constantPool.hpp revision 9111:a41fe5ffa839
1193323Sed/* 2193323Sed * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved. 3193323Sed * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4193323Sed * 5193323Sed * This code is free software; you can redistribute it and/or modify it 6193323Sed * under the terms of the GNU General Public License version 2 only, as 7193323Sed * published by the Free Software Foundation. 8193323Sed * 9193323Sed * This code is distributed in the hope that it will be useful, but WITHOUT 10193323Sed * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11193323Sed * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12193323Sed * version 2 for more details (a copy is included in the LICENSE file that 13193323Sed * accompanied this code). 14193323Sed * 15249423Sdim * You should have received a copy of the GNU General Public License version 16249423Sdim * 2 along with this work; if not, write to the Free Software Foundation, 17193323Sed * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18206083Srdivacky * 19249423Sdim * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20193323Sed * or visit www.oracle.com if you need additional information or have any 21218893Sdim * questions. 22218893Sdim * 23249423Sdim */ 24193323Sed 25193323Sed#ifndef SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP 26206083Srdivacky#define SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP 27206083Srdivacky 28193323Sed#include "oops/arrayOop.hpp" 29193323Sed#include "oops/cpCache.hpp" 30193323Sed#include "oops/objArrayOop.hpp" 31193323Sed#include "oops/symbol.hpp" 32193323Sed#include "oops/typeArrayOop.hpp" 33193323Sed#include "runtime/handles.hpp" 34193323Sed#include "utilities/bytes.hpp" 35193323Sed#include "utilities/constantTag.hpp" 36193323Sed 37193323Sed// A ConstantPool is an array containing class constants as described in the 38193323Sed// class file. 39193323Sed// 40193323Sed// Most of the constant pool entries are written during class parsing, which 41193323Sed// is safe. For klass types, the constant pool entry is 42195098Sed// modified when the entry is resolved. If a klass constant pool 43195098Sed// entry is read without a lock, only the resolved state guarantees that 44193323Sed// the entry in the constant pool is a klass object and not a Symbol*. 45193323Sed 46193323Sedclass SymbolHashMap; 47193323Sed 48193323Sedclass CPSlot VALUE_OBJ_CLASS_SPEC { 49193323Sed intptr_t _ptr; 50193323Sed public: 51193323Sed enum TagBits { _resolved_value = 0, _symbol_bit = 1, _pseudo_bit = 2, _symbol_mask = 3 }; 52193323Sed 53193323Sed CPSlot(intptr_t ptr): _ptr(ptr) {} 54193323Sed CPSlot(Klass* ptr): _ptr((intptr_t)ptr) {} 55193323Sed CPSlot(Symbol* ptr): _ptr((intptr_t)ptr | _symbol_bit) {} 56206083Srdivacky CPSlot(Symbol* ptr, int tag_bits): _ptr((intptr_t)ptr | tag_bits) {} 57206083Srdivacky 58206083Srdivacky intptr_t value() { return _ptr; } 59206083Srdivacky bool is_resolved() { return (_ptr & _symbol_bit ) == _resolved_value; } 60206083Srdivacky bool is_unresolved() { return (_ptr & _symbol_bit ) != _resolved_value; } 61206083Srdivacky bool is_pseudo_string() { return (_ptr & _symbol_mask) == _symbol_bit + _pseudo_bit; } 62206083Srdivacky 63206083Srdivacky Symbol* get_symbol() { 64208599Srdivacky assert(is_unresolved(), "bad call"); 65208599Srdivacky return (Symbol*)(_ptr & ~_symbol_mask); 66208599Srdivacky } 67208599Srdivacky Klass* get_klass() { 68206083Srdivacky assert(is_resolved(), "bad call"); 69263508Sdim return (Klass*)_ptr; 70263508Sdim } 71206083Srdivacky}; 72206083Srdivacky 73206083Srdivackyclass KlassSizeStats; 74206083Srdivacky 75206083Srdivackyclass ConstantPool : public Metadata { 76206083Srdivacky friend class VMStructs; 77206083Srdivacky friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast 78206083Srdivacky friend class Universe; // For null constructor 79206083Srdivacky private: 80206083Srdivacky Array<u1>* _tags; // the tag array describing the constant pool's contents 81194754Sed ConstantPoolCache* _cache; // the cache holding interpreter runtime information 82193323Sed InstanceKlass* _pool_holder; // the corresponding class 83206083Srdivacky Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty 84194754Sed 85206083Srdivacky // Array of resolved objects from the constant pool and map from resolved 86206083Srdivacky // object index to original constant pool index 87206083Srdivacky jobject _resolved_references; 88206083Srdivacky Array<u2>* _reference_map; 89194754Sed 90206083Srdivacky enum { 91206083Srdivacky _has_preresolution = 1, // Flags 92206083Srdivacky _on_stack = 2 93194754Sed }; 94206083Srdivacky 95199481Srdivacky int _flags; // old fashioned bit twiddling 96194754Sed int _length; // number of elements in the array 97193323Sed 98193323Sed union { 99206083Srdivacky // set for CDS to restore resolved references 100206083Srdivacky int _resolved_reference_length; 101206083Srdivacky // keeps version number for redefined classes (used in backtrace) 102193323Sed int _version; 103206083Srdivacky } _saved; 104206083Srdivacky 105206083Srdivacky void set_tags(Array<u1>* tags) { _tags = tags; } 106206083Srdivacky void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); } 107206083Srdivacky void release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); } 108206083Srdivacky 109193323Sed u1* tag_addr_at(int which) const { return tags()->adr_at(which); } 110193323Sed 111206083Srdivacky void set_operands(Array<u2>* operands) { _operands = operands; } 112206083Srdivacky 113206083Srdivacky int flags() const { return _flags; } 114206083Srdivacky void set_flags(int f) { _flags = f; } 115206083Srdivacky 116206083Srdivacky private: 117193323Sed intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); } 118193323Sed 119193323Sed CPSlot slot_at(int which) { 120206083Srdivacky assert(is_within_bounds(which), "index out of bounds"); 121206083Srdivacky // Uses volatile because the klass slot changes without a lock. 122193323Sed volatile intptr_t adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which)); 123193323Sed assert(adr != 0 || which == 0, "cp entry for klass should not be zero"); 124193323Sed return CPSlot(adr); 125206083Srdivacky } 126206083Srdivacky 127193323Sed void slot_at_put(int which, CPSlot s) const { 128193323Sed assert(is_within_bounds(which), "index out of bounds"); 129206083Srdivacky assert(s.value() != 0, "Caught something"); 130193323Sed *(intptr_t*)&base()[which] = s.value(); 131206083Srdivacky } 132206083Srdivacky intptr_t* obj_at_addr_raw(int which) const { 133193323Sed assert(is_within_bounds(which), "index out of bounds"); 134206083Srdivacky return (intptr_t*) &base()[which]; 135206083Srdivacky } 136193323Sed 137206083Srdivacky jint* int_at_addr(int which) const { 138206083Srdivacky assert(is_within_bounds(which), "index out of bounds"); 139193323Sed return (jint*) &base()[which]; 140193323Sed } 141206083Srdivacky 142206083Srdivacky jlong* long_at_addr(int which) const { 143206083Srdivacky assert(is_within_bounds(which), "index out of bounds"); 144193323Sed return (jlong*) &base()[which]; 145193323Sed } 146193323Sed 147193323Sed jfloat* float_at_addr(int which) const { 148193323Sed assert(is_within_bounds(which), "index out of bounds"); 149193323Sed return (jfloat*) &base()[which]; 150193323Sed } 151193323Sed 152206083Srdivacky jdouble* double_at_addr(int which) const { 153193323Sed assert(is_within_bounds(which), "index out of bounds"); 154193323Sed return (jdouble*) &base()[which]; 155193323Sed } 156206083Srdivacky 157193323Sed ConstantPool(Array<u1>* tags); 158193323Sed ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); } 159193323Sed public: 160193323Sed static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS); 161193323Sed 162193323Sed bool is_constantPool() const volatile { return true; } 163193323Sed 164193323Sed Array<u1>* tags() const { return _tags; } 165193323Sed Array<u2>* operands() const { return _operands; } 166193323Sed 167193323Sed bool has_preresolution() const { return (_flags & _has_preresolution) != 0; } 168206083Srdivacky void set_has_preresolution() { _flags |= _has_preresolution; } 169206083Srdivacky 170206083Srdivacky // Redefine classes support. If a method refering to this constant pool 171234353Sdim // is on the executing stack, or as a handle in vm code, this constant pool 172234353Sdim // can't be removed from the set of previous versions saved in the instance 173193323Sed // class. 174193323Sed bool on_stack() const { return (_flags &_on_stack) != 0; } 175206083Srdivacky void set_on_stack(const bool value); 176206083Srdivacky 177206083Srdivacky // Klass holding pool 178206083Srdivacky InstanceKlass* pool_holder() const { return _pool_holder; } 179206083Srdivacky void set_pool_holder(InstanceKlass* k) { _pool_holder = k; } 180206083Srdivacky InstanceKlass** pool_holder_addr() { return &_pool_holder; } 181206083Srdivacky 182206083Srdivacky // Interpreter runtime support 183206083Srdivacky ConstantPoolCache* cache() const { return _cache; } 184206083Srdivacky void set_cache(ConstantPoolCache* cache){ _cache = cache; } 185206083Srdivacky 186206083Srdivacky // Create object cache in the constant pool 187234353Sdim void initialize_resolved_references(ClassLoaderData* loader_data, 188193323Sed intStack reference_map, 189193323Sed int constant_pool_map_length, 190206083Srdivacky TRAPS); 191193323Sed 192193323Sed // resolved strings, methodHandles and callsite objects from the constant pool 193193323Sed objArrayOop resolved_references() const; 194193323Sed // mapping resolved object array indexes to cp indexes and back. 195207618Srdivacky int object_to_cp_index(int index) { return _reference_map->at(index); } 196207618Srdivacky int cp_to_object_index(int index); 197206083Srdivacky 198193323Sed // Invokedynamic indexes. 199206083Srdivacky // They must look completely different from normal indexes. 200206083Srdivacky // The main reason is that byte swapping is sometimes done on normal indexes. 201206083Srdivacky // Finally, it is helpful for debugging to tell the two apart. 202206083Srdivacky static bool is_invokedynamic_index(int i) { return (i < 0); } 203206083Srdivacky static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; } 204206083Srdivacky static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; } 205206083Srdivacky 206206083Srdivacky 207206083Srdivacky // The invokedynamic points at a CP cache entry. This entry points back 208206083Srdivacky // at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry 209206083Srdivacky // in the resolved_references array (which provides the appendix argument). 210206083Srdivacky int invokedynamic_cp_cache_index(int index) const { 211206083Srdivacky assert (is_invokedynamic_index(index), "should be a invokedynamic index"); 212206083Srdivacky int cache_index = decode_invokedynamic_index(index); 213206083Srdivacky return cache_index; 214206083Srdivacky } 215206083Srdivacky ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int index) const { 216206083Srdivacky // decode index that invokedynamic points to. 217206083Srdivacky int cp_cache_index = invokedynamic_cp_cache_index(index); 218206083Srdivacky return cache()->entry_at(cp_cache_index); 219206083Srdivacky } 220206083Srdivacky 221206083Srdivacky // Assembly code support 222193323Sed static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); } 223207618Srdivacky static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); } 224207618Srdivacky static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); } 225206083Srdivacky static int resolved_references_offset_in_bytes() { return offset_of(ConstantPool, _resolved_references); } 226206083Srdivacky 227193323Sed // Storing constants 228206083Srdivacky 229198090Srdivacky void klass_at_put(int which, Klass* k) { 230206083Srdivacky assert(k != NULL, "resolved class shouldn't be null"); 231206083Srdivacky assert(is_within_bounds(which), "index out of bounds"); 232206083Srdivacky OrderAccess::release_store_ptr((Klass* volatile *)obj_at_addr_raw(which), k); 233206083Srdivacky // The interpreter assumes when the tag is stored, the klass is resolved 234206083Srdivacky // and the Klass* is a klass rather than a Symbol*, so we need 235193323Sed // hardware store ordering here. 236193323Sed release_tag_at_put(which, JVM_CONSTANT_Class); 237210299Sed } 238210299Sed 239210299Sed // For temporary use while constructing constant pool 240193323Sed void klass_index_at_put(int which, int name_index) { 241210299Sed tag_at_put(which, JVM_CONSTANT_ClassIndex); 242210299Sed *int_at_addr(which) = name_index; 243210299Sed } 244193323Sed 245193323Sed // Temporary until actual use 246193323Sed void unresolved_klass_at_put(int which, Symbol* s) { 247193323Sed release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass); 248193323Sed slot_at_put(which, s); 249206083Srdivacky } 250206083Srdivacky 251206083Srdivacky void method_handle_index_at_put(int which, int ref_kind, int ref_index) { 252193323Sed tag_at_put(which, JVM_CONSTANT_MethodHandle); 253206083Srdivacky *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind; 254206083Srdivacky } 255206083Srdivacky 256206083Srdivacky void method_type_index_at_put(int which, int ref_index) { 257206083Srdivacky tag_at_put(which, JVM_CONSTANT_MethodType); 258206083Srdivacky *int_at_addr(which) = ref_index; 259206083Srdivacky } 260206083Srdivacky 261206083Srdivacky void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) { 262206083Srdivacky tag_at_put(which, JVM_CONSTANT_InvokeDynamic); 263193323Sed *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index; 264193323Sed } 265206083Srdivacky 266206083Srdivacky void unresolved_string_at_put(int which, Symbol* s) { 267206083Srdivacky release_tag_at_put(which, JVM_CONSTANT_String); 268206083Srdivacky slot_at_put(which, CPSlot(s, CPSlot::_symbol_bit)); 269206083Srdivacky } 270206083Srdivacky 271206083Srdivacky void int_at_put(int which, jint i) { 272199481Srdivacky tag_at_put(which, JVM_CONSTANT_Integer); 273206083Srdivacky *int_at_addr(which) = i; 274206083Srdivacky } 275206083Srdivacky 276206083Srdivacky void long_at_put(int which, jlong l) { 277193323Sed tag_at_put(which, JVM_CONSTANT_Long); 278193323Sed // *long_at_addr(which) = l; 279206083Srdivacky Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l)); 280206083Srdivacky } 281206083Srdivacky 282206083Srdivacky void float_at_put(int which, jfloat f) { 283206083Srdivacky tag_at_put(which, JVM_CONSTANT_Float); 284206083Srdivacky *float_at_addr(which) = f; 285193323Sed } 286206083Srdivacky 287206083Srdivacky void double_at_put(int which, jdouble d) { 288206083Srdivacky tag_at_put(which, JVM_CONSTANT_Double); 289206083Srdivacky // *double_at_addr(which) = d; 290206083Srdivacky // u8 temp = *(u8*) &d; 291206083Srdivacky Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d)); 292206083Srdivacky } 293206083Srdivacky 294206083Srdivacky Symbol** symbol_at_addr(int which) const { 295206083Srdivacky assert(is_within_bounds(which), "index out of bounds"); 296206083Srdivacky return (Symbol**) &base()[which]; 297206083Srdivacky } 298206083Srdivacky 299206083Srdivacky void symbol_at_put(int which, Symbol* s) { 300206083Srdivacky assert(s->refcount() != 0, "should have nonzero refcount"); 301193323Sed tag_at_put(which, JVM_CONSTANT_Utf8); 302193323Sed *symbol_at_addr(which) = s; 303206083Srdivacky } 304206083Srdivacky 305206083Srdivacky void string_at_put(int which, int obj_index, oop str) { 306206083Srdivacky resolved_references()->obj_at_put(obj_index, str); 307206083Srdivacky } 308206083Srdivacky 309206083Srdivacky // For temporary use while constructing constant pool 310206083Srdivacky void string_index_at_put(int which, int string_index) { 311206083Srdivacky tag_at_put(which, JVM_CONSTANT_StringIndex); 312206083Srdivacky *int_at_addr(which) = string_index; 313193323Sed } 314206083Srdivacky 315206083Srdivacky void field_at_put(int which, int class_index, int name_and_type_index) { 316206083Srdivacky tag_at_put(which, JVM_CONSTANT_Fieldref); 317206083Srdivacky *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; 318206083Srdivacky } 319206083Srdivacky 320206083Srdivacky void method_at_put(int which, int class_index, int name_and_type_index) { 321206083Srdivacky tag_at_put(which, JVM_CONSTANT_Methodref); 322206083Srdivacky *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; 323206083Srdivacky } 324206083Srdivacky 325206083Srdivacky void interface_method_at_put(int which, int class_index, int name_and_type_index) { 326206083Srdivacky tag_at_put(which, JVM_CONSTANT_InterfaceMethodref); 327206083Srdivacky *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice 328206083Srdivacky } 329206083Srdivacky 330206083Srdivacky void name_and_type_at_put(int which, int name_index, int signature_index) { 331206083Srdivacky tag_at_put(which, JVM_CONSTANT_NameAndType); 332206083Srdivacky *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice 333234353Sdim } 334234353Sdim 335234353Sdim // Tag query 336206083Srdivacky 337206083Srdivacky constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); } 338206083Srdivacky 339206083Srdivacky // Fetching constants 340206083Srdivacky 341206083Srdivacky Klass* klass_at(int which, TRAPS) { 342206083Srdivacky constantPoolHandle h_this(THREAD, this); 343206083Srdivacky return klass_at_impl(h_this, which, true, THREAD); 344206083Srdivacky } 345206083Srdivacky 346206083Srdivacky // Version of klass_at that doesn't save the resolution error, called during deopt 347206083Srdivacky Klass* klass_at_ignore_error(int which, TRAPS) { 348206083Srdivacky constantPoolHandle h_this(THREAD, this); 349206083Srdivacky return klass_at_impl(h_this, which, false, THREAD); 350206083Srdivacky } 351206083Srdivacky 352206083Srdivacky Symbol* klass_name_at(int which); // Returns the name, w/o resolving. 353206083Srdivacky 354206083Srdivacky Klass* resolved_klass_at(int which) const { // Used by Compiler 355206083Srdivacky guarantee(tag_at(which).is_klass(), "Corrupted constant pool"); 356206083Srdivacky // Must do an acquire here in case another thread resolved the klass 357206083Srdivacky // behind our back, lest we later load stale values thru the oop. 358206083Srdivacky return CPSlot((Klass*)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_klass(); 359206083Srdivacky } 360206083Srdivacky 361193323Sed // RedefineClasses() API support: 362193323Sed Symbol* klass_at_noresolve(int which) { return klass_name_at(which); } 363206083Srdivacky 364206083Srdivacky jint int_at(int which) { 365198090Srdivacky assert(tag_at(which).is_int(), "Corrupted constant pool"); 366193323Sed return *int_at_addr(which); 367206083Srdivacky } 368206083Srdivacky 369206083Srdivacky jlong long_at(int which) { 370206083Srdivacky assert(tag_at(which).is_long(), "Corrupted constant pool"); 371206083Srdivacky // return *long_at_addr(which); 372206083Srdivacky u8 tmp = Bytes::get_native_u8((address)&base()[which]); 373206083Srdivacky return *((jlong*)&tmp); 374206083Srdivacky } 375206083Srdivacky 376206083Srdivacky jfloat float_at(int which) { 377193323Sed assert(tag_at(which).is_float(), "Corrupted constant pool"); 378206083Srdivacky return *float_at_addr(which); 379206083Srdivacky } 380206083Srdivacky 381193323Sed jdouble double_at(int which) { 382193323Sed assert(tag_at(which).is_double(), "Corrupted constant pool"); 383206083Srdivacky u8 tmp = Bytes::get_native_u8((address)&base()[which]); 384206083Srdivacky return *((jdouble*)&tmp); 385198090Srdivacky } 386195098Sed 387206083Srdivacky Symbol* symbol_at(int which) { 388206083Srdivacky assert(tag_at(which).is_utf8(), "Corrupted constant pool"); 389195098Sed return *symbol_at_addr(which); 390 } 391 392 oop string_at(int which, int obj_index, TRAPS) { 393 constantPoolHandle h_this(THREAD, this); 394 return string_at_impl(h_this, which, obj_index, THREAD); 395 } 396 oop string_at(int which, TRAPS) { 397 int obj_index = cp_to_object_index(which); 398 return string_at(which, obj_index, THREAD); 399 } 400 401 // Version that can be used before string oop array is created. 402 oop uncached_string_at(int which, TRAPS); 403 404 // A "pseudo-string" is an non-string oop that has found its way into 405 // a String entry. 406 // This can happen if the user patches a live 407 // object into a CONSTANT_String entry of an anonymous class. 408 // Method oops internally created for method handles may also 409 // use pseudo-strings to link themselves to related metaobjects. 410 411 bool is_pseudo_string_at(int which) { 412 assert(tag_at(which).is_string(), "Corrupted constant pool"); 413 return slot_at(which).is_pseudo_string(); 414 } 415 416 oop pseudo_string_at(int which, int obj_index) { 417 assert(is_pseudo_string_at(which), "must be a pseudo-string"); 418 oop s = resolved_references()->obj_at(obj_index); 419 return s; 420 } 421 422 oop pseudo_string_at(int which) { 423 assert(is_pseudo_string_at(which), "must be a pseudo-string"); 424 int obj_index = cp_to_object_index(which); 425 oop s = resolved_references()->obj_at(obj_index); 426 return s; 427 } 428 429 void pseudo_string_at_put(int which, int obj_index, oop x) { 430 assert(tag_at(which).is_string(), "Corrupted constant pool"); 431 Symbol* sym = unresolved_string_at(which); 432 slot_at_put(which, CPSlot(sym, (CPSlot::_symbol_bit | CPSlot::_pseudo_bit))); 433 string_at_put(which, obj_index, x); // this works just fine 434 } 435 436 // only called when we are sure a string entry is already resolved (via an 437 // earlier string_at call. 438 oop resolved_string_at(int which) { 439 assert(tag_at(which).is_string(), "Corrupted constant pool"); 440 // Must do an acquire here in case another thread resolved the klass 441 // behind our back, lest we later load stale values thru the oop. 442 // we might want a volatile_obj_at in ObjArrayKlass. 443 int obj_index = cp_to_object_index(which); 444 return resolved_references()->obj_at(obj_index); 445 } 446 447 Symbol* unresolved_string_at(int which) { 448 assert(tag_at(which).is_string(), "Corrupted constant pool"); 449 Symbol* sym = slot_at(which).get_symbol(); 450 return sym; 451 } 452 453 // Returns an UTF8 for a CONSTANT_String entry at a given index. 454 // UTF8 char* representation was chosen to avoid conversion of 455 // java_lang_Strings at resolved entries into Symbol*s 456 // or vice versa. 457 char* string_at_noresolve(int which); 458 459 jint name_and_type_at(int which) { 460 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool"); 461 return *int_at_addr(which); 462 } 463 464 private: 465 int method_handle_ref_kind_at(int which, bool error_ok) { 466 assert(tag_at(which).is_method_handle() || 467 (error_ok && tag_at(which).is_method_handle_in_error()), "Corrupted constant pool"); 468 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits 469 } 470 int method_handle_index_at(int which, bool error_ok) { 471 assert(tag_at(which).is_method_handle() || 472 (error_ok && tag_at(which).is_method_handle_in_error()), "Corrupted constant pool"); 473 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits 474 } 475 int method_type_index_at(int which, bool error_ok) { 476 assert(tag_at(which).is_method_type() || 477 (error_ok && tag_at(which).is_method_type_in_error()), "Corrupted constant pool"); 478 return *int_at_addr(which); 479 } 480 public: 481 int method_handle_ref_kind_at(int which) { 482 return method_handle_ref_kind_at(which, false); 483 } 484 int method_handle_ref_kind_at_error_ok(int which) { 485 return method_handle_ref_kind_at(which, true); 486 } 487 int method_handle_index_at(int which) { 488 return method_handle_index_at(which, false); 489 } 490 int method_handle_index_at_error_ok(int which) { 491 return method_handle_index_at(which, true); 492 } 493 int method_type_index_at(int which) { 494 return method_type_index_at(which, false); 495 } 496 int method_type_index_at_error_ok(int which) { 497 return method_type_index_at(which, true); 498 } 499 500 // Derived queries: 501 Symbol* method_handle_name_ref_at(int which) { 502 int member = method_handle_index_at(which); 503 return impl_name_ref_at(member, true); 504 } 505 Symbol* method_handle_signature_ref_at(int which) { 506 int member = method_handle_index_at(which); 507 return impl_signature_ref_at(member, true); 508 } 509 int method_handle_klass_index_at(int which) { 510 int member = method_handle_index_at(which); 511 return impl_klass_ref_index_at(member, true); 512 } 513 Symbol* method_type_signature_at(int which) { 514 int sym = method_type_index_at(which); 515 return symbol_at(sym); 516 } 517 518 int invoke_dynamic_name_and_type_ref_index_at(int which) { 519 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 520 return extract_high_short_from_int(*int_at_addr(which)); 521 } 522 int invoke_dynamic_bootstrap_specifier_index(int which) { 523 assert(tag_at(which).value() == JVM_CONSTANT_InvokeDynamic, "Corrupted constant pool"); 524 return extract_low_short_from_int(*int_at_addr(which)); 525 } 526 int invoke_dynamic_operand_base(int which) { 527 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which); 528 return operand_offset_at(operands(), bootstrap_specifier_index); 529 } 530 // The first part of the operands array consists of an index into the second part. 531 // Extract a 32-bit index value from the first part. 532 static int operand_offset_at(Array<u2>* operands, int bootstrap_specifier_index) { 533 int n = (bootstrap_specifier_index * 2); 534 assert(n >= 0 && n+2 <= operands->length(), "oob"); 535 // The first 32-bit index points to the beginning of the second part 536 // of the operands array. Make sure this index is in the first part. 537 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0), 538 operands->at(1))); 539 assert(second_part == 0 || n+2 <= second_part, "oob (2)"); 540 int offset = build_int_from_shorts(operands->at(n+0), 541 operands->at(n+1)); 542 // The offset itself must point into the second part of the array. 543 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)"); 544 return offset; 545 } 546 static void operand_offset_at_put(Array<u2>* operands, int bootstrap_specifier_index, int offset) { 547 int n = bootstrap_specifier_index * 2; 548 assert(n >= 0 && n+2 <= operands->length(), "oob"); 549 operands->at_put(n+0, extract_low_short_from_int(offset)); 550 operands->at_put(n+1, extract_high_short_from_int(offset)); 551 } 552 static int operand_array_length(Array<u2>* operands) { 553 if (operands == NULL || operands->length() == 0) return 0; 554 int second_part = operand_offset_at(operands, 0); 555 return (second_part / 2); 556 } 557 558#ifdef ASSERT 559 // operand tuples fit together exactly, end to end 560 static int operand_limit_at(Array<u2>* operands, int bootstrap_specifier_index) { 561 int nextidx = bootstrap_specifier_index + 1; 562 if (nextidx == operand_array_length(operands)) 563 return operands->length(); 564 else 565 return operand_offset_at(operands, nextidx); 566 } 567 int invoke_dynamic_operand_limit(int which) { 568 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which); 569 return operand_limit_at(operands(), bootstrap_specifier_index); 570 } 571#endif //ASSERT 572 573 // layout of InvokeDynamic bootstrap method specifier (in second part of operands array): 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 bootstrap_specifier_index) { 583 assert(0 <= bootstrap_specifier_index && 584 bootstrap_specifier_index < operand_array_length(operands()), 585 "Corrupted CP operands"); 586 return operand_offset_at(operands(), bootstrap_specifier_index); 587 } 588 int operand_bootstrap_method_ref_index_at(int bootstrap_specifier_index) { 589 int offset = operand_offset_at(bootstrap_specifier_index); 590 return operands()->at(offset + _indy_bsm_offset); 591 } 592 int operand_argument_count_at(int bootstrap_specifier_index) { 593 int offset = operand_offset_at(bootstrap_specifier_index); 594 int argc = operands()->at(offset + _indy_argc_offset); 595 return argc; 596 } 597 int operand_argument_index_at(int bootstrap_specifier_index, int j) { 598 int offset = operand_offset_at(bootstrap_specifier_index); 599 return operands()->at(offset + _indy_argv_offset + j); 600 } 601 int operand_next_offset_at(int bootstrap_specifier_index) { 602 int offset = operand_offset_at(bootstrap_specifier_index) + _indy_argv_offset 603 + operand_argument_count_at(bootstrap_specifier_index); 604 return offset; 605 } 606 // Compare a bootsrap specifier in the operands arrays 607 bool compare_operand_to(int bootstrap_specifier_index1, constantPoolHandle cp2, 608 int bootstrap_specifier_index2, TRAPS); 609 // Find a bootsrap specifier in the operands array 610 int find_matching_operand(int bootstrap_specifier_index, constantPoolHandle search_cp, 611 int operands_cur_len, TRAPS); 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(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); 618 619 620 int invoke_dynamic_bootstrap_method_ref_index_at(int which) { 621 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 622 int op_base = invoke_dynamic_operand_base(which); 623 return operands()->at(op_base + _indy_bsm_offset); 624 } 625 int invoke_dynamic_argument_count_at(int which) { 626 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool"); 627 int op_base = invoke_dynamic_operand_base(which); 628 int argc = operands()->at(op_base + _indy_argc_offset); 629 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc; 630 int next_offset = invoke_dynamic_operand_limit(which)); 631 assert(end_offset == next_offset, "matched ending"); 632 return argc; 633 } 634 int invoke_dynamic_argument_index_at(int which, int j) { 635 int op_base = invoke_dynamic_operand_base(which); 636 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset)); 637 assert((uint)j < (uint)argc, "oob"); 638 return operands()->at(op_base + _indy_argv_offset + j); 639 } 640 641 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve, 642 // name_and_type_ref_index_at) all expect to be passed indices obtained 643 // directly from the bytecode. 644 // If the indices are meant to refer to fields or methods, they are 645 // actually rewritten constant pool cache indices. 646 // The routine remap_instruction_operand_from_cache 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 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear. 652 // In a few cases (the verifier) there are uses before a cpcache has been built, 653 // which are handled by a dynamic check in remap_instruction_operand_from_cache. 654 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode. 655 656 // Lookup for entries consisting of (klass_index, name_and_type index) 657 Klass* klass_ref_at(int which, TRAPS); 658 Symbol* klass_ref_at_noresolve(int which); 659 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); } 660 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); } 661 662 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); } 663 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); } 664 665 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG 666 667 // Lookup for entries consisting of (name_index, signature_index) 668 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt) 669 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt) 670 671 BasicType basic_type_for_signature_at(int which); 672 673 // Resolve string constants (to prevent allocation during compilation) 674 void resolve_string_constants(TRAPS) { 675 constantPoolHandle h_this(THREAD, this); 676 resolve_string_constants_impl(h_this, CHECK); 677 } 678 679 // CDS support 680 void remove_unshareable_info(); 681 void restore_unshareable_info(TRAPS); 682 bool resolve_class_constants(TRAPS); 683 // The ConstantPool vtable is restored by this call when the ConstantPool is 684 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for 685 // all the gory details. SA, dtrace and pstack helpers distinguish metadata 686 // by their vtable. 687 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); } 688 689 private: 690 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 }; 691 public: 692 693 // Resolve late bound constants. 694 oop resolve_constant_at(int index, TRAPS) { 695 constantPoolHandle h_this(THREAD, this); 696 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD); 697 } 698 699 oop resolve_cached_constant_at(int cache_index, TRAPS) { 700 constantPoolHandle h_this(THREAD, this); 701 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD); 702 } 703 704 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) { 705 constantPoolHandle h_this(THREAD, this); 706 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD); 707 } 708 709 oop resolve_bootstrap_specifier_at(int index, TRAPS) { 710 constantPoolHandle h_this(THREAD, this); 711 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD); 712 } 713 714 // Klass name matches name at offset 715 bool klass_name_at_matches(instanceKlassHandle k, int which); 716 717 // Sizing 718 int length() const { return _length; } 719 void set_length(int length) { _length = length; } 720 721 // Tells whether index is within bounds. 722 bool is_within_bounds(int index) const { 723 return 0 <= index && index < length(); 724 } 725 726 // Sizing (in words) 727 static int header_size() { return sizeof(ConstantPool)/HeapWordSize; } 728 static int size(int length) { return align_object_size(header_size() + length); } 729 int size() const { return size(length()); } 730#if INCLUDE_SERVICES 731 void collect_statistics(KlassSizeStats *sz) const; 732#endif 733 734 friend class ClassFileParser; 735 friend class SystemDictionary; 736 737 // Used by compiler to prevent classloading. 738 static Method* method_at_if_loaded (constantPoolHandle this_cp, int which); 739 static bool has_appendix_at_if_loaded (constantPoolHandle this_cp, int which); 740 static oop appendix_at_if_loaded (constantPoolHandle this_cp, int which); 741 static bool has_method_type_at_if_loaded (constantPoolHandle this_cp, int which); 742 static oop method_type_at_if_loaded (constantPoolHandle this_cp, int which); 743 static Klass* klass_at_if_loaded (constantPoolHandle this_cp, int which); 744 static Klass* klass_ref_at_if_loaded (constantPoolHandle this_cp, int which); 745 746 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the 747 // future by other Java code. These take constant pool indices rather than 748 // constant pool cache indices as do the peer methods above. 749 Symbol* uncached_klass_ref_at_noresolve(int which); 750 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); } 751 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); } 752 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); } 753 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); } 754 755 // Sharing 756 int pre_resolve_shared_klasses(TRAPS); 757 758 // Debugging 759 const char* printable_name_at(int which) PRODUCT_RETURN0; 760 761#ifdef ASSERT 762 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices 763#else 764 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op 765#endif //ASSERT 766 767 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) { 768 if (invokedynamic_ok && is_invokedynamic_index(raw_index)) 769 return decode_invokedynamic_index(raw_index); 770 else 771 return raw_index - CPCACHE_INDEX_TAG; 772 } 773 774 private: 775 776 void set_resolved_references(jobject s) { _resolved_references = s; } 777 Array<u2>* reference_map() const { return _reference_map; } 778 void set_reference_map(Array<u2>* o) { _reference_map = o; } 779 780 // patch JSR 292 resolved references after the class is linked. 781 void patch_resolved_references(GrowableArray<Handle>* cp_patches); 782 783 Symbol* impl_name_ref_at(int which, bool uncached); 784 Symbol* impl_signature_ref_at(int which, bool uncached); 785 int impl_klass_ref_index_at(int which, bool uncached); 786 int impl_name_and_type_ref_index_at(int which, bool uncached); 787 788 // Used while constructing constant pool (only by ClassFileParser) 789 jint klass_index_at(int which) { 790 assert(tag_at(which).is_klass_index(), "Corrupted constant pool"); 791 return *int_at_addr(which); 792 } 793 794 jint string_index_at(int which) { 795 assert(tag_at(which).is_string_index(), "Corrupted constant pool"); 796 return *int_at_addr(which); 797 } 798 799 // Performs the LinkResolver checks 800 static void verify_constant_pool_resolve(constantPoolHandle this_cp, KlassHandle klass, TRAPS); 801 802 // Implementation of methods that needs an exposed 'this' pointer, in order to 803 // handle GC while executing the method 804 static Klass* klass_at_impl(constantPoolHandle this_cp, int which, 805 bool save_resolution_error, TRAPS); 806 static oop string_at_impl(constantPoolHandle this_cp, int which, int obj_index, TRAPS); 807 808 static void trace_class_resolution(constantPoolHandle this_cp, KlassHandle k); 809 810 // Resolve string constants (to prevent allocation during compilation) 811 static void resolve_string_constants_impl(constantPoolHandle this_cp, TRAPS); 812 813 static oop resolve_constant_at_impl(constantPoolHandle this_cp, int index, int cache_index, TRAPS); 814 static oop resolve_bootstrap_specifier_at_impl(constantPoolHandle this_cp, int index, TRAPS); 815 816 // Exception handling 817 static void throw_resolution_error(constantPoolHandle this_cp, int which, TRAPS); 818 static Symbol* exception_message(constantPoolHandle this_cp, int which, constantTag tag, oop pending_exception); 819 static void save_and_throw_exception(constantPoolHandle this_cp, int which, constantTag tag, TRAPS); 820 821 public: 822 // Merging ConstantPool* support: 823 bool compare_entry_to(int index1, constantPoolHandle cp2, int index2, TRAPS); 824 void copy_cp_to(int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS) { 825 constantPoolHandle h_this(THREAD, this); 826 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD); 827 } 828 static void copy_cp_to_impl(constantPoolHandle from_cp, int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS); 829 static void copy_entry_to(constantPoolHandle from_cp, int from_i, constantPoolHandle to_cp, int to_i, TRAPS); 830 static void copy_operands(constantPoolHandle from_cp, constantPoolHandle to_cp, TRAPS); 831 int find_matching_entry(int pattern_i, constantPoolHandle search_cp, TRAPS); 832 int version() const { return _saved._version; } 833 void set_version(int version) { _saved._version = version; } 834 void increment_and_save_version(int version) { 835 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow 836 } 837 838 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; } 839 int resolved_reference_length() const { return _saved._resolved_reference_length; } 840 841 // Decrease ref counts of symbols that are in the constant pool 842 // when the holder class is unloaded 843 void unreference_symbols(); 844 845 // Deallocate constant pool for RedefineClasses 846 void deallocate_contents(ClassLoaderData* loader_data); 847 void release_C_heap_structures(); 848 849 // JVMTI accesss - GetConstantPool, RetransformClasses, ... 850 friend class JvmtiConstantPoolReconstituter; 851 852 private: 853 jint cpool_entry_size(jint idx); 854 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap); 855 856 // Copy cpool bytes into byte array. 857 // Returns: 858 // int > 0, count of the raw cpool bytes that have been copied 859 // 0, OutOfMemory error 860 // -1, Internal error 861 int copy_cpool_bytes(int cpool_size, 862 SymbolHashMap* tbl, 863 unsigned char *bytes); 864 865 public: 866 // Verify 867 void verify_on(outputStream* st); 868 869 // Printing 870 void print_on(outputStream* st) const; 871 void print_value_on(outputStream* st) const; 872 void print_entry_on(int index, outputStream* st); 873 874 const char* internal_name() const { return "{constant pool}"; } 875 876#ifndef PRODUCT 877 // Compile the world support 878 static void preload_and_initialize_all_classes(ConstantPool* constant_pool, TRAPS); 879#endif 880}; 881 882class SymbolHashMapEntry : public CHeapObj<mtSymbol> { 883 private: 884 unsigned int _hash; // 32-bit hash for item 885 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket 886 Symbol* _symbol; // 1-st part of the mapping: symbol => value 887 u2 _value; // 2-nd part of the mapping: symbol => value 888 889 public: 890 unsigned int hash() const { return _hash; } 891 void set_hash(unsigned int hash) { _hash = hash; } 892 893 SymbolHashMapEntry* next() const { return _next; } 894 void set_next(SymbolHashMapEntry* next) { _next = next; } 895 896 Symbol* symbol() const { return _symbol; } 897 void set_symbol(Symbol* sym) { _symbol = sym; } 898 899 u2 value() const { return _value; } 900 void set_value(u2 value) { _value = value; } 901 902 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value) 903 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {} 904 905}; // End SymbolHashMapEntry class 906 907 908class SymbolHashMapBucket : public CHeapObj<mtSymbol> { 909 910private: 911 SymbolHashMapEntry* _entry; 912 913public: 914 SymbolHashMapEntry* entry() const { return _entry; } 915 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; } 916 void clear() { _entry = NULL; } 917 918}; // End SymbolHashMapBucket class 919 920 921class SymbolHashMap: public CHeapObj<mtSymbol> { 922 923 private: 924 // Default number of entries in the table 925 enum SymbolHashMap_Constants { 926 _Def_HashMap_Size = 256 927 }; 928 929 int _table_size; 930 SymbolHashMapBucket* _buckets; 931 932 void initialize_table(int table_size) { 933 _table_size = table_size; 934 _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size, mtSymbol); 935 for (int index = 0; index < table_size; index++) { 936 _buckets[index].clear(); 937 } 938 } 939 940 public: 941 942 int table_size() const { return _table_size; } 943 944 SymbolHashMap() { initialize_table(_Def_HashMap_Size); } 945 SymbolHashMap(int table_size) { initialize_table(table_size); } 946 947 // hash P(31) from Kernighan & Ritchie 948 static unsigned int compute_hash(const char* str, int len) { 949 unsigned int hash = 0; 950 while (len-- > 0) { 951 hash = 31*hash + (unsigned) *str; 952 str++; 953 } 954 return hash; 955 } 956 957 SymbolHashMapEntry* bucket(int i) { 958 return _buckets[i].entry(); 959 } 960 961 void add_entry(Symbol* sym, u2 value); 962 SymbolHashMapEntry* find_entry(Symbol* sym); 963 964 u2 symbol_to_value(Symbol* sym) { 965 SymbolHashMapEntry *entry = find_entry(sym); 966 return (entry == NULL) ? 0 : entry->value(); 967 } 968 969 ~SymbolHashMap() { 970 SymbolHashMapEntry* next; 971 for (int i = 0; i < _table_size; i++) { 972 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) { 973 next = cur->next(); 974 delete(cur); 975 } 976 } 977 delete _buckets; 978 } 979}; // End SymbolHashMap class 980 981#endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP 982