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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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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 class KlassSizeStats;
66
67 class ConstantPool : public Metadata {
68 friend class VMStructs;
69 friend class JVMCIVMStructs;
70 friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast
71 friend class Universe; // For null constructor
72 private:
73 Array<u1>* _tags; // the tag array describing the constant pool's contents
74 ConstantPoolCache* _cache; // the cache holding interpreter runtime information
75 InstanceKlass* _pool_holder; // the corresponding class
76 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
77
78 // ... will be changed to support compressed pointers
79 Array<Klass*>* _resolved_klasses;
80
81 enum {
82 _has_preresolution = 1, // Flags
83 _on_stack = 2,
84 _is_shared_quick = 4
85 };
86 enum {
87 _invalid_resolved_klass_index = 0xffff
88 };
89
90 int _flags; // old fashioned bit twiddling
91 int _length; // number of elements in the array
92
93 union {
94 // set for CDS to restore resolved references
95 int _resolved_reference_length;
96 // keeps version number for redefined classes (used in backtrace)
97 int _version;
98 } _saved;
99
100 void set_tags(Array<u1>* tags) { _tags = tags; }
101 void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); }
102 void release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); }
103
104 u1* tag_addr_at(int which) const { return tags()->adr_at(which); }
105
106 void set_operands(Array<u2>* operands) { _operands = operands; }
107
108 int flags() const { return _flags; }
109 void set_flags(int f) { _flags = f; }
110
111 private:
112 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); }
113
114 CPSlot slot_at(int which) const {
115 assert(is_within_bounds(which), "index out of bounds");
116 assert(!tag_at(which).is_unresolved_klass() && !tag_at(which).is_unresolved_klass_in_error(), "Corrupted constant pool");
117 // Uses volatile because the klass slot changes without a lock.
118 volatile intptr_t adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which));
119 assert(adr != 0 || which == 0, "cp entry for klass should not be zero");
120 return CPSlot(adr);
121 }
122
123 void slot_at_put(int which, CPSlot s) const {
124 assert(is_within_bounds(which), "index out of bounds");
125 assert(s.value() != 0, "Caught something");
126 *(intptr_t*)&base()[which] = s.value();
127 }
128 intptr_t* obj_at_addr_raw(int which) const {
129 assert(is_within_bounds(which), "index out of bounds");
130 return (intptr_t*) &base()[which];
131 }
132
133 jint* int_at_addr(int which) const {
134 assert(is_within_bounds(which), "index out of bounds");
135 return (jint*) &base()[which];
136 }
137
138 jlong* long_at_addr(int which) const {
139 assert(is_within_bounds(which), "index out of bounds");
140 return (jlong*) &base()[which];
141 }
142
143 jfloat* float_at_addr(int which) const {
144 assert(is_within_bounds(which), "index out of bounds");
145 return (jfloat*) &base()[which];
146 }
147
148 jdouble* double_at_addr(int which) const {
149 assert(is_within_bounds(which), "index out of bounds");
150 return (jdouble*) &base()[which];
151 }
152
153 ConstantPool(Array<u1>* tags);
154 ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
155 public:
156 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS);
157
158 bool is_constantPool() const volatile { return true; }
159
160 Array<u1>* tags() const { return _tags; }
161 Array<u2>* operands() const { return _operands; }
162
163 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; }
164 void set_has_preresolution() {
165 assert(!is_shared_quick(), "should never be called on shared ConstantPools");
166 _flags |= _has_preresolution;
167 }
168
169 // Redefine classes support. If a method refering to this constant pool
170 // is on the executing stack, or as a handle in vm code, this constant pool
171 // can't be removed from the set of previous versions saved in the instance
172 // class.
173 bool on_stack() const { return (_flags &_on_stack) != 0; }
174 void set_on_stack(const bool value);
175
176 // Faster than MetaspaceObj::is_shared() - used by set_on_stack()
177 bool is_shared_quick() const { return (_flags & _is_shared_quick) != 0; }
178 void set_is_shared_quick() { _flags |= _is_shared_quick; }
179
180 // Klass holding pool
181 InstanceKlass* pool_holder() const { return _pool_holder; }
182 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; }
183 InstanceKlass** pool_holder_addr() { return &_pool_holder; }
184
185 // Interpreter runtime support
186 ConstantPoolCache* cache() const { return _cache; }
187 void set_cache(ConstantPoolCache* cache){ _cache = cache; }
188
189 // Create object cache in the constant pool
190 void initialize_resolved_references(ClassLoaderData* loader_data,
191 const intStack& reference_map,
192 int constant_pool_map_length,
193 TRAPS);
194
195 // resolved strings, methodHandles and callsite objects from the constant pool
196 objArrayOop resolved_references() const;
197 // mapping resolved object array indexes to cp indexes and back.
198 int object_to_cp_index(int index) { return reference_map()->at(index); }
199 int cp_to_object_index(int index);
200
201 void set_resolved_klasses(Array<Klass*>* rk) { _resolved_klasses = rk; }
202 Array<Klass*>* resolved_klasses() const { return _resolved_klasses; }
203 void allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS);
204 void initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS);
205
206 // Invokedynamic indexes.
207 // They must look completely different from normal indexes.
208 // The main reason is that byte swapping is sometimes done on normal indexes.
209 // Finally, it is helpful for debugging to tell the two apart.
210 static bool is_invokedynamic_index(int i) { return (i < 0); }
211 static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; }
212 static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; }
213
214
215 // The invokedynamic points at a CP cache entry. This entry points back
216 // at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry
217 // in the resolved_references array (which provides the appendix argument).
218 int invokedynamic_cp_cache_index(int index) const {
219 assert (is_invokedynamic_index(index), "should be a invokedynamic index");
220 int cache_index = decode_invokedynamic_index(index);
221 return cache_index;
222 }
223 ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int index) const {
224 // decode index that invokedynamic points to.
225 int cp_cache_index = invokedynamic_cp_cache_index(index);
226 return cache()->entry_at(cp_cache_index);
227 }
228
229 // Assembly code support
230 static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); }
231 static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); }
232 static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); }
233 static int resolved_klasses_offset_in_bytes() { return offset_of(ConstantPool, _resolved_klasses); }
234
235 // Storing constants
236
237 // For temporary use while constructing constant pool
238 void klass_index_at_put(int which, int name_index) {
239 tag_at_put(which, JVM_CONSTANT_ClassIndex);
240 *int_at_addr(which) = name_index;
241 }
242
243 void klass_at_put(int class_index, int name_index, int resolved_klass_index, Klass* k, Symbol* name);
244
245 void unresolved_klass_at_put(int which, int name_index, int resolved_klass_index) {
246 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
247
248 assert((name_index & 0xffff0000) == 0, "must be");
249 assert((resolved_klass_index & 0xffff0000) == 0, "must be");
250 *int_at_addr(which) =
251 build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
252 }
253
254 void temp_unresolved_klass_at_put(int which, int name_index) {
255 unresolved_klass_at_put(which, name_index, _invalid_resolved_klass_index);
256 }
257
258 void method_handle_index_at_put(int which, int ref_kind, int ref_index) {
259 tag_at_put(which, JVM_CONSTANT_MethodHandle);
260 *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind;
261 }
262
263 void method_type_index_at_put(int which, int ref_index) {
264 tag_at_put(which, JVM_CONSTANT_MethodType);
265 *int_at_addr(which) = ref_index;
266 }
267
268 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
269 tag_at_put(which, JVM_CONSTANT_InvokeDynamic);
270 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
271 }
272
273 void unresolved_string_at_put(int which, Symbol* s) {
274 release_tag_at_put(which, JVM_CONSTANT_String);
275 slot_at_put(which, CPSlot(s));
276 }
277
278 void int_at_put(int which, jint i) {
279 tag_at_put(which, JVM_CONSTANT_Integer);
280 *int_at_addr(which) = i;
281 }
282
283 void long_at_put(int which, jlong l) {
284 tag_at_put(which, JVM_CONSTANT_Long);
285 // *long_at_addr(which) = l;
286 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
287 }
288
289 void float_at_put(int which, jfloat f) {
290 tag_at_put(which, JVM_CONSTANT_Float);
291 *float_at_addr(which) = f;
292 }
293
294 void double_at_put(int which, jdouble d) {
295 tag_at_put(which, JVM_CONSTANT_Double);
296 // *double_at_addr(which) = d;
297 // u8 temp = *(u8*) &d;
298 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
299 }
300
301 Symbol** symbol_at_addr(int which) const {
302 assert(is_within_bounds(which), "index out of bounds");
303 return (Symbol**) &base()[which];
304 }
305
306 void symbol_at_put(int which, Symbol* s) {
307 assert(s->refcount() != 0, "should have nonzero refcount");
308 tag_at_put(which, JVM_CONSTANT_Utf8);
309 *symbol_at_addr(which) = s;
310 }
311
312 void string_at_put(int which, int obj_index, oop str);
313
314 // For temporary use while constructing constant pool
315 void string_index_at_put(int which, int string_index) {
316 tag_at_put(which, JVM_CONSTANT_StringIndex);
317 *int_at_addr(which) = string_index;
318 }
319
320 void field_at_put(int which, int class_index, int name_and_type_index) {
321 tag_at_put(which, JVM_CONSTANT_Fieldref);
322 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
323 }
324
325 void method_at_put(int which, int class_index, int name_and_type_index) {
326 tag_at_put(which, JVM_CONSTANT_Methodref);
327 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
328 }
329
330 void interface_method_at_put(int which, int class_index, int name_and_type_index) {
331 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
332 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
333 }
334
335 void name_and_type_at_put(int which, int name_index, int signature_index) {
336 tag_at_put(which, JVM_CONSTANT_NameAndType);
337 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
338 }
339
340 // Tag query
341
342 constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); }
343
344 // Fetching constants
345
346 Klass* klass_at(int which, TRAPS) {
347 constantPoolHandle h_this(THREAD, this);
348 return klass_at_impl(h_this, which, true, THREAD);
349 }
350
351 // Version of klass_at that doesn't save the resolution error, called during deopt
352 Klass* klass_at_ignore_error(int which, TRAPS) {
353 constantPoolHandle h_this(THREAD, this);
354 return klass_at_impl(h_this, which, false, THREAD);
355 }
356
357 Symbol* klass_name_at(int which) const; // Returns the name, w/o resolving.
358 int klass_name_index_at(int which) const;
359
360 Klass* resolved_klass_at(int which) const { // Used by Compiler
361 guarantee(tag_at(which).is_klass(), "Corrupted constant pool");
362 // Must do an acquire here in case another thread resolved the klass
363 // behind our back, lest we later load stale values thru the oop.
364 int value = *int_at_addr(which);
365 int resolved_klass_index = extract_low_short_from_int(value);
366 int name_index = extract_high_short_from_int(value);
367 assert(tag_at(name_index).is_symbol(), "sanity");
368
369 Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
370 return (Klass*)OrderAccess::load_ptr_acquire(adr);
371 }
372
373 // RedefineClasses() API support:
374 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); }
375
376 jint int_at(int which) {
377 assert(tag_at(which).is_int(), "Corrupted constant pool");
378 return *int_at_addr(which);
379 }
380
381 jlong long_at(int which) {
382 assert(tag_at(which).is_long(), "Corrupted constant pool");
383 // return *long_at_addr(which);
384 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
385 return *((jlong*)&tmp);
386 }
387
388 jfloat float_at(int which) {
389 assert(tag_at(which).is_float(), "Corrupted constant pool");
390 return *float_at_addr(which);
391 }
392
393 jdouble double_at(int which) {
394 assert(tag_at(which).is_double(), "Corrupted constant pool");
395 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
396 return *((jdouble*)&tmp);
397 }
398
399 Symbol* symbol_at(int which) const {
400 assert(tag_at(which).is_utf8(), "Corrupted constant pool");
401 return *symbol_at_addr(which);
402 }
403
404 oop string_at(int which, int obj_index, TRAPS) {
405 constantPoolHandle h_this(THREAD, this);
406 return string_at_impl(h_this, which, obj_index, THREAD);
407 }
408 oop string_at(int which, TRAPS) {
409 int obj_index = cp_to_object_index(which);
410 return string_at(which, obj_index, THREAD);
411 }
412
413 // Version that can be used before string oop array is created.
414 oop uncached_string_at(int which, TRAPS);
415
416 // A "pseudo-string" is an non-string oop that has found its way into
417 // a String entry.
418 // This can happen if the user patches a live
419 // object into a CONSTANT_String entry of an anonymous class.
420 // Method oops internally created for method handles may also
421 // use pseudo-strings to link themselves to related metaobjects.
422
423 bool is_pseudo_string_at(int which) {
424 assert(tag_at(which).is_string(), "Corrupted constant pool");
425 return slot_at(which).is_pseudo_string();
426 }
427
428 oop pseudo_string_at(int which, int obj_index) {
429 assert(is_pseudo_string_at(which), "must be a pseudo-string");
430 oop s = resolved_references()->obj_at(obj_index);
431 return s;
432 }
433
434 oop pseudo_string_at(int which) {
435 assert(is_pseudo_string_at(which), "must be a pseudo-string");
436 int obj_index = cp_to_object_index(which);
437 oop s = resolved_references()->obj_at(obj_index);
438 return s;
439 }
440
441 void pseudo_string_at_put(int which, int obj_index, oop x) {
442 assert(tag_at(which).is_string(), "Corrupted constant pool");
443 Symbol* sym = unresolved_string_at(which);
444 slot_at_put(which, CPSlot(sym, CPSlot::_pseudo_bit));
445 string_at_put(which, obj_index, x); // this works just fine
446 }
447
448 // only called when we are sure a string entry is already resolved (via an
449 // earlier string_at call.
450 oop resolved_string_at(int which) {
451 assert(tag_at(which).is_string(), "Corrupted constant pool");
452 // Must do an acquire here in case another thread resolved the klass
453 // behind our back, lest we later load stale values thru the oop.
454 // we might want a volatile_obj_at in ObjArrayKlass.
455 int obj_index = cp_to_object_index(which);
456 return resolved_references()->obj_at(obj_index);
457 }
458
459 Symbol* unresolved_string_at(int which) {
460 assert(tag_at(which).is_string(), "Corrupted constant pool");
461 Symbol* sym = slot_at(which).get_symbol();
462 return sym;
463 }
464
465 // Returns an UTF8 for a CONSTANT_String entry at a given index.
466 // UTF8 char* representation was chosen to avoid conversion of
467 // java_lang_Strings at resolved entries into Symbol*s
468 // or vice versa.
469 char* string_at_noresolve(int which);
470
471 jint name_and_type_at(int which) {
472 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
473 return *int_at_addr(which);
474 }
475
476 int method_handle_ref_kind_at(int which) {
477 assert(tag_at(which).is_method_handle() ||
478 tag_at(which).is_method_handle_in_error(), "Corrupted constant pool");
479 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits
480 }
481 int method_handle_index_at(int which) {
482 assert(tag_at(which).is_method_handle() ||
483 tag_at(which).is_method_handle_in_error(), "Corrupted constant pool");
484 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits
485 }
486 int method_type_index_at(int which) {
487 assert(tag_at(which).is_method_type() ||
488 tag_at(which).is_method_type_in_error(), "Corrupted constant pool");
489 return *int_at_addr(which);
490 }
491
492 // Derived queries:
493 Symbol* method_handle_name_ref_at(int which) {
494 int member = method_handle_index_at(which);
495 return impl_name_ref_at(member, true);
496 }
497 Symbol* method_handle_signature_ref_at(int which) {
498 int member = method_handle_index_at(which);
499 return impl_signature_ref_at(member, true);
500 }
501 int method_handle_klass_index_at(int which) {
502 int member = method_handle_index_at(which);
503 return impl_klass_ref_index_at(member, true);
504 }
505 Symbol* method_type_signature_at(int which) {
506 int sym = method_type_index_at(which);
507 return symbol_at(sym);
508 }
509
510 int invoke_dynamic_name_and_type_ref_index_at(int which) {
511 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
512 return extract_high_short_from_int(*int_at_addr(which));
513 }
514 int invoke_dynamic_bootstrap_specifier_index(int which) {
515 assert(tag_at(which).value() == JVM_CONSTANT_InvokeDynamic, "Corrupted constant pool");
516 return extract_low_short_from_int(*int_at_addr(which));
517 }
518 int invoke_dynamic_operand_base(int which) {
519 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
520 return operand_offset_at(operands(), bootstrap_specifier_index);
521 }
522 // The first part of the operands array consists of an index into the second part.
523 // Extract a 32-bit index value from the first part.
524 static int operand_offset_at(Array<u2>* operands, int bootstrap_specifier_index) {
525 int n = (bootstrap_specifier_index * 2);
526 assert(n >= 0 && n+2 <= operands->length(), "oob");
527 // The first 32-bit index points to the beginning of the second part
528 // of the operands array. Make sure this index is in the first part.
529 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0),
530 operands->at(1)));
531 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
532 int offset = build_int_from_shorts(operands->at(n+0),
533 operands->at(n+1));
534 // The offset itself must point into the second part of the array.
535 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)");
536 return offset;
537 }
538 static void operand_offset_at_put(Array<u2>* operands, int bootstrap_specifier_index, int offset) {
539 int n = bootstrap_specifier_index * 2;
540 assert(n >= 0 && n+2 <= operands->length(), "oob");
541 operands->at_put(n+0, extract_low_short_from_int(offset));
542 operands->at_put(n+1, extract_high_short_from_int(offset));
543 }
544 static int operand_array_length(Array<u2>* operands) {
545 if (operands == NULL || operands->length() == 0) return 0;
546 int second_part = operand_offset_at(operands, 0);
547 return (second_part / 2);
548 }
549
550 #ifdef ASSERT
551 // operand tuples fit together exactly, end to end
552 static int operand_limit_at(Array<u2>* operands, int bootstrap_specifier_index) {
553 int nextidx = bootstrap_specifier_index + 1;
554 if (nextidx == operand_array_length(operands))
555 return operands->length();
556 else
557 return operand_offset_at(operands, nextidx);
558 }
559 int invoke_dynamic_operand_limit(int which) {
560 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
561 return operand_limit_at(operands(), bootstrap_specifier_index);
562 }
563 #endif //ASSERT
564
565 // layout of InvokeDynamic bootstrap method specifier (in second part of operands array):
566 enum {
567 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
568 _indy_argc_offset = 1, // u2 argc
569 _indy_argv_offset = 2 // u2 argv[argc]
570 };
571
572 // These functions are used in RedefineClasses for CP merge
573
574 int operand_offset_at(int bootstrap_specifier_index) {
575 assert(0 <= bootstrap_specifier_index &&
576 bootstrap_specifier_index < operand_array_length(operands()),
577 "Corrupted CP operands");
578 return operand_offset_at(operands(), bootstrap_specifier_index);
579 }
580 int operand_bootstrap_method_ref_index_at(int bootstrap_specifier_index) {
581 int offset = operand_offset_at(bootstrap_specifier_index);
582 return operands()->at(offset + _indy_bsm_offset);
583 }
584 int operand_argument_count_at(int bootstrap_specifier_index) {
585 int offset = operand_offset_at(bootstrap_specifier_index);
586 int argc = operands()->at(offset + _indy_argc_offset);
587 return argc;
588 }
589 int operand_argument_index_at(int bootstrap_specifier_index, int j) {
590 int offset = operand_offset_at(bootstrap_specifier_index);
591 return operands()->at(offset + _indy_argv_offset + j);
592 }
593 int operand_next_offset_at(int bootstrap_specifier_index) {
594 int offset = operand_offset_at(bootstrap_specifier_index) + _indy_argv_offset
595 + operand_argument_count_at(bootstrap_specifier_index);
596 return offset;
597 }
598 // Compare a bootsrap specifier in the operands arrays
599 bool compare_operand_to(int bootstrap_specifier_index1, const constantPoolHandle& cp2,
600 int bootstrap_specifier_index2, TRAPS);
601 // Find a bootsrap specifier in the operands array
602 int find_matching_operand(int bootstrap_specifier_index, const constantPoolHandle& search_cp,
603 int operands_cur_len, TRAPS);
604 // Resize the operands array with delta_len and delta_size
605 void resize_operands(int delta_len, int delta_size, TRAPS);
606 // Extend the operands array with the length and size of the ext_cp operands
607 void extend_operands(const constantPoolHandle& ext_cp, TRAPS);
608 // Shrink the operands array to a smaller array with new_len length
609 void shrink_operands(int new_len, TRAPS);
610
611
612 int invoke_dynamic_bootstrap_method_ref_index_at(int which) {
613 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
614 int op_base = invoke_dynamic_operand_base(which);
615 return operands()->at(op_base + _indy_bsm_offset);
616 }
617 int invoke_dynamic_argument_count_at(int which) {
618 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
619 int op_base = invoke_dynamic_operand_base(which);
620 int argc = operands()->at(op_base + _indy_argc_offset);
621 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
622 int next_offset = invoke_dynamic_operand_limit(which));
623 assert(end_offset == next_offset, "matched ending");
624 return argc;
625 }
626 int invoke_dynamic_argument_index_at(int which, int j) {
627 int op_base = invoke_dynamic_operand_base(which);
628 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset));
629 assert((uint)j < (uint)argc, "oob");
630 return operands()->at(op_base + _indy_argv_offset + j);
631 }
632
633 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
634 // name_and_type_ref_index_at) all expect to be passed indices obtained
635 // directly from the bytecode.
636 // If the indices are meant to refer to fields or methods, they are
637 // actually rewritten constant pool cache indices.
638 // The routine remap_instruction_operand_from_cache manages the adjustment
639 // of these values back to constant pool indices.
640
641 // There are also "uncached" versions which do not adjust the operand index; see below.
642
643 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear.
644 // In a few cases (the verifier) there are uses before a cpcache has been built,
645 // which are handled by a dynamic check in remap_instruction_operand_from_cache.
646 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode.
647
648 // Lookup for entries consisting of (klass_index, name_and_type index)
649 Klass* klass_ref_at(int which, TRAPS);
650 Symbol* klass_ref_at_noresolve(int which);
651 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); }
652 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); }
653
654 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); }
655 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); }
656
657 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG
658
659 constantTag tag_ref_at(int cp_cache_index) { return impl_tag_ref_at(cp_cache_index, false); }
660
661 // Lookup for entries consisting of (name_index, signature_index)
662 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt)
663 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt)
664
665 BasicType basic_type_for_signature_at(int which) const;
666
667 // Resolve string constants (to prevent allocation during compilation)
668 void resolve_string_constants(TRAPS) {
669 constantPoolHandle h_this(THREAD, this);
670 resolve_string_constants_impl(h_this, CHECK);
671 }
672
673 // CDS support
674 void remove_unshareable_info();
675 void restore_unshareable_info(TRAPS);
676 bool resolve_class_constants(TRAPS);
677 // The ConstantPool vtable is restored by this call when the ConstantPool is
678 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for
679 // all the gory details. SA, dtrace and pstack helpers distinguish metadata
680 // by their vtable.
681 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); }
682
683 private:
684 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
685 public:
686
687 // Resolve late bound constants.
688 oop resolve_constant_at(int index, TRAPS) {
689 constantPoolHandle h_this(THREAD, this);
690 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD);
691 }
692
693 oop resolve_cached_constant_at(int cache_index, TRAPS) {
694 constantPoolHandle h_this(THREAD, this);
695 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD);
696 }
697
698 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) {
699 constantPoolHandle h_this(THREAD, this);
700 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD);
701 }
702
703 oop resolve_bootstrap_specifier_at(int index, TRAPS) {
704 constantPoolHandle h_this(THREAD, this);
705 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD);
706 }
707
708 // Klass name matches name at offset
709 bool klass_name_at_matches(const InstanceKlass* k, int which);
710
711 // Sizing
712 int length() const { return _length; }
713 void set_length(int length) { _length = length; }
714
715 // Tells whether index is within bounds.
716 bool is_within_bounds(int index) const {
717 return 0 <= index && index < length();
718 }
719
720 // Sizing (in words)
721 static int header_size() { return sizeof(ConstantPool)/wordSize; }
722 static int size(int length) { return align_metadata_size(header_size() + length); }
723 int size() const { return size(length()); }
724 #if INCLUDE_SERVICES
725 void collect_statistics(KlassSizeStats *sz) const;
726 #endif
727
728 friend class ClassFileParser;
729 friend class SystemDictionary;
730
731 // Used by CDS. These classes need to access the private ConstantPool() constructor.
732 template <class T> friend class CppVtableTesterA;
733 template <class T> friend class CppVtableTesterB;
734 template <class T> friend class CppVtableCloner;
735
736 // Used by compiler to prevent classloading.
737 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which);
738 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
739 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
740 static bool has_method_type_at_if_loaded (const constantPoolHandle& this_cp, int which);
741 static oop method_type_at_if_loaded (const constantPoolHandle& this_cp, int which);
742 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which);
743 static Klass* klass_ref_at_if_loaded (const constantPoolHandle& this_cp, int which);
744
745 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
746 // future by other Java code. These take constant pool indices rather than
747 // constant pool cache indices as do the peer methods above.
748 Symbol* uncached_klass_ref_at_noresolve(int which);
749 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); }
750 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); }
751 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); }
752 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); }
753
754 // Sharing
755 int pre_resolve_shared_klasses(TRAPS);
756
757 // Debugging
758 const char* printable_name_at(int which) PRODUCT_RETURN0;
759
760 #ifdef ASSERT
761 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices
762 #else
763 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op
764 #endif //ASSERT
765
766 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) {
767 if (invokedynamic_ok && is_invokedynamic_index(raw_index))
768 return decode_invokedynamic_index(raw_index);
769 else
770 return raw_index - CPCACHE_INDEX_TAG;
771 }
772
773 private:
774
775 void set_resolved_references(jobject s) { _cache->set_resolved_references(s); }
776 Array<u2>* reference_map() const { return (_cache == NULL) ? NULL : _cache->reference_map(); }
777 void set_reference_map(Array<u2>* o) { _cache->set_reference_map(o); }
778
779 // patch JSR 292 resolved references after the class is linked.
780 void patch_resolved_references(GrowableArray<Handle>* cp_patches);
781
782 Symbol* impl_name_ref_at(int which, bool uncached);
783 Symbol* impl_signature_ref_at(int which, bool uncached);
784 int impl_klass_ref_index_at(int which, bool uncached);
785 int impl_name_and_type_ref_index_at(int which, bool uncached);
786 constantTag impl_tag_ref_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(const constantPoolHandle& this_cp, Klass* 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(const constantPoolHandle& this_cp, int which,
805 bool save_resolution_error, TRAPS);
806 static oop string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS);
807
808 static void trace_class_resolution(const constantPoolHandle& this_cp, Klass* k);
809
810 // Resolve string constants (to prevent allocation during compilation)
811 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS);
812
813 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int index, int cache_index, TRAPS);
814 static oop resolve_bootstrap_specifier_at_impl(const constantPoolHandle& this_cp, int index, TRAPS);
815
816 // Exception handling
817 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS);
818 static Symbol* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception);
819 static void save_and_throw_exception(const constantPoolHandle& this_cp, int which, constantTag tag, TRAPS);
820
821 public:
822 // Merging ConstantPool* support:
823 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2, TRAPS);
824 void copy_cp_to(int start_i, int end_i, const 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(const constantPoolHandle& from_cp, int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
829 static void copy_entry_to(const constantPoolHandle& from_cp, int from_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
830 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS);
831 int find_matching_entry(int pattern_i, const 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
882 class 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
908 class SymbolHashMapBucket : public CHeapObj<mtSymbol> {
909
910 private:
911 SymbolHashMapEntry* _entry;
912
913 public:
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
921 class 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