1 /* 2 * Copyright (c) 1997, 2017, 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_VM_OOPS_CONSTANTPOOLOOP_HPP 26 #define SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP 27 28 #include "oops/arrayOop.hpp" 29 #include "oops/cpCache.hpp" 30 #include "oops/objArrayOop.hpp" 31 #include "oops/oopHandle.hpp" 32 #include "oops/symbol.hpp" 33 #include "oops/typeArrayOop.hpp" 34 #include "runtime/handles.hpp" 35 #include "utilities/align.hpp" 36 #include "utilities/bytes.hpp" 37 #include "utilities/constantTag.hpp" 38 39 // A ConstantPool is an array containing class constants as described in the 40 // class file. 41 // 42 // Most of the constant pool entries are written during class parsing, which 43 // is safe. For klass types, the constant pool entry is 44 // modified when the entry is resolved. If a klass constant pool 45 // entry is read without a lock, only the resolved state guarantees that 46 // the entry in the constant pool is a klass object and not a Symbol*. 47 48 class SymbolHashMap; 49 50 class CPSlot VALUE_OBJ_CLASS_SPEC { 51 friend class ConstantPool; 52 intptr_t _ptr; 53 enum TagBits {_pseudo_bit = 1}; 54 public: 55 56 CPSlot(intptr_t ptr): _ptr(ptr) {} 57 CPSlot(Symbol* ptr, int tag_bits = 0): _ptr((intptr_t)ptr | tag_bits) {} 58 59 intptr_t value() { return _ptr; } 60 bool is_pseudo_string() { return (_ptr & _pseudo_bit) != 0; } 61 62 Symbol* get_symbol() { 63 return (Symbol*)(_ptr & ~_pseudo_bit); 64 } 65 }; 66 67 // This represents a JVM_CONSTANT_Class, JVM_CONSTANT_UnresolvedClass, or 68 // JVM_CONSTANT_UnresolvedClassInError slot in the constant pool. 69 class CPKlassSlot VALUE_OBJ_CLASS_SPEC { 70 // cp->symbol_at(_name_index) gives the name of the class. 71 int _name_index; 72 73 // cp->_resolved_klasses->at(_resolved_klass_index) gives the Klass* for the class. 74 int _resolved_klass_index; 75 public: 76 enum { 77 // This is used during constant pool merging where the resolved klass index is 78 // not yet known, and will be computed at a later stage (during a call to 79 // initialize_unresolved_klasses()). 80 _temp_resolved_klass_index = 0xffff 81 }; 82 CPKlassSlot(int n, int rk) { 83 _name_index = n; 84 _resolved_klass_index = rk; 85 } 86 int name_index() const { 87 return _name_index; 88 } 89 int resolved_klass_index() const { 90 assert(_resolved_klass_index != _temp_resolved_klass_index, "constant pool merging was incomplete"); 91 return _resolved_klass_index; 92 } 93 }; 94 95 class KlassSizeStats; 96 97 class ConstantPool : public Metadata { 98 friend class VMStructs; 99 friend class JVMCIVMStructs; 100 friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast 101 friend class Universe; // For null constructor 102 private: 103 // If you add a new field that points to any metaspace object, you 104 // must add this field to ConstantPool::metaspace_pointers_do(). 105 Array<u1>* _tags; // the tag array describing the constant pool's contents 106 ConstantPoolCache* _cache; // the cache holding interpreter runtime information 107 InstanceKlass* _pool_holder; // the corresponding class 108 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty 109 110 // Consider using an array of compressed klass pointers to 111 // save space on 64-bit platforms. 112 Array<Klass*>* _resolved_klasses; 113 114 enum { 115 _has_preresolution = 1, // Flags 116 _on_stack = 2, 117 _is_shared = 4 118 }; 119 120 int _flags; // old fashioned bit twiddling 121 int _length; // number of elements in the array 122 123 union { 124 // set for CDS to restore resolved references 125 int _resolved_reference_length; 126 // keeps version number for redefined classes (used in backtrace) 127 int _version; 128 } _saved; 129 130 void set_tags(Array<u1>* tags) { _tags = tags; } 131 void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); } 132 void release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); } 133 134 u1* tag_addr_at(int which) const { return tags()->adr_at(which); } 135 136 void set_operands(Array<u2>* operands) { _operands = operands; } 137 138 int flags() const { return _flags; } 139 void set_flags(int f) { _flags = f; } 140 141 private: 142 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); } 143 144 CPSlot slot_at(int which) const { 145 assert(is_within_bounds(which), "index out of bounds"); 146 assert(!tag_at(which).is_unresolved_klass() && !tag_at(which).is_unresolved_klass_in_error(), "Corrupted constant pool"); 147 // Uses volatile because the klass slot changes without a lock. 148 volatile intptr_t adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which)); 149 assert(adr != 0 || which == 0, "cp entry for klass should not be zero"); 150 return CPSlot(adr); 151 } 152 153 void slot_at_put(int which, CPSlot s) const { 154 assert(is_within_bounds(which), "index out of bounds"); 155 assert(s.value() != 0, "Caught something"); 156 *(intptr_t*)&base()[which] = s.value(); 157 } 158 intptr_t* obj_at_addr_raw(int which) const { 159 assert(is_within_bounds(which), "index out of bounds"); 160 return (intptr_t*) &base()[which]; 161 } 162 163 jint* int_at_addr(int which) const { 164 assert(is_within_bounds(which), "index out of bounds"); 165 return (jint*) &base()[which]; 166 } 167 168 jlong* long_at_addr(int which) const { 169 assert(is_within_bounds(which), "index out of bounds"); 170 return (jlong*) &base()[which]; 171 } 172 173 jfloat* float_at_addr(int which) const { 174 assert(is_within_bounds(which), "index out of bounds"); 175 return (jfloat*) &base()[which]; 176 } 177 178 jdouble* double_at_addr(int which) const { 179 assert(is_within_bounds(which), "index out of bounds"); 180 return (jdouble*) &base()[which]; 181 } 182 183 ConstantPool(Array<u1>* tags); 184 ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); } 185 public: 186 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS); 187 188 bool is_constantPool() const volatile { return true; } 189 190 Array<u1>* tags() const { return _tags; } 191 Array<u2>* operands() const { return _operands; } 192 193 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; } 194 void set_has_preresolution() { 195 assert(!is_shared(), "should never be called on shared ConstantPools"); 196 _flags |= _has_preresolution; 197 } 198 199 // Redefine classes support. If a method refering to this constant pool 200 // is on the executing stack, or as a handle in vm code, this constant pool 201 // can't be removed from the set of previous versions saved in the instance 202 // class. 203 bool on_stack() const { return (_flags &_on_stack) != 0; } 204 void set_on_stack(const bool value); 205 206 // Faster than MetaspaceObj::is_shared() - used by set_on_stack() 207 bool is_shared() const { return (_flags & _is_shared) != 0; } 208 209 // Klass holding pool 210 InstanceKlass* pool_holder() const { return _pool_holder; } 211 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; } 212 InstanceKlass** pool_holder_addr() { return &_pool_holder; } 213 214 // Interpreter runtime support 215 ConstantPoolCache* cache() const { return _cache; } 216 void set_cache(ConstantPoolCache* cache){ _cache = cache; } 217 218 virtual void metaspace_pointers_do(MetaspaceClosure* iter); 219 virtual MetaspaceObj::Type type() const { return ConstantPoolType; } 220 221 // Create object cache in the constant pool 222 void initialize_resolved_references(ClassLoaderData* loader_data, 223 const intStack& reference_map, 224 int constant_pool_map_length, 225 TRAPS); 226 227 // resolved strings, methodHandles and callsite objects from the constant pool 228 objArrayOop resolved_references() const; 229 // mapping resolved object array indexes to cp indexes and back. 230 int object_to_cp_index(int index) { return reference_map()->at(index); } 231 int cp_to_object_index(int index); 232 233 void set_resolved_klasses(Array<Klass*>* rk) { _resolved_klasses = rk; } 234 Array<Klass*>* resolved_klasses() const { return _resolved_klasses; } 235 void allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS); 236 void initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS); 237 238 // Invokedynamic indexes. 239 // They must look completely different from normal indexes. 240 // The main reason is that byte swapping is sometimes done on normal indexes. 241 // Finally, it is helpful for debugging to tell the two apart. 242 static bool is_invokedynamic_index(int i) { return (i < 0); } 243 static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; } 244 static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; } 245 246 247 // The invokedynamic points at a CP cache entry. This entry points back 248 // at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry 249 // in the resolved_references array (which provides the appendix argument). 250 int invokedynamic_cp_cache_index(int index) const { 251 assert (is_invokedynamic_index(index), "should be a invokedynamic index"); 252 int cache_index = decode_invokedynamic_index(index); 253 return cache_index; 254 } 255 ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int index) const { 256 // decode index that invokedynamic points to. 257 int cp_cache_index = invokedynamic_cp_cache_index(index); 258 return cache()->entry_at(cp_cache_index); 259 } 260 261 // Assembly code support 262 static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); } 263 static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); } 264 static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); } 265 static int resolved_klasses_offset_in_bytes() { return offset_of(ConstantPool, _resolved_klasses); } 266 267 // Storing constants 268 269 // For temporary use while constructing constant pool 270 void klass_index_at_put(int which, int name_index) { 271 tag_at_put(which, JVM_CONSTANT_ClassIndex); 272 *int_at_addr(which) = name_index; 273 } 274 275 // Anonymous class support: 276 void klass_at_put(int class_index, int name_index, int resolved_klass_index, Klass* k, Symbol* name); 277 void klass_at_put(int class_index, Klass* k); 278 279 void unresolved_klass_at_put(int which, int name_index, int resolved_klass_index) { 280 release_tag_at_put(which, 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(which) = 285 build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index); 286 } 287 288 void method_handle_index_at_put(int which, int ref_kind, int ref_index) { 289 tag_at_put(which, JVM_CONSTANT_MethodHandle); 290 *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind; 291 } 292 293 void method_type_index_at_put(int which, int ref_index) { 294 tag_at_put(which, JVM_CONSTANT_MethodType); 295 *int_at_addr(which) = ref_index; 296 } 297 298 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) { 299 tag_at_put(which, JVM_CONSTANT_InvokeDynamic); 300 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index; 301 } 302 303 void unresolved_string_at_put(int which, Symbol* s) { 304 release_tag_at_put(which, JVM_CONSTANT_String); 305 slot_at_put(which, CPSlot(s)); 306 } 307 308 void int_at_put(int which, jint i) { 309 tag_at_put(which, JVM_CONSTANT_Integer); 310 *int_at_addr(which) = i; 311 } 312 313 void long_at_put(int which, jlong l) { 314 tag_at_put(which, JVM_CONSTANT_Long); 315 // *long_at_addr(which) = l; 316 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l)); 317 } 318 319 void float_at_put(int which, jfloat f) { 320 tag_at_put(which, JVM_CONSTANT_Float); 321 *float_at_addr(which) = f; 322 } 323 324 void double_at_put(int which, jdouble d) { 325 tag_at_put(which, JVM_CONSTANT_Double); 326 // *double_at_addr(which) = d; 327 // u8 temp = *(u8*) &d; 328 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d)); 329 } 330 331 Symbol** symbol_at_addr(int which) const { 332 assert(is_within_bounds(which), "index out of bounds"); 333 return (Symbol**) &base()[which]; 334 } 335 336 void symbol_at_put(int which, Symbol* s) { 337 assert(s->refcount() != 0, "should have nonzero refcount"); 338 tag_at_put(which, JVM_CONSTANT_Utf8); 339 *symbol_at_addr(which) = s; 340 } 341 342 void string_at_put(int which, int obj_index, oop str); 343 344 // For temporary use while constructing constant pool 345 void string_index_at_put(int which, int string_index) { 346 tag_at_put(which, JVM_CONSTANT_StringIndex); 347 *int_at_addr(which) = string_index; 348 } 349 350 void field_at_put(int which, int class_index, int name_and_type_index) { 351 tag_at_put(which, JVM_CONSTANT_Fieldref); 352 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; 353 } 354 355 void method_at_put(int which, int class_index, int name_and_type_index) { 356 tag_at_put(which, JVM_CONSTANT_Methodref); 357 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; 358 } 359 360 void interface_method_at_put(int which, int class_index, int name_and_type_index) { 361 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref); 362 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice 363 } 364 365 void name_and_type_at_put(int which, int name_index, int signature_index) { 366 tag_at_put(which, JVM_CONSTANT_NameAndType); 367 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice 368 } 369 370 // Tag query 371 372 constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); } 373 374 // Fetching constants 375 376 Klass* klass_at(int which, TRAPS) { 377 constantPoolHandle h_this(THREAD, this); 378 return klass_at_impl(h_this, which, true, THREAD); 379 } 380 381 // Version of klass_at that doesn't save the resolution error, called during deopt 382 Klass* klass_at_ignore_error(int which, TRAPS) { 383 constantPoolHandle h_this(THREAD, this); 384 return klass_at_impl(h_this, which, false, THREAD); 385 } 386 387 CPKlassSlot klass_slot_at(int which) const { 388 assert(tag_at(which).is_unresolved_klass() || tag_at(which).is_klass(), 389 "Corrupted constant pool"); 390 int value = *int_at_addr(which); 391 int name_index = extract_high_short_from_int(value); 392 int resolved_klass_index = extract_low_short_from_int(value); 393 return CPKlassSlot(name_index, resolved_klass_index); 394 } 395 396 Symbol* klass_name_at(int which) const; // Returns the name, w/o resolving. 397 int klass_name_index_at(int which) const { 398 return klass_slot_at(which).name_index(); 399 } 400 401 Klass* resolved_klass_at(int which) const { // Used by Compiler 402 guarantee(tag_at(which).is_klass(), "Corrupted constant pool"); 403 // Must do an acquire here in case another thread resolved the klass 404 // behind our back, lest we later load stale values thru the oop. 405 CPKlassSlot kslot = klass_slot_at(which); 406 assert(tag_at(kslot.name_index()).is_symbol(), "sanity"); 407 408 Klass** adr = resolved_klasses()->adr_at(kslot.resolved_klass_index()); 409 return (Klass*)OrderAccess::load_ptr_acquire(adr); 410 } 411 412 // RedefineClasses() API support: 413 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); } 414 void temp_unresolved_klass_at_put(int which, int name_index) { 415 // Used only during constant pool merging for class redefinition. The resolved klass index 416 // will be initialized later by a call to initialize_unresolved_klasses(). 417 unresolved_klass_at_put(which, name_index, CPKlassSlot::_temp_resolved_klass_index); 418 } 419 420 jint int_at(int which) { 421 assert(tag_at(which).is_int(), "Corrupted constant pool"); 422 return *int_at_addr(which); 423 } 424 425 jlong long_at(int which) { 426 assert(tag_at(which).is_long(), "Corrupted constant pool"); 427 // return *long_at_addr(which); 428 u8 tmp = Bytes::get_native_u8((address)&base()[which]); 429 return *((jlong*)&tmp); 430 } 431 432 jfloat float_at(int which) { 433 assert(tag_at(which).is_float(), "Corrupted constant pool"); 434 return *float_at_addr(which); 435 } 436 437 jdouble double_at(int which) { 438 assert(tag_at(which).is_double(), "Corrupted constant pool"); 439 u8 tmp = Bytes::get_native_u8((address)&base()[which]); 440 return *((jdouble*)&tmp); 441 } 442 443 Symbol* symbol_at(int which) const { 444 assert(tag_at(which).is_utf8(), "Corrupted constant pool"); 445 return *symbol_at_addr(which); 446 } 447 448 oop string_at(int which, int obj_index, TRAPS) { 449 constantPoolHandle h_this(THREAD, this); 450 return string_at_impl(h_this, which, obj_index, THREAD); 451 } 452 oop string_at(int which, TRAPS) { 453 int obj_index = cp_to_object_index(which); 454 return string_at(which, obj_index, THREAD); 455 } 456 457 // Version that can be used before string oop array is created. 458 oop uncached_string_at(int which, TRAPS); 459 460 // A "pseudo-string" is an non-string oop that has found its way into 461 // a String entry. 462 // This can happen if the user patches a live 463 // object into a CONSTANT_String entry of an anonymous class. 464 // Method oops internally created for method handles may also 465 // use pseudo-strings to link themselves to related metaobjects. 466 467 bool is_pseudo_string_at(int which) { 468 assert(tag_at(which).is_string(), "Corrupted constant pool"); 469 return slot_at(which).is_pseudo_string(); 470 } 471 472 oop pseudo_string_at(int which, int obj_index) { 473 assert(is_pseudo_string_at(which), "must be a pseudo-string"); 474 oop s = resolved_references()->obj_at(obj_index); 475 return s; 476 } 477 478 oop pseudo_string_at(int which) { 479 assert(is_pseudo_string_at(which), "must be a pseudo-string"); 480 int obj_index = cp_to_object_index(which); 481 oop s = resolved_references()->obj_at(obj_index); 482 return s; 483 } 484 485 void pseudo_string_at_put(int which, int obj_index, oop x) { 486 assert(tag_at(which).is_string(), "Corrupted constant pool"); 487 Symbol* sym = unresolved_string_at(which); 488 slot_at_put(which, CPSlot(sym, CPSlot::_pseudo_bit)); 489 string_at_put(which, obj_index, x); // this works just fine 490 } 491 492 // only called when we are sure a string entry is already resolved (via an 493 // earlier string_at call. 494 oop resolved_string_at(int which) { 495 assert(tag_at(which).is_string(), "Corrupted constant pool"); 496 // Must do an acquire here in case another thread resolved the klass 497 // behind our back, lest we later load stale values thru the oop. 498 // we might want a volatile_obj_at in ObjArrayKlass. 499 int obj_index = cp_to_object_index(which); 500 return resolved_references()->obj_at(obj_index); 501 } 502 503 Symbol* unresolved_string_at(int which) { 504 assert(tag_at(which).is_string(), "Corrupted constant pool"); 505 Symbol* sym = slot_at(which).get_symbol(); 506 return sym; 507 } 508 509 // Returns an UTF8 for a CONSTANT_String entry at a given index. 510 // UTF8 char* representation was chosen to avoid conversion of 511 // java_lang_Strings at resolved entries into Symbol*s 512 // or vice versa. 513 char* string_at_noresolve(int which); 514 515 jint name_and_type_at(int which) { 516 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool"); 517 return *int_at_addr(which); 518 } 519 520 int method_handle_ref_kind_at(int which) { 521 assert(tag_at(which).is_method_handle() || 522 tag_at(which).is_method_handle_in_error(), "Corrupted constant pool"); 523 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits 524 } 525 int method_handle_index_at(int which) { 526 assert(tag_at(which).is_method_handle() || 527 tag_at(which).is_method_handle_in_error(), "Corrupted constant pool"); 528 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits 529 } 530 int method_type_index_at(int which) { 531 assert(tag_at(which).is_method_type() || 532 tag_at(which).is_method_type_in_error(), "Corrupted constant pool"); 533 return *int_at_addr(which); 534 } 535 536 // Derived queries: 537 Symbol* method_handle_name_ref_at(int which) { 538 int member = method_handle_index_at(which); 539 return impl_name_ref_at(member, true); 540 } 541 Symbol* method_handle_signature_ref_at(int which) { 542 int member = method_handle_index_at(which); 543 return impl_signature_ref_at(member, true); 544 } 545 int method_handle_klass_index_at(int which) { 546 int member = method_handle_index_at(which); 547 return impl_klass_ref_index_at(member, true); 548 } 549 Symbol* method_type_signature_at(int which) { 550 int sym = method_type_index_at(which); 551 return symbol_at(sym); 552 } 553 554 int invoke_dynamic_name_and_type_ref_index_at(int which) { 555 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 556 return extract_high_short_from_int(*int_at_addr(which)); 557 } 558 int invoke_dynamic_bootstrap_specifier_index(int which) { 559 assert(tag_at(which).value() == JVM_CONSTANT_InvokeDynamic, "Corrupted constant pool"); 560 return extract_low_short_from_int(*int_at_addr(which)); 561 } 562 int invoke_dynamic_operand_base(int which) { 563 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which); 564 return operand_offset_at(operands(), bootstrap_specifier_index); 565 } 566 // The first part of the operands array consists of an index into the second part. 567 // Extract a 32-bit index value from the first part. 568 static int operand_offset_at(Array<u2>* operands, int bootstrap_specifier_index) { 569 int n = (bootstrap_specifier_index * 2); 570 assert(n >= 0 && n+2 <= operands->length(), "oob"); 571 // The first 32-bit index points to the beginning of the second part 572 // of the operands array. Make sure this index is in the first part. 573 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0), 574 operands->at(1))); 575 assert(second_part == 0 || n+2 <= second_part, "oob (2)"); 576 int offset = build_int_from_shorts(operands->at(n+0), 577 operands->at(n+1)); 578 // The offset itself must point into the second part of the array. 579 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)"); 580 return offset; 581 } 582 static void operand_offset_at_put(Array<u2>* operands, int bootstrap_specifier_index, int offset) { 583 int n = bootstrap_specifier_index * 2; 584 assert(n >= 0 && n+2 <= operands->length(), "oob"); 585 operands->at_put(n+0, extract_low_short_from_int(offset)); 586 operands->at_put(n+1, extract_high_short_from_int(offset)); 587 } 588 static int operand_array_length(Array<u2>* operands) { 589 if (operands == NULL || operands->length() == 0) return 0; 590 int second_part = operand_offset_at(operands, 0); 591 return (second_part / 2); 592 } 593 594 #ifdef ASSERT 595 // operand tuples fit together exactly, end to end 596 static int operand_limit_at(Array<u2>* operands, int bootstrap_specifier_index) { 597 int nextidx = bootstrap_specifier_index + 1; 598 if (nextidx == operand_array_length(operands)) 599 return operands->length(); 600 else 601 return operand_offset_at(operands, nextidx); 602 } 603 int invoke_dynamic_operand_limit(int which) { 604 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which); 605 return operand_limit_at(operands(), bootstrap_specifier_index); 606 } 607 #endif //ASSERT 608 609 // layout of InvokeDynamic bootstrap method specifier (in second part of operands array): 610 enum { 611 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm 612 _indy_argc_offset = 1, // u2 argc 613 _indy_argv_offset = 2 // u2 argv[argc] 614 }; 615 616 // These functions are used in RedefineClasses for CP merge 617 618 int operand_offset_at(int bootstrap_specifier_index) { 619 assert(0 <= bootstrap_specifier_index && 620 bootstrap_specifier_index < operand_array_length(operands()), 621 "Corrupted CP operands"); 622 return operand_offset_at(operands(), bootstrap_specifier_index); 623 } 624 int operand_bootstrap_method_ref_index_at(int bootstrap_specifier_index) { 625 int offset = operand_offset_at(bootstrap_specifier_index); 626 return operands()->at(offset + _indy_bsm_offset); 627 } 628 int operand_argument_count_at(int bootstrap_specifier_index) { 629 int offset = operand_offset_at(bootstrap_specifier_index); 630 int argc = operands()->at(offset + _indy_argc_offset); 631 return argc; 632 } 633 int operand_argument_index_at(int bootstrap_specifier_index, int j) { 634 int offset = operand_offset_at(bootstrap_specifier_index); 635 return operands()->at(offset + _indy_argv_offset + j); 636 } 637 int operand_next_offset_at(int bootstrap_specifier_index) { 638 int offset = operand_offset_at(bootstrap_specifier_index) + _indy_argv_offset 639 + operand_argument_count_at(bootstrap_specifier_index); 640 return offset; 641 } 642 // Compare a bootsrap specifier in the operands arrays 643 bool compare_operand_to(int bootstrap_specifier_index1, const constantPoolHandle& cp2, 644 int bootstrap_specifier_index2, TRAPS); 645 // Find a bootsrap specifier in the operands array 646 int find_matching_operand(int bootstrap_specifier_index, const constantPoolHandle& search_cp, 647 int operands_cur_len, TRAPS); 648 // Resize the operands array with delta_len and delta_size 649 void resize_operands(int delta_len, int delta_size, TRAPS); 650 // Extend the operands array with the length and size of the ext_cp operands 651 void extend_operands(const constantPoolHandle& ext_cp, TRAPS); 652 // Shrink the operands array to a smaller array with new_len length 653 void shrink_operands(int new_len, TRAPS); 654 655 656 int invoke_dynamic_bootstrap_method_ref_index_at(int which) { 657 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 658 int op_base = invoke_dynamic_operand_base(which); 659 return operands()->at(op_base + _indy_bsm_offset); 660 } 661 int invoke_dynamic_argument_count_at(int which) { 662 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 663 int op_base = invoke_dynamic_operand_base(which); 664 int argc = operands()->at(op_base + _indy_argc_offset); 665 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc; 666 int next_offset = invoke_dynamic_operand_limit(which)); 667 assert(end_offset == next_offset, "matched ending"); 668 return argc; 669 } 670 int invoke_dynamic_argument_index_at(int which, int j) { 671 int op_base = invoke_dynamic_operand_base(which); 672 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset)); 673 assert((uint)j < (uint)argc, "oob"); 674 return operands()->at(op_base + _indy_argv_offset + j); 675 } 676 677 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve, 678 // name_and_type_ref_index_at) all expect to be passed indices obtained 679 // directly from the bytecode. 680 // If the indices are meant to refer to fields or methods, they are 681 // actually rewritten constant pool cache indices. 682 // The routine remap_instruction_operand_from_cache manages the adjustment 683 // of these values back to constant pool indices. 684 685 // There are also "uncached" versions which do not adjust the operand index; see below. 686 687 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear. 688 // In a few cases (the verifier) there are uses before a cpcache has been built, 689 // which are handled by a dynamic check in remap_instruction_operand_from_cache. 690 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode. 691 692 // Lookup for entries consisting of (klass_index, name_and_type index) 693 Klass* klass_ref_at(int which, TRAPS); 694 Symbol* klass_ref_at_noresolve(int which); 695 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); } 696 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); } 697 698 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); } 699 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); } 700 701 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG 702 703 constantTag tag_ref_at(int cp_cache_index) { return impl_tag_ref_at(cp_cache_index, false); } 704 705 // Lookup for entries consisting of (name_index, signature_index) 706 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt) 707 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt) 708 709 BasicType basic_type_for_signature_at(int which) const; 710 711 // Resolve string constants (to prevent allocation during compilation) 712 void resolve_string_constants(TRAPS) { 713 constantPoolHandle h_this(THREAD, this); 714 resolve_string_constants_impl(h_this, CHECK); 715 } 716 717 // CDS support 718 void archive_resolved_references(Thread *THREAD) NOT_CDS_JAVA_HEAP_RETURN; 719 void remove_unshareable_info(); 720 void restore_unshareable_info(TRAPS); 721 bool resolve_class_constants(TRAPS); 722 // The ConstantPool vtable is restored by this call when the ConstantPool is 723 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for 724 // all the gory details. SA, dtrace and pstack helpers distinguish metadata 725 // by their vtable. 726 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); } 727 728 private: 729 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 }; 730 public: 731 732 // Resolve late bound constants. 733 oop resolve_constant_at(int index, TRAPS) { 734 constantPoolHandle h_this(THREAD, this); 735 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD); 736 } 737 738 oop resolve_cached_constant_at(int cache_index, TRAPS) { 739 constantPoolHandle h_this(THREAD, this); 740 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD); 741 } 742 743 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) { 744 constantPoolHandle h_this(THREAD, this); 745 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD); 746 } 747 748 oop resolve_bootstrap_specifier_at(int index, TRAPS) { 749 constantPoolHandle h_this(THREAD, this); 750 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD); 751 } 752 753 // Klass name matches name at offset 754 bool klass_name_at_matches(const InstanceKlass* k, int which); 755 756 // Sizing 757 int length() const { return _length; } 758 void set_length(int length) { _length = length; } 759 760 // Tells whether index is within bounds. 761 bool is_within_bounds(int index) const { 762 return 0 <= index && index < length(); 763 } 764 765 // Sizing (in words) 766 static int header_size() { 767 return align_up((int)sizeof(ConstantPool), wordSize) / wordSize; 768 } 769 static int size(int length) { return align_metadata_size(header_size() + length); } 770 int size() const { return size(length()); } 771 #if INCLUDE_SERVICES 772 void collect_statistics(KlassSizeStats *sz) const; 773 #endif 774 775 // ConstantPools should be stored in the read-only region of CDS archive. 776 static bool is_read_only_by_default() { return true; } 777 778 friend class ClassFileParser; 779 friend class SystemDictionary; 780 781 // Used by CDS. These classes need to access the private ConstantPool() constructor. 782 template <class T> friend class CppVtableTesterA; 783 template <class T> friend class CppVtableTesterB; 784 template <class T> friend class CppVtableCloner; 785 786 // Used by compiler to prevent classloading. 787 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which); 788 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which); 789 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which); 790 static bool has_method_type_at_if_loaded (const constantPoolHandle& this_cp, int which); 791 static oop method_type_at_if_loaded (const constantPoolHandle& this_cp, int which); 792 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which); 793 static Klass* klass_ref_at_if_loaded (const constantPoolHandle& this_cp, int which); 794 795 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the 796 // future by other Java code. These take constant pool indices rather than 797 // constant pool cache indices as do the peer methods above. 798 Symbol* uncached_klass_ref_at_noresolve(int which); 799 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); } 800 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); } 801 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); } 802 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); } 803 804 // Sharing 805 int pre_resolve_shared_klasses(TRAPS); 806 807 // Debugging 808 const char* printable_name_at(int which) PRODUCT_RETURN0; 809 810 #ifdef ASSERT 811 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices 812 #else 813 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op 814 #endif //ASSERT 815 816 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) { 817 if (invokedynamic_ok && is_invokedynamic_index(raw_index)) 818 return decode_invokedynamic_index(raw_index); 819 else 820 return raw_index - CPCACHE_INDEX_TAG; 821 } 822 823 private: 824 825 void set_resolved_references(OopHandle s) { _cache->set_resolved_references(s); } 826 Array<u2>* reference_map() const { return (_cache == NULL) ? NULL : _cache->reference_map(); } 827 void set_reference_map(Array<u2>* o) { _cache->set_reference_map(o); } 828 829 // patch JSR 292 resolved references after the class is linked. 830 void patch_resolved_references(GrowableArray<Handle>* cp_patches); 831 832 Symbol* impl_name_ref_at(int which, bool uncached); 833 Symbol* impl_signature_ref_at(int which, bool uncached); 834 int impl_klass_ref_index_at(int which, bool uncached); 835 int impl_name_and_type_ref_index_at(int which, bool uncached); 836 constantTag impl_tag_ref_at(int which, bool uncached); 837 838 // Used while constructing constant pool (only by ClassFileParser) 839 jint klass_index_at(int which) { 840 assert(tag_at(which).is_klass_index(), "Corrupted constant pool"); 841 return *int_at_addr(which); 842 } 843 844 jint string_index_at(int which) { 845 assert(tag_at(which).is_string_index(), "Corrupted constant pool"); 846 return *int_at_addr(which); 847 } 848 849 // Performs the LinkResolver checks 850 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* klass, TRAPS); 851 852 // Implementation of methods that needs an exposed 'this' pointer, in order to 853 // handle GC while executing the method 854 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int which, 855 bool save_resolution_error, TRAPS); 856 static oop string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS); 857 858 static void trace_class_resolution(const constantPoolHandle& this_cp, Klass* k); 859 860 // Resolve string constants (to prevent allocation during compilation) 861 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS); 862 863 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int index, int cache_index, TRAPS); 864 static oop resolve_bootstrap_specifier_at_impl(const constantPoolHandle& this_cp, int index, TRAPS); 865 866 // Exception handling 867 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS); 868 static Symbol* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception); 869 static void save_and_throw_exception(const constantPoolHandle& this_cp, int which, constantTag tag, TRAPS); 870 871 public: 872 // Merging ConstantPool* support: 873 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2, TRAPS); 874 void copy_cp_to(int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS) { 875 constantPoolHandle h_this(THREAD, this); 876 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD); 877 } 878 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS); 879 static void copy_entry_to(const constantPoolHandle& from_cp, int from_i, const constantPoolHandle& to_cp, int to_i, TRAPS); 880 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS); 881 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp, TRAPS); 882 int version() const { return _saved._version; } 883 void set_version(int version) { _saved._version = version; } 884 void increment_and_save_version(int version) { 885 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow 886 } 887 888 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; } 889 int resolved_reference_length() const { return _saved._resolved_reference_length; } 890 891 // Decrease ref counts of symbols that are in the constant pool 892 // when the holder class is unloaded 893 void unreference_symbols(); 894 895 // Deallocate constant pool for RedefineClasses 896 void deallocate_contents(ClassLoaderData* loader_data); 897 void release_C_heap_structures(); 898 899 // JVMTI accesss - GetConstantPool, RetransformClasses, ... 900 friend class JvmtiConstantPoolReconstituter; 901 902 private: 903 jint cpool_entry_size(jint idx); 904 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap); 905 906 // Copy cpool bytes into byte array. 907 // Returns: 908 // int > 0, count of the raw cpool bytes that have been copied 909 // 0, OutOfMemory error 910 // -1, Internal error 911 int copy_cpool_bytes(int cpool_size, 912 SymbolHashMap* tbl, 913 unsigned char *bytes); 914 915 public: 916 // Verify 917 void verify_on(outputStream* st); 918 919 // Printing 920 void print_on(outputStream* st) const; 921 void print_value_on(outputStream* st) const; 922 void print_entry_on(int index, outputStream* st); 923 924 const char* internal_name() const { return "{constant pool}"; } 925 926 #ifndef PRODUCT 927 // Compile the world support 928 static void preload_and_initialize_all_classes(ConstantPool* constant_pool, TRAPS); 929 #endif 930 }; 931 932 class SymbolHashMapEntry : public CHeapObj<mtSymbol> { 933 private: 934 unsigned int _hash; // 32-bit hash for item 935 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket 936 Symbol* _symbol; // 1-st part of the mapping: symbol => value 937 u2 _value; // 2-nd part of the mapping: symbol => value 938 939 public: 940 unsigned int hash() const { return _hash; } 941 void set_hash(unsigned int hash) { _hash = hash; } 942 943 SymbolHashMapEntry* next() const { return _next; } 944 void set_next(SymbolHashMapEntry* next) { _next = next; } 945 946 Symbol* symbol() const { return _symbol; } 947 void set_symbol(Symbol* sym) { _symbol = sym; } 948 949 u2 value() const { return _value; } 950 void set_value(u2 value) { _value = value; } 951 952 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value) 953 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {} 954 955 }; // End SymbolHashMapEntry class 956 957 958 class SymbolHashMapBucket : public CHeapObj<mtSymbol> { 959 960 private: 961 SymbolHashMapEntry* _entry; 962 963 public: 964 SymbolHashMapEntry* entry() const { return _entry; } 965 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; } 966 void clear() { _entry = NULL; } 967 968 }; // End SymbolHashMapBucket class 969 970 971 class SymbolHashMap: public CHeapObj<mtSymbol> { 972 973 private: 974 // Default number of entries in the table 975 enum SymbolHashMap_Constants { 976 _Def_HashMap_Size = 256 977 }; 978 979 int _table_size; 980 SymbolHashMapBucket* _buckets; 981 982 void initialize_table(int table_size) { 983 _table_size = table_size; 984 _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size, mtSymbol); 985 for (int index = 0; index < table_size; index++) { 986 _buckets[index].clear(); 987 } 988 } 989 990 public: 991 992 int table_size() const { return _table_size; } 993 994 SymbolHashMap() { initialize_table(_Def_HashMap_Size); } 995 SymbolHashMap(int table_size) { initialize_table(table_size); } 996 997 // hash P(31) from Kernighan & Ritchie 998 static unsigned int compute_hash(const char* str, int len) { 999 unsigned int hash = 0; 1000 while (len-- > 0) { 1001 hash = 31*hash + (unsigned) *str; 1002 str++; 1003 } 1004 return hash; 1005 } 1006 1007 SymbolHashMapEntry* bucket(int i) { 1008 return _buckets[i].entry(); 1009 } 1010 1011 void add_entry(Symbol* sym, u2 value); 1012 SymbolHashMapEntry* find_entry(Symbol* sym); 1013 1014 u2 symbol_to_value(Symbol* sym) { 1015 SymbolHashMapEntry *entry = find_entry(sym); 1016 return (entry == NULL) ? 0 : entry->value(); 1017 } 1018 1019 ~SymbolHashMap() { 1020 SymbolHashMapEntry* next; 1021 for (int i = 0; i < _table_size; i++) { 1022 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) { 1023 next = cur->next(); 1024 delete(cur); 1025 } 1026 } 1027 delete _buckets; 1028 } 1029 }; // End SymbolHashMap class 1030 1031 #endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP