1 /*
2 * Copyright (c) 1997, 2018, 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 "memory/allocation.inline.hpp"
29 #include "oops/arrayOop.hpp"
30 #include "oops/cpCache.hpp"
31 #include "oops/objArrayOop.hpp"
32 #include "oops/oopHandle.hpp"
33 #include "oops/symbol.hpp"
34 #include "oops/typeArrayOop.hpp"
35 #include "runtime/handles.hpp"
36 #include "utilities/align.hpp"
37 #include "utilities/bytes.hpp"
38 #include "utilities/constantTag.hpp"
39
40 // A ConstantPool is an array containing class constants as described in the
41 // class file.
42 //
43 // Most of the constant pool entries are written during class parsing, which
44 // is safe. For klass types, the constant pool entry is
45 // modified when the entry is resolved. If a klass constant pool
46 // entry is read without a lock, only the resolved state guarantees that
47 // the entry in the constant pool is a klass object and not a Symbol*.
48
49 class SymbolHashMap;
50
51 class CPSlot VALUE_OBJ_CLASS_SPEC {
52 friend class ConstantPool;
53 intptr_t _ptr;
54 enum TagBits {_pseudo_bit = 1};
55 public:
56
57 CPSlot(intptr_t ptr): _ptr(ptr) {}
58 CPSlot(Symbol* ptr, int tag_bits = 0): _ptr((intptr_t)ptr | tag_bits) {}
59
60 intptr_t value() { return _ptr; }
61 bool is_pseudo_string() { return (_ptr & _pseudo_bit) != 0; }
62
63 Symbol* get_symbol() {
64 return (Symbol*)(_ptr & ~_pseudo_bit);
65 }
66 };
67
68 // This represents a JVM_CONSTANT_Class, JVM_CONSTANT_UnresolvedClass, or
69 // JVM_CONSTANT_UnresolvedClassInError slot in the constant pool.
70 class CPKlassSlot VALUE_OBJ_CLASS_SPEC {
71 // cp->symbol_at(_name_index) gives the name of the class.
72 int _name_index;
73
74 // cp->_resolved_klasses->at(_resolved_klass_index) gives the Klass* for the class.
75 int _resolved_klass_index;
76 public:
77 enum {
78 // This is used during constant pool merging where the resolved klass index is
79 // not yet known, and will be computed at a later stage (during a call to
80 // initialize_unresolved_klasses()).
81 _temp_resolved_klass_index = 0xffff
82 };
83 CPKlassSlot(int n, int rk) {
84 _name_index = n;
85 _resolved_klass_index = rk;
86 }
87 int name_index() const {
88 return _name_index;
89 }
90 int resolved_klass_index() const {
91 assert(_resolved_klass_index != _temp_resolved_klass_index, "constant pool merging was incomplete");
92 return _resolved_klass_index;
93 }
94 };
95
96 class KlassSizeStats;
97
98 class ConstantPool : public Metadata {
99 friend class VMStructs;
100 friend class JVMCIVMStructs;
101 friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast
102 friend class Universe; // For null constructor
103 private:
104 // If you add a new field that points to any metaspace object, you
105 // must add this field to ConstantPool::metaspace_pointers_do().
106 Array<u1>* _tags; // the tag array describing the constant pool's contents
107 ConstantPoolCache* _cache; // the cache holding interpreter runtime information
108 InstanceKlass* _pool_holder; // the corresponding class
109 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
110
111 // Consider using an array of compressed klass pointers to
112 // save space on 64-bit platforms.
113 Array<Klass*>* _resolved_klasses;
114
115 enum {
116 _has_preresolution = 1, // Flags
117 _on_stack = 2,
118 _is_shared = 4,
119 _has_dynamic_constant = 8
120 };
121
122 int _flags; // old fashioned bit twiddling
123 int _length; // number of elements in the array
124
125 union {
126 // set for CDS to restore resolved references
127 int _resolved_reference_length;
128 // keeps version number for redefined classes (used in backtrace)
129 int _version;
130 } _saved;
131
132 void set_tags(Array<u1>* tags) { _tags = tags; }
133 void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); }
134 void release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); }
135
136 u1* tag_addr_at(int which) const { return tags()->adr_at(which); }
137
138 void set_operands(Array<u2>* operands) { _operands = operands; }
139
140 int flags() const { return _flags; }
141 void set_flags(int f) { _flags = f; }
142
143 private:
144 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); }
145
146 CPSlot slot_at(int which) const {
147 assert(is_within_bounds(which), "index out of bounds");
148 assert(!tag_at(which).is_unresolved_klass() && !tag_at(which).is_unresolved_klass_in_error(), "Corrupted constant pool");
149 // Uses volatile because the klass slot changes without a lock.
150 intptr_t adr = OrderAccess::load_acquire(obj_at_addr(which));
151 assert(adr != 0 || which == 0, "cp entry for klass should not be zero");
152 return CPSlot(adr);
153 }
154
155 void slot_at_put(int which, CPSlot s) const {
156 assert(is_within_bounds(which), "index out of bounds");
157 assert(s.value() != 0, "Caught something");
158 *(intptr_t*)&base()[which] = s.value();
159 }
160 intptr_t* obj_at_addr(int which) const {
161 assert(is_within_bounds(which), "index out of bounds");
162 return (intptr_t*) &base()[which];
163 }
164
165 jint* int_at_addr(int which) const {
166 assert(is_within_bounds(which), "index out of bounds");
167 return (jint*) &base()[which];
168 }
169
170 jlong* long_at_addr(int which) const {
171 assert(is_within_bounds(which), "index out of bounds");
172 return (jlong*) &base()[which];
173 }
174
175 jfloat* float_at_addr(int which) const {
176 assert(is_within_bounds(which), "index out of bounds");
177 return (jfloat*) &base()[which];
178 }
179
180 jdouble* double_at_addr(int which) const {
181 assert(is_within_bounds(which), "index out of bounds");
182 return (jdouble*) &base()[which];
183 }
184
185 ConstantPool(Array<u1>* tags);
186 ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
187 public:
188 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS);
189
190 bool is_constantPool() const volatile { return true; }
191
192 Array<u1>* tags() const { return _tags; }
193 Array<u2>* operands() const { return _operands; }
194
195 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; }
196 void set_has_preresolution() {
197 assert(!is_shared(), "should never be called on shared ConstantPools");
198 _flags |= _has_preresolution;
199 }
200
201 // Redefine classes support. If a method refering to this constant pool
202 // is on the executing stack, or as a handle in vm code, this constant pool
203 // can't be removed from the set of previous versions saved in the instance
204 // class.
205 bool on_stack() const { return (_flags &_on_stack) != 0; }
206 void set_on_stack(const bool value);
207
208 // Faster than MetaspaceObj::is_shared() - used by set_on_stack()
209 bool is_shared() const { return (_flags & _is_shared) != 0; }
210
211 bool has_dynamic_constant() const { return (_flags & _has_dynamic_constant) != 0; }
212 void set_has_dynamic_constant() { _flags |= _has_dynamic_constant; }
213
214 // Klass holding pool
215 InstanceKlass* pool_holder() const { return _pool_holder; }
216 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; }
217 InstanceKlass** pool_holder_addr() { return &_pool_holder; }
218
219 // Interpreter runtime support
220 ConstantPoolCache* cache() const { return _cache; }
221 void set_cache(ConstantPoolCache* cache){ _cache = cache; }
222
223 virtual void metaspace_pointers_do(MetaspaceClosure* iter);
224 virtual MetaspaceObj::Type type() const { return ConstantPoolType; }
225
226 // Create object cache in the constant pool
227 void initialize_resolved_references(ClassLoaderData* loader_data,
228 const intStack& reference_map,
229 int constant_pool_map_length,
230 TRAPS);
231
232 // resolved strings, methodHandles and callsite objects from the constant pool
233 objArrayOop resolved_references() const;
234 objArrayOop resolved_references_or_null() const;
235 // mapping resolved object array indexes to cp indexes and back.
236 int object_to_cp_index(int index) { return reference_map()->at(index); }
237 int cp_to_object_index(int index);
238
239 void set_resolved_klasses(Array<Klass*>* rk) { _resolved_klasses = rk; }
240 Array<Klass*>* resolved_klasses() const { return _resolved_klasses; }
241 void allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS);
242 void initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS);
243
244 // Invokedynamic indexes.
245 // They must look completely different from normal indexes.
246 // The main reason is that byte swapping is sometimes done on normal indexes.
247 // Finally, it is helpful for debugging to tell the two apart.
248 static bool is_invokedynamic_index(int i) { return (i < 0); }
249 static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; }
250 static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; }
251
252
253 // The invokedynamic points at a CP cache entry. This entry points back
254 // at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry
255 // in the resolved_references array (which provides the appendix argument).
256 int invokedynamic_cp_cache_index(int index) const {
257 assert (is_invokedynamic_index(index), "should be a invokedynamic index");
258 int cache_index = decode_invokedynamic_index(index);
259 return cache_index;
260 }
261 ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int index) const {
262 // decode index that invokedynamic points to.
263 int cp_cache_index = invokedynamic_cp_cache_index(index);
264 return cache()->entry_at(cp_cache_index);
265 }
266
267 // Assembly code support
268 static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); }
269 static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); }
270 static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); }
271 static int resolved_klasses_offset_in_bytes() { return offset_of(ConstantPool, _resolved_klasses); }
272
273 // Storing constants
274
275 // For temporary use while constructing constant pool
276 void klass_index_at_put(int which, int name_index) {
277 tag_at_put(which, JVM_CONSTANT_ClassIndex);
278 *int_at_addr(which) = name_index;
279 }
280
281 // Anonymous class support:
282 void klass_at_put(int class_index, int name_index, int resolved_klass_index, Klass* k, Symbol* name);
283 void klass_at_put(int class_index, Klass* k);
284
285 void unresolved_klass_at_put(int which, int name_index, int resolved_klass_index) {
286 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
287
288 assert((name_index & 0xffff0000) == 0, "must be");
289 assert((resolved_klass_index & 0xffff0000) == 0, "must be");
290 *int_at_addr(which) =
291 build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
292 }
293
294 void method_handle_index_at_put(int which, int ref_kind, int ref_index) {
295 tag_at_put(which, JVM_CONSTANT_MethodHandle);
296 *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind;
297 }
298
299 void method_type_index_at_put(int which, int ref_index) {
300 tag_at_put(which, JVM_CONSTANT_MethodType);
301 *int_at_addr(which) = ref_index;
302 }
303
304 void dynamic_constant_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
305 tag_at_put(which, JVM_CONSTANT_Dynamic);
306 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
307 }
308
309 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
310 tag_at_put(which, JVM_CONSTANT_InvokeDynamic);
311 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
312 }
313
314 void unresolved_string_at_put(int which, Symbol* s) {
315 release_tag_at_put(which, JVM_CONSTANT_String);
316 slot_at_put(which, CPSlot(s));
317 }
318
319 void int_at_put(int which, jint i) {
320 tag_at_put(which, JVM_CONSTANT_Integer);
321 *int_at_addr(which) = i;
322 }
323
324 void long_at_put(int which, jlong l) {
325 tag_at_put(which, JVM_CONSTANT_Long);
326 // *long_at_addr(which) = l;
327 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
328 }
329
330 void float_at_put(int which, jfloat f) {
331 tag_at_put(which, JVM_CONSTANT_Float);
332 *float_at_addr(which) = f;
333 }
334
335 void double_at_put(int which, jdouble d) {
336 tag_at_put(which, JVM_CONSTANT_Double);
337 // *double_at_addr(which) = d;
338 // u8 temp = *(u8*) &d;
339 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
340 }
341
342 Symbol** symbol_at_addr(int which) const {
343 assert(is_within_bounds(which), "index out of bounds");
344 return (Symbol**) &base()[which];
345 }
346
347 void symbol_at_put(int which, Symbol* s) {
348 assert(s->refcount() != 0, "should have nonzero refcount");
349 tag_at_put(which, JVM_CONSTANT_Utf8);
350 *symbol_at_addr(which) = s;
351 }
352
353 void string_at_put(int which, int obj_index, oop str);
354
355 // For temporary use while constructing constant pool
356 void string_index_at_put(int which, int string_index) {
357 tag_at_put(which, JVM_CONSTANT_StringIndex);
358 *int_at_addr(which) = string_index;
359 }
360
361 void field_at_put(int which, int class_index, int name_and_type_index) {
362 tag_at_put(which, JVM_CONSTANT_Fieldref);
363 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
364 }
365
366 void method_at_put(int which, int class_index, int name_and_type_index) {
367 tag_at_put(which, JVM_CONSTANT_Methodref);
368 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
369 }
370
371 void interface_method_at_put(int which, int class_index, int name_and_type_index) {
372 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
373 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
374 }
375
376 void name_and_type_at_put(int which, int name_index, int signature_index) {
377 tag_at_put(which, JVM_CONSTANT_NameAndType);
378 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
379 }
380
381 // Tag query
382
383 constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); }
384
385 // Fetching constants
386
387 Klass* klass_at(int which, TRAPS) {
388 constantPoolHandle h_this(THREAD, this);
389 return klass_at_impl(h_this, which, true, THREAD);
390 }
391
392 // Version of klass_at that doesn't save the resolution error, called during deopt
393 Klass* klass_at_ignore_error(int which, TRAPS) {
394 constantPoolHandle h_this(THREAD, this);
395 return klass_at_impl(h_this, which, false, THREAD);
396 }
397
398 CPKlassSlot klass_slot_at(int which) const {
399 assert(tag_at(which).is_unresolved_klass() || tag_at(which).is_klass(),
400 "Corrupted constant pool");
401 int value = *int_at_addr(which);
402 int name_index = extract_high_short_from_int(value);
403 int resolved_klass_index = extract_low_short_from_int(value);
404 return CPKlassSlot(name_index, resolved_klass_index);
405 }
406
407 Symbol* klass_name_at(int which) const; // Returns the name, w/o resolving.
408 int klass_name_index_at(int which) const {
409 return klass_slot_at(which).name_index();
410 }
411
412 Klass* resolved_klass_at(int which) const { // Used by Compiler
413 guarantee(tag_at(which).is_klass(), "Corrupted constant pool");
414 // Must do an acquire here in case another thread resolved the klass
415 // behind our back, lest we later load stale values thru the oop.
416 CPKlassSlot kslot = klass_slot_at(which);
417 assert(tag_at(kslot.name_index()).is_symbol(), "sanity");
418
419 Klass** adr = resolved_klasses()->adr_at(kslot.resolved_klass_index());
420 return OrderAccess::load_acquire(adr);
421 }
422
423 // RedefineClasses() API support:
424 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); }
425 void temp_unresolved_klass_at_put(int which, int name_index) {
426 // Used only during constant pool merging for class redefinition. The resolved klass index
427 // will be initialized later by a call to initialize_unresolved_klasses().
428 unresolved_klass_at_put(which, name_index, CPKlassSlot::_temp_resolved_klass_index);
429 }
430
431 jint int_at(int which) {
432 assert(tag_at(which).is_int(), "Corrupted constant pool");
433 return *int_at_addr(which);
434 }
435
436 jlong long_at(int which) {
437 assert(tag_at(which).is_long(), "Corrupted constant pool");
438 // return *long_at_addr(which);
439 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
440 return *((jlong*)&tmp);
441 }
442
443 jfloat float_at(int which) {
444 assert(tag_at(which).is_float(), "Corrupted constant pool");
445 return *float_at_addr(which);
446 }
447
448 jdouble double_at(int which) {
449 assert(tag_at(which).is_double(), "Corrupted constant pool");
450 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
451 return *((jdouble*)&tmp);
452 }
453
454 Symbol* symbol_at(int which) const {
455 assert(tag_at(which).is_utf8(), "Corrupted constant pool");
456 return *symbol_at_addr(which);
457 }
458
459 oop string_at(int which, int obj_index, TRAPS) {
460 constantPoolHandle h_this(THREAD, this);
461 return string_at_impl(h_this, which, obj_index, THREAD);
462 }
463 oop string_at(int which, TRAPS) {
464 int obj_index = cp_to_object_index(which);
465 return string_at(which, obj_index, THREAD);
466 }
467
468 // Version that can be used before string oop array is created.
469 oop uncached_string_at(int which, TRAPS);
470
471 // A "pseudo-string" is an non-string oop that has found its way into
472 // a String entry.
473 // This can happen if the user patches a live
474 // object into a CONSTANT_String entry of an anonymous class.
475 // Method oops internally created for method handles may also
476 // use pseudo-strings to link themselves to related metaobjects.
477
478 bool is_pseudo_string_at(int which) {
479 assert(tag_at(which).is_string(), "Corrupted constant pool");
480 return slot_at(which).is_pseudo_string();
481 }
482
483 oop pseudo_string_at(int which, int obj_index) {
484 assert(is_pseudo_string_at(which), "must be a pseudo-string");
485 oop s = resolved_references()->obj_at(obj_index);
486 return s;
487 }
488
489 oop pseudo_string_at(int which) {
490 assert(is_pseudo_string_at(which), "must be a pseudo-string");
491 int obj_index = cp_to_object_index(which);
492 oop s = resolved_references()->obj_at(obj_index);
493 return s;
494 }
495
496 void pseudo_string_at_put(int which, int obj_index, oop x) {
497 assert(tag_at(which).is_string(), "Corrupted constant pool");
498 Symbol* sym = unresolved_string_at(which);
499 slot_at_put(which, CPSlot(sym, CPSlot::_pseudo_bit));
500 string_at_put(which, obj_index, x); // this works just fine
501 }
502
503 // only called when we are sure a string entry is already resolved (via an
504 // earlier string_at call.
505 oop resolved_string_at(int which) {
506 assert(tag_at(which).is_string(), "Corrupted constant pool");
507 // Must do an acquire here in case another thread resolved the klass
508 // behind our back, lest we later load stale values thru the oop.
509 // we might want a volatile_obj_at in ObjArrayKlass.
510 int obj_index = cp_to_object_index(which);
511 return resolved_references()->obj_at(obj_index);
512 }
513
514 Symbol* unresolved_string_at(int which) {
515 assert(tag_at(which).is_string(), "Corrupted constant pool");
516 Symbol* sym = slot_at(which).get_symbol();
517 return sym;
518 }
519
520 // Returns an UTF8 for a CONSTANT_String entry at a given index.
521 // UTF8 char* representation was chosen to avoid conversion of
522 // java_lang_Strings at resolved entries into Symbol*s
523 // or vice versa.
524 char* string_at_noresolve(int which);
525
526 jint name_and_type_at(int which) {
527 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
528 return *int_at_addr(which);
529 }
530
531 int method_handle_ref_kind_at(int which) {
532 assert(tag_at(which).is_method_handle() ||
533 tag_at(which).is_method_handle_in_error(), "Corrupted constant pool");
534 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits
535 }
536 int method_handle_index_at(int which) {
537 assert(tag_at(which).is_method_handle() ||
538 tag_at(which).is_method_handle_in_error(), "Corrupted constant pool");
539 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits
540 }
541 int method_type_index_at(int which) {
542 assert(tag_at(which).is_method_type() ||
543 tag_at(which).is_method_type_in_error(), "Corrupted constant pool");
544 return *int_at_addr(which);
545 }
546
547 // Derived queries:
548 Symbol* method_handle_name_ref_at(int which) {
549 int member = method_handle_index_at(which);
550 return impl_name_ref_at(member, true);
551 }
552 Symbol* method_handle_signature_ref_at(int which) {
553 int member = method_handle_index_at(which);
554 return impl_signature_ref_at(member, true);
555 }
556 int method_handle_klass_index_at(int which) {
557 int member = method_handle_index_at(which);
558 return impl_klass_ref_index_at(member, true);
559 }
560 Symbol* method_type_signature_at(int which) {
561 int sym = method_type_index_at(which);
562 return symbol_at(sym);
563 }
564
565 int invoke_dynamic_name_and_type_ref_index_at(int which) {
566 assert(tag_at(which).is_invoke_dynamic() ||
567 tag_at(which).is_dynamic_constant() ||
568 tag_at(which).is_dynamic_constant_in_error(), "Corrupted constant pool");
569 return extract_high_short_from_int(*int_at_addr(which));
570 }
571 int invoke_dynamic_bootstrap_specifier_index(int which) {
572 assert(tag_at(which).is_invoke_dynamic() ||
573 tag_at(which).is_dynamic_constant() ||
574 tag_at(which).is_dynamic_constant_in_error(), "Corrupted constant pool");
575 return extract_low_short_from_int(*int_at_addr(which));
576 }
577 int invoke_dynamic_operand_base(int which) {
578 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
579 return operand_offset_at(operands(), bootstrap_specifier_index);
580 }
581 // The first part of the operands array consists of an index into the second part.
582 // Extract a 32-bit index value from the first part.
583 static int operand_offset_at(Array<u2>* operands, int bootstrap_specifier_index) {
584 int n = (bootstrap_specifier_index * 2);
585 assert(n >= 0 && n+2 <= operands->length(), "oob");
586 // The first 32-bit index points to the beginning of the second part
587 // of the operands array. Make sure this index is in the first part.
588 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0),
589 operands->at(1)));
590 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
591 int offset = build_int_from_shorts(operands->at(n+0),
592 operands->at(n+1));
593 // The offset itself must point into the second part of the array.
594 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)");
595 return offset;
596 }
597 static void operand_offset_at_put(Array<u2>* operands, int bootstrap_specifier_index, int offset) {
598 int n = bootstrap_specifier_index * 2;
599 assert(n >= 0 && n+2 <= operands->length(), "oob");
600 operands->at_put(n+0, extract_low_short_from_int(offset));
601 operands->at_put(n+1, extract_high_short_from_int(offset));
602 }
603 static int operand_array_length(Array<u2>* operands) {
604 if (operands == NULL || operands->length() == 0) return 0;
605 int second_part = operand_offset_at(operands, 0);
606 return (second_part / 2);
607 }
608
609 #ifdef ASSERT
610 // operand tuples fit together exactly, end to end
611 static int operand_limit_at(Array<u2>* operands, int bootstrap_specifier_index) {
612 int nextidx = bootstrap_specifier_index + 1;
613 if (nextidx == operand_array_length(operands))
614 return operands->length();
615 else
616 return operand_offset_at(operands, nextidx);
617 }
618 int invoke_dynamic_operand_limit(int which) {
619 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
620 return operand_limit_at(operands(), bootstrap_specifier_index);
621 }
622 #endif //ASSERT
623
624 // layout of InvokeDynamic and Dynamic bootstrap method specifier (in second part of operands array):
625 enum {
626 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
627 _indy_argc_offset = 1, // u2 argc
628 _indy_argv_offset = 2 // u2 argv[argc]
629 };
630
631 // These functions are used in RedefineClasses for CP merge
632
633 int operand_offset_at(int bootstrap_specifier_index) {
634 assert(0 <= bootstrap_specifier_index &&
635 bootstrap_specifier_index < operand_array_length(operands()),
636 "Corrupted CP operands");
637 return operand_offset_at(operands(), bootstrap_specifier_index);
638 }
639 int operand_bootstrap_method_ref_index_at(int bootstrap_specifier_index) {
640 int offset = operand_offset_at(bootstrap_specifier_index);
641 return operands()->at(offset + _indy_bsm_offset);
642 }
643 int operand_argument_count_at(int bootstrap_specifier_index) {
644 int offset = operand_offset_at(bootstrap_specifier_index);
645 int argc = operands()->at(offset + _indy_argc_offset);
646 return argc;
647 }
648 int operand_argument_index_at(int bootstrap_specifier_index, int j) {
649 int offset = operand_offset_at(bootstrap_specifier_index);
650 return operands()->at(offset + _indy_argv_offset + j);
651 }
652 int operand_next_offset_at(int bootstrap_specifier_index) {
653 int offset = operand_offset_at(bootstrap_specifier_index) + _indy_argv_offset
654 + operand_argument_count_at(bootstrap_specifier_index);
655 return offset;
656 }
657 // Compare a bootsrap specifier in the operands arrays
658 bool compare_operand_to(int bootstrap_specifier_index1, const constantPoolHandle& cp2,
659 int bootstrap_specifier_index2, TRAPS);
660 // Find a bootsrap specifier in the operands array
661 int find_matching_operand(int bootstrap_specifier_index, const constantPoolHandle& search_cp,
662 int operands_cur_len, TRAPS);
663 // Resize the operands array with delta_len and delta_size
664 void resize_operands(int delta_len, int delta_size, TRAPS);
665 // Extend the operands array with the length and size of the ext_cp operands
666 void extend_operands(const constantPoolHandle& ext_cp, TRAPS);
667 // Shrink the operands array to a smaller array with new_len length
668 void shrink_operands(int new_len, TRAPS);
669
670 int invoke_dynamic_bootstrap_method_ref_index_at(int which) {
671 assert(tag_at(which).is_invoke_dynamic() ||
672 tag_at(which).is_dynamic_constant() ||
673 tag_at(which).is_dynamic_constant_in_error(), "Corrupted constant pool");
674 int op_base = invoke_dynamic_operand_base(which);
675 return operands()->at(op_base + _indy_bsm_offset);
676 }
677 int invoke_dynamic_argument_count_at(int which) {
678 assert(tag_at(which).is_invoke_dynamic() ||
679 tag_at(which).is_dynamic_constant() ||
680 tag_at(which).is_dynamic_constant_in_error(), "Corrupted constant pool");
681 int op_base = invoke_dynamic_operand_base(which);
682 int argc = operands()->at(op_base + _indy_argc_offset);
683 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
684 int next_offset = invoke_dynamic_operand_limit(which));
685 assert(end_offset == next_offset, "matched ending");
686 return argc;
687 }
688 int invoke_dynamic_argument_index_at(int which, int j) {
689 int op_base = invoke_dynamic_operand_base(which);
690 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset));
691 assert((uint)j < (uint)argc, "oob");
692 return operands()->at(op_base + _indy_argv_offset + j);
693 }
694
695 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
696 // name_and_type_ref_index_at) all expect to be passed indices obtained
697 // directly from the bytecode.
698 // If the indices are meant to refer to fields or methods, they are
699 // actually rewritten constant pool cache indices.
700 // The routine remap_instruction_operand_from_cache manages the adjustment
701 // of these values back to constant pool indices.
702
703 // There are also "uncached" versions which do not adjust the operand index; see below.
704
705 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear.
706 // In a few cases (the verifier) there are uses before a cpcache has been built,
707 // which are handled by a dynamic check in remap_instruction_operand_from_cache.
708 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode.
709
710 // Lookup for entries consisting of (klass_index, name_and_type index)
711 Klass* klass_ref_at(int which, TRAPS);
712 Symbol* klass_ref_at_noresolve(int which);
713 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); }
714 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); }
715
716 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); }
717 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); }
718
719 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG
720
721 constantTag tag_ref_at(int cp_cache_index) { return impl_tag_ref_at(cp_cache_index, false); }
722
723 // Lookup for entries consisting of (name_index, signature_index)
724 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt)
725 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt)
726
727 BasicType basic_type_for_signature_at(int which) const;
728
729 // Resolve string constants (to prevent allocation during compilation)
730 void resolve_string_constants(TRAPS) {
731 constantPoolHandle h_this(THREAD, this);
732 resolve_string_constants_impl(h_this, CHECK);
733 }
734
735 // CDS support
736 void archive_resolved_references(Thread *THREAD) NOT_CDS_JAVA_HEAP_RETURN;
737 void resolve_class_constants(TRAPS) NOT_CDS_JAVA_HEAP_RETURN;
738 void remove_unshareable_info();
739 void restore_unshareable_info(TRAPS);
740 // The ConstantPool vtable is restored by this call when the ConstantPool is
741 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for
742 // all the gory details. SA, dtrace and pstack helpers distinguish metadata
743 // by their vtable.
744 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); }
745
746 private:
747 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
748 public:
749
750 BasicType basic_type_for_constant_at(int which);
751
752 // Resolve late bound constants.
753 oop resolve_constant_at(int index, TRAPS) {
754 constantPoolHandle h_this(THREAD, this);
755 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, NULL, THREAD);
756 }
757
758 oop resolve_cached_constant_at(int cache_index, TRAPS) {
759 constantPoolHandle h_this(THREAD, this);
760 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, NULL, THREAD);
761 }
762
763 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) {
764 constantPoolHandle h_this(THREAD, this);
765 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, NULL, THREAD);
766 }
767
768 oop find_cached_constant_at(int pool_index, bool& found_it, TRAPS) {
769 constantPoolHandle h_this(THREAD, this);
770 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, &found_it, THREAD);
771 }
772
773 oop resolve_bootstrap_specifier_at(int index, TRAPS) {
774 constantPoolHandle h_this(THREAD, this);
775 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD);
776 }
777
778 void copy_bootstrap_arguments_at(int index,
779 int start_arg, int end_arg,
780 objArrayHandle info, int pos,
781 bool must_resolve, Handle if_not_available, TRAPS) {
782 constantPoolHandle h_this(THREAD, this);
783 copy_bootstrap_arguments_at_impl(h_this, index, start_arg, end_arg,
784 info, pos, must_resolve, if_not_available, THREAD);
785 }
786
787 // Klass name matches name at offset
788 bool klass_name_at_matches(const InstanceKlass* k, int which);
789
790 // Sizing
791 int length() const { return _length; }
792 void set_length(int length) { _length = length; }
793
794 // Tells whether index is within bounds.
795 bool is_within_bounds(int index) const {
796 return 0 <= index && index < length();
797 }
798
799 // Sizing (in words)
800 static int header_size() {
801 return align_up((int)sizeof(ConstantPool), wordSize) / wordSize;
802 }
803 static int size(int length) { return align_metadata_size(header_size() + length); }
804 int size() const { return size(length()); }
805 #if INCLUDE_SERVICES
806 void collect_statistics(KlassSizeStats *sz) const;
807 #endif
808
809 // ConstantPools should be stored in the read-only region of CDS archive.
810 static bool is_read_only_by_default() { return true; }
811
812 friend class ClassFileParser;
813 friend class SystemDictionary;
814
815 // Used by CDS. These classes need to access the private ConstantPool() constructor.
816 template <class T> friend class CppVtableTesterA;
817 template <class T> friend class CppVtableTesterB;
818 template <class T> friend class CppVtableCloner;
819
820 // Used by compiler to prevent classloading.
821 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which);
822 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
823 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
824 static bool has_method_type_at_if_loaded (const constantPoolHandle& this_cp, int which);
825 static oop method_type_at_if_loaded (const constantPoolHandle& this_cp, int which);
826 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which);
827
828 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
829 // future by other Java code. These take constant pool indices rather than
830 // constant pool cache indices as do the peer methods above.
831 Symbol* uncached_klass_ref_at_noresolve(int which);
832 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); }
833 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); }
834 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); }
835 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); }
836
837 // Sharing
838 int pre_resolve_shared_klasses(TRAPS);
839
840 // Debugging
841 const char* printable_name_at(int which) PRODUCT_RETURN0;
842
843 #ifdef ASSERT
844 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices
845 #else
846 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op
847 #endif //ASSERT
848
849 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) {
850 if (invokedynamic_ok && is_invokedynamic_index(raw_index))
851 return decode_invokedynamic_index(raw_index);
852 else
853 return raw_index - CPCACHE_INDEX_TAG;
854 }
855
856 private:
857
858 void set_resolved_references(OopHandle s) { _cache->set_resolved_references(s); }
859 Array<u2>* reference_map() const { return (_cache == NULL) ? NULL : _cache->reference_map(); }
860 void set_reference_map(Array<u2>* o) { _cache->set_reference_map(o); }
861
862 // patch JSR 292 resolved references after the class is linked.
863 void patch_resolved_references(GrowableArray<Handle>* cp_patches);
864
865 Symbol* impl_name_ref_at(int which, bool uncached);
866 Symbol* impl_signature_ref_at(int which, bool uncached);
867
868 int impl_klass_ref_index_at(int which, bool uncached);
869 int impl_name_and_type_ref_index_at(int which, bool uncached);
870 constantTag impl_tag_ref_at(int which, bool uncached);
871
872 // Used while constructing constant pool (only by ClassFileParser)
873 jint klass_index_at(int which) {
874 assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
875 return *int_at_addr(which);
876 }
877
878 jint string_index_at(int which) {
879 assert(tag_at(which).is_string_index(), "Corrupted constant pool");
880 return *int_at_addr(which);
881 }
882
883 // Performs the LinkResolver checks
884 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* klass, TRAPS);
885
886 // Implementation of methods that needs an exposed 'this' pointer, in order to
887 // handle GC while executing the method
888 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int which,
889 bool save_resolution_error, TRAPS);
890 static oop string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS);
891
892 static void trace_class_resolution(const constantPoolHandle& this_cp, Klass* k);
893
894 // Resolve string constants (to prevent allocation during compilation)
895 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS);
896
897 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int index, int cache_index,
898 bool* status_return, TRAPS);
899 static oop resolve_bootstrap_specifier_at_impl(const constantPoolHandle& this_cp, int index, TRAPS);
900 static void copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int index,
901 int start_arg, int end_arg,
902 objArrayHandle info, int pos,
903 bool must_resolve, Handle if_not_available, TRAPS);
904
905 // Exception handling
906 static Symbol* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception);
907 static void save_and_throw_exception(const constantPoolHandle& this_cp, int which, constantTag tag, TRAPS);
908
909 public:
910 // Exception handling
911 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS);
912
913 // Merging ConstantPool* support:
914 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2, TRAPS);
915 void copy_cp_to(int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS) {
916 constantPoolHandle h_this(THREAD, this);
917 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD);
918 }
919 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
920 static void copy_entry_to(const constantPoolHandle& from_cp, int from_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
921 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS);
922 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp, TRAPS);
923 int version() const { return _saved._version; }
924 void set_version(int version) { _saved._version = version; }
925 void increment_and_save_version(int version) {
926 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow
927 }
928
929 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; }
930 int resolved_reference_length() const { return _saved._resolved_reference_length; }
931
932 // Decrease ref counts of symbols that are in the constant pool
933 // when the holder class is unloaded
934 void unreference_symbols();
935
936 // Deallocate constant pool for RedefineClasses
937 void deallocate_contents(ClassLoaderData* loader_data);
938 void release_C_heap_structures();
939
940 // JVMTI accesss - GetConstantPool, RetransformClasses, ...
941 friend class JvmtiConstantPoolReconstituter;
942
943 private:
944 jint cpool_entry_size(jint idx);
945 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap);
946
947 // Copy cpool bytes into byte array.
948 // Returns:
949 // int > 0, count of the raw cpool bytes that have been copied
950 // 0, OutOfMemory error
951 // -1, Internal error
952 int copy_cpool_bytes(int cpool_size,
953 SymbolHashMap* tbl,
954 unsigned char *bytes);
955
956 public:
957 // Verify
958 void verify_on(outputStream* st);
959
960 // Printing
961 void print_on(outputStream* st) const;
962 void print_value_on(outputStream* st) const;
963 void print_entry_on(int index, outputStream* st);
964
965 const char* internal_name() const { return "{constant pool}"; }
966
967 #ifndef PRODUCT
968 // Compile the world support
969 static void preload_and_initialize_all_classes(ConstantPool* constant_pool, TRAPS);
970 #endif
971 };
972
973 class SymbolHashMapEntry : public CHeapObj<mtSymbol> {
974 private:
975 unsigned int _hash; // 32-bit hash for item
976 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket
977 Symbol* _symbol; // 1-st part of the mapping: symbol => value
978 u2 _value; // 2-nd part of the mapping: symbol => value
979
980 public:
981 unsigned int hash() const { return _hash; }
982 void set_hash(unsigned int hash) { _hash = hash; }
983
984 SymbolHashMapEntry* next() const { return _next; }
985 void set_next(SymbolHashMapEntry* next) { _next = next; }
986
987 Symbol* symbol() const { return _symbol; }
988 void set_symbol(Symbol* sym) { _symbol = sym; }
989
990 u2 value() const { return _value; }
991 void set_value(u2 value) { _value = value; }
992
993 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value)
994 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {}
995
996 }; // End SymbolHashMapEntry class
997
998
999 class SymbolHashMapBucket : public CHeapObj<mtSymbol> {
1000
1001 private:
1002 SymbolHashMapEntry* _entry;
1003
1004 public:
1005 SymbolHashMapEntry* entry() const { return _entry; }
1006 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; }
1007 void clear() { _entry = NULL; }
1008
1009 }; // End SymbolHashMapBucket class
1010
1011
1012 class SymbolHashMap: public CHeapObj<mtSymbol> {
1013
1014 private:
1015 // Default number of entries in the table
1016 enum SymbolHashMap_Constants {
1017 _Def_HashMap_Size = 256
1018 };
1019
1020 int _table_size;
1021 SymbolHashMapBucket* _buckets;
1022
1023 void initialize_table(int table_size);
1024
1025 public:
1026
1027 int table_size() const { return _table_size; }
1028
1029 SymbolHashMap() { initialize_table(_Def_HashMap_Size); }
1030 SymbolHashMap(int table_size) { initialize_table(table_size); }
1031
1032 // hash P(31) from Kernighan & Ritchie
1033 static unsigned int compute_hash(const char* str, int len) {
1034 unsigned int hash = 0;
1035 while (len-- > 0) {
1036 hash = 31*hash + (unsigned) *str;
1037 str++;
1038 }
1039 return hash;
1040 }
1041
1042 SymbolHashMapEntry* bucket(int i) {
1043 return _buckets[i].entry();
1044 }
1045
1046 void add_entry(Symbol* sym, u2 value);
1047 SymbolHashMapEntry* find_entry(Symbol* sym);
1048
1049 u2 symbol_to_value(Symbol* sym) {
1050 SymbolHashMapEntry *entry = find_entry(sym);
1051 return (entry == NULL) ? 0 : entry->value();
1052 }
1053
1054 ~SymbolHashMap() {
1055 SymbolHashMapEntry* next;
1056 for (int i = 0; i < _table_size; i++) {
1057 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
1058 next = cur->next();
1059 delete(cur);
1060 }
1061 }
1062 FREE_C_HEAP_ARRAY(SymbolHashMapBucket, _buckets);
1063 }
1064 }; // End SymbolHashMap class
1065
1066 #endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP