1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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24
25 #ifndef SHARE_OOPS_CONSTANTPOOL_HPP
26 #define SHARE_OOPS_CONSTANTPOOL_HPP
27
28 #include "memory/allocation.hpp"
29 #include "oops/arrayOop.hpp"
30 #include "oops/bsmAttribute.hpp"
31 #include "oops/cpCache.hpp"
32 #include "oops/objArrayOop.hpp"
33 #include "oops/oopHandle.hpp"
34 #include "oops/symbol.hpp"
35 #include "oops/typeArrayOop.hpp"
36 #include "runtime/handles.hpp"
37 #include "runtime/javaThread.hpp"
38 #include "utilities/align.hpp"
39 #include "utilities/bytes.hpp"
40 #include "utilities/constantTag.hpp"
41 #include "utilities/hashTable.hpp"
42 #include "utilities/macros.hpp"
43
44 // A ConstantPool is an array containing class constants as described in the
45 // class file.
46 //
47 // Most of the constant pool entries are written during class parsing, which
48 // is safe. For klass types, the constant pool entry is
49 // modified when the entry is resolved. If a klass constant pool
50 // entry is read without a lock, only the resolved state guarantees that
51 // the entry in the constant pool is a klass object and not a Symbol*.
52
53 // This represents a JVM_CONSTANT_Class, JVM_CONSTANT_UnresolvedClass, or
54 // JVM_CONSTANT_UnresolvedClassInError slot in the constant pool.
55 class CPKlassSlot {
56 // cp->symbol_at(_name_index) gives the name of the class.
57 int _name_index;
58
59 // cp->_resolved_klasses->at(_resolved_klass_index) gives the Klass* for the class.
60 int _resolved_klass_index;
61 public:
62 enum {
63 // This is used during constant pool merging where the resolved klass index is
64 // not yet known, and will be computed at a later stage (during a call to
65 // initialize_unresolved_klasses()).
66 _temp_resolved_klass_index = 0xffff
67 };
68 CPKlassSlot(int n, int rk) {
69 _name_index = n;
70 _resolved_klass_index = rk;
71 }
72 int name_index() const {
73 return _name_index;
74 }
75 int resolved_klass_index() const {
76 assert(_resolved_klass_index != _temp_resolved_klass_index, "constant pool merging was incomplete");
77 return _resolved_klass_index;
78 }
79 };
80
81 class ConstantPool : public Metadata {
82 friend class VMStructs;
83 friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast
84 friend class Universe; // For null constructor
85 friend class AOTConstantPoolResolver;
86 private:
87 // If you add a new field that points to any metaspace object, you
88 // must add this field to ConstantPool::metaspace_pointers_do().
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
93 BSMAttributeEntries _bsm_entries;
94
95 // Consider using an array of compressed klass pointers to
96 // save space on 64-bit platforms.
97 Array<Klass*>* _resolved_klasses;
98
99 u2 _major_version; // major version number of class file
100 u2 _minor_version; // minor version number of class file
101
102 // Constant pool index to the utf8 entry of the Generic signature,
103 // or 0 if none.
104 u2 _generic_signature_index;
105 // Constant pool index to the utf8 entry for the name of source file
106 // containing this klass, 0 if not specified.
107 u2 _source_file_name_index;
108
109 enum {
110 _has_preresolution = 1, // Flags
111 _on_stack = 2,
112 _in_aot_cache = 4,
113 _has_dynamic_constant = 8,
114 _is_for_method_handle_intrinsic = 16
115 };
116
117 u2 _flags; // old fashioned bit twiddling
118
119 int _length; // number of elements in the array
120
121 union {
122 // set for CDS to restore resolved references
123 int _resolved_reference_length;
124 // keeps version number for redefined classes (used in backtrace)
125 int _version;
126 } _saved;
127
128 void set_tags(Array<u1>* tags) { _tags = tags; }
129 void tag_at_put(int cp_index, jbyte t) { tags()->at_put(cp_index, t); }
130 void release_tag_at_put(int cp_index, jbyte t) { tags()->release_at_put(cp_index, t); }
131
132 u1* tag_addr_at(int cp_index) const { return tags()->adr_at(cp_index); }
133
134 u2 flags() const { return _flags; }
135 void set_flags(u2 f) { _flags = f; }
136
137 private:
138 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); }
139
140 intptr_t* obj_at_addr(int cp_index) const {
141 assert(is_within_bounds(cp_index), "index out of bounds");
142 return (intptr_t*) &base()[cp_index];
143 }
144
145 jint* int_at_addr(int cp_index) const {
146 assert(is_within_bounds(cp_index), "index out of bounds");
147 return (jint*) &base()[cp_index];
148 }
149
150 jlong* long_at_addr(int cp_index) const {
151 assert(is_within_bounds(cp_index), "index out of bounds");
152 return (jlong*) &base()[cp_index];
153 }
154
155 jfloat* float_at_addr(int cp_index) const {
156 assert(is_within_bounds(cp_index), "index out of bounds");
157 return (jfloat*) &base()[cp_index];
158 }
159
160 jdouble* double_at_addr(int cp_index) const {
161 assert(is_within_bounds(cp_index), "index out of bounds");
162 return (jdouble*) &base()[cp_index];
163 }
164
165 ConstantPool(Array<u1>* tags);
166 ConstantPool();
167 public:
168 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS);
169
170 virtual bool is_constantPool() const { return true; }
171
172 Array<u1>* tags() const { return _tags; }
173
174 BSMAttributeEntries& bsm_entries() {
175 return _bsm_entries;
176 }
177 const BSMAttributeEntries& bsm_entries() const {
178 return _bsm_entries;
179 }
180
181 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; }
182 void set_has_preresolution() {
183 assert(!in_aot_cache(), "should never be called on ConstantPools in AOT cache");
184 _flags |= _has_preresolution;
185 }
186
187 // minor and major version numbers of class file
188 u2 major_version() const { return _major_version; }
189 void set_major_version(u2 major_version) { _major_version = major_version; }
190 u2 minor_version() const { return _minor_version; }
191 void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
192
193 // generics support
194 Symbol* generic_signature() const {
195 return (_generic_signature_index == 0) ?
196 nullptr : symbol_at(_generic_signature_index);
197 }
198 u2 generic_signature_index() const { return _generic_signature_index; }
199 void set_generic_signature_index(u2 sig_index) { _generic_signature_index = sig_index; }
200
201 // source file name
202 Symbol* source_file_name() const {
203 return (_source_file_name_index == 0) ?
204 nullptr : symbol_at(_source_file_name_index);
205 }
206 u2 source_file_name_index() const { return _source_file_name_index; }
207 void set_source_file_name_index(u2 sourcefile_index) { _source_file_name_index = sourcefile_index; }
208
209 void copy_fields(const ConstantPool* orig);
210
211 // Redefine classes support. If a method referring to this constant pool
212 // is on the executing stack, or as a handle in vm code, this constant pool
213 // can't be removed from the set of previous versions saved in the instance
214 // class.
215 bool on_stack() const;
216 bool is_maybe_on_stack() const;
217 void set_on_stack(const bool value);
218
219 // Shadows MetaspaceObj::in_aot_cache(). It's faster and is used by set_on_stack()
220 bool in_aot_cache() const { return (_flags & _in_aot_cache) != 0; }
221
222 bool has_dynamic_constant() const { return (_flags & _has_dynamic_constant) != 0; }
223 void set_has_dynamic_constant() { _flags |= _has_dynamic_constant; }
224
225 bool is_for_method_handle_intrinsic() const { return (_flags & _is_for_method_handle_intrinsic) != 0; }
226 void set_is_for_method_handle_intrinsic() { _flags |= _is_for_method_handle_intrinsic; }
227
228 // Klass holding pool
229 InstanceKlass* pool_holder() const { return _pool_holder; }
230 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; }
231 InstanceKlass** pool_holder_addr() { return &_pool_holder; }
232
233 // Interpreter runtime support
234 ConstantPoolCache* cache() const { return _cache; }
235 void set_cache(ConstantPoolCache* cache){ _cache = cache; }
236
237 virtual void metaspace_pointers_do(MetaspaceClosure* iter);
238 virtual MetaspaceObj::Type type() const { return ConstantPoolType; }
239
240 // Create object cache in the constant pool
241 void initialize_resolved_references(ClassLoaderData* loader_data,
242 const intStack& reference_map,
243 int constant_pool_map_length,
244 TRAPS);
245
246 // resolved strings, methodHandles and callsite objects from the constant pool
247 objArrayOop resolved_references() const;
248 objArrayOop resolved_references_or_null() const;
249 oop resolved_reference_at(int obj_index) const;
250 oop set_resolved_reference_at(int index, oop new_value);
251
252 // mapping resolved object array indexes to cp indexes and back.
253 int object_to_cp_index(int index) { return reference_map()->at(index); }
254 int cp_to_object_index(int index);
255
256 void set_resolved_klasses(Array<Klass*>* rk) { _resolved_klasses = rk; }
257 Array<Klass*>* resolved_klasses() const { return _resolved_klasses; }
258 void allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS);
259 void initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS);
260
261 // Given the per-instruction index of an indy instruction, report the
262 // main constant pool entry for its bootstrap specifier.
263 // From there, uncached_name/signature_ref_at will get the name/type.
264 inline u2 invokedynamic_bootstrap_ref_index_at(int indy_index) const;
265
266 // Assembly code support
267 static ByteSize tags_offset() { return byte_offset_of(ConstantPool, _tags); }
268 static ByteSize cache_offset() { return byte_offset_of(ConstantPool, _cache); }
269 static ByteSize pool_holder_offset() { return byte_offset_of(ConstantPool, _pool_holder); }
270 static ByteSize resolved_klasses_offset() { return byte_offset_of(ConstantPool, _resolved_klasses); }
271
272 // Storing constants
273
274 // For temporary use while constructing constant pool
275 void klass_index_at_put(int cp_index, int name_index) {
276 tag_at_put(cp_index, JVM_CONSTANT_ClassIndex);
277 *int_at_addr(cp_index) = name_index;
278 }
279
280 // Hidden class support:
281 void klass_at_put(int class_index, Klass* k);
282
283 void unresolved_klass_at_put(int cp_index, int name_index, int resolved_klass_index) {
284 release_tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
285
286 assert((name_index & 0xffff0000) == 0, "must be");
287 assert((resolved_klass_index & 0xffff0000) == 0, "must be");
288 *int_at_addr(cp_index) =
289 build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
290 }
291
292 void method_handle_index_at_put(int cp_index, int ref_kind, int ref_index) {
293 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle);
294 *int_at_addr(cp_index) = ((jint) ref_index<<16) | ref_kind;
295 }
296
297 void method_type_index_at_put(int cp_index, int ref_index) {
298 tag_at_put(cp_index, JVM_CONSTANT_MethodType);
299 *int_at_addr(cp_index) = ref_index;
300 }
301
302 void dynamic_constant_at_put(int cp_index, int bsms_attribute_index, int name_and_type_index) {
303 tag_at_put(cp_index, JVM_CONSTANT_Dynamic);
304 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | bsms_attribute_index;
305 }
306
307 void invoke_dynamic_at_put(int cp_index, int bsms_attribute_index, int name_and_type_index) {
308 tag_at_put(cp_index, JVM_CONSTANT_InvokeDynamic);
309 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | bsms_attribute_index;
310 }
311
312 void unresolved_string_at_put(int cp_index, Symbol* s) {
313 assert(s->refcount() != 0, "should have nonzero refcount");
314 // Note that release_tag_at_put is not needed here because this is called only
315 // when constructing a ConstantPool in a single thread, with no possibility
316 // of concurrent access.
317 tag_at_put(cp_index, JVM_CONSTANT_String);
318 *symbol_at_addr(cp_index) = s;
319 }
320
321 void int_at_put(int cp_index, jint i) {
322 tag_at_put(cp_index, JVM_CONSTANT_Integer);
323 *int_at_addr(cp_index) = i;
324 }
325
326 void long_at_put(int cp_index, jlong l) {
327 tag_at_put(cp_index, JVM_CONSTANT_Long);
328 // *long_at_addr(which) = l;
329 Bytes::put_native_u8((address)long_at_addr(cp_index), *((u8*) &l));
330 }
331
332 void float_at_put(int cp_index, jfloat f) {
333 tag_at_put(cp_index, JVM_CONSTANT_Float);
334 *float_at_addr(cp_index) = f;
335 }
336
337 void double_at_put(int cp_index, jdouble d) {
338 tag_at_put(cp_index, JVM_CONSTANT_Double);
339 // *double_at_addr(which) = d;
340 // u8 temp = *(u8*) &d;
341 Bytes::put_native_u8((address) double_at_addr(cp_index), *((u8*) &d));
342 }
343
344 Symbol** symbol_at_addr(int cp_index) const {
345 assert(is_within_bounds(cp_index), "index out of bounds");
346 return (Symbol**) &base()[cp_index];
347 }
348
349 void symbol_at_put(int cp_index, Symbol* s) {
350 assert(s->refcount() != 0, "should have nonzero refcount");
351 tag_at_put(cp_index, JVM_CONSTANT_Utf8);
352 *symbol_at_addr(cp_index) = s;
353 }
354
355 void string_at_put(int obj_index, oop str);
356
357 // For temporary use while constructing constant pool
358 void string_index_at_put(int cp_index, int string_index) {
359 tag_at_put(cp_index, JVM_CONSTANT_StringIndex);
360 *int_at_addr(cp_index) = string_index;
361 }
362
363 void field_at_put(int cp_index, int class_index, int name_and_type_index) {
364 tag_at_put(cp_index, JVM_CONSTANT_Fieldref);
365 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index;
366 }
367
368 void method_at_put(int cp_index, int class_index, int name_and_type_index) {
369 tag_at_put(cp_index, JVM_CONSTANT_Methodref);
370 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index;
371 }
372
373 void interface_method_at_put(int cp_index, int class_index, int name_and_type_index) {
374 tag_at_put(cp_index, JVM_CONSTANT_InterfaceMethodref);
375 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
376 }
377
378 void name_and_type_at_put(int cp_index, int name_index, int signature_index) {
379 tag_at_put(cp_index, JVM_CONSTANT_NameAndType);
380 *int_at_addr(cp_index) = ((jint) signature_index<<16) | name_index; // Not so nice
381 }
382
383 // Tag query
384
385 constantTag tag_at(int cp_index) const { return (constantTag)tags()->at_acquire(cp_index); }
386
387 // Fetching constants
388
389 Klass* klass_at(int cp_index, TRAPS) {
390 constantPoolHandle h_this(THREAD, this);
391 return klass_at_impl(h_this, cp_index, THREAD);
392 }
393
394 CPKlassSlot klass_slot_at(int cp_index) const {
395 assert(tag_at(cp_index).is_unresolved_klass() || tag_at(cp_index).is_klass(),
396 "Corrupted constant pool");
397 int value = *int_at_addr(cp_index);
398 int name_index = extract_high_short_from_int(value);
399 int resolved_klass_index = extract_low_short_from_int(value);
400 return CPKlassSlot(name_index, resolved_klass_index);
401 }
402
403 Symbol* klass_name_at(int cp_index) const; // Returns the name, w/o resolving.
404 int klass_name_index_at(int cp_index) const {
405 return klass_slot_at(cp_index).name_index();
406 }
407
408 Klass* resolved_klass_at(int cp_index) const; // Used by Compiler
409
410 // RedefineClasses() API support:
411 Symbol* klass_at_noresolve(int cp_index) { return klass_name_at(cp_index); }
412 void temp_unresolved_klass_at_put(int cp_index, int name_index) {
413 // Used only during constant pool merging for class redefinition. The resolved klass index
414 // will be initialized later by a call to initialize_unresolved_klasses().
415 unresolved_klass_at_put(cp_index, name_index, CPKlassSlot::_temp_resolved_klass_index);
416 }
417
418 jint int_at(int cp_index) const {
419 assert(tag_at(cp_index).is_int(), "Corrupted constant pool");
420 return *int_at_addr(cp_index);
421 }
422
423 jlong long_at(int cp_index) {
424 assert(tag_at(cp_index).is_long(), "Corrupted constant pool");
425 // return *long_at_addr(cp_index);
426 u8 tmp = Bytes::get_native_u8((address)&base()[cp_index]);
427 return *((jlong*)&tmp);
428 }
429
430 jfloat float_at(int cp_index) {
431 assert(tag_at(cp_index).is_float(), "Corrupted constant pool");
432 return *float_at_addr(cp_index);
433 }
434
435 jdouble double_at(int cp_index) {
436 assert(tag_at(cp_index).is_double(), "Corrupted constant pool");
437 u8 tmp = Bytes::get_native_u8((address)&base()[cp_index]);
438 return *((jdouble*)&tmp);
439 }
440
441 Symbol* symbol_at(int cp_index) const {
442 assert(tag_at(cp_index).is_utf8(), "Corrupted constant pool");
443 return *symbol_at_addr(cp_index);
444 }
445
446 oop string_at(int cp_index, int obj_index, TRAPS) {
447 constantPoolHandle h_this(THREAD, this);
448 return string_at_impl(h_this, cp_index, obj_index, THREAD);
449 }
450 oop string_at(int cp_index, TRAPS) {
451 int obj_index = cp_to_object_index(cp_index);
452 return string_at(cp_index, obj_index, THREAD);
453 }
454
455 // Version that can be used before string oop array is created.
456 oop uncached_string_at(int cp_index, TRAPS);
457
458 // only called when we are sure a string entry is already resolved (via an
459 // earlier string_at call.
460 oop resolved_string_at(int cp_index) {
461 assert(tag_at(cp_index).is_string(), "Corrupted constant pool");
462 // Must do an acquire here in case another thread resolved the klass
463 // behind our back, lest we later load stale values thru the oop.
464 // we might want a volatile_obj_at in ObjArrayKlass.
465 int obj_index = cp_to_object_index(cp_index);
466 return resolved_reference_at(obj_index);
467 }
468
469 Symbol* unresolved_string_at(int cp_index) {
470 assert(tag_at(cp_index).is_string(), "Corrupted constant pool");
471 return *symbol_at_addr(cp_index);
472 }
473
474 // Returns an UTF8 for a CONSTANT_String entry at a given index.
475 // UTF8 char* representation was chosen to avoid conversion of
476 // java_lang_Strings at resolved entries into Symbol*s
477 // or vice versa.
478 char* string_at_noresolve(int cp_index);
479
480 jint name_and_type_at(int cp_index) {
481 assert(tag_at(cp_index).is_name_and_type(), "Corrupted constant pool");
482 return *int_at_addr(cp_index);
483 }
484
485 int method_handle_ref_kind_at(int cp_index) {
486 assert(tag_at(cp_index).is_method_handle() ||
487 tag_at(cp_index).is_method_handle_in_error(), "Corrupted constant pool");
488 return extract_low_short_from_int(*int_at_addr(cp_index)); // mask out unwanted ref_index bits
489 }
490 int method_handle_index_at(int cp_index) {
491 assert(tag_at(cp_index).is_method_handle() ||
492 tag_at(cp_index).is_method_handle_in_error(), "Corrupted constant pool");
493 return extract_high_short_from_int(*int_at_addr(cp_index)); // shift out unwanted ref_kind bits
494 }
495 int method_type_index_at(int cp_index) {
496 assert(tag_at(cp_index).is_method_type() ||
497 tag_at(cp_index).is_method_type_in_error(), "Corrupted constant pool");
498 return *int_at_addr(cp_index);
499 }
500
501 // Derived queries:
502 Symbol* method_handle_name_ref_at(int cp_index) {
503 int member = method_handle_index_at(cp_index);
504 return uncached_name_ref_at(member);
505 }
506 Symbol* method_handle_signature_ref_at(int cp_index) {
507 int member = method_handle_index_at(cp_index);
508 return uncached_signature_ref_at(member);
509 }
510 u2 method_handle_klass_index_at(int cp_index) {
511 int member = method_handle_index_at(cp_index);
512 return uncached_klass_ref_index_at(member);
513 }
514 Symbol* method_type_signature_at(int cp_index) {
515 int sym = method_type_index_at(cp_index);
516 return symbol_at(sym);
517 }
518
519 u2 bootstrap_name_and_type_ref_index_at(int cp_index) {
520 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
521 return extract_high_short_from_int(*int_at_addr(cp_index));
522 }
523 u2 bootstrap_methods_attribute_index(int cp_index) {
524 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
525 return extract_low_short_from_int(*int_at_addr(cp_index));
526 }
527
528 BSMAttributeEntry* bsm_attribute_entry(int bsms_attribute_index) {
529 return _bsm_entries.entry(bsms_attribute_index);
530 }
531
532 bool compare_bootstrap_entry_to(int bsms_attribute_index1, const constantPoolHandle& cp2,
533 int bsms_attribute_index2);
534 // Find a BSM entry in search_cp that matches the BSM at bsm_attribute_index.
535 // Return -1 if not found.
536 int find_matching_bsm_entry(int bsms_attribute_index, const constantPoolHandle& search_cp,
537 int offset_limit);
538 // Extend the BSM attribute storage to fit both the current data and the BSM data in ext_cp.
539 // Use the returned InsertionIterator to fill out the newly allocated space.
540 BSMAttributeEntries::InsertionIterator start_extension(const constantPoolHandle& ext_cp, TRAPS);
541 void end_extension(BSMAttributeEntries::InsertionIterator iter, TRAPS);
542
543 u2 bootstrap_method_ref_index_at(int cp_index) {
544 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
545 int bsmai = bootstrap_methods_attribute_index(cp_index);
546 return bsm_attribute_entry(bsmai)->bootstrap_method_index();
547 }
548 u2 bootstrap_argument_count_at(int cp_index) {
549 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
550 int bsmai = bootstrap_methods_attribute_index(cp_index);
551 return bsm_attribute_entry(bsmai)->argument_count();
552 }
553 u2 bootstrap_argument_index_at(int cp_index, int j) {
554 int bsmai = bootstrap_methods_attribute_index(cp_index);
555 BSMAttributeEntry* bsme = bsm_attribute_entry(bsmai);
556 assert(j < bsme->argument_count(), "oob");
557 return bsm_attribute_entry(bsmai)->argument(checked_cast<u2>(j));
558 }
559
560 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
561 // name_and_type_ref_index_at) all expect to be passed indices obtained
562 // directly from the bytecode.
563 // If the indices are meant to refer to fields or methods, they are
564 // actually rewritten indices that point to entries in their respective structures
565 // i.e. ResolvedMethodEntries or ResolvedFieldEntries.
566 // The routine to_cp_index manages the adjustment
567 // of these values back to constant pool indices.
568
569 // There are also "uncached" versions which do not adjust the operand index; see below.
570
571 // Lookup for entries consisting of (klass_index, name_and_type index)
572 Klass* klass_ref_at(int which, Bytecodes::Code code, TRAPS);
573 Symbol* klass_ref_at_noresolve(int which, Bytecodes::Code code);
574 Symbol* name_ref_at(int which, Bytecodes::Code code) {
575 int name_index = name_ref_index_at(name_and_type_ref_index_at(which, code));
576 return symbol_at(name_index);
577 }
578 Symbol* signature_ref_at(int which, Bytecodes::Code code) {
579 int signature_index = signature_ref_index_at(name_and_type_ref_index_at(which, code));
580 return symbol_at(signature_index);
581 }
582
583 u2 klass_ref_index_at(int which, Bytecodes::Code code);
584 u2 name_and_type_ref_index_at(int which, Bytecodes::Code code);
585
586 constantTag tag_ref_at(int cp_cache_index, Bytecodes::Code code);
587
588 int to_cp_index(int which, Bytecodes::Code code);
589
590 bool is_resolved(int which, Bytecodes::Code code);
591
592 // Lookup for entries consisting of (name_index, signature_index)
593 u2 name_ref_index_at(int cp_index); // == low-order jshort of name_and_type_at(cp_index)
594 u2 signature_ref_index_at(int cp_index); // == high-order jshort of name_and_type_at(cp_index)
595
596 BasicType basic_type_for_signature_at(int cp_index) const;
597
598 // Resolve string constants (to prevent allocation during compilation)
599 void resolve_string_constants(TRAPS) {
600 constantPoolHandle h_this(THREAD, this);
601 resolve_string_constants_impl(h_this, CHECK);
602 }
603
604 #if INCLUDE_CDS
605 // CDS support
606 objArrayOop prepare_resolved_references_for_archiving() NOT_CDS_JAVA_HEAP_RETURN_(nullptr);
607 void remove_unshareable_info();
608 void restore_unshareable_info(TRAPS);
609 private:
610 void remove_unshareable_entries();
611 void remove_resolved_klass_if_non_deterministic(int cp_index);
612 template <typename Function> void iterate_archivable_resolved_references(Function function);
613 #endif
614
615 private:
616 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
617 public:
618
619 // Get the tag for a constant, which may involve a constant dynamic
620 constantTag constant_tag_at(int cp_index);
621 // Get the basic type for a constant, which may involve a constant dynamic
622 BasicType basic_type_for_constant_at(int cp_index);
623
624 // Resolve late bound constants.
625 oop resolve_constant_at(int cp_index, TRAPS) {
626 constantPoolHandle h_this(THREAD, this);
627 return resolve_constant_at_impl(h_this, cp_index, _no_index_sentinel, nullptr, THREAD);
628 }
629
630 oop resolve_cached_constant_at(int cache_index, TRAPS) {
631 constantPoolHandle h_this(THREAD, this);
632 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, nullptr, THREAD);
633 }
634
635 oop resolve_possibly_cached_constant_at(int cp_index, TRAPS) {
636 constantPoolHandle h_this(THREAD, this);
637 return resolve_constant_at_impl(h_this, cp_index, _possible_index_sentinel, nullptr, THREAD);
638 }
639
640 oop find_cached_constant_at(int cp_index, bool& found_it, TRAPS) {
641 constantPoolHandle h_this(THREAD, this);
642 return resolve_constant_at_impl(h_this, cp_index, _possible_index_sentinel, &found_it, THREAD);
643 }
644
645 void copy_bootstrap_arguments_at(int cp_index,
646 int start_arg, int end_arg,
647 objArrayHandle info, int pos,
648 bool must_resolve, Handle if_not_available, TRAPS) {
649 constantPoolHandle h_this(THREAD, this);
650 copy_bootstrap_arguments_at_impl(h_this, cp_index, start_arg, end_arg,
651 info, pos, must_resolve, if_not_available, THREAD);
652 }
653
654 // Klass name matches name at offset
655 bool klass_name_at_matches(const InstanceKlass* k, int cp_index);
656
657 // Sizing
658 int length() const { return _length; }
659 void set_length(int length) { _length = length; }
660
661 // Tells whether index is within bounds.
662 bool is_within_bounds(int index) const {
663 return 0 <= index && index < length();
664 }
665
666 // Sizing (in words)
667 static int header_size() {
668 return align_up((int)sizeof(ConstantPool), wordSize) / wordSize;
669 }
670 static int size(int length) { return align_metadata_size(header_size() + length); }
671 int size() const { return size(length()); }
672
673 // ConstantPools should be stored in the read-only region of CDS archive.
674 static bool is_read_only_by_default() { return true; }
675
676 friend class ClassFileParser;
677 friend class SystemDictionary;
678
679 // Used by CDS. These classes need to access the private ConstantPool() constructor.
680 template <class T> friend class CppVtableTesterA;
681 template <class T> friend class CppVtableTesterB;
682 template <class T> friend class CppVtableCloner;
683
684 // Used by compiler to prevent classloading.
685 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which);
686 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code);
687 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code);
688 static bool has_local_signature_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code);
689 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which);
690
691 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
692 // future by other Java code. These take constant pool indices rather than
693 // constant pool cache indices as do the peer methods above.
694 Symbol* uncached_klass_ref_at_noresolve(int cp_index);
695 Symbol* uncached_name_ref_at(int cp_index) {
696 int name_index = name_ref_index_at(uncached_name_and_type_ref_index_at(cp_index));
697 return symbol_at(name_index);
698 }
699 Symbol* uncached_signature_ref_at(int cp_index) {
700 int signature_index = signature_ref_index_at(uncached_name_and_type_ref_index_at(cp_index));
701 return symbol_at(signature_index);
702 }
703 u2 uncached_klass_ref_index_at(int cp_index);
704 u2 uncached_name_and_type_ref_index_at(int cp_index);
705
706 // Sharing
707 int pre_resolve_shared_klasses(TRAPS);
708
709 // Debugging
710 const char* printable_name_at(int cp_index) PRODUCT_RETURN_NULL;
711
712 private:
713
714 void set_resolved_references(OopHandle s) { _cache->set_resolved_references(s); }
715 Array<u2>* reference_map() const { return (_cache == nullptr) ? nullptr : _cache->reference_map(); }
716 void set_reference_map(Array<u2>* o) { _cache->set_reference_map(o); }
717
718 // Used while constructing constant pool (only by ClassFileParser)
719 jint klass_index_at(int cp_index) {
720 assert(tag_at(cp_index).is_klass_index(), "Corrupted constant pool");
721 return *int_at_addr(cp_index);
722 }
723
724 jint string_index_at(int cp_index) {
725 assert(tag_at(cp_index).is_string_index(), "Corrupted constant pool");
726 return *int_at_addr(cp_index);
727 }
728
729 // Performs the LinkResolver checks
730 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* klass, TRAPS);
731
732 // Implementation of methods that needs an exposed 'this' pointer, in order to
733 // handle GC while executing the method
734 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int cp_index, TRAPS);
735 static oop string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS);
736
737 static void trace_class_resolution(const constantPoolHandle& this_cp, Klass* k);
738
739 // Resolve string constants (to prevent allocation during compilation)
740 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS);
741
742 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int cp_index, int cache_index,
743 bool* status_return, TRAPS);
744 static void copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index,
745 int start_arg, int end_arg,
746 objArrayHandle info, int pos,
747 bool must_resolve, Handle if_not_available, TRAPS);
748
749 // Exception handling
750 static void save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index, constantTag tag, TRAPS);
751
752 public:
753 // Exception handling
754 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS);
755
756 // Merging ConstantPool* support:
757 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2);
758 void copy_cp_to(int start_cpi, int end_cpi, const constantPoolHandle& to_cp, int to_cpi, TRAPS) {
759 constantPoolHandle h_this(THREAD, this);
760 copy_cp_to_impl(h_this, start_cpi, end_cpi, to_cp, to_cpi, THREAD);
761 }
762 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_cpi, int end_cpi, const constantPoolHandle& to_cp, int to_cpi, TRAPS);
763 static void copy_entry_to(const constantPoolHandle& from_cp, int from_cpi, const constantPoolHandle& to_cp, int to_cpi);
764 static void copy_bsm_entries(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS);
765 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp);
766 int version() const { return _saved._version; }
767 void set_version(int version) { _saved._version = version; }
768 void increment_and_save_version(int version) {
769 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow
770 }
771
772 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; }
773 int resolved_reference_length() const { return _saved._resolved_reference_length; }
774
775 // Decrease ref counts of symbols that are in the constant pool
776 // when the holder class is unloaded
777 void unreference_symbols();
778
779 // Deallocate constant pool for RedefineClasses
780 void deallocate_contents(ClassLoaderData* loader_data);
781 void release_C_heap_structures();
782
783 // JVMTI access - GetConstantPool, RetransformClasses, ...
784 friend class JvmtiConstantPoolReconstituter;
785
786 private:
787 class SymbolHash: public CHeapObj<mtSymbol> {
788 HashTable<const Symbol*, u2, 256, AnyObj::C_HEAP, mtSymbol, Symbol::compute_hash> _table;
789
790 public:
791 void add_if_absent(const Symbol* sym, u2 value) {
792 bool created;
793 _table.put_if_absent(sym, value, &created);
794 }
795
796 u2 symbol_to_value(const Symbol* sym) {
797 u2* value = _table.get(sym);
798 return (value == nullptr) ? 0 : *value;
799 }
800 }; // End SymbolHash class
801
802 jint cpool_entry_size(jint idx);
803 jint hash_entries_to(SymbolHash *symmap, SymbolHash *classmap);
804
805 // Copy cpool bytes into byte array.
806 // Returns:
807 // int > 0, count of the raw cpool bytes that have been copied
808 // 0, OutOfMemory error
809 // -1, Internal error
810 int copy_cpool_bytes(int cpool_size,
811 SymbolHash* tbl,
812 unsigned char *bytes);
813
814 public:
815 // Verify
816 void verify_on(outputStream* st);
817
818 // Printing
819 void print_on(outputStream* st) const;
820 void print_value_on(outputStream* st) const;
821 void print_entry_on(int index, outputStream* st);
822
823 const char* internal_name() const { return "{constant pool}"; }
824
825 // ResolvedFieldEntry getters
826 inline ResolvedFieldEntry* resolved_field_entry_at(int field_index);
827 inline int resolved_field_entries_length() const;
828
829 // ResolvedMethodEntry getters
830 inline ResolvedMethodEntry* resolved_method_entry_at(int method_index);
831 inline int resolved_method_entries_length() const;
832 inline oop appendix_if_resolved(int method_index) const;
833
834 // ResolvedIndyEntry getters
835 inline ResolvedIndyEntry* resolved_indy_entry_at(int index);
836 inline int resolved_indy_entries_length() const;
837 inline oop resolved_reference_from_indy(int index) const;
838 inline oop resolved_reference_from_method(int index) const;
839 };
840
841 #endif // SHARE_OOPS_CONSTANTPOOL_HPP