Mercurial > hg > truffle
annotate src/share/vm/runtime/relocator.cpp @ 2904:1916da1d3e11
Merge.
author | Thomas Wuerthinger <thomas@wuerthinger.net> |
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date | Wed, 08 Jun 2011 17:26:49 +0200 |
parents | f95d63e2154a |
children | 8150fa46d2ed |
rev | line source |
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0 | 1 /* |
1972 | 2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved. |
0 | 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 * | |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #include "precompiled.hpp" |
26 #include "classfile/stackMapTableFormat.hpp" | |
27 #include "interpreter/bytecodes.hpp" | |
28 #include "memory/oopFactory.hpp" | |
29 #include "memory/universe.inline.hpp" | |
30 #include "oops/oop.inline.hpp" | |
31 #include "runtime/handles.inline.hpp" | |
32 #include "runtime/relocator.hpp" | |
0 | 33 |
34 #define MAX_METHOD_LENGTH 65535 | |
35 | |
36 #define MAX_SHORT ((1 << 15) - 1) | |
37 #define MIN_SHORT (- (1 << 15)) | |
38 | |
39 // Encapsulates a code change request. There are 3 types. | |
40 // General instruction, jump instruction, and table/lookup switches | |
41 // | |
42 class ChangeItem : public ResourceObj { | |
43 int _bci; | |
44 public: | |
45 ChangeItem(int bci) { _bci = bci; } | |
46 virtual bool handle_code_change(Relocator *r) = 0; | |
47 | |
48 // type info | |
49 virtual bool is_widen() { return false; } | |
50 virtual bool is_jump_widen() { return false; } | |
51 virtual bool is_switch_pad() { return false; } | |
52 | |
53 // accessors | |
54 int bci() { return _bci; } | |
55 void relocate(int break_bci, int delta) { if (_bci > break_bci) { _bci += delta; } } | |
56 | |
57 virtual bool adjust(int bci, int delta) { return false; } | |
58 | |
59 // debug | |
60 virtual void print() = 0; | |
61 }; | |
62 | |
63 class ChangeWiden : public ChangeItem { | |
64 int _new_ilen; // New length of instruction at bci | |
65 u_char* _inst_buffer; // New bytecodes | |
66 public: | |
67 ChangeWiden(int bci, int new_ilen, u_char* inst_buffer) : ChangeItem(bci) { | |
68 _new_ilen = new_ilen; | |
69 _inst_buffer = inst_buffer; | |
70 } | |
71 | |
72 // Callback to do instruction | |
73 bool handle_code_change(Relocator *r) { return r->handle_widen(bci(), _new_ilen, _inst_buffer); }; | |
74 | |
75 bool is_widen() { return true; } | |
76 | |
77 void print() { tty->print_cr("ChangeWiden. bci: %d New_ilen: %d", bci(), _new_ilen); } | |
78 }; | |
79 | |
80 class ChangeJumpWiden : public ChangeItem { | |
81 int _delta; // New length of instruction at bci | |
82 public: | |
83 ChangeJumpWiden(int bci, int delta) : ChangeItem(bci) { _delta = delta; } | |
84 | |
85 // Callback to do instruction | |
86 bool handle_code_change(Relocator *r) { return r->handle_jump_widen(bci(), _delta); }; | |
87 | |
88 bool is_jump_widen() { return true; } | |
89 | |
90 // If the bci matches, adjust the delta in the change jump request. | |
91 bool adjust(int jump_bci, int delta) { | |
92 if (bci() == jump_bci) { | |
93 if (_delta > 0) | |
94 _delta += delta; | |
95 else | |
96 _delta -= delta; | |
97 return true; | |
98 } | |
99 return false; | |
100 } | |
101 | |
102 void print() { tty->print_cr("ChangeJumpWiden. bci: %d Delta: %d", bci(), _delta); } | |
103 }; | |
104 | |
105 class ChangeSwitchPad : public ChangeItem { | |
106 int _padding; | |
107 bool _is_lookup_switch; | |
108 public: | |
109 ChangeSwitchPad(int bci, int padding, bool is_lookup_switch) : ChangeItem(bci) { | |
110 _padding = padding; | |
111 _is_lookup_switch = is_lookup_switch; | |
112 } | |
113 | |
114 // Callback to do instruction | |
115 bool handle_code_change(Relocator *r) { return r->handle_switch_pad(bci(), _padding, _is_lookup_switch); }; | |
116 | |
117 bool is_switch_pad() { return true; } | |
118 int padding() { return _padding; } | |
119 bool is_lookup_switch() { return _is_lookup_switch; } | |
120 | |
121 void print() { tty->print_cr("ChangeSwitchPad. bci: %d Padding: %d IsLookupSwitch: %d", bci(), _padding, _is_lookup_switch); } | |
122 }; | |
123 | |
124 //----------------------------------------------------------------------------------------------------------- | |
125 // Relocator code | |
126 | |
127 Relocator::Relocator(methodHandle m, RelocatorListener* listener) { | |
128 set_method(m); | |
129 set_code_length(method()->code_size()); | |
130 set_code_array(NULL); | |
131 // Allocate code array and copy bytecodes | |
132 if (!expand_code_array(0)) { | |
133 // Should have at least MAX_METHOD_LENGTH available or the verifier | |
134 // would have failed. | |
135 ShouldNotReachHere(); | |
136 } | |
137 set_compressed_line_number_table(NULL); | |
138 set_compressed_line_number_table_size(0); | |
139 _listener = listener; | |
140 } | |
141 | |
142 // size is the new size of the instruction at bci. Hence, if size is less than the current | |
143 // instruction sice, we will shrink the code. | |
144 methodHandle Relocator::insert_space_at(int bci, int size, u_char inst_buffer[], TRAPS) { | |
145 _changes = new GrowableArray<ChangeItem*> (10); | |
146 _changes->push(new ChangeWiden(bci, size, inst_buffer)); | |
147 | |
148 if (TraceRelocator) { | |
149 tty->print_cr("Space at: %d Size: %d", bci, size); | |
150 _method->print(); | |
151 _method->print_codes(); | |
152 tty->print_cr("-------------------------------------------------"); | |
153 } | |
154 | |
155 if (!handle_code_changes()) return methodHandle(); | |
156 | |
157 // Construct the new method | |
158 methodHandle new_method = methodOopDesc::clone_with_new_data(method(), | |
159 code_array(), code_length(), | |
160 compressed_line_number_table(), | |
161 compressed_line_number_table_size(), | |
162 CHECK_(methodHandle())); | |
163 set_method(new_method); | |
164 | |
165 if (TraceRelocator) { | |
166 tty->print_cr("-------------------------------------------------"); | |
167 tty->print_cr("new method"); | |
168 _method->print_codes(); | |
169 } | |
170 | |
171 return new_method; | |
172 } | |
173 | |
174 | |
175 bool Relocator::handle_code_changes() { | |
176 assert(_changes != NULL, "changes vector must be initialized"); | |
177 | |
178 while (!_changes->is_empty()) { | |
179 // Inv: everything is aligned. | |
180 ChangeItem* ci = _changes->first(); | |
181 | |
182 if (TraceRelocator) { | |
183 ci->print(); | |
184 } | |
185 | |
186 // Execute operation | |
187 if (!ci->handle_code_change(this)) return false; | |
188 | |
189 // Shuffel items up | |
190 for (int index = 1; index < _changes->length(); index++) { | |
191 _changes->at_put(index-1, _changes->at(index)); | |
192 } | |
193 _changes->pop(); | |
194 } | |
195 return true; | |
196 } | |
197 | |
198 | |
199 bool Relocator::is_opcode_lookupswitch(Bytecodes::Code bc) { | |
200 switch (bc) { | |
201 case Bytecodes::_tableswitch: return false; | |
202 case Bytecodes::_lookupswitch: // not rewritten on ia64 | |
203 case Bytecodes::_fast_linearswitch: // rewritten _lookupswitch | |
204 case Bytecodes::_fast_binaryswitch: return true; // rewritten _lookupswitch | |
205 default: ShouldNotReachHere(); | |
206 } | |
207 return true; // dummy | |
208 } | |
209 | |
210 // We need a special instruction size method, since lookupswitches and tableswitches might not be | |
211 // properly alligned during relocation | |
212 int Relocator::rc_instr_len(int bci) { | |
213 Bytecodes::Code bc= code_at(bci); | |
214 switch (bc) { | |
215 // In the case of switch instructions, see if we have the original | |
216 // padding recorded. | |
217 case Bytecodes::_tableswitch: | |
218 case Bytecodes::_lookupswitch: | |
219 case Bytecodes::_fast_linearswitch: | |
220 case Bytecodes::_fast_binaryswitch: | |
221 { | |
222 int pad = get_orig_switch_pad(bci, is_opcode_lookupswitch(bc)); | |
223 if (pad == -1) { | |
224 return instruction_length_at(bci); | |
225 } | |
226 // Otherwise, depends on the switch type. | |
227 switch (bc) { | |
228 case Bytecodes::_tableswitch: { | |
229 int lo = int_at(bci + 1 + pad + 4 * 1); | |
230 int hi = int_at(bci + 1 + pad + 4 * 2); | |
231 int n = hi - lo + 1; | |
232 return 1 + pad + 4*(3 + n); | |
233 } | |
234 case Bytecodes::_lookupswitch: | |
235 case Bytecodes::_fast_linearswitch: | |
236 case Bytecodes::_fast_binaryswitch: { | |
237 int npairs = int_at(bci + 1 + pad + 4 * 1); | |
238 return 1 + pad + 4*(2 + 2*npairs); | |
239 } | |
240 default: | |
241 ShouldNotReachHere(); | |
242 } | |
243 } | |
244 } | |
245 return instruction_length_at(bci); | |
246 } | |
247 | |
248 // If a change item is recorded for "pc", with type "ct", returns the | |
249 // associated padding, else -1. | |
250 int Relocator::get_orig_switch_pad(int bci, bool is_lookup_switch) { | |
251 for (int k = 0; k < _changes->length(); k++) { | |
252 ChangeItem* ci = _changes->at(k); | |
253 if (ci->is_switch_pad()) { | |
254 ChangeSwitchPad* csp = (ChangeSwitchPad*)ci; | |
255 if (csp->is_lookup_switch() == is_lookup_switch && csp->bci() == bci) { | |
256 return csp->padding(); | |
257 } | |
258 } | |
259 } | |
260 return -1; | |
261 } | |
262 | |
263 | |
264 // Push a ChangeJumpWiden if it doesn't already exist on the work queue, | |
265 // otherwise adjust the item already there by delta. The calculation for | |
266 // new_delta is wrong for this because it uses the offset stored in the | |
267 // code stream itself which wasn't fixed when item was pushed on the work queue. | |
268 void Relocator::push_jump_widen(int bci, int delta, int new_delta) { | |
269 for (int j = 0; j < _changes->length(); j++) { | |
270 ChangeItem* ci = _changes->at(j); | |
271 if (ci->adjust(bci, delta)) return; | |
272 } | |
273 _changes->push(new ChangeJumpWiden(bci, new_delta)); | |
274 } | |
275 | |
276 | |
277 // The current instruction of "c" is a jump; one of its offset starts | |
278 // at "offset" and is a short if "isShort" is "TRUE", | |
279 // and an integer otherwise. If the jump crosses "breakPC", change | |
280 // the span of the jump by "delta". | |
281 void Relocator::change_jump(int bci, int offset, bool is_short, int break_bci, int delta) { | |
282 int bci_delta = (is_short) ? short_at(offset) : int_at(offset); | |
283 int targ = bci + bci_delta; | |
284 | |
285 if ((bci <= break_bci && targ > break_bci) || | |
286 (bci > break_bci && targ <= break_bci)) { | |
287 int new_delta; | |
288 if (bci_delta > 0) | |
289 new_delta = bci_delta + delta; | |
290 else | |
291 new_delta = bci_delta - delta; | |
292 | |
293 if (is_short && ((new_delta > MAX_SHORT) || new_delta < MIN_SHORT)) { | |
294 push_jump_widen(bci, delta, new_delta); | |
295 } else if (is_short) { | |
296 short_at_put(offset, new_delta); | |
297 } else { | |
298 int_at_put(offset, new_delta); | |
299 } | |
300 } | |
301 } | |
302 | |
303 | |
304 // Changes all jumps crossing "break_bci" by "delta". May enqueue things | |
305 // on "rc->changes" | |
306 void Relocator::change_jumps(int break_bci, int delta) { | |
307 int bci = 0; | |
308 Bytecodes::Code bc; | |
309 // Now, adjust any affected instructions. | |
310 while (bci < code_length()) { | |
311 switch (bc= code_at(bci)) { | |
312 case Bytecodes::_ifeq: | |
313 case Bytecodes::_ifne: | |
314 case Bytecodes::_iflt: | |
315 case Bytecodes::_ifge: | |
316 case Bytecodes::_ifgt: | |
317 case Bytecodes::_ifle: | |
318 case Bytecodes::_if_icmpeq: | |
319 case Bytecodes::_if_icmpne: | |
320 case Bytecodes::_if_icmplt: | |
321 case Bytecodes::_if_icmpge: | |
322 case Bytecodes::_if_icmpgt: | |
323 case Bytecodes::_if_icmple: | |
324 case Bytecodes::_if_acmpeq: | |
325 case Bytecodes::_if_acmpne: | |
326 case Bytecodes::_ifnull: | |
327 case Bytecodes::_ifnonnull: | |
328 case Bytecodes::_goto: | |
329 case Bytecodes::_jsr: | |
330 change_jump(bci, bci+1, true, break_bci, delta); | |
331 break; | |
332 case Bytecodes::_goto_w: | |
333 case Bytecodes::_jsr_w: | |
334 change_jump(bci, bci+1, false, break_bci, delta); | |
335 break; | |
336 case Bytecodes::_tableswitch: | |
337 case Bytecodes::_lookupswitch: | |
338 case Bytecodes::_fast_linearswitch: | |
339 case Bytecodes::_fast_binaryswitch: { | |
340 int recPad = get_orig_switch_pad(bci, (bc != Bytecodes::_tableswitch)); | |
341 int oldPad = (recPad != -1) ? recPad : align(bci+1) - (bci+1); | |
342 if (bci > break_bci) { | |
343 int new_bci = bci + delta; | |
344 int newPad = align(new_bci+1) - (new_bci+1); | |
345 // Do we need to check the padding? | |
346 if (newPad != oldPad) { | |
347 if (recPad == -1) { | |
348 _changes->push(new ChangeSwitchPad(bci, oldPad, (bc != Bytecodes::_tableswitch))); | |
349 } | |
350 } | |
351 } | |
352 | |
353 // Then the rest, which depend on the kind of switch. | |
354 switch (bc) { | |
355 case Bytecodes::_tableswitch: { | |
356 change_jump(bci, bci +1 + oldPad, false, break_bci, delta); | |
357 // We cannot use the Bytecode_tableswitch abstraction, since the padding might not be correct. | |
358 int lo = int_at(bci + 1 + oldPad + 4 * 1); | |
359 int hi = int_at(bci + 1 + oldPad + 4 * 2); | |
360 int n = hi - lo + 1; | |
361 for (int k = 0; k < n; k++) { | |
362 change_jump(bci, bci +1 + oldPad + 4*(k+3), false, break_bci, delta); | |
363 } | |
364 // Special next-bci calculation here... | |
365 bci += 1 + oldPad + (n+3)*4; | |
366 continue; | |
367 } | |
368 case Bytecodes::_lookupswitch: | |
369 case Bytecodes::_fast_linearswitch: | |
370 case Bytecodes::_fast_binaryswitch: { | |
371 change_jump(bci, bci +1 + oldPad, false, break_bci, delta); | |
372 // We cannot use the Bytecode_lookupswitch abstraction, since the padding might not be correct. | |
373 int npairs = int_at(bci + 1 + oldPad + 4 * 1); | |
374 for (int k = 0; k < npairs; k++) { | |
375 change_jump(bci, bci + 1 + oldPad + 4*(2 + 2*k + 1), false, break_bci, delta); | |
376 } | |
377 /* Special next-bci calculation here... */ | |
378 bci += 1 + oldPad + (2 + (npairs*2))*4; | |
379 continue; | |
380 } | |
381 default: | |
382 ShouldNotReachHere(); | |
383 } | |
384 } | |
385 default: | |
386 break; | |
387 } | |
388 bci += rc_instr_len(bci); | |
389 } | |
390 } | |
391 | |
392 // The width of instruction at "pc" is changing by "delta". Adjust the | |
393 // exception table, if any, of "rc->mb". | |
394 void Relocator::adjust_exception_table(int bci, int delta) { | |
395 typeArrayOop table = method()->exception_table(); | |
396 for (int index = 0; index < table->length(); index +=4) { | |
397 if (table->int_at(index) > bci) { | |
398 table->int_at_put(index+0, table->int_at(index+0) + delta); | |
399 table->int_at_put(index+1, table->int_at(index+1) + delta); | |
400 } else if (bci < table->int_at(index+1)) { | |
401 table->int_at_put(index+1, table->int_at(index+1) + delta); | |
402 } | |
403 if (table->int_at(index+2) > bci) | |
404 table->int_at_put(index+2, table->int_at(index+2) + delta); | |
405 } | |
406 } | |
407 | |
408 | |
409 // The width of instruction at "bci" is changing by "delta". Adjust the line number table. | |
410 void Relocator::adjust_line_no_table(int bci, int delta) { | |
411 if (method()->has_linenumber_table()) { | |
412 CompressedLineNumberReadStream reader(method()->compressed_linenumber_table()); | |
413 CompressedLineNumberWriteStream writer(64); // plenty big for most line number tables | |
414 while (reader.read_pair()) { | |
415 int adjustment = (reader.bci() > bci) ? delta : 0; | |
416 writer.write_pair(reader.bci() + adjustment, reader.line()); | |
417 } | |
418 writer.write_terminator(); | |
419 set_compressed_line_number_table(writer.buffer()); | |
420 set_compressed_line_number_table_size(writer.position()); | |
421 } | |
422 } | |
423 | |
424 | |
425 // The width of instruction at "bci" is changing by "delta". Adjust the local variable table. | |
426 void Relocator::adjust_local_var_table(int bci, int delta) { | |
427 int localvariable_table_length = method()->localvariable_table_length(); | |
428 if (localvariable_table_length > 0) { | |
429 LocalVariableTableElement* table = method()->localvariable_table_start(); | |
430 for (int i = 0; i < localvariable_table_length; i++) { | |
431 u2 current_bci = table[i].start_bci; | |
432 if (current_bci > bci) { | |
433 table[i].start_bci = current_bci + delta; | |
434 } else { | |
435 u2 current_length = table[i].length; | |
436 if (current_bci + current_length > bci) { | |
437 table[i].length = current_length + delta; | |
438 } | |
439 } | |
440 } | |
441 } | |
442 } | |
443 | |
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444 // Create a new array, copying the src array but adding a hole at |
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445 // the specified location |
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446 static typeArrayOop insert_hole_at( |
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447 size_t where, int hole_sz, typeArrayOop src) { |
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448 Thread* THREAD = Thread::current(); |
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449 Handle src_hnd(THREAD, src); |
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450 typeArrayOop dst = |
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451 oopFactory::new_permanent_byteArray(src->length() + hole_sz, CHECK_NULL); |
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452 src = (typeArrayOop)src_hnd(); |
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453 |
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454 address src_addr = (address)src->byte_at_addr(0); |
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455 address dst_addr = (address)dst->byte_at_addr(0); |
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456 |
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457 memcpy(dst_addr, src_addr, where); |
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458 memcpy(dst_addr + where + hole_sz, |
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459 src_addr + where, src->length() - where); |
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460 return dst; |
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461 } |
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462 |
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463 // The width of instruction at "bci" is changing by "delta". Adjust the stack |
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464 // map frames. |
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465 void Relocator::adjust_stack_map_table(int bci, int delta) { |
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466 if (method()->has_stackmap_table()) { |
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467 typeArrayOop data = method()->stackmap_data(); |
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468 // The data in the array is a classfile representation of the stackmap |
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469 // table attribute, less the initial u2 tag and u4 attribute_length fields. |
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470 stack_map_table_attribute* attr = stack_map_table_attribute::at( |
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471 (address)data->byte_at_addr(0) - (sizeof(u2) + sizeof(u4))); |
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472 |
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473 int count = attr->number_of_entries(); |
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474 stack_map_frame* frame = attr->entries(); |
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475 int bci_iter = -1; |
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476 bool offset_adjusted = false; // only need to adjust one offset |
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477 |
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478 for (int i = 0; i < count; ++i) { |
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479 int offset_delta = frame->offset_delta(); |
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480 bci_iter += offset_delta; |
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481 |
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482 if (!offset_adjusted && bci_iter > bci) { |
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483 int new_offset_delta = offset_delta + delta; |
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484 |
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485 if (frame->is_valid_offset(new_offset_delta)) { |
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486 frame->set_offset_delta(new_offset_delta); |
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487 } else { |
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488 assert(frame->is_same_frame() || |
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489 frame->is_same_frame_1_stack_item_frame(), |
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490 "Frame must be one of the compressed forms"); |
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491 // The new delta exceeds the capacity of the 'same_frame' or |
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492 // 'same_frame_1_stack_item_frame' frame types. We need to |
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493 // convert these frames to the extended versions, but the extended |
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494 // version is bigger and requires more room. So we allocate a |
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495 // new array and copy the data, being sure to leave u2-sized hole |
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496 // right after the 'frame_type' for the new offset field. |
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497 // |
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498 // We can safely ignore the reverse situation as a small delta |
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499 // can still be used in an extended version of the frame. |
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500 |
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501 size_t frame_offset = (address)frame - (address)data->byte_at_addr(0); |
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502 |
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503 data = insert_hole_at(frame_offset + 1, 2, data); |
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504 if (data == NULL) { |
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505 return; // out-of-memory? |
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506 } |
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507 |
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508 address frame_addr = (address)(data->byte_at_addr(0) + frame_offset); |
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509 frame = stack_map_frame::at(frame_addr); |
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510 |
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511 |
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512 // Now convert the frames in place |
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513 if (frame->is_same_frame()) { |
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514 same_frame_extended::create_at(frame_addr, new_offset_delta); |
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515 } else { |
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516 same_frame_1_stack_item_extended::create_at( |
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517 frame_addr, new_offset_delta, NULL); |
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518 // the verification_info_type should already be at the right spot |
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519 } |
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520 } |
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521 offset_adjusted = true; // needs to be done only once, since subsequent |
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522 // values are offsets from the current |
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523 } |
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524 |
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525 // The stack map frame may contain verification types, if so we need to |
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526 // check and update any Uninitialized type's bci (no matter where it is). |
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527 int number_of_types = frame->number_of_types(); |
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528 verification_type_info* types = frame->types(); |
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529 |
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530 for (int i = 0; i < number_of_types; ++i) { |
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531 if (types->is_uninitialized() && types->bci() > bci) { |
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532 types->set_bci(types->bci() + delta); |
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533 } |
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534 types = types->next(); |
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535 } |
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536 |
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537 // Full frame has stack values too |
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538 full_frame* ff = frame->as_full_frame(); |
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539 if (ff != NULL) { |
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540 address eol = (address)types; |
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541 number_of_types = ff->stack_slots(eol); |
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542 types = ff->stack(eol); |
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543 for (int i = 0; i < number_of_types; ++i) { |
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544 if (types->is_uninitialized() && types->bci() > bci) { |
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545 types->set_bci(types->bci() + delta); |
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546 } |
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547 types = types->next(); |
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548 } |
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549 } |
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550 |
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551 frame = frame->next(); |
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552 } |
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553 |
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554 method()->set_stackmap_data(data); // in case it has changed |
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555 } |
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556 } |
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557 |
0 | 558 |
559 bool Relocator::expand_code_array(int delta) { | |
560 int length = MAX2(code_length() + delta, code_length() * (100+code_slop_pct()) / 100); | |
561 | |
562 if (length > MAX_METHOD_LENGTH) { | |
563 if (delta == 0 && code_length() <= MAX_METHOD_LENGTH) { | |
564 length = MAX_METHOD_LENGTH; | |
565 } else { | |
566 return false; | |
567 } | |
568 } | |
569 | |
570 unsigned char* new_code_array = NEW_RESOURCE_ARRAY(unsigned char, length); | |
571 if (!new_code_array) return false; | |
572 | |
573 // Expanding current array | |
574 if (code_array() != NULL) { | |
575 memcpy(new_code_array, code_array(), code_length()); | |
576 } else { | |
577 // Initial copy. Copy directly from methodOop | |
578 memcpy(new_code_array, method()->code_base(), code_length()); | |
579 } | |
580 | |
581 set_code_array(new_code_array); | |
582 set_code_array_length(length); | |
583 | |
584 return true; | |
585 } | |
586 | |
587 | |
588 // The instruction at "bci", whose size is "ilen", is changing size by | |
589 // "delta". Reallocate, move code, recalculate jumps, and enqueue | |
590 // change items as necessary. | |
591 bool Relocator::relocate_code(int bci, int ilen, int delta) { | |
592 int next_bci = bci + ilen; | |
593 if (delta > 0 && code_length() + delta > code_array_length()) { | |
594 // Expand allocated code space, if necessary. | |
595 if (!expand_code_array(delta)) { | |
596 return false; | |
597 } | |
598 } | |
599 | |
600 // We require 4-byte alignment of code arrays. | |
601 assert(((intptr_t)code_array() & 3) == 0, "check code alignment"); | |
602 // Change jumps before doing the copying; this routine requires aligned switches. | |
603 change_jumps(bci, delta); | |
604 | |
605 // In case we have shrunken a tableswitch/lookupswitch statement, we store the last | |
606 // bytes that get overwritten. We have to copy the bytes after the change_jumps method | |
607 // has been called, since it is likly to update last offset in a tableswitch/lookupswitch | |
608 if (delta < 0) { | |
609 assert(delta>=-3, "we cannot overwrite more than 3 bytes"); | |
610 memcpy(_overwrite, addr_at(bci + ilen + delta), -delta); | |
611 } | |
612 | |
613 memmove(addr_at(next_bci + delta), addr_at(next_bci), code_length() - next_bci); | |
614 set_code_length(code_length() + delta); | |
615 // Also adjust exception tables... | |
616 adjust_exception_table(bci, delta); | |
617 // Line number tables... | |
618 adjust_line_no_table(bci, delta); | |
619 // And local variable table... | |
620 adjust_local_var_table(bci, delta); | |
621 | |
1877
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622 // Adjust stack maps |
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623 adjust_stack_map_table(bci, delta); |
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624 |
0 | 625 // Relocate the pending change stack... |
626 for (int j = 0; j < _changes->length(); j++) { | |
627 ChangeItem* ci = _changes->at(j); | |
628 ci->relocate(bci, delta); | |
629 } | |
630 | |
631 // Notify any listeners about code relocation | |
632 notify(bci, delta, code_length()); | |
633 | |
634 return true; | |
635 } | |
636 | |
637 // relocate a general instruction. Called by ChangeWiden class | |
638 bool Relocator::handle_widen(int bci, int new_ilen, u_char inst_buffer[]) { | |
639 int ilen = rc_instr_len(bci); | |
640 if (!relocate_code(bci, ilen, new_ilen - ilen)) | |
641 return false; | |
642 | |
643 // Insert new bytecode(s) | |
644 for(int k = 0; k < new_ilen; k++) { | |
645 code_at_put(bci + k, (Bytecodes::Code)inst_buffer[k]); | |
646 } | |
647 | |
648 return true; | |
649 } | |
650 | |
651 // handle jump_widen instruction. Called be ChangeJumpWiden class | |
652 bool Relocator::handle_jump_widen(int bci, int delta) { | |
653 int ilen = rc_instr_len(bci); | |
654 | |
655 Bytecodes::Code bc = code_at(bci); | |
656 switch (bc) { | |
657 case Bytecodes::_ifeq: | |
658 case Bytecodes::_ifne: | |
659 case Bytecodes::_iflt: | |
660 case Bytecodes::_ifge: | |
661 case Bytecodes::_ifgt: | |
662 case Bytecodes::_ifle: | |
663 case Bytecodes::_if_icmpeq: | |
664 case Bytecodes::_if_icmpne: | |
665 case Bytecodes::_if_icmplt: | |
666 case Bytecodes::_if_icmpge: | |
667 case Bytecodes::_if_icmpgt: | |
668 case Bytecodes::_if_icmple: | |
669 case Bytecodes::_if_acmpeq: | |
670 case Bytecodes::_if_acmpne: | |
671 case Bytecodes::_ifnull: | |
672 case Bytecodes::_ifnonnull: { | |
673 const int goto_length = Bytecodes::length_for(Bytecodes::_goto); | |
674 | |
675 // If 'if' points to the next bytecode after goto, it's already handled. | |
676 // it shouldn't be. | |
677 assert (short_at(bci+1) != ilen+goto_length, "if relocation already handled"); | |
678 assert(ilen == 3, "check length"); | |
679 | |
680 // Convert to 0 if <cond> goto 6 | |
681 // 3 _goto 11 | |
682 // 6 _goto_w <wide delta offset> | |
683 // 11 <else code> | |
684 const int goto_w_length = Bytecodes::length_for(Bytecodes::_goto_w); | |
685 const int add_bci = goto_length + goto_w_length; | |
686 | |
687 if (!relocate_code(bci, 3, /*delta*/add_bci)) return false; | |
688 | |
689 // if bytecode points to goto_w instruction | |
690 short_at_put(bci + 1, ilen + goto_length); | |
691 | |
692 int cbci = bci + ilen; | |
693 // goto around | |
694 code_at_put(cbci, Bytecodes::_goto); | |
695 short_at_put(cbci + 1, add_bci); | |
696 // goto_w <wide delta> | |
697 cbci = cbci + goto_length; | |
698 code_at_put(cbci, Bytecodes::_goto_w); | |
699 if (delta > 0) { | |
700 delta += 2; // goto_w is 2 bytes more than "if" code | |
701 } else { | |
702 delta -= ilen+goto_length; // branch starts at goto_w offset | |
703 } | |
704 int_at_put(cbci + 1, delta); | |
705 break; | |
706 | |
707 } | |
708 case Bytecodes::_goto: | |
709 case Bytecodes::_jsr: | |
710 assert(ilen == 3, "check length"); | |
711 | |
712 if (!relocate_code(bci, 3, 2)) return false; | |
713 if (bc == Bytecodes::_goto) | |
714 code_at_put(bci, Bytecodes::_goto_w); | |
715 else | |
716 code_at_put(bci, Bytecodes::_jsr_w); | |
717 | |
718 // If it's a forward jump, add 2 for the widening. | |
719 if (delta > 0) delta += 2; | |
720 int_at_put(bci + 1, delta); | |
721 break; | |
722 | |
723 default: ShouldNotReachHere(); | |
724 } | |
725 | |
726 return true; | |
727 } | |
728 | |
729 // handle lookup/table switch instructions. Called be ChangeSwitchPad class | |
730 bool Relocator::handle_switch_pad(int bci, int old_pad, bool is_lookup_switch) { | |
731 int ilen = rc_instr_len(bci); | |
732 int new_pad = align(bci+1) - (bci+1); | |
733 int pad_delta = new_pad - old_pad; | |
734 if (pad_delta != 0) { | |
735 int len; | |
736 if (!is_lookup_switch) { | |
737 int low = int_at(bci+1+old_pad+4); | |
738 int high = int_at(bci+1+old_pad+8); | |
739 len = high-low+1 + 3; // 3 for default, hi, lo. | |
740 } else { | |
741 int npairs = int_at(bci+1+old_pad+4); | |
742 len = npairs*2 + 2; // 2 for default, npairs. | |
743 } | |
744 // Because "relocateCode" does a "changeJumps" loop, | |
745 // which parses instructions to determine their length, | |
746 // we need to call that before messing with the current | |
747 // instruction. Since it may also overwrite the current | |
748 // instruction when moving down, remember the possibly | |
749 // overwritten part. | |
750 | |
751 // Move the code following the instruction... | |
752 if (!relocate_code(bci, ilen, pad_delta)) return false; | |
753 | |
754 if (pad_delta < 0) { | |
755 // Move the shrunken instruction down. | |
756 memmove(addr_at(bci + 1 + new_pad), | |
757 addr_at(bci + 1 + old_pad), | |
758 len * 4 + pad_delta); | |
759 memmove(addr_at(bci + 1 + new_pad + len*4 + pad_delta), | |
760 _overwrite, -pad_delta); | |
761 } else { | |
762 assert(pad_delta > 0, "check"); | |
763 // Move the expanded instruction up. | |
764 memmove(addr_at(bci +1 + new_pad), | |
765 addr_at(bci +1 + old_pad), | |
766 len * 4); | |
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a4c7fe54bf3f
6991315: RedefineClasses fails with java.lang.VerifyError
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changeset
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767 memset(addr_at(bci + 1), 0, new_pad); // pad must be 0 |
0 | 768 } |
769 } | |
770 return true; | |
771 } |