1 /*
2 * Copyright (c) 1997, 2024, 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
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7 * published by the Free Software Foundation.
8 *
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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23 */
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/cpCache.hpp"
31 #include "oops/objArrayOop.hpp"
32 #include "oops/oopHandle.hpp"
33 #include "oops/symbol.hpp"
34 #include "oops/typeArrayOop.hpp"
35 #include "runtime/handles.hpp"
36 #include "runtime/javaThread.hpp"
37 #include "utilities/align.hpp"
38 #include "utilities/bytes.hpp"
39 #include "utilities/constantTag.hpp"
40 #include "utilities/resourceHash.hpp"
41
42 // A ConstantPool is an array containing class constants as described in the
43 // class file.
44 //
45 // Most of the constant pool entries are written during class parsing, which
46 // is safe. For klass types, the constant pool entry is
47 // modified when the entry is resolved. If a klass constant pool
48 // entry is read without a lock, only the resolved state guarantees that
49 // the entry in the constant pool is a klass object and not a Symbol*.
50
51 // This represents a JVM_CONSTANT_Class, JVM_CONSTANT_UnresolvedClass, or
52 // JVM_CONSTANT_UnresolvedClassInError slot in the constant pool.
53 class CPKlassSlot {
54 // cp->symbol_at(_name_index) gives the name of the class.
55 int _name_index;
56
57 // cp->_resolved_klasses->at(_resolved_klass_index) gives the Klass* for the class.
58 int _resolved_klass_index;
59 public:
60 enum {
61 // This is used during constant pool merging where the resolved klass index is
62 // not yet known, and will be computed at a later stage (during a call to
63 // initialize_unresolved_klasses()).
64 _temp_resolved_klass_index = 0xffff
65 };
66 CPKlassSlot(int n, int rk) {
67 _name_index = n;
68 _resolved_klass_index = rk;
69 }
70 int name_index() const {
71 return _name_index;
72 }
73 int resolved_klass_index() const {
74 assert(_resolved_klass_index != _temp_resolved_klass_index, "constant pool merging was incomplete");
75 return _resolved_klass_index;
76 }
77 };
78
79 class ConstantPool : public Metadata {
80 friend class VMStructs;
81 friend class JVMCIVMStructs;
82 friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast
83 friend class Universe; // For null constructor
84 friend class ClassPrelinker; // CDS
85 private:
86 // If you add a new field that points to any metaspace object, you
87 // must add this field to ConstantPool::metaspace_pointers_do().
88 Array<u1>* _tags; // the tag array describing the constant pool's contents
89 ConstantPoolCache* _cache; // the cache holding interpreter runtime information
90 InstanceKlass* _pool_holder; // the corresponding class
91 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
92
93 // Consider using an array of compressed klass pointers to
94 // save space on 64-bit platforms.
95 Array<Klass*>* _resolved_klasses;
96
97 u2 _major_version; // major version number of class file
98 u2 _minor_version; // minor version number of class file
99
100 // Constant pool index to the utf8 entry of the Generic signature,
101 // or 0 if none.
102 u2 _generic_signature_index;
103 // Constant pool index to the utf8 entry for the name of source file
104 // containing this klass, 0 if not specified.
105 u2 _source_file_name_index;
106
107 enum {
108 _has_preresolution = 1, // Flags
109 _on_stack = 2,
110 _is_shared = 4,
111 _has_dynamic_constant = 8,
112 _is_for_method_handle_intrinsic = 16
113 };
114
115 u2 _flags; // old fashioned bit twiddling
116
117 int _length; // number of elements in the array
118
119 union {
120 // set for CDS to restore resolved references
121 int _resolved_reference_length;
122 // keeps version number for redefined classes (used in backtrace)
123 int _version;
124 } _saved;
125
126 void set_tags(Array<u1>* tags) { _tags = tags; }
127 void tag_at_put(int cp_index, jbyte t) { tags()->at_put(cp_index, t); }
128 void release_tag_at_put(int cp_index, jbyte t) { tags()->release_at_put(cp_index, t); }
129
130 u1* tag_addr_at(int cp_index) const { return tags()->adr_at(cp_index); }
131
132 void set_operands(Array<u2>* operands) { _operands = operands; }
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 Array<u2>* operands() const { return _operands; }
174
175 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; }
176 void set_has_preresolution() {
177 assert(!is_shared(), "should never be called on shared ConstantPools");
178 _flags |= _has_preresolution;
179 }
180
181 // minor and major version numbers of class file
182 u2 major_version() const { return _major_version; }
183 void set_major_version(u2 major_version) { _major_version = major_version; }
184 u2 minor_version() const { return _minor_version; }
185 void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
186
187 // generics support
188 Symbol* generic_signature() const {
189 return (_generic_signature_index == 0) ?
190 nullptr : symbol_at(_generic_signature_index);
191 }
192 u2 generic_signature_index() const { return _generic_signature_index; }
193 void set_generic_signature_index(u2 sig_index) { _generic_signature_index = sig_index; }
194
195 // source file name
196 Symbol* source_file_name() const {
197 return (_source_file_name_index == 0) ?
198 nullptr : symbol_at(_source_file_name_index);
199 }
200 u2 source_file_name_index() const { return _source_file_name_index; }
201 void set_source_file_name_index(u2 sourcefile_index) { _source_file_name_index = sourcefile_index; }
202
203 void copy_fields(const ConstantPool* orig);
204
205 // Redefine classes support. If a method referring to this constant pool
206 // is on the executing stack, or as a handle in vm code, this constant pool
207 // can't be removed from the set of previous versions saved in the instance
208 // class.
209 bool on_stack() const;
210 bool is_maybe_on_stack() const;
211 void set_on_stack(const bool value);
212
213 // Faster than MetaspaceObj::is_shared() - used by set_on_stack()
214 bool is_shared() const { return (_flags & _is_shared) != 0; }
215
216 bool has_dynamic_constant() const { return (_flags & _has_dynamic_constant) != 0; }
217 void set_has_dynamic_constant() { _flags |= _has_dynamic_constant; }
218
219 bool is_for_method_handle_intrinsic() const { return (_flags & _is_for_method_handle_intrinsic) != 0; }
220 void set_is_for_method_handle_intrinsic() { _flags |= _is_for_method_handle_intrinsic; }
221
222 // Klass holding pool
223 InstanceKlass* pool_holder() const { return _pool_holder; }
224 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; }
225 InstanceKlass** pool_holder_addr() { return &_pool_holder; }
226
227 // Interpreter runtime support
228 ConstantPoolCache* cache() const { return _cache; }
229 void set_cache(ConstantPoolCache* cache){ _cache = cache; }
230
231 virtual void metaspace_pointers_do(MetaspaceClosure* iter);
232 virtual MetaspaceObj::Type type() const { return ConstantPoolType; }
233
234 // Create object cache in the constant pool
235 void initialize_resolved_references(ClassLoaderData* loader_data,
236 const intStack& reference_map,
237 int constant_pool_map_length,
238 TRAPS);
239
240 // resolved strings, methodHandles and callsite objects from the constant pool
241 objArrayOop resolved_references() const;
242 objArrayOop resolved_references_or_null() const;
243 oop resolved_reference_at(int obj_index) const;
244 oop set_resolved_reference_at(int index, oop new_value);
245
246 // mapping resolved object array indexes to cp indexes and back.
247 int object_to_cp_index(int index) { return reference_map()->at(index); }
248 int cp_to_object_index(int index);
249
250 void set_resolved_klasses(Array<Klass*>* rk) { _resolved_klasses = rk; }
251 Array<Klass*>* resolved_klasses() const { return _resolved_klasses; }
252 void allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS);
253 void initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS);
254
255 // Given the per-instruction index of an indy instruction, report the
256 // main constant pool entry for its bootstrap specifier.
257 // From there, uncached_name/signature_ref_at will get the name/type.
258 inline u2 invokedynamic_bootstrap_ref_index_at(int indy_index) const;
259
260 // Assembly code support
261 static ByteSize tags_offset() { return byte_offset_of(ConstantPool, _tags); }
262 static ByteSize cache_offset() { return byte_offset_of(ConstantPool, _cache); }
263 static ByteSize pool_holder_offset() { return byte_offset_of(ConstantPool, _pool_holder); }
264 static ByteSize resolved_klasses_offset() { return byte_offset_of(ConstantPool, _resolved_klasses); }
265
266 // Storing constants
267
268 // For temporary use while constructing constant pool
269 void klass_index_at_put(int cp_index, int name_index) {
270 tag_at_put(cp_index, JVM_CONSTANT_ClassIndex);
271 *int_at_addr(cp_index) = name_index;
272 }
273
274 // Hidden class support:
275 void klass_at_put(int class_index, Klass* k);
276
277 void unresolved_klass_at_put(int cp_index, int name_index, int resolved_klass_index) {
278 release_tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
279
280 assert((name_index & 0xffff0000) == 0, "must be");
281 assert((resolved_klass_index & 0xffff0000) == 0, "must be");
282 *int_at_addr(cp_index) =
283 build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
284 }
285
286 void method_handle_index_at_put(int cp_index, int ref_kind, int ref_index) {
287 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle);
288 *int_at_addr(cp_index) = ((jint) ref_index<<16) | ref_kind;
289 }
290
291 void method_type_index_at_put(int cp_index, int ref_index) {
292 tag_at_put(cp_index, JVM_CONSTANT_MethodType);
293 *int_at_addr(cp_index) = ref_index;
294 }
295
296 void dynamic_constant_at_put(int cp_index, int bsms_attribute_index, int name_and_type_index) {
297 tag_at_put(cp_index, JVM_CONSTANT_Dynamic);
298 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | bsms_attribute_index;
299 }
300
301 void invoke_dynamic_at_put(int cp_index, int bsms_attribute_index, int name_and_type_index) {
302 tag_at_put(cp_index, JVM_CONSTANT_InvokeDynamic);
303 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | bsms_attribute_index;
304 }
305
306 void unresolved_string_at_put(int cp_index, Symbol* s) {
307 assert(s->refcount() != 0, "should have nonzero refcount");
308 // Note that release_tag_at_put is not needed here because this is called only
309 // when constructing a ConstantPool in a single thread, with no possibility
310 // of concurrent access.
311 tag_at_put(cp_index, JVM_CONSTANT_String);
312 *symbol_at_addr(cp_index) = s;
313 }
314
315 void int_at_put(int cp_index, jint i) {
316 tag_at_put(cp_index, JVM_CONSTANT_Integer);
317 *int_at_addr(cp_index) = i;
318 }
319
320 void long_at_put(int cp_index, jlong l) {
321 tag_at_put(cp_index, JVM_CONSTANT_Long);
322 // *long_at_addr(which) = l;
323 Bytes::put_native_u8((address)long_at_addr(cp_index), *((u8*) &l));
324 }
325
326 void float_at_put(int cp_index, jfloat f) {
327 tag_at_put(cp_index, JVM_CONSTANT_Float);
328 *float_at_addr(cp_index) = f;
329 }
330
331 void double_at_put(int cp_index, jdouble d) {
332 tag_at_put(cp_index, JVM_CONSTANT_Double);
333 // *double_at_addr(which) = d;
334 // u8 temp = *(u8*) &d;
335 Bytes::put_native_u8((address) double_at_addr(cp_index), *((u8*) &d));
336 }
337
338 Symbol** symbol_at_addr(int cp_index) const {
339 assert(is_within_bounds(cp_index), "index out of bounds");
340 return (Symbol**) &base()[cp_index];
341 }
342
343 void symbol_at_put(int cp_index, Symbol* s) {
344 assert(s->refcount() != 0, "should have nonzero refcount");
345 tag_at_put(cp_index, JVM_CONSTANT_Utf8);
346 *symbol_at_addr(cp_index) = s;
347 }
348
349 void string_at_put(int obj_index, oop str);
350
351 // For temporary use while constructing constant pool
352 void string_index_at_put(int cp_index, int string_index) {
353 tag_at_put(cp_index, JVM_CONSTANT_StringIndex);
354 *int_at_addr(cp_index) = string_index;
355 }
356
357 void field_at_put(int cp_index, int class_index, int name_and_type_index) {
358 tag_at_put(cp_index, JVM_CONSTANT_Fieldref);
359 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index;
360 }
361
362 void method_at_put(int cp_index, int class_index, int name_and_type_index) {
363 tag_at_put(cp_index, JVM_CONSTANT_Methodref);
364 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index;
365 }
366
367 void interface_method_at_put(int cp_index, int class_index, int name_and_type_index) {
368 tag_at_put(cp_index, JVM_CONSTANT_InterfaceMethodref);
369 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
370 }
371
372 void name_and_type_at_put(int cp_index, int name_index, int signature_index) {
373 tag_at_put(cp_index, JVM_CONSTANT_NameAndType);
374 *int_at_addr(cp_index) = ((jint) signature_index<<16) | name_index; // Not so nice
375 }
376
377 // Tag query
378
379 constantTag tag_at(int cp_index) const { return (constantTag)tags()->at_acquire(cp_index); }
380
381 // Fetching constants
382
383 Klass* klass_at(int cp_index, TRAPS) {
384 constantPoolHandle h_this(THREAD, this);
385 return klass_at_impl(h_this, cp_index, THREAD);
386 }
387
388 CPKlassSlot klass_slot_at(int cp_index) const {
389 assert(tag_at(cp_index).is_unresolved_klass() || tag_at(cp_index).is_klass(),
390 "Corrupted constant pool");
391 int value = *int_at_addr(cp_index);
392 int name_index = extract_high_short_from_int(value);
393 int resolved_klass_index = extract_low_short_from_int(value);
394 return CPKlassSlot(name_index, resolved_klass_index);
395 }
396
397 Symbol* klass_name_at(int cp_index) const; // Returns the name, w/o resolving.
398 int klass_name_index_at(int cp_index) const {
399 return klass_slot_at(cp_index).name_index();
400 }
401
402 Klass* resolved_klass_at(int cp_index) const; // Used by Compiler
403
404 // RedefineClasses() API support:
405 Symbol* klass_at_noresolve(int cp_index) { return klass_name_at(cp_index); }
406 void temp_unresolved_klass_at_put(int cp_index, int name_index) {
407 // Used only during constant pool merging for class redefinition. The resolved klass index
408 // will be initialized later by a call to initialize_unresolved_klasses().
409 unresolved_klass_at_put(cp_index, name_index, CPKlassSlot::_temp_resolved_klass_index);
410 }
411
412 jint int_at(int cp_index) const {
413 assert(tag_at(cp_index).is_int(), "Corrupted constant pool");
414 return *int_at_addr(cp_index);
415 }
416
417 jlong long_at(int cp_index) {
418 assert(tag_at(cp_index).is_long(), "Corrupted constant pool");
419 // return *long_at_addr(cp_index);
420 u8 tmp = Bytes::get_native_u8((address)&base()[cp_index]);
421 return *((jlong*)&tmp);
422 }
423
424 jfloat float_at(int cp_index) {
425 assert(tag_at(cp_index).is_float(), "Corrupted constant pool");
426 return *float_at_addr(cp_index);
427 }
428
429 jdouble double_at(int cp_index) {
430 assert(tag_at(cp_index).is_double(), "Corrupted constant pool");
431 u8 tmp = Bytes::get_native_u8((address)&base()[cp_index]);
432 return *((jdouble*)&tmp);
433 }
434
435 Symbol* symbol_at(int cp_index) const {
436 assert(tag_at(cp_index).is_utf8(), "Corrupted constant pool");
437 return *symbol_at_addr(cp_index);
438 }
439
440 oop string_at(int cp_index, int obj_index, TRAPS) {
441 constantPoolHandle h_this(THREAD, this);
442 return string_at_impl(h_this, cp_index, obj_index, THREAD);
443 }
444 oop string_at(int cp_index, TRAPS) {
445 int obj_index = cp_to_object_index(cp_index);
446 return string_at(cp_index, obj_index, THREAD);
447 }
448
449 // Version that can be used before string oop array is created.
450 oop uncached_string_at(int cp_index, TRAPS);
451
452 // only called when we are sure a string entry is already resolved (via an
453 // earlier string_at call.
454 oop resolved_string_at(int cp_index) {
455 assert(tag_at(cp_index).is_string(), "Corrupted constant pool");
456 // Must do an acquire here in case another thread resolved the klass
457 // behind our back, lest we later load stale values thru the oop.
458 // we might want a volatile_obj_at in ObjArrayKlass.
459 int obj_index = cp_to_object_index(cp_index);
460 return resolved_reference_at(obj_index);
461 }
462
463 Symbol* unresolved_string_at(int cp_index) {
464 assert(tag_at(cp_index).is_string(), "Corrupted constant pool");
465 return *symbol_at_addr(cp_index);
466 }
467
468 // Returns an UTF8 for a CONSTANT_String entry at a given index.
469 // UTF8 char* representation was chosen to avoid conversion of
470 // java_lang_Strings at resolved entries into Symbol*s
471 // or vice versa.
472 char* string_at_noresolve(int cp_index);
473
474 jint name_and_type_at(int cp_index) {
475 assert(tag_at(cp_index).is_name_and_type(), "Corrupted constant pool");
476 return *int_at_addr(cp_index);
477 }
478
479 int method_handle_ref_kind_at(int cp_index) {
480 assert(tag_at(cp_index).is_method_handle() ||
481 tag_at(cp_index).is_method_handle_in_error(), "Corrupted constant pool");
482 return extract_low_short_from_int(*int_at_addr(cp_index)); // mask out unwanted ref_index bits
483 }
484 int method_handle_index_at(int cp_index) {
485 assert(tag_at(cp_index).is_method_handle() ||
486 tag_at(cp_index).is_method_handle_in_error(), "Corrupted constant pool");
487 return extract_high_short_from_int(*int_at_addr(cp_index)); // shift out unwanted ref_kind bits
488 }
489 int method_type_index_at(int cp_index) {
490 assert(tag_at(cp_index).is_method_type() ||
491 tag_at(cp_index).is_method_type_in_error(), "Corrupted constant pool");
492 return *int_at_addr(cp_index);
493 }
494
495 // Derived queries:
496 Symbol* method_handle_name_ref_at(int cp_index) {
497 int member = method_handle_index_at(cp_index);
498 return uncached_name_ref_at(member);
499 }
500 Symbol* method_handle_signature_ref_at(int cp_index) {
501 int member = method_handle_index_at(cp_index);
502 return uncached_signature_ref_at(member);
503 }
504 u2 method_handle_klass_index_at(int cp_index) {
505 int member = method_handle_index_at(cp_index);
506 return uncached_klass_ref_index_at(member);
507 }
508 Symbol* method_type_signature_at(int cp_index) {
509 int sym = method_type_index_at(cp_index);
510 return symbol_at(sym);
511 }
512
513 u2 bootstrap_name_and_type_ref_index_at(int cp_index) {
514 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
515 return extract_high_short_from_int(*int_at_addr(cp_index));
516 }
517 u2 bootstrap_methods_attribute_index(int cp_index) {
518 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
519 return extract_low_short_from_int(*int_at_addr(cp_index));
520 }
521 int bootstrap_operand_base(int cp_index) {
522 int bsms_attribute_index = bootstrap_methods_attribute_index(cp_index);
523 return operand_offset_at(operands(), bsms_attribute_index);
524 }
525 // The first part of the operands array consists of an index into the second part.
526 // Extract a 32-bit index value from the first part.
527 static int operand_offset_at(Array<u2>* operands, int bsms_attribute_index) {
528 int n = (bsms_attribute_index * 2);
529 assert(n >= 0 && n+2 <= operands->length(), "oob");
530 // The first 32-bit index points to the beginning of the second part
531 // of the operands array. Make sure this index is in the first part.
532 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0),
533 operands->at(1)));
534 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
535 int offset = build_int_from_shorts(operands->at(n+0),
536 operands->at(n+1));
537 // The offset itself must point into the second part of the array.
538 assert(offset == 0 || (offset >= second_part && offset <= operands->length()), "oob (3)");
539 return offset;
540 }
541 static void operand_offset_at_put(Array<u2>* operands, int bsms_attribute_index, int offset) {
542 int n = bsms_attribute_index * 2;
543 assert(n >= 0 && n+2 <= operands->length(), "oob");
544 operands->at_put(n+0, extract_low_short_from_int(offset));
545 operands->at_put(n+1, extract_high_short_from_int(offset));
546 }
547 static int operand_array_length(Array<u2>* operands) {
548 if (operands == nullptr || operands->length() == 0) return 0;
549 int second_part = operand_offset_at(operands, 0);
550 return (second_part / 2);
551 }
552
553 #ifdef ASSERT
554 // operand tuples fit together exactly, end to end
555 static int operand_limit_at(Array<u2>* operands, int bsms_attribute_index) {
556 int nextidx = bsms_attribute_index + 1;
557 if (nextidx == operand_array_length(operands))
558 return operands->length();
559 else
560 return operand_offset_at(operands, nextidx);
561 }
562 int bootstrap_operand_limit(int cp_index) {
563 int bsms_attribute_index = bootstrap_methods_attribute_index(cp_index);
564 return operand_limit_at(operands(), bsms_attribute_index);
565 }
566 #endif //ASSERT
567
568 // Layout of InvokeDynamic and Dynamic bootstrap method specifier
569 // data in second part of operands array. This encodes one record in
570 // the BootstrapMethods attribute. The whole specifier also includes
571 // the name and type information from the main constant pool entry.
572 enum {
573 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
574 _indy_argc_offset = 1, // u2 argc
575 _indy_argv_offset = 2 // u2 argv[argc]
576 };
577
578 // These functions are used in RedefineClasses for CP merge
579
580 int operand_offset_at(int bsms_attribute_index) {
581 assert(0 <= bsms_attribute_index &&
582 bsms_attribute_index < operand_array_length(operands()),
583 "Corrupted CP operands");
584 return operand_offset_at(operands(), bsms_attribute_index);
585 }
586 u2 operand_bootstrap_method_ref_index_at(int bsms_attribute_index) {
587 int offset = operand_offset_at(bsms_attribute_index);
588 return operands()->at(offset + _indy_bsm_offset);
589 }
590 u2 operand_argument_count_at(int bsms_attribute_index) {
591 int offset = operand_offset_at(bsms_attribute_index);
592 u2 argc = operands()->at(offset + _indy_argc_offset);
593 return argc;
594 }
595 u2 operand_argument_index_at(int bsms_attribute_index, int j) {
596 int offset = operand_offset_at(bsms_attribute_index);
597 return operands()->at(offset + _indy_argv_offset + j);
598 }
599 int operand_next_offset_at(int bsms_attribute_index) {
600 int offset = operand_offset_at(bsms_attribute_index) + _indy_argv_offset
601 + operand_argument_count_at(bsms_attribute_index);
602 return offset;
603 }
604 // Compare a bootstrap specifier data in the operands arrays
605 bool compare_operand_to(int bsms_attribute_index1, const constantPoolHandle& cp2,
606 int bsms_attribute_index2);
607 // Find a bootstrap specifier data in the operands array
608 int find_matching_operand(int bsms_attribute_index, const constantPoolHandle& search_cp,
609 int operands_cur_len);
610 // Resize the operands array with delta_len and delta_size
611 void resize_operands(int delta_len, int delta_size, TRAPS);
612 // Extend the operands array with the length and size of the ext_cp operands
613 void extend_operands(const constantPoolHandle& ext_cp, TRAPS);
614 // Shrink the operands array to a smaller array with new_len length
615 void shrink_operands(int new_len, TRAPS);
616
617 u2 bootstrap_method_ref_index_at(int cp_index) {
618 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
619 int op_base = bootstrap_operand_base(cp_index);
620 return operands()->at(op_base + _indy_bsm_offset);
621 }
622 u2 bootstrap_argument_count_at(int cp_index) {
623 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
624 int op_base = bootstrap_operand_base(cp_index);
625 u2 argc = operands()->at(op_base + _indy_argc_offset);
626 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
627 int next_offset = bootstrap_operand_limit(cp_index));
628 assert(end_offset == next_offset, "matched ending");
629 return argc;
630 }
631 u2 bootstrap_argument_index_at(int cp_index, int j) {
632 int op_base = bootstrap_operand_base(cp_index);
633 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset));
634 assert((uint)j < (uint)argc, "oob");
635 return operands()->at(op_base + _indy_argv_offset + j);
636 }
637
638 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
639 // name_and_type_ref_index_at) all expect to be passed indices obtained
640 // directly from the bytecode.
641 // If the indices are meant to refer to fields or methods, they are
642 // actually rewritten indices that point to entries in their respective structures
643 // i.e. ResolvedMethodEntries or ResolvedFieldEntries.
644 // The routine to_cp_index manages the adjustment
645 // of these values back to constant pool indices.
646
647 // There are also "uncached" versions which do not adjust the operand index; see below.
648
649 // Lookup for entries consisting of (klass_index, name_and_type index)
650 Klass* klass_ref_at(int which, Bytecodes::Code code, TRAPS);
651 Symbol* klass_ref_at_noresolve(int which, Bytecodes::Code code);
652 Symbol* name_ref_at(int which, Bytecodes::Code code) {
653 int name_index = name_ref_index_at(name_and_type_ref_index_at(which, code));
654 return symbol_at(name_index);
655 }
656 Symbol* signature_ref_at(int which, Bytecodes::Code code) {
657 int signature_index = signature_ref_index_at(name_and_type_ref_index_at(which, code));
658 return symbol_at(signature_index);
659 }
660
661 u2 klass_ref_index_at(int which, Bytecodes::Code code);
662 u2 name_and_type_ref_index_at(int which, Bytecodes::Code code);
663
664 constantTag tag_ref_at(int cp_cache_index, Bytecodes::Code code);
665
666 int to_cp_index(int which, Bytecodes::Code code);
667
668 bool is_resolved(int which, Bytecodes::Code code);
669
670 // Lookup for entries consisting of (name_index, signature_index)
671 u2 name_ref_index_at(int cp_index); // == low-order jshort of name_and_type_at(cp_index)
672 u2 signature_ref_index_at(int cp_index); // == high-order jshort of name_and_type_at(cp_index)
673
674 BasicType basic_type_for_signature_at(int cp_index) const;
675
676 // Resolve string constants (to prevent allocation during compilation)
677 void resolve_string_constants(TRAPS) {
678 constantPoolHandle h_this(THREAD, this);
679 resolve_string_constants_impl(h_this, CHECK);
680 }
681
682 #if INCLUDE_CDS
683 // CDS support
684 objArrayOop prepare_resolved_references_for_archiving() NOT_CDS_JAVA_HEAP_RETURN_(nullptr);
685 void add_dumped_interned_strings() NOT_CDS_JAVA_HEAP_RETURN;
686 bool can_archive_invokehandle(ResolvedMethodEntry* rme);
687 bool can_archive_resolved_method(ResolvedMethodEntry* method_entry);
688 void remove_unshareable_info();
689 void remove_unshareable_entries();
690 void restore_unshareable_info(TRAPS);
691 private:
692 void remove_resolved_klass_if_non_deterministic(int cp_index);
693 void remove_resolved_field_entries_if_non_deterministic();
694 void remove_resolved_method_entries_if_non_deterministic();
695 void remove_resolved_indy_entries_if_non_deterministic();
696 #endif
697
698 private:
699 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
700 public:
701
702 // Get the tag for a constant, which may involve a constant dynamic
703 constantTag constant_tag_at(int cp_index);
704 // Get the basic type for a constant, which may involve a constant dynamic
705 BasicType basic_type_for_constant_at(int cp_index);
706
707 // Resolve late bound constants.
708 oop resolve_constant_at(int cp_index, TRAPS) {
709 constantPoolHandle h_this(THREAD, this);
710 return resolve_constant_at_impl(h_this, cp_index, _no_index_sentinel, nullptr, THREAD);
711 }
712
713 oop resolve_cached_constant_at(int cache_index, TRAPS) {
714 constantPoolHandle h_this(THREAD, this);
715 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, nullptr, THREAD);
716 }
717
718 oop resolve_possibly_cached_constant_at(int cp_index, TRAPS) {
719 constantPoolHandle h_this(THREAD, this);
720 return resolve_constant_at_impl(h_this, cp_index, _possible_index_sentinel, nullptr, THREAD);
721 }
722
723 oop find_cached_constant_at(int cp_index, bool& found_it, TRAPS) {
724 constantPoolHandle h_this(THREAD, this);
725 return resolve_constant_at_impl(h_this, cp_index, _possible_index_sentinel, &found_it, THREAD);
726 }
727
728 void copy_bootstrap_arguments_at(int cp_index,
729 int start_arg, int end_arg,
730 objArrayHandle info, int pos,
731 bool must_resolve, Handle if_not_available, TRAPS) {
732 constantPoolHandle h_this(THREAD, this);
733 copy_bootstrap_arguments_at_impl(h_this, cp_index, start_arg, end_arg,
734 info, pos, must_resolve, if_not_available, THREAD);
735 }
736
737 // Klass name matches name at offset
738 bool klass_name_at_matches(const InstanceKlass* k, int cp_index);
739
740 // Sizing
741 int length() const { return _length; }
742 void set_length(int length) { _length = length; }
743
744 // Tells whether index is within bounds.
745 bool is_within_bounds(int index) const {
746 return 0 <= index && index < length();
747 }
748
749 // Sizing (in words)
750 static int header_size() {
751 return align_up((int)sizeof(ConstantPool), wordSize) / wordSize;
752 }
753 static int size(int length) { return align_metadata_size(header_size() + length); }
754 int size() const { return size(length()); }
755
756 // ConstantPools should be stored in the read-only region of CDS archive.
757 static bool is_read_only_by_default() { return true; }
758
759 friend class ClassFileParser;
760 friend class SystemDictionary;
761
762 // Used by CDS. These classes need to access the private ConstantPool() constructor.
763 template <class T> friend class CppVtableTesterA;
764 template <class T> friend class CppVtableTesterB;
765 template <class T> friend class CppVtableCloner;
766
767 // Used by compiler to prevent classloading.
768 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which);
769 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code);
770 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code);
771 static bool has_local_signature_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code);
772 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which);
773
774 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
775 // future by other Java code. These take constant pool indices rather than
776 // constant pool cache indices as do the peer methods above.
777 Symbol* uncached_klass_ref_at_noresolve(int cp_index);
778 Symbol* uncached_name_ref_at(int cp_index) {
779 int name_index = name_ref_index_at(uncached_name_and_type_ref_index_at(cp_index));
780 return symbol_at(name_index);
781 }
782 Symbol* uncached_signature_ref_at(int cp_index) {
783 int signature_index = signature_ref_index_at(uncached_name_and_type_ref_index_at(cp_index));
784 return symbol_at(signature_index);
785 }
786 u2 uncached_klass_ref_index_at(int cp_index);
787 u2 uncached_name_and_type_ref_index_at(int cp_index);
788
789 // Sharing
790 int pre_resolve_shared_klasses(TRAPS);
791
792 // Debugging
793 const char* printable_name_at(int cp_index) PRODUCT_RETURN0;
794
795 private:
796
797 void set_resolved_references(OopHandle s) { _cache->set_resolved_references(s); }
798 Array<u2>* reference_map() const { return (_cache == nullptr) ? nullptr : _cache->reference_map(); }
799 void set_reference_map(Array<u2>* o) { _cache->set_reference_map(o); }
800
801 // Used while constructing constant pool (only by ClassFileParser)
802 jint klass_index_at(int cp_index) {
803 assert(tag_at(cp_index).is_klass_index(), "Corrupted constant pool");
804 return *int_at_addr(cp_index);
805 }
806
807 jint string_index_at(int cp_index) {
808 assert(tag_at(cp_index).is_string_index(), "Corrupted constant pool");
809 return *int_at_addr(cp_index);
810 }
811
812 // Performs the LinkResolver checks
813 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* klass, TRAPS);
814
815 // Implementation of methods that needs an exposed 'this' pointer, in order to
816 // handle GC while executing the method
817 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int cp_index, TRAPS);
818 static oop string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS);
819
820 static void trace_class_resolution(const constantPoolHandle& this_cp, Klass* k);
821
822 // Resolve string constants (to prevent allocation during compilation)
823 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS);
824
825 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int cp_index, int cache_index,
826 bool* status_return, TRAPS);
827 static void copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index,
828 int start_arg, int end_arg,
829 objArrayHandle info, int pos,
830 bool must_resolve, Handle if_not_available, TRAPS);
831
832 // Exception handling
833 static void save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index, constantTag tag, TRAPS);
834
835 public:
836 // Exception handling
837 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS);
838
839 // Merging ConstantPool* support:
840 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2);
841 void copy_cp_to(int start_cpi, int end_cpi, const constantPoolHandle& to_cp, int to_cpi, TRAPS) {
842 constantPoolHandle h_this(THREAD, this);
843 copy_cp_to_impl(h_this, start_cpi, end_cpi, to_cp, to_cpi, THREAD);
844 }
845 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_cpi, int end_cpi, const constantPoolHandle& to_cp, int to_cpi, TRAPS);
846 static void copy_entry_to(const constantPoolHandle& from_cp, int from_cpi, const constantPoolHandle& to_cp, int to_cpi);
847 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS);
848 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp);
849 int version() const { return _saved._version; }
850 void set_version(int version) { _saved._version = version; }
851 void increment_and_save_version(int version) {
852 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow
853 }
854
855 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; }
856 int resolved_reference_length() const { return _saved._resolved_reference_length; }
857
858 // Decrease ref counts of symbols that are in the constant pool
859 // when the holder class is unloaded
860 void unreference_symbols();
861
862 // Deallocate constant pool for RedefineClasses
863 void deallocate_contents(ClassLoaderData* loader_data);
864 void release_C_heap_structures();
865
866 // JVMTI access - GetConstantPool, RetransformClasses, ...
867 friend class JvmtiConstantPoolReconstituter;
868
869 private:
870 class SymbolHash: public CHeapObj<mtSymbol> {
871 ResourceHashtable<const Symbol*, u2, 256, AnyObj::C_HEAP, mtSymbol, Symbol::compute_hash> _table;
872
873 public:
874 void add_if_absent(const Symbol* sym, u2 value) {
875 bool created;
876 _table.put_if_absent(sym, value, &created);
877 }
878
879 u2 symbol_to_value(const Symbol* sym) {
880 u2* value = _table.get(sym);
881 return (value == nullptr) ? 0 : *value;
882 }
883 }; // End SymbolHash class
884
885 jint cpool_entry_size(jint idx);
886 jint hash_entries_to(SymbolHash *symmap, SymbolHash *classmap);
887
888 // Copy cpool bytes into byte array.
889 // Returns:
890 // int > 0, count of the raw cpool bytes that have been copied
891 // 0, OutOfMemory error
892 // -1, Internal error
893 int copy_cpool_bytes(int cpool_size,
894 SymbolHash* tbl,
895 unsigned char *bytes);
896
897 public:
898 // Verify
899 void verify_on(outputStream* st);
900
901 // Printing
902 void print_on(outputStream* st) const;
903 void print_value_on(outputStream* st) const;
904 void print_entry_on(int index, outputStream* st);
905
906 const char* internal_name() const { return "{constant pool}"; }
907
908 // ResolvedFieldEntry getters
909 inline ResolvedFieldEntry* resolved_field_entry_at(int field_index);
910 inline int resolved_field_entries_length() const;
911
912 // ResolvedMethodEntry getters
913 inline ResolvedMethodEntry* resolved_method_entry_at(int method_index);
914 inline int resolved_method_entries_length() const;
915 inline oop appendix_if_resolved(int method_index) const;
916
917 // ResolvedIndyEntry getters
918 inline ResolvedIndyEntry* resolved_indy_entry_at(int index);
919 inline int resolved_indy_entries_length() const;
920 inline oop resolved_reference_from_indy(int index) const;
921 inline oop resolved_reference_from_method(int index) const;
922 };
923
924 #endif // SHARE_OOPS_CONSTANTPOOL_HPP