1 /*
2 * Copyright (c) 2000, 2012, 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 *
38 private:
39 static BytecodeStream *_s_old, *_s_new;
40 static ConstantPool* _old_cp;
41 static ConstantPool* _new_cp;
42 static BciMap *_bci_map;
43 static bool _switchable_test;
44 static GrowableArray<int> *_fwd_jmps;
45
46 static bool args_same(Bytecodes::Code c_old, Bytecodes::Code c_new);
47 static bool pool_constants_same(int cpi_old, int cpi_new);
48 static int check_stack_and_locals_size(Method* old_method, Method* new_method);
49
50 public:
51 // Check if the new method is equivalent to the old one modulo constant pool (EMCP).
52 // Intuitive definition: two versions of the same method are EMCP, if they don't differ
53 // on the source code level. Practically, we check whether the only difference between
54 // method versions is some constantpool indices embedded into the bytecodes, and whether
55 // these indices eventually point to the same constants for both method versions.
56 static bool methods_EMCP(Method* old_method, Method* new_method);
57
58 static bool methods_switchable(Method* old_method, Method* new_method, BciMap &bci_map);
59 };
60
61
62 // ByteCode Index Map. For two versions of the same method, where the new version may contain
63 // fragments not found in the old version, provides a mapping from an index of a bytecode in
64 // the old method to the index of the same bytecode in the new method.
65
66 class BciMap {
67 private:
68 int *_old_bci, *_new_st_bci, *_new_end_bci;
69 int _cur_size, _cur_pos;
70 int _pos;
71
72 public:
73 BciMap() {
74 _cur_size = 50;
75 _old_bci = (int*) malloc(sizeof(int) * _cur_size);
76 _new_st_bci = (int*) malloc(sizeof(int) * _cur_size);
77 _new_end_bci = (int*) malloc(sizeof(int) * _cur_size);
78 _cur_pos = 0;
79 }
80
81 ~BciMap() {
82 free(_old_bci);
83 free(_new_st_bci);
84 free(_new_end_bci);
85 }
86
87 // Store the position of an added fragment, e.g.
88 //
89 // |<- old_bci
90 // -----------------------------------------
91 // Old method |invokevirtual 5|aload 1|...
92 // -----------------------------------------
93 //
94 // |<- new_st_bci |<- new_end_bci
95 // --------------------------------------------------------------------
96 // New method |invokevirual 5|aload 2|invokevirtual 6|aload 1|...
97 // --------------------------------------------------------------------
98 // ^^^^^^^^^^^^^^^^^^^^^^^^
99 // Added fragment
100
101 void store_fragment_location(int old_bci, int new_st_bci, int new_end_bci) {
102 if (_cur_pos == _cur_size) {
103 _cur_size += 10;
104 _old_bci = (int*) realloc(_old_bci, sizeof(int) * _cur_size);
105 _new_st_bci = (int*) realloc(_new_st_bci, sizeof(int) * _cur_size);
106 _new_end_bci = (int*) realloc(_new_end_bci, sizeof(int) * _cur_size);
107 }
108 _old_bci[_cur_pos] = old_bci;
109 _new_st_bci[_cur_pos] = new_st_bci;
110 _new_end_bci[_cur_pos] = new_end_bci;
111 _cur_pos++;
112 }
113
114 int new_bci_for_old(int old_bci) {
115 if (_cur_pos == 0 || old_bci < _old_bci[0]) return old_bci;
116 _pos = 1;
117 while (_pos < _cur_pos && old_bci >= _old_bci[_pos])
118 _pos++;
119 return _new_end_bci[_pos-1] + (old_bci - _old_bci[_pos-1]);
120 }
121
122 // Test if two indexes - one in the old method and another in the new one - correspond
123 // to the same bytecode
124 bool old_and_new_locations_same(int old_dest_bci, int new_dest_bci) {
125 if (new_bci_for_old(old_dest_bci) == new_dest_bci)
126 return true;
127 else if (_old_bci[_pos-1] == old_dest_bci)
128 return (new_dest_bci == _new_st_bci[_pos-1]);
129 else return false;
130 }
131 };
|
1 /*
2 * Copyright (c) 2000, 2016, 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 *
38 private:
39 static BytecodeStream *_s_old, *_s_new;
40 static ConstantPool* _old_cp;
41 static ConstantPool* _new_cp;
42 static BciMap *_bci_map;
43 static bool _switchable_test;
44 static GrowableArray<int> *_fwd_jmps;
45
46 static bool args_same(Bytecodes::Code c_old, Bytecodes::Code c_new);
47 static bool pool_constants_same(int cpi_old, int cpi_new);
48 static int check_stack_and_locals_size(Method* old_method, Method* new_method);
49
50 public:
51 // Check if the new method is equivalent to the old one modulo constant pool (EMCP).
52 // Intuitive definition: two versions of the same method are EMCP, if they don't differ
53 // on the source code level. Practically, we check whether the only difference between
54 // method versions is some constantpool indices embedded into the bytecodes, and whether
55 // these indices eventually point to the same constants for both method versions.
56 static bool methods_EMCP(Method* old_method, Method* new_method);
57
58 };
59
60
61 // ByteCode Index Map. For two versions of the same method, where the new version may contain
62 // fragments not found in the old version, provides a mapping from an index of a bytecode in
63 // the old method to the index of the same bytecode in the new method.
64
65 class BciMap {
66 private:
67 int *_old_bci, *_new_st_bci, *_new_end_bci;
68 int _cur_size, _cur_pos;
69 int _pos;
70
71 public:
72 BciMap() {
73 _cur_size = 50;
74 _old_bci = (int*) malloc(sizeof(int) * _cur_size);
75 _new_st_bci = (int*) malloc(sizeof(int) * _cur_size);
76 _new_end_bci = (int*) malloc(sizeof(int) * _cur_size);
77 _cur_pos = 0;
78 }
79
80 ~BciMap() {
81 free(_old_bci);
82 free(_new_st_bci);
83 free(_new_end_bci);
84 }
85
86 int new_bci_for_old(int old_bci) {
87 if (_cur_pos == 0 || old_bci < _old_bci[0]) return old_bci;
88 _pos = 1;
89 while (_pos < _cur_pos && old_bci >= _old_bci[_pos])
90 _pos++;
91 return _new_end_bci[_pos-1] + (old_bci - _old_bci[_pos-1]);
92 }
93
94 // Test if two indexes - one in the old method and another in the new one - correspond
95 // to the same bytecode
96 bool old_and_new_locations_same(int old_dest_bci, int new_dest_bci) {
97 if (new_bci_for_old(old_dest_bci) == new_dest_bci)
98 return true;
99 else if (_old_bci[_pos-1] == old_dest_bci)
100 return (new_dest_bci == _new_st_bci[_pos-1]);
101 else return false;
102 }
103 };
|