1 /*
2 * Copyright (c) 2000, 2016, 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.
18 *
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.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "oops/oop.inline.hpp"
27 #include "oops/symbol.hpp"
28 #include "prims/jvmtiRedefineClassesTrace.hpp"
29 #include "prims/methodComparator.hpp"
30 #include "runtime/handles.inline.hpp"
31 #include "utilities/globalDefinitions.hpp"
32
33 BytecodeStream *MethodComparator::_s_old;
34 BytecodeStream *MethodComparator::_s_new;
35 ConstantPool* MethodComparator::_old_cp;
36 ConstantPool* MethodComparator::_new_cp;
37 BciMap *MethodComparator::_bci_map;
38 bool MethodComparator::_switchable_test;
39 GrowableArray<int> *MethodComparator::_fwd_jmps;
40
41 bool MethodComparator::methods_EMCP(Method* old_method, Method* new_method) {
42 if (old_method->code_size() != new_method->code_size())
43 return false;
44 if (check_stack_and_locals_size(old_method, new_method) != 0) {
45 // RC_TRACE macro has an embedded ResourceMark
46 RC_TRACE(0x00800000, ("Methods %s non-comparable with diagnosis %d",
47 old_method->name()->as_C_string(),
48 check_stack_and_locals_size(old_method, new_method)));
49 return false;
50 }
51
52 _old_cp = old_method->constants();
53 _new_cp = new_method->constants();
54 BytecodeStream s_old(old_method);
55 BytecodeStream s_new(new_method);
56 _s_old = &s_old;
57 _s_new = &s_new;
58 _switchable_test = false;
59 Bytecodes::Code c_old, c_new;
60
61 while ((c_old = s_old.next()) >= 0) {
62 if ((c_new = s_new.next()) < 0 || c_old != c_new)
63 return false;
64
65 if (! args_same(c_old, c_new))
66 return false;
67 }
68 return true;
69 }
70
71 bool MethodComparator::args_same(Bytecodes::Code c_old, Bytecodes::Code c_new) {
72 // BytecodeStream returns the correct standard Java bytecodes for various "fast"
73 // bytecode versions, so we don't have to bother about them here..
74 switch (c_old) {
75 case Bytecodes::_new : // fall through
76 case Bytecodes::_anewarray : // fall through
77 case Bytecodes::_multianewarray : // fall through
78 case Bytecodes::_checkcast : // fall through
79 case Bytecodes::_instanceof : {
80 u2 cpi_old = _s_old->get_index_u2();
81 u2 cpi_new = _s_new->get_index_u2();
82 if ((_old_cp->klass_at_noresolve(cpi_old) != _new_cp->klass_at_noresolve(cpi_new)))
83 return false;
84 if (c_old == Bytecodes::_multianewarray &&
85 *(jbyte*)(_s_old->bcp() + 3) != *(jbyte*)(_s_new->bcp() + 3))
86 return false;
87 break;
88 }
89
90 case Bytecodes::_getstatic : // fall through
91 case Bytecodes::_putstatic : // fall through
92 case Bytecodes::_getfield : // fall through
93 case Bytecodes::_putfield : // fall through
94 case Bytecodes::_invokevirtual : // fall through
95 case Bytecodes::_invokespecial : // fall through
96 case Bytecodes::_invokestatic : // fall through
97 case Bytecodes::_invokeinterface : {
98 int cpci_old = _s_old->get_index_u2_cpcache();
99 int cpci_new = _s_new->get_index_u2_cpcache();
100 // Check if the names of classes, field/method names and signatures at these indexes
101 // are the same. Indices which are really into constantpool cache (rather than constant
102 // pool itself) are accepted by the constantpool query routines below.
103 if ((_old_cp->klass_ref_at_noresolve(cpci_old) != _new_cp->klass_ref_at_noresolve(cpci_new)) ||
104 (_old_cp->name_ref_at(cpci_old) != _new_cp->name_ref_at(cpci_new)) ||
105 (_old_cp->signature_ref_at(cpci_old) != _new_cp->signature_ref_at(cpci_new)))
106 return false;
107 break;
108 }
109 case Bytecodes::_invokedynamic: {
110 int cpci_old = _s_old->get_index_u4();
111 int cpci_new = _s_new->get_index_u4();
112
113 // Check if the names of classes, field/method names and signatures at these indexes
114 // are the same. Indices which are really into constantpool cache (rather than constant
115 // pool itself) are accepted by the constantpool query routines below.
116 if ((_old_cp->name_ref_at(cpci_old) != _new_cp->name_ref_at(cpci_new)) ||
117 (_old_cp->signature_ref_at(cpci_old) != _new_cp->signature_ref_at(cpci_new)))
118 return false;
119
120 // Translate object indexes to constant pool cache indexes.
121 cpci_old = _old_cp->invokedynamic_cp_cache_index(cpci_old);
122 cpci_new = _new_cp->invokedynamic_cp_cache_index(cpci_new);
123
124 int cpi_old = _old_cp->cache()->entry_at(cpci_old)->constant_pool_index();
125 int cpi_new = _new_cp->cache()->entry_at(cpci_new)->constant_pool_index();
126 int bsm_old = _old_cp->invoke_dynamic_bootstrap_method_ref_index_at(cpi_old);
127 int bsm_new = _new_cp->invoke_dynamic_bootstrap_method_ref_index_at(cpi_new);
128 if (!pool_constants_same(bsm_old, bsm_new))
129 return false;
130 int cnt_old = _old_cp->invoke_dynamic_argument_count_at(cpi_old);
131 int cnt_new = _new_cp->invoke_dynamic_argument_count_at(cpi_new);
132 if (cnt_old != cnt_new)
133 return false;
134 for (int arg_i = 0; arg_i < cnt_old; arg_i++) {
135 int idx_old = _old_cp->invoke_dynamic_argument_index_at(cpi_old, arg_i);
136 int idx_new = _new_cp->invoke_dynamic_argument_index_at(cpi_new, arg_i);
137 if (!pool_constants_same(idx_old, idx_new))
138 return false;
139 }
140 break;
141 }
142
143 case Bytecodes::_ldc : // fall through
144 case Bytecodes::_ldc_w : {
145 Bytecode_loadconstant ldc_old(_s_old->method(), _s_old->bci());
146 Bytecode_loadconstant ldc_new(_s_new->method(), _s_new->bci());
147 int cpi_old = ldc_old.pool_index();
148 int cpi_new = ldc_new.pool_index();
149 if (!pool_constants_same(cpi_old, cpi_new))
150 return false;
151 break;
152 }
153
154 case Bytecodes::_ldc2_w : {
155 u2 cpi_old = _s_old->get_index_u2();
156 u2 cpi_new = _s_new->get_index_u2();
157 constantTag tag_old = _old_cp->tag_at(cpi_old);
158 constantTag tag_new = _new_cp->tag_at(cpi_new);
159 if (tag_old.value() != tag_new.value())
160 return false;
161 if (tag_old.is_long()) {
162 if (_old_cp->long_at(cpi_old) != _new_cp->long_at(cpi_new))
163 return false;
164 } else {
165 // Use jlong_cast to compare the bits rather than numerical values.
166 // This makes a difference for NaN constants.
167 if (jlong_cast(_old_cp->double_at(cpi_old)) != jlong_cast(_new_cp->double_at(cpi_new)))
168 return false;
169 }
170 break;
171 }
172
173 case Bytecodes::_bipush :
174 if (_s_old->bcp()[1] != _s_new->bcp()[1])
175 return false;
176 break;
177
178 case Bytecodes::_sipush :
179 if (_s_old->get_index_u2() != _s_new->get_index_u2())
180 return false;
181 break;
182
183 case Bytecodes::_aload : // fall through
184 case Bytecodes::_astore : // fall through
185 case Bytecodes::_dload : // fall through
186 case Bytecodes::_dstore : // fall through
187 case Bytecodes::_fload : // fall through
188 case Bytecodes::_fstore : // fall through
189 case Bytecodes::_iload : // fall through
190 case Bytecodes::_istore : // fall through
191 case Bytecodes::_lload : // fall through
192 case Bytecodes::_lstore : // fall through
193 case Bytecodes::_ret :
194 if (_s_old->is_wide() != _s_new->is_wide())
195 return false;
196 if (_s_old->get_index() != _s_new->get_index())
197 return false;
198 break;
199
200 case Bytecodes::_goto : // fall through
201 case Bytecodes::_if_acmpeq : // fall through
202 case Bytecodes::_if_acmpne : // fall through
203 case Bytecodes::_if_icmpeq : // fall through
204 case Bytecodes::_if_icmpne : // fall through
205 case Bytecodes::_if_icmplt : // fall through
206 case Bytecodes::_if_icmpge : // fall through
207 case Bytecodes::_if_icmpgt : // fall through
208 case Bytecodes::_if_icmple : // fall through
209 case Bytecodes::_ifeq : // fall through
210 case Bytecodes::_ifne : // fall through
211 case Bytecodes::_iflt : // fall through
212 case Bytecodes::_ifge : // fall through
213 case Bytecodes::_ifgt : // fall through
214 case Bytecodes::_ifle : // fall through
215 case Bytecodes::_ifnonnull : // fall through
216 case Bytecodes::_ifnull : // fall through
217 case Bytecodes::_jsr : {
218 int old_ofs = _s_old->bytecode().get_offset_s2(c_old);
219 int new_ofs = _s_new->bytecode().get_offset_s2(c_new);
220 if (_switchable_test) {
221 int old_dest = _s_old->bci() + old_ofs;
222 int new_dest = _s_new->bci() + new_ofs;
223 if (old_ofs < 0 && new_ofs < 0) {
224 if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))
225 return false;
226 } else if (old_ofs > 0 && new_ofs > 0) {
227 _fwd_jmps->append(old_dest);
228 _fwd_jmps->append(new_dest);
229 } else {
230 return false;
231 }
232 } else {
233 if (old_ofs != new_ofs)
234 return false;
235 }
236 break;
237 }
238
239 case Bytecodes::_iinc :
240 if (_s_old->is_wide() != _s_new->is_wide())
241 return false;
242 if (! _s_old->is_wide()) {
243 // We could use get_index_u1 and get_constant_u1, but it's simpler to grab both bytes at once:
244 if (Bytes::get_Java_u2(_s_old->bcp() + 1) != Bytes::get_Java_u2(_s_new->bcp() + 1))
245 return false;
246 } else {
247 // We could use get_index_u2 and get_constant_u2, but it's simpler to grab all four bytes at once:
248 if (Bytes::get_Java_u4(_s_old->bcp() + 1) != Bytes::get_Java_u4(_s_new->bcp() + 1))
249 return false;
250 }
251 break;
252
253 case Bytecodes::_goto_w : // fall through
254 case Bytecodes::_jsr_w : {
255 int old_ofs = _s_old->bytecode().get_offset_s4(c_old);
256 int new_ofs = _s_new->bytecode().get_offset_s4(c_new);
257 if (_switchable_test) {
258 int old_dest = _s_old->bci() + old_ofs;
259 int new_dest = _s_new->bci() + new_ofs;
260 if (old_ofs < 0 && new_ofs < 0) {
261 if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))
262 return false;
263 } else if (old_ofs > 0 && new_ofs > 0) {
264 _fwd_jmps->append(old_dest);
265 _fwd_jmps->append(new_dest);
266 } else {
267 return false;
268 }
269 } else {
270 if (old_ofs != new_ofs)
271 return false;
272 }
273 break;
274 }
275
276 case Bytecodes::_lookupswitch : // fall through
277 case Bytecodes::_tableswitch : {
278 if (_switchable_test) {
279 address aligned_bcp_old = (address) round_to((intptr_t)_s_old->bcp() + 1, jintSize);
280 address aligned_bcp_new = (address) round_to((intptr_t)_s_new->bcp() + 1, jintSize);
281 int default_old = (int) Bytes::get_Java_u4(aligned_bcp_old);
282 int default_new = (int) Bytes::get_Java_u4(aligned_bcp_new);
283 _fwd_jmps->append(_s_old->bci() + default_old);
284 _fwd_jmps->append(_s_new->bci() + default_new);
285 if (c_old == Bytecodes::_lookupswitch) {
286 int npairs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);
287 int npairs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);
288 if (npairs_old != npairs_new)
289 return false;
290 for (int i = 0; i < npairs_old; i++) {
291 int match_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i)*jintSize);
292 int match_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i)*jintSize);
293 if (match_old != match_new)
294 return false;
295 int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i+1)*jintSize);
296 int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i+1)*jintSize);
297 _fwd_jmps->append(_s_old->bci() + ofs_old);
298 _fwd_jmps->append(_s_new->bci() + ofs_new);
299 }
300 } else if (c_old == Bytecodes::_tableswitch) {
301 int lo_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);
302 int lo_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);
303 if (lo_old != lo_new)
304 return false;
305 int hi_old = (int) Bytes::get_Java_u4(aligned_bcp_old + 2*jintSize);
306 int hi_new = (int) Bytes::get_Java_u4(aligned_bcp_new + 2*jintSize);
307 if (hi_old != hi_new)
308 return false;
309 for (int i = 0; i < hi_old - lo_old + 1; i++) {
310 int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (3+i)*jintSize);
311 int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (3+i)*jintSize);
312 _fwd_jmps->append(_s_old->bci() + ofs_old);
313 _fwd_jmps->append(_s_new->bci() + ofs_new);
314 }
315 }
316 } else { // !_switchable_test, can use fast rough compare
317 int len_old = _s_old->instruction_size();
318 int len_new = _s_new->instruction_size();
319 if (len_old != len_new)
320 return false;
321 if (memcmp(_s_old->bcp(), _s_new->bcp(), len_old) != 0)
322 return false;
323 }
324 break;
325 }
326 }
327
328 return true;
329 }
330
331 bool MethodComparator::pool_constants_same(int cpi_old, int cpi_new) {
332 constantTag tag_old = _old_cp->tag_at(cpi_old);
333 constantTag tag_new = _new_cp->tag_at(cpi_new);
334 if (tag_old.is_int() || tag_old.is_float()) {
335 if (tag_old.value() != tag_new.value())
336 return false;
337 if (tag_old.is_int()) {
338 if (_old_cp->int_at(cpi_old) != _new_cp->int_at(cpi_new))
339 return false;
340 } else {
341 // Use jint_cast to compare the bits rather than numerical values.
342 // This makes a difference for NaN constants.
343 if (jint_cast(_old_cp->float_at(cpi_old)) != jint_cast(_new_cp->float_at(cpi_new)))
344 return false;
345 }
346 } else if (tag_old.is_string() && tag_new.is_string()) {
347 if (strcmp(_old_cp->string_at_noresolve(cpi_old),
348 _new_cp->string_at_noresolve(cpi_new)) != 0)
349 return false;
350 if (_old_cp->is_pseudo_string_at(cpi_old) || _new_cp->is_pseudo_string_at(cpi_new))
351 return (_old_cp->is_pseudo_string_at(cpi_old) == _new_cp->is_pseudo_string_at(cpi_new));
352 } else if (tag_old.is_klass() || tag_old.is_unresolved_klass()) {
353 // tag_old should be klass - 4881222
354 if (! (tag_new.is_unresolved_klass() || tag_new.is_klass()))
355 return false;
356 if (_old_cp->klass_at_noresolve(cpi_old) !=
357 _new_cp->klass_at_noresolve(cpi_new))
358 return false;
359 } else if (tag_old.is_method_type() && tag_new.is_method_type()) {
360 int mti_old = _old_cp->method_type_index_at(cpi_old);
361 int mti_new = _new_cp->method_type_index_at(cpi_new);
362 if ((_old_cp->symbol_at(mti_old) != _new_cp->symbol_at(mti_new)))
363 return false;
364 } else if (tag_old.is_method_handle() && tag_new.is_method_handle()) {
365 if (_old_cp->method_handle_ref_kind_at(cpi_old) !=
366 _new_cp->method_handle_ref_kind_at(cpi_new))
367 return false;
368 int mhi_old = _old_cp->method_handle_index_at(cpi_old);
369 int mhi_new = _new_cp->method_handle_index_at(cpi_new);
370 if ((_old_cp->uncached_klass_ref_at_noresolve(mhi_old) != _new_cp->uncached_klass_ref_at_noresolve(mhi_new)) ||
371 (_old_cp->uncached_name_ref_at(mhi_old) != _new_cp->uncached_name_ref_at(mhi_new)) ||
372 (_old_cp->uncached_signature_ref_at(mhi_old) != _new_cp->uncached_signature_ref_at(mhi_new)))
373 return false;
374 } else {
375 return false; // unknown tag
376 }
377 return true;
378 }
379
380
381 int MethodComparator::check_stack_and_locals_size(Method* old_method, Method* new_method) {
382 if (old_method->max_stack() != new_method->max_stack()) {
383 return 1;
384 } else if (old_method->max_locals() != new_method->max_locals()) {
385 return 2;
386 } else if (old_method->size_of_parameters() != new_method->size_of_parameters()) {
387 return 3;
388 } else return 0;
389 }