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