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/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 // Invokedynamic indexes.
252 // They must look completely different from normal indexes.
253 // The main reason is that byte swapping is sometimes done on normal indexes.
254 // Finally, it is helpful for debugging to tell the two apart.
255 static bool is_invokedynamic_index(int i) { return (i < 0); }
256 static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; }
257 static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; }
258
259 // Given the per-instruction index of an indy instruction, report the
260 // main constant pool entry for its bootstrap specifier.
261 // From there, uncached_name/signature_ref_at will get the name/type.
262 inline u2 invokedynamic_bootstrap_ref_index_at(int indy_index) const;
263
264 // Assembly code support
265 static ByteSize tags_offset() { return byte_offset_of(ConstantPool, _tags); }
266 static ByteSize cache_offset() { return byte_offset_of(ConstantPool, _cache); }
267 static ByteSize pool_holder_offset() { return byte_offset_of(ConstantPool, _pool_holder); }
268 static ByteSize resolved_klasses_offset() { return byte_offset_of(ConstantPool, _resolved_klasses); }
269
270 // Storing constants
271
272 // For temporary use while constructing constant pool
273 void klass_index_at_put(int cp_index, int name_index) {
274 tag_at_put(cp_index, JVM_CONSTANT_ClassIndex);
275 *int_at_addr(cp_index) = name_index;
276 }
277
278 // Hidden class support:
279 void klass_at_put(int class_index, Klass* k);
280
281 void unresolved_klass_at_put(int cp_index, int name_index, int resolved_klass_index) {
282 release_tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
283
284 assert((name_index & 0xffff0000) == 0, "must be");
285 assert((resolved_klass_index & 0xffff0000) == 0, "must be");
286 *int_at_addr(cp_index) =
287 build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
288 }
289
290 void method_handle_index_at_put(int cp_index, int ref_kind, int ref_index) {
291 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle);
292 *int_at_addr(cp_index) = ((jint) ref_index<<16) | ref_kind;
293 }
294
295 void method_type_index_at_put(int cp_index, int ref_index) {
296 tag_at_put(cp_index, JVM_CONSTANT_MethodType);
297 *int_at_addr(cp_index) = ref_index;
298 }
299
300 void dynamic_constant_at_put(int cp_index, int bsms_attribute_index, int name_and_type_index) {
301 tag_at_put(cp_index, JVM_CONSTANT_Dynamic);
302 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | bsms_attribute_index;
303 }
304
305 void invoke_dynamic_at_put(int cp_index, int bsms_attribute_index, int name_and_type_index) {
306 tag_at_put(cp_index, JVM_CONSTANT_InvokeDynamic);
307 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | bsms_attribute_index;
308 }
309
310 void unresolved_string_at_put(int cp_index, Symbol* s) {
311 assert(s->refcount() != 0, "should have nonzero refcount");
312 // Note that release_tag_at_put is not needed here because this is called only
313 // when constructing a ConstantPool in a single thread, with no possibility
314 // of concurrent access.
315 tag_at_put(cp_index, JVM_CONSTANT_String);
316 *symbol_at_addr(cp_index) = s;
317 }
318
319 void int_at_put(int cp_index, jint i) {
320 tag_at_put(cp_index, JVM_CONSTANT_Integer);
321 *int_at_addr(cp_index) = i;
322 }
323
324 void long_at_put(int cp_index, jlong l) {
325 tag_at_put(cp_index, JVM_CONSTANT_Long);
326 // *long_at_addr(which) = l;
327 Bytes::put_native_u8((address)long_at_addr(cp_index), *((u8*) &l));
328 }
329
330 void float_at_put(int cp_index, jfloat f) {
331 tag_at_put(cp_index, JVM_CONSTANT_Float);
332 *float_at_addr(cp_index) = f;
333 }
334
335 void double_at_put(int cp_index, jdouble d) {
336 tag_at_put(cp_index, JVM_CONSTANT_Double);
337 // *double_at_addr(which) = d;
338 // u8 temp = *(u8*) &d;
339 Bytes::put_native_u8((address) double_at_addr(cp_index), *((u8*) &d));
340 }
341
342 Symbol** symbol_at_addr(int cp_index) const {
343 assert(is_within_bounds(cp_index), "index out of bounds");
344 return (Symbol**) &base()[cp_index];
345 }
346
347 void symbol_at_put(int cp_index, Symbol* s) {
348 assert(s->refcount() != 0, "should have nonzero refcount");
349 tag_at_put(cp_index, JVM_CONSTANT_Utf8);
350 *symbol_at_addr(cp_index) = s;
351 }
352
353 void string_at_put(int obj_index, oop str);
354
355 // For temporary use while constructing constant pool
356 void string_index_at_put(int cp_index, int string_index) {
357 tag_at_put(cp_index, JVM_CONSTANT_StringIndex);
358 *int_at_addr(cp_index) = string_index;
359 }
360
361 void field_at_put(int cp_index, int class_index, int name_and_type_index) {
362 tag_at_put(cp_index, JVM_CONSTANT_Fieldref);
363 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index;
364 }
365
366 void method_at_put(int cp_index, int class_index, int name_and_type_index) {
367 tag_at_put(cp_index, JVM_CONSTANT_Methodref);
368 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index;
369 }
370
371 void interface_method_at_put(int cp_index, int class_index, int name_and_type_index) {
372 tag_at_put(cp_index, JVM_CONSTANT_InterfaceMethodref);
373 *int_at_addr(cp_index) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
374 }
375
376 void name_and_type_at_put(int cp_index, int name_index, int signature_index) {
377 tag_at_put(cp_index, JVM_CONSTANT_NameAndType);
378 *int_at_addr(cp_index) = ((jint) signature_index<<16) | name_index; // Not so nice
379 }
380
381 // Tag query
382
383 constantTag tag_at(int cp_index) const { return (constantTag)tags()->at_acquire(cp_index); }
384
385 // Fetching constants
386
387 Klass* klass_at(int cp_index, TRAPS) {
388 constantPoolHandle h_this(THREAD, this);
389 return klass_at_impl(h_this, cp_index, THREAD);
390 }
391
392 CPKlassSlot klass_slot_at(int cp_index) const {
393 assert(tag_at(cp_index).is_unresolved_klass() || tag_at(cp_index).is_klass(),
394 "Corrupted constant pool");
395 int value = *int_at_addr(cp_index);
396 int name_index = extract_high_short_from_int(value);
397 int resolved_klass_index = extract_low_short_from_int(value);
398 return CPKlassSlot(name_index, resolved_klass_index);
399 }
400
401 Symbol* klass_name_at(int cp_index) const; // Returns the name, w/o resolving.
402 int klass_name_index_at(int cp_index) const {
403 return klass_slot_at(cp_index).name_index();
404 }
405
406 Klass* resolved_klass_at(int cp_index) const; // Used by Compiler
407
408 // RedefineClasses() API support:
409 Symbol* klass_at_noresolve(int cp_index) { return klass_name_at(cp_index); }
410 void temp_unresolved_klass_at_put(int cp_index, int name_index) {
411 // Used only during constant pool merging for class redefinition. The resolved klass index
412 // will be initialized later by a call to initialize_unresolved_klasses().
413 unresolved_klass_at_put(cp_index, name_index, CPKlassSlot::_temp_resolved_klass_index);
414 }
415
416 jint int_at(int cp_index) const {
417 assert(tag_at(cp_index).is_int(), "Corrupted constant pool");
418 return *int_at_addr(cp_index);
419 }
420
421 jlong long_at(int cp_index) {
422 assert(tag_at(cp_index).is_long(), "Corrupted constant pool");
423 // return *long_at_addr(cp_index);
424 u8 tmp = Bytes::get_native_u8((address)&base()[cp_index]);
425 return *((jlong*)&tmp);
426 }
427
428 jfloat float_at(int cp_index) {
429 assert(tag_at(cp_index).is_float(), "Corrupted constant pool");
430 return *float_at_addr(cp_index);
431 }
432
433 jdouble double_at(int cp_index) {
434 assert(tag_at(cp_index).is_double(), "Corrupted constant pool");
435 u8 tmp = Bytes::get_native_u8((address)&base()[cp_index]);
436 return *((jdouble*)&tmp);
437 }
438
439 Symbol* symbol_at(int cp_index) const {
440 assert(tag_at(cp_index).is_utf8(), "Corrupted constant pool");
441 return *symbol_at_addr(cp_index);
442 }
443
444 oop string_at(int cp_index, int obj_index, TRAPS) {
445 constantPoolHandle h_this(THREAD, this);
446 return string_at_impl(h_this, cp_index, obj_index, THREAD);
447 }
448 oop string_at(int cp_index, TRAPS) {
449 int obj_index = cp_to_object_index(cp_index);
450 return string_at(cp_index, obj_index, THREAD);
451 }
452
453 // Version that can be used before string oop array is created.
454 oop uncached_string_at(int cp_index, TRAPS);
455
456 // only called when we are sure a string entry is already resolved (via an
457 // earlier string_at call.
458 oop resolved_string_at(int cp_index) {
459 assert(tag_at(cp_index).is_string(), "Corrupted constant pool");
460 // Must do an acquire here in case another thread resolved the klass
461 // behind our back, lest we later load stale values thru the oop.
462 // we might want a volatile_obj_at in ObjArrayKlass.
463 int obj_index = cp_to_object_index(cp_index);
464 return resolved_reference_at(obj_index);
465 }
466
467 Symbol* unresolved_string_at(int cp_index) {
468 assert(tag_at(cp_index).is_string(), "Corrupted constant pool");
469 return *symbol_at_addr(cp_index);
470 }
471
472 // Returns an UTF8 for a CONSTANT_String entry at a given index.
473 // UTF8 char* representation was chosen to avoid conversion of
474 // java_lang_Strings at resolved entries into Symbol*s
475 // or vice versa.
476 char* string_at_noresolve(int cp_index);
477
478 jint name_and_type_at(int cp_index) {
479 assert(tag_at(cp_index).is_name_and_type(), "Corrupted constant pool");
480 return *int_at_addr(cp_index);
481 }
482
483 int method_handle_ref_kind_at(int cp_index) {
484 assert(tag_at(cp_index).is_method_handle() ||
485 tag_at(cp_index).is_method_handle_in_error(), "Corrupted constant pool");
486 return extract_low_short_from_int(*int_at_addr(cp_index)); // mask out unwanted ref_index bits
487 }
488 int method_handle_index_at(int cp_index) {
489 assert(tag_at(cp_index).is_method_handle() ||
490 tag_at(cp_index).is_method_handle_in_error(), "Corrupted constant pool");
491 return extract_high_short_from_int(*int_at_addr(cp_index)); // shift out unwanted ref_kind bits
492 }
493 int method_type_index_at(int cp_index) {
494 assert(tag_at(cp_index).is_method_type() ||
495 tag_at(cp_index).is_method_type_in_error(), "Corrupted constant pool");
496 return *int_at_addr(cp_index);
497 }
498
499 // Derived queries:
500 Symbol* method_handle_name_ref_at(int cp_index) {
501 int member = method_handle_index_at(cp_index);
502 return uncached_name_ref_at(member);
503 }
504 Symbol* method_handle_signature_ref_at(int cp_index) {
505 int member = method_handle_index_at(cp_index);
506 return uncached_signature_ref_at(member);
507 }
508 u2 method_handle_klass_index_at(int cp_index) {
509 int member = method_handle_index_at(cp_index);
510 return uncached_klass_ref_index_at(member);
511 }
512 Symbol* method_type_signature_at(int cp_index) {
513 int sym = method_type_index_at(cp_index);
514 return symbol_at(sym);
515 }
516
517 u2 bootstrap_name_and_type_ref_index_at(int cp_index) {
518 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
519 return extract_high_short_from_int(*int_at_addr(cp_index));
520 }
521 u2 bootstrap_methods_attribute_index(int cp_index) {
522 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
523 return extract_low_short_from_int(*int_at_addr(cp_index));
524 }
525 int bootstrap_operand_base(int cp_index) {
526 int bsms_attribute_index = bootstrap_methods_attribute_index(cp_index);
527 return operand_offset_at(operands(), bsms_attribute_index);
528 }
529 // The first part of the operands array consists of an index into the second part.
530 // Extract a 32-bit index value from the first part.
531 static int operand_offset_at(Array<u2>* operands, int bsms_attribute_index) {
532 int n = (bsms_attribute_index * 2);
533 assert(n >= 0 && n+2 <= operands->length(), "oob");
534 // The first 32-bit index points to the beginning of the second part
535 // of the operands array. Make sure this index is in the first part.
536 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0),
537 operands->at(1)));
538 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
539 int offset = build_int_from_shorts(operands->at(n+0),
540 operands->at(n+1));
541 // The offset itself must point into the second part of the array.
542 assert(offset == 0 || (offset >= second_part && offset <= operands->length()), "oob (3)");
543 return offset;
544 }
545 static void operand_offset_at_put(Array<u2>* operands, int bsms_attribute_index, int offset) {
546 int n = bsms_attribute_index * 2;
547 assert(n >= 0 && n+2 <= operands->length(), "oob");
548 operands->at_put(n+0, extract_low_short_from_int(offset));
549 operands->at_put(n+1, extract_high_short_from_int(offset));
550 }
551 static int operand_array_length(Array<u2>* operands) {
552 if (operands == nullptr || operands->length() == 0) return 0;
553 int second_part = operand_offset_at(operands, 0);
554 return (second_part / 2);
555 }
556
557 #ifdef ASSERT
558 // operand tuples fit together exactly, end to end
559 static int operand_limit_at(Array<u2>* operands, int bsms_attribute_index) {
560 int nextidx = bsms_attribute_index + 1;
561 if (nextidx == operand_array_length(operands))
562 return operands->length();
563 else
564 return operand_offset_at(operands, nextidx);
565 }
566 int bootstrap_operand_limit(int cp_index) {
567 int bsms_attribute_index = bootstrap_methods_attribute_index(cp_index);
568 return operand_limit_at(operands(), bsms_attribute_index);
569 }
570 #endif //ASSERT
571
572 // Layout of InvokeDynamic and Dynamic bootstrap method specifier
573 // data in second part of operands array. This encodes one record in
574 // the BootstrapMethods attribute. The whole specifier also includes
575 // the name and type information from the main constant pool entry.
576 enum {
577 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
578 _indy_argc_offset = 1, // u2 argc
579 _indy_argv_offset = 2 // u2 argv[argc]
580 };
581
582 // These functions are used in RedefineClasses for CP merge
583
584 int operand_offset_at(int bsms_attribute_index) {
585 assert(0 <= bsms_attribute_index &&
586 bsms_attribute_index < operand_array_length(operands()),
587 "Corrupted CP operands");
588 return operand_offset_at(operands(), bsms_attribute_index);
589 }
590 u2 operand_bootstrap_method_ref_index_at(int bsms_attribute_index) {
591 int offset = operand_offset_at(bsms_attribute_index);
592 return operands()->at(offset + _indy_bsm_offset);
593 }
594 u2 operand_argument_count_at(int bsms_attribute_index) {
595 int offset = operand_offset_at(bsms_attribute_index);
596 u2 argc = operands()->at(offset + _indy_argc_offset);
597 return argc;
598 }
599 u2 operand_argument_index_at(int bsms_attribute_index, int j) {
600 int offset = operand_offset_at(bsms_attribute_index);
601 return operands()->at(offset + _indy_argv_offset + j);
602 }
603 int operand_next_offset_at(int bsms_attribute_index) {
604 int offset = operand_offset_at(bsms_attribute_index) + _indy_argv_offset
605 + operand_argument_count_at(bsms_attribute_index);
606 return offset;
607 }
608 // Compare a bootstrap specifier data in the operands arrays
609 bool compare_operand_to(int bsms_attribute_index1, const constantPoolHandle& cp2,
610 int bsms_attribute_index2);
611 // Find a bootstrap specifier data in the operands array
612 int find_matching_operand(int bsms_attribute_index, const constantPoolHandle& search_cp,
613 int operands_cur_len);
614 // Resize the operands array with delta_len and delta_size
615 void resize_operands(int delta_len, int delta_size, TRAPS);
616 // Extend the operands array with the length and size of the ext_cp operands
617 void extend_operands(const constantPoolHandle& ext_cp, TRAPS);
618 // Shrink the operands array to a smaller array with new_len length
619 void shrink_operands(int new_len, TRAPS);
620
621 u2 bootstrap_method_ref_index_at(int cp_index) {
622 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
623 int op_base = bootstrap_operand_base(cp_index);
624 return operands()->at(op_base + _indy_bsm_offset);
625 }
626 u2 bootstrap_argument_count_at(int cp_index) {
627 assert(tag_at(cp_index).has_bootstrap(), "Corrupted constant pool");
628 int op_base = bootstrap_operand_base(cp_index);
629 u2 argc = operands()->at(op_base + _indy_argc_offset);
630 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
631 int next_offset = bootstrap_operand_limit(cp_index));
632 assert(end_offset == next_offset, "matched ending");
633 return argc;
634 }
635 u2 bootstrap_argument_index_at(int cp_index, int j) {
636 int op_base = bootstrap_operand_base(cp_index);
637 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset));
638 assert((uint)j < (uint)argc, "oob");
639 return operands()->at(op_base + _indy_argv_offset + j);
640 }
641
642 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
643 // name_and_type_ref_index_at) all expect to be passed indices obtained
644 // directly from the bytecode.
645 // If the indices are meant to refer to fields or methods, they are
646 // actually rewritten indices that point to entries in their respective structures
647 // i.e. ResolvedMethodEntries or ResolvedFieldEntries.
648 // The routine to_cp_index manages the adjustment
649 // of these values back to constant pool indices.
650
651 // There are also "uncached" versions which do not adjust the operand index; see below.
652
653 // Lookup for entries consisting of (klass_index, name_and_type index)
654 Klass* klass_ref_at(int which, Bytecodes::Code code, TRAPS);
655 Symbol* klass_ref_at_noresolve(int which, Bytecodes::Code code);
656 Symbol* name_ref_at(int which, Bytecodes::Code code) {
657 int name_index = name_ref_index_at(name_and_type_ref_index_at(which, code));
658 return symbol_at(name_index);
659 }
660 Symbol* signature_ref_at(int which, Bytecodes::Code code) {
661 int signature_index = signature_ref_index_at(name_and_type_ref_index_at(which, code));
662 return symbol_at(signature_index);
663 }
664
665 u2 klass_ref_index_at(int which, Bytecodes::Code code);
666 u2 name_and_type_ref_index_at(int which, Bytecodes::Code code);
667
668 constantTag tag_ref_at(int cp_cache_index, Bytecodes::Code code);
669
670 int to_cp_index(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 bool maybe_archive_resolved_klass_at(int cp_index);
689 void remove_unshareable_info();
690 void restore_unshareable_info(TRAPS);
691 #endif
692
693 private:
694 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
695 public:
696
697 // Get the tag for a constant, which may involve a constant dynamic
698 constantTag constant_tag_at(int cp_index);
699 // Get the basic type for a constant, which may involve a constant dynamic
700 BasicType basic_type_for_constant_at(int cp_index);
701
702 // Resolve late bound constants.
703 oop resolve_constant_at(int cp_index, TRAPS) {
704 constantPoolHandle h_this(THREAD, this);
705 return resolve_constant_at_impl(h_this, cp_index, _no_index_sentinel, nullptr, THREAD);
706 }
707
708 oop resolve_cached_constant_at(int cache_index, TRAPS) {
709 constantPoolHandle h_this(THREAD, this);
710 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, nullptr, THREAD);
711 }
712
713 oop resolve_possibly_cached_constant_at(int cp_index, TRAPS) {
714 constantPoolHandle h_this(THREAD, this);
715 return resolve_constant_at_impl(h_this, cp_index, _possible_index_sentinel, nullptr, THREAD);
716 }
717
718 oop find_cached_constant_at(int cp_index, bool& found_it, TRAPS) {
719 constantPoolHandle h_this(THREAD, this);
720 return resolve_constant_at_impl(h_this, cp_index, _possible_index_sentinel, &found_it, THREAD);
721 }
722
723 void copy_bootstrap_arguments_at(int cp_index,
724 int start_arg, int end_arg,
725 objArrayHandle info, int pos,
726 bool must_resolve, Handle if_not_available, TRAPS) {
727 constantPoolHandle h_this(THREAD, this);
728 copy_bootstrap_arguments_at_impl(h_this, cp_index, start_arg, end_arg,
729 info, pos, must_resolve, if_not_available, THREAD);
730 }
731
732 // Klass name matches name at offset
733 bool klass_name_at_matches(const InstanceKlass* k, int cp_index);
734
735 // Sizing
736 int length() const { return _length; }
737 void set_length(int length) { _length = length; }
738
739 // Tells whether index is within bounds.
740 bool is_within_bounds(int index) const {
741 return 0 <= index && index < length();
742 }
743
744 // Sizing (in words)
745 static int header_size() {
746 return align_up((int)sizeof(ConstantPool), wordSize) / wordSize;
747 }
748 static int size(int length) { return align_metadata_size(header_size() + length); }
749 int size() const { return size(length()); }
750
751 // ConstantPools should be stored in the read-only region of CDS archive.
752 static bool is_read_only_by_default() { return true; }
753
754 friend class ClassFileParser;
755 friend class SystemDictionary;
756
757 // Used by CDS. These classes need to access the private ConstantPool() constructor.
758 template <class T> friend class CppVtableTesterA;
759 template <class T> friend class CppVtableTesterB;
760 template <class T> friend class CppVtableCloner;
761
762 // Used by compiler to prevent classloading.
763 static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which);
764 static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
765 static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
766 static bool has_local_signature_at_if_loaded (const constantPoolHandle& this_cp, int which);
767 static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which);
768
769 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
770 // future by other Java code. These take constant pool indices rather than
771 // constant pool cache indices as do the peer methods above.
772 Symbol* uncached_klass_ref_at_noresolve(int cp_index);
773 Symbol* uncached_name_ref_at(int cp_index) {
774 int name_index = name_ref_index_at(uncached_name_and_type_ref_index_at(cp_index));
775 return symbol_at(name_index);
776 }
777 Symbol* uncached_signature_ref_at(int cp_index) {
778 int signature_index = signature_ref_index_at(uncached_name_and_type_ref_index_at(cp_index));
779 return symbol_at(signature_index);
780 }
781 u2 uncached_klass_ref_index_at(int cp_index);
782 u2 uncached_name_and_type_ref_index_at(int cp_index);
783
784 // Sharing
785 int pre_resolve_shared_klasses(TRAPS);
786
787 // Debugging
788 const char* printable_name_at(int cp_index) PRODUCT_RETURN0;
789
790 private:
791
792 void set_resolved_references(OopHandle s) { _cache->set_resolved_references(s); }
793 Array<u2>* reference_map() const { return (_cache == nullptr) ? nullptr : _cache->reference_map(); }
794 void set_reference_map(Array<u2>* o) { _cache->set_reference_map(o); }
795
796 // Used while constructing constant pool (only by ClassFileParser)
797 jint klass_index_at(int cp_index) {
798 assert(tag_at(cp_index).is_klass_index(), "Corrupted constant pool");
799 return *int_at_addr(cp_index);
800 }
801
802 jint string_index_at(int cp_index) {
803 assert(tag_at(cp_index).is_string_index(), "Corrupted constant pool");
804 return *int_at_addr(cp_index);
805 }
806
807 // Performs the LinkResolver checks
808 static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* klass, TRAPS);
809
810 // Implementation of methods that needs an exposed 'this' pointer, in order to
811 // handle GC while executing the method
812 static Klass* klass_at_impl(const constantPoolHandle& this_cp, int cp_index, TRAPS);
813 static oop string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS);
814
815 static void trace_class_resolution(const constantPoolHandle& this_cp, Klass* k);
816
817 // Resolve string constants (to prevent allocation during compilation)
818 static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS);
819
820 static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int cp_index, int cache_index,
821 bool* status_return, TRAPS);
822 static void copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index,
823 int start_arg, int end_arg,
824 objArrayHandle info, int pos,
825 bool must_resolve, Handle if_not_available, TRAPS);
826
827 // Exception handling
828 static void save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index, constantTag tag, TRAPS);
829
830 public:
831 // Exception handling
832 static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS);
833
834 // Merging ConstantPool* support:
835 bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2);
836 void copy_cp_to(int start_cpi, int end_cpi, const constantPoolHandle& to_cp, int to_cpi, TRAPS) {
837 constantPoolHandle h_this(THREAD, this);
838 copy_cp_to_impl(h_this, start_cpi, end_cpi, to_cp, to_cpi, THREAD);
839 }
840 static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_cpi, int end_cpi, const constantPoolHandle& to_cp, int to_cpi, TRAPS);
841 static void copy_entry_to(const constantPoolHandle& from_cp, int from_cpi, const constantPoolHandle& to_cp, int to_cpi);
842 static void copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS);
843 int find_matching_entry(int pattern_i, const constantPoolHandle& search_cp);
844 int version() const { return _saved._version; }
845 void set_version(int version) { _saved._version = version; }
846 void increment_and_save_version(int version) {
847 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow
848 }
849
850 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; }
851 int resolved_reference_length() const { return _saved._resolved_reference_length; }
852
853 // Decrease ref counts of symbols that are in the constant pool
854 // when the holder class is unloaded
855 void unreference_symbols();
856
857 // Deallocate constant pool for RedefineClasses
858 void deallocate_contents(ClassLoaderData* loader_data);
859 void release_C_heap_structures();
860
861 // JVMTI access - GetConstantPool, RetransformClasses, ...
862 friend class JvmtiConstantPoolReconstituter;
863
864 private:
865 class SymbolHash: public CHeapObj<mtSymbol> {
866 ResourceHashtable<const Symbol*, u2, 256, AnyObj::C_HEAP, mtSymbol, Symbol::compute_hash> _table;
867
868 public:
869 void add_if_absent(const Symbol* sym, u2 value) {
870 bool created;
871 _table.put_if_absent(sym, value, &created);
872 }
873
874 u2 symbol_to_value(const Symbol* sym) {
875 u2* value = _table.get(sym);
876 return (value == nullptr) ? 0 : *value;
877 }
878 }; // End SymbolHash class
879
880 jint cpool_entry_size(jint idx);
881 jint hash_entries_to(SymbolHash *symmap, SymbolHash *classmap);
882
883 // Copy cpool bytes into byte array.
884 // Returns:
885 // int > 0, count of the raw cpool bytes that have been copied
886 // 0, OutOfMemory error
887 // -1, Internal error
888 int copy_cpool_bytes(int cpool_size,
889 SymbolHash* tbl,
890 unsigned char *bytes);
891
892 public:
893 // Verify
894 void verify_on(outputStream* st);
895
896 // Printing
897 void print_on(outputStream* st) const;
898 void print_value_on(outputStream* st) const;
899 void print_entry_on(int index, outputStream* st);
900
901 const char* internal_name() const { return "{constant pool}"; }
902
903 // ResolvedFieldEntry getters
904 inline ResolvedFieldEntry* resolved_field_entry_at(int field_index);
905 inline int resolved_field_entries_length() const;
906
907 // ResolvedMethodEntry getters
908 inline ResolvedMethodEntry* resolved_method_entry_at(int method_index);
909 inline int resolved_method_entries_length() const;
910 inline oop appendix_if_resolved(int method_index) const;
911
912 // ResolvedIndyEntry getters
913 inline ResolvedIndyEntry* resolved_indy_entry_at(int index);
914 inline int resolved_indy_entries_length() const;
915 inline oop resolved_reference_from_indy(int index) const;
916 inline oop resolved_reference_from_method(int index) const;
917 };
918
919 #endif // SHARE_OOPS_CONSTANTPOOL_HPP