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