1 /*
2 * Copyright (c) 2003, 2015, 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,
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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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 // (*)RewriteByteCodes and RewriteFrequentPairs is an exception but turned off in 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
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
171 class ConstMethod : public MetaspaceObj {
172 friend class VMStructs;
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 int _constMethod_size;
206 u2 _flags;
207
208 // Size of Java bytecodes allocated immediately after Method*.
209 u2 _code_size;
210 u2 _name_index; // Method name (index in constant pool)
211 u2 _signature_index; // Method signature (index in constant pool)
212 u2 _method_idnum; // unique identification number for the method within the class
213 // initially corresponds to the index into the methods array.
214 // but this may change with redefinition
215 u2 _max_stack; // Maximum number of entries on the expression stack
216 u2 _max_locals; // Number of local variables used by this method
217 u2 _size_of_parameters; // size of the parameter block (receiver + arguments) in words
218 u2 _orig_method_idnum; // Original unique identification number for the method
219
220 // Constructor
221 ConstMethod(int byte_code_size,
222 InlineTableSizes* sizes,
223 MethodType is_overpass,
224 int size);
225 public:
226
227 static ConstMethod* allocate(ClassLoaderData* loader_data,
228 int byte_code_size,
229 InlineTableSizes* sizes,
230 MethodType mt,
231 TRAPS);
232
233 bool is_constMethod() const { return true; }
234
235 // Inlined tables
236 void set_inlined_tables_length(InlineTableSizes* sizes);
237
238 bool has_generic_signature() const
239 { return (_flags & _has_generic_signature) != 0; }
240
241 bool has_linenumber_table() const
242 { return (_flags & _has_linenumber_table) != 0; }
243
244 bool has_checked_exceptions() const
245 { return (_flags & _has_checked_exceptions) != 0; }
246
247 bool has_localvariable_table() const
248 { return (_flags & _has_localvariable_table) != 0; }
249
250 bool has_exception_handler() const
251 { return (_flags & _has_exception_table) != 0; }
252
253 bool has_method_parameters() const
254 { return (_flags & _has_method_parameters) != 0; }
255
256 MethodType method_type() const {
257 return ((_flags & _is_overpass) == 0) ? NORMAL : OVERPASS;
258 }
259
260 void set_method_type(MethodType mt) {
261 if (mt == NORMAL) {
262 _flags &= ~(_is_overpass);
263 } else {
264 _flags |= _is_overpass;
265 }
266 }
267
268 // constant pool
269 ConstantPool* constants() const { return _constants; }
270 void set_constants(ConstantPool* c) { _constants = c; }
271
272 Method* method() const;
273
274 // stackmap table data
275 Array<u1>* stackmap_data() const { return _stackmap_data; }
276 void set_stackmap_data(Array<u1>* sd) { _stackmap_data = sd; }
277 void copy_stackmap_data(ClassLoaderData* loader_data, u1* sd, int length, TRAPS);
278 bool has_stackmap_table() const { return _stackmap_data != NULL; }
279
280 void init_fingerprint() {
281 const uint64_t initval = UCONST64(0x8000000000000000);
282 _fingerprint = initval;
283 }
284
285 uint64_t fingerprint() const {
286 // Since reads aren't atomic for 64 bits, if any of the high or low order
287 // word is the initial value, return 0. See init_fingerprint for initval.
288 uint high_fp = (uint)(_fingerprint >> 32);
289 if ((int) _fingerprint == 0 || high_fp == 0x80000000) {
290 return 0L;
291 } else {
292 return _fingerprint;
293 }
294 }
295
296 uint64_t set_fingerprint(uint64_t new_fingerprint) {
297 #ifdef ASSERT
298 // Assert only valid if complete/valid 64 bit _fingerprint value is read.
299 uint64_t oldfp = fingerprint();
300 #endif // ASSERT
301 _fingerprint = new_fingerprint;
302 assert(oldfp == 0L || new_fingerprint == oldfp,
303 "fingerprint cannot change");
304 assert(((new_fingerprint >> 32) != 0x80000000) && (int)new_fingerprint !=0,
305 "fingerprint should call init to set initial value");
306 return new_fingerprint;
307 }
308
309 // name
310 int name_index() const { return _name_index; }
311 void set_name_index(int index) { _name_index = index; }
312
313 // signature
314 int signature_index() const { return _signature_index; }
315 void set_signature_index(int index) { _signature_index = index; }
316
317 // generics support
318 int generic_signature_index() const {
319 if (has_generic_signature()) {
320 return *generic_signature_index_addr();
321 } else {
322 return 0;
323 }
324 }
325 void set_generic_signature_index(u2 index) {
326 assert(has_generic_signature(), "");
327 u2* addr = generic_signature_index_addr();
328 *addr = index;
329 }
330
331 // Sizing
332 static int header_size() {
333 return sizeof(ConstMethod)/HeapWordSize;
334 }
335
336 // Size needed
337 static int size(int code_size, InlineTableSizes* sizes);
338
339 int size() const { return _constMethod_size;}
340 void set_constMethod_size(int size) { _constMethod_size = size; }
341 #if INCLUDE_SERVICES
342 void collect_statistics(KlassSizeStats *sz) const;
343 #endif
344
345 // code size
346 int code_size() const { return _code_size; }
347 void set_code_size(int size) {
348 assert(max_method_code_size < (1 << 16),
349 "u2 is too small to hold method code size in general");
350 assert(0 <= size && size <= max_method_code_size, "invalid code size");
351 _code_size = size;
352 }
353
354 // linenumber table - note that length is unknown until decompression,
355 // see class CompressedLineNumberReadStream.
356 u_char* compressed_linenumber_table() const; // not preserved by gc
357 u2* generic_signature_index_addr() const;
358 u2* checked_exceptions_length_addr() const;
359 u2* localvariable_table_length_addr() const;
360 u2* exception_table_length_addr() const;
361 u2* method_parameters_length_addr() const;
362
363 // checked exceptions
364 int checked_exceptions_length() const;
365 CheckedExceptionElement* checked_exceptions_start() const;
366
367 // localvariable table
368 int localvariable_table_length() const;
369 LocalVariableTableElement* localvariable_table_start() const;
370
371 // exception table
372 int exception_table_length() const;
373 ExceptionTableElement* exception_table_start() const;
374
375 // method parameters table
376
377 // This returns -1 if no parameters are present, a non-negative
378 // value otherwise. Note: sometimes, there are 0-length parameters
379 // attributes that must be reported up to the reflection API all the
380 // same.
381 int method_parameters_length() const;
382 MethodParametersElement* method_parameters_start() const;
383
384 // method annotations
385 bool has_method_annotations() const
386 { return (_flags & _has_method_annotations) != 0; }
387
388 bool has_parameter_annotations() const
389 { return (_flags & _has_parameter_annotations) != 0; }
390
391 bool has_type_annotations() const
392 { return (_flags & _has_type_annotations) != 0; }
393
394 bool has_default_annotations() const
395 { return (_flags & _has_default_annotations) != 0; }
396
397
398 AnnotationArray** method_annotations_addr() const;
399 AnnotationArray* method_annotations() const {
400 return has_method_annotations() ? *(method_annotations_addr()) : NULL;
401 }
402 void set_method_annotations(AnnotationArray* anno) {
403 *(method_annotations_addr()) = anno;
404 }
405
406 AnnotationArray** parameter_annotations_addr() const;
407 AnnotationArray* parameter_annotations() const {
408 return has_parameter_annotations() ? *(parameter_annotations_addr()) : NULL;
409 }
410 void set_parameter_annotations(AnnotationArray* anno) {
411 *(parameter_annotations_addr()) = anno;
412 }
413
414 AnnotationArray** type_annotations_addr() const;
415 AnnotationArray* type_annotations() const {
416 return has_type_annotations() ? *(type_annotations_addr()) : NULL;
417 }
418 void set_type_annotations(AnnotationArray* anno) {
419 *(type_annotations_addr()) = anno;
420 }
421
422 AnnotationArray** default_annotations_addr() const;
423 AnnotationArray* default_annotations() const {
424 return has_default_annotations() ? *(default_annotations_addr()) : NULL;
425 }
426 void set_default_annotations(AnnotationArray* anno) {
427 *(default_annotations_addr()) = anno;
428 }
429
430 int method_annotations_length() const {
431 return has_method_annotations() ? method_annotations()->length() : 0;
432 }
433 int parameter_annotations_length() const {
434 return has_parameter_annotations() ? parameter_annotations()->length() : 0;
435 }
436 int type_annotations_length() const {
437 return has_type_annotations() ? type_annotations()->length() : 0;
438 }
439 int default_annotations_length() const {
440 return has_default_annotations() ? default_annotations()->length() : 0;
441 }
442
443 // Copy annotations from other ConstMethod
444 void copy_annotations_from(ConstMethod* cm);
445
446 // byte codes
447 void set_code(address code) {
448 if (code_size() > 0) {
449 memcpy(code_base(), code, code_size());
450 }
451 }
452 address code_base() const { return (address) (this+1); }
453 address code_end() const { return code_base() + code_size(); }
454 bool contains(address bcp) const { return code_base() <= bcp
455 && bcp < code_end(); }
456 // Offset to bytecodes
457 static ByteSize codes_offset()
458 { return in_ByteSize(sizeof(ConstMethod)); }
459
460 static ByteSize constants_offset()
461 { return byte_offset_of(ConstMethod, _constants); }
462
463 static ByteSize max_stack_offset()
464 { return byte_offset_of(ConstMethod, _max_stack); }
465 static ByteSize size_of_locals_offset()
466 { return byte_offset_of(ConstMethod, _max_locals); }
467 static ByteSize size_of_parameters_offset()
468 { return byte_offset_of(ConstMethod, _size_of_parameters); }
469
470
471 // Unique id for the method
472 static const u2 MAX_IDNUM;
473 static const u2 UNSET_IDNUM;
474 u2 method_idnum() const { return _method_idnum; }
475 void set_method_idnum(u2 idnum) { _method_idnum = idnum; }
476
477 u2 orig_method_idnum() const { return _orig_method_idnum; }
478 void set_orig_method_idnum(u2 idnum) { _orig_method_idnum = idnum; }
479
480 // max stack
481 int max_stack() const { return _max_stack; }
482 void set_max_stack(int size) { _max_stack = size; }
483
484 // max locals
485 int max_locals() const { return _max_locals; }
486 void set_max_locals(int size) { _max_locals = size; }
487
488 // size of parameters
489 int size_of_parameters() const { return _size_of_parameters; }
490 void set_size_of_parameters(int size) { _size_of_parameters = size; }
491
492 // Deallocation for RedefineClasses
493 void deallocate_contents(ClassLoaderData* loader_data);
494 bool is_klass() const { return false; }
495 DEBUG_ONLY(bool on_stack() { return false; })
496
497 private:
498 // Since the size of the compressed line number table is unknown, the
499 // offsets of the other variable sized sections are computed backwards
500 // from the end of the ConstMethod*.
501
502 // First byte after ConstMethod*
503 address constMethod_end() const
504 { return (address)((intptr_t*)this + _constMethod_size); }
505
506 // Last short in ConstMethod*
507 u2* last_u2_element() const;
508
509 public:
510 // Printing
511 void print_on (outputStream* st) const;
512 void print_value_on(outputStream* st) const;
513
514 const char* internal_name() const { return "{constMethod}"; }
515
516 // Verify
517 void verify_on(outputStream* st);
518 };
519
520 #endif // SHARE_VM_OOPS_CONSTMETHODOOP_HPP