1 /*
2 * Copyright (c) 1997, 2015, 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,
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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 intptr_t _ptr;
50 public:
51 enum TagBits { _resolved_value = 0, _symbol_bit = 1, _pseudo_bit = 2, _symbol_mask = 3 };
52
53 CPSlot(intptr_t ptr): _ptr(ptr) {}
54 CPSlot(Klass* ptr): _ptr((intptr_t)ptr) {}
55 CPSlot(Symbol* ptr): _ptr((intptr_t)ptr | _symbol_bit) {}
56 CPSlot(Symbol* ptr, int tag_bits): _ptr((intptr_t)ptr | tag_bits) {}
57
58 intptr_t value() { return _ptr; }
59 bool is_resolved() { return (_ptr & _symbol_bit ) == _resolved_value; }
60 bool is_unresolved() { return (_ptr & _symbol_bit ) != _resolved_value; }
61 bool is_pseudo_string() { return (_ptr & _symbol_mask) == _symbol_bit + _pseudo_bit; }
62
63 Symbol* get_symbol() {
64 assert(is_unresolved(), "bad call");
65 return (Symbol*)(_ptr & ~_symbol_mask);
66 }
67 Klass* get_klass() {
68 assert(is_resolved(), "bad call");
69 return (Klass*)_ptr;
70 }
71 };
72
73 class KlassSizeStats;
74
75 class ConstantPool : public Metadata {
76 friend class VMStructs;
77 friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast
78 friend class Universe; // For null constructor
79 private:
80 Array<u1>* _tags; // the tag array describing the constant pool's contents
81 ConstantPoolCache* _cache; // the cache holding interpreter runtime information
82 InstanceKlass* _pool_holder; // the corresponding class
83 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
84
85 // Array of resolved objects from the constant pool and map from resolved
86 // object index to original constant pool index
87 jobject _resolved_references;
88 Array<u2>* _reference_map;
89
90 enum {
91 _has_preresolution = 1, // Flags
92 _on_stack = 2
93 };
94
95 int _flags; // old fashioned bit twiddling
96 int _length; // number of elements in the array
97
98 union {
99 // set for CDS to restore resolved references
100 int _resolved_reference_length;
101 // keeps version number for redefined classes (used in backtrace)
102 int _version;
103 } _saved;
104
105 void set_tags(Array<u1>* tags) { _tags = tags; }
106 void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); }
107 void release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); }
108
109 u1* tag_addr_at(int which) const { return tags()->adr_at(which); }
110
111 void set_operands(Array<u2>* operands) { _operands = operands; }
112
113 int flags() const { return _flags; }
114 void set_flags(int f) { _flags = f; }
115
116 private:
117 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); }
118
119 CPSlot slot_at(int which) {
120 assert(is_within_bounds(which), "index out of bounds");
121 // Uses volatile because the klass slot changes without a lock.
122 volatile intptr_t adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which));
123 assert(adr != 0 || which == 0, "cp entry for klass should not be zero");
124 return CPSlot(adr);
125 }
126
127 void slot_at_put(int which, CPSlot s) const {
128 assert(is_within_bounds(which), "index out of bounds");
129 assert(s.value() != 0, "Caught something");
130 *(intptr_t*)&base()[which] = s.value();
131 }
132 intptr_t* obj_at_addr_raw(int which) const {
133 assert(is_within_bounds(which), "index out of bounds");
134 return (intptr_t*) &base()[which];
135 }
136
137 jint* int_at_addr(int which) const {
138 assert(is_within_bounds(which), "index out of bounds");
139 return (jint*) &base()[which];
140 }
141
142 jlong* long_at_addr(int which) const {
143 assert(is_within_bounds(which), "index out of bounds");
144 return (jlong*) &base()[which];
145 }
146
147 jfloat* float_at_addr(int which) const {
148 assert(is_within_bounds(which), "index out of bounds");
149 return (jfloat*) &base()[which];
150 }
151
152 jdouble* double_at_addr(int which) const {
153 assert(is_within_bounds(which), "index out of bounds");
154 return (jdouble*) &base()[which];
155 }
156
157 ConstantPool(Array<u1>* tags);
158 ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
159 public:
160 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS);
161
162 bool is_constantPool() const volatile { return true; }
163
164 Array<u1>* tags() const { return _tags; }
165 Array<u2>* operands() const { return _operands; }
166
167 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; }
168 void set_has_preresolution() { _flags |= _has_preresolution; }
169
170 // Redefine classes support. If a method refering to this constant pool
171 // is on the executing stack, or as a handle in vm code, this constant pool
172 // can't be removed from the set of previous versions saved in the instance
173 // class.
174 bool on_stack() const { return (_flags &_on_stack) != 0; }
175 void set_on_stack(const bool value);
176
177 // Klass holding pool
178 InstanceKlass* pool_holder() const { return _pool_holder; }
179 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; }
180 InstanceKlass** pool_holder_addr() { return &_pool_holder; }
181
182 // Interpreter runtime support
183 ConstantPoolCache* cache() const { return _cache; }
184 void set_cache(ConstantPoolCache* cache){ _cache = cache; }
185
186 // Create object cache in the constant pool
187 void initialize_resolved_references(ClassLoaderData* loader_data,
188 const intStack& reference_map,
189 int constant_pool_map_length,
190 TRAPS);
191
192 // resolved strings, methodHandles and callsite objects from the constant pool
193 objArrayOop resolved_references() const;
194 // mapping resolved object array indexes to cp indexes and back.
195 int object_to_cp_index(int index) { return _reference_map->at(index); }
196 int cp_to_object_index(int index);
197
198 // Invokedynamic indexes.
199 // They must look completely different from normal indexes.
200 // The main reason is that byte swapping is sometimes done on normal indexes.
201 // Finally, it is helpful for debugging to tell the two apart.
202 static bool is_invokedynamic_index(int i) { return (i < 0); }
203 static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; }
204 static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; }
205
206
207 // The invokedynamic points at a CP cache entry. This entry points back
208 // at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry
209 // in the resolved_references array (which provides the appendix argument).
210 int invokedynamic_cp_cache_index(int index) const {
211 assert (is_invokedynamic_index(index), "should be a invokedynamic index");
212 int cache_index = decode_invokedynamic_index(index);
213 return cache_index;
214 }
215 ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int index) const {
216 // decode index that invokedynamic points to.
217 int cp_cache_index = invokedynamic_cp_cache_index(index);
218 return cache()->entry_at(cp_cache_index);
219 }
220
221 // Assembly code support
222 static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); }
223 static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); }
224 static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); }
225 static int resolved_references_offset_in_bytes() { return offset_of(ConstantPool, _resolved_references); }
226
227 // Storing constants
228
229 void klass_at_put(int which, Klass* k) {
230 assert(k != NULL, "resolved class shouldn't be null");
231 assert(is_within_bounds(which), "index out of bounds");
232 OrderAccess::release_store_ptr((Klass* volatile *)obj_at_addr_raw(which), k);
233 // The interpreter assumes when the tag is stored, the klass is resolved
234 // and the Klass* is a klass rather than a Symbol*, so we need
235 // hardware store ordering here.
236 release_tag_at_put(which, JVM_CONSTANT_Class);
237 }
238
239 // For temporary use while constructing constant pool
240 void klass_index_at_put(int which, int name_index) {
241 tag_at_put(which, JVM_CONSTANT_ClassIndex);
242 *int_at_addr(which) = name_index;
243 }
244
245 // Temporary until actual use
246 void unresolved_klass_at_put(int which, Symbol* s) {
247 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
248 slot_at_put(which, s);
249 }
250
251 void method_handle_index_at_put(int which, int ref_kind, int ref_index) {
252 tag_at_put(which, JVM_CONSTANT_MethodHandle);
253 *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind;
254 }
255
256 void method_type_index_at_put(int which, int ref_index) {
257 tag_at_put(which, JVM_CONSTANT_MethodType);
258 *int_at_addr(which) = ref_index;
259 }
260
261 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
262 tag_at_put(which, JVM_CONSTANT_InvokeDynamic);
263 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
264 }
265
266 void unresolved_string_at_put(int which, Symbol* s) {
267 release_tag_at_put(which, JVM_CONSTANT_String);
268 slot_at_put(which, CPSlot(s, CPSlot::_symbol_bit));
269 }
270
271 void int_at_put(int which, jint i) {
272 tag_at_put(which, JVM_CONSTANT_Integer);
273 *int_at_addr(which) = i;
274 }
275
276 void long_at_put(int which, jlong l) {
277 tag_at_put(which, JVM_CONSTANT_Long);
278 // *long_at_addr(which) = l;
279 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
280 }
281
282 void float_at_put(int which, jfloat f) {
283 tag_at_put(which, JVM_CONSTANT_Float);
284 *float_at_addr(which) = f;
285 }
286
287 void double_at_put(int which, jdouble d) {
288 tag_at_put(which, JVM_CONSTANT_Double);
289 // *double_at_addr(which) = d;
290 // u8 temp = *(u8*) &d;
291 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
292 }
293
294 Symbol** symbol_at_addr(int which) const {
295 assert(is_within_bounds(which), "index out of bounds");
296 return (Symbol**) &base()[which];
297 }
298
299 void symbol_at_put(int which, Symbol* s) {
300 assert(s->refcount() != 0, "should have nonzero refcount");
301 tag_at_put(which, JVM_CONSTANT_Utf8);
302 *symbol_at_addr(which) = s;
303 }
304
305 void string_at_put(int which, int obj_index, oop str) {
306 resolved_references()->obj_at_put(obj_index, str);
307 }
308
309 // For temporary use while constructing constant pool
310 void string_index_at_put(int which, int string_index) {
311 tag_at_put(which, JVM_CONSTANT_StringIndex);
312 *int_at_addr(which) = string_index;
313 }
314
315 void field_at_put(int which, int class_index, int name_and_type_index) {
316 tag_at_put(which, JVM_CONSTANT_Fieldref);
317 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
318 }
319
320 void method_at_put(int which, int class_index, int name_and_type_index) {
321 tag_at_put(which, JVM_CONSTANT_Methodref);
322 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
323 }
324
325 void interface_method_at_put(int which, int class_index, int name_and_type_index) {
326 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
327 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
328 }
329
330 void name_and_type_at_put(int which, int name_index, int signature_index) {
331 tag_at_put(which, JVM_CONSTANT_NameAndType);
332 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
333 }
334
335 // Tag query
336
337 constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); }
338
339 // Fetching constants
340
341 Klass* klass_at(int which, TRAPS) {
342 constantPoolHandle h_this(THREAD, this);
343 return klass_at_impl(h_this, which, true, THREAD);
344 }
345
346 // Version of klass_at that doesn't save the resolution error, called during deopt
347 Klass* klass_at_ignore_error(int which, TRAPS) {
348 constantPoolHandle h_this(THREAD, this);
349 return klass_at_impl(h_this, which, false, THREAD);
350 }
351
352 Symbol* klass_name_at(int which); // Returns the name, w/o resolving.
353
354 Klass* resolved_klass_at(int which) const { // Used by Compiler
355 guarantee(tag_at(which).is_klass(), "Corrupted constant pool");
356 // Must do an acquire here in case another thread resolved the klass
357 // behind our back, lest we later load stale values thru the oop.
358 return CPSlot((Klass*)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_klass();
359 }
360
361 // RedefineClasses() API support:
362 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); }
363
364 jint int_at(int which) {
365 assert(tag_at(which).is_int(), "Corrupted constant pool");
366 return *int_at_addr(which);
367 }
368
369 jlong long_at(int which) {
370 assert(tag_at(which).is_long(), "Corrupted constant pool");
371 // return *long_at_addr(which);
372 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
373 return *((jlong*)&tmp);
374 }
375
376 jfloat float_at(int which) {
377 assert(tag_at(which).is_float(), "Corrupted constant pool");
378 return *float_at_addr(which);
379 }
380
381 jdouble double_at(int which) {
382 assert(tag_at(which).is_double(), "Corrupted constant pool");
383 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
384 return *((jdouble*)&tmp);
385 }
386
387 Symbol* symbol_at(int which) {
388 assert(tag_at(which).is_utf8(), "Corrupted constant pool");
389 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, const 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, const 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(const constantPoolHandle& ext_cp, TRAPS);
616 // Shrink the operands array to a smaller array with new_len length
617 void shrink_operands(int new_len, TRAPS);
618
619
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 constantTag tag_ref_at(int cp_cache_index) { return impl_tag_ref_at(cp_cache_index, false); }
668
669 // Lookup for entries consisting of (name_index, signature_index)
670 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt)
671 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt)
672
673 BasicType basic_type_for_signature_at(int which);
674
675 // Resolve string constants (to prevent allocation during compilation)
676 void resolve_string_constants(TRAPS) {
677 constantPoolHandle h_this(THREAD, this);
678 resolve_string_constants_impl(h_this, CHECK);
679 }
680
681 // CDS support
682 void remove_unshareable_info();
683 void restore_unshareable_info(TRAPS);
684 bool resolve_class_constants(TRAPS);
685 // The ConstantPool vtable is restored by this call when the ConstantPool is
686 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for
687 // all the gory details. SA, dtrace and pstack helpers distinguish metadata
688 // by their vtable.
689 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); }
690
691 private:
692 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
693 public:
694
695 // Resolve late bound constants.
696 oop resolve_constant_at(int index, TRAPS) {
697 constantPoolHandle h_this(THREAD, this);
698 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD);
699 }
700
701 oop resolve_cached_constant_at(int cache_index, TRAPS) {
702 constantPoolHandle h_this(THREAD, this);
703 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD);
704 }
705
706 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) {
707 constantPoolHandle h_this(THREAD, this);
708 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD);
709 }
710
711 oop resolve_bootstrap_specifier_at(int index, TRAPS) {
712 constantPoolHandle h_this(THREAD, this);
713 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD);
714 }
715
716 // Klass name matches name at offset
717 bool klass_name_at_matches(instanceKlassHandle k, int which);
718
719 // Sizing
720 int length() const { return _length; }
721 void set_length(int length) { _length = length; }
722
723 // Tells whether index is within bounds.
724 bool is_within_bounds(int index) const {
725 return 0 <= index && index < length();
726 }
727
728 // Sizing (in words)
729 static int header_size() { return sizeof(ConstantPool)/HeapWordSize; }
730 static int size(int length) { return align_object_size(header_size() + length); }
731 int size() const { return size(length()); }
732 #if INCLUDE_SERVICES
733 void collect_statistics(KlassSizeStats *sz) const;
734 #endif
735
736 friend class ClassFileParser;
737 friend class SystemDictionary;
738
739 // Used by compiler to prevent classloading.
740 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which);
741 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
742 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
743 static bool has_method_type_at_if_loaded (const constantPoolHandle& this_cp, int which);
744 static oop method_type_at_if_loaded (const constantPoolHandle& this_cp, int which);
745 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which);
746 static Klass* klass_ref_at_if_loaded (const constantPoolHandle& this_cp, int which);
747
748 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
749 // future by other Java code. These take constant pool indices rather than
750 // constant pool cache indices as do the peer methods above.
751 Symbol* uncached_klass_ref_at_noresolve(int which);
752 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); }
753 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); }
754 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); }
755 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); }
756
757 // Sharing
758 int pre_resolve_shared_klasses(TRAPS);
759
760 // Debugging
761 const char* printable_name_at(int which) PRODUCT_RETURN0;
762
763 #ifdef ASSERT
764 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices
765 #else
766 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op
767 #endif //ASSERT
768
769 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) {
770 if (invokedynamic_ok && is_invokedynamic_index(raw_index))
771 return decode_invokedynamic_index(raw_index);
772 else
773 return raw_index - CPCACHE_INDEX_TAG;
774 }
775
776 private:
777
778 void set_resolved_references(jobject s) { _resolved_references = s; }
779 Array<u2>* reference_map() const { return _reference_map; }
780 void set_reference_map(Array<u2>* o) { _reference_map = o; }
781
782 // patch JSR 292 resolved references after the class is linked.
783 void patch_resolved_references(GrowableArray<Handle>* cp_patches);
784
785 Symbol* impl_name_ref_at(int which, bool uncached);
786 Symbol* impl_signature_ref_at(int which, bool uncached);
787 int impl_klass_ref_index_at(int which, bool uncached);
788 int impl_name_and_type_ref_index_at(int which, bool uncached);
789 constantTag impl_tag_ref_at(int which, bool uncached);
790
791 // Used while constructing constant pool (only by ClassFileParser)
792 jint klass_index_at(int which) {
793 assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
794 return *int_at_addr(which);
795 }
796
797 jint string_index_at(int which) {
798 assert(tag_at(which).is_string_index(), "Corrupted constant pool");
799 return *int_at_addr(which);
800 }
801
802 // Performs the LinkResolver checks
803 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, KlassHandle klass, TRAPS);
804
805 // Implementation of methods that needs an exposed 'this' pointer, in order to
806 // handle GC while executing the method
807 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int which,
808 bool save_resolution_error, TRAPS);
809 static oop string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS);
810
811 static void trace_class_resolution(const constantPoolHandle& this_cp, KlassHandle k);
812
813 // Resolve string constants (to prevent allocation during compilation)
814 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS);
815
816 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int index, int cache_index, TRAPS);
817 static oop resolve_bootstrap_specifier_at_impl(const constantPoolHandle& this_cp, int index, TRAPS);
818
819 // Exception handling
820 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS);
821 static Symbol* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception);
822 static void save_and_throw_exception(const constantPoolHandle& this_cp, int which, constantTag tag, TRAPS);
823
824 public:
825 // Merging ConstantPool* support:
826 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2, TRAPS);
827 void copy_cp_to(int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS) {
828 constantPoolHandle h_this(THREAD, this);
829 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD);
830 }
831 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
832 static void copy_entry_to(const constantPoolHandle& from_cp, int from_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
833 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS);
834 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp, TRAPS);
835 int version() const { return _saved._version; }
836 void set_version(int version) { _saved._version = version; }
837 void increment_and_save_version(int version) {
838 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow
839 }
840
841 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; }
842 int resolved_reference_length() const { return _saved._resolved_reference_length; }
843
844 // Decrease ref counts of symbols that are in the constant pool
845 // when the holder class is unloaded
846 void unreference_symbols();
847
848 // Deallocate constant pool for RedefineClasses
849 void deallocate_contents(ClassLoaderData* loader_data);
850 void release_C_heap_structures();
851
852 // JVMTI accesss - GetConstantPool, RetransformClasses, ...
853 friend class JvmtiConstantPoolReconstituter;
854
855 private:
856 jint cpool_entry_size(jint idx);
857 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap);
858
859 // Copy cpool bytes into byte array.
860 // Returns:
861 // int > 0, count of the raw cpool bytes that have been copied
862 // 0, OutOfMemory error
863 // -1, Internal error
864 int copy_cpool_bytes(int cpool_size,
865 SymbolHashMap* tbl,
866 unsigned char *bytes);
867
868 public:
869 // Verify
870 void verify_on(outputStream* st);
871
872 // Printing
873 void print_on(outputStream* st) const;
874 void print_value_on(outputStream* st) const;
875 void print_entry_on(int index, outputStream* st);
876
877 const char* internal_name() const { return "{constant pool}"; }
878
879 #ifndef PRODUCT
880 // Compile the world support
881 static void preload_and_initialize_all_classes(ConstantPool* constant_pool, TRAPS);
882 #endif
883 };
884
885 class SymbolHashMapEntry : public CHeapObj<mtSymbol> {
886 private:
887 unsigned int _hash; // 32-bit hash for item
888 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket
889 Symbol* _symbol; // 1-st part of the mapping: symbol => value
890 u2 _value; // 2-nd part of the mapping: symbol => value
891
892 public:
893 unsigned int hash() const { return _hash; }
894 void set_hash(unsigned int hash) { _hash = hash; }
895
896 SymbolHashMapEntry* next() const { return _next; }
897 void set_next(SymbolHashMapEntry* next) { _next = next; }
898
899 Symbol* symbol() const { return _symbol; }
900 void set_symbol(Symbol* sym) { _symbol = sym; }
901
902 u2 value() const { return _value; }
903 void set_value(u2 value) { _value = value; }
904
905 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value)
906 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {}
907
908 }; // End SymbolHashMapEntry class
909
910
911 class SymbolHashMapBucket : public CHeapObj<mtSymbol> {
912
913 private:
914 SymbolHashMapEntry* _entry;
915
916 public:
917 SymbolHashMapEntry* entry() const { return _entry; }
918 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; }
919 void clear() { _entry = NULL; }
920
921 }; // End SymbolHashMapBucket class
922
923
924 class SymbolHashMap: public CHeapObj<mtSymbol> {
925
926 private:
927 // Default number of entries in the table
928 enum SymbolHashMap_Constants {
929 _Def_HashMap_Size = 256
930 };
931
932 int _table_size;
933 SymbolHashMapBucket* _buckets;
934
935 void initialize_table(int table_size) {
936 _table_size = table_size;
937 _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size, mtSymbol);
938 for (int index = 0; index < table_size; index++) {
939 _buckets[index].clear();
940 }
941 }
942
943 public:
944
945 int table_size() const { return _table_size; }
946
947 SymbolHashMap() { initialize_table(_Def_HashMap_Size); }
948 SymbolHashMap(int table_size) { initialize_table(table_size); }
949
950 // hash P(31) from Kernighan & Ritchie
951 static unsigned int compute_hash(const char* str, int len) {
952 unsigned int hash = 0;
953 while (len-- > 0) {
954 hash = 31*hash + (unsigned) *str;
955 str++;
956 }
957 return hash;
958 }
959
960 SymbolHashMapEntry* bucket(int i) {
961 return _buckets[i].entry();
962 }
963
964 void add_entry(Symbol* sym, u2 value);
965 SymbolHashMapEntry* find_entry(Symbol* sym);
966
967 u2 symbol_to_value(Symbol* sym) {
968 SymbolHashMapEntry *entry = find_entry(sym);
969 return (entry == NULL) ? 0 : entry->value();
970 }
971
972 ~SymbolHashMap() {
973 SymbolHashMapEntry* next;
974 for (int i = 0; i < _table_size; i++) {
975 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
976 next = cur->next();
977 delete(cur);
978 }
979 }
980 delete _buckets;
981 }
982 }; // End SymbolHashMap class
983
984 #endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP