1 /*
2 * Copyright (c) 2003, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_OOPS_CONSTMETHODOOP_HPP
26 #define SHARE_VM_OOPS_CONSTMETHODOOP_HPP
27
28 #include "oops/oop.hpp"
29 #include "utilities/align.hpp"
30
31 // An ConstMethod represents portions of a Java method which are not written to after
32 // the classfile is parsed(*see below). This part of the method can be shared across
33 // processes in a read-only section with Class Data Sharing (CDS). It's important
34 // that this class doesn't have virtual functions because the vptr cannot be shared
35 // with CDS.
36 //
37 // Note that most applications load thousands of methods, so keeping the size of this
38 // structure small has a big impact on footprint.
39
40 // The actual bytecodes are inlined after the end of the ConstMethod struct.
41 //
42 // The line number table is compressed and inlined following the byte codes. It is
43 // found as the first byte following the byte codes. Note that accessing the line
44 // number and local variable tables is not performance critical at all.
45 //
46 // The checked exceptions table and the local variable table are inlined after the
47 // line number table, and indexed from the end of the method. We do not compress the
48 // checked exceptions table since the average length is less than 2, and it is used
49 // by reflection so access should be fast. We do not bother to compress the local
50 // variable table either since it is mostly absent.
51 //
52 //
53 // ConstMethod embedded field layout (after declared fields):
54 // [EMBEDDED byte codes]
55 // [EMBEDDED compressed linenumber table]
56 // (see class CompressedLineNumberReadStream)
57 // (note that length is unknown until decompressed)
58 // (access flags bit tells whether table is present)
59 // (indexed from start of ConstMethod)
60 // (elements not necessarily sorted!)
61 // [EMBEDDED localvariable table elements + length (length last)]
62 // (length is u2, elements are 6-tuples of u2)
63 // (see class LocalVariableTableElement)
64 // (access flags bit tells whether table is present)
65 // (indexed from end of ConstMethod*)
66 // [EMBEDDED exception table + length (length last)]
67 // (length is u2, elements are 4-tuples of u2)
68 // (see class ExceptionTableElement)
69 // (access flags bit tells whether table is present)
70 // (indexed from end of ConstMethod*)
71 // [EMBEDDED checked exceptions elements + length (length last)]
72 // (length is u2, elements are u2)
73 // (see class CheckedExceptionElement)
74 // (access flags bit tells whether table is present)
75 // (indexed from end of ConstMethod*)
76 // [EMBEDDED method parameters elements + length (length last)]
77 // (length is u2, elements are u2, u4 structures)
78 // (see class MethodParametersElement)
79 // (access flags bit tells whether table is present)
80 // (indexed from end of ConstMethod*)
81 // [EMBEDDED generic signature index (u2)]
82 // (indexed from end of constMethodOop)
83 // [EMBEDDED annotations arrays - method, parameter, type, default]
84 // pointer to Array<u1> if annotation is present
85 //
86 // IMPORTANT: If anything gets added here, there need to be changes to
87 // ensure that ServicabilityAgent doesn't get broken as a result!
88
89
90 // Utility class describing elements in checked exceptions table inlined in Method*.
91 class CheckedExceptionElement VALUE_OBJ_CLASS_SPEC {
92 public:
93 u2 class_cp_index;
94 };
95
96
97 // Utility class describing elements in local variable table inlined in Method*.
98 class LocalVariableTableElement VALUE_OBJ_CLASS_SPEC {
99 public:
100 u2 start_bci;
101 u2 length;
102 u2 name_cp_index;
103 u2 descriptor_cp_index;
104 u2 signature_cp_index;
105 u2 slot;
106 };
107
108 // Utility class describing elements in exception table
109 class ExceptionTableElement VALUE_OBJ_CLASS_SPEC {
110 public:
111 u2 start_pc;
112 u2 end_pc;
113 u2 handler_pc;
114 u2 catch_type_index;
115 };
116
117 // Utility class describing elements in method parameters
118 class MethodParametersElement VALUE_OBJ_CLASS_SPEC {
119 public:
120 u2 name_cp_index;
121 u2 flags;
122 };
123
124 class KlassSizeStats;
125 class AdapterHandlerEntry;
126
127 // Class to collect the sizes of ConstMethod inline tables
128 #define INLINE_TABLES_DO(do_element) \
129 do_element(localvariable_table_length) \
130 do_element(compressed_linenumber_size) \
131 do_element(exception_table_length) \
132 do_element(checked_exceptions_length) \
133 do_element(method_parameters_length) \
134 do_element(generic_signature_index) \
135 do_element(method_annotations_length) \
136 do_element(parameter_annotations_length) \
137 do_element(type_annotations_length) \
138 do_element(default_annotations_length)
139
140 #define INLINE_TABLE_DECLARE(sym) int _##sym;
141 #define INLINE_TABLE_PARAM(sym) int sym,
142 #define INLINE_TABLE_INIT(sym) _##sym(sym),
143 #define INLINE_TABLE_NULL(sym) _##sym(0),
144 #define INLINE_TABLE_ACCESSOR(sym) int sym() const { return _##sym; }
145
146 class InlineTableSizes : StackObj {
147 // declarations
148 INLINE_TABLES_DO(INLINE_TABLE_DECLARE)
149 int _end;
150 public:
151 InlineTableSizes(
152 INLINE_TABLES_DO(INLINE_TABLE_PARAM)
153 int end) :
154 INLINE_TABLES_DO(INLINE_TABLE_INIT)
155 _end(end) {}
156
157 // Default constructor for no inlined tables
158 InlineTableSizes() :
159 INLINE_TABLES_DO(INLINE_TABLE_NULL)
160 _end(0) {}
161
162 // Accessors
163 INLINE_TABLES_DO(INLINE_TABLE_ACCESSOR)
164 };
165 #undef INLINE_TABLE_ACCESSOR
166 #undef INLINE_TABLE_NULL
167 #undef INLINE_TABLE_INIT
168 #undef INLINE_TABLE_PARAM
169 #undef INLINE_TABLE_DECLARE
170
171 class ConstMethod : public MetaspaceObj {
172 friend class VMStructs;
173 friend class JVMCIVMStructs;
174
175 public:
176 typedef enum { NORMAL, OVERPASS } MethodType;
177
178 private:
179 enum {
180 _has_linenumber_table = 0x0001,
181 _has_checked_exceptions = 0x0002,
182 _has_localvariable_table = 0x0004,
183 _has_exception_table = 0x0008,
184 _has_generic_signature = 0x0010,
185 _has_method_parameters = 0x0020,
186 _is_overpass = 0x0040,
187 _has_method_annotations = 0x0080,
188 _has_parameter_annotations = 0x0100,
189 _has_type_annotations = 0x0200,
190 _has_default_annotations = 0x0400
191 };
192
193 // Bit vector of signature
194 // Callers interpret 0=not initialized yet and
195 // -1=too many args to fix, must parse the slow way.
196 // The real initial value is special to account for nonatomicity of 64 bit
197 // loads and stores. This value may updated and read without a lock by
198 // multiple threads, so is volatile.
199 volatile uint64_t _fingerprint;
200
201 ConstantPool* _constants; // Constant pool
202
203 // Raw stackmap data for the method
204 Array<u1>* _stackmap_data;
205
206 // Adapter blob (i2c/c2i) for this Method*. Set once when method is linked.
207 union {
208 AdapterHandlerEntry* _adapter;
209 AdapterHandlerEntry** _adapter_trampoline; // see comments around Method::link_method()
210 };
211
212 int _constMethod_size;
213 u2 _flags;
214 u1 _result_type; // BasicType of result
215
216 // Size of Java bytecodes allocated immediately after Method*.
217 u2 _code_size;
218 u2 _name_index; // Method name (index in constant pool)
219 u2 _signature_index; // Method signature (index in constant pool)
220 u2 _method_idnum; // unique identification number for the method within the class
221 // initially corresponds to the index into the methods array.
222 // but this may change with redefinition
223 u2 _max_stack; // Maximum number of entries on the expression stack
224 u2 _max_locals; // Number of local variables used by this method
225 u2 _size_of_parameters; // size of the parameter block (receiver + arguments) in words
226 u2 _orig_method_idnum; // Original unique identification number for the method
227
228 // Constructor
229 ConstMethod(int byte_code_size,
230 InlineTableSizes* sizes,
231 MethodType is_overpass,
232 int size);
233 public:
234
235 static ConstMethod* allocate(ClassLoaderData* loader_data,
236 int byte_code_size,
237 InlineTableSizes* sizes,
238 MethodType mt,
239 TRAPS);
240
241 bool is_constMethod() const { return true; }
242
243 // Inlined tables
244 void set_inlined_tables_length(InlineTableSizes* sizes);
245
246 bool has_generic_signature() const
247 { return (_flags & _has_generic_signature) != 0; }
248
249 bool has_linenumber_table() const
250 { return (_flags & _has_linenumber_table) != 0; }
251
252 bool has_checked_exceptions() const
253 { return (_flags & _has_checked_exceptions) != 0; }
254
255 bool has_localvariable_table() const
256 { return (_flags & _has_localvariable_table) != 0; }
257
258 bool has_exception_handler() const
259 { return (_flags & _has_exception_table) != 0; }
260
261 bool has_method_parameters() const
262 { return (_flags & _has_method_parameters) != 0; }
263
264 MethodType method_type() const {
265 return ((_flags & _is_overpass) == 0) ? NORMAL : OVERPASS;
266 }
267
268 void set_method_type(MethodType mt) {
269 if (mt == NORMAL) {
270 _flags &= ~(_is_overpass);
271 } else {
272 _flags |= _is_overpass;
273 }
274 }
275
276 // constant pool
277 ConstantPool* constants() const { return _constants; }
278 void set_constants(ConstantPool* c) { _constants = c; }
279
280 Method* method() const;
281
282 // stackmap table data
283 Array<u1>* stackmap_data() const { return _stackmap_data; }
284 void set_stackmap_data(Array<u1>* sd) { _stackmap_data = sd; }
285 void copy_stackmap_data(ClassLoaderData* loader_data, u1* sd, int length, TRAPS);
286 bool has_stackmap_table() const { return _stackmap_data != NULL; }
287
288 // adapter
289 void set_adapter_entry(AdapterHandlerEntry* adapter) {
290 assert(!is_shared(), "shared methods have fixed adapter_trampoline");
291 _adapter = adapter;
292 }
293 void set_adapter_trampoline(AdapterHandlerEntry** trampoline) {
294 assert(DumpSharedSpaces, "must be");
295 assert(*trampoline == NULL, "must be NULL during dump time, to be initialized at run time");
296 _adapter_trampoline = trampoline;
297 }
298 void update_adapter_trampoline(AdapterHandlerEntry* adapter) {
299 assert(is_shared(), "must be");
300 *_adapter_trampoline = adapter;
301 assert(this->adapter() == adapter, "must be");
302 }
303 AdapterHandlerEntry* adapter() {
304 if (is_shared()) {
305 return *_adapter_trampoline;
306 } else {
307 return _adapter;
308 }
309 }
310
311 void init_fingerprint() {
312 const uint64_t initval = UCONST64(0x8000000000000000);
313 _fingerprint = initval;
314 }
315
316 uint64_t fingerprint() const {
317 // Since reads aren't atomic for 64 bits, if any of the high or low order
318 // word is the initial value, return 0. See init_fingerprint for initval.
319 uint high_fp = (uint)(_fingerprint >> 32);
320 if ((int) _fingerprint == 0 || high_fp == 0x80000000) {
321 return 0L;
322 } else {
323 return _fingerprint;
324 }
325 }
326
327 uint64_t set_fingerprint(uint64_t new_fingerprint) {
328 #ifdef ASSERT
329 // Assert only valid if complete/valid 64 bit _fingerprint value is read.
330 uint64_t oldfp = fingerprint();
331 #endif // ASSERT
332 _fingerprint = new_fingerprint;
333 assert(oldfp == 0L || new_fingerprint == oldfp,
334 "fingerprint cannot change");
335 assert(((new_fingerprint >> 32) != 0x80000000) && (int)new_fingerprint !=0,
336 "fingerprint should call init to set initial value");
337 return new_fingerprint;
338 }
339
340 // name
341 int name_index() const { return _name_index; }
342 void set_name_index(int index) { _name_index = index; }
343
344 // signature
345 int signature_index() const { return _signature_index; }
346 void set_signature_index(int index) { _signature_index = index; }
347
348 // generics support
349 int generic_signature_index() const {
350 if (has_generic_signature()) {
351 return *generic_signature_index_addr();
352 } else {
353 return 0;
354 }
355 }
356 void set_generic_signature_index(u2 index) {
357 assert(has_generic_signature(), "");
358 u2* addr = generic_signature_index_addr();
359 *addr = index;
360 }
361
362 // Sizing
363 static int header_size() {
364 return align_up((int)sizeof(ConstMethod), wordSize) / wordSize;
365 }
366
367 // Size needed
368 static int size(int code_size, InlineTableSizes* sizes);
369
370 int size() const { return _constMethod_size;}
371 void set_constMethod_size(int size) { _constMethod_size = size; }
372
373 // ConstMethods should be stored in the read-only region of CDS archive.
374 static bool is_read_only_by_default() { return true; }
375
376 #if INCLUDE_SERVICES
377 void collect_statistics(KlassSizeStats *sz) const;
378 #endif
379
380 // code size
381 int code_size() const { return _code_size; }
382 void set_code_size(int size) {
383 assert(max_method_code_size < (1 << 16),
384 "u2 is too small to hold method code size in general");
385 assert(0 <= size && size <= max_method_code_size, "invalid code size");
386 _code_size = size;
387 }
388
389 // linenumber table - note that length is unknown until decompression,
390 // see class CompressedLineNumberReadStream.
391 u_char* compressed_linenumber_table() const; // not preserved by gc
392 u2* generic_signature_index_addr() const;
393 u2* checked_exceptions_length_addr() const;
394 u2* localvariable_table_length_addr() const;
395 u2* exception_table_length_addr() const;
396 u2* method_parameters_length_addr() const;
397
398 // checked exceptions
399 int checked_exceptions_length() const;
400 CheckedExceptionElement* checked_exceptions_start() const;
401
402 // localvariable table
403 int localvariable_table_length() const;
404 LocalVariableTableElement* localvariable_table_start() const;
405
406 // exception table
407 int exception_table_length() const;
408 ExceptionTableElement* exception_table_start() const;
409
410 // method parameters table
411
412 // This returns -1 if no parameters are present, a non-negative
413 // value otherwise. Note: sometimes, there are 0-length parameters
414 // attributes that must be reported up to the reflection API all the
415 // same.
416 int method_parameters_length() const;
417 MethodParametersElement* method_parameters_start() const;
418
419 // method annotations
420 bool has_method_annotations() const
421 { return (_flags & _has_method_annotations) != 0; }
422
423 bool has_parameter_annotations() const
424 { return (_flags & _has_parameter_annotations) != 0; }
425
426 bool has_type_annotations() const
427 { return (_flags & _has_type_annotations) != 0; }
428
429 bool has_default_annotations() const
430 { return (_flags & _has_default_annotations) != 0; }
431
432
433 AnnotationArray** method_annotations_addr() const;
434 AnnotationArray* method_annotations() const {
435 return has_method_annotations() ? *(method_annotations_addr()) : NULL;
436 }
437 void set_method_annotations(AnnotationArray* anno) {
438 *(method_annotations_addr()) = anno;
439 }
440
441 AnnotationArray** parameter_annotations_addr() const;
442 AnnotationArray* parameter_annotations() const {
443 return has_parameter_annotations() ? *(parameter_annotations_addr()) : NULL;
444 }
445 void set_parameter_annotations(AnnotationArray* anno) {
446 *(parameter_annotations_addr()) = anno;
447 }
448
449 AnnotationArray** type_annotations_addr() const;
450 AnnotationArray* type_annotations() const {
451 return has_type_annotations() ? *(type_annotations_addr()) : NULL;
452 }
453 void set_type_annotations(AnnotationArray* anno) {
454 *(type_annotations_addr()) = anno;
455 }
456
457 AnnotationArray** default_annotations_addr() const;
458 AnnotationArray* default_annotations() const {
459 return has_default_annotations() ? *(default_annotations_addr()) : NULL;
460 }
461 void set_default_annotations(AnnotationArray* anno) {
462 *(default_annotations_addr()) = anno;
463 }
464
465 int method_annotations_length() const {
466 return has_method_annotations() ? method_annotations()->length() : 0;
467 }
468 int parameter_annotations_length() const {
469 return has_parameter_annotations() ? parameter_annotations()->length() : 0;
470 }
471 int type_annotations_length() const {
472 return has_type_annotations() ? type_annotations()->length() : 0;
473 }
474 int default_annotations_length() const {
475 return has_default_annotations() ? default_annotations()->length() : 0;
476 }
477
478 // Copy annotations from other ConstMethod
479 void copy_annotations_from(ClassLoaderData* loader_data, ConstMethod* cm, TRAPS);
480
481 // byte codes
482 void set_code(address code) {
483 if (code_size() > 0) {
484 memcpy(code_base(), code, code_size());
485 }
486 }
487 address code_base() const { return (address) (this+1); }
488 address code_end() const { return code_base() + code_size(); }
489 bool contains(address bcp) const { return code_base() <= bcp
490 && bcp < code_end(); }
491 // Offset to bytecodes
492 static ByteSize codes_offset()
493 { return in_ByteSize(sizeof(ConstMethod)); }
494
495 static ByteSize constants_offset()
496 { return byte_offset_of(ConstMethod, _constants); }
497
498 static ByteSize max_stack_offset()
499 { return byte_offset_of(ConstMethod, _max_stack); }
500 static ByteSize size_of_locals_offset()
501 { return byte_offset_of(ConstMethod, _max_locals); }
502 static ByteSize size_of_parameters_offset()
503 { return byte_offset_of(ConstMethod, _size_of_parameters); }
504
505 static ByteSize result_type_offset()
506 { return byte_offset_of(ConstMethod, _result_type); }
507
508 // Unique id for the method
509 static const u2 MAX_IDNUM;
510 static const u2 UNSET_IDNUM;
511 u2 method_idnum() const { return _method_idnum; }
512 void set_method_idnum(u2 idnum) { _method_idnum = idnum; }
513
514 u2 orig_method_idnum() const { return _orig_method_idnum; }
515 void set_orig_method_idnum(u2 idnum) { _orig_method_idnum = idnum; }
516
517 // max stack
518 int max_stack() const { return _max_stack; }
519 void set_max_stack(int size) { _max_stack = size; }
520
521 // max locals
522 int max_locals() const { return _max_locals; }
523 void set_max_locals(int size) { _max_locals = size; }
524
525 // size of parameters
526 int size_of_parameters() const { return _size_of_parameters; }
527 void set_size_of_parameters(int size) { _size_of_parameters = size; }
528
529 void set_result_type(BasicType rt) { assert(rt < 16, "result type too large");
530 _result_type = (u1)rt; }
531 // Deallocation for RedefineClasses
532 void deallocate_contents(ClassLoaderData* loader_data);
533 bool is_klass() const { return false; }
534 DEBUG_ONLY(bool on_stack() { return false; })
535
536 void metaspace_pointers_do(MetaspaceClosure* it);
537 MetaspaceObj::Type type() const { return ConstMethodType; }
538 private:
539 // Since the size of the compressed line number table is unknown, the
540 // offsets of the other variable sized sections are computed backwards
541 // from the end of the ConstMethod*.
542
543 // First byte after ConstMethod*
544 address constMethod_end() const
545 { return (address)((intptr_t*)this + _constMethod_size); }
546
547 // Last short in ConstMethod*
548 u2* last_u2_element() const;
549
550 public:
551 // Printing
552 void print_on (outputStream* st) const;
553 void print_value_on(outputStream* st) const;
554
555 const char* internal_name() const { return "{constMethod}"; }
556
557 // Verify
558 void verify_on(outputStream* st);
559 };
560
561 #endif // SHARE_VM_OOPS_CONSTMETHODOOP_HPP