1 /*
2 * Copyright (c) 1997, 2017, 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
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21 * questions.
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23 */
24
25 #ifndef SHARE_VM_OOPS_GENERATEOOPMAP_HPP
26 #define SHARE_VM_OOPS_GENERATEOOPMAP_HPP
27
28 #include "interpreter/bytecodeStream.hpp"
29 #include "memory/allocation.hpp"
30 #include "memory/universe.inline.hpp"
31 #include "oops/method.hpp"
32 #include "oops/oopsHierarchy.hpp"
33 #include "runtime/signature.hpp"
34 #include "utilities/bitMap.hpp"
35
36 // Forward definition
37 class GenerateOopMap;
38 class BasicBlock;
39 class CellTypeState;
40 class StackMap;
41
42 // These two should be removed. But requires som code to be cleaned up
43 #define MAXARGSIZE 256 // This should be enough
44 #define MAX_LOCAL_VARS 65536 // 16-bit entry
45
46 typedef void (*jmpFct_t)(GenerateOopMap *c, int bcpDelta, int* data);
47
48
49 // RetTable
50 //
51 // Contains maping between jsr targets and there return addresses. One-to-many mapping
52 //
53 class RetTableEntry : public ResourceObj {
54 private:
55 static int _init_nof_jsrs; // Default size of jsrs list
56 int _target_bci; // Target PC address of jump (bytecode index)
57 GrowableArray<intptr_t> * _jsrs; // List of return addresses (bytecode index)
58 RetTableEntry *_next; // Link to next entry
59 public:
60 RetTableEntry(int target, RetTableEntry *next);
61
62 // Query
63 int target_bci() const { return _target_bci; }
64 int nof_jsrs() const { return _jsrs->length(); }
65 int jsrs(int i) const { assert(i>=0 && i<nof_jsrs(), "Index out of bounds"); return _jsrs->at(i); }
66
67 // Update entry
68 void add_jsr (int return_bci) { _jsrs->append(return_bci); }
69 void add_delta (int bci, int delta);
70 RetTableEntry * next() const { return _next; }
71 };
72
73
74 class RetTable VALUE_OBJ_CLASS_SPEC {
75 private:
76 RetTableEntry *_first;
77 static int _init_nof_entries;
78
79 void add_jsr(int return_bci, int target_bci); // Adds entry to list
80 public:
81 RetTable() { _first = NULL; }
82 void compute_ret_table(const methodHandle& method);
83 void update_ret_table(int bci, int delta);
84 RetTableEntry* find_jsrs_for_target(int targBci);
85 };
86
87 //
88 // CellTypeState
89 //
90 class CellTypeState VALUE_OBJ_CLASS_SPEC {
91 private:
92 unsigned int _state;
93
94 // Masks for separating the BITS and INFO portions of a CellTypeState
95 enum { info_mask = right_n_bits(27),
96 bits_mask = (int)(~info_mask) };
97
98 // These constant are used for manipulating the BITS portion of a
99 // CellTypeState
100 enum { uninit_bit = (int)(nth_bit(31)),
101 ref_bit = nth_bit(30),
102 val_bit = nth_bit(29),
103 addr_bit = nth_bit(28),
104 valuetype_bit = nth_bit(27),
105 live_bits_mask = (int)(bits_mask & ~uninit_bit) };
106
107 // These constants are used for manipulating the INFO portion of a
108 // CellTypeState
109 enum { top_info_bit = nth_bit(26),
110 not_bottom_info_bit = nth_bit(25),
111 info_data_mask = right_n_bits(25),
112 info_conflict = info_mask };
113
114 // Within the INFO data, these values are used to distinguish different
115 // kinds of references.
116 enum { ref_not_lock_bit = nth_bit(24), // 0 if this reference is locked as a monitor
117 ref_slot_bit = nth_bit(23), // 1 if this reference is a "slot" reference,
118 // 0 if it is a "line" reference.
119 ref_data_mask = right_n_bits(23) };
120
121 // Within the INFO data, these values are used to distinguish different
122 // kinds of value types.
123 enum { valuetype_slot_bit = nth_bit(24), // 1 if this reference is a "slot" value type,
124 // 0 if it is a "line" value type.
125 valuetype_data_mask = right_n_bits(24) };
126
127 // These values are used to initialize commonly used CellTypeState
128 // constants.
129 enum { bottom_value = 0,
130 uninit_value = (int)(uninit_bit | info_conflict),
131 ref_value = ref_bit,
132 ref_conflict = ref_bit | info_conflict,
133 val_value = val_bit | info_conflict,
134 valuetype_conflict = valuetype_bit | info_conflict,
135 addr_value = addr_bit,
136 addr_conflict = addr_bit | info_conflict };
137
138 public:
139
140 // Since some C++ constructors generate poor code for declarations of the
141 // form...
142 //
143 // CellTypeState vector[length];
144 //
145 // ...we avoid making a constructor for this class. CellTypeState values
146 // should be constructed using one of the make_* methods:
147
148 static CellTypeState make_any(int state) {
149 CellTypeState s;
150 s._state = state;
151 // Causes SS10 warning.
152 // assert(s.is_valid_state(), "check to see if CellTypeState is valid");
153 return s;
154 }
155
156 static CellTypeState make_bottom() {
157 return make_any(0);
158 }
159
160 static CellTypeState make_top() {
161 return make_any(AllBits);
162 }
163
164 static CellTypeState make_addr(int bci) {
165 assert((bci >= 0) && (bci < info_data_mask), "check to see if ret addr is valid");
166 return make_any(addr_bit | not_bottom_info_bit | (bci & info_data_mask));
167 }
168
169 static CellTypeState make_slot_ref(int slot_num) {
170 assert(slot_num >= 0 && slot_num < ref_data_mask, "slot out of range");
171 return make_any(ref_bit | not_bottom_info_bit | ref_not_lock_bit | ref_slot_bit |
172 (slot_num & ref_data_mask));
173 }
174
175 static CellTypeState make_line_ref(int bci) {
176 assert(bci >= 0 && bci < ref_data_mask, "line out of range");
177 return make_any(ref_bit | not_bottom_info_bit | ref_not_lock_bit |
178 (bci & ref_data_mask));
179 }
180
181 static CellTypeState make_lock_ref(int bci) {
182 assert(bci >= 0 && bci < ref_data_mask, "line out of range");
183 return make_any(ref_bit | not_bottom_info_bit | (bci & ref_data_mask));
184 }
185
186
187 static CellTypeState make_slot_valuetype(int slot_num) {
188 assert(slot_num >= 0 && slot_num < valuetype_data_mask, "slot out of range");
189 return make_any(valuetype_bit | not_bottom_info_bit | valuetype_slot_bit |
190 (slot_num & valuetype_data_mask));
191 }
192
193 static CellTypeState make_line_valuetype(int bci) {
194 assert(bci >= 0 && bci < valuetype_data_mask, "line out of range");
195 return make_any(valuetype_bit | not_bottom_info_bit |
196 (bci & valuetype_data_mask));
197 }
198
199 // Query methods:
200 bool is_bottom() const { return _state == 0; }
201 bool is_live() const { return ((_state & live_bits_mask) != 0); }
202 bool is_valid_state() const {
203 // Uninitialized and value cells must contain no data in their info field:
204 if ((can_be_uninit() || can_be_value()) && !is_info_top()) {
205 return false;
206 }
207 // The top bit is only set when all info bits are set:
208 if (is_info_top() && ((_state & info_mask) != info_mask)) {
209 return false;
210 }
211 // The not_bottom_bit must be set when any other info bit is set:
212 if (is_info_bottom() && ((_state & info_mask) != 0)) {
213 return false;
214 }
215 return true;
216 }
217
218 bool is_address() const { return ((_state & bits_mask) == addr_bit); }
219 bool is_reference() const { return ((_state & bits_mask) == ref_bit); }
220 bool is_value() const { return ((_state & bits_mask) == val_bit); }
221 bool is_valuetype() const { return ((_state & bits_mask) == valuetype_bit); }
222 bool is_uninit() const { return ((_state & bits_mask) == (uint)uninit_bit); }
223
224 bool can_be_address() const { return ((_state & addr_bit) != 0); }
225 bool can_be_reference() const { return ((_state & ref_bit) != 0); }
226 bool can_be_value() const { return ((_state & val_bit) != 0); }
227 bool can_be_valuetype() const { return ((_state & valuetype_bit) != 0); }
228 bool can_be_uninit() const { return ((_state & uninit_bit) != 0); }
229
230 bool is_info_bottom() const { return ((_state & not_bottom_info_bit) == 0); }
231 bool is_info_top() const { return ((_state & top_info_bit) != 0); }
232 int get_info() const {
233 assert((!is_info_top() && !is_info_bottom()),
234 "check to make sure top/bottom info is not used");
235 return (_state & info_data_mask);
236 }
237
238 bool is_good_address() const { return is_address() && !is_info_top(); }
239 bool is_lock_reference() const {
240 return ((_state & (bits_mask | top_info_bit | ref_not_lock_bit)) == ref_bit);
241 }
242 bool is_nonlock_reference() const {
243 return ((_state & (bits_mask | top_info_bit | ref_not_lock_bit)) == (ref_bit | ref_not_lock_bit));
244 }
245
246 bool equal(CellTypeState a) const { return _state == a._state; }
247 bool equal_kind(CellTypeState a) const {
248 return (_state & bits_mask) == (a._state & bits_mask);
249 }
250
251 char to_char() const;
252
253 // Merge
254 CellTypeState merge (CellTypeState cts, int slot) const;
255
256 // Debugging output
257 void print(outputStream *os);
258
259 // Default values of common values
260 static CellTypeState bottom;
261 static CellTypeState uninit;
262 static CellTypeState ref;
263 static CellTypeState value;
264 static CellTypeState valuetype;
265 static CellTypeState refOrValueType;
266 static CellTypeState refUninit;
267 static CellTypeState varUninit;
268 static CellTypeState top;
269 static CellTypeState addr;
270 };
271
272
273 //
274 // BasicBlockStruct
275 //
276 class BasicBlock: ResourceObj {
277 private:
278 bool _changed; // Reached a fixpoint or not
279 public:
280 enum Constants {
281 _dead_basic_block = -2,
282 _unreached = -1 // Alive but not yet reached by analysis
283 // >=0 // Alive and has a merged state
284 };
285
286 int _bci; // Start of basic block
287 int _end_bci; // Bci of last instruction in basicblock
288 int _max_locals; // Determines split between vars and stack
289 int _max_stack; // Determines split between stack and monitors
290 CellTypeState* _state; // State (vars, stack) at entry.
291 int _stack_top; // -1 indicates bottom stack value.
292 int _monitor_top; // -1 indicates bottom monitor stack value.
293
294 CellTypeState* vars() { return _state; }
295 CellTypeState* stack() { return _state + _max_locals; }
296
297 bool changed() { return _changed; }
298 void set_changed(bool s) { _changed = s; }
299
300 bool is_reachable() const { return _stack_top >= 0; } // Analysis has reached this basicblock
301
302 // All basicblocks that are unreachable are going to have a _stack_top == _dead_basic_block.
303 // This info. is setup in a pre-parse before the real abstract interpretation starts.
304 bool is_dead() const { return _stack_top == _dead_basic_block; }
305 bool is_alive() const { return _stack_top != _dead_basic_block; }
306 void mark_as_alive() { assert(is_dead(), "must be dead"); _stack_top = _unreached; }
307 };
308
309
310 //
311 // GenerateOopMap
312 //
313 // Main class used to compute the pointer-maps in a Method
314 //
315 class GenerateOopMap VALUE_OBJ_CLASS_SPEC {
316 protected:
317
318 // _monitor_top is set to this constant to indicate that a monitor matching
319 // problem was encountered prior to this point in control flow.
320 enum { bad_monitors = -1 };
321
322 // Main variables
323 methodHandle _method; // The method we are examine
324 RetTable _rt; // Contains the return address mappings
325 int _max_locals; // Cached value of no. of locals
326 int _max_stack; // Cached value of max. stack depth
327 int _max_monitors; // Cached value of max. monitor stack depth
328 int _has_exceptions; // True, if exceptions exist for method
329 bool _got_error; // True, if an error occurred during interpretation.
330 Handle _exception; // Exception if got_error is true.
331 bool _did_rewriting; // was bytecodes rewritten
332 bool _did_relocation; // was relocation neccessary
333 bool _monitor_safe; // The monitors in this method have been determined
334 // to be safe.
335
336 // Working Cell type state
337 int _state_len; // Size of states
338 CellTypeState *_state; // list of states
339 char *_state_vec_buf; // Buffer used to print a readable version of a state
340 int _stack_top;
341 int _monitor_top;
342
343 // Timing and statistics
344 static elapsedTimer _total_oopmap_time; // Holds cumulative oopmap generation time
345 static long _total_byte_count; // Holds cumulative number of bytes inspected
346
347 // Cell type methods
348 void init_state();
349 void make_context_uninitialized ();
350 int methodsig_to_effect (Symbol* signature, bool isStatic, CellTypeState* effect);
351 bool merge_local_state_vectors (CellTypeState* cts, CellTypeState* bbts);
352 bool merge_monitor_state_vectors(CellTypeState* cts, CellTypeState* bbts);
353 void copy_state (CellTypeState *dst, CellTypeState *src);
354 void merge_state_into_bb (BasicBlock *bb);
355 static void merge_state (GenerateOopMap *gom, int bcidelta, int* data);
356 void set_var (int localNo, CellTypeState cts);
357 CellTypeState get_var (int localNo);
358 CellTypeState pop ();
359 void push (CellTypeState cts);
360 CellTypeState monitor_pop ();
361 void monitor_push (CellTypeState cts);
362 CellTypeState * vars () { return _state; }
363 CellTypeState * stack () { return _state+_max_locals; }
364 CellTypeState * monitors () { return _state+_max_locals+_max_stack; }
365
366 void replace_all_CTS_matches (CellTypeState match,
367 CellTypeState replace);
368 void print_states (outputStream *os, CellTypeState *vector, int num);
369 void print_current_state (outputStream *os,
370 BytecodeStream *itr,
371 bool detailed);
372 void report_monitor_mismatch (const char *msg);
373
374 // Basicblock info
375 BasicBlock * _basic_blocks; // Array of basicblock info
376 int _gc_points;
377 int _bb_count;
378 ResourceBitMap _bb_hdr_bits;
379
380 // Basicblocks methods
381 void initialize_bb ();
382 void mark_bbheaders_and_count_gc_points();
383 bool is_bb_header (int bci) const {
384 return _bb_hdr_bits.at(bci);
385 }
386 int gc_points () const { return _gc_points; }
387 int bb_count () const { return _bb_count; }
388 void set_bbmark_bit (int bci);
389 BasicBlock * get_basic_block_at (int bci) const;
390 BasicBlock * get_basic_block_containing (int bci) const;
391 void interp_bb (BasicBlock *bb);
392 void restore_state (BasicBlock *bb);
393 int next_bb_start_pc (BasicBlock *bb);
394 void update_basic_blocks (int bci, int delta, int new_method_size);
395 static void bb_mark_fct (GenerateOopMap *c, int deltaBci, int *data);
396
397 // Dead code detection
398 void mark_reachable_code();
399 static void reachable_basicblock (GenerateOopMap *c, int deltaBci, int *data);
400
401 // Interpretation methods (primary)
402 void do_interpretation ();
403 void init_basic_blocks ();
404 void setup_method_entry_state ();
405 void interp_all ();
406
407 // Interpretation methods (secondary)
408 void interp1 (BytecodeStream *itr);
409 void do_exception_edge (BytecodeStream *itr);
410 void check_type (CellTypeState expected, CellTypeState actual);
411 void ppstore (CellTypeState *in, int loc_no);
412 void ppload (CellTypeState *out, int loc_no);
413 void ppush1 (CellTypeState in);
414 void ppush (CellTypeState *in);
415 void ppop1 (CellTypeState out);
416 void ppop (CellTypeState *out);
417 void ppop_any (int poplen);
418 void pp (CellTypeState *in, CellTypeState *out);
419 void pp_new_ref (CellTypeState *in, int bci);
420 void pp_new_valuetype (CellTypeState *in, int bci);
421 void ppdupswap (int poplen, const char *out);
422 void do_ldc (int bci);
423 void do_astore (int idx);
424 void do_vstore (int idx);
425 void do_jsr (int delta);
426 void do_field (int is_get, int is_static, int idx, int bci);
427 void do_method (int is_static, int idx, int bci);
428 void do_vwithfield (int idx, int bci);
429 void do_multianewarray (int dims, int bci);
430 void do_monitorenter (int bci);
431 void do_monitorexit (int bci);
432 void do_return_monitor_check ();
433 void do_checkcast ();
434 CellTypeState *sigchar_to_effect (char sigch, int bci, CellTypeState *out);
435 int copy_cts (CellTypeState *dst, CellTypeState *src);
436
437 // Error handling
438 void error_work (const char *format, va_list ap) ATTRIBUTE_PRINTF(2, 0);
439 void report_error (const char *format, ...) ATTRIBUTE_PRINTF(2, 3);
440 void verify_error (const char *format, ...) ATTRIBUTE_PRINTF(2, 3);
441 bool got_error() { return _got_error; }
442
443 // Create result set
444 bool _report_result;
445 bool _report_result_for_send; // Unfortunatly, stackmaps for sends are special, so we need some extra
446 BytecodeStream *_itr_send; // variables to handle them properly.
447
448 void report_result ();
449
450 // Initvars
451 GrowableArray<intptr_t> * _init_vars;
452
453 void initialize_vars ();
454 void add_to_ref_init_set (int localNo);
455
456 // Conflicts rewrite logic
457 bool _conflict; // True, if a conflict occurred during interpretation
458 int _nof_refval_conflicts; // No. of conflicts that require rewrites
459 int * _new_var_map;
460
461 void record_refval_conflict (int varNo);
462 void rewrite_refval_conflicts ();
463 void rewrite_refval_conflict (int from, int to);
464 bool rewrite_refval_conflict_inst (BytecodeStream *i, int from, int to);
465 bool rewrite_load_or_store (BytecodeStream *i, Bytecodes::Code bc, Bytecodes::Code bc0, unsigned int varNo);
466
467 void expand_current_instr (int bci, int ilen, int newIlen, u_char inst_buffer[]);
468 bool is_astore (BytecodeStream *itr, int *index);
469 bool is_aload (BytecodeStream *itr, int *index);
470
471 // List of bci's where a return address is on top of the stack
472 GrowableArray<intptr_t> *_ret_adr_tos;
473
474 bool stack_top_holds_ret_addr (int bci);
475 void compute_ret_adr_at_TOS ();
476 void update_ret_adr_at_TOS (int bci, int delta);
477
478 int binsToHold (int no) { return ((no+(BitsPerWord-1))/BitsPerWord); }
479 char *state_vec_to_string (CellTypeState* vec, int len);
480
481 // Helper method. Can be used in subclasses to fx. calculate gc_points. If the current instuction
482 // is a control transfer, then calls the jmpFct all possible destinations.
483 void ret_jump_targets_do (BytecodeStream *bcs, jmpFct_t jmpFct, int varNo,int *data);
484 bool jump_targets_do (BytecodeStream *bcs, jmpFct_t jmpFct, int *data);
485
486 friend class RelocCallback;
487 public:
488 GenerateOopMap(const methodHandle& method);
489
490 // Compute the map.
491 void compute_map(TRAPS);
492 void result_for_basicblock(int bci); // Do a callback on fill_stackmap_for_opcodes for basicblock containing bci
493
494 // Query
495 int max_locals() const { return _max_locals; }
496 Method* method() const { return _method(); }
497 methodHandle method_as_handle() const { return _method; }
498
499 bool did_rewriting() { return _did_rewriting; }
500 bool did_relocation() { return _did_relocation; }
501
502 static void print_time();
503
504 // Monitor query
505 bool monitor_safe() { return _monitor_safe; }
506
507 // Specialization methods. Intended use:
508 // - possible_gc_point must return true for every bci for which the stackmaps must be returned
509 // - fill_stackmap_prolog is called just before the result is reported. The arguments tells the estimated
510 // number of gc points
511 // - fill_stackmap_for_opcodes is called once for each bytecode index in order (0...code_length-1)
512 // - fill_stackmap_epilog is called after all results has been reported. Note: Since the algorithm does not report
513 // stackmaps for deadcode, fewer gc_points might have been encounted than assumed during the epilog. It is the
514 // responsibility of the subclass to count the correct number.
515 // - fill_init_vars are called once with the result of the init_vars computation
516 //
517 // All these methods are used during a call to: compute_map. Note: Non of the return results are valid
518 // after compute_map returns, since all values are allocated as resource objects.
519 //
520 // All virtual method must be implemented in subclasses
521 virtual bool allow_rewrites () const { return false; }
522 virtual bool report_results () const { return true; }
523 virtual bool report_init_vars () const { return true; }
524 virtual bool possible_gc_point (BytecodeStream *bcs) { ShouldNotReachHere(); return false; }
525 virtual void fill_stackmap_prolog (int nof_gc_points) { ShouldNotReachHere(); }
526 virtual void fill_stackmap_epilog () { ShouldNotReachHere(); }
527 virtual void fill_stackmap_for_opcodes (BytecodeStream *bcs,
528 CellTypeState* vars,
529 CellTypeState* stack,
530 int stackTop) { ShouldNotReachHere(); }
531 virtual void fill_init_vars (GrowableArray<intptr_t> *init_vars) { ShouldNotReachHere();; }
532 };
533
534 //
535 // Subclass of the GenerateOopMap Class that just do rewrites of the method, if needed.
536 // It does not store any oopmaps.
537 //
538 class ResolveOopMapConflicts: public GenerateOopMap {
539 private:
540
541 bool _must_clear_locals;
542
543 virtual bool report_results() const { return false; }
544 virtual bool report_init_vars() const { return true; }
545 virtual bool allow_rewrites() const { return true; }
546 virtual bool possible_gc_point (BytecodeStream *bcs) { return false; }
547 virtual void fill_stackmap_prolog (int nof_gc_points) {}
548 virtual void fill_stackmap_epilog () {}
549 virtual void fill_stackmap_for_opcodes (BytecodeStream *bcs,
550 CellTypeState* vars,
551 CellTypeState* stack,
552 int stack_top) {}
553 virtual void fill_init_vars (GrowableArray<intptr_t> *init_vars) { _must_clear_locals = init_vars->length() > 0; }
554
555 #ifndef PRODUCT
556 // Statistics
557 static int _nof_invocations;
558 static int _nof_rewrites;
559 static int _nof_relocations;
560 #endif
561
562 public:
563 ResolveOopMapConflicts(const methodHandle& method) : GenerateOopMap(method) { _must_clear_locals = false; };
564
565 methodHandle do_potential_rewrite(TRAPS);
566 bool must_clear_locals() const { return _must_clear_locals; }
567 };
568
569
570 //
571 // Subclass used by the compiler to generate pairing infomation
572 //
573 class GeneratePairingInfo: public GenerateOopMap {
574 private:
575
576 virtual bool report_results() const { return false; }
577 virtual bool report_init_vars() const { return false; }
578 virtual bool allow_rewrites() const { return false; }
579 virtual bool possible_gc_point (BytecodeStream *bcs) { return false; }
580 virtual void fill_stackmap_prolog (int nof_gc_points) {}
581 virtual void fill_stackmap_epilog () {}
582 virtual void fill_stackmap_for_opcodes (BytecodeStream *bcs,
583 CellTypeState* vars,
584 CellTypeState* stack,
585 int stack_top) {}
586 virtual void fill_init_vars (GrowableArray<intptr_t> *init_vars) {}
587 public:
588 GeneratePairingInfo(const methodHandle& method) : GenerateOopMap(method) {};
589
590 // Call compute_map(CHECK) to generate info.
591 };
592
593 #endif // SHARE_VM_OOPS_GENERATEOOPMAP_HPP