relocator.hpp revision 2073:b92c45f2bc75 
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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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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#ifdef TARGET_ARCH_arm
40# include "bytes_arm.hpp"
41#endif
42#ifdef TARGET_ARCH_ppc
43# include "bytes_ppc.hpp"
44#endif
45
46// This code has been converted from the 1.1E java virtual machine
47// Thanks to the JavaTopics group for using the code
48
49class ChangeItem;
50
51// Callback object for code relocations
52class RelocatorListener : public StackObj {
53 public:
54  RelocatorListener() {};
55  virtual void relocated(int bci, int delta, int new_method_size) = 0;
56};
57
58
59class Relocator : public ResourceObj {
60 public:
61  Relocator(methodHandle method, RelocatorListener* listener);
62  methodHandle insert_space_at(int bci, int space, u_char inst_buffer[], TRAPS);
63
64  // Callbacks from ChangeItem's
65  bool handle_code_changes();
66  bool handle_widen       (int bci, int new_ilen, u_char inst_buffer[]);  // handles general instructions
67  void push_jump_widen  (int bci, int delta, int new_delta);    // pushes jumps
68  bool handle_jump_widen  (int bci, int delta);     // handles jumps
69  bool handle_switch_pad  (int bci, int old_pad, bool is_lookup_switch); // handles table and lookup switches
70
71 private:
72  unsigned char* _code_array;
73  int            _code_array_length;
74  int            _code_length;
75  unsigned char* _compressed_line_number_table;
76  int            _compressed_line_number_table_size;
77  methodHandle   _method;
78  u_char         _overwrite[3];             // stores overwritten bytes for shrunken instructions
79
80  GrowableArray<ChangeItem*>* _changes;
81
82  unsigned char* code_array() const         { return _code_array; }
83  void set_code_array(unsigned char* array) { _code_array = array; }
84
85  int code_length() const                   { return _code_length; }
86  void set_code_length(int length)          { _code_length = length; }
87
88  int code_array_length() const             { return _code_array_length; }
89  void set_code_array_length(int length)    { _code_array_length = length; }
90
91  unsigned char* compressed_line_number_table() const         { return _compressed_line_number_table; }
92  void set_compressed_line_number_table(unsigned char* table) { _compressed_line_number_table = table; }
93
94  int compressed_line_number_table_size() const               { return _compressed_line_number_table_size; }
95  void set_compressed_line_number_table_size(int size)        { _compressed_line_number_table_size = size; }
96
97  methodHandle method() const               { return _method; }
98  void set_method(methodHandle method)      { _method = method; }
99
100  // This will return a raw bytecode, which is possibly rewritten.
101  Bytecodes::Code code_at(int bci) const          { return (Bytecodes::Code) code_array()[bci]; }
102  void code_at_put(int bci, Bytecodes::Code code) { code_array()[bci] = (char) code; }
103
104  // get and set signed integers in the code_array
105  inline int   int_at(int bci) const               { return Bytes::get_Java_u4(&code_array()[bci]); }
106  inline void  int_at_put(int bci, int value)      { Bytes::put_Java_u4(&code_array()[bci], value); }
107
108  // get and set signed shorts in the code_array
109  inline short short_at(int bci) const            { return (short)Bytes::get_Java_u2(&code_array()[bci]); }
110  inline void  short_at_put(int bci, short value) { Bytes::put_Java_u2((address) &code_array()[bci], value); }
111
112  // get the address of in the code_array
113  inline char* addr_at(int bci) const             { return (char*) &code_array()[bci]; }
114
115  int  instruction_length_at(int bci)             { return Bytecodes::length_at(NULL, code_array() + bci); }
116
117  // Helper methods
118  int  align(int n) const                          { return (n+3) & ~3; }
119  int  code_slop_pct() const                       { return 25; }
120  bool is_opcode_lookupswitch(Bytecodes::Code bc);
121
122  // basic relocation methods
123  bool relocate_code         (int bci, int ilen, int delta);
124  void change_jumps          (int break_bci, int delta);
125  void change_jump           (int bci, int offset, bool is_short, int break_bci, int delta);
126  void adjust_exception_table(int bci, int delta);
127  void adjust_line_no_table  (int bci, int delta);
128  void adjust_local_var_table(int bci, int delta);
129  void adjust_stack_map_table(int bci, int delta);
130  int  get_orig_switch_pad   (int bci, bool is_lookup_switch);
131  int  rc_instr_len          (int bci);
132  bool expand_code_array     (int delta);
133
134  // Callback support
135  RelocatorListener *_listener;
136  void notify(int bci, int delta, int new_code_length) {
137    if (_listener != NULL)
138      _listener->relocated(bci, delta, new_code_length);
139  }
140};
141
142#endif // SHARE_VM_RUNTIME_RELOCATOR_HPP
143