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
60 package jdk.internal.org.objectweb.asm;
61
62 import java.io.ByteArrayOutputStream;
63 import java.io.IOException;
64 import java.io.InputStream;
65
66 /**
67 * A parser to make a {@link ClassVisitor} visit a ClassFile structure, as defined in the Java
68 * Virtual Machine Specification (JVMS). This class parses the ClassFile content and calls the
69 * appropriate visit methods of a given {@link ClassVisitor} for each field, method and bytecode
70 * instruction encountered.
71 *
72 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html">JVMS 4</a>
73 * @author Eric Bruneton
74 * @author Eugene Kuleshov
75 */
76 public class ClassReader {
77
78 /**
79 * A flag to skip the Code attributes. If this flag is set the Code attributes are neither parsed
80 * nor visited.
81 */
82 public static final int SKIP_CODE = 1;
83
84 /**
85 * A flag to skip the SourceFile, SourceDebugExtension, LocalVariableTable,
86 * LocalVariableTypeTable, LineNumberTable and MethodParameters attributes. If this flag is set
87 * these attributes are neither parsed nor visited (i.e. {@link ClassVisitor#visitSource}, {@link
88 * MethodVisitor#visitLocalVariable}, {@link MethodVisitor#visitLineNumber} and {@link
89 * MethodVisitor#visitParameter} are not called).
90 */
91 public static final int SKIP_DEBUG = 2;
92
93 /**
94 * A flag to skip the StackMap and StackMapTable attributes. If this flag is set these attributes
95 * are neither parsed nor visited (i.e. {@link MethodVisitor#visitFrame} is not called). This flag
96 * is useful when the {@link ClassWriter#COMPUTE_FRAMES} option is used: it avoids visiting frames
97 * that will be ignored and recomputed from scratch.
98 */
99 public static final int SKIP_FRAMES = 4;
100
101 /**
102 * A flag to expand the stack map frames. By default stack map frames are visited in their
103 * original format (i.e. "expanded" for classes whose version is less than V1_6, and "compressed"
104 * for the other classes). If this flag is set, stack map frames are always visited in expanded
105 * format (this option adds a decompression/compression step in ClassReader and ClassWriter which
106 * degrades performance quite a lot).
107 */
108 public static final int EXPAND_FRAMES = 8;
109
110 /**
111 * A flag to expand the ASM specific instructions into an equivalent sequence of standard bytecode
112 * instructions. When resolving a forward jump it may happen that the signed 2 bytes offset
113 * reserved for it is not sufficient to store the bytecode offset. In this case the jump
114 * instruction is replaced with a temporary ASM specific instruction using an unsigned 2 bytes
115 * offset (see {@link Label#resolve}). This internal flag is used to re-read classes containing
116 * such instructions, in order to replace them with standard instructions. In addition, when this
117 * flag is used, goto_w and jsr_w are <i>not</i> converted into goto and jsr, to make sure that
118 * infinite loops where a goto_w is replaced with a goto in ClassReader and converted back to a
119 * goto_w in ClassWriter cannot occur.
120 */
121 static final int EXPAND_ASM_INSNS = 256;
122
123 /** The maximum size of array to allocate. */
124 private static final int MAX_BUFFER_SIZE = 1024 * 1024;
125
126 /** The size of the temporary byte array used to read class input streams chunk by chunk. */
127 private static final int INPUT_STREAM_DATA_CHUNK_SIZE = 4096;
128
129 /**
130 * A byte array containing the JVMS ClassFile structure to be parsed.
131 *
132 * @deprecated Use {@link #readByte(int)} and the other read methods instead. This field will
133 * eventually be deleted.
134 */
135 @Deprecated
136 // DontCheck(MemberName): can't be renamed (for backward binary compatibility).
137 public final byte[] b;
138
139 /** The offset in bytes of the ClassFile's access_flags field. */
140 public final int header;
141
142 /**
143 * A byte array containing the JVMS ClassFile structure to be parsed. <i>The content of this array
144 * must not be modified. This field is intended for {@link Attribute} sub classes, and is normally
145 * not needed by class visitors.</i>
146 *
147 * <p>NOTE: the ClassFile structure can start at any offset within this array, i.e. it does not
148 * necessarily start at offset 0. Use {@link #getItem} and {@link #header} to get correct
149 * ClassFile element offsets within this byte array.
150 */
151 final byte[] classFileBuffer;
152
153 /**
154 * The offset in bytes, in {@link #classFileBuffer}, of each cp_info entry of the ClassFile's
155 * constant_pool array, <i>plus one</i>. In other words, the offset of constant pool entry i is
156 * given by cpInfoOffsets[i] - 1, i.e. its cp_info's tag field is given by b[cpInfoOffsets[i] -
157 * 1].
158 */
159 private final int[] cpInfoOffsets;
160
161 /**
162 * The String objects corresponding to the CONSTANT_Utf8 constant pool items. This cache avoids
163 * multiple parsing of a given CONSTANT_Utf8 constant pool item.
164 */
165 private final String[] constantUtf8Values;
166
167 /**
168 * The ConstantDynamic objects corresponding to the CONSTANT_Dynamic constant pool items. This
169 * cache avoids multiple parsing of a given CONSTANT_Dynamic constant pool item.
170 */
171 private final ConstantDynamic[] constantDynamicValues;
172
173 /**
174 * The start offsets in {@link #classFileBuffer} of each element of the bootstrap_methods array
175 * (in the BootstrapMethods attribute).
176 *
177 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.23">JVMS
178 * 4.7.23</a>
179 */
180 private final int[] bootstrapMethodOffsets;
181
182 /**
183 * A conservative estimate of the maximum length of the strings contained in the constant pool of
184 * the class.
185 */
186 private final int maxStringLength;
187
188 // -----------------------------------------------------------------------------------------------
189 // Constructors
190 // -----------------------------------------------------------------------------------------------
191
192 /**
193 * Constructs a new {@link ClassReader} object.
194 *
195 * @param classFile the JVMS ClassFile structure to be read.
196 */
197 public ClassReader(final byte[] classFile) {
198 this(classFile, 0, classFile.length);
199 }
200
201 /**
202 * Constructs a new {@link ClassReader} object.
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 classFileLength the length in bytes of the ClassFile to be read.
207 */
208 public ClassReader(
209 final byte[] classFileBuffer,
210 final int classFileOffset,
211 final int classFileLength) { // NOPMD(UnusedFormalParameter) used for backward compatibility.
212 this(classFileBuffer, classFileOffset, /* checkClassVersion = */ true);
213 }
214
215 /**
216 * Constructs a new {@link ClassReader} object. <i>This internal constructor must not be exposed
217 * as a public API</i>.
218 *
219 * @param classFileBuffer a byte array containing the JVMS ClassFile structure to be read.
220 * @param classFileOffset the offset in byteBuffer of the first byte of the ClassFile to be read.
221 * @param checkClassVersion whether to check the class version or not.
222 */
223 ClassReader(
224 final byte[] classFileBuffer, final int classFileOffset, final boolean checkClassVersion) {
225 this.classFileBuffer = classFileBuffer;
226 this.b = classFileBuffer;
227 // Check the class' major_version. This field is after the magic and minor_version fields, which
228 // use 4 and 2 bytes respectively.
229 if (checkClassVersion && readShort(classFileOffset + 6) > Opcodes.V21) {
230 throw new IllegalArgumentException(
231 "Unsupported class file major version " + readShort(classFileOffset + 6));
232 }
233 // Create the constant pool arrays. The constant_pool_count field is after the magic,
234 // minor_version and major_version fields, which use 4, 2 and 2 bytes respectively.
235 int constantPoolCount = readUnsignedShort(classFileOffset + 8);
236 cpInfoOffsets = new int[constantPoolCount];
237 constantUtf8Values = new String[constantPoolCount];
238 // Compute the offset of each constant pool entry, as well as a conservative estimate of the
239 // maximum length of the constant pool strings. The first constant pool entry is after the
240 // magic, minor_version, major_version and constant_pool_count fields, which use 4, 2, 2 and 2
241 // bytes respectively.
242 int currentCpInfoIndex = 1;
243 int currentCpInfoOffset = classFileOffset + 10;
244 int currentMaxStringLength = 0;
245 boolean hasBootstrapMethods = false;
246 boolean hasConstantDynamic = false;
247 // The offset of the other entries depend on the total size of all the previous entries.
248 while (currentCpInfoIndex < constantPoolCount) {
249 cpInfoOffsets[currentCpInfoIndex++] = currentCpInfoOffset + 1;
250 int cpInfoSize;
251 switch (classFileBuffer[currentCpInfoOffset]) {
252 case Symbol.CONSTANT_FIELDREF_TAG:
253 case Symbol.CONSTANT_METHODREF_TAG:
254 case Symbol.CONSTANT_INTERFACE_METHODREF_TAG:
255 case Symbol.CONSTANT_INTEGER_TAG:
256 case Symbol.CONSTANT_FLOAT_TAG:
257 case Symbol.CONSTANT_NAME_AND_TYPE_TAG:
258 cpInfoSize = 5;
259 break;
260 case Symbol.CONSTANT_DYNAMIC_TAG:
261 cpInfoSize = 5;
262 hasBootstrapMethods = true;
263 hasConstantDynamic = true;
264 break;
265 case Symbol.CONSTANT_INVOKE_DYNAMIC_TAG:
266 cpInfoSize = 5;
267 hasBootstrapMethods = true;
268 break;
269 case Symbol.CONSTANT_LONG_TAG:
270 case Symbol.CONSTANT_DOUBLE_TAG:
271 cpInfoSize = 9;
272 currentCpInfoIndex++;
273 break;
274 case Symbol.CONSTANT_UTF8_TAG:
275 cpInfoSize = 3 + readUnsignedShort(currentCpInfoOffset + 1);
276 if (cpInfoSize > currentMaxStringLength) {
277 // The size in bytes of this CONSTANT_Utf8 structure provides a conservative estimate
278 // of the length in characters of the corresponding string, and is much cheaper to
279 // compute than this exact length.
280 currentMaxStringLength = cpInfoSize;
281 }
282 break;
283 case Symbol.CONSTANT_METHOD_HANDLE_TAG:
284 cpInfoSize = 4;
285 break;
286 case Symbol.CONSTANT_CLASS_TAG:
287 case Symbol.CONSTANT_STRING_TAG:
288 case Symbol.CONSTANT_METHOD_TYPE_TAG:
289 case Symbol.CONSTANT_PACKAGE_TAG:
290 case Symbol.CONSTANT_MODULE_TAG:
291 cpInfoSize = 3;
292 break;
293 default:
294 throw new IllegalArgumentException();
295 }
296 currentCpInfoOffset += cpInfoSize;
297 }
298 maxStringLength = currentMaxStringLength;
299 // The Classfile's access_flags field is just after the last constant pool entry.
300 header = currentCpInfoOffset;
301
302 // Allocate the cache of ConstantDynamic values, if there is at least one.
303 constantDynamicValues = hasConstantDynamic ? new ConstantDynamic[constantPoolCount] : null;
304
305 // Read the BootstrapMethods attribute, if any (only get the offset of each method).
306 bootstrapMethodOffsets =
307 hasBootstrapMethods ? readBootstrapMethodsAttribute(currentMaxStringLength) : null;
308 }
309
310 /**
311 * Constructs a new {@link ClassReader} object.
312 *
313 * @param inputStream an input stream of the JVMS ClassFile structure to be read. This input
314 * stream must contain nothing more than the ClassFile structure itself. It is read from its
315 * current position to its end.
316 * @throws IOException if a problem occurs during reading.
317 */
318 public ClassReader(final InputStream inputStream) throws IOException {
319 this(readStream(inputStream, false));
320 }
321
322 /**
323 * Constructs a new {@link ClassReader} object.
324 *
325 * @param className the fully qualified name of the class to be read. The ClassFile structure is
326 * retrieved with the current class loader's {@link ClassLoader#getSystemResourceAsStream}.
327 * @throws IOException if an exception occurs during reading.
328 */
329 public ClassReader(final String className) throws IOException {
330 this(
331 readStream(
332 ClassLoader.getSystemResourceAsStream(className.replace('.', '/') + ".class"), true));
333 }
334
335 /**
336 * Reads the given input stream and returns its content as a byte array.
337 *
338 * @param inputStream an input stream.
339 * @param close true to close the input stream after reading.
340 * @return the content of the given input stream.
341 * @throws IOException if a problem occurs during reading.
342 */
343 @SuppressWarnings("PMD.UseTryWithResources")
344 private static byte[] readStream(final InputStream inputStream, final boolean close)
345 throws IOException {
346 if (inputStream == null) {
347 throw new IOException("Class not found");
348 }
349 int bufferSize = computeBufferSize(inputStream);
350 try (ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {
351 byte[] data = new byte[bufferSize];
352 int bytesRead;
353 int readCount = 0;
354 while ((bytesRead = inputStream.read(data, 0, bufferSize)) != -1) {
355 outputStream.write(data, 0, bytesRead);
356 readCount++;
357 }
358 outputStream.flush();
359 if (readCount == 1) {
360 return data;
361 }
362 return outputStream.toByteArray();
363 } finally {
364 if (close) {
365 inputStream.close();
366 }
367 }
368 }
369
370 private static int computeBufferSize(final InputStream inputStream) throws IOException {
371 int expectedLength = inputStream.available();
372 /*
373 * Some implementations can return 0 while holding available data (e.g. new
374 * FileInputStream("/proc/a_file")). Also in some pathological cases a very small number might
375 * be returned, and in this case we use a default size.
376 */
377 if (expectedLength < 256) {
378 return INPUT_STREAM_DATA_CHUNK_SIZE;
379 }
380 return Math.min(expectedLength, MAX_BUFFER_SIZE);
381 }
382
383 // -----------------------------------------------------------------------------------------------
384 // Accessors
385 // -----------------------------------------------------------------------------------------------
386
387 /**
388 * Returns the class's access flags (see {@link Opcodes}). This value may not reflect Deprecated
389 * and Synthetic flags when bytecode is before 1.5 and those flags are represented by attributes.
390 *
391 * @return the class access flags.
392 * @see ClassVisitor#visit(int, int, String, String, String, String[])
393 */
394 public int getAccess() {
395 return readUnsignedShort(header);
396 }
397
398 /**
399 * Returns the internal name of the class (see {@link Type#getInternalName()}).
400 *
401 * @return the internal class name.
402 * @see ClassVisitor#visit(int, int, String, String, String, String[])
403 */
404 public String getClassName() {
405 // this_class is just after the access_flags field (using 2 bytes).
406 return readClass(header + 2, new char[maxStringLength]);
407 }
408
409 /**
410 * Returns the internal of name of the super class (see {@link Type#getInternalName()}). For
411 * interfaces, the super class is {@link Object}.
412 *
413 * @return the internal name of the super class, or {@literal null} for {@link Object} class.
414 * @see ClassVisitor#visit(int, int, String, String, String, String[])
415 */
416 public String getSuperName() {
417 // super_class is after the access_flags and this_class fields (2 bytes each).
418 return readClass(header + 4, new char[maxStringLength]);
419 }
420
421 /**
422 * Returns the internal names of the implemented interfaces (see {@link Type#getInternalName()}).
423 *
424 * @return the internal names of the directly implemented interfaces. Inherited implemented
425 * interfaces are not returned.
426 * @see ClassVisitor#visit(int, int, String, String, String, String[])
427 */
428 public String[] getInterfaces() {
429 // interfaces_count is after the access_flags, this_class and super_class fields (2 bytes each).
430 int currentOffset = header + 6;
431 int interfacesCount = readUnsignedShort(currentOffset);
432 String[] interfaces = new String[interfacesCount];
433 if (interfacesCount > 0) {
434 char[] charBuffer = new char[maxStringLength];
435 for (int i = 0; i < interfacesCount; ++i) {
436 currentOffset += 2;
437 interfaces[i] = readClass(currentOffset, charBuffer);
438 }
439 }
440 return interfaces;
441 }
442
443 // -----------------------------------------------------------------------------------------------
444 // Public methods
445 // -----------------------------------------------------------------------------------------------
446
447 /**
448 * Makes the given visitor visit the JVMS ClassFile structure passed to the constructor of this
449 * {@link ClassReader}.
450 *
451 * @param classVisitor the visitor that must visit this class.
452 * @param parsingOptions the options to use to parse this class. One or more of {@link
453 * #SKIP_CODE}, {@link #SKIP_DEBUG}, {@link #SKIP_FRAMES} or {@link #EXPAND_FRAMES}.
454 */
455 public void accept(final ClassVisitor classVisitor, final int parsingOptions) {
456 accept(classVisitor, new Attribute[0], parsingOptions);
457 }
458
459 /**
460 * Makes the given visitor visit the JVMS ClassFile structure passed to the constructor of this
461 * {@link ClassReader}.
462 *
463 * @param classVisitor the visitor that must visit this class.
464 * @param attributePrototypes prototypes of the attributes that must be parsed during the visit of
465 * the class. Any attribute whose type is not equal to the type of one the prototypes will not
466 * be parsed: its byte array value will be passed unchanged to the ClassWriter. <i>This may
467 * corrupt it if this value contains references to the constant pool, or has syntactic or
468 * semantic links with a class element that has been transformed by a class adapter between
469 * the reader and the writer</i>.
470 * @param parsingOptions the options to use to parse this class. One or more of {@link
471 * #SKIP_CODE}, {@link #SKIP_DEBUG}, {@link #SKIP_FRAMES} or {@link #EXPAND_FRAMES}.
472 */
473 public void accept(
474 final ClassVisitor classVisitor,
475 final Attribute[] attributePrototypes,
476 final int parsingOptions) {
477 Context context = new Context();
478 context.attributePrototypes = attributePrototypes;
479 context.parsingOptions = parsingOptions;
480 context.charBuffer = new char[maxStringLength];
481
482 // Read the access_flags, this_class, super_class, interface_count and interfaces fields.
483 char[] charBuffer = context.charBuffer;
484 int currentOffset = header;
485 int accessFlags = readUnsignedShort(currentOffset);
486 String thisClass = readClass(currentOffset + 2, charBuffer);
487 String superClass = readClass(currentOffset + 4, charBuffer);
488 String[] interfaces = new String[readUnsignedShort(currentOffset + 6)];
489 currentOffset += 8;
490 for (int i = 0; i < interfaces.length; ++i) {
491 interfaces[i] = readClass(currentOffset, charBuffer);
492 currentOffset += 2;
493 }
494
495 // Read the class attributes (the variables are ordered as in Section 4.7 of the JVMS).
496 // Attribute offsets exclude the attribute_name_index and attribute_length fields.
497 // - The offset of the InnerClasses attribute, or 0.
498 int innerClassesOffset = 0;
499 // - The offset of the EnclosingMethod attribute, or 0.
500 int enclosingMethodOffset = 0;
501 // - The string corresponding to the Signature attribute, or null.
502 String signature = null;
503 // - The string corresponding to the SourceFile attribute, or null.
504 String sourceFile = null;
505 // - The string corresponding to the SourceDebugExtension attribute, or null.
506 String sourceDebugExtension = null;
507 // - The offset of the RuntimeVisibleAnnotations attribute, or 0.
508 int runtimeVisibleAnnotationsOffset = 0;
509 // - The offset of the RuntimeInvisibleAnnotations attribute, or 0.
510 int runtimeInvisibleAnnotationsOffset = 0;
511 // - The offset of the RuntimeVisibleTypeAnnotations attribute, or 0.
512 int runtimeVisibleTypeAnnotationsOffset = 0;
513 // - The offset of the RuntimeInvisibleTypeAnnotations attribute, or 0.
514 int runtimeInvisibleTypeAnnotationsOffset = 0;
515 // - The offset of the Module attribute, or 0.
516 int moduleOffset = 0;
517 // - The offset of the ModulePackages attribute, or 0.
518 int modulePackagesOffset = 0;
519 // - The string corresponding to the ModuleMainClass attribute, or null.
520 String moduleMainClass = null;
521 // - The string corresponding to the NestHost attribute, or null.
522 String nestHostClass = null;
523 // - The offset of the NestMembers attribute, or 0.
524 int nestMembersOffset = 0;
525 // - The offset of the PermittedSubclasses attribute, or 0
526 int permittedSubclassesOffset = 0;
527 // - The offset of the Record attribute, or 0.
528 int recordOffset = 0;
529 // - The non standard attributes (linked with their {@link Attribute#nextAttribute} field).
530 // This list in the <i>reverse order</i> or their order in the ClassFile structure.
531 Attribute attributes = null;
532
533 int currentAttributeOffset = getFirstAttributeOffset();
534 for (int i = readUnsignedShort(currentAttributeOffset - 2); i > 0; --i) {
535 // Read the attribute_info's attribute_name and attribute_length fields.
536 String attributeName = readUTF8(currentAttributeOffset, charBuffer);
537 int attributeLength = readInt(currentAttributeOffset + 2);
538 currentAttributeOffset += 6;
539 // The tests are sorted in decreasing frequency order (based on frequencies observed on
540 // typical classes).
541 if (Constants.SOURCE_FILE.equals(attributeName)) {
542 sourceFile = readUTF8(currentAttributeOffset, charBuffer);
543 } else if (Constants.INNER_CLASSES.equals(attributeName)) {
544 innerClassesOffset = currentAttributeOffset;
545 } else if (Constants.ENCLOSING_METHOD.equals(attributeName)) {
546 enclosingMethodOffset = currentAttributeOffset;
547 } else if (Constants.NEST_HOST.equals(attributeName)) {
548 nestHostClass = readClass(currentAttributeOffset, charBuffer);
549 } else if (Constants.NEST_MEMBERS.equals(attributeName)) {
550 nestMembersOffset = currentAttributeOffset;
551 } else if (Constants.PERMITTED_SUBCLASSES.equals(attributeName)) {
552 permittedSubclassesOffset = currentAttributeOffset;
553 } else if (Constants.SIGNATURE.equals(attributeName)) {
554 signature = readUTF8(currentAttributeOffset, charBuffer);
555 } else if (Constants.RUNTIME_VISIBLE_ANNOTATIONS.equals(attributeName)) {
556 runtimeVisibleAnnotationsOffset = currentAttributeOffset;
557 } else if (Constants.RUNTIME_VISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
558 runtimeVisibleTypeAnnotationsOffset = currentAttributeOffset;
559 } else if (Constants.DEPRECATED.equals(attributeName)) {
560 accessFlags |= Opcodes.ACC_DEPRECATED;
561 } else if (Constants.SYNTHETIC.equals(attributeName)) {
562 accessFlags |= Opcodes.ACC_SYNTHETIC;
563 } else if (Constants.SOURCE_DEBUG_EXTENSION.equals(attributeName)) {
564 if (attributeLength > classFileBuffer.length - currentAttributeOffset) {
565 throw new IllegalArgumentException();
566 }
567 sourceDebugExtension =
568 readUtf(currentAttributeOffset, attributeLength, new char[attributeLength]);
569 } else if (Constants.RUNTIME_INVISIBLE_ANNOTATIONS.equals(attributeName)) {
570 runtimeInvisibleAnnotationsOffset = currentAttributeOffset;
571 } else if (Constants.RUNTIME_INVISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
572 runtimeInvisibleTypeAnnotationsOffset = currentAttributeOffset;
573 } else if (Constants.RECORD.equals(attributeName)) {
574 recordOffset = currentAttributeOffset;
575 accessFlags |= Opcodes.ACC_RECORD;
576 } else if (Constants.MODULE.equals(attributeName)) {
577 moduleOffset = currentAttributeOffset;
578 } else if (Constants.MODULE_MAIN_CLASS.equals(attributeName)) {
579 moduleMainClass = readClass(currentAttributeOffset, charBuffer);
580 } else if (Constants.MODULE_PACKAGES.equals(attributeName)) {
581 modulePackagesOffset = currentAttributeOffset;
582 } else if (!Constants.BOOTSTRAP_METHODS.equals(attributeName)) {
583 // The BootstrapMethods attribute is read in the constructor.
584 Attribute attribute =
585 readAttribute(
586 attributePrototypes,
587 attributeName,
588 currentAttributeOffset,
589 attributeLength,
590 charBuffer,
591 -1,
592 null);
593 attribute.nextAttribute = attributes;
594 attributes = attribute;
595 }
596 currentAttributeOffset += attributeLength;
597 }
598
599 // Visit the class declaration. The minor_version and major_version fields start 6 bytes before
600 // the first constant pool entry, which itself starts at cpInfoOffsets[1] - 1 (by definition).
601 classVisitor.visit(
602 readInt(cpInfoOffsets[1] - 7), accessFlags, thisClass, signature, superClass, interfaces);
603
604 // Visit the SourceFile and SourceDebugExtenstion attributes.
605 if ((parsingOptions & SKIP_DEBUG) == 0
606 && (sourceFile != null || sourceDebugExtension != null)) {
607 classVisitor.visitSource(sourceFile, sourceDebugExtension);
608 }
609
610 // Visit the Module, ModulePackages and ModuleMainClass attributes.
611 if (moduleOffset != 0) {
612 readModuleAttributes(
613 classVisitor, context, moduleOffset, modulePackagesOffset, moduleMainClass);
614 }
615
616 // Visit the NestHost attribute.
617 if (nestHostClass != null) {
618 classVisitor.visitNestHost(nestHostClass);
619 }
620
621 // Visit the EnclosingMethod attribute.
622 if (enclosingMethodOffset != 0) {
623 String className = readClass(enclosingMethodOffset, charBuffer);
624 int methodIndex = readUnsignedShort(enclosingMethodOffset + 2);
625 String name = methodIndex == 0 ? null : readUTF8(cpInfoOffsets[methodIndex], charBuffer);
626 String type = methodIndex == 0 ? null : readUTF8(cpInfoOffsets[methodIndex] + 2, charBuffer);
627 classVisitor.visitOuterClass(className, name, type);
628 }
629
630 // Visit the RuntimeVisibleAnnotations attribute.
631 if (runtimeVisibleAnnotationsOffset != 0) {
632 int numAnnotations = readUnsignedShort(runtimeVisibleAnnotationsOffset);
633 int currentAnnotationOffset = runtimeVisibleAnnotationsOffset + 2;
634 while (numAnnotations-- > 0) {
635 // Parse the type_index field.
636 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
637 currentAnnotationOffset += 2;
638 // Parse num_element_value_pairs and element_value_pairs and visit these values.
639 currentAnnotationOffset =
640 readElementValues(
641 classVisitor.visitAnnotation(annotationDescriptor, /* visible = */ true),
642 currentAnnotationOffset,
643 /* named = */ true,
644 charBuffer);
645 }
646 }
647
648 // Visit the RuntimeInvisibleAnnotations attribute.
649 if (runtimeInvisibleAnnotationsOffset != 0) {
650 int numAnnotations = readUnsignedShort(runtimeInvisibleAnnotationsOffset);
651 int currentAnnotationOffset = runtimeInvisibleAnnotationsOffset + 2;
652 while (numAnnotations-- > 0) {
653 // Parse the type_index field.
654 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
655 currentAnnotationOffset += 2;
656 // Parse num_element_value_pairs and element_value_pairs and visit these values.
657 currentAnnotationOffset =
658 readElementValues(
659 classVisitor.visitAnnotation(annotationDescriptor, /* visible = */ false),
660 currentAnnotationOffset,
661 /* named = */ true,
662 charBuffer);
663 }
664 }
665
666 // Visit the RuntimeVisibleTypeAnnotations attribute.
667 if (runtimeVisibleTypeAnnotationsOffset != 0) {
668 int numAnnotations = readUnsignedShort(runtimeVisibleTypeAnnotationsOffset);
669 int currentAnnotationOffset = runtimeVisibleTypeAnnotationsOffset + 2;
670 while (numAnnotations-- > 0) {
671 // Parse the target_type, target_info and target_path fields.
672 currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
673 // Parse the type_index field.
674 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
675 currentAnnotationOffset += 2;
676 // Parse num_element_value_pairs and element_value_pairs and visit these values.
677 currentAnnotationOffset =
678 readElementValues(
679 classVisitor.visitTypeAnnotation(
680 context.currentTypeAnnotationTarget,
681 context.currentTypeAnnotationTargetPath,
682 annotationDescriptor,
683 /* visible = */ true),
684 currentAnnotationOffset,
685 /* named = */ true,
686 charBuffer);
687 }
688 }
689
690 // Visit the RuntimeInvisibleTypeAnnotations attribute.
691 if (runtimeInvisibleTypeAnnotationsOffset != 0) {
692 int numAnnotations = readUnsignedShort(runtimeInvisibleTypeAnnotationsOffset);
693 int currentAnnotationOffset = runtimeInvisibleTypeAnnotationsOffset + 2;
694 while (numAnnotations-- > 0) {
695 // Parse the target_type, target_info and target_path fields.
696 currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
697 // Parse the type_index field.
698 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
699 currentAnnotationOffset += 2;
700 // Parse num_element_value_pairs and element_value_pairs and visit these values.
701 currentAnnotationOffset =
702 readElementValues(
703 classVisitor.visitTypeAnnotation(
704 context.currentTypeAnnotationTarget,
705 context.currentTypeAnnotationTargetPath,
706 annotationDescriptor,
707 /* visible = */ false),
708 currentAnnotationOffset,
709 /* named = */ true,
710 charBuffer);
711 }
712 }
713
714 // Visit the non standard attributes.
715 while (attributes != null) {
716 // Copy and reset the nextAttribute field so that it can also be used in ClassWriter.
717 Attribute nextAttribute = attributes.nextAttribute;
718 attributes.nextAttribute = null;
719 classVisitor.visitAttribute(attributes);
720 attributes = nextAttribute;
721 }
722
723 // Visit the NestedMembers attribute.
724 if (nestMembersOffset != 0) {
725 int numberOfNestMembers = readUnsignedShort(nestMembersOffset);
726 int currentNestMemberOffset = nestMembersOffset + 2;
727 while (numberOfNestMembers-- > 0) {
728 classVisitor.visitNestMember(readClass(currentNestMemberOffset, charBuffer));
729 currentNestMemberOffset += 2;
730 }
731 }
732
733 // Visit the PermittedSubclasses attribute.
734 if (permittedSubclassesOffset != 0) {
735 int numberOfPermittedSubclasses = readUnsignedShort(permittedSubclassesOffset);
736 int currentPermittedSubclassesOffset = permittedSubclassesOffset + 2;
737 while (numberOfPermittedSubclasses-- > 0) {
738 classVisitor.visitPermittedSubclass(
739 readClass(currentPermittedSubclassesOffset, charBuffer));
740 currentPermittedSubclassesOffset += 2;
741 }
742 }
743
744 // Visit the InnerClasses attribute.
745 if (innerClassesOffset != 0) {
746 int numberOfClasses = readUnsignedShort(innerClassesOffset);
747 int currentClassesOffset = innerClassesOffset + 2;
748 while (numberOfClasses-- > 0) {
749 classVisitor.visitInnerClass(
750 readClass(currentClassesOffset, charBuffer),
751 readClass(currentClassesOffset + 2, charBuffer),
752 readUTF8(currentClassesOffset + 4, charBuffer),
753 readUnsignedShort(currentClassesOffset + 6));
754 currentClassesOffset += 8;
755 }
756 }
757
758 // Visit Record components.
759 if (recordOffset != 0) {
760 int recordComponentsCount = readUnsignedShort(recordOffset);
761 recordOffset += 2;
762 while (recordComponentsCount-- > 0) {
763 recordOffset = readRecordComponent(classVisitor, context, recordOffset);
764 }
765 }
766
767 // Visit the fields and methods.
768 int fieldsCount = readUnsignedShort(currentOffset);
769 currentOffset += 2;
770 while (fieldsCount-- > 0) {
771 currentOffset = readField(classVisitor, context, currentOffset);
772 }
773 int methodsCount = readUnsignedShort(currentOffset);
774 currentOffset += 2;
775 while (methodsCount-- > 0) {
776 currentOffset = readMethod(classVisitor, context, currentOffset);
777 }
778
779 // Visit the end of the class.
780 classVisitor.visitEnd();
781 }
782
783 // ----------------------------------------------------------------------------------------------
784 // Methods to parse modules, fields and methods
785 // ----------------------------------------------------------------------------------------------
786
787 /**
788 * Reads the Module, ModulePackages and ModuleMainClass attributes and visit them.
789 *
790 * @param classVisitor the current class visitor
791 * @param context information about the class being parsed.
792 * @param moduleOffset the offset of the Module attribute (excluding the attribute_info's
793 * attribute_name_index and attribute_length fields).
794 * @param modulePackagesOffset the offset of the ModulePackages attribute (excluding the
795 * attribute_info's attribute_name_index and attribute_length fields), or 0.
796 * @param moduleMainClass the string corresponding to the ModuleMainClass attribute, or {@literal
797 * null}.
798 */
799 private void readModuleAttributes(
800 final ClassVisitor classVisitor,
801 final Context context,
802 final int moduleOffset,
803 final int modulePackagesOffset,
804 final String moduleMainClass) {
805 char[] buffer = context.charBuffer;
806
807 // Read the module_name_index, module_flags and module_version_index fields and visit them.
808 int currentOffset = moduleOffset;
809 String moduleName = readModule(currentOffset, buffer);
810 int moduleFlags = readUnsignedShort(currentOffset + 2);
811 String moduleVersion = readUTF8(currentOffset + 4, buffer);
812 currentOffset += 6;
813 ModuleVisitor moduleVisitor = classVisitor.visitModule(moduleName, moduleFlags, moduleVersion);
814 if (moduleVisitor == null) {
815 return;
816 }
817
818 // Visit the ModuleMainClass attribute.
819 if (moduleMainClass != null) {
820 moduleVisitor.visitMainClass(moduleMainClass);
821 }
822
823 // Visit the ModulePackages attribute.
824 if (modulePackagesOffset != 0) {
825 int packageCount = readUnsignedShort(modulePackagesOffset);
826 int currentPackageOffset = modulePackagesOffset + 2;
827 while (packageCount-- > 0) {
828 moduleVisitor.visitPackage(readPackage(currentPackageOffset, buffer));
829 currentPackageOffset += 2;
830 }
831 }
832
833 // Read the 'requires_count' and 'requires' fields.
834 int requiresCount = readUnsignedShort(currentOffset);
835 currentOffset += 2;
836 while (requiresCount-- > 0) {
837 // Read the requires_index, requires_flags and requires_version fields and visit them.
838 String requires = readModule(currentOffset, buffer);
839 int requiresFlags = readUnsignedShort(currentOffset + 2);
840 String requiresVersion = readUTF8(currentOffset + 4, buffer);
841 currentOffset += 6;
842 moduleVisitor.visitRequire(requires, requiresFlags, requiresVersion);
843 }
844
845 // Read the 'exports_count' and 'exports' fields.
846 int exportsCount = readUnsignedShort(currentOffset);
847 currentOffset += 2;
848 while (exportsCount-- > 0) {
849 // Read the exports_index, exports_flags, exports_to_count and exports_to_index fields
850 // and visit them.
851 String exports = readPackage(currentOffset, buffer);
852 int exportsFlags = readUnsignedShort(currentOffset + 2);
853 int exportsToCount = readUnsignedShort(currentOffset + 4);
854 currentOffset += 6;
855 String[] exportsTo = null;
856 if (exportsToCount != 0) {
857 exportsTo = new String[exportsToCount];
858 for (int i = 0; i < exportsToCount; ++i) {
859 exportsTo[i] = readModule(currentOffset, buffer);
860 currentOffset += 2;
861 }
862 }
863 moduleVisitor.visitExport(exports, exportsFlags, exportsTo);
864 }
865
866 // Reads the 'opens_count' and 'opens' fields.
867 int opensCount = readUnsignedShort(currentOffset);
868 currentOffset += 2;
869 while (opensCount-- > 0) {
870 // Read the opens_index, opens_flags, opens_to_count and opens_to_index fields and visit them.
871 String opens = readPackage(currentOffset, buffer);
872 int opensFlags = readUnsignedShort(currentOffset + 2);
873 int opensToCount = readUnsignedShort(currentOffset + 4);
874 currentOffset += 6;
875 String[] opensTo = null;
876 if (opensToCount != 0) {
877 opensTo = new String[opensToCount];
878 for (int i = 0; i < opensToCount; ++i) {
879 opensTo[i] = readModule(currentOffset, buffer);
880 currentOffset += 2;
881 }
882 }
883 moduleVisitor.visitOpen(opens, opensFlags, opensTo);
884 }
885
886 // Read the 'uses_count' and 'uses' fields.
887 int usesCount = readUnsignedShort(currentOffset);
888 currentOffset += 2;
889 while (usesCount-- > 0) {
890 moduleVisitor.visitUse(readClass(currentOffset, buffer));
891 currentOffset += 2;
892 }
893
894 // Read the 'provides_count' and 'provides' fields.
895 int providesCount = readUnsignedShort(currentOffset);
896 currentOffset += 2;
897 while (providesCount-- > 0) {
898 // Read the provides_index, provides_with_count and provides_with_index fields and visit them.
899 String provides = readClass(currentOffset, buffer);
900 int providesWithCount = readUnsignedShort(currentOffset + 2);
901 currentOffset += 4;
902 String[] providesWith = new String[providesWithCount];
903 for (int i = 0; i < providesWithCount; ++i) {
904 providesWith[i] = readClass(currentOffset, buffer);
905 currentOffset += 2;
906 }
907 moduleVisitor.visitProvide(provides, providesWith);
908 }
909
910 // Visit the end of the module attributes.
911 moduleVisitor.visitEnd();
912 }
913
914 /**
915 * Reads a record component and visit it.
916 *
917 * @param classVisitor the current class visitor
918 * @param context information about the class being parsed.
919 * @param recordComponentOffset the offset of the current record component.
920 * @return the offset of the first byte following the record component.
921 */
922 private int readRecordComponent(
923 final ClassVisitor classVisitor, final Context context, final int recordComponentOffset) {
924 char[] charBuffer = context.charBuffer;
925
926 int currentOffset = recordComponentOffset;
927 String name = readUTF8(currentOffset, charBuffer);
928 String descriptor = readUTF8(currentOffset + 2, charBuffer);
929 currentOffset += 4;
930
931 // Read the record component attributes (the variables are ordered as in Section 4.7 of the
932 // JVMS).
933
934 // Attribute offsets exclude the attribute_name_index and attribute_length fields.
935 // - The string corresponding to the Signature attribute, or null.
936 String signature = null;
937 // - The offset of the RuntimeVisibleAnnotations attribute, or 0.
938 int runtimeVisibleAnnotationsOffset = 0;
939 // - The offset of the RuntimeInvisibleAnnotations attribute, or 0.
940 int runtimeInvisibleAnnotationsOffset = 0;
941 // - The offset of the RuntimeVisibleTypeAnnotations attribute, or 0.
942 int runtimeVisibleTypeAnnotationsOffset = 0;
943 // - The offset of the RuntimeInvisibleTypeAnnotations attribute, or 0.
944 int runtimeInvisibleTypeAnnotationsOffset = 0;
945 // - The non standard attributes (linked with their {@link Attribute#nextAttribute} field).
946 // This list in the <i>reverse order</i> or their order in the ClassFile structure.
947 Attribute attributes = null;
948
949 int attributesCount = readUnsignedShort(currentOffset);
950 currentOffset += 2;
951 while (attributesCount-- > 0) {
952 // Read the attribute_info's attribute_name and attribute_length fields.
953 String attributeName = readUTF8(currentOffset, charBuffer);
954 int attributeLength = readInt(currentOffset + 2);
955 currentOffset += 6;
956 // The tests are sorted in decreasing frequency order (based on frequencies observed on
957 // typical classes).
958 if (Constants.SIGNATURE.equals(attributeName)) {
959 signature = readUTF8(currentOffset, charBuffer);
960 } else if (Constants.RUNTIME_VISIBLE_ANNOTATIONS.equals(attributeName)) {
961 runtimeVisibleAnnotationsOffset = currentOffset;
962 } else if (Constants.RUNTIME_VISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
963 runtimeVisibleTypeAnnotationsOffset = currentOffset;
964 } else if (Constants.RUNTIME_INVISIBLE_ANNOTATIONS.equals(attributeName)) {
965 runtimeInvisibleAnnotationsOffset = currentOffset;
966 } else if (Constants.RUNTIME_INVISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
967 runtimeInvisibleTypeAnnotationsOffset = currentOffset;
968 } else {
969 Attribute attribute =
970 readAttribute(
971 context.attributePrototypes,
972 attributeName,
973 currentOffset,
974 attributeLength,
975 charBuffer,
976 -1,
977 null);
978 attribute.nextAttribute = attributes;
979 attributes = attribute;
980 }
981 currentOffset += attributeLength;
982 }
983
984 RecordComponentVisitor recordComponentVisitor =
985 classVisitor.visitRecordComponent(name, descriptor, signature);
986 if (recordComponentVisitor == null) {
987 return currentOffset;
988 }
989
990 // Visit the RuntimeVisibleAnnotations attribute.
991 if (runtimeVisibleAnnotationsOffset != 0) {
992 int numAnnotations = readUnsignedShort(runtimeVisibleAnnotationsOffset);
993 int currentAnnotationOffset = runtimeVisibleAnnotationsOffset + 2;
994 while (numAnnotations-- > 0) {
995 // Parse the type_index field.
996 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
997 currentAnnotationOffset += 2;
998 // Parse num_element_value_pairs and element_value_pairs and visit these values.
999 currentAnnotationOffset =
1000 readElementValues(
1001 recordComponentVisitor.visitAnnotation(annotationDescriptor, /* visible = */ true),
1002 currentAnnotationOffset,
1003 /* named = */ true,
1004 charBuffer);
1005 }
1006 }
1007
1008 // Visit the RuntimeInvisibleAnnotations attribute.
1009 if (runtimeInvisibleAnnotationsOffset != 0) {
1010 int numAnnotations = readUnsignedShort(runtimeInvisibleAnnotationsOffset);
1011 int currentAnnotationOffset = runtimeInvisibleAnnotationsOffset + 2;
1012 while (numAnnotations-- > 0) {
1013 // Parse the type_index field.
1014 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1015 currentAnnotationOffset += 2;
1016 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1017 currentAnnotationOffset =
1018 readElementValues(
1019 recordComponentVisitor.visitAnnotation(annotationDescriptor, /* visible = */ false),
1020 currentAnnotationOffset,
1021 /* named = */ true,
1022 charBuffer);
1023 }
1024 }
1025
1026 // Visit the RuntimeVisibleTypeAnnotations attribute.
1027 if (runtimeVisibleTypeAnnotationsOffset != 0) {
1028 int numAnnotations = readUnsignedShort(runtimeVisibleTypeAnnotationsOffset);
1029 int currentAnnotationOffset = runtimeVisibleTypeAnnotationsOffset + 2;
1030 while (numAnnotations-- > 0) {
1031 // Parse the target_type, target_info and target_path fields.
1032 currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
1033 // Parse the type_index field.
1034 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1035 currentAnnotationOffset += 2;
1036 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1037 currentAnnotationOffset =
1038 readElementValues(
1039 recordComponentVisitor.visitTypeAnnotation(
1040 context.currentTypeAnnotationTarget,
1041 context.currentTypeAnnotationTargetPath,
1042 annotationDescriptor,
1043 /* visible = */ true),
1044 currentAnnotationOffset,
1045 /* named = */ true,
1046 charBuffer);
1047 }
1048 }
1049
1050 // Visit the RuntimeInvisibleTypeAnnotations attribute.
1051 if (runtimeInvisibleTypeAnnotationsOffset != 0) {
1052 int numAnnotations = readUnsignedShort(runtimeInvisibleTypeAnnotationsOffset);
1053 int currentAnnotationOffset = runtimeInvisibleTypeAnnotationsOffset + 2;
1054 while (numAnnotations-- > 0) {
1055 // Parse the target_type, target_info and target_path fields.
1056 currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
1057 // Parse the type_index field.
1058 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1059 currentAnnotationOffset += 2;
1060 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1061 currentAnnotationOffset =
1062 readElementValues(
1063 recordComponentVisitor.visitTypeAnnotation(
1064 context.currentTypeAnnotationTarget,
1065 context.currentTypeAnnotationTargetPath,
1066 annotationDescriptor,
1067 /* visible = */ false),
1068 currentAnnotationOffset,
1069 /* named = */ true,
1070 charBuffer);
1071 }
1072 }
1073
1074 // Visit the non standard attributes.
1075 while (attributes != null) {
1076 // Copy and reset the nextAttribute field so that it can also be used in FieldWriter.
1077 Attribute nextAttribute = attributes.nextAttribute;
1078 attributes.nextAttribute = null;
1079 recordComponentVisitor.visitAttribute(attributes);
1080 attributes = nextAttribute;
1081 }
1082
1083 // Visit the end of the field.
1084 recordComponentVisitor.visitEnd();
1085 return currentOffset;
1086 }
1087
1088 /**
1089 * Reads a JVMS field_info structure and makes the given visitor visit it.
1090 *
1091 * @param classVisitor the visitor that must visit the field.
1092 * @param context information about the class being parsed.
1093 * @param fieldInfoOffset the start offset of the field_info structure.
1094 * @return the offset of the first byte following the field_info structure.
1095 */
1096 private int readField(
1097 final ClassVisitor classVisitor, final Context context, final int fieldInfoOffset) {
1098 char[] charBuffer = context.charBuffer;
1099
1100 // Read the access_flags, name_index and descriptor_index fields.
1101 int currentOffset = fieldInfoOffset;
1102 int accessFlags = readUnsignedShort(currentOffset);
1103 String name = readUTF8(currentOffset + 2, charBuffer);
1104 String descriptor = readUTF8(currentOffset + 4, charBuffer);
1105 currentOffset += 6;
1106
1107 // Read the field attributes (the variables are ordered as in Section 4.7 of the JVMS).
1108 // Attribute offsets exclude the attribute_name_index and attribute_length fields.
1109 // - The value corresponding to the ConstantValue attribute, or null.
1110 Object constantValue = null;
1111 // - The string corresponding to the Signature attribute, or null.
1112 String signature = null;
1113 // - The offset of the RuntimeVisibleAnnotations attribute, or 0.
1114 int runtimeVisibleAnnotationsOffset = 0;
1115 // - The offset of the RuntimeInvisibleAnnotations attribute, or 0.
1116 int runtimeInvisibleAnnotationsOffset = 0;
1117 // - The offset of the RuntimeVisibleTypeAnnotations attribute, or 0.
1118 int runtimeVisibleTypeAnnotationsOffset = 0;
1119 // - The offset of the RuntimeInvisibleTypeAnnotations attribute, or 0.
1120 int runtimeInvisibleTypeAnnotationsOffset = 0;
1121 // - The non standard attributes (linked with their {@link Attribute#nextAttribute} field).
1122 // This list in the <i>reverse order</i> or their order in the ClassFile structure.
1123 Attribute attributes = null;
1124
1125 int attributesCount = readUnsignedShort(currentOffset);
1126 currentOffset += 2;
1127 while (attributesCount-- > 0) {
1128 // Read the attribute_info's attribute_name and attribute_length fields.
1129 String attributeName = readUTF8(currentOffset, charBuffer);
1130 int attributeLength = readInt(currentOffset + 2);
1131 currentOffset += 6;
1132 // The tests are sorted in decreasing frequency order (based on frequencies observed on
1133 // typical classes).
1134 if (Constants.CONSTANT_VALUE.equals(attributeName)) {
1135 int constantvalueIndex = readUnsignedShort(currentOffset);
1136 constantValue = constantvalueIndex == 0 ? null : readConst(constantvalueIndex, charBuffer);
1137 } else if (Constants.SIGNATURE.equals(attributeName)) {
1138 signature = readUTF8(currentOffset, charBuffer);
1139 } else if (Constants.DEPRECATED.equals(attributeName)) {
1140 accessFlags |= Opcodes.ACC_DEPRECATED;
1141 } else if (Constants.SYNTHETIC.equals(attributeName)) {
1142 accessFlags |= Opcodes.ACC_SYNTHETIC;
1143 } else if (Constants.RUNTIME_VISIBLE_ANNOTATIONS.equals(attributeName)) {
1144 runtimeVisibleAnnotationsOffset = currentOffset;
1145 } else if (Constants.RUNTIME_VISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
1146 runtimeVisibleTypeAnnotationsOffset = currentOffset;
1147 } else if (Constants.RUNTIME_INVISIBLE_ANNOTATIONS.equals(attributeName)) {
1148 runtimeInvisibleAnnotationsOffset = currentOffset;
1149 } else if (Constants.RUNTIME_INVISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
1150 runtimeInvisibleTypeAnnotationsOffset = currentOffset;
1151 } else {
1152 Attribute attribute =
1153 readAttribute(
1154 context.attributePrototypes,
1155 attributeName,
1156 currentOffset,
1157 attributeLength,
1158 charBuffer,
1159 -1,
1160 null);
1161 attribute.nextAttribute = attributes;
1162 attributes = attribute;
1163 }
1164 currentOffset += attributeLength;
1165 }
1166
1167 // Visit the field declaration.
1168 FieldVisitor fieldVisitor =
1169 classVisitor.visitField(accessFlags, name, descriptor, signature, constantValue);
1170 if (fieldVisitor == null) {
1171 return currentOffset;
1172 }
1173
1174 // Visit the RuntimeVisibleAnnotations attribute.
1175 if (runtimeVisibleAnnotationsOffset != 0) {
1176 int numAnnotations = readUnsignedShort(runtimeVisibleAnnotationsOffset);
1177 int currentAnnotationOffset = runtimeVisibleAnnotationsOffset + 2;
1178 while (numAnnotations-- > 0) {
1179 // Parse the type_index field.
1180 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1181 currentAnnotationOffset += 2;
1182 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1183 currentAnnotationOffset =
1184 readElementValues(
1185 fieldVisitor.visitAnnotation(annotationDescriptor, /* visible = */ true),
1186 currentAnnotationOffset,
1187 /* named = */ true,
1188 charBuffer);
1189 }
1190 }
1191
1192 // Visit the RuntimeInvisibleAnnotations attribute.
1193 if (runtimeInvisibleAnnotationsOffset != 0) {
1194 int numAnnotations = readUnsignedShort(runtimeInvisibleAnnotationsOffset);
1195 int currentAnnotationOffset = runtimeInvisibleAnnotationsOffset + 2;
1196 while (numAnnotations-- > 0) {
1197 // Parse the type_index field.
1198 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1199 currentAnnotationOffset += 2;
1200 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1201 currentAnnotationOffset =
1202 readElementValues(
1203 fieldVisitor.visitAnnotation(annotationDescriptor, /* visible = */ false),
1204 currentAnnotationOffset,
1205 /* named = */ true,
1206 charBuffer);
1207 }
1208 }
1209
1210 // Visit the RuntimeVisibleTypeAnnotations attribute.
1211 if (runtimeVisibleTypeAnnotationsOffset != 0) {
1212 int numAnnotations = readUnsignedShort(runtimeVisibleTypeAnnotationsOffset);
1213 int currentAnnotationOffset = runtimeVisibleTypeAnnotationsOffset + 2;
1214 while (numAnnotations-- > 0) {
1215 // Parse the target_type, target_info and target_path fields.
1216 currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
1217 // Parse the type_index field.
1218 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1219 currentAnnotationOffset += 2;
1220 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1221 currentAnnotationOffset =
1222 readElementValues(
1223 fieldVisitor.visitTypeAnnotation(
1224 context.currentTypeAnnotationTarget,
1225 context.currentTypeAnnotationTargetPath,
1226 annotationDescriptor,
1227 /* visible = */ true),
1228 currentAnnotationOffset,
1229 /* named = */ true,
1230 charBuffer);
1231 }
1232 }
1233
1234 // Visit the RuntimeInvisibleTypeAnnotations attribute.
1235 if (runtimeInvisibleTypeAnnotationsOffset != 0) {
1236 int numAnnotations = readUnsignedShort(runtimeInvisibleTypeAnnotationsOffset);
1237 int currentAnnotationOffset = runtimeInvisibleTypeAnnotationsOffset + 2;
1238 while (numAnnotations-- > 0) {
1239 // Parse the target_type, target_info and target_path fields.
1240 currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
1241 // Parse the type_index field.
1242 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1243 currentAnnotationOffset += 2;
1244 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1245 currentAnnotationOffset =
1246 readElementValues(
1247 fieldVisitor.visitTypeAnnotation(
1248 context.currentTypeAnnotationTarget,
1249 context.currentTypeAnnotationTargetPath,
1250 annotationDescriptor,
1251 /* visible = */ false),
1252 currentAnnotationOffset,
1253 /* named = */ true,
1254 charBuffer);
1255 }
1256 }
1257
1258 // Visit the non standard attributes.
1259 while (attributes != null) {
1260 // Copy and reset the nextAttribute field so that it can also be used in FieldWriter.
1261 Attribute nextAttribute = attributes.nextAttribute;
1262 attributes.nextAttribute = null;
1263 fieldVisitor.visitAttribute(attributes);
1264 attributes = nextAttribute;
1265 }
1266
1267 // Visit the end of the field.
1268 fieldVisitor.visitEnd();
1269 return currentOffset;
1270 }
1271
1272 /**
1273 * Reads a JVMS method_info structure and makes the given visitor visit it.
1274 *
1275 * @param classVisitor the visitor that must visit the method.
1276 * @param context information about the class being parsed.
1277 * @param methodInfoOffset the start offset of the method_info structure.
1278 * @return the offset of the first byte following the method_info structure.
1279 */
1280 private int readMethod(
1281 final ClassVisitor classVisitor, final Context context, final int methodInfoOffset) {
1282 char[] charBuffer = context.charBuffer;
1283
1284 // Read the access_flags, name_index and descriptor_index fields.
1285 int currentOffset = methodInfoOffset;
1286 context.currentMethodAccessFlags = readUnsignedShort(currentOffset);
1287 context.currentMethodName = readUTF8(currentOffset + 2, charBuffer);
1288 context.currentMethodDescriptor = readUTF8(currentOffset + 4, charBuffer);
1289 currentOffset += 6;
1290
1291 // Read the method attributes (the variables are ordered as in Section 4.7 of the JVMS).
1292 // Attribute offsets exclude the attribute_name_index and attribute_length fields.
1293 // - The offset of the Code attribute, or 0.
1294 int codeOffset = 0;
1295 // - The offset of the Exceptions attribute, or 0.
1296 int exceptionsOffset = 0;
1297 // - The strings corresponding to the Exceptions attribute, or null.
1298 String[] exceptions = null;
1299 // - Whether the method has a Synthetic attribute.
1300 boolean synthetic = false;
1301 // - The constant pool index contained in the Signature attribute, or 0.
1302 int signatureIndex = 0;
1303 // - The offset of the RuntimeVisibleAnnotations attribute, or 0.
1304 int runtimeVisibleAnnotationsOffset = 0;
1305 // - The offset of the RuntimeInvisibleAnnotations attribute, or 0.
1306 int runtimeInvisibleAnnotationsOffset = 0;
1307 // - The offset of the RuntimeVisibleParameterAnnotations attribute, or 0.
1308 int runtimeVisibleParameterAnnotationsOffset = 0;
1309 // - The offset of the RuntimeInvisibleParameterAnnotations attribute, or 0.
1310 int runtimeInvisibleParameterAnnotationsOffset = 0;
1311 // - The offset of the RuntimeVisibleTypeAnnotations attribute, or 0.
1312 int runtimeVisibleTypeAnnotationsOffset = 0;
1313 // - The offset of the RuntimeInvisibleTypeAnnotations attribute, or 0.
1314 int runtimeInvisibleTypeAnnotationsOffset = 0;
1315 // - The offset of the AnnotationDefault attribute, or 0.
1316 int annotationDefaultOffset = 0;
1317 // - The offset of the MethodParameters attribute, or 0.
1318 int methodParametersOffset = 0;
1319 // - The non standard attributes (linked with their {@link Attribute#nextAttribute} field).
1320 // This list in the <i>reverse order</i> or their order in the ClassFile structure.
1321 Attribute attributes = null;
1322
1323 int attributesCount = readUnsignedShort(currentOffset);
1324 currentOffset += 2;
1325 while (attributesCount-- > 0) {
1326 // Read the attribute_info's attribute_name and attribute_length fields.
1327 String attributeName = readUTF8(currentOffset, charBuffer);
1328 int attributeLength = readInt(currentOffset + 2);
1329 currentOffset += 6;
1330 // The tests are sorted in decreasing frequency order (based on frequencies observed on
1331 // typical classes).
1332 if (Constants.CODE.equals(attributeName)) {
1333 if ((context.parsingOptions & SKIP_CODE) == 0) {
1334 codeOffset = currentOffset;
1335 }
1336 } else if (Constants.EXCEPTIONS.equals(attributeName)) {
1337 exceptionsOffset = currentOffset;
1338 exceptions = new String[readUnsignedShort(exceptionsOffset)];
1339 int currentExceptionOffset = exceptionsOffset + 2;
1340 for (int i = 0; i < exceptions.length; ++i) {
1341 exceptions[i] = readClass(currentExceptionOffset, charBuffer);
1342 currentExceptionOffset += 2;
1343 }
1344 } else if (Constants.SIGNATURE.equals(attributeName)) {
1345 signatureIndex = readUnsignedShort(currentOffset);
1346 } else if (Constants.DEPRECATED.equals(attributeName)) {
1347 context.currentMethodAccessFlags |= Opcodes.ACC_DEPRECATED;
1348 } else if (Constants.RUNTIME_VISIBLE_ANNOTATIONS.equals(attributeName)) {
1349 runtimeVisibleAnnotationsOffset = currentOffset;
1350 } else if (Constants.RUNTIME_VISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
1351 runtimeVisibleTypeAnnotationsOffset = currentOffset;
1352 } else if (Constants.ANNOTATION_DEFAULT.equals(attributeName)) {
1353 annotationDefaultOffset = currentOffset;
1354 } else if (Constants.SYNTHETIC.equals(attributeName)) {
1355 synthetic = true;
1356 context.currentMethodAccessFlags |= Opcodes.ACC_SYNTHETIC;
1357 } else if (Constants.RUNTIME_INVISIBLE_ANNOTATIONS.equals(attributeName)) {
1358 runtimeInvisibleAnnotationsOffset = currentOffset;
1359 } else if (Constants.RUNTIME_INVISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
1360 runtimeInvisibleTypeAnnotationsOffset = currentOffset;
1361 } else if (Constants.RUNTIME_VISIBLE_PARAMETER_ANNOTATIONS.equals(attributeName)) {
1362 runtimeVisibleParameterAnnotationsOffset = currentOffset;
1363 } else if (Constants.RUNTIME_INVISIBLE_PARAMETER_ANNOTATIONS.equals(attributeName)) {
1364 runtimeInvisibleParameterAnnotationsOffset = currentOffset;
1365 } else if (Constants.METHOD_PARAMETERS.equals(attributeName)) {
1366 methodParametersOffset = currentOffset;
1367 } else {
1368 Attribute attribute =
1369 readAttribute(
1370 context.attributePrototypes,
1371 attributeName,
1372 currentOffset,
1373 attributeLength,
1374 charBuffer,
1375 -1,
1376 null);
1377 attribute.nextAttribute = attributes;
1378 attributes = attribute;
1379 }
1380 currentOffset += attributeLength;
1381 }
1382
1383 // Visit the method declaration.
1384 MethodVisitor methodVisitor =
1385 classVisitor.visitMethod(
1386 context.currentMethodAccessFlags,
1387 context.currentMethodName,
1388 context.currentMethodDescriptor,
1389 signatureIndex == 0 ? null : readUtf(signatureIndex, charBuffer),
1390 exceptions);
1391 if (methodVisitor == null) {
1392 return currentOffset;
1393 }
1394
1395 // If the returned MethodVisitor is in fact a MethodWriter, it means there is no method
1396 // adapter between the reader and the writer. In this case, it might be possible to copy
1397 // the method attributes directly into the writer. If so, return early without visiting
1398 // the content of these attributes.
1399 if (methodVisitor instanceof MethodWriter) {
1400 MethodWriter methodWriter = (MethodWriter) methodVisitor;
1401 if (methodWriter.canCopyMethodAttributes(
1402 this,
1403 synthetic,
1404 (context.currentMethodAccessFlags & Opcodes.ACC_DEPRECATED) != 0,
1405 readUnsignedShort(methodInfoOffset + 4),
1406 signatureIndex,
1407 exceptionsOffset)) {
1408 methodWriter.setMethodAttributesSource(methodInfoOffset, currentOffset - methodInfoOffset);
1409 return currentOffset;
1410 }
1411 }
1412
1413 // Visit the MethodParameters attribute.
1414 if (methodParametersOffset != 0 && (context.parsingOptions & SKIP_DEBUG) == 0) {
1415 int parametersCount = readByte(methodParametersOffset);
1416 int currentParameterOffset = methodParametersOffset + 1;
1417 while (parametersCount-- > 0) {
1418 // Read the name_index and access_flags fields and visit them.
1419 methodVisitor.visitParameter(
1420 readUTF8(currentParameterOffset, charBuffer),
1421 readUnsignedShort(currentParameterOffset + 2));
1422 currentParameterOffset += 4;
1423 }
1424 }
1425
1426 // Visit the AnnotationDefault attribute.
1427 if (annotationDefaultOffset != 0) {
1428 AnnotationVisitor annotationVisitor = methodVisitor.visitAnnotationDefault();
1429 readElementValue(annotationVisitor, annotationDefaultOffset, null, charBuffer);
1430 if (annotationVisitor != null) {
1431 annotationVisitor.visitEnd();
1432 }
1433 }
1434
1435 // Visit the RuntimeVisibleAnnotations attribute.
1436 if (runtimeVisibleAnnotationsOffset != 0) {
1437 int numAnnotations = readUnsignedShort(runtimeVisibleAnnotationsOffset);
1438 int currentAnnotationOffset = runtimeVisibleAnnotationsOffset + 2;
1439 while (numAnnotations-- > 0) {
1440 // Parse the type_index field.
1441 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1442 currentAnnotationOffset += 2;
1443 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1444 currentAnnotationOffset =
1445 readElementValues(
1446 methodVisitor.visitAnnotation(annotationDescriptor, /* visible = */ true),
1447 currentAnnotationOffset,
1448 /* named = */ true,
1449 charBuffer);
1450 }
1451 }
1452
1453 // Visit the RuntimeInvisibleAnnotations attribute.
1454 if (runtimeInvisibleAnnotationsOffset != 0) {
1455 int numAnnotations = readUnsignedShort(runtimeInvisibleAnnotationsOffset);
1456 int currentAnnotationOffset = runtimeInvisibleAnnotationsOffset + 2;
1457 while (numAnnotations-- > 0) {
1458 // Parse the type_index field.
1459 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1460 currentAnnotationOffset += 2;
1461 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1462 currentAnnotationOffset =
1463 readElementValues(
1464 methodVisitor.visitAnnotation(annotationDescriptor, /* visible = */ false),
1465 currentAnnotationOffset,
1466 /* named = */ true,
1467 charBuffer);
1468 }
1469 }
1470
1471 // Visit the RuntimeVisibleTypeAnnotations attribute.
1472 if (runtimeVisibleTypeAnnotationsOffset != 0) {
1473 int numAnnotations = readUnsignedShort(runtimeVisibleTypeAnnotationsOffset);
1474 int currentAnnotationOffset = runtimeVisibleTypeAnnotationsOffset + 2;
1475 while (numAnnotations-- > 0) {
1476 // Parse the target_type, target_info and target_path fields.
1477 currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
1478 // Parse the type_index field.
1479 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1480 currentAnnotationOffset += 2;
1481 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1482 currentAnnotationOffset =
1483 readElementValues(
1484 methodVisitor.visitTypeAnnotation(
1485 context.currentTypeAnnotationTarget,
1486 context.currentTypeAnnotationTargetPath,
1487 annotationDescriptor,
1488 /* visible = */ true),
1489 currentAnnotationOffset,
1490 /* named = */ true,
1491 charBuffer);
1492 }
1493 }
1494
1495 // Visit the RuntimeInvisibleTypeAnnotations attribute.
1496 if (runtimeInvisibleTypeAnnotationsOffset != 0) {
1497 int numAnnotations = readUnsignedShort(runtimeInvisibleTypeAnnotationsOffset);
1498 int currentAnnotationOffset = runtimeInvisibleTypeAnnotationsOffset + 2;
1499 while (numAnnotations-- > 0) {
1500 // Parse the target_type, target_info and target_path fields.
1501 currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
1502 // Parse the type_index field.
1503 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
1504 currentAnnotationOffset += 2;
1505 // Parse num_element_value_pairs and element_value_pairs and visit these values.
1506 currentAnnotationOffset =
1507 readElementValues(
1508 methodVisitor.visitTypeAnnotation(
1509 context.currentTypeAnnotationTarget,
1510 context.currentTypeAnnotationTargetPath,
1511 annotationDescriptor,
1512 /* visible = */ false),
1513 currentAnnotationOffset,
1514 /* named = */ true,
1515 charBuffer);
1516 }
1517 }
1518
1519 // Visit the RuntimeVisibleParameterAnnotations attribute.
1520 if (runtimeVisibleParameterAnnotationsOffset != 0) {
1521 readParameterAnnotations(
1522 methodVisitor, context, runtimeVisibleParameterAnnotationsOffset, /* visible = */ true);
1523 }
1524
1525 // Visit the RuntimeInvisibleParameterAnnotations attribute.
1526 if (runtimeInvisibleParameterAnnotationsOffset != 0) {
1527 readParameterAnnotations(
1528 methodVisitor,
1529 context,
1530 runtimeInvisibleParameterAnnotationsOffset,
1531 /* visible = */ false);
1532 }
1533
1534 // Visit the non standard attributes.
1535 while (attributes != null) {
1536 // Copy and reset the nextAttribute field so that it can also be used in MethodWriter.
1537 Attribute nextAttribute = attributes.nextAttribute;
1538 attributes.nextAttribute = null;
1539 methodVisitor.visitAttribute(attributes);
1540 attributes = nextAttribute;
1541 }
1542
1543 // Visit the Code attribute.
1544 if (codeOffset != 0) {
1545 methodVisitor.visitCode();
1546 readCode(methodVisitor, context, codeOffset);
1547 }
1548
1549 // Visit the end of the method.
1550 methodVisitor.visitEnd();
1551 return currentOffset;
1552 }
1553
1554 // ----------------------------------------------------------------------------------------------
1555 // Methods to parse a Code attribute
1556 // ----------------------------------------------------------------------------------------------
1557
1558 /**
1559 * Reads a JVMS 'Code' attribute and makes the given visitor visit it.
1560 *
1561 * @param methodVisitor the visitor that must visit the Code attribute.
1562 * @param context information about the class being parsed.
1563 * @param codeOffset the start offset in {@link #classFileBuffer} of the Code attribute, excluding
1564 * its attribute_name_index and attribute_length fields.
1565 */
1566 private void readCode(
1567 final MethodVisitor methodVisitor, final Context context, final int codeOffset) {
1568 int currentOffset = codeOffset;
1569
1570 // Read the max_stack, max_locals and code_length fields.
1571 final byte[] classBuffer = classFileBuffer;
1572 final char[] charBuffer = context.charBuffer;
1573 final int maxStack = readUnsignedShort(currentOffset);
1574 final int maxLocals = readUnsignedShort(currentOffset + 2);
1575 final int codeLength = readInt(currentOffset + 4);
1576 currentOffset += 8;
1577 if (codeLength > classFileBuffer.length - currentOffset) {
1578 throw new IllegalArgumentException();
1579 }
1580
1581 // Read the bytecode 'code' array to create a label for each referenced instruction.
1582 final int bytecodeStartOffset = currentOffset;
1583 final int bytecodeEndOffset = currentOffset + codeLength;
1584 final Label[] labels = context.currentMethodLabels = new Label[codeLength + 1];
1585 while (currentOffset < bytecodeEndOffset) {
1586 final int bytecodeOffset = currentOffset - bytecodeStartOffset;
1587 final int opcode = classBuffer[currentOffset] & 0xFF;
1588 switch (opcode) {
1589 case Opcodes.NOP:
1590 case Opcodes.ACONST_NULL:
1591 case Opcodes.ICONST_M1:
1592 case Opcodes.ICONST_0:
1593 case Opcodes.ICONST_1:
1594 case Opcodes.ICONST_2:
1595 case Opcodes.ICONST_3:
1596 case Opcodes.ICONST_4:
1597 case Opcodes.ICONST_5:
1598 case Opcodes.LCONST_0:
1599 case Opcodes.LCONST_1:
1600 case Opcodes.FCONST_0:
1601 case Opcodes.FCONST_1:
1602 case Opcodes.FCONST_2:
1603 case Opcodes.DCONST_0:
1604 case Opcodes.DCONST_1:
1605 case Opcodes.IALOAD:
1606 case Opcodes.LALOAD:
1607 case Opcodes.FALOAD:
1608 case Opcodes.DALOAD:
1609 case Opcodes.AALOAD:
1610 case Opcodes.BALOAD:
1611 case Opcodes.CALOAD:
1612 case Opcodes.SALOAD:
1613 case Opcodes.IASTORE:
1614 case Opcodes.LASTORE:
1615 case Opcodes.FASTORE:
1616 case Opcodes.DASTORE:
1617 case Opcodes.AASTORE:
1618 case Opcodes.BASTORE:
1619 case Opcodes.CASTORE:
1620 case Opcodes.SASTORE:
1621 case Opcodes.POP:
1622 case Opcodes.POP2:
1623 case Opcodes.DUP:
1624 case Opcodes.DUP_X1:
1625 case Opcodes.DUP_X2:
1626 case Opcodes.DUP2:
1627 case Opcodes.DUP2_X1:
1628 case Opcodes.DUP2_X2:
1629 case Opcodes.SWAP:
1630 case Opcodes.IADD:
1631 case Opcodes.LADD:
1632 case Opcodes.FADD:
1633 case Opcodes.DADD:
1634 case Opcodes.ISUB:
1635 case Opcodes.LSUB:
1636 case Opcodes.FSUB:
1637 case Opcodes.DSUB:
1638 case Opcodes.IMUL:
1639 case Opcodes.LMUL:
1640 case Opcodes.FMUL:
1641 case Opcodes.DMUL:
1642 case Opcodes.IDIV:
1643 case Opcodes.LDIV:
1644 case Opcodes.FDIV:
1645 case Opcodes.DDIV:
1646 case Opcodes.IREM:
1647 case Opcodes.LREM:
1648 case Opcodes.FREM:
1649 case Opcodes.DREM:
1650 case Opcodes.INEG:
1651 case Opcodes.LNEG:
1652 case Opcodes.FNEG:
1653 case Opcodes.DNEG:
1654 case Opcodes.ISHL:
1655 case Opcodes.LSHL:
1656 case Opcodes.ISHR:
1657 case Opcodes.LSHR:
1658 case Opcodes.IUSHR:
1659 case Opcodes.LUSHR:
1660 case Opcodes.IAND:
1661 case Opcodes.LAND:
1662 case Opcodes.IOR:
1663 case Opcodes.LOR:
1664 case Opcodes.IXOR:
1665 case Opcodes.LXOR:
1666 case Opcodes.I2L:
1667 case Opcodes.I2F:
1668 case Opcodes.I2D:
1669 case Opcodes.L2I:
1670 case Opcodes.L2F:
1671 case Opcodes.L2D:
1672 case Opcodes.F2I:
1673 case Opcodes.F2L:
1674 case Opcodes.F2D:
1675 case Opcodes.D2I:
1676 case Opcodes.D2L:
1677 case Opcodes.D2F:
1678 case Opcodes.I2B:
1679 case Opcodes.I2C:
1680 case Opcodes.I2S:
1681 case Opcodes.LCMP:
1682 case Opcodes.FCMPL:
1683 case Opcodes.FCMPG:
1684 case Opcodes.DCMPL:
1685 case Opcodes.DCMPG:
1686 case Opcodes.IRETURN:
1687 case Opcodes.LRETURN:
1688 case Opcodes.FRETURN:
1689 case Opcodes.DRETURN:
1690 case Opcodes.ARETURN:
1691 case Opcodes.RETURN:
1692 case Opcodes.ARRAYLENGTH:
1693 case Opcodes.ATHROW:
1694 case Opcodes.MONITORENTER:
1695 case Opcodes.MONITOREXIT:
1696 case Constants.ILOAD_0:
1697 case Constants.ILOAD_1:
1698 case Constants.ILOAD_2:
1699 case Constants.ILOAD_3:
1700 case Constants.LLOAD_0:
1701 case Constants.LLOAD_1:
1702 case Constants.LLOAD_2:
1703 case Constants.LLOAD_3:
1704 case Constants.FLOAD_0:
1705 case Constants.FLOAD_1:
1706 case Constants.FLOAD_2:
1707 case Constants.FLOAD_3:
1708 case Constants.DLOAD_0:
1709 case Constants.DLOAD_1:
1710 case Constants.DLOAD_2:
1711 case Constants.DLOAD_3:
1712 case Constants.ALOAD_0:
1713 case Constants.ALOAD_1:
1714 case Constants.ALOAD_2:
1715 case Constants.ALOAD_3:
1716 case Constants.ISTORE_0:
1717 case Constants.ISTORE_1:
1718 case Constants.ISTORE_2:
1719 case Constants.ISTORE_3:
1720 case Constants.LSTORE_0:
1721 case Constants.LSTORE_1:
1722 case Constants.LSTORE_2:
1723 case Constants.LSTORE_3:
1724 case Constants.FSTORE_0:
1725 case Constants.FSTORE_1:
1726 case Constants.FSTORE_2:
1727 case Constants.FSTORE_3:
1728 case Constants.DSTORE_0:
1729 case Constants.DSTORE_1:
1730 case Constants.DSTORE_2:
1731 case Constants.DSTORE_3:
1732 case Constants.ASTORE_0:
1733 case Constants.ASTORE_1:
1734 case Constants.ASTORE_2:
1735 case Constants.ASTORE_3:
1736 currentOffset += 1;
1737 break;
1738 case Opcodes.IFEQ:
1739 case Opcodes.IFNE:
1740 case Opcodes.IFLT:
1741 case Opcodes.IFGE:
1742 case Opcodes.IFGT:
1743 case Opcodes.IFLE:
1744 case Opcodes.IF_ICMPEQ:
1745 case Opcodes.IF_ICMPNE:
1746 case Opcodes.IF_ICMPLT:
1747 case Opcodes.IF_ICMPGE:
1748 case Opcodes.IF_ICMPGT:
1749 case Opcodes.IF_ICMPLE:
1750 case Opcodes.IF_ACMPEQ:
1751 case Opcodes.IF_ACMPNE:
1752 case Opcodes.GOTO:
1753 case Opcodes.JSR:
1754 case Opcodes.IFNULL:
1755 case Opcodes.IFNONNULL:
1756 createLabel(bytecodeOffset + readShort(currentOffset + 1), labels);
1757 currentOffset += 3;
1758 break;
1759 case Constants.ASM_IFEQ:
1760 case Constants.ASM_IFNE:
1761 case Constants.ASM_IFLT:
1762 case Constants.ASM_IFGE:
1763 case Constants.ASM_IFGT:
1764 case Constants.ASM_IFLE:
1765 case Constants.ASM_IF_ICMPEQ:
1766 case Constants.ASM_IF_ICMPNE:
1767 case Constants.ASM_IF_ICMPLT:
1768 case Constants.ASM_IF_ICMPGE:
1769 case Constants.ASM_IF_ICMPGT:
1770 case Constants.ASM_IF_ICMPLE:
1771 case Constants.ASM_IF_ACMPEQ:
1772 case Constants.ASM_IF_ACMPNE:
1773 case Constants.ASM_GOTO:
1774 case Constants.ASM_JSR:
1775 case Constants.ASM_IFNULL:
1776 case Constants.ASM_IFNONNULL:
1777 createLabel(bytecodeOffset + readUnsignedShort(currentOffset + 1), labels);
1778 currentOffset += 3;
1779 break;
1780 case Constants.GOTO_W:
1781 case Constants.JSR_W:
1782 case Constants.ASM_GOTO_W:
1783 createLabel(bytecodeOffset + readInt(currentOffset + 1), labels);
1784 currentOffset += 5;
1785 break;
1786 case Constants.WIDE:
1787 switch (classBuffer[currentOffset + 1] & 0xFF) {
1788 case Opcodes.ILOAD:
1789 case Opcodes.FLOAD:
1790 case Opcodes.ALOAD:
1791 case Opcodes.LLOAD:
1792 case Opcodes.DLOAD:
1793 case Opcodes.ISTORE:
1794 case Opcodes.FSTORE:
1795 case Opcodes.ASTORE:
1796 case Opcodes.LSTORE:
1797 case Opcodes.DSTORE:
1798 case Opcodes.RET:
1799 currentOffset += 4;
1800 break;
1801 case Opcodes.IINC:
1802 currentOffset += 6;
1803 break;
1804 default:
1805 throw new IllegalArgumentException();
1806 }
1807 break;
1808 case Opcodes.TABLESWITCH:
1809 // Skip 0 to 3 padding bytes.
1810 currentOffset += 4 - (bytecodeOffset & 3);
1811 // Read the default label and the number of table entries.
1812 createLabel(bytecodeOffset + readInt(currentOffset), labels);
1813 int numTableEntries = readInt(currentOffset + 8) - readInt(currentOffset + 4) + 1;
1814 currentOffset += 12;
1815 // Read the table labels.
1816 while (numTableEntries-- > 0) {
1817 createLabel(bytecodeOffset + readInt(currentOffset), labels);
1818 currentOffset += 4;
1819 }
1820 break;
1821 case Opcodes.LOOKUPSWITCH:
1822 // Skip 0 to 3 padding bytes.
1823 currentOffset += 4 - (bytecodeOffset & 3);
1824 // Read the default label and the number of switch cases.
1825 createLabel(bytecodeOffset + readInt(currentOffset), labels);
1826 int numSwitchCases = readInt(currentOffset + 4);
1827 currentOffset += 8;
1828 // Read the switch labels.
1829 while (numSwitchCases-- > 0) {
1830 createLabel(bytecodeOffset + readInt(currentOffset + 4), labels);
1831 currentOffset += 8;
1832 }
1833 break;
1834 case Opcodes.ILOAD:
1835 case Opcodes.LLOAD:
1836 case Opcodes.FLOAD:
1837 case Opcodes.DLOAD:
1838 case Opcodes.ALOAD:
1839 case Opcodes.ISTORE:
1840 case Opcodes.LSTORE:
1841 case Opcodes.FSTORE:
1842 case Opcodes.DSTORE:
1843 case Opcodes.ASTORE:
1844 case Opcodes.RET:
1845 case Opcodes.BIPUSH:
1846 case Opcodes.NEWARRAY:
1847 case Opcodes.LDC:
1848 currentOffset += 2;
1849 break;
1850 case Opcodes.SIPUSH:
1851 case Constants.LDC_W:
1852 case Constants.LDC2_W:
1853 case Opcodes.GETSTATIC:
1854 case Opcodes.PUTSTATIC:
1855 case Opcodes.GETFIELD:
1856 case Opcodes.PUTFIELD:
1857 case Opcodes.INVOKEVIRTUAL:
1858 case Opcodes.INVOKESPECIAL:
1859 case Opcodes.INVOKESTATIC:
1860 case Opcodes.NEW:
1861 case Opcodes.ANEWARRAY:
1862 case Opcodes.CHECKCAST:
1863 case Opcodes.INSTANCEOF:
1864 case Opcodes.IINC:
1865 currentOffset += 3;
1866 break;
1867 case Opcodes.INVOKEINTERFACE:
1868 case Opcodes.INVOKEDYNAMIC:
1869 currentOffset += 5;
1870 break;
1871 case Opcodes.MULTIANEWARRAY:
1872 currentOffset += 4;
1873 break;
1874 default:
1875 throw new IllegalArgumentException();
1876 }
1877 }
1878
1879 // Read the 'exception_table_length' and 'exception_table' field to create a label for each
1880 // referenced instruction, and to make methodVisitor visit the corresponding try catch blocks.
1881 int exceptionTableLength = readUnsignedShort(currentOffset);
1882 currentOffset += 2;
1883 while (exceptionTableLength-- > 0) {
1884 Label start = createLabel(readUnsignedShort(currentOffset), labels);
1885 Label end = createLabel(readUnsignedShort(currentOffset + 2), labels);
1886 Label handler = createLabel(readUnsignedShort(currentOffset + 4), labels);
1887 String catchType = readUTF8(cpInfoOffsets[readUnsignedShort(currentOffset + 6)], charBuffer);
1888 currentOffset += 8;
1889 methodVisitor.visitTryCatchBlock(start, end, handler, catchType);
1890 }
1891
1892 // Read the Code attributes to create a label for each referenced instruction (the variables
1893 // are ordered as in Section 4.7 of the JVMS). Attribute offsets exclude the
1894 // attribute_name_index and attribute_length fields.
1895 // - The offset of the current 'stack_map_frame' in the StackMap[Table] attribute, or 0.
1896 // Initially, this is the offset of the first 'stack_map_frame' entry. Then this offset is
1897 // updated after each stack_map_frame is read.
1898 int stackMapFrameOffset = 0;
1899 // - The end offset of the StackMap[Table] attribute, or 0.
1900 int stackMapTableEndOffset = 0;
1901 // - Whether the stack map frames are compressed (i.e. in a StackMapTable) or not.
1902 boolean compressedFrames = true;
1903 // - The offset of the LocalVariableTable attribute, or 0.
1904 int localVariableTableOffset = 0;
1905 // - The offset of the LocalVariableTypeTable attribute, or 0.
1906 int localVariableTypeTableOffset = 0;
1907 // - The offset of each 'type_annotation' entry in the RuntimeVisibleTypeAnnotations
1908 // attribute, or null.
1909 int[] visibleTypeAnnotationOffsets = null;
1910 // - The offset of each 'type_annotation' entry in the RuntimeInvisibleTypeAnnotations
1911 // attribute, or null.
1912 int[] invisibleTypeAnnotationOffsets = null;
1913 // - The non standard attributes (linked with their {@link Attribute#nextAttribute} field).
1914 // This list in the <i>reverse order</i> or their order in the ClassFile structure.
1915 Attribute attributes = null;
1916
1917 int attributesCount = readUnsignedShort(currentOffset);
1918 currentOffset += 2;
1919 while (attributesCount-- > 0) {
1920 // Read the attribute_info's attribute_name and attribute_length fields.
1921 String attributeName = readUTF8(currentOffset, charBuffer);
1922 int attributeLength = readInt(currentOffset + 2);
1923 currentOffset += 6;
1924 if (Constants.LOCAL_VARIABLE_TABLE.equals(attributeName)) {
1925 if ((context.parsingOptions & SKIP_DEBUG) == 0) {
1926 localVariableTableOffset = currentOffset;
1927 // Parse the attribute to find the corresponding (debug only) labels.
1928 int currentLocalVariableTableOffset = currentOffset;
1929 int localVariableTableLength = readUnsignedShort(currentLocalVariableTableOffset);
1930 currentLocalVariableTableOffset += 2;
1931 while (localVariableTableLength-- > 0) {
1932 int startPc = readUnsignedShort(currentLocalVariableTableOffset);
1933 createDebugLabel(startPc, labels);
1934 int length = readUnsignedShort(currentLocalVariableTableOffset + 2);
1935 createDebugLabel(startPc + length, labels);
1936 // Skip the name_index, descriptor_index and index fields (2 bytes each).
1937 currentLocalVariableTableOffset += 10;
1938 }
1939 }
1940 } else if (Constants.LOCAL_VARIABLE_TYPE_TABLE.equals(attributeName)) {
1941 localVariableTypeTableOffset = currentOffset;
1942 // Here we do not extract the labels corresponding to the attribute content. We assume they
1943 // are the same or a subset of those of the LocalVariableTable attribute.
1944 } else if (Constants.LINE_NUMBER_TABLE.equals(attributeName)) {
1945 if ((context.parsingOptions & SKIP_DEBUG) == 0) {
1946 // Parse the attribute to find the corresponding (debug only) labels.
1947 int currentLineNumberTableOffset = currentOffset;
1948 int lineNumberTableLength = readUnsignedShort(currentLineNumberTableOffset);
1949 currentLineNumberTableOffset += 2;
1950 while (lineNumberTableLength-- > 0) {
1951 int startPc = readUnsignedShort(currentLineNumberTableOffset);
1952 int lineNumber = readUnsignedShort(currentLineNumberTableOffset + 2);
1953 currentLineNumberTableOffset += 4;
1954 createDebugLabel(startPc, labels);
1955 labels[startPc].addLineNumber(lineNumber);
1956 }
1957 }
1958 } else if (Constants.RUNTIME_VISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
1959 visibleTypeAnnotationOffsets =
1960 readTypeAnnotations(methodVisitor, context, currentOffset, /* visible = */ true);
1961 // Here we do not extract the labels corresponding to the attribute content. This would
1962 // require a full parsing of the attribute, which would need to be repeated when parsing
1963 // the bytecode instructions (see below). Instead, the content of the attribute is read one
1964 // type annotation at a time (i.e. after a type annotation has been visited, the next type
1965 // annotation is read), and the labels it contains are also extracted one annotation at a
1966 // time. This assumes that type annotations are ordered by increasing bytecode offset.
1967 } else if (Constants.RUNTIME_INVISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
1968 invisibleTypeAnnotationOffsets =
1969 readTypeAnnotations(methodVisitor, context, currentOffset, /* visible = */ false);
1970 // Same comment as above for the RuntimeVisibleTypeAnnotations attribute.
1971 } else if (Constants.STACK_MAP_TABLE.equals(attributeName)) {
1972 if ((context.parsingOptions & SKIP_FRAMES) == 0) {
1973 stackMapFrameOffset = currentOffset + 2;
1974 stackMapTableEndOffset = currentOffset + attributeLength;
1975 }
1976 // Here we do not extract the labels corresponding to the attribute content. This would
1977 // require a full parsing of the attribute, which would need to be repeated when parsing
1978 // the bytecode instructions (see below). Instead, the content of the attribute is read one
1979 // frame at a time (i.e. after a frame has been visited, the next frame is read), and the
1980 // labels it contains are also extracted one frame at a time. Thanks to the ordering of
1981 // frames, having only a "one frame lookahead" is not a problem, i.e. it is not possible to
1982 // see an offset smaller than the offset of the current instruction and for which no Label
1983 // exist. Except for UNINITIALIZED type offsets. We solve this by parsing the stack map
1984 // table without a full decoding (see below).
1985 } else if ("StackMap".equals(attributeName)) {
1986 if ((context.parsingOptions & SKIP_FRAMES) == 0) {
1987 stackMapFrameOffset = currentOffset + 2;
1988 stackMapTableEndOffset = currentOffset + attributeLength;
1989 compressedFrames = false;
1990 }
1991 // IMPORTANT! Here we assume that the frames are ordered, as in the StackMapTable attribute,
1992 // although this is not guaranteed by the attribute format. This allows an incremental
1993 // extraction of the labels corresponding to this attribute (see the comment above for the
1994 // StackMapTable attribute).
1995 } else {
1996 Attribute attribute =
1997 readAttribute(
1998 context.attributePrototypes,
1999 attributeName,
2000 currentOffset,
2001 attributeLength,
2002 charBuffer,
2003 codeOffset,
2004 labels);
2005 attribute.nextAttribute = attributes;
2006 attributes = attribute;
2007 }
2008 currentOffset += attributeLength;
2009 }
2010
2011 // Initialize the context fields related to stack map frames, and generate the first
2012 // (implicit) stack map frame, if needed.
2013 final boolean expandFrames = (context.parsingOptions & EXPAND_FRAMES) != 0;
2014 if (stackMapFrameOffset != 0) {
2015 // The bytecode offset of the first explicit frame is not offset_delta + 1 but only
2016 // offset_delta. Setting the implicit frame offset to -1 allows us to use of the
2017 // "offset_delta + 1" rule in all cases.
2018 context.currentFrameOffset = -1;
2019 context.currentFrameType = 0;
2020 context.currentFrameLocalCount = 0;
2021 context.currentFrameLocalCountDelta = 0;
2022 context.currentFrameLocalTypes = new Object[maxLocals];
2023 context.currentFrameStackCount = 0;
2024 context.currentFrameStackTypes = new Object[maxStack];
2025 if (expandFrames) {
2026 computeImplicitFrame(context);
2027 }
2028 // Find the labels for UNINITIALIZED frame types. Instead of decoding each element of the
2029 // stack map table, we look for 3 consecutive bytes that "look like" an UNINITIALIZED type
2030 // (tag ITEM_Uninitialized, offset within bytecode bounds, NEW instruction at this offset).
2031 // We may find false positives (i.e. not real UNINITIALIZED types), but this should be rare,
2032 // and the only consequence will be the creation of an unneeded label. This is better than
2033 // creating a label for each NEW instruction, and faster than fully decoding the whole stack
2034 // map table.
2035 for (int offset = stackMapFrameOffset; offset < stackMapTableEndOffset - 2; ++offset) {
2036 if (classBuffer[offset] == Frame.ITEM_UNINITIALIZED) {
2037 int potentialBytecodeOffset = readUnsignedShort(offset + 1);
2038 if (potentialBytecodeOffset >= 0
2039 && potentialBytecodeOffset < codeLength
2040 && (classBuffer[bytecodeStartOffset + potentialBytecodeOffset] & 0xFF)
2041 == Opcodes.NEW) {
2042 createLabel(potentialBytecodeOffset, labels);
2043 }
2044 }
2045 }
2046 }
2047 if (expandFrames && (context.parsingOptions & EXPAND_ASM_INSNS) != 0) {
2048 // Expanding the ASM specific instructions can introduce F_INSERT frames, even if the method
2049 // does not currently have any frame. These inserted frames must be computed by simulating the
2050 // effect of the bytecode instructions, one by one, starting from the implicit first frame.
2051 // For this, MethodWriter needs to know maxLocals before the first instruction is visited. To
2052 // ensure this, we visit the implicit first frame here (passing only maxLocals - the rest is
2053 // computed in MethodWriter).
2054 methodVisitor.visitFrame(Opcodes.F_NEW, maxLocals, null, 0, null);
2055 }
2056
2057 // Visit the bytecode instructions. First, introduce state variables for the incremental parsing
2058 // of the type annotations.
2059
2060 // Index of the next runtime visible type annotation to read (in the
2061 // visibleTypeAnnotationOffsets array).
2062 int currentVisibleTypeAnnotationIndex = 0;
2063 // The bytecode offset of the next runtime visible type annotation to read, or -1.
2064 int currentVisibleTypeAnnotationBytecodeOffset =
2065 getTypeAnnotationBytecodeOffset(visibleTypeAnnotationOffsets, 0);
2066 // Index of the next runtime invisible type annotation to read (in the
2067 // invisibleTypeAnnotationOffsets array).
2068 int currentInvisibleTypeAnnotationIndex = 0;
2069 // The bytecode offset of the next runtime invisible type annotation to read, or -1.
2070 int currentInvisibleTypeAnnotationBytecodeOffset =
2071 getTypeAnnotationBytecodeOffset(invisibleTypeAnnotationOffsets, 0);
2072
2073 // Whether a F_INSERT stack map frame must be inserted before the current instruction.
2074 boolean insertFrame = false;
2075
2076 // The delta to subtract from a goto_w or jsr_w opcode to get the corresponding goto or jsr
2077 // opcode, or 0 if goto_w and jsr_w must be left unchanged (i.e. when expanding ASM specific
2078 // instructions).
2079 final int wideJumpOpcodeDelta =
2080 (context.parsingOptions & EXPAND_ASM_INSNS) == 0 ? Constants.WIDE_JUMP_OPCODE_DELTA : 0;
2081
2082 currentOffset = bytecodeStartOffset;
2083 while (currentOffset < bytecodeEndOffset) {
2084 final int currentBytecodeOffset = currentOffset - bytecodeStartOffset;
2085
2086 // Visit the label and the line number(s) for this bytecode offset, if any.
2087 Label currentLabel = labels[currentBytecodeOffset];
2088 if (currentLabel != null) {
2089 currentLabel.accept(methodVisitor, (context.parsingOptions & SKIP_DEBUG) == 0);
2090 }
2091
2092 // Visit the stack map frame for this bytecode offset, if any.
2093 while (stackMapFrameOffset != 0
2094 && (context.currentFrameOffset == currentBytecodeOffset
2095 || context.currentFrameOffset == -1)) {
2096 // If there is a stack map frame for this offset, make methodVisitor visit it, and read the
2097 // next stack map frame if there is one.
2098 if (context.currentFrameOffset != -1) {
2099 if (!compressedFrames || expandFrames) {
2100 methodVisitor.visitFrame(
2101 Opcodes.F_NEW,
2102 context.currentFrameLocalCount,
2103 context.currentFrameLocalTypes,
2104 context.currentFrameStackCount,
2105 context.currentFrameStackTypes);
2106 } else {
2107 methodVisitor.visitFrame(
2108 context.currentFrameType,
2109 context.currentFrameLocalCountDelta,
2110 context.currentFrameLocalTypes,
2111 context.currentFrameStackCount,
2112 context.currentFrameStackTypes);
2113 }
2114 // Since there is already a stack map frame for this bytecode offset, there is no need to
2115 // insert a new one.
2116 insertFrame = false;
2117 }
2118 if (stackMapFrameOffset < stackMapTableEndOffset) {
2119 stackMapFrameOffset =
2120 readStackMapFrame(stackMapFrameOffset, compressedFrames, expandFrames, context);
2121 } else {
2122 stackMapFrameOffset = 0;
2123 }
2124 }
2125
2126 // Insert a stack map frame for this bytecode offset, if requested by setting insertFrame to
2127 // true during the previous iteration. The actual frame content is computed in MethodWriter.
2128 if (insertFrame) {
2129 if ((context.parsingOptions & EXPAND_FRAMES) != 0) {
2130 methodVisitor.visitFrame(Constants.F_INSERT, 0, null, 0, null);
2131 }
2132 insertFrame = false;
2133 }
2134
2135 // Visit the instruction at this bytecode offset.
2136 int opcode = classBuffer[currentOffset] & 0xFF;
2137 switch (opcode) {
2138 case Opcodes.NOP:
2139 case Opcodes.ACONST_NULL:
2140 case Opcodes.ICONST_M1:
2141 case Opcodes.ICONST_0:
2142 case Opcodes.ICONST_1:
2143 case Opcodes.ICONST_2:
2144 case Opcodes.ICONST_3:
2145 case Opcodes.ICONST_4:
2146 case Opcodes.ICONST_5:
2147 case Opcodes.LCONST_0:
2148 case Opcodes.LCONST_1:
2149 case Opcodes.FCONST_0:
2150 case Opcodes.FCONST_1:
2151 case Opcodes.FCONST_2:
2152 case Opcodes.DCONST_0:
2153 case Opcodes.DCONST_1:
2154 case Opcodes.IALOAD:
2155 case Opcodes.LALOAD:
2156 case Opcodes.FALOAD:
2157 case Opcodes.DALOAD:
2158 case Opcodes.AALOAD:
2159 case Opcodes.BALOAD:
2160 case Opcodes.CALOAD:
2161 case Opcodes.SALOAD:
2162 case Opcodes.IASTORE:
2163 case Opcodes.LASTORE:
2164 case Opcodes.FASTORE:
2165 case Opcodes.DASTORE:
2166 case Opcodes.AASTORE:
2167 case Opcodes.BASTORE:
2168 case Opcodes.CASTORE:
2169 case Opcodes.SASTORE:
2170 case Opcodes.POP:
2171 case Opcodes.POP2:
2172 case Opcodes.DUP:
2173 case Opcodes.DUP_X1:
2174 case Opcodes.DUP_X2:
2175 case Opcodes.DUP2:
2176 case Opcodes.DUP2_X1:
2177 case Opcodes.DUP2_X2:
2178 case Opcodes.SWAP:
2179 case Opcodes.IADD:
2180 case Opcodes.LADD:
2181 case Opcodes.FADD:
2182 case Opcodes.DADD:
2183 case Opcodes.ISUB:
2184 case Opcodes.LSUB:
2185 case Opcodes.FSUB:
2186 case Opcodes.DSUB:
2187 case Opcodes.IMUL:
2188 case Opcodes.LMUL:
2189 case Opcodes.FMUL:
2190 case Opcodes.DMUL:
2191 case Opcodes.IDIV:
2192 case Opcodes.LDIV:
2193 case Opcodes.FDIV:
2194 case Opcodes.DDIV:
2195 case Opcodes.IREM:
2196 case Opcodes.LREM:
2197 case Opcodes.FREM:
2198 case Opcodes.DREM:
2199 case Opcodes.INEG:
2200 case Opcodes.LNEG:
2201 case Opcodes.FNEG:
2202 case Opcodes.DNEG:
2203 case Opcodes.ISHL:
2204 case Opcodes.LSHL:
2205 case Opcodes.ISHR:
2206 case Opcodes.LSHR:
2207 case Opcodes.IUSHR:
2208 case Opcodes.LUSHR:
2209 case Opcodes.IAND:
2210 case Opcodes.LAND:
2211 case Opcodes.IOR:
2212 case Opcodes.LOR:
2213 case Opcodes.IXOR:
2214 case Opcodes.LXOR:
2215 case Opcodes.I2L:
2216 case Opcodes.I2F:
2217 case Opcodes.I2D:
2218 case Opcodes.L2I:
2219 case Opcodes.L2F:
2220 case Opcodes.L2D:
2221 case Opcodes.F2I:
2222 case Opcodes.F2L:
2223 case Opcodes.F2D:
2224 case Opcodes.D2I:
2225 case Opcodes.D2L:
2226 case Opcodes.D2F:
2227 case Opcodes.I2B:
2228 case Opcodes.I2C:
2229 case Opcodes.I2S:
2230 case Opcodes.LCMP:
2231 case Opcodes.FCMPL:
2232 case Opcodes.FCMPG:
2233 case Opcodes.DCMPL:
2234 case Opcodes.DCMPG:
2235 case Opcodes.IRETURN:
2236 case Opcodes.LRETURN:
2237 case Opcodes.FRETURN:
2238 case Opcodes.DRETURN:
2239 case Opcodes.ARETURN:
2240 case Opcodes.RETURN:
2241 case Opcodes.ARRAYLENGTH:
2242 case Opcodes.ATHROW:
2243 case Opcodes.MONITORENTER:
2244 case Opcodes.MONITOREXIT:
2245 methodVisitor.visitInsn(opcode);
2246 currentOffset += 1;
2247 break;
2248 case Constants.ILOAD_0:
2249 case Constants.ILOAD_1:
2250 case Constants.ILOAD_2:
2251 case Constants.ILOAD_3:
2252 case Constants.LLOAD_0:
2253 case Constants.LLOAD_1:
2254 case Constants.LLOAD_2:
2255 case Constants.LLOAD_3:
2256 case Constants.FLOAD_0:
2257 case Constants.FLOAD_1:
2258 case Constants.FLOAD_2:
2259 case Constants.FLOAD_3:
2260 case Constants.DLOAD_0:
2261 case Constants.DLOAD_1:
2262 case Constants.DLOAD_2:
2263 case Constants.DLOAD_3:
2264 case Constants.ALOAD_0:
2265 case Constants.ALOAD_1:
2266 case Constants.ALOAD_2:
2267 case Constants.ALOAD_3:
2268 opcode -= Constants.ILOAD_0;
2269 methodVisitor.visitVarInsn(Opcodes.ILOAD + (opcode >> 2), opcode & 0x3);
2270 currentOffset += 1;
2271 break;
2272 case Constants.ISTORE_0:
2273 case Constants.ISTORE_1:
2274 case Constants.ISTORE_2:
2275 case Constants.ISTORE_3:
2276 case Constants.LSTORE_0:
2277 case Constants.LSTORE_1:
2278 case Constants.LSTORE_2:
2279 case Constants.LSTORE_3:
2280 case Constants.FSTORE_0:
2281 case Constants.FSTORE_1:
2282 case Constants.FSTORE_2:
2283 case Constants.FSTORE_3:
2284 case Constants.DSTORE_0:
2285 case Constants.DSTORE_1:
2286 case Constants.DSTORE_2:
2287 case Constants.DSTORE_3:
2288 case Constants.ASTORE_0:
2289 case Constants.ASTORE_1:
2290 case Constants.ASTORE_2:
2291 case Constants.ASTORE_3:
2292 opcode -= Constants.ISTORE_0;
2293 methodVisitor.visitVarInsn(Opcodes.ISTORE + (opcode >> 2), opcode & 0x3);
2294 currentOffset += 1;
2295 break;
2296 case Opcodes.IFEQ:
2297 case Opcodes.IFNE:
2298 case Opcodes.IFLT:
2299 case Opcodes.IFGE:
2300 case Opcodes.IFGT:
2301 case Opcodes.IFLE:
2302 case Opcodes.IF_ICMPEQ:
2303 case Opcodes.IF_ICMPNE:
2304 case Opcodes.IF_ICMPLT:
2305 case Opcodes.IF_ICMPGE:
2306 case Opcodes.IF_ICMPGT:
2307 case Opcodes.IF_ICMPLE:
2308 case Opcodes.IF_ACMPEQ:
2309 case Opcodes.IF_ACMPNE:
2310 case Opcodes.GOTO:
2311 case Opcodes.JSR:
2312 case Opcodes.IFNULL:
2313 case Opcodes.IFNONNULL:
2314 methodVisitor.visitJumpInsn(
2315 opcode, labels[currentBytecodeOffset + readShort(currentOffset + 1)]);
2316 currentOffset += 3;
2317 break;
2318 case Constants.GOTO_W:
2319 case Constants.JSR_W:
2320 methodVisitor.visitJumpInsn(
2321 opcode - wideJumpOpcodeDelta,
2322 labels[currentBytecodeOffset + readInt(currentOffset + 1)]);
2323 currentOffset += 5;
2324 break;
2325 case Constants.ASM_IFEQ:
2326 case Constants.ASM_IFNE:
2327 case Constants.ASM_IFLT:
2328 case Constants.ASM_IFGE:
2329 case Constants.ASM_IFGT:
2330 case Constants.ASM_IFLE:
2331 case Constants.ASM_IF_ICMPEQ:
2332 case Constants.ASM_IF_ICMPNE:
2333 case Constants.ASM_IF_ICMPLT:
2334 case Constants.ASM_IF_ICMPGE:
2335 case Constants.ASM_IF_ICMPGT:
2336 case Constants.ASM_IF_ICMPLE:
2337 case Constants.ASM_IF_ACMPEQ:
2338 case Constants.ASM_IF_ACMPNE:
2339 case Constants.ASM_GOTO:
2340 case Constants.ASM_JSR:
2341 case Constants.ASM_IFNULL:
2342 case Constants.ASM_IFNONNULL:
2343 {
2344 // A forward jump with an offset > 32767. In this case we automatically replace ASM_GOTO
2345 // with GOTO_W, ASM_JSR with JSR_W and ASM_IFxxx <l> with IFNOTxxx <L> GOTO_W <l> L:...,
2346 // where IFNOTxxx is the "opposite" opcode of ASMS_IFxxx (e.g. IFNE for ASM_IFEQ) and
2347 // where <L> designates the instruction just after the GOTO_W.
2348 // First, change the ASM specific opcodes ASM_IFEQ ... ASM_JSR, ASM_IFNULL and
2349 // ASM_IFNONNULL to IFEQ ... JSR, IFNULL and IFNONNULL.
2350 opcode =
2351 opcode < Constants.ASM_IFNULL
2352 ? opcode - Constants.ASM_OPCODE_DELTA
2353 : opcode - Constants.ASM_IFNULL_OPCODE_DELTA;
2354 Label target = labels[currentBytecodeOffset + readUnsignedShort(currentOffset + 1)];
2355 if (opcode == Opcodes.GOTO || opcode == Opcodes.JSR) {
2356 // Replace GOTO with GOTO_W and JSR with JSR_W.
2357 methodVisitor.visitJumpInsn(opcode + Constants.WIDE_JUMP_OPCODE_DELTA, target);
2358 } else {
2359 // Compute the "opposite" of opcode. This can be done by flipping the least
2360 // significant bit for IFNULL and IFNONNULL, and similarly for IFEQ ... IF_ACMPEQ
2361 // (with a pre and post offset by 1).
2362 opcode = opcode < Opcodes.GOTO ? ((opcode + 1) ^ 1) - 1 : opcode ^ 1;
2363 Label endif = createLabel(currentBytecodeOffset + 3, labels);
2364 methodVisitor.visitJumpInsn(opcode, endif);
2365 methodVisitor.visitJumpInsn(Constants.GOTO_W, target);
2366 // endif designates the instruction just after GOTO_W, and is visited as part of the
2367 // next instruction. Since it is a jump target, we need to insert a frame here.
2368 insertFrame = true;
2369 }
2370 currentOffset += 3;
2371 break;
2372 }
2373 case Constants.ASM_GOTO_W:
2374 // Replace ASM_GOTO_W with GOTO_W.
2375 methodVisitor.visitJumpInsn(
2376 Constants.GOTO_W, labels[currentBytecodeOffset + readInt(currentOffset + 1)]);
2377 // The instruction just after is a jump target (because ASM_GOTO_W is used in patterns
2378 // IFNOTxxx <L> ASM_GOTO_W <l> L:..., see MethodWriter), so we need to insert a frame
2379 // here.
2380 insertFrame = true;
2381 currentOffset += 5;
2382 break;
2383 case Constants.WIDE:
2384 opcode = classBuffer[currentOffset + 1] & 0xFF;
2385 if (opcode == Opcodes.IINC) {
2386 methodVisitor.visitIincInsn(
2387 readUnsignedShort(currentOffset + 2), readShort(currentOffset + 4));
2388 currentOffset += 6;
2389 } else {
2390 methodVisitor.visitVarInsn(opcode, readUnsignedShort(currentOffset + 2));
2391 currentOffset += 4;
2392 }
2393 break;
2394 case Opcodes.TABLESWITCH:
2395 {
2396 // Skip 0 to 3 padding bytes.
2397 currentOffset += 4 - (currentBytecodeOffset & 3);
2398 // Read the instruction.
2399 Label defaultLabel = labels[currentBytecodeOffset + readInt(currentOffset)];
2400 int low = readInt(currentOffset + 4);
2401 int high = readInt(currentOffset + 8);
2402 currentOffset += 12;
2403 Label[] table = new Label[high - low + 1];
2404 for (int i = 0; i < table.length; ++i) {
2405 table[i] = labels[currentBytecodeOffset + readInt(currentOffset)];
2406 currentOffset += 4;
2407 }
2408 methodVisitor.visitTableSwitchInsn(low, high, defaultLabel, table);
2409 break;
2410 }
2411 case Opcodes.LOOKUPSWITCH:
2412 {
2413 // Skip 0 to 3 padding bytes.
2414 currentOffset += 4 - (currentBytecodeOffset & 3);
2415 // Read the instruction.
2416 Label defaultLabel = labels[currentBytecodeOffset + readInt(currentOffset)];
2417 int numPairs = readInt(currentOffset + 4);
2418 currentOffset += 8;
2419 int[] keys = new int[numPairs];
2420 Label[] values = new Label[numPairs];
2421 for (int i = 0; i < numPairs; ++i) {
2422 keys[i] = readInt(currentOffset);
2423 values[i] = labels[currentBytecodeOffset + readInt(currentOffset + 4)];
2424 currentOffset += 8;
2425 }
2426 methodVisitor.visitLookupSwitchInsn(defaultLabel, keys, values);
2427 break;
2428 }
2429 case Opcodes.ILOAD:
2430 case Opcodes.LLOAD:
2431 case Opcodes.FLOAD:
2432 case Opcodes.DLOAD:
2433 case Opcodes.ALOAD:
2434 case Opcodes.ISTORE:
2435 case Opcodes.LSTORE:
2436 case Opcodes.FSTORE:
2437 case Opcodes.DSTORE:
2438 case Opcodes.ASTORE:
2439 case Opcodes.RET:
2440 methodVisitor.visitVarInsn(opcode, classBuffer[currentOffset + 1] & 0xFF);
2441 currentOffset += 2;
2442 break;
2443 case Opcodes.BIPUSH:
2444 case Opcodes.NEWARRAY:
2445 methodVisitor.visitIntInsn(opcode, classBuffer[currentOffset + 1]);
2446 currentOffset += 2;
2447 break;
2448 case Opcodes.SIPUSH:
2449 methodVisitor.visitIntInsn(opcode, readShort(currentOffset + 1));
2450 currentOffset += 3;
2451 break;
2452 case Opcodes.LDC:
2453 methodVisitor.visitLdcInsn(readConst(classBuffer[currentOffset + 1] & 0xFF, charBuffer));
2454 currentOffset += 2;
2455 break;
2456 case Constants.LDC_W:
2457 case Constants.LDC2_W:
2458 methodVisitor.visitLdcInsn(readConst(readUnsignedShort(currentOffset + 1), charBuffer));
2459 currentOffset += 3;
2460 break;
2461 case Opcodes.GETSTATIC:
2462 case Opcodes.PUTSTATIC:
2463 case Opcodes.GETFIELD:
2464 case Opcodes.PUTFIELD:
2465 case Opcodes.INVOKEVIRTUAL:
2466 case Opcodes.INVOKESPECIAL:
2467 case Opcodes.INVOKESTATIC:
2468 case Opcodes.INVOKEINTERFACE:
2469 {
2470 int cpInfoOffset = cpInfoOffsets[readUnsignedShort(currentOffset + 1)];
2471 int nameAndTypeCpInfoOffset = cpInfoOffsets[readUnsignedShort(cpInfoOffset + 2)];
2472 String owner = readClass(cpInfoOffset, charBuffer);
2473 String name = readUTF8(nameAndTypeCpInfoOffset, charBuffer);
2474 String descriptor = readUTF8(nameAndTypeCpInfoOffset + 2, charBuffer);
2475 if (opcode < Opcodes.INVOKEVIRTUAL) {
2476 methodVisitor.visitFieldInsn(opcode, owner, name, descriptor);
2477 } else {
2478 boolean isInterface =
2479 classBuffer[cpInfoOffset - 1] == Symbol.CONSTANT_INTERFACE_METHODREF_TAG;
2480 methodVisitor.visitMethodInsn(opcode, owner, name, descriptor, isInterface);
2481 }
2482 if (opcode == Opcodes.INVOKEINTERFACE) {
2483 currentOffset += 5;
2484 } else {
2485 currentOffset += 3;
2486 }
2487 break;
2488 }
2489 case Opcodes.INVOKEDYNAMIC:
2490 {
2491 int cpInfoOffset = cpInfoOffsets[readUnsignedShort(currentOffset + 1)];
2492 int nameAndTypeCpInfoOffset = cpInfoOffsets[readUnsignedShort(cpInfoOffset + 2)];
2493 String name = readUTF8(nameAndTypeCpInfoOffset, charBuffer);
2494 String descriptor = readUTF8(nameAndTypeCpInfoOffset + 2, charBuffer);
2495 int bootstrapMethodOffset = bootstrapMethodOffsets[readUnsignedShort(cpInfoOffset)];
2496 Handle handle =
2497 (Handle) readConst(readUnsignedShort(bootstrapMethodOffset), charBuffer);
2498 Object[] bootstrapMethodArguments =
2499 new Object[readUnsignedShort(bootstrapMethodOffset + 2)];
2500 bootstrapMethodOffset += 4;
2501 for (int i = 0; i < bootstrapMethodArguments.length; i++) {
2502 bootstrapMethodArguments[i] =
2503 readConst(readUnsignedShort(bootstrapMethodOffset), charBuffer);
2504 bootstrapMethodOffset += 2;
2505 }
2506 methodVisitor.visitInvokeDynamicInsn(
2507 name, descriptor, handle, bootstrapMethodArguments);
2508 currentOffset += 5;
2509 break;
2510 }
2511 case Opcodes.NEW:
2512 case Opcodes.ANEWARRAY:
2513 case Opcodes.CHECKCAST:
2514 case Opcodes.INSTANCEOF:
2515 methodVisitor.visitTypeInsn(opcode, readClass(currentOffset + 1, charBuffer));
2516 currentOffset += 3;
2517 break;
2518 case Opcodes.IINC:
2519 methodVisitor.visitIincInsn(
2520 classBuffer[currentOffset + 1] & 0xFF, classBuffer[currentOffset + 2]);
2521 currentOffset += 3;
2522 break;
2523 case Opcodes.MULTIANEWARRAY:
2524 methodVisitor.visitMultiANewArrayInsn(
2525 readClass(currentOffset + 1, charBuffer), classBuffer[currentOffset + 3] & 0xFF);
2526 currentOffset += 4;
2527 break;
2528 default:
2529 throw new AssertionError();
2530 }
2531
2532 // Visit the runtime visible instruction annotations, if any.
2533 while (visibleTypeAnnotationOffsets != null
2534 && currentVisibleTypeAnnotationIndex < visibleTypeAnnotationOffsets.length
2535 && currentVisibleTypeAnnotationBytecodeOffset <= currentBytecodeOffset) {
2536 if (currentVisibleTypeAnnotationBytecodeOffset == currentBytecodeOffset) {
2537 // Parse the target_type, target_info and target_path fields.
2538 int currentAnnotationOffset =
2539 readTypeAnnotationTarget(
2540 context, visibleTypeAnnotationOffsets[currentVisibleTypeAnnotationIndex]);
2541 // Parse the type_index field.
2542 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
2543 currentAnnotationOffset += 2;
2544 // Parse num_element_value_pairs and element_value_pairs and visit these values.
2545 readElementValues(
2546 methodVisitor.visitInsnAnnotation(
2547 context.currentTypeAnnotationTarget,
2548 context.currentTypeAnnotationTargetPath,
2549 annotationDescriptor,
2550 /* visible = */ true),
2551 currentAnnotationOffset,
2552 /* named = */ true,
2553 charBuffer);
2554 }
2555 currentVisibleTypeAnnotationBytecodeOffset =
2556 getTypeAnnotationBytecodeOffset(
2557 visibleTypeAnnotationOffsets, ++currentVisibleTypeAnnotationIndex);
2558 }
2559
2560 // Visit the runtime invisible instruction annotations, if any.
2561 while (invisibleTypeAnnotationOffsets != null
2562 && currentInvisibleTypeAnnotationIndex < invisibleTypeAnnotationOffsets.length
2563 && currentInvisibleTypeAnnotationBytecodeOffset <= currentBytecodeOffset) {
2564 if (currentInvisibleTypeAnnotationBytecodeOffset == currentBytecodeOffset) {
2565 // Parse the target_type, target_info and target_path fields.
2566 int currentAnnotationOffset =
2567 readTypeAnnotationTarget(
2568 context, invisibleTypeAnnotationOffsets[currentInvisibleTypeAnnotationIndex]);
2569 // Parse the type_index field.
2570 String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
2571 currentAnnotationOffset += 2;
2572 // Parse num_element_value_pairs and element_value_pairs and visit these values.
2573 readElementValues(
2574 methodVisitor.visitInsnAnnotation(
2575 context.currentTypeAnnotationTarget,
2576 context.currentTypeAnnotationTargetPath,
2577 annotationDescriptor,
2578 /* visible = */ false),
2579 currentAnnotationOffset,
2580 /* named = */ true,
2581 charBuffer);
2582 }
2583 currentInvisibleTypeAnnotationBytecodeOffset =
2584 getTypeAnnotationBytecodeOffset(
2585 invisibleTypeAnnotationOffsets, ++currentInvisibleTypeAnnotationIndex);
2586 }
2587 }
2588 if (labels[codeLength] != null) {
2589 methodVisitor.visitLabel(labels[codeLength]);
2590 }
2591
2592 // Visit LocalVariableTable and LocalVariableTypeTable attributes.
2593 if (localVariableTableOffset != 0 && (context.parsingOptions & SKIP_DEBUG) == 0) {
2594 // The (start_pc, index, signature_index) fields of each entry of the LocalVariableTypeTable.
2595 int[] typeTable = null;
2596 if (localVariableTypeTableOffset != 0) {
2597 typeTable = new int[readUnsignedShort(localVariableTypeTableOffset) * 3];
2598 currentOffset = localVariableTypeTableOffset + 2;
2599 int typeTableIndex = typeTable.length;
2600 while (typeTableIndex > 0) {
2601 // Store the offset of 'signature_index', and the value of 'index' and 'start_pc'.
2602 typeTable[--typeTableIndex] = currentOffset + 6;
2603 typeTable[--typeTableIndex] = readUnsignedShort(currentOffset + 8);
2604 typeTable[--typeTableIndex] = readUnsignedShort(currentOffset);
2605 currentOffset += 10;
2606 }
2607 }
2608 int localVariableTableLength = readUnsignedShort(localVariableTableOffset);
2609 currentOffset = localVariableTableOffset + 2;
2610 while (localVariableTableLength-- > 0) {
2611 int startPc = readUnsignedShort(currentOffset);
2612 int length = readUnsignedShort(currentOffset + 2);
2613 String name = readUTF8(currentOffset + 4, charBuffer);
2614 String descriptor = readUTF8(currentOffset + 6, charBuffer);
2615 int index = readUnsignedShort(currentOffset + 8);
2616 currentOffset += 10;
2617 String signature = null;
2618 if (typeTable != null) {
2619 for (int i = 0; i < typeTable.length; i += 3) {
2620 if (typeTable[i] == startPc && typeTable[i + 1] == index) {
2621 signature = readUTF8(typeTable[i + 2], charBuffer);
2622 break;
2623 }
2624 }
2625 }
2626 methodVisitor.visitLocalVariable(
2627 name, descriptor, signature, labels[startPc], labels[startPc + length], index);
2628 }
2629 }
2630
2631 // Visit the local variable type annotations of the RuntimeVisibleTypeAnnotations attribute.
2632 if (visibleTypeAnnotationOffsets != null) {
2633 for (int typeAnnotationOffset : visibleTypeAnnotationOffsets) {
2634 int targetType = readByte(typeAnnotationOffset);
2635 if (targetType == TypeReference.LOCAL_VARIABLE
2636 || targetType == TypeReference.RESOURCE_VARIABLE) {
2637 // Parse the target_type, target_info and target_path fields.
2638 currentOffset = readTypeAnnotationTarget(context, typeAnnotationOffset);
2639 // Parse the type_index field.
2640 String annotationDescriptor = readUTF8(currentOffset, charBuffer);
2641 currentOffset += 2;
2642 // Parse num_element_value_pairs and element_value_pairs and visit these values.
2643 readElementValues(
2644 methodVisitor.visitLocalVariableAnnotation(
2645 context.currentTypeAnnotationTarget,
2646 context.currentTypeAnnotationTargetPath,
2647 context.currentLocalVariableAnnotationRangeStarts,
2648 context.currentLocalVariableAnnotationRangeEnds,
2649 context.currentLocalVariableAnnotationRangeIndices,
2650 annotationDescriptor,
2651 /* visible = */ true),
2652 currentOffset,
2653 /* named = */ true,
2654 charBuffer);
2655 }
2656 }
2657 }
2658
2659 // Visit the local variable type annotations of the RuntimeInvisibleTypeAnnotations attribute.
2660 if (invisibleTypeAnnotationOffsets != null) {
2661 for (int typeAnnotationOffset : invisibleTypeAnnotationOffsets) {
2662 int targetType = readByte(typeAnnotationOffset);
2663 if (targetType == TypeReference.LOCAL_VARIABLE
2664 || targetType == TypeReference.RESOURCE_VARIABLE) {
2665 // Parse the target_type, target_info and target_path fields.
2666 currentOffset = readTypeAnnotationTarget(context, typeAnnotationOffset);
2667 // Parse the type_index field.
2668 String annotationDescriptor = readUTF8(currentOffset, charBuffer);
2669 currentOffset += 2;
2670 // Parse num_element_value_pairs and element_value_pairs and visit these values.
2671 readElementValues(
2672 methodVisitor.visitLocalVariableAnnotation(
2673 context.currentTypeAnnotationTarget,
2674 context.currentTypeAnnotationTargetPath,
2675 context.currentLocalVariableAnnotationRangeStarts,
2676 context.currentLocalVariableAnnotationRangeEnds,
2677 context.currentLocalVariableAnnotationRangeIndices,
2678 annotationDescriptor,
2679 /* visible = */ false),
2680 currentOffset,
2681 /* named = */ true,
2682 charBuffer);
2683 }
2684 }
2685 }
2686
2687 // Visit the non standard attributes.
2688 while (attributes != null) {
2689 // Copy and reset the nextAttribute field so that it can also be used in MethodWriter.
2690 Attribute nextAttribute = attributes.nextAttribute;
2691 attributes.nextAttribute = null;
2692 methodVisitor.visitAttribute(attributes);
2693 attributes = nextAttribute;
2694 }
2695
2696 // Visit the max stack and max locals values.
2697 methodVisitor.visitMaxs(maxStack, maxLocals);
2698 }
2699
2700 /**
2701 * Returns the label corresponding to the given bytecode offset. The default implementation of
2702 * this method creates a label for the given offset if it has not been already created.
2703 *
2704 * @param bytecodeOffset a bytecode offset in a method.
2705 * @param labels the already created labels, indexed by their offset. If a label already exists
2706 * for bytecodeOffset this method must not create a new one. Otherwise it must store the new
2707 * label in this array.
2708 * @return a non null Label, which must be equal to labels[bytecodeOffset].
2709 */
2710 protected Label readLabel(final int bytecodeOffset, final Label[] labels) {
2711 if (labels[bytecodeOffset] == null) {
2712 labels[bytecodeOffset] = new Label();
2713 }
2714 return labels[bytecodeOffset];
2715 }
2716
2717 /**
2718 * Creates a label without the {@link Label#FLAG_DEBUG_ONLY} flag set, for the given bytecode
2719 * offset. The label is created with a call to {@link #readLabel} and its {@link
2720 * Label#FLAG_DEBUG_ONLY} flag is cleared.
2721 *
2722 * @param bytecodeOffset a bytecode offset in a method.
2723 * @param labels the already created labels, indexed by their offset.
2724 * @return a Label without the {@link Label#FLAG_DEBUG_ONLY} flag set.
2725 */
2726 private Label createLabel(final int bytecodeOffset, final Label[] labels) {
2727 Label label = readLabel(bytecodeOffset, labels);
2728 label.flags &= ~Label.FLAG_DEBUG_ONLY;
2729 return label;
2730 }
2731
2732 /**
2733 * Creates a label with the {@link Label#FLAG_DEBUG_ONLY} flag set, if there is no already
2734 * existing label for the given bytecode offset (otherwise does nothing). The label is created
2735 * with a call to {@link #readLabel}.
2736 *
2737 * @param bytecodeOffset a bytecode offset in a method.
2738 * @param labels the already created labels, indexed by their offset.
2739 */
2740 private void createDebugLabel(final int bytecodeOffset, final Label[] labels) {
2741 if (labels[bytecodeOffset] == null) {
2742 readLabel(bytecodeOffset, labels).flags |= Label.FLAG_DEBUG_ONLY;
2743 }
2744 }
2745
2746 // ----------------------------------------------------------------------------------------------
2747 // Methods to parse annotations, type annotations and parameter annotations
2748 // ----------------------------------------------------------------------------------------------
2749
2750 /**
2751 * Parses a Runtime[In]VisibleTypeAnnotations attribute to find the offset of each type_annotation
2752 * entry it contains, to find the corresponding labels, and to visit the try catch block
2753 * annotations.
2754 *
2755 * @param methodVisitor the method visitor to be used to visit the try catch block annotations.
2756 * @param context information about the class being parsed.
2757 * @param runtimeTypeAnnotationsOffset the start offset of a Runtime[In]VisibleTypeAnnotations
2758 * attribute, excluding the attribute_info's attribute_name_index and attribute_length fields.
2759 * @param visible true if the attribute to parse is a RuntimeVisibleTypeAnnotations attribute,
2760 * false it is a RuntimeInvisibleTypeAnnotations attribute.
2761 * @return the start offset of each entry of the Runtime[In]VisibleTypeAnnotations_attribute's
2762 * 'annotations' array field.
2763 */
2764 private int[] readTypeAnnotations(
2765 final MethodVisitor methodVisitor,
2766 final Context context,
2767 final int runtimeTypeAnnotationsOffset,
2768 final boolean visible) {
2769 char[] charBuffer = context.charBuffer;
2770 int currentOffset = runtimeTypeAnnotationsOffset;
2771 // Read the num_annotations field and create an array to store the type_annotation offsets.
2772 int[] typeAnnotationsOffsets = new int[readUnsignedShort(currentOffset)];
2773 currentOffset += 2;
2774 // Parse the 'annotations' array field.
2775 for (int i = 0; i < typeAnnotationsOffsets.length; ++i) {
2776 typeAnnotationsOffsets[i] = currentOffset;
2777 // Parse the type_annotation's target_type and the target_info fields. The size of the
2778 // target_info field depends on the value of target_type.
2779 int targetType = readInt(currentOffset);
2780 switch (targetType >>> 24) {
2781 case TypeReference.LOCAL_VARIABLE:
2782 case TypeReference.RESOURCE_VARIABLE:
2783 // A localvar_target has a variable size, which depends on the value of their table_length
2784 // field. It also references bytecode offsets, for which we need labels.
2785 int tableLength = readUnsignedShort(currentOffset + 1);
2786 currentOffset += 3;
2787 while (tableLength-- > 0) {
2788 int startPc = readUnsignedShort(currentOffset);
2789 int length = readUnsignedShort(currentOffset + 2);
2790 // Skip the index field (2 bytes).
2791 currentOffset += 6;
2792 createLabel(startPc, context.currentMethodLabels);
2793 createLabel(startPc + length, context.currentMethodLabels);
2794 }
2795 break;
2796 case TypeReference.CAST:
2797 case TypeReference.CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT:
2798 case TypeReference.METHOD_INVOCATION_TYPE_ARGUMENT:
2799 case TypeReference.CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT:
2800 case TypeReference.METHOD_REFERENCE_TYPE_ARGUMENT:
2801 currentOffset += 4;
2802 break;
2803 case TypeReference.CLASS_EXTENDS:
2804 case TypeReference.CLASS_TYPE_PARAMETER_BOUND:
2805 case TypeReference.METHOD_TYPE_PARAMETER_BOUND:
2806 case TypeReference.THROWS:
2807 case TypeReference.EXCEPTION_PARAMETER:
2808 case TypeReference.INSTANCEOF:
2809 case TypeReference.NEW:
2810 case TypeReference.CONSTRUCTOR_REFERENCE:
2811 case TypeReference.METHOD_REFERENCE:
2812 currentOffset += 3;
2813 break;
2814 case TypeReference.CLASS_TYPE_PARAMETER:
2815 case TypeReference.METHOD_TYPE_PARAMETER:
2816 case TypeReference.METHOD_FORMAL_PARAMETER:
2817 case TypeReference.FIELD:
2818 case TypeReference.METHOD_RETURN:
2819 case TypeReference.METHOD_RECEIVER:
2820 default:
2821 // TypeReference type which can't be used in Code attribute, or which is unknown.
2822 throw new IllegalArgumentException();
2823 }
2824 // Parse the rest of the type_annotation structure, starting with the target_path structure
2825 // (whose size depends on its path_length field).
2826 int pathLength = readByte(currentOffset);
2827 if ((targetType >>> 24) == TypeReference.EXCEPTION_PARAMETER) {
2828 // Parse the target_path structure and create a corresponding TypePath.
2829 TypePath path = pathLength == 0 ? null : new TypePath(classFileBuffer, currentOffset);
2830 currentOffset += 1 + 2 * pathLength;
2831 // Parse the type_index field.
2832 String annotationDescriptor = readUTF8(currentOffset, charBuffer);
2833 currentOffset += 2;
2834 // Parse num_element_value_pairs and element_value_pairs and visit these values.
2835 currentOffset =
2836 readElementValues(
2837 methodVisitor.visitTryCatchAnnotation(
2838 targetType & 0xFFFFFF00, path, annotationDescriptor, visible),
2839 currentOffset,
2840 /* named = */ true,
2841 charBuffer);
2842 } else {
2843 // We don't want to visit the other target_type annotations, so we just skip them (which
2844 // requires some parsing because the element_value_pairs array has a variable size). First,
2845 // skip the target_path structure:
2846 currentOffset += 3 + 2 * pathLength;
2847 // Then skip the num_element_value_pairs and element_value_pairs fields (by reading them
2848 // with a null AnnotationVisitor).
2849 currentOffset =
2850 readElementValues(
2851 /* annotationVisitor = */ null, currentOffset, /* named = */ true, charBuffer);
2852 }
2853 }
2854 return typeAnnotationsOffsets;
2855 }
2856
2857 /**
2858 * Returns the bytecode offset corresponding to the specified JVMS 'type_annotation' structure, or
2859 * -1 if there is no such type_annotation of if it does not have a bytecode offset.
2860 *
2861 * @param typeAnnotationOffsets the offset of each 'type_annotation' entry in a
2862 * Runtime[In]VisibleTypeAnnotations attribute, or {@literal null}.
2863 * @param typeAnnotationIndex the index a 'type_annotation' entry in typeAnnotationOffsets.
2864 * @return bytecode offset corresponding to the specified JVMS 'type_annotation' structure, or -1
2865 * if there is no such type_annotation of if it does not have a bytecode offset.
2866 */
2867 private int getTypeAnnotationBytecodeOffset(
2868 final int[] typeAnnotationOffsets, final int typeAnnotationIndex) {
2869 if (typeAnnotationOffsets == null
2870 || typeAnnotationIndex >= typeAnnotationOffsets.length
2871 || readByte(typeAnnotationOffsets[typeAnnotationIndex]) < TypeReference.INSTANCEOF) {
2872 return -1;
2873 }
2874 return readUnsignedShort(typeAnnotationOffsets[typeAnnotationIndex] + 1);
2875 }
2876
2877 /**
2878 * Parses the header of a JVMS type_annotation structure to extract its target_type, target_info
2879 * and target_path (the result is stored in the given context), and returns the start offset of
2880 * the rest of the type_annotation structure.
2881 *
2882 * @param context information about the class being parsed. This is where the extracted
2883 * target_type and target_path must be stored.
2884 * @param typeAnnotationOffset the start offset of a type_annotation structure.
2885 * @return the start offset of the rest of the type_annotation structure.
2886 */
2887 private int readTypeAnnotationTarget(final Context context, final int typeAnnotationOffset) {
2888 int currentOffset = typeAnnotationOffset;
2889 // Parse and store the target_type structure.
2890 int targetType = readInt(typeAnnotationOffset);
2891 switch (targetType >>> 24) {
2892 case TypeReference.CLASS_TYPE_PARAMETER:
2893 case TypeReference.METHOD_TYPE_PARAMETER:
2894 case TypeReference.METHOD_FORMAL_PARAMETER:
2895 targetType &= 0xFFFF0000;
2896 currentOffset += 2;
2897 break;
2898 case TypeReference.FIELD:
2899 case TypeReference.METHOD_RETURN:
2900 case TypeReference.METHOD_RECEIVER:
2901 targetType &= 0xFF000000;
2902 currentOffset += 1;
2903 break;
2904 case TypeReference.LOCAL_VARIABLE:
2905 case TypeReference.RESOURCE_VARIABLE:
2906 targetType &= 0xFF000000;
2907 int tableLength = readUnsignedShort(currentOffset + 1);
2908 currentOffset += 3;
2909 context.currentLocalVariableAnnotationRangeStarts = new Label[tableLength];
2910 context.currentLocalVariableAnnotationRangeEnds = new Label[tableLength];
2911 context.currentLocalVariableAnnotationRangeIndices = new int[tableLength];
2912 for (int i = 0; i < tableLength; ++i) {
2913 int startPc = readUnsignedShort(currentOffset);
2914 int length = readUnsignedShort(currentOffset + 2);
2915 int index = readUnsignedShort(currentOffset + 4);
2916 currentOffset += 6;
2917 context.currentLocalVariableAnnotationRangeStarts[i] =
2918 createLabel(startPc, context.currentMethodLabels);
2919 context.currentLocalVariableAnnotationRangeEnds[i] =
2920 createLabel(startPc + length, context.currentMethodLabels);
2921 context.currentLocalVariableAnnotationRangeIndices[i] = index;
2922 }
2923 break;
2924 case TypeReference.CAST:
2925 case TypeReference.CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT:
2926 case TypeReference.METHOD_INVOCATION_TYPE_ARGUMENT:
2927 case TypeReference.CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT:
2928 case TypeReference.METHOD_REFERENCE_TYPE_ARGUMENT:
2929 targetType &= 0xFF0000FF;
2930 currentOffset += 4;
2931 break;
2932 case TypeReference.CLASS_EXTENDS:
2933 case TypeReference.CLASS_TYPE_PARAMETER_BOUND:
2934 case TypeReference.METHOD_TYPE_PARAMETER_BOUND:
2935 case TypeReference.THROWS:
2936 case TypeReference.EXCEPTION_PARAMETER:
2937 targetType &= 0xFFFFFF00;
2938 currentOffset += 3;
2939 break;
2940 case TypeReference.INSTANCEOF:
2941 case TypeReference.NEW:
2942 case TypeReference.CONSTRUCTOR_REFERENCE:
2943 case TypeReference.METHOD_REFERENCE:
2944 targetType &= 0xFF000000;
2945 currentOffset += 3;
2946 break;
2947 default:
2948 throw new IllegalArgumentException();
2949 }
2950 context.currentTypeAnnotationTarget = targetType;
2951 // Parse and store the target_path structure.
2952 int pathLength = readByte(currentOffset);
2953 context.currentTypeAnnotationTargetPath =
2954 pathLength == 0 ? null : new TypePath(classFileBuffer, currentOffset);
2955 // Return the start offset of the rest of the type_annotation structure.
2956 return currentOffset + 1 + 2 * pathLength;
2957 }
2958
2959 /**
2960 * Reads a Runtime[In]VisibleParameterAnnotations attribute and makes the given visitor visit it.
2961 *
2962 * @param methodVisitor the visitor that must visit the parameter annotations.
2963 * @param context information about the class being parsed.
2964 * @param runtimeParameterAnnotationsOffset the start offset of a
2965 * Runtime[In]VisibleParameterAnnotations attribute, excluding the attribute_info's
2966 * attribute_name_index and attribute_length fields.
2967 * @param visible true if the attribute to parse is a RuntimeVisibleParameterAnnotations
2968 * attribute, false it is a RuntimeInvisibleParameterAnnotations attribute.
2969 */
2970 private void readParameterAnnotations(
2971 final MethodVisitor methodVisitor,
2972 final Context context,
2973 final int runtimeParameterAnnotationsOffset,
2974 final boolean visible) {
2975 int currentOffset = runtimeParameterAnnotationsOffset;
2976 int numParameters = classFileBuffer[currentOffset++] & 0xFF;
2977 methodVisitor.visitAnnotableParameterCount(numParameters, visible);
2978 char[] charBuffer = context.charBuffer;
2979 for (int i = 0; i < numParameters; ++i) {
2980 int numAnnotations = readUnsignedShort(currentOffset);
2981 currentOffset += 2;
2982 while (numAnnotations-- > 0) {
2983 // Parse the type_index field.
2984 String annotationDescriptor = readUTF8(currentOffset, charBuffer);
2985 currentOffset += 2;
2986 // Parse num_element_value_pairs and element_value_pairs and visit these values.
2987 currentOffset =
2988 readElementValues(
2989 methodVisitor.visitParameterAnnotation(i, annotationDescriptor, visible),
2990 currentOffset,
2991 /* named = */ true,
2992 charBuffer);
2993 }
2994 }
2995 }
2996
2997 /**
2998 * Reads the element values of a JVMS 'annotation' structure and makes the given visitor visit
2999 * them. This method can also be used to read the values of the JVMS 'array_value' field of an
3000 * annotation's 'element_value'.
3001 *
3002 * @param annotationVisitor the visitor that must visit the values.
3003 * @param annotationOffset the start offset of an 'annotation' structure (excluding its type_index
3004 * field) or of an 'array_value' structure.
3005 * @param named if the annotation values are named or not. This should be true to parse the values
3006 * of a JVMS 'annotation' structure, and false to parse the JVMS 'array_value' of an
3007 * annotation's element_value.
3008 * @param charBuffer the buffer used to read strings in the constant pool.
3009 * @return the end offset of the JVMS 'annotation' or 'array_value' structure.
3010 */
3011 private int readElementValues(
3012 final AnnotationVisitor annotationVisitor,
3013 final int annotationOffset,
3014 final boolean named,
3015 final char[] charBuffer) {
3016 int currentOffset = annotationOffset;
3017 // Read the num_element_value_pairs field (or num_values field for an array_value).
3018 int numElementValuePairs = readUnsignedShort(currentOffset);
3019 currentOffset += 2;
3020 if (named) {
3021 // Parse the element_value_pairs array.
3022 while (numElementValuePairs-- > 0) {
3023 String elementName = readUTF8(currentOffset, charBuffer);
3024 currentOffset =
3025 readElementValue(annotationVisitor, currentOffset + 2, elementName, charBuffer);
3026 }
3027 } else {
3028 // Parse the array_value array.
3029 while (numElementValuePairs-- > 0) {
3030 currentOffset =
3031 readElementValue(annotationVisitor, currentOffset, /* elementName= */ null, charBuffer);
3032 }
3033 }
3034 if (annotationVisitor != null) {
3035 annotationVisitor.visitEnd();
3036 }
3037 return currentOffset;
3038 }
3039
3040 /**
3041 * Reads a JVMS 'element_value' structure and makes the given visitor visit it.
3042 *
3043 * @param annotationVisitor the visitor that must visit the element_value structure.
3044 * @param elementValueOffset the start offset in {@link #classFileBuffer} of the element_value
3045 * structure to be read.
3046 * @param elementName the name of the element_value structure to be read, or {@literal null}.
3047 * @param charBuffer the buffer used to read strings in the constant pool.
3048 * @return the end offset of the JVMS 'element_value' structure.
3049 */
3050 private int readElementValue(
3051 final AnnotationVisitor annotationVisitor,
3052 final int elementValueOffset,
3053 final String elementName,
3054 final char[] charBuffer) {
3055 int currentOffset = elementValueOffset;
3056 if (annotationVisitor == null) {
3057 switch (classFileBuffer[currentOffset] & 0xFF) {
3058 case 'e': // enum_const_value
3059 return currentOffset + 5;
3060 case '@': // annotation_value
3061 return readElementValues(null, currentOffset + 3, /* named = */ true, charBuffer);
3062 case '[': // array_value
3063 return readElementValues(null, currentOffset + 1, /* named = */ false, charBuffer);
3064 default:
3065 return currentOffset + 3;
3066 }
3067 }
3068 switch (classFileBuffer[currentOffset++] & 0xFF) {
3069 case 'B': // const_value_index, CONSTANT_Integer
3070 annotationVisitor.visit(
3071 elementName, (byte) readInt(cpInfoOffsets[readUnsignedShort(currentOffset)]));
3072 currentOffset += 2;
3073 break;
3074 case 'C': // const_value_index, CONSTANT_Integer
3075 annotationVisitor.visit(
3076 elementName, (char) readInt(cpInfoOffsets[readUnsignedShort(currentOffset)]));
3077 currentOffset += 2;
3078 break;
3079 case 'D': // const_value_index, CONSTANT_Double
3080 case 'F': // const_value_index, CONSTANT_Float
3081 case 'I': // const_value_index, CONSTANT_Integer
3082 case 'J': // const_value_index, CONSTANT_Long
3083 annotationVisitor.visit(
3084 elementName, readConst(readUnsignedShort(currentOffset), charBuffer));
3085 currentOffset += 2;
3086 break;
3087 case 'S': // const_value_index, CONSTANT_Integer
3088 annotationVisitor.visit(
3089 elementName, (short) readInt(cpInfoOffsets[readUnsignedShort(currentOffset)]));
3090 currentOffset += 2;
3091 break;
3092
3093 case 'Z': // const_value_index, CONSTANT_Integer
3094 annotationVisitor.visit(
3095 elementName,
3096 readInt(cpInfoOffsets[readUnsignedShort(currentOffset)]) == 0
3097 ? Boolean.FALSE
3098 : Boolean.TRUE);
3099 currentOffset += 2;
3100 break;
3101 case 's': // const_value_index, CONSTANT_Utf8
3102 annotationVisitor.visit(elementName, readUTF8(currentOffset, charBuffer));
3103 currentOffset += 2;
3104 break;
3105 case 'e': // enum_const_value
3106 annotationVisitor.visitEnum(
3107 elementName,
3108 readUTF8(currentOffset, charBuffer),
3109 readUTF8(currentOffset + 2, charBuffer));
3110 currentOffset += 4;
3111 break;
3112 case 'c': // class_info
3113 annotationVisitor.visit(elementName, Type.getType(readUTF8(currentOffset, charBuffer)));
3114 currentOffset += 2;
3115 break;
3116 case '@': // annotation_value
3117 currentOffset =
3118 readElementValues(
3119 annotationVisitor.visitAnnotation(elementName, readUTF8(currentOffset, charBuffer)),
3120 currentOffset + 2,
3121 true,
3122 charBuffer);
3123 break;
3124 case '[': // array_value
3125 int numValues = readUnsignedShort(currentOffset);
3126 currentOffset += 2;
3127 if (numValues == 0) {
3128 return readElementValues(
3129 annotationVisitor.visitArray(elementName),
3130 currentOffset - 2,
3131 /* named = */ false,
3132 charBuffer);
3133 }
3134 switch (classFileBuffer[currentOffset] & 0xFF) {
3135 case 'B':
3136 byte[] byteValues = new byte[numValues];
3137 for (int i = 0; i < numValues; i++) {
3138 byteValues[i] = (byte) readInt(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]);
3139 currentOffset += 3;
3140 }
3141 annotationVisitor.visit(elementName, byteValues);
3142 break;
3143 case 'Z':
3144 boolean[] booleanValues = new boolean[numValues];
3145 for (int i = 0; i < numValues; i++) {
3146 booleanValues[i] = readInt(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]) != 0;
3147 currentOffset += 3;
3148 }
3149 annotationVisitor.visit(elementName, booleanValues);
3150 break;
3151 case 'S':
3152 short[] shortValues = new short[numValues];
3153 for (int i = 0; i < numValues; i++) {
3154 shortValues[i] = (short) readInt(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]);
3155 currentOffset += 3;
3156 }
3157 annotationVisitor.visit(elementName, shortValues);
3158 break;
3159 case 'C':
3160 char[] charValues = new char[numValues];
3161 for (int i = 0; i < numValues; i++) {
3162 charValues[i] = (char) readInt(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]);
3163 currentOffset += 3;
3164 }
3165 annotationVisitor.visit(elementName, charValues);
3166 break;
3167 case 'I':
3168 int[] intValues = new int[numValues];
3169 for (int i = 0; i < numValues; i++) {
3170 intValues[i] = readInt(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]);
3171 currentOffset += 3;
3172 }
3173 annotationVisitor.visit(elementName, intValues);
3174 break;
3175 case 'J':
3176 long[] longValues = new long[numValues];
3177 for (int i = 0; i < numValues; i++) {
3178 longValues[i] = readLong(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]);
3179 currentOffset += 3;
3180 }
3181 annotationVisitor.visit(elementName, longValues);
3182 break;
3183 case 'F':
3184 float[] floatValues = new float[numValues];
3185 for (int i = 0; i < numValues; i++) {
3186 floatValues[i] =
3187 Float.intBitsToFloat(
3188 readInt(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]));
3189 currentOffset += 3;
3190 }
3191 annotationVisitor.visit(elementName, floatValues);
3192 break;
3193 case 'D':
3194 double[] doubleValues = new double[numValues];
3195 for (int i = 0; i < numValues; i++) {
3196 doubleValues[i] =
3197 Double.longBitsToDouble(
3198 readLong(cpInfoOffsets[readUnsignedShort(currentOffset + 1)]));
3199 currentOffset += 3;
3200 }
3201 annotationVisitor.visit(elementName, doubleValues);
3202 break;
3203 default:
3204 currentOffset =
3205 readElementValues(
3206 annotationVisitor.visitArray(elementName),
3207 currentOffset - 2,
3208 /* named = */ false,
3209 charBuffer);
3210 break;
3211 }
3212 break;
3213 default:
3214 throw new IllegalArgumentException();
3215 }
3216 return currentOffset;
3217 }
3218
3219 // ----------------------------------------------------------------------------------------------
3220 // Methods to parse stack map frames
3221 // ----------------------------------------------------------------------------------------------
3222
3223 /**
3224 * Computes the implicit frame of the method currently being parsed (as defined in the given
3225 * {@link Context}) and stores it in the given context.
3226 *
3227 * @param context information about the class being parsed.
3228 */
3229 private void computeImplicitFrame(final Context context) {
3230 String methodDescriptor = context.currentMethodDescriptor;
3231 Object[] locals = context.currentFrameLocalTypes;
3232 int numLocal = 0;
3233 if ((context.currentMethodAccessFlags & Opcodes.ACC_STATIC) == 0) {
3234 if ("<init>".equals(context.currentMethodName)) {
3235 locals[numLocal++] = Opcodes.UNINITIALIZED_THIS;
3236 } else {
3237 locals[numLocal++] = readClass(header + 2, context.charBuffer);
3238 }
3239 }
3240 // Parse the method descriptor, one argument type descriptor at each iteration. Start by
3241 // skipping the first method descriptor character, which is always '('.
3242 int currentMethodDescritorOffset = 1;
3243 while (true) {
3244 int currentArgumentDescriptorStartOffset = currentMethodDescritorOffset;
3245 switch (methodDescriptor.charAt(currentMethodDescritorOffset++)) {
3246 case 'Z':
3247 case 'C':
3248 case 'B':
3249 case 'S':
3250 case 'I':
3251 locals[numLocal++] = Opcodes.INTEGER;
3252 break;
3253 case 'F':
3254 locals[numLocal++] = Opcodes.FLOAT;
3255 break;
3256 case 'J':
3257 locals[numLocal++] = Opcodes.LONG;
3258 break;
3259 case 'D':
3260 locals[numLocal++] = Opcodes.DOUBLE;
3261 break;
3262 case '[':
3263 while (methodDescriptor.charAt(currentMethodDescritorOffset) == '[') {
3264 ++currentMethodDescritorOffset;
3265 }
3266 if (methodDescriptor.charAt(currentMethodDescritorOffset) == 'L') {
3267 ++currentMethodDescritorOffset;
3268 while (methodDescriptor.charAt(currentMethodDescritorOffset) != ';') {
3269 ++currentMethodDescritorOffset;
3270 }
3271 }
3272 locals[numLocal++] =
3273 methodDescriptor.substring(
3274 currentArgumentDescriptorStartOffset, ++currentMethodDescritorOffset);
3275 break;
3276 case 'L':
3277 while (methodDescriptor.charAt(currentMethodDescritorOffset) != ';') {
3278 ++currentMethodDescritorOffset;
3279 }
3280 locals[numLocal++] =
3281 methodDescriptor.substring(
3282 currentArgumentDescriptorStartOffset + 1, currentMethodDescritorOffset++);
3283 break;
3284 default:
3285 context.currentFrameLocalCount = numLocal;
3286 return;
3287 }
3288 }
3289 }
3290
3291 /**
3292 * Reads a JVMS 'stack_map_frame' structure and stores the result in the given {@link Context}
3293 * object. This method can also be used to read a full_frame structure, excluding its frame_type
3294 * field (this is used to parse the legacy StackMap attributes).
3295 *
3296 * @param stackMapFrameOffset the start offset in {@link #classFileBuffer} of the
3297 * stack_map_frame_value structure to be read, or the start offset of a full_frame structure
3298 * (excluding its frame_type field).
3299 * @param compressed true to read a 'stack_map_frame' structure, false to read a 'full_frame'
3300 * structure without its frame_type field.
3301 * @param expand if the stack map frame must be expanded. See {@link #EXPAND_FRAMES}.
3302 * @param context where the parsed stack map frame must be stored.
3303 * @return the end offset of the JVMS 'stack_map_frame' or 'full_frame' structure.
3304 */
3305 private int readStackMapFrame(
3306 final int stackMapFrameOffset,
3307 final boolean compressed,
3308 final boolean expand,
3309 final Context context) {
3310 int currentOffset = stackMapFrameOffset;
3311 final char[] charBuffer = context.charBuffer;
3312 final Label[] labels = context.currentMethodLabels;
3313 int frameType;
3314 if (compressed) {
3315 // Read the frame_type field.
3316 frameType = classFileBuffer[currentOffset++] & 0xFF;
3317 } else {
3318 frameType = Frame.FULL_FRAME;
3319 context.currentFrameOffset = -1;
3320 }
3321 int offsetDelta;
3322 context.currentFrameLocalCountDelta = 0;
3323 if (frameType < Frame.SAME_LOCALS_1_STACK_ITEM_FRAME) {
3324 offsetDelta = frameType;
3325 context.currentFrameType = Opcodes.F_SAME;
3326 context.currentFrameStackCount = 0;
3327 } else if (frameType < Frame.RESERVED) {
3328 offsetDelta = frameType - Frame.SAME_LOCALS_1_STACK_ITEM_FRAME;
3329 currentOffset =
3330 readVerificationTypeInfo(
3331 currentOffset, context.currentFrameStackTypes, 0, charBuffer, labels);
3332 context.currentFrameType = Opcodes.F_SAME1;
3333 context.currentFrameStackCount = 1;
3334 } else if (frameType >= Frame.SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED) {
3335 offsetDelta = readUnsignedShort(currentOffset);
3336 currentOffset += 2;
3337 if (frameType == Frame.SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED) {
3338 currentOffset =
3339 readVerificationTypeInfo(
3340 currentOffset, context.currentFrameStackTypes, 0, charBuffer, labels);
3341 context.currentFrameType = Opcodes.F_SAME1;
3342 context.currentFrameStackCount = 1;
3343 } else if (frameType >= Frame.CHOP_FRAME && frameType < Frame.SAME_FRAME_EXTENDED) {
3344 context.currentFrameType = Opcodes.F_CHOP;
3345 context.currentFrameLocalCountDelta = Frame.SAME_FRAME_EXTENDED - frameType;
3346 context.currentFrameLocalCount -= context.currentFrameLocalCountDelta;
3347 context.currentFrameStackCount = 0;
3348 } else if (frameType == Frame.SAME_FRAME_EXTENDED) {
3349 context.currentFrameType = Opcodes.F_SAME;
3350 context.currentFrameStackCount = 0;
3351 } else if (frameType < Frame.FULL_FRAME) {
3352 int local = expand ? context.currentFrameLocalCount : 0;
3353 for (int k = frameType - Frame.SAME_FRAME_EXTENDED; k > 0; k--) {
3354 currentOffset =
3355 readVerificationTypeInfo(
3356 currentOffset, context.currentFrameLocalTypes, local++, charBuffer, labels);
3357 }
3358 context.currentFrameType = Opcodes.F_APPEND;
3359 context.currentFrameLocalCountDelta = frameType - Frame.SAME_FRAME_EXTENDED;
3360 context.currentFrameLocalCount += context.currentFrameLocalCountDelta;
3361 context.currentFrameStackCount = 0;
3362 } else {
3363 final int numberOfLocals = readUnsignedShort(currentOffset);
3364 currentOffset += 2;
3365 context.currentFrameType = Opcodes.F_FULL;
3366 context.currentFrameLocalCountDelta = numberOfLocals;
3367 context.currentFrameLocalCount = numberOfLocals;
3368 for (int local = 0; local < numberOfLocals; ++local) {
3369 currentOffset =
3370 readVerificationTypeInfo(
3371 currentOffset, context.currentFrameLocalTypes, local, charBuffer, labels);
3372 }
3373 final int numberOfStackItems = readUnsignedShort(currentOffset);
3374 currentOffset += 2;
3375 context.currentFrameStackCount = numberOfStackItems;
3376 for (int stack = 0; stack < numberOfStackItems; ++stack) {
3377 currentOffset =
3378 readVerificationTypeInfo(
3379 currentOffset, context.currentFrameStackTypes, stack, charBuffer, labels);
3380 }
3381 }
3382 } else {
3383 throw new IllegalArgumentException();
3384 }
3385 context.currentFrameOffset += offsetDelta + 1;
3386 createLabel(context.currentFrameOffset, labels);
3387 return currentOffset;
3388 }
3389
3390 /**
3391 * Reads a JVMS 'verification_type_info' structure and stores it at the given index in the given
3392 * array.
3393 *
3394 * @param verificationTypeInfoOffset the start offset of the 'verification_type_info' structure to
3395 * read.
3396 * @param frame the array where the parsed type must be stored.
3397 * @param index the index in 'frame' where the parsed type must be stored.
3398 * @param charBuffer the buffer used to read strings in the constant pool.
3399 * @param labels the labels of the method currently being parsed, indexed by their offset. If the
3400 * parsed type is an ITEM_Uninitialized, a new label for the corresponding NEW instruction is
3401 * stored in this array if it does not already exist.
3402 * @return the end offset of the JVMS 'verification_type_info' structure.
3403 */
3404 private int readVerificationTypeInfo(
3405 final int verificationTypeInfoOffset,
3406 final Object[] frame,
3407 final int index,
3408 final char[] charBuffer,
3409 final Label[] labels) {
3410 int currentOffset = verificationTypeInfoOffset;
3411 int tag = classFileBuffer[currentOffset++] & 0xFF;
3412 switch (tag) {
3413 case Frame.ITEM_TOP:
3414 frame[index] = Opcodes.TOP;
3415 break;
3416 case Frame.ITEM_INTEGER:
3417 frame[index] = Opcodes.INTEGER;
3418 break;
3419 case Frame.ITEM_FLOAT:
3420 frame[index] = Opcodes.FLOAT;
3421 break;
3422 case Frame.ITEM_DOUBLE:
3423 frame[index] = Opcodes.DOUBLE;
3424 break;
3425 case Frame.ITEM_LONG:
3426 frame[index] = Opcodes.LONG;
3427 break;
3428 case Frame.ITEM_NULL:
3429 frame[index] = Opcodes.NULL;
3430 break;
3431 case Frame.ITEM_UNINITIALIZED_THIS:
3432 frame[index] = Opcodes.UNINITIALIZED_THIS;
3433 break;
3434 case Frame.ITEM_OBJECT:
3435 frame[index] = readClass(currentOffset, charBuffer);
3436 currentOffset += 2;
3437 break;
3438 case Frame.ITEM_UNINITIALIZED:
3439 frame[index] = createLabel(readUnsignedShort(currentOffset), labels);
3440 currentOffset += 2;
3441 break;
3442 default:
3443 throw new IllegalArgumentException();
3444 }
3445 return currentOffset;
3446 }
3447
3448 // ----------------------------------------------------------------------------------------------
3449 // Methods to parse attributes
3450 // ----------------------------------------------------------------------------------------------
3451
3452 /**
3453 * Returns the offset in {@link #classFileBuffer} of the first ClassFile's 'attributes' array
3454 * field entry.
3455 *
3456 * @return the offset in {@link #classFileBuffer} of the first ClassFile's 'attributes' array
3457 * field entry.
3458 */
3459 final int getFirstAttributeOffset() {
3460 // Skip the access_flags, this_class, super_class, and interfaces_count fields (using 2 bytes
3461 // each), as well as the interfaces array field (2 bytes per interface).
3462 int currentOffset = header + 8 + readUnsignedShort(header + 6) * 2;
3463
3464 // Read the fields_count field.
3465 int fieldsCount = readUnsignedShort(currentOffset);
3466 currentOffset += 2;
3467 // Skip the 'fields' array field.
3468 while (fieldsCount-- > 0) {
3469 // Invariant: currentOffset is the offset of a field_info structure.
3470 // Skip the access_flags, name_index and descriptor_index fields (2 bytes each), and read the
3471 // attributes_count field.
3472 int attributesCount = readUnsignedShort(currentOffset + 6);
3473 currentOffset += 8;
3474 // Skip the 'attributes' array field.
3475 while (attributesCount-- > 0) {
3476 // Invariant: currentOffset is the offset of an attribute_info structure.
3477 // Read the attribute_length field (2 bytes after the start of the attribute_info) and skip
3478 // this many bytes, plus 6 for the attribute_name_index and attribute_length fields
3479 // (yielding the total size of the attribute_info structure).
3480 currentOffset += 6 + readInt(currentOffset + 2);
3481 }
3482 }
3483
3484 // Skip the methods_count and 'methods' fields, using the same method as above.
3485 int methodsCount = readUnsignedShort(currentOffset);
3486 currentOffset += 2;
3487 while (methodsCount-- > 0) {
3488 int attributesCount = readUnsignedShort(currentOffset + 6);
3489 currentOffset += 8;
3490 while (attributesCount-- > 0) {
3491 currentOffset += 6 + readInt(currentOffset + 2);
3492 }
3493 }
3494
3495 // Skip the ClassFile's attributes_count field.
3496 return currentOffset + 2;
3497 }
3498
3499 /**
3500 * Reads the BootstrapMethods attribute to compute the offset of each bootstrap method.
3501 *
3502 * @param maxStringLength a conservative estimate of the maximum length of the strings contained
3503 * in the constant pool of the class.
3504 * @return the offsets of the bootstrap methods.
3505 */
3506 private int[] readBootstrapMethodsAttribute(final int maxStringLength) {
3507 char[] charBuffer = new char[maxStringLength];
3508 int currentAttributeOffset = getFirstAttributeOffset();
3509 for (int i = readUnsignedShort(currentAttributeOffset - 2); i > 0; --i) {
3510 // Read the attribute_info's attribute_name and attribute_length fields.
3511 String attributeName = readUTF8(currentAttributeOffset, charBuffer);
3512 int attributeLength = readInt(currentAttributeOffset + 2);
3513 currentAttributeOffset += 6;
3514 if (Constants.BOOTSTRAP_METHODS.equals(attributeName)) {
3515 // Read the num_bootstrap_methods field and create an array of this size.
3516 int[] result = new int[readUnsignedShort(currentAttributeOffset)];
3517 // Compute and store the offset of each 'bootstrap_methods' array field entry.
3518 int currentBootstrapMethodOffset = currentAttributeOffset + 2;
3519 for (int j = 0; j < result.length; ++j) {
3520 result[j] = currentBootstrapMethodOffset;
3521 // Skip the bootstrap_method_ref and num_bootstrap_arguments fields (2 bytes each),
3522 // as well as the bootstrap_arguments array field (of size num_bootstrap_arguments * 2).
3523 currentBootstrapMethodOffset +=
3524 4 + readUnsignedShort(currentBootstrapMethodOffset + 2) * 2;
3525 }
3526 return result;
3527 }
3528 currentAttributeOffset += attributeLength;
3529 }
3530 throw new IllegalArgumentException();
3531 }
3532
3533 /**
3534 * Reads a non standard JVMS 'attribute' structure in {@link #classFileBuffer}.
3535 *
3536 * @param attributePrototypes prototypes of the attributes that must be parsed during the visit of
3537 * the class. Any attribute whose type is not equal to the type of one the prototypes will not
3538 * be parsed: its byte array value will be passed unchanged to the ClassWriter.
3539 * @param type the type of the attribute.
3540 * @param offset the start offset of the JVMS 'attribute' structure in {@link #classFileBuffer}.
3541 * The 6 attribute header bytes (attribute_name_index and attribute_length) are not taken into
3542 * account here.
3543 * @param length the length of the attribute's content (excluding the 6 attribute header bytes).
3544 * @param charBuffer the buffer to be used to read strings in the constant pool.
3545 * @param codeAttributeOffset the start offset of the enclosing Code attribute in {@link
3546 * #classFileBuffer}, or -1 if the attribute to be read is not a code attribute. The 6
3547 * attribute header bytes (attribute_name_index and attribute_length) are not taken into
3548 * account here.
3549 * @param labels the labels of the method's code, or {@literal null} if the attribute to be read
3550 * is not a code attribute.
3551 * @return the attribute that has been read.
3552 */
3553 private Attribute readAttribute(
3554 final Attribute[] attributePrototypes,
3555 final String type,
3556 final int offset,
3557 final int length,
3558 final char[] charBuffer,
3559 final int codeAttributeOffset,
3560 final Label[] labels) {
3561 for (Attribute attributePrototype : attributePrototypes) {
3562 if (attributePrototype.type.equals(type)) {
3563 return attributePrototype.read(
3564 this, offset, length, charBuffer, codeAttributeOffset, labels);
3565 }
3566 }
3567 return new Attribute(type).read(this, offset, length, null, -1, null);
3568 }
3569
3570 // -----------------------------------------------------------------------------------------------
3571 // Utility methods: low level parsing
3572 // -----------------------------------------------------------------------------------------------
3573
3574 /**
3575 * Returns the number of entries in the class's constant pool table.
3576 *
3577 * @return the number of entries in the class's constant pool table.
3578 */
3579 public int getItemCount() {
3580 return cpInfoOffsets.length;
3581 }
3582
3583 /**
3584 * Returns the start offset in this {@link ClassReader} of a JVMS 'cp_info' structure (i.e. a
3585 * constant pool entry), plus one. <i>This method is intended for {@link Attribute} sub classes,
3586 * and is normally not needed by class generators or adapters.</i>
3587 *
3588 * @param constantPoolEntryIndex the index a constant pool entry in the class's constant pool
3589 * table.
3590 * @return the start offset in this {@link ClassReader} of the corresponding JVMS 'cp_info'
3591 * structure, plus one.
3592 */
3593 public int getItem(final int constantPoolEntryIndex) {
3594 return cpInfoOffsets[constantPoolEntryIndex];
3595 }
3596
3597 /**
3598 * Returns a conservative estimate of the maximum length of the strings contained in the class's
3599 * constant pool table.
3600 *
3601 * @return a conservative estimate of the maximum length of the strings contained in the class's
3602 * constant pool table.
3603 */
3604 public int getMaxStringLength() {
3605 return maxStringLength;
3606 }
3607
3608 /**
3609 * Reads a byte value in this {@link ClassReader}. <i>This method is intended for {@link
3610 * Attribute} sub classes, and is normally not needed by class generators or adapters.</i>
3611 *
3612 * @param offset the start offset of the value to be read in this {@link ClassReader}.
3613 * @return the read value.
3614 */
3615 public int readByte(final int offset) {
3616 return classFileBuffer[offset] & 0xFF;
3617 }
3618
3619 /**
3620 * Reads an unsigned short value in this {@link ClassReader}. <i>This method is intended for
3621 * {@link Attribute} sub classes, and is normally not needed by class generators or adapters.</i>
3622 *
3623 * @param offset the start index of the value to be read in this {@link ClassReader}.
3624 * @return the read value.
3625 */
3626 public int readUnsignedShort(final int offset) {
3627 byte[] classBuffer = classFileBuffer;
3628 return ((classBuffer[offset] & 0xFF) << 8) | (classBuffer[offset + 1] & 0xFF);
3629 }
3630
3631 /**
3632 * Reads a signed short value in this {@link ClassReader}. <i>This method is intended for {@link
3633 * Attribute} sub classes, and is normally not needed by class generators or adapters.</i>
3634 *
3635 * @param offset the start offset of the value to be read in this {@link ClassReader}.
3636 * @return the read value.
3637 */
3638 public short readShort(final int offset) {
3639 byte[] classBuffer = classFileBuffer;
3640 return (short) (((classBuffer[offset] & 0xFF) << 8) | (classBuffer[offset + 1] & 0xFF));
3641 }
3642
3643 /**
3644 * Reads a signed int value in this {@link ClassReader}. <i>This method is intended for {@link
3645 * Attribute} sub classes, and is normally not needed by class generators or adapters.</i>
3646 *
3647 * @param offset the start offset of the value to be read in this {@link ClassReader}.
3648 * @return the read value.
3649 */
3650 public int readInt(final int offset) {
3651 byte[] classBuffer = classFileBuffer;
3652 return ((classBuffer[offset] & 0xFF) << 24)
3653 | ((classBuffer[offset + 1] & 0xFF) << 16)
3654 | ((classBuffer[offset + 2] & 0xFF) << 8)
3655 | (classBuffer[offset + 3] & 0xFF);
3656 }
3657
3658 /**
3659 * Reads a signed long value in this {@link ClassReader}. <i>This method is intended for {@link
3660 * Attribute} sub classes, and is normally not needed by class generators or adapters.</i>
3661 *
3662 * @param offset the start offset of the value to be read in this {@link ClassReader}.
3663 * @return the read value.
3664 */
3665 public long readLong(final int offset) {
3666 long l1 = readInt(offset);
3667 long l0 = readInt(offset + 4) & 0xFFFFFFFFL;
3668 return (l1 << 32) | l0;
3669 }
3670
3671 /**
3672 * Reads a CONSTANT_Utf8 constant pool entry in this {@link ClassReader}. <i>This method is
3673 * intended for {@link Attribute} sub classes, and is normally not needed by class generators or
3674 * adapters.</i>
3675 *
3676 * @param offset the start offset of an unsigned short value in this {@link ClassReader}, whose
3677 * value is the index of a CONSTANT_Utf8 entry in the class's constant pool table.
3678 * @param charBuffer the buffer to be used to read the string. This buffer must be sufficiently
3679 * large. It is not automatically resized.
3680 * @return the String corresponding to the specified CONSTANT_Utf8 entry.
3681 */
3682 // DontCheck(AbbreviationAsWordInName): can't be renamed (for backward binary compatibility).
3683 public String readUTF8(final int offset, final char[] charBuffer) {
3684 int constantPoolEntryIndex = readUnsignedShort(offset);
3685 if (offset == 0 || constantPoolEntryIndex == 0) {
3686 return null;
3687 }
3688 return readUtf(constantPoolEntryIndex, charBuffer);
3689 }
3690
3691 /**
3692 * Reads a CONSTANT_Utf8 constant pool entry in {@link #classFileBuffer}.
3693 *
3694 * @param constantPoolEntryIndex the index of a CONSTANT_Utf8 entry in the class's constant pool
3695 * table.
3696 * @param charBuffer the buffer to be used to read the string. This buffer must be sufficiently
3697 * large. It is not automatically resized.
3698 * @return the String corresponding to the specified CONSTANT_Utf8 entry.
3699 */
3700 final String readUtf(final int constantPoolEntryIndex, final char[] charBuffer) {
3701 String value = constantUtf8Values[constantPoolEntryIndex];
3702 if (value != null) {
3703 return value;
3704 }
3705 int cpInfoOffset = cpInfoOffsets[constantPoolEntryIndex];
3706 return constantUtf8Values[constantPoolEntryIndex] =
3707 readUtf(cpInfoOffset + 2, readUnsignedShort(cpInfoOffset), charBuffer);
3708 }
3709
3710 /**
3711 * Reads an UTF8 string in {@link #classFileBuffer}.
3712 *
3713 * @param utfOffset the start offset of the UTF8 string to be read.
3714 * @param utfLength the length of the UTF8 string to be read.
3715 * @param charBuffer the buffer to be used to read the string. This buffer must be sufficiently
3716 * large. It is not automatically resized.
3717 * @return the String corresponding to the specified UTF8 string.
3718 */
3719 private String readUtf(final int utfOffset, final int utfLength, final char[] charBuffer) {
3720 int currentOffset = utfOffset;
3721 int endOffset = currentOffset + utfLength;
3722 int strLength = 0;
3723 byte[] classBuffer = classFileBuffer;
3724 while (currentOffset < endOffset) {
3725 int currentByte = classBuffer[currentOffset++];
3726 if ((currentByte & 0x80) == 0) {
3727 charBuffer[strLength++] = (char) (currentByte & 0x7F);
3728 } else if ((currentByte & 0xE0) == 0xC0) {
3729 charBuffer[strLength++] =
3730 (char) (((currentByte & 0x1F) << 6) + (classBuffer[currentOffset++] & 0x3F));
3731 } else {
3732 charBuffer[strLength++] =
3733 (char)
3734 (((currentByte & 0xF) << 12)
3735 + ((classBuffer[currentOffset++] & 0x3F) << 6)
3736 + (classBuffer[currentOffset++] & 0x3F));
3737 }
3738 }
3739 return new String(charBuffer, 0, strLength);
3740 }
3741
3742 /**
3743 * Reads a CONSTANT_Class, CONSTANT_String, CONSTANT_MethodType, CONSTANT_Module or
3744 * CONSTANT_Package constant pool entry in {@link #classFileBuffer}. <i>This method is intended
3745 * for {@link Attribute} sub classes, and is normally not needed by class generators or
3746 * adapters.</i>
3747 *
3748 * @param offset the start offset of an unsigned short value in {@link #classFileBuffer}, whose
3749 * value is the index of a CONSTANT_Class, CONSTANT_String, CONSTANT_MethodType,
3750 * CONSTANT_Module or CONSTANT_Package entry in class's constant pool table.
3751 * @param charBuffer the buffer to be used to read the item. This buffer must be sufficiently
3752 * large. It is not automatically resized.
3753 * @return the String corresponding to the specified constant pool entry.
3754 */
3755 private String readStringish(final int offset, final char[] charBuffer) {
3756 // Get the start offset of the cp_info structure (plus one), and read the CONSTANT_Utf8 entry
3757 // designated by the first two bytes of this cp_info.
3758 return readUTF8(cpInfoOffsets[readUnsignedShort(offset)], charBuffer);
3759 }
3760
3761 /**
3762 * Reads a CONSTANT_Class constant pool entry in this {@link ClassReader}. <i>This method is
3763 * intended for {@link Attribute} sub classes, and is normally not needed by class generators or
3764 * adapters.</i>
3765 *
3766 * @param offset the start offset of an unsigned short value in this {@link ClassReader}, whose
3767 * value is the index of a CONSTANT_Class entry in class's constant pool table.
3768 * @param charBuffer the buffer to be used to read the item. This buffer must be sufficiently
3769 * large. It is not automatically resized.
3770 * @return the String corresponding to the specified CONSTANT_Class entry.
3771 */
3772 public String readClass(final int offset, final char[] charBuffer) {
3773 return readStringish(offset, charBuffer);
3774 }
3775
3776 /**
3777 * Reads a CONSTANT_Module constant pool entry in this {@link ClassReader}. <i>This method is
3778 * intended for {@link Attribute} sub classes, and is normally not needed by class generators or
3779 * adapters.</i>
3780 *
3781 * @param offset the start offset of an unsigned short value in this {@link ClassReader}, whose
3782 * value is the index of a CONSTANT_Module entry in class's constant pool table.
3783 * @param charBuffer the buffer to be used to read the item. This buffer must be sufficiently
3784 * large. It is not automatically resized.
3785 * @return the String corresponding to the specified CONSTANT_Module entry.
3786 */
3787 public String readModule(final int offset, final char[] charBuffer) {
3788 return readStringish(offset, charBuffer);
3789 }
3790
3791 /**
3792 * Reads a CONSTANT_Package constant pool entry in this {@link ClassReader}. <i>This method is
3793 * intended for {@link Attribute} sub classes, and is normally not needed by class generators or
3794 * adapters.</i>
3795 *
3796 * @param offset the start offset of an unsigned short value in this {@link ClassReader}, whose
3797 * value is the index of a CONSTANT_Package entry in class's constant pool table.
3798 * @param charBuffer the buffer to be used to read the item. This buffer must be sufficiently
3799 * large. It is not automatically resized.
3800 * @return the String corresponding to the specified CONSTANT_Package entry.
3801 */
3802 public String readPackage(final int offset, final char[] charBuffer) {
3803 return readStringish(offset, charBuffer);
3804 }
3805
3806 /**
3807 * Reads a CONSTANT_Dynamic constant pool entry in {@link #classFileBuffer}.
3808 *
3809 * @param constantPoolEntryIndex the index of a CONSTANT_Dynamic entry in the class's constant
3810 * pool table.
3811 * @param charBuffer the buffer to be used to read the string. This buffer must be sufficiently
3812 * large. It is not automatically resized.
3813 * @return the ConstantDynamic corresponding to the specified CONSTANT_Dynamic entry.
3814 */
3815 private ConstantDynamic readConstantDynamic(
3816 final int constantPoolEntryIndex, final char[] charBuffer) {
3817 ConstantDynamic constantDynamic = constantDynamicValues[constantPoolEntryIndex];
3818 if (constantDynamic != null) {
3819 return constantDynamic;
3820 }
3821 int cpInfoOffset = cpInfoOffsets[constantPoolEntryIndex];
3822 int nameAndTypeCpInfoOffset = cpInfoOffsets[readUnsignedShort(cpInfoOffset + 2)];
3823 String name = readUTF8(nameAndTypeCpInfoOffset, charBuffer);
3824 String descriptor = readUTF8(nameAndTypeCpInfoOffset + 2, charBuffer);
3825 int bootstrapMethodOffset = bootstrapMethodOffsets[readUnsignedShort(cpInfoOffset)];
3826 Handle handle = (Handle) readConst(readUnsignedShort(bootstrapMethodOffset), charBuffer);
3827 Object[] bootstrapMethodArguments = new Object[readUnsignedShort(bootstrapMethodOffset + 2)];
3828 bootstrapMethodOffset += 4;
3829 for (int i = 0; i < bootstrapMethodArguments.length; i++) {
3830 bootstrapMethodArguments[i] = readConst(readUnsignedShort(bootstrapMethodOffset), charBuffer);
3831 bootstrapMethodOffset += 2;
3832 }
3833 return constantDynamicValues[constantPoolEntryIndex] =
3834 new ConstantDynamic(name, descriptor, handle, bootstrapMethodArguments);
3835 }
3836
3837 /**
3838 * Reads a numeric or string constant pool entry in this {@link ClassReader}. <i>This method is
3839 * intended for {@link Attribute} sub classes, and is normally not needed by class generators or
3840 * adapters.</i>
3841 *
3842 * @param constantPoolEntryIndex the index of a CONSTANT_Integer, CONSTANT_Float, CONSTANT_Long,
3843 * CONSTANT_Double, CONSTANT_Class, CONSTANT_String, CONSTANT_MethodType,
3844 * CONSTANT_MethodHandle or CONSTANT_Dynamic entry in the class's constant pool.
3845 * @param charBuffer the buffer to be used to read strings. This buffer must be sufficiently
3846 * large. It is not automatically resized.
3847 * @return the {@link Integer}, {@link Float}, {@link Long}, {@link Double}, {@link String},
3848 * {@link Type}, {@link Handle} or {@link ConstantDynamic} corresponding to the specified
3849 * constant pool entry.
3850 */
3851 public Object readConst(final int constantPoolEntryIndex, final char[] charBuffer) {
3852 int cpInfoOffset = cpInfoOffsets[constantPoolEntryIndex];
3853 switch (classFileBuffer[cpInfoOffset - 1]) {
3854 case Symbol.CONSTANT_INTEGER_TAG:
3855 return readInt(cpInfoOffset);
3856 case Symbol.CONSTANT_FLOAT_TAG:
3857 return Float.intBitsToFloat(readInt(cpInfoOffset));
3858 case Symbol.CONSTANT_LONG_TAG:
3859 return readLong(cpInfoOffset);
3860 case Symbol.CONSTANT_DOUBLE_TAG:
3861 return Double.longBitsToDouble(readLong(cpInfoOffset));
3862 case Symbol.CONSTANT_CLASS_TAG:
3863 return Type.getObjectType(readUTF8(cpInfoOffset, charBuffer));
3864 case Symbol.CONSTANT_STRING_TAG:
3865 return readUTF8(cpInfoOffset, charBuffer);
3866 case Symbol.CONSTANT_METHOD_TYPE_TAG:
3867 return Type.getMethodType(readUTF8(cpInfoOffset, charBuffer));
3868 case Symbol.CONSTANT_METHOD_HANDLE_TAG:
3869 int referenceKind = readByte(cpInfoOffset);
3870 int referenceCpInfoOffset = cpInfoOffsets[readUnsignedShort(cpInfoOffset + 1)];
3871 int nameAndTypeCpInfoOffset = cpInfoOffsets[readUnsignedShort(referenceCpInfoOffset + 2)];
3872 String owner = readClass(referenceCpInfoOffset, charBuffer);
3873 String name = readUTF8(nameAndTypeCpInfoOffset, charBuffer);
3874 String descriptor = readUTF8(nameAndTypeCpInfoOffset + 2, charBuffer);
3875 boolean isInterface =
3876 classFileBuffer[referenceCpInfoOffset - 1] == Symbol.CONSTANT_INTERFACE_METHODREF_TAG;
3877 return new Handle(referenceKind, owner, name, descriptor, isInterface);
3878 case Symbol.CONSTANT_DYNAMIC_TAG:
3879 return readConstantDynamic(constantPoolEntryIndex, charBuffer);
3880 default:
3881 throw new IllegalArgumentException();
3882 }
3883 }
3884 }
3885