/* * Copyright (c) 2000, 2021, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "logging/log.hpp" #include "memory/resourceArea.hpp" #include "oops/constantPool.inline.hpp" #include "oops/oop.inline.hpp" #include "oops/symbol.hpp" #include "prims/methodComparator.hpp" #include "runtime/handles.inline.hpp" #include "utilities/globalDefinitions.hpp" bool MethodComparator::methods_EMCP(Method* old_method, Method* new_method) { if (old_method->code_size() != new_method->code_size()) return false; if (check_stack_and_locals_size(old_method, new_method) != 0) { if (log_is_enabled(Debug, redefine, class, methodcomparator)) { ResourceMark rm; log_debug(redefine, class, methodcomparator) ("Methods %s non-comparable with diagnosis %d", old_method->name()->as_C_string(), check_stack_and_locals_size(old_method, new_method)); } return false; } ConstantPool* old_cp = old_method->constants(); ConstantPool* new_cp = new_method->constants(); Thread* THREAD = Thread::current(); BytecodeStream s_old(methodHandle(THREAD, old_method)); BytecodeStream s_new(methodHandle(THREAD, new_method)); Bytecodes::Code c_old, c_new; while ((c_old = s_old.next()) >= 0) { if ((c_new = s_new.next()) < 0 || c_old != c_new) return false; if (!args_same(c_old, c_new, &s_old, &s_new, old_cp, new_cp)) return false; } return true; } bool MethodComparator::args_same(Bytecodes::Code const c_old, Bytecodes::Code const c_new, BytecodeStream* const s_old, BytecodeStream* const s_new, ConstantPool* const old_cp, ConstantPool* const new_cp) { // BytecodeStream returns the correct standard Java bytecodes for various "fast" // bytecode versions, so we don't have to bother about them here.. switch (c_old) { case Bytecodes::_new : // fall through case Bytecodes::_anewarray : // fall through case Bytecodes::_multianewarray : // fall through case Bytecodes::_checkcast : // fall through case Bytecodes::_instanceof : { u2 cpi_old = s_old->get_index_u2(); u2 cpi_new = s_new->get_index_u2(); if (old_cp->klass_at_noresolve(cpi_old) != new_cp->klass_at_noresolve(cpi_new)) return false; if (c_old == Bytecodes::_multianewarray && *(jbyte*)(s_old->bcp() + 3) != *(jbyte*)(s_new->bcp() + 3)) return false; break; } case Bytecodes::_getstatic : // fall through case Bytecodes::_putstatic : // fall through case Bytecodes::_getfield : // fall through case Bytecodes::_putfield : // fall through case Bytecodes::_invokevirtual : // fall through case Bytecodes::_invokespecial : // fall through case Bytecodes::_invokestatic : // fall through case Bytecodes::_invokeinterface : { int cpci_old = s_old->get_index_u2_cpcache(); int cpci_new = s_new->get_index_u2_cpcache(); // Check if the names of classes, field/method names and signatures at these indexes // are the same. Indices which are really into constantpool cache (rather than constant // pool itself) are accepted by the constantpool query routines below. if ((old_cp->klass_ref_at_noresolve(cpci_old) != new_cp->klass_ref_at_noresolve(cpci_new)) || (old_cp->name_ref_at(cpci_old) != new_cp->name_ref_at(cpci_new)) || (old_cp->signature_ref_at(cpci_old) != new_cp->signature_ref_at(cpci_new))) return false; break; } case Bytecodes::_invokedynamic: { int cpci_old = s_old->get_index_u4(); int cpci_new = s_new->get_index_u4(); // Check if the names of classes, field/method names and signatures at these indexes // are the same. Indices which are really into constantpool cache (rather than constant // pool itself) are accepted by the constantpool query routines below. if ((old_cp->name_ref_at(cpci_old) != new_cp->name_ref_at(cpci_new)) || (old_cp->signature_ref_at(cpci_old) != new_cp->signature_ref_at(cpci_new))) return false; // Translate object indexes to constant pool cache indexes. cpci_old = old_cp->invokedynamic_cp_cache_index(cpci_old); cpci_new = new_cp->invokedynamic_cp_cache_index(cpci_new); int cpi_old = old_cp->cache()->entry_at(cpci_old)->constant_pool_index(); int cpi_new = new_cp->cache()->entry_at(cpci_new)->constant_pool_index(); int bsm_old = old_cp->bootstrap_method_ref_index_at(cpi_old); int bsm_new = new_cp->bootstrap_method_ref_index_at(cpi_new); if (!pool_constants_same(bsm_old, bsm_new, old_cp, new_cp)) return false; int cnt_old = old_cp->bootstrap_argument_count_at(cpi_old); int cnt_new = new_cp->bootstrap_argument_count_at(cpi_new); if (cnt_old != cnt_new) return false; for (int arg_i = 0; arg_i < cnt_old; arg_i++) { int idx_old = old_cp->bootstrap_argument_index_at(cpi_old, arg_i); int idx_new = new_cp->bootstrap_argument_index_at(cpi_new, arg_i); if (!pool_constants_same(idx_old, idx_new, old_cp, new_cp)) return false; } break; } case Bytecodes::_ldc : // fall through case Bytecodes::_ldc_w : { Bytecode_loadconstant ldc_old(s_old->method(), s_old->bci()); Bytecode_loadconstant ldc_new(s_new->method(), s_new->bci()); int cpi_old = ldc_old.pool_index(); int cpi_new = ldc_new.pool_index(); if (!pool_constants_same(cpi_old, cpi_new, old_cp, new_cp)) return false; break; } case Bytecodes::_ldc2_w : { u2 cpi_old = s_old->get_index_u2(); u2 cpi_new = s_new->get_index_u2(); constantTag tag_old = old_cp->tag_at(cpi_old); constantTag tag_new = new_cp->tag_at(cpi_new); if (tag_old.value() != tag_new.value()) return false; if (tag_old.is_long()) { if (old_cp->long_at(cpi_old) != new_cp->long_at(cpi_new)) return false; } else { // Use jlong_cast to compare the bits rather than numerical values. // This makes a difference for NaN constants. if (jlong_cast(old_cp->double_at(cpi_old)) != jlong_cast(new_cp->double_at(cpi_new))) return false; } break; } case Bytecodes::_bipush : if (s_old->bcp()[1] != s_new->bcp()[1]) return false; break; case Bytecodes::_sipush : if (s_old->get_index_u2() != s_new->get_index_u2()) return false; break; case Bytecodes::_aload : // fall through case Bytecodes::_astore : // fall through case Bytecodes::_dload : // fall through case Bytecodes::_dstore : // fall through case Bytecodes::_fload : // fall through case Bytecodes::_fstore : // fall through case Bytecodes::_iload : // fall through case Bytecodes::_istore : // fall through case Bytecodes::_lload : // fall through case Bytecodes::_lstore : // fall through case Bytecodes::_ret : if (s_old->is_wide() != s_new->is_wide()) return false; if (s_old->get_index() != s_new->get_index()) return false; break; case Bytecodes::_goto : // fall through case Bytecodes::_if_acmpeq : // fall through case Bytecodes::_if_acmpne : // fall through case Bytecodes::_if_icmpeq : // fall through case Bytecodes::_if_icmpne : // fall through case Bytecodes::_if_icmplt : // fall through case Bytecodes::_if_icmpge : // fall through case Bytecodes::_if_icmpgt : // fall through case Bytecodes::_if_icmple : // fall through case Bytecodes::_ifeq : // fall through case Bytecodes::_ifne : // fall through case Bytecodes::_iflt : // fall through case Bytecodes::_ifge : // fall through case Bytecodes::_ifgt : // fall through case Bytecodes::_ifle : // fall through case Bytecodes::_ifnonnull : // fall through case Bytecodes::_ifnull : // fall through case Bytecodes::_jsr : { int old_ofs = s_old->bytecode().get_offset_s2(c_old); int new_ofs = s_new->bytecode().get_offset_s2(c_new); if (old_ofs != new_ofs) return false; break; } case Bytecodes::_iinc : if (s_old->is_wide() != s_new->is_wide()) return false; if (!s_old->is_wide()) { // We could use get_index_u1 and get_constant_u1, but it's simpler to grab both bytes at once: if (Bytes::get_Java_u2(s_old->bcp() + 1) != Bytes::get_Java_u2(s_new->bcp() + 1)) return false; } else { // We could use get_index_u2 and get_constant_u2, but it's simpler to grab all four bytes at once: if (Bytes::get_Java_u4(s_old->bcp() + 1) != Bytes::get_Java_u4(s_new->bcp() + 1)) return false; } break; case Bytecodes::_goto_w : // fall through case Bytecodes::_jsr_w : { int old_ofs = s_old->bytecode().get_offset_s4(c_old); int new_ofs = s_new->bytecode().get_offset_s4(c_new); if (old_ofs != new_ofs) return false; break; } case Bytecodes::_lookupswitch : // fall through case Bytecodes::_tableswitch : { int len_old = s_old->instruction_size(); int len_new = s_new->instruction_size(); if (len_old != len_new) return false; if (memcmp(s_old->bcp(), s_new->bcp(), len_old) != 0) return false; break; } default: break; } return true; } bool MethodComparator::pool_constants_same(const int cpi_old, const int cpi_new, ConstantPool* const old_cp, ConstantPool* const new_cp) { constantTag tag_old = old_cp->tag_at(cpi_old); constantTag tag_new = new_cp->tag_at(cpi_new); if (tag_old.is_int() || tag_old.is_float()) { if (tag_old.value() != tag_new.value()) return false; if (tag_old.is_int()) { if (old_cp->int_at(cpi_old) != new_cp->int_at(cpi_new)) return false; } else { // Use jint_cast to compare the bits rather than numerical values. // This makes a difference for NaN constants. if (jint_cast(old_cp->float_at(cpi_old)) != jint_cast(new_cp->float_at(cpi_new))) return false; } } else if (tag_old.is_string() && tag_new.is_string()) { if (strcmp(old_cp->string_at_noresolve(cpi_old), new_cp->string_at_noresolve(cpi_new)) != 0) return false; } else if (tag_old.is_klass() || tag_old.is_unresolved_klass()) { // tag_old should be klass - 4881222 if (! (tag_new.is_unresolved_klass() || tag_new.is_klass())) return false; if (old_cp->klass_at_noresolve(cpi_old) != new_cp->klass_at_noresolve(cpi_new)) return false; } else if (tag_old.is_method_type() && tag_new.is_method_type()) { int mti_old = old_cp->method_type_index_at(cpi_old); int mti_new = new_cp->method_type_index_at(cpi_new); if ((old_cp->symbol_at(mti_old) != new_cp->symbol_at(mti_new))) return false; } else if (tag_old.is_method_handle() && tag_new.is_method_handle()) { if (old_cp->method_handle_ref_kind_at(cpi_old) != new_cp->method_handle_ref_kind_at(cpi_new)) return false; int mhi_old = old_cp->method_handle_index_at(cpi_old); int mhi_new = new_cp->method_handle_index_at(cpi_new); if ((old_cp->uncached_klass_ref_at_noresolve(mhi_old) != new_cp->uncached_klass_ref_at_noresolve(mhi_new)) || (old_cp->uncached_name_ref_at(mhi_old) != new_cp->uncached_name_ref_at(mhi_new)) || (old_cp->uncached_signature_ref_at(mhi_old) != new_cp->uncached_signature_ref_at(mhi_new))) return false; } else { return false; // unknown tag } return true; } int MethodComparator::check_stack_and_locals_size(Method* old_method, Method* new_method) { if (old_method->max_stack() != new_method->max_stack()) { return 1; } else if (old_method->max_locals() != new_method->max_locals()) { return 2; } else if (old_method->size_of_parameters() != new_method->size_of_parameters()) { return 3; } else return 0; }