1 /*
2 * Copyright (c) 1997, 2016, 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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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) const {
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
307 // For temporary use while constructing constant pool
308 void string_index_at_put(int which, int string_index) {
309 tag_at_put(which, JVM_CONSTANT_StringIndex);
310 *int_at_addr(which) = string_index;
311 }
312
313 void field_at_put(int which, int class_index, int name_and_type_index) {
314 tag_at_put(which, JVM_CONSTANT_Fieldref);
315 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
316 }
317
318 void method_at_put(int which, int class_index, int name_and_type_index) {
319 tag_at_put(which, JVM_CONSTANT_Methodref);
320 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
321 }
322
323 void interface_method_at_put(int which, int class_index, int name_and_type_index) {
324 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
325 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
326 }
327
328 void name_and_type_at_put(int which, int name_index, int signature_index) {
329 tag_at_put(which, JVM_CONSTANT_NameAndType);
330 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
331 }
332
333 // Tag query
334
335 constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); }
336
337 // Fetching constants
338
339 Klass* klass_at(int which, TRAPS) {
340 constantPoolHandle h_this(THREAD, this);
341 return klass_at_impl(h_this, which, true, THREAD);
342 }
343
344 // Version of klass_at that doesn't save the resolution error, called during deopt
345 Klass* klass_at_ignore_error(int which, TRAPS) {
346 constantPoolHandle h_this(THREAD, this);
347 return klass_at_impl(h_this, which, false, THREAD);
348 }
349
350 Symbol* klass_name_at(int which) const; // Returns the name, w/o resolving.
351
352 Klass* resolved_klass_at(int which) const { // Used by Compiler
353 guarantee(tag_at(which).is_klass(), "Corrupted constant pool");
354 // Must do an acquire here in case another thread resolved the klass
355 // behind our back, lest we later load stale values thru the oop.
356 return CPSlot((Klass*)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_klass();
357 }
358
359 // RedefineClasses() API support:
360 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); }
361
362 jint int_at(int which) {
363 assert(tag_at(which).is_int(), "Corrupted constant pool");
364 return *int_at_addr(which);
365 }
366
367 jlong long_at(int which) {
368 assert(tag_at(which).is_long(), "Corrupted constant pool");
369 // return *long_at_addr(which);
370 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
371 return *((jlong*)&tmp);
372 }
373
374 jfloat float_at(int which) {
375 assert(tag_at(which).is_float(), "Corrupted constant pool");
376 return *float_at_addr(which);
377 }
378
379 jdouble double_at(int which) {
380 assert(tag_at(which).is_double(), "Corrupted constant pool");
381 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
382 return *((jdouble*)&tmp);
383 }
384
385 Symbol* symbol_at(int which) const {
386 assert(tag_at(which).is_utf8(), "Corrupted constant pool");
387 return *symbol_at_addr(which);
388 }
389
390 oop string_at(int which, int obj_index, TRAPS) {
391 constantPoolHandle h_this(THREAD, this);
392 return string_at_impl(h_this, which, obj_index, THREAD);
393 }
394 oop string_at(int which, TRAPS) {
395 int obj_index = cp_to_object_index(which);
396 return string_at(which, obj_index, THREAD);
397 }
398
399 // Version that can be used before string oop array is created.
400 oop uncached_string_at(int which, TRAPS);
401
402 // A "pseudo-string" is an non-string oop that has found its way into
403 // a String entry.
404 // This can happen if the user patches a live
405 // object into a CONSTANT_String entry of an anonymous class.
406 // Method oops internally created for method handles may also
407 // use pseudo-strings to link themselves to related metaobjects.
408
409 bool is_pseudo_string_at(int which) {
410 assert(tag_at(which).is_string(), "Corrupted constant pool");
411 return slot_at(which).is_pseudo_string();
412 }
413
414 oop pseudo_string_at(int which, int obj_index) {
415 assert(is_pseudo_string_at(which), "must be a pseudo-string");
416 oop s = resolved_references()->obj_at(obj_index);
417 return s;
418 }
419
420 oop pseudo_string_at(int which) {
421 assert(is_pseudo_string_at(which), "must be a pseudo-string");
422 int obj_index = cp_to_object_index(which);
423 oop s = resolved_references()->obj_at(obj_index);
424 return s;
425 }
426
427 void pseudo_string_at_put(int which, int obj_index, oop x) {
428 assert(tag_at(which).is_string(), "Corrupted constant pool");
429 Symbol* sym = unresolved_string_at(which);
430 slot_at_put(which, CPSlot(sym, (CPSlot::_symbol_bit | CPSlot::_pseudo_bit)));
431 string_at_put(which, obj_index, x); // this works just fine
432 }
433
434 // only called when we are sure a string entry is already resolved (via an
435 // earlier string_at call.
436 oop resolved_string_at(int which) {
437 assert(tag_at(which).is_string(), "Corrupted constant pool");
438 // Must do an acquire here in case another thread resolved the klass
439 // behind our back, lest we later load stale values thru the oop.
440 // we might want a volatile_obj_at in ObjArrayKlass.
441 int obj_index = cp_to_object_index(which);
442 return resolved_references()->obj_at(obj_index);
443 }
444
445 Symbol* unresolved_string_at(int which) {
446 assert(tag_at(which).is_string(), "Corrupted constant pool");
447 Symbol* sym = slot_at(which).get_symbol();
448 return sym;
449 }
450
451 // Returns an UTF8 for a CONSTANT_String entry at a given index.
452 // UTF8 char* representation was chosen to avoid conversion of
453 // java_lang_Strings at resolved entries into Symbol*s
454 // or vice versa.
455 char* string_at_noresolve(int which);
456
457 jint name_and_type_at(int which) {
458 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
459 return *int_at_addr(which);
460 }
461
462 private:
463 int method_handle_ref_kind_at(int which, bool error_ok) {
464 assert(tag_at(which).is_method_handle() ||
465 (error_ok && tag_at(which).is_method_handle_in_error()), "Corrupted constant pool");
466 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits
467 }
468 int method_handle_index_at(int which, bool error_ok) {
469 assert(tag_at(which).is_method_handle() ||
470 (error_ok && tag_at(which).is_method_handle_in_error()), "Corrupted constant pool");
471 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits
472 }
473 int method_type_index_at(int which, bool error_ok) {
474 assert(tag_at(which).is_method_type() ||
475 (error_ok && tag_at(which).is_method_type_in_error()), "Corrupted constant pool");
476 return *int_at_addr(which);
477 }
478 public:
479 int method_handle_ref_kind_at(int which) {
480 return method_handle_ref_kind_at(which, false);
481 }
482 int method_handle_ref_kind_at_error_ok(int which) {
483 return method_handle_ref_kind_at(which, true);
484 }
485 int method_handle_index_at(int which) {
486 return method_handle_index_at(which, false);
487 }
488 int method_handle_index_at_error_ok(int which) {
489 return method_handle_index_at(which, true);
490 }
491 int method_type_index_at(int which) {
492 return method_type_index_at(which, false);
493 }
494 int method_type_index_at_error_ok(int which) {
495 return method_type_index_at(which, true);
496 }
497
498 // Derived queries:
499 Symbol* method_handle_name_ref_at(int which) {
500 int member = method_handle_index_at(which);
501 return impl_name_ref_at(member, true);
502 }
503 Symbol* method_handle_signature_ref_at(int which) {
504 int member = method_handle_index_at(which);
505 return impl_signature_ref_at(member, true);
506 }
507 int method_handle_klass_index_at(int which) {
508 int member = method_handle_index_at(which);
509 return impl_klass_ref_index_at(member, true);
510 }
511 Symbol* method_type_signature_at(int which) {
512 int sym = method_type_index_at(which);
513 return symbol_at(sym);
514 }
515
516 int invoke_dynamic_name_and_type_ref_index_at(int which) {
517 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
518 return extract_high_short_from_int(*int_at_addr(which));
519 }
520 int invoke_dynamic_bootstrap_specifier_index(int which) {
521 assert(tag_at(which).value() == JVM_CONSTANT_InvokeDynamic, "Corrupted constant pool");
522 return extract_low_short_from_int(*int_at_addr(which));
523 }
524 int invoke_dynamic_operand_base(int which) {
525 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
526 return operand_offset_at(operands(), bootstrap_specifier_index);
527 }
528 // The first part of the operands array consists of an index into the second part.
529 // Extract a 32-bit index value from the first part.
530 static int operand_offset_at(Array<u2>* operands, int bootstrap_specifier_index) {
531 int n = (bootstrap_specifier_index * 2);
532 assert(n >= 0 && n+2 <= operands->length(), "oob");
533 // The first 32-bit index points to the beginning of the second part
534 // of the operands array. Make sure this index is in the first part.
535 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0),
536 operands->at(1)));
537 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
538 int offset = build_int_from_shorts(operands->at(n+0),
539 operands->at(n+1));
540 // The offset itself must point into the second part of the array.
541 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)");
542 return offset;
543 }
544 static void operand_offset_at_put(Array<u2>* operands, int bootstrap_specifier_index, int offset) {
545 int n = bootstrap_specifier_index * 2;
546 assert(n >= 0 && n+2 <= operands->length(), "oob");
547 operands->at_put(n+0, extract_low_short_from_int(offset));
548 operands->at_put(n+1, extract_high_short_from_int(offset));
549 }
550 static int operand_array_length(Array<u2>* operands) {
551 if (operands == NULL || operands->length() == 0) return 0;
552 int second_part = operand_offset_at(operands, 0);
553 return (second_part / 2);
554 }
555
556 #ifdef ASSERT
557 // operand tuples fit together exactly, end to end
558 static int operand_limit_at(Array<u2>* operands, int bootstrap_specifier_index) {
559 int nextidx = bootstrap_specifier_index + 1;
560 if (nextidx == operand_array_length(operands))
561 return operands->length();
562 else
563 return operand_offset_at(operands, nextidx);
564 }
565 int invoke_dynamic_operand_limit(int which) {
566 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
567 return operand_limit_at(operands(), bootstrap_specifier_index);
568 }
569 #endif //ASSERT
570
571 // layout of InvokeDynamic bootstrap method specifier (in second part of operands array):
572 enum {
573 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
574 _indy_argc_offset = 1, // u2 argc
575 _indy_argv_offset = 2 // u2 argv[argc]
576 };
577
578 // These functions are used in RedefineClasses for CP merge
579
580 int operand_offset_at(int bootstrap_specifier_index) {
581 assert(0 <= bootstrap_specifier_index &&
582 bootstrap_specifier_index < operand_array_length(operands()),
583 "Corrupted CP operands");
584 return operand_offset_at(operands(), bootstrap_specifier_index);
585 }
586 int operand_bootstrap_method_ref_index_at(int bootstrap_specifier_index) {
587 int offset = operand_offset_at(bootstrap_specifier_index);
588 return operands()->at(offset + _indy_bsm_offset);
589 }
590 int operand_argument_count_at(int bootstrap_specifier_index) {
591 int offset = operand_offset_at(bootstrap_specifier_index);
592 int argc = operands()->at(offset + _indy_argc_offset);
593 return argc;
594 }
595 int operand_argument_index_at(int bootstrap_specifier_index, int j) {
596 int offset = operand_offset_at(bootstrap_specifier_index);
597 return operands()->at(offset + _indy_argv_offset + j);
598 }
599 int operand_next_offset_at(int bootstrap_specifier_index) {
600 int offset = operand_offset_at(bootstrap_specifier_index) + _indy_argv_offset
601 + operand_argument_count_at(bootstrap_specifier_index);
602 return offset;
603 }
604 // Compare a bootsrap specifier in the operands arrays
605 bool compare_operand_to(int bootstrap_specifier_index1, const constantPoolHandle& cp2,
606 int bootstrap_specifier_index2, TRAPS);
607 // Find a bootsrap specifier in the operands array
608 int find_matching_operand(int bootstrap_specifier_index, const constantPoolHandle& search_cp,
609 int operands_cur_len, TRAPS);
610 // Resize the operands array with delta_len and delta_size
611 void resize_operands(int delta_len, int delta_size, TRAPS);
612 // Extend the operands array with the length and size of the ext_cp operands
613 void extend_operands(const constantPoolHandle& ext_cp, TRAPS);
614 // Shrink the operands array to a smaller array with new_len length
615 void shrink_operands(int new_len, TRAPS);
616
617
618 int invoke_dynamic_bootstrap_method_ref_index_at(int which) {
619 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
620 int op_base = invoke_dynamic_operand_base(which);
621 return operands()->at(op_base + _indy_bsm_offset);
622 }
623 int invoke_dynamic_argument_count_at(int which) {
624 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
625 int op_base = invoke_dynamic_operand_base(which);
626 int argc = operands()->at(op_base + _indy_argc_offset);
627 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
628 int next_offset = invoke_dynamic_operand_limit(which));
629 assert(end_offset == next_offset, "matched ending");
630 return argc;
631 }
632 int invoke_dynamic_argument_index_at(int which, int j) {
633 int op_base = invoke_dynamic_operand_base(which);
634 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset));
635 assert((uint)j < (uint)argc, "oob");
636 return operands()->at(op_base + _indy_argv_offset + j);
637 }
638
639 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
640 // name_and_type_ref_index_at) all expect to be passed indices obtained
641 // directly from the bytecode.
642 // If the indices are meant to refer to fields or methods, they are
643 // actually rewritten constant pool cache indices.
644 // The routine remap_instruction_operand_from_cache manages the adjustment
645 // of these values back to constant pool indices.
646
647 // There are also "uncached" versions which do not adjust the operand index; see below.
648
649 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear.
650 // In a few cases (the verifier) there are uses before a cpcache has been built,
651 // which are handled by a dynamic check in remap_instruction_operand_from_cache.
652 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode.
653
654 // Lookup for entries consisting of (klass_index, name_and_type index)
655 Klass* klass_ref_at(int which, TRAPS);
656 Symbol* klass_ref_at_noresolve(int which);
657 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); }
658 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); }
659
660 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); }
661 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); }
662
663 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG
664
665 // Lookup for entries consisting of (name_index, signature_index)
666 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt)
667 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt)
668
669 BasicType basic_type_for_signature_at(int which) const;
670
671 // Resolve string constants (to prevent allocation during compilation)
672 void resolve_string_constants(TRAPS) {
673 constantPoolHandle h_this(THREAD, this);
674 resolve_string_constants_impl(h_this, CHECK);
675 }
676
677 // CDS support
678 void remove_unshareable_info();
679 void restore_unshareable_info(TRAPS);
680 bool resolve_class_constants(TRAPS);
681 // The ConstantPool vtable is restored by this call when the ConstantPool is
682 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for
683 // all the gory details. SA, dtrace and pstack helpers distinguish metadata
684 // by their vtable.
685 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); }
686
687 private:
688 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
689 public:
690
691 // Resolve late bound constants.
692 oop resolve_constant_at(int index, TRAPS) {
693 constantPoolHandle h_this(THREAD, this);
694 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD);
695 }
696
697 oop resolve_cached_constant_at(int cache_index, TRAPS) {
698 constantPoolHandle h_this(THREAD, this);
699 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD);
700 }
701
702 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) {
703 constantPoolHandle h_this(THREAD, this);
704 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD);
705 }
706
707 oop resolve_bootstrap_specifier_at(int index, TRAPS) {
708 constantPoolHandle h_this(THREAD, this);
709 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD);
710 }
711
712 // Klass name matches name at offset
713 bool klass_name_at_matches(instanceKlassHandle k, int which);
714
715 // Sizing
716 int length() const { return _length; }
717 void set_length(int length) { _length = length; }
718
719 // Tells whether index is within bounds.
720 bool is_within_bounds(int index) const {
721 return 0 <= index && index < length();
722 }
723
724 // Sizing (in words)
725 static int header_size() { return sizeof(ConstantPool)/HeapWordSize; }
726 static int size(int length) { return align_object_size(header_size() + length); }
727 int size() const { return size(length()); }
728 #if INCLUDE_SERVICES
729 void collect_statistics(KlassSizeStats *sz) const;
730 #endif
731
732 friend class ClassFileParser;
733 friend class SystemDictionary;
734
735 // Used by compiler to prevent classloading.
736 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which);
737 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
738 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
739 static bool has_method_type_at_if_loaded (const constantPoolHandle& this_cp, int which);
740 static oop method_type_at_if_loaded (const constantPoolHandle& this_cp, int which);
741 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which);
742 static Klass* klass_ref_at_if_loaded (const constantPoolHandle& this_cp, int which);
743
744 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
745 // future by other Java code. These take constant pool indices rather than
746 // constant pool cache indices as do the peer methods above.
747 Symbol* uncached_klass_ref_at_noresolve(int which);
748 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); }
749 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); }
750 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); }
751 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); }
752
753 // Sharing
754 int pre_resolve_shared_klasses(TRAPS);
755
756 // Debugging
757 const char* printable_name_at(int which) PRODUCT_RETURN0;
758
759 #ifdef ASSERT
760 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices
761 #else
762 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op
763 #endif //ASSERT
764
765 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) {
766 if (invokedynamic_ok && is_invokedynamic_index(raw_index))
767 return decode_invokedynamic_index(raw_index);
768 else
769 return raw_index - CPCACHE_INDEX_TAG;
770 }
771
772 private:
773
774 void set_resolved_references(jobject s) { _resolved_references = s; }
775 Array<u2>* reference_map() const { return _reference_map; }
776 void set_reference_map(Array<u2>* o) { _reference_map = o; }
777
778 // patch JSR 292 resolved references after the class is linked.
779 void patch_resolved_references(GrowableArray<Handle>* cp_patches);
780
781 Symbol* impl_name_ref_at(int which, bool uncached);
782 Symbol* impl_signature_ref_at(int which, bool uncached);
783 int impl_klass_ref_index_at(int which, bool uncached);
784 int impl_name_and_type_ref_index_at(int which, bool uncached);
785
786 // Used while constructing constant pool (only by ClassFileParser)
787 jint klass_index_at(int which) {
788 assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
789 return *int_at_addr(which);
790 }
791
792 jint string_index_at(int which) {
793 assert(tag_at(which).is_string_index(), "Corrupted constant pool");
794 return *int_at_addr(which);
795 }
796
797 // Performs the LinkResolver checks
798 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, KlassHandle klass, TRAPS);
799
800 // Implementation of methods that needs an exposed 'this' pointer, in order to
801 // handle GC while executing the method
802 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int which,
803 bool save_resolution_error, TRAPS);
804 static oop string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS);
805
806 static void trace_class_resolution(const constantPoolHandle& this_cp, KlassHandle k);
807
808 // Resolve string constants (to prevent allocation during compilation)
809 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS);
810
811 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int index, int cache_index, TRAPS);
812 static oop resolve_bootstrap_specifier_at_impl(const constantPoolHandle& this_cp, int index, TRAPS);
813
814 // Exception handling
815 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS);
816 static Symbol* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception);
817 static void save_and_throw_exception(const constantPoolHandle& this_cp, int which, constantTag tag, TRAPS);
818
819 public:
820 // Merging ConstantPool* support:
821 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2, TRAPS);
822 void copy_cp_to(int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS) {
823 constantPoolHandle h_this(THREAD, this);
824 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD);
825 }
826 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
827 static void copy_entry_to(const constantPoolHandle& from_cp, int from_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
828 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS);
829 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp, TRAPS);
830 int version() const { return _saved._version; }
831 void set_version(int version) { _saved._version = version; }
832 void increment_and_save_version(int version) {
833 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow
834 }
835
836 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; }
837 int resolved_reference_length() const { return _saved._resolved_reference_length; }
838
839 // Decrease ref counts of symbols that are in the constant pool
840 // when the holder class is unloaded
841 void unreference_symbols();
842
843 // Deallocate constant pool for RedefineClasses
844 void deallocate_contents(ClassLoaderData* loader_data);
845 void release_C_heap_structures();
846
847 // JVMTI accesss - GetConstantPool, RetransformClasses, ...
848 friend class JvmtiConstantPoolReconstituter;
849
850 private:
851 jint cpool_entry_size(jint idx);
852 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap);
853
854 // Copy cpool bytes into byte array.
855 // Returns:
856 // int > 0, count of the raw cpool bytes that have been copied
857 // 0, OutOfMemory error
858 // -1, Internal error
859 int copy_cpool_bytes(int cpool_size,
860 SymbolHashMap* tbl,
861 unsigned char *bytes);
862
863 public:
864 // Verify
865 void verify_on(outputStream* st);
866
867 // Printing
868 void print_on(outputStream* st) const;
869 void print_value_on(outputStream* st) const;
870 void print_entry_on(int index, outputStream* st);
871
872 const char* internal_name() const { return "{constant pool}"; }
873
874 #ifndef PRODUCT
875 // Compile the world support
876 static void preload_and_initialize_all_classes(ConstantPool* constant_pool, TRAPS);
877 #endif
878 };
879
880 class SymbolHashMapEntry : public CHeapObj<mtSymbol> {
881 private:
882 unsigned int _hash; // 32-bit hash for item
883 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket
884 Symbol* _symbol; // 1-st part of the mapping: symbol => value
885 u2 _value; // 2-nd part of the mapping: symbol => value
886
887 public:
888 unsigned int hash() const { return _hash; }
889 void set_hash(unsigned int hash) { _hash = hash; }
890
891 SymbolHashMapEntry* next() const { return _next; }
892 void set_next(SymbolHashMapEntry* next) { _next = next; }
893
894 Symbol* symbol() const { return _symbol; }
895 void set_symbol(Symbol* sym) { _symbol = sym; }
896
897 u2 value() const { return _value; }
898 void set_value(u2 value) { _value = value; }
899
900 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value)
901 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {}
902
903 }; // End SymbolHashMapEntry class
904
905
906 class SymbolHashMapBucket : public CHeapObj<mtSymbol> {
907
908 private:
909 SymbolHashMapEntry* _entry;
910
911 public:
912 SymbolHashMapEntry* entry() const { return _entry; }
913 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; }
914 void clear() { _entry = NULL; }
915
916 }; // End SymbolHashMapBucket class
917
918
919 class SymbolHashMap: public CHeapObj<mtSymbol> {
920
921 private:
922 // Default number of entries in the table
923 enum SymbolHashMap_Constants {
924 _Def_HashMap_Size = 256
925 };
926
927 int _table_size;
928 SymbolHashMapBucket* _buckets;
929
930 void initialize_table(int table_size) {
931 _table_size = table_size;
932 _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size, mtSymbol);
933 for (int index = 0; index < table_size; index++) {
934 _buckets[index].clear();
935 }
936 }
937
938 public:
939
940 int table_size() const { return _table_size; }
941
942 SymbolHashMap() { initialize_table(_Def_HashMap_Size); }
943 SymbolHashMap(int table_size) { initialize_table(table_size); }
944
945 // hash P(31) from Kernighan & Ritchie
946 static unsigned int compute_hash(const char* str, int len) {
947 unsigned int hash = 0;
948 while (len-- > 0) {
949 hash = 31*hash + (unsigned) *str;
950 str++;
951 }
952 return hash;
953 }
954
955 SymbolHashMapEntry* bucket(int i) {
956 return _buckets[i].entry();
957 }
958
959 void add_entry(Symbol* sym, u2 value);
960 SymbolHashMapEntry* find_entry(Symbol* sym);
961
962 u2 symbol_to_value(Symbol* sym) {
963 SymbolHashMapEntry *entry = find_entry(sym);
964 return (entry == NULL) ? 0 : entry->value();
965 }
966
967 ~SymbolHashMap() {
968 SymbolHashMapEntry* next;
969 for (int i = 0; i < _table_size; i++) {
970 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
971 next = cur->next();
972 delete(cur);
973 }
974 }
975 delete _buckets;
976 }
977 }; // End SymbolHashMap class
978
979 #endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP