1 /*
   2  * Copyright (c) 2005, 2021, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/symbolTable.hpp"
  27 #include "interpreter/bytecodeStream.hpp"
  28 #include "memory/universe.hpp"
  29 #include "oops/fieldStreams.inline.hpp"
  30 #include "oops/recordComponent.hpp"
  31 #include "prims/jvmtiClassFileReconstituter.hpp"
  32 #include "runtime/handles.inline.hpp"
  33 #include "runtime/signature.hpp"
  34 #include "utilities/bytes.hpp"
  35 
  36 // FIXME: add Deprecated attribute
  37 // FIXME: fix Synthetic attribute
  38 // FIXME: per Serguei, add error return handling for ConstantPool::copy_cpool_bytes()
  39 
  40 JvmtiConstantPoolReconstituter::JvmtiConstantPoolReconstituter(InstanceKlass* ik) {
  41   set_error(JVMTI_ERROR_NONE);
  42   _ik = ik;
  43   _cpool = constantPoolHandle(Thread::current(), ik->constants());
  44   _symmap = new SymbolHashMap();
  45   _classmap = new SymbolHashMap();
  46   _cpool_size = _cpool->hash_entries_to(_symmap, _classmap);
  47   if (_cpool_size == 0) {
  48     set_error(JVMTI_ERROR_OUT_OF_MEMORY);
  49   } else if (_cpool_size < 0) {
  50     set_error(JVMTI_ERROR_INTERNAL);
  51   }
  52 }
  53 
  54 // Write the field information portion of ClassFile structure
  55 // JVMSpec|     u2 fields_count;
  56 // JVMSpec|     field_info fields[fields_count];
  57 void JvmtiClassFileReconstituter::write_field_infos() {
  58   HandleMark hm(thread());
  59   Array<AnnotationArray*>* fields_anno = ik()->fields_annotations();
  60   Array<AnnotationArray*>* fields_type_anno = ik()->fields_type_annotations();
  61 
  62   // Compute the real number of Java fields
  63   int java_fields = ik()->java_fields_count();
  64 
  65   write_u2(java_fields);
  66   for (JavaFieldStream fs(ik()); !fs.done(); fs.next()) {
  67     AccessFlags access_flags = fs.access_flags();
  68     int name_index = fs.name_index();
  69     int signature_index = fs.signature_index();
  70     int initial_value_index = fs.initval_index();
  71     guarantee(name_index != 0 && signature_index != 0, "bad constant pool index for field");
  72     // int offset = ik()->field_offset( index );
  73     int generic_signature_index = fs.generic_signature_index();
  74     AnnotationArray* anno = fields_anno == NULL ? NULL : fields_anno->at(fs.index());
  75     AnnotationArray* type_anno = fields_type_anno == NULL ? NULL : fields_type_anno->at(fs.index());
  76 
  77     // JVMSpec|   field_info {
  78     // JVMSpec|         u2 access_flags;
  79     // JVMSpec|         u2 name_index;
  80     // JVMSpec|         u2 descriptor_index;
  81     // JVMSpec|         u2 attributes_count;
  82     // JVMSpec|         attribute_info attributes[attributes_count];
  83     // JVMSpec|   }
  84 
  85     write_u2(access_flags.as_int() & JVM_RECOGNIZED_FIELD_MODIFIERS);
  86     write_u2(name_index);
  87     write_u2(signature_index);
  88     int attr_count = 0;
  89     if (initial_value_index != 0) {
  90       ++attr_count;
  91     }
  92     if (access_flags.is_synthetic()) {
  93       // ++attr_count;
  94     }
  95     if (generic_signature_index != 0) {
  96       ++attr_count;
  97     }
  98     if (anno != NULL) {
  99       ++attr_count;     // has RuntimeVisibleAnnotations attribute
 100     }
 101     if (type_anno != NULL) {
 102       ++attr_count;     // has RuntimeVisibleTypeAnnotations attribute
 103     }
 104 
 105     write_u2(attr_count);
 106 
 107     if (initial_value_index != 0) {
 108       write_attribute_name_index("ConstantValue");
 109       write_u4(2); //length always 2
 110       write_u2(initial_value_index);
 111     }
 112     if (access_flags.is_synthetic()) {
 113       // write_synthetic_attribute();
 114     }
 115     if (generic_signature_index != 0) {
 116       write_signature_attribute(generic_signature_index);
 117     }
 118     if (anno != NULL) {
 119       write_annotations_attribute("RuntimeVisibleAnnotations", anno);
 120     }
 121     if (type_anno != NULL) {
 122       write_annotations_attribute("RuntimeVisibleTypeAnnotations", type_anno);
 123     }
 124   }
 125 }
 126 
 127 // Write Code attribute
 128 // JVMSpec|   Code_attribute {
 129 // JVMSpec|     u2 attribute_name_index;
 130 // JVMSpec|     u4 attribute_length;
 131 // JVMSpec|     u2 max_stack;
 132 // JVMSpec|     u2 max_locals;
 133 // JVMSpec|     u4 code_length;
 134 // JVMSpec|     u1 code[code_length];
 135 // JVMSpec|     u2 exception_table_length;
 136 // JVMSpec|     {       u2 start_pc;
 137 // JVMSpec|             u2 end_pc;
 138 // JVMSpec|             u2  handler_pc;
 139 // JVMSpec|             u2  catch_type;
 140 // JVMSpec|     }       exception_table[exception_table_length];
 141 // JVMSpec|     u2 attributes_count;
 142 // JVMSpec|     attribute_info attributes[attributes_count];
 143 // JVMSpec|   }
 144 void JvmtiClassFileReconstituter::write_code_attribute(const methodHandle& method) {
 145   ConstMethod* const_method = method->constMethod();
 146   u2 line_num_cnt = 0;
 147   int stackmap_len = 0;
 148   int local_variable_table_length = 0;
 149   int local_variable_type_table_length = 0;
 150 
 151   // compute number and length of attributes
 152   int attr_count = 0;
 153   int attr_size = 0;
 154   if (const_method->has_linenumber_table()) {
 155     line_num_cnt = line_number_table_entries(method);
 156     if (line_num_cnt != 0) {
 157       ++attr_count;
 158       // Compute the complete size of the line number table attribute:
 159       //      LineNumberTable_attribute {
 160       //        u2 attribute_name_index;
 161       //        u4 attribute_length;
 162       //        u2 line_number_table_length;
 163       //        {  u2 start_pc;
 164       //           u2 line_number;
 165       //        } line_number_table[line_number_table_length];
 166       //      }
 167       attr_size += 2 + 4 + 2 + line_num_cnt * (2 + 2);
 168     }
 169   }
 170   if (method->has_stackmap_table()) {
 171     stackmap_len = method->stackmap_data()->length();
 172     if (stackmap_len != 0) {
 173       ++attr_count;
 174       // Compute the  size of the stack map table attribute (VM stores raw):
 175       //      StackMapTable_attribute {
 176       //        u2 attribute_name_index;
 177       //        u4 attribute_length;
 178       //        u2 number_of_entries;
 179       //        stack_map_frame_entries[number_of_entries];
 180       //      }
 181       attr_size += 2 + 4 + stackmap_len;
 182     }
 183   }
 184   if (method->has_localvariable_table()) {
 185     local_variable_table_length = method->localvariable_table_length();
 186     if (local_variable_table_length != 0) {
 187       ++attr_count;
 188       // Compute the size of the local variable table attribute (VM stores raw):
 189       // LocalVariableTable_attribute {
 190       //   u2 attribute_name_index;
 191       //   u4 attribute_length;
 192       //   u2 local_variable_table_length;
 193       //   {
 194       //     u2 start_pc;
 195       //     u2 length;
 196       //     u2 name_index;
 197       //     u2 descriptor_index;
 198       //     u2 index;
 199       //   }
 200       attr_size += 2 + 4 + 2 + local_variable_table_length * (2 + 2 + 2 + 2 + 2);
 201 
 202       // Local variables with generic signatures must have LVTT entries
 203       LocalVariableTableElement *elem = method->localvariable_table_start();
 204       for (int idx = 0; idx < local_variable_table_length; idx++) {
 205         if (elem[idx].signature_cp_index != 0) {
 206           local_variable_type_table_length++;
 207         }
 208       }
 209 
 210       if (local_variable_type_table_length != 0) {
 211         ++attr_count;
 212         // Compute the size of the local variable type table attribute (VM stores raw):
 213         // LocalVariableTypeTable_attribute {
 214         //   u2 attribute_name_index;
 215         //   u4 attribute_length;
 216         //   u2 local_variable_type_table_length;
 217         //   {
 218         //     u2 start_pc;
 219         //     u2 length;
 220         //     u2 name_index;
 221         //     u2 signature_index;
 222         //     u2 index;
 223         //   }
 224         attr_size += 2 + 4 + 2 + local_variable_type_table_length * (2 + 2 + 2 + 2 + 2);
 225       }
 226     }
 227   }
 228 
 229   ExceptionTable exception_table(method());
 230   int exception_table_length = exception_table.length();
 231   int code_size = const_method->code_size();
 232   int size =
 233     2+2+4 +                                // max_stack, max_locals, code_length
 234     code_size +                            // code
 235     2 +                                    // exception_table_length
 236     (2+2+2+2) * exception_table_length +   // exception_table
 237     2 +                                    // attributes_count
 238     attr_size;                             // attributes
 239 
 240   write_attribute_name_index("Code");
 241   write_u4(size);
 242   write_u2(method->verifier_max_stack());
 243   write_u2(method->max_locals());
 244   write_u4(code_size);
 245   copy_bytecodes(method, (unsigned char*)writeable_address(code_size));
 246   write_u2(exception_table_length);
 247   for (int index = 0; index < exception_table_length; index++) {
 248     write_u2(exception_table.start_pc(index));
 249     write_u2(exception_table.end_pc(index));
 250     write_u2(exception_table.handler_pc(index));
 251     write_u2(exception_table.catch_type_index(index));
 252   }
 253   write_u2(attr_count);
 254   if (line_num_cnt != 0) {
 255     write_line_number_table_attribute(method, line_num_cnt);
 256   }
 257   if (stackmap_len != 0) {
 258     write_stackmap_table_attribute(method, stackmap_len);
 259   }
 260   if (local_variable_table_length != 0) {
 261     write_local_variable_table_attribute(method, local_variable_table_length);
 262   }
 263   if (local_variable_type_table_length != 0) {
 264     write_local_variable_type_table_attribute(method, local_variable_type_table_length);
 265   }
 266 }
 267 
 268 // Write Exceptions attribute
 269 // JVMSpec|   Exceptions_attribute {
 270 // JVMSpec|     u2 attribute_name_index;
 271 // JVMSpec|     u4 attribute_length;
 272 // JVMSpec|     u2 number_of_exceptions;
 273 // JVMSpec|     u2 exception_index_table[number_of_exceptions];
 274 // JVMSpec|   }
 275 void JvmtiClassFileReconstituter::write_exceptions_attribute(ConstMethod* const_method) {
 276   CheckedExceptionElement* checked_exceptions = const_method->checked_exceptions_start();
 277   int checked_exceptions_length = const_method->checked_exceptions_length();
 278   int size =
 279     2 +                                    // number_of_exceptions
 280     2 * checked_exceptions_length;         // exception_index_table
 281 
 282   write_attribute_name_index("Exceptions");
 283   write_u4(size);
 284   write_u2(checked_exceptions_length);
 285   for (int index = 0; index < checked_exceptions_length; index++) {
 286     write_u2(checked_exceptions[index].class_cp_index);
 287   }
 288 }
 289 
 290 // Write SourceFile attribute
 291 // JVMSpec|   SourceFile_attribute {
 292 // JVMSpec|     u2 attribute_name_index;
 293 // JVMSpec|     u4 attribute_length;
 294 // JVMSpec|     u2 sourcefile_index;
 295 // JVMSpec|   }
 296 void JvmtiClassFileReconstituter::write_source_file_attribute() {
 297   assert(ik()->source_file_name() != NULL, "caller must check");
 298 
 299   write_attribute_name_index("SourceFile");
 300   write_u4(2);  // always length 2
 301   write_u2(symbol_to_cpool_index(ik()->source_file_name()));
 302 }
 303 
 304 // Write SourceDebugExtension attribute
 305 // JSR45|   SourceDebugExtension_attribute {
 306 // JSR45|       u2 attribute_name_index;
 307 // JSR45|       u4 attribute_length;
 308 // JSR45|       u1 debug_extension[attribute_length];
 309 // JSR45|   }
 310 void JvmtiClassFileReconstituter::write_source_debug_extension_attribute() {
 311   assert(ik()->source_debug_extension() != NULL, "caller must check");
 312 
 313   write_attribute_name_index("SourceDebugExtension");
 314   int len = (int)strlen(ik()->source_debug_extension());
 315   write_u4(len);
 316   u1* ext = (u1*)ik()->source_debug_extension();
 317   for (int i=0; i<len; i++) {
 318     write_u1(ext[i]);
 319   }
 320 }
 321 
 322 // Write (generic) Signature attribute
 323 // JVMSpec|   Signature_attribute {
 324 // JVMSpec|     u2 attribute_name_index;
 325 // JVMSpec|     u4 attribute_length;
 326 // JVMSpec|     u2 signature_index;
 327 // JVMSpec|   }
 328 void JvmtiClassFileReconstituter::write_signature_attribute(u2 generic_signature_index) {
 329   write_attribute_name_index("Signature");
 330   write_u4(2);  // always length 2
 331   write_u2(generic_signature_index);
 332 }
 333 
 334 // Compute the number of entries in the InnerClasses attribute
 335 u2 JvmtiClassFileReconstituter::inner_classes_attribute_length() {
 336   InnerClassesIterator iter(ik());
 337   return iter.length();
 338 }
 339 
 340 // Write an annotation attribute.  The VM stores them in raw form, so all we need
 341 // to do is add the attrubute name and fill in the length.
 342 // JSR202|   *Annotations_attribute {
 343 // JSR202|     u2 attribute_name_index;
 344 // JSR202|     u4 attribute_length;
 345 // JSR202|     ...
 346 // JSR202|   }
 347 void JvmtiClassFileReconstituter::write_annotations_attribute(const char* attr_name,
 348                                                               AnnotationArray* annos) {
 349   u4 length = annos->length();
 350   write_attribute_name_index(attr_name);
 351   write_u4(length);
 352   memcpy(writeable_address(length), annos->adr_at(0), length);
 353 }
 354 
 355 //  BootstrapMethods_attribute {
 356 //    u2 attribute_name_index;
 357 //    u4 attribute_length;
 358 //    u2 num_bootstrap_methods;
 359 //    {   u2 bootstrap_method_ref;
 360 //        u2 num_bootstrap_arguments;
 361 //        u2 bootstrap_arguments[num_bootstrap_arguments];
 362 //    } bootstrap_methods[num_bootstrap_methods];
 363 //  }
 364 void JvmtiClassFileReconstituter::write_bootstrapmethod_attribute() {
 365   Array<u2>* operands = cpool()->operands();
 366   write_attribute_name_index("BootstrapMethods");
 367   int num_bootstrap_methods = ConstantPool::operand_array_length(operands);
 368 
 369   // calculate length of attribute
 370   int length = sizeof(u2); // num_bootstrap_methods
 371   for (int n = 0; n < num_bootstrap_methods; n++) {
 372     u2 num_bootstrap_arguments = cpool()->operand_argument_count_at(n);
 373     length += sizeof(u2); // bootstrap_method_ref
 374     length += sizeof(u2); // num_bootstrap_arguments
 375     length += sizeof(u2) * num_bootstrap_arguments; // bootstrap_arguments[num_bootstrap_arguments]
 376   }
 377   write_u4(length);
 378 
 379   // write attribute
 380   write_u2(num_bootstrap_methods);
 381   for (int n = 0; n < num_bootstrap_methods; n++) {
 382     u2 bootstrap_method_ref = cpool()->operand_bootstrap_method_ref_index_at(n);
 383     u2 num_bootstrap_arguments = cpool()->operand_argument_count_at(n);
 384     write_u2(bootstrap_method_ref);
 385     write_u2(num_bootstrap_arguments);
 386     for (int arg = 0; arg < num_bootstrap_arguments; arg++) {
 387       u2 bootstrap_argument = cpool()->operand_argument_index_at(n, arg);
 388       write_u2(bootstrap_argument);
 389     }
 390   }
 391 }
 392 
 393 //  NestHost_attribute {
 394 //    u2 attribute_name_index;
 395 //    u4 attribute_length;
 396 //    u2 host_class_index;
 397 //  }
 398 void JvmtiClassFileReconstituter::write_nest_host_attribute() {
 399   int length = sizeof(u2);
 400   int host_class_index = ik()->nest_host_index();
 401 
 402   write_attribute_name_index("NestHost");
 403   write_u4(length);
 404   write_u2(host_class_index);
 405 }
 406 
 407 //  NestMembers_attribute {
 408 //    u2 attribute_name_index;
 409 //    u4 attribute_length;
 410 //    u2 number_of_classes;
 411 //    u2 classes[number_of_classes];
 412 //  }
 413 void JvmtiClassFileReconstituter::write_nest_members_attribute() {
 414   Array<u2>* nest_members = ik()->nest_members();
 415   int number_of_classes = nest_members->length();
 416   int length = sizeof(u2) * (1 + number_of_classes);
 417 
 418   write_attribute_name_index("NestMembers");
 419   write_u4(length);
 420   write_u2(number_of_classes);
 421   for (int i = 0; i < number_of_classes; i++) {
 422     u2 class_cp_index = nest_members->at(i);
 423     write_u2(class_cp_index);
 424   }
 425 }
 426 
 427 //  PermittedSubclasses {
 428 //    u2 attribute_name_index;
 429 //    u4 attribute_length;
 430 //    u2 number_of_classes;
 431 //    u2 classes[number_of_classes];
 432 //  }
 433 void JvmtiClassFileReconstituter::write_permitted_subclasses_attribute() {
 434   Array<u2>* permitted_subclasses = ik()->permitted_subclasses();
 435   int number_of_classes = permitted_subclasses->length();
 436   int length = sizeof(u2) * (1 + number_of_classes); // '1 +' is for number_of_classes field
 437 
 438   write_attribute_name_index("PermittedSubclasses");
 439   write_u4(length);
 440   write_u2(number_of_classes);
 441   for (int i = 0; i < number_of_classes; i++) {
 442     u2 class_cp_index = permitted_subclasses->at(i);
 443     write_u2(class_cp_index);
 444   }
 445 }
 446 
 447 //  Record {
 448 //    u2 attribute_name_index;
 449 //    u4 attribute_length;
 450 //    u2 components_count;
 451 //    component_info components[components_count];
 452 //  }
 453 //  component_info {
 454 //    u2 name_index;
 455 //    u2 descriptor_index
 456 //    u2 attributes_count;
 457 //    attribute_info_attributes[attributes_count];
 458 //  }
 459 void JvmtiClassFileReconstituter::write_record_attribute() {
 460   Array<RecordComponent*>* components = ik()->record_components();
 461   int number_of_components = components->length();
 462 
 463   // Each component has a u2 for name, descr, attribute count
 464   int length = sizeof(u2) + (sizeof(u2) * 3 * number_of_components);
 465   for (int x = 0; x < number_of_components; x++) {
 466     RecordComponent* component = components->at(x);
 467     if (component->generic_signature_index() != 0) {
 468       length += 8; // Signature attribute size
 469       assert(component->attributes_count() > 0, "Bad component attributes count");
 470     }
 471     if (component->annotations() != NULL) {
 472       length += 6 + component->annotations()->length();
 473     }
 474     if (component->type_annotations() != NULL) {
 475       length += 6 + component->type_annotations()->length();
 476     }
 477   }
 478 
 479   write_attribute_name_index("Record");
 480   write_u4(length);
 481   write_u2(number_of_components);
 482   for (int i = 0; i < number_of_components; i++) {
 483     RecordComponent* component = components->at(i);
 484     write_u2(component->name_index());
 485     write_u2(component->descriptor_index());
 486     write_u2(component->attributes_count());
 487     if (component->generic_signature_index() != 0) {
 488       write_signature_attribute(component->generic_signature_index());
 489     }
 490     if (component->annotations() != NULL) {
 491       write_annotations_attribute("RuntimeVisibleAnnotations", component->annotations());
 492     }
 493     if (component->type_annotations() != NULL) {
 494       write_annotations_attribute("RuntimeVisibleTypeAnnotations", component->type_annotations());
 495     }
 496   }
 497 }
 498 
 499 // Write InnerClasses attribute
 500 // JVMSpec|   InnerClasses_attribute {
 501 // JVMSpec|     u2 attribute_name_index;
 502 // JVMSpec|     u4 attribute_length;
 503 // JVMSpec|     u2 number_of_classes;
 504 // JVMSpec|     {  u2 inner_class_info_index;
 505 // JVMSpec|        u2 outer_class_info_index;
 506 // JVMSpec|        u2 inner_name_index;
 507 // JVMSpec|        u2 inner_class_access_flags;
 508 // JVMSpec|     } classes[number_of_classes];
 509 // JVMSpec|   }
 510 void JvmtiClassFileReconstituter::write_inner_classes_attribute(int length) {
 511   InnerClassesIterator iter(ik());
 512   guarantee(iter.length() != 0 && iter.length() == length,
 513             "caller must check");
 514   u2 entry_count = length / InstanceKlass::inner_class_next_offset;
 515   u4 size = 2 + entry_count * (2+2+2+2);
 516 
 517   write_attribute_name_index("InnerClasses");
 518   write_u4(size);
 519   write_u2(entry_count);
 520   for (; !iter.done(); iter.next()) {
 521     write_u2(iter.inner_class_info_index());
 522     write_u2(iter.outer_class_info_index());
 523     write_u2(iter.inner_name_index());
 524     write_u2(iter.inner_access_flags());
 525   }
 526 }
 527 
 528 // Write Synthetic attribute
 529 // JVMSpec|   Synthetic_attribute {
 530 // JVMSpec|     u2 attribute_name_index;
 531 // JVMSpec|     u4 attribute_length;
 532 // JVMSpec|   }
 533 void JvmtiClassFileReconstituter::write_synthetic_attribute() {
 534   write_attribute_name_index("Synthetic");
 535   write_u4(0); //length always zero
 536 }
 537 
 538 // Compute size of LineNumberTable
 539 u2 JvmtiClassFileReconstituter::line_number_table_entries(const methodHandle& method) {
 540   // The line number table is compressed so we don't know how big it is until decompressed.
 541   // Decompression is really fast so we just do it twice.
 542   u2 num_entries = 0;
 543   CompressedLineNumberReadStream stream(method->compressed_linenumber_table());
 544   while (stream.read_pair()) {
 545     num_entries++;
 546   }
 547   return num_entries;
 548 }
 549 
 550 // Write LineNumberTable attribute
 551 // JVMSpec|   LineNumberTable_attribute {
 552 // JVMSpec|     u2 attribute_name_index;
 553 // JVMSpec|     u4 attribute_length;
 554 // JVMSpec|     u2 line_number_table_length;
 555 // JVMSpec|     {  u2 start_pc;
 556 // JVMSpec|        u2 line_number;
 557 // JVMSpec|     } line_number_table[line_number_table_length];
 558 // JVMSpec|   }
 559 void JvmtiClassFileReconstituter::write_line_number_table_attribute(const methodHandle& method,
 560                                                                     u2 num_entries) {
 561 
 562   write_attribute_name_index("LineNumberTable");
 563   write_u4(2 + num_entries * (2 + 2));
 564   write_u2(num_entries);
 565 
 566   CompressedLineNumberReadStream stream(method->compressed_linenumber_table());
 567   while (stream.read_pair()) {
 568     write_u2(stream.bci());
 569     write_u2(stream.line());
 570   }
 571 }
 572 
 573 // Write LocalVariableTable attribute
 574 // JVMSpec|   LocalVariableTable_attribute {
 575 // JVMSpec|     u2 attribute_name_index;
 576 // JVMSpec|     u4 attribute_length;
 577 // JVMSpec|     u2 local_variable_table_length;
 578 // JVMSpec|     {  u2 start_pc;
 579 // JVMSpec|       u2 length;
 580 // JVMSpec|       u2 name_index;
 581 // JVMSpec|       u2 descriptor_index;
 582 // JVMSpec|       u2 index;
 583 // JVMSpec|     } local_variable_table[local_variable_table_length];
 584 // JVMSpec|   }
 585 void JvmtiClassFileReconstituter::write_local_variable_table_attribute(const methodHandle& method, u2 num_entries) {
 586     write_attribute_name_index("LocalVariableTable");
 587     write_u4(2 + num_entries * (2 + 2 + 2 + 2 + 2));
 588     write_u2(num_entries);
 589 
 590     assert(method->localvariable_table_length() == num_entries, "just checking");
 591 
 592     LocalVariableTableElement *elem = method->localvariable_table_start();
 593     for (int j=0; j<method->localvariable_table_length(); j++) {
 594       write_u2(elem->start_bci);
 595       write_u2(elem->length);
 596       write_u2(elem->name_cp_index);
 597       write_u2(elem->descriptor_cp_index);
 598       write_u2(elem->slot);
 599       elem++;
 600     }
 601 }
 602 
 603 // Write LocalVariableTypeTable attribute
 604 // JVMSpec|   LocalVariableTypeTable_attribute {
 605 // JVMSpec|     u2 attribute_name_index;
 606 // JVMSpec|     u4 attribute_length;
 607 // JVMSpec|     u2 local_variable_type_table_length;
 608 // JVMSpec|     { u2 start_pc;
 609 // JVMSpec|       u2 length;
 610 // JVMSpec|       u2 name_index;
 611 // JVMSpec|       u2 signature_index;
 612 // JVMSpec|       u2 index;
 613 // JVMSpec|     } local_variable_type_table[local_variable_type_table_length];
 614 // JVMSpec|   }
 615 void JvmtiClassFileReconstituter::write_local_variable_type_table_attribute(const methodHandle& method, u2 num_entries) {
 616     write_attribute_name_index("LocalVariableTypeTable");
 617     write_u4(2 + num_entries * (2 + 2 + 2 + 2 + 2));
 618     write_u2(num_entries);
 619 
 620     LocalVariableTableElement *elem = method->localvariable_table_start();
 621     for (int j=0; j<method->localvariable_table_length(); j++) {
 622       if (elem->signature_cp_index > 0) {
 623         // Local variable has a generic signature - write LVTT attribute entry
 624         write_u2(elem->start_bci);
 625         write_u2(elem->length);
 626         write_u2(elem->name_cp_index);
 627         write_u2(elem->signature_cp_index);
 628         write_u2(elem->slot);
 629         num_entries--;
 630       }
 631       elem++;
 632     }
 633     assert(num_entries == 0, "just checking");
 634 }
 635 
 636 // Write stack map table attribute
 637 // JSR-202|   StackMapTable_attribute {
 638 // JSR-202|     u2 attribute_name_index;
 639 // JSR-202|     u4 attribute_length;
 640 // JSR-202|     u2 number_of_entries;
 641 // JSR-202|     stack_map_frame_entries[number_of_entries];
 642 // JSR-202|   }
 643 void JvmtiClassFileReconstituter::write_stackmap_table_attribute(const methodHandle& method,
 644                                                                  int stackmap_len) {
 645 
 646   write_attribute_name_index("StackMapTable");
 647   write_u4(stackmap_len);
 648   memcpy(
 649     writeable_address(stackmap_len),
 650     (void*)(method->stackmap_data()->adr_at(0)),
 651     stackmap_len);
 652 }
 653 
 654 // Write one method_info structure
 655 // JVMSpec|   method_info {
 656 // JVMSpec|     u2 access_flags;
 657 // JVMSpec|     u2 name_index;
 658 // JVMSpec|     u2 descriptor_index;
 659 // JVMSpec|     u2 attributes_count;
 660 // JVMSpec|     attribute_info attributes[attributes_count];
 661 // JVMSpec|   }
 662 void JvmtiClassFileReconstituter::write_method_info(const methodHandle& method) {
 663   AccessFlags access_flags = method->access_flags();
 664   ConstMethod* const_method = method->constMethod();
 665   u2 generic_signature_index = const_method->generic_signature_index();
 666   AnnotationArray* anno = method->annotations();
 667   AnnotationArray* param_anno = method->parameter_annotations();
 668   AnnotationArray* default_anno = method->annotation_default();
 669   AnnotationArray* type_anno = method->type_annotations();
 670 
 671   // skip generated default interface methods
 672   if (method->is_overpass()) {
 673     return;
 674   }
 675 
 676   write_u2(access_flags.get_flags() & JVM_RECOGNIZED_METHOD_MODIFIERS);
 677   write_u2(const_method->name_index());
 678   write_u2(const_method->signature_index());
 679 
 680   // write attributes in the same order javac does, so we can test with byte for
 681   // byte comparison
 682   int attr_count = 0;
 683   if (const_method->code_size() != 0) {
 684     ++attr_count;     // has Code attribute
 685   }
 686   if (const_method->has_checked_exceptions()) {
 687     ++attr_count;     // has Exceptions attribute
 688   }
 689   if (default_anno != NULL) {
 690     ++attr_count;     // has AnnotationDefault attribute
 691   }
 692   // Deprecated attribute would go here
 693   if (access_flags.is_synthetic()) { // FIXME
 694     // ++attr_count;
 695   }
 696   if (generic_signature_index != 0) {
 697     ++attr_count;
 698   }
 699   if (anno != NULL) {
 700     ++attr_count;     // has RuntimeVisibleAnnotations attribute
 701   }
 702   if (param_anno != NULL) {
 703     ++attr_count;     // has RuntimeVisibleParameterAnnotations attribute
 704   }
 705   if (type_anno != NULL) {
 706     ++attr_count;     // has RuntimeVisibleTypeAnnotations attribute
 707   }
 708 
 709   write_u2(attr_count);
 710   if (const_method->code_size() > 0) {
 711     write_code_attribute(method);
 712   }
 713   if (const_method->has_checked_exceptions()) {
 714     write_exceptions_attribute(const_method);
 715   }
 716   if (default_anno != NULL) {
 717     write_annotations_attribute("AnnotationDefault", default_anno);
 718   }
 719   // Deprecated attribute would go here
 720   if (access_flags.is_synthetic()) {
 721     // write_synthetic_attribute();
 722   }
 723   if (generic_signature_index != 0) {
 724     write_signature_attribute(generic_signature_index);
 725   }
 726   if (anno != NULL) {
 727     write_annotations_attribute("RuntimeVisibleAnnotations", anno);
 728   }
 729   if (param_anno != NULL) {
 730     write_annotations_attribute("RuntimeVisibleParameterAnnotations", param_anno);
 731   }
 732   if (type_anno != NULL) {
 733     write_annotations_attribute("RuntimeVisibleTypeAnnotations", type_anno);
 734   }
 735 }
 736 
 737 // Write the class attributes portion of ClassFile structure
 738 // JVMSpec|     u2 attributes_count;
 739 // JVMSpec|     attribute_info attributes[attributes_count];
 740 void JvmtiClassFileReconstituter::write_class_attributes() {
 741   u2 inner_classes_length = inner_classes_attribute_length();
 742   Symbol* generic_signature = ik()->generic_signature();
 743   AnnotationArray* anno = ik()->class_annotations();
 744   AnnotationArray* type_anno = ik()->class_type_annotations();
 745 
 746   int attr_count = 0;
 747   if (generic_signature != NULL) {
 748     ++attr_count;
 749   }
 750   if (ik()->source_file_name() != NULL) {
 751     ++attr_count;
 752   }
 753   if (ik()->source_debug_extension() != NULL) {
 754     ++attr_count;
 755   }
 756   if (inner_classes_length > 0) {
 757     ++attr_count;
 758   }
 759   if (anno != NULL) {
 760     ++attr_count;     // has RuntimeVisibleAnnotations attribute
 761   }
 762   if (type_anno != NULL) {
 763     ++attr_count;     // has RuntimeVisibleTypeAnnotations attribute
 764   }
 765   if (cpool()->operands() != NULL) {
 766     ++attr_count;
 767   }
 768   if (ik()->nest_host_index() != 0) {
 769     ++attr_count;
 770   }
 771   if (ik()->nest_members() != Universe::the_empty_short_array()) {
 772     ++attr_count;
 773   }
 774   if (ik()->permitted_subclasses() != Universe::the_empty_short_array()) {
 775     ++attr_count;
 776   }
 777   if (ik()->record_components() != NULL) {
 778     ++attr_count;
 779   }
 780 
 781   write_u2(attr_count);
 782 
 783   if (generic_signature != NULL) {
 784     write_signature_attribute(symbol_to_cpool_index(generic_signature));
 785   }
 786   if (ik()->source_file_name() != NULL) {
 787     write_source_file_attribute();
 788   }
 789   if (ik()->source_debug_extension() != NULL) {
 790     write_source_debug_extension_attribute();
 791   }
 792   if (anno != NULL) {
 793     write_annotations_attribute("RuntimeVisibleAnnotations", anno);
 794   }
 795   if (type_anno != NULL) {
 796     write_annotations_attribute("RuntimeVisibleTypeAnnotations", type_anno);
 797   }
 798   if (ik()->nest_host_index() != 0) {
 799     write_nest_host_attribute();
 800   }
 801   if (ik()->nest_members() != Universe::the_empty_short_array()) {
 802     write_nest_members_attribute();
 803   }
 804   if (ik()->permitted_subclasses() != Universe::the_empty_short_array()) {
 805     write_permitted_subclasses_attribute();
 806   }
 807   if (ik()->record_components() != NULL) {
 808     write_record_attribute();
 809   }
 810   if (cpool()->operands() != NULL) {
 811     write_bootstrapmethod_attribute();
 812   }
 813   if (inner_classes_length > 0) {
 814     write_inner_classes_attribute(inner_classes_length);
 815   }
 816 }
 817 
 818 // Write the method information portion of ClassFile structure
 819 // JVMSpec|     u2 methods_count;
 820 // JVMSpec|     method_info methods[methods_count];
 821 void JvmtiClassFileReconstituter::write_method_infos() {
 822   HandleMark hm(thread());
 823   Array<Method*>* methods = ik()->methods();
 824   int num_methods = methods->length();
 825   int num_overpass = 0;
 826 
 827   // count the generated default interface methods
 828   // these will not be re-created by write_method_info
 829   // and should not be included in the total count
 830   for (int index = 0; index < num_methods; index++) {
 831     Method* method = methods->at(index);
 832     if (method->is_overpass()) {
 833       num_overpass++;
 834     }
 835   }
 836 
 837   write_u2(num_methods - num_overpass);
 838   if (JvmtiExport::can_maintain_original_method_order()) {
 839     int index;
 840     int original_index;
 841     intArray method_order(num_methods, num_methods, 0);
 842 
 843     // invert the method order mapping
 844     for (index = 0; index < num_methods; index++) {
 845       original_index = ik()->method_ordering()->at(index);
 846       assert(original_index >= 0 && original_index < num_methods,
 847              "invalid original method index");
 848       method_order.at_put(original_index, index);
 849     }
 850 
 851     // write in original order
 852     for (original_index = 0; original_index < num_methods; original_index++) {
 853       index = method_order.at(original_index);
 854       methodHandle method(thread(), methods->at(index));
 855       write_method_info(method);
 856     }
 857   } else {
 858     // method order not preserved just dump the method infos
 859     for (int index = 0; index < num_methods; index++) {
 860       methodHandle method(thread(), methods->at(index));
 861       write_method_info(method);
 862     }
 863   }
 864 }
 865 
 866 void JvmtiClassFileReconstituter::write_class_file_format() {
 867   ReallocMark();
 868 
 869   // JVMSpec|   ClassFile {
 870   // JVMSpec|           u4 magic;
 871   write_u4(0xCAFEBABE);
 872 
 873   // JVMSpec|           u2 minor_version;
 874   // JVMSpec|           u2 major_version;
 875   write_u2(ik()->minor_version());
 876   u2 major = ik()->major_version();
 877   write_u2(major);
 878 
 879   // JVMSpec|           u2 constant_pool_count;
 880   // JVMSpec|           cp_info constant_pool[constant_pool_count-1];
 881   write_u2(cpool()->length());
 882   copy_cpool_bytes(writeable_address(cpool_size()));
 883 
 884   // JVMSpec|           u2 access_flags;
 885   write_u2(ik()->access_flags().get_flags() & JVM_RECOGNIZED_CLASS_MODIFIERS);
 886 
 887   // JVMSpec|           u2 this_class;
 888   // JVMSpec|           u2 super_class;
 889   write_u2(class_symbol_to_cpool_index(ik()->name()));
 890   Klass* super_class = ik()->super();
 891   write_u2(super_class == NULL? 0 :  // zero for java.lang.Object
 892                 class_symbol_to_cpool_index(super_class->name()));
 893 
 894   // JVMSpec|           u2 interfaces_count;
 895   // JVMSpec|           u2 interfaces[interfaces_count];
 896   Array<InstanceKlass*>* interfaces =  ik()->local_interfaces();
 897   int num_interfaces = interfaces->length();
 898   write_u2(num_interfaces);
 899   for (int index = 0; index < num_interfaces; index++) {
 900     HandleMark hm(thread());
 901     InstanceKlass* iik = interfaces->at(index);
 902     write_u2(class_symbol_to_cpool_index(iik->name()));
 903   }
 904 
 905   // JVMSpec|           u2 fields_count;
 906   // JVMSpec|           field_info fields[fields_count];
 907   write_field_infos();
 908 
 909   // JVMSpec|           u2 methods_count;
 910   // JVMSpec|           method_info methods[methods_count];
 911   write_method_infos();
 912 
 913   // JVMSpec|           u2 attributes_count;
 914   // JVMSpec|           attribute_info attributes[attributes_count];
 915   // JVMSpec|   } /* end ClassFile 8?
 916   write_class_attributes();
 917 }
 918 
 919 address JvmtiClassFileReconstituter::writeable_address(size_t size) {
 920   size_t used_size = _buffer_ptr - _buffer;
 921   if (size + used_size >= _buffer_size) {
 922     // compute the new buffer size: must be at least twice as big as before
 923     // plus whatever new is being used; then convert to nice clean block boundary
 924     size_t new_buffer_size = (size + _buffer_size*2 + 1) / initial_buffer_size
 925                                                          * initial_buffer_size;
 926 
 927     // VM goes belly-up if the memory isn't available, so cannot do OOM processing
 928     _buffer = REALLOC_RESOURCE_ARRAY(u1, _buffer, _buffer_size, new_buffer_size);
 929     _buffer_size = new_buffer_size;
 930     _buffer_ptr = _buffer + used_size;
 931   }
 932   u1* ret_ptr = _buffer_ptr;
 933   _buffer_ptr += size;
 934   return ret_ptr;
 935 }
 936 
 937 void JvmtiClassFileReconstituter::write_attribute_name_index(const char* name) {
 938   TempNewSymbol sym = SymbolTable::probe(name, (int)strlen(name));
 939   assert(sym != NULL, "attribute name symbol not found");
 940   u2 attr_name_index = symbol_to_cpool_index(sym);
 941   assert(attr_name_index != 0, "attribute name symbol not in constant pool");
 942   write_u2(attr_name_index);
 943 }
 944 
 945 void JvmtiClassFileReconstituter::write_u1(u1 x) {
 946   *writeable_address(1) = x;
 947 }
 948 
 949 void JvmtiClassFileReconstituter::write_u2(u2 x) {
 950   Bytes::put_Java_u2(writeable_address(2), x);
 951 }
 952 
 953 void JvmtiClassFileReconstituter::write_u4(u4 x) {
 954   Bytes::put_Java_u4(writeable_address(4), x);
 955 }
 956 
 957 void JvmtiClassFileReconstituter::write_u8(u8 x) {
 958   Bytes::put_Java_u8(writeable_address(8), x);
 959 }
 960 
 961 void JvmtiClassFileReconstituter::copy_bytecodes(const methodHandle& mh,
 962                                                  unsigned char* bytecodes) {
 963   // use a BytecodeStream to iterate over the bytecodes. JVM/fast bytecodes
 964   // and the breakpoint bytecode are converted to their original bytecodes.
 965 
 966   BytecodeStream bs(mh);
 967 
 968   unsigned char* p = bytecodes;
 969   Bytecodes::Code code;
 970   bool is_rewritten = mh->method_holder()->is_rewritten();
 971 
 972   while ((code = bs.next()) >= 0) {
 973     assert(Bytecodes::is_java_code(code), "sanity check");
 974     assert(code != Bytecodes::_breakpoint, "sanity check");
 975 
 976     // length of bytecode (mnemonic + operands)
 977     address bcp = bs.bcp();
 978     int     len = bs.instruction_size();
 979     assert(len > 0, "length must be > 0");
 980 
 981     // copy the bytecodes
 982     *p = (unsigned char) (bs.is_wide()? Bytecodes::_wide : code);
 983     if (len > 1) {
 984       memcpy(p+1, bcp+1, len-1);
 985     }
 986 
 987     // During linking the get/put and invoke instructions are rewritten
 988     // with an index into the constant pool cache. The original constant
 989     // pool index must be returned to caller.  Rewrite the index.
 990     if (is_rewritten && len > 1) {
 991       bool is_wide = false;
 992       switch (code) {
 993       case Bytecodes::_getstatic       :  // fall through
 994       case Bytecodes::_putstatic       :  // fall through
 995       case Bytecodes::_getfield        :  // fall through
 996       case Bytecodes::_putfield        :  // fall through
 997       case Bytecodes::_invokevirtual   :  // fall through
 998       case Bytecodes::_invokespecial   :  // fall through
 999       case Bytecodes::_invokestatic    :  // fall through
1000       case Bytecodes::_invokedynamic   :  // fall through
1001       case Bytecodes::_invokeinterface : {
1002         assert(len == 3 ||
1003                (code == Bytecodes::_invokeinterface && len == 5) ||
1004                (code == Bytecodes::_invokedynamic   && len == 5),
1005                "sanity check");
1006 
1007         int cpci = Bytes::get_native_u2(bcp+1);
1008         bool is_invokedynamic = (code == Bytecodes::_invokedynamic);
1009         ConstantPoolCacheEntry* entry;
1010         if (is_invokedynamic) {
1011           cpci = Bytes::get_native_u4(bcp+1);
1012           entry = mh->constants()->invokedynamic_cp_cache_entry_at(cpci);
1013         } else {
1014         // cache cannot be pre-fetched since some classes won't have it yet
1015           entry = mh->constants()->cache()->entry_at(cpci);
1016         }
1017         int i = entry->constant_pool_index();
1018         assert(i < mh->constants()->length(), "sanity check");
1019         Bytes::put_Java_u2((address)(p+1), (u2)i);     // java byte ordering
1020         if (is_invokedynamic)  *(p+3) = *(p+4) = 0;
1021         break;
1022       }
1023       case Bytecodes::_ldc_w:
1024         is_wide = true; // fall through
1025       case Bytecodes::_ldc: {
1026         if (bs.raw_code() == Bytecodes::_fast_aldc || bs.raw_code() == Bytecodes::_fast_aldc_w) {
1027           int cpci = is_wide ? Bytes::get_native_u2(bcp+1) : (u1)(*(bcp+1));
1028           int i = mh->constants()->object_to_cp_index(cpci);
1029           assert(i < mh->constants()->length(), "sanity check");
1030           if (is_wide) {
1031             Bytes::put_Java_u2((address)(p+1), (u2)i);     // java byte ordering
1032           } else {
1033             *(p+1) = (u1)i;
1034           }
1035         }
1036         break;
1037         }
1038       default:
1039         break;
1040       }
1041     }
1042 
1043     p += len;
1044   }
1045 }