1 /*
2  * ProGuard -- shrinking, optimization, obfuscation, and preverification
3  *             of Java bytecode.
4  *
5  * Copyright (c) 2002-2014 Eric Lafortune (eric@graphics.cornell.edu)
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License as published by the Free
9  * Software Foundation; either version 2 of the License, or (at your option)
10  * any later version.
11  *
12  * This program is distributed in the hope that it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15  * more details.
16  *
17  * You should have received a copy of the GNU General Public License along
18  * with this program; if not, write to the Free Software Foundation, Inc.,
19  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20  */
21 package proguard.optimize.info;
22 
23 import proguard.classfile.*;
24 import proguard.classfile.attribute.CodeAttribute;
25 import proguard.classfile.constant.*;
26 import proguard.classfile.constant.visitor.ConstantVisitor;
27 import proguard.classfile.instruction.*;
28 import proguard.classfile.instruction.visitor.InstructionVisitor;
29 import proguard.classfile.util.SimplifiedVisitor;
30 import proguard.classfile.visitor.ClassVisitor;
31 
32 /**
33  * This InstructionVisitor marks all classes that are used in a .class
34  * construct by any of the instructions that it visits.
35  *
36  * @author Eric Lafortune
37  */
38 public class DotClassMarker
39 extends      SimplifiedVisitor
40 implements   InstructionVisitor,
41              ConstantVisitor,
42              ClassVisitor
43 {
44     // Implementations for InstructionVisitor.
45 
visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction)46     public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction) {}
47 
48 
visitConstantInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, ConstantInstruction constantInstruction)49     public void visitConstantInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, ConstantInstruction constantInstruction)
50     {
51         if (constantInstruction.opcode == InstructionConstants.OP_LDC ||
52             constantInstruction.opcode == InstructionConstants.OP_LDC_W)
53         {
54             clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this);
55         }
56     }
57 
58 
59     // Implementations for ConstantVisitor.
60 
visitAnyConstant(Clazz clazz, Constant constant)61     public void visitAnyConstant(Clazz clazz, Constant constant) {}
62 
visitClassConstant(Clazz clazz, ClassConstant classConstant)63     public void visitClassConstant(Clazz clazz, ClassConstant classConstant)
64     {
65         classConstant.referencedClassAccept(this);
66     }
67 
68 
69     // Implementations for ClassVisitor.
70 
visitLibraryClass(LibraryClass libraryClass)71     public void visitLibraryClass(LibraryClass libraryClass) {}
72 
visitProgramClass(ProgramClass programClass)73     public void visitProgramClass(ProgramClass programClass)
74     {
75         setDotClassed(programClass);
76     }
77 
78 
79     // Small utility methods.
80 
setDotClassed(Clazz clazz)81     private static void setDotClassed(Clazz clazz)
82     {
83         ClassOptimizationInfo info = ClassOptimizationInfo.getClassOptimizationInfo(clazz);
84         if (info != null)
85         {
86             info.setDotClassed();
87         }
88     }
89 
90 
isDotClassed(Clazz clazz)91     public static boolean isDotClassed(Clazz clazz)
92     {
93         ClassOptimizationInfo info = ClassOptimizationInfo.getClassOptimizationInfo(clazz);
94         return info == null || info.isDotClassed();
95     }
96 }