| /* |
| * Copyright (c) 2000, 2016, 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. |
| * |
| */ |
| |
| #ifndef SHARE_VM_PRIMS_METHODCOMPARATOR_HPP |
| #define SHARE_VM_PRIMS_METHODCOMPARATOR_HPP |
| |
| #include "interpreter/bytecodeStream.hpp" |
| #include "oops/constantPool.hpp" |
| #include "oops/method.hpp" |
| |
| // methodComparator provides an interface for determining if methods of |
| // different versions of classes are equivalent or switchable |
| |
| class MethodComparator { |
| private: |
| static BytecodeStream *_s_old, *_s_new; |
| static ConstantPool* _old_cp; |
| static ConstantPool* _new_cp; |
| |
| static bool args_same(Bytecodes::Code c_old, Bytecodes::Code c_new); |
| static bool pool_constants_same(int cpi_old, int cpi_new); |
| static int check_stack_and_locals_size(Method* old_method, Method* new_method); |
| |
| public: |
| // Check if the new method is equivalent to the old one modulo constant pool (EMCP). |
| // Intuitive definition: two versions of the same method are EMCP, if they don't differ |
| // on the source code level. Practically, we check whether the only difference between |
| // method versions is some constantpool indices embedded into the bytecodes, and whether |
| // these indices eventually point to the same constants for both method versions. |
| static bool methods_EMCP(Method* old_method, Method* new_method); |
| |
| }; |
| |
| #endif // SHARE_VM_PRIMS_METHODCOMPARATOR_HPP |