1 /*
2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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23 */
24
25 #ifndef SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP
26 #define SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP
27
28 #include "oops/arrayOop.hpp"
29 #include "oops/cpCache.hpp"
30 #include "oops/objArrayOop.hpp"
31 #include "oops/symbol.hpp"
32 #include "oops/typeArrayOop.hpp"
33 #include "runtime/handles.hpp"
34 #include "utilities/constantTag.hpp"
35 #ifdef TARGET_ARCH_x86
36 # include "bytes_x86.hpp"
37 #endif
38 #ifdef TARGET_ARCH_sparc
39 # include "bytes_sparc.hpp"
40 #endif
41 #ifdef TARGET_ARCH_zero
42 # include "bytes_zero.hpp"
43 #endif
44 #ifdef TARGET_ARCH_arm
45 # include "bytes_arm.hpp"
46 #endif
47 #ifdef TARGET_ARCH_ppc
48 # include "bytes_ppc.hpp"
49 #endif
50
51 // A constantPool is an array containing class constants as described in the
52 // class file.
53 //
54 // Most of the constant pool entries are written during class parsing, which
55 // is safe. For klass types, the constant pool entry is
56 // modified when the entry is resolved. If a klass constant pool
57 // entry is read without a lock, only the resolved state guarantees that
58 // the entry in the constant pool is a klass object and not a Symbol*.
59
60 class SymbolHashMap;
61
62 class CPSlot VALUE_OBJ_CLASS_SPEC {
63 intptr_t _ptr;
64 public:
65 CPSlot(intptr_t ptr): _ptr(ptr) {}
66 CPSlot(Klass* ptr): _ptr((intptr_t)ptr) {}
67 CPSlot(Symbol* ptr): _ptr((intptr_t)ptr | 1) {}
68
69 intptr_t value() { return _ptr; }
70 bool is_resolved() { return (_ptr & 1) == 0; }
71 bool is_unresolved() { return (_ptr & 1) == 1; }
72
73 Symbol* get_symbol() {
74 assert(is_unresolved(), "bad call");
75 return (Symbol*)(_ptr & ~1);
76 }
77 Klass* get_klass() {
78 assert(is_resolved(), "bad call");
79 return (Klass*)_ptr;
80 }
81 };
82
83 class KlassSizeStats;
84 class ConstantPool : public Metadata {
85 friend class VMStructs;
86 friend class BytecodeInterpreter; // Directly extracts an oop in the pool for fast instanceof/checkcast
87 friend class Universe; // For null constructor
88 private:
89 Array<u1>* _tags; // the tag array describing the constant pool's contents
90 ConstantPoolCache* _cache; // the cache holding interpreter runtime information
91 InstanceKlass* _pool_holder; // the corresponding class
92 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
93
94 // Array of resolved objects from the constant pool and map from resolved
95 // object index to original constant pool index
96 jobject _resolved_references;
97 Array<u2>* _reference_map;
98
99 enum {
100 _has_preresolution = 1, // Flags
101 _on_stack = 2
102 };
103
104 int _flags; // old fashioned bit twiddling
105 int _length; // number of elements in the array
106
107 union {
108 // set for CDS to restore resolved references
109 int _resolved_reference_length;
110 // keeps version number for redefined classes (used in backtrace)
111 int _version;
112 } _saved;
113
114
115 void set_tags(Array<u1>* tags) { _tags = tags; }
116 void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); }
117 void release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); }
118
119 void set_operands(Array<u2>* operands) { _operands = operands; }
120
121 int flags() const { return _flags; }
122 void set_flags(int f) { _flags = f; }
123
124 private:
125 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); }
126
127 CPSlot slot_at(int which) {
128 assert(is_within_bounds(which), "index out of bounds");
129 // Uses volatile because the klass slot changes without a lock.
130 volatile intptr_t adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which));
131 assert(adr != 0 || which == 0, "cp entry for klass should not be zero");
132 return CPSlot(adr);
133 }
134
135 void slot_at_put(int which, CPSlot s) const {
136 assert(is_within_bounds(which), "index out of bounds");
137 assert(s.value() != 0, "Caught something");
138 *(intptr_t*)&base()[which] = s.value();
139 }
140 intptr_t* obj_at_addr_raw(int which) const {
141 assert(is_within_bounds(which), "index out of bounds");
142 return (intptr_t*) &base()[which];
143 }
144
145 jint* int_at_addr(int which) const {
146 assert(is_within_bounds(which), "index out of bounds");
147 return (jint*) &base()[which];
148 }
149
150 jlong* long_at_addr(int which) const {
151 assert(is_within_bounds(which), "index out of bounds");
152 return (jlong*) &base()[which];
153 }
154
155 jfloat* float_at_addr(int which) const {
156 assert(is_within_bounds(which), "index out of bounds");
157 return (jfloat*) &base()[which];
158 }
159
160 jdouble* double_at_addr(int which) const {
161 assert(is_within_bounds(which), "index out of bounds");
162 return (jdouble*) &base()[which];
163 }
164
165 ConstantPool(Array<u1>* tags);
166 ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
167 public:
168 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS);
169
170 bool is_constantPool() const volatile { return true; }
171
172 Array<u1>* tags() const { return _tags; }
173 Array<u2>* operands() const { return _operands; }
174
175 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; }
176 void set_has_preresolution() { _flags |= _has_preresolution; }
177
178 // Redefine classes support. If a method refering to this constant pool
179 // is on the executing stack, or as a handle in vm code, this constant pool
180 // can't be removed from the set of previous versions saved in the instance
181 // class.
182 bool on_stack() const { return (_flags &_on_stack) != 0; }
183 void set_on_stack(const bool value);
184
185 // Klass holding pool
186 InstanceKlass* pool_holder() const { return _pool_holder; }
187 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; }
188 InstanceKlass** pool_holder_addr() { return &_pool_holder; }
189
190 // Interpreter runtime support
191 ConstantPoolCache* cache() const { return _cache; }
192 void set_cache(ConstantPoolCache* cache){ _cache = cache; }
193
194 // Create object cache in the constant pool
195 void initialize_resolved_references(ClassLoaderData* loader_data,
196 intStack reference_map,
197 int constant_pool_map_length,
198 TRAPS);
199
200 // resolved strings, methodHandles and callsite objects from the constant pool
201 objArrayOop resolved_references() const;
202 // mapping resolved object array indexes to cp indexes and back.
203 int object_to_cp_index(int index) { return _reference_map->at(index); }
204 int cp_to_object_index(int index);
205
206 // Invokedynamic indexes.
207 // They must look completely different from normal indexes.
208 // The main reason is that byte swapping is sometimes done on normal indexes.
209 // Finally, it is helpful for debugging to tell the two apart.
210 static bool is_invokedynamic_index(int i) { return (i < 0); }
211 static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; }
212 static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; }
213
214
215 // The invokedynamic points at a CP cache entry. This entry points back
216 // at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry
217 // in the resolved_references array (which provides the appendix argument).
218 int invokedynamic_cp_cache_index(int index) const {
219 assert (is_invokedynamic_index(index), "should be a invokedynamic index");
220 int cache_index = decode_invokedynamic_index(index);
221 return cache_index;
222 }
223 ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int index) const {
224 // decode index that invokedynamic points to.
225 int cp_cache_index = invokedynamic_cp_cache_index(index);
226 return cache()->entry_at(cp_cache_index);
227 }
228
229 // Assembly code support
230 static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); }
231 static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); }
232 static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); }
233 static int resolved_references_offset_in_bytes() { return offset_of(ConstantPool, _resolved_references); }
234 static int reference_map_offset_in_bytes() { return offset_of(ConstantPool, _reference_map); }
235
236 // Storing constants
237
238 void klass_at_put(int which, Klass* k) {
239 assert(k != NULL, "resolved class shouldn't be null");
240 assert(is_within_bounds(which), "index out of bounds");
241 OrderAccess::release_store_ptr((Klass* volatile *)obj_at_addr_raw(which), k);
242 // The interpreter assumes when the tag is stored, the klass is resolved
243 // and the Klass* is a klass rather than a Symbol*, so we need
244 // hardware store ordering here.
245 release_tag_at_put(which, JVM_CONSTANT_Class);
246 }
247
248 // For temporary use while constructing constant pool
249 void klass_index_at_put(int which, int name_index) {
250 tag_at_put(which, JVM_CONSTANT_ClassIndex);
251 *int_at_addr(which) = name_index;
252 }
253
254 // Temporary until actual use
255 void unresolved_klass_at_put(int which, Symbol* s) {
256 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
257 slot_at_put(which, s);
258 }
259
260 void method_handle_index_at_put(int which, int ref_kind, int ref_index) {
261 tag_at_put(which, JVM_CONSTANT_MethodHandle);
262 *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind;
263 }
264
265 void method_type_index_at_put(int which, int ref_index) {
266 tag_at_put(which, JVM_CONSTANT_MethodType);
267 *int_at_addr(which) = ref_index;
268 }
269
270 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
271 tag_at_put(which, JVM_CONSTANT_InvokeDynamic);
272 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
273 }
274
275 void unresolved_string_at_put(int which, Symbol* s) {
276 release_tag_at_put(which, JVM_CONSTANT_String);
277 *symbol_at_addr(which) = s;
278 }
279
280 void int_at_put(int which, jint i) {
281 tag_at_put(which, JVM_CONSTANT_Integer);
282 *int_at_addr(which) = i;
283 }
284
285 void long_at_put(int which, jlong l) {
286 tag_at_put(which, JVM_CONSTANT_Long);
287 // *long_at_addr(which) = l;
288 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
289 }
290
291 void float_at_put(int which, jfloat f) {
292 tag_at_put(which, JVM_CONSTANT_Float);
293 *float_at_addr(which) = f;
294 }
295
296 void double_at_put(int which, jdouble d) {
297 tag_at_put(which, JVM_CONSTANT_Double);
298 // *double_at_addr(which) = d;
299 // u8 temp = *(u8*) &d;
300 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
301 }
302
303 Symbol** symbol_at_addr(int which) const {
304 assert(is_within_bounds(which), "index out of bounds");
305 return (Symbol**) &base()[which];
306 }
307
308 void symbol_at_put(int which, Symbol* s) {
309 assert(s->refcount() != 0, "should have nonzero refcount");
310 tag_at_put(which, JVM_CONSTANT_Utf8);
311 *symbol_at_addr(which) = s;
312 }
313
314 void string_at_put(int which, int obj_index, oop str) {
315 resolved_references()->obj_at_put(obj_index, str);
316 }
317
318 // For temporary use while constructing constant pool
319 void string_index_at_put(int which, int string_index) {
320 tag_at_put(which, JVM_CONSTANT_StringIndex);
321 *int_at_addr(which) = string_index;
322 }
323
324 void field_at_put(int which, int class_index, int name_and_type_index) {
325 tag_at_put(which, JVM_CONSTANT_Fieldref);
326 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
327 }
328
329 void method_at_put(int which, int class_index, int name_and_type_index) {
330 tag_at_put(which, JVM_CONSTANT_Methodref);
331 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
332 }
333
334 void interface_method_at_put(int which, int class_index, int name_and_type_index) {
335 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
336 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
337 }
338
339 void name_and_type_at_put(int which, int name_index, int signature_index) {
340 tag_at_put(which, JVM_CONSTANT_NameAndType);
341 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
342 }
343
344 // Tag query
345
346 constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); }
347
348 // Fetching constants
349
350 Klass* klass_at(int which, TRAPS) {
351 constantPoolHandle h_this(THREAD, this);
352 return klass_at_impl(h_this, which, CHECK_NULL);
353 }
354
355 Symbol* klass_name_at(int which); // Returns the name, w/o resolving.
356
357 Klass* resolved_klass_at(int which) const { // Used by Compiler
358 guarantee(tag_at(which).is_klass(), "Corrupted constant pool");
359 // Must do an acquire here in case another thread resolved the klass
360 // behind our back, lest we later load stale values thru the oop.
361 return CPSlot((Klass*)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_klass();
362 }
363
364 // This method should only be used with a cpool lock or during parsing or gc
365 Symbol* unresolved_klass_at(int which) { // Temporary until actual use
366 Symbol* s = CPSlot((Symbol*)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_symbol();
367 // check that the klass is still unresolved.
368 assert(tag_at(which).is_unresolved_klass(), "Corrupted constant pool");
369 return s;
370 }
371
372 // RedefineClasses() API support:
373 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); }
374
375 jint int_at(int which) {
376 assert(tag_at(which).is_int(), "Corrupted constant pool");
377 return *int_at_addr(which);
378 }
379
380 jlong long_at(int which) {
381 assert(tag_at(which).is_long(), "Corrupted constant pool");
382 // return *long_at_addr(which);
383 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
384 return *((jlong*)&tmp);
385 }
386
387 jfloat float_at(int which) {
388 assert(tag_at(which).is_float(), "Corrupted constant pool");
389 return *float_at_addr(which);
390 }
391
392 jdouble double_at(int which) {
393 assert(tag_at(which).is_double(), "Corrupted constant pool");
394 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
395 return *((jdouble*)&tmp);
396 }
397
398 Symbol* symbol_at(int which) {
399 assert(tag_at(which).is_utf8(), "Corrupted constant pool");
400 return *symbol_at_addr(which);
401 }
402
403 oop string_at(int which, int obj_index, TRAPS) {
404 constantPoolHandle h_this(THREAD, this);
405 return string_at_impl(h_this, which, obj_index, THREAD);
406 }
407 oop string_at(int which, TRAPS) {
408 int obj_index = cp_to_object_index(which);
409 return string_at(which, obj_index, THREAD);
410 }
411
412 // Version that can be used before string oop array is created.
413 oop uncached_string_at(int which, TRAPS);
414
415 // A "pseudo-string" is an non-string oop that has found is way into
416 // a String entry.
417 // Under EnableInvokeDynamic this can happen if the user patches a live
418 // object into a CONSTANT_String entry of an anonymous class.
419 // Method oops internally created for method handles may also
420 // use pseudo-strings to link themselves to related metaobjects.
421
422 bool is_pseudo_string_at(int which) {
423 // A pseudo string is a string that doesn't have a symbol in the cpSlot
424 return unresolved_string_at(which) == NULL;
425 }
426
427 oop pseudo_string_at(int which, int obj_index) {
428 assert(tag_at(which).is_string(), "Corrupted constant pool");
429 assert(unresolved_string_at(which) == NULL, "shouldn't have symbol");
430 oop s = resolved_references()->obj_at(obj_index);
431 return s;
432 }
433
434 oop pseudo_string_at(int which) {
435 assert(tag_at(which).is_string(), "Corrupted constant pool");
436 assert(unresolved_string_at(which) == NULL, "shouldn't have symbol");
437 int obj_index = cp_to_object_index(which);
438 oop s = resolved_references()->obj_at(obj_index);
439 return s;
440 }
441
442 void pseudo_string_at_put(int which, int obj_index, oop x) {
443 assert(EnableInvokeDynamic, "");
444 assert(tag_at(which).is_string(), "Corrupted constant pool");
445 unresolved_string_at_put(which, NULL); // indicates patched string
446 string_at_put(which, obj_index, x); // this works just fine
447 }
448
449 // only called when we are sure a string entry is already resolved (via an
450 // earlier string_at call.
451 oop resolved_string_at(int which) {
452 assert(tag_at(which).is_string(), "Corrupted constant pool");
453 // Must do an acquire here in case another thread resolved the klass
454 // behind our back, lest we later load stale values thru the oop.
455 // we might want a volatile_obj_at in ObjArrayKlass.
456 int obj_index = cp_to_object_index(which);
457 return resolved_references()->obj_at(obj_index);
458 }
459
460 Symbol* unresolved_string_at(int which) {
461 assert(tag_at(which).is_string(), "Corrupted constant pool");
462 Symbol* s = *symbol_at_addr(which);
463 return s;
464 }
465
466 // Returns an UTF8 for a CONSTANT_String entry at a given index.
467 // UTF8 char* representation was chosen to avoid conversion of
468 // java_lang_Strings at resolved entries into Symbol*s
469 // or vice versa.
470 // Caller is responsible for checking for pseudo-strings.
471 char* string_at_noresolve(int which);
472
473 jint name_and_type_at(int which) {
474 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
475 return *int_at_addr(which);
476 }
477
478 int method_handle_ref_kind_at(int which) {
479 assert(tag_at(which).is_method_handle(), "Corrupted constant pool");
480 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits
481 }
482 int method_handle_index_at(int which) {
483 assert(tag_at(which).is_method_handle(), "Corrupted constant pool");
484 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits
485 }
486 int method_type_index_at(int which) {
487 assert(tag_at(which).is_method_type(), "Corrupted constant pool");
488 return *int_at_addr(which);
489 }
490 // Derived queries:
491 Symbol* method_handle_name_ref_at(int which) {
492 int member = method_handle_index_at(which);
493 return impl_name_ref_at(member, true);
494 }
495 Symbol* method_handle_signature_ref_at(int which) {
496 int member = method_handle_index_at(which);
497 return impl_signature_ref_at(member, true);
498 }
499 int method_handle_klass_index_at(int which) {
500 int member = method_handle_index_at(which);
501 return impl_klass_ref_index_at(member, true);
502 }
503 Symbol* method_type_signature_at(int which) {
504 int sym = method_type_index_at(which);
505 return symbol_at(sym);
506 }
507
508 int invoke_dynamic_name_and_type_ref_index_at(int which) {
509 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
510 return extract_high_short_from_int(*int_at_addr(which));
511 }
512 int invoke_dynamic_bootstrap_specifier_index(int which) {
513 assert(tag_at(which).value() == JVM_CONSTANT_InvokeDynamic, "Corrupted constant pool");
514 return extract_low_short_from_int(*int_at_addr(which));
515 }
516 int invoke_dynamic_operand_base(int which) {
517 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
518 return operand_offset_at(operands(), bootstrap_specifier_index);
519 }
520 // The first part of the operands array consists of an index into the second part.
521 // Extract a 32-bit index value from the first part.
522 static int operand_offset_at(Array<u2>* operands, int bootstrap_specifier_index) {
523 int n = (bootstrap_specifier_index * 2);
524 assert(n >= 0 && n+2 <= operands->length(), "oob");
525 // The first 32-bit index points to the beginning of the second part
526 // of the operands array. Make sure this index is in the first part.
527 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0),
528 operands->at(1)));
529 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
530 int offset = build_int_from_shorts(operands->at(n+0),
531 operands->at(n+1));
532 // The offset itself must point into the second part of the array.
533 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)");
534 return offset;
535 }
536 static void operand_offset_at_put(Array<u2>* operands, int bootstrap_specifier_index, int offset) {
537 int n = bootstrap_specifier_index * 2;
538 assert(n >= 0 && n+2 <= operands->length(), "oob");
539 operands->at_put(n+0, extract_low_short_from_int(offset));
540 operands->at_put(n+1, extract_high_short_from_int(offset));
541 }
542 static int operand_array_length(Array<u2>* operands) {
543 if (operands == NULL || operands->length() == 0) return 0;
544 int second_part = operand_offset_at(operands, 0);
545 return (second_part / 2);
546 }
547
548 #ifdef ASSERT
549 // operand tuples fit together exactly, end to end
550 static int operand_limit_at(Array<u2>* operands, int bootstrap_specifier_index) {
551 int nextidx = bootstrap_specifier_index + 1;
552 if (nextidx == operand_array_length(operands))
553 return operands->length();
554 else
555 return operand_offset_at(operands, nextidx);
556 }
557 int invoke_dynamic_operand_limit(int which) {
558 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
559 return operand_limit_at(operands(), bootstrap_specifier_index);
560 }
561 #endif //ASSERT
562
563 // layout of InvokeDynamic bootstrap method specifier (in second part of operands array):
564 enum {
565 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
566 _indy_argc_offset = 1, // u2 argc
567 _indy_argv_offset = 2 // u2 argv[argc]
568 };
569
570 // These functions are used in RedefineClasses for CP merge
571
572 int operand_offset_at(int bootstrap_specifier_index) {
573 assert(0 <= bootstrap_specifier_index &&
574 bootstrap_specifier_index < operand_array_length(operands()),
575 "Corrupted CP operands");
576 return operand_offset_at(operands(), bootstrap_specifier_index);
577 }
578 int operand_bootstrap_method_ref_index_at(int bootstrap_specifier_index) {
579 int offset = operand_offset_at(bootstrap_specifier_index);
580 return operands()->at(offset + _indy_bsm_offset);
581 }
582 int operand_argument_count_at(int bootstrap_specifier_index) {
583 int offset = operand_offset_at(bootstrap_specifier_index);
584 int argc = operands()->at(offset + _indy_argc_offset);
585 return argc;
586 }
587 int operand_argument_index_at(int bootstrap_specifier_index, int j) {
588 int offset = operand_offset_at(bootstrap_specifier_index);
589 return operands()->at(offset + _indy_argv_offset + j);
590 }
591 int operand_next_offset_at(int bootstrap_specifier_index) {
592 int offset = operand_offset_at(bootstrap_specifier_index) + _indy_argv_offset
593 + operand_argument_count_at(bootstrap_specifier_index);
594 return offset;
595 }
596 // Compare a bootsrap specifier in the operands arrays
597 bool compare_operand_to(int bootstrap_specifier_index1, constantPoolHandle cp2,
598 int bootstrap_specifier_index2, TRAPS);
599 // Find a bootsrap specifier in the operands array
600 int find_matching_operand(int bootstrap_specifier_index, constantPoolHandle search_cp,
601 int operands_cur_len, TRAPS);
602 // Resize the operands array with delta_len and delta_size
603 void resize_operands(int delta_len, int delta_size, TRAPS);
604 // Extend the operands array with the length and size of the ext_cp operands
605 void extend_operands(constantPoolHandle ext_cp, TRAPS);
606 // Shrink the operands array to a smaller array with new_len length
607 void shrink_operands(int new_len, TRAPS);
608
609
610 int invoke_dynamic_bootstrap_method_ref_index_at(int which) {
611 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
612 int op_base = invoke_dynamic_operand_base(which);
613 return operands()->at(op_base + _indy_bsm_offset);
614 }
615 int invoke_dynamic_argument_count_at(int which) {
616 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
617 int op_base = invoke_dynamic_operand_base(which);
618 int argc = operands()->at(op_base + _indy_argc_offset);
619 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
620 int next_offset = invoke_dynamic_operand_limit(which));
621 assert(end_offset == next_offset, "matched ending");
622 return argc;
623 }
624 int invoke_dynamic_argument_index_at(int which, int j) {
625 int op_base = invoke_dynamic_operand_base(which);
626 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset));
627 assert((uint)j < (uint)argc, "oob");
628 return operands()->at(op_base + _indy_argv_offset + j);
629 }
630
631 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
632 // name_and_type_ref_index_at) all expect to be passed indices obtained
633 // directly from the bytecode.
634 // If the indices are meant to refer to fields or methods, they are
635 // actually rewritten constant pool cache indices.
636 // The routine remap_instruction_operand_from_cache manages the adjustment
637 // of these values back to constant pool indices.
638
639 // There are also "uncached" versions which do not adjust the operand index; see below.
640
641 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear.
642 // In a few cases (the verifier) there are uses before a cpcache has been built,
643 // which are handled by a dynamic check in remap_instruction_operand_from_cache.
644 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode.
645
646 // Lookup for entries consisting of (klass_index, name_and_type index)
647 Klass* klass_ref_at(int which, TRAPS);
648 Symbol* klass_ref_at_noresolve(int which);
649 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); }
650 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); }
651
652 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); }
653 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); }
654
655 // Lookup for entries consisting of (name_index, signature_index)
656 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt)
657 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt)
658
659 BasicType basic_type_for_signature_at(int which);
660
661 // Resolve string constants (to prevent allocation during compilation)
662 void resolve_string_constants(TRAPS) {
663 constantPoolHandle h_this(THREAD, this);
664 resolve_string_constants_impl(h_this, CHECK);
665 }
666
667 // CDS support
668 void remove_unshareable_info();
669 void restore_unshareable_info(TRAPS);
670 bool resolve_class_constants(TRAPS);
671 // The ConstantPool vtable is restored by this call when the ConstantPool is
672 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for
673 // all the gory details. SA, dtrace and pstack helpers distinguish metadata
674 // by their vtable.
675 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); }
676
677 private:
678 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
679 public:
680
681 // Resolve late bound constants.
682 oop resolve_constant_at(int index, TRAPS) {
683 constantPoolHandle h_this(THREAD, this);
684 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD);
685 }
686
687 oop resolve_cached_constant_at(int cache_index, TRAPS) {
688 constantPoolHandle h_this(THREAD, this);
689 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD);
690 }
691
692 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) {
693 constantPoolHandle h_this(THREAD, this);
694 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD);
695 }
696
697 oop resolve_bootstrap_specifier_at(int index, TRAPS) {
698 constantPoolHandle h_this(THREAD, this);
699 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD);
700 }
701
702 // Klass name matches name at offset
703 bool klass_name_at_matches(instanceKlassHandle k, int which);
704
705 // Sizing
706 int length() const { return _length; }
707 void set_length(int length) { _length = length; }
708
709 // Tells whether index is within bounds.
710 bool is_within_bounds(int index) const {
711 return 0 <= index && index < length();
712 }
713
714 // Sizing (in words)
715 static int header_size() { return sizeof(ConstantPool)/HeapWordSize; }
716 static int size(int length) { return align_object_size(header_size() + length); }
717 int size() const { return size(length()); }
718 #if INCLUDE_SERVICES
719 void collect_statistics(KlassSizeStats *sz) const;
720 #endif
721
722 friend class ClassFileParser;
723 friend class SystemDictionary;
724
725 // Used by compiler to prevent classloading.
726 static Method* method_at_if_loaded (constantPoolHandle this_oop, int which);
727 static bool has_appendix_at_if_loaded (constantPoolHandle this_oop, int which);
728 static oop appendix_at_if_loaded (constantPoolHandle this_oop, int which);
729 static bool has_method_type_at_if_loaded (constantPoolHandle this_oop, int which);
730 static oop method_type_at_if_loaded (constantPoolHandle this_oop, int which);
731 static Klass* klass_at_if_loaded (constantPoolHandle this_oop, int which);
732 static Klass* klass_ref_at_if_loaded (constantPoolHandle this_oop, int which);
733
734 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
735 // future by other Java code. These take constant pool indices rather than
736 // constant pool cache indices as do the peer methods above.
737 Symbol* uncached_klass_ref_at_noresolve(int which);
738 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); }
739 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); }
740 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); }
741 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); }
742
743 // Sharing
744 int pre_resolve_shared_klasses(TRAPS);
745
746 // Debugging
747 const char* printable_name_at(int which) PRODUCT_RETURN0;
748
749 #ifdef ASSERT
750 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices
751 #else
752 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op
753 #endif //ASSERT
754
755 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) {
756 if (invokedynamic_ok && is_invokedynamic_index(raw_index))
757 return decode_invokedynamic_index(raw_index);
758 else
759 return raw_index - CPCACHE_INDEX_TAG;
760 }
761
762 private:
763
764 void set_resolved_references(jobject s) { _resolved_references = s; }
765 Array<u2>* reference_map() const { return _reference_map; }
766 void set_reference_map(Array<u2>* o) { _reference_map = o; }
767
768 // patch JSR 292 resolved references after the class is linked.
769 void patch_resolved_references(GrowableArray<Handle>* cp_patches);
770
771 Symbol* impl_name_ref_at(int which, bool uncached);
772 Symbol* impl_signature_ref_at(int which, bool uncached);
773 int impl_klass_ref_index_at(int which, bool uncached);
774 int impl_name_and_type_ref_index_at(int which, bool uncached);
775
776 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG
777
778 // Used while constructing constant pool (only by ClassFileParser)
779 jint klass_index_at(int which) {
780 assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
781 return *int_at_addr(which);
782 }
783
784 jint string_index_at(int which) {
785 assert(tag_at(which).is_string_index(), "Corrupted constant pool");
786 return *int_at_addr(which);
787 }
788
789 // Performs the LinkResolver checks
790 static void verify_constant_pool_resolve(constantPoolHandle this_oop, KlassHandle klass, TRAPS);
791
792 // Implementation of methods that needs an exposed 'this' pointer, in order to
793 // handle GC while executing the method
794 static Klass* klass_at_impl(constantPoolHandle this_oop, int which, TRAPS);
795 static oop string_at_impl(constantPoolHandle this_oop, int which, int obj_index, TRAPS);
796
797 // Resolve string constants (to prevent allocation during compilation)
798 static void resolve_string_constants_impl(constantPoolHandle this_oop, TRAPS);
799
800 static oop resolve_constant_at_impl(constantPoolHandle this_oop, int index, int cache_index, TRAPS);
801 static void save_and_throw_exception(constantPoolHandle this_oop, int which, int tag_value, TRAPS);
802 static oop resolve_bootstrap_specifier_at_impl(constantPoolHandle this_oop, int index, TRAPS);
803
804 public:
805 // Merging ConstantPool* support:
806 bool compare_entry_to(int index1, constantPoolHandle cp2, int index2, TRAPS);
807 void copy_cp_to(int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS) {
808 constantPoolHandle h_this(THREAD, this);
809 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD);
810 }
811 static void copy_cp_to_impl(constantPoolHandle from_cp, int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS);
812 static void copy_entry_to(constantPoolHandle from_cp, int from_i, constantPoolHandle to_cp, int to_i, TRAPS);
813 static void copy_operands(constantPoolHandle from_cp, constantPoolHandle to_cp, TRAPS);
814 int find_matching_entry(int pattern_i, constantPoolHandle search_cp, TRAPS);
815 int version() const { return _saved._version; }
816 void set_version(int version) { _saved._version = version; }
817 void increment_and_save_version(int version) {
818 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow
819 }
820
821 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; }
822 int resolved_reference_length() const { return _saved._resolved_reference_length; }
823
824 // lock() may return null -- constant pool updates may happen before this lock is
825 // initialized, because the _pool_holder has not been fully initialized and
826 // has not been registered into the system dictionary. In this case, no other
827 // thread can be modifying this constantpool, so no synchronization is
828 // necessary.
829 //
830 // Use cplock() like this:
831 // oop cplock = cp->lock();
832 // ObjectLocker ol(cplock , THREAD, cplock != NULL);
833 oop lock();
834
835 // Decrease ref counts of symbols that are in the constant pool
836 // when the holder class is unloaded
837 void unreference_symbols();
838
839 // Deallocate constant pool for RedefineClasses
840 void deallocate_contents(ClassLoaderData* loader_data);
841 void release_C_heap_structures();
842
843 // JVMTI accesss - GetConstantPool, RetransformClasses, ...
844 friend class JvmtiConstantPoolReconstituter;
845
846 private:
847 jint cpool_entry_size(jint idx);
848 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap);
849
850 // Copy cpool bytes into byte array.
851 // Returns:
852 // int > 0, count of the raw cpool bytes that have been copied
853 // 0, OutOfMemory error
854 // -1, Internal error
855 int copy_cpool_bytes(int cpool_size,
856 SymbolHashMap* tbl,
857 unsigned char *bytes);
858
859 public:
860 // Verify
861 void verify_on(outputStream* st);
862
863 // Printing
864 void print_on(outputStream* st) const;
865 void print_value_on(outputStream* st) const;
866 void print_entry_on(int index, outputStream* st);
867
868 const char* internal_name() const { return "{constant pool}"; }
869
870 #ifndef PRODUCT
871 // Compile the world support
872 static void preload_and_initialize_all_classes(ConstantPool* constant_pool, TRAPS);
873 #endif
874 };
875
876 class SymbolHashMapEntry : public CHeapObj<mtSymbol> {
877 private:
878 unsigned int _hash; // 32-bit hash for item
879 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket
880 Symbol* _symbol; // 1-st part of the mapping: symbol => value
881 u2 _value; // 2-nd part of the mapping: symbol => value
882
883 public:
884 unsigned int hash() const { return _hash; }
885 void set_hash(unsigned int hash) { _hash = hash; }
886
887 SymbolHashMapEntry* next() const { return _next; }
888 void set_next(SymbolHashMapEntry* next) { _next = next; }
889
890 Symbol* symbol() const { return _symbol; }
891 void set_symbol(Symbol* sym) { _symbol = sym; }
892
893 u2 value() const { return _value; }
894 void set_value(u2 value) { _value = value; }
895
896 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value)
897 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {}
898
899 }; // End SymbolHashMapEntry class
900
901
902 class SymbolHashMapBucket : public CHeapObj<mtSymbol> {
903
904 private:
905 SymbolHashMapEntry* _entry;
906
907 public:
908 SymbolHashMapEntry* entry() const { return _entry; }
909 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; }
910 void clear() { _entry = NULL; }
911
912 }; // End SymbolHashMapBucket class
913
914
915 class SymbolHashMap: public CHeapObj<mtSymbol> {
916
917 private:
918 // Default number of entries in the table
919 enum SymbolHashMap_Constants {
920 _Def_HashMap_Size = 256
921 };
922
923 int _table_size;
924 SymbolHashMapBucket* _buckets;
925
926 void initialize_table(int table_size) {
927 _table_size = table_size;
928 _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size, mtSymbol);
929 for (int index = 0; index < table_size; index++) {
930 _buckets[index].clear();
931 }
932 }
933
934 public:
935
936 int table_size() const { return _table_size; }
937
938 SymbolHashMap() { initialize_table(_Def_HashMap_Size); }
939 SymbolHashMap(int table_size) { initialize_table(table_size); }
940
941 // hash P(31) from Kernighan & Ritchie
942 static unsigned int compute_hash(const char* str, int len) {
943 unsigned int hash = 0;
944 while (len-- > 0) {
945 hash = 31*hash + (unsigned) *str;
946 str++;
947 }
948 return hash;
949 }
950
951 SymbolHashMapEntry* bucket(int i) {
952 return _buckets[i].entry();
953 }
954
955 void add_entry(Symbol* sym, u2 value);
956 SymbolHashMapEntry* find_entry(Symbol* sym);
957
958 u2 symbol_to_value(Symbol* sym) {
959 SymbolHashMapEntry *entry = find_entry(sym);
960 return (entry == NULL) ? 0 : entry->value();
961 }
962
963 ~SymbolHashMap() {
964 SymbolHashMapEntry* next;
965 for (int i = 0; i < _table_size; i++) {
966 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
967 next = cur->next();
968 delete(cur);
969 }
970 }
971 delete _buckets;
972 }
973 }; // End SymbolHashMap class
974
975 #endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP