1 /*
2 * Copyright (c) 2003, 2014, 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.
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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.
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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
125 // Class to collect the sizes of ConstMethod inline tables
126 #define INLINE_TABLES_DO(do_element) \
127 do_element(localvariable_table_length) \
128 do_element(compressed_linenumber_size) \
129 do_element(exception_table_length) \
130 do_element(checked_exceptions_length) \
131 do_element(method_parameters_length) \
132 do_element(generic_signature_index) \
133 do_element(method_annotations_length) \
134 do_element(parameter_annotations_length) \
135 do_element(type_annotations_length) \
136 do_element(default_annotations_length)
137
138 #define INLINE_TABLE_DECLARE(sym) int _##sym;
139 #define INLINE_TABLE_PARAM(sym) int sym,
140 #define INLINE_TABLE_INIT(sym) _##sym(sym),
141 #define INLINE_TABLE_NULL(sym) _##sym(0),
142 #define INLINE_TABLE_ACCESSOR(sym) int sym() const { return _##sym; }
143
144 class InlineTableSizes : StackObj {
145 // declarations
146 INLINE_TABLES_DO(INLINE_TABLE_DECLARE)
147 int _end;
148 public:
149 InlineTableSizes(
150 INLINE_TABLES_DO(INLINE_TABLE_PARAM)
151 int end) :
152 INLINE_TABLES_DO(INLINE_TABLE_INIT)
153 _end(end) {}
154
155 // Default constructor for no inlined tables
156 InlineTableSizes() :
157 INLINE_TABLES_DO(INLINE_TABLE_NULL)
158 _end(0) {}
159
160 // Accessors
161 INLINE_TABLES_DO(INLINE_TABLE_ACCESSOR)
162 };
163 #undef INLINE_TABLE_ACCESSOR
164 #undef INLINE_TABLE_NULL
165 #undef INLINE_TABLE_INIT
166 #undef INLINE_TABLE_PARAM
167 #undef INLINE_TABLE_DECLARE
168
169
170 class ConstMethod : public MetaspaceObj {
171 friend class VMStructs;
172
173 public:
174 typedef enum { NORMAL, OVERPASS } MethodType;
175
176 private:
177 enum {
178 _has_linenumber_table = 0x0001,
179 _has_checked_exceptions = 0x0002,
180 _has_localvariable_table = 0x0004,
181 _has_exception_table = 0x0008,
182 _has_generic_signature = 0x0010,
183 _has_method_parameters = 0x0020,
184 _is_overpass = 0x0040,
185 _has_method_annotations = 0x0080,
186 _has_parameter_annotations = 0x0100,
187 _has_type_annotations = 0x0200,
188 _has_default_annotations = 0x0400
189 };
190
191 // Bit vector of signature
192 // Callers interpret 0=not initialized yet and
193 // -1=too many args to fix, must parse the slow way.
194 // The real initial value is special to account for nonatomicity of 64 bit
195 // loads and stores. This value may updated and read without a lock by
196 // multiple threads, so is volatile.
197 volatile uint64_t _fingerprint;
198
199 ConstantPool* _constants; // Constant pool
200
201 // Raw stackmap data for the method
202 Array<u1>* _stackmap_data;
203
204 int _constMethod_size;
205 u2 _flags;
206
207 // Size of Java bytecodes allocated immediately after Method*.
208 u2 _code_size;
209 u2 _name_index; // Method name (index in constant pool)
210 u2 _signature_index; // Method signature (index in constant pool)
211 u2 _method_idnum; // unique identification number for the method within the class
212 // initially corresponds to the index into the methods array.
213 // but this may change with redefinition
214 u2 _max_stack; // Maximum number of entries on the expression stack
215 u2 _max_locals; // Number of local variables used by this method
216 u2 _size_of_parameters; // size of the parameter block (receiver + arguments) in words
217
218 // Constructor
219 ConstMethod(int byte_code_size,
220 InlineTableSizes* sizes,
221 MethodType is_overpass,
222 int size);
223 public:
224
225 static ConstMethod* allocate(ClassLoaderData* loader_data,
226 int byte_code_size,
227 InlineTableSizes* sizes,
228 MethodType mt,
229 TRAPS);
230
231 bool is_constMethod() const { return true; }
232
233 // Inlined tables
234 void set_inlined_tables_length(InlineTableSizes* sizes);
235
236 bool has_generic_signature() const
237 { return (_flags & _has_generic_signature) != 0; }
238
239 bool has_linenumber_table() const
240 { return (_flags & _has_linenumber_table) != 0; }
241
242 bool has_checked_exceptions() const
243 { return (_flags & _has_checked_exceptions) != 0; }
244
245 bool has_localvariable_table() const
246 { return (_flags & _has_localvariable_table) != 0; }
247
248 bool has_exception_handler() const
249 { return (_flags & _has_exception_table) != 0; }
250
251 bool has_method_parameters() const
252 { return (_flags & _has_method_parameters) != 0; }
253
254 MethodType method_type() const {
255 return ((_flags & _is_overpass) == 0) ? NORMAL : OVERPASS;
256 }
257
258 void set_method_type(MethodType mt) {
259 if (mt == NORMAL) {
260 _flags &= ~(_is_overpass);
261 } else {
262 _flags |= _is_overpass;
263 }
264 }
265
266 // constant pool
267 ConstantPool* constants() const { return _constants; }
268 void set_constants(ConstantPool* c) { _constants = c; }
269
270 Method* method() const;
271
272 // stackmap table data
273 Array<u1>* stackmap_data() const { return _stackmap_data; }
274 void set_stackmap_data(Array<u1>* sd) { _stackmap_data = sd; }
275 void copy_stackmap_data(ClassLoaderData* loader_data, u1* sd, int length, TRAPS);
276 bool has_stackmap_table() const { return _stackmap_data != NULL; }
277
278 void init_fingerprint() {
279 const uint64_t initval = UCONST64(0x8000000000000000);
280 _fingerprint = initval;
281 }
282
283 uint64_t fingerprint() const {
284 // Since reads aren't atomic for 64 bits, if any of the high or low order
285 // word is the initial value, return 0. See init_fingerprint for initval.
286 uint high_fp = (uint)(_fingerprint >> 32);
287 if ((int) _fingerprint == 0 || high_fp == 0x80000000) {
288 return 0L;
289 } else {
290 return _fingerprint;
291 }
292 }
293
294 uint64_t set_fingerprint(uint64_t new_fingerprint) {
295 #ifdef ASSERT
296 // Assert only valid if complete/valid 64 bit _fingerprint value is read.
297 uint64_t oldfp = fingerprint();
298 #endif // ASSERT
299 _fingerprint = new_fingerprint;
300 assert(oldfp == 0L || new_fingerprint == oldfp,
301 "fingerprint cannot change");
302 assert(((new_fingerprint >> 32) != 0x80000000) && (int)new_fingerprint !=0,
303 "fingerprint should call init to set initial value");
304 return new_fingerprint;
305 }
306
307 // name
308 int name_index() const { return _name_index; }
309 void set_name_index(int index) { _name_index = index; }
310
311 // signature
312 int signature_index() const { return _signature_index; }
313 void set_signature_index(int index) { _signature_index = index; }
314
315 // generics support
316 int generic_signature_index() const {
317 if (has_generic_signature()) {
318 return *generic_signature_index_addr();
319 } else {
320 return 0;
321 }
322 }
323 void set_generic_signature_index(u2 index) {
324 assert(has_generic_signature(), "");
325 u2* addr = generic_signature_index_addr();
326 *addr = index;
327 }
328
329 // Sizing
330 static int header_size() {
331 return sizeof(ConstMethod)/HeapWordSize;
332 }
333
334 // Size needed
335 static int size(int code_size, InlineTableSizes* sizes);
336
337 int size() const { return _constMethod_size;}
338 void set_constMethod_size(int size) { _constMethod_size = size; }
339 #if INCLUDE_SERVICES
340 void collect_statistics(KlassSizeStats *sz) const;
341 #endif
342
343 // code size
344 int code_size() const { return _code_size; }
345 void set_code_size(int size) {
346 assert(max_method_code_size < (1 << 16),
347 "u2 is too small to hold method code size in general");
348 assert(0 <= size && size <= max_method_code_size, "invalid code size");
349 _code_size = size;
350 }
351
352 // linenumber table - note that length is unknown until decompression,
353 // see class CompressedLineNumberReadStream.
354 u_char* compressed_linenumber_table() const; // not preserved by gc
355 u2* generic_signature_index_addr() const;
356 u2* checked_exceptions_length_addr() const;
357 u2* localvariable_table_length_addr() const;
358 u2* exception_table_length_addr() const;
359 u2* method_parameters_length_addr() const;
360
361 // checked exceptions
362 int checked_exceptions_length() const;
363 CheckedExceptionElement* checked_exceptions_start() const;
364
365 // localvariable table
366 int localvariable_table_length() const;
367 LocalVariableTableElement* localvariable_table_start() const;
368
369 // exception table
370 int exception_table_length() const;
371 ExceptionTableElement* exception_table_start() const;
372
373 // method parameters table
374
375 // This returns -1 if no parameters are present, a non-negative
376 // value otherwise. Note: sometimes, there are 0-length parameters
377 // attributes that must be reported up to the reflection API all the
378 // same.
379 int method_parameters_length() const;
380 MethodParametersElement* method_parameters_start() const;
381
382 // method annotations
383 bool has_method_annotations() const
384 { return (_flags & _has_method_annotations) != 0; }
385
386 bool has_parameter_annotations() const
387 { return (_flags & _has_parameter_annotations) != 0; }
388
389 bool has_type_annotations() const
390 { return (_flags & _has_type_annotations) != 0; }
391
392 bool has_default_annotations() const
393 { return (_flags & _has_default_annotations) != 0; }
394
395
396 AnnotationArray** method_annotations_addr() const;
397 AnnotationArray* method_annotations() const {
398 return has_method_annotations() ? *(method_annotations_addr()) : NULL;
399 }
400 void set_method_annotations(AnnotationArray* anno) {
401 *(method_annotations_addr()) = anno;
402 }
403
404 AnnotationArray** parameter_annotations_addr() const;
405 AnnotationArray* parameter_annotations() const {
406 return has_parameter_annotations() ? *(parameter_annotations_addr()) : NULL;
407 }
408 void set_parameter_annotations(AnnotationArray* anno) {
409 *(parameter_annotations_addr()) = anno;
410 }
411
412 AnnotationArray** type_annotations_addr() const;
413 AnnotationArray* type_annotations() const {
414 return has_type_annotations() ? *(type_annotations_addr()) : NULL;
415 }
416 void set_type_annotations(AnnotationArray* anno) {
417 *(type_annotations_addr()) = anno;
418 }
419
420 AnnotationArray** default_annotations_addr() const;
421 AnnotationArray* default_annotations() const {
422 return has_default_annotations() ? *(default_annotations_addr()) : NULL;
423 }
424 void set_default_annotations(AnnotationArray* anno) {
425 *(default_annotations_addr()) = anno;
426 }
427
428 int method_annotations_length() const {
429 return has_method_annotations() ? method_annotations()->length() : 0;
430 }
431 int parameter_annotations_length() const {
432 return has_parameter_annotations() ? parameter_annotations()->length() : 0;
433 }
434 int type_annotations_length() const {
435 return has_type_annotations() ? type_annotations()->length() : 0;
436 }
437 int default_annotations_length() const {
438 return has_default_annotations() ? default_annotations()->length() : 0;
439 }
440
441 // Copy annotations from other ConstMethod
442 void copy_annotations_from(ConstMethod* cm);
443
444 // byte codes
445 void set_code(address code) {
446 if (code_size() > 0) {
447 memcpy(code_base(), code, code_size());
448 }
449 }
450 address code_base() const { return (address) (this+1); }
451 address code_end() const { return code_base() + code_size(); }
452 bool contains(address bcp) const { return code_base() <= bcp
453 && bcp < code_end(); }
454 // Offset to bytecodes
455 static ByteSize codes_offset()
456 { return in_ByteSize(sizeof(ConstMethod)); }
457
458 static ByteSize constants_offset()
459 { return byte_offset_of(ConstMethod, _constants); }
460
461 static ByteSize max_stack_offset()
462 { return byte_offset_of(ConstMethod, _max_stack); }
463 static ByteSize size_of_locals_offset()
464 { return byte_offset_of(ConstMethod, _max_locals); }
465 static ByteSize size_of_parameters_offset()
466 { return byte_offset_of(ConstMethod, _size_of_parameters); }
467
468
469 // Unique id for the method
470 static const u2 MAX_IDNUM;
471 static const u2 UNSET_IDNUM;
472 u2 method_idnum() const { return _method_idnum; }
473 void set_method_idnum(u2 idnum) { _method_idnum = idnum; }
474
475 // max stack
476 int max_stack() const { return _max_stack; }
477 void set_max_stack(int size) { _max_stack = size; }
478
479 // max locals
480 int max_locals() const { return _max_locals; }
481 void set_max_locals(int size) { _max_locals = size; }
482
483 // size of parameters
484 int size_of_parameters() const { return _size_of_parameters; }
485 void set_size_of_parameters(int size) { _size_of_parameters = size; }
486
487 // Deallocation for RedefineClasses
488 void deallocate_contents(ClassLoaderData* loader_data);
489 bool is_klass() const { return false; }
490 DEBUG_ONLY(bool on_stack() { return false; })
491
492 private:
493 // Since the size of the compressed line number table is unknown, the
494 // offsets of the other variable sized sections are computed backwards
495 // from the end of the ConstMethod*.
496
497 // First byte after ConstMethod*
498 address constMethod_end() const
499 { return (address)((intptr_t*)this + _constMethod_size); }
500
501 // Last short in ConstMethod*
502 u2* last_u2_element() const;
503
504 public:
505 // Printing
506 void print_on (outputStream* st) const;
507 void print_value_on(outputStream* st) const;
508
509 const char* internal_name() const { return "{constMethod}"; }
510
511 // Verify
512 void verify_on(outputStream* st);
513 };
514
515 #endif // SHARE_VM_OOPS_CONSTMETHODOOP_HPP