1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
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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.hpp"
29 #include "oops/arrayOop.hpp"
30 #include "oops/cpCache.hpp"
31 #include "oops/objArrayOop.hpp"
32 #include "oops/oopHandle.hpp"
33 #include "oops/symbol.hpp"
34 #include "oops/typeArrayOop.hpp"
35 #include "runtime/handles.hpp"
36 #include "utilities/align.hpp"
37 #include "utilities/bytes.hpp"
38 #include "utilities/constantTag.hpp"
39
40 // A ConstantPool is an array containing class constants as described in the
41 // class file.
42 //
43 // Most of the constant pool entries are written during class parsing, which
44 // is safe. For klass types, the constant pool entry is
45 // modified when the entry is resolved. If a klass constant pool
46 // entry is read without a lock, only the resolved state guarantees that
47 // the entry in the constant pool is a klass object and not a Symbol*.
48
49 class SymbolHashMap;
50
51 class CPSlot VALUE_OBJ_CLASS_SPEC {
52 friend class ConstantPool;
53 intptr_t _ptr;
54 enum TagBits {_pseudo_bit = 1};
55 public:
56
57 CPSlot(intptr_t ptr): _ptr(ptr) {}
58 CPSlot(Symbol* ptr, int tag_bits = 0): _ptr((intptr_t)ptr | tag_bits) {}
59
60 intptr_t value() { return _ptr; }
61 bool is_pseudo_string() { return (_ptr & _pseudo_bit) != 0; }
62
63 Symbol* get_symbol() {
64 return (Symbol*)(_ptr & ~_pseudo_bit);
65 }
66 };
67
68 // This represents a JVM_CONSTANT_Class, JVM_CONSTANT_UnresolvedClass, or
69 // JVM_CONSTANT_UnresolvedClassInError slot in the constant pool.
70 class CPKlassSlot VALUE_OBJ_CLASS_SPEC {
71 // cp->symbol_at(_name_index) gives the name of the class.
72 int _name_index;
73
74 // cp->_resolved_klasses->at(_resolved_klass_index) gives the Klass* for the class.
75 int _resolved_klass_index;
76 public:
77 enum {
78 // This is used during constant pool merging where the resolved klass index is
79 // not yet known, and will be computed at a later stage (during a call to
80 // initialize_unresolved_klasses()).
81 _temp_resolved_klass_index = 0xffff
82 };
83 CPKlassSlot(int n, int rk) {
84 _name_index = n;
85 _resolved_klass_index = rk;
86 }
87 int name_index() const {
88 return _name_index;
89 }
90 int resolved_klass_index() const {
91 assert(_resolved_klass_index != _temp_resolved_klass_index, "constant pool merging was incomplete");
92 return _resolved_klass_index;
93 }
94 };
95
96 class KlassSizeStats;
97
98 class ConstantPool : public Metadata {
99 friend class VMStructs;
100 friend class JVMCIVMStructs;
101 friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast
102 friend class Universe; // For null constructor
103 private:
104 // If you add a new field that points to any metaspace object, you
105 // must add this field to ConstantPool::metaspace_pointers_do().
106 Array<u1>* _tags; // the tag array describing the constant pool's contents
107 ConstantPoolCache* _cache; // the cache holding interpreter runtime information
108 InstanceKlass* _pool_holder; // the corresponding class
109 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
110
111 // Consider using an array of compressed klass pointers to
112 // save space on 64-bit platforms.
113 Array<Klass*>* _resolved_klasses;
114
115 enum {
116 _has_preresolution = 1, // Flags
117 _on_stack = 2,
118 _is_shared = 4,
119 _has_dynamic_constant = 8
120 };
121
122 int _flags; // old fashioned bit twiddling
123 int _length; // number of elements in the array
124
125 union {
126 // set for CDS to restore resolved references
127 int _resolved_reference_length;
128 // keeps version number for redefined classes (used in backtrace)
129 int _version;
130 } _saved;
131
132 void set_tags(Array<u1>* tags) { _tags = tags; }
133 void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); }
134 void release_tag_at_put(int which, jbyte t);
135
136 u1* tag_addr_at(int which) const { return tags()->adr_at(which); }
137
138 void set_operands(Array<u2>* operands) { _operands = operands; }
139
140 int flags() const { return _flags; }
141 void set_flags(int f) { _flags = f; }
142
143 private:
144 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); }
145
146 CPSlot slot_at(int which) const;
147
148 void slot_at_put(int which, CPSlot s) const {
149 assert(is_within_bounds(which), "index out of bounds");
150 assert(s.value() != 0, "Caught something");
151 *(intptr_t*)&base()[which] = s.value();
152 }
153 intptr_t* obj_at_addr(int which) const {
154 assert(is_within_bounds(which), "index out of bounds");
155 return (intptr_t*) &base()[which];
156 }
157
158 jint* int_at_addr(int which) const {
159 assert(is_within_bounds(which), "index out of bounds");
160 return (jint*) &base()[which];
161 }
162
163 jlong* long_at_addr(int which) const {
164 assert(is_within_bounds(which), "index out of bounds");
165 return (jlong*) &base()[which];
166 }
167
168 jfloat* float_at_addr(int which) const {
169 assert(is_within_bounds(which), "index out of bounds");
170 return (jfloat*) &base()[which];
171 }
172
173 jdouble* double_at_addr(int which) const {
174 assert(is_within_bounds(which), "index out of bounds");
175 return (jdouble*) &base()[which];
176 }
177
178 ConstantPool(Array<u1>* tags);
179 ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
180 public:
181 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS);
182
183 bool is_constantPool() const volatile { return true; }
184
185 Array<u1>* tags() const { return _tags; }
186 Array<u2>* operands() const { return _operands; }
187
188 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; }
189 void set_has_preresolution() {
190 assert(!is_shared(), "should never be called on shared ConstantPools");
191 _flags |= _has_preresolution;
192 }
193
194 // Redefine classes support. If a method refering to this constant pool
195 // is on the executing stack, or as a handle in vm code, this constant pool
196 // can't be removed from the set of previous versions saved in the instance
197 // class.
198 bool on_stack() const { return (_flags &_on_stack) != 0; }
199 void set_on_stack(const bool value);
200
201 // Faster than MetaspaceObj::is_shared() - used by set_on_stack()
202 bool is_shared() const { return (_flags & _is_shared) != 0; }
203
204 bool has_dynamic_constant() const { return (_flags & _has_dynamic_constant) != 0; }
205 void set_has_dynamic_constant() { _flags |= _has_dynamic_constant; }
206
207 // Klass holding pool
208 InstanceKlass* pool_holder() const { return _pool_holder; }
209 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; }
210 InstanceKlass** pool_holder_addr() { return &_pool_holder; }
211
212 // Interpreter runtime support
213 ConstantPoolCache* cache() const { return _cache; }
214 void set_cache(ConstantPoolCache* cache){ _cache = cache; }
215
216 virtual void metaspace_pointers_do(MetaspaceClosure* iter);
217 virtual MetaspaceObj::Type type() const { return ConstantPoolType; }
218
219 // Create object cache in the constant pool
220 void initialize_resolved_references(ClassLoaderData* loader_data,
221 const intStack& reference_map,
222 int constant_pool_map_length,
223 TRAPS);
224
225 // resolved strings, methodHandles and callsite objects from the constant pool
226 objArrayOop resolved_references() const;
227 objArrayOop resolved_references_or_null() const;
228 // mapping resolved object array indexes to cp indexes and back.
229 int object_to_cp_index(int index) { return reference_map()->at(index); }
230 int cp_to_object_index(int index);
231
232 void set_resolved_klasses(Array<Klass*>* rk) { _resolved_klasses = rk; }
233 Array<Klass*>* resolved_klasses() const { return _resolved_klasses; }
234 void allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS);
235 void initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS);
236
237 // Invokedynamic indexes.
238 // They must look completely different from normal indexes.
239 // The main reason is that byte swapping is sometimes done on normal indexes.
240 // Finally, it is helpful for debugging to tell the two apart.
241 static bool is_invokedynamic_index(int i) { return (i < 0); }
242 static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; }
243 static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; }
244
245
246 // The invokedynamic points at a CP cache entry. This entry points back
247 // at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry
248 // in the resolved_references array (which provides the appendix argument).
249 int invokedynamic_cp_cache_index(int index) const {
250 assert (is_invokedynamic_index(index), "should be a invokedynamic index");
251 int cache_index = decode_invokedynamic_index(index);
252 return cache_index;
253 }
254 ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int index) const {
255 // decode index that invokedynamic points to.
256 int cp_cache_index = invokedynamic_cp_cache_index(index);
257 return cache()->entry_at(cp_cache_index);
258 }
259
260 // Assembly code support
261 static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); }
262 static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); }
263 static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); }
264 static int resolved_klasses_offset_in_bytes() { return offset_of(ConstantPool, _resolved_klasses); }
265
266 // Storing constants
267
268 // For temporary use while constructing constant pool
269 void klass_index_at_put(int which, int name_index) {
270 tag_at_put(which, JVM_CONSTANT_ClassIndex);
271 *int_at_addr(which) = name_index;
272 }
273
274 // Anonymous class support:
275 void klass_at_put(int class_index, int name_index, int resolved_klass_index, Klass* k, Symbol* name);
276 void klass_at_put(int class_index, Klass* k);
277
278 void unresolved_klass_at_put(int which, int name_index, int resolved_klass_index) {
279 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
280
281 assert((name_index & 0xffff0000) == 0, "must be");
282 assert((resolved_klass_index & 0xffff0000) == 0, "must be");
283 *int_at_addr(which) =
284 build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
285 }
286
287 void method_handle_index_at_put(int which, int ref_kind, int ref_index) {
288 tag_at_put(which, JVM_CONSTANT_MethodHandle);
289 *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind;
290 }
291
292 void method_type_index_at_put(int which, int ref_index) {
293 tag_at_put(which, JVM_CONSTANT_MethodType);
294 *int_at_addr(which) = ref_index;
295 }
296
297 void dynamic_constant_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
298 tag_at_put(which, JVM_CONSTANT_Dynamic);
299 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
300 }
301
302 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
303 tag_at_put(which, JVM_CONSTANT_InvokeDynamic);
304 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
305 }
306
307 void unresolved_string_at_put(int which, Symbol* s) {
308 release_tag_at_put(which, JVM_CONSTANT_String);
309 slot_at_put(which, CPSlot(s));
310 }
311
312 void int_at_put(int which, jint i) {
313 tag_at_put(which, JVM_CONSTANT_Integer);
314 *int_at_addr(which) = i;
315 }
316
317 void long_at_put(int which, jlong l) {
318 tag_at_put(which, JVM_CONSTANT_Long);
319 // *long_at_addr(which) = l;
320 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
321 }
322
323 void float_at_put(int which, jfloat f) {
324 tag_at_put(which, JVM_CONSTANT_Float);
325 *float_at_addr(which) = f;
326 }
327
328 void double_at_put(int which, jdouble d) {
329 tag_at_put(which, JVM_CONSTANT_Double);
330 // *double_at_addr(which) = d;
331 // u8 temp = *(u8*) &d;
332 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
333 }
334
335 Symbol** symbol_at_addr(int which) const {
336 assert(is_within_bounds(which), "index out of bounds");
337 return (Symbol**) &base()[which];
338 }
339
340 void symbol_at_put(int which, Symbol* s) {
341 assert(s->refcount() != 0, "should have nonzero refcount");
342 tag_at_put(which, JVM_CONSTANT_Utf8);
343 *symbol_at_addr(which) = s;
344 }
345
346 void string_at_put(int which, int obj_index, oop str);
347
348 // For temporary use while constructing constant pool
349 void string_index_at_put(int which, int string_index) {
350 tag_at_put(which, JVM_CONSTANT_StringIndex);
351 *int_at_addr(which) = string_index;
352 }
353
354 void field_at_put(int which, int class_index, int name_and_type_index) {
355 tag_at_put(which, JVM_CONSTANT_Fieldref);
356 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
357 }
358
359 void method_at_put(int which, int class_index, int name_and_type_index) {
360 tag_at_put(which, JVM_CONSTANT_Methodref);
361 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
362 }
363
364 void interface_method_at_put(int which, int class_index, int name_and_type_index) {
365 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
366 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
367 }
368
369 void name_and_type_at_put(int which, int name_index, int signature_index) {
370 tag_at_put(which, JVM_CONSTANT_NameAndType);
371 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
372 }
373
374 // Tag query
375
376 constantTag tag_at(int which) const;
377
378 // Fetching constants
379
380 Klass* klass_at(int which, TRAPS) {
381 constantPoolHandle h_this(THREAD, this);
382 return klass_at_impl(h_this, which, true, THREAD);
383 }
384
385 // Version of klass_at that doesn't save the resolution error, called during deopt
386 Klass* klass_at_ignore_error(int which, TRAPS) {
387 constantPoolHandle h_this(THREAD, this);
388 return klass_at_impl(h_this, which, false, THREAD);
389 }
390
391 CPKlassSlot klass_slot_at(int which) const {
392 assert(tag_at(which).is_unresolved_klass() || tag_at(which).is_klass(),
393 "Corrupted constant pool");
394 int value = *int_at_addr(which);
395 int name_index = extract_high_short_from_int(value);
396 int resolved_klass_index = extract_low_short_from_int(value);
397 return CPKlassSlot(name_index, resolved_klass_index);
398 }
399
400 Symbol* klass_name_at(int which) const; // Returns the name, w/o resolving.
401 int klass_name_index_at(int which) const {
402 return klass_slot_at(which).name_index();
403 }
404
405 Klass* resolved_klass_at(int which) const; // Used by Compiler
406
407 // RedefineClasses() API support:
408 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); }
409 void temp_unresolved_klass_at_put(int which, int name_index) {
410 // Used only during constant pool merging for class redefinition. The resolved klass index
411 // will be initialized later by a call to initialize_unresolved_klasses().
412 unresolved_klass_at_put(which, name_index, CPKlassSlot::_temp_resolved_klass_index);
413 }
414
415 jint int_at(int which) {
416 assert(tag_at(which).is_int(), "Corrupted constant pool");
417 return *int_at_addr(which);
418 }
419
420 jlong long_at(int which) {
421 assert(tag_at(which).is_long(), "Corrupted constant pool");
422 // return *long_at_addr(which);
423 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
424 return *((jlong*)&tmp);
425 }
426
427 jfloat float_at(int which) {
428 assert(tag_at(which).is_float(), "Corrupted constant pool");
429 return *float_at_addr(which);
430 }
431
432 jdouble double_at(int which) {
433 assert(tag_at(which).is_double(), "Corrupted constant pool");
434 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
435 return *((jdouble*)&tmp);
436 }
437
438 Symbol* symbol_at(int which) const {
439 assert(tag_at(which).is_utf8(), "Corrupted constant pool");
440 return *symbol_at_addr(which);
441 }
442
443 oop string_at(int which, int obj_index, TRAPS) {
444 constantPoolHandle h_this(THREAD, this);
445 return string_at_impl(h_this, which, obj_index, THREAD);
446 }
447 oop string_at(int which, TRAPS) {
448 int obj_index = cp_to_object_index(which);
449 return string_at(which, obj_index, THREAD);
450 }
451
452 // Version that can be used before string oop array is created.
453 oop uncached_string_at(int which, TRAPS);
454
455 // A "pseudo-string" is an non-string oop that has found its way into
456 // a String entry.
457 // This can happen if the user patches a live
458 // object into a CONSTANT_String entry of an anonymous class.
459 // Method oops internally created for method handles may also
460 // use pseudo-strings to link themselves to related metaobjects.
461
462 bool is_pseudo_string_at(int which);
463
464 oop pseudo_string_at(int which, int obj_index);
465
466 oop pseudo_string_at(int which);
467
468 void pseudo_string_at_put(int which, int obj_index, oop x) {
469 assert(tag_at(which).is_string(), "Corrupted constant pool");
470 Symbol* sym = unresolved_string_at(which);
471 slot_at_put(which, CPSlot(sym, CPSlot::_pseudo_bit));
472 string_at_put(which, obj_index, x); // this works just fine
473 }
474
475 // only called when we are sure a string entry is already resolved (via an
476 // earlier string_at call.
477 oop resolved_string_at(int which) {
478 assert(tag_at(which).is_string(), "Corrupted constant pool");
479 // Must do an acquire here in case another thread resolved the klass
480 // behind our back, lest we later load stale values thru the oop.
481 // we might want a volatile_obj_at in ObjArrayKlass.
482 int obj_index = cp_to_object_index(which);
483 return resolved_references()->obj_at(obj_index);
484 }
485
486 Symbol* unresolved_string_at(int which) {
487 assert(tag_at(which).is_string(), "Corrupted constant pool");
488 Symbol* sym = slot_at(which).get_symbol();
489 return sym;
490 }
491
492 // Returns an UTF8 for a CONSTANT_String entry at a given index.
493 // UTF8 char* representation was chosen to avoid conversion of
494 // java_lang_Strings at resolved entries into Symbol*s
495 // or vice versa.
496 char* string_at_noresolve(int which);
497
498 jint name_and_type_at(int which) {
499 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
500 return *int_at_addr(which);
501 }
502
503 int method_handle_ref_kind_at(int which) {
504 assert(tag_at(which).is_method_handle() ||
505 tag_at(which).is_method_handle_in_error(), "Corrupted constant pool");
506 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits
507 }
508 int method_handle_index_at(int which) {
509 assert(tag_at(which).is_method_handle() ||
510 tag_at(which).is_method_handle_in_error(), "Corrupted constant pool");
511 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits
512 }
513 int method_type_index_at(int which) {
514 assert(tag_at(which).is_method_type() ||
515 tag_at(which).is_method_type_in_error(), "Corrupted constant pool");
516 return *int_at_addr(which);
517 }
518
519 // Derived queries:
520 Symbol* method_handle_name_ref_at(int which) {
521 int member = method_handle_index_at(which);
522 return impl_name_ref_at(member, true);
523 }
524 Symbol* method_handle_signature_ref_at(int which) {
525 int member = method_handle_index_at(which);
526 return impl_signature_ref_at(member, true);
527 }
528 int method_handle_klass_index_at(int which) {
529 int member = method_handle_index_at(which);
530 return impl_klass_ref_index_at(member, true);
531 }
532 Symbol* method_type_signature_at(int which) {
533 int sym = method_type_index_at(which);
534 return symbol_at(sym);
535 }
536
537 int invoke_dynamic_name_and_type_ref_index_at(int which) {
538 assert(tag_at(which).is_invoke_dynamic() ||
539 tag_at(which).is_dynamic_constant() ||
540 tag_at(which).is_dynamic_constant_in_error(), "Corrupted constant pool");
541 return extract_high_short_from_int(*int_at_addr(which));
542 }
543 int invoke_dynamic_bootstrap_specifier_index(int which) {
544 assert(tag_at(which).is_invoke_dynamic() ||
545 tag_at(which).is_dynamic_constant() ||
546 tag_at(which).is_dynamic_constant_in_error(), "Corrupted constant pool");
547 return extract_low_short_from_int(*int_at_addr(which));
548 }
549 int invoke_dynamic_operand_base(int which) {
550 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
551 return operand_offset_at(operands(), bootstrap_specifier_index);
552 }
553 // The first part of the operands array consists of an index into the second part.
554 // Extract a 32-bit index value from the first part.
555 static int operand_offset_at(Array<u2>* operands, int bootstrap_specifier_index) {
556 int n = (bootstrap_specifier_index * 2);
557 assert(n >= 0 && n+2 <= operands->length(), "oob");
558 // The first 32-bit index points to the beginning of the second part
559 // of the operands array. Make sure this index is in the first part.
560 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0),
561 operands->at(1)));
562 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
563 int offset = build_int_from_shorts(operands->at(n+0),
564 operands->at(n+1));
565 // The offset itself must point into the second part of the array.
566 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)");
567 return offset;
568 }
569 static void operand_offset_at_put(Array<u2>* operands, int bootstrap_specifier_index, int offset) {
570 int n = bootstrap_specifier_index * 2;
571 assert(n >= 0 && n+2 <= operands->length(), "oob");
572 operands->at_put(n+0, extract_low_short_from_int(offset));
573 operands->at_put(n+1, extract_high_short_from_int(offset));
574 }
575 static int operand_array_length(Array<u2>* operands) {
576 if (operands == NULL || operands->length() == 0) return 0;
577 int second_part = operand_offset_at(operands, 0);
578 return (second_part / 2);
579 }
580
581 #ifdef ASSERT
582 // operand tuples fit together exactly, end to end
583 static int operand_limit_at(Array<u2>* operands, int bootstrap_specifier_index) {
584 int nextidx = bootstrap_specifier_index + 1;
585 if (nextidx == operand_array_length(operands))
586 return operands->length();
587 else
588 return operand_offset_at(operands, nextidx);
589 }
590 int invoke_dynamic_operand_limit(int which) {
591 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
592 return operand_limit_at(operands(), bootstrap_specifier_index);
593 }
594 #endif //ASSERT
595
596 // layout of InvokeDynamic and Dynamic bootstrap method specifier (in second part of operands array):
597 enum {
598 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
599 _indy_argc_offset = 1, // u2 argc
600 _indy_argv_offset = 2 // u2 argv[argc]
601 };
602
603 // These functions are used in RedefineClasses for CP merge
604
605 int operand_offset_at(int bootstrap_specifier_index) {
606 assert(0 <= bootstrap_specifier_index &&
607 bootstrap_specifier_index < operand_array_length(operands()),
608 "Corrupted CP operands");
609 return operand_offset_at(operands(), bootstrap_specifier_index);
610 }
611 int operand_bootstrap_method_ref_index_at(int bootstrap_specifier_index) {
612 int offset = operand_offset_at(bootstrap_specifier_index);
613 return operands()->at(offset + _indy_bsm_offset);
614 }
615 int operand_argument_count_at(int bootstrap_specifier_index) {
616 int offset = operand_offset_at(bootstrap_specifier_index);
617 int argc = operands()->at(offset + _indy_argc_offset);
618 return argc;
619 }
620 int operand_argument_index_at(int bootstrap_specifier_index, int j) {
621 int offset = operand_offset_at(bootstrap_specifier_index);
622 return operands()->at(offset + _indy_argv_offset + j);
623 }
624 int operand_next_offset_at(int bootstrap_specifier_index) {
625 int offset = operand_offset_at(bootstrap_specifier_index) + _indy_argv_offset
626 + operand_argument_count_at(bootstrap_specifier_index);
627 return offset;
628 }
629 // Compare a bootsrap specifier in the operands arrays
630 bool compare_operand_to(int bootstrap_specifier_index1, const constantPoolHandle& cp2,
631 int bootstrap_specifier_index2, TRAPS);
632 // Find a bootsrap specifier in the operands array
633 int find_matching_operand(int bootstrap_specifier_index, const constantPoolHandle& search_cp,
634 int operands_cur_len, TRAPS);
635 // Resize the operands array with delta_len and delta_size
636 void resize_operands(int delta_len, int delta_size, TRAPS);
637 // Extend the operands array with the length and size of the ext_cp operands
638 void extend_operands(const constantPoolHandle& ext_cp, TRAPS);
639 // Shrink the operands array to a smaller array with new_len length
640 void shrink_operands(int new_len, TRAPS);
641
642 int invoke_dynamic_bootstrap_method_ref_index_at(int which) {
643 assert(tag_at(which).is_invoke_dynamic() ||
644 tag_at(which).is_dynamic_constant() ||
645 tag_at(which).is_dynamic_constant_in_error(), "Corrupted constant pool");
646 int op_base = invoke_dynamic_operand_base(which);
647 return operands()->at(op_base + _indy_bsm_offset);
648 }
649 int invoke_dynamic_argument_count_at(int which) {
650 assert(tag_at(which).is_invoke_dynamic() ||
651 tag_at(which).is_dynamic_constant() ||
652 tag_at(which).is_dynamic_constant_in_error(), "Corrupted constant pool");
653 int op_base = invoke_dynamic_operand_base(which);
654 int argc = operands()->at(op_base + _indy_argc_offset);
655 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
656 int next_offset = invoke_dynamic_operand_limit(which));
657 assert(end_offset == next_offset, "matched ending");
658 return argc;
659 }
660 int invoke_dynamic_argument_index_at(int which, int j) {
661 int op_base = invoke_dynamic_operand_base(which);
662 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset));
663 assert((uint)j < (uint)argc, "oob");
664 return operands()->at(op_base + _indy_argv_offset + j);
665 }
666
667 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
668 // name_and_type_ref_index_at) all expect to be passed indices obtained
669 // directly from the bytecode.
670 // If the indices are meant to refer to fields or methods, they are
671 // actually rewritten constant pool cache indices.
672 // The routine remap_instruction_operand_from_cache manages the adjustment
673 // of these values back to constant pool indices.
674
675 // There are also "uncached" versions which do not adjust the operand index; see below.
676
677 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear.
678 // In a few cases (the verifier) there are uses before a cpcache has been built,
679 // which are handled by a dynamic check in remap_instruction_operand_from_cache.
680 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode.
681
682 // Lookup for entries consisting of (klass_index, name_and_type index)
683 Klass* klass_ref_at(int which, TRAPS);
684 Symbol* klass_ref_at_noresolve(int which);
685 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); }
686 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); }
687
688 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); }
689 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); }
690
691 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG
692
693 constantTag tag_ref_at(int cp_cache_index) { return impl_tag_ref_at(cp_cache_index, false); }
694
695 // Lookup for entries consisting of (name_index, signature_index)
696 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt)
697 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt)
698
699 BasicType basic_type_for_signature_at(int which) const;
700
701 // Resolve string constants (to prevent allocation during compilation)
702 void resolve_string_constants(TRAPS) {
703 constantPoolHandle h_this(THREAD, this);
704 resolve_string_constants_impl(h_this, CHECK);
705 }
706
707 // CDS support
708 void archive_resolved_references(Thread *THREAD) NOT_CDS_JAVA_HEAP_RETURN;
709 void resolve_class_constants(TRAPS) NOT_CDS_JAVA_HEAP_RETURN;
710 void remove_unshareable_info();
711 void restore_unshareable_info(TRAPS);
712 // The ConstantPool vtable is restored by this call when the ConstantPool is
713 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for
714 // all the gory details. SA, dtrace and pstack helpers distinguish metadata
715 // by their vtable.
716 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); }
717
718 private:
719 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
720 public:
721
722 BasicType basic_type_for_constant_at(int which);
723
724 // Resolve late bound constants.
725 oop resolve_constant_at(int index, TRAPS) {
726 constantPoolHandle h_this(THREAD, this);
727 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, NULL, THREAD);
728 }
729
730 oop resolve_cached_constant_at(int cache_index, TRAPS) {
731 constantPoolHandle h_this(THREAD, this);
732 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, NULL, THREAD);
733 }
734
735 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) {
736 constantPoolHandle h_this(THREAD, this);
737 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, NULL, THREAD);
738 }
739
740 oop find_cached_constant_at(int pool_index, bool& found_it, TRAPS) {
741 constantPoolHandle h_this(THREAD, this);
742 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, &found_it, THREAD);
743 }
744
745 oop resolve_bootstrap_specifier_at(int index, TRAPS) {
746 constantPoolHandle h_this(THREAD, this);
747 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD);
748 }
749
750 void copy_bootstrap_arguments_at(int index,
751 int start_arg, int end_arg,
752 objArrayHandle info, int pos,
753 bool must_resolve, Handle if_not_available, TRAPS) {
754 constantPoolHandle h_this(THREAD, this);
755 copy_bootstrap_arguments_at_impl(h_this, index, start_arg, end_arg,
756 info, pos, must_resolve, if_not_available, THREAD);
757 }
758
759 // Klass name matches name at offset
760 bool klass_name_at_matches(const InstanceKlass* k, int which);
761
762 // Sizing
763 int length() const { return _length; }
764 void set_length(int length) { _length = length; }
765
766 // Tells whether index is within bounds.
767 bool is_within_bounds(int index) const {
768 return 0 <= index && index < length();
769 }
770
771 // Sizing (in words)
772 static int header_size() {
773 return align_up((int)sizeof(ConstantPool), wordSize) / wordSize;
774 }
775 static int size(int length) { return align_metadata_size(header_size() + length); }
776 int size() const { return size(length()); }
777 #if INCLUDE_SERVICES
778 void collect_statistics(KlassSizeStats *sz) const;
779 #endif
780
781 // ConstantPools should be stored in the read-only region of CDS archive.
782 static bool is_read_only_by_default() { return true; }
783
784 friend class ClassFileParser;
785 friend class SystemDictionary;
786
787 // Used by CDS. These classes need to access the private ConstantPool() constructor.
788 template <class T> friend class CppVtableTesterA;
789 template <class T> friend class CppVtableTesterB;
790 template <class T> friend class CppVtableCloner;
791
792 // Used by compiler to prevent classloading.
793 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which);
794 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
795 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
796 static bool has_method_type_at_if_loaded (const constantPoolHandle& this_cp, int which);
797 static oop method_type_at_if_loaded (const constantPoolHandle& this_cp, int which);
798 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which);
799
800 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
801 // future by other Java code. These take constant pool indices rather than
802 // constant pool cache indices as do the peer methods above.
803 Symbol* uncached_klass_ref_at_noresolve(int which);
804 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); }
805 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); }
806 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); }
807 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); }
808
809 // Sharing
810 int pre_resolve_shared_klasses(TRAPS);
811
812 // Debugging
813 const char* printable_name_at(int which) PRODUCT_RETURN0;
814
815 #ifdef ASSERT
816 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices
817 #else
818 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op
819 #endif //ASSERT
820
821 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) {
822 if (invokedynamic_ok && is_invokedynamic_index(raw_index))
823 return decode_invokedynamic_index(raw_index);
824 else
825 return raw_index - CPCACHE_INDEX_TAG;
826 }
827
828 private:
829
830 void set_resolved_references(OopHandle s) { _cache->set_resolved_references(s); }
831 Array<u2>* reference_map() const { return (_cache == NULL) ? NULL : _cache->reference_map(); }
832 void set_reference_map(Array<u2>* o) { _cache->set_reference_map(o); }
833
834 // patch JSR 292 resolved references after the class is linked.
835 void patch_resolved_references(GrowableArray<Handle>* cp_patches);
836
837 Symbol* impl_name_ref_at(int which, bool uncached);
838 Symbol* impl_signature_ref_at(int which, bool uncached);
839
840 int impl_klass_ref_index_at(int which, bool uncached);
841 int impl_name_and_type_ref_index_at(int which, bool uncached);
842 constantTag impl_tag_ref_at(int which, bool uncached);
843
844 // Used while constructing constant pool (only by ClassFileParser)
845 jint klass_index_at(int which) {
846 assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
847 return *int_at_addr(which);
848 }
849
850 jint string_index_at(int which) {
851 assert(tag_at(which).is_string_index(), "Corrupted constant pool");
852 return *int_at_addr(which);
853 }
854
855 // Performs the LinkResolver checks
856 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* klass, TRAPS);
857
858 // Implementation of methods that needs an exposed 'this' pointer, in order to
859 // handle GC while executing the method
860 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int which,
861 bool save_resolution_error, TRAPS);
862 static oop string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS);
863
864 static void trace_class_resolution(const constantPoolHandle& this_cp, Klass* k);
865
866 // Resolve string constants (to prevent allocation during compilation)
867 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS);
868
869 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int index, int cache_index,
870 bool* status_return, TRAPS);
871 static oop resolve_bootstrap_specifier_at_impl(const constantPoolHandle& this_cp, int index, TRAPS);
872 static void copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int index,
873 int start_arg, int end_arg,
874 objArrayHandle info, int pos,
875 bool must_resolve, Handle if_not_available, TRAPS);
876
877 // Exception handling
878 static Symbol* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception);
879 static void save_and_throw_exception(const constantPoolHandle& this_cp, int which, constantTag tag, TRAPS);
880
881 public:
882 // Exception handling
883 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS);
884
885 // Merging ConstantPool* support:
886 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2, TRAPS);
887 void copy_cp_to(int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS) {
888 constantPoolHandle h_this(THREAD, this);
889 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD);
890 }
891 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
892 static void copy_entry_to(const constantPoolHandle& from_cp, int from_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
893 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS);
894 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp, TRAPS);
895 int version() const { return _saved._version; }
896 void set_version(int version) { _saved._version = version; }
897 void increment_and_save_version(int version) {
898 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow
899 }
900
901 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; }
902 int resolved_reference_length() const { return _saved._resolved_reference_length; }
903
904 // Decrease ref counts of symbols that are in the constant pool
905 // when the holder class is unloaded
906 void unreference_symbols();
907
908 // Deallocate constant pool for RedefineClasses
909 void deallocate_contents(ClassLoaderData* loader_data);
910 void release_C_heap_structures();
911
912 // JVMTI accesss - GetConstantPool, RetransformClasses, ...
913 friend class JvmtiConstantPoolReconstituter;
914
915 private:
916 jint cpool_entry_size(jint idx);
917 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap);
918
919 // Copy cpool bytes into byte array.
920 // Returns:
921 // int > 0, count of the raw cpool bytes that have been copied
922 // 0, OutOfMemory error
923 // -1, Internal error
924 int copy_cpool_bytes(int cpool_size,
925 SymbolHashMap* tbl,
926 unsigned char *bytes);
927
928 public:
929 // Verify
930 void verify_on(outputStream* st);
931
932 // Printing
933 void print_on(outputStream* st) const;
934 void print_value_on(outputStream* st) const;
935 void print_entry_on(int index, outputStream* st);
936
937 const char* internal_name() const { return "{constant pool}"; }
938
939 #ifndef PRODUCT
940 // Compile the world support
941 static void preload_and_initialize_all_classes(ConstantPool* constant_pool, TRAPS);
942 #endif
943 };
944
945 class SymbolHashMapEntry : public CHeapObj<mtSymbol> {
946 private:
947 unsigned int _hash; // 32-bit hash for item
948 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket
949 Symbol* _symbol; // 1-st part of the mapping: symbol => value
950 u2 _value; // 2-nd part of the mapping: symbol => value
951
952 public:
953 unsigned int hash() const { return _hash; }
954 void set_hash(unsigned int hash) { _hash = hash; }
955
956 SymbolHashMapEntry* next() const { return _next; }
957 void set_next(SymbolHashMapEntry* next) { _next = next; }
958
959 Symbol* symbol() const { return _symbol; }
960 void set_symbol(Symbol* sym) { _symbol = sym; }
961
962 u2 value() const { return _value; }
963 void set_value(u2 value) { _value = value; }
964
965 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value)
966 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {}
967
968 }; // End SymbolHashMapEntry class
969
970
971 class SymbolHashMapBucket : public CHeapObj<mtSymbol> {
972
973 private:
974 SymbolHashMapEntry* _entry;
975
976 public:
977 SymbolHashMapEntry* entry() const { return _entry; }
978 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; }
979 void clear() { _entry = NULL; }
980
981 }; // End SymbolHashMapBucket class
982
983
984 class SymbolHashMap: public CHeapObj<mtSymbol> {
985
986 private:
987 // Default number of entries in the table
988 enum SymbolHashMap_Constants {
989 _Def_HashMap_Size = 256
990 };
991
992 int _table_size;
993 SymbolHashMapBucket* _buckets;
994
995 void initialize_table(int table_size);
996
997 public:
998
999 int table_size() const { return _table_size; }
1000
1001 SymbolHashMap() { initialize_table(_Def_HashMap_Size); }
1002 SymbolHashMap(int table_size) { initialize_table(table_size); }
1003
1004 // hash P(31) from Kernighan & Ritchie
1005 static unsigned int compute_hash(const char* str, int len) {
1006 unsigned int hash = 0;
1007 while (len-- > 0) {
1008 hash = 31*hash + (unsigned) *str;
1009 str++;
1010 }
1011 return hash;
1012 }
1013
1014 SymbolHashMapEntry* bucket(int i) {
1015 return _buckets[i].entry();
1016 }
1017
1018 void add_entry(Symbol* sym, u2 value);
1019 SymbolHashMapEntry* find_entry(Symbol* sym);
1020
1021 u2 symbol_to_value(Symbol* sym) {
1022 SymbolHashMapEntry *entry = find_entry(sym);
1023 return (entry == NULL) ? 0 : entry->value();
1024 }
1025
1026 ~SymbolHashMap();
1027 }; // End SymbolHashMap class
1028
1029 #endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP