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