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/symbol.hpp" 32 #include "oops/typeArrayOop.hpp" 33 #include "runtime/handles.hpp" 34 #include "utilities/bytes.hpp" 35 #include "utilities/constantTag.hpp" 36 37 // A ConstantPool is an array containing class constants as described in the 38 // class file. 39 // 40 // Most of the constant pool entries are written during class parsing, which 41 // is safe. For klass types, the constant pool entry is 42 // modified when the entry is resolved. If a klass constant pool 43 // entry is read without a lock, only the resolved state guarantees that 44 // the entry in the constant pool is a klass object and not a Symbol*. 45 46 class SymbolHashMap; 47 48 class CPSlot VALUE_OBJ_CLASS_SPEC { 49 friend class ConstantPool; 50 intptr_t _ptr; 51 enum TagBits {_pseudo_bit = 1}; 52 public: 53 54 CPSlot(intptr_t ptr): _ptr(ptr) {} 55 CPSlot(Symbol* ptr, int tag_bits = 0): _ptr((intptr_t)ptr | tag_bits) {} 56 57 intptr_t value() { return _ptr; } 58 bool is_pseudo_string() { return (_ptr & _pseudo_bit) != 0; } 59 60 Symbol* get_symbol() { 61 return (Symbol*)(_ptr & ~_pseudo_bit); 62 } 63 }; 64 65 // This represents a JVM_CONSTANT_Class, JVM_CONSTANT_UnresolvedClass, or 66 // JVM_CONSTANT_UnresolvedClassInError slot in the constant pool. 67 class CPKlassSlot VALUE_OBJ_CLASS_SPEC { 68 // cp->symbol_at(_name_index) gives the name of the class. 69 int _name_index; 70 71 // cp->_resolved_klasses->at(_resolved_klass_index) gives the Klass* for the class. 72 int _resolved_klass_index; 73 public: 74 enum { 75 // This is used during constant pool merging where the resolved klass index is 76 // not yet known, and will be computed at a later stage (during a call to 77 // initialize_unresolved_klasses()). 78 _temp_resolved_klass_index = 0xffff 79 }; 80 CPKlassSlot(int n, int rk) { 81 _name_index = n; 82 _resolved_klass_index = rk; 83 } 84 int name_index() const { 85 return _name_index; 86 } 87 int resolved_klass_index() const { 88 assert(_resolved_klass_index != _temp_resolved_klass_index, "constant pool merging was incomplete"); 89 return _resolved_klass_index; 90 } 91 }; 92 93 class KlassSizeStats; 94 95 class ConstantPool : public Metadata { 96 friend class VMStructs; 97 friend class JVMCIVMStructs; 98 friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast 99 friend class Universe; // For null constructor 100 private: 101 Array<u1>* _tags; // the tag array describing the constant pool's contents 102 ConstantPoolCache* _cache; // the cache holding interpreter runtime information 103 InstanceKlass* _pool_holder; // the corresponding class 104 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty 105 106 // Consider using an array of compressed klass pointers to 107 // save space on 64-bit platforms. 108 Array<Klass*>* _resolved_klasses; 109 110 enum { 111 _has_preresolution = 1, // Flags 112 _on_stack = 2, 113 _is_shared = 4 114 }; 115 116 int _flags; // old fashioned bit twiddling 117 int _length; // number of elements in the array 118 119 union { 120 // set for CDS to restore resolved references 121 int _resolved_reference_length; 122 // keeps version number for redefined classes (used in backtrace) 123 int _version; 124 } _saved; 125 126 void set_tags(Array<u1>* tags) { _tags = tags; } 127 void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); } 128 void release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); } 129 130 u1* tag_addr_at(int which) const { return tags()->adr_at(which); } 131 132 void set_operands(Array<u2>* operands) { _operands = operands; } 133 134 int flags() const { return _flags; } 135 void set_flags(int f) { _flags = f; } 136 137 private: 138 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); } 139 140 CPSlot slot_at(int which) const { 141 assert(is_within_bounds(which), "index out of bounds"); 142 assert(!tag_at(which).is_unresolved_klass() && !tag_at(which).is_unresolved_klass_in_error(), "Corrupted constant pool"); 143 // Uses volatile because the klass slot changes without a lock. 144 volatile intptr_t adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which)); 145 assert(adr != 0 || which == 0, "cp entry for klass should not be zero"); 146 return CPSlot(adr); 147 } 148 149 void slot_at_put(int which, CPSlot s) const { 150 assert(is_within_bounds(which), "index out of bounds"); 151 assert(s.value() != 0, "Caught something"); 152 *(intptr_t*)&base()[which] = s.value(); 153 } 154 intptr_t* obj_at_addr_raw(int which) const { 155 assert(is_within_bounds(which), "index out of bounds"); 156 return (intptr_t*) &base()[which]; 157 } 158 159 jint* int_at_addr(int which) const { 160 assert(is_within_bounds(which), "index out of bounds"); 161 return (jint*) &base()[which]; 162 } 163 164 jlong* long_at_addr(int which) const { 165 assert(is_within_bounds(which), "index out of bounds"); 166 return (jlong*) &base()[which]; 167 } 168 169 jfloat* float_at_addr(int which) const { 170 assert(is_within_bounds(which), "index out of bounds"); 171 return (jfloat*) &base()[which]; 172 } 173 174 jdouble* double_at_addr(int which) const { 175 assert(is_within_bounds(which), "index out of bounds"); 176 return (jdouble*) &base()[which]; 177 } 178 179 ConstantPool(Array<u1>* tags); 180 ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); } 181 public: 182 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS); 183 184 bool is_constantPool() const volatile { return true; } 185 186 Array<u1>* tags() const { return _tags; } 187 Array<u2>* operands() const { return _operands; } 188 189 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; } 190 void set_has_preresolution() { 191 assert(!is_shared(), "should never be called on shared ConstantPools"); 192 _flags |= _has_preresolution; 193 } 194 195 // Redefine classes support. If a method refering to this constant pool 196 // is on the executing stack, or as a handle in vm code, this constant pool 197 // can't be removed from the set of previous versions saved in the instance 198 // class. 199 bool on_stack() const { return (_flags &_on_stack) != 0; } 200 void set_on_stack(const bool value); 201 202 // Faster than MetaspaceObj::is_shared() - used by set_on_stack() 203 bool is_shared() const { return (_flags & _is_shared) != 0; } 204 205 // Klass holding pool 206 InstanceKlass* pool_holder() const { return _pool_holder; } 207 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; } 208 InstanceKlass** pool_holder_addr() { return &_pool_holder; } 209 210 // Interpreter runtime support 211 ConstantPoolCache* cache() const { return _cache; } 212 void set_cache(ConstantPoolCache* cache){ _cache = cache; } 213 214 // Create object cache in the constant pool 215 void initialize_resolved_references(ClassLoaderData* loader_data, 216 const intStack& reference_map, 217 int constant_pool_map_length, 218 TRAPS); 219 220 // resolved strings, methodHandles and callsite objects from the constant pool 221 objArrayOop resolved_references() const; 222 // mapping resolved object array indexes to cp indexes and back. 223 int object_to_cp_index(int index) { return reference_map()->at(index); } 224 int cp_to_object_index(int index); 225 226 void set_resolved_klasses(Array<Klass*>* rk) { _resolved_klasses = rk; } 227 Array<Klass*>* resolved_klasses() const { return _resolved_klasses; } 228 void allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS); 229 void initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS); 230 231 // Invokedynamic indexes. 232 // They must look completely different from normal indexes. 233 // The main reason is that byte swapping is sometimes done on normal indexes. 234 // Finally, it is helpful for debugging to tell the two apart. 235 static bool is_invokedynamic_index(int i) { return (i < 0); } 236 static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; } 237 static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; } 238 239 240 // The invokedynamic points at a CP cache entry. This entry points back 241 // at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry 242 // in the resolved_references array (which provides the appendix argument). 243 int invokedynamic_cp_cache_index(int index) const { 244 assert (is_invokedynamic_index(index), "should be a invokedynamic index"); 245 int cache_index = decode_invokedynamic_index(index); 246 return cache_index; 247 } 248 ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int index) const { 249 // decode index that invokedynamic points to. 250 int cp_cache_index = invokedynamic_cp_cache_index(index); 251 return cache()->entry_at(cp_cache_index); 252 } 253 254 // Assembly code support 255 static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); } 256 static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); } 257 static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); } 258 static int resolved_klasses_offset_in_bytes() { return offset_of(ConstantPool, _resolved_klasses); } 259 260 // Storing constants 261 262 // For temporary use while constructing constant pool 263 void klass_index_at_put(int which, int name_index) { 264 tag_at_put(which, JVM_CONSTANT_ClassIndex); 265 *int_at_addr(which) = name_index; 266 } 267 268 // Anonymous class support: 269 void klass_at_put(int class_index, int name_index, int resolved_klass_index, Klass* k, Symbol* name); 270 void klass_at_put(int class_index, Klass* k); 271 272 void unresolved_klass_at_put(int which, int name_index, int resolved_klass_index) { 273 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass); 274 275 assert((name_index & 0xffff0000) == 0, "must be"); 276 assert((resolved_klass_index & 0xffff0000) == 0, "must be"); 277 *int_at_addr(which) = 278 build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index); 279 } 280 281 void method_handle_index_at_put(int which, int ref_kind, int ref_index) { 282 tag_at_put(which, JVM_CONSTANT_MethodHandle); 283 *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind; 284 } 285 286 void method_type_index_at_put(int which, int ref_index) { 287 tag_at_put(which, JVM_CONSTANT_MethodType); 288 *int_at_addr(which) = ref_index; 289 } 290 291 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) { 292 tag_at_put(which, JVM_CONSTANT_InvokeDynamic); 293 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index; 294 } 295 296 void unresolved_string_at_put(int which, Symbol* s) { 297 release_tag_at_put(which, JVM_CONSTANT_String); 298 slot_at_put(which, CPSlot(s)); 299 } 300 301 void int_at_put(int which, jint i) { 302 tag_at_put(which, JVM_CONSTANT_Integer); 303 *int_at_addr(which) = i; 304 } 305 306 void long_at_put(int which, jlong l) { 307 tag_at_put(which, JVM_CONSTANT_Long); 308 // *long_at_addr(which) = l; 309 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l)); 310 } 311 312 void float_at_put(int which, jfloat f) { 313 tag_at_put(which, JVM_CONSTANT_Float); 314 *float_at_addr(which) = f; 315 } 316 317 void double_at_put(int which, jdouble d) { 318 tag_at_put(which, JVM_CONSTANT_Double); 319 // *double_at_addr(which) = d; 320 // u8 temp = *(u8*) &d; 321 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d)); 322 } 323 324 Symbol** symbol_at_addr(int which) const { 325 assert(is_within_bounds(which), "index out of bounds"); 326 return (Symbol**) &base()[which]; 327 } 328 329 void symbol_at_put(int which, Symbol* s) { 330 assert(s->refcount() != 0, "should have nonzero refcount"); 331 tag_at_put(which, JVM_CONSTANT_Utf8); 332 *symbol_at_addr(which) = s; 333 } 334 335 void string_at_put(int which, int obj_index, oop str); 336 337 // For temporary use while constructing constant pool 338 void string_index_at_put(int which, int string_index) { 339 tag_at_put(which, JVM_CONSTANT_StringIndex); 340 *int_at_addr(which) = string_index; 341 } 342 343 void field_at_put(int which, int class_index, int name_and_type_index) { 344 tag_at_put(which, JVM_CONSTANT_Fieldref); 345 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; 346 } 347 348 void method_at_put(int which, int class_index, int name_and_type_index) { 349 tag_at_put(which, JVM_CONSTANT_Methodref); 350 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; 351 } 352 353 void interface_method_at_put(int which, int class_index, int name_and_type_index) { 354 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref); 355 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice 356 } 357 358 void name_and_type_at_put(int which, int name_index, int signature_index) { 359 tag_at_put(which, JVM_CONSTANT_NameAndType); 360 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice 361 } 362 363 // Tag query 364 365 constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); } 366 367 // Fetching constants 368 369 Klass* klass_at(int which, TRAPS) { 370 constantPoolHandle h_this(THREAD, this); 371 return klass_at_impl(h_this, which, true, THREAD); 372 } 373 374 // Version of klass_at that doesn't save the resolution error, called during deopt 375 Klass* klass_at_ignore_error(int which, TRAPS) { 376 constantPoolHandle h_this(THREAD, this); 377 return klass_at_impl(h_this, which, false, THREAD); 378 } 379 380 CPKlassSlot klass_slot_at(int which) const { 381 assert(tag_at(which).is_unresolved_klass() || tag_at(which).is_klass(), 382 "Corrupted constant pool"); 383 int value = *int_at_addr(which); 384 int name_index = extract_high_short_from_int(value); 385 int resolved_klass_index = extract_low_short_from_int(value); 386 return CPKlassSlot(name_index, resolved_klass_index); 387 } 388 389 Symbol* klass_name_at(int which) const; // Returns the name, w/o resolving. 390 int klass_name_index_at(int which) const { 391 return klass_slot_at(which).name_index(); 392 } 393 394 Klass* resolved_klass_at(int which) const { // Used by Compiler 395 guarantee(tag_at(which).is_klass(), "Corrupted constant pool"); 396 // Must do an acquire here in case another thread resolved the klass 397 // behind our back, lest we later load stale values thru the oop. 398 CPKlassSlot kslot = klass_slot_at(which); 399 assert(tag_at(kslot.name_index()).is_symbol(), "sanity"); 400 401 Klass** adr = resolved_klasses()->adr_at(kslot.resolved_klass_index()); 402 return (Klass*)OrderAccess::load_ptr_acquire(adr); 403 } 404 405 // RedefineClasses() API support: 406 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); } 407 void temp_unresolved_klass_at_put(int which, int name_index) { 408 // Used only during constant pool merging for class redefinition. The resolved klass index 409 // will be initialized later by a call to initialize_unresolved_klasses(). 410 unresolved_klass_at_put(which, name_index, CPKlassSlot::_temp_resolved_klass_index); 411 } 412 413 jint int_at(int which) { 414 assert(tag_at(which).is_int(), "Corrupted constant pool"); 415 return *int_at_addr(which); 416 } 417 418 jlong long_at(int which) { 419 assert(tag_at(which).is_long(), "Corrupted constant pool"); 420 // return *long_at_addr(which); 421 u8 tmp = Bytes::get_native_u8((address)&base()[which]); 422 return *((jlong*)&tmp); 423 } 424 425 jfloat float_at(int which) { 426 assert(tag_at(which).is_float(), "Corrupted constant pool"); 427 return *float_at_addr(which); 428 } 429 430 jdouble double_at(int which) { 431 assert(tag_at(which).is_double(), "Corrupted constant pool"); 432 u8 tmp = Bytes::get_native_u8((address)&base()[which]); 433 return *((jdouble*)&tmp); 434 } 435 436 Symbol* symbol_at(int which) const { 437 assert(tag_at(which).is_utf8(), "Corrupted constant pool"); 438 return *symbol_at_addr(which); 439 } 440 441 oop string_at(int which, int obj_index, TRAPS) { 442 constantPoolHandle h_this(THREAD, this); 443 return string_at_impl(h_this, which, obj_index, THREAD); 444 } 445 oop string_at(int which, TRAPS) { 446 int obj_index = cp_to_object_index(which); 447 return string_at(which, obj_index, THREAD); 448 } 449 450 // Version that can be used before string oop array is created. 451 oop uncached_string_at(int which, TRAPS); 452 453 // A "pseudo-string" is an non-string oop that has found its way into 454 // a String entry. 455 // This can happen if the user patches a live 456 // object into a CONSTANT_String entry of an anonymous class. 457 // Method oops internally created for method handles may also 458 // use pseudo-strings to link themselves to related metaobjects. 459 460 bool is_pseudo_string_at(int which) { 461 assert(tag_at(which).is_string(), "Corrupted constant pool"); 462 return slot_at(which).is_pseudo_string(); 463 } 464 465 oop pseudo_string_at(int which, int obj_index) { 466 assert(is_pseudo_string_at(which), "must be a pseudo-string"); 467 oop s = resolved_references()->obj_at(obj_index); 468 return s; 469 } 470 471 oop pseudo_string_at(int which) { 472 assert(is_pseudo_string_at(which), "must be a pseudo-string"); 473 int obj_index = cp_to_object_index(which); 474 oop s = resolved_references()->obj_at(obj_index); 475 return s; 476 } 477 478 void pseudo_string_at_put(int which, int obj_index, oop x) { 479 assert(tag_at(which).is_string(), "Corrupted constant pool"); 480 Symbol* sym = unresolved_string_at(which); 481 slot_at_put(which, CPSlot(sym, CPSlot::_pseudo_bit)); 482 string_at_put(which, obj_index, x); // this works just fine 483 } 484 485 // only called when we are sure a string entry is already resolved (via an 486 // earlier string_at call. 487 oop resolved_string_at(int which) { 488 assert(tag_at(which).is_string(), "Corrupted constant pool"); 489 // Must do an acquire here in case another thread resolved the klass 490 // behind our back, lest we later load stale values thru the oop. 491 // we might want a volatile_obj_at in ObjArrayKlass. 492 int obj_index = cp_to_object_index(which); 493 return resolved_references()->obj_at(obj_index); 494 } 495 496 Symbol* unresolved_string_at(int which) { 497 assert(tag_at(which).is_string(), "Corrupted constant pool"); 498 Symbol* sym = slot_at(which).get_symbol(); 499 return sym; 500 } 501 502 // Returns an UTF8 for a CONSTANT_String entry at a given index. 503 // UTF8 char* representation was chosen to avoid conversion of 504 // java_lang_Strings at resolved entries into Symbol*s 505 // or vice versa. 506 char* string_at_noresolve(int which); 507 508 jint name_and_type_at(int which) { 509 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool"); 510 return *int_at_addr(which); 511 } 512 513 int method_handle_ref_kind_at(int which) { 514 assert(tag_at(which).is_method_handle() || 515 tag_at(which).is_method_handle_in_error(), "Corrupted constant pool"); 516 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits 517 } 518 int method_handle_index_at(int which) { 519 assert(tag_at(which).is_method_handle() || 520 tag_at(which).is_method_handle_in_error(), "Corrupted constant pool"); 521 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits 522 } 523 int method_type_index_at(int which) { 524 assert(tag_at(which).is_method_type() || 525 tag_at(which).is_method_type_in_error(), "Corrupted constant pool"); 526 return *int_at_addr(which); 527 } 528 529 // Derived queries: 530 Symbol* method_handle_name_ref_at(int which) { 531 int member = method_handle_index_at(which); 532 return impl_name_ref_at(member, true); 533 } 534 Symbol* method_handle_signature_ref_at(int which) { 535 int member = method_handle_index_at(which); 536 return impl_signature_ref_at(member, true); 537 } 538 int method_handle_klass_index_at(int which) { 539 int member = method_handle_index_at(which); 540 return impl_klass_ref_index_at(member, true); 541 } 542 Symbol* method_type_signature_at(int which) { 543 int sym = method_type_index_at(which); 544 return symbol_at(sym); 545 } 546 547 int invoke_dynamic_name_and_type_ref_index_at(int which) { 548 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 549 return extract_high_short_from_int(*int_at_addr(which)); 550 } 551 int invoke_dynamic_bootstrap_specifier_index(int which) { 552 assert(tag_at(which).value() == JVM_CONSTANT_InvokeDynamic, "Corrupted constant pool"); 553 return extract_low_short_from_int(*int_at_addr(which)); 554 } 555 int invoke_dynamic_operand_base(int which) { 556 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which); 557 return operand_offset_at(operands(), bootstrap_specifier_index); 558 } 559 // The first part of the operands array consists of an index into the second part. 560 // Extract a 32-bit index value from the first part. 561 static int operand_offset_at(Array<u2>* operands, int bootstrap_specifier_index) { 562 int n = (bootstrap_specifier_index * 2); 563 assert(n >= 0 && n+2 <= operands->length(), "oob"); 564 // The first 32-bit index points to the beginning of the second part 565 // of the operands array. Make sure this index is in the first part. 566 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0), 567 operands->at(1))); 568 assert(second_part == 0 || n+2 <= second_part, "oob (2)"); 569 int offset = build_int_from_shorts(operands->at(n+0), 570 operands->at(n+1)); 571 // The offset itself must point into the second part of the array. 572 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)"); 573 return offset; 574 } 575 static void operand_offset_at_put(Array<u2>* operands, int bootstrap_specifier_index, int offset) { 576 int n = bootstrap_specifier_index * 2; 577 assert(n >= 0 && n+2 <= operands->length(), "oob"); 578 operands->at_put(n+0, extract_low_short_from_int(offset)); 579 operands->at_put(n+1, extract_high_short_from_int(offset)); 580 } 581 static int operand_array_length(Array<u2>* operands) { 582 if (operands == NULL || operands->length() == 0) return 0; 583 int second_part = operand_offset_at(operands, 0); 584 return (second_part / 2); 585 } 586 587 #ifdef ASSERT 588 // operand tuples fit together exactly, end to end 589 static int operand_limit_at(Array<u2>* operands, int bootstrap_specifier_index) { 590 int nextidx = bootstrap_specifier_index + 1; 591 if (nextidx == operand_array_length(operands)) 592 return operands->length(); 593 else 594 return operand_offset_at(operands, nextidx); 595 } 596 int invoke_dynamic_operand_limit(int which) { 597 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which); 598 return operand_limit_at(operands(), bootstrap_specifier_index); 599 } 600 #endif //ASSERT 601 602 // layout of InvokeDynamic bootstrap method specifier (in second part of operands array): 603 enum { 604 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm 605 _indy_argc_offset = 1, // u2 argc 606 _indy_argv_offset = 2 // u2 argv[argc] 607 }; 608 609 // These functions are used in RedefineClasses for CP merge 610 611 int operand_offset_at(int bootstrap_specifier_index) { 612 assert(0 <= bootstrap_specifier_index && 613 bootstrap_specifier_index < operand_array_length(operands()), 614 "Corrupted CP operands"); 615 return operand_offset_at(operands(), bootstrap_specifier_index); 616 } 617 int operand_bootstrap_method_ref_index_at(int bootstrap_specifier_index) { 618 int offset = operand_offset_at(bootstrap_specifier_index); 619 return operands()->at(offset + _indy_bsm_offset); 620 } 621 int operand_argument_count_at(int bootstrap_specifier_index) { 622 int offset = operand_offset_at(bootstrap_specifier_index); 623 int argc = operands()->at(offset + _indy_argc_offset); 624 return argc; 625 } 626 int operand_argument_index_at(int bootstrap_specifier_index, int j) { 627 int offset = operand_offset_at(bootstrap_specifier_index); 628 return operands()->at(offset + _indy_argv_offset + j); 629 } 630 int operand_next_offset_at(int bootstrap_specifier_index) { 631 int offset = operand_offset_at(bootstrap_specifier_index) + _indy_argv_offset 632 + operand_argument_count_at(bootstrap_specifier_index); 633 return offset; 634 } 635 // Compare a bootsrap specifier in the operands arrays 636 bool compare_operand_to(int bootstrap_specifier_index1, const constantPoolHandle& cp2, 637 int bootstrap_specifier_index2, TRAPS); 638 // Find a bootsrap specifier in the operands array 639 int find_matching_operand(int bootstrap_specifier_index, const constantPoolHandle& search_cp, 640 int operands_cur_len, TRAPS); 641 // Resize the operands array with delta_len and delta_size 642 void resize_operands(int delta_len, int delta_size, TRAPS); 643 // Extend the operands array with the length and size of the ext_cp operands 644 void extend_operands(const constantPoolHandle& ext_cp, TRAPS); 645 // Shrink the operands array to a smaller array with new_len length 646 void shrink_operands(int new_len, TRAPS); 647 648 649 int invoke_dynamic_bootstrap_method_ref_index_at(int which) { 650 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 651 int op_base = invoke_dynamic_operand_base(which); 652 return operands()->at(op_base + _indy_bsm_offset); 653 } 654 int invoke_dynamic_argument_count_at(int which) { 655 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 656 int op_base = invoke_dynamic_operand_base(which); 657 int argc = operands()->at(op_base + _indy_argc_offset); 658 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc; 659 int next_offset = invoke_dynamic_operand_limit(which)); 660 assert(end_offset == next_offset, "matched ending"); 661 return argc; 662 } 663 int invoke_dynamic_argument_index_at(int which, int j) { 664 int op_base = invoke_dynamic_operand_base(which); 665 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset)); 666 assert((uint)j < (uint)argc, "oob"); 667 return operands()->at(op_base + _indy_argv_offset + j); 668 } 669 670 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve, 671 // name_and_type_ref_index_at) all expect to be passed indices obtained 672 // directly from the bytecode. 673 // If the indices are meant to refer to fields or methods, they are 674 // actually rewritten constant pool cache indices. 675 // The routine remap_instruction_operand_from_cache manages the adjustment 676 // of these values back to constant pool indices. 677 678 // There are also "uncached" versions which do not adjust the operand index; see below. 679 680 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear. 681 // In a few cases (the verifier) there are uses before a cpcache has been built, 682 // which are handled by a dynamic check in remap_instruction_operand_from_cache. 683 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode. 684 685 // Lookup for entries consisting of (klass_index, name_and_type index) 686 Klass* klass_ref_at(int which, TRAPS); 687 Symbol* klass_ref_at_noresolve(int which); 688 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); } 689 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); } 690 691 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); } 692 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); } 693 694 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG 695 696 constantTag tag_ref_at(int cp_cache_index) { return impl_tag_ref_at(cp_cache_index, false); } 697 698 // Lookup for entries consisting of (name_index, signature_index) 699 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt) 700 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt) 701 702 BasicType basic_type_for_signature_at(int which) const; 703 704 // Resolve string constants (to prevent allocation during compilation) 705 void resolve_string_constants(TRAPS) { 706 constantPoolHandle h_this(THREAD, this); 707 resolve_string_constants_impl(h_this, CHECK); 708 } 709 710 // CDS support 711 void remove_unshareable_info(); 712 void restore_unshareable_info(TRAPS); 713 bool resolve_class_constants(TRAPS); 714 // The ConstantPool vtable is restored by this call when the ConstantPool is 715 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for 716 // all the gory details. SA, dtrace and pstack helpers distinguish metadata 717 // by their vtable. 718 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); } 719 720 private: 721 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 }; 722 public: 723 724 // Resolve late bound constants. 725 oop resolve_constant_at(int index, TRAPS) { 726 constantPoolHandle h_this(THREAD, this); 727 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD); 728 } 729 730 oop resolve_cached_constant_at(int cache_index, TRAPS) { 731 constantPoolHandle h_this(THREAD, this); 732 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD); 733 } 734 735 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) { 736 constantPoolHandle h_this(THREAD, this); 737 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD); 738 } 739 740 oop resolve_bootstrap_specifier_at(int index, TRAPS) { 741 constantPoolHandle h_this(THREAD, this); 742 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD); 743 } 744 745 // Klass name matches name at offset 746 bool klass_name_at_matches(const InstanceKlass* k, int which); 747 748 // Sizing 749 int length() const { return _length; } 750 void set_length(int length) { _length = length; } 751 752 // Tells whether index is within bounds. 753 bool is_within_bounds(int index) const { 754 return 0 <= index && index < length(); 755 } 756 757 // Sizing (in words) 758 static int header_size() { 759 return align_size_up(sizeof(ConstantPool), wordSize) / wordSize; 760 } 761 static int size(int length) { return align_metadata_size(header_size() + length); } 762 int size() const { return size(length()); } 763 #if INCLUDE_SERVICES 764 void collect_statistics(KlassSizeStats *sz) const; 765 #endif 766 767 friend class ClassFileParser; 768 friend class SystemDictionary; 769 770 // Used by CDS. These classes need to access the private ConstantPool() constructor. 771 template <class T> friend class CppVtableTesterA; 772 template <class T> friend class CppVtableTesterB; 773 template <class T> friend class CppVtableCloner; 774 775 // Used by compiler to prevent classloading. 776 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which); 777 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which); 778 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which); 779 static bool has_method_type_at_if_loaded (const constantPoolHandle& this_cp, int which); 780 static oop method_type_at_if_loaded (const constantPoolHandle& this_cp, int which); 781 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which); 782 static Klass* klass_ref_at_if_loaded (const constantPoolHandle& this_cp, int which); 783 784 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the 785 // future by other Java code. These take constant pool indices rather than 786 // constant pool cache indices as do the peer methods above. 787 Symbol* uncached_klass_ref_at_noresolve(int which); 788 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); } 789 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); } 790 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); } 791 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); } 792 793 // Sharing 794 int pre_resolve_shared_klasses(TRAPS); 795 796 // Debugging 797 const char* printable_name_at(int which) PRODUCT_RETURN0; 798 799 #ifdef ASSERT 800 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices 801 #else 802 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op 803 #endif //ASSERT 804 805 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) { 806 if (invokedynamic_ok && is_invokedynamic_index(raw_index)) 807 return decode_invokedynamic_index(raw_index); 808 else 809 return raw_index - CPCACHE_INDEX_TAG; 810 } 811 812 private: 813 814 void set_resolved_references(jobject s) { _cache->set_resolved_references(s); } 815 Array<u2>* reference_map() const { return (_cache == NULL) ? NULL : _cache->reference_map(); } 816 void set_reference_map(Array<u2>* o) { _cache->set_reference_map(o); } 817 818 // patch JSR 292 resolved references after the class is linked. 819 void patch_resolved_references(GrowableArray<Handle>* cp_patches); 820 821 Symbol* impl_name_ref_at(int which, bool uncached); 822 Symbol* impl_signature_ref_at(int which, bool uncached); 823 int impl_klass_ref_index_at(int which, bool uncached); 824 int impl_name_and_type_ref_index_at(int which, bool uncached); 825 constantTag impl_tag_ref_at(int which, bool uncached); 826 827 // Used while constructing constant pool (only by ClassFileParser) 828 jint klass_index_at(int which) { 829 assert(tag_at(which).is_klass_index(), "Corrupted constant pool"); 830 return *int_at_addr(which); 831 } 832 833 jint string_index_at(int which) { 834 assert(tag_at(which).is_string_index(), "Corrupted constant pool"); 835 return *int_at_addr(which); 836 } 837 838 // Performs the LinkResolver checks 839 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* klass, TRAPS); 840 841 // Implementation of methods that needs an exposed 'this' pointer, in order to 842 // handle GC while executing the method 843 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int which, 844 bool save_resolution_error, TRAPS); 845 static oop string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS); 846 847 static void trace_class_resolution(const constantPoolHandle& this_cp, Klass* k); 848 849 // Resolve string constants (to prevent allocation during compilation) 850 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS); 851 852 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int index, int cache_index, TRAPS); 853 static oop resolve_bootstrap_specifier_at_impl(const constantPoolHandle& this_cp, int index, TRAPS); 854 855 // Exception handling 856 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS); 857 static Symbol* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception); 858 static void save_and_throw_exception(const constantPoolHandle& this_cp, int which, constantTag tag, TRAPS); 859 860 public: 861 // Merging ConstantPool* support: 862 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2, TRAPS); 863 void copy_cp_to(int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS) { 864 constantPoolHandle h_this(THREAD, this); 865 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD); 866 } 867 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS); 868 static void copy_entry_to(const constantPoolHandle& from_cp, int from_i, const constantPoolHandle& to_cp, int to_i, TRAPS); 869 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS); 870 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp, TRAPS); 871 int version() const { return _saved._version; } 872 void set_version(int version) { _saved._version = version; } 873 void increment_and_save_version(int version) { 874 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow 875 } 876 877 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; } 878 int resolved_reference_length() const { return _saved._resolved_reference_length; } 879 880 // Decrease ref counts of symbols that are in the constant pool 881 // when the holder class is unloaded 882 void unreference_symbols(); 883 884 // Deallocate constant pool for RedefineClasses 885 void deallocate_contents(ClassLoaderData* loader_data); 886 void release_C_heap_structures(); 887 888 // JVMTI accesss - GetConstantPool, RetransformClasses, ... 889 friend class JvmtiConstantPoolReconstituter; 890 891 private: 892 jint cpool_entry_size(jint idx); 893 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap); 894 895 // Copy cpool bytes into byte array. 896 // Returns: 897 // int > 0, count of the raw cpool bytes that have been copied 898 // 0, OutOfMemory error 899 // -1, Internal error 900 int copy_cpool_bytes(int cpool_size, 901 SymbolHashMap* tbl, 902 unsigned char *bytes); 903 904 public: 905 // Verify 906 void verify_on(outputStream* st); 907 908 // Printing 909 void print_on(outputStream* st) const; 910 void print_value_on(outputStream* st) const; 911 void print_entry_on(int index, outputStream* st); 912 913 const char* internal_name() const { return "{constant pool}"; } 914 915 #ifndef PRODUCT 916 // Compile the world support 917 static void preload_and_initialize_all_classes(ConstantPool* constant_pool, TRAPS); 918 #endif 919 }; 920 921 class SymbolHashMapEntry : public CHeapObj<mtSymbol> { 922 private: 923 unsigned int _hash; // 32-bit hash for item 924 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket 925 Symbol* _symbol; // 1-st part of the mapping: symbol => value 926 u2 _value; // 2-nd part of the mapping: symbol => value 927 928 public: 929 unsigned int hash() const { return _hash; } 930 void set_hash(unsigned int hash) { _hash = hash; } 931 932 SymbolHashMapEntry* next() const { return _next; } 933 void set_next(SymbolHashMapEntry* next) { _next = next; } 934 935 Symbol* symbol() const { return _symbol; } 936 void set_symbol(Symbol* sym) { _symbol = sym; } 937 938 u2 value() const { return _value; } 939 void set_value(u2 value) { _value = value; } 940 941 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value) 942 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {} 943 944 }; // End SymbolHashMapEntry class 945 946 947 class SymbolHashMapBucket : public CHeapObj<mtSymbol> { 948 949 private: 950 SymbolHashMapEntry* _entry; 951 952 public: 953 SymbolHashMapEntry* entry() const { return _entry; } 954 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; } 955 void clear() { _entry = NULL; } 956 957 }; // End SymbolHashMapBucket class 958 959 960 class SymbolHashMap: public CHeapObj<mtSymbol> { 961 962 private: 963 // Default number of entries in the table 964 enum SymbolHashMap_Constants { 965 _Def_HashMap_Size = 256 966 }; 967 968 int _table_size; 969 SymbolHashMapBucket* _buckets; 970 971 void initialize_table(int table_size) { 972 _table_size = table_size; 973 _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size, mtSymbol); 974 for (int index = 0; index < table_size; index++) { 975 _buckets[index].clear(); 976 } 977 } 978 979 public: 980 981 int table_size() const { return _table_size; } 982 983 SymbolHashMap() { initialize_table(_Def_HashMap_Size); } 984 SymbolHashMap(int table_size) { initialize_table(table_size); } 985 986 // hash P(31) from Kernighan & Ritchie 987 static unsigned int compute_hash(const char* str, int len) { 988 unsigned int hash = 0; 989 while (len-- > 0) { 990 hash = 31*hash + (unsigned) *str; 991 str++; 992 } 993 return hash; 994 } 995 996 SymbolHashMapEntry* bucket(int i) { 997 return _buckets[i].entry(); 998 } 999 1000 void add_entry(Symbol* sym, u2 value); 1001 SymbolHashMapEntry* find_entry(Symbol* sym); 1002 1003 u2 symbol_to_value(Symbol* sym) { 1004 SymbolHashMapEntry *entry = find_entry(sym); 1005 return (entry == NULL) ? 0 : entry->value(); 1006 } 1007 1008 ~SymbolHashMap() { 1009 SymbolHashMapEntry* next; 1010 for (int i = 0; i < _table_size; i++) { 1011 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) { 1012 next = cur->next(); 1013 delete(cur); 1014 } 1015 } 1016 delete _buckets; 1017 } 1018 }; // End SymbolHashMap class 1019 1020 #endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP