1 /* 2 * Copyright (c) 1997, 2024, 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 #ifndef SHARE_OOPS_CONSTANTPOOL_HPP 26 #define SHARE_OOPS_CONSTANTPOOL_HPP 27 28 #include "memory/allocation.hpp" 29 #include "oops/arrayOop.hpp" 30 #include "oops/cpCache.hpp" 31 #include "oops/objArrayOop.hpp" 32 #include "oops/oopHandle.hpp" 33 #include "oops/symbol.hpp" 34 #include "oops/typeArrayOop.hpp" 35 #include "runtime/handles.hpp" 36 #include "runtime/javaThread.hpp" 37 #include "utilities/align.hpp" 38 #include "utilities/bytes.hpp" 39 #include "utilities/constantTag.hpp" 40 #include "utilities/resourceHash.hpp" 41 42 // A ConstantPool is an array containing class constants as described in the 43 // class file. 44 // 45 // Most of the constant pool entries are written during class parsing, which 46 // is safe. For klass types, the constant pool entry is 47 // modified when the entry is resolved. If a klass constant pool 48 // entry is read without a lock, only the resolved state guarantees that 49 // the entry in the constant pool is a klass object and not a Symbol*. 50 51 // This represents a JVM_CONSTANT_Class, JVM_CONSTANT_UnresolvedClass, or 52 // JVM_CONSTANT_UnresolvedClassInError slot in the constant pool. 53 class CPKlassSlot { 54 // cp->symbol_at(_name_index) gives the name of the class. 55 int _name_index; 56 57 // cp->_resolved_klasses->at(_resolved_klass_index) gives the Klass* for the class. 58 int _resolved_klass_index; 59 public: 60 enum { 61 // This is used during constant pool merging where the resolved klass index is 62 // not yet known, and will be computed at a later stage (during a call to 63 // initialize_unresolved_klasses()). 64 _temp_resolved_klass_index = 0xffff 65 }; 66 CPKlassSlot(int n, int rk) { 67 _name_index = n; 68 _resolved_klass_index = rk; 69 } 70 int name_index() const { 71 return _name_index; 72 } 73 int resolved_klass_index() const { 74 assert(_resolved_klass_index != _temp_resolved_klass_index, "constant pool merging was incomplete"); 75 return _resolved_klass_index; 76 } 77 }; 78 79 class ConstantPool : public Metadata { 80 friend class VMStructs; 81 friend class JVMCIVMStructs; 82 friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast 83 friend class Universe; // For null constructor 84 friend class ClassPrelinker; // CDS 85 private: 86 // If you add a new field that points to any metaspace object, you 87 // must add this field to ConstantPool::metaspace_pointers_do(). 88 Array<u1>* _tags; // the tag array describing the constant pool's contents 89 ConstantPoolCache* _cache; // the cache holding interpreter runtime information 90 InstanceKlass* _pool_holder; // the corresponding class 91 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty 92 93 // Consider using an array of compressed klass pointers to 94 // save space on 64-bit platforms. 95 Array<Klass*>* _resolved_klasses; 96 97 u2 _major_version; // major version number of class file 98 u2 _minor_version; // minor version number of class file 99 100 // Constant pool index to the utf8 entry of the Generic signature, 101 // or 0 if none. 102 u2 _generic_signature_index; 103 // Constant pool index to the utf8 entry for the name of source file 104 // containing this klass, 0 if not specified. 105 u2 _source_file_name_index; 106 107 enum { 108 _has_preresolution = 1, // Flags 109 _on_stack = 2, 110 _is_shared = 4, 111 _has_dynamic_constant = 8 112 }; 113 114 u2 _flags; // old fashioned bit twiddling 115 116 int _length; // number of elements in the array 117 118 union { 119 // set for CDS to restore resolved references 120 int _resolved_reference_length; 121 // keeps version number for redefined classes (used in backtrace) 122 int _version; 123 } _saved; 124 125 void set_tags(Array<u1>* tags) { _tags = tags; } 126 void tag_at_put(int cp_index, jbyte t) { tags()->at_put(cp_index, t); } 127 void release_tag_at_put(int cp_index, jbyte t) { tags()->release_at_put(cp_index, t); } 128 129 u1* tag_addr_at(int cp_index) const { return tags()->adr_at(cp_index); } 130 131 void set_operands(Array<u2>* operands) { _operands = operands; } 132 133 u2 flags() const { return _flags; } 134 void set_flags(u2 f) { _flags = f; } 135 136 private: 137 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); } 138 139 intptr_t* obj_at_addr(int cp_index) const { 140 assert(is_within_bounds(cp_index), "index out of bounds"); 141 return (intptr_t*) &base()[cp_index]; 142 } 143 144 jint* int_at_addr(int cp_index) const { 145 assert(is_within_bounds(cp_index), "index out of bounds"); 146 return (jint*) &base()[cp_index]; 147 } 148 149 jlong* long_at_addr(int cp_index) const { 150 assert(is_within_bounds(cp_index), "index out of bounds"); 151 return (jlong*) &base()[cp_index]; 152 } 153 154 jfloat* float_at_addr(int cp_index) const { 155 assert(is_within_bounds(cp_index), "index out of bounds"); 156 return (jfloat*) &base()[cp_index]; 157 } 158 159 jdouble* double_at_addr(int cp_index) const { 160 assert(is_within_bounds(cp_index), "index out of bounds"); 161 return (jdouble*) &base()[cp_index]; 162 } 163 164 ConstantPool(Array<u1>* tags); 165 ConstantPool(); 166 public: 167 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS); 168 169 virtual bool is_constantPool() const { return true; } 170 171 Array<u1>* tags() const { return _tags; } 172 Array<u2>* operands() const { return _operands; } 173 174 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; } 175 void set_has_preresolution() { 176 assert(!is_shared(), "should never be called on shared ConstantPools"); 177 _flags |= _has_preresolution; 178 } 179 180 // minor and major version numbers of class file 181 u2 major_version() const { return _major_version; } 182 void set_major_version(u2 major_version) { _major_version = major_version; } 183 u2 minor_version() const { return _minor_version; } 184 void set_minor_version(u2 minor_version) { _minor_version = minor_version; } 185 186 // generics support 187 Symbol* generic_signature() const { 188 return (_generic_signature_index == 0) ? 189 nullptr : symbol_at(_generic_signature_index); 190 } 191 u2 generic_signature_index() const { return _generic_signature_index; } 192 void set_generic_signature_index(u2 sig_index) { _generic_signature_index = sig_index; } 193 194 // source file name 195 Symbol* source_file_name() const { 196 return (_source_file_name_index == 0) ? 197 nullptr : symbol_at(_source_file_name_index); 198 } 199 u2 source_file_name_index() const { return _source_file_name_index; } 200 void set_source_file_name_index(u2 sourcefile_index) { _source_file_name_index = sourcefile_index; } 201 202 void copy_fields(const ConstantPool* orig); 203 204 // Redefine classes support. If a method referring to this constant pool 205 // is on the executing stack, or as a handle in vm code, this constant pool 206 // can't be removed from the set of previous versions saved in the instance 207 // class. 208 bool on_stack() const; 209 bool is_maybe_on_stack() const; 210 void set_on_stack(const bool value); 211 212 // Faster than MetaspaceObj::is_shared() - used by set_on_stack() 213 bool is_shared() const { return (_flags & _is_shared) != 0; } 214 215 bool has_dynamic_constant() const { return (_flags & _has_dynamic_constant) != 0; } 216 void set_has_dynamic_constant() { _flags |= _has_dynamic_constant; } 217 218 // Klass holding pool 219 InstanceKlass* pool_holder() const { return _pool_holder; } 220 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; } 221 InstanceKlass** pool_holder_addr() { return &_pool_holder; } 222 223 // Interpreter runtime support 224 ConstantPoolCache* cache() const { return _cache; } 225 void set_cache(ConstantPoolCache* cache){ _cache = cache; } 226 227 virtual void metaspace_pointers_do(MetaspaceClosure* iter); 228 virtual MetaspaceObj::Type type() const { return ConstantPoolType; } 229 230 // Create object cache in the constant pool 231 void initialize_resolved_references(ClassLoaderData* loader_data, 232 const intStack& reference_map, 233 int constant_pool_map_length, 234 TRAPS); 235 236 // resolved strings, methodHandles and callsite objects from the constant pool 237 objArrayOop resolved_references() const; 238 objArrayOop resolved_references_or_null() const; 239 oop resolved_reference_at(int obj_index) const; 240 oop set_resolved_reference_at(int index, oop new_value); 241 242 // mapping resolved object array indexes to cp indexes and back. 243 int object_to_cp_index(int index) { return reference_map()->at(index); } 244 int cp_to_object_index(int index); 245 246 void set_resolved_klasses(Array<Klass*>* rk) { _resolved_klasses = rk; } 247 Array<Klass*>* resolved_klasses() const { return _resolved_klasses; } 248 void allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS); 249 void initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS); 250 251 // Given the per-instruction index of an indy instruction, report the 252 // main constant pool entry for its bootstrap specifier. 253 // From there, uncached_name/signature_ref_at will get the name/type. 254 inline u2 invokedynamic_bootstrap_ref_index_at(int indy_index) const; 255 256 // Assembly code support 257 static ByteSize tags_offset() { return byte_offset_of(ConstantPool, _tags); } 258 static ByteSize cache_offset() { return byte_offset_of(ConstantPool, _cache); } 259 static ByteSize pool_holder_offset() { return byte_offset_of(ConstantPool, _pool_holder); } 260 static ByteSize resolved_klasses_offset() { return byte_offset_of(ConstantPool, _resolved_klasses); } 261 262 // Storing constants 263 264 // For temporary use while constructing constant pool. Used during a retransform/class redefinition as well. 265 void klass_index_at_put(int cp_index, int name_index) { 266 tag_at_put(cp_index, JVM_CONSTANT_ClassIndex); 267 *int_at_addr(cp_index) = name_index; 268 } 269 270 // Hidden class support: 271 void klass_at_put(int class_index, Klass* k); 272 273 void unresolved_klass_at_put(int cp_index, int name_index, int resolved_klass_index) { 274 release_tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass); 275 276 assert((name_index & 0xffff0000) == 0, "must be"); 277 assert((resolved_klass_index & 0xffff0000) == 0, "must be"); 278 *int_at_addr(cp_index) = 279 build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index); 280 } 281 282 void method_handle_index_at_put(int cp_index, int ref_kind, int ref_index) { 283 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle); 284 *int_at_addr(cp_index) = ((jint) ref_index<<16) | ref_kind; 285 } 286 287 void method_type_index_at_put(int cp_index, int ref_index) { 288 tag_at_put(cp_index, JVM_CONSTANT_MethodType); 289 *int_at_addr(cp_index) = ref_index; 290 } 291 292 void dynamic_constant_at_put(int cp_index, int bsms_attribute_index, int name_and_type_index) { 293 tag_at_put(cp_index, JVM_CONSTANT_Dynamic); 294 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | bsms_attribute_index; 295 } 296 297 void invoke_dynamic_at_put(int cp_index, int bsms_attribute_index, int name_and_type_index) { 298 tag_at_put(cp_index, JVM_CONSTANT_InvokeDynamic); 299 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | bsms_attribute_index; 300 } 301 302 void unresolved_string_at_put(int cp_index, Symbol* s) { 303 assert(s->refcount() != 0, "should have nonzero refcount"); 304 // Note that release_tag_at_put is not needed here because this is called only 305 // when constructing a ConstantPool in a single thread, with no possibility 306 // of concurrent access. 307 tag_at_put(cp_index, JVM_CONSTANT_String); 308 *symbol_at_addr(cp_index) = s; 309 } 310 311 void int_at_put(int cp_index, jint i) { 312 tag_at_put(cp_index, JVM_CONSTANT_Integer); 313 *int_at_addr(cp_index) = i; 314 } 315 316 void long_at_put(int cp_index, jlong l) { 317 tag_at_put(cp_index, JVM_CONSTANT_Long); 318 // *long_at_addr(which) = l; 319 Bytes::put_native_u8((address)long_at_addr(cp_index), *((u8*) &l)); 320 } 321 322 void float_at_put(int cp_index, jfloat f) { 323 tag_at_put(cp_index, JVM_CONSTANT_Float); 324 *float_at_addr(cp_index) = f; 325 } 326 327 void double_at_put(int cp_index, jdouble d) { 328 tag_at_put(cp_index, JVM_CONSTANT_Double); 329 // *double_at_addr(which) = d; 330 // u8 temp = *(u8*) &d; 331 Bytes::put_native_u8((address) double_at_addr(cp_index), *((u8*) &d)); 332 } 333 334 Symbol** symbol_at_addr(int cp_index) const { 335 assert(is_within_bounds(cp_index), "index out of bounds"); 336 return (Symbol**) &base()[cp_index]; 337 } 338 339 void symbol_at_put(int cp_index, Symbol* s) { 340 assert(s->refcount() != 0, "should have nonzero refcount"); 341 tag_at_put(cp_index, JVM_CONSTANT_Utf8); 342 *symbol_at_addr(cp_index) = s; 343 } 344 345 void string_at_put(int obj_index, oop str); 346 347 // For temporary use while constructing constant pool 348 void string_index_at_put(int cp_index, int string_index) { 349 tag_at_put(cp_index, JVM_CONSTANT_StringIndex); 350 *int_at_addr(cp_index) = string_index; 351 } 352 353 void field_at_put(int cp_index, int class_index, int name_and_type_index) { 354 tag_at_put(cp_index, JVM_CONSTANT_Fieldref); 355 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index; 356 } 357 358 void method_at_put(int cp_index, int class_index, int name_and_type_index) { 359 tag_at_put(cp_index, JVM_CONSTANT_Methodref); 360 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index; 361 } 362 363 void interface_method_at_put(int cp_index, int class_index, int name_and_type_index) { 364 tag_at_put(cp_index, JVM_CONSTANT_InterfaceMethodref); 365 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index; // Not so nice 366 } 367 368 void name_and_type_at_put(int cp_index, int name_index, int signature_index) { 369 tag_at_put(cp_index, JVM_CONSTANT_NameAndType); 370 *int_at_addr(cp_index) = ((jint) signature_index<<16) | name_index; // Not so nice 371 } 372 373 // Tag query 374 375 constantTag tag_at(int cp_index) const { return (constantTag)tags()->at_acquire(cp_index); } 376 377 // Fetching constants 378 379 Klass* klass_at(int cp_index, TRAPS) { 380 constantPoolHandle h_this(THREAD, this); 381 return klass_at_impl(h_this, cp_index, THREAD); 382 } 383 384 CPKlassSlot klass_slot_at(int cp_index) const { 385 assert(tag_at(cp_index).is_unresolved_klass() || tag_at(cp_index).is_klass(), 386 "Corrupted constant pool"); 387 int value = *int_at_addr(cp_index); 388 int name_index = extract_high_short_from_int(value); 389 int resolved_klass_index = extract_low_short_from_int(value); 390 return CPKlassSlot(name_index, resolved_klass_index); 391 } 392 393 Symbol* klass_name_at(int cp_index) const; // Returns the name, w/o resolving. 394 int klass_name_index_at(int cp_index) const { 395 return klass_slot_at(cp_index).name_index(); 396 } 397 398 Klass* resolved_klass_at(int cp_index) const; // Used by Compiler 399 400 // RedefineClasses() API support: 401 Symbol* klass_at_noresolve(int cp_index) { return klass_name_at(cp_index); } 402 void temp_unresolved_klass_at_put(int cp_index, int name_index) { 403 // Used only during constant pool merging for class redefinition. The resolved klass index 404 // will be initialized later by a call to initialize_unresolved_klasses(). 405 unresolved_klass_at_put(cp_index, name_index, CPKlassSlot::_temp_resolved_klass_index); 406 } 407 408 jint int_at(int cp_index) const { 409 assert(tag_at(cp_index).is_int(), "Corrupted constant pool"); 410 return *int_at_addr(cp_index); 411 } 412 413 jlong long_at(int cp_index) { 414 assert(tag_at(cp_index).is_long(), "Corrupted constant pool"); 415 // return *long_at_addr(cp_index); 416 u8 tmp = Bytes::get_native_u8((address)&base()[cp_index]); 417 return *((jlong*)&tmp); 418 } 419 420 jfloat float_at(int cp_index) { 421 assert(tag_at(cp_index).is_float(), "Corrupted constant pool"); 422 return *float_at_addr(cp_index); 423 } 424 425 jdouble double_at(int cp_index) { 426 assert(tag_at(cp_index).is_double(), "Corrupted constant pool"); 427 u8 tmp = Bytes::get_native_u8((address)&base()[cp_index]); 428 return *((jdouble*)&tmp); 429 } 430 431 Symbol* symbol_at(int cp_index) const { 432 assert(tag_at(cp_index).is_utf8(), "Corrupted constant pool"); 433 return *symbol_at_addr(cp_index); 434 } 435 436 oop string_at(int cp_index, int obj_index, TRAPS) { 437 constantPoolHandle h_this(THREAD, this); 438 return string_at_impl(h_this, cp_index, obj_index, THREAD); 439 } 440 oop string_at(int cp_index, TRAPS) { 441 int obj_index = cp_to_object_index(cp_index); 442 return string_at(cp_index, obj_index, THREAD); 443 } 444 445 // Version that can be used before string oop array is created. 446 oop uncached_string_at(int cp_index, TRAPS); 447 448 // only called when we are sure a string entry is already resolved (via an 449 // earlier string_at call. 450 oop resolved_string_at(int cp_index) { 451 assert(tag_at(cp_index).is_string(), "Corrupted constant pool"); 452 // Must do an acquire here in case another thread resolved the klass 453 // behind our back, lest we later load stale values thru the oop. 454 // we might want a volatile_obj_at in ObjArrayKlass. 455 int obj_index = cp_to_object_index(cp_index); 456 return resolved_reference_at(obj_index); 457 } 458 459 Symbol* unresolved_string_at(int cp_index) { 460 assert(tag_at(cp_index).is_string(), "Corrupted constant pool"); 461 return *symbol_at_addr(cp_index); 462 } 463 464 // Returns an UTF8 for a CONSTANT_String entry at a given index. 465 // UTF8 char* representation was chosen to avoid conversion of 466 // java_lang_Strings at resolved entries into Symbol*s 467 // or vice versa. 468 char* string_at_noresolve(int cp_index); 469 470 jint name_and_type_at(int cp_index) { 471 assert(tag_at(cp_index).is_name_and_type(), "Corrupted constant pool"); 472 return *int_at_addr(cp_index); 473 } 474 475 int method_handle_ref_kind_at(int cp_index) { 476 assert(tag_at(cp_index).is_method_handle() || 477 tag_at(cp_index).is_method_handle_in_error(), "Corrupted constant pool"); 478 return extract_low_short_from_int(*int_at_addr(cp_index)); // mask out unwanted ref_index bits 479 } 480 int method_handle_index_at(int cp_index) { 481 assert(tag_at(cp_index).is_method_handle() || 482 tag_at(cp_index).is_method_handle_in_error(), "Corrupted constant pool"); 483 return extract_high_short_from_int(*int_at_addr(cp_index)); // shift out unwanted ref_kind bits 484 } 485 int method_type_index_at(int cp_index) { 486 assert(tag_at(cp_index).is_method_type() || 487 tag_at(cp_index).is_method_type_in_error(), "Corrupted constant pool"); 488 return *int_at_addr(cp_index); 489 } 490 491 // Derived queries: 492 Symbol* method_handle_name_ref_at(int cp_index) { 493 int member = method_handle_index_at(cp_index); 494 return uncached_name_ref_at(member); 495 } 496 Symbol* method_handle_signature_ref_at(int cp_index) { 497 int member = method_handle_index_at(cp_index); 498 return uncached_signature_ref_at(member); 499 } 500 u2 method_handle_klass_index_at(int cp_index) { 501 int member = method_handle_index_at(cp_index); 502 return uncached_klass_ref_index_at(member); 503 } 504 Symbol* method_type_signature_at(int cp_index) { 505 int sym = method_type_index_at(cp_index); 506 return symbol_at(sym); 507 } 508 509 u2 bootstrap_name_and_type_ref_index_at(int cp_index) { 510 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool"); 511 return extract_high_short_from_int(*int_at_addr(cp_index)); 512 } 513 u2 bootstrap_methods_attribute_index(int cp_index) { 514 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool"); 515 return extract_low_short_from_int(*int_at_addr(cp_index)); 516 } 517 int bootstrap_operand_base(int cp_index) { 518 int bsms_attribute_index = bootstrap_methods_attribute_index(cp_index); 519 return operand_offset_at(operands(), bsms_attribute_index); 520 } 521 // The first part of the operands array consists of an index into the second part. 522 // Extract a 32-bit index value from the first part. 523 static int operand_offset_at(Array<u2>* operands, int bsms_attribute_index) { 524 int n = (bsms_attribute_index * 2); 525 assert(n >= 0 && n+2 <= operands->length(), "oob"); 526 // The first 32-bit index points to the beginning of the second part 527 // of the operands array. Make sure this index is in the first part. 528 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0), 529 operands->at(1))); 530 assert(second_part == 0 || n+2 <= second_part, "oob (2)"); 531 int offset = build_int_from_shorts(operands->at(n+0), 532 operands->at(n+1)); 533 // The offset itself must point into the second part of the array. 534 assert(offset == 0 || (offset >= second_part && offset <= operands->length()), "oob (3)"); 535 return offset; 536 } 537 static void operand_offset_at_put(Array<u2>* operands, int bsms_attribute_index, int offset) { 538 int n = bsms_attribute_index * 2; 539 assert(n >= 0 && n+2 <= operands->length(), "oob"); 540 operands->at_put(n+0, extract_low_short_from_int(offset)); 541 operands->at_put(n+1, extract_high_short_from_int(offset)); 542 } 543 static int operand_array_length(Array<u2>* operands) { 544 if (operands == nullptr || operands->length() == 0) return 0; 545 int second_part = operand_offset_at(operands, 0); 546 return (second_part / 2); 547 } 548 549 #ifdef ASSERT 550 // operand tuples fit together exactly, end to end 551 static int operand_limit_at(Array<u2>* operands, int bsms_attribute_index) { 552 int nextidx = bsms_attribute_index + 1; 553 if (nextidx == operand_array_length(operands)) 554 return operands->length(); 555 else 556 return operand_offset_at(operands, nextidx); 557 } 558 int bootstrap_operand_limit(int cp_index) { 559 int bsms_attribute_index = bootstrap_methods_attribute_index(cp_index); 560 return operand_limit_at(operands(), bsms_attribute_index); 561 } 562 #endif //ASSERT 563 564 // Layout of InvokeDynamic and Dynamic bootstrap method specifier 565 // data in second part of operands array. This encodes one record in 566 // the BootstrapMethods attribute. The whole specifier also includes 567 // the name and type information from the main constant pool entry. 568 enum { 569 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm 570 _indy_argc_offset = 1, // u2 argc 571 _indy_argv_offset = 2 // u2 argv[argc] 572 }; 573 574 // These functions are used in RedefineClasses for CP merge 575 576 int operand_offset_at(int bsms_attribute_index) { 577 assert(0 <= bsms_attribute_index && 578 bsms_attribute_index < operand_array_length(operands()), 579 "Corrupted CP operands"); 580 return operand_offset_at(operands(), bsms_attribute_index); 581 } 582 u2 operand_bootstrap_method_ref_index_at(int bsms_attribute_index) { 583 int offset = operand_offset_at(bsms_attribute_index); 584 return operands()->at(offset + _indy_bsm_offset); 585 } 586 u2 operand_argument_count_at(int bsms_attribute_index) { 587 int offset = operand_offset_at(bsms_attribute_index); 588 u2 argc = operands()->at(offset + _indy_argc_offset); 589 return argc; 590 } 591 u2 operand_argument_index_at(int bsms_attribute_index, int j) { 592 int offset = operand_offset_at(bsms_attribute_index); 593 return operands()->at(offset + _indy_argv_offset + j); 594 } 595 int operand_next_offset_at(int bsms_attribute_index) { 596 int offset = operand_offset_at(bsms_attribute_index) + _indy_argv_offset 597 + operand_argument_count_at(bsms_attribute_index); 598 return offset; 599 } 600 // Compare a bootstrap specifier data in the operands arrays 601 bool compare_operand_to(int bsms_attribute_index1, const constantPoolHandle& cp2, 602 int bsms_attribute_index2); 603 // Find a bootstrap specifier data in the operands array 604 int find_matching_operand(int bsms_attribute_index, const constantPoolHandle& search_cp, 605 int operands_cur_len); 606 // Resize the operands array with delta_len and delta_size 607 void resize_operands(int delta_len, int delta_size, TRAPS); 608 // Extend the operands array with the length and size of the ext_cp operands 609 void extend_operands(const constantPoolHandle& ext_cp, TRAPS); 610 // Shrink the operands array to a smaller array with new_len length 611 void shrink_operands(int new_len, TRAPS); 612 613 u2 bootstrap_method_ref_index_at(int cp_index) { 614 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool"); 615 int op_base = bootstrap_operand_base(cp_index); 616 return operands()->at(op_base + _indy_bsm_offset); 617 } 618 u2 bootstrap_argument_count_at(int cp_index) { 619 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool"); 620 int op_base = bootstrap_operand_base(cp_index); 621 u2 argc = operands()->at(op_base + _indy_argc_offset); 622 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc; 623 int next_offset = bootstrap_operand_limit(cp_index)); 624 assert(end_offset == next_offset, "matched ending"); 625 return argc; 626 } 627 u2 bootstrap_argument_index_at(int cp_index, int j) { 628 int op_base = bootstrap_operand_base(cp_index); 629 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset)); 630 assert((uint)j < (uint)argc, "oob"); 631 return operands()->at(op_base + _indy_argv_offset + j); 632 } 633 634 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve, 635 // name_and_type_ref_index_at) all expect to be passed indices obtained 636 // directly from the bytecode. 637 // If the indices are meant to refer to fields or methods, they are 638 // actually rewritten indices that point to entries in their respective structures 639 // i.e. ResolvedMethodEntries or ResolvedFieldEntries. 640 // The routine to_cp_index manages the adjustment 641 // of these values back to constant pool indices. 642 643 // There are also "uncached" versions which do not adjust the operand index; see below. 644 645 // Lookup for entries consisting of (klass_index, name_and_type index) 646 Klass* klass_ref_at(int which, Bytecodes::Code code, TRAPS); 647 Symbol* klass_ref_at_noresolve(int which, Bytecodes::Code code); 648 Symbol* name_ref_at(int which, Bytecodes::Code code) { 649 int name_index = name_ref_index_at(name_and_type_ref_index_at(which, code)); 650 return symbol_at(name_index); 651 } 652 Symbol* signature_ref_at(int which, Bytecodes::Code code) { 653 int signature_index = signature_ref_index_at(name_and_type_ref_index_at(which, code)); 654 return symbol_at(signature_index); 655 } 656 657 u2 klass_ref_index_at(int which, Bytecodes::Code code); 658 u2 name_and_type_ref_index_at(int which, Bytecodes::Code code); 659 660 constantTag tag_ref_at(int cp_cache_index, Bytecodes::Code code); 661 662 int to_cp_index(int which, Bytecodes::Code code); 663 664 bool is_resolved(int which, Bytecodes::Code code); 665 666 // Lookup for entries consisting of (name_index, signature_index) 667 u2 name_ref_index_at(int cp_index); // == low-order jshort of name_and_type_at(cp_index) 668 u2 signature_ref_index_at(int cp_index); // == high-order jshort of name_and_type_at(cp_index) 669 670 BasicType basic_type_for_signature_at(int cp_index) const; 671 672 // Resolve string constants (to prevent allocation during compilation) 673 void resolve_string_constants(TRAPS) { 674 constantPoolHandle h_this(THREAD, this); 675 resolve_string_constants_impl(h_this, CHECK); 676 } 677 678 #if INCLUDE_CDS 679 // CDS support 680 objArrayOop prepare_resolved_references_for_archiving() NOT_CDS_JAVA_HEAP_RETURN_(nullptr); 681 void add_dumped_interned_strings() NOT_CDS_JAVA_HEAP_RETURN; 682 void remove_unshareable_info(); 683 void restore_unshareable_info(TRAPS); 684 private: 685 void remove_unshareable_entries(); 686 void remove_resolved_klass_if_non_deterministic(int cp_index); 687 #endif 688 689 private: 690 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 }; 691 public: 692 693 // Get the tag for a constant, which may involve a constant dynamic 694 constantTag constant_tag_at(int cp_index); 695 // Get the basic type for a constant, which may involve a constant dynamic 696 BasicType basic_type_for_constant_at(int cp_index); 697 698 // Resolve late bound constants. 699 oop resolve_constant_at(int cp_index, TRAPS) { 700 constantPoolHandle h_this(THREAD, this); 701 return resolve_constant_at_impl(h_this, cp_index, _no_index_sentinel, nullptr, THREAD); 702 } 703 704 oop resolve_cached_constant_at(int cache_index, TRAPS) { 705 constantPoolHandle h_this(THREAD, this); 706 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, nullptr, THREAD); 707 } 708 709 oop resolve_possibly_cached_constant_at(int cp_index, TRAPS) { 710 constantPoolHandle h_this(THREAD, this); 711 return resolve_constant_at_impl(h_this, cp_index, _possible_index_sentinel, nullptr, THREAD); 712 } 713 714 oop find_cached_constant_at(int cp_index, bool& found_it, TRAPS) { 715 constantPoolHandle h_this(THREAD, this); 716 return resolve_constant_at_impl(h_this, cp_index, _possible_index_sentinel, &found_it, THREAD); 717 } 718 719 void copy_bootstrap_arguments_at(int cp_index, 720 int start_arg, int end_arg, 721 objArrayHandle info, int pos, 722 bool must_resolve, Handle if_not_available, TRAPS) { 723 constantPoolHandle h_this(THREAD, this); 724 copy_bootstrap_arguments_at_impl(h_this, cp_index, start_arg, end_arg, 725 info, pos, must_resolve, if_not_available, THREAD); 726 } 727 728 // Klass name matches name at offset 729 bool klass_name_at_matches(const InstanceKlass* k, int cp_index); 730 731 // Sizing 732 int length() const { return _length; } 733 void set_length(int length) { _length = length; } 734 735 // Tells whether index is within bounds. 736 bool is_within_bounds(int index) const { 737 return 0 <= index && index < length(); 738 } 739 740 // Sizing (in words) 741 static int header_size() { 742 return align_up((int)sizeof(ConstantPool), wordSize) / wordSize; 743 } 744 static int size(int length) { return align_metadata_size(header_size() + length); } 745 int size() const { return size(length()); } 746 747 // ConstantPools should be stored in the read-only region of CDS archive. 748 static bool is_read_only_by_default() { return true; } 749 750 friend class ClassFileParser; 751 friend class SystemDictionary; 752 753 // Used by CDS. These classes need to access the private ConstantPool() constructor. 754 template <class T> friend class CppVtableTesterA; 755 template <class T> friend class CppVtableTesterB; 756 template <class T> friend class CppVtableCloner; 757 758 // Used by compiler to prevent classloading. 759 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which); 760 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code); 761 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code); 762 static bool has_local_signature_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code); 763 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which); 764 765 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the 766 // future by other Java code. These take constant pool indices rather than 767 // constant pool cache indices as do the peer methods above. 768 Symbol* uncached_klass_ref_at_noresolve(int cp_index); 769 Symbol* uncached_name_ref_at(int cp_index) { 770 int name_index = name_ref_index_at(uncached_name_and_type_ref_index_at(cp_index)); 771 return symbol_at(name_index); 772 } 773 Symbol* uncached_signature_ref_at(int cp_index) { 774 int signature_index = signature_ref_index_at(uncached_name_and_type_ref_index_at(cp_index)); 775 return symbol_at(signature_index); 776 } 777 u2 uncached_klass_ref_index_at(int cp_index); 778 u2 uncached_name_and_type_ref_index_at(int cp_index); 779 780 // Sharing 781 int pre_resolve_shared_klasses(TRAPS); 782 783 // Debugging 784 const char* printable_name_at(int cp_index) PRODUCT_RETURN0; 785 786 private: 787 788 void set_resolved_references(OopHandle s) { _cache->set_resolved_references(s); } 789 Array<u2>* reference_map() const { return (_cache == nullptr) ? nullptr : _cache->reference_map(); } 790 void set_reference_map(Array<u2>* o) { _cache->set_reference_map(o); } 791 792 // Used while constructing constant pool (only by ClassFileParser) 793 jint klass_index_at(int cp_index) { 794 assert(tag_at(cp_index).is_klass_index(), "Corrupted constant pool"); 795 return *int_at_addr(cp_index); 796 } 797 798 jint string_index_at(int cp_index) { 799 assert(tag_at(cp_index).is_string_index(), "Corrupted constant pool"); 800 return *int_at_addr(cp_index); 801 } 802 803 // Performs the LinkResolver checks 804 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* klass, TRAPS); 805 806 // Implementation of methods that needs an exposed 'this' pointer, in order to 807 // handle GC while executing the method 808 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int cp_index, TRAPS); 809 static oop string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS); 810 811 static void trace_class_resolution(const constantPoolHandle& this_cp, Klass* k); 812 813 // Resolve string constants (to prevent allocation during compilation) 814 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS); 815 816 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int cp_index, int cache_index, 817 bool* status_return, TRAPS); 818 static void copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index, 819 int start_arg, int end_arg, 820 objArrayHandle info, int pos, 821 bool must_resolve, Handle if_not_available, TRAPS); 822 823 // Exception handling 824 static void save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index, constantTag tag, TRAPS); 825 826 public: 827 // Exception handling 828 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS); 829 830 // Merging ConstantPool* support: 831 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2); 832 void copy_cp_to(int start_cpi, int end_cpi, const constantPoolHandle& to_cp, int to_cpi, TRAPS) { 833 constantPoolHandle h_this(THREAD, this); 834 copy_cp_to_impl(h_this, start_cpi, end_cpi, to_cp, to_cpi, THREAD); 835 } 836 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_cpi, int end_cpi, const constantPoolHandle& to_cp, int to_cpi, TRAPS); 837 static void copy_entry_to(const constantPoolHandle& from_cp, int from_cpi, const constantPoolHandle& to_cp, int to_cpi); 838 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS); 839 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp); 840 int version() const { return _saved._version; } 841 void set_version(int version) { _saved._version = version; } 842 void increment_and_save_version(int version) { 843 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow 844 } 845 846 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; } 847 int resolved_reference_length() const { return _saved._resolved_reference_length; } 848 849 // Decrease ref counts of symbols that are in the constant pool 850 // when the holder class is unloaded 851 void unreference_symbols(); 852 853 // Deallocate constant pool for RedefineClasses 854 void deallocate_contents(ClassLoaderData* loader_data); 855 void release_C_heap_structures(); 856 857 // JVMTI access - GetConstantPool, RetransformClasses, ... 858 friend class JvmtiConstantPoolReconstituter; 859 860 private: 861 class SymbolHash: public CHeapObj<mtSymbol> { 862 ResourceHashtable<const Symbol*, u2, 256, AnyObj::C_HEAP, mtSymbol, Symbol::compute_hash> _table; 863 864 public: 865 void add_if_absent(const Symbol* sym, u2 value) { 866 bool created; 867 _table.put_if_absent(sym, value, &created); 868 } 869 870 u2 symbol_to_value(const Symbol* sym) { 871 u2* value = _table.get(sym); 872 return (value == nullptr) ? 0 : *value; 873 } 874 }; // End SymbolHash class 875 876 jint cpool_entry_size(jint idx); 877 jint hash_entries_to(SymbolHash *symmap, SymbolHash *classmap); 878 879 // Copy cpool bytes into byte array. 880 // Returns: 881 // int > 0, count of the raw cpool bytes that have been copied 882 // 0, OutOfMemory error 883 // -1, Internal error 884 int copy_cpool_bytes(int cpool_size, 885 SymbolHash* tbl, 886 unsigned char *bytes); 887 888 public: 889 // Verify 890 void verify_on(outputStream* st); 891 892 // Printing 893 void print_on(outputStream* st) const; 894 void print_value_on(outputStream* st) const; 895 void print_entry_on(int index, outputStream* st); 896 897 const char* internal_name() const { return "{constant pool}"; } 898 899 // ResolvedFieldEntry getters 900 inline ResolvedFieldEntry* resolved_field_entry_at(int field_index); 901 inline int resolved_field_entries_length() const; 902 903 // ResolvedMethodEntry getters 904 inline ResolvedMethodEntry* resolved_method_entry_at(int method_index); 905 inline int resolved_method_entries_length() const; 906 inline oop appendix_if_resolved(int method_index) const; 907 908 // ResolvedIndyEntry getters 909 inline ResolvedIndyEntry* resolved_indy_entry_at(int index); 910 inline int resolved_indy_entries_length() const; 911 inline oop resolved_reference_from_indy(int index) const; 912 inline oop resolved_reference_from_method(int index) const; 913 }; 914 915 #endif // SHARE_OOPS_CONSTANTPOOL_HPP