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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20 * or visit www.oracle.com if you need additional information or have any
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23 */
24
25 #ifndef SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP
26 #define SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP
27
28 #include "memory/allocation.inline.hpp"
29 #include "oops/arrayOop.hpp"
30 #include "oops/cpCache.hpp"
31 #include "oops/objArrayOop.hpp"
32 #include "oops/oopHandle.hpp"
33 #include "oops/symbol.hpp"
34 #include "oops/typeArrayOop.hpp"
35 #include "runtime/handles.hpp"
36 #include "utilities/align.hpp"
37 #include "utilities/bytes.hpp"
38 #include "utilities/constantTag.hpp"
39
40 // A ConstantPool is an array containing class constants as described in the
41 // class file.
42 //
43 // Most of the constant pool entries are written during class parsing, which
44 // is safe. For klass types, the constant pool entry is
45 // modified when the entry is resolved. If a klass constant pool
46 // entry is read without a lock, only the resolved state guarantees that
47 // the entry in the constant pool is a klass object and not a Symbol*.
48
49 class SymbolHashMap;
50
51 class CPSlot VALUE_OBJ_CLASS_SPEC {
52 friend class ConstantPool;
53 intptr_t _ptr;
54 enum TagBits {_pseudo_bit = 1};
55 public:
56
57 CPSlot(intptr_t ptr): _ptr(ptr) {}
58 CPSlot(Symbol* ptr, int tag_bits = 0): _ptr((intptr_t)ptr | tag_bits) {}
59
60 intptr_t value() { return _ptr; }
61 bool is_pseudo_string() { return (_ptr & _pseudo_bit) != 0; }
62
63 Symbol* get_symbol() {
64 return (Symbol*)(_ptr & ~_pseudo_bit);
65 }
66 };
67
68 // This represents a (JVM_CONSTANT_Class, JVM_CONSTANT_UnresolvedClass or JVM_CONSTANT_UnresolvedClassInError) or
69 // (JVM_CONSTANT_Value, JVM_CONSTANT_UnresolvedValue or JVM_CONSTANT_UnresolvedValueInError)
70 // slot in the constant pool.
71 class CPKlassSlot VALUE_OBJ_CLASS_SPEC {
72 // cp->symbol_at(_name_index) gives the name of the class.
73 int _name_index;
74
75 // cp->_resolved_klasses->at(_resolved_klass_index) gives the Klass* for the class.
76 int _resolved_klass_index;
77 public:
78 enum {
79 // This is used during constant pool merging where the resolved klass index is
80 // not yet known, and will be computed at a later stage (during a call to
81 // initialize_unresolved_klasses()).
82 _temp_resolved_klass_index = 0xffff
83 };
84 CPKlassSlot(int n, int rk) {
85 _name_index = n;
86 _resolved_klass_index = rk;
87 }
88 int name_index() const {
89 return _name_index;
90 }
91 int resolved_klass_index() const {
92 assert(_resolved_klass_index != _temp_resolved_klass_index, "constant pool merging was incomplete");
93 return _resolved_klass_index;
94 }
95 };
96
97 class KlassSizeStats;
98
99 class ConstantPool : public Metadata {
100 friend class VMStructs;
101 friend class JVMCIVMStructs;
102 friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast
103 friend class Universe; // For null constructor
104 private:
105 // If you add a new field that points to any metaspace object, you
106 // must add this field to ConstantPool::metaspace_pointers_do().
107 Array<u1>* _tags; // the tag array describing the constant pool's contents
108 ConstantPoolCache* _cache; // the cache holding interpreter runtime information
109 InstanceKlass* _pool_holder; // the corresponding class
110 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
111
112 // Consider using an array of compressed klass pointers to
113 // save space on 64-bit platforms.
114 Array<Klass*>* _resolved_klasses;
115
116 enum {
117 _has_preresolution = 1, // Flags
118 _on_stack = 2,
119 _is_shared = 4,
120 _has_dynamic_constant = 8
121 };
122
123 int _flags; // old fashioned bit twiddling
124 int _length; // number of elements in the array
125
126 union {
127 // set for CDS to restore resolved references
128 int _resolved_reference_length;
129 // keeps version number for redefined classes (used in backtrace)
130 int _version;
131 } _saved;
132
133 void set_tags(Array<u1>* tags) { _tags = tags; }
134 void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); }
135 void release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); }
136
137 u1* tag_addr_at(int which) const { return tags()->adr_at(which); }
138
139 void set_operands(Array<u2>* operands) { _operands = operands; }
140
141 int flags() const { return _flags; }
142 void set_flags(int f) { _flags = f; }
143
144 private:
145 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); }
146
147 CPSlot slot_at(int which) const {
148 assert(is_within_bounds(which), "index out of bounds");
149 assert(!tag_at(which).is_unresolved_klass() && !tag_at(which).is_unresolved_klass_in_error() &&
150 !tag_at(which).is_unresolved_value_type() && !tag_at(which).is_unresolved_value_type_in_error(), "Corrupted constant pool");
151 // Uses volatile because the klass slot changes without a lock.
152 intptr_t adr = OrderAccess::load_acquire(obj_at_addr_raw(which));
153 assert(adr != 0 || which == 0, "cp entry for klass should not be zero");
154 return CPSlot(adr);
155 }
156
157 void slot_at_put(int which, CPSlot s) const {
158 assert(is_within_bounds(which), "index out of bounds");
159 assert(s.value() != 0, "Caught something");
160 *(intptr_t*)&base()[which] = s.value();
161 }
162 intptr_t* obj_at_addr_raw(int which) const {
163 assert(is_within_bounds(which), "index out of bounds");
164 return (intptr_t*) &base()[which];
165 }
166
167 jint* int_at_addr(int which) const {
168 assert(is_within_bounds(which), "index out of bounds");
169 return (jint*) &base()[which];
170 }
171
172 jlong* long_at_addr(int which) const {
173 assert(is_within_bounds(which), "index out of bounds");
174 return (jlong*) &base()[which];
175 }
176
177 jfloat* float_at_addr(int which) const {
178 assert(is_within_bounds(which), "index out of bounds");
179 return (jfloat*) &base()[which];
180 }
181
182 jdouble* double_at_addr(int which) const {
183 assert(is_within_bounds(which), "index out of bounds");
184 return (jdouble*) &base()[which];
185 }
186
187 ConstantPool(Array<u1>* tags);
188 ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
189 public:
190 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS);
191
192 bool is_constantPool() const volatile { return true; }
193
194 Array<u1>* tags() const { return _tags; }
195 Array<u2>* operands() const { return _operands; }
196
197 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; }
198 void set_has_preresolution() {
199 assert(!is_shared(), "should never be called on shared ConstantPools");
200 _flags |= _has_preresolution;
201 }
202
203 // Redefine classes support. If a method refering to this constant pool
204 // is on the executing stack, or as a handle in vm code, this constant pool
205 // can't be removed from the set of previous versions saved in the instance
206 // class.
207 bool on_stack() const { return (_flags &_on_stack) != 0; }
208 void set_on_stack(const bool value);
209
210 // Faster than MetaspaceObj::is_shared() - used by set_on_stack()
211 bool is_shared() const { return (_flags & _is_shared) != 0; }
212
213 bool has_dynamic_constant() const { return (_flags & _has_dynamic_constant) != 0; }
214 void set_has_dynamic_constant() { _flags |= _has_dynamic_constant; }
215
216 // Klass holding pool
217 InstanceKlass* pool_holder() const { return _pool_holder; }
218 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; }
219 InstanceKlass** pool_holder_addr() { return &_pool_holder; }
220
221 // Interpreter runtime support
222 ConstantPoolCache* cache() const { return _cache; }
223 void set_cache(ConstantPoolCache* cache){ _cache = cache; }
224
225 virtual void metaspace_pointers_do(MetaspaceClosure* iter);
226 virtual MetaspaceObj::Type type() const { return ConstantPoolType; }
227
228 // Create object cache in the constant pool
229 void initialize_resolved_references(ClassLoaderData* loader_data,
230 const intStack& reference_map,
231 int constant_pool_map_length,
232 TRAPS);
233
234 // resolved strings, methodHandles and callsite objects from the constant pool
235 objArrayOop resolved_references() const;
236 objArrayOop resolved_references_or_null() const;
237 // mapping resolved object array indexes to cp indexes and back.
238 int object_to_cp_index(int index) { return reference_map()->at(index); }
239 int cp_to_object_index(int index);
240
241 void set_resolved_klasses(Array<Klass*>* rk) { _resolved_klasses = rk; }
242 Array<Klass*>* resolved_klasses() const { return _resolved_klasses; }
243 void allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS);
244 void initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS);
245
246 // Invokedynamic indexes.
247 // They must look completely different from normal indexes.
248 // The main reason is that byte swapping is sometimes done on normal indexes.
249 // Finally, it is helpful for debugging to tell the two apart.
250 static bool is_invokedynamic_index(int i) { return (i < 0); }
251 static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; }
252 static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; }
253
254
255 // The invokedynamic points at a CP cache entry. This entry points back
256 // at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry
257 // in the resolved_references array (which provides the appendix argument).
258 int invokedynamic_cp_cache_index(int index) const {
259 assert (is_invokedynamic_index(index), "should be a invokedynamic index");
260 int cache_index = decode_invokedynamic_index(index);
261 return cache_index;
262 }
263 ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int index) const {
264 // decode index that invokedynamic points to.
265 int cp_cache_index = invokedynamic_cp_cache_index(index);
266 return cache()->entry_at(cp_cache_index);
267 }
268
269 // Assembly code support
270 static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); }
271 static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); }
272 static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); }
273 static int resolved_klasses_offset_in_bytes() { return offset_of(ConstantPool, _resolved_klasses); }
274
275 // Storing constants
276
277 // For temporary use while constructing constant pool. Used during a retransform/class redefinition as well.
278 void klass_index_at_put(int which, int name_index) {
279 tag_at_put(which, JVM_CONSTANT_ClassIndex);
280 *int_at_addr(which) = name_index;
281 }
282
283 // For temporary use while constructing constant pool. Used during a retransform/class redefinition as well.
284 void value_type_index_at_put(int which, int name_index) {
285 tag_at_put(which, JVM_CONSTANT_ValueIndex);
286 *int_at_addr(which) = name_index;
287 }
288
289 // Anonymous class support:
290 void klass_at_put(int class_index, int name_index, int resolved_klass_index, Klass* k, Symbol* name);
291 void klass_at_put(int class_index, Klass* k);
292
293 void unresolved_klass_at_put(int which, int name_index, int resolved_klass_index) {
294 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
295
296 assert((name_index & 0xffff0000) == 0, "must be");
297 assert((resolved_klass_index & 0xffff0000) == 0, "must be");
298 *int_at_addr(which) =
299 build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
300 }
301
302 void unresolved_value_type_at_put(int which, int name_index, int resolved_klass_index) {
303 release_tag_at_put(which, JVM_CONSTANT_UnresolvedValue);
304
305 assert((name_index & 0xffff0000) == 0, "must be");
306 assert((resolved_klass_index & 0xffff0000) == 0, "must be");
307 *int_at_addr(which) =
308 build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
309 }
310
311 void method_handle_index_at_put(int which, int ref_kind, int ref_index) {
312 tag_at_put(which, JVM_CONSTANT_MethodHandle);
313 *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind;
314 }
315
316 void method_type_index_at_put(int which, int ref_index) {
317 tag_at_put(which, JVM_CONSTANT_MethodType);
318 *int_at_addr(which) = ref_index;
319 }
320
321 void dynamic_constant_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
322 tag_at_put(which, JVM_CONSTANT_Dynamic);
323 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
324 }
325
326 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
327 tag_at_put(which, JVM_CONSTANT_InvokeDynamic);
328 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
329 }
330
331 void unresolved_string_at_put(int which, Symbol* s) {
332 release_tag_at_put(which, JVM_CONSTANT_String);
333 slot_at_put(which, CPSlot(s));
334 }
335
336 void int_at_put(int which, jint i) {
337 tag_at_put(which, JVM_CONSTANT_Integer);
338 *int_at_addr(which) = i;
339 }
340
341 void long_at_put(int which, jlong l) {
342 tag_at_put(which, JVM_CONSTANT_Long);
343 // *long_at_addr(which) = l;
344 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
345 }
346
347 void float_at_put(int which, jfloat f) {
348 tag_at_put(which, JVM_CONSTANT_Float);
349 *float_at_addr(which) = f;
350 }
351
352 void double_at_put(int which, jdouble d) {
353 tag_at_put(which, JVM_CONSTANT_Double);
354 // *double_at_addr(which) = d;
355 // u8 temp = *(u8*) &d;
356 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
357 }
358
359 Symbol** symbol_at_addr(int which) const {
360 assert(is_within_bounds(which), "index out of bounds");
361 return (Symbol**) &base()[which];
362 }
363
364 void symbol_at_put(int which, Symbol* s) {
365 assert(s->refcount() != 0, "should have nonzero refcount");
366 tag_at_put(which, JVM_CONSTANT_Utf8);
367 *symbol_at_addr(which) = s;
368 }
369
370 void string_at_put(int which, int obj_index, oop str);
371
372 // For temporary use while constructing constant pool
373 void string_index_at_put(int which, int string_index) {
374 tag_at_put(which, JVM_CONSTANT_StringIndex);
375 *int_at_addr(which) = string_index;
376 }
377
378 void field_at_put(int which, int class_index, int name_and_type_index) {
379 tag_at_put(which, JVM_CONSTANT_Fieldref);
380 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
381 }
382
383 void method_at_put(int which, int class_index, int name_and_type_index) {
384 tag_at_put(which, JVM_CONSTANT_Methodref);
385 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
386 }
387
388 void interface_method_at_put(int which, int class_index, int name_and_type_index) {
389 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
390 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
391 }
392
393 void name_and_type_at_put(int which, int name_index, int signature_index) {
394 tag_at_put(which, JVM_CONSTANT_NameAndType);
395 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
396 }
397
398 // Tag query
399
400 constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); }
401
402 // Fetching constants
403
404 Klass* klass_at(int which, TRAPS) {
405 constantPoolHandle h_this(THREAD, this);
406 return klass_at_impl(h_this, which, true, THREAD);
407 }
408
409 // Version of klass_at that doesn't save the resolution error, called during deopt
410 Klass* klass_at_ignore_error(int which, TRAPS) {
411 constantPoolHandle h_this(THREAD, this);
412 return klass_at_impl(h_this, which, false, THREAD);
413 }
414
415 CPKlassSlot klass_slot_at(int which) const {
416 assert(tag_at(which).is_unresolved_klass() || tag_at(which).is_klass() ||
417 tag_at(which).is_unresolved_value_type() || tag_at(which).is_value_type(),
418 "Corrupted constant pool");
419 int value = *int_at_addr(which);
420 int name_index = extract_high_short_from_int(value);
421 int resolved_klass_index = extract_low_short_from_int(value);
422 return CPKlassSlot(name_index, resolved_klass_index);
423 }
424
425 Symbol* klass_name_at(int which) const; // Returns the name, w/o resolving.
426 int klass_name_index_at(int which) const {
427 return klass_slot_at(which).name_index();
428 }
429
430 Klass* resolved_klass_at(int which) const { // Used by Compiler
431 guarantee(tag_at(which).is_klass() || tag_at(which).is_value_type(), "Corrupted constant pool");
432 // Must do an acquire here in case another thread resolved the klass
433 // behind our back, lest we later load stale values thru the oop.
434 CPKlassSlot kslot = klass_slot_at(which);
435 assert(tag_at(kslot.name_index()).is_symbol(), "sanity");
436
437 Klass** adr = resolved_klasses()->adr_at(kslot.resolved_klass_index());
438 return OrderAccess::load_acquire(adr);
439 }
440
441 // RedefineClasses() API support:
442 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); }
443 void temp_unresolved_klass_at_put(int which, int name_index) {
444 // Used only during constant pool merging for class redefinition. The resolved klass index
445 // will be initialized later by a call to initialize_unresolved_klasses().
446 unresolved_klass_at_put(which, name_index, CPKlassSlot::_temp_resolved_klass_index);
447 }
448 void temp_unresolved_value_type_at_put(int which, int name_index) {
449 // Used only during constant pool merging for class redefinition. The resolved klass index
450 // will be initialized later by a call to initialize_unresolved_klasses().
451 unresolved_value_type_at_put(which, name_index, CPKlassSlot::_temp_resolved_klass_index);
452 }
453
454 jint int_at(int which) {
455 assert(tag_at(which).is_int(), "Corrupted constant pool");
456 return *int_at_addr(which);
457 }
458
459 jlong long_at(int which) {
460 assert(tag_at(which).is_long(), "Corrupted constant pool");
461 // return *long_at_addr(which);
462 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
463 return *((jlong*)&tmp);
464 }
465
466 jfloat float_at(int which) {
467 assert(tag_at(which).is_float(), "Corrupted constant pool");
468 return *float_at_addr(which);
469 }
470
471 jdouble double_at(int which) {
472 assert(tag_at(which).is_double(), "Corrupted constant pool");
473 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
474 return *((jdouble*)&tmp);
475 }
476
477 Symbol* symbol_at(int which) const {
478 assert(tag_at(which).is_utf8(), "Corrupted constant pool");
479 return *symbol_at_addr(which);
480 }
481
482 oop string_at(int which, int obj_index, TRAPS) {
483 constantPoolHandle h_this(THREAD, this);
484 return string_at_impl(h_this, which, obj_index, THREAD);
485 }
486 oop string_at(int which, TRAPS) {
487 int obj_index = cp_to_object_index(which);
488 return string_at(which, obj_index, THREAD);
489 }
490
491 // Version that can be used before string oop array is created.
492 oop uncached_string_at(int which, TRAPS);
493
494 // A "pseudo-string" is an non-string oop that has found its way into
495 // a String entry.
496 // This can happen if the user patches a live
497 // object into a CONSTANT_String entry of an anonymous class.
498 // Method oops internally created for method handles may also
499 // use pseudo-strings to link themselves to related metaobjects.
500
501 bool is_pseudo_string_at(int which) {
502 assert(tag_at(which).is_string(), "Corrupted constant pool");
503 return slot_at(which).is_pseudo_string();
504 }
505
506 oop pseudo_string_at(int which, int obj_index) {
507 assert(is_pseudo_string_at(which), "must be a pseudo-string");
508 oop s = resolved_references()->obj_at(obj_index);
509 return s;
510 }
511
512 oop pseudo_string_at(int which) {
513 assert(is_pseudo_string_at(which), "must be a pseudo-string");
514 int obj_index = cp_to_object_index(which);
515 oop s = resolved_references()->obj_at(obj_index);
516 return s;
517 }
518
519 void pseudo_string_at_put(int which, int obj_index, oop x) {
520 assert(tag_at(which).is_string(), "Corrupted constant pool");
521 Symbol* sym = unresolved_string_at(which);
522 slot_at_put(which, CPSlot(sym, CPSlot::_pseudo_bit));
523 string_at_put(which, obj_index, x); // this works just fine
524 }
525
526 // only called when we are sure a string entry is already resolved (via an
527 // earlier string_at call.
528 oop resolved_string_at(int which) {
529 assert(tag_at(which).is_string(), "Corrupted constant pool");
530 // Must do an acquire here in case another thread resolved the klass
531 // behind our back, lest we later load stale values thru the oop.
532 // we might want a volatile_obj_at in ObjArrayKlass.
533 int obj_index = cp_to_object_index(which);
534 return resolved_references()->obj_at(obj_index);
535 }
536
537 Symbol* unresolved_string_at(int which) {
538 assert(tag_at(which).is_string(), "Corrupted constant pool");
539 Symbol* sym = slot_at(which).get_symbol();
540 return sym;
541 }
542
543 // Returns an UTF8 for a CONSTANT_String entry at a given index.
544 // UTF8 char* representation was chosen to avoid conversion of
545 // java_lang_Strings at resolved entries into Symbol*s
546 // or vice versa.
547 char* string_at_noresolve(int which);
548
549 jint name_and_type_at(int which) {
550 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
551 return *int_at_addr(which);
552 }
553
554 int method_handle_ref_kind_at(int which) {
555 assert(tag_at(which).is_method_handle() ||
556 tag_at(which).is_method_handle_in_error(), "Corrupted constant pool");
557 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits
558 }
559 int method_handle_index_at(int which) {
560 assert(tag_at(which).is_method_handle() ||
561 tag_at(which).is_method_handle_in_error(), "Corrupted constant pool");
562 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits
563 }
564 int method_type_index_at(int which) {
565 assert(tag_at(which).is_method_type() ||
566 tag_at(which).is_method_type_in_error(), "Corrupted constant pool");
567 return *int_at_addr(which);
568 }
569
570 // Derived queries:
571 Symbol* method_handle_name_ref_at(int which) {
572 int member = method_handle_index_at(which);
573 return impl_name_ref_at(member, true);
574 }
575 Symbol* method_handle_signature_ref_at(int which) {
576 int member = method_handle_index_at(which);
577 return impl_signature_ref_at(member, true);
578 }
579 int method_handle_klass_index_at(int which) {
580 int member = method_handle_index_at(which);
581 return impl_klass_ref_index_at(member, true);
582 }
583 Symbol* method_type_signature_at(int which) {
584 int sym = method_type_index_at(which);
585 return symbol_at(sym);
586 }
587
588 int invoke_dynamic_name_and_type_ref_index_at(int which) {
589 assert(tag_at(which).is_invoke_dynamic() ||
590 tag_at(which).is_dynamic_constant() ||
591 tag_at(which).is_dynamic_constant_in_error(), "Corrupted constant pool");
592 return extract_high_short_from_int(*int_at_addr(which));
593 }
594 int invoke_dynamic_bootstrap_specifier_index(int which) {
595 assert(tag_at(which).is_invoke_dynamic() ||
596 tag_at(which).is_dynamic_constant() ||
597 tag_at(which).is_dynamic_constant_in_error(), "Corrupted constant pool");
598 return extract_low_short_from_int(*int_at_addr(which));
599 }
600 int invoke_dynamic_operand_base(int which) {
601 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
602 return operand_offset_at(operands(), bootstrap_specifier_index);
603 }
604 // The first part of the operands array consists of an index into the second part.
605 // Extract a 32-bit index value from the first part.
606 static int operand_offset_at(Array<u2>* operands, int bootstrap_specifier_index) {
607 int n = (bootstrap_specifier_index * 2);
608 assert(n >= 0 && n+2 <= operands->length(), "oob");
609 // The first 32-bit index points to the beginning of the second part
610 // of the operands array. Make sure this index is in the first part.
611 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0),
612 operands->at(1)));
613 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
614 int offset = build_int_from_shorts(operands->at(n+0),
615 operands->at(n+1));
616 // The offset itself must point into the second part of the array.
617 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)");
618 return offset;
619 }
620 static void operand_offset_at_put(Array<u2>* operands, int bootstrap_specifier_index, int offset) {
621 int n = bootstrap_specifier_index * 2;
622 assert(n >= 0 && n+2 <= operands->length(), "oob");
623 operands->at_put(n+0, extract_low_short_from_int(offset));
624 operands->at_put(n+1, extract_high_short_from_int(offset));
625 }
626 static int operand_array_length(Array<u2>* operands) {
627 if (operands == NULL || operands->length() == 0) return 0;
628 int second_part = operand_offset_at(operands, 0);
629 return (second_part / 2);
630 }
631
632 #ifdef ASSERT
633 // operand tuples fit together exactly, end to end
634 static int operand_limit_at(Array<u2>* operands, int bootstrap_specifier_index) {
635 int nextidx = bootstrap_specifier_index + 1;
636 if (nextidx == operand_array_length(operands))
637 return operands->length();
638 else
639 return operand_offset_at(operands, nextidx);
640 }
641 int invoke_dynamic_operand_limit(int which) {
642 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
643 return operand_limit_at(operands(), bootstrap_specifier_index);
644 }
645 #endif //ASSERT
646
647 // layout of InvokeDynamic and Dynamic bootstrap method specifier (in second part of operands array):
648 enum {
649 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
650 _indy_argc_offset = 1, // u2 argc
651 _indy_argv_offset = 2 // u2 argv[argc]
652 };
653
654 // These functions are used in RedefineClasses for CP merge
655
656 int operand_offset_at(int bootstrap_specifier_index) {
657 assert(0 <= bootstrap_specifier_index &&
658 bootstrap_specifier_index < operand_array_length(operands()),
659 "Corrupted CP operands");
660 return operand_offset_at(operands(), bootstrap_specifier_index);
661 }
662 int operand_bootstrap_method_ref_index_at(int bootstrap_specifier_index) {
663 int offset = operand_offset_at(bootstrap_specifier_index);
664 return operands()->at(offset + _indy_bsm_offset);
665 }
666 int operand_argument_count_at(int bootstrap_specifier_index) {
667 int offset = operand_offset_at(bootstrap_specifier_index);
668 int argc = operands()->at(offset + _indy_argc_offset);
669 return argc;
670 }
671 int operand_argument_index_at(int bootstrap_specifier_index, int j) {
672 int offset = operand_offset_at(bootstrap_specifier_index);
673 return operands()->at(offset + _indy_argv_offset + j);
674 }
675 int operand_next_offset_at(int bootstrap_specifier_index) {
676 int offset = operand_offset_at(bootstrap_specifier_index) + _indy_argv_offset
677 + operand_argument_count_at(bootstrap_specifier_index);
678 return offset;
679 }
680 // Compare a bootsrap specifier in the operands arrays
681 bool compare_operand_to(int bootstrap_specifier_index1, const constantPoolHandle& cp2,
682 int bootstrap_specifier_index2, TRAPS);
683 // Find a bootsrap specifier in the operands array
684 int find_matching_operand(int bootstrap_specifier_index, const constantPoolHandle& search_cp,
685 int operands_cur_len, TRAPS);
686 // Resize the operands array with delta_len and delta_size
687 void resize_operands(int delta_len, int delta_size, TRAPS);
688 // Extend the operands array with the length and size of the ext_cp operands
689 void extend_operands(const constantPoolHandle& ext_cp, TRAPS);
690 // Shrink the operands array to a smaller array with new_len length
691 void shrink_operands(int new_len, TRAPS);
692
693 int invoke_dynamic_bootstrap_method_ref_index_at(int which) {
694 assert(tag_at(which).is_invoke_dynamic() ||
695 tag_at(which).is_dynamic_constant() ||
696 tag_at(which).is_dynamic_constant_in_error(), "Corrupted constant pool");
697 int op_base = invoke_dynamic_operand_base(which);
698 return operands()->at(op_base + _indy_bsm_offset);
699 }
700 int invoke_dynamic_argument_count_at(int which) {
701 assert(tag_at(which).is_invoke_dynamic() ||
702 tag_at(which).is_dynamic_constant() ||
703 tag_at(which).is_dynamic_constant_in_error(), "Corrupted constant pool");
704 int op_base = invoke_dynamic_operand_base(which);
705 int argc = operands()->at(op_base + _indy_argc_offset);
706 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
707 int next_offset = invoke_dynamic_operand_limit(which));
708 assert(end_offset == next_offset, "matched ending");
709 return argc;
710 }
711 int invoke_dynamic_argument_index_at(int which, int j) {
712 int op_base = invoke_dynamic_operand_base(which);
713 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset));
714 assert((uint)j < (uint)argc, "oob");
715 return operands()->at(op_base + _indy_argv_offset + j);
716 }
717
718 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
719 // name_and_type_ref_index_at) all expect to be passed indices obtained
720 // directly from the bytecode.
721 // If the indices are meant to refer to fields or methods, they are
722 // actually rewritten constant pool cache indices.
723 // The routine remap_instruction_operand_from_cache manages the adjustment
724 // of these values back to constant pool indices.
725
726 // There are also "uncached" versions which do not adjust the operand index; see below.
727
728 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear.
729 // In a few cases (the verifier) there are uses before a cpcache has been built,
730 // which are handled by a dynamic check in remap_instruction_operand_from_cache.
731 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode.
732
733 // Lookup for entries consisting of (klass_index, name_and_type index)
734 Klass* klass_ref_at(int which, TRAPS);
735 Symbol* klass_ref_at_noresolve(int which);
736 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); }
737 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); }
738
739 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); }
740 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); }
741
742 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG
743
744 constantTag tag_ref_at(int cp_cache_index) { return impl_tag_ref_at(cp_cache_index, false); }
745
746 // Lookup for entries consisting of (name_index, signature_index)
747 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt)
748 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt)
749
750 BasicType basic_type_for_signature_at(int which) const;
751
752 // Resolve string constants (to prevent allocation during compilation)
753 void resolve_string_constants(TRAPS) {
754 constantPoolHandle h_this(THREAD, this);
755 resolve_string_constants_impl(h_this, CHECK);
756 }
757
758 // CDS support
759 void archive_resolved_references(Thread *THREAD) NOT_CDS_JAVA_HEAP_RETURN;
760 void resolve_class_constants(TRAPS) NOT_CDS_JAVA_HEAP_RETURN;
761 void remove_unshareable_info();
762 void restore_unshareable_info(TRAPS);
763 // The ConstantPool vtable is restored by this call when the ConstantPool is
764 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for
765 // all the gory details. SA, dtrace and pstack helpers distinguish metadata
766 // by their vtable.
767 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); }
768
769 private:
770 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
771 public:
772
773 BasicType basic_type_for_constant_at(int which);
774
775 // Resolve late bound constants.
776 oop resolve_constant_at(int index, TRAPS) {
777 constantPoolHandle h_this(THREAD, this);
778 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, NULL, THREAD);
779 }
780
781 oop resolve_cached_constant_at(int cache_index, TRAPS) {
782 constantPoolHandle h_this(THREAD, this);
783 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, NULL, THREAD);
784 }
785
786 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) {
787 constantPoolHandle h_this(THREAD, this);
788 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, NULL, THREAD);
789 }
790
791 oop find_cached_constant_at(int pool_index, bool& found_it, TRAPS) {
792 constantPoolHandle h_this(THREAD, this);
793 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, &found_it, THREAD);
794 }
795
796 oop resolve_bootstrap_specifier_at(int index, TRAPS) {
797 constantPoolHandle h_this(THREAD, this);
798 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD);
799 }
800
801 void copy_bootstrap_arguments_at(int index,
802 int start_arg, int end_arg,
803 objArrayHandle info, int pos,
804 bool must_resolve, Handle if_not_available, TRAPS) {
805 constantPoolHandle h_this(THREAD, this);
806 copy_bootstrap_arguments_at_impl(h_this, index, start_arg, end_arg,
807 info, pos, must_resolve, if_not_available, THREAD);
808 }
809
810 // Klass name matches name at offset
811 bool klass_name_at_matches(const InstanceKlass* k, int which);
812
813 // Sizing
814 int length() const { return _length; }
815 void set_length(int length) { _length = length; }
816
817 // Tells whether index is within bounds.
818 bool is_within_bounds(int index) const {
819 return 0 <= index && index < length();
820 }
821
822 // Sizing (in words)
823 static int header_size() {
824 return align_up((int)sizeof(ConstantPool), wordSize) / wordSize;
825 }
826 static int size(int length) { return align_metadata_size(header_size() + length); }
827 int size() const { return size(length()); }
828 #if INCLUDE_SERVICES
829 void collect_statistics(KlassSizeStats *sz) const;
830 #endif
831
832 // ConstantPools should be stored in the read-only region of CDS archive.
833 static bool is_read_only_by_default() { return true; }
834
835 friend class ClassFileParser;
836 friend class SystemDictionary;
837
838 // Used by CDS. These classes need to access the private ConstantPool() constructor.
839 template <class T> friend class CppVtableTesterA;
840 template <class T> friend class CppVtableTesterB;
841 template <class T> friend class CppVtableCloner;
842
843 // Used by compiler to prevent classloading.
844 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which);
845 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
846 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
847 static bool has_method_type_at_if_loaded (const constantPoolHandle& this_cp, int which);
848 static oop method_type_at_if_loaded (const constantPoolHandle& this_cp, int which);
849 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which);
850 static Klass* klass_ref_at_if_loaded (const constantPoolHandle& this_cp, int which);
851
852 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
853 // future by other Java code. These take constant pool indices rather than
854 // constant pool cache indices as do the peer methods above.
855 Symbol* uncached_klass_ref_at_noresolve(int which);
856 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); }
857 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); }
858 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); }
859 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); }
860
861 // Sharing
862 int pre_resolve_shared_klasses(TRAPS);
863
864 // Debugging
865 const char* printable_name_at(int which) PRODUCT_RETURN0;
866
867 #ifdef ASSERT
868 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices
869 #else
870 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op
871 #endif //ASSERT
872
873 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) {
874 if (invokedynamic_ok && is_invokedynamic_index(raw_index))
875 return decode_invokedynamic_index(raw_index);
876 else
877 return raw_index - CPCACHE_INDEX_TAG;
878 }
879
880 private:
881
882 void set_resolved_references(OopHandle s) { _cache->set_resolved_references(s); }
883 Array<u2>* reference_map() const { return (_cache == NULL) ? NULL : _cache->reference_map(); }
884 void set_reference_map(Array<u2>* o) { _cache->set_reference_map(o); }
885
886 // patch JSR 292 resolved references after the class is linked.
887 void patch_resolved_references(GrowableArray<Handle>* cp_patches);
888
889 Symbol* impl_name_ref_at(int which, bool uncached);
890 Symbol* impl_signature_ref_at(int which, bool uncached);
891
892 int impl_klass_ref_index_at(int which, bool uncached);
893 int impl_name_and_type_ref_index_at(int which, bool uncached);
894 constantTag impl_tag_ref_at(int which, bool uncached);
895
896 // Used while constructing constant pool (only by ClassFileParser)
897 jint klass_index_at(int which) {
898 assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
899 return *int_at_addr(which);
900 }
901
902 jint value_type_index_at(int which) {
903 assert(tag_at(which).is_value_type_index(), "Corrupted constant pool");
904 return *int_at_addr(which);
905 }
906
907 jint string_index_at(int which) {
908 assert(tag_at(which).is_string_index(), "Corrupted constant pool");
909 return *int_at_addr(which);
910 }
911
912 // Performs the LinkResolver checks
913 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* klass, TRAPS);
914
915 // Implementation of methods that needs an exposed 'this' pointer, in order to
916 // handle GC while executing the method
917 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int which,
918 bool save_resolution_error, TRAPS);
919 static oop string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS);
920
921 static void trace_class_resolution(const constantPoolHandle& this_cp, Klass* k);
922
923 // Resolve string constants (to prevent allocation during compilation)
924 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS);
925
926 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int index, int cache_index,
927 bool* status_return, TRAPS);
928 static oop resolve_bootstrap_specifier_at_impl(const constantPoolHandle& this_cp, int index, TRAPS);
929 static void copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int index,
930 int start_arg, int end_arg,
931 objArrayHandle info, int pos,
932 bool must_resolve, Handle if_not_available, TRAPS);
933
934 // Exception handling
935 static Symbol* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception);
936 static void save_and_throw_exception(const constantPoolHandle& this_cp, int which, constantTag tag, TRAPS);
937
938 public:
939 // Exception handling
940 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS);
941
942 // Merging ConstantPool* support:
943 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2, TRAPS);
944 void copy_cp_to(int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS) {
945 constantPoolHandle h_this(THREAD, this);
946 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD);
947 }
948 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
949 static void copy_entry_to(const constantPoolHandle& from_cp, int from_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
950 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS);
951 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp, TRAPS);
952 int version() const { return _saved._version; }
953 void set_version(int version) { _saved._version = version; }
954 void increment_and_save_version(int version) {
955 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow
956 }
957
958 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; }
959 int resolved_reference_length() const { return _saved._resolved_reference_length; }
960
961 // Decrease ref counts of symbols that are in the constant pool
962 // when the holder class is unloaded
963 void unreference_symbols();
964
965 // Deallocate constant pool for RedefineClasses
966 void deallocate_contents(ClassLoaderData* loader_data);
967 void release_C_heap_structures();
968
969 // JVMTI accesss - GetConstantPool, RetransformClasses, ...
970 friend class JvmtiConstantPoolReconstituter;
971
972 private:
973 jint cpool_entry_size(jint idx);
974 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap);
975
976 // Copy cpool bytes into byte array.
977 // Returns:
978 // int > 0, count of the raw cpool bytes that have been copied
979 // 0, OutOfMemory error
980 // -1, Internal error
981 int copy_cpool_bytes(int cpool_size,
982 SymbolHashMap* tbl,
983 unsigned char *bytes);
984
985 public:
986 // Verify
987 void verify_on(outputStream* st);
988
989 // Printing
990 void print_on(outputStream* st) const;
991 void print_value_on(outputStream* st) const;
992 void print_entry_on(int index, outputStream* st);
993
994 const char* internal_name() const { return "{constant pool}"; }
995
996 #ifndef PRODUCT
997 // Compile the world support
998 static void preload_and_initialize_all_classes(ConstantPool* constant_pool, TRAPS);
999 #endif
1000 };
1001
1002 class SymbolHashMapEntry : public CHeapObj<mtSymbol> {
1003 private:
1004 unsigned int _hash; // 32-bit hash for item
1005 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket
1006 Symbol* _symbol; // 1-st part of the mapping: symbol => value
1007 u2 _value; // 2-nd part of the mapping: symbol => value
1008
1009 public:
1010 unsigned int hash() const { return _hash; }
1011 void set_hash(unsigned int hash) { _hash = hash; }
1012
1013 SymbolHashMapEntry* next() const { return _next; }
1014 void set_next(SymbolHashMapEntry* next) { _next = next; }
1015
1016 Symbol* symbol() const { return _symbol; }
1017 void set_symbol(Symbol* sym) { _symbol = sym; }
1018
1019 u2 value() const { return _value; }
1020 void set_value(u2 value) { _value = value; }
1021
1022 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value)
1023 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {}
1024
1025 }; // End SymbolHashMapEntry class
1026
1027
1028 class SymbolHashMapBucket : public CHeapObj<mtSymbol> {
1029
1030 private:
1031 SymbolHashMapEntry* _entry;
1032
1033 public:
1034 SymbolHashMapEntry* entry() const { return _entry; }
1035 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; }
1036 void clear() { _entry = NULL; }
1037
1038 }; // End SymbolHashMapBucket class
1039
1040
1041 class SymbolHashMap: public CHeapObj<mtSymbol> {
1042
1043 private:
1044 // Default number of entries in the table
1045 enum SymbolHashMap_Constants {
1046 _Def_HashMap_Size = 256
1047 };
1048
1049 int _table_size;
1050 SymbolHashMapBucket* _buckets;
1051
1052 void initialize_table(int table_size);
1053
1054 public:
1055
1056 int table_size() const { return _table_size; }
1057
1058 SymbolHashMap() { initialize_table(_Def_HashMap_Size); }
1059 SymbolHashMap(int table_size) { initialize_table(table_size); }
1060
1061 // hash P(31) from Kernighan & Ritchie
1062 static unsigned int compute_hash(const char* str, int len) {
1063 unsigned int hash = 0;
1064 while (len-- > 0) {
1065 hash = 31*hash + (unsigned) *str;
1066 str++;
1067 }
1068 return hash;
1069 }
1070
1071 SymbolHashMapEntry* bucket(int i) {
1072 return _buckets[i].entry();
1073 }
1074
1075 void add_entry(Symbol* sym, u2 value);
1076 SymbolHashMapEntry* find_entry(Symbol* sym);
1077
1078 u2 symbol_to_value(Symbol* sym) {
1079 SymbolHashMapEntry *entry = find_entry(sym);
1080 return (entry == NULL) ? 0 : entry->value();
1081 }
1082
1083 ~SymbolHashMap() {
1084 SymbolHashMapEntry* next;
1085 for (int i = 0; i < _table_size; i++) {
1086 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
1087 next = cur->next();
1088 delete(cur);
1089 }
1090 }
1091 FREE_C_HEAP_ARRAY(SymbolHashMapBucket, _buckets);
1092 }
1093 }; // End SymbolHashMap class
1094
1095 #endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP