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