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/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 };
113
114 u2 _flags; // old fashioned bit twiddling
115
116 int _length; // number of elements in the array
117
118 union {
119 // set for CDS to restore resolved references
120 int _resolved_reference_length;
121 // keeps version number for redefined classes (used in backtrace)
122 int _version;
123 } _saved;
124
125 void set_tags(Array<u1>* tags) { _tags = tags; }
126 void tag_at_put(int cp_index, jbyte t) { tags()->at_put(cp_index, t); }
127 void release_tag_at_put(int cp_index, jbyte t) { tags()->release_at_put(cp_index, t); }
128
129 u1* tag_addr_at(int cp_index) const { return tags()->adr_at(cp_index); }
130
131 void set_operands(Array<u2>* operands) { _operands = operands; }
132
133 u2 flags() const { return _flags; }
134 void set_flags(u2 f) { _flags = f; }
135
136 private:
137 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); }
138
139 intptr_t* obj_at_addr(int cp_index) const {
140 assert(is_within_bounds(cp_index), "index out of bounds");
141 return (intptr_t*) &base()[cp_index];
142 }
143
144 jint* int_at_addr(int cp_index) const {
145 assert(is_within_bounds(cp_index), "index out of bounds");
146 return (jint*) &base()[cp_index];
147 }
148
149 jlong* long_at_addr(int cp_index) const {
150 assert(is_within_bounds(cp_index), "index out of bounds");
151 return (jlong*) &base()[cp_index];
152 }
153
154 jfloat* float_at_addr(int cp_index) const {
155 assert(is_within_bounds(cp_index), "index out of bounds");
156 return (jfloat*) &base()[cp_index];
157 }
158
159 jdouble* double_at_addr(int cp_index) const {
160 assert(is_within_bounds(cp_index), "index out of bounds");
161 return (jdouble*) &base()[cp_index];
162 }
163
164 ConstantPool(Array<u1>* tags);
165 ConstantPool();
166 public:
167 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS);
168
169 virtual bool is_constantPool() const { return true; }
170
171 Array<u1>* tags() const { return _tags; }
172 Array<u2>* operands() const { return _operands; }
173
174 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; }
175 void set_has_preresolution() {
176 assert(!is_shared(), "should never be called on shared ConstantPools");
177 _flags |= _has_preresolution;
178 }
179
180 // minor and major version numbers of class file
181 u2 major_version() const { return _major_version; }
182 void set_major_version(u2 major_version) { _major_version = major_version; }
183 u2 minor_version() const { return _minor_version; }
184 void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
185
186 // generics support
187 Symbol* generic_signature() const {
188 return (_generic_signature_index == 0) ?
189 nullptr : symbol_at(_generic_signature_index);
190 }
191 u2 generic_signature_index() const { return _generic_signature_index; }
192 void set_generic_signature_index(u2 sig_index) { _generic_signature_index = sig_index; }
193
194 // source file name
195 Symbol* source_file_name() const {
196 return (_source_file_name_index == 0) ?
197 nullptr : symbol_at(_source_file_name_index);
198 }
199 u2 source_file_name_index() const { return _source_file_name_index; }
200 void set_source_file_name_index(u2 sourcefile_index) { _source_file_name_index = sourcefile_index; }
201
202 void copy_fields(const ConstantPool* orig);
203
204 // Redefine classes support. If a method referring to this constant pool
205 // is on the executing stack, or as a handle in vm code, this constant pool
206 // can't be removed from the set of previous versions saved in the instance
207 // class.
208 bool on_stack() const;
209 bool is_maybe_on_stack() const;
210 void set_on_stack(const bool value);
211
212 // Faster than MetaspaceObj::is_shared() - used by set_on_stack()
213 bool is_shared() const { return (_flags & _is_shared) != 0; }
214
215 bool has_dynamic_constant() const { return (_flags & _has_dynamic_constant) != 0; }
216 void set_has_dynamic_constant() { _flags |= _has_dynamic_constant; }
217
218 // Klass holding pool
219 InstanceKlass* pool_holder() const { return _pool_holder; }
220 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; }
221 InstanceKlass** pool_holder_addr() { return &_pool_holder; }
222
223 // Interpreter runtime support
224 ConstantPoolCache* cache() const { return _cache; }
225 void set_cache(ConstantPoolCache* cache){ _cache = cache; }
226
227 virtual void metaspace_pointers_do(MetaspaceClosure* iter);
228 virtual MetaspaceObj::Type type() const { return ConstantPoolType; }
229
230 // Create object cache in the constant pool
231 void initialize_resolved_references(ClassLoaderData* loader_data,
232 const intStack& reference_map,
233 int constant_pool_map_length,
234 TRAPS);
235
236 // resolved strings, methodHandles and callsite objects from the constant pool
237 objArrayOop resolved_references() const;
238 objArrayOop resolved_references_or_null() const;
239 oop resolved_reference_at(int obj_index) const;
240 oop set_resolved_reference_at(int index, oop new_value);
241
242 // mapping resolved object array indexes to cp indexes and back.
243 int object_to_cp_index(int index) { return reference_map()->at(index); }
244 int cp_to_object_index(int index);
245
246 void set_resolved_klasses(Array<Klass*>* rk) { _resolved_klasses = rk; }
247 Array<Klass*>* resolved_klasses() const { return _resolved_klasses; }
248 void allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS);
249 void initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS);
250
251 // Given the per-instruction index of an indy instruction, report the
252 // main constant pool entry for its bootstrap specifier.
253 // From there, uncached_name/signature_ref_at will get the name/type.
254 inline u2 invokedynamic_bootstrap_ref_index_at(int indy_index) const;
255
256 // Assembly code support
257 static ByteSize tags_offset() { return byte_offset_of(ConstantPool, _tags); }
258 static ByteSize cache_offset() { return byte_offset_of(ConstantPool, _cache); }
259 static ByteSize pool_holder_offset() { return byte_offset_of(ConstantPool, _pool_holder); }
260 static ByteSize resolved_klasses_offset() { return byte_offset_of(ConstantPool, _resolved_klasses); }
261
262 // Storing constants
263
264 // For temporary use while constructing constant pool
265 void klass_index_at_put(int cp_index, int name_index) {
266 tag_at_put(cp_index, JVM_CONSTANT_ClassIndex);
267 *int_at_addr(cp_index) = name_index;
268 }
269
270 // Hidden class support:
271 void klass_at_put(int class_index, Klass* k);
272
273 void unresolved_klass_at_put(int cp_index, int name_index, int resolved_klass_index) {
274 release_tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
275
276 assert((name_index & 0xffff0000) == 0, "must be");
277 assert((resolved_klass_index & 0xffff0000) == 0, "must be");
278 *int_at_addr(cp_index) =
279 build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
280 }
281
282 void method_handle_index_at_put(int cp_index, int ref_kind, int ref_index) {
283 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle);
284 *int_at_addr(cp_index) = ((jint) ref_index<<16) | ref_kind;
285 }
286
287 void method_type_index_at_put(int cp_index, int ref_index) {
288 tag_at_put(cp_index, JVM_CONSTANT_MethodType);
289 *int_at_addr(cp_index) = ref_index;
290 }
291
292 void dynamic_constant_at_put(int cp_index, int bsms_attribute_index, int name_and_type_index) {
293 tag_at_put(cp_index, JVM_CONSTANT_Dynamic);
294 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | bsms_attribute_index;
295 }
296
297 void invoke_dynamic_at_put(int cp_index, int bsms_attribute_index, int name_and_type_index) {
298 tag_at_put(cp_index, JVM_CONSTANT_InvokeDynamic);
299 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | bsms_attribute_index;
300 }
301
302 void unresolved_string_at_put(int cp_index, Symbol* s) {
303 assert(s->refcount() != 0, "should have nonzero refcount");
304 // Note that release_tag_at_put is not needed here because this is called only
305 // when constructing a ConstantPool in a single thread, with no possibility
306 // of concurrent access.
307 tag_at_put(cp_index, JVM_CONSTANT_String);
308 *symbol_at_addr(cp_index) = s;
309 }
310
311 void int_at_put(int cp_index, jint i) {
312 tag_at_put(cp_index, JVM_CONSTANT_Integer);
313 *int_at_addr(cp_index) = i;
314 }
315
316 void long_at_put(int cp_index, jlong l) {
317 tag_at_put(cp_index, JVM_CONSTANT_Long);
318 // *long_at_addr(which) = l;
319 Bytes::put_native_u8((address)long_at_addr(cp_index), *((u8*) &l));
320 }
321
322 void float_at_put(int cp_index, jfloat f) {
323 tag_at_put(cp_index, JVM_CONSTANT_Float);
324 *float_at_addr(cp_index) = f;
325 }
326
327 void double_at_put(int cp_index, jdouble d) {
328 tag_at_put(cp_index, JVM_CONSTANT_Double);
329 // *double_at_addr(which) = d;
330 // u8 temp = *(u8*) &d;
331 Bytes::put_native_u8((address) double_at_addr(cp_index), *((u8*) &d));
332 }
333
334 Symbol** symbol_at_addr(int cp_index) const {
335 assert(is_within_bounds(cp_index), "index out of bounds");
336 return (Symbol**) &base()[cp_index];
337 }
338
339 void symbol_at_put(int cp_index, Symbol* s) {
340 assert(s->refcount() != 0, "should have nonzero refcount");
341 tag_at_put(cp_index, JVM_CONSTANT_Utf8);
342 *symbol_at_addr(cp_index) = s;
343 }
344
345 void string_at_put(int obj_index, oop str);
346
347 // For temporary use while constructing constant pool
348 void string_index_at_put(int cp_index, int string_index) {
349 tag_at_put(cp_index, JVM_CONSTANT_StringIndex);
350 *int_at_addr(cp_index) = string_index;
351 }
352
353 void field_at_put(int cp_index, int class_index, int name_and_type_index) {
354 tag_at_put(cp_index, JVM_CONSTANT_Fieldref);
355 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index;
356 }
357
358 void method_at_put(int cp_index, int class_index, int name_and_type_index) {
359 tag_at_put(cp_index, JVM_CONSTANT_Methodref);
360 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index;
361 }
362
363 void interface_method_at_put(int cp_index, int class_index, int name_and_type_index) {
364 tag_at_put(cp_index, JVM_CONSTANT_InterfaceMethodref);
365 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
366 }
367
368 void name_and_type_at_put(int cp_index, int name_index, int signature_index) {
369 tag_at_put(cp_index, JVM_CONSTANT_NameAndType);
370 *int_at_addr(cp_index) = ((jint) signature_index<<16) | name_index; // Not so nice
371 }
372
373 // Tag query
374
375 constantTag tag_at(int cp_index) const { return (constantTag)tags()->at_acquire(cp_index); }
376
377 // Fetching constants
378
379 Klass* klass_at(int cp_index, TRAPS) {
380 constantPoolHandle h_this(THREAD, this);
381 return klass_at_impl(h_this, cp_index, THREAD);
382 }
383
384 CPKlassSlot klass_slot_at(int cp_index) const {
385 assert(tag_at(cp_index).is_unresolved_klass() || tag_at(cp_index).is_klass(),
386 "Corrupted constant pool");
387 int value = *int_at_addr(cp_index);
388 int name_index = extract_high_short_from_int(value);
389 int resolved_klass_index = extract_low_short_from_int(value);
390 return CPKlassSlot(name_index, resolved_klass_index);
391 }
392
393 Symbol* klass_name_at(int cp_index) const; // Returns the name, w/o resolving.
394 int klass_name_index_at(int cp_index) const {
395 return klass_slot_at(cp_index).name_index();
396 }
397
398 Klass* resolved_klass_at(int cp_index) const; // Used by Compiler
399
400 // RedefineClasses() API support:
401 Symbol* klass_at_noresolve(int cp_index) { return klass_name_at(cp_index); }
402 void temp_unresolved_klass_at_put(int cp_index, int name_index) {
403 // Used only during constant pool merging for class redefinition. The resolved klass index
404 // will be initialized later by a call to initialize_unresolved_klasses().
405 unresolved_klass_at_put(cp_index, name_index, CPKlassSlot::_temp_resolved_klass_index);
406 }
407
408 jint int_at(int cp_index) const {
409 assert(tag_at(cp_index).is_int(), "Corrupted constant pool");
410 return *int_at_addr(cp_index);
411 }
412
413 jlong long_at(int cp_index) {
414 assert(tag_at(cp_index).is_long(), "Corrupted constant pool");
415 // return *long_at_addr(cp_index);
416 u8 tmp = Bytes::get_native_u8((address)&base()[cp_index]);
417 return *((jlong*)&tmp);
418 }
419
420 jfloat float_at(int cp_index) {
421 assert(tag_at(cp_index).is_float(), "Corrupted constant pool");
422 return *float_at_addr(cp_index);
423 }
424
425 jdouble double_at(int cp_index) {
426 assert(tag_at(cp_index).is_double(), "Corrupted constant pool");
427 u8 tmp = Bytes::get_native_u8((address)&base()[cp_index]);
428 return *((jdouble*)&tmp);
429 }
430
431 Symbol* symbol_at(int cp_index) const {
432 assert(tag_at(cp_index).is_utf8(), "Corrupted constant pool");
433 return *symbol_at_addr(cp_index);
434 }
435
436 oop string_at(int cp_index, int obj_index, TRAPS) {
437 constantPoolHandle h_this(THREAD, this);
438 return string_at_impl(h_this, cp_index, obj_index, THREAD);
439 }
440 oop string_at(int cp_index, TRAPS) {
441 int obj_index = cp_to_object_index(cp_index);
442 return string_at(cp_index, obj_index, THREAD);
443 }
444
445 // Version that can be used before string oop array is created.
446 oop uncached_string_at(int cp_index, TRAPS);
447
448 // only called when we are sure a string entry is already resolved (via an
449 // earlier string_at call.
450 oop resolved_string_at(int cp_index) {
451 assert(tag_at(cp_index).is_string(), "Corrupted constant pool");
452 // Must do an acquire here in case another thread resolved the klass
453 // behind our back, lest we later load stale values thru the oop.
454 // we might want a volatile_obj_at in ObjArrayKlass.
455 int obj_index = cp_to_object_index(cp_index);
456 return resolved_reference_at(obj_index);
457 }
458
459 Symbol* unresolved_string_at(int cp_index) {
460 assert(tag_at(cp_index).is_string(), "Corrupted constant pool");
461 return *symbol_at_addr(cp_index);
462 }
463
464 // Returns an UTF8 for a CONSTANT_String entry at a given index.
465 // UTF8 char* representation was chosen to avoid conversion of
466 // java_lang_Strings at resolved entries into Symbol*s
467 // or vice versa.
468 char* string_at_noresolve(int cp_index);
469
470 jint name_and_type_at(int cp_index) {
471 assert(tag_at(cp_index).is_name_and_type(), "Corrupted constant pool");
472 return *int_at_addr(cp_index);
473 }
474
475 int method_handle_ref_kind_at(int cp_index) {
476 assert(tag_at(cp_index).is_method_handle() ||
477 tag_at(cp_index).is_method_handle_in_error(), "Corrupted constant pool");
478 return extract_low_short_from_int(*int_at_addr(cp_index)); // mask out unwanted ref_index bits
479 }
480 int method_handle_index_at(int cp_index) {
481 assert(tag_at(cp_index).is_method_handle() ||
482 tag_at(cp_index).is_method_handle_in_error(), "Corrupted constant pool");
483 return extract_high_short_from_int(*int_at_addr(cp_index)); // shift out unwanted ref_kind bits
484 }
485 int method_type_index_at(int cp_index) {
486 assert(tag_at(cp_index).is_method_type() ||
487 tag_at(cp_index).is_method_type_in_error(), "Corrupted constant pool");
488 return *int_at_addr(cp_index);
489 }
490
491 // Derived queries:
492 Symbol* method_handle_name_ref_at(int cp_index) {
493 int member = method_handle_index_at(cp_index);
494 return uncached_name_ref_at(member);
495 }
496 Symbol* method_handle_signature_ref_at(int cp_index) {
497 int member = method_handle_index_at(cp_index);
498 return uncached_signature_ref_at(member);
499 }
500 u2 method_handle_klass_index_at(int cp_index) {
501 int member = method_handle_index_at(cp_index);
502 return uncached_klass_ref_index_at(member);
503 }
504 Symbol* method_type_signature_at(int cp_index) {
505 int sym = method_type_index_at(cp_index);
506 return symbol_at(sym);
507 }
508
509 u2 bootstrap_name_and_type_ref_index_at(int cp_index) {
510 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
511 return extract_high_short_from_int(*int_at_addr(cp_index));
512 }
513 u2 bootstrap_methods_attribute_index(int cp_index) {
514 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
515 return extract_low_short_from_int(*int_at_addr(cp_index));
516 }
517 int bootstrap_operand_base(int cp_index) {
518 int bsms_attribute_index = bootstrap_methods_attribute_index(cp_index);
519 return operand_offset_at(operands(), bsms_attribute_index);
520 }
521 // The first part of the operands array consists of an index into the second part.
522 // Extract a 32-bit index value from the first part.
523 static int operand_offset_at(Array<u2>* operands, int bsms_attribute_index) {
524 int n = (bsms_attribute_index * 2);
525 assert(n >= 0 && n+2 <= operands->length(), "oob");
526 // The first 32-bit index points to the beginning of the second part
527 // of the operands array. Make sure this index is in the first part.
528 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0),
529 operands->at(1)));
530 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
531 int offset = build_int_from_shorts(operands->at(n+0),
532 operands->at(n+1));
533 // The offset itself must point into the second part of the array.
534 assert(offset == 0 || (offset >= second_part && offset <= operands->length()), "oob (3)");
535 return offset;
536 }
537 static void operand_offset_at_put(Array<u2>* operands, int bsms_attribute_index, int offset) {
538 int n = bsms_attribute_index * 2;
539 assert(n >= 0 && n+2 <= operands->length(), "oob");
540 operands->at_put(n+0, extract_low_short_from_int(offset));
541 operands->at_put(n+1, extract_high_short_from_int(offset));
542 }
543 static int operand_array_length(Array<u2>* operands) {
544 if (operands == nullptr || operands->length() == 0) return 0;
545 int second_part = operand_offset_at(operands, 0);
546 return (second_part / 2);
547 }
548
549 #ifdef ASSERT
550 // operand tuples fit together exactly, end to end
551 static int operand_limit_at(Array<u2>* operands, int bsms_attribute_index) {
552 int nextidx = bsms_attribute_index + 1;
553 if (nextidx == operand_array_length(operands))
554 return operands->length();
555 else
556 return operand_offset_at(operands, nextidx);
557 }
558 int bootstrap_operand_limit(int cp_index) {
559 int bsms_attribute_index = bootstrap_methods_attribute_index(cp_index);
560 return operand_limit_at(operands(), bsms_attribute_index);
561 }
562 #endif //ASSERT
563
564 // Layout of InvokeDynamic and Dynamic bootstrap method specifier
565 // data in second part of operands array. This encodes one record in
566 // the BootstrapMethods attribute. The whole specifier also includes
567 // the name and type information from the main constant pool entry.
568 enum {
569 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
570 _indy_argc_offset = 1, // u2 argc
571 _indy_argv_offset = 2 // u2 argv[argc]
572 };
573
574 // These functions are used in RedefineClasses for CP merge
575
576 int operand_offset_at(int bsms_attribute_index) {
577 assert(0 <= bsms_attribute_index &&
578 bsms_attribute_index < operand_array_length(operands()),
579 "Corrupted CP operands");
580 return operand_offset_at(operands(), bsms_attribute_index);
581 }
582 u2 operand_bootstrap_method_ref_index_at(int bsms_attribute_index) {
583 int offset = operand_offset_at(bsms_attribute_index);
584 return operands()->at(offset + _indy_bsm_offset);
585 }
586 u2 operand_argument_count_at(int bsms_attribute_index) {
587 int offset = operand_offset_at(bsms_attribute_index);
588 u2 argc = operands()->at(offset + _indy_argc_offset);
589 return argc;
590 }
591 u2 operand_argument_index_at(int bsms_attribute_index, int j) {
592 int offset = operand_offset_at(bsms_attribute_index);
593 return operands()->at(offset + _indy_argv_offset + j);
594 }
595 int operand_next_offset_at(int bsms_attribute_index) {
596 int offset = operand_offset_at(bsms_attribute_index) + _indy_argv_offset
597 + operand_argument_count_at(bsms_attribute_index);
598 return offset;
599 }
600 // Compare a bootstrap specifier data in the operands arrays
601 bool compare_operand_to(int bsms_attribute_index1, const constantPoolHandle& cp2,
602 int bsms_attribute_index2);
603 // Find a bootstrap specifier data in the operands array
604 int find_matching_operand(int bsms_attribute_index, const constantPoolHandle& search_cp,
605 int operands_cur_len);
606 // Resize the operands array with delta_len and delta_size
607 void resize_operands(int delta_len, int delta_size, TRAPS);
608 // Extend the operands array with the length and size of the ext_cp operands
609 void extend_operands(const constantPoolHandle& ext_cp, TRAPS);
610 // Shrink the operands array to a smaller array with new_len length
611 void shrink_operands(int new_len, TRAPS);
612
613 u2 bootstrap_method_ref_index_at(int cp_index) {
614 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
615 int op_base = bootstrap_operand_base(cp_index);
616 return operands()->at(op_base + _indy_bsm_offset);
617 }
618 u2 bootstrap_argument_count_at(int cp_index) {
619 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
620 int op_base = bootstrap_operand_base(cp_index);
621 u2 argc = operands()->at(op_base + _indy_argc_offset);
622 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
623 int next_offset = bootstrap_operand_limit(cp_index));
624 assert(end_offset == next_offset, "matched ending");
625 return argc;
626 }
627 u2 bootstrap_argument_index_at(int cp_index, int j) {
628 int op_base = bootstrap_operand_base(cp_index);
629 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset));
630 assert((uint)j < (uint)argc, "oob");
631 return operands()->at(op_base + _indy_argv_offset + j);
632 }
633
634 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
635 // name_and_type_ref_index_at) all expect to be passed indices obtained
636 // directly from the bytecode.
637 // If the indices are meant to refer to fields or methods, they are
638 // actually rewritten indices that point to entries in their respective structures
639 // i.e. ResolvedMethodEntries or ResolvedFieldEntries.
640 // The routine to_cp_index manages the adjustment
641 // of these values back to constant pool indices.
642
643 // There are also "uncached" versions which do not adjust the operand index; see below.
644
645 // Lookup for entries consisting of (klass_index, name_and_type index)
646 Klass* klass_ref_at(int which, Bytecodes::Code code, TRAPS);
647 Symbol* klass_ref_at_noresolve(int which, Bytecodes::Code code);
648 Symbol* name_ref_at(int which, Bytecodes::Code code) {
649 int name_index = name_ref_index_at(name_and_type_ref_index_at(which, code));
650 return symbol_at(name_index);
651 }
652 Symbol* signature_ref_at(int which, Bytecodes::Code code) {
653 int signature_index = signature_ref_index_at(name_and_type_ref_index_at(which, code));
654 return symbol_at(signature_index);
655 }
656
657 u2 klass_ref_index_at(int which, Bytecodes::Code code);
658 u2 name_and_type_ref_index_at(int which, Bytecodes::Code code);
659
660 constantTag tag_ref_at(int cp_cache_index, Bytecodes::Code code);
661
662 int to_cp_index(int which, Bytecodes::Code code);
663
664 // Lookup for entries consisting of (name_index, signature_index)
665 u2 name_ref_index_at(int cp_index); // == low-order jshort of name_and_type_at(cp_index)
666 u2 signature_ref_index_at(int cp_index); // == high-order jshort of name_and_type_at(cp_index)
667
668 BasicType basic_type_for_signature_at(int cp_index) const;
669
670 // Resolve string constants (to prevent allocation during compilation)
671 void resolve_string_constants(TRAPS) {
672 constantPoolHandle h_this(THREAD, this);
673 resolve_string_constants_impl(h_this, CHECK);
674 }
675
676 #if INCLUDE_CDS
677 // CDS support
678 objArrayOop prepare_resolved_references_for_archiving() NOT_CDS_JAVA_HEAP_RETURN_(nullptr);
679 void add_dumped_interned_strings() NOT_CDS_JAVA_HEAP_RETURN;
680 bool maybe_archive_resolved_klass_at(int cp_index);
681 void remove_unshareable_info();
682 void restore_unshareable_info(TRAPS);
683 #endif
684
685 private:
686 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
687 public:
688
689 // Get the tag for a constant, which may involve a constant dynamic
690 constantTag constant_tag_at(int cp_index);
691 // Get the basic type for a constant, which may involve a constant dynamic
692 BasicType basic_type_for_constant_at(int cp_index);
693
694 // Resolve late bound constants.
695 oop resolve_constant_at(int cp_index, TRAPS) {
696 constantPoolHandle h_this(THREAD, this);
697 return resolve_constant_at_impl(h_this, cp_index, _no_index_sentinel, nullptr, THREAD);
698 }
699
700 oop resolve_cached_constant_at(int cache_index, TRAPS) {
701 constantPoolHandle h_this(THREAD, this);
702 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, nullptr, THREAD);
703 }
704
705 oop resolve_possibly_cached_constant_at(int cp_index, TRAPS) {
706 constantPoolHandle h_this(THREAD, this);
707 return resolve_constant_at_impl(h_this, cp_index, _possible_index_sentinel, nullptr, THREAD);
708 }
709
710 oop find_cached_constant_at(int cp_index, bool& found_it, TRAPS) {
711 constantPoolHandle h_this(THREAD, this);
712 return resolve_constant_at_impl(h_this, cp_index, _possible_index_sentinel, &found_it, THREAD);
713 }
714
715 void copy_bootstrap_arguments_at(int cp_index,
716 int start_arg, int end_arg,
717 objArrayHandle info, int pos,
718 bool must_resolve, Handle if_not_available, TRAPS) {
719 constantPoolHandle h_this(THREAD, this);
720 copy_bootstrap_arguments_at_impl(h_this, cp_index, start_arg, end_arg,
721 info, pos, must_resolve, if_not_available, THREAD);
722 }
723
724 // Klass name matches name at offset
725 bool klass_name_at_matches(const InstanceKlass* k, int cp_index);
726
727 // Sizing
728 int length() const { return _length; }
729 void set_length(int length) { _length = length; }
730
731 // Tells whether index is within bounds.
732 bool is_within_bounds(int index) const {
733 return 0 <= index && index < length();
734 }
735
736 // Sizing (in words)
737 static int header_size() {
738 return align_up((int)sizeof(ConstantPool), wordSize) / wordSize;
739 }
740 static int size(int length) { return align_metadata_size(header_size() + length); }
741 int size() const { return size(length()); }
742
743 // ConstantPools should be stored in the read-only region of CDS archive.
744 static bool is_read_only_by_default() { return true; }
745
746 friend class ClassFileParser;
747 friend class SystemDictionary;
748
749 // Used by CDS. These classes need to access the private ConstantPool() constructor.
750 template <class T> friend class CppVtableTesterA;
751 template <class T> friend class CppVtableTesterB;
752 template <class T> friend class CppVtableCloner;
753
754 // Used by compiler to prevent classloading.
755 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which);
756 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code);
757 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code);
758 static bool has_local_signature_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code);
759 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which);
760
761 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
762 // future by other Java code. These take constant pool indices rather than
763 // constant pool cache indices as do the peer methods above.
764 Symbol* uncached_klass_ref_at_noresolve(int cp_index);
765 Symbol* uncached_name_ref_at(int cp_index) {
766 int name_index = name_ref_index_at(uncached_name_and_type_ref_index_at(cp_index));
767 return symbol_at(name_index);
768 }
769 Symbol* uncached_signature_ref_at(int cp_index) {
770 int signature_index = signature_ref_index_at(uncached_name_and_type_ref_index_at(cp_index));
771 return symbol_at(signature_index);
772 }
773 u2 uncached_klass_ref_index_at(int cp_index);
774 u2 uncached_name_and_type_ref_index_at(int cp_index);
775
776 // Sharing
777 int pre_resolve_shared_klasses(TRAPS);
778
779 // Debugging
780 const char* printable_name_at(int cp_index) PRODUCT_RETURN0;
781
782 private:
783
784 void set_resolved_references(OopHandle s) { _cache->set_resolved_references(s); }
785 Array<u2>* reference_map() const { return (_cache == nullptr) ? nullptr : _cache->reference_map(); }
786 void set_reference_map(Array<u2>* o) { _cache->set_reference_map(o); }
787
788 // Used while constructing constant pool (only by ClassFileParser)
789 jint klass_index_at(int cp_index) {
790 assert(tag_at(cp_index).is_klass_index(), "Corrupted constant pool");
791 return *int_at_addr(cp_index);
792 }
793
794 jint string_index_at(int cp_index) {
795 assert(tag_at(cp_index).is_string_index(), "Corrupted constant pool");
796 return *int_at_addr(cp_index);
797 }
798
799 // Performs the LinkResolver checks
800 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* klass, TRAPS);
801
802 // Implementation of methods that needs an exposed 'this' pointer, in order to
803 // handle GC while executing the method
804 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int cp_index, TRAPS);
805 static oop string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS);
806
807 static void trace_class_resolution(const constantPoolHandle& this_cp, Klass* k);
808
809 // Resolve string constants (to prevent allocation during compilation)
810 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS);
811
812 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int cp_index, int cache_index,
813 bool* status_return, TRAPS);
814 static void copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index,
815 int start_arg, int end_arg,
816 objArrayHandle info, int pos,
817 bool must_resolve, Handle if_not_available, TRAPS);
818
819 // Exception handling
820 static void save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index, constantTag tag, TRAPS);
821
822 public:
823 // Exception handling
824 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS);
825
826 // Merging ConstantPool* support:
827 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2);
828 void copy_cp_to(int start_cpi, int end_cpi, const constantPoolHandle& to_cp, int to_cpi, TRAPS) {
829 constantPoolHandle h_this(THREAD, this);
830 copy_cp_to_impl(h_this, start_cpi, end_cpi, to_cp, to_cpi, THREAD);
831 }
832 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_cpi, int end_cpi, const constantPoolHandle& to_cp, int to_cpi, TRAPS);
833 static void copy_entry_to(const constantPoolHandle& from_cp, int from_cpi, const constantPoolHandle& to_cp, int to_cpi);
834 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS);
835 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp);
836 int version() const { return _saved._version; }
837 void set_version(int version) { _saved._version = version; }
838 void increment_and_save_version(int version) {
839 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow
840 }
841
842 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; }
843 int resolved_reference_length() const { return _saved._resolved_reference_length; }
844
845 // Decrease ref counts of symbols that are in the constant pool
846 // when the holder class is unloaded
847 void unreference_symbols();
848
849 // Deallocate constant pool for RedefineClasses
850 void deallocate_contents(ClassLoaderData* loader_data);
851 void release_C_heap_structures();
852
853 // JVMTI access - GetConstantPool, RetransformClasses, ...
854 friend class JvmtiConstantPoolReconstituter;
855
856 private:
857 class SymbolHash: public CHeapObj<mtSymbol> {
858 ResourceHashtable<const Symbol*, u2, 256, AnyObj::C_HEAP, mtSymbol, Symbol::compute_hash> _table;
859
860 public:
861 void add_if_absent(const Symbol* sym, u2 value) {
862 bool created;
863 _table.put_if_absent(sym, value, &created);
864 }
865
866 u2 symbol_to_value(const Symbol* sym) {
867 u2* value = _table.get(sym);
868 return (value == nullptr) ? 0 : *value;
869 }
870 }; // End SymbolHash class
871
872 jint cpool_entry_size(jint idx);
873 jint hash_entries_to(SymbolHash *symmap, SymbolHash *classmap);
874
875 // Copy cpool bytes into byte array.
876 // Returns:
877 // int > 0, count of the raw cpool bytes that have been copied
878 // 0, OutOfMemory error
879 // -1, Internal error
880 int copy_cpool_bytes(int cpool_size,
881 SymbolHash* tbl,
882 unsigned char *bytes);
883
884 public:
885 // Verify
886 void verify_on(outputStream* st);
887
888 // Printing
889 void print_on(outputStream* st) const;
890 void print_value_on(outputStream* st) const;
891 void print_entry_on(int index, outputStream* st);
892
893 const char* internal_name() const { return "{constant pool}"; }
894
895 // ResolvedFieldEntry getters
896 inline ResolvedFieldEntry* resolved_field_entry_at(int field_index);
897 inline int resolved_field_entries_length() const;
898
899 // ResolvedMethodEntry getters
900 inline ResolvedMethodEntry* resolved_method_entry_at(int method_index);
901 inline int resolved_method_entries_length() const;
902 inline oop appendix_if_resolved(int method_index) const;
903
904 // ResolvedIndyEntry getters
905 inline ResolvedIndyEntry* resolved_indy_entry_at(int index);
906 inline int resolved_indy_entries_length() const;
907 inline oop resolved_reference_from_indy(int index) const;
908 inline oop resolved_reference_from_method(int index) const;
909 };
910
911 #endif // SHARE_OOPS_CONSTANTPOOL_HPP