1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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/macros.hpp"
41 #include "utilities/resourceHash.hpp"
42
43 // A ConstantPool is an array containing class constants as described in the
44 // class file.
45 //
46 // Most of the constant pool entries are written during class parsing, which
47 // is safe. For klass types, the constant pool entry is
48 // modified when the entry is resolved. If a klass constant pool
49 // entry is read without a lock, only the resolved state guarantees that
50 // the entry in the constant pool is a klass object and not a Symbol*.
51
52 // This represents a JVM_CONSTANT_Class, JVM_CONSTANT_UnresolvedClass, or
53 // JVM_CONSTANT_UnresolvedClassInError slot in the constant pool.
54 class CPKlassSlot {
55 // cp->symbol_at(_name_index) gives the name of the class.
56 int _name_index;
57
58 // cp->_resolved_klasses->at(_resolved_klass_index) gives the Klass* for the class.
59 int _resolved_klass_index;
60 public:
61 enum {
62 // This is used during constant pool merging where the resolved klass index is
63 // not yet known, and will be computed at a later stage (during a call to
64 // initialize_unresolved_klasses()).
65 _temp_resolved_klass_index = 0xffff
66 };
67 CPKlassSlot(int n, int rk) {
68 _name_index = n;
69 _resolved_klass_index = rk;
70 }
71 int name_index() const {
72 return _name_index;
73 }
74 int resolved_klass_index() const {
75 assert(_resolved_klass_index != _temp_resolved_klass_index, "constant pool merging was incomplete");
76 return _resolved_klass_index;
77 }
78 };
79
80 class ConstantPool : public Metadata {
81 friend class VMStructs;
82 friend class JVMCIVMStructs;
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 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
93
94 // Consider using an array of compressed klass pointers to
95 // save space on 64-bit platforms.
96 Array<Klass*>* _resolved_klasses;
97
98 u2 _major_version; // major version number of class file
99 u2 _minor_version; // minor version number of class file
100
101 // Constant pool index to the utf8 entry of the Generic signature,
102 // or 0 if none.
103 u2 _generic_signature_index;
104 // Constant pool index to the utf8 entry for the name of source file
105 // containing this klass, 0 if not specified.
106 u2 _source_file_name_index;
107
108 enum {
109 _has_preresolution = 1, // Flags
110 _on_stack = 2,
111 _is_shared = 4,
112 _has_dynamic_constant = 8,
113 _is_for_method_handle_intrinsic = 16
114 };
115
116 u2 _flags; // old fashioned bit twiddling
117
118 int _length; // number of elements in the array
119
120 union {
121 // set for CDS to restore resolved references
122 int _resolved_reference_length;
123 // keeps version number for redefined classes (used in backtrace)
124 int _version;
125 } _saved;
126
127 void set_tags(Array<u1>* tags) { _tags = tags; }
128 void tag_at_put(int cp_index, jbyte t) { tags()->at_put(cp_index, t); }
129 void release_tag_at_put(int cp_index, jbyte t) { tags()->release_at_put(cp_index, t); }
130
131 u1* tag_addr_at(int cp_index) const { return tags()->adr_at(cp_index); }
132
133 void set_operands(Array<u2>* operands) { _operands = operands; }
134
135 u2 flags() const { return _flags; }
136 void set_flags(u2 f) { _flags = f; }
137
138 private:
139 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); }
140
141 intptr_t* obj_at_addr(int cp_index) const {
142 assert(is_within_bounds(cp_index), "index out of bounds");
143 return (intptr_t*) &base()[cp_index];
144 }
145
146 jint* int_at_addr(int cp_index) const {
147 assert(is_within_bounds(cp_index), "index out of bounds");
148 return (jint*) &base()[cp_index];
149 }
150
151 jlong* long_at_addr(int cp_index) const {
152 assert(is_within_bounds(cp_index), "index out of bounds");
153 return (jlong*) &base()[cp_index];
154 }
155
156 jfloat* float_at_addr(int cp_index) const {
157 assert(is_within_bounds(cp_index), "index out of bounds");
158 return (jfloat*) &base()[cp_index];
159 }
160
161 jdouble* double_at_addr(int cp_index) const {
162 assert(is_within_bounds(cp_index), "index out of bounds");
163 return (jdouble*) &base()[cp_index];
164 }
165 static void check_and_add_dumped_interned_string(oop obj);
166
167 ConstantPool(Array<u1>* tags);
168 ConstantPool();
169 public:
170 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS);
171
172 virtual bool is_constantPool() const { return true; }
173
174 Array<u1>* tags() const { return _tags; }
175 Array<u2>* operands() const { return _operands; }
176
177 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; }
178 void set_has_preresolution() {
179 assert(!is_shared(), "should never be called on shared ConstantPools");
180 _flags |= _has_preresolution;
181 }
182
183 // minor and major version numbers of class file
184 u2 major_version() const { return _major_version; }
185 void set_major_version(u2 major_version) { _major_version = major_version; }
186 u2 minor_version() const { return _minor_version; }
187 void set_minor_version(u2 minor_version) { _minor_version = minor_version; }
188
189 // generics support
190 Symbol* generic_signature() const {
191 return (_generic_signature_index == 0) ?
192 nullptr : symbol_at(_generic_signature_index);
193 }
194 u2 generic_signature_index() const { return _generic_signature_index; }
195 void set_generic_signature_index(u2 sig_index) { _generic_signature_index = sig_index; }
196
197 // source file name
198 Symbol* source_file_name() const {
199 return (_source_file_name_index == 0) ?
200 nullptr : symbol_at(_source_file_name_index);
201 }
202 u2 source_file_name_index() const { return _source_file_name_index; }
203 void set_source_file_name_index(u2 sourcefile_index) { _source_file_name_index = sourcefile_index; }
204
205 void copy_fields(const ConstantPool* orig);
206
207 // Redefine classes support. If a method referring to this constant pool
208 // is on the executing stack, or as a handle in vm code, this constant pool
209 // can't be removed from the set of previous versions saved in the instance
210 // class.
211 bool on_stack() const;
212 bool is_maybe_on_stack() const;
213 void set_on_stack(const bool value);
214
215 // Faster than MetaspaceObj::is_shared() - used by set_on_stack()
216 bool is_shared() const { return (_flags & _is_shared) != 0; }
217
218 bool has_dynamic_constant() const { return (_flags & _has_dynamic_constant) != 0; }
219 void set_has_dynamic_constant() { _flags |= _has_dynamic_constant; }
220
221 bool is_for_method_handle_intrinsic() const { return (_flags & _is_for_method_handle_intrinsic) != 0; }
222 void set_is_for_method_handle_intrinsic() { _flags |= _is_for_method_handle_intrinsic; }
223
224 // Klass holding pool
225 InstanceKlass* pool_holder() const { return _pool_holder; }
226 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; }
227 InstanceKlass** pool_holder_addr() { return &_pool_holder; }
228
229 // Interpreter runtime support
230 ConstantPoolCache* cache() const { return _cache; }
231 void set_cache(ConstantPoolCache* cache){ _cache = cache; }
232
233 virtual void metaspace_pointers_do(MetaspaceClosure* iter);
234 virtual MetaspaceObj::Type type() const { return ConstantPoolType; }
235
236 // Create object cache in the constant pool
237 void initialize_resolved_references(ClassLoaderData* loader_data,
238 const intStack& reference_map,
239 int constant_pool_map_length,
240 TRAPS);
241
242 // resolved strings, methodHandles and callsite objects from the constant pool
243 objArrayOop resolved_references() const;
244 objArrayOop resolved_references_or_null() const;
245 oop resolved_reference_at(int obj_index) const;
246 oop set_resolved_reference_at(int index, oop new_value);
247
248 // mapping resolved object array indexes to cp indexes and back.
249 int object_to_cp_index(int index) { return reference_map()->at(index); }
250 int cp_to_object_index(int index);
251
252 void set_resolved_klasses(Array<Klass*>* rk) { _resolved_klasses = rk; }
253 Array<Klass*>* resolved_klasses() const { return _resolved_klasses; }
254 void allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS);
255 void initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS);
256
257 // Given the per-instruction index of an indy instruction, report the
258 // main constant pool entry for its bootstrap specifier.
259 // From there, uncached_name/signature_ref_at will get the name/type.
260 inline u2 invokedynamic_bootstrap_ref_index_at(int indy_index) const;
261
262 // Assembly code support
263 static ByteSize tags_offset() { return byte_offset_of(ConstantPool, _tags); }
264 static ByteSize cache_offset() { return byte_offset_of(ConstantPool, _cache); }
265 static ByteSize pool_holder_offset() { return byte_offset_of(ConstantPool, _pool_holder); }
266 static ByteSize resolved_klasses_offset() { return byte_offset_of(ConstantPool, _resolved_klasses); }
267
268 // Storing constants
269
270 // For temporary use while constructing constant pool. Used during a retransform/class redefinition as well.
271 void klass_index_at_put(int cp_index, int name_index) {
272 tag_at_put(cp_index, JVM_CONSTANT_ClassIndex);
273 *int_at_addr(cp_index) = name_index;
274 }
275
276 // Hidden class support:
277 void klass_at_put(int class_index, Klass* k);
278
279 void unresolved_klass_at_put(int cp_index, int name_index, int resolved_klass_index) {
280 release_tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
281
282 assert((name_index & 0xffff0000) == 0, "must be");
283 assert((resolved_klass_index & 0xffff0000) == 0, "must be");
284 *int_at_addr(cp_index) =
285 build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
286 }
287
288 void method_handle_index_at_put(int cp_index, int ref_kind, int ref_index) {
289 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle);
290 *int_at_addr(cp_index) = ((jint) ref_index<<16) | ref_kind;
291 }
292
293 void method_type_index_at_put(int cp_index, int ref_index) {
294 tag_at_put(cp_index, JVM_CONSTANT_MethodType);
295 *int_at_addr(cp_index) = ref_index;
296 }
297
298 void dynamic_constant_at_put(int cp_index, int bsms_attribute_index, int name_and_type_index) {
299 tag_at_put(cp_index, JVM_CONSTANT_Dynamic);
300 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | bsms_attribute_index;
301 }
302
303 void invoke_dynamic_at_put(int cp_index, int bsms_attribute_index, int name_and_type_index) {
304 tag_at_put(cp_index, JVM_CONSTANT_InvokeDynamic);
305 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | bsms_attribute_index;
306 }
307
308 void unresolved_string_at_put(int cp_index, Symbol* s) {
309 assert(s->refcount() != 0, "should have nonzero refcount");
310 // Note that release_tag_at_put is not needed here because this is called only
311 // when constructing a ConstantPool in a single thread, with no possibility
312 // of concurrent access.
313 tag_at_put(cp_index, JVM_CONSTANT_String);
314 *symbol_at_addr(cp_index) = s;
315 }
316
317 void int_at_put(int cp_index, jint i) {
318 tag_at_put(cp_index, JVM_CONSTANT_Integer);
319 *int_at_addr(cp_index) = i;
320 }
321
322 void long_at_put(int cp_index, jlong l) {
323 tag_at_put(cp_index, JVM_CONSTANT_Long);
324 // *long_at_addr(which) = l;
325 Bytes::put_native_u8((address)long_at_addr(cp_index), *((u8*) &l));
326 }
327
328 void float_at_put(int cp_index, jfloat f) {
329 tag_at_put(cp_index, JVM_CONSTANT_Float);
330 *float_at_addr(cp_index) = f;
331 }
332
333 void double_at_put(int cp_index, jdouble d) {
334 tag_at_put(cp_index, JVM_CONSTANT_Double);
335 // *double_at_addr(which) = d;
336 // u8 temp = *(u8*) &d;
337 Bytes::put_native_u8((address) double_at_addr(cp_index), *((u8*) &d));
338 }
339
340 Symbol** symbol_at_addr(int cp_index) const {
341 assert(is_within_bounds(cp_index), "index out of bounds");
342 return (Symbol**) &base()[cp_index];
343 }
344
345 void symbol_at_put(int cp_index, Symbol* s) {
346 assert(s->refcount() != 0, "should have nonzero refcount");
347 tag_at_put(cp_index, JVM_CONSTANT_Utf8);
348 *symbol_at_addr(cp_index) = s;
349 }
350
351 void string_at_put(int obj_index, oop str);
352
353 // For temporary use while constructing constant pool
354 void string_index_at_put(int cp_index, int string_index) {
355 tag_at_put(cp_index, JVM_CONSTANT_StringIndex);
356 *int_at_addr(cp_index) = string_index;
357 }
358
359 void field_at_put(int cp_index, int class_index, int name_and_type_index) {
360 tag_at_put(cp_index, JVM_CONSTANT_Fieldref);
361 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index;
362 }
363
364 void method_at_put(int cp_index, int class_index, int name_and_type_index) {
365 tag_at_put(cp_index, JVM_CONSTANT_Methodref);
366 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index;
367 }
368
369 void interface_method_at_put(int cp_index, int class_index, int name_and_type_index) {
370 tag_at_put(cp_index, JVM_CONSTANT_InterfaceMethodref);
371 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
372 }
373
374 void name_and_type_at_put(int cp_index, int name_index, int signature_index) {
375 tag_at_put(cp_index, JVM_CONSTANT_NameAndType);
376 *int_at_addr(cp_index) = ((jint) signature_index<<16) | name_index; // Not so nice
377 }
378
379 // Tag query
380
381 constantTag tag_at(int cp_index) const { return (constantTag)tags()->at_acquire(cp_index); }
382
383 // Fetching constants
384
385 Klass* klass_at(int cp_index, TRAPS) {
386 constantPoolHandle h_this(THREAD, this);
387 return klass_at_impl(h_this, cp_index, THREAD);
388 }
389
390 CPKlassSlot klass_slot_at(int cp_index) const {
391 assert(tag_at(cp_index).is_unresolved_klass() || tag_at(cp_index).is_klass(),
392 "Corrupted constant pool");
393 int value = *int_at_addr(cp_index);
394 int name_index = extract_high_short_from_int(value);
395 int resolved_klass_index = extract_low_short_from_int(value);
396 return CPKlassSlot(name_index, resolved_klass_index);
397 }
398
399 Symbol* klass_name_at(int cp_index) const; // Returns the name, w/o resolving.
400 int klass_name_index_at(int cp_index) const {
401 return klass_slot_at(cp_index).name_index();
402 }
403
404 Klass* resolved_klass_at(int cp_index) const; // Used by Compiler
405
406 // RedefineClasses() API support:
407 Symbol* klass_at_noresolve(int cp_index) { return klass_name_at(cp_index); }
408 void temp_unresolved_klass_at_put(int cp_index, int name_index) {
409 // Used only during constant pool merging for class redefinition. The resolved klass index
410 // will be initialized later by a call to initialize_unresolved_klasses().
411 unresolved_klass_at_put(cp_index, name_index, CPKlassSlot::_temp_resolved_klass_index);
412 }
413
414 jint int_at(int cp_index) const {
415 assert(tag_at(cp_index).is_int(), "Corrupted constant pool");
416 return *int_at_addr(cp_index);
417 }
418
419 jlong long_at(int cp_index) {
420 assert(tag_at(cp_index).is_long(), "Corrupted constant pool");
421 // return *long_at_addr(cp_index);
422 u8 tmp = Bytes::get_native_u8((address)&base()[cp_index]);
423 return *((jlong*)&tmp);
424 }
425
426 jfloat float_at(int cp_index) {
427 assert(tag_at(cp_index).is_float(), "Corrupted constant pool");
428 return *float_at_addr(cp_index);
429 }
430
431 jdouble double_at(int cp_index) {
432 assert(tag_at(cp_index).is_double(), "Corrupted constant pool");
433 u8 tmp = Bytes::get_native_u8((address)&base()[cp_index]);
434 return *((jdouble*)&tmp);
435 }
436
437 Symbol* symbol_at(int cp_index) const {
438 assert(tag_at(cp_index).is_utf8(), "Corrupted constant pool");
439 return *symbol_at_addr(cp_index);
440 }
441
442 oop string_at(int cp_index, int obj_index, TRAPS) {
443 constantPoolHandle h_this(THREAD, this);
444 return string_at_impl(h_this, cp_index, obj_index, THREAD);
445 }
446 oop string_at(int cp_index, TRAPS) {
447 int obj_index = cp_to_object_index(cp_index);
448 return string_at(cp_index, obj_index, THREAD);
449 }
450
451 // Version that can be used before string oop array is created.
452 oop uncached_string_at(int cp_index, TRAPS);
453
454 // only called when we are sure a string entry is already resolved (via an
455 // earlier string_at call.
456 oop resolved_string_at(int cp_index) {
457 assert(tag_at(cp_index).is_string(), "Corrupted constant pool");
458 // Must do an acquire here in case another thread resolved the klass
459 // behind our back, lest we later load stale values thru the oop.
460 // we might want a volatile_obj_at in ObjArrayKlass.
461 int obj_index = cp_to_object_index(cp_index);
462 return resolved_reference_at(obj_index);
463 }
464
465 Symbol* unresolved_string_at(int cp_index) {
466 assert(tag_at(cp_index).is_string(), "Corrupted constant pool");
467 return *symbol_at_addr(cp_index);
468 }
469
470 // Returns an UTF8 for a CONSTANT_String entry at a given index.
471 // UTF8 char* representation was chosen to avoid conversion of
472 // java_lang_Strings at resolved entries into Symbol*s
473 // or vice versa.
474 char* string_at_noresolve(int cp_index);
475
476 jint name_and_type_at(int cp_index) {
477 assert(tag_at(cp_index).is_name_and_type(), "Corrupted constant pool");
478 return *int_at_addr(cp_index);
479 }
480
481 int method_handle_ref_kind_at(int cp_index) {
482 assert(tag_at(cp_index).is_method_handle() ||
483 tag_at(cp_index).is_method_handle_in_error(), "Corrupted constant pool");
484 return extract_low_short_from_int(*int_at_addr(cp_index)); // mask out unwanted ref_index bits
485 }
486 int method_handle_index_at(int cp_index) {
487 assert(tag_at(cp_index).is_method_handle() ||
488 tag_at(cp_index).is_method_handle_in_error(), "Corrupted constant pool");
489 return extract_high_short_from_int(*int_at_addr(cp_index)); // shift out unwanted ref_kind bits
490 }
491 int method_type_index_at(int cp_index) {
492 assert(tag_at(cp_index).is_method_type() ||
493 tag_at(cp_index).is_method_type_in_error(), "Corrupted constant pool");
494 return *int_at_addr(cp_index);
495 }
496
497 // Derived queries:
498 Symbol* method_handle_name_ref_at(int cp_index) {
499 int member = method_handle_index_at(cp_index);
500 return uncached_name_ref_at(member);
501 }
502 Symbol* method_handle_signature_ref_at(int cp_index) {
503 int member = method_handle_index_at(cp_index);
504 return uncached_signature_ref_at(member);
505 }
506 u2 method_handle_klass_index_at(int cp_index) {
507 int member = method_handle_index_at(cp_index);
508 return uncached_klass_ref_index_at(member);
509 }
510 Symbol* method_type_signature_at(int cp_index) {
511 int sym = method_type_index_at(cp_index);
512 return symbol_at(sym);
513 }
514
515 u2 bootstrap_name_and_type_ref_index_at(int cp_index) {
516 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
517 return extract_high_short_from_int(*int_at_addr(cp_index));
518 }
519 u2 bootstrap_methods_attribute_index(int cp_index) {
520 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
521 return extract_low_short_from_int(*int_at_addr(cp_index));
522 }
523 int bootstrap_operand_base(int cp_index) {
524 int bsms_attribute_index = bootstrap_methods_attribute_index(cp_index);
525 return operand_offset_at(operands(), bsms_attribute_index);
526 }
527 // The first part of the operands array consists of an index into the second part.
528 // Extract a 32-bit index value from the first part.
529 static int operand_offset_at(Array<u2>* operands, int bsms_attribute_index) {
530 int n = (bsms_attribute_index * 2);
531 assert(n >= 0 && n+2 <= operands->length(), "oob");
532 // The first 32-bit index points to the beginning of the second part
533 // of the operands array. Make sure this index is in the first part.
534 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0),
535 operands->at(1)));
536 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
537 int offset = build_int_from_shorts(operands->at(n+0),
538 operands->at(n+1));
539 // The offset itself must point into the second part of the array.
540 assert(offset == 0 || (offset >= second_part && offset <= operands->length()), "oob (3)");
541 return offset;
542 }
543 static void operand_offset_at_put(Array<u2>* operands, int bsms_attribute_index, int offset) {
544 int n = bsms_attribute_index * 2;
545 assert(n >= 0 && n+2 <= operands->length(), "oob");
546 operands->at_put(n+0, extract_low_short_from_int(offset));
547 operands->at_put(n+1, extract_high_short_from_int(offset));
548 }
549 static int operand_array_length(Array<u2>* operands) {
550 if (operands == nullptr || operands->length() == 0) return 0;
551 int second_part = operand_offset_at(operands, 0);
552 return (second_part / 2);
553 }
554
555 #ifdef ASSERT
556 // operand tuples fit together exactly, end to end
557 static int operand_limit_at(Array<u2>* operands, int bsms_attribute_index) {
558 int nextidx = bsms_attribute_index + 1;
559 if (nextidx == operand_array_length(operands))
560 return operands->length();
561 else
562 return operand_offset_at(operands, nextidx);
563 }
564 int bootstrap_operand_limit(int cp_index) {
565 int bsms_attribute_index = bootstrap_methods_attribute_index(cp_index);
566 return operand_limit_at(operands(), bsms_attribute_index);
567 }
568 #endif //ASSERT
569
570 // Layout of InvokeDynamic and Dynamic bootstrap method specifier
571 // data in second part of operands array. This encodes one record in
572 // the BootstrapMethods attribute. The whole specifier also includes
573 // the name and type information from the main constant pool entry.
574 enum {
575 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
576 _indy_argc_offset = 1, // u2 argc
577 _indy_argv_offset = 2 // u2 argv[argc]
578 };
579
580 // These functions are used in RedefineClasses for CP merge
581
582 int operand_offset_at(int bsms_attribute_index) {
583 assert(0 <= bsms_attribute_index &&
584 bsms_attribute_index < operand_array_length(operands()),
585 "Corrupted CP operands");
586 return operand_offset_at(operands(), bsms_attribute_index);
587 }
588 u2 operand_bootstrap_method_ref_index_at(int bsms_attribute_index) {
589 int offset = operand_offset_at(bsms_attribute_index);
590 return operands()->at(offset + _indy_bsm_offset);
591 }
592 u2 operand_argument_count_at(int bsms_attribute_index) {
593 int offset = operand_offset_at(bsms_attribute_index);
594 u2 argc = operands()->at(offset + _indy_argc_offset);
595 return argc;
596 }
597 u2 operand_argument_index_at(int bsms_attribute_index, int j) {
598 int offset = operand_offset_at(bsms_attribute_index);
599 return operands()->at(offset + _indy_argv_offset + j);
600 }
601 int operand_next_offset_at(int bsms_attribute_index) {
602 int offset = operand_offset_at(bsms_attribute_index) + _indy_argv_offset
603 + operand_argument_count_at(bsms_attribute_index);
604 return offset;
605 }
606 // Compare a bootstrap specifier data in the operands arrays
607 bool compare_operand_to(int bsms_attribute_index1, const constantPoolHandle& cp2,
608 int bsms_attribute_index2);
609 // Find a bootstrap specifier data in the operands array
610 int find_matching_operand(int bsms_attribute_index, const constantPoolHandle& search_cp,
611 int operands_cur_len);
612 // Resize the operands array with delta_len and delta_size
613 void resize_operands(int delta_len, int delta_size, TRAPS);
614 // Extend the operands array with the length and size of the ext_cp operands
615 void extend_operands(const constantPoolHandle& ext_cp, TRAPS);
616 // Shrink the operands array to a smaller array with new_len length
617 void shrink_operands(int new_len, TRAPS);
618
619 u2 bootstrap_method_ref_index_at(int cp_index) {
620 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
621 int op_base = bootstrap_operand_base(cp_index);
622 return operands()->at(op_base + _indy_bsm_offset);
623 }
624 u2 bootstrap_argument_count_at(int cp_index) {
625 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
626 int op_base = bootstrap_operand_base(cp_index);
627 u2 argc = operands()->at(op_base + _indy_argc_offset);
628 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
629 int next_offset = bootstrap_operand_limit(cp_index));
630 assert(end_offset == next_offset, "matched ending");
631 return argc;
632 }
633 u2 bootstrap_argument_index_at(int cp_index, int j) {
634 int op_base = bootstrap_operand_base(cp_index);
635 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset));
636 assert((uint)j < (uint)argc, "oob");
637 return operands()->at(op_base + _indy_argv_offset + j);
638 }
639
640 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
641 // name_and_type_ref_index_at) all expect to be passed indices obtained
642 // directly from the bytecode.
643 // If the indices are meant to refer to fields or methods, they are
644 // actually rewritten indices that point to entries in their respective structures
645 // i.e. ResolvedMethodEntries or ResolvedFieldEntries.
646 // The routine to_cp_index manages the adjustment
647 // of these values back to constant pool indices.
648
649 // There are also "uncached" versions which do not adjust the operand index; see below.
650
651 // Lookup for entries consisting of (klass_index, name_and_type index)
652 Klass* klass_ref_at(int which, Bytecodes::Code code, TRAPS);
653 Symbol* klass_ref_at_noresolve(int which, Bytecodes::Code code);
654 Symbol* name_ref_at(int which, Bytecodes::Code code) {
655 int name_index = name_ref_index_at(name_and_type_ref_index_at(which, code));
656 return symbol_at(name_index);
657 }
658 Symbol* signature_ref_at(int which, Bytecodes::Code code) {
659 int signature_index = signature_ref_index_at(name_and_type_ref_index_at(which, code));
660 return symbol_at(signature_index);
661 }
662
663 u2 klass_ref_index_at(int which, Bytecodes::Code code);
664 u2 name_and_type_ref_index_at(int which, Bytecodes::Code code);
665
666 constantTag tag_ref_at(int cp_cache_index, Bytecodes::Code code);
667
668 int to_cp_index(int which, Bytecodes::Code code);
669
670 bool is_resolved(int which, Bytecodes::Code code);
671
672 // Lookup for entries consisting of (name_index, signature_index)
673 u2 name_ref_index_at(int cp_index); // == low-order jshort of name_and_type_at(cp_index)
674 u2 signature_ref_index_at(int cp_index); // == high-order jshort of name_and_type_at(cp_index)
675
676 BasicType basic_type_for_signature_at(int cp_index) const;
677
678 // Resolve string constants (to prevent allocation during compilation)
679 void resolve_string_constants(TRAPS) {
680 constantPoolHandle h_this(THREAD, this);
681 resolve_string_constants_impl(h_this, CHECK);
682 }
683
684 #if INCLUDE_CDS
685 // CDS support
686 objArrayOop prepare_resolved_references_for_archiving() NOT_CDS_JAVA_HEAP_RETURN_(nullptr);
687 void add_dumped_interned_strings() NOT_CDS_JAVA_HEAP_RETURN;
688 void remove_unshareable_info();
689 void restore_unshareable_info(TRAPS);
690 private:
691 void remove_unshareable_entries();
692 void remove_resolved_klass_if_non_deterministic(int cp_index);
693 template <typename Function> void iterate_archivable_resolved_references(Function function);
694 #endif
695
696 private:
697 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
698 public:
699
700 // Get the tag for a constant, which may involve a constant dynamic
701 constantTag constant_tag_at(int cp_index);
702 // Get the basic type for a constant, which may involve a constant dynamic
703 BasicType basic_type_for_constant_at(int cp_index);
704
705 // Resolve late bound constants.
706 oop resolve_constant_at(int cp_index, TRAPS) {
707 constantPoolHandle h_this(THREAD, this);
708 return resolve_constant_at_impl(h_this, cp_index, _no_index_sentinel, nullptr, THREAD);
709 }
710
711 oop resolve_cached_constant_at(int cache_index, TRAPS) {
712 constantPoolHandle h_this(THREAD, this);
713 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, nullptr, THREAD);
714 }
715
716 oop resolve_possibly_cached_constant_at(int cp_index, TRAPS) {
717 constantPoolHandle h_this(THREAD, this);
718 return resolve_constant_at_impl(h_this, cp_index, _possible_index_sentinel, nullptr, THREAD);
719 }
720
721 oop find_cached_constant_at(int cp_index, bool& found_it, TRAPS) {
722 constantPoolHandle h_this(THREAD, this);
723 return resolve_constant_at_impl(h_this, cp_index, _possible_index_sentinel, &found_it, THREAD);
724 }
725
726 void copy_bootstrap_arguments_at(int cp_index,
727 int start_arg, int end_arg,
728 objArrayHandle info, int pos,
729 bool must_resolve, Handle if_not_available, TRAPS) {
730 constantPoolHandle h_this(THREAD, this);
731 copy_bootstrap_arguments_at_impl(h_this, cp_index, start_arg, end_arg,
732 info, pos, must_resolve, if_not_available, THREAD);
733 }
734
735 // Klass name matches name at offset
736 bool klass_name_at_matches(const InstanceKlass* k, int cp_index);
737
738 // Sizing
739 int length() const { return _length; }
740 void set_length(int length) { _length = length; }
741
742 // Tells whether index is within bounds.
743 bool is_within_bounds(int index) const {
744 return 0 <= index && index < length();
745 }
746
747 // Sizing (in words)
748 static int header_size() {
749 return align_up((int)sizeof(ConstantPool), wordSize) / wordSize;
750 }
751 static int size(int length) { return align_metadata_size(header_size() + length); }
752 int size() const { return size(length()); }
753
754 // ConstantPools should be stored in the read-only region of CDS archive.
755 static bool is_read_only_by_default() { return true; }
756
757 friend class ClassFileParser;
758 friend class SystemDictionary;
759
760 // Used by CDS. These classes need to access the private ConstantPool() constructor.
761 template <class T> friend class CppVtableTesterA;
762 template <class T> friend class CppVtableTesterB;
763 template <class T> friend class CppVtableCloner;
764
765 // Used by compiler to prevent classloading.
766 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which);
767 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code);
768 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code);
769 static bool has_local_signature_at_if_loaded (const constantPoolHandle& this_cp, int which, Bytecodes::Code code);
770 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which);
771
772 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
773 // future by other Java code. These take constant pool indices rather than
774 // constant pool cache indices as do the peer methods above.
775 Symbol* uncached_klass_ref_at_noresolve(int cp_index);
776 Symbol* uncached_name_ref_at(int cp_index) {
777 int name_index = name_ref_index_at(uncached_name_and_type_ref_index_at(cp_index));
778 return symbol_at(name_index);
779 }
780 Symbol* uncached_signature_ref_at(int cp_index) {
781 int signature_index = signature_ref_index_at(uncached_name_and_type_ref_index_at(cp_index));
782 return symbol_at(signature_index);
783 }
784 u2 uncached_klass_ref_index_at(int cp_index);
785 u2 uncached_name_and_type_ref_index_at(int cp_index);
786
787 // Sharing
788 int pre_resolve_shared_klasses(TRAPS);
789
790 // Debugging
791 const char* printable_name_at(int cp_index) PRODUCT_RETURN_NULL;
792
793 private:
794
795 void set_resolved_references(OopHandle s) { _cache->set_resolved_references(s); }
796 Array<u2>* reference_map() const { return (_cache == nullptr) ? nullptr : _cache->reference_map(); }
797 void set_reference_map(Array<u2>* o) { _cache->set_reference_map(o); }
798
799 // Used while constructing constant pool (only by ClassFileParser)
800 jint klass_index_at(int cp_index) {
801 assert(tag_at(cp_index).is_klass_index(), "Corrupted constant pool");
802 return *int_at_addr(cp_index);
803 }
804
805 jint string_index_at(int cp_index) {
806 assert(tag_at(cp_index).is_string_index(), "Corrupted constant pool");
807 return *int_at_addr(cp_index);
808 }
809
810 // Performs the LinkResolver checks
811 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* klass, TRAPS);
812
813 // Implementation of methods that needs an exposed 'this' pointer, in order to
814 // handle GC while executing the method
815 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int cp_index, TRAPS);
816 static oop string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS);
817
818 static void trace_class_resolution(const constantPoolHandle& this_cp, Klass* k);
819
820 // Resolve string constants (to prevent allocation during compilation)
821 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS);
822
823 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int cp_index, int cache_index,
824 bool* status_return, TRAPS);
825 static void copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index,
826 int start_arg, int end_arg,
827 objArrayHandle info, int pos,
828 bool must_resolve, Handle if_not_available, TRAPS);
829
830 // Exception handling
831 static void save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index, constantTag tag, TRAPS);
832
833 public:
834 // Exception handling
835 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS);
836
837 // Merging ConstantPool* support:
838 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2);
839 void copy_cp_to(int start_cpi, int end_cpi, const constantPoolHandle& to_cp, int to_cpi, TRAPS) {
840 constantPoolHandle h_this(THREAD, this);
841 copy_cp_to_impl(h_this, start_cpi, end_cpi, to_cp, to_cpi, THREAD);
842 }
843 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_cpi, int end_cpi, const constantPoolHandle& to_cp, int to_cpi, TRAPS);
844 static void copy_entry_to(const constantPoolHandle& from_cp, int from_cpi, const constantPoolHandle& to_cp, int to_cpi);
845 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS);
846 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp);
847 int version() const { return _saved._version; }
848 void set_version(int version) { _saved._version = version; }
849 void increment_and_save_version(int version) {
850 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow
851 }
852
853 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; }
854 int resolved_reference_length() const { return _saved._resolved_reference_length; }
855
856 // Decrease ref counts of symbols that are in the constant pool
857 // when the holder class is unloaded
858 void unreference_symbols();
859
860 // Deallocate constant pool for RedefineClasses
861 void deallocate_contents(ClassLoaderData* loader_data);
862 void release_C_heap_structures();
863
864 // JVMTI access - GetConstantPool, RetransformClasses, ...
865 friend class JvmtiConstantPoolReconstituter;
866
867 private:
868 class SymbolHash: public CHeapObj<mtSymbol> {
869 ResourceHashtable<const Symbol*, u2, 256, AnyObj::C_HEAP, mtSymbol, Symbol::compute_hash> _table;
870
871 public:
872 void add_if_absent(const Symbol* sym, u2 value) {
873 bool created;
874 _table.put_if_absent(sym, value, &created);
875 }
876
877 u2 symbol_to_value(const Symbol* sym) {
878 u2* value = _table.get(sym);
879 return (value == nullptr) ? 0 : *value;
880 }
881 }; // End SymbolHash class
882
883 jint cpool_entry_size(jint idx);
884 jint hash_entries_to(SymbolHash *symmap, SymbolHash *classmap);
885
886 // Copy cpool bytes into byte array.
887 // Returns:
888 // int > 0, count of the raw cpool bytes that have been copied
889 // 0, OutOfMemory error
890 // -1, Internal error
891 int copy_cpool_bytes(int cpool_size,
892 SymbolHash* tbl,
893 unsigned char *bytes);
894
895 public:
896 // Verify
897 void verify_on(outputStream* st);
898
899 // Printing
900 void print_on(outputStream* st) const;
901 void print_value_on(outputStream* st) const;
902 void print_entry_on(int index, outputStream* st);
903
904 const char* internal_name() const { return "{constant pool}"; }
905
906 // ResolvedFieldEntry getters
907 inline ResolvedFieldEntry* resolved_field_entry_at(int field_index);
908 inline int resolved_field_entries_length() const;
909
910 // ResolvedMethodEntry getters
911 inline ResolvedMethodEntry* resolved_method_entry_at(int method_index);
912 inline int resolved_method_entries_length() const;
913 inline oop appendix_if_resolved(int method_index) const;
914
915 // ResolvedIndyEntry getters
916 inline ResolvedIndyEntry* resolved_indy_entry_at(int index);
917 inline int resolved_indy_entries_length() const;
918 inline oop resolved_reference_from_indy(int index) const;
919 inline oop resolved_reference_from_method(int index) const;
920 };
921
922 #endif // SHARE_OOPS_CONSTANTPOOL_HPP