1 /* 2 * Copyright (c) 1997, 2011, 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/methodOop.hpp" 30 #ifdef TARGET_ARCH_x86 31 # include "bytes_x86.hpp" 32 #endif 33 #ifdef TARGET_ARCH_sparc 34 # include "bytes_sparc.hpp" 35 #endif 36 #ifdef TARGET_ARCH_zero 37 # include "bytes_zero.hpp" 38 #endif 39 40 // This code has been converted from the 1.1E java virtual machine 41 // Thanks to the JavaTopics group for using the code 42 43 class ChangeItem; 44 45 // Callback object for code relocations 46 class RelocatorListener : public StackObj { 47 public: 48 RelocatorListener() {}; 49 virtual void relocated(int bci, int delta, int new_method_size) = 0; 50 }; 51 52 53 class Relocator : public ResourceObj { 54 public: 55 Relocator(methodHandle method, RelocatorListener* listener); 56 methodHandle insert_space_at(int bci, int space, u_char inst_buffer[], TRAPS); 57 58 // Callbacks from ChangeItem's 59 bool handle_code_changes(); 60 bool handle_widen (int bci, int new_ilen, u_char inst_buffer[]); // handles general instructions 61 void push_jump_widen (int bci, int delta, int new_delta); // pushes jumps 62 bool handle_jump_widen (int bci, int delta); // handles jumps 63 bool handle_switch_pad (int bci, int old_pad, bool is_lookup_switch); // handles table and lookup switches 64 65 private: 66 unsigned char* _code_array; 67 int _code_array_length; 68 int _code_length; 69 unsigned char* _compressed_line_number_table; 70 int _compressed_line_number_table_size; 71 methodHandle _method; 72 u_char _overwrite[3]; // stores overwritten bytes for shrunken instructions 73 74 GrowableArray<ChangeItem*>* _changes; 75 76 unsigned char* code_array() const { return _code_array; } 77 void set_code_array(unsigned char* array) { _code_array = array; } 78 79 int code_length() const { return _code_length; } 80 void set_code_length(int length) { _code_length = length; } 81 82 int code_array_length() const { return _code_array_length; } 83 void set_code_array_length(int length) { _code_array_length = length; } 84 85 unsigned char* compressed_line_number_table() const { return _compressed_line_number_table; } 86 void set_compressed_line_number_table(unsigned char* table) { _compressed_line_number_table = table; } 87 88 int compressed_line_number_table_size() const { return _compressed_line_number_table_size; } 89 void set_compressed_line_number_table_size(int size) { _compressed_line_number_table_size = size; } 90 91 methodHandle method() const { return _method; } 92 void set_method(methodHandle method) { _method = method; } 93 94 // This will return a raw bytecode, which is possibly rewritten. 95 Bytecodes::Code code_at(int bci) const { return (Bytecodes::Code) code_array()[bci]; } 96 void code_at_put(int bci, Bytecodes::Code code) { code_array()[bci] = (char) code; } 97 98 // get and set signed integers in the code_array 99 inline int int_at(int bci) const { return Bytes::get_Java_u4(&code_array()[bci]); } 100 inline void int_at_put(int bci, int value) { Bytes::put_Java_u4(&code_array()[bci], value); } 101 102 // get and set signed shorts in the code_array 103 inline short short_at(int bci) const { return (short)Bytes::get_Java_u2(&code_array()[bci]); } 104 inline void short_at_put(int bci, short value) { Bytes::put_Java_u2((address) &code_array()[bci], value); } 105 106 // get the address of in the code_array 107 inline char* addr_at(int bci) const { return (char*) &code_array()[bci]; } 108 109 int instruction_length_at(int bci) { return Bytecodes::length_at(_method(), code_array() + bci); } 110 111 // Helper methods 112 int align(int n) const { return (n+3) & ~3; } 113 int code_slop_pct() const { return 25; } 114 bool is_opcode_lookupswitch(Bytecodes::Code bc); 115 116 // basic relocation methods 117 bool relocate_code (int bci, int ilen, int delta); 118 void change_jumps (int break_bci, int delta); 119 void change_jump (int bci, int offset, bool is_short, int break_bci, int delta); 120 void adjust_exception_table(int bci, int delta); 121 void adjust_line_no_table (int bci, int delta); 122 void adjust_local_var_table(int bci, int delta); 123 void adjust_stack_map_table(int bci, int delta); 124 int get_orig_switch_pad (int bci, bool is_lookup_switch); 125 int rc_instr_len (int bci); 126 bool expand_code_array (int delta); 127 128 // Callback support 129 RelocatorListener *_listener; 130 void notify(int bci, int delta, int new_code_length) { 131 if (_listener != NULL) 132 _listener->relocated(bci, delta, new_code_length); 133 } 134 }; 135 136 #endif // SHARE_VM_RUNTIME_RELOCATOR_HPP