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