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