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;
60
61 import java.io.ByteArrayOutputStream;
62 import java.io.IOException;
63 import java.io.InputStream;
64
65 /**
66 * A parser to make a {@link ClassVisitor} visit a ClassFile structure, as defined in the Java
67 * Virtual Machine Specification (JVMS). This class parses the ClassFile content and calls the
68 * appropriate visit methods of a given {@link ClassVisitor} for each field, method and bytecode
69 * instruction encountered.
70 *
71 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html">JVMS 4</a>
72 * @author Eric Bruneton
73 * @author Eugene Kuleshov
74 */
75 public class ClassReader {
76
77 /**
78 * A flag to skip the Code attributes. If this flag is set the Code attributes are neither parsed
79 * nor visited.
80 */
81 public static final int SKIP_CODE = 1;
82
83 /**
84 * A flag to skip the SourceFile, SourceDebugExtension, LocalVariableTable, LocalVariableTypeTable
85 * and LineNumberTable attributes. If this flag is set these attributes are neither parsed nor
86 * visited (i.e. {@link ClassVisitor#visitSource}, {@link MethodVisitor#visitLocalVariable} and
87 * {@link MethodVisitor#visitLineNumber} are not called).
88 */
89 public static final int SKIP_DEBUG = 2;
90
91 /**
92 * A flag to skip the StackMap and StackMapTable attributes. If this flag is set these attributes
93 * are neither parsed nor visited (i.e. {@link MethodVisitor#visitFrame} is not called). This flag
94 * is useful when the {@link ClassWriter#COMPUTE_FRAMES} option is used: it avoids visiting frames
95 * that will be ignored and recomputed from scratch.
96 */
97 public static final int SKIP_FRAMES = 4;
98
99 /**
100 * A flag to expand the stack map frames. By default stack map frames are visited in their
101 * original format (i.e. "expanded" for classes whose version is less than V1_6, and "compressed"
102 * for the other classes). If this flag is set, stack map frames are always visited in expanded
103 * format (this option adds a decompression/compression step in ClassReader and ClassWriter which
104 * degrades performance quite a lot).
105 */
106 public static final int EXPAND_FRAMES = 8;
107
108 /**
109 * A flag to expand the ASM specific instructions into an equivalent sequence of standard bytecode
110 * instructions. When resolving a forward jump it may happen that the signed 2 bytes offset
111 * reserved for it is not sufficient to store the bytecode offset. In this case the jump
112 * instruction is replaced with a temporary ASM specific instruction using an unsigned 2 bytes
113 * offset (see {@link Label#resolve}). This internal flag is used to re-read classes containing
114 * such instructions, in order to replace them with standard instructions. In addition, when this
115 * flag is used, goto_w and jsr_w are <i>not</i> converted into goto and jsr, to make sure that
116 * infinite loops where a goto_w is replaced with a goto in ClassReader and converted back to a
117 * goto_w in ClassWriter cannot occur.
118 */
119 static final int EXPAND_ASM_INSNS = 256;
120
121 /** The size of the temporary byte array used to read class input streams chunk by chunk. */
122 private static final int INPUT_STREAM_DATA_CHUNK_SIZE = 4096;
123
124 /**
125 * A byte array containing the JVMS ClassFile structure to be parsed. <i>The content of this array
126 * must not be modified. This field is intended for {@link Attribute} sub classes, and is normally
127 * not needed by class visitors.</i>
128 *
129 * <p>NOTE: the ClassFile structure can start at any offset within this array, i.e. it does not
130 * necessarily start at offset 0. Use {@link #getItem} and {@link #header} to get correct
131 * ClassFile element offsets within this byte array.
132 */
133 // DontCheck(MemberName): can't be renamed (for backward binary compatibility).
134 public final byte[] b;
135
136 /**
137 * The offset in bytes, in {@link #b}, of each cp_info entry of the ClassFile's constant_pool
138 * array, <i>plus one</i>. In other words, the offset of constant pool entry i is given by
139 * cpInfoOffsets[i] - 1, i.e. its cp_info's tag field is given by b[cpInfoOffsets[i] - 1].
140 */
141 private final int[] cpInfoOffsets;
142
143 /**
144 * The String objects corresponding to the CONSTANT_Utf8 constant pool items. This cache avoids
145 * multiple parsing of a given CONSTANT_Utf8 constant pool item.
146 */
147 private final String[] constantUtf8Values;
148
149 /**
150 * The ConstantDynamic objects corresponding to the CONSTANT_Dynamic constant pool items. This
151 * cache avoids multiple parsing of a given CONSTANT_Dynamic constant pool item.
152 */
153 private final ConstantDynamic[] constantDynamicValues;
154
155 /**
156 * The start offsets in {@link #b} of each element of the bootstrap_methods array (in the
157 * BootstrapMethods attribute).
158 *
159 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.23">JVMS
160 * 4.7.23</a>
161 */
162 private final int[] bootstrapMethodOffsets;
163
164 /**
165 * A conservative estimate of the maximum length of the strings contained in the constant pool of
166 * the class.
167 */
168 private final int maxStringLength;
169
170 /** The offset in bytes, in {@link #b}, of the ClassFile's access_flags field. */
171 public final int header;
172
173 // -----------------------------------------------------------------------------------------------
174 // Constructors
175 // -----------------------------------------------------------------------------------------------
176
177 /**
178 * Constructs a new {@link ClassReader} object.
179 *
180 * @param classFile the JVMS ClassFile structure to be read.
181 */
182 public ClassReader(final byte[] classFile) {
183 this(classFile, 0, classFile.length);
184 }
185
186 /**
187 * Constructs a new {@link ClassReader} object.
188 *
189 * @param classFileBuffer a byte array containing the JVMS ClassFile structure to be read.
190 * @param classFileOffset the offset in byteBuffer of the first byte of the ClassFile to be read.
191 * @param classFileLength the length in bytes of the ClassFile to be read.
192 */
193 public ClassReader(
194 final byte[] classFileBuffer,
195 final int classFileOffset,
196 final int classFileLength) { // NOPMD(UnusedFormalParameter) used for backward compatibility.
197 this(classFileBuffer, classFileOffset, /* checkClassVersion = */ true);
198 }
199
200 /**
201 * Constructs a new {@link ClassReader} object. <i>This internal constructor must not be exposed
202 * as a public API</i>.
203 *
204 * @param classFileBuffer a byte array containing the JVMS ClassFile structure to be read.
205 * @param classFileOffset the offset in byteBuffer of the first byte of the ClassFile to be read.
206 * @param checkClassVersion whether to check the class version or not.
207 */
208 ClassReader(
209 final byte[] classFileBuffer, final int classFileOffset, final boolean checkClassVersion) {
210 b = classFileBuffer;
211 // Check the class' major_version. This field is after the magic and minor_version fields, which
212 // use 4 and 2 bytes respectively.
213 if (checkClassVersion && readShort(classFileOffset + 6) > Opcodes.V13) {
214 throw new IllegalArgumentException(
215 "Unsupported class file major version " + readShort(classFileOffset + 6));
216 }
217 // Create the constant pool arrays. The constant_pool_count field is after the magic,
218 // minor_version and major_version fields, which use 4, 2 and 2 bytes respectively.
219 int constantPoolCount = readUnsignedShort(classFileOffset + 8);
220 cpInfoOffsets = new int[constantPoolCount];
221 constantUtf8Values = new String[constantPoolCount];
222 // Compute the offset of each constant pool entry, as well as a conservative estimate of the
223 // maximum length of the constant pool strings. The first constant pool entry is after the
224 // magic, minor_version, major_version and constant_pool_count fields, which use 4, 2, 2 and 2
225 // bytes respectively.
226 int currentCpInfoIndex = 1;
227 int currentCpInfoOffset = classFileOffset + 10;
228 int currentMaxStringLength = 0;
229 boolean hasConstantDynamic = false;
230 boolean hasConstantInvokeDynamic = false;
231 // The offset of the other entries depend on the total size of all the previous entries.
232 while (currentCpInfoIndex < constantPoolCount) {
233 cpInfoOffsets[currentCpInfoIndex++] = currentCpInfoOffset + 1;
234 int cpInfoSize;
235 switch (classFileBuffer[currentCpInfoOffset]) {
236 case Symbol.CONSTANT_FIELDREF_TAG:
237 case Symbol.CONSTANT_METHODREF_TAG:
238 case Symbol.CONSTANT_INTERFACE_METHODREF_TAG:
239 case Symbol.CONSTANT_INTEGER_TAG:
240 case Symbol.CONSTANT_FLOAT_TAG:
241 case Symbol.CONSTANT_NAME_AND_TYPE_TAG:
242 cpInfoSize = 5;
243 break;
244 case Symbol.CONSTANT_DYNAMIC_TAG:
245 cpInfoSize = 5;
246 hasConstantDynamic = true;
247 break;
248 case Symbol.CONSTANT_INVOKE_DYNAMIC_TAG:
249 cpInfoSize = 5;
250 hasConstantInvokeDynamic = true;
251 break;
252 case Symbol.CONSTANT_LONG_TAG:
253 case Symbol.CONSTANT_DOUBLE_TAG:
254 cpInfoSize = 9;
255 currentCpInfoIndex++;
256 break;
257 case Symbol.CONSTANT_UTF8_TAG:
258 cpInfoSize = 3 + readUnsignedShort(currentCpInfoOffset + 1);
259 if (cpInfoSize > currentMaxStringLength) {
260 // The size in bytes of this CONSTANT_Utf8 structure provides a conservative estimate
261 // of the length in characters of the corresponding string, and is much cheaper to
262 // compute than this exact length.
263 currentMaxStringLength = cpInfoSize;
264 }
265 break;
266 case Symbol.CONSTANT_METHOD_HANDLE_TAG:
267 cpInfoSize = 4;
268 break;
269 case Symbol.CONSTANT_CLASS_TAG:
270 case Symbol.CONSTANT_STRING_TAG:
271 case Symbol.CONSTANT_METHOD_TYPE_TAG:
272 case Symbol.CONSTANT_PACKAGE_TAG:
273 case Symbol.CONSTANT_MODULE_TAG:
274 cpInfoSize = 3;
275 break;
276 default:
277 throw new IllegalArgumentException();
278 }
279 currentCpInfoOffset += cpInfoSize;
280 }
281 maxStringLength = currentMaxStringLength;
282 // The Classfile's access_flags field is just after the last constant pool entry.
283 header = currentCpInfoOffset;
284
285 // Allocate the cache of ConstantDynamic values, if there is at least one.
286 constantDynamicValues = hasConstantDynamic ? new ConstantDynamic[constantPoolCount] : null;
287
288 // Read the BootstrapMethods attribute, if any (only get the offset of each method).
289 bootstrapMethodOffsets =
290 (hasConstantDynamic | hasConstantInvokeDynamic)
291 ? readBootstrapMethodsAttribute(currentMaxStringLength)
292 : null;
293 }
294
295 /**
296 * Constructs a new {@link ClassReader} object.
297 *
298 * @param inputStream an input stream of the JVMS ClassFile structure to be read. This input
299 * stream must contain nothing more than the ClassFile structure itself. It is read from its
300 * current position to its end.
301 * @throws IOException if a problem occurs during reading.
302 */
303 public ClassReader(final InputStream inputStream) throws IOException {
304 this(readStream(inputStream, false));
305 }
306
307 /**
308 * Constructs a new {@link ClassReader} object.
309 *
310 * @param className the fully qualified name of the class to be read. The ClassFile structure is
311 * retrieved with the current class loader's {@link ClassLoader#getSystemResourceAsStream}.
312 * @throws IOException if an exception occurs during reading.
313 */
314 public ClassReader(final String className) throws IOException {
315 this(
316 readStream(
317 ClassLoader.getSystemResourceAsStream(className.replace('.', '/') + ".class"), true));
318 }
319
320 /**
321 * Reads the given input stream and returns its content as a byte array.
322 *
323 * @param inputStream an input stream.
324 * @param close true to close the input stream after reading.
325 * @return the content of the given input stream.
326 * @throws IOException if a problem occurs during reading.
327 */
328 private static byte[] readStream(final InputStream inputStream, final boolean close)
329 throws IOException {
330 if (inputStream == null) {
331 throw new IOException("Class not found");
332 }
333 try {
334 ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
335 byte[] data = new byte[INPUT_STREAM_DATA_CHUNK_SIZE];
336 int bytesRead;
337 while ((bytesRead = inputStream.read(data, 0, data.length)) != -1) {
338 outputStream.write(data, 0, bytesRead);
339 }
340 outputStream.flush();
341 return outputStream.toByteArray();
342 } finally {
343 if (close) {
344 inputStream.close();
345 }
346 }
347 }
348
349 // -----------------------------------------------------------------------------------------------
350 // Accessors
351 // -----------------------------------------------------------------------------------------------
352
353 /**
354 * Returns the class's access flags (see {@link Opcodes}). This value may not reflect Deprecated
355 * and Synthetic flags when bytecode is before 1.5 and those flags are represented by attributes.
356 *
357 * @return the class access flags.
358 * @see ClassVisitor#visit(int, int, String, String, String, String[])
359 */
360 public int getAccess() {
361 return readUnsignedShort(header);
362 }
363
364 /**
365 * Returns the internal name of the class (see {@link Type#getInternalName()}).
366 *
367 * @return the internal class name.
368 * @see ClassVisitor#visit(int, int, String, String, String, String[])
369 */
370 public String getClassName() {
371 // this_class is just after the access_flags field (using 2 bytes).
372 return readClass(header + 2, new char[maxStringLength]);
373 }
374
375 /**
376 * Returns the internal of name of the super class (see {@link Type#getInternalName()}). For
377 * interfaces, the super class is {@link Object}.
378 *
379 * @return the internal name of the super class, or {@literal null} for {@link Object} class.
380 * @see ClassVisitor#visit(int, int, String, String, String, String[])
381 */
382 public String getSuperName() {
383 // super_class is after the access_flags and this_class fields (2 bytes each).
384 return readClass(header + 4, new char[maxStringLength]);
385 }
386
387 /**
388 * Returns the internal names of the implemented interfaces (see {@link Type#getInternalName()}).
389 *
390 * @return the internal names of the directly implemented interfaces. Inherited implemented
391 * interfaces are not returned.
392 * @see ClassVisitor#visit(int, int, String, String, String, String[])
393 */
394 public String[] getInterfaces() {
395 // interfaces_count is after the access_flags, this_class and super_class fields (2 bytes each).
396 int currentOffset = header + 6;
397 int interfacesCount = readUnsignedShort(currentOffset);
398 String[] interfaces = new String[interfacesCount];
399 if (interfacesCount > 0) {
400 char[] charBuffer = new char[maxStringLength];
401 for (int i = 0; i < interfacesCount; ++i) {
402 currentOffset += 2;
403 interfaces[i] = readClass(currentOffset, charBuffer);
404 }
405 }
406 return interfaces;
407 }
408
409 // -----------------------------------------------------------------------------------------------
410 // Public methods
411 // -----------------------------------------------------------------------------------------------
412
413 /**
414 * Makes the given visitor visit the JVMS ClassFile structure passed to the constructor of this
415 * {@link ClassReader}.
416 *
417 * @param classVisitor the visitor that must visit this class.
418 * @param parsingOptions the options to use to parse this class. One or more of {@link
419 * #SKIP_CODE}, {@link #SKIP_DEBUG}, {@link #SKIP_FRAMES} or {@link #EXPAND_FRAMES}.
420 */
421 public void accept(final ClassVisitor classVisitor, final int parsingOptions) {
422 accept(classVisitor, new Attribute[0], parsingOptions);
423 }
424
425 /**
426 * Makes the given visitor visit the JVMS ClassFile structure passed to the constructor of this
427 * {@link ClassReader}.
428 *
429 * @param classVisitor the visitor that must visit this class.
430 * @param attributePrototypes prototypes of the attributes that must be parsed during the visit of
431 * the class. Any attribute whose type is not equal to the type of one the prototypes will not
432 * be parsed: its byte array value will be passed unchanged to the ClassWriter. <i>This may
433 * corrupt it if this value contains references to the constant pool, or has syntactic or
434 * semantic links with a class element that has been transformed by a class adapter between
435 * the reader and the writer</i>.
436 * @param parsingOptions the options to use to parse this class. One or more of {@link
437 * #SKIP_CODE}, {@link #SKIP_DEBUG}, {@link #SKIP_FRAMES} or {@link #EXPAND_FRAMES}.
438 */
439 public void accept(
440 final ClassVisitor classVisitor,
441 final Attribute[] attributePrototypes,
442 final int parsingOptions) {
443 Context context = new Context();
444 context.attributePrototypes = attributePrototypes;
445 context.parsingOptions = parsingOptions;
446 context.charBuffer = new char[maxStringLength];
447
448 // Read the access_flags, this_class, super_class, interface_count and interfaces fields.
449 char[] charBuffer = context.charBuffer;
450 int currentOffset = header;
451 int accessFlags = readUnsignedShort(currentOffset);
452 String thisClass = readClass(currentOffset + 2, charBuffer);
453 String superClass = readClass(currentOffset + 4, charBuffer);
454 String[] interfaces = new String[readUnsignedShort(currentOffset + 6)];
455 currentOffset += 8;
456 for (int i = 0; i < interfaces.length; ++i) {
457 interfaces[i] = readClass(currentOffset, charBuffer);
458 currentOffset += 2;
459 }
460
461 // Read the class attributes (the variables are ordered as in Section 4.7 of the JVMS).
462 // Attribute offsets exclude the attribute_name_index and attribute_length fields.
463 // - The offset of the InnerClasses attribute, or 0.
464 int innerClassesOffset = 0;
465 // - The offset of the EnclosingMethod attribute, or 0.
466 int enclosingMethodOffset = 0;
467 // - The string corresponding to the Signature attribute, or null.
468 String signature = null;
469 // - The string corresponding to the SourceFile attribute, or null.
470 String sourceFile = null;
471 // - The string corresponding to the SourceDebugExtension attribute, or null.
472 String sourceDebugExtension = null;
473 // - The offset of the RuntimeVisibleAnnotations attribute, or 0.
474 int runtimeVisibleAnnotationsOffset = 0;
475 // - The offset of the RuntimeInvisibleAnnotations attribute, or 0.
476 int runtimeInvisibleAnnotationsOffset = 0;
477 // - The offset of the RuntimeVisibleTypeAnnotations attribute, or 0.
478 int runtimeVisibleTypeAnnotationsOffset = 0;
479 // - The offset of the RuntimeInvisibleTypeAnnotations attribute, or 0.
480 int runtimeInvisibleTypeAnnotationsOffset = 0;
481 // - The offset of the Module attribute, or 0.
482 int moduleOffset = 0;
483 // - The offset of the ModulePackages attribute, or 0.
484 int modulePackagesOffset = 0;
485 // - The string corresponding to the ModuleMainClass attribute, or null.
486 String moduleMainClass = null;
487 // - The string corresponding to the NestHost attribute, or null.
488 String nestHostClass = null;
489 // - The offset of the NestMembers attribute, or 0.
490 int nestMembersOffset = 0;
491 // - The non standard attributes (linked with their {@link Attribute#nextAttribute} field).
492 // This list in the <i>reverse order</i> or their order in the ClassFile structure.
493 Attribute attributes = null;
494
495 int currentAttributeOffset = getFirstAttributeOffset();
496 for (int i = readUnsignedShort(currentAttributeOffset - 2); i > 0; --i) {
497 // Read the attribute_info's attribute_name and attribute_length fields.
498 String attributeName = readUTF8(currentAttributeOffset, charBuffer);
499 int attributeLength = readInt(currentAttributeOffset + 2);
500 currentAttributeOffset += 6;
501 // The tests are sorted in decreasing frequency order (based on frequencies observed on
502 // typical classes).
503 if (Constants.SOURCE_FILE.equals(attributeName)) {
504 sourceFile = readUTF8(currentAttributeOffset, charBuffer);
505 } else if (Constants.INNER_CLASSES.equals(attributeName)) {
506 innerClassesOffset = currentAttributeOffset;
507 } else if (Constants.ENCLOSING_METHOD.equals(attributeName)) {
508 enclosingMethodOffset = currentAttributeOffset;
509 } else if (Constants.NEST_HOST.equals(attributeName)) {
510 nestHostClass = readClass(currentAttributeOffset, charBuffer);
511 } else if (Constants.NEST_MEMBERS.equals(attributeName)) {
512 nestMembersOffset = currentAttributeOffset;
513 } else if (Constants.SIGNATURE.equals(attributeName)) {
514 signature = readUTF8(currentAttributeOffset, charBuffer);
515 } else if (Constants.RUNTIME_VISIBLE_ANNOTATIONS.equals(attributeName)) {
516 runtimeVisibleAnnotationsOffset = currentAttributeOffset;
517 } else if (Constants.RUNTIME_VISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
518 runtimeVisibleTypeAnnotationsOffset = currentAttributeOffset;
519 } else if (Constants.DEPRECATED.equals(attributeName)) {
520 accessFlags |= Opcodes.ACC_DEPRECATED;
521 } else if (Constants.SYNTHETIC.equals(attributeName)) {
522 accessFlags |= Opcodes.ACC_SYNTHETIC;
523 } else if (Constants.SOURCE_DEBUG_EXTENSION.equals(attributeName)) {
524 sourceDebugExtension =
525 readUtf(currentAttributeOffset, attributeLength, new char[attributeLength]);
526 } else if (Constants.RUNTIME_INVISIBLE_ANNOTATIONS.equals(attributeName)) {
527 runtimeInvisibleAnnotationsOffset = currentAttributeOffset;
528 } else if (Constants.RUNTIME_INVISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
529 runtimeInvisibleTypeAnnotationsOffset = currentAttributeOffset;
530 } else if (Constants.MODULE.equals(attributeName)) {
531 moduleOffset = currentAttributeOffset;
532 } else if (Constants.MODULE_MAIN_CLASS.equals(attributeName)) {
533 moduleMainClass = readClass(currentAttributeOffset, charBuffer);
534 } else if (Constants.MODULE_PACKAGES.equals(attributeName)) {
535 modulePackagesOffset = currentAttributeOffset;
536 } else if (!Constants.BOOTSTRAP_METHODS.equals(attributeName)) {
537 // The BootstrapMethods attribute is read in the constructor.
538 Attribute attribute =
539 readAttribute(
540 attributePrototypes,
541 attributeName,
542 currentAttributeOffset,
543 attributeLength,
544 charBuffer,
545 -1,
546 null);
547 attribute.nextAttribute = attributes;
548 attributes = attribute;
549 }
550 currentAttributeOffset += attributeLength;
551 }
552
553 // Visit the class declaration. The minor_version and major_version fields start 6 bytes before
554 // the first constant pool entry, which itself starts at cpInfoOffsets[1] - 1 (by definition).
555 classVisitor.visit(
556 readInt(cpInfoOffsets[1] - 7), accessFlags, thisClass, signature, superClass, interfaces);
557
558 // Visit the SourceFile and SourceDebugExtenstion attributes.
559 if ((parsingOptions & SKIP_DEBUG) == 0
560 && (sourceFile != null || sourceDebugExtension != null)) {
561 classVisitor.visitSource(sourceFile, sourceDebugExtension);
562 }
563
564 // Visit the Module, ModulePackages and ModuleMainClass attributes.
565 if (moduleOffset != 0) {
566 readModuleAttributes(
567 classVisitor, context, moduleOffset, modulePackagesOffset, moduleMainClass);
568 }
569
570 // Visit the NestHost attribute.
571 if (nestHostClass != null) {
572 classVisitor.visitNestHost(nestHostClass);
573 }
574
575 // Visit the EnclosingMethod attribute.
576 if (enclosingMethodOffset != 0) {
577 String className = readClass(enclosingMethodOffset, charBuffer);
578 int methodIndex = readUnsignedShort(enclosingMethodOffset + 2);
579 String name = methodIndex == 0 ? null : readUTF8(cpInfoOffsets[methodIndex], charBuffer);
580 String type = methodIndex == 0 ? null : readUTF8(cpInfoOffsets[methodIndex] + 2, charBuffer);
581 classVisitor.visitOuterClass(className, name, type);
582 }
583
584 // Visit the RuntimeVisibleAnnotations attribute.
585 if (runtimeVisibleAnnotationsOffset != 0) {
586 int numAnnotations = readUnsignedShort(runtimeVisibleAnnotationsOffset);
587 int currentAnnotationOffset = runtimeVisibleAnnotationsOffset + 2;
588 while (numAnnotations-- > 0) {
589 // Parse the type_index field.
590 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
591 currentAnnotationOffset += 2;
592 // Parse num_element_value_pairs and element_value_pairs and visit these values.
593 currentAnnotationOffset =
594 readElementValues(
595 classVisitor.visitAnnotation(annotationDescriptor, /* visible = */ true),
596 currentAnnotationOffset,
597 /* named = */ true,
598 charBuffer);
599 }
600 }
601
602 // Visit the RuntimeInvisibleAnnotations attribute.
603 if (runtimeInvisibleAnnotationsOffset != 0) {
604 int numAnnotations = readUnsignedShort(runtimeInvisibleAnnotationsOffset);
605 int currentAnnotationOffset = runtimeInvisibleAnnotationsOffset + 2;
606 while (numAnnotations-- > 0) {
607 // Parse the type_index field.
608 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
609 currentAnnotationOffset += 2;
610 // Parse num_element_value_pairs and element_value_pairs and visit these values.
611 currentAnnotationOffset =
612 readElementValues(
613 classVisitor.visitAnnotation(annotationDescriptor, /* visible = */ false),
614 currentAnnotationOffset,
615 /* named = */ true,
616 charBuffer);
617 }
618 }
619
620 // Visit the RuntimeVisibleTypeAnnotations attribute.
621 if (runtimeVisibleTypeAnnotationsOffset != 0) {
622 int numAnnotations = readUnsignedShort(runtimeVisibleTypeAnnotationsOffset);
623 int currentAnnotationOffset = runtimeVisibleTypeAnnotationsOffset + 2;
624 while (numAnnotations-- > 0) {
625 // Parse the target_type, target_info and target_path fields.
626 currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
627 // Parse the type_index field.
628 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
629 currentAnnotationOffset += 2;
630 // Parse num_element_value_pairs and element_value_pairs and visit these values.
631 currentAnnotationOffset =
632 readElementValues(
633 classVisitor.visitTypeAnnotation(
634 context.currentTypeAnnotationTarget,
635 context.currentTypeAnnotationTargetPath,
636 annotationDescriptor,
637 /* visible = */ true),
638 currentAnnotationOffset,
639 /* named = */ true,
640 charBuffer);
641 }
642 }
643
644 // Visit the RuntimeInvisibleTypeAnnotations attribute.
645 if (runtimeInvisibleTypeAnnotationsOffset != 0) {
646 int numAnnotations = readUnsignedShort(runtimeInvisibleTypeAnnotationsOffset);
647 int currentAnnotationOffset = runtimeInvisibleTypeAnnotationsOffset + 2;
648 while (numAnnotations-- > 0) {
649 // Parse the target_type, target_info and target_path fields.
650 currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
651 // Parse the type_index field.
652 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
653 currentAnnotationOffset += 2;
654 // Parse num_element_value_pairs and element_value_pairs and visit these values.
655 currentAnnotationOffset =
656 readElementValues(
657 classVisitor.visitTypeAnnotation(
658 context.currentTypeAnnotationTarget,
659 context.currentTypeAnnotationTargetPath,
660 annotationDescriptor,
661 /* visible = */ false),
662 currentAnnotationOffset,
663 /* named = */ true,
664 charBuffer);
665 }
666 }
667
668 // Visit the non standard attributes.
669 while (attributes != null) {
670 // Copy and reset the nextAttribute field so that it can also be used in ClassWriter.
671 Attribute nextAttribute = attributes.nextAttribute;
672 attributes.nextAttribute = null;
673 classVisitor.visitAttribute(attributes);
674 attributes = nextAttribute;
675 }
676
677 // Visit the NestedMembers attribute.
678 if (nestMembersOffset != 0) {
679 int numberOfNestMembers = readUnsignedShort(nestMembersOffset);
680 int currentNestMemberOffset = nestMembersOffset + 2;
681 while (numberOfNestMembers-- > 0) {
682 classVisitor.visitNestMember(readClass(currentNestMemberOffset, charBuffer));
683 currentNestMemberOffset += 2;
684 }
685 }
686
687 // Visit the InnerClasses attribute.
688 if (innerClassesOffset != 0) {
689 int numberOfClasses = readUnsignedShort(innerClassesOffset);
690 int currentClassesOffset = innerClassesOffset + 2;
691 while (numberOfClasses-- > 0) {
692 classVisitor.visitInnerClass(
693 readClass(currentClassesOffset, charBuffer),
694 readClass(currentClassesOffset + 2, charBuffer),
695 readUTF8(currentClassesOffset + 4, charBuffer),
696 readUnsignedShort(currentClassesOffset + 6));
697 currentClassesOffset += 8;
698 }
699 }
700
701 // Visit the fields and methods.
702 int fieldsCount = readUnsignedShort(currentOffset);
703 currentOffset += 2;
704 while (fieldsCount-- > 0) {
705 currentOffset = readField(classVisitor, context, currentOffset);
706 }
707 int methodsCount = readUnsignedShort(currentOffset);
708 currentOffset += 2;
709 while (methodsCount-- > 0) {
710 currentOffset = readMethod(classVisitor, context, currentOffset);
711 }
712
713 // Visit the end of the class.
714 classVisitor.visitEnd();
715 }
716
717 // ----------------------------------------------------------------------------------------------
718 // Methods to parse modules, fields and methods
719 // ----------------------------------------------------------------------------------------------
720
721 /**
722 * Reads the Module, ModulePackages and ModuleMainClass attributes and visit them.
723 *
724 * @param classVisitor the current class visitor
725 * @param context information about the class being parsed.
726 * @param moduleOffset the offset of the Module attribute (excluding the attribute_info's
727 * attribute_name_index and attribute_length fields).
728 * @param modulePackagesOffset the offset of the ModulePackages attribute (excluding the
729 * attribute_info's attribute_name_index and attribute_length fields), or 0.
730 * @param moduleMainClass the string corresponding to the ModuleMainClass attribute, or null.
731 */
732 private void readModuleAttributes(
733 final ClassVisitor classVisitor,
734 final Context context,
735 final int moduleOffset,
736 final int modulePackagesOffset,
737 final String moduleMainClass) {
738 char[] buffer = context.charBuffer;
739
740 // Read the module_name_index, module_flags and module_version_index fields and visit them.
741 int currentOffset = moduleOffset;
742 String moduleName = readModule(currentOffset, buffer);
743 int moduleFlags = readUnsignedShort(currentOffset + 2);
744 String moduleVersion = readUTF8(currentOffset + 4, buffer);
745 currentOffset += 6;
746 ModuleVisitor moduleVisitor = classVisitor.visitModule(moduleName, moduleFlags, moduleVersion);
747 if (moduleVisitor == null) {
748 return;
749 }
750
751 // Visit the ModuleMainClass attribute.
752 if (moduleMainClass != null) {
753 moduleVisitor.visitMainClass(moduleMainClass);
754 }
755
756 // Visit the ModulePackages attribute.
757 if (modulePackagesOffset != 0) {
758 int packageCount = readUnsignedShort(modulePackagesOffset);
759 int currentPackageOffset = modulePackagesOffset + 2;
760 while (packageCount-- > 0) {
761 moduleVisitor.visitPackage(readPackage(currentPackageOffset, buffer));
762 currentPackageOffset += 2;
763 }
764 }
765
766 // Read the 'requires_count' and 'requires' fields.
767 int requiresCount = readUnsignedShort(currentOffset);
768 currentOffset += 2;
769 while (requiresCount-- > 0) {
770 // Read the requires_index, requires_flags and requires_version fields and visit them.
771 String requires = readModule(currentOffset, buffer);
772 int requiresFlags = readUnsignedShort(currentOffset + 2);
773 String requiresVersion = readUTF8(currentOffset + 4, buffer);
774 currentOffset += 6;
775 moduleVisitor.visitRequire(requires, requiresFlags, requiresVersion);
776 }
777
778 // Read the 'exports_count' and 'exports' fields.
779 int exportsCount = readUnsignedShort(currentOffset);
780 currentOffset += 2;
781 while (exportsCount-- > 0) {
782 // Read the exports_index, exports_flags, exports_to_count and exports_to_index fields
783 // and visit them.
784 String exports = readPackage(currentOffset, buffer);
785 int exportsFlags = readUnsignedShort(currentOffset + 2);
786 int exportsToCount = readUnsignedShort(currentOffset + 4);
787 currentOffset += 6;
788 String[] exportsTo = null;
789 if (exportsToCount != 0) {
790 exportsTo = new String[exportsToCount];
791 for (int i = 0; i < exportsToCount; ++i) {
792 exportsTo[i] = readModule(currentOffset, buffer);
793 currentOffset += 2;
794 }
795 }
796 moduleVisitor.visitExport(exports, exportsFlags, exportsTo);
797 }
798
799 // Reads the 'opens_count' and 'opens' fields.
800 int opensCount = readUnsignedShort(currentOffset);
801 currentOffset += 2;
802 while (opensCount-- > 0) {
803 // Read the opens_index, opens_flags, opens_to_count and opens_to_index fields and visit them.
804 String opens = readPackage(currentOffset, buffer);
805 int opensFlags = readUnsignedShort(currentOffset + 2);
806 int opensToCount = readUnsignedShort(currentOffset + 4);
807 currentOffset += 6;
808 String[] opensTo = null;
809 if (opensToCount != 0) {
810 opensTo = new String[opensToCount];
811 for (int i = 0; i < opensToCount; ++i) {
812 opensTo[i] = readModule(currentOffset, buffer);
813 currentOffset += 2;
814 }
815 }
816 moduleVisitor.visitOpen(opens, opensFlags, opensTo);
817 }
818
819 // Read the 'uses_count' and 'uses' fields.
820 int usesCount = readUnsignedShort(currentOffset);
821 currentOffset += 2;
822 while (usesCount-- > 0) {
823 moduleVisitor.visitUse(readClass(currentOffset, buffer));
824 currentOffset += 2;
825 }
826
827 // Read the 'provides_count' and 'provides' fields.
828 int providesCount = readUnsignedShort(currentOffset);
829 currentOffset += 2;
830 while (providesCount-- > 0) {
831 // Read the provides_index, provides_with_count and provides_with_index fields and visit them.
832 String provides = readClass(currentOffset, buffer);
833 int providesWithCount = readUnsignedShort(currentOffset + 2);
834 currentOffset += 4;
835 String[] providesWith = new String[providesWithCount];
836 for (int i = 0; i < providesWithCount; ++i) {
837 providesWith[i] = readClass(currentOffset, buffer);
838 currentOffset += 2;
839 }
840 moduleVisitor.visitProvide(provides, providesWith);
841 }
842
843 // Visit the end of the module attributes.
844 moduleVisitor.visitEnd();
845 }
846
847 /**
848 * Reads a JVMS field_info structure and makes the given visitor visit it.
849 *
850 * @param classVisitor the visitor that must visit the field.
851 * @param context information about the class being parsed.
852 * @param fieldInfoOffset the start offset of the field_info structure.
853 * @return the offset of the first byte following the field_info structure.
854 */
855 private int readField(
856 final ClassVisitor classVisitor, final Context context, final int fieldInfoOffset) {
857 char[] charBuffer = context.charBuffer;
858
859 // Read the access_flags, name_index and descriptor_index fields.
860 int currentOffset = fieldInfoOffset;
861 int accessFlags = readUnsignedShort(currentOffset);
862 String name = readUTF8(currentOffset + 2, charBuffer);
863 String descriptor = readUTF8(currentOffset + 4, charBuffer);
864 currentOffset += 6;
865
866 // Read the field attributes (the variables are ordered as in Section 4.7 of the JVMS).
867 // Attribute offsets exclude the attribute_name_index and attribute_length fields.
868 // - The value corresponding to the ConstantValue attribute, or null.
869 Object constantValue = null;
870 // - The string corresponding to the Signature attribute, or null.
871 String signature = null;
872 // - The offset of the RuntimeVisibleAnnotations attribute, or 0.
873 int runtimeVisibleAnnotationsOffset = 0;
874 // - The offset of the RuntimeInvisibleAnnotations attribute, or 0.
875 int runtimeInvisibleAnnotationsOffset = 0;
876 // - The offset of the RuntimeVisibleTypeAnnotations attribute, or 0.
877 int runtimeVisibleTypeAnnotationsOffset = 0;
878 // - The offset of the RuntimeInvisibleTypeAnnotations attribute, or 0.
879 int runtimeInvisibleTypeAnnotationsOffset = 0;
880 // - The non standard attributes (linked with their {@link Attribute#nextAttribute} field).
881 // This list in the <i>reverse order</i> or their order in the ClassFile structure.
882 Attribute attributes = null;
883
884 int attributesCount = readUnsignedShort(currentOffset);
885 currentOffset += 2;
886 while (attributesCount-- > 0) {
887 // Read the attribute_info's attribute_name and attribute_length fields.
888 String attributeName = readUTF8(currentOffset, charBuffer);
889 int attributeLength = readInt(currentOffset + 2);
890 currentOffset += 6;
891 // The tests are sorted in decreasing frequency order (based on frequencies observed on
892 // typical classes).
893 if (Constants.CONSTANT_VALUE.equals(attributeName)) {
894 int constantvalueIndex = readUnsignedShort(currentOffset);
895 constantValue = constantvalueIndex == 0 ? null : readConst(constantvalueIndex, charBuffer);
896 } else if (Constants.SIGNATURE.equals(attributeName)) {
897 signature = readUTF8(currentOffset, charBuffer);
898 } else if (Constants.DEPRECATED.equals(attributeName)) {
899 accessFlags |= Opcodes.ACC_DEPRECATED;
900 } else if (Constants.SYNTHETIC.equals(attributeName)) {
901 accessFlags |= Opcodes.ACC_SYNTHETIC;
902 } else if (Constants.RUNTIME_VISIBLE_ANNOTATIONS.equals(attributeName)) {
903 runtimeVisibleAnnotationsOffset = currentOffset;
904 } else if (Constants.RUNTIME_VISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
905 runtimeVisibleTypeAnnotationsOffset = currentOffset;
906 } else if (Constants.RUNTIME_INVISIBLE_ANNOTATIONS.equals(attributeName)) {
907 runtimeInvisibleAnnotationsOffset = currentOffset;
908 } else if (Constants.RUNTIME_INVISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
909 runtimeInvisibleTypeAnnotationsOffset = currentOffset;
910 } else {
911 Attribute attribute =
912 readAttribute(
913 context.attributePrototypes,
914 attributeName,
915 currentOffset,
916 attributeLength,
917 charBuffer,
918 -1,
919 null);
920 attribute.nextAttribute = attributes;
921 attributes = attribute;
922 }
923 currentOffset += attributeLength;
924 }
925
926 // Visit the field declaration.
927 FieldVisitor fieldVisitor =
928 classVisitor.visitField(accessFlags, name, descriptor, signature, constantValue);
929 if (fieldVisitor == null) {
930 return currentOffset;
931 }
932
933 // Visit the RuntimeVisibleAnnotations attribute.
934 if (runtimeVisibleAnnotationsOffset != 0) {
935 int numAnnotations = readUnsignedShort(runtimeVisibleAnnotationsOffset);
936 int currentAnnotationOffset = runtimeVisibleAnnotationsOffset + 2;
937 while (numAnnotations-- > 0) {
938 // Parse the type_index field.
939 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
940 currentAnnotationOffset += 2;
941 // Parse num_element_value_pairs and element_value_pairs and visit these values.
942 currentAnnotationOffset =
943 readElementValues(
944 fieldVisitor.visitAnnotation(annotationDescriptor, /* visible = */ true),
945 currentAnnotationOffset,
946 /* named = */ true,
947 charBuffer);
948 }
949 }
950
951 // Visit the RuntimeInvisibleAnnotations attribute.
952 if (runtimeInvisibleAnnotationsOffset != 0) {
953 int numAnnotations = readUnsignedShort(runtimeInvisibleAnnotationsOffset);
954 int currentAnnotationOffset = runtimeInvisibleAnnotationsOffset + 2;
955 while (numAnnotations-- > 0) {
956 // Parse the type_index field.
957 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
958 currentAnnotationOffset += 2;
959 // Parse num_element_value_pairs and element_value_pairs and visit these values.
960 currentAnnotationOffset =
961 readElementValues(
962 fieldVisitor.visitAnnotation(annotationDescriptor, /* visible = */ false),
963 currentAnnotationOffset,
964 /* named = */ true,
965 charBuffer);
966 }
967 }
968
969 // Visit the RuntimeVisibleTypeAnnotations attribute.
970 if (runtimeVisibleTypeAnnotationsOffset != 0) {
971 int numAnnotations = readUnsignedShort(runtimeVisibleTypeAnnotationsOffset);
972 int currentAnnotationOffset = runtimeVisibleTypeAnnotationsOffset + 2;
973 while (numAnnotations-- > 0) {
974 // Parse the target_type, target_info and target_path fields.
975 currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
976 // Parse the type_index field.
977 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
978 currentAnnotationOffset += 2;
979 // Parse num_element_value_pairs and element_value_pairs and visit these values.
980 currentAnnotationOffset =
981 readElementValues(
982 fieldVisitor.visitTypeAnnotation(
983 context.currentTypeAnnotationTarget,
984 context.currentTypeAnnotationTargetPath,
985 annotationDescriptor,
986 /* visible = */ true),
987 currentAnnotationOffset,
988 /* named = */ true,
989 charBuffer);
990 }
991 }
992
993 // Visit the RuntimeInvisibleTypeAnnotations attribute.
994 if (runtimeInvisibleTypeAnnotationsOffset != 0) {
995 int numAnnotations = readUnsignedShort(runtimeInvisibleTypeAnnotationsOffset);
996 int currentAnnotationOffset = runtimeInvisibleTypeAnnotationsOffset + 2;
997 while (numAnnotations-- > 0) {
998 // Parse the target_type, target_info and target_path fields.
999 currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
1000 // Parse the type_index field.
1001 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1002 currentAnnotationOffset += 2;
1003 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1004 currentAnnotationOffset =
1005 readElementValues(
1006 fieldVisitor.visitTypeAnnotation(
1007 context.currentTypeAnnotationTarget,
1008 context.currentTypeAnnotationTargetPath,
1009 annotationDescriptor,
1010 /* visible = */ false),
1011 currentAnnotationOffset,
1012 /* named = */ true,
1013 charBuffer);
1014 }
1015 }
1016
1017 // Visit the non standard attributes.
1018 while (attributes != null) {
1019 // Copy and reset the nextAttribute field so that it can also be used in FieldWriter.
1020 Attribute nextAttribute = attributes.nextAttribute;
1021 attributes.nextAttribute = null;
1022 fieldVisitor.visitAttribute(attributes);
1023 attributes = nextAttribute;
1024 }
1025
1026 // Visit the end of the field.
1027 fieldVisitor.visitEnd();
1028 return currentOffset;
1029 }
1030
1031 /**
1032 * Reads a JVMS method_info structure and makes the given visitor visit it.
1033 *
1034 * @param classVisitor the visitor that must visit the method.
1035 * @param context information about the class being parsed.
1036 * @param methodInfoOffset the start offset of the method_info structure.
1037 * @return the offset of the first byte following the method_info structure.
1038 */
1039 private int readMethod(
1040 final ClassVisitor classVisitor, final Context context, final int methodInfoOffset) {
1041 char[] charBuffer = context.charBuffer;
1042
1043 // Read the access_flags, name_index and descriptor_index fields.
1044 int currentOffset = methodInfoOffset;
1045 context.currentMethodAccessFlags = readUnsignedShort(currentOffset);
1046 context.currentMethodName = readUTF8(currentOffset + 2, charBuffer);
1047 context.currentMethodDescriptor = readUTF8(currentOffset + 4, charBuffer);
1048 currentOffset += 6;
1049
1050 // Read the method attributes (the variables are ordered as in Section 4.7 of the JVMS).
1051 // Attribute offsets exclude the attribute_name_index and attribute_length fields.
1052 // - The offset of the Code attribute, or 0.
1053 int codeOffset = 0;
1054 // - The offset of the Exceptions attribute, or 0.
1055 int exceptionsOffset = 0;
1056 // - The strings corresponding to the Exceptions attribute, or null.
1057 String[] exceptions = null;
1058 // - Whether the method has a Synthetic attribute.
1059 boolean synthetic = false;
1060 // - The constant pool index contained in the Signature attribute, or 0.
1061 int signatureIndex = 0;
1062 // - The offset of the RuntimeVisibleAnnotations attribute, or 0.
1063 int runtimeVisibleAnnotationsOffset = 0;
1064 // - The offset of the RuntimeInvisibleAnnotations attribute, or 0.
1065 int runtimeInvisibleAnnotationsOffset = 0;
1066 // - The offset of the RuntimeVisibleParameterAnnotations attribute, or 0.
1067 int runtimeVisibleParameterAnnotationsOffset = 0;
1068 // - The offset of the RuntimeInvisibleParameterAnnotations attribute, or 0.
1069 int runtimeInvisibleParameterAnnotationsOffset = 0;
1070 // - The offset of the RuntimeVisibleTypeAnnotations attribute, or 0.
1071 int runtimeVisibleTypeAnnotationsOffset = 0;
1072 // - The offset of the RuntimeInvisibleTypeAnnotations attribute, or 0.
1073 int runtimeInvisibleTypeAnnotationsOffset = 0;
1074 // - The offset of the AnnotationDefault attribute, or 0.
1075 int annotationDefaultOffset = 0;
1076 // - The offset of the MethodParameters attribute, or 0.
1077 int methodParametersOffset = 0;
1078 // - The non standard attributes (linked with their {@link Attribute#nextAttribute} field).
1079 // This list in the <i>reverse order</i> or their order in the ClassFile structure.
1080 Attribute attributes = null;
1081
1082 int attributesCount = readUnsignedShort(currentOffset);
1083 currentOffset += 2;
1084 while (attributesCount-- > 0) {
1085 // Read the attribute_info's attribute_name and attribute_length fields.
1086 String attributeName = readUTF8(currentOffset, charBuffer);
1087 int attributeLength = readInt(currentOffset + 2);
1088 currentOffset += 6;
1089 // The tests are sorted in decreasing frequency order (based on frequencies observed on
1090 // typical classes).
1091 if (Constants.CODE.equals(attributeName)) {
1092 if ((context.parsingOptions & SKIP_CODE) == 0) {
1093 codeOffset = currentOffset;
1094 }
1095 } else if (Constants.EXCEPTIONS.equals(attributeName)) {
1096 exceptionsOffset = currentOffset;
1097 exceptions = new String[readUnsignedShort(exceptionsOffset)];
1098 int currentExceptionOffset = exceptionsOffset + 2;
1099 for (int i = 0; i < exceptions.length; ++i) {
1100 exceptions[i] = readClass(currentExceptionOffset, charBuffer);
1101 currentExceptionOffset += 2;
1102 }
1103 } else if (Constants.SIGNATURE.equals(attributeName)) {
1104 signatureIndex = readUnsignedShort(currentOffset);
1105 } else if (Constants.DEPRECATED.equals(attributeName)) {
1106 context.currentMethodAccessFlags |= Opcodes.ACC_DEPRECATED;
1107 } else if (Constants.RUNTIME_VISIBLE_ANNOTATIONS.equals(attributeName)) {
1108 runtimeVisibleAnnotationsOffset = currentOffset;
1109 } else if (Constants.RUNTIME_VISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
1110 runtimeVisibleTypeAnnotationsOffset = currentOffset;
1111 } else if (Constants.ANNOTATION_DEFAULT.equals(attributeName)) {
1112 annotationDefaultOffset = currentOffset;
1113 } else if (Constants.SYNTHETIC.equals(attributeName)) {
1114 synthetic = true;
1115 context.currentMethodAccessFlags |= Opcodes.ACC_SYNTHETIC;
1116 } else if (Constants.RUNTIME_INVISIBLE_ANNOTATIONS.equals(attributeName)) {
1117 runtimeInvisibleAnnotationsOffset = currentOffset;
1118 } else if (Constants.RUNTIME_INVISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
1119 runtimeInvisibleTypeAnnotationsOffset = currentOffset;
1120 } else if (Constants.RUNTIME_VISIBLE_PARAMETER_ANNOTATIONS.equals(attributeName)) {
1121 runtimeVisibleParameterAnnotationsOffset = currentOffset;
1122 } else if (Constants.RUNTIME_INVISIBLE_PARAMETER_ANNOTATIONS.equals(attributeName)) {
1123 runtimeInvisibleParameterAnnotationsOffset = currentOffset;
1124 } else if (Constants.METHOD_PARAMETERS.equals(attributeName)) {
1125 methodParametersOffset = currentOffset;
1126 } else {
1127 Attribute attribute =
1128 readAttribute(
1129 context.attributePrototypes,
1130 attributeName,
1131 currentOffset,
1132 attributeLength,
1133 charBuffer,
1134 -1,
1135 null);
1136 attribute.nextAttribute = attributes;
1137 attributes = attribute;
1138 }
1139 currentOffset += attributeLength;
1140 }
1141
1142 // Visit the method declaration.
1143 MethodVisitor methodVisitor =
1144 classVisitor.visitMethod(
1145 context.currentMethodAccessFlags,
1146 context.currentMethodName,
1147 context.currentMethodDescriptor,
1148 signatureIndex == 0 ? null : readUtf(signatureIndex, charBuffer),
1149 exceptions);
1150 if (methodVisitor == null) {
1151 return currentOffset;
1152 }
1153
1154 // If the returned MethodVisitor is in fact a MethodWriter, it means there is no method
1155 // adapter between the reader and the writer. In this case, it might be possible to copy
1156 // the method attributes directly into the writer. If so, return early without visiting
1157 // the content of these attributes.
1158 if (methodVisitor instanceof MethodWriter) {
1159 MethodWriter methodWriter = (MethodWriter) methodVisitor;
1160 if (methodWriter.canCopyMethodAttributes(
1161 this,
1162 methodInfoOffset,
1163 currentOffset - methodInfoOffset,
1164 synthetic,
1165 (context.currentMethodAccessFlags & Opcodes.ACC_DEPRECATED) != 0,
1166 readUnsignedShort(methodInfoOffset + 4),
1167 signatureIndex,
1168 exceptionsOffset)) {
1169 return currentOffset;
1170 }
1171 }
1172
1173 // Visit the MethodParameters attribute.
1174 if (methodParametersOffset != 0) {
1175 int parametersCount = readByte(methodParametersOffset);
1176 int currentParameterOffset = methodParametersOffset + 1;
1177 while (parametersCount-- > 0) {
1178 // Read the name_index and access_flags fields and visit them.
1179 methodVisitor.visitParameter(
1180 readUTF8(currentParameterOffset, charBuffer),
1181 readUnsignedShort(currentParameterOffset + 2));
1182 currentParameterOffset += 4;
1183 }
1184 }
1185
1186 // Visit the AnnotationDefault attribute.
1187 if (annotationDefaultOffset != 0) {
1188 AnnotationVisitor annotationVisitor = methodVisitor.visitAnnotationDefault();
1189 readElementValue(annotationVisitor, annotationDefaultOffset, null, charBuffer);
1190 if (annotationVisitor != null) {
1191 annotationVisitor.visitEnd();
1192 }
1193 }
1194
1195 // Visit the RuntimeVisibleAnnotations attribute.
1196 if (runtimeVisibleAnnotationsOffset != 0) {
1197 int numAnnotations = readUnsignedShort(runtimeVisibleAnnotationsOffset);
1198 int currentAnnotationOffset = runtimeVisibleAnnotationsOffset + 2;
1199 while (numAnnotations-- > 0) {
1200 // Parse the type_index field.
1201 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1202 currentAnnotationOffset += 2;
1203 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1204 currentAnnotationOffset =
1205 readElementValues(
1206 methodVisitor.visitAnnotation(annotationDescriptor, /* visible = */ true),
1207 currentAnnotationOffset,
1208 /* named = */ true,
1209 charBuffer);
1210 }
1211 }
1212
1213 // Visit the RuntimeInvisibleAnnotations attribute.
1214 if (runtimeInvisibleAnnotationsOffset != 0) {
1215 int numAnnotations = readUnsignedShort(runtimeInvisibleAnnotationsOffset);
1216 int currentAnnotationOffset = runtimeInvisibleAnnotationsOffset + 2;
1217 while (numAnnotations-- > 0) {
1218 // Parse the type_index field.
1219 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1220 currentAnnotationOffset += 2;
1221 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1222 currentAnnotationOffset =
1223 readElementValues(
1224 methodVisitor.visitAnnotation(annotationDescriptor, /* visible = */ false),
1225 currentAnnotationOffset,
1226 /* named = */ true,
1227 charBuffer);
1228 }
1229 }
1230
1231 // Visit the RuntimeVisibleTypeAnnotations attribute.
1232 if (runtimeVisibleTypeAnnotationsOffset != 0) {
1233 int numAnnotations = readUnsignedShort(runtimeVisibleTypeAnnotationsOffset);
1234 int currentAnnotationOffset = runtimeVisibleTypeAnnotationsOffset + 2;
1235 while (numAnnotations-- > 0) {
1236 // Parse the target_type, target_info and target_path fields.
1237 currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
1238 // Parse the type_index field.
1239 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1240 currentAnnotationOffset += 2;
1241 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1242 currentAnnotationOffset =
1243 readElementValues(
1244 methodVisitor.visitTypeAnnotation(
1245 context.currentTypeAnnotationTarget,
1246 context.currentTypeAnnotationTargetPath,
1247 annotationDescriptor,
1248 /* visible = */ true),
1249 currentAnnotationOffset,
1250 /* named = */ true,
1251 charBuffer);
1252 }
1253 }
1254
1255 // Visit the RuntimeInvisibleTypeAnnotations attribute.
1256 if (runtimeInvisibleTypeAnnotationsOffset != 0) {
1257 int numAnnotations = readUnsignedShort(runtimeInvisibleTypeAnnotationsOffset);
1258 int currentAnnotationOffset = runtimeInvisibleTypeAnnotationsOffset + 2;
1259 while (numAnnotations-- > 0) {
1260 // Parse the target_type, target_info and target_path fields.
1261 currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
1262 // Parse the type_index field.
1263 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1264 currentAnnotationOffset += 2;
1265 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1266 currentAnnotationOffset =
1267 readElementValues(
1268 methodVisitor.visitTypeAnnotation(
1269 context.currentTypeAnnotationTarget,
1270 context.currentTypeAnnotationTargetPath,
1271 annotationDescriptor,
1272 /* visible = */ false),
1273 currentAnnotationOffset,
1274 /* named = */ true,
1275 charBuffer);
1276 }
1277 }
1278
1279 // Visit the RuntimeVisibleParameterAnnotations attribute.
1280 if (runtimeVisibleParameterAnnotationsOffset != 0) {
1281 readParameterAnnotations(
1282 methodVisitor, context, runtimeVisibleParameterAnnotationsOffset, /* visible = */ true);
1283 }
1284
1285 // Visit the RuntimeInvisibleParameterAnnotations attribute.
1286 if (runtimeInvisibleParameterAnnotationsOffset != 0) {
1287 readParameterAnnotations(
1288 methodVisitor,
1289 context,
1290 runtimeInvisibleParameterAnnotationsOffset,
1291 /* visible = */ false);
1292 }
1293
1294 // Visit the non standard attributes.
1295 while (attributes != null) {
1296 // Copy and reset the nextAttribute field so that it can also be used in MethodWriter.
1297 Attribute nextAttribute = attributes.nextAttribute;
1298 attributes.nextAttribute = null;
1299 methodVisitor.visitAttribute(attributes);
1300 attributes = nextAttribute;
1301 }
1302
1303 // Visit the Code attribute.
1304 if (codeOffset != 0) {
1305 methodVisitor.visitCode();
1306 readCode(methodVisitor, context, codeOffset);
1307 }
1308
1309 // Visit the end of the method.
1310 methodVisitor.visitEnd();
1311 return currentOffset;
1312 }
1313
1314 // ----------------------------------------------------------------------------------------------
1315 // Methods to parse a Code attribute
1316 // ----------------------------------------------------------------------------------------------
1317
1318 /**
1319 * Reads a JVMS 'Code' attribute and makes the given visitor visit it.
1320 *
1321 * @param methodVisitor the visitor that must visit the Code attribute.
1322 * @param context information about the class being parsed.
1323 * @param codeOffset the start offset in {@link #b} of the Code attribute, excluding its
1324 * attribute_name_index and attribute_length fields.
1325 */
1326 private void readCode(
1327 final MethodVisitor methodVisitor, final Context context, final int codeOffset) {
1328 int currentOffset = codeOffset;
1329
1330 // Read the max_stack, max_locals and code_length fields.
1331 final byte[] classFileBuffer = b;
1332 final char[] charBuffer = context.charBuffer;
1333 final int maxStack = readUnsignedShort(currentOffset);
1334 final int maxLocals = readUnsignedShort(currentOffset + 2);
1335 final int codeLength = readInt(currentOffset + 4);
1336 currentOffset += 8;
1337
1338 // Read the bytecode 'code' array to create a label for each referenced instruction.
1339 final int bytecodeStartOffset = currentOffset;
1340 final int bytecodeEndOffset = currentOffset + codeLength;
1341 final Label[] labels = context.currentMethodLabels = new Label[codeLength + 1];
1342 while (currentOffset < bytecodeEndOffset) {
1343 final int bytecodeOffset = currentOffset - bytecodeStartOffset;
1344 final int opcode = classFileBuffer[currentOffset] & 0xFF;
1345 switch (opcode) {
1346 case Constants.NOP:
1347 case Constants.ACONST_NULL:
1348 case Constants.ICONST_M1:
1349 case Constants.ICONST_0:
1350 case Constants.ICONST_1:
1351 case Constants.ICONST_2:
1352 case Constants.ICONST_3:
1353 case Constants.ICONST_4:
1354 case Constants.ICONST_5:
1355 case Constants.LCONST_0:
1356 case Constants.LCONST_1:
1357 case Constants.FCONST_0:
1358 case Constants.FCONST_1:
1359 case Constants.FCONST_2:
1360 case Constants.DCONST_0:
1361 case Constants.DCONST_1:
1362 case Constants.IALOAD:
1363 case Constants.LALOAD:
1364 case Constants.FALOAD:
1365 case Constants.DALOAD:
1366 case Constants.AALOAD:
1367 case Constants.BALOAD:
1368 case Constants.CALOAD:
1369 case Constants.SALOAD:
1370 case Constants.IASTORE:
1371 case Constants.LASTORE:
1372 case Constants.FASTORE:
1373 case Constants.DASTORE:
1374 case Constants.AASTORE:
1375 case Constants.BASTORE:
1376 case Constants.CASTORE:
1377 case Constants.SASTORE:
1378 case Constants.POP:
1379 case Constants.POP2:
1380 case Constants.DUP:
1381 case Constants.DUP_X1:
1382 case Constants.DUP_X2:
1383 case Constants.DUP2:
1384 case Constants.DUP2_X1:
1385 case Constants.DUP2_X2:
1386 case Constants.SWAP:
1387 case Constants.IADD:
1388 case Constants.LADD:
1389 case Constants.FADD:
1390 case Constants.DADD:
1391 case Constants.ISUB:
1392 case Constants.LSUB:
1393 case Constants.FSUB:
1394 case Constants.DSUB:
1395 case Constants.IMUL:
1396 case Constants.LMUL:
1397 case Constants.FMUL:
1398 case Constants.DMUL:
1399 case Constants.IDIV:
1400 case Constants.LDIV:
1401 case Constants.FDIV:
1402 case Constants.DDIV:
1403 case Constants.IREM:
1404 case Constants.LREM:
1405 case Constants.FREM:
1406 case Constants.DREM:
1407 case Constants.INEG:
1408 case Constants.LNEG:
1409 case Constants.FNEG:
1410 case Constants.DNEG:
1411 case Constants.ISHL:
1412 case Constants.LSHL:
1413 case Constants.ISHR:
1414 case Constants.LSHR:
1415 case Constants.IUSHR:
1416 case Constants.LUSHR:
1417 case Constants.IAND:
1418 case Constants.LAND:
1419 case Constants.IOR:
1420 case Constants.LOR:
1421 case Constants.IXOR:
1422 case Constants.LXOR:
1423 case Constants.I2L:
1424 case Constants.I2F:
1425 case Constants.I2D:
1426 case Constants.L2I:
1427 case Constants.L2F:
1428 case Constants.L2D:
1429 case Constants.F2I:
1430 case Constants.F2L:
1431 case Constants.F2D:
1432 case Constants.D2I:
1433 case Constants.D2L:
1434 case Constants.D2F:
1435 case Constants.I2B:
1436 case Constants.I2C:
1437 case Constants.I2S:
1438 case Constants.LCMP:
1439 case Constants.FCMPL:
1440 case Constants.FCMPG:
1441 case Constants.DCMPL:
1442 case Constants.DCMPG:
1443 case Constants.IRETURN:
1444 case Constants.LRETURN:
1445 case Constants.FRETURN:
1446 case Constants.DRETURN:
1447 case Constants.ARETURN:
1448 case Constants.RETURN:
1449 case Constants.ARRAYLENGTH:
1450 case Constants.ATHROW:
1451 case Constants.MONITORENTER:
1452 case Constants.MONITOREXIT:
1453 case Constants.ILOAD_0:
1454 case Constants.ILOAD_1:
1455 case Constants.ILOAD_2:
1456 case Constants.ILOAD_3:
1457 case Constants.LLOAD_0:
1458 case Constants.LLOAD_1:
1459 case Constants.LLOAD_2:
1460 case Constants.LLOAD_3:
1461 case Constants.FLOAD_0:
1462 case Constants.FLOAD_1:
1463 case Constants.FLOAD_2:
1464 case Constants.FLOAD_3:
1465 case Constants.DLOAD_0:
1466 case Constants.DLOAD_1:
1467 case Constants.DLOAD_2:
1468 case Constants.DLOAD_3:
1469 case Constants.ALOAD_0:
1470 case Constants.ALOAD_1:
1471 case Constants.ALOAD_2:
1472 case Constants.ALOAD_3:
1473 case Constants.ISTORE_0:
1474 case Constants.ISTORE_1:
1475 case Constants.ISTORE_2:
1476 case Constants.ISTORE_3:
1477 case Constants.LSTORE_0:
1478 case Constants.LSTORE_1:
1479 case Constants.LSTORE_2:
1480 case Constants.LSTORE_3:
1481 case Constants.FSTORE_0:
1482 case Constants.FSTORE_1:
1483 case Constants.FSTORE_2:
1484 case Constants.FSTORE_3:
1485 case Constants.DSTORE_0:
1486 case Constants.DSTORE_1:
1487 case Constants.DSTORE_2:
1488 case Constants.DSTORE_3:
1489 case Constants.ASTORE_0:
1490 case Constants.ASTORE_1:
1491 case Constants.ASTORE_2:
1492 case Constants.ASTORE_3:
1493 currentOffset += 1;
1494 break;
1495 case Constants.IFEQ:
1496 case Constants.IFNE:
1497 case Constants.IFLT:
1498 case Constants.IFGE:
1499 case Constants.IFGT:
1500 case Constants.IFLE:
1501 case Constants.IF_ICMPEQ:
1502 case Constants.IF_ICMPNE:
1503 case Constants.IF_ICMPLT:
1504 case Constants.IF_ICMPGE:
1505 case Constants.IF_ICMPGT:
1506 case Constants.IF_ICMPLE:
1507 case Constants.IF_ACMPEQ:
1508 case Constants.IF_ACMPNE:
1509 case Constants.GOTO:
1510 case Constants.JSR:
1511 case Constants.IFNULL:
1512 case Constants.IFNONNULL:
1513 createLabel(bytecodeOffset + readShort(currentOffset + 1), labels);
1514 currentOffset += 3;
1515 break;
1516 case Constants.ASM_IFEQ:
1517 case Constants.ASM_IFNE:
1518 case Constants.ASM_IFLT:
1519 case Constants.ASM_IFGE:
1520 case Constants.ASM_IFGT:
1521 case Constants.ASM_IFLE:
1522 case Constants.ASM_IF_ICMPEQ:
1523 case Constants.ASM_IF_ICMPNE:
1524 case Constants.ASM_IF_ICMPLT:
1525 case Constants.ASM_IF_ICMPGE:
1526 case Constants.ASM_IF_ICMPGT:
1527 case Constants.ASM_IF_ICMPLE:
1528 case Constants.ASM_IF_ACMPEQ:
1529 case Constants.ASM_IF_ACMPNE:
1530 case Constants.ASM_GOTO:
1531 case Constants.ASM_JSR:
1532 case Constants.ASM_IFNULL:
1533 case Constants.ASM_IFNONNULL:
1534 createLabel(bytecodeOffset + readUnsignedShort(currentOffset + 1), labels);
1535 currentOffset += 3;
1536 break;
1537 case Constants.GOTO_W:
1538 case Constants.JSR_W:
1539 case Constants.ASM_GOTO_W:
1540 createLabel(bytecodeOffset + readInt(currentOffset + 1), labels);
1541 currentOffset += 5;
1542 break;
1543 case Constants.WIDE:
1544 switch (classFileBuffer[currentOffset + 1] & 0xFF) {
1545 case Constants.ILOAD:
1546 case Constants.FLOAD:
1547 case Constants.ALOAD:
1548 case Constants.LLOAD:
1549 case Constants.DLOAD:
1550 case Constants.ISTORE:
1551 case Constants.FSTORE:
1552 case Constants.ASTORE:
1553 case Constants.LSTORE:
1554 case Constants.DSTORE:
1555 case Constants.RET:
1556 currentOffset += 4;
1557 break;
1558 case Constants.IINC:
1559 currentOffset += 6;
1560 break;
1561 default:
1562 throw new IllegalArgumentException();
1563 }
1564 break;
1565 case Constants.TABLESWITCH:
1566 // Skip 0 to 3 padding bytes.
1567 currentOffset += 4 - (bytecodeOffset & 3);
1568 // Read the default label and the number of table entries.
1569 createLabel(bytecodeOffset + readInt(currentOffset), labels);
1570 int numTableEntries = readInt(currentOffset + 8) - readInt(currentOffset + 4) + 1;
1571 currentOffset += 12;
1572 // Read the table labels.
1573 while (numTableEntries-- > 0) {
1574 createLabel(bytecodeOffset + readInt(currentOffset), labels);
1575 currentOffset += 4;
1576 }
1577 break;
1578 case Constants.LOOKUPSWITCH:
1579 // Skip 0 to 3 padding bytes.
1580 currentOffset += 4 - (bytecodeOffset & 3);
1581 // Read the default label and the number of switch cases.
1582 createLabel(bytecodeOffset + readInt(currentOffset), labels);
1583 int numSwitchCases = readInt(currentOffset + 4);
1584 currentOffset += 8;
1585 // Read the switch labels.
1586 while (numSwitchCases-- > 0) {
1587 createLabel(bytecodeOffset + readInt(currentOffset + 4), labels);
1588 currentOffset += 8;
1589 }
1590 break;
1591 case Constants.ILOAD:
1592 case Constants.LLOAD:
1593 case Constants.FLOAD:
1594 case Constants.DLOAD:
1595 case Constants.ALOAD:
1596 case Constants.ISTORE:
1597 case Constants.LSTORE:
1598 case Constants.FSTORE:
1599 case Constants.DSTORE:
1600 case Constants.ASTORE:
1601 case Constants.RET:
1602 case Constants.BIPUSH:
1603 case Constants.NEWARRAY:
1604 case Constants.LDC:
1605 currentOffset += 2;
1606 break;
1607 case Constants.SIPUSH:
1608 case Constants.LDC_W:
1609 case Constants.LDC2_W:
1610 case Constants.GETSTATIC:
1611 case Constants.PUTSTATIC:
1612 case Constants.GETFIELD:
1613 case Constants.PUTFIELD:
1614 case Constants.INVOKEVIRTUAL:
1615 case Constants.INVOKESPECIAL:
1616 case Constants.INVOKESTATIC:
1617 case Constants.NEW:
1618 case Constants.ANEWARRAY:
1619 case Constants.CHECKCAST:
1620 case Constants.INSTANCEOF:
1621 case Constants.IINC:
1622 currentOffset += 3;
1623 break;
1624 case Constants.INVOKEINTERFACE:
1625 case Constants.INVOKEDYNAMIC:
1626 currentOffset += 5;
1627 break;
1628 case Constants.MULTIANEWARRAY:
1629 currentOffset += 4;
1630 break;
1631 default:
1632 throw new IllegalArgumentException();
1633 }
1634 }
1635
1636 // Read the 'exception_table_length' and 'exception_table' field to create a label for each
1637 // referenced instruction, and to make methodVisitor visit the corresponding try catch blocks.
1638 int exceptionTableLength = readUnsignedShort(currentOffset);
1639 currentOffset += 2;
1640 while (exceptionTableLength-- > 0) {
1641 Label start = createLabel(readUnsignedShort(currentOffset), labels);
1642 Label end = createLabel(readUnsignedShort(currentOffset + 2), labels);
1643 Label handler = createLabel(readUnsignedShort(currentOffset + 4), labels);
1644 String catchType = readUTF8(cpInfoOffsets[readUnsignedShort(currentOffset + 6)], charBuffer);
1645 currentOffset += 8;
1646 methodVisitor.visitTryCatchBlock(start, end, handler, catchType);
1647 }
1648
1649 // Read the Code attributes to create a label for each referenced instruction (the variables
1650 // are ordered as in Section 4.7 of the JVMS). Attribute offsets exclude the
1651 // attribute_name_index and attribute_length fields.
1652 // - The offset of the current 'stack_map_frame' in the StackMap[Table] attribute, or 0.
1653 // Initially, this is the offset of the first 'stack_map_frame' entry. Then this offset is
1654 // updated after each stack_map_frame is read.
1655 int stackMapFrameOffset = 0;
1656 // - The end offset of the StackMap[Table] attribute, or 0.
1657 int stackMapTableEndOffset = 0;
1658 // - Whether the stack map frames are compressed (i.e. in a StackMapTable) or not.
1659 boolean compressedFrames = true;
1660 // - The offset of the LocalVariableTable attribute, or 0.
1661 int localVariableTableOffset = 0;
1662 // - The offset of the LocalVariableTypeTable attribute, or 0.
1663 int localVariableTypeTableOffset = 0;
1664 // - The offset of each 'type_annotation' entry in the RuntimeVisibleTypeAnnotations
1665 // attribute, or null.
1666 int[] visibleTypeAnnotationOffsets = null;
1667 // - The offset of each 'type_annotation' entry in the RuntimeInvisibleTypeAnnotations
1668 // attribute, or null.
1669 int[] invisibleTypeAnnotationOffsets = null;
1670 // - The non standard attributes (linked with their {@link Attribute#nextAttribute} field).
1671 // This list in the <i>reverse order</i> or their order in the ClassFile structure.
1672 Attribute attributes = null;
1673
1674 int attributesCount = readUnsignedShort(currentOffset);
1675 currentOffset += 2;
1676 while (attributesCount-- > 0) {
1677 // Read the attribute_info's attribute_name and attribute_length fields.
1678 String attributeName = readUTF8(currentOffset, charBuffer);
1679 int attributeLength = readInt(currentOffset + 2);
1680 currentOffset += 6;
1681 if (Constants.LOCAL_VARIABLE_TABLE.equals(attributeName)) {
1682 if ((context.parsingOptions & SKIP_DEBUG) == 0) {
1683 localVariableTableOffset = currentOffset;
1684 // Parse the attribute to find the corresponding (debug only) labels.
1685 int currentLocalVariableTableOffset = currentOffset;
1686 int localVariableTableLength = readUnsignedShort(currentLocalVariableTableOffset);
1687 currentLocalVariableTableOffset += 2;
1688 while (localVariableTableLength-- > 0) {
1689 int startPc = readUnsignedShort(currentLocalVariableTableOffset);
1690 createDebugLabel(startPc, labels);
1691 int length = readUnsignedShort(currentLocalVariableTableOffset + 2);
1692 createDebugLabel(startPc + length, labels);
1693 // Skip the name_index, descriptor_index and index fields (2 bytes each).
1694 currentLocalVariableTableOffset += 10;
1695 }
1696 }
1697 } else if (Constants.LOCAL_VARIABLE_TYPE_TABLE.equals(attributeName)) {
1698 localVariableTypeTableOffset = currentOffset;
1699 // Here we do not extract the labels corresponding to the attribute content. We assume they
1700 // are the same or a subset of those of the LocalVariableTable attribute.
1701 } else if (Constants.LINE_NUMBER_TABLE.equals(attributeName)) {
1702 if ((context.parsingOptions & SKIP_DEBUG) == 0) {
1703 // Parse the attribute to find the corresponding (debug only) labels.
1704 int currentLineNumberTableOffset = currentOffset;
1705 int lineNumberTableLength = readUnsignedShort(currentLineNumberTableOffset);
1706 currentLineNumberTableOffset += 2;
1707 while (lineNumberTableLength-- > 0) {
1708 int startPc = readUnsignedShort(currentLineNumberTableOffset);
1709 int lineNumber = readUnsignedShort(currentLineNumberTableOffset + 2);
1710 currentLineNumberTableOffset += 4;
1711 createDebugLabel(startPc, labels);
1712 labels[startPc].addLineNumber(lineNumber);
1713 }
1714 }
1715 } else if (Constants.RUNTIME_VISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
1716 visibleTypeAnnotationOffsets =
1717 readTypeAnnotations(methodVisitor, context, currentOffset, /* visible = */ true);
1718 // Here we do not extract the labels corresponding to the attribute content. This would
1719 // require a full parsing of the attribute, which would need to be repeated when parsing
1720 // the bytecode instructions (see below). Instead, the content of the attribute is read one
1721 // type annotation at a time (i.e. after a type annotation has been visited, the next type
1722 // annotation is read), and the labels it contains are also extracted one annotation at a
1723 // time. This assumes that type annotations are ordered by increasing bytecode offset.
1724 } else if (Constants.RUNTIME_INVISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
1725 invisibleTypeAnnotationOffsets =
1726 readTypeAnnotations(methodVisitor, context, currentOffset, /* visible = */ false);
1727 // Same comment as above for the RuntimeVisibleTypeAnnotations attribute.
1728 } else if (Constants.STACK_MAP_TABLE.equals(attributeName)) {
1729 if ((context.parsingOptions & SKIP_FRAMES) == 0) {
1730 stackMapFrameOffset = currentOffset + 2;
1731 stackMapTableEndOffset = currentOffset + attributeLength;
1732 }
1733 // Here we do not extract the labels corresponding to the attribute content. This would
1734 // require a full parsing of the attribute, which would need to be repeated when parsing
1735 // the bytecode instructions (see below). Instead, the content of the attribute is read one
1736 // frame at a time (i.e. after a frame has been visited, the next frame is read), and the
1737 // labels it contains are also extracted one frame at a time. Thanks to the ordering of
1738 // frames, having only a "one frame lookahead" is not a problem, i.e. it is not possible to
1739 // see an offset smaller than the offset of the current instruction and for which no Label
1740 // exist. Except for UNINITIALIZED type offsets. We solve this by parsing the stack map
1741 // table without a full decoding (see below).
1742 } else if ("StackMap".equals(attributeName)) {
1743 if ((context.parsingOptions & SKIP_FRAMES) == 0) {
1744 stackMapFrameOffset = currentOffset + 2;
1745 stackMapTableEndOffset = currentOffset + attributeLength;
1746 compressedFrames = false;
1747 }
1748 // IMPORTANT! Here we assume that the frames are ordered, as in the StackMapTable attribute,
1749 // although this is not guaranteed by the attribute format. This allows an incremental
1750 // extraction of the labels corresponding to this attribute (see the comment above for the
1751 // StackMapTable attribute).
1752 } else {
1753 Attribute attribute =
1754 readAttribute(
1755 context.attributePrototypes,
1756 attributeName,
1757 currentOffset,
1758 attributeLength,
1759 charBuffer,
1760 codeOffset,
1761 labels);
1762 attribute.nextAttribute = attributes;
1763 attributes = attribute;
1764 }
1765 currentOffset += attributeLength;
1766 }
1767
1768 // Initialize the context fields related to stack map frames, and generate the first
1769 // (implicit) stack map frame, if needed.
1770 final boolean expandFrames = (context.parsingOptions & EXPAND_FRAMES) != 0;
1771 if (stackMapFrameOffset != 0) {
1772 // The bytecode offset of the first explicit frame is not offset_delta + 1 but only
1773 // offset_delta. Setting the implicit frame offset to -1 allows us to use of the
1774 // "offset_delta + 1" rule in all cases.
1775 context.currentFrameOffset = -1;
1776 context.currentFrameType = 0;
1777 context.currentFrameLocalCount = 0;
1778 context.currentFrameLocalCountDelta = 0;
1779 context.currentFrameLocalTypes = new Object[maxLocals];
1780 context.currentFrameStackCount = 0;
1781 context.currentFrameStackTypes = new Object[maxStack];
1782 if (expandFrames) {
1783 computeImplicitFrame(context);
1784 }
1785 // Find the labels for UNINITIALIZED frame types. Instead of decoding each element of the
1786 // stack map table, we look for 3 consecutive bytes that "look like" an UNINITIALIZED type
1787 // (tag ITEM_Uninitialized, offset within bytecode bounds, NEW instruction at this offset).
1788 // We may find false positives (i.e. not real UNINITIALIZED types), but this should be rare,
1789 // and the only consequence will be the creation of an unneeded label. This is better than
1790 // creating a label for each NEW instruction, and faster than fully decoding the whole stack
1791 // map table.
1792 for (int offset = stackMapFrameOffset; offset < stackMapTableEndOffset - 2; ++offset) {
1793 if (classFileBuffer[offset] == Frame.ITEM_UNINITIALIZED) {
1794 int potentialBytecodeOffset = readUnsignedShort(offset + 1);
1795 if (potentialBytecodeOffset >= 0
1796 && potentialBytecodeOffset < codeLength
1797 && (classFileBuffer[bytecodeStartOffset + potentialBytecodeOffset] & 0xFF)
1798 == Opcodes.NEW) {
1799 createLabel(potentialBytecodeOffset, labels);
1800 }
1801 }
1802 }
1803 }
1804 if (expandFrames && (context.parsingOptions & EXPAND_ASM_INSNS) != 0) {
1805 // Expanding the ASM specific instructions can introduce F_INSERT frames, even if the method
1806 // does not currently have any frame. These inserted frames must be computed by simulating the
1807 // effect of the bytecode instructions, one by one, starting from the implicit first frame.
1808 // For this, MethodWriter needs to know maxLocals before the first instruction is visited. To
1809 // ensure this, we visit the implicit first frame here (passing only maxLocals - the rest is
1810 // computed in MethodWriter).
1811 methodVisitor.visitFrame(Opcodes.F_NEW, maxLocals, null, 0, null);
1812 }
1813
1814 // Visit the bytecode instructions. First, introduce state variables for the incremental parsing
1815 // of the type annotations.
1816
1817 // Index of the next runtime visible type annotation to read (in the
1818 // visibleTypeAnnotationOffsets array).
1819 int currentVisibleTypeAnnotationIndex = 0;
1820 // The bytecode offset of the next runtime visible type annotation to read, or -1.
1821 int currentVisibleTypeAnnotationBytecodeOffset =
1822 getTypeAnnotationBytecodeOffset(visibleTypeAnnotationOffsets, 0);
1823 // Index of the next runtime invisible type annotation to read (in the
1824 // invisibleTypeAnnotationOffsets array).
1825 int currentInvisibleTypeAnnotationIndex = 0;
1826 // The bytecode offset of the next runtime invisible type annotation to read, or -1.
1827 int currentInvisibleTypeAnnotationBytecodeOffset =
1828 getTypeAnnotationBytecodeOffset(invisibleTypeAnnotationOffsets, 0);
1829
1830 // Whether a F_INSERT stack map frame must be inserted before the current instruction.
1831 boolean insertFrame = false;
1832
1833 // The delta to subtract from a goto_w or jsr_w opcode to get the corresponding goto or jsr
1834 // opcode, or 0 if goto_w and jsr_w must be left unchanged (i.e. when expanding ASM specific
1835 // instructions).
1836 final int wideJumpOpcodeDelta =
1837 (context.parsingOptions & EXPAND_ASM_INSNS) == 0 ? Constants.WIDE_JUMP_OPCODE_DELTA : 0;
1838
1839 currentOffset = bytecodeStartOffset;
1840 while (currentOffset < bytecodeEndOffset) {
1841 final int currentBytecodeOffset = currentOffset - bytecodeStartOffset;
1842
1843 // Visit the label and the line number(s) for this bytecode offset, if any.
1844 Label currentLabel = labels[currentBytecodeOffset];
1845 if (currentLabel != null) {
1846 currentLabel.accept(methodVisitor, (context.parsingOptions & SKIP_DEBUG) == 0);
1847 }
1848
1849 // Visit the stack map frame for this bytecode offset, if any.
1850 while (stackMapFrameOffset != 0
1851 && (context.currentFrameOffset == currentBytecodeOffset
1852 || context.currentFrameOffset == -1)) {
1853 // If there is a stack map frame for this offset, make methodVisitor visit it, and read the
1854 // next stack map frame if there is one.
1855 if (context.currentFrameOffset != -1) {
1856 if (!compressedFrames || expandFrames) {
1857 methodVisitor.visitFrame(
1858 Opcodes.F_NEW,
1859 context.currentFrameLocalCount,
1860 context.currentFrameLocalTypes,
1861 context.currentFrameStackCount,
1862 context.currentFrameStackTypes);
1863 } else {
1864 methodVisitor.visitFrame(
1865 context.currentFrameType,
1866 context.currentFrameLocalCountDelta,
1867 context.currentFrameLocalTypes,
1868 context.currentFrameStackCount,
1869 context.currentFrameStackTypes);
1870 }
1871 // Since there is already a stack map frame for this bytecode offset, there is no need to
1872 // insert a new one.
1873 insertFrame = false;
1874 }
1875 if (stackMapFrameOffset < stackMapTableEndOffset) {
1876 stackMapFrameOffset =
1877 readStackMapFrame(stackMapFrameOffset, compressedFrames, expandFrames, context);
1878 } else {
1879 stackMapFrameOffset = 0;
1880 }
1881 }
1882
1883 // Insert a stack map frame for this bytecode offset, if requested by setting insertFrame to
1884 // true during the previous iteration. The actual frame content is computed in MethodWriter.
1885 if (insertFrame) {
1886 if ((context.parsingOptions & EXPAND_FRAMES) != 0) {
1887 methodVisitor.visitFrame(Constants.F_INSERT, 0, null, 0, null);
1888 }
1889 insertFrame = false;
1890 }
1891
1892 // Visit the instruction at this bytecode offset.
1893 int opcode = classFileBuffer[currentOffset] & 0xFF;
1894 switch (opcode) {
1895 case Constants.NOP:
1896 case Constants.ACONST_NULL:
1897 case Constants.ICONST_M1:
1898 case Constants.ICONST_0:
1899 case Constants.ICONST_1:
1900 case Constants.ICONST_2:
1901 case Constants.ICONST_3:
1902 case Constants.ICONST_4:
1903 case Constants.ICONST_5:
1904 case Constants.LCONST_0:
1905 case Constants.LCONST_1:
1906 case Constants.FCONST_0:
1907 case Constants.FCONST_1:
1908 case Constants.FCONST_2:
1909 case Constants.DCONST_0:
1910 case Constants.DCONST_1:
1911 case Constants.IALOAD:
1912 case Constants.LALOAD:
1913 case Constants.FALOAD:
1914 case Constants.DALOAD:
1915 case Constants.AALOAD:
1916 case Constants.BALOAD:
1917 case Constants.CALOAD:
1918 case Constants.SALOAD:
1919 case Constants.IASTORE:
1920 case Constants.LASTORE:
1921 case Constants.FASTORE:
1922 case Constants.DASTORE:
1923 case Constants.AASTORE:
1924 case Constants.BASTORE:
1925 case Constants.CASTORE:
1926 case Constants.SASTORE:
1927 case Constants.POP:
1928 case Constants.POP2:
1929 case Constants.DUP:
1930 case Constants.DUP_X1:
1931 case Constants.DUP_X2:
1932 case Constants.DUP2:
1933 case Constants.DUP2_X1:
1934 case Constants.DUP2_X2:
1935 case Constants.SWAP:
1936 case Constants.IADD:
1937 case Constants.LADD:
1938 case Constants.FADD:
1939 case Constants.DADD:
1940 case Constants.ISUB:
1941 case Constants.LSUB:
1942 case Constants.FSUB:
1943 case Constants.DSUB:
1944 case Constants.IMUL:
1945 case Constants.LMUL:
1946 case Constants.FMUL:
1947 case Constants.DMUL:
1948 case Constants.IDIV:
1949 case Constants.LDIV:
1950 case Constants.FDIV:
1951 case Constants.DDIV:
1952 case Constants.IREM:
1953 case Constants.LREM:
1954 case Constants.FREM:
1955 case Constants.DREM:
1956 case Constants.INEG:
1957 case Constants.LNEG:
1958 case Constants.FNEG:
1959 case Constants.DNEG:
1960 case Constants.ISHL:
1961 case Constants.LSHL:
1962 case Constants.ISHR:
1963 case Constants.LSHR:
1964 case Constants.IUSHR:
1965 case Constants.LUSHR:
1966 case Constants.IAND:
1967 case Constants.LAND:
1968 case Constants.IOR:
1969 case Constants.LOR:
1970 case Constants.IXOR:
1971 case Constants.LXOR:
1972 case Constants.I2L:
1973 case Constants.I2F:
1974 case Constants.I2D:
1975 case Constants.L2I:
1976 case Constants.L2F:
1977 case Constants.L2D:
1978 case Constants.F2I:
1979 case Constants.F2L:
1980 case Constants.F2D:
1981 case Constants.D2I:
1982 case Constants.D2L:
1983 case Constants.D2F:
1984 case Constants.I2B:
1985 case Constants.I2C:
1986 case Constants.I2S:
1987 case Constants.LCMP:
1988 case Constants.FCMPL:
1989 case Constants.FCMPG:
1990 case Constants.DCMPL:
1991 case Constants.DCMPG:
1992 case Constants.IRETURN:
1993 case Constants.LRETURN:
1994 case Constants.FRETURN:
1995 case Constants.DRETURN:
1996 case Constants.ARETURN:
1997 case Constants.RETURN:
1998 case Constants.ARRAYLENGTH:
1999 case Constants.ATHROW:
2000 case Constants.MONITORENTER:
2001 case Constants.MONITOREXIT:
2002 methodVisitor.visitInsn(opcode);
2003 currentOffset += 1;
2004 break;
2005 case Constants.ILOAD_0:
2006 case Constants.ILOAD_1:
2007 case Constants.ILOAD_2:
2008 case Constants.ILOAD_3:
2009 case Constants.LLOAD_0:
2010 case Constants.LLOAD_1:
2011 case Constants.LLOAD_2:
2012 case Constants.LLOAD_3:
2013 case Constants.FLOAD_0:
2014 case Constants.FLOAD_1:
2015 case Constants.FLOAD_2:
2016 case Constants.FLOAD_3:
2017 case Constants.DLOAD_0:
2018 case Constants.DLOAD_1:
2019 case Constants.DLOAD_2:
2020 case Constants.DLOAD_3:
2021 case Constants.ALOAD_0:
2022 case Constants.ALOAD_1:
2023 case Constants.ALOAD_2:
2024 case Constants.ALOAD_3:
2025 opcode -= Constants.ILOAD_0;
2026 methodVisitor.visitVarInsn(Opcodes.ILOAD + (opcode >> 2), opcode & 0x3);
2027 currentOffset += 1;
2028 break;
2029 case Constants.ISTORE_0:
2030 case Constants.ISTORE_1:
2031 case Constants.ISTORE_2:
2032 case Constants.ISTORE_3:
2033 case Constants.LSTORE_0:
2034 case Constants.LSTORE_1:
2035 case Constants.LSTORE_2:
2036 case Constants.LSTORE_3:
2037 case Constants.FSTORE_0:
2038 case Constants.FSTORE_1:
2039 case Constants.FSTORE_2:
2040 case Constants.FSTORE_3:
2041 case Constants.DSTORE_0:
2042 case Constants.DSTORE_1:
2043 case Constants.DSTORE_2:
2044 case Constants.DSTORE_3:
2045 case Constants.ASTORE_0:
2046 case Constants.ASTORE_1:
2047 case Constants.ASTORE_2:
2048 case Constants.ASTORE_3:
2049 opcode -= Constants.ISTORE_0;
2050 methodVisitor.visitVarInsn(Opcodes.ISTORE + (opcode >> 2), opcode & 0x3);
2051 currentOffset += 1;
2052 break;
2053 case Constants.IFEQ:
2054 case Constants.IFNE:
2055 case Constants.IFLT:
2056 case Constants.IFGE:
2057 case Constants.IFGT:
2058 case Constants.IFLE:
2059 case Constants.IF_ICMPEQ:
2060 case Constants.IF_ICMPNE:
2061 case Constants.IF_ICMPLT:
2062 case Constants.IF_ICMPGE:
2063 case Constants.IF_ICMPGT:
2064 case Constants.IF_ICMPLE:
2065 case Constants.IF_ACMPEQ:
2066 case Constants.IF_ACMPNE:
2067 case Constants.GOTO:
2068 case Constants.JSR:
2069 case Constants.IFNULL:
2070 case Constants.IFNONNULL:
2071 methodVisitor.visitJumpInsn(
2072 opcode, labels[currentBytecodeOffset + readShort(currentOffset + 1)]);
2073 currentOffset += 3;
2074 break;
2075 case Constants.GOTO_W:
2076 case Constants.JSR_W:
2077 methodVisitor.visitJumpInsn(
2078 opcode - wideJumpOpcodeDelta,
2079 labels[currentBytecodeOffset + readInt(currentOffset + 1)]);
2080 currentOffset += 5;
2081 break;
2082 case Constants.ASM_IFEQ:
2083 case Constants.ASM_IFNE:
2084 case Constants.ASM_IFLT:
2085 case Constants.ASM_IFGE:
2086 case Constants.ASM_IFGT:
2087 case Constants.ASM_IFLE:
2088 case Constants.ASM_IF_ICMPEQ:
2089 case Constants.ASM_IF_ICMPNE:
2090 case Constants.ASM_IF_ICMPLT:
2091 case Constants.ASM_IF_ICMPGE:
2092 case Constants.ASM_IF_ICMPGT:
2093 case Constants.ASM_IF_ICMPLE:
2094 case Constants.ASM_IF_ACMPEQ:
2095 case Constants.ASM_IF_ACMPNE:
2096 case Constants.ASM_GOTO:
2097 case Constants.ASM_JSR:
2098 case Constants.ASM_IFNULL:
2099 case Constants.ASM_IFNONNULL:
2100 {
2101 // A forward jump with an offset > 32767. In this case we automatically replace ASM_GOTO
2102 // with GOTO_W, ASM_JSR with JSR_W and ASM_IFxxx <l> with IFNOTxxx <L> GOTO_W <l> L:...,
2103 // where IFNOTxxx is the "opposite" opcode of ASMS_IFxxx (e.g. IFNE for ASM_IFEQ) and
2104 // where <L> designates the instruction just after the GOTO_W.
2105 // First, change the ASM specific opcodes ASM_IFEQ ... ASM_JSR, ASM_IFNULL and
2106 // ASM_IFNONNULL to IFEQ ... JSR, IFNULL and IFNONNULL.
2107 opcode =
2108 opcode < Constants.ASM_IFNULL
2109 ? opcode - Constants.ASM_OPCODE_DELTA
2110 : opcode - Constants.ASM_IFNULL_OPCODE_DELTA;
2111 Label target = labels[currentBytecodeOffset + readUnsignedShort(currentOffset + 1)];
2112 if (opcode == Opcodes.GOTO || opcode == Opcodes.JSR) {
2113 // Replace GOTO with GOTO_W and JSR with JSR_W.
2114 methodVisitor.visitJumpInsn(opcode + Constants.WIDE_JUMP_OPCODE_DELTA, target);
2115 } else {
2116 // Compute the "opposite" of opcode. This can be done by flipping the least
2117 // significant bit for IFNULL and IFNONNULL, and similarly for IFEQ ... IF_ACMPEQ
2118 // (with a pre and post offset by 1).
2119 opcode = opcode < Opcodes.GOTO ? ((opcode + 1) ^ 1) - 1 : opcode ^ 1;
2120 Label endif = createLabel(currentBytecodeOffset + 3, labels);
2121 methodVisitor.visitJumpInsn(opcode, endif);
2122 methodVisitor.visitJumpInsn(Constants.GOTO_W, target);
2123 // endif designates the instruction just after GOTO_W, and is visited as part of the
2124 // next instruction. Since it is a jump target, we need to insert a frame here.
2125 insertFrame = true;
2126 }
2127 currentOffset += 3;
2128 break;
2129 }
2130 case Constants.ASM_GOTO_W:
2131 {
2132 // Replace ASM_GOTO_W with GOTO_W.
2133 methodVisitor.visitJumpInsn(
2134 Constants.GOTO_W, labels[currentBytecodeOffset + readInt(currentOffset + 1)]);
2135 // The instruction just after is a jump target (because ASM_GOTO_W is used in patterns
2136 // IFNOTxxx <L> ASM_GOTO_W <l> L:..., see MethodWriter), so we need to insert a frame
2137 // here.
2138 insertFrame = true;
2139 currentOffset += 5;
2140 break;
2141 }
2142 case Constants.WIDE:
2143 opcode = classFileBuffer[currentOffset + 1] & 0xFF;
2144 if (opcode == Opcodes.IINC) {
2145 methodVisitor.visitIincInsn(
2146 readUnsignedShort(currentOffset + 2), readShort(currentOffset + 4));
2147 currentOffset += 6;
2148 } else {
2149 methodVisitor.visitVarInsn(opcode, readUnsignedShort(currentOffset + 2));
2150 currentOffset += 4;
2151 }
2152 break;
2153 case Constants.TABLESWITCH:
2154 {
2155 // Skip 0 to 3 padding bytes.
2156 currentOffset += 4 - (currentBytecodeOffset & 3);
2157 // Read the instruction.
2158 Label defaultLabel = labels[currentBytecodeOffset + readInt(currentOffset)];
2159 int low = readInt(currentOffset + 4);
2160 int high = readInt(currentOffset + 8);
2161 currentOffset += 12;
2162 Label[] table = new Label[high - low + 1];
2163 for (int i = 0; i < table.length; ++i) {
2164 table[i] = labels[currentBytecodeOffset + readInt(currentOffset)];
2165 currentOffset += 4;
2166 }
2167 methodVisitor.visitTableSwitchInsn(low, high, defaultLabel, table);
2168 break;
2169 }
2170 case Constants.LOOKUPSWITCH:
2171 {
2172 // Skip 0 to 3 padding bytes.
2173 currentOffset += 4 - (currentBytecodeOffset & 3);
2174 // Read the instruction.
2175 Label defaultLabel = labels[currentBytecodeOffset + readInt(currentOffset)];
2176 int numPairs = readInt(currentOffset + 4);
2177 currentOffset += 8;
2178 int[] keys = new int[numPairs];
2179 Label[] values = new Label[numPairs];
2180 for (int i = 0; i < numPairs; ++i) {
2181 keys[i] = readInt(currentOffset);
2182 values[i] = labels[currentBytecodeOffset + readInt(currentOffset + 4)];
2183 currentOffset += 8;
2184 }
2185 methodVisitor.visitLookupSwitchInsn(defaultLabel, keys, values);
2186 break;
2187 }
2188 case Constants.ILOAD:
2189 case Constants.LLOAD:
2190 case Constants.FLOAD:
2191 case Constants.DLOAD:
2192 case Constants.ALOAD:
2193 case Constants.ISTORE:
2194 case Constants.LSTORE:
2195 case Constants.FSTORE:
2196 case Constants.DSTORE:
2197 case Constants.ASTORE:
2198 case Constants.RET:
2199 methodVisitor.visitVarInsn(opcode, classFileBuffer[currentOffset + 1] & 0xFF);
2200 currentOffset += 2;
2201 break;
2202 case Constants.BIPUSH:
2203 case Constants.NEWARRAY:
2204 methodVisitor.visitIntInsn(opcode, classFileBuffer[currentOffset + 1]);
2205 currentOffset += 2;
2206 break;
2207 case Constants.SIPUSH:
2208 methodVisitor.visitIntInsn(opcode, readShort(currentOffset + 1));
2209 currentOffset += 3;
2210 break;
2211 case Constants.LDC:
2212 methodVisitor.visitLdcInsn(
2213 readConst(classFileBuffer[currentOffset + 1] & 0xFF, charBuffer));
2214 currentOffset += 2;
2215 break;
2216 case Constants.LDC_W:
2217 case Constants.LDC2_W:
2218 methodVisitor.visitLdcInsn(readConst(readUnsignedShort(currentOffset + 1), charBuffer));
2219 currentOffset += 3;
2220 break;
2221 case Constants.GETSTATIC:
2222 case Constants.PUTSTATIC:
2223 case Constants.GETFIELD:
2224 case Constants.PUTFIELD:
2225 case Constants.INVOKEVIRTUAL:
2226 case Constants.INVOKESPECIAL:
2227 case Constants.INVOKESTATIC:
2228 case Constants.INVOKEINTERFACE:
2229 {
2230 int cpInfoOffset = cpInfoOffsets[readUnsignedShort(currentOffset + 1)];
2231 int nameAndTypeCpInfoOffset = cpInfoOffsets[readUnsignedShort(cpInfoOffset + 2)];
2232 String owner = readClass(cpInfoOffset, charBuffer);
2233 String name = readUTF8(nameAndTypeCpInfoOffset, charBuffer);
2234 String descriptor = readUTF8(nameAndTypeCpInfoOffset + 2, charBuffer);
2235 if (opcode < Opcodes.INVOKEVIRTUAL) {
2236 methodVisitor.visitFieldInsn(opcode, owner, name, descriptor);
2237 } else {
2238 boolean isInterface =
2239 classFileBuffer[cpInfoOffset - 1] == Symbol.CONSTANT_INTERFACE_METHODREF_TAG;
2240 methodVisitor.visitMethodInsn(opcode, owner, name, descriptor, isInterface);
2241 }
2242 if (opcode == Opcodes.INVOKEINTERFACE) {
2243 currentOffset += 5;
2244 } else {
2245 currentOffset += 3;
2246 }
2247 break;
2248 }
2249 case Constants.INVOKEDYNAMIC:
2250 {
2251 int cpInfoOffset = cpInfoOffsets[readUnsignedShort(currentOffset + 1)];
2252 int nameAndTypeCpInfoOffset = cpInfoOffsets[readUnsignedShort(cpInfoOffset + 2)];
2253 String name = readUTF8(nameAndTypeCpInfoOffset, charBuffer);
2254 String descriptor = readUTF8(nameAndTypeCpInfoOffset + 2, charBuffer);
2255 int bootstrapMethodOffset = bootstrapMethodOffsets[readUnsignedShort(cpInfoOffset)];
2256 Handle handle =
2257 (Handle) readConst(readUnsignedShort(bootstrapMethodOffset), charBuffer);
2258 Object[] bootstrapMethodArguments =
2259 new Object[readUnsignedShort(bootstrapMethodOffset + 2)];
2260 bootstrapMethodOffset += 4;
2261 for (int i = 0; i < bootstrapMethodArguments.length; i++) {
2262 bootstrapMethodArguments[i] =
2263 readConst(readUnsignedShort(bootstrapMethodOffset), charBuffer);
2264 bootstrapMethodOffset += 2;
2265 }
2266 methodVisitor.visitInvokeDynamicInsn(
2267 name, descriptor, handle, bootstrapMethodArguments);
2268 currentOffset += 5;
2269 break;
2270 }
2271 case Constants.NEW:
2272 case Constants.ANEWARRAY:
2273 case Constants.CHECKCAST:
2274 case Constants.INSTANCEOF:
2275 methodVisitor.visitTypeInsn(opcode, readClass(currentOffset + 1, charBuffer));
2276 currentOffset += 3;
2277 break;
2278 case Constants.IINC:
2279 methodVisitor.visitIincInsn(
2280 classFileBuffer[currentOffset + 1] & 0xFF, classFileBuffer[currentOffset + 2]);
2281 currentOffset += 3;
2282 break;
2283 case Constants.MULTIANEWARRAY:
2284 methodVisitor.visitMultiANewArrayInsn(
2285 readClass(currentOffset + 1, charBuffer), classFileBuffer[currentOffset + 3] & 0xFF);
2286 currentOffset += 4;
2287 break;
2288 default:
2289 throw new AssertionError();
2290 }
2291
2292 // Visit the runtime visible instruction annotations, if any.
2293 while (visibleTypeAnnotationOffsets != null
2294 && currentVisibleTypeAnnotationIndex < visibleTypeAnnotationOffsets.length
2295 && currentVisibleTypeAnnotationBytecodeOffset <= currentBytecodeOffset) {
2296 if (currentVisibleTypeAnnotationBytecodeOffset == currentBytecodeOffset) {
2297 // Parse the target_type, target_info and target_path fields.
2298 int currentAnnotationOffset =
2299 readTypeAnnotationTarget(
2300 context, visibleTypeAnnotationOffsets[currentVisibleTypeAnnotationIndex]);
2301 // Parse the type_index field.
2302 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
2303 currentAnnotationOffset += 2;
2304 // Parse num_element_value_pairs and element_value_pairs and visit these values.
2305 readElementValues(
2306 methodVisitor.visitInsnAnnotation(
2307 context.currentTypeAnnotationTarget,
2308 context.currentTypeAnnotationTargetPath,
2309 annotationDescriptor,
2310 /* visible = */ true),
2311 currentAnnotationOffset,
2312 /* named = */ true,
2313 charBuffer);
2314 }
2315 currentVisibleTypeAnnotationBytecodeOffset =
2316 getTypeAnnotationBytecodeOffset(
2317 visibleTypeAnnotationOffsets, ++currentVisibleTypeAnnotationIndex);
2318 }
2319
2320 // Visit the runtime invisible instruction annotations, if any.
2321 while (invisibleTypeAnnotationOffsets != null
2322 && currentInvisibleTypeAnnotationIndex < invisibleTypeAnnotationOffsets.length
2323 && currentInvisibleTypeAnnotationBytecodeOffset <= currentBytecodeOffset) {
2324 if (currentInvisibleTypeAnnotationBytecodeOffset == currentBytecodeOffset) {
2325 // Parse the target_type, target_info and target_path fields.
2326 int currentAnnotationOffset =
2327 readTypeAnnotationTarget(
2328 context, invisibleTypeAnnotationOffsets[currentInvisibleTypeAnnotationIndex]);
2329 // Parse the type_index field.
2330 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
2331 currentAnnotationOffset += 2;
2332 // Parse num_element_value_pairs and element_value_pairs and visit these values.
2333 readElementValues(
2334 methodVisitor.visitInsnAnnotation(
2335 context.currentTypeAnnotationTarget,
2336 context.currentTypeAnnotationTargetPath,
2337 annotationDescriptor,
2338 /* visible = */ false),
2339 currentAnnotationOffset,
2340 /* named = */ true,
2341 charBuffer);
2342 }
2343 currentInvisibleTypeAnnotationBytecodeOffset =
2344 getTypeAnnotationBytecodeOffset(
2345 invisibleTypeAnnotationOffsets, ++currentInvisibleTypeAnnotationIndex);
2346 }
2347 }
2348 if (labels[codeLength] != null) {
2349 methodVisitor.visitLabel(labels[codeLength]);
2350 }
2351
2352 // Visit LocalVariableTable and LocalVariableTypeTable attributes.
2353 if (localVariableTableOffset != 0 && (context.parsingOptions & SKIP_DEBUG) == 0) {
2354 // The (start_pc, index, signature_index) fields of each entry of the LocalVariableTypeTable.
2355 int[] typeTable = null;
2356 if (localVariableTypeTableOffset != 0) {
2357 typeTable = new int[readUnsignedShort(localVariableTypeTableOffset) * 3];
2358 currentOffset = localVariableTypeTableOffset + 2;
2359 int typeTableIndex = typeTable.length;
2360 while (typeTableIndex > 0) {
2361 // Store the offset of 'signature_index', and the value of 'index' and 'start_pc'.
2362 typeTable[--typeTableIndex] = currentOffset + 6;
2363 typeTable[--typeTableIndex] = readUnsignedShort(currentOffset + 8);
2364 typeTable[--typeTableIndex] = readUnsignedShort(currentOffset);
2365 currentOffset += 10;
2366 }
2367 }
2368 int localVariableTableLength = readUnsignedShort(localVariableTableOffset);
2369 currentOffset = localVariableTableOffset + 2;
2370 while (localVariableTableLength-- > 0) {
2371 int startPc = readUnsignedShort(currentOffset);
2372 int length = readUnsignedShort(currentOffset + 2);
2373 String name = readUTF8(currentOffset + 4, charBuffer);
2374 String descriptor = readUTF8(currentOffset + 6, charBuffer);
2375 int index = readUnsignedShort(currentOffset + 8);
2376 currentOffset += 10;
2377 String signature = null;
2378 if (typeTable != null) {
2379 for (int i = 0; i < typeTable.length; i += 3) {
2380 if (typeTable[i] == startPc && typeTable[i + 1] == index) {
2381 signature = readUTF8(typeTable[i + 2], charBuffer);
2382 break;
2383 }
2384 }
2385 }
2386 methodVisitor.visitLocalVariable(
2387 name, descriptor, signature, labels[startPc], labels[startPc + length], index);
2388 }
2389 }
2390
2391 // Visit the local variable type annotations of the RuntimeVisibleTypeAnnotations attribute.
2392 if (visibleTypeAnnotationOffsets != null) {
2393 for (int typeAnnotationOffset : visibleTypeAnnotationOffsets) {
2394 int targetType = readByte(typeAnnotationOffset);
2395 if (targetType == TypeReference.LOCAL_VARIABLE
2396 || targetType == TypeReference.RESOURCE_VARIABLE) {
2397 // Parse the target_type, target_info and target_path fields.
2398 currentOffset = readTypeAnnotationTarget(context, typeAnnotationOffset);
2399 // Parse the type_index field.
2400 String annotationDescriptor = readUTF8(currentOffset, charBuffer);
2401 currentOffset += 2;
2402 // Parse num_element_value_pairs and element_value_pairs and visit these values.
2403 readElementValues(
2404 methodVisitor.visitLocalVariableAnnotation(
2405 context.currentTypeAnnotationTarget,
2406 context.currentTypeAnnotationTargetPath,
2407 context.currentLocalVariableAnnotationRangeStarts,
2408 context.currentLocalVariableAnnotationRangeEnds,
2409 context.currentLocalVariableAnnotationRangeIndices,
2410 annotationDescriptor,
2411 /* visible = */ true),
2412 currentOffset,
2413 /* named = */ true,
2414 charBuffer);
2415 }
2416 }
2417 }
2418
2419 // Visit the local variable type annotations of the RuntimeInvisibleTypeAnnotations attribute.
2420 if (invisibleTypeAnnotationOffsets != null) {
2421 for (int typeAnnotationOffset : invisibleTypeAnnotationOffsets) {
2422 int targetType = readByte(typeAnnotationOffset);
2423 if (targetType == TypeReference.LOCAL_VARIABLE
2424 || targetType == TypeReference.RESOURCE_VARIABLE) {
2425 // Parse the target_type, target_info and target_path fields.
2426 currentOffset = readTypeAnnotationTarget(context, typeAnnotationOffset);
2427 // Parse the type_index field.
2428 String annotationDescriptor = readUTF8(currentOffset, charBuffer);
2429 currentOffset += 2;
2430 // Parse num_element_value_pairs and element_value_pairs and visit these values.
2431 readElementValues(
2432 methodVisitor.visitLocalVariableAnnotation(
2433 context.currentTypeAnnotationTarget,
2434 context.currentTypeAnnotationTargetPath,
2435 context.currentLocalVariableAnnotationRangeStarts,
2436 context.currentLocalVariableAnnotationRangeEnds,
2437 context.currentLocalVariableAnnotationRangeIndices,
2438 annotationDescriptor,
2439 /* visible = */ false),
2440 currentOffset,
2441 /* named = */ true,
2442 charBuffer);
2443 }
2444 }
2445 }
2446
2447 // Visit the non standard attributes.
2448 while (attributes != null) {
2449 // Copy and reset the nextAttribute field so that it can also be used in MethodWriter.
2450 Attribute nextAttribute = attributes.nextAttribute;
2451 attributes.nextAttribute = null;
2452 methodVisitor.visitAttribute(attributes);
2453 attributes = nextAttribute;
2454 }
2455
2456 // Visit the max stack and max locals values.
2457 methodVisitor.visitMaxs(maxStack, maxLocals);
2458 }
2459
2460 /**
2461 * Returns the label corresponding to the given bytecode offset. The default implementation of
2462 * this method creates a label for the given offset if it has not been already created.
2463 *
2464 * @param bytecodeOffset a bytecode offset in a method.
2465 * @param labels the already created labels, indexed by their offset. If a label already exists
2466 * for bytecodeOffset this method must not create a new one. Otherwise it must store the new
2467 * label in this array.
2468 * @return a non null Label, which must be equal to labels[bytecodeOffset].
2469 */
2470 protected Label readLabel(final int bytecodeOffset, final Label[] labels) {
2471 if (labels[bytecodeOffset] == null) {
2472 labels[bytecodeOffset] = new Label();
2473 }
2474 return labels[bytecodeOffset];
2475 }
2476
2477 /**
2478 * Creates a label without the {@link Label#FLAG_DEBUG_ONLY} flag set, for the given bytecode
2479 * offset. The label is created with a call to {@link #readLabel} and its {@link
2480 * Label#FLAG_DEBUG_ONLY} flag is cleared.
2481 *
2482 * @param bytecodeOffset a bytecode offset in a method.
2483 * @param labels the already created labels, indexed by their offset.
2484 * @return a Label without the {@link Label#FLAG_DEBUG_ONLY} flag set.
2485 */
2486 private Label createLabel(final int bytecodeOffset, final Label[] labels) {
2487 Label label = readLabel(bytecodeOffset, labels);
2488 label.flags &= ~Label.FLAG_DEBUG_ONLY;
2489 return label;
2490 }
2491
2492 /**
2493 * Creates a label with the {@link Label#FLAG_DEBUG_ONLY} flag set, if there is no already
2494 * existing label for the given bytecode offset (otherwise does nothing). The label is created
2495 * with a call to {@link #readLabel}.
2496 *
2497 * @param bytecodeOffset a bytecode offset in a method.
2498 * @param labels the already created labels, indexed by their offset.
2499 */
2500 private void createDebugLabel(final int bytecodeOffset, final Label[] labels) {
2501 if (labels[bytecodeOffset] == null) {
2502 readLabel(bytecodeOffset, labels).flags |= Label.FLAG_DEBUG_ONLY;
2503 }
2504 }
2505
2506 // ----------------------------------------------------------------------------------------------
2507 // Methods to parse annotations, type annotations and parameter annotations
2508 // ----------------------------------------------------------------------------------------------
2509
2510 /**
2511 * Parses a Runtime[In]VisibleTypeAnnotations attribute to find the offset of each type_annotation
2512 * entry it contains, to find the corresponding labels, and to visit the try catch block
2513 * annotations.
2514 *
2515 * @param methodVisitor the method visitor to be used to visit the try catch block annotations.
2516 * @param context information about the class being parsed.
2517 * @param runtimeTypeAnnotationsOffset the start offset of a Runtime[In]VisibleTypeAnnotations
2518 * attribute, excluding the attribute_info's attribute_name_index and attribute_length fields.
2519 * @param visible true if the attribute to parse is a RuntimeVisibleTypeAnnotations attribute,
2520 * false it is a RuntimeInvisibleTypeAnnotations attribute.
2521 * @return the start offset of each entry of the Runtime[In]VisibleTypeAnnotations_attribute's
2522 * 'annotations' array field.
2523 */
2524 private int[] readTypeAnnotations(
2525 final MethodVisitor methodVisitor,
2526 final Context context,
2527 final int runtimeTypeAnnotationsOffset,
2528 final boolean visible) {
2529 char[] charBuffer = context.charBuffer;
2530 int currentOffset = runtimeTypeAnnotationsOffset;
2531 // Read the num_annotations field and create an array to store the type_annotation offsets.
2532 int[] typeAnnotationsOffsets = new int[readUnsignedShort(currentOffset)];
2533 currentOffset += 2;
2534 // Parse the 'annotations' array field.
2535 for (int i = 0; i < typeAnnotationsOffsets.length; ++i) {
2536 typeAnnotationsOffsets[i] = currentOffset;
2537 // Parse the type_annotation's target_type and the target_info fields. The size of the
2538 // target_info field depends on the value of target_type.
2539 int targetType = readInt(currentOffset);
2540 switch (targetType >>> 24) {
2541 case TypeReference.LOCAL_VARIABLE:
2542 case TypeReference.RESOURCE_VARIABLE:
2543 // A localvar_target has a variable size, which depends on the value of their table_length
2544 // field. It also references bytecode offsets, for which we need labels.
2545 int tableLength = readUnsignedShort(currentOffset + 1);
2546 currentOffset += 3;
2547 while (tableLength-- > 0) {
2548 int startPc = readUnsignedShort(currentOffset);
2549 int length = readUnsignedShort(currentOffset + 2);
2550 // Skip the index field (2 bytes).
2551 currentOffset += 6;
2552 createLabel(startPc, context.currentMethodLabels);
2553 createLabel(startPc + length, context.currentMethodLabels);
2554 }
2555 break;
2556 case TypeReference.CAST:
2557 case TypeReference.CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT:
2558 case TypeReference.METHOD_INVOCATION_TYPE_ARGUMENT:
2559 case TypeReference.CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT:
2560 case TypeReference.METHOD_REFERENCE_TYPE_ARGUMENT:
2561 currentOffset += 4;
2562 break;
2563 case TypeReference.CLASS_EXTENDS:
2564 case TypeReference.CLASS_TYPE_PARAMETER_BOUND:
2565 case TypeReference.METHOD_TYPE_PARAMETER_BOUND:
2566 case TypeReference.THROWS:
2567 case TypeReference.EXCEPTION_PARAMETER:
2568 case TypeReference.INSTANCEOF:
2569 case TypeReference.NEW:
2570 case TypeReference.CONSTRUCTOR_REFERENCE:
2571 case TypeReference.METHOD_REFERENCE:
2572 currentOffset += 3;
2573 break;
2574 case TypeReference.CLASS_TYPE_PARAMETER:
2575 case TypeReference.METHOD_TYPE_PARAMETER:
2576 case TypeReference.METHOD_FORMAL_PARAMETER:
2577 case TypeReference.FIELD:
2578 case TypeReference.METHOD_RETURN:
2579 case TypeReference.METHOD_RECEIVER:
2580 default:
2581 // TypeReference type which can't be used in Code attribute, or which is unknown.
2582 throw new IllegalArgumentException();
2583 }
2584 // Parse the rest of the type_annotation structure, starting with the target_path structure
2585 // (whose size depends on its path_length field).
2586 int pathLength = readByte(currentOffset);
2587 if ((targetType >>> 24) == TypeReference.EXCEPTION_PARAMETER) {
2588 // Parse the target_path structure and create a corresponding TypePath.
2589 TypePath path = pathLength == 0 ? null : new TypePath(b, currentOffset);
2590 currentOffset += 1 + 2 * pathLength;
2591 // Parse the type_index field.
2592 String annotationDescriptor = readUTF8(currentOffset, charBuffer);
2593 currentOffset += 2;
2594 // Parse num_element_value_pairs and element_value_pairs and visit these values.
2595 currentOffset =
2596 readElementValues(
2597 methodVisitor.visitTryCatchAnnotation(
2598 targetType & 0xFFFFFF00, path, annotationDescriptor, visible),
2599 currentOffset,
2600 /* named = */ true,
2601 charBuffer);
2602 } else {
2603 // We don't want to visit the other target_type annotations, so we just skip them (which
2604 // requires some parsing because the element_value_pairs array has a variable size). First,
2605 // skip the target_path structure:
2606 currentOffset += 3 + 2 * pathLength;
2607 // Then skip the num_element_value_pairs and element_value_pairs fields (by reading them
2608 // with a null AnnotationVisitor).
2609 currentOffset =
2610 readElementValues(
2611 /* annotationVisitor = */ null, currentOffset, /* named = */ true, charBuffer);
2612 }
2613 }
2614 return typeAnnotationsOffsets;
2615 }
2616
2617 /**
2618 * Returns the bytecode offset corresponding to the specified JVMS 'type_annotation' structure, or
2619 * -1 if there is no such type_annotation of if it does not have a bytecode offset.
2620 *
2621 * @param typeAnnotationOffsets the offset of each 'type_annotation' entry in a
2622 * Runtime[In]VisibleTypeAnnotations attribute, or null.
2623 * @param typeAnnotationIndex the index a 'type_annotation' entry in typeAnnotationOffsets.
2624 * @return bytecode offset corresponding to the specified JVMS 'type_annotation' structure, or -1
2625 * if there is no such type_annotation of if it does not have a bytecode offset.
2626 */
2627 private int getTypeAnnotationBytecodeOffset(
2628 final int[] typeAnnotationOffsets, final int typeAnnotationIndex) {
2629 if (typeAnnotationOffsets == null
2630 || typeAnnotationIndex >= typeAnnotationOffsets.length
2631 || readByte(typeAnnotationOffsets[typeAnnotationIndex]) < TypeReference.INSTANCEOF) {
2632 return -1;
2633 }
2634 return readUnsignedShort(typeAnnotationOffsets[typeAnnotationIndex] + 1);
2635 }
2636
2637 /**
2638 * Parses the header of a JVMS type_annotation structure to extract its target_type, target_info
2639 * and target_path (the result is stored in the given context), and returns the start offset of
2640 * the rest of the type_annotation structure.
2641 *
2642 * @param context information about the class being parsed. This is where the extracted
2643 * target_type and target_path must be stored.
2644 * @param typeAnnotationOffset the start offset of a type_annotation structure.
2645 * @return the start offset of the rest of the type_annotation structure.
2646 */
2647 private int readTypeAnnotationTarget(final Context context, final int typeAnnotationOffset) {
2648 int currentOffset = typeAnnotationOffset;
2649 // Parse and store the target_type structure.
2650 int targetType = readInt(typeAnnotationOffset);
2651 switch (targetType >>> 24) {
2652 case TypeReference.CLASS_TYPE_PARAMETER:
2653 case TypeReference.METHOD_TYPE_PARAMETER:
2654 case TypeReference.METHOD_FORMAL_PARAMETER:
2655 targetType &= 0xFFFF0000;
2656 currentOffset += 2;
2657 break;
2658 case TypeReference.FIELD:
2659 case TypeReference.METHOD_RETURN:
2660 case TypeReference.METHOD_RECEIVER:
2661 targetType &= 0xFF000000;
2662 currentOffset += 1;
2663 break;
2664 case TypeReference.LOCAL_VARIABLE:
2665 case TypeReference.RESOURCE_VARIABLE:
2666 targetType &= 0xFF000000;
2667 int tableLength = readUnsignedShort(currentOffset + 1);
2668 currentOffset += 3;
2669 context.currentLocalVariableAnnotationRangeStarts = new Label[tableLength];
2670 context.currentLocalVariableAnnotationRangeEnds = new Label[tableLength];
2671 context.currentLocalVariableAnnotationRangeIndices = new int[tableLength];
2672 for (int i = 0; i < tableLength; ++i) {
2673 int startPc = readUnsignedShort(currentOffset);
2674 int length = readUnsignedShort(currentOffset + 2);
2675 int index = readUnsignedShort(currentOffset + 4);
2676 currentOffset += 6;
2677 context.currentLocalVariableAnnotationRangeStarts[i] =
2678 createLabel(startPc, context.currentMethodLabels);
2679 context.currentLocalVariableAnnotationRangeEnds[i] =
2680 createLabel(startPc + length, context.currentMethodLabels);
2681 context.currentLocalVariableAnnotationRangeIndices[i] = index;
2682 }
2683 break;
2684 case TypeReference.CAST:
2685 case TypeReference.CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT:
2686 case TypeReference.METHOD_INVOCATION_TYPE_ARGUMENT:
2687 case TypeReference.CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT:
2688 case TypeReference.METHOD_REFERENCE_TYPE_ARGUMENT:
2689 targetType &= 0xFF0000FF;
2690 currentOffset += 4;
2691 break;
2692 case TypeReference.CLASS_EXTENDS:
2693 case TypeReference.CLASS_TYPE_PARAMETER_BOUND:
2694 case TypeReference.METHOD_TYPE_PARAMETER_BOUND:
2695 case TypeReference.THROWS:
2696 case TypeReference.EXCEPTION_PARAMETER:
2697 targetType &= 0xFFFFFF00;
2698 currentOffset += 3;
2699 break;
2700 case TypeReference.INSTANCEOF:
2701 case TypeReference.NEW:
2702 case TypeReference.CONSTRUCTOR_REFERENCE:
2703 case TypeReference.METHOD_REFERENCE:
2704 targetType &= 0xFF000000;
2705 currentOffset += 3;
2706 break;
2707 default:
2708 throw new IllegalArgumentException();
2709 }
2710 context.currentTypeAnnotationTarget = targetType;
2711 // Parse and store the target_path structure.
2712 int pathLength = readByte(currentOffset);
2713 context.currentTypeAnnotationTargetPath =
2714 pathLength == 0 ? null : new TypePath(b, currentOffset);
2715 // Return the start offset of the rest of the type_annotation structure.
2716 return currentOffset + 1 + 2 * pathLength;
2717 }
2718
2719 /**
2720 * Reads a Runtime[In]VisibleParameterAnnotations attribute and makes the given visitor visit it.
2721 *
2722 * @param methodVisitor the visitor that must visit the parameter annotations.
2723 * @param context information about the class being parsed.
2724 * @param runtimeParameterAnnotationsOffset the start offset of a
2725 * Runtime[In]VisibleParameterAnnotations attribute, excluding the attribute_info's
2726 * attribute_name_index and attribute_length fields.
2727 * @param visible true if the attribute to parse is a RuntimeVisibleParameterAnnotations
2728 * attribute, false it is a RuntimeInvisibleParameterAnnotations attribute.
2729 */
2730 private void readParameterAnnotations(
2731 final MethodVisitor methodVisitor,
2732 final Context context,
2733 final int runtimeParameterAnnotationsOffset,
2734 final boolean visible) {
2735 int currentOffset = runtimeParameterAnnotationsOffset;
2736 int numParameters = b[currentOffset++] & 0xFF;
2737 methodVisitor.visitAnnotableParameterCount(numParameters, visible);
2738 char[] charBuffer = context.charBuffer;
2739 for (int i = 0; i < numParameters; ++i) {
2740 int numAnnotations = readUnsignedShort(currentOffset);
2741 currentOffset += 2;
2742 while (numAnnotations-- > 0) {
2743 // Parse the type_index field.
2744 String annotationDescriptor = readUTF8(currentOffset, charBuffer);
2745 currentOffset += 2;
2746 // Parse num_element_value_pairs and element_value_pairs and visit these values.
2747 currentOffset =
2748 readElementValues(
2749 methodVisitor.visitParameterAnnotation(i, annotationDescriptor, visible),
2750 currentOffset,
2751 /* named = */ true,
2752 charBuffer);
2753 }
2754 }
2755 }
2756
2757 /**
2758 * Reads the element values of a JVMS 'annotation' structure and makes the given visitor visit
2759 * them. This method can also be used to read the values of the JVMS 'array_value' field of an
2760 * annotation's 'element_value'.
2761 *
2762 * @param annotationVisitor the visitor that must visit the values.
2763 * @param annotationOffset the start offset of an 'annotation' structure (excluding its type_index
2764 * field) or of an 'array_value' structure.
2765 * @param named if the annotation values are named or not. This should be true to parse the values
2766 * of a JVMS 'annotation' structure, and false to parse the JVMS 'array_value' of an
2767 * annotation's element_value.
2768 * @param charBuffer the buffer used to read strings in the constant pool.
2769 * @return the end offset of the JVMS 'annotation' or 'array_value' structure.
2770 */
2771 private int readElementValues(
2772 final AnnotationVisitor annotationVisitor,
2773 final int annotationOffset,
2774 final boolean named,
2775 final char[] charBuffer) {
2776 int currentOffset = annotationOffset;
2777 // Read the num_element_value_pairs field (or num_values field for an array_value).
2778 int numElementValuePairs = readUnsignedShort(currentOffset);
2779 currentOffset += 2;
2780 if (named) {
2781 // Parse the element_value_pairs array.
2782 while (numElementValuePairs-- > 0) {
2783 String elementName = readUTF8(currentOffset, charBuffer);
2784 currentOffset =
2785 readElementValue(annotationVisitor, currentOffset + 2, elementName, charBuffer);
2786 }
2787 } else {
2788 // Parse the array_value array.
2789 while (numElementValuePairs-- > 0) {
2790 currentOffset =
2791 readElementValue(annotationVisitor, currentOffset, /* named = */ null, charBuffer);
2792 }
2793 }
2794 if (annotationVisitor != null) {
2795 annotationVisitor.visitEnd();
2796 }
2797 return currentOffset;
2798 }
2799
2800 /**
2801 * Reads a JVMS 'element_value' structure and makes the given visitor visit it.
2802 *
2803 * @param annotationVisitor the visitor that must visit the element_value structure.
2804 * @param elementValueOffset the start offset in {@link #b} of the element_value structure to be
2805 * read.
2806 * @param elementName the name of the element_value structure to be read, or {@literal null}.
2807 * @param charBuffer the buffer used to read strings in the constant pool.
2808 * @return the end offset of the JVMS 'element_value' structure.
2809 */
2810 private int readElementValue(
2811 final AnnotationVisitor annotationVisitor,
2812 final int elementValueOffset,
2813 final String elementName,
2814 final char[] charBuffer) {
2815 int currentOffset = elementValueOffset;
2816 if (annotationVisitor == null) {
2817 switch (b[currentOffset] & 0xFF) {
2818 case 'e': // enum_const_value
2819 return currentOffset + 5;
2820 case '@': // annotation_value
2821 return readElementValues(null, currentOffset + 3, /* named = */ true, charBuffer);
2822 case '[': // array_value
2823 return readElementValues(null, currentOffset + 1, /* named = */ false, charBuffer);
2824 default:
2825 return currentOffset + 3;
2826 }
2827 }
2828 switch (b[currentOffset++] & 0xFF) {
2829 case 'B': // const_value_index, CONSTANT_Integer
2830 annotationVisitor.visit(
2831 elementName, (byte) readInt(cpInfoOffsets[readUnsignedShort(currentOffset)]));
2832 currentOffset += 2;
2833 break;
2834 case 'C': // const_value_index, CONSTANT_Integer
2835 annotationVisitor.visit(
2836 elementName, (char) readInt(cpInfoOffsets[readUnsignedShort(currentOffset)]));
2837 currentOffset += 2;
2838 break;
2839 case 'D': // const_value_index, CONSTANT_Double
2840 case 'F': // const_value_index, CONSTANT_Float
2841 case 'I': // const_value_index, CONSTANT_Integer
2842 case 'J': // const_value_index, CONSTANT_Long
2843 annotationVisitor.visit(
2844 elementName, readConst(readUnsignedShort(currentOffset), charBuffer));
2845 currentOffset += 2;
2846 break;
2847 case 'S': // const_value_index, CONSTANT_Integer
2848 annotationVisitor.visit(
2849 elementName, (short) readInt(cpInfoOffsets[readUnsignedShort(currentOffset)]));
2850 currentOffset += 2;
2851 break;
2852
2853 case 'Z': // const_value_index, CONSTANT_Integer
2854 annotationVisitor.visit(
2855 elementName,
2856 readInt(cpInfoOffsets[readUnsignedShort(currentOffset)]) == 0
2857 ? Boolean.FALSE
2858 : Boolean.TRUE);
2859 currentOffset += 2;
2860 break;
2861 case 's': // const_value_index, CONSTANT_Utf8
2862 annotationVisitor.visit(elementName, readUTF8(currentOffset, charBuffer));
2863 currentOffset += 2;
2864 break;
2865 case 'e': // enum_const_value
2866 annotationVisitor.visitEnum(
2867 elementName,
2868 readUTF8(currentOffset, charBuffer),
2869 readUTF8(currentOffset + 2, charBuffer));
2870 currentOffset += 4;
2871 break;
2872 case 'c': // class_info
2873 annotationVisitor.visit(elementName, Type.getType(readUTF8(currentOffset, charBuffer)));
2874 currentOffset += 2;
2875 break;
2876 case '@': // annotation_value
2877 currentOffset =
2878 readElementValues(
2879 annotationVisitor.visitAnnotation(elementName, readUTF8(currentOffset, charBuffer)),
2880 currentOffset + 2,
2881 true,
2882 charBuffer);
2883 break;
2884 case '[': // array_value
2885 int numValues = readUnsignedShort(currentOffset);
2886 currentOffset += 2;
2887 if (numValues == 0) {
2888 return readElementValues(
2889 annotationVisitor.visitArray(elementName),
2890 currentOffset - 2,
2891 /* named = */ false,
2892 charBuffer);
2893 }
2894 switch (b[currentOffset] & 0xFF) {
2895 case 'B':
2896 byte[] byteValues = new byte[numValues];
2897 for (int i = 0; i < numValues; i++) {
2898 byteValues[i] = (byte) readInt(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]);
2899 currentOffset += 3;
2900 }
2901 annotationVisitor.visit(elementName, byteValues);
2902 break;
2903 case 'Z':
2904 boolean[] booleanValues = new boolean[numValues];
2905 for (int i = 0; i < numValues; i++) {
2906 booleanValues[i] = readInt(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]) != 0;
2907 currentOffset += 3;
2908 }
2909 annotationVisitor.visit(elementName, booleanValues);
2910 break;
2911 case 'S':
2912 short[] shortValues = new short[numValues];
2913 for (int i = 0; i < numValues; i++) {
2914 shortValues[i] = (short) readInt(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]);
2915 currentOffset += 3;
2916 }
2917 annotationVisitor.visit(elementName, shortValues);
2918 break;
2919 case 'C':
2920 char[] charValues = new char[numValues];
2921 for (int i = 0; i < numValues; i++) {
2922 charValues[i] = (char) readInt(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]);
2923 currentOffset += 3;
2924 }
2925 annotationVisitor.visit(elementName, charValues);
2926 break;
2927 case 'I':
2928 int[] intValues = new int[numValues];
2929 for (int i = 0; i < numValues; i++) {
2930 intValues[i] = readInt(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]);
2931 currentOffset += 3;
2932 }
2933 annotationVisitor.visit(elementName, intValues);
2934 break;
2935 case 'J':
2936 long[] longValues = new long[numValues];
2937 for (int i = 0; i < numValues; i++) {
2938 longValues[i] = readLong(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]);
2939 currentOffset += 3;
2940 }
2941 annotationVisitor.visit(elementName, longValues);
2942 break;
2943 case 'F':
2944 float[] floatValues = new float[numValues];
2945 for (int i = 0; i < numValues; i++) {
2946 floatValues[i] =
2947 Float.intBitsToFloat(
2948 readInt(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]));
2949 currentOffset += 3;
2950 }
2951 annotationVisitor.visit(elementName, floatValues);
2952 break;
2953 case 'D':
2954 double[] doubleValues = new double[numValues];
2955 for (int i = 0; i < numValues; i++) {
2956 doubleValues[i] =
2957 Double.longBitsToDouble(
2958 readLong(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]));
2959 currentOffset += 3;
2960 }
2961 annotationVisitor.visit(elementName, doubleValues);
2962 break;
2963 default:
2964 currentOffset =
2965 readElementValues(
2966 annotationVisitor.visitArray(elementName),
2967 currentOffset - 2,
2968 /* named = */ false,
2969 charBuffer);
2970 break;
2971 }
2972 break;
2973 default:
2974 throw new IllegalArgumentException();
2975 }
2976 return currentOffset;
2977 }
2978
2979 // ----------------------------------------------------------------------------------------------
2980 // Methods to parse stack map frames
2981 // ----------------------------------------------------------------------------------------------
2982
2983 /**
2984 * Computes the implicit frame of the method currently being parsed (as defined in the given
2985 * {@link Context}) and stores it in the given context.
2986 *
2987 * @param context information about the class being parsed.
2988 */
2989 private void computeImplicitFrame(final Context context) {
2990 String methodDescriptor = context.currentMethodDescriptor;
2991 Object[] locals = context.currentFrameLocalTypes;
2992 int numLocal = 0;
2993 if ((context.currentMethodAccessFlags & Opcodes.ACC_STATIC) == 0) {
2994 if ("<init>".equals(context.currentMethodName)) {
2995 locals[numLocal++] = Opcodes.UNINITIALIZED_THIS;
2996 } else {
2997 locals[numLocal++] = readClass(header + 2, context.charBuffer);
2998 }
2999 }
3000 // Parse the method descriptor, one argument type descriptor at each iteration. Start by
3001 // skipping the first method descriptor character, which is always '('.
3002 int currentMethodDescritorOffset = 1;
3003 while (true) {
3004 int currentArgumentDescriptorStartOffset = currentMethodDescritorOffset;
3005 switch (methodDescriptor.charAt(currentMethodDescritorOffset++)) {
3006 case 'Z':
3007 case 'C':
3008 case 'B':
3009 case 'S':
3010 case 'I':
3011 locals[numLocal++] = Opcodes.INTEGER;
3012 break;
3013 case 'F':
3014 locals[numLocal++] = Opcodes.FLOAT;
3015 break;
3016 case 'J':
3017 locals[numLocal++] = Opcodes.LONG;
3018 break;
3019 case 'D':
3020 locals[numLocal++] = Opcodes.DOUBLE;
3021 break;
3022 case '[':
3023 while (methodDescriptor.charAt(currentMethodDescritorOffset) == '[') {
3024 ++currentMethodDescritorOffset;
3025 }
3026 if (methodDescriptor.charAt(currentMethodDescritorOffset) == 'L') {
3027 ++currentMethodDescritorOffset;
3028 while (methodDescriptor.charAt(currentMethodDescritorOffset) != ';') {
3029 ++currentMethodDescritorOffset;
3030 }
3031 }
3032 locals[numLocal++] =
3033 methodDescriptor.substring(
3034 currentArgumentDescriptorStartOffset, ++currentMethodDescritorOffset);
3035 break;
3036 case 'L':
3037 while (methodDescriptor.charAt(currentMethodDescritorOffset) != ';') {
3038 ++currentMethodDescritorOffset;
3039 }
3040 locals[numLocal++] =
3041 methodDescriptor.substring(
3042 currentArgumentDescriptorStartOffset + 1, currentMethodDescritorOffset++);
3043 break;
3044 default:
3045 context.currentFrameLocalCount = numLocal;
3046 return;
3047 }
3048 }
3049 }
3050
3051 /**
3052 * Reads a JVMS 'stack_map_frame' structure and stores the result in the given {@link Context}
3053 * object. This method can also be used to read a full_frame structure, excluding its frame_type
3054 * field (this is used to parse the legacy StackMap attributes).
3055 *
3056 * @param stackMapFrameOffset the start offset in {@link #b} of the stack_map_frame_value
3057 * structure to be read, or the start offset of a full_frame structure (excluding its
3058 * frame_type field).
3059 * @param compressed true to read a 'stack_map_frame' structure, false to read a 'full_frame'
3060 * structure without its frame_type field.
3061 * @param expand if the stack map frame must be expanded. See {@link #EXPAND_FRAMES}.
3062 * @param context where the parsed stack map frame must be stored.
3063 * @return the end offset of the JVMS 'stack_map_frame' or 'full_frame' structure.
3064 */
3065 private int readStackMapFrame(
3066 final int stackMapFrameOffset,
3067 final boolean compressed,
3068 final boolean expand,
3069 final Context context) {
3070 int currentOffset = stackMapFrameOffset;
3071 final char[] charBuffer = context.charBuffer;
3072 final Label[] labels = context.currentMethodLabels;
3073 int frameType;
3074 if (compressed) {
3075 // Read the frame_type field.
3076 frameType = b[currentOffset++] & 0xFF;
3077 } else {
3078 frameType = Frame.FULL_FRAME;
3079 context.currentFrameOffset = -1;
3080 }
3081 int offsetDelta;
3082 context.currentFrameLocalCountDelta = 0;
3083 if (frameType < Frame.SAME_LOCALS_1_STACK_ITEM_FRAME) {
3084 offsetDelta = frameType;
3085 context.currentFrameType = Opcodes.F_SAME;
3086 context.currentFrameStackCount = 0;
3087 } else if (frameType < Frame.RESERVED) {
3088 offsetDelta = frameType - Frame.SAME_LOCALS_1_STACK_ITEM_FRAME;
3089 currentOffset =
3090 readVerificationTypeInfo(
3091 currentOffset, context.currentFrameStackTypes, 0, charBuffer, labels);
3092 context.currentFrameType = Opcodes.F_SAME1;
3093 context.currentFrameStackCount = 1;
3094 } else if (frameType >= Frame.SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED) {
3095 offsetDelta = readUnsignedShort(currentOffset);
3096 currentOffset += 2;
3097 if (frameType == Frame.SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED) {
3098 currentOffset =
3099 readVerificationTypeInfo(
3100 currentOffset, context.currentFrameStackTypes, 0, charBuffer, labels);
3101 context.currentFrameType = Opcodes.F_SAME1;
3102 context.currentFrameStackCount = 1;
3103 } else if (frameType >= Frame.CHOP_FRAME && frameType < Frame.SAME_FRAME_EXTENDED) {
3104 context.currentFrameType = Opcodes.F_CHOP;
3105 context.currentFrameLocalCountDelta = Frame.SAME_FRAME_EXTENDED - frameType;
3106 context.currentFrameLocalCount -= context.currentFrameLocalCountDelta;
3107 context.currentFrameStackCount = 0;
3108 } else if (frameType == Frame.SAME_FRAME_EXTENDED) {
3109 context.currentFrameType = Opcodes.F_SAME;
3110 context.currentFrameStackCount = 0;
3111 } else if (frameType < Frame.FULL_FRAME) {
3112 int local = expand ? context.currentFrameLocalCount : 0;
3113 for (int k = frameType - Frame.SAME_FRAME_EXTENDED; k > 0; k--) {
3114 currentOffset =
3115 readVerificationTypeInfo(
3116 currentOffset, context.currentFrameLocalTypes, local++, charBuffer, labels);
3117 }
3118 context.currentFrameType = Opcodes.F_APPEND;
3119 context.currentFrameLocalCountDelta = frameType - Frame.SAME_FRAME_EXTENDED;
3120 context.currentFrameLocalCount += context.currentFrameLocalCountDelta;
3121 context.currentFrameStackCount = 0;
3122 } else {
3123 final int numberOfLocals = readUnsignedShort(currentOffset);
3124 currentOffset += 2;
3125 context.currentFrameType = Opcodes.F_FULL;
3126 context.currentFrameLocalCountDelta = numberOfLocals;
3127 context.currentFrameLocalCount = numberOfLocals;
3128 for (int local = 0; local < numberOfLocals; ++local) {
3129 currentOffset =
3130 readVerificationTypeInfo(
3131 currentOffset, context.currentFrameLocalTypes, local, charBuffer, labels);
3132 }
3133 final int numberOfStackItems = readUnsignedShort(currentOffset);
3134 currentOffset += 2;
3135 context.currentFrameStackCount = numberOfStackItems;
3136 for (int stack = 0; stack < numberOfStackItems; ++stack) {
3137 currentOffset =
3138 readVerificationTypeInfo(
3139 currentOffset, context.currentFrameStackTypes, stack, charBuffer, labels);
3140 }
3141 }
3142 } else {
3143 throw new IllegalArgumentException();
3144 }
3145 context.currentFrameOffset += offsetDelta + 1;
3146 createLabel(context.currentFrameOffset, labels);
3147 return currentOffset;
3148 }
3149
3150 /**
3151 * Reads a JVMS 'verification_type_info' structure and stores it at the given index in the given
3152 * array.
3153 *
3154 * @param verificationTypeInfoOffset the start offset of the 'verification_type_info' structure to
3155 * read.
3156 * @param frame the array where the parsed type must be stored.
3157 * @param index the index in 'frame' where the parsed type must be stored.
3158 * @param charBuffer the buffer used to read strings in the constant pool.
3159 * @param labels the labels of the method currently being parsed, indexed by their offset. If the
3160 * parsed type is an ITEM_Uninitialized, a new label for the corresponding NEW instruction is
3161 * stored in this array if it does not already exist.
3162 * @return the end offset of the JVMS 'verification_type_info' structure.
3163 */
3164 private int readVerificationTypeInfo(
3165 final int verificationTypeInfoOffset,
3166 final Object[] frame,
3167 final int index,
3168 final char[] charBuffer,
3169 final Label[] labels) {
3170 int currentOffset = verificationTypeInfoOffset;
3171 int tag = b[currentOffset++] & 0xFF;
3172 switch (tag) {
3173 case Frame.ITEM_TOP:
3174 frame[index] = Opcodes.TOP;
3175 break;
3176 case Frame.ITEM_INTEGER:
3177 frame[index] = Opcodes.INTEGER;
3178 break;
3179 case Frame.ITEM_FLOAT:
3180 frame[index] = Opcodes.FLOAT;
3181 break;
3182 case Frame.ITEM_DOUBLE:
3183 frame[index] = Opcodes.DOUBLE;
3184 break;
3185 case Frame.ITEM_LONG:
3186 frame[index] = Opcodes.LONG;
3187 break;
3188 case Frame.ITEM_NULL:
3189 frame[index] = Opcodes.NULL;
3190 break;
3191 case Frame.ITEM_UNINITIALIZED_THIS:
3192 frame[index] = Opcodes.UNINITIALIZED_THIS;
3193 break;
3194 case Frame.ITEM_OBJECT:
3195 frame[index] = readClass(currentOffset, charBuffer);
3196 currentOffset += 2;
3197 break;
3198 case Frame.ITEM_UNINITIALIZED:
3199 frame[index] = createLabel(readUnsignedShort(currentOffset), labels);
3200 currentOffset += 2;
3201 break;
3202 default:
3203 throw new IllegalArgumentException();
3204 }
3205 return currentOffset;
3206 }
3207
3208 // ----------------------------------------------------------------------------------------------
3209 // Methods to parse attributes
3210 // ----------------------------------------------------------------------------------------------
3211
3212 /**
3213 * Returns the offset in {@link #b} of the first ClassFile's 'attributes' array field entry.
3214 *
3215 * @return the offset in {@link #b} of the first ClassFile's 'attributes' array field entry.
3216 */
3217 final int getFirstAttributeOffset() {
3218 // Skip the access_flags, this_class, super_class, and interfaces_count fields (using 2 bytes
3219 // each), as well as the interfaces array field (2 bytes per interface).
3220 int currentOffset = header + 8 + readUnsignedShort(header + 6) * 2;
3221
3222 // Read the fields_count field.
3223 int fieldsCount = readUnsignedShort(currentOffset);
3224 currentOffset += 2;
3225 // Skip the 'fields' array field.
3226 while (fieldsCount-- > 0) {
3227 // Invariant: currentOffset is the offset of a field_info structure.
3228 // Skip the access_flags, name_index and descriptor_index fields (2 bytes each), and read the
3229 // attributes_count field.
3230 int attributesCount = readUnsignedShort(currentOffset + 6);
3231 currentOffset += 8;
3232 // Skip the 'attributes' array field.
3233 while (attributesCount-- > 0) {
3234 // Invariant: currentOffset is the offset of an attribute_info structure.
3235 // Read the attribute_length field (2 bytes after the start of the attribute_info) and skip
3236 // this many bytes, plus 6 for the attribute_name_index and attribute_length fields
3237 // (yielding the total size of the attribute_info structure).
3238 currentOffset += 6 + readInt(currentOffset + 2);
3239 }
3240 }
3241
3242 // Skip the methods_count and 'methods' fields, using the same method as above.
3243 int methodsCount = readUnsignedShort(currentOffset);
3244 currentOffset += 2;
3245 while (methodsCount-- > 0) {
3246 int attributesCount = readUnsignedShort(currentOffset + 6);
3247 currentOffset += 8;
3248 while (attributesCount-- > 0) {
3249 currentOffset += 6 + readInt(currentOffset + 2);
3250 }
3251 }
3252
3253 // Skip the ClassFile's attributes_count field.
3254 return currentOffset + 2;
3255 }
3256
3257 /**
3258 * Reads the BootstrapMethods attribute to compute the offset of each bootstrap method.
3259 *
3260 * @param maxStringLength a conservative estimate of the maximum length of the strings contained
3261 * in the constant pool of the class.
3262 * @return the offsets of the bootstrap methods or null.
3263 */
3264 private int[] readBootstrapMethodsAttribute(final int maxStringLength) {
3265 char[] charBuffer = new char[maxStringLength];
3266 int currentAttributeOffset = getFirstAttributeOffset();
3267 int[] currentBootstrapMethodOffsets = null;
3268 for (int i = readUnsignedShort(currentAttributeOffset - 2); i > 0; --i) {
3269 // Read the attribute_info's attribute_name and attribute_length fields.
3270 String attributeName = readUTF8(currentAttributeOffset, charBuffer);
3271 int attributeLength = readInt(currentAttributeOffset + 2);
3272 currentAttributeOffset += 6;
3273 if (Constants.BOOTSTRAP_METHODS.equals(attributeName)) {
3274 // Read the num_bootstrap_methods field and create an array of this size.
3275 currentBootstrapMethodOffsets = new int[readUnsignedShort(currentAttributeOffset)];
3276 // Compute and store the offset of each 'bootstrap_methods' array field entry.
3277 int currentBootstrapMethodOffset = currentAttributeOffset + 2;
3278 for (int j = 0; j < currentBootstrapMethodOffsets.length; ++j) {
3279 currentBootstrapMethodOffsets[j] = currentBootstrapMethodOffset;
3280 // Skip the bootstrap_method_ref and num_bootstrap_arguments fields (2 bytes each),
3281 // as well as the bootstrap_arguments array field (of size num_bootstrap_arguments * 2).
3282 currentBootstrapMethodOffset +=
3283 4 + readUnsignedShort(currentBootstrapMethodOffset + 2) * 2;
3284 }
3285 return currentBootstrapMethodOffsets;
3286 }
3287 currentAttributeOffset += attributeLength;
3288 }
3289 return null;
3290 }
3291
3292 /**
3293 * Reads a non standard JVMS 'attribute' structure in {@link #b}.
3294 *
3295 * @param attributePrototypes prototypes of the attributes that must be parsed during the visit of
3296 * the class. Any attribute whose type is not equal to the type of one the prototypes will not
3297 * be parsed: its byte array value will be passed unchanged to the ClassWriter.
3298 * @param type the type of the attribute.
3299 * @param offset the start offset of the JVMS 'attribute' structure in {@link #b}. The 6 attribute
3300 * header bytes (attribute_name_index and attribute_length) are not taken into account here.
3301 * @param length the length of the attribute's content (excluding the 6 attribute header bytes).
3302 * @param charBuffer the buffer to be used to read strings in the constant pool.
3303 * @param codeAttributeOffset the start offset of the enclosing Code attribute in {@link #b}, or
3304 * -1 if the attribute to be read is not a code attribute. The 6 attribute header bytes
3305 * (attribute_name_index and attribute_length) are not taken into account here.
3306 * @param labels the labels of the method's code, or {@literal null} if the attribute to be read
3307 * is not a code attribute.
3308 * @return the attribute that has been read.
3309 */
3310 private Attribute readAttribute(
3311 final Attribute[] attributePrototypes,
3312 final String type,
3313 final int offset,
3314 final int length,
3315 final char[] charBuffer,
3316 final int codeAttributeOffset,
3317 final Label[] labels) {
3318 for (Attribute attributePrototype : attributePrototypes) {
3319 if (attributePrototype.type.equals(type)) {
3320 return attributePrototype.read(
3321 this, offset, length, charBuffer, codeAttributeOffset, labels);
3322 }
3323 }
3324 return new Attribute(type).read(this, offset, length, null, -1, null);
3325 }
3326
3327 // -----------------------------------------------------------------------------------------------
3328 // Utility methods: low level parsing
3329 // -----------------------------------------------------------------------------------------------
3330
3331 /**
3332 * Returns the number of entries in the class's constant pool table.
3333 *
3334 * @return the number of entries in the class's constant pool table.
3335 */
3336 public int getItemCount() {
3337 return cpInfoOffsets.length;
3338 }
3339
3340 /**
3341 * Returns the start offset in {@link #b} of a JVMS 'cp_info' structure (i.e. a constant pool
3342 * entry), plus one. <i>This method is intended for {@link Attribute} sub classes, and is normally
3343 * not needed by class generators or adapters.</i>
3344 *
3345 * @param constantPoolEntryIndex the index a constant pool entry in the class's constant pool
3346 * table.
3347 * @return the start offset in {@link #b} of the corresponding JVMS 'cp_info' structure, plus one.
3348 */
3349 public int getItem(final int constantPoolEntryIndex) {
3350 return cpInfoOffsets[constantPoolEntryIndex];
3351 }
3352
3353 /**
3354 * Returns a conservative estimate of the maximum length of the strings contained in the class's
3355 * constant pool table.
3356 *
3357 * @return a conservative estimate of the maximum length of the strings contained in the class's
3358 * constant pool table.
3359 */
3360 public int getMaxStringLength() {
3361 return maxStringLength;
3362 }
3363
3364 /**
3365 * Reads a byte value in {@link #b}. <i>This method is intended for {@link Attribute} sub classes,
3366 * and is normally not needed by class generators or adapters.</i>
3367 *
3368 * @param offset the start offset of the value to be read in {@link #b}.
3369 * @return the read value.
3370 */
3371 public int readByte(final int offset) {
3372 return b[offset] & 0xFF;
3373 }
3374
3375 /**
3376 * Reads an unsigned short value in {@link #b}. <i>This method is intended for {@link Attribute}
3377 * sub classes, and is normally not needed by class generators or adapters.</i>
3378 *
3379 * @param offset the start index of the value to be read in {@link #b}.
3380 * @return the read value.
3381 */
3382 public int readUnsignedShort(final int offset) {
3383 byte[] classFileBuffer = b;
3384 return ((classFileBuffer[offset] & 0xFF) << 8) | (classFileBuffer[offset + 1] & 0xFF);
3385 }
3386
3387 /**
3388 * Reads a signed short value in {@link #b}. <i>This method is intended for {@link Attribute} sub
3389 * classes, and is normally not needed by class generators or adapters.</i>
3390 *
3391 * @param offset the start offset of the value to be read in {@link #b}.
3392 * @return the read value.
3393 */
3394 public short readShort(final int offset) {
3395 byte[] classFileBuffer = b;
3396 return (short) (((classFileBuffer[offset] & 0xFF) << 8) | (classFileBuffer[offset + 1] & 0xFF));
3397 }
3398
3399 /**
3400 * Reads a signed int value in {@link #b}. <i>This method is intended for {@link Attribute} sub
3401 * classes, and is normally not needed by class generators or adapters.</i>
3402 *
3403 * @param offset the start offset of the value to be read in {@link #b}.
3404 * @return the read value.
3405 */
3406 public int readInt(final int offset) {
3407 byte[] classFileBuffer = b;
3408 return ((classFileBuffer[offset] & 0xFF) << 24)
3409 | ((classFileBuffer[offset + 1] & 0xFF) << 16)
3410 | ((classFileBuffer[offset + 2] & 0xFF) << 8)
3411 | (classFileBuffer[offset + 3] & 0xFF);
3412 }
3413
3414 /**
3415 * Reads a signed long value in {@link #b}. <i>This method is intended for {@link Attribute} sub
3416 * classes, and is normally not needed by class generators or adapters.</i>
3417 *
3418 * @param offset the start offset of the value to be read in {@link #b}.
3419 * @return the read value.
3420 */
3421 public long readLong(final int offset) {
3422 long l1 = readInt(offset);
3423 long l0 = readInt(offset + 4) & 0xFFFFFFFFL;
3424 return (l1 << 32) | l0;
3425 }
3426
3427 /**
3428 * Reads a CONSTANT_Utf8 constant pool entry in {@link #b}. <i>This method is intended for {@link
3429 * Attribute} sub classes, and is normally not needed by class generators or adapters.</i>
3430 *
3431 * @param offset the start offset of an unsigned short value in {@link #b}, whose value is the
3432 * index of a CONSTANT_Utf8 entry in the class's constant pool table.
3433 * @param charBuffer the buffer to be used to read the string. This buffer must be sufficiently
3434 * large. It is not automatically resized.
3435 * @return the String corresponding to the specified CONSTANT_Utf8 entry.
3436 */
3437 // DontCheck(AbbreviationAsWordInName): can't be renamed (for backward binary compatibility).
3438 public String readUTF8(final int offset, final char[] charBuffer) {
3439 int constantPoolEntryIndex = readUnsignedShort(offset);
3440 if (offset == 0 || constantPoolEntryIndex == 0) {
3441 return null;
3442 }
3443 return readUtf(constantPoolEntryIndex, charBuffer);
3444 }
3445
3446 /**
3447 * Reads a CONSTANT_Utf8 constant pool entry in {@link #b}.
3448 *
3449 * @param constantPoolEntryIndex the index of a CONSTANT_Utf8 entry in the class's constant pool
3450 * table.
3451 * @param charBuffer the buffer to be used to read the string. This buffer must be sufficiently
3452 * large. It is not automatically resized.
3453 * @return the String corresponding to the specified CONSTANT_Utf8 entry.
3454 */
3455 final String readUtf(final int constantPoolEntryIndex, final char[] charBuffer) {
3456 String value = constantUtf8Values[constantPoolEntryIndex];
3457 if (value != null) {
3458 return value;
3459 }
3460 int cpInfoOffset = cpInfoOffsets[constantPoolEntryIndex];
3461 return constantUtf8Values[constantPoolEntryIndex] =
3462 readUtf(cpInfoOffset + 2, readUnsignedShort(cpInfoOffset), charBuffer);
3463 }
3464
3465 /**
3466 * Reads an UTF8 string in {@link #b}.
3467 *
3468 * @param utfOffset the start offset of the UTF8 string to be read.
3469 * @param utfLength the length of the UTF8 string to be read.
3470 * @param charBuffer the buffer to be used to read the string. This buffer must be sufficiently
3471 * large. It is not automatically resized.
3472 * @return the String corresponding to the specified UTF8 string.
3473 */
3474 private String readUtf(final int utfOffset, final int utfLength, final char[] charBuffer) {
3475 int currentOffset = utfOffset;
3476 int endOffset = currentOffset + utfLength;
3477 int strLength = 0;
3478 byte[] classFileBuffer = b;
3479 while (currentOffset < endOffset) {
3480 int currentByte = classFileBuffer[currentOffset++];
3481 if ((currentByte & 0x80) == 0) {
3482 charBuffer[strLength++] = (char) (currentByte & 0x7F);
3483 } else if ((currentByte & 0xE0) == 0xC0) {
3484 charBuffer[strLength++] =
3485 (char) (((currentByte & 0x1F) << 6) + (classFileBuffer[currentOffset++] & 0x3F));
3486 } else {
3487 charBuffer[strLength++] =
3488 (char)
3489 (((currentByte & 0xF) << 12)
3490 + ((classFileBuffer[currentOffset++] & 0x3F) << 6)
3491 + (classFileBuffer[currentOffset++] & 0x3F));
3492 }
3493 }
3494 return new String(charBuffer, 0, strLength);
3495 }
3496
3497 /**
3498 * Reads a CONSTANT_Class, CONSTANT_String, CONSTANT_MethodType, CONSTANT_Module or
3499 * CONSTANT_Package constant pool entry in {@link #b}. <i>This method is intended for {@link
3500 * Attribute} sub classes, and is normally not needed by class generators or adapters.</i>
3501 *
3502 * @param offset the start offset of an unsigned short value in {@link #b}, whose value is the
3503 * index of a CONSTANT_Class, CONSTANT_String, CONSTANT_MethodType, CONSTANT_Module or
3504 * CONSTANT_Package entry in class's constant pool table.
3505 * @param charBuffer the buffer to be used to read the item. This buffer must be sufficiently
3506 * large. It is not automatically resized.
3507 * @return the String corresponding to the specified constant pool entry.
3508 */
3509 private String readStringish(final int offset, final char[] charBuffer) {
3510 // Get the start offset of the cp_info structure (plus one), and read the CONSTANT_Utf8 entry
3511 // designated by the first two bytes of this cp_info.
3512 return readUTF8(cpInfoOffsets[readUnsignedShort(offset)], charBuffer);
3513 }
3514
3515 /**
3516 * Reads a CONSTANT_Class constant pool entry in {@link #b}. <i>This method is intended for {@link
3517 * Attribute} sub classes, and is normally not needed by class generators or adapters.</i>
3518 *
3519 * @param offset the start offset of an unsigned short value in {@link #b}, whose value is the
3520 * index of a CONSTANT_Class entry in class's constant pool table.
3521 * @param charBuffer the buffer to be used to read the item. This buffer must be sufficiently
3522 * large. It is not automatically resized.
3523 * @return the String corresponding to the specified CONSTANT_Class entry.
3524 */
3525 public String readClass(final int offset, final char[] charBuffer) {
3526 return readStringish(offset, charBuffer);
3527 }
3528
3529 /**
3530 * Reads a CONSTANT_Module constant pool entry in {@link #b}. <i>This method is intended for
3531 * {@link Attribute} sub classes, and is normally not needed by class generators or adapters.</i>
3532 *
3533 * @param offset the start offset of an unsigned short value in {@link #b}, whose value is the
3534 * index of a CONSTANT_Module entry in class's constant pool table.
3535 * @param charBuffer the buffer to be used to read the item. This buffer must be sufficiently
3536 * large. It is not automatically resized.
3537 * @return the String corresponding to the specified CONSTANT_Module entry.
3538 */
3539 public String readModule(final int offset, final char[] charBuffer) {
3540 return readStringish(offset, charBuffer);
3541 }
3542
3543 /**
3544 * Reads a CONSTANT_Package constant pool entry in {@link #b}. <i>This method is intended for
3545 * {@link Attribute} sub classes, and is normally not needed by class generators or adapters.</i>
3546 *
3547 * @param offset the start offset of an unsigned short value in {@link #b}, whose value is the
3548 * index of a CONSTANT_Package entry in class's constant pool table.
3549 * @param charBuffer the buffer to be used to read the item. This buffer must be sufficiently
3550 * large. It is not automatically resized.
3551 * @return the String corresponding to the specified CONSTANT_Package entry.
3552 */
3553 public String readPackage(final int offset, final char[] charBuffer) {
3554 return readStringish(offset, charBuffer);
3555 }
3556
3557 /**
3558 * Reads a CONSTANT_Dynamic constant pool entry in {@link #b}.
3559 *
3560 * @param constantPoolEntryIndex the index of a CONSTANT_Dynamic entry in the class's constant
3561 * pool table.
3562 * @param charBuffer the buffer to be used to read the string. This buffer must be sufficiently
3563 * large. It is not automatically resized.
3564 * @return the ConstantDynamic corresponding to the specified CONSTANT_Dynamic entry.
3565 */
3566 private ConstantDynamic readConstantDynamic(
3567 final int constantPoolEntryIndex, final char[] charBuffer) {
3568 ConstantDynamic constantDynamic = constantDynamicValues[constantPoolEntryIndex];
3569 if (constantDynamic != null) {
3570 return constantDynamic;
3571 }
3572 int cpInfoOffset = cpInfoOffsets[constantPoolEntryIndex];
3573 int nameAndTypeCpInfoOffset = cpInfoOffsets[readUnsignedShort(cpInfoOffset + 2)];
3574 String name = readUTF8(nameAndTypeCpInfoOffset, charBuffer);
3575 String descriptor = readUTF8(nameAndTypeCpInfoOffset + 2, charBuffer);
3576 int bootstrapMethodOffset = bootstrapMethodOffsets[readUnsignedShort(cpInfoOffset)];
3577 Handle handle = (Handle) readConst(readUnsignedShort(bootstrapMethodOffset), charBuffer);
3578 Object[] bootstrapMethodArguments = new Object[readUnsignedShort(bootstrapMethodOffset + 2)];
3579 bootstrapMethodOffset += 4;
3580 for (int i = 0; i < bootstrapMethodArguments.length; i++) {
3581 bootstrapMethodArguments[i] = readConst(readUnsignedShort(bootstrapMethodOffset), charBuffer);
3582 bootstrapMethodOffset += 2;
3583 }
3584 return constantDynamicValues[constantPoolEntryIndex] =
3585 new ConstantDynamic(name, descriptor, handle, bootstrapMethodArguments);
3586 }
3587
3588 /**
3589 * Reads a numeric or string constant pool entry in {@link #b}. <i>This method is intended for
3590 * {@link Attribute} sub classes, and is normally not needed by class generators or adapters.</i>
3591 *
3592 * @param constantPoolEntryIndex the index of a CONSTANT_Integer, CONSTANT_Float, CONSTANT_Long,
3593 * CONSTANT_Double, CONSTANT_Class, CONSTANT_String, CONSTANT_MethodType,
3594 * CONSTANT_MethodHandle or CONSTANT_Dynamic entry in the class's constant pool.
3595 * @param charBuffer the buffer to be used to read strings. This buffer must be sufficiently
3596 * large. It is not automatically resized.
3597 * @return the {@link Integer}, {@link Float}, {@link Long}, {@link Double}, {@link String},
3598 * {@link Type}, {@link Handle} or {@link ConstantDynamic} corresponding to the specified
3599 * constant pool entry.
3600 */
3601 public Object readConst(final int constantPoolEntryIndex, final char[] charBuffer) {
3602 int cpInfoOffset = cpInfoOffsets[constantPoolEntryIndex];
3603 switch (b[cpInfoOffset - 1]) {
3604 case Symbol.CONSTANT_INTEGER_TAG:
3605 return readInt(cpInfoOffset);
3606 case Symbol.CONSTANT_FLOAT_TAG:
3607 return Float.intBitsToFloat(readInt(cpInfoOffset));
3608 case Symbol.CONSTANT_LONG_TAG:
3609 return readLong(cpInfoOffset);
3610 case Symbol.CONSTANT_DOUBLE_TAG:
3611 return Double.longBitsToDouble(readLong(cpInfoOffset));
3612 case Symbol.CONSTANT_CLASS_TAG:
3613 return Type.getObjectType(readUTF8(cpInfoOffset, charBuffer));
3614 case Symbol.CONSTANT_STRING_TAG:
3615 return readUTF8(cpInfoOffset, charBuffer);
3616 case Symbol.CONSTANT_METHOD_TYPE_TAG:
3617 return Type.getMethodType(readUTF8(cpInfoOffset, charBuffer));
3618 case Symbol.CONSTANT_METHOD_HANDLE_TAG:
3619 int referenceKind = readByte(cpInfoOffset);
3620 int referenceCpInfoOffset = cpInfoOffsets[readUnsignedShort(cpInfoOffset + 1)];
3621 int nameAndTypeCpInfoOffset = cpInfoOffsets[readUnsignedShort(referenceCpInfoOffset + 2)];
3622 String owner = readClass(referenceCpInfoOffset, charBuffer);
3623 String name = readUTF8(nameAndTypeCpInfoOffset, charBuffer);
3624 String descriptor = readUTF8(nameAndTypeCpInfoOffset + 2, charBuffer);
3625 boolean isInterface =
3626 b[referenceCpInfoOffset - 1] == Symbol.CONSTANT_INTERFACE_METHODREF_TAG;
3627 return new Handle(referenceKind, owner, name, descriptor, isInterface);
3628 case Symbol.CONSTANT_DYNAMIC_TAG:
3629 return readConstantDynamic(constantPoolEntryIndex, charBuffer);
3630 default:
3631 throw new IllegalArgumentException();
3632 }
3633 }
3634 }