1 /* 2 * Copyright (c) 1997, 2025, 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/macros.hpp" 41 #include "utilities/resourceHash.hpp" 42 43 // A ConstantPool is an array containing class constants as described in the 44 // class file. 45 // 46 // Most of the constant pool entries are written during class parsing, which 47 // is safe. For klass types, the constant pool entry is 48 // modified when the entry is resolved. If a klass constant pool 49 // entry is read without a lock, only the resolved state guarantees that 50 // the entry in the constant pool is a klass object and not a Symbol*. 51 52 // This represents a JVM_CONSTANT_Class, JVM_CONSTANT_UnresolvedClass, or 53 // JVM_CONSTANT_UnresolvedClassInError slot in the constant pool. 54 class CPKlassSlot { 55 // cp->symbol_at(_name_index) gives the name of the class. 56 int _name_index; 57 58 // cp->_resolved_klasses->at(_resolved_klass_index) gives the Klass* for the class. 59 int _resolved_klass_index; 60 public: 61 enum { 62 // This is used during constant pool merging where the resolved klass index is 63 // not yet known, and will be computed at a later stage (during a call to 64 // initialize_unresolved_klasses()). 65 _temp_resolved_klass_index = 0xffff 66 }; 67 CPKlassSlot(int n, int rk) { 68 _name_index = n; 69 _resolved_klass_index = rk; 70 } 71 int name_index() const { 72 return _name_index; 73 } 74 int resolved_klass_index() const { 75 assert(_resolved_klass_index != _temp_resolved_klass_index, "constant pool merging was incomplete"); 76 return _resolved_klass_index; 77 } 78 }; 79 80 class ConstantPool : public Metadata { 81 friend class VMStructs; 82 friend class JVMCIVMStructs; 83 friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast 84 friend class Universe; // For null constructor 85 friend class AOTConstantPoolResolver; 86 private: 87 // If you add a new field that points to any metaspace object, you 88 // must add this field to ConstantPool::metaspace_pointers_do(). 89 Array<u1>* _tags; // the tag array describing the constant pool's contents 90 ConstantPoolCache* _cache; // the cache holding interpreter runtime information 91 InstanceKlass* _pool_holder; // the corresponding class 92 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty 93 94 // Consider using an array of compressed klass pointers to 95 // save space on 64-bit platforms. 96 Array<Klass*>* _resolved_klasses; 97 98 u2 _major_version; // major version number of class file 99 u2 _minor_version; // minor version number of class file 100 101 // Constant pool index to the utf8 entry of the Generic signature, 102 // or 0 if none. 103 u2 _generic_signature_index; 104 // Constant pool index to the utf8 entry for the name of source file 105 // containing this klass, 0 if not specified. 106 u2 _source_file_name_index; 107 108 enum { 109 _has_preresolution = 1, // Flags 110 _on_stack = 2, 111 _is_shared = 4, 112 _has_dynamic_constant = 8, 113 _is_for_method_handle_intrinsic = 16 114 }; 115 116 u2 _flags; // old fashioned bit twiddling 117 118 int _length; // number of elements in the array 119 120 union { 121 // set for CDS to restore resolved references 122 int _resolved_reference_length; 123 // keeps version number for redefined classes (used in backtrace) 124 int _version; 125 } _saved; 126 127 void set_tags(Array<u1>* tags) { _tags = tags; } 128 void tag_at_put(int cp_index, jbyte t) { tags()->at_put(cp_index, t); } 129 void release_tag_at_put(int cp_index, jbyte t) { tags()->release_at_put(cp_index, t); } 130 131 u1* tag_addr_at(int cp_index) const { return tags()->adr_at(cp_index); } 132 133 void set_operands(Array<u2>* operands) { _operands = operands; } 134 135 u2 flags() const { return _flags; } 136 void set_flags(u2 f) { _flags = f; } 137 138 private: 139 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); } 140 141 intptr_t* obj_at_addr(int cp_index) const { 142 assert(is_within_bounds(cp_index), "index out of bounds"); 143 return (intptr_t*) &base()[cp_index]; 144 } 145 146 jint* int_at_addr(int cp_index) const { 147 assert(is_within_bounds(cp_index), "index out of bounds"); 148 return (jint*) &base()[cp_index]; 149 } 150 151 jlong* long_at_addr(int cp_index) const { 152 assert(is_within_bounds(cp_index), "index out of bounds"); 153 return (jlong*) &base()[cp_index]; 154 } 155 156 jfloat* float_at_addr(int cp_index) const { 157 assert(is_within_bounds(cp_index), "index out of bounds"); 158 return (jfloat*) &base()[cp_index]; 159 } 160 161 jdouble* double_at_addr(int cp_index) const { 162 assert(is_within_bounds(cp_index), "index out of bounds"); 163 return (jdouble*) &base()[cp_index]; 164 } 165 static void check_and_add_dumped_interned_string(oop obj); 166 167 ConstantPool(Array<u1>* tags); 168 ConstantPool(); 169 public: 170 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS); 171 172 virtual bool is_constantPool() const { return true; } 173 174 Array<u1>* tags() const { return _tags; } 175 Array<u2>* operands() const { return _operands; } 176 177 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; } 178 void set_has_preresolution() { 179 assert(!is_shared(), "should never be called on shared ConstantPools"); 180 _flags |= _has_preresolution; 181 } 182 183 // minor and major version numbers of class file 184 u2 major_version() const { return _major_version; } 185 void set_major_version(u2 major_version) { _major_version = major_version; } 186 u2 minor_version() const { return _minor_version; } 187 void set_minor_version(u2 minor_version) { _minor_version = minor_version; } 188 189 // generics support 190 Symbol* generic_signature() const { 191 return (_generic_signature_index == 0) ? 192 nullptr : symbol_at(_generic_signature_index); 193 } 194 u2 generic_signature_index() const { return _generic_signature_index; } 195 void set_generic_signature_index(u2 sig_index) { _generic_signature_index = sig_index; } 196 197 // source file name 198 Symbol* source_file_name() const { 199 return (_source_file_name_index == 0) ? 200 nullptr : symbol_at(_source_file_name_index); 201 } 202 u2 source_file_name_index() const { return _source_file_name_index; } 203 void set_source_file_name_index(u2 sourcefile_index) { _source_file_name_index = sourcefile_index; } 204 205 void copy_fields(const ConstantPool* orig); 206 207 // Redefine classes support. If a method referring to this constant pool 208 // is on the executing stack, or as a handle in vm code, this constant pool 209 // can't be removed from the set of previous versions saved in the instance 210 // class. 211 bool on_stack() const; 212 bool is_maybe_on_stack() const; 213 void set_on_stack(const bool value); 214 215 // Faster than MetaspaceObj::is_shared() - used by set_on_stack() 216 bool is_shared() const { return (_flags & _is_shared) != 0; } 217 218 bool has_dynamic_constant() const { return (_flags & _has_dynamic_constant) != 0; } 219 void set_has_dynamic_constant() { _flags |= _has_dynamic_constant; } 220 221 bool is_for_method_handle_intrinsic() const { return (_flags & _is_for_method_handle_intrinsic) != 0; } 222 void set_is_for_method_handle_intrinsic() { _flags |= _is_for_method_handle_intrinsic; } 223 224 // Klass holding pool 225 InstanceKlass* pool_holder() const { return _pool_holder; } 226 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; } 227 InstanceKlass** pool_holder_addr() { return &_pool_holder; } 228 229 // Interpreter runtime support 230 ConstantPoolCache* cache() const { return _cache; } 231 void set_cache(ConstantPoolCache* cache){ _cache = cache; } 232 233 virtual void metaspace_pointers_do(MetaspaceClosure* iter); 234 virtual MetaspaceObj::Type type() const { return ConstantPoolType; } 235 236 // Create object cache in the constant pool 237 void initialize_resolved_references(ClassLoaderData* loader_data, 238 const intStack& reference_map, 239 int constant_pool_map_length, 240 TRAPS); 241 242 // resolved strings, methodHandles and callsite objects from the constant pool 243 objArrayOop resolved_references() const; 244 objArrayOop resolved_references_or_null() const; 245 oop resolved_reference_at(int obj_index) const; 246 oop set_resolved_reference_at(int index, oop new_value); 247 248 // mapping resolved object array indexes to cp indexes and back. 249 int object_to_cp_index(int index) { return reference_map()->at(index); } 250 int cp_to_object_index(int index); 251 252 void set_resolved_klasses(Array<Klass*>* rk) { _resolved_klasses = rk; } 253 Array<Klass*>* resolved_klasses() const { return _resolved_klasses; } 254 void allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS); 255 void initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS); 256 257 // Given the per-instruction index of an indy instruction, report the 258 // main constant pool entry for its bootstrap specifier. 259 // From there, uncached_name/signature_ref_at will get the name/type. 260 inline u2 invokedynamic_bootstrap_ref_index_at(int indy_index) const; 261 262 // Assembly code support 263 static ByteSize tags_offset() { return byte_offset_of(ConstantPool, _tags); } 264 static ByteSize cache_offset() { return byte_offset_of(ConstantPool, _cache); } 265 static ByteSize pool_holder_offset() { return byte_offset_of(ConstantPool, _pool_holder); } 266 static ByteSize resolved_klasses_offset() { return byte_offset_of(ConstantPool, _resolved_klasses); } 267 268 // Storing constants 269 270 // For temporary use while constructing constant pool. Used during a retransform/class redefinition as well. 271 void klass_index_at_put(int cp_index, int name_index) { 272 tag_at_put(cp_index, JVM_CONSTANT_ClassIndex); 273 *int_at_addr(cp_index) = name_index; 274 } 275 276 // Hidden class support: 277 void klass_at_put(int class_index, Klass* k); 278 279 void unresolved_klass_at_put(int cp_index, int name_index, int resolved_klass_index) { 280 release_tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass); 281 282 assert((name_index & 0xffff0000) == 0, "must be"); 283 assert((resolved_klass_index & 0xffff0000) == 0, "must be"); 284 *int_at_addr(cp_index) = 285 build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index); 286 } 287 288 void method_handle_index_at_put(int cp_index, int ref_kind, int ref_index) { 289 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle); 290 *int_at_addr(cp_index) = ((jint) ref_index<<16) | ref_kind; 291 } 292 293 void method_type_index_at_put(int cp_index, int ref_index) { 294 tag_at_put(cp_index, JVM_CONSTANT_MethodType); 295 *int_at_addr(cp_index) = ref_index; 296 } 297 298 void dynamic_constant_at_put(int cp_index, int bsms_attribute_index, int name_and_type_index) { 299 tag_at_put(cp_index, JVM_CONSTANT_Dynamic); 300 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | bsms_attribute_index; 301 } 302 303 void invoke_dynamic_at_put(int cp_index, int bsms_attribute_index, int name_and_type_index) { 304 tag_at_put(cp_index, JVM_CONSTANT_InvokeDynamic); 305 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | bsms_attribute_index; 306 } 307 308 void unresolved_string_at_put(int cp_index, Symbol* s) { 309 assert(s->refcount() != 0, "should have nonzero refcount"); 310 // Note that release_tag_at_put is not needed here because this is called only 311 // when constructing a ConstantPool in a single thread, with no possibility 312 // of concurrent access. 313 tag_at_put(cp_index, JVM_CONSTANT_String); 314 *symbol_at_addr(cp_index) = s; 315 } 316 317 void int_at_put(int cp_index, jint i) { 318 tag_at_put(cp_index, JVM_CONSTANT_Integer); 319 *int_at_addr(cp_index) = i; 320 } 321 322 void long_at_put(int cp_index, jlong l) { 323 tag_at_put(cp_index, JVM_CONSTANT_Long); 324 // *long_at_addr(which) = l; 325 Bytes::put_native_u8((address)long_at_addr(cp_index), *((u8*) &l)); 326 } 327 328 void float_at_put(int cp_index, jfloat f) { 329 tag_at_put(cp_index, JVM_CONSTANT_Float); 330 *float_at_addr(cp_index) = f; 331 } 332 333 void double_at_put(int cp_index, jdouble d) { 334 tag_at_put(cp_index, JVM_CONSTANT_Double); 335 // *double_at_addr(which) = d; 336 // u8 temp = *(u8*) &d; 337 Bytes::put_native_u8((address) double_at_addr(cp_index), *((u8*) &d)); 338 } 339 340 Symbol** symbol_at_addr(int cp_index) const { 341 assert(is_within_bounds(cp_index), "index out of bounds"); 342 return (Symbol**) &base()[cp_index]; 343 } 344 345 void symbol_at_put(int cp_index, Symbol* s) { 346 assert(s->refcount() != 0, "should have nonzero refcount"); 347 tag_at_put(cp_index, JVM_CONSTANT_Utf8); 348 *symbol_at_addr(cp_index) = s; 349 } 350 351 void string_at_put(int obj_index, oop str); 352 353 // For temporary use while constructing constant pool 354 void string_index_at_put(int cp_index, int string_index) { 355 tag_at_put(cp_index, JVM_CONSTANT_StringIndex); 356 *int_at_addr(cp_index) = string_index; 357 } 358 359 void field_at_put(int cp_index, int class_index, int name_and_type_index) { 360 tag_at_put(cp_index, JVM_CONSTANT_Fieldref); 361 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index; 362 } 363 364 void method_at_put(int cp_index, int class_index, int name_and_type_index) { 365 tag_at_put(cp_index, JVM_CONSTANT_Methodref); 366 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index; 367 } 368 369 void interface_method_at_put(int cp_index, int class_index, int name_and_type_index) { 370 tag_at_put(cp_index, JVM_CONSTANT_InterfaceMethodref); 371 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index; // Not so nice 372 } 373 374 void name_and_type_at_put(int cp_index, int name_index, int signature_index) { 375 tag_at_put(cp_index, JVM_CONSTANT_NameAndType); 376 *int_at_addr(cp_index) = ((jint) signature_index<<16) | name_index; // Not so nice 377 } 378 379 // Tag query 380 381 constantTag tag_at(int cp_index) const { return (constantTag)tags()->at_acquire(cp_index); } 382 383 // Fetching constants 384 385 Klass* klass_at(int cp_index, TRAPS) { 386 constantPoolHandle h_this(THREAD, this); 387 return klass_at_impl(h_this, cp_index, THREAD); 388 } 389 390 CPKlassSlot klass_slot_at(int cp_index) const { 391 assert(tag_at(cp_index).is_unresolved_klass() || tag_at(cp_index).is_klass(), 392 "Corrupted constant pool"); 393 int value = *int_at_addr(cp_index); 394 int name_index = extract_high_short_from_int(value); 395 int resolved_klass_index = extract_low_short_from_int(value); 396 return CPKlassSlot(name_index, resolved_klass_index); 397 } 398 399 Symbol* klass_name_at(int cp_index) const; // Returns the name, w/o resolving. 400 int klass_name_index_at(int cp_index) const { 401 return klass_slot_at(cp_index).name_index(); 402 } 403 404 Klass* resolved_klass_at(int cp_index) const; // Used by Compiler 405 406 // RedefineClasses() API support: 407 Symbol* klass_at_noresolve(int cp_index) { return klass_name_at(cp_index); } 408 void temp_unresolved_klass_at_put(int cp_index, int name_index) { 409 // Used only during constant pool merging for class redefinition. The resolved klass index 410 // will be initialized later by a call to initialize_unresolved_klasses(). 411 unresolved_klass_at_put(cp_index, name_index, CPKlassSlot::_temp_resolved_klass_index); 412 } 413 414 jint int_at(int cp_index) const { 415 assert(tag_at(cp_index).is_int(), "Corrupted constant pool"); 416 return *int_at_addr(cp_index); 417 } 418 419 jlong long_at(int cp_index) { 420 assert(tag_at(cp_index).is_long(), "Corrupted constant pool"); 421 // return *long_at_addr(cp_index); 422 u8 tmp = Bytes::get_native_u8((address)&base()[cp_index]); 423 return *((jlong*)&tmp); 424 } 425 426 jfloat float_at(int cp_index) { 427 assert(tag_at(cp_index).is_float(), "Corrupted constant pool"); 428 return *float_at_addr(cp_index); 429 } 430 431 jdouble double_at(int cp_index) { 432 assert(tag_at(cp_index).is_double(), "Corrupted constant pool"); 433 u8 tmp = Bytes::get_native_u8((address)&base()[cp_index]); 434 return *((jdouble*)&tmp); 435 } 436 437 Symbol* symbol_at(int cp_index) const { 438 assert(tag_at(cp_index).is_utf8(), "Corrupted constant pool"); 439 return *symbol_at_addr(cp_index); 440 } 441 442 oop string_at(int cp_index, int obj_index, TRAPS) { 443 constantPoolHandle h_this(THREAD, this); 444 return string_at_impl(h_this, cp_index, obj_index, THREAD); 445 } 446 oop string_at(int cp_index, TRAPS) { 447 int obj_index = cp_to_object_index(cp_index); 448 return string_at(cp_index, obj_index, THREAD); 449 } 450 451 // Version that can be used before string oop array is created. 452 oop uncached_string_at(int cp_index, TRAPS); 453 454 // only called when we are sure a string entry is already resolved (via an 455 // earlier string_at call. 456 oop resolved_string_at(int cp_index) { 457 assert(tag_at(cp_index).is_string(), "Corrupted constant pool"); 458 // Must do an acquire here in case another thread resolved the klass 459 // behind our back, lest we later load stale values thru the oop. 460 // we might want a volatile_obj_at in ObjArrayKlass. 461 int obj_index = cp_to_object_index(cp_index); 462 return resolved_reference_at(obj_index); 463 } 464 465 Symbol* unresolved_string_at(int cp_index) { 466 assert(tag_at(cp_index).is_string(), "Corrupted constant pool"); 467 return *symbol_at_addr(cp_index); 468 } 469 470 // Returns an UTF8 for a CONSTANT_String entry at a given index. 471 // UTF8 char* representation was chosen to avoid conversion of 472 // java_lang_Strings at resolved entries into Symbol*s 473 // or vice versa. 474 char* string_at_noresolve(int cp_index); 475 476 jint name_and_type_at(int cp_index) { 477 assert(tag_at(cp_index).is_name_and_type(), "Corrupted constant pool"); 478 return *int_at_addr(cp_index); 479 } 480 481 int method_handle_ref_kind_at(int cp_index) { 482 assert(tag_at(cp_index).is_method_handle() || 483 tag_at(cp_index).is_method_handle_in_error(), "Corrupted constant pool"); 484 return extract_low_short_from_int(*int_at_addr(cp_index)); // mask out unwanted ref_index bits 485 } 486 int method_handle_index_at(int cp_index) { 487 assert(tag_at(cp_index).is_method_handle() || 488 tag_at(cp_index).is_method_handle_in_error(), "Corrupted constant pool"); 489 return extract_high_short_from_int(*int_at_addr(cp_index)); // shift out unwanted ref_kind bits 490 } 491 int method_type_index_at(int cp_index) { 492 assert(tag_at(cp_index).is_method_type() || 493 tag_at(cp_index).is_method_type_in_error(), "Corrupted constant pool"); 494 return *int_at_addr(cp_index); 495 } 496 497 // Derived queries: 498 Symbol* method_handle_name_ref_at(int cp_index) { 499 int member = method_handle_index_at(cp_index); 500 return uncached_name_ref_at(member); 501 } 502 Symbol* method_handle_signature_ref_at(int cp_index) { 503 int member = method_handle_index_at(cp_index); 504 return uncached_signature_ref_at(member); 505 } 506 u2 method_handle_klass_index_at(int cp_index) { 507 int member = method_handle_index_at(cp_index); 508 return uncached_klass_ref_index_at(member); 509 } 510 Symbol* method_type_signature_at(int cp_index) { 511 int sym = method_type_index_at(cp_index); 512 return symbol_at(sym); 513 } 514 515 u2 bootstrap_name_and_type_ref_index_at(int cp_index) { 516 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool"); 517 return extract_high_short_from_int(*int_at_addr(cp_index)); 518 } 519 u2 bootstrap_methods_attribute_index(int cp_index) { 520 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool"); 521 return extract_low_short_from_int(*int_at_addr(cp_index)); 522 } 523 int bootstrap_operand_base(int cp_index) { 524 int bsms_attribute_index = bootstrap_methods_attribute_index(cp_index); 525 return operand_offset_at(operands(), bsms_attribute_index); 526 } 527 // The first part of the operands array consists of an index into the second part. 528 // Extract a 32-bit index value from the first part. 529 static int operand_offset_at(Array<u2>* operands, int bsms_attribute_index) { 530 int n = (bsms_attribute_index * 2); 531 assert(n >= 0 && n+2 <= operands->length(), "oob"); 532 // The first 32-bit index points to the beginning of the second part 533 // of the operands array. Make sure this index is in the first part. 534 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0), 535 operands->at(1))); 536 assert(second_part == 0 || n+2 <= second_part, "oob (2)"); 537 int offset = build_int_from_shorts(operands->at(n+0), 538 operands->at(n+1)); 539 // The offset itself must point into the second part of the array. 540 assert(offset == 0 || (offset >= second_part && offset <= operands->length()), "oob (3)"); 541 return offset; 542 } 543 static void operand_offset_at_put(Array<u2>* operands, int bsms_attribute_index, int offset) { 544 int n = bsms_attribute_index * 2; 545 assert(n >= 0 && n+2 <= operands->length(), "oob"); 546 operands->at_put(n+0, extract_low_short_from_int(offset)); 547 operands->at_put(n+1, extract_high_short_from_int(offset)); 548 } 549 static int operand_array_length(Array<u2>* operands) { 550 if (operands == nullptr || operands->length() == 0) return 0; 551 int second_part = operand_offset_at(operands, 0); 552 return (second_part / 2); 553 } 554 555 #ifdef ASSERT 556 // operand tuples fit together exactly, end to end 557 static int operand_limit_at(Array<u2>* operands, int bsms_attribute_index) { 558 int nextidx = bsms_attribute_index + 1; 559 if (nextidx == operand_array_length(operands)) 560 return operands->length(); 561 else 562 return operand_offset_at(operands, nextidx); 563 } 564 int bootstrap_operand_limit(int cp_index) { 565 int bsms_attribute_index = bootstrap_methods_attribute_index(cp_index); 566 return operand_limit_at(operands(), bsms_attribute_index); 567 } 568 #endif //ASSERT 569 570 // Layout of InvokeDynamic and Dynamic bootstrap method specifier 571 // data in second part of operands array. This encodes one record in 572 // the BootstrapMethods attribute. The whole specifier also includes 573 // the name and type information from the main constant pool entry. 574 enum { 575 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm 576 _indy_argc_offset = 1, // u2 argc 577 _indy_argv_offset = 2 // u2 argv[argc] 578 }; 579 580 // These functions are used in RedefineClasses for CP merge 581 582 int operand_offset_at(int bsms_attribute_index) { 583 assert(0 <= bsms_attribute_index && 584 bsms_attribute_index < operand_array_length(operands()), 585 "Corrupted CP operands"); 586 return operand_offset_at(operands(), bsms_attribute_index); 587 } 588 u2 operand_bootstrap_method_ref_index_at(int bsms_attribute_index) { 589 int offset = operand_offset_at(bsms_attribute_index); 590 return operands()->at(offset + _indy_bsm_offset); 591 } 592 u2 operand_argument_count_at(int bsms_attribute_index) { 593 int offset = operand_offset_at(bsms_attribute_index); 594 u2 argc = operands()->at(offset + _indy_argc_offset); 595 return argc; 596 } 597 u2 operand_argument_index_at(int bsms_attribute_index, int j) { 598 int offset = operand_offset_at(bsms_attribute_index); 599 return operands()->at(offset + _indy_argv_offset + j); 600 } 601 int operand_next_offset_at(int bsms_attribute_index) { 602 int offset = operand_offset_at(bsms_attribute_index) + _indy_argv_offset 603 + operand_argument_count_at(bsms_attribute_index); 604 return offset; 605 } 606 // Compare a bootstrap specifier data in the operands arrays 607 bool compare_operand_to(int bsms_attribute_index1, const constantPoolHandle& cp2, 608 int bsms_attribute_index2); 609 // Find a bootstrap specifier data in the operands array 610 int find_matching_operand(int bsms_attribute_index, const constantPoolHandle& search_cp, 611 int operands_cur_len); 612 // Resize the operands array with delta_len and delta_size 613 void resize_operands(int delta_len, int delta_size, TRAPS); 614 // Extend the operands array with the length and size of the ext_cp operands 615 void extend_operands(const constantPoolHandle& ext_cp, TRAPS); 616 // Shrink the operands array to a smaller array with new_len length 617 void shrink_operands(int new_len, TRAPS); 618 619 u2 bootstrap_method_ref_index_at(int cp_index) { 620 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool"); 621 int op_base = bootstrap_operand_base(cp_index); 622 return operands()->at(op_base + _indy_bsm_offset); 623 } 624 u2 bootstrap_argument_count_at(int cp_index) { 625 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool"); 626 int op_base = bootstrap_operand_base(cp_index); 627 u2 argc = operands()->at(op_base + _indy_argc_offset); 628 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc; 629 int next_offset = bootstrap_operand_limit(cp_index)); 630 assert(end_offset == next_offset, "matched ending"); 631 return argc; 632 } 633 u2 bootstrap_argument_index_at(int cp_index, int j) { 634 int op_base = bootstrap_operand_base(cp_index); 635 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset)); 636 assert((uint)j < (uint)argc, "oob"); 637 return operands()->at(op_base + _indy_argv_offset + j); 638 } 639 640 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve, 641 // name_and_type_ref_index_at) all expect to be passed indices obtained 642 // directly from the bytecode. 643 // If the indices are meant to refer to fields or methods, they are 644 // actually rewritten indices that point to entries in their respective structures 645 // i.e. ResolvedMethodEntries or ResolvedFieldEntries. 646 // The routine to_cp_index manages the adjustment 647 // of these values back to constant pool indices. 648 649 // There are also "uncached" versions which do not adjust the operand index; see below. 650 651 // Lookup for entries consisting of (klass_index, name_and_type index) 652 Klass* klass_ref_at(int which, Bytecodes::Code code, TRAPS); 653 Symbol* klass_ref_at_noresolve(int which, Bytecodes::Code code); 654 Symbol* name_ref_at(int which, Bytecodes::Code code) { 655 int name_index = name_ref_index_at(name_and_type_ref_index_at(which, code)); 656 return symbol_at(name_index); 657 } 658 Symbol* signature_ref_at(int which, Bytecodes::Code code) { 659 int signature_index = signature_ref_index_at(name_and_type_ref_index_at(which, code)); 660 return symbol_at(signature_index); 661 } 662 663 u2 klass_ref_index_at(int which, Bytecodes::Code code); 664 u2 name_and_type_ref_index_at(int which, Bytecodes::Code code); 665 666 constantTag tag_ref_at(int cp_cache_index, Bytecodes::Code code); 667 668 int to_cp_index(int which, Bytecodes::Code code); 669 670 bool is_resolved(int which, Bytecodes::Code code); 671 672 // Lookup for entries consisting of (name_index, signature_index) 673 u2 name_ref_index_at(int cp_index); // == low-order jshort of name_and_type_at(cp_index) 674 u2 signature_ref_index_at(int cp_index); // == high-order jshort of name_and_type_at(cp_index) 675 676 BasicType basic_type_for_signature_at(int cp_index) const; 677 678 // Resolve string constants (to prevent allocation during compilation) 679 void resolve_string_constants(TRAPS) { 680 constantPoolHandle h_this(THREAD, this); 681 resolve_string_constants_impl(h_this, CHECK); 682 } 683 684 #if INCLUDE_CDS 685 // CDS support 686 objArrayOop prepare_resolved_references_for_archiving() NOT_CDS_JAVA_HEAP_RETURN_(nullptr); 687 void add_dumped_interned_strings() NOT_CDS_JAVA_HEAP_RETURN; 688 void remove_unshareable_info(); 689 void restore_unshareable_info(TRAPS); 690 private: 691 void remove_unshareable_entries(); 692 void remove_resolved_klass_if_non_deterministic(int cp_index); 693 template <typename Function> void iterate_archivable_resolved_references(Function function); 694 #endif 695 696 private: 697 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 }; 698 public: 699 700 // Get the tag for a constant, which may involve a constant dynamic 701 constantTag constant_tag_at(int cp_index); 702 // Get the basic type for a constant, which may involve a constant dynamic 703 BasicType basic_type_for_constant_at(int cp_index); 704 705 // Resolve late bound constants. 706 oop resolve_constant_at(int cp_index, TRAPS) { 707 constantPoolHandle h_this(THREAD, this); 708 return resolve_constant_at_impl(h_this, cp_index, _no_index_sentinel, nullptr, THREAD); 709 } 710 711 oop resolve_cached_constant_at(int cache_index, TRAPS) { 712 constantPoolHandle h_this(THREAD, this); 713 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, nullptr, THREAD); 714 } 715 716 oop resolve_possibly_cached_constant_at(int cp_index, TRAPS) { 717 constantPoolHandle h_this(THREAD, this); 718 return resolve_constant_at_impl(h_this, cp_index, _possible_index_sentinel, nullptr, THREAD); 719 } 720 721 oop find_cached_constant_at(int cp_index, bool& found_it, TRAPS) { 722 constantPoolHandle h_this(THREAD, this); 723 return resolve_constant_at_impl(h_this, cp_index, _possible_index_sentinel, &found_it, THREAD); 724 } 725 726 void copy_bootstrap_arguments_at(int cp_index, 727 int start_arg, int end_arg, 728 objArrayHandle info, int pos, 729 bool must_resolve, Handle if_not_available, TRAPS) { 730 constantPoolHandle h_this(THREAD, this); 731 copy_bootstrap_arguments_at_impl(h_this, cp_index, start_arg, end_arg, 732 info, pos, must_resolve, if_not_available, THREAD); 733 } 734 735 // Klass name matches name at offset 736 bool klass_name_at_matches(const InstanceKlass* k, int cp_index); 737 738 // Sizing 739 int length() const { return _length; } 740 void set_length(int length) { _length = length; } 741 742 // Tells whether index is within bounds. 743 bool is_within_bounds(int index) const { 744 return 0 <= index && index < length(); 745 } 746 747 // Sizing (in words) 748 static int header_size() { 749 return align_up((int)sizeof(ConstantPool), wordSize) / wordSize; 750 } 751 static int size(int length) { return align_metadata_size(header_size() + length); } 752 int size() const { return size(length()); } 753 754 // ConstantPools should be stored in the read-only region of CDS archive. 755 static bool is_read_only_by_default() { return true; } 756 757 friend class ClassFileParser; 758 friend class SystemDictionary; 759 760 // Used by CDS. These classes need to access the private ConstantPool() constructor. 761 template <class T> friend class CppVtableTesterA; 762 template <class T> friend class CppVtableTesterB; 763 template <class T> friend class CppVtableCloner; 764 765 // Used by compiler to prevent classloading. 766 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which); 767 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code); 768 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code); 769 static bool has_local_signature_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code); 770 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which); 771 772 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the 773 // future by other Java code. These take constant pool indices rather than 774 // constant pool cache indices as do the peer methods above. 775 Symbol* uncached_klass_ref_at_noresolve(int cp_index); 776 Symbol* uncached_name_ref_at(int cp_index) { 777 int name_index = name_ref_index_at(uncached_name_and_type_ref_index_at(cp_index)); 778 return symbol_at(name_index); 779 } 780 Symbol* uncached_signature_ref_at(int cp_index) { 781 int signature_index = signature_ref_index_at(uncached_name_and_type_ref_index_at(cp_index)); 782 return symbol_at(signature_index); 783 } 784 u2 uncached_klass_ref_index_at(int cp_index); 785 u2 uncached_name_and_type_ref_index_at(int cp_index); 786 787 // Sharing 788 int pre_resolve_shared_klasses(TRAPS); 789 790 // Debugging 791 const char* printable_name_at(int cp_index) PRODUCT_RETURN_NULL; 792 793 private: 794 795 void set_resolved_references(OopHandle s) { _cache->set_resolved_references(s); } 796 Array<u2>* reference_map() const { return (_cache == nullptr) ? nullptr : _cache->reference_map(); } 797 void set_reference_map(Array<u2>* o) { _cache->set_reference_map(o); } 798 799 // Used while constructing constant pool (only by ClassFileParser) 800 jint klass_index_at(int cp_index) { 801 assert(tag_at(cp_index).is_klass_index(), "Corrupted constant pool"); 802 return *int_at_addr(cp_index); 803 } 804 805 jint string_index_at(int cp_index) { 806 assert(tag_at(cp_index).is_string_index(), "Corrupted constant pool"); 807 return *int_at_addr(cp_index); 808 } 809 810 // Performs the LinkResolver checks 811 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* klass, TRAPS); 812 813 // Implementation of methods that needs an exposed 'this' pointer, in order to 814 // handle GC while executing the method 815 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int cp_index, TRAPS); 816 static oop string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS); 817 818 static void trace_class_resolution(const constantPoolHandle& this_cp, Klass* k); 819 820 // Resolve string constants (to prevent allocation during compilation) 821 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS); 822 823 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int cp_index, int cache_index, 824 bool* status_return, TRAPS); 825 static void copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index, 826 int start_arg, int end_arg, 827 objArrayHandle info, int pos, 828 bool must_resolve, Handle if_not_available, TRAPS); 829 830 // Exception handling 831 static void save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index, constantTag tag, TRAPS); 832 833 public: 834 // Exception handling 835 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS); 836 837 // Merging ConstantPool* support: 838 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2); 839 void copy_cp_to(int start_cpi, int end_cpi, const constantPoolHandle& to_cp, int to_cpi, TRAPS) { 840 constantPoolHandle h_this(THREAD, this); 841 copy_cp_to_impl(h_this, start_cpi, end_cpi, to_cp, to_cpi, THREAD); 842 } 843 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_cpi, int end_cpi, const constantPoolHandle& to_cp, int to_cpi, TRAPS); 844 static void copy_entry_to(const constantPoolHandle& from_cp, int from_cpi, const constantPoolHandle& to_cp, int to_cpi); 845 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS); 846 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp); 847 int version() const { return _saved._version; } 848 void set_version(int version) { _saved._version = version; } 849 void increment_and_save_version(int version) { 850 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow 851 } 852 853 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; } 854 int resolved_reference_length() const { return _saved._resolved_reference_length; } 855 856 // Decrease ref counts of symbols that are in the constant pool 857 // when the holder class is unloaded 858 void unreference_symbols(); 859 860 // Deallocate constant pool for RedefineClasses 861 void deallocate_contents(ClassLoaderData* loader_data); 862 void release_C_heap_structures(); 863 864 // JVMTI access - GetConstantPool, RetransformClasses, ... 865 friend class JvmtiConstantPoolReconstituter; 866 867 private: 868 class SymbolHash: public CHeapObj<mtSymbol> { 869 ResourceHashtable<const Symbol*, u2, 256, AnyObj::C_HEAP, mtSymbol, Symbol::compute_hash> _table; 870 871 public: 872 void add_if_absent(const Symbol* sym, u2 value) { 873 bool created; 874 _table.put_if_absent(sym, value, &created); 875 } 876 877 u2 symbol_to_value(const Symbol* sym) { 878 u2* value = _table.get(sym); 879 return (value == nullptr) ? 0 : *value; 880 } 881 }; // End SymbolHash class 882 883 jint cpool_entry_size(jint idx); 884 jint hash_entries_to(SymbolHash *symmap, SymbolHash *classmap); 885 886 // Copy cpool bytes into byte array. 887 // Returns: 888 // int > 0, count of the raw cpool bytes that have been copied 889 // 0, OutOfMemory error 890 // -1, Internal error 891 int copy_cpool_bytes(int cpool_size, 892 SymbolHash* tbl, 893 unsigned char *bytes); 894 895 public: 896 // Verify 897 void verify_on(outputStream* st); 898 899 // Printing 900 void print_on(outputStream* st) const; 901 void print_value_on(outputStream* st) const; 902 void print_entry_on(int index, outputStream* st); 903 904 const char* internal_name() const { return "{constant pool}"; } 905 906 // ResolvedFieldEntry getters 907 inline ResolvedFieldEntry* resolved_field_entry_at(int field_index); 908 inline int resolved_field_entries_length() const; 909 910 // ResolvedMethodEntry getters 911 inline ResolvedMethodEntry* resolved_method_entry_at(int method_index); 912 inline int resolved_method_entries_length() const; 913 inline oop appendix_if_resolved(int method_index) const; 914 915 // ResolvedIndyEntry getters 916 inline ResolvedIndyEntry* resolved_indy_entry_at(int index); 917 inline int resolved_indy_entries_length() const; 918 inline oop resolved_reference_from_indy(int index) const; 919 inline oop resolved_reference_from_method(int index) const; 920 }; 921 922 #endif // SHARE_OOPS_CONSTANTPOOL_HPP