilerConstants.Call TO_STRING = staticCallNoLookup(Boolean.class, "toString", String.class, boolean.class);
  49 
  50     /**
  51      * Constructor
  52      */
  53     protected BooleanType() {
  54         super("boolean", boolean.class, 1, 1);
  55     }
  56 
  57     @Override
  58     public Type nextWider() {
  59         return INT;
  60     }
  61 
  62     @Override
  63     public Class<?> getBoxedType() {
  64         return Boolean.class;
  65     }
  66 
  67     @Override
  68     public char getBytecodeStackType() {
  69         return 'I';
  70     }
  71 
  72     @Override
  73     public Type loadUndefined(final MethodVisitor method) {
  74         method.visitLdcInsn(UNDEFINED_INT);
  75         return BOOLEAN;
  76     }
  77 
  78     @Override
  79     public Type loadForcedInitializer(final MethodVisitor method) {
  80         method.visitInsn(ICONST_0);
  81         return BOOLEAN;
  82     }
  83 
  84     @Override
  85     public void _return(final MethodVisitor method) {
  86         method.visitInsn(IRETURN);
  87     }
  88 
  89     @Override
  90     public Type load(final MethodVisitor method, final int slot) {
  91         assert slot != -1;
  92         method.visitVarInsn(ILOAD, slot);
  93         return BOOLEAN;
  94     }
  95 
  96     @Override
  97     public void store(final MethodVisitor method, final int slot) {
  98         assert slot != -1;
  99         method.visitVarInsn(ISTORE, slot);
 100     }
 101 
 102     @Override
 103     public Type ldc(final MethodVisitor method, final Object c) {
 104         assert c instanceof Boolean;
 105         method.visitInsn((Boolean) c ? ICONST_1 : ICONST_0);
 106         return BOOLEAN;
 107     }
 108 
 109     @Override
 110     public Type convert(final MethodVisitor method, final Type to) {
 111         if (isEquivalentTo(to)) {
 112             return to;
 113         }
 114 
 115         if (to.isNumber()) {
 116             method.visitInsn(I2D);
 117         } else if (to.isLong()) {
 118             method.visitInsn(I2L);
 119         } else if (to.isInteger()) {
 120             //nop
 121         } else if (to.isString()) {
 122             invokestatic(method, TO_STRING);
 123         } else if (to.isObject()) {
 124             invokestatic(method, VALUE_OF);
 125         } else {
 126             throw new UnsupportedOperationException("Illegal conversion " + this + " -> " + to);
 127         }
 128 
 129         return to;
 130     }
 131 
 132     @Override
 133     public Type add(final MethodVisitor method, final int programPoint) {
 134         // Adding booleans in JavaScript is perfectly valid, they add as if false=0 and true=1
 135         return Type.INT.add(method, programPoint);
 136     }
 137 }