1 <!doctype html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2 <html> 3 <head> 4 <meta http-equiv="content-type" content="text/html; charset=iso-8859-1"> 5 <meta http-equiv="content-style-type" content="text/css"> 6 <link rel="stylesheet" type="text/css" href="style.css"> 7 <title>Attributes</title> 8 </head> 9 <body> 10 11 <script type="text/javascript" language="JavaScript"> 12 <!-- 13 if (window.self==window.top) 14 document.write('<a class="largebutton" target="_top" href="../index.html#manual/attributes.html">ProGuard index</a> <a class="largebutton" target="_top" href="http://www.saikoa.com/dexguard">DexGuard</a> <a class="largebutton" target="_top" href="http://www.saikoa.com/">Saikoa</a> <a class="largebutton" target="other" href="http://sourceforge.net/projects/proguard/">Sourceforge</a>') 15 //--> 16 </script> 17 <noscript> 18 <a class="largebutton" target="_top" href="../index.html#manual/attributes.html">ProGuard index</a> 19 <a class="largebutton" target="_top" href="http://www.saikoa.com/dexguard">DexGuard</a> 20 <a class="largebutton" target="_top" href="http://www.saikoa.com/">Saikoa</a> 21 <a class="largebutton" target="other" href="http://sourceforge.net/projects/proguard/">Sourceforge</a> 22 </noscript> 23 24 <h2>Attributes</h2> 25 26 Class files essentially define classes, their fields, and their methods. A lot 27 of essential and non-essential data are attached to these classes, fields, and 28 methods as <i>attributes</i>. For instance, attributes can contain bytecode, 29 source file names, line number tables, etc. 30 <p> 31 32 ProGuard's obfuscation step removes attributes that are generally not 33 necessary for executing the code. With 34 the <a href="usage.html#keepattributes"><code>-keepattributes</code></a> 35 option, you can specify a filter for attributes that you do want to keep, for 36 instance, if your code accesses them through reflection or if you want to 37 preserve some compilation or debugging information. The filter works like 38 any <a href="usage.html#filters">filter</a> in ProGuard. 39 <p> 40 41 The following wildcards are supported: 42 43 <table cellspacing="10"> 44 <tr><td valign="top"><code><b>?</b></code></td> 45 <td>matches any single character in an attribute name.</td></tr> 46 <tr><td valign="top"><code><b>*</b></code></td> 47 <td>matches any part of an attribute name.</td></tr> 48 </table> 49 50 An attribute name that is preceded by an exclamation mark '<b>!</b>' is 51 <i>excluded</i> from further attempts to match with <i>subsequent</i> 52 attribute names in the filter. Make sure to specify filters correctly, since 53 they are not checked for potential typos. 54 <p> 55 56 For example, the following setting preserves the optional attributes that are 57 typically necessary when processing code that is intended to be used as a 58 library: 59 <pre> 60 -keepattributes Exceptions,InnerClasses,Signature,Deprecated, 61 SourceFile,LineNumberTable,*Annotation*,EnclosingMethod 62 </pre> 63 <p> 64 65 The Java bytecode specifications currently specify the following list of 66 attributes. 67 68 <h3>Optional attributes</h3> 69 70 ProGuard's obfuscation step by default discards the following optional 71 attributes. You can keep them with 72 the <a href="usage.html#keepattributes"><code>-keepattributes</code></a> 73 option. 74 75 <dl> 76 <dt><code><b>SourceFile</b></code></dt> 77 <dd>Specifies the name of the source file from which the class file was 78 compiled. If present, this name is reported in stack traces.</dd> 79 80 <dt><div>(J++ extension)</div> 81 <code><b>SourceDir</b></code></dt> 82 <dd>Specifies the name of the source directory from which the class file was 83 compiled.</dd> 84 85 <dt><code><b>InnerClasses</b></code></dt> 86 <dd>Specifies the relationship between a class and its inner classes and outer 87 classes. Other than this and the naming convention with a '$' separator 88 between the names of inner classes and outer classes, inner classes are 89 just like ordinary classes. Compilers may need this information to find 90 classes referenced in a compiled library. Code may access this information 91 by reflection, for instance to derive the simple name of the class.</dd> 92 93 <dt><div>(Java 5 or higher)</div> 94 <code><b>EnclosingMethod</b></code></dt> 95 <dd>Specifies the method in which the class was defined. Compilers may need 96 this information to find classes referenced in a compiled library. Code 97 may access this information by reflection, for instance to derive the 98 simple name of the class.</dd> 99 100 <dt><code><b>Deprecated</b></code></dt> 101 <dd>Indicates that the class, field, or method is deprecated.</dd> 102 103 <dt><code><b>Synthetic</b></code></dt> 104 <dd>Indicates that the class, field, or method was generated by the 105 compiler.</dd> 106 107 <dt><div>(Java 5 or higher)</div> 108 <code><b>Signature</b></code></dt> 109 <dd>Specifies the generic signature of the class, field, or method. Compilers 110 may need this information to properly compile classes that use generic 111 types from compiled libraries. Code may access this signature by 112 reflection.</dd> 113 114 <dt><div>(Java 8 or higher)</div> 115 <code><b>MethodParameters</b></code></dt> 116 <dd>Specifies the names and access flags of the parameters of the method. Code 117 may access this information by reflection.</dd> 118 119 <dt><code><b>Exceptions</b></code></dt> 120 <dd>Specifies the exceptions that a method may throw. Compilers may use this 121 information to enforce catching them.</dd> 122 123 <dt><code><b>LineNumberTable</b></code></dt> 124 <dd>Specifies the line numbers of the method. If present, these line numbers 125 are reported in stack traces.</dd> 126 127 <dt><code><b>LocalVariableTable</b></code></dt> 128 <dd>Specifies the names and types of local variables of the method. If present, 129 some IDEs may use this information for helping with auto-completion.</dd> 130 131 <dt><div>(Java 5 or higher)</div> 132 <code><b>LocalVariableTypeTable</b></code></dt> 133 <dd>Specifies the names and generic types of local variables of the method. If 134 present, some IDEs may use this information for helping with 135 auto-completion.</dd> 136 137 <dt><div>(Java 5 or higher)</div> 138 <code><b>RuntimeVisibleAnnotations</b></code></dt> 139 <dd>Specifies the annotations that are visible at run-time, for classes, 140 fields, and methods. Compilers and annotation processors may use these 141 annotations. Code may access them by reflection.</dd> 142 143 <dt><div>(Java 5 or higher)</div> 144 <code><b>RuntimeInvisibleAnnotations</b></code></dt> 145 <dd>Specifies the annotations that are visible at compile-time, for classes, 146 fields, and methods. Compilers and annotation processors may use these 147 annotations.</dd> 148 149 <dt><div>(Java 5 or higher)</div> 150 <code><b>RuntimeVisibleParameterAnnotations</b></code></dt> 151 <dd>Specifies the annotations that are visible at run-time, for method 152 parameters. Compilers and annotation processors may use these 153 annotations. Code may access them by reflection.</dd> 154 155 <dt><div>(Java 5 or higher)</div> 156 <code><b>RuntimeInvisibleParameterAnnotations</b></code></dt> 157 <dd>Specifies the annotations that are visible at compile-time, for method 158 parameters. Compilers and annotation processors may use these 159 annotations.</dd> 160 161 <dt><div>(Java 8 or higher)</div> 162 <code><b>RuntimeVisibleTypeAnnotations</b></code></dt> 163 <dd>Specifies the annotations that are visible at run-time, for generic types, 164 instructions, etc. Compilers and annotation processors may use these 165 annotations. Code may access them by reflection.</dd> 166 167 <dt><div>(Java 8 or higher)</div> 168 <code><b>RuntimeInvisibleTypeAnnotations</b></code></dt> 169 <dd>Specifies the annotations that are visible at compile-time, for generic 170 types, instructions, etc. Compilers and annotation processors may use 171 these annotations.</dd> 172 173 <dt><div>(Java 5 or higher)</div> 174 <code><b>AnnotationDefault</b></code></dt> 175 <dd>Specifies a default value for an annotation.</dd> 176 177 </dl> 178 <p> 179 180 <h3>Essential attributes</h3> 181 182 ProGuard automatically keeps the following essential attributes, processing 183 them as necessary. We're listing them for the sake of completeness. 184 185 <dl> 186 <dt><code><b>ConstantValue</b></code></dt> 187 <dd>Specifies a constant integer, float, class, string, etc.</dd> 188 189 <dt><code><b>Code</b></code></dt> 190 <dd>Specifies the actual bytecode of a method.</dd> 191 192 <dt><div>(Java Micro Edition)</div> 193 <code><b>StackMap</b></code></dt> 194 <dd>Provides preverification information. The Java Virtual Machine can use 195 this information to speed up the verification step when loading a 196 class.</dd> 197 198 <dt><div>(Java 6 or higher)</div> 199 <code><b>StackMapTable</b></code></dt> 200 <dd>Provides preverification information. The Java Virtual Machine can use 201 this information to speed up the verification step when loading a 202 class.</dd> 203 204 <dt><div>(Java 7 or higher)</div> 205 <code><b>BootstrapMethods</b></code></dt> 206 <dd>Specifies the methods to bootstrap dynamic method invocations.</dd> 207 208 </dl> 209 <p> 210 211 <hr /> 212 <address> 213 Copyright © 2002-2014 214 <a target="other" href="http://www.lafortune.eu/">Eric Lafortune</a> @ <a target="top" href="http://www.saikoa.com/">Saikoa</a>. 215 </address> 216 </body> 217 </html> 218
