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. 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_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 init_maps(int length)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; record_map_limits()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 cp_cache_delta()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 cp_entry_to_cp_cache(int i)95 int cp_entry_to_cp_cache(int i) { assert(has_cp_cache(i), "oob"); return _cp_map.at(i); } has_cp_cache(int i)96 bool has_cp_cache(int i) { return (uint) i < (uint) _cp_map.length() && _cp_map.at(i) >= 0; } 97 add_map_entry(int cp_index,GrowableArray<int> * cp_map,GrowableArray<int> * cp_cache_map)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 add_cp_cache_entry(int cp_index)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 add_invokedynamic_cp_cache_entry(int cp_index)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 invokedynamic_cp_cache_entry_pool_index(int cache_index)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. add_invokespecial_cp_cache_entry(int cp_index)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 cp_entry_to_resolved_references(int cp_index) const147 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 } has_entry_in_resolved_references(int cp_index) const151 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 add_resolved_references_entry(int cp_index)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) add_invokedynamic_resolved_references_entry(int cp_index,int cache_index)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 resolved_references_entry_to_pool_index(int ref_index)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. cp_cache_entry_pool_index(int cache_index)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(Thread* thread, 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(Thread* thread); 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 210