1 /* 2 * Copyright (c) 2000, 2018, 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 "logging/log.hpp" 27 #include "memory/resourceArea.hpp" 28 #include "oops/constantPool.inline.hpp" 29 #include "oops/oop.inline.hpp" 30 #include "oops/symbol.hpp" 31 #include "prims/methodComparator.hpp" 32 #include "runtime/handles.inline.hpp" 33 #include "utilities/globalDefinitions.hpp" 34 35 BytecodeStream *MethodComparator::_s_old; 36 BytecodeStream *MethodComparator::_s_new; 37 ConstantPool* MethodComparator::_old_cp; 38 ConstantPool* MethodComparator::_new_cp; 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 if (log_is_enabled(Debug, redefine, class, methodcomparator)) { 45 ResourceMark rm; 46 log_debug(redefine, class, methodcomparator) 47 ("Methods %s non-comparable with diagnosis %d", 48 old_method->name()->as_C_string(), check_stack_and_locals_size(old_method, new_method)); 49 } 50 return false; 51 } 52 53 _old_cp = old_method->constants(); 54 _new_cp = new_method->constants(); 55 BytecodeStream s_old(old_method); 56 BytecodeStream s_new(new_method); 57 _s_old = &s_old; 58 _s_new = &s_new; 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 (old_ofs != new_ofs) 221 return false; 222 break; 223 } 224 225 case Bytecodes::_iinc : 226 if (_s_old->is_wide() != _s_new->is_wide()) 227 return false; 228 if (! _s_old->is_wide()) { 229 // We could use get_index_u1 and get_constant_u1, but it's simpler to grab both bytes at once: 230 if (Bytes::get_Java_u2(_s_old->bcp() + 1) != Bytes::get_Java_u2(_s_new->bcp() + 1)) 231 return false; 232 } else { 233 // We could use get_index_u2 and get_constant_u2, but it's simpler to grab all four bytes at once: 234 if (Bytes::get_Java_u4(_s_old->bcp() + 1) != Bytes::get_Java_u4(_s_new->bcp() + 1)) 235 return false; 236 } 237 break; 238 239 case Bytecodes::_goto_w : // fall through 240 case Bytecodes::_jsr_w : { 241 int old_ofs = _s_old->bytecode().get_offset_s4(c_old); 242 int new_ofs = _s_new->bytecode().get_offset_s4(c_new); 243 if (old_ofs != new_ofs) 244 return false; 245 break; 246 } 247 248 case Bytecodes::_lookupswitch : // fall through 249 case Bytecodes::_tableswitch : { 250 int len_old = _s_old->instruction_size(); 251 int len_new = _s_new->instruction_size(); 252 if (len_old != len_new) 253 return false; 254 if (memcmp(_s_old->bcp(), _s_new->bcp(), len_old) != 0) 255 return false; 256 break; 257 } 258 259 default: 260 break; 261 } 262 263 return true; 264 } 265 266 bool MethodComparator::pool_constants_same(int cpi_old, int cpi_new) { 267 constantTag tag_old = _old_cp->tag_at(cpi_old); 268 constantTag tag_new = _new_cp->tag_at(cpi_new); 269 if (tag_old.is_int() || tag_old.is_float()) { 270 if (tag_old.value() != tag_new.value()) 271 return false; 272 if (tag_old.is_int()) { 273 if (_old_cp->int_at(cpi_old) != _new_cp->int_at(cpi_new)) 274 return false; 275 } else { 276 // Use jint_cast to compare the bits rather than numerical values. 277 // This makes a difference for NaN constants. 278 if (jint_cast(_old_cp->float_at(cpi_old)) != jint_cast(_new_cp->float_at(cpi_new))) 279 return false; 280 } 281 } else if (tag_old.is_string() && tag_new.is_string()) { 282 if (strcmp(_old_cp->string_at_noresolve(cpi_old), 283 _new_cp->string_at_noresolve(cpi_new)) != 0) 284 return false; 285 if (_old_cp->is_pseudo_string_at(cpi_old) || _new_cp->is_pseudo_string_at(cpi_new)) 286 return (_old_cp->is_pseudo_string_at(cpi_old) == _new_cp->is_pseudo_string_at(cpi_new)); 287 } else if (tag_old.is_klass() || tag_old.is_unresolved_klass()) { 288 // tag_old should be klass - 4881222 289 if (! (tag_new.is_unresolved_klass() || tag_new.is_klass())) 290 return false; 291 if (_old_cp->klass_at_noresolve(cpi_old) != 292 _new_cp->klass_at_noresolve(cpi_new)) 293 return false; 294 } else if (tag_old.is_method_type() && tag_new.is_method_type()) { 295 int mti_old = _old_cp->method_type_index_at(cpi_old); 296 int mti_new = _new_cp->method_type_index_at(cpi_new); 297 if ((_old_cp->symbol_at(mti_old) != _new_cp->symbol_at(mti_new))) 298 return false; 299 } else if (tag_old.is_method_handle() && tag_new.is_method_handle()) { 300 if (_old_cp->method_handle_ref_kind_at(cpi_old) != 301 _new_cp->method_handle_ref_kind_at(cpi_new)) 302 return false; 303 int mhi_old = _old_cp->method_handle_index_at(cpi_old); 304 int mhi_new = _new_cp->method_handle_index_at(cpi_new); 305 if ((_old_cp->uncached_klass_ref_at_noresolve(mhi_old) != _new_cp->uncached_klass_ref_at_noresolve(mhi_new)) || 306 (_old_cp->uncached_name_ref_at(mhi_old) != _new_cp->uncached_name_ref_at(mhi_new)) || 307 (_old_cp->uncached_signature_ref_at(mhi_old) != _new_cp->uncached_signature_ref_at(mhi_new))) 308 return false; 309 } else { 310 return false; // unknown tag 311 } 312 return true; 313 } 314 315 316 int MethodComparator::check_stack_and_locals_size(Method* old_method, Method* new_method) { 317 if (old_method->max_stack() != new_method->max_stack()) { 318 return 1; 319 } else if (old_method->max_locals() != new_method->max_locals()) { 320 return 2; 321 } else if (old_method->size_of_parameters() != new_method->size_of_parameters()) { 322 return 3; 323 } else return 0; 324 }