1 /* 2 * Copyright (c) 1997, 2015, 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 #ifndef SHARE_VM_RUNTIME_RELOCATOR_HPP 26 #define SHARE_VM_RUNTIME_RELOCATOR_HPP 27 28 #include "interpreter/bytecodes.hpp" 29 #include "oops/method.hpp" 30 #include "utilities/bytes.hpp" 31 32 // This code has been converted from the 1.1E java virtual machine 33 // Thanks to the JavaTopics group for using the code 34 35 class ChangeItem; 36 37 // Callback object for code relocations 38 class RelocatorListener : public StackObj { 39 public: RelocatorListener()40 RelocatorListener() {}; 41 virtual void relocated(int bci, int delta, int new_method_size) = 0; 42 }; 43 44 45 class Relocator : public ResourceObj { 46 public: 47 Relocator(const methodHandle& method, RelocatorListener* listener); 48 methodHandle insert_space_at(int bci, int space, u_char inst_buffer[], TRAPS); 49 50 // Callbacks from ChangeItem's 51 bool handle_code_changes(); 52 bool handle_widen (int bci, int new_ilen, u_char inst_buffer[]); // handles general instructions 53 void push_jump_widen (int bci, int delta, int new_delta); // pushes jumps 54 bool handle_jump_widen (int bci, int delta); // handles jumps 55 bool handle_switch_pad (int bci, int old_pad, bool is_lookup_switch); // handles table and lookup switches 56 57 private: 58 unsigned char* _code_array; 59 int _code_array_length; 60 int _code_length; 61 unsigned char* _compressed_line_number_table; 62 int _compressed_line_number_table_size; 63 methodHandle _method; 64 u_char _overwrite[3]; // stores overwritten bytes for shrunken instructions 65 66 GrowableArray<ChangeItem*>* _changes; 67 code_array() const68 unsigned char* code_array() const { return _code_array; } set_code_array(unsigned char * array)69 void set_code_array(unsigned char* array) { _code_array = array; } 70 code_length() const71 int code_length() const { return _code_length; } set_code_length(int length)72 void set_code_length(int length) { _code_length = length; } 73 code_array_length() const74 int code_array_length() const { return _code_array_length; } set_code_array_length(int length)75 void set_code_array_length(int length) { _code_array_length = length; } 76 compressed_line_number_table() const77 unsigned char* compressed_line_number_table() const { return _compressed_line_number_table; } set_compressed_line_number_table(unsigned char * table)78 void set_compressed_line_number_table(unsigned char* table) { _compressed_line_number_table = table; } 79 compressed_line_number_table_size() const80 int compressed_line_number_table_size() const { return _compressed_line_number_table_size; } set_compressed_line_number_table_size(int size)81 void set_compressed_line_number_table_size(int size) { _compressed_line_number_table_size = size; } 82 method() const83 methodHandle method() const { return _method; } set_method(const methodHandle & method)84 void set_method(const methodHandle& method) { _method = method; } 85 86 // This will return a raw bytecode, which is possibly rewritten. code_at(int bci) const87 Bytecodes::Code code_at(int bci) const { return (Bytecodes::Code) code_array()[bci]; } code_at_put(int bci,Bytecodes::Code code)88 void code_at_put(int bci, Bytecodes::Code code) { code_array()[bci] = (char) code; } 89 90 // get and set signed integers in the code_array int_at(int bci) const91 inline int int_at(int bci) const { return Bytes::get_Java_u4(&code_array()[bci]); } int_at_put(int bci,int value)92 inline void int_at_put(int bci, int value) { Bytes::put_Java_u4(&code_array()[bci], value); } 93 94 // get and set signed shorts in the code_array short_at(int bci) const95 inline short short_at(int bci) const { return (short)Bytes::get_Java_u2(&code_array()[bci]); } short_at_put(int bci,short value)96 inline void short_at_put(int bci, short value) { Bytes::put_Java_u2((address) &code_array()[bci], value); } 97 98 // get the address of in the code_array addr_at(int bci) const99 inline char* addr_at(int bci) const { return (char*) &code_array()[bci]; } 100 instruction_length_at(int bci)101 int instruction_length_at(int bci) { return Bytecodes::length_at(NULL, code_array() + bci); } 102 103 // Helper methods align(int n) const104 int align(int n) const { return (n+3) & ~3; } code_slop_pct() const105 int code_slop_pct() const { return 25; } 106 bool is_opcode_lookupswitch(Bytecodes::Code bc); 107 108 // basic relocation methods 109 bool relocate_code (int bci, int ilen, int delta); 110 void change_jumps (int break_bci, int delta); 111 void change_jump (int bci, int offset, bool is_short, int break_bci, int delta); 112 void adjust_exception_table(int bci, int delta); 113 void adjust_line_no_table (int bci, int delta); 114 void adjust_local_var_table(int bci, int delta); 115 void adjust_stack_map_table(int bci, int delta); 116 int get_orig_switch_pad (int bci, bool is_lookup_switch); 117 int rc_instr_len (int bci); 118 bool expand_code_array (int delta); 119 120 // Callback support 121 RelocatorListener *_listener; notify(int bci,int delta,int new_code_length)122 void notify(int bci, int delta, int new_code_length) { 123 if (_listener != NULL) 124 _listener->relocated(bci, delta, new_code_length); 125 } 126 }; 127 128 #endif // SHARE_VM_RUNTIME_RELOCATOR_HPP 129