1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/prims/methodComparator.cpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,445 @@
1.4 +/*
1.5 + * Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "precompiled.hpp"
1.29 +#include "oops/oop.inline.hpp"
1.30 +#include "oops/symbol.hpp"
1.31 +#include "prims/jvmtiRedefineClassesTrace.hpp"
1.32 +#include "prims/methodComparator.hpp"
1.33 +#include "runtime/handles.inline.hpp"
1.34 +#include "utilities/globalDefinitions.hpp"
1.35 +
1.36 +BytecodeStream *MethodComparator::_s_old;
1.37 +BytecodeStream *MethodComparator::_s_new;
1.38 +ConstantPool* MethodComparator::_old_cp;
1.39 +ConstantPool* MethodComparator::_new_cp;
1.40 +BciMap *MethodComparator::_bci_map;
1.41 +bool MethodComparator::_switchable_test;
1.42 +GrowableArray<int> *MethodComparator::_fwd_jmps;
1.43 +
1.44 +bool MethodComparator::methods_EMCP(Method* old_method, Method* new_method) {
1.45 + if (old_method->code_size() != new_method->code_size())
1.46 + return false;
1.47 + if (check_stack_and_locals_size(old_method, new_method) != 0) {
1.48 + // RC_TRACE macro has an embedded ResourceMark
1.49 + RC_TRACE(0x00800000, ("Methods %s non-comparable with diagnosis %d",
1.50 + old_method->name()->as_C_string(),
1.51 + check_stack_and_locals_size(old_method, new_method)));
1.52 + return false;
1.53 + }
1.54 +
1.55 + _old_cp = old_method->constants();
1.56 + _new_cp = new_method->constants();
1.57 + BytecodeStream s_old(old_method);
1.58 + BytecodeStream s_new(new_method);
1.59 + _s_old = &s_old;
1.60 + _s_new = &s_new;
1.61 + _switchable_test = false;
1.62 + Bytecodes::Code c_old, c_new;
1.63 +
1.64 + while ((c_old = s_old.next()) >= 0) {
1.65 + if ((c_new = s_new.next()) < 0 || c_old != c_new)
1.66 + return false;
1.67 +
1.68 + if (! args_same(c_old, c_new))
1.69 + return false;
1.70 + }
1.71 + return true;
1.72 +}
1.73 +
1.74 +
1.75 +bool MethodComparator::methods_switchable(Method* old_method, Method* new_method,
1.76 + BciMap &bci_map) {
1.77 + if (old_method->code_size() > new_method->code_size())
1.78 + // Something has definitely been deleted in the new method, compared to the old one.
1.79 + return false;
1.80 +
1.81 + if (! check_stack_and_locals_size(old_method, new_method))
1.82 + return false;
1.83 +
1.84 + _old_cp = old_method->constants();
1.85 + _new_cp = new_method->constants();
1.86 + BytecodeStream s_old(old_method);
1.87 + BytecodeStream s_new(new_method);
1.88 + _s_old = &s_old;
1.89 + _s_new = &s_new;
1.90 + _bci_map = &bci_map;
1.91 + _switchable_test = true;
1.92 + GrowableArray<int> fwd_jmps(16);
1.93 + _fwd_jmps = &fwd_jmps;
1.94 + Bytecodes::Code c_old, c_new;
1.95 +
1.96 + while ((c_old = s_old.next()) >= 0) {
1.97 + if ((c_new = s_new.next()) < 0)
1.98 + return false;
1.99 + if (! (c_old == c_new && args_same(c_old, c_new))) {
1.100 + int old_bci = s_old.bci();
1.101 + int new_st_bci = s_new.bci();
1.102 + bool found_match = false;
1.103 + do {
1.104 + c_new = s_new.next();
1.105 + if (c_new == c_old && args_same(c_old, c_new)) {
1.106 + found_match = true;
1.107 + break;
1.108 + }
1.109 + } while (c_new >= 0);
1.110 + if (! found_match)
1.111 + return false;
1.112 + int new_end_bci = s_new.bci();
1.113 + bci_map.store_fragment_location(old_bci, new_st_bci, new_end_bci);
1.114 + }
1.115 + }
1.116 +
1.117 + // Now we can test all forward jumps
1.118 + for (int i = 0; i < fwd_jmps.length() / 2; i++) {
1.119 + if (! bci_map.old_and_new_locations_same(fwd_jmps.at(i*2), fwd_jmps.at(i*2+1))) {
1.120 + RC_TRACE(0x00800000,
1.121 + ("Fwd jump miss: old dest = %d, calc new dest = %d, act new dest = %d",
1.122 + fwd_jmps.at(i*2), bci_map.new_bci_for_old(fwd_jmps.at(i*2)),
1.123 + fwd_jmps.at(i*2+1)));
1.124 + return false;
1.125 + }
1.126 + }
1.127 +
1.128 + return true;
1.129 +}
1.130 +
1.131 +
1.132 +bool MethodComparator::args_same(Bytecodes::Code c_old, Bytecodes::Code c_new) {
1.133 + // BytecodeStream returns the correct standard Java bytecodes for various "fast"
1.134 + // bytecode versions, so we don't have to bother about them here..
1.135 + switch (c_old) {
1.136 + case Bytecodes::_new : // fall through
1.137 + case Bytecodes::_anewarray : // fall through
1.138 + case Bytecodes::_multianewarray : // fall through
1.139 + case Bytecodes::_checkcast : // fall through
1.140 + case Bytecodes::_instanceof : {
1.141 + u2 cpi_old = _s_old->get_index_u2();
1.142 + u2 cpi_new = _s_new->get_index_u2();
1.143 + if ((_old_cp->klass_at_noresolve(cpi_old) != _new_cp->klass_at_noresolve(cpi_new)))
1.144 + return false;
1.145 + if (c_old == Bytecodes::_multianewarray &&
1.146 + *(jbyte*)(_s_old->bcp() + 3) != *(jbyte*)(_s_new->bcp() + 3))
1.147 + return false;
1.148 + break;
1.149 + }
1.150 +
1.151 + case Bytecodes::_getstatic : // fall through
1.152 + case Bytecodes::_putstatic : // fall through
1.153 + case Bytecodes::_getfield : // fall through
1.154 + case Bytecodes::_putfield : // fall through
1.155 + case Bytecodes::_invokevirtual : // fall through
1.156 + case Bytecodes::_invokespecial : // fall through
1.157 + case Bytecodes::_invokestatic : // fall through
1.158 + case Bytecodes::_invokeinterface : {
1.159 + int cpci_old = _s_old->get_index_u2_cpcache();
1.160 + int cpci_new = _s_new->get_index_u2_cpcache();
1.161 + // Check if the names of classes, field/method names and signatures at these indexes
1.162 + // are the same. Indices which are really into constantpool cache (rather than constant
1.163 + // pool itself) are accepted by the constantpool query routines below.
1.164 + if ((_old_cp->klass_ref_at_noresolve(cpci_old) != _new_cp->klass_ref_at_noresolve(cpci_new)) ||
1.165 + (_old_cp->name_ref_at(cpci_old) != _new_cp->name_ref_at(cpci_new)) ||
1.166 + (_old_cp->signature_ref_at(cpci_old) != _new_cp->signature_ref_at(cpci_new)))
1.167 + return false;
1.168 + break;
1.169 + }
1.170 + case Bytecodes::_invokedynamic: {
1.171 + int cpci_old = _s_old->get_index_u4();
1.172 + int cpci_new = _s_new->get_index_u4();
1.173 +
1.174 + // Check if the names of classes, field/method names and signatures at these indexes
1.175 + // are the same. Indices which are really into constantpool cache (rather than constant
1.176 + // pool itself) are accepted by the constantpool query routines below.
1.177 + if ((_old_cp->name_ref_at(cpci_old) != _new_cp->name_ref_at(cpci_new)) ||
1.178 + (_old_cp->signature_ref_at(cpci_old) != _new_cp->signature_ref_at(cpci_new)))
1.179 + return false;
1.180 +
1.181 + // Translate object indexes to constant pool cache indexes.
1.182 + cpci_old = _old_cp->invokedynamic_cp_cache_index(cpci_old);
1.183 + cpci_new = _new_cp->invokedynamic_cp_cache_index(cpci_new);
1.184 +
1.185 + int cpi_old = _old_cp->cache()->entry_at(cpci_old)->constant_pool_index();
1.186 + int cpi_new = _new_cp->cache()->entry_at(cpci_new)->constant_pool_index();
1.187 + int bsm_old = _old_cp->invoke_dynamic_bootstrap_method_ref_index_at(cpi_old);
1.188 + int bsm_new = _new_cp->invoke_dynamic_bootstrap_method_ref_index_at(cpi_new);
1.189 + if (!pool_constants_same(bsm_old, bsm_new))
1.190 + return false;
1.191 + int cnt_old = _old_cp->invoke_dynamic_argument_count_at(cpi_old);
1.192 + int cnt_new = _new_cp->invoke_dynamic_argument_count_at(cpi_new);
1.193 + if (cnt_old != cnt_new)
1.194 + return false;
1.195 + for (int arg_i = 0; arg_i < cnt_old; arg_i++) {
1.196 + int idx_old = _old_cp->invoke_dynamic_argument_index_at(cpi_old, arg_i);
1.197 + int idx_new = _new_cp->invoke_dynamic_argument_index_at(cpi_new, arg_i);
1.198 + if (!pool_constants_same(idx_old, idx_new))
1.199 + return false;
1.200 + }
1.201 + break;
1.202 + }
1.203 +
1.204 + case Bytecodes::_ldc : // fall through
1.205 + case Bytecodes::_ldc_w : {
1.206 + Bytecode_loadconstant ldc_old(_s_old->method(), _s_old->bci());
1.207 + Bytecode_loadconstant ldc_new(_s_new->method(), _s_new->bci());
1.208 + int cpi_old = ldc_old.pool_index();
1.209 + int cpi_new = ldc_new.pool_index();
1.210 + if (!pool_constants_same(cpi_old, cpi_new))
1.211 + return false;
1.212 + break;
1.213 + }
1.214 +
1.215 + case Bytecodes::_ldc2_w : {
1.216 + u2 cpi_old = _s_old->get_index_u2();
1.217 + u2 cpi_new = _s_new->get_index_u2();
1.218 + constantTag tag_old = _old_cp->tag_at(cpi_old);
1.219 + constantTag tag_new = _new_cp->tag_at(cpi_new);
1.220 + if (tag_old.value() != tag_new.value())
1.221 + return false;
1.222 + if (tag_old.is_long()) {
1.223 + if (_old_cp->long_at(cpi_old) != _new_cp->long_at(cpi_new))
1.224 + return false;
1.225 + } else {
1.226 + // Use jlong_cast to compare the bits rather than numerical values.
1.227 + // This makes a difference for NaN constants.
1.228 + if (jlong_cast(_old_cp->double_at(cpi_old)) != jlong_cast(_new_cp->double_at(cpi_new)))
1.229 + return false;
1.230 + }
1.231 + break;
1.232 + }
1.233 +
1.234 + case Bytecodes::_bipush :
1.235 + if (_s_old->bcp()[1] != _s_new->bcp()[1])
1.236 + return false;
1.237 + break;
1.238 +
1.239 + case Bytecodes::_sipush :
1.240 + if (_s_old->get_index_u2() != _s_new->get_index_u2())
1.241 + return false;
1.242 + break;
1.243 +
1.244 + case Bytecodes::_aload : // fall through
1.245 + case Bytecodes::_astore : // fall through
1.246 + case Bytecodes::_dload : // fall through
1.247 + case Bytecodes::_dstore : // fall through
1.248 + case Bytecodes::_fload : // fall through
1.249 + case Bytecodes::_fstore : // fall through
1.250 + case Bytecodes::_iload : // fall through
1.251 + case Bytecodes::_istore : // fall through
1.252 + case Bytecodes::_lload : // fall through
1.253 + case Bytecodes::_lstore : // fall through
1.254 + case Bytecodes::_ret :
1.255 + if (_s_old->is_wide() != _s_new->is_wide())
1.256 + return false;
1.257 + if (_s_old->get_index() != _s_new->get_index())
1.258 + return false;
1.259 + break;
1.260 +
1.261 + case Bytecodes::_goto : // fall through
1.262 + case Bytecodes::_if_acmpeq : // fall through
1.263 + case Bytecodes::_if_acmpne : // fall through
1.264 + case Bytecodes::_if_icmpeq : // fall through
1.265 + case Bytecodes::_if_icmpne : // fall through
1.266 + case Bytecodes::_if_icmplt : // fall through
1.267 + case Bytecodes::_if_icmpge : // fall through
1.268 + case Bytecodes::_if_icmpgt : // fall through
1.269 + case Bytecodes::_if_icmple : // fall through
1.270 + case Bytecodes::_ifeq : // fall through
1.271 + case Bytecodes::_ifne : // fall through
1.272 + case Bytecodes::_iflt : // fall through
1.273 + case Bytecodes::_ifge : // fall through
1.274 + case Bytecodes::_ifgt : // fall through
1.275 + case Bytecodes::_ifle : // fall through
1.276 + case Bytecodes::_ifnonnull : // fall through
1.277 + case Bytecodes::_ifnull : // fall through
1.278 + case Bytecodes::_jsr : {
1.279 + int old_ofs = _s_old->bytecode().get_offset_s2(c_old);
1.280 + int new_ofs = _s_new->bytecode().get_offset_s2(c_new);
1.281 + if (_switchable_test) {
1.282 + int old_dest = _s_old->bci() + old_ofs;
1.283 + int new_dest = _s_new->bci() + new_ofs;
1.284 + if (old_ofs < 0 && new_ofs < 0) {
1.285 + if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))
1.286 + return false;
1.287 + } else if (old_ofs > 0 && new_ofs > 0) {
1.288 + _fwd_jmps->append(old_dest);
1.289 + _fwd_jmps->append(new_dest);
1.290 + } else {
1.291 + return false;
1.292 + }
1.293 + } else {
1.294 + if (old_ofs != new_ofs)
1.295 + return false;
1.296 + }
1.297 + break;
1.298 + }
1.299 +
1.300 + case Bytecodes::_iinc :
1.301 + if (_s_old->is_wide() != _s_new->is_wide())
1.302 + return false;
1.303 + if (! _s_old->is_wide()) {
1.304 + // We could use get_index_u1 and get_constant_u1, but it's simpler to grab both bytes at once:
1.305 + if (Bytes::get_Java_u2(_s_old->bcp() + 1) != Bytes::get_Java_u2(_s_new->bcp() + 1))
1.306 + return false;
1.307 + } else {
1.308 + // We could use get_index_u2 and get_constant_u2, but it's simpler to grab all four bytes at once:
1.309 + if (Bytes::get_Java_u4(_s_old->bcp() + 1) != Bytes::get_Java_u4(_s_new->bcp() + 1))
1.310 + return false;
1.311 + }
1.312 + break;
1.313 +
1.314 + case Bytecodes::_goto_w : // fall through
1.315 + case Bytecodes::_jsr_w : {
1.316 + int old_ofs = _s_old->bytecode().get_offset_s4(c_old);
1.317 + int new_ofs = _s_new->bytecode().get_offset_s4(c_new);
1.318 + if (_switchable_test) {
1.319 + int old_dest = _s_old->bci() + old_ofs;
1.320 + int new_dest = _s_new->bci() + new_ofs;
1.321 + if (old_ofs < 0 && new_ofs < 0) {
1.322 + if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))
1.323 + return false;
1.324 + } else if (old_ofs > 0 && new_ofs > 0) {
1.325 + _fwd_jmps->append(old_dest);
1.326 + _fwd_jmps->append(new_dest);
1.327 + } else {
1.328 + return false;
1.329 + }
1.330 + } else {
1.331 + if (old_ofs != new_ofs)
1.332 + return false;
1.333 + }
1.334 + break;
1.335 + }
1.336 +
1.337 + case Bytecodes::_lookupswitch : // fall through
1.338 + case Bytecodes::_tableswitch : {
1.339 + if (_switchable_test) {
1.340 + address aligned_bcp_old = (address) round_to((intptr_t)_s_old->bcp() + 1, jintSize);
1.341 + address aligned_bcp_new = (address) round_to((intptr_t)_s_new->bcp() + 1, jintSize);
1.342 + int default_old = (int) Bytes::get_Java_u4(aligned_bcp_old);
1.343 + int default_new = (int) Bytes::get_Java_u4(aligned_bcp_new);
1.344 + _fwd_jmps->append(_s_old->bci() + default_old);
1.345 + _fwd_jmps->append(_s_new->bci() + default_new);
1.346 + if (c_old == Bytecodes::_lookupswitch) {
1.347 + int npairs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);
1.348 + int npairs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);
1.349 + if (npairs_old != npairs_new)
1.350 + return false;
1.351 + for (int i = 0; i < npairs_old; i++) {
1.352 + int match_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i)*jintSize);
1.353 + int match_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i)*jintSize);
1.354 + if (match_old != match_new)
1.355 + return false;
1.356 + int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i+1)*jintSize);
1.357 + int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i+1)*jintSize);
1.358 + _fwd_jmps->append(_s_old->bci() + ofs_old);
1.359 + _fwd_jmps->append(_s_new->bci() + ofs_new);
1.360 + }
1.361 + } else if (c_old == Bytecodes::_tableswitch) {
1.362 + int lo_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);
1.363 + int lo_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);
1.364 + if (lo_old != lo_new)
1.365 + return false;
1.366 + int hi_old = (int) Bytes::get_Java_u4(aligned_bcp_old + 2*jintSize);
1.367 + int hi_new = (int) Bytes::get_Java_u4(aligned_bcp_new + 2*jintSize);
1.368 + if (hi_old != hi_new)
1.369 + return false;
1.370 + for (int i = 0; i < hi_old - lo_old + 1; i++) {
1.371 + int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (3+i)*jintSize);
1.372 + int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (3+i)*jintSize);
1.373 + _fwd_jmps->append(_s_old->bci() + ofs_old);
1.374 + _fwd_jmps->append(_s_new->bci() + ofs_new);
1.375 + }
1.376 + }
1.377 + } else { // !_switchable_test, can use fast rough compare
1.378 + int len_old = _s_old->instruction_size();
1.379 + int len_new = _s_new->instruction_size();
1.380 + if (len_old != len_new)
1.381 + return false;
1.382 + if (memcmp(_s_old->bcp(), _s_new->bcp(), len_old) != 0)
1.383 + return false;
1.384 + }
1.385 + break;
1.386 + }
1.387 + }
1.388 +
1.389 + return true;
1.390 +}
1.391 +
1.392 +bool MethodComparator::pool_constants_same(int cpi_old, int cpi_new) {
1.393 + constantTag tag_old = _old_cp->tag_at(cpi_old);
1.394 + constantTag tag_new = _new_cp->tag_at(cpi_new);
1.395 + if (tag_old.is_int() || tag_old.is_float()) {
1.396 + if (tag_old.value() != tag_new.value())
1.397 + return false;
1.398 + if (tag_old.is_int()) {
1.399 + if (_old_cp->int_at(cpi_old) != _new_cp->int_at(cpi_new))
1.400 + return false;
1.401 + } else {
1.402 + // Use jint_cast to compare the bits rather than numerical values.
1.403 + // This makes a difference for NaN constants.
1.404 + if (jint_cast(_old_cp->float_at(cpi_old)) != jint_cast(_new_cp->float_at(cpi_new)))
1.405 + return false;
1.406 + }
1.407 + } else if (tag_old.is_string() && tag_new.is_string()) {
1.408 + if (strcmp(_old_cp->string_at_noresolve(cpi_old),
1.409 + _new_cp->string_at_noresolve(cpi_new)) != 0)
1.410 + return false;
1.411 + } else if (tag_old.is_klass() || tag_old.is_unresolved_klass()) {
1.412 + // tag_old should be klass - 4881222
1.413 + if (! (tag_new.is_unresolved_klass() || tag_new.is_klass()))
1.414 + return false;
1.415 + if (_old_cp->klass_at_noresolve(cpi_old) !=
1.416 + _new_cp->klass_at_noresolve(cpi_new))
1.417 + return false;
1.418 + } else if (tag_old.is_method_type() && tag_new.is_method_type()) {
1.419 + int mti_old = _old_cp->method_type_index_at(cpi_old);
1.420 + int mti_new = _new_cp->method_type_index_at(cpi_new);
1.421 + if ((_old_cp->symbol_at(mti_old) != _new_cp->symbol_at(mti_new)))
1.422 + return false;
1.423 + } else if (tag_old.is_method_handle() && tag_new.is_method_handle()) {
1.424 + if (_old_cp->method_handle_ref_kind_at(cpi_old) !=
1.425 + _new_cp->method_handle_ref_kind_at(cpi_new))
1.426 + return false;
1.427 + int mhi_old = _old_cp->method_handle_index_at(cpi_old);
1.428 + int mhi_new = _new_cp->method_handle_index_at(cpi_new);
1.429 + if ((_old_cp->uncached_klass_ref_at_noresolve(mhi_old) != _new_cp->uncached_klass_ref_at_noresolve(mhi_new)) ||
1.430 + (_old_cp->uncached_name_ref_at(mhi_old) != _new_cp->uncached_name_ref_at(mhi_new)) ||
1.431 + (_old_cp->uncached_signature_ref_at(mhi_old) != _new_cp->uncached_signature_ref_at(mhi_new)))
1.432 + return false;
1.433 + } else {
1.434 + return false; // unknown tag
1.435 + }
1.436 + return true;
1.437 +}
1.438 +
1.439 +
1.440 +int MethodComparator::check_stack_and_locals_size(Method* old_method, Method* new_method) {
1.441 + if (old_method->max_stack() != new_method->max_stack()) {
1.442 + return 1;
1.443 + } else if (old_method->max_locals() != new_method->max_locals()) {
1.444 + return 2;
1.445 + } else if (old_method->size_of_parameters() != new_method->size_of_parameters()) {
1.446 + return 3;
1.447 + } else return 0;
1.448 +}
