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19 package org.apache.bcel.util;
20
21 import java.io.IOException;
22 import java.io.OutputStream;
23 import java.io.OutputStreamWriter;
24 import java.io.PrintWriter;
25 import java.nio.charset.StandardCharsets;
26
27 import org.apache.bcel.Const;
28 import org.apache.bcel.Repository;
29 import org.apache.bcel.classfile.ClassParser;
30 import org.apache.bcel.classfile.Code;
31 import org.apache.bcel.classfile.ConstantValue;
32 import org.apache.bcel.classfile.ExceptionTable;
33 import org.apache.bcel.classfile.Field;
34 import org.apache.bcel.classfile.JavaClass;
35 import org.apache.bcel.classfile.Method;
36 import org.apache.bcel.classfile.StackMap;
37 import org.apache.bcel.classfile.StackMapEntry;
38 import org.apache.bcel.classfile.StackMapType;
39 import org.apache.bcel.classfile.Utility;
40 import org.apache.bcel.generic.ArrayType;
41 import org.apache.bcel.generic.ConstantPoolGen;
42 import org.apache.bcel.generic.MethodGen;
43 import org.apache.bcel.generic.Type;
44 import org.apache.commons.lang3.ArrayUtils;
45 import org.apache.commons.lang3.StringUtils;
46
47
48
49
50
51
52 public class BCELifier extends org.apache.bcel.classfile.EmptyVisitor {
53
54
55
56
57 public enum FLAGS {
58
59
60 UNKNOWN,
61
62
63 CLASS,
64
65
66 METHOD,
67 }
68
69
70
71 private static final String BASE_PACKAGE = Const.class.getPackage().getName();
72 private static final String CONSTANT_PREFIX = Const.class.getSimpleName() + ".";
73
74
75 static JavaClass getJavaClass(final String name) throws ClassNotFoundException, IOException {
76 JavaClass javaClass;
77 if ((javaClass = Repository.lookupClass(name)) == null) {
78 javaClass = new ClassParser(name).parse();
79 }
80 return javaClass;
81 }
82
83
84
85
86
87
88
89 public static void main(final String[] argv) throws Exception {
90 if (argv.length != 1) {
91 System.out.println("Usage: BCELifier className");
92 System.out.println("\tThe class must exist on the classpath");
93 return;
94 }
95 final BCELifier bcelifier = new BCELifier(getJavaClass(argv[0]), System.out);
96 bcelifier.start();
97 }
98
99 static String printArgumentTypes(final Type[] argTypes) {
100 if (argTypes.length == 0) {
101 return "Type.NO_ARGS";
102 }
103 final StringBuilder args = new StringBuilder();
104 for (int i = 0; i < argTypes.length; i++) {
105 args.append(printType(argTypes[i]));
106 if (i < argTypes.length - 1) {
107 args.append(", ");
108 }
109 }
110 return "new Type[] { " + args.toString() + " }";
111 }
112
113 static String printFlags(final int flags) {
114 return printFlags(flags, FLAGS.UNKNOWN);
115 }
116
117
118
119
120
121
122
123
124
125 public static String printFlags(final int flags, final FLAGS location) {
126 if (flags == 0) {
127 return "0";
128 }
129 final StringBuilder buf = new StringBuilder();
130 for (int i = 0, pow = 1; pow <= Const.MAX_ACC_FLAG_I; i++) {
131 if ((flags & pow) != 0) {
132 if (pow == Const.ACC_SYNCHRONIZED && location == FLAGS.CLASS) {
133 buf.append(CONSTANT_PREFIX).append("ACC_SUPER | ");
134 } else if (pow == Const.ACC_VOLATILE && location == FLAGS.METHOD) {
135 buf.append(CONSTANT_PREFIX).append("ACC_BRIDGE | ");
136 } else if (pow == Const.ACC_TRANSIENT && location == FLAGS.METHOD) {
137 buf.append(CONSTANT_PREFIX).append("ACC_VARARGS | ");
138 } else if (i < Const.ACCESS_NAMES_LENGTH) {
139 buf.append(CONSTANT_PREFIX).append("ACC_").append(StringUtils.toRootUpperCase(Const.getAccessName(i))).append(" | ");
140 } else {
141 buf.append(String.format(CONSTANT_PREFIX + "ACC_BIT %x | ", pow));
142 }
143 }
144 pow <<= 1;
145 }
146 final String str = buf.toString();
147 return str.substring(0, str.length() - 3);
148 }
149
150 static String printType(final String signature) {
151 final Type type = Type.getType(signature);
152 final byte t = type.getType();
153 if (t <= Const.T_VOID) {
154 return "Type." + StringUtils.toRootUpperCase(Const.getTypeName(t));
155 }
156 if (type.toString().equals("java.lang.String")) {
157 return "Type.STRING";
158 }
159 if (type.toString().equals("java.lang.Object")) {
160 return "Type.OBJECT";
161 }
162 if (type.toString().equals("java.lang.StringBuffer")) {
163 return "Type.STRINGBUFFER";
164 }
165 if (type instanceof ArrayType) {
166 final ArrayType at = (ArrayType) type;
167 return "new ArrayType(" + printType(at.getBasicType()) + ", " + at.getDimensions() + ")";
168 }
169 return "new ObjectType(\"" + Utility.signatureToString(signature, false) + "\")";
170 }
171
172 static String printType(final Type type) {
173 return printType(type.getSignature());
174 }
175
176 private final JavaClass clazz;
177
178 private final PrintWriter printWriter;
179
180 private final ConstantPoolGen constantPoolGen;
181
182
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184
185
186
187
188 public BCELifier(final JavaClass clazz, final OutputStream out) {
189 this.clazz = clazz;
190 this.printWriter = new PrintWriter(new OutputStreamWriter(out, StandardCharsets.UTF_8), false);
191 this.constantPoolGen = new ConstantPoolGen(this.clazz.getConstantPool());
192 }
193
194 private void printCreate() {
195 printWriter.println(" public void create(OutputStream out) throws IOException {");
196 final Field[] fields = clazz.getFields();
197 if (fields.length > 0) {
198 printWriter.println(" createFields();");
199 }
200 final Method[] methods = clazz.getMethods();
201 for (int i = 0; i < methods.length; i++) {
202 printWriter.println(" createMethod_" + i + "();");
203 }
204 printWriter.println(" _cg.getJavaClass().dump(out);");
205 printWriter.println(" }");
206 printWriter.println();
207 }
208
209 private void printMain() {
210 final String className = clazz.getClassName();
211 printWriter.println(" public static void main(String[] args) throws Exception {");
212 printWriter.println(" " + className + "Creator creator = new " + className + "Creator();");
213 printWriter.println(" creator.create(new FileOutputStream(\"" + className + ".class\"));");
214 printWriter.println(" }");
215 }
216
217
218
219
220 public void start() {
221 visitJavaClass(clazz);
222 printWriter.flush();
223 }
224
225 @Override
226 public void visitField(final Field field) {
227 printWriter.println();
228 printWriter.println(
229 " field = new FieldGen(" + printFlags(field.getAccessFlags()) + ", " + printType(field.getSignature()) + ", \"" + field.getName() + "\", _cp);");
230 final ConstantValue cv = field.getConstantValue();
231 if (cv != null) {
232 printWriter.print(" field.setInitValue(");
233 if (field.getType() == Type.CHAR) {
234 printWriter.print("(char)");
235 }
236 if (field.getType() == Type.SHORT) {
237 printWriter.print("(short)");
238 }
239 if (field.getType() == Type.BYTE) {
240 printWriter.print("(byte)");
241 }
242 printWriter.print(cv);
243 if (field.getType() == Type.LONG) {
244 printWriter.print("L");
245 }
246 if (field.getType() == Type.FLOAT) {
247 printWriter.print("F");
248 }
249 if (field.getType() == Type.DOUBLE) {
250 printWriter.print("D");
251 }
252 printWriter.println(");");
253 }
254 printWriter.println(" _cg.addField(field.getField());");
255 }
256
257 @Override
258 public void visitJavaClass(final JavaClass clazz) {
259 String className = clazz.getClassName();
260 final String superName = clazz.getSuperclassName();
261 final String packageName = clazz.getPackageName();
262 final String inter = Utility.printArray(clazz.getInterfaceNames(), false, true);
263 if (StringUtils.isNotEmpty(packageName)) {
264 className = className.substring(packageName.length() + 1);
265 printWriter.println("package " + packageName + ";");
266 printWriter.println();
267 }
268 printWriter.println("import " + BASE_PACKAGE + ".generic.*;");
269 printWriter.println("import " + BASE_PACKAGE + ".classfile.*;");
270 printWriter.println("import " + BASE_PACKAGE + ".*;");
271 printWriter.println("import java.io.*;");
272 printWriter.println();
273 printWriter.println("public class " + className + "Creator {");
274 printWriter.println(" private InstructionFactory _factory;");
275 printWriter.println(" private ConstantPoolGen _cp;");
276 printWriter.println(" private ClassGen _cg;");
277 printWriter.println();
278 printWriter.println(" public " + className + "Creator() {");
279 printWriter.println(" _cg = new ClassGen(\"" + (packageName.isEmpty() ? className : packageName + "." + className) + "\", \"" + superName
280 + "\", \"" + clazz.getSourceFileName() + "\", " + printFlags(clazz.getAccessFlags(), FLAGS.CLASS) + ", " + "new String[] { " + inter + " });");
281 printWriter.println(" _cg.setMajor(" + clazz.getMajor() + ");");
282 printWriter.println(" _cg.setMinor(" + clazz.getMinor() + ");");
283 printWriter.println();
284 printWriter.println(" _cp = _cg.getConstantPool();");
285 printWriter.println(" _factory = new InstructionFactory(_cg, _cp);");
286 printWriter.println(" }");
287 printWriter.println();
288 printCreate();
289 final Field[] fields = clazz.getFields();
290 if (fields.length > 0) {
291 printWriter.println(" private void createFields() {");
292 printWriter.println(" FieldGen field;");
293 for (final Field field : fields) {
294 field.accept(this);
295 }
296 printWriter.println(" }");
297 printWriter.println();
298 }
299 final Method[] methods = clazz.getMethods();
300 for (int i = 0; i < methods.length; i++) {
301 printWriter.println(" private void createMethod_" + i + "() {");
302 methods[i].accept(this);
303 printWriter.println(" }");
304 printWriter.println();
305 }
306 printMain();
307 printWriter.println("}");
308 }
309
310 @Override
311 public void visitMethod(final Method method) {
312 final MethodGen mg = new MethodGen(method, clazz.getClassName(), constantPoolGen);
313 printWriter.println(" InstructionList il = new InstructionList();");
314 printWriter.println(" MethodGen method = new MethodGen(" + printFlags(method.getAccessFlags(), FLAGS.METHOD) + ", " + printType(mg.getReturnType())
315 + ", " + printArgumentTypes(mg.getArgumentTypes()) + ", new String[] { " + Utility.printArray(mg.getArgumentNames(), false, true) + " }, \""
316 + method.getName() + "\", \"" + clazz.getClassName() + "\", il, _cp);");
317 final ExceptionTable exceptionTable = method.getExceptionTable();
318 if (exceptionTable != null) {
319 final String[] exceptionNames = exceptionTable.getExceptionNames();
320 for (final String exceptionName : exceptionNames) {
321 printWriter.print(" method.addException(\"");
322 printWriter.print(exceptionName);
323 printWriter.println("\");");
324 }
325 }
326 final Code code = method.getCode();
327 if (code != null) {
328 final StackMap stackMap = code.getStackMap();
329 if (stackMap != null) {
330 stackMap.accept(this);
331 }
332 }
333 printWriter.println();
334 final BCELFactory factory = new BCELFactory(mg, printWriter);
335 factory.start();
336 printWriter.println(" method.setMaxStack();");
337 printWriter.println(" method.setMaxLocals();");
338 printWriter.println(" _cg.addMethod(method.getMethod());");
339 printWriter.println(" il.dispose();");
340 }
341
342 @Override
343 public void visitStackMap(final StackMap stackMap) {
344 super.visitStackMap(stackMap);
345 printWriter.print(" method.addCodeAttribute(");
346 printWriter.print("new StackMap(_cp.addUtf8(\"");
347 printWriter.print(stackMap.getName());
348 printWriter.print("\"), ");
349 printWriter.print(stackMap.getLength());
350 printWriter.print(", ");
351 printWriter.print("new StackMapEntry[] {");
352 final StackMapEntry[] table = stackMap.getStackMap();
353 for (int i = 0; i < table.length; i++) {
354 table[i].accept(this);
355 if (i < table.length - 1) {
356 printWriter.print(", ");
357 } else {
358 printWriter.print(" }");
359 }
360 }
361 printWriter.print(", _cp.getConstantPool())");
362 printWriter.println(");");
363 }
364
365 @Override
366 public void visitStackMapEntry(final StackMapEntry stackMapEntry) {
367 super.visitStackMapEntry(stackMapEntry);
368 printWriter.print("new StackMapEntry(");
369 printWriter.print(stackMapEntry.getFrameType());
370 printWriter.print(", ");
371 printWriter.print(stackMapEntry.getByteCodeOffset());
372 printWriter.print(", ");
373 visitStackMapTypeArray(stackMapEntry.getTypesOfLocals());
374 printWriter.print(", ");
375 visitStackMapTypeArray(stackMapEntry.getTypesOfStackItems());
376 printWriter.print(", _cp.getConstantPool())");
377 }
378
379
380
381
382
383
384
385 @Override
386 public void visitStackMapType(final StackMapType stackMapType) {
387 super.visitStackMapType(stackMapType);
388 printWriter.print("new StackMapType((byte)");
389 printWriter.print(stackMapType.getType());
390 printWriter.print(", ");
391 if (stackMapType.hasIndex()) {
392 printWriter.print("_cp.addClass(\"");
393 printWriter.print(stackMapType.getClassName());
394 printWriter.print("\")");
395 } else {
396 printWriter.print("-1");
397 }
398 printWriter.print(", _cp.getConstantPool())");
399 }
400
401 private void visitStackMapTypeArray(final StackMapType[] types) {
402 if (ArrayUtils.isEmpty(types)) {
403 printWriter.print("null");
404 } else {
405 printWriter.print("new StackMapType[] {");
406 for (int i = 0; i < types.length; i++) {
407 types[i].accept(this);
408 if (i < types.length - 1) {
409 printWriter.print(", ");
410 } else {
411 printWriter.print(" }");
412 }
413 }
414 }
415 }
416 }