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