1 /*
2 * Copyright (c) 1998, 2019, 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
20 * or visit www.oracle.com if you need additional information or have any
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23 */
24
25 #ifndef SHARE_INTERPRETER_REWRITER_HPP
26 #define SHARE_INTERPRETER_REWRITER_HPP
27
28 #include "memory/allocation.hpp"
29 #include "utilities/growableArray.hpp"
30
31 // The Rewriter adds caches to the constant pool and rewrites bytecode indices
32 // pointing into the constant pool for better interpreter performance.
33
34 class Rewriter: public StackObj {
35 private:
36 InstanceKlass* _klass;
37 constantPoolHandle _pool;
38 Array<Method*>* _methods;
39 GrowableArray<int> _cp_map;
40 GrowableArray<int> _cp_cache_map; // for Methodref, Fieldref,
41 // InterfaceMethodref and InvokeDynamic
42 GrowableArray<int> _reference_map; // maps from cp index to resolved_refs index (or -1)
43 GrowableArray<int> _resolved_references_map; // for strings, methodHandle, methodType
44 GrowableArray<int> _invokedynamic_references_map; // for invokedynamic resolved refs
45 GrowableArray<int> _method_handle_invokers;
46 int _resolved_reference_limit;
47
48 // For mapping invokedynamic bytecodes, which are discovered during method
49 // scanning. The invokedynamic entries are added at the end of the cpCache.
50 // If there are any invokespecial/InterfaceMethodref special case bytecodes,
51 // these entries are added before invokedynamic entries so that the
52 // invokespecial bytecode 16 bit index doesn't overflow.
53 GrowableArray<int> _invokedynamic_cp_cache_map;
54
55 // For patching.
56 GrowableArray<address>* _patch_invokedynamic_bcps;
57 GrowableArray<int>* _patch_invokedynamic_refs;
58
59 void init_maps(int length) {
60 _cp_map.trunc_to(0);
61 _cp_map.at_grow(length, -1);
62
63 _cp_cache_map.trunc_to(0);
64 // Also cache resolved objects, in another different cache.
65 _reference_map.trunc_to(0);
66 _reference_map.at_grow(length, -1);
67
68 _method_handle_invokers.trunc_to(0);
69 _resolved_references_map.trunc_to(0);
70 _invokedynamic_references_map.trunc_to(0);
71 _resolved_reference_limit = -1;
72 _first_iteration_cp_cache_limit = -1;
73
74 // invokedynamic specific fields
75 _invokedynamic_cp_cache_map.trunc_to(0);
76 _patch_invokedynamic_bcps = new GrowableArray<address>(length / 4);
77 _patch_invokedynamic_refs = new GrowableArray<int>(length / 4);
78 }
79
80 int _first_iteration_cp_cache_limit;
81 void record_map_limits() {
82 // Record initial size of the two arrays generated for the CP cache
83 // relative to walking the constant pool.
84 _first_iteration_cp_cache_limit = _cp_cache_map.length();
85 _resolved_reference_limit = _resolved_references_map.length();
86 }
87
88 int cp_cache_delta() {
89 // How many cp cache entries were added since recording map limits after
90 // cp cache initialization?
91 assert(_first_iteration_cp_cache_limit != -1, "only valid after first iteration");
92 return _cp_cache_map.length() - _first_iteration_cp_cache_limit;
93 }
94
95 int cp_entry_to_cp_cache(int i) { assert(has_cp_cache(i), "oob"); return _cp_map.at(i); }
96 bool has_cp_cache(int i) { return (uint) i < (uint) _cp_map.length() && _cp_map.at(i) >= 0; }
97
98 int add_map_entry(int cp_index, GrowableArray<int>* cp_map, GrowableArray<int>* cp_cache_map) {
99 assert(cp_map->at(cp_index) == -1, "not twice on same cp_index");
100 int cache_index = cp_cache_map->append(cp_index);
101 cp_map->at_put(cp_index, cache_index);
102 return cache_index;
103 }
104
105 int add_cp_cache_entry(int cp_index) {
106 assert(_pool->tag_at(cp_index).value() != JVM_CONSTANT_InvokeDynamic, "use indy version");
107 assert(_first_iteration_cp_cache_limit == -1, "do not add cache entries after first iteration");
108 int cache_index = add_map_entry(cp_index, &_cp_map, &_cp_cache_map);
109 assert(cp_entry_to_cp_cache(cp_index) == cache_index, "");
110 assert(cp_cache_entry_pool_index(cache_index) == cp_index, "");
111 return cache_index;
112 }
113
114 int add_invokedynamic_cp_cache_entry(int cp_index) {
115 assert(_pool->tag_at(cp_index).value() == JVM_CONSTANT_InvokeDynamic, "use non-indy version");
116 assert(_first_iteration_cp_cache_limit >= 0, "add indy cache entries after first iteration");
117 // add to the invokedynamic index map.
118 int cache_index = _invokedynamic_cp_cache_map.append(cp_index);
119 // do not update _cp_map, since the mapping is one-to-many
120 assert(invokedynamic_cp_cache_entry_pool_index(cache_index) == cp_index, "");
121 // this index starts at one but in the bytecode it's appended to the end.
122 return cache_index + _first_iteration_cp_cache_limit;
123 }
124
125 int invokedynamic_cp_cache_entry_pool_index(int cache_index) {
126 int cp_index = _invokedynamic_cp_cache_map.at(cache_index);
127 return cp_index;
128 }
129
130 // add a new CP cache entry beyond the normal cache for the special case of
131 // invokespecial with InterfaceMethodref as cpool operand.
132 int add_invokespecial_cp_cache_entry(int cp_index) {
133 assert(_first_iteration_cp_cache_limit >= 0, "add these special cache entries after first iteration");
134 // Don't add InterfaceMethodref if it already exists at the end.
135 for (int i = _first_iteration_cp_cache_limit; i < _cp_cache_map.length(); i++) {
136 if (cp_cache_entry_pool_index(i) == cp_index) {
137 return i;
138 }
139 }
140 int cache_index = _cp_cache_map.append(cp_index);
141 assert(cache_index >= _first_iteration_cp_cache_limit, "");
142 // do not update _cp_map, since the mapping is one-to-many
143 assert(cp_cache_entry_pool_index(cache_index) == cp_index, "");
144 return cache_index;
145 }
146
147 int cp_entry_to_resolved_references(int cp_index) const {
148 assert(has_entry_in_resolved_references(cp_index), "oob");
149 return _reference_map.at(cp_index);
150 }
151 bool has_entry_in_resolved_references(int cp_index) const {
152 return (uint) cp_index < (uint) _reference_map.length() && _reference_map.at(cp_index) >= 0;
153 }
154
155 // add a new entry to the resolved_references map
156 int add_resolved_references_entry(int cp_index) {
157 int ref_index = add_map_entry(cp_index, &_reference_map, &_resolved_references_map);
158 assert(cp_entry_to_resolved_references(cp_index) == ref_index, "");
159 return ref_index;
160 }
161
162 // add a new entry to the resolved_references map (for invokedynamic and invokehandle only)
163 int add_invokedynamic_resolved_references_entry(int cp_index, int cache_index) {
164 assert(_resolved_reference_limit >= 0, "must add indy refs after first iteration");
165 int ref_index = _resolved_references_map.append(cp_index); // many-to-one
166 assert(ref_index >= _resolved_reference_limit, "");
167 _invokedynamic_references_map.at_put_grow(ref_index, cache_index, -1);
168 return ref_index;
169 }
170
171 int resolved_references_entry_to_pool_index(int ref_index) {
172 int cp_index = _resolved_references_map.at(ref_index);
173 return cp_index;
174 }
175
176 // Access the contents of _cp_cache_map to determine CP cache layout.
177 int cp_cache_entry_pool_index(int cache_index) {
178 int cp_index = _cp_cache_map.at(cache_index);
179 return cp_index;
180 }
181
182 // All the work goes in here:
183 Rewriter(InstanceKlass* klass, const constantPoolHandle& cpool, Array<Method*>* methods, TRAPS);
184
185 void compute_index_maps();
186 void make_constant_pool_cache(TRAPS);
187 void scan_method(Method* m, bool reverse, bool* invokespecial_error);
188 void rewrite_Object_init(const methodHandle& m, TRAPS);
189 void rewrite_member_reference(address bcp, int offset, bool reverse);
190 void maybe_rewrite_invokehandle(address opc, int cp_index, int cache_index, bool reverse);
191 void rewrite_invokedynamic(address bcp, int offset, bool reverse);
192 void maybe_rewrite_ldc(address bcp, int offset, bool is_wide, bool reverse);
193 void rewrite_invokespecial(address bcp, int offset, bool reverse, bool* invokespecial_error);
194
195 void patch_invokedynamic_bytecodes();
196
197 // Do all the work.
198 void rewrite_bytecodes(TRAPS);
199
200 // Revert bytecodes in case of an exception.
201 void restore_bytecodes();
202
203 static methodHandle rewrite_jsrs(const methodHandle& m, TRAPS);
204 public:
205 // Driver routine:
206 static void rewrite(InstanceKlass* klass, TRAPS);
207 };
208
209 #endif // SHARE_INTERPRETER_REWRITER_HPP