1 /*
   2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.  Oracle designates this
   7  * particular file as subject to the "Classpath" exception as provided
   8  * by Oracle in the LICENSE file that accompanied this code.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  */
  24 
  25 /*
  26  * This file is available under and governed by the GNU General Public
  27  * License version 2 only, as published by the Free Software Foundation.
  28  * However, the following notice accompanied the original version of this
  29  * file:
  30  *
  31  * ASM: a very small and fast Java bytecode manipulation framework
  32  * Copyright (c) 2000-2011 INRIA, France Telecom
  33  * All rights reserved.
  34  *
  35  * Redistribution and use in source and binary forms, with or without
  36  * modification, are permitted provided that the following conditions
  37  * are met:
  38  * 1. Redistributions of source code must retain the above copyright
  39  *    notice, this list of conditions and the following disclaimer.
  40  * 2. Redistributions in binary form must reproduce the above copyright
  41  *    notice, this list of conditions and the following disclaimer in the
  42  *    documentation and/or other materials provided with the distribution.
  43  * 3. Neither the name of the copyright holders nor the names of its
  44  *    contributors may be used to endorse or promote products derived from
  45  *    this software without specific prior written permission.
  46  *
  47  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  48  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  49  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  50  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  51  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  52  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  53  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  54  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  55  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  56  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  57  * THE POSSIBILITY OF SUCH DAMAGE.
  58  */
  59 package jdk.internal.org.objectweb.asm.commons;
  60 
  61 import jdk.internal.org.objectweb.asm.Handle;
  62 import jdk.internal.org.objectweb.asm.Label;
  63 import jdk.internal.org.objectweb.asm.MethodVisitor;
  64 import jdk.internal.org.objectweb.asm.Opcodes;
  65 
  66 /**
  67  * A {@link MethodVisitor} that can be used to approximate method size.
  68  *
  69  * @author Eugene Kuleshov
  70  */
  71 public class CodeSizeEvaluator extends MethodVisitor implements Opcodes {
  72 
  73     private int minSize;
  74 
  75     private int maxSize;
  76 
  77     public CodeSizeEvaluator(final MethodVisitor mv) {
  78         this(Opcodes.ASM6, mv);
  79     }
  80 
  81     protected CodeSizeEvaluator(final int api, final MethodVisitor mv) {
  82         super(api, mv);
  83     }
  84 
  85     public int getMinSize() {
  86         return this.minSize;
  87     }
  88 
  89     public int getMaxSize() {
  90         return this.maxSize;
  91     }
  92 
  93     @Override
  94     public void visitInsn(final int opcode) {
  95         minSize += 1;
  96         maxSize += 1;
  97         if (mv != null) {
  98             mv.visitInsn(opcode);
  99         }
 100     }
 101 
 102     @Override
 103     public void visitIntInsn(final int opcode, final int operand) {
 104         if (opcode == SIPUSH) {
 105             minSize += 3;
 106             maxSize += 3;
 107         } else {
 108             minSize += 2;
 109             maxSize += 2;
 110         }
 111         if (mv != null) {
 112             mv.visitIntInsn(opcode, operand);
 113         }
 114     }
 115 
 116     @Override
 117     public void visitVarInsn(final int opcode, final int var) {
 118         if (var < 4 && opcode != RET) {
 119             minSize += 1;
 120             maxSize += 1;
 121         } else if (var >= 256) {
 122             minSize += 4;
 123             maxSize += 4;
 124         } else {
 125             minSize += 2;
 126             maxSize += 2;
 127         }
 128         if (mv != null) {
 129             mv.visitVarInsn(opcode, var);
 130         }
 131     }
 132 
 133     @Override
 134     public void visitTypeInsn(final int opcode, final String type) {
 135         minSize += 3;
 136         maxSize += 3;
 137         if (mv != null) {
 138             mv.visitTypeInsn(opcode, type);
 139         }
 140     }
 141 
 142     @Override
 143     public void visitFieldInsn(final int opcode, final String owner,
 144             final String name, final String desc) {
 145         minSize += 3;
 146         maxSize += 3;
 147         if (mv != null) {
 148             mv.visitFieldInsn(opcode, owner, name, desc);
 149         }
 150     }
 151 
 152     @Deprecated
 153     @Override
 154     public void visitMethodInsn(final int opcode, final String owner,
 155             final String name, final String desc) {
 156         if (api >= Opcodes.ASM5) {
 157             super.visitMethodInsn(opcode, owner, name, desc);
 158             return;
 159         }
 160         doVisitMethodInsn(opcode, owner, name, desc,
 161                 opcode == Opcodes.INVOKEINTERFACE);
 162     }
 163 
 164     @Override
 165     public void visitMethodInsn(final int opcode, final String owner,
 166             final String name, final String desc, final boolean itf) {
 167         if (api < Opcodes.ASM5) {
 168             super.visitMethodInsn(opcode, owner, name, desc, itf);
 169             return;
 170         }
 171         doVisitMethodInsn(opcode, owner, name, desc, itf);
 172     }
 173 
 174     private void doVisitMethodInsn(int opcode, final String owner,
 175             final String name, final String desc, final boolean itf) {
 176         if (opcode == INVOKEINTERFACE) {
 177             minSize += 5;
 178             maxSize += 5;
 179         } else {
 180             minSize += 3;
 181             maxSize += 3;
 182         }
 183         if (mv != null) {
 184             mv.visitMethodInsn(opcode, owner, name, desc, itf);
 185         }
 186     }
 187 
 188     @Override
 189     public void visitInvokeDynamicInsn(String name, String desc, Handle bsm,
 190             Object... bsmArgs) {
 191         minSize += 5;
 192         maxSize += 5;
 193         if (mv != null) {
 194             mv.visitInvokeDynamicInsn(name, desc, bsm, bsmArgs);
 195         }
 196     }
 197 
 198     @Override
 199     public void visitJumpInsn(final int opcode, final Label label) {
 200         minSize += 3;
 201         if (opcode == GOTO || opcode == JSR) {
 202             maxSize += 5;
 203         } else {
 204             maxSize += 8;
 205         }
 206         if (mv != null) {
 207             mv.visitJumpInsn(opcode, label);
 208         }
 209     }
 210 
 211     @Override
 212     public void visitLdcInsn(final Object cst) {
 213         if (cst instanceof Long || cst instanceof Double) {
 214             minSize += 3;
 215             maxSize += 3;
 216         } else {
 217             minSize += 2;
 218             maxSize += 3;
 219         }
 220         if (mv != null) {
 221             mv.visitLdcInsn(cst);
 222         }
 223     }
 224 
 225     @Override
 226     public void visitIincInsn(final int var, final int increment) {
 227         if (var > 255 || increment > 127 || increment < -128) {
 228             minSize += 6;
 229             maxSize += 6;
 230         } else {
 231             minSize += 3;
 232             maxSize += 3;
 233         }
 234         if (mv != null) {
 235             mv.visitIincInsn(var, increment);
 236         }
 237     }
 238 
 239     @Override
 240     public void visitTableSwitchInsn(final int min, final int max,
 241             final Label dflt, final Label... labels) {
 242         minSize += 13 + labels.length * 4;
 243         maxSize += 16 + labels.length * 4;
 244         if (mv != null) {
 245             mv.visitTableSwitchInsn(min, max, dflt, labels);
 246         }
 247     }
 248 
 249     @Override
 250     public void visitLookupSwitchInsn(final Label dflt, final int[] keys,
 251             final Label[] labels) {
 252         minSize += 9 + keys.length * 8;
 253         maxSize += 12 + keys.length * 8;
 254         if (mv != null) {
 255             mv.visitLookupSwitchInsn(dflt, keys, labels);
 256         }
 257     }
 258 
 259     @Override
 260     public void visitMultiANewArrayInsn(final String desc, final int dims) {
 261         minSize += 4;
 262         maxSize += 4;
 263         if (mv != null) {
 264             mv.visitMultiANewArrayInsn(desc, dims);
 265         }
 266     }
 267 }