1 /*
2 * Copyright (c) 1997, 2016, 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
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23 */
24
25 #ifndef SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP
26 #define SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP
27
28 #include "oops/arrayOop.hpp"
29 #include "oops/cpCache.hpp"
30 #include "oops/objArrayOop.hpp"
31 #include "oops/symbol.hpp"
32 #include "oops/typeArrayOop.hpp"
33 #include "runtime/handles.hpp"
34 #include "utilities/bytes.hpp"
35 #include "utilities/constantTag.hpp"
36
37 // A ConstantPool is an array containing class constants as described in the
38 // class file.
39 //
40 // Most of the constant pool entries are written during class parsing, which
41 // is safe. For klass types, the constant pool entry is
42 // modified when the entry is resolved. If a klass constant pool
43 // entry is read without a lock, only the resolved state guarantees that
44 // the entry in the constant pool is a klass object and not a Symbol*.
45
46 class SymbolHashMap;
47
48 class CPSlot VALUE_OBJ_CLASS_SPEC {
49 intptr_t _ptr;
50 public:
51 enum TagBits { _resolved_value = 0, _symbol_bit = 1, _pseudo_bit = 2, _symbol_mask = 3 };
52
53 CPSlot(intptr_t ptr): _ptr(ptr) {}
54 CPSlot(Klass* ptr): _ptr((intptr_t)ptr) {}
55 CPSlot(Symbol* ptr): _ptr((intptr_t)ptr | _symbol_bit) {}
56 CPSlot(Symbol* ptr, int tag_bits): _ptr((intptr_t)ptr | tag_bits) {}
57
58 intptr_t value() { return _ptr; }
59 bool is_resolved() { return (_ptr & _symbol_bit ) == _resolved_value; }
60 bool is_unresolved() { return (_ptr & _symbol_bit ) != _resolved_value; }
61 bool is_pseudo_string() { return (_ptr & _symbol_mask) == _symbol_bit + _pseudo_bit; }
62
63 Symbol* get_symbol() {
64 assert(is_unresolved(), "bad call");
65 return (Symbol*)(_ptr & ~_symbol_mask);
66 }
67 Klass* get_klass() {
68 assert(is_resolved(), "bad call");
69 return (Klass*)_ptr;
70 }
71 };
72
73 class KlassSizeStats;
74
75 class ConstantPool : public Metadata {
76 friend class VMStructs;
77 friend class JVMCIVMStructs;
78 friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast
79 friend class Universe; // For null constructor
80 private:
81 Array<u1>* _tags; // the tag array describing the constant pool's contents
82 ConstantPoolCache* _cache; // the cache holding interpreter runtime information
83 InstanceKlass* _pool_holder; // the corresponding class
84 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
85
86 // Array of resolved objects from the constant pool and map from resolved
87 // object index to original constant pool index
88 jobject _resolved_references;
89 Array<u2>* _reference_map;
90
91 enum {
92 _has_preresolution = 1, // Flags
93 _on_stack = 2
94 };
95
96 int _flags; // old fashioned bit twiddling
97 int _length; // number of elements in the array
98
99 union {
100 // set for CDS to restore resolved references
101 int _resolved_reference_length;
102 // keeps version number for redefined classes (used in backtrace)
103 int _version;
104 } _saved;
105
106 void set_tags(Array<u1>* tags) { _tags = tags; }
107 void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); }
108 void release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); }
109
110 u1* tag_addr_at(int which) const { return tags()->adr_at(which); }
111
112 void set_operands(Array<u2>* operands) { _operands = operands; }
113
114 int flags() const { return _flags; }
115 void set_flags(int f) { _flags = f; }
116
117 private:
118 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); }
119
120 CPSlot slot_at(int which) const {
121 assert(is_within_bounds(which), "index out of bounds");
122 // Uses volatile because the klass slot changes without a lock.
123 volatile intptr_t adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which));
124 assert(adr != 0 || which == 0, "cp entry for klass should not be zero");
125 return CPSlot(adr);
126 }
127
128 void slot_at_put(int which, CPSlot s) const {
129 assert(is_within_bounds(which), "index out of bounds");
130 assert(s.value() != 0, "Caught something");
131 *(intptr_t*)&base()[which] = s.value();
132 }
133 intptr_t* obj_at_addr_raw(int which) const {
134 assert(is_within_bounds(which), "index out of bounds");
135 return (intptr_t*) &base()[which];
136 }
137
138 jint* int_at_addr(int which) const {
139 assert(is_within_bounds(which), "index out of bounds");
140 return (jint*) &base()[which];
141 }
142
143 jlong* long_at_addr(int which) const {
144 assert(is_within_bounds(which), "index out of bounds");
145 return (jlong*) &base()[which];
146 }
147
148 jfloat* float_at_addr(int which) const {
149 assert(is_within_bounds(which), "index out of bounds");
150 return (jfloat*) &base()[which];
151 }
152
153 jdouble* double_at_addr(int which) const {
154 assert(is_within_bounds(which), "index out of bounds");
155 return (jdouble*) &base()[which];
156 }
157
158 ConstantPool(Array<u1>* tags);
159 ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
160 public:
161 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS);
162
163 bool is_constantPool() const volatile { return true; }
164
165 Array<u1>* tags() const { return _tags; }
166 Array<u2>* operands() const { return _operands; }
167
168 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; }
169 void set_has_preresolution() { _flags |= _has_preresolution; }
170
171 // Redefine classes support. If a method refering to this constant pool
172 // is on the executing stack, or as a handle in vm code, this constant pool
173 // can't be removed from the set of previous versions saved in the instance
174 // class.
175 bool on_stack() const { return (_flags &_on_stack) != 0; }
176 void set_on_stack(const bool value);
177
178 // Klass holding pool
179 InstanceKlass* pool_holder() const { return _pool_holder; }
180 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; }
181 InstanceKlass** pool_holder_addr() { return &_pool_holder; }
182
183 // Interpreter runtime support
184 ConstantPoolCache* cache() const { return _cache; }
185 void set_cache(ConstantPoolCache* cache){ _cache = cache; }
186
187 // Create object cache in the constant pool
188 void initialize_resolved_references(ClassLoaderData* loader_data,
189 const intStack& reference_map,
190 int constant_pool_map_length,
191 TRAPS);
192
193 // resolved strings, methodHandles and callsite objects from the constant pool
194 objArrayOop resolved_references() const;
195 // mapping resolved object array indexes to cp indexes and back.
196 int object_to_cp_index(int index) { return _reference_map->at(index); }
197 int cp_to_object_index(int index);
198
199 // Invokedynamic indexes.
200 // They must look completely different from normal indexes.
201 // The main reason is that byte swapping is sometimes done on normal indexes.
202 // Finally, it is helpful for debugging to tell the two apart.
203 static bool is_invokedynamic_index(int i) { return (i < 0); }
204 static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; }
205 static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; }
206
207
208 // The invokedynamic points at a CP cache entry. This entry points back
209 // at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry
210 // in the resolved_references array (which provides the appendix argument).
211 int invokedynamic_cp_cache_index(int index) const {
212 assert (is_invokedynamic_index(index), "should be a invokedynamic index");
213 int cache_index = decode_invokedynamic_index(index);
214 return cache_index;
215 }
216 ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int index) const {
217 // decode index that invokedynamic points to.
218 int cp_cache_index = invokedynamic_cp_cache_index(index);
219 return cache()->entry_at(cp_cache_index);
220 }
221
222 // Assembly code support
223 static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); }
224 static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); }
225 static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); }
226 static int resolved_references_offset_in_bytes() { return offset_of(ConstantPool, _resolved_references); }
227
228 // Storing constants
229
230 void klass_at_put(int which, Klass* k) {
231 assert(k != NULL, "resolved class shouldn't be null");
232 assert(is_within_bounds(which), "index out of bounds");
233 OrderAccess::release_store_ptr((Klass* volatile *)obj_at_addr_raw(which), k);
234 // The interpreter assumes when the tag is stored, the klass is resolved
235 // and the Klass* is a klass rather than a Symbol*, so we need
236 // hardware store ordering here.
237 release_tag_at_put(which, JVM_CONSTANT_Class);
238 }
239
240 // For temporary use while constructing constant pool
241 void klass_index_at_put(int which, int name_index) {
242 tag_at_put(which, JVM_CONSTANT_ClassIndex);
243 *int_at_addr(which) = name_index;
244 }
245
246 // Temporary until actual use
247 void unresolved_klass_at_put(int which, Symbol* s) {
248 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
249 slot_at_put(which, s);
250 }
251
252 void method_handle_index_at_put(int which, int ref_kind, int ref_index) {
253 tag_at_put(which, JVM_CONSTANT_MethodHandle);
254 *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind;
255 }
256
257 void method_type_index_at_put(int which, int ref_index) {
258 tag_at_put(which, JVM_CONSTANT_MethodType);
259 *int_at_addr(which) = ref_index;
260 }
261
262 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
263 tag_at_put(which, JVM_CONSTANT_InvokeDynamic);
264 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
265 }
266
267 void unresolved_string_at_put(int which, Symbol* s) {
268 release_tag_at_put(which, JVM_CONSTANT_String);
269 slot_at_put(which, CPSlot(s, CPSlot::_symbol_bit));
270 }
271
272 void int_at_put(int which, jint i) {
273 tag_at_put(which, JVM_CONSTANT_Integer);
274 *int_at_addr(which) = i;
275 }
276
277 void long_at_put(int which, jlong l) {
278 tag_at_put(which, JVM_CONSTANT_Long);
279 // *long_at_addr(which) = l;
280 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
281 }
282
283 void float_at_put(int which, jfloat f) {
284 tag_at_put(which, JVM_CONSTANT_Float);
285 *float_at_addr(which) = f;
286 }
287
288 void double_at_put(int which, jdouble d) {
289 tag_at_put(which, JVM_CONSTANT_Double);
290 // *double_at_addr(which) = d;
291 // u8 temp = *(u8*) &d;
292 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
293 }
294
295 Symbol** symbol_at_addr(int which) const {
296 assert(is_within_bounds(which), "index out of bounds");
297 return (Symbol**) &base()[which];
298 }
299
300 void symbol_at_put(int which, Symbol* s) {
301 assert(s->refcount() != 0, "should have nonzero refcount");
302 tag_at_put(which, JVM_CONSTANT_Utf8);
303 *symbol_at_addr(which) = s;
304 }
305
306 void string_at_put(int which, int obj_index, oop str);
307
308 // For temporary use while constructing constant pool
309 void string_index_at_put(int which, int string_index) {
310 tag_at_put(which, JVM_CONSTANT_StringIndex);
311 *int_at_addr(which) = string_index;
312 }
313
314 void field_at_put(int which, int class_index, int name_and_type_index) {
315 tag_at_put(which, JVM_CONSTANT_Fieldref);
316 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
317 }
318
319 void method_at_put(int which, int class_index, int name_and_type_index) {
320 tag_at_put(which, JVM_CONSTANT_Methodref);
321 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
322 }
323
324 void interface_method_at_put(int which, int class_index, int name_and_type_index) {
325 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
326 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
327 }
328
329 void name_and_type_at_put(int which, int name_index, int signature_index) {
330 tag_at_put(which, JVM_CONSTANT_NameAndType);
331 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
332 }
333
334 // Tag query
335
336 constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); }
337
338 // Fetching constants
339
340 Klass* klass_at(int which, TRAPS) {
341 constantPoolHandle h_this(THREAD, this);
342 return klass_at_impl(h_this, which, true, THREAD);
343 }
344
345 // Version of klass_at that doesn't save the resolution error, called during deopt
346 Klass* klass_at_ignore_error(int which, TRAPS) {
347 constantPoolHandle h_this(THREAD, this);
348 return klass_at_impl(h_this, which, false, THREAD);
349 }
350
351 Symbol* klass_name_at(int which) const; // Returns the name, w/o resolving.
352
353 Klass* resolved_klass_at(int which) const { // Used by Compiler
354 guarantee(tag_at(which).is_klass(), "Corrupted constant pool");
355 // Must do an acquire here in case another thread resolved the klass
356 // behind our back, lest we later load stale values thru the oop.
357 return CPSlot((Klass*)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_klass();
358 }
359
360 // RedefineClasses() API support:
361 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); }
362
363 jint int_at(int which) {
364 assert(tag_at(which).is_int(), "Corrupted constant pool");
365 return *int_at_addr(which);
366 }
367
368 jlong long_at(int which) {
369 assert(tag_at(which).is_long(), "Corrupted constant pool");
370 // return *long_at_addr(which);
371 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
372 return *((jlong*)&tmp);
373 }
374
375 jfloat float_at(int which) {
376 assert(tag_at(which).is_float(), "Corrupted constant pool");
377 return *float_at_addr(which);
378 }
379
380 jdouble double_at(int which) {
381 assert(tag_at(which).is_double(), "Corrupted constant pool");
382 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
383 return *((jdouble*)&tmp);
384 }
385
386 Symbol* symbol_at(int which) const {
387 assert(tag_at(which).is_utf8(), "Corrupted constant pool");
388 return *symbol_at_addr(which);
389 }
390
391 oop string_at(int which, int obj_index, TRAPS) {
392 constantPoolHandle h_this(THREAD, this);
393 return string_at_impl(h_this, which, obj_index, THREAD);
394 }
395 oop string_at(int which, TRAPS) {
396 int obj_index = cp_to_object_index(which);
397 return string_at(which, obj_index, THREAD);
398 }
399
400 // Version that can be used before string oop array is created.
401 oop uncached_string_at(int which, TRAPS);
402
403 // A "pseudo-string" is an non-string oop that has found its way into
404 // a String entry.
405 // This can happen if the user patches a live
406 // object into a CONSTANT_String entry of an anonymous class.
407 // Method oops internally created for method handles may also
408 // use pseudo-strings to link themselves to related metaobjects.
409
410 bool is_pseudo_string_at(int which) {
411 assert(tag_at(which).is_string(), "Corrupted constant pool");
412 return slot_at(which).is_pseudo_string();
413 }
414
415 oop pseudo_string_at(int which, int obj_index) {
416 assert(is_pseudo_string_at(which), "must be a pseudo-string");
417 oop s = resolved_references()->obj_at(obj_index);
418 return s;
419 }
420
421 oop pseudo_string_at(int which) {
422 assert(is_pseudo_string_at(which), "must be a pseudo-string");
423 int obj_index = cp_to_object_index(which);
424 oop s = resolved_references()->obj_at(obj_index);
425 return s;
426 }
427
428 void pseudo_string_at_put(int which, int obj_index, oop x) {
429 assert(tag_at(which).is_string(), "Corrupted constant pool");
430 Symbol* sym = unresolved_string_at(which);
431 slot_at_put(which, CPSlot(sym, (CPSlot::_symbol_bit | CPSlot::_pseudo_bit)));
432 string_at_put(which, obj_index, x); // this works just fine
433 }
434
435 // only called when we are sure a string entry is already resolved (via an
436 // earlier string_at call.
437 oop resolved_string_at(int which) {
438 assert(tag_at(which).is_string(), "Corrupted constant pool");
439 // Must do an acquire here in case another thread resolved the klass
440 // behind our back, lest we later load stale values thru the oop.
441 // we might want a volatile_obj_at in ObjArrayKlass.
442 int obj_index = cp_to_object_index(which);
443 return resolved_references()->obj_at(obj_index);
444 }
445
446 Symbol* unresolved_string_at(int which) {
447 assert(tag_at(which).is_string(), "Corrupted constant pool");
448 Symbol* sym = slot_at(which).get_symbol();
449 return sym;
450 }
451
452 // Returns an UTF8 for a CONSTANT_String entry at a given index.
453 // UTF8 char* representation was chosen to avoid conversion of
454 // java_lang_Strings at resolved entries into Symbol*s
455 // or vice versa.
456 char* string_at_noresolve(int which);
457
458 jint name_and_type_at(int which) {
459 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
460 return *int_at_addr(which);
461 }
462
463 private:
464 int method_handle_ref_kind_at(int which, bool error_ok) {
465 assert(tag_at(which).is_method_handle() ||
466 (error_ok && tag_at(which).is_method_handle_in_error()), "Corrupted constant pool");
467 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits
468 }
469 int method_handle_index_at(int which, bool error_ok) {
470 assert(tag_at(which).is_method_handle() ||
471 (error_ok && tag_at(which).is_method_handle_in_error()), "Corrupted constant pool");
472 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits
473 }
474 int method_type_index_at(int which, bool error_ok) {
475 assert(tag_at(which).is_method_type() ||
476 (error_ok && tag_at(which).is_method_type_in_error()), "Corrupted constant pool");
477 return *int_at_addr(which);
478 }
479 public:
480 int method_handle_ref_kind_at(int which) {
481 return method_handle_ref_kind_at(which, false);
482 }
483 int method_handle_ref_kind_at_error_ok(int which) {
484 return method_handle_ref_kind_at(which, true);
485 }
486 int method_handle_index_at(int which) {
487 return method_handle_index_at(which, false);
488 }
489 int method_handle_index_at_error_ok(int which) {
490 return method_handle_index_at(which, true);
491 }
492 int method_type_index_at(int which) {
493 return method_type_index_at(which, false);
494 }
495 int method_type_index_at_error_ok(int which) {
496 return method_type_index_at(which, true);
497 }
498
499 // Derived queries:
500 Symbol* method_handle_name_ref_at(int which) {
501 int member = method_handle_index_at(which);
502 return impl_name_ref_at(member, true);
503 }
504 Symbol* method_handle_signature_ref_at(int which) {
505 int member = method_handle_index_at(which);
506 return impl_signature_ref_at(member, true);
507 }
508 int method_handle_klass_index_at(int which) {
509 int member = method_handle_index_at(which);
510 return impl_klass_ref_index_at(member, true);
511 }
512 Symbol* method_type_signature_at(int which) {
513 int sym = method_type_index_at(which);
514 return symbol_at(sym);
515 }
516
517 int invoke_dynamic_name_and_type_ref_index_at(int which) {
518 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
519 return extract_high_short_from_int(*int_at_addr(which));
520 }
521 int invoke_dynamic_bootstrap_specifier_index(int which) {
522 assert(tag_at(which).value() == JVM_CONSTANT_InvokeDynamic, "Corrupted constant pool");
523 return extract_low_short_from_int(*int_at_addr(which));
524 }
525 int invoke_dynamic_operand_base(int which) {
526 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
527 return operand_offset_at(operands(), bootstrap_specifier_index);
528 }
529 // The first part of the operands array consists of an index into the second part.
530 // Extract a 32-bit index value from the first part.
531 static int operand_offset_at(Array<u2>* operands, int bootstrap_specifier_index) {
532 int n = (bootstrap_specifier_index * 2);
533 assert(n >= 0 && n+2 <= operands->length(), "oob");
534 // The first 32-bit index points to the beginning of the second part
535 // of the operands array. Make sure this index is in the first part.
536 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0),
537 operands->at(1)));
538 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
539 int offset = build_int_from_shorts(operands->at(n+0),
540 operands->at(n+1));
541 // The offset itself must point into the second part of the array.
542 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)");
543 return offset;
544 }
545 static void operand_offset_at_put(Array<u2>* operands, int bootstrap_specifier_index, int offset) {
546 int n = bootstrap_specifier_index * 2;
547 assert(n >= 0 && n+2 <= operands->length(), "oob");
548 operands->at_put(n+0, extract_low_short_from_int(offset));
549 operands->at_put(n+1, extract_high_short_from_int(offset));
550 }
551 static int operand_array_length(Array<u2>* operands) {
552 if (operands == NULL || operands->length() == 0) return 0;
553 int second_part = operand_offset_at(operands, 0);
554 return (second_part / 2);
555 }
556
557 #ifdef ASSERT
558 // operand tuples fit together exactly, end to end
559 static int operand_limit_at(Array<u2>* operands, int bootstrap_specifier_index) {
560 int nextidx = bootstrap_specifier_index + 1;
561 if (nextidx == operand_array_length(operands))
562 return operands->length();
563 else
564 return operand_offset_at(operands, nextidx);
565 }
566 int invoke_dynamic_operand_limit(int which) {
567 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
568 return operand_limit_at(operands(), bootstrap_specifier_index);
569 }
570 #endif //ASSERT
571
572 // layout of InvokeDynamic bootstrap method specifier (in second part of operands array):
573 enum {
574 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
575 _indy_argc_offset = 1, // u2 argc
576 _indy_argv_offset = 2 // u2 argv[argc]
577 };
578
579 // These functions are used in RedefineClasses for CP merge
580
581 int operand_offset_at(int bootstrap_specifier_index) {
582 assert(0 <= bootstrap_specifier_index &&
583 bootstrap_specifier_index < operand_array_length(operands()),
584 "Corrupted CP operands");
585 return operand_offset_at(operands(), bootstrap_specifier_index);
586 }
587 int operand_bootstrap_method_ref_index_at(int bootstrap_specifier_index) {
588 int offset = operand_offset_at(bootstrap_specifier_index);
589 return operands()->at(offset + _indy_bsm_offset);
590 }
591 int operand_argument_count_at(int bootstrap_specifier_index) {
592 int offset = operand_offset_at(bootstrap_specifier_index);
593 int argc = operands()->at(offset + _indy_argc_offset);
594 return argc;
595 }
596 int operand_argument_index_at(int bootstrap_specifier_index, int j) {
597 int offset = operand_offset_at(bootstrap_specifier_index);
598 return operands()->at(offset + _indy_argv_offset + j);
599 }
600 int operand_next_offset_at(int bootstrap_specifier_index) {
601 int offset = operand_offset_at(bootstrap_specifier_index) + _indy_argv_offset
602 + operand_argument_count_at(bootstrap_specifier_index);
603 return offset;
604 }
605 // Compare a bootsrap specifier in the operands arrays
606 bool compare_operand_to(int bootstrap_specifier_index1, const constantPoolHandle& cp2,
607 int bootstrap_specifier_index2, TRAPS);
608 // Find a bootsrap specifier in the operands array
609 int find_matching_operand(int bootstrap_specifier_index, const constantPoolHandle& search_cp,
610 int operands_cur_len, TRAPS);
611 // Resize the operands array with delta_len and delta_size
612 void resize_operands(int delta_len, int delta_size, TRAPS);
613 // Extend the operands array with the length and size of the ext_cp operands
614 void extend_operands(const constantPoolHandle& ext_cp, TRAPS);
615 // Shrink the operands array to a smaller array with new_len length
616 void shrink_operands(int new_len, TRAPS);
617
618
619 int invoke_dynamic_bootstrap_method_ref_index_at(int which) {
620 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
621 int op_base = invoke_dynamic_operand_base(which);
622 return operands()->at(op_base + _indy_bsm_offset);
623 }
624 int invoke_dynamic_argument_count_at(int which) {
625 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
626 int op_base = invoke_dynamic_operand_base(which);
627 int argc = operands()->at(op_base + _indy_argc_offset);
628 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
629 int next_offset = invoke_dynamic_operand_limit(which));
630 assert(end_offset == next_offset, "matched ending");
631 return argc;
632 }
633 int invoke_dynamic_argument_index_at(int which, int j) {
634 int op_base = invoke_dynamic_operand_base(which);
635 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset));
636 assert((uint)j < (uint)argc, "oob");
637 return operands()->at(op_base + _indy_argv_offset + j);
638 }
639
640 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
641 // name_and_type_ref_index_at) all expect to be passed indices obtained
642 // directly from the bytecode.
643 // If the indices are meant to refer to fields or methods, they are
644 // actually rewritten constant pool cache indices.
645 // The routine remap_instruction_operand_from_cache manages the adjustment
646 // of these values back to constant pool indices.
647
648 // There are also "uncached" versions which do not adjust the operand index; see below.
649
650 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear.
651 // In a few cases (the verifier) there are uses before a cpcache has been built,
652 // which are handled by a dynamic check in remap_instruction_operand_from_cache.
653 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode.
654
655 // Lookup for entries consisting of (klass_index, name_and_type index)
656 Klass* klass_ref_at(int which, TRAPS);
657 Symbol* klass_ref_at_noresolve(int which);
658 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); }
659 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); }
660
661 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); }
662 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); }
663
664 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG
665
666 // Lookup for entries consisting of (name_index, signature_index)
667 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt)
668 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt)
669
670 BasicType basic_type_for_signature_at(int which) const;
671
672 // Resolve string constants (to prevent allocation during compilation)
673 void resolve_string_constants(TRAPS) {
674 constantPoolHandle h_this(THREAD, this);
675 resolve_string_constants_impl(h_this, CHECK);
676 }
677
678 // CDS support
679 void remove_unshareable_info();
680 void restore_unshareable_info(TRAPS);
681 bool resolve_class_constants(TRAPS);
682 // The ConstantPool vtable is restored by this call when the ConstantPool is
683 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for
684 // all the gory details. SA, dtrace and pstack helpers distinguish metadata
685 // by their vtable.
686 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); }
687
688 private:
689 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
690 public:
691
692 // Resolve late bound constants.
693 oop resolve_constant_at(int index, TRAPS) {
694 constantPoolHandle h_this(THREAD, this);
695 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD);
696 }
697
698 oop resolve_cached_constant_at(int cache_index, TRAPS) {
699 constantPoolHandle h_this(THREAD, this);
700 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD);
701 }
702
703 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) {
704 constantPoolHandle h_this(THREAD, this);
705 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD);
706 }
707
708 oop resolve_bootstrap_specifier_at(int index, TRAPS) {
709 constantPoolHandle h_this(THREAD, this);
710 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD);
711 }
712
713 // Klass name matches name at offset
714 bool klass_name_at_matches(instanceKlassHandle k, int which);
715
716 // Sizing
717 int length() const { return _length; }
718 void set_length(int length) { _length = length; }
719
720 // Tells whether index is within bounds.
721 bool is_within_bounds(int index) const {
722 return 0 <= index && index < length();
723 }
724
725 // Sizing (in words)
726 static int header_size() { return sizeof(ConstantPool)/HeapWordSize; }
727 static int size(int length) { return align_object_size(header_size() + length); }
728 int size() const { return size(length()); }
729 #if INCLUDE_SERVICES
730 void collect_statistics(KlassSizeStats *sz) const;
731 #endif
732
733 friend class ClassFileParser;
734 friend class SystemDictionary;
735
736 // Used by compiler to prevent classloading.
737 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which);
738 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
739 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
740 static bool has_method_type_at_if_loaded (const constantPoolHandle& this_cp, int which);
741 static oop method_type_at_if_loaded (const constantPoolHandle& this_cp, int which);
742 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which);
743 static Klass* klass_ref_at_if_loaded (const constantPoolHandle& this_cp, int which);
744
745 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
746 // future by other Java code. These take constant pool indices rather than
747 // constant pool cache indices as do the peer methods above.
748 Symbol* uncached_klass_ref_at_noresolve(int which);
749 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); }
750 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); }
751 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); }
752 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); }
753
754 // Sharing
755 int pre_resolve_shared_klasses(TRAPS);
756
757 // Debugging
758 const char* printable_name_at(int which) PRODUCT_RETURN0;
759
760 #ifdef ASSERT
761 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices
762 #else
763 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op
764 #endif //ASSERT
765
766 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) {
767 if (invokedynamic_ok && is_invokedynamic_index(raw_index))
768 return decode_invokedynamic_index(raw_index);
769 else
770 return raw_index - CPCACHE_INDEX_TAG;
771 }
772
773 private:
774
775 void set_resolved_references(jobject s) { _resolved_references = s; }
776 Array<u2>* reference_map() const { return _reference_map; }
777 void set_reference_map(Array<u2>* o) { _reference_map = o; }
778
779 // patch JSR 292 resolved references after the class is linked.
780 void patch_resolved_references(GrowableArray<Handle>* cp_patches);
781
782 Symbol* impl_name_ref_at(int which, bool uncached);
783 Symbol* impl_signature_ref_at(int which, bool uncached);
784 int impl_klass_ref_index_at(int which, bool uncached);
785 int impl_name_and_type_ref_index_at(int which, bool uncached);
786
787 // Used while constructing constant pool (only by ClassFileParser)
788 jint klass_index_at(int which) {
789 assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
790 return *int_at_addr(which);
791 }
792
793 jint string_index_at(int which) {
794 assert(tag_at(which).is_string_index(), "Corrupted constant pool");
795 return *int_at_addr(which);
796 }
797
798 // Performs the LinkResolver checks
799 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, KlassHandle klass, TRAPS);
800
801 // Implementation of methods that needs an exposed 'this' pointer, in order to
802 // handle GC while executing the method
803 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int which,
804 bool save_resolution_error, TRAPS);
805 static oop string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS);
806
807 static void trace_class_resolution(const constantPoolHandle& this_cp, KlassHandle k);
808
809 // Resolve string constants (to prevent allocation during compilation)
810 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS);
811
812 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int index, int cache_index, TRAPS);
813 static oop resolve_bootstrap_specifier_at_impl(const constantPoolHandle& this_cp, int index, TRAPS);
814
815 // Exception handling
816 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS);
817 static Symbol* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception);
818 static void save_and_throw_exception(const constantPoolHandle& this_cp, int which, constantTag tag, TRAPS);
819
820 public:
821 // Merging ConstantPool* support:
822 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2, TRAPS);
823 void copy_cp_to(int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS) {
824 constantPoolHandle h_this(THREAD, this);
825 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD);
826 }
827 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
828 static void copy_entry_to(const constantPoolHandle& from_cp, int from_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
829 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS);
830 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp, TRAPS);
831 int version() const { return _saved._version; }
832 void set_version(int version) { _saved._version = version; }
833 void increment_and_save_version(int version) {
834 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow
835 }
836
837 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; }
838 int resolved_reference_length() const { return _saved._resolved_reference_length; }
839
840 // Decrease ref counts of symbols that are in the constant pool
841 // when the holder class is unloaded
842 void unreference_symbols();
843
844 // Deallocate constant pool for RedefineClasses
845 void deallocate_contents(ClassLoaderData* loader_data);
846 void release_C_heap_structures();
847
848 // JVMTI accesss - GetConstantPool, RetransformClasses, ...
849 friend class JvmtiConstantPoolReconstituter;
850
851 private:
852 jint cpool_entry_size(jint idx);
853 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap);
854
855 // Copy cpool bytes into byte array.
856 // Returns:
857 // int > 0, count of the raw cpool bytes that have been copied
858 // 0, OutOfMemory error
859 // -1, Internal error
860 int copy_cpool_bytes(int cpool_size,
861 SymbolHashMap* tbl,
862 unsigned char *bytes);
863
864 public:
865 // Verify
866 void verify_on(outputStream* st);
867
868 // Printing
869 void print_on(outputStream* st) const;
870 void print_value_on(outputStream* st) const;
871 void print_entry_on(int index, outputStream* st);
872
873 const char* internal_name() const { return "{constant pool}"; }
874
875 #ifndef PRODUCT
876 // Compile the world support
877 static void preload_and_initialize_all_classes(ConstantPool* constant_pool, TRAPS);
878 #endif
879 };
880
881 class SymbolHashMapEntry : public CHeapObj<mtSymbol> {
882 private:
883 unsigned int _hash; // 32-bit hash for item
884 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket
885 Symbol* _symbol; // 1-st part of the mapping: symbol => value
886 u2 _value; // 2-nd part of the mapping: symbol => value
887
888 public:
889 unsigned int hash() const { return _hash; }
890 void set_hash(unsigned int hash) { _hash = hash; }
891
892 SymbolHashMapEntry* next() const { return _next; }
893 void set_next(SymbolHashMapEntry* next) { _next = next; }
894
895 Symbol* symbol() const { return _symbol; }
896 void set_symbol(Symbol* sym) { _symbol = sym; }
897
898 u2 value() const { return _value; }
899 void set_value(u2 value) { _value = value; }
900
901 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value)
902 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {}
903
904 }; // End SymbolHashMapEntry class
905
906
907 class SymbolHashMapBucket : public CHeapObj<mtSymbol> {
908
909 private:
910 SymbolHashMapEntry* _entry;
911
912 public:
913 SymbolHashMapEntry* entry() const { return _entry; }
914 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; }
915 void clear() { _entry = NULL; }
916
917 }; // End SymbolHashMapBucket class
918
919
920 class SymbolHashMap: public CHeapObj<mtSymbol> {
921
922 private:
923 // Default number of entries in the table
924 enum SymbolHashMap_Constants {
925 _Def_HashMap_Size = 256
926 };
927
928 int _table_size;
929 SymbolHashMapBucket* _buckets;
930
931 void initialize_table(int table_size) {
932 _table_size = table_size;
933 _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size, mtSymbol);
934 for (int index = 0; index < table_size; index++) {
935 _buckets[index].clear();
936 }
937 }
938
939 public:
940
941 int table_size() const { return _table_size; }
942
943 SymbolHashMap() { initialize_table(_Def_HashMap_Size); }
944 SymbolHashMap(int table_size) { initialize_table(table_size); }
945
946 // hash P(31) from Kernighan & Ritchie
947 static unsigned int compute_hash(const char* str, int len) {
948 unsigned int hash = 0;
949 while (len-- > 0) {
950 hash = 31*hash + (unsigned) *str;
951 str++;
952 }
953 return hash;
954 }
955
956 SymbolHashMapEntry* bucket(int i) {
957 return _buckets[i].entry();
958 }
959
960 void add_entry(Symbol* sym, u2 value);
961 SymbolHashMapEntry* find_entry(Symbol* sym);
962
963 u2 symbol_to_value(Symbol* sym) {
964 SymbolHashMapEntry *entry = find_entry(sym);
965 return (entry == NULL) ? 0 : entry->value();
966 }
967
968 ~SymbolHashMap() {
969 SymbolHashMapEntry* next;
970 for (int i = 0; i < _table_size; i++) {
971 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
972 next = cur->next();
973 delete(cur);
974 }
975 }
976 delete _buckets;
977 }
978 }; // End SymbolHashMap class
979
980 #endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP