1 /*
   2  * Copyright (c) 2005, 2015, 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 "oops/fieldStreams.hpp"
  29 #include "prims/jvmtiClassFileReconstituter.hpp"
  30 #include "runtime/signature.hpp"
  31 #include "utilities/bytes.hpp"
  32 
  33 // FIXME: add Deprecated attribute
  34 // FIXME: fix Synthetic attribute
  35 // FIXME: per Serguei, add error return handling for ConstantPool::copy_cpool_bytes()
  36 
  37 
  38 // Write the field information portion of ClassFile structure
  39 // JVMSpec|     u2 fields_count;
  40 // JVMSpec|     field_info fields[fields_count];
  41 void JvmtiClassFileReconstituter::write_field_infos() {
  42   HandleMark hm(thread());
  43   Array<AnnotationArray*>* fields_anno = ikh()->fields_annotations();
  44   Array<AnnotationArray*>* fields_type_anno = ikh()->fields_type_annotations();
  45 
  46   // Compute the real number of Java fields
  47   int java_fields = ikh()->java_fields_count();
  48 
  49   write_u2(java_fields);
  50   for (JavaFieldStream fs(ikh()); !fs.done(); fs.next()) {
  51     AccessFlags access_flags = fs.access_flags();
  52     int name_index = fs.name_index();
  53     int signature_index = fs.signature_index();
  54     int initial_value_index = fs.initval_index();
  55     guarantee(name_index != 0 && signature_index != 0, "bad constant pool index for field");
  56     // int offset = ikh()->field_offset( index );
  57     int generic_signature_index = fs.generic_signature_index();
  58     AnnotationArray* anno = fields_anno == NULL ? NULL : fields_anno->at(fs.index());
  59     AnnotationArray* type_anno = fields_type_anno == NULL ? NULL : fields_type_anno->at(fs.index());
  60 
  61     // JVMSpec|   field_info {
  62     // JVMSpec|         u2 access_flags;
  63     // JVMSpec|         u2 name_index;
  64     // JVMSpec|         u2 descriptor_index;
  65     // JVMSpec|         u2 attributes_count;
  66     // JVMSpec|         attribute_info attributes[attributes_count];
  67     // JVMSpec|   }
  68 
  69     write_u2(access_flags.as_int() & JVM_RECOGNIZED_FIELD_MODIFIERS);
  70     write_u2(name_index);
  71     write_u2(signature_index);
  72     int attr_count = 0;
  73     if (initial_value_index != 0) {
  74       ++attr_count;
  75     }
  76     if (access_flags.is_synthetic()) {
  77       // ++attr_count;
  78     }
  79     if (generic_signature_index != 0) {
  80       ++attr_count;
  81     }
  82     if (anno != NULL) {
  83       ++attr_count;     // has RuntimeVisibleAnnotations attribute
  84     }
  85     if (type_anno != NULL) {
  86       ++attr_count;     // has RuntimeVisibleTypeAnnotations attribute
  87     }
  88 
  89     write_u2(attr_count);
  90 
  91     if (initial_value_index != 0) {
  92       write_attribute_name_index("ConstantValue");
  93       write_u4(2); //length always 2
  94       write_u2(initial_value_index);
  95     }
  96     if (access_flags.is_synthetic()) {
  97       // write_synthetic_attribute();
  98     }
  99     if (generic_signature_index != 0) {
 100       write_signature_attribute(generic_signature_index);
 101     }
 102     if (anno != NULL) {
 103       write_annotations_attribute("RuntimeVisibleAnnotations", anno);
 104     }
 105     if (type_anno != NULL) {
 106       write_annotations_attribute("RuntimeVisibleTypeAnnotations", type_anno);
 107     }
 108   }
 109 }
 110 
 111 // Write Code attribute
 112 // JVMSpec|   Code_attribute {
 113 // JVMSpec|     u2 attribute_name_index;
 114 // JVMSpec|     u4 attribute_length;
 115 // JVMSpec|     u2 max_stack;
 116 // JVMSpec|     u2 max_locals;
 117 // JVMSpec|     u4 code_length;
 118 // JVMSpec|     u1 code[code_length];
 119 // JVMSpec|     u2 exception_table_length;
 120 // JVMSpec|     {       u2 start_pc;
 121 // JVMSpec|             u2 end_pc;
 122 // JVMSpec|             u2  handler_pc;
 123 // JVMSpec|             u2  catch_type;
 124 // JVMSpec|     }       exception_table[exception_table_length];
 125 // JVMSpec|     u2 attributes_count;
 126 // JVMSpec|     attribute_info attributes[attributes_count];
 127 // JVMSpec|   }
 128 void JvmtiClassFileReconstituter::write_code_attribute(const methodHandle& method) {
 129   ConstMethod* const_method = method->constMethod();
 130   u2 line_num_cnt = 0;
 131   int stackmap_len = 0;
 132   int local_variable_table_length = 0;
 133   int local_variable_type_table_length = 0;
 134 
 135   // compute number and length of attributes
 136   int attr_count = 0;
 137   int attr_size = 0;
 138   if (const_method->has_linenumber_table()) {
 139     line_num_cnt = line_number_table_entries(method);
 140     if (line_num_cnt != 0) {
 141       ++attr_count;
 142       // Compute the complete size of the line number table attribute:
 143       //      LineNumberTable_attribute {
 144       //        u2 attribute_name_index;
 145       //        u4 attribute_length;
 146       //        u2 line_number_table_length;
 147       //        {  u2 start_pc;
 148       //           u2 line_number;
 149       //        } line_number_table[line_number_table_length];
 150       //      }
 151       attr_size += 2 + 4 + 2 + line_num_cnt * (2 + 2);
 152     }
 153   }
 154   if (method->has_stackmap_table()) {
 155     stackmap_len = method->stackmap_data()->length();
 156     if (stackmap_len != 0) {
 157       ++attr_count;
 158       // Compute the  size of the stack map table attribute (VM stores raw):
 159       //      StackMapTable_attribute {
 160       //        u2 attribute_name_index;
 161       //        u4 attribute_length;
 162       //        u2 number_of_entries;
 163       //        stack_map_frame_entries[number_of_entries];
 164       //      }
 165       attr_size += 2 + 4 + stackmap_len;
 166     }
 167   }
 168   if (method->has_localvariable_table()) {
 169     local_variable_table_length = method->localvariable_table_length();
 170     if (local_variable_table_length != 0) {
 171       ++attr_count;
 172       // Compute the size of the local variable table attribute (VM stores raw):
 173       // LocalVariableTable_attribute {
 174       //   u2 attribute_name_index;
 175       //   u4 attribute_length;
 176       //   u2 local_variable_table_length;
 177       //   {
 178       //     u2 start_pc;
 179       //     u2 length;
 180       //     u2 name_index;
 181       //     u2 descriptor_index;
 182       //     u2 index;
 183       //   }
 184       attr_size += 2 + 4 + 2 + local_variable_table_length * (2 + 2 + 2 + 2 + 2);
 185 
 186       // Local variables with generic signatures must have LVTT entries
 187       LocalVariableTableElement *elem = method->localvariable_table_start();
 188       for (int idx = 0; idx < local_variable_table_length; idx++) {
 189         if (elem[idx].signature_cp_index != 0) {
 190           local_variable_type_table_length++;
 191         }
 192       }
 193 
 194       if (local_variable_type_table_length != 0) {
 195         ++attr_count;
 196         // Compute the size of the local variable type table attribute (VM stores raw):
 197         // LocalVariableTypeTable_attribute {
 198         //   u2 attribute_name_index;
 199         //   u4 attribute_length;
 200         //   u2 local_variable_type_table_length;
 201         //   {
 202         //     u2 start_pc;
 203         //     u2 length;
 204         //     u2 name_index;
 205         //     u2 signature_index;
 206         //     u2 index;
 207         //   }
 208         attr_size += 2 + 4 + 2 + local_variable_type_table_length * (2 + 2 + 2 + 2 + 2);
 209       }
 210     }
 211   }
 212 
 213   ExceptionTable exception_table(method());
 214   int exception_table_length = exception_table.length();
 215   int code_size = const_method->code_size();
 216   int size =
 217     2+2+4 +                                // max_stack, max_locals, code_length
 218     code_size +                            // code
 219     2 +                                    // exception_table_length
 220     (2+2+2+2) * exception_table_length +   // exception_table
 221     2 +                                    // attributes_count
 222     attr_size;                             // attributes
 223 
 224   write_attribute_name_index("Code");
 225   write_u4(size);
 226   write_u2(method->verifier_max_stack());
 227   write_u2(method->max_locals());
 228   write_u4(code_size);
 229   copy_bytecodes(method, (unsigned char*)writeable_address(code_size));
 230   write_u2(exception_table_length);
 231   for (int index = 0; index < exception_table_length; index++) {
 232     write_u2(exception_table.start_pc(index));
 233     write_u2(exception_table.end_pc(index));
 234     write_u2(exception_table.handler_pc(index));
 235     write_u2(exception_table.catch_type_index(index));
 236   }
 237   write_u2(attr_count);
 238   if (line_num_cnt != 0) {
 239     write_line_number_table_attribute(method, line_num_cnt);
 240   }
 241   if (stackmap_len != 0) {
 242     write_stackmap_table_attribute(method, stackmap_len);
 243   }
 244   if (local_variable_table_length != 0) {
 245     write_local_variable_table_attribute(method, local_variable_table_length);
 246   }
 247   if (local_variable_type_table_length != 0) {
 248     write_local_variable_type_table_attribute(method, local_variable_type_table_length);
 249   }
 250 }
 251 
 252 // Write Exceptions attribute
 253 // JVMSpec|   Exceptions_attribute {
 254 // JVMSpec|     u2 attribute_name_index;
 255 // JVMSpec|     u4 attribute_length;
 256 // JVMSpec|     u2 number_of_exceptions;
 257 // JVMSpec|     u2 exception_index_table[number_of_exceptions];
 258 // JVMSpec|   }
 259 void JvmtiClassFileReconstituter::write_exceptions_attribute(ConstMethod* const_method) {
 260   CheckedExceptionElement* checked_exceptions = const_method->checked_exceptions_start();
 261   int checked_exceptions_length = const_method->checked_exceptions_length();
 262   int size =
 263     2 +                                    // number_of_exceptions
 264     2 * checked_exceptions_length;         // exception_index_table
 265 
 266   write_attribute_name_index("Exceptions");
 267   write_u4(size);
 268   write_u2(checked_exceptions_length);
 269   for (int index = 0; index < checked_exceptions_length; index++) {
 270     write_u2(checked_exceptions[index].class_cp_index);
 271   }
 272 }
 273 
 274 // Write SourceFile attribute
 275 // JVMSpec|   SourceFile_attribute {
 276 // JVMSpec|     u2 attribute_name_index;
 277 // JVMSpec|     u4 attribute_length;
 278 // JVMSpec|     u2 sourcefile_index;
 279 // JVMSpec|   }
 280 void JvmtiClassFileReconstituter::write_source_file_attribute() {
 281   assert(ikh()->source_file_name() != NULL, "caller must check");
 282 
 283   write_attribute_name_index("SourceFile");
 284   write_u4(2);  // always length 2
 285   write_u2(symbol_to_cpool_index(ikh()->source_file_name()));
 286 }
 287 
 288 // Write SourceDebugExtension attribute
 289 // JSR45|   SourceDebugExtension_attribute {
 290 // JSR45|       u2 attribute_name_index;
 291 // JSR45|       u4 attribute_length;
 292 // JSR45|       u1 debug_extension[attribute_length];
 293 // JSR45|   }
 294 void JvmtiClassFileReconstituter::write_source_debug_extension_attribute() {
 295   assert(ikh()->source_debug_extension() != NULL, "caller must check");
 296 
 297   write_attribute_name_index("SourceDebugExtension");
 298   int len = (int)strlen(ikh()->source_debug_extension());
 299   write_u4(len);
 300   u1* ext = (u1*)ikh()->source_debug_extension();
 301   for (int i=0; i<len; i++) {
 302     write_u1(ext[i]);
 303   }
 304 }
 305 
 306 // Write (generic) Signature attribute
 307 // JVMSpec|   Signature_attribute {
 308 // JVMSpec|     u2 attribute_name_index;
 309 // JVMSpec|     u4 attribute_length;
 310 // JVMSpec|     u2 signature_index;
 311 // JVMSpec|   }
 312 void JvmtiClassFileReconstituter::write_signature_attribute(u2 generic_signature_index) {
 313   write_attribute_name_index("Signature");
 314   write_u4(2);  // always length 2
 315   write_u2(generic_signature_index);
 316 }
 317 
 318 // Compute the number of entries in the InnerClasses attribute
 319 u2 JvmtiClassFileReconstituter::inner_classes_attribute_length() {
 320   InnerClassesIterator iter(ikh());
 321   return iter.length();
 322 }
 323 
 324 // Write an annotation attribute.  The VM stores them in raw form, so all we need
 325 // to do is add the attrubute name and fill in the length.
 326 // JSR202|   *Annotations_attribute {
 327 // JSR202|     u2 attribute_name_index;
 328 // JSR202|     u4 attribute_length;
 329 // JSR202|     ...
 330 // JSR202|   }
 331 void JvmtiClassFileReconstituter::write_annotations_attribute(const char* attr_name,
 332                                                               AnnotationArray* annos) {
 333   u4 length = annos->length();
 334   write_attribute_name_index(attr_name);
 335   write_u4(length);
 336   memcpy(writeable_address(length), annos->adr_at(0), length);
 337 }
 338 
 339 //  BootstrapMethods_attribute {
 340 //    u2 attribute_name_index;
 341 //    u4 attribute_length;
 342 //    u2 num_bootstrap_methods;
 343 //    {   u2 bootstrap_method_ref;
 344 //        u2 num_bootstrap_arguments;
 345 //        u2 bootstrap_arguments[num_bootstrap_arguments];
 346 //    } bootstrap_methods[num_bootstrap_methods];
 347 //  }
 348 void JvmtiClassFileReconstituter::write_bootstrapmethod_attribute() {
 349   Array<u2>* operands = cpool()->operands();
 350   write_attribute_name_index("BootstrapMethods");
 351   int num_bootstrap_methods = ConstantPool::operand_array_length(operands);
 352 
 353   // calculate length of attribute
 354   int length = sizeof(u2); // num_bootstrap_methods
 355   for (int n = 0; n < num_bootstrap_methods; n++) {
 356     u2 num_bootstrap_arguments = cpool()->operand_argument_count_at(n);
 357     length += sizeof(u2); // bootstrap_method_ref
 358     length += sizeof(u2); // num_bootstrap_arguments
 359     length += sizeof(u2) * num_bootstrap_arguments; // bootstrap_arguments[num_bootstrap_arguments]
 360   }
 361   write_u4(length);
 362 
 363   // write attribute
 364   write_u2(num_bootstrap_methods);
 365   for (int n = 0; n < num_bootstrap_methods; n++) {
 366     u2 bootstrap_method_ref = cpool()->operand_bootstrap_method_ref_index_at(n);
 367     u2 num_bootstrap_arguments = cpool()->operand_argument_count_at(n);
 368     write_u2(bootstrap_method_ref);
 369     write_u2(num_bootstrap_arguments);
 370     for (int arg = 0; arg < num_bootstrap_arguments; arg++) {
 371       u2 bootstrap_argument = cpool()->operand_argument_index_at(n, arg);
 372       write_u2(bootstrap_argument);
 373     }
 374   }
 375 }
 376 
 377 
 378 // Write InnerClasses attribute
 379 // JVMSpec|   InnerClasses_attribute {
 380 // JVMSpec|     u2 attribute_name_index;
 381 // JVMSpec|     u4 attribute_length;
 382 // JVMSpec|     u2 number_of_classes;
 383 // JVMSpec|     {  u2 inner_class_info_index;
 384 // JVMSpec|        u2 outer_class_info_index;
 385 // JVMSpec|        u2 inner_name_index;
 386 // JVMSpec|        u2 inner_class_access_flags;
 387 // JVMSpec|     } classes[number_of_classes];
 388 // JVMSpec|   }
 389 void JvmtiClassFileReconstituter::write_inner_classes_attribute(int length) {
 390   InnerClassesIterator iter(ikh());
 391   guarantee(iter.length() != 0 && iter.length() == length,
 392             "caller must check");
 393   u2 entry_count = length / InstanceKlass::inner_class_next_offset;
 394   u4 size = 2 + entry_count * (2+2+2+2);
 395 
 396   write_attribute_name_index("InnerClasses");
 397   write_u4(size);
 398   write_u2(entry_count);
 399   for (; !iter.done(); iter.next()) {
 400     write_u2(iter.inner_class_info_index());
 401     write_u2(iter.outer_class_info_index());
 402     write_u2(iter.inner_name_index());
 403     write_u2(iter.inner_access_flags());
 404   }
 405 }
 406 
 407 // Write Synthetic attribute
 408 // JVMSpec|   Synthetic_attribute {
 409 // JVMSpec|     u2 attribute_name_index;
 410 // JVMSpec|     u4 attribute_length;
 411 // JVMSpec|   }
 412 void JvmtiClassFileReconstituter::write_synthetic_attribute() {
 413   write_attribute_name_index("Synthetic");
 414   write_u4(0); //length always zero
 415 }
 416 
 417 // Compute size of LineNumberTable
 418 u2 JvmtiClassFileReconstituter::line_number_table_entries(const methodHandle& method) {
 419   // The line number table is compressed so we don't know how big it is until decompressed.
 420   // Decompression is really fast so we just do it twice.
 421   u2 num_entries = 0;
 422   CompressedLineNumberReadStream stream(method->compressed_linenumber_table());
 423   while (stream.read_pair()) {
 424     num_entries++;
 425   }
 426   return num_entries;
 427 }
 428 
 429 // Write LineNumberTable attribute
 430 // JVMSpec|   LineNumberTable_attribute {
 431 // JVMSpec|     u2 attribute_name_index;
 432 // JVMSpec|     u4 attribute_length;
 433 // JVMSpec|     u2 line_number_table_length;
 434 // JVMSpec|     {  u2 start_pc;
 435 // JVMSpec|        u2 line_number;
 436 // JVMSpec|     } line_number_table[line_number_table_length];
 437 // JVMSpec|   }
 438 void JvmtiClassFileReconstituter::write_line_number_table_attribute(const methodHandle& method,
 439                                                                     u2 num_entries) {
 440 
 441   write_attribute_name_index("LineNumberTable");
 442   write_u4(2 + num_entries * (2 + 2));
 443   write_u2(num_entries);
 444 
 445   CompressedLineNumberReadStream stream(method->compressed_linenumber_table());
 446   while (stream.read_pair()) {
 447     write_u2(stream.bci());
 448     write_u2(stream.line());
 449   }
 450 }
 451 
 452 // Write LocalVariableTable attribute
 453 // JVMSpec|   LocalVariableTable_attribute {
 454 // JVMSpec|     u2 attribute_name_index;
 455 // JVMSpec|     u4 attribute_length;
 456 // JVMSpec|     u2 local_variable_table_length;
 457 // JVMSpec|     {  u2 start_pc;
 458 // JVMSpec|       u2 length;
 459 // JVMSpec|       u2 name_index;
 460 // JVMSpec|       u2 descriptor_index;
 461 // JVMSpec|       u2 index;
 462 // JVMSpec|     } local_variable_table[local_variable_table_length];
 463 // JVMSpec|   }
 464 void JvmtiClassFileReconstituter::write_local_variable_table_attribute(const methodHandle& method, u2 num_entries) {
 465     write_attribute_name_index("LocalVariableTable");
 466     write_u4(2 + num_entries * (2 + 2 + 2 + 2 + 2));
 467     write_u2(num_entries);
 468 
 469     assert(method->localvariable_table_length() == num_entries, "just checking");
 470 
 471     LocalVariableTableElement *elem = method->localvariable_table_start();
 472     for (int j=0; j<method->localvariable_table_length(); j++) {
 473       write_u2(elem->start_bci);
 474       write_u2(elem->length);
 475       write_u2(elem->name_cp_index);
 476       write_u2(elem->descriptor_cp_index);
 477       write_u2(elem->slot);
 478       elem++;
 479     }
 480 }
 481 
 482 // Write LocalVariableTypeTable attribute
 483 // JVMSpec|   LocalVariableTypeTable_attribute {
 484 // JVMSpec|     u2 attribute_name_index;
 485 // JVMSpec|     u4 attribute_length;
 486 // JVMSpec|     u2 local_variable_type_table_length;
 487 // JVMSpec|     { u2 start_pc;
 488 // JVMSpec|       u2 length;
 489 // JVMSpec|       u2 name_index;
 490 // JVMSpec|       u2 signature_index;
 491 // JVMSpec|       u2 index;
 492 // JVMSpec|     } local_variable_type_table[local_variable_type_table_length];
 493 // JVMSpec|   }
 494 void JvmtiClassFileReconstituter::write_local_variable_type_table_attribute(const methodHandle& method, u2 num_entries) {
 495     write_attribute_name_index("LocalVariableTypeTable");
 496     write_u4(2 + num_entries * (2 + 2 + 2 + 2 + 2));
 497     write_u2(num_entries);
 498 
 499     LocalVariableTableElement *elem = method->localvariable_table_start();
 500     for (int j=0; j<method->localvariable_table_length(); j++) {
 501       if (elem->signature_cp_index > 0) {
 502         // Local variable has a generic signature - write LVTT attribute entry
 503         write_u2(elem->start_bci);
 504         write_u2(elem->length);
 505         write_u2(elem->name_cp_index);
 506         write_u2(elem->signature_cp_index);
 507         write_u2(elem->slot);
 508         num_entries--;
 509       }
 510       elem++;
 511     }
 512     assert(num_entries == 0, "just checking");
 513 }
 514 
 515 // Write stack map table attribute
 516 // JSR-202|   StackMapTable_attribute {
 517 // JSR-202|     u2 attribute_name_index;
 518 // JSR-202|     u4 attribute_length;
 519 // JSR-202|     u2 number_of_entries;
 520 // JSR-202|     stack_map_frame_entries[number_of_entries];
 521 // JSR-202|   }
 522 void JvmtiClassFileReconstituter::write_stackmap_table_attribute(const methodHandle& method,
 523                                                                  int stackmap_len) {
 524 
 525   write_attribute_name_index("StackMapTable");
 526   write_u4(stackmap_len);
 527   memcpy(
 528     writeable_address(stackmap_len),
 529     (void*)(method->stackmap_data()->adr_at(0)),
 530     stackmap_len);
 531 }
 532 
 533 // Write one method_info structure
 534 // JVMSpec|   method_info {
 535 // JVMSpec|     u2 access_flags;
 536 // JVMSpec|     u2 name_index;
 537 // JVMSpec|     u2 descriptor_index;
 538 // JVMSpec|     u2 attributes_count;
 539 // JVMSpec|     attribute_info attributes[attributes_count];
 540 // JVMSpec|   }
 541 void JvmtiClassFileReconstituter::write_method_info(const methodHandle& method) {
 542   AccessFlags access_flags = method->access_flags();
 543   ConstMethod* const_method = method->constMethod();
 544   u2 generic_signature_index = const_method->generic_signature_index();
 545   AnnotationArray* anno = method->annotations();
 546   AnnotationArray* param_anno = method->parameter_annotations();
 547   AnnotationArray* default_anno = method->annotation_default();
 548   AnnotationArray* type_anno = method->type_annotations();
 549 
 550   // skip generated default interface methods
 551   if (method->is_overpass()) {
 552     return;
 553   }
 554 
 555   write_u2(access_flags.get_flags() & JVM_RECOGNIZED_METHOD_MODIFIERS);
 556   write_u2(const_method->name_index());
 557   write_u2(const_method->signature_index());
 558 
 559   // write attributes in the same order javac does, so we can test with byte for
 560   // byte comparison
 561   int attr_count = 0;
 562   if (const_method->code_size() != 0) {
 563     ++attr_count;     // has Code attribute
 564   }
 565   if (const_method->has_checked_exceptions()) {
 566     ++attr_count;     // has Exceptions attribute
 567   }
 568   if (default_anno != NULL) {
 569     ++attr_count;     // has AnnotationDefault attribute
 570   }
 571   // Deprecated attribute would go here
 572   if (access_flags.is_synthetic()) { // FIXME
 573     // ++attr_count;
 574   }
 575   if (generic_signature_index != 0) {
 576     ++attr_count;
 577   }
 578   if (anno != NULL) {
 579     ++attr_count;     // has RuntimeVisibleAnnotations attribute
 580   }
 581   if (param_anno != NULL) {
 582     ++attr_count;     // has RuntimeVisibleParameterAnnotations attribute
 583   }
 584   if (type_anno != NULL) {
 585     ++attr_count;     // has RuntimeVisibleTypeAnnotations attribute
 586   }
 587 
 588   write_u2(attr_count);
 589   if (const_method->code_size() > 0) {
 590     write_code_attribute(method);
 591   }
 592   if (const_method->has_checked_exceptions()) {
 593     write_exceptions_attribute(const_method);
 594   }
 595   if (default_anno != NULL) {
 596     write_annotations_attribute("AnnotationDefault", default_anno);
 597   }
 598   // Deprecated attribute would go here
 599   if (access_flags.is_synthetic()) {
 600     // write_synthetic_attribute();
 601   }
 602   if (generic_signature_index != 0) {
 603     write_signature_attribute(generic_signature_index);
 604   }
 605   if (anno != NULL) {
 606     write_annotations_attribute("RuntimeVisibleAnnotations", anno);
 607   }
 608   if (param_anno != NULL) {
 609     write_annotations_attribute("RuntimeVisibleParameterAnnotations", param_anno);
 610   }
 611   if (type_anno != NULL) {
 612     write_annotations_attribute("RuntimeVisibleTypeAnnotations", type_anno);
 613   }
 614 }
 615 
 616 // Write the class attributes portion of ClassFile structure
 617 // JVMSpec|     u2 attributes_count;
 618 // JVMSpec|     attribute_info attributes[attributes_count];
 619 void JvmtiClassFileReconstituter::write_class_attributes() {
 620   u2 inner_classes_length = inner_classes_attribute_length();
 621   Symbol* generic_signature = ikh()->generic_signature();
 622   AnnotationArray* anno = ikh()->class_annotations();
 623   AnnotationArray* type_anno = ikh()->class_type_annotations();
 624 
 625   int attr_count = 0;
 626   if (generic_signature != NULL) {
 627     ++attr_count;
 628   }
 629   if (ikh()->source_file_name() != NULL) {
 630     ++attr_count;
 631   }
 632   if (ikh()->source_debug_extension() != NULL) {
 633     ++attr_count;
 634   }
 635   if (inner_classes_length > 0) {
 636     ++attr_count;
 637   }
 638   if (anno != NULL) {
 639     ++attr_count;     // has RuntimeVisibleAnnotations attribute
 640   }
 641   if (type_anno != NULL) {
 642     ++attr_count;     // has RuntimeVisibleTypeAnnotations attribute
 643   }
 644   if (cpool()->operands() != NULL) {
 645     ++attr_count;
 646   }
 647 
 648   write_u2(attr_count);
 649 
 650   if (generic_signature != NULL) {
 651     write_signature_attribute(symbol_to_cpool_index(generic_signature));
 652   }
 653   if (ikh()->source_file_name() != NULL) {
 654     write_source_file_attribute();
 655   }
 656   if (ikh()->source_debug_extension() != NULL) {
 657     write_source_debug_extension_attribute();
 658   }
 659   if (inner_classes_length > 0) {
 660     write_inner_classes_attribute(inner_classes_length);
 661   }
 662   if (anno != NULL) {
 663     write_annotations_attribute("RuntimeVisibleAnnotations", anno);
 664   }
 665   if (type_anno != NULL) {
 666     write_annotations_attribute("RuntimeVisibleTypeAnnotations", type_anno);
 667   }
 668   if (cpool()->operands() != NULL) {
 669     write_bootstrapmethod_attribute();
 670   }
 671 }
 672 
 673 // Write the method information portion of ClassFile structure
 674 // JVMSpec|     u2 methods_count;
 675 // JVMSpec|     method_info methods[methods_count];
 676 void JvmtiClassFileReconstituter::write_method_infos() {
 677   HandleMark hm(thread());
 678   Array<Method*>* methods = ikh()->methods();
 679   int num_methods = methods->length();
 680   int num_overpass = 0;
 681 
 682   // count the generated default interface methods
 683   // these will not be re-created by write_method_info
 684   // and should not be included in the total count
 685   for (int index = 0; index < num_methods; index++) {
 686     Method* method = methods->at(index);
 687     if (method->is_overpass()) {
 688       num_overpass++;
 689     }
 690   }
 691 
 692   write_u2(num_methods - num_overpass);
 693   if (JvmtiExport::can_maintain_original_method_order()) {
 694     int index;
 695     int original_index;
 696     intArray method_order(num_methods, 0);
 697 
 698     // invert the method order mapping
 699     for (index = 0; index < num_methods; index++) {
 700       original_index = ikh()->method_ordering()->at(index);
 701       assert(original_index >= 0 && original_index < num_methods,
 702              "invalid original method index");
 703       method_order.at_put(original_index, index);
 704     }
 705 
 706     // write in original order
 707     for (original_index = 0; original_index < num_methods; original_index++) {
 708       index = method_order.at(original_index);
 709       methodHandle method(thread(), methods->at(index));
 710       write_method_info(method);
 711     }
 712   } else {
 713     // method order not preserved just dump the method infos
 714     for (int index = 0; index < num_methods; index++) {
 715       methodHandle method(thread(), methods->at(index));
 716       write_method_info(method);
 717     }
 718   }
 719 }
 720 
 721 void JvmtiClassFileReconstituter::write_class_file_format() {
 722   ReallocMark();
 723 
 724   // JVMSpec|   ClassFile {
 725   // JVMSpec|           u4 magic;
 726   write_u4(0xCAFEBABE);
 727 
 728   // JVMSpec|           u2 minor_version;
 729   // JVMSpec|           u2 major_version;
 730   write_u2(ikh()->minor_version());
 731   u2 major = ikh()->major_version();
 732   write_u2(major);
 733 
 734   // JVMSpec|           u2 constant_pool_count;
 735   // JVMSpec|           cp_info constant_pool[constant_pool_count-1];
 736   write_u2(cpool()->length());
 737   copy_cpool_bytes(writeable_address(cpool_size()));
 738 
 739   // JVMSpec|           u2 access_flags;
 740   write_u2(ikh()->access_flags().get_flags() & JVM_RECOGNIZED_CLASS_MODIFIERS);
 741 
 742   // JVMSpec|           u2 this_class;
 743   // JVMSpec|           u2 super_class;
 744   write_u2(class_symbol_to_cpool_index(ikh()->name()));
 745   Klass* super_class = ikh()->super();
 746   write_u2(super_class == NULL? 0 :  // zero for java.lang.Object
 747                 class_symbol_to_cpool_index(super_class->name()));
 748 
 749   // JVMSpec|           u2 interfaces_count;
 750   // JVMSpec|           u2 interfaces[interfaces_count];
 751   Array<Klass*>* interfaces =  ikh()->local_interfaces();
 752   int num_interfaces = interfaces->length();
 753   write_u2(num_interfaces);
 754   for (int index = 0; index < num_interfaces; index++) {
 755     HandleMark hm(thread());
 756     instanceKlassHandle iikh(thread(), interfaces->at(index));
 757     write_u2(class_symbol_to_cpool_index(iikh->name()));
 758   }
 759 
 760   // JVMSpec|           u2 fields_count;
 761   // JVMSpec|           field_info fields[fields_count];
 762   write_field_infos();
 763 
 764   // JVMSpec|           u2 methods_count;
 765   // JVMSpec|           method_info methods[methods_count];
 766   write_method_infos();
 767 
 768   // JVMSpec|           u2 attributes_count;
 769   // JVMSpec|           attribute_info attributes[attributes_count];
 770   // JVMSpec|   } /* end ClassFile 8?
 771   write_class_attributes();
 772 }
 773 
 774 address JvmtiClassFileReconstituter::writeable_address(size_t size) {
 775   size_t used_size = _buffer_ptr - _buffer;
 776   if (size + used_size >= _buffer_size) {
 777     // compute the new buffer size: must be at least twice as big as before
 778     // plus whatever new is being used; then convert to nice clean block boundary
 779     size_t new_buffer_size = (size + _buffer_size*2 + 1) / initial_buffer_size
 780                                                          * initial_buffer_size;
 781 
 782     // VM goes belly-up if the memory isn't available, so cannot do OOM processing
 783     _buffer = REALLOC_RESOURCE_ARRAY(u1, _buffer, _buffer_size, new_buffer_size);
 784     _buffer_size = new_buffer_size;
 785     _buffer_ptr = _buffer + used_size;
 786   }
 787   u1* ret_ptr = _buffer_ptr;
 788   _buffer_ptr += size;
 789   return ret_ptr;
 790 }
 791 
 792 void JvmtiClassFileReconstituter::write_attribute_name_index(const char* name) {
 793   TempNewSymbol sym = SymbolTable::probe(name, (int)strlen(name));
 794   assert(sym != NULL, "attribute name symbol not found");
 795   u2 attr_name_index = symbol_to_cpool_index(sym);
 796   assert(attr_name_index != 0, "attribute name symbol not in constant pool");
 797   write_u2(attr_name_index);
 798 }
 799 
 800 void JvmtiClassFileReconstituter::write_u1(u1 x) {
 801   *writeable_address(1) = x;
 802 }
 803 
 804 void JvmtiClassFileReconstituter::write_u2(u2 x) {
 805   Bytes::put_Java_u2(writeable_address(2), x);
 806 }
 807 
 808 void JvmtiClassFileReconstituter::write_u4(u4 x) {
 809   Bytes::put_Java_u4(writeable_address(4), x);
 810 }
 811 
 812 void JvmtiClassFileReconstituter::write_u8(u8 x) {
 813   Bytes::put_Java_u8(writeable_address(8), x);
 814 }
 815 
 816 void JvmtiClassFileReconstituter::copy_bytecodes(const methodHandle& mh,
 817                                                  unsigned char* bytecodes) {
 818   // use a BytecodeStream to iterate over the bytecodes. JVM/fast bytecodes
 819   // and the breakpoint bytecode are converted to their original bytecodes.
 820 
 821   BytecodeStream bs(mh);
 822 
 823   unsigned char* p = bytecodes;
 824   Bytecodes::Code code;
 825   bool is_rewritten = mh->method_holder()->is_rewritten();
 826 
 827   while ((code = bs.next()) >= 0) {
 828     assert(Bytecodes::is_java_code(code), "sanity check");
 829     assert(code != Bytecodes::_breakpoint, "sanity check");
 830 
 831     // length of bytecode (mnemonic + operands)
 832     address bcp = bs.bcp();
 833     int     len = bs.instruction_size();
 834     assert(len > 0, "length must be > 0");
 835 
 836     // copy the bytecodes
 837     *p = (unsigned char) (bs.is_wide()? Bytecodes::_wide : code);
 838     if (len > 1) {
 839       memcpy(p+1, bcp+1, len-1);
 840     }
 841 
 842     // During linking the get/put and invoke instructions are rewritten
 843     // with an index into the constant pool cache. The original constant
 844     // pool index must be returned to caller.  Rewrite the index.
 845     if (is_rewritten && len > 1) {
 846       bool is_wide = false;
 847       switch (code) {
 848       case Bytecodes::_getstatic       :  // fall through
 849       case Bytecodes::_putstatic       :  // fall through
 850       case Bytecodes::_getfield        :  // fall through
 851       case Bytecodes::_putfield        :  // fall through
 852       case Bytecodes::_invokevirtual   :  // fall through
 853       case Bytecodes::_invokespecial   :  // fall through
 854       case Bytecodes::_invokestatic    :  // fall through
 855       case Bytecodes::_invokedynamic   :  // fall through
 856       case Bytecodes::_invokeinterface : {
 857         assert(len == 3 ||
 858                (code == Bytecodes::_invokeinterface && len == 5) ||
 859                (code == Bytecodes::_invokedynamic   && len == 5),
 860                "sanity check");
 861 
 862         int cpci = Bytes::get_native_u2(bcp+1);
 863         bool is_invokedynamic = (code == Bytecodes::_invokedynamic);
 864         ConstantPoolCacheEntry* entry;
 865         if (is_invokedynamic) {
 866           cpci = Bytes::get_native_u4(bcp+1);
 867           entry = mh->constants()->invokedynamic_cp_cache_entry_at(cpci);
 868         } else {
 869         // cache cannot be pre-fetched since some classes won't have it yet
 870           entry = mh->constants()->cache()->entry_at(cpci);
 871         }
 872         int i = entry->constant_pool_index();
 873         assert(i < mh->constants()->length(), "sanity check");
 874         Bytes::put_Java_u2((address)(p+1), (u2)i);     // java byte ordering
 875         if (is_invokedynamic)  *(p+3) = *(p+4) = 0;
 876         break;
 877       }
 878       case Bytecodes::_ldc_w:
 879         is_wide = true; // fall through
 880       case Bytecodes::_ldc: {
 881         if (bs.raw_code() == Bytecodes::_fast_aldc || bs.raw_code() == Bytecodes::_fast_aldc_w) {
 882           int cpci = is_wide ? Bytes::get_native_u2(bcp+1) : (u1)(*(bcp+1));
 883           int i = mh->constants()->object_to_cp_index(cpci);
 884           assert(i < mh->constants()->length(), "sanity check");
 885           if (is_wide) {
 886             Bytes::put_Java_u2((address)(p+1), (u2)i);     // java byte ordering
 887           } else {
 888             *(p+1) = (u1)i;
 889           }
 890         }
 891         break;
 892         }
 893       }
 894     }
 895 
 896     p += len;
 897   }
 898 }