1 /* 2 * Copyright (c) 1997, 2015, 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_INTERPRETER_LINKRESOLVER_HPP 26 #define SHARE_VM_INTERPRETER_LINKRESOLVER_HPP 27 28 #include "oops/method.hpp" 29 #include "utilities/top.hpp" 30 31 // All the necessary definitions for run-time link resolution. 32 33 // CallInfo provides all the information gathered for a particular 34 // linked call site after resolving it. A link is any reference 35 // made from within the bytecodes of a method to an object outside of 36 // that method. If the info is invalid, the link has not been resolved 37 // successfully. 38 39 class CallInfo : public StackObj { 40 public: 41 // Ways that a method call might be selected (or not) based on receiver type. 42 // Note that an invokevirtual instruction might be linked with no_dispatch, 43 // and an invokeinterface instruction might be linked with any of the three options 44 enum CallKind { 45 direct_call, // jump into resolved_method (must be concrete) 46 vtable_call, // select recv.klass.method_at_vtable(index) 47 itable_call, // select recv.klass.method_at_itable(resolved_method.holder, index) 48 unknown_kind = -1 49 }; 50 private: 51 KlassHandle _resolved_klass; // static receiver klass, resolved from a symbolic reference 52 KlassHandle _selected_klass; // dynamic receiver class (same as static, or subklass) 53 methodHandle _resolved_method; // static target method 54 methodHandle _selected_method; // dynamic (actual) target method 55 CallKind _call_kind; // kind of call (static(=bytecode static/special + 56 // others inferred), vtable, itable) 57 int _call_index; // vtable or itable index of selected class method (if any) 58 Handle _resolved_appendix; // extra argument in constant pool (if CPCE::has_appendix) 59 Handle _resolved_method_type; // MethodType (for invokedynamic and invokehandle call sites) 60 61 void set_static(KlassHandle resolved_klass, const methodHandle& resolved_method, TRAPS); 62 void set_interface(KlassHandle resolved_klass, KlassHandle selected_klass, 63 const methodHandle& resolved_method, 64 const methodHandle& selected_method, 65 int itable_index, TRAPS); 66 void set_virtual(KlassHandle resolved_klass, KlassHandle selected_klass, 67 const methodHandle& resolved_method, 68 const methodHandle& selected_method, 69 int vtable_index, TRAPS); 70 void set_handle(const methodHandle& resolved_method, 71 Handle resolved_appendix, Handle resolved_method_type, TRAPS); 72 void set_common(KlassHandle resolved_klass, KlassHandle selected_klass, 73 const methodHandle& resolved_method, 74 const methodHandle& selected_method, 75 CallKind kind, 76 int index, TRAPS); 77 78 friend class LinkResolver; 79 80 public: 81 CallInfo() { 82 #ifndef PRODUCT 83 _call_kind = CallInfo::unknown_kind; 84 _call_index = Method::garbage_vtable_index; 85 #endif //PRODUCT 86 } 87 88 // utility to extract an effective CallInfo from a method and an optional receiver limit 89 // does not queue the method for compilation 90 CallInfo(Method* resolved_method, Klass* resolved_klass = NULL); 91 92 KlassHandle resolved_klass() const { return _resolved_klass; } 93 KlassHandle selected_klass() const { return _selected_klass; } 94 methodHandle resolved_method() const { return _resolved_method; } 95 methodHandle selected_method() const { return _selected_method; } 96 Handle resolved_appendix() const { return _resolved_appendix; } 97 Handle resolved_method_type() const { return _resolved_method_type; } 98 99 BasicType result_type() const { return selected_method()->result_type(); } 100 CallKind call_kind() const { return _call_kind; } 101 int call_index() const { return _call_index; } 102 int vtable_index() const { 103 // Even for interface calls the vtable index could be non-negative. 104 // See CallInfo::set_interface. 105 assert(has_vtable_index() || is_statically_bound(), ""); 106 assert(call_kind() == vtable_call || call_kind() == direct_call, ""); 107 // The returned value is < 0 if the call is statically bound. 108 // But, the returned value may be >= 0 even if the kind is direct_call. 109 // It is up to the caller to decide which way to go. 110 return _call_index; 111 } 112 int itable_index() const { 113 assert(call_kind() == itable_call, ""); 114 // The returned value is always >= 0, a valid itable index. 115 return _call_index; 116 } 117 118 // debugging 119 #ifdef ASSERT 120 bool has_vtable_index() const { return _call_index >= 0 && _call_kind != CallInfo::itable_call; } 121 bool is_statically_bound() const { return _call_index == Method::nonvirtual_vtable_index; } 122 #endif //ASSERT 123 void verify() PRODUCT_RETURN; 124 void print() PRODUCT_RETURN; 125 }; 126 127 128 // Condensed information from constant pool to use to resolve the method or field. 129 // resolved_klass = specified class (i.e., static receiver class) 130 // current_klass = sending method holder (i.e., class containing the method 131 // containing the call being resolved) 132 class LinkInfo : public StackObj { 133 Symbol* _name; // extracted from JVM_CONSTANT_NameAndType 134 Symbol* _signature; 135 KlassHandle _resolved_klass; // class that the constant pool entry points to 136 KlassHandle _current_klass; // class that owns the constant pool 137 bool _check_access; 138 public: 139 LinkInfo(const constantPoolHandle& pool, int index, TRAPS); 140 // Condensed information from other call sites within the vm. 141 LinkInfo(KlassHandle resolved_klass, Symbol* name, Symbol* signature, 142 KlassHandle current_klass, bool check_access = true) : 143 _resolved_klass(resolved_klass), 144 _name(name), _signature(signature), _current_klass(current_klass), 145 _check_access(check_access) {} 146 147 // accessors 148 Symbol* name() const { return _name; } 149 Symbol* signature() const { return _signature; } 150 KlassHandle resolved_klass() const { return _resolved_klass; } 151 KlassHandle current_klass() const { return _current_klass; } 152 bool check_access() const { return _check_access; } 153 char* method_string() const; 154 155 void print() PRODUCT_RETURN; 156 }; 157 158 // Link information for getfield/putfield & getstatic/putstatic bytecodes 159 // is represented using a fieldDescriptor. 160 161 // The LinkResolver is used to resolve constant-pool references at run-time. 162 // It does all necessary link-time checks & throws exceptions if necessary. 163 164 class LinkResolver: AllStatic { 165 friend class klassVtable; 166 friend class klassItable; 167 168 private: 169 170 static methodHandle lookup_method_in_klasses(const LinkInfo& link_info, 171 bool checkpolymorphism, 172 bool in_imethod_resolve, TRAPS); 173 static methodHandle lookup_method_in_interfaces(const LinkInfo& link_info, TRAPS); 174 static methodHandle lookup_polymorphic_method(const LinkInfo& link_info, 175 Handle *appendix_result_or_null, 176 Handle *method_type_result, TRAPS); 177 JVMCI_ONLY(public:) // Needed for CompilerToVM.resolveMethod() 178 // Not Linktime so doesn't take LinkInfo 179 static methodHandle lookup_instance_method_in_klasses ( 180 KlassHandle klass, Symbol* name, Symbol* signature, TRAPS); 181 JVMCI_ONLY(private:) 182 183 // Similar loader constraint checking functions that throw 184 // LinkageError with descriptive message. 185 static void check_method_loader_constraints(const LinkInfo& link_info, 186 const methodHandle& resolved_method, 187 const char* method_type, TRAPS); 188 static void check_field_loader_constraints(Symbol* field, Symbol* sig, 189 KlassHandle current_klass, 190 KlassHandle sel_klass, TRAPS); 191 192 static methodHandle resolve_interface_method(const LinkInfo& link_info, bool nostatics, TRAPS); 193 static methodHandle resolve_method (const LinkInfo& link_info, bool require_methodref, TRAPS); 194 195 static methodHandle linktime_resolve_static_method (const LinkInfo& link_info, TRAPS); 196 static methodHandle linktime_resolve_special_method (const LinkInfo& link_info, TRAPS); 197 static methodHandle linktime_resolve_virtual_method (const LinkInfo& link_info, TRAPS); 198 static methodHandle linktime_resolve_interface_method (const LinkInfo& link_info, TRAPS); 199 200 static void runtime_resolve_special_method (CallInfo& result, 201 const methodHandle& resolved_method, 202 KlassHandle resolved_klass, 203 KlassHandle current_klass, 204 bool check_access, TRAPS); 205 static void runtime_resolve_virtual_method (CallInfo& result, 206 const methodHandle& resolved_method, 207 KlassHandle resolved_klass, 208 Handle recv, 209 KlassHandle recv_klass, 210 bool check_null_and_abstract, TRAPS); 211 static void runtime_resolve_interface_method (CallInfo& result, 212 const methodHandle& resolved_method, 213 KlassHandle resolved_klass, 214 Handle recv, 215 KlassHandle recv_klass, 216 bool check_null_and_abstract, TRAPS); 217 218 static void check_field_accessability(KlassHandle ref_klass, 219 KlassHandle resolved_klass, 220 KlassHandle sel_klass, 221 const fieldDescriptor& fd, TRAPS); 222 static void check_method_accessability(KlassHandle ref_klass, 223 KlassHandle resolved_klass, 224 KlassHandle sel_klass, 225 const methodHandle& sel_method, TRAPS); 226 227 // runtime resolving from constant pool 228 static void resolve_invokestatic (CallInfo& result, 229 const constantPoolHandle& pool, int index, TRAPS); 230 static void resolve_invokespecial (CallInfo& result, 231 const constantPoolHandle& pool, int index, TRAPS); 232 static void resolve_invokevirtual (CallInfo& result, Handle recv, 233 const constantPoolHandle& pool, int index, TRAPS); 234 static void resolve_invokeinterface(CallInfo& result, Handle recv, 235 const constantPoolHandle& pool, int index, TRAPS); 236 static void resolve_invokedynamic (CallInfo& result, 237 const constantPoolHandle& pool, int index, TRAPS); 238 static void resolve_invokehandle (CallInfo& result, 239 const constantPoolHandle& pool, int index, TRAPS); 240 public: 241 // constant pool resolving 242 static void check_klass_accessability(KlassHandle ref_klass, KlassHandle sel_klass, TRAPS); 243 244 // static resolving calls (will not run any Java code); 245 // used only from Bytecode_invoke::static_target 246 static methodHandle resolve_method_statically(Bytecodes::Code code, 247 const constantPoolHandle& pool, 248 int index, TRAPS); 249 250 static void resolve_field_access(fieldDescriptor& result, 251 const constantPoolHandle& pool, 252 int index, Bytecodes::Code byte, TRAPS); 253 static void resolve_field(fieldDescriptor& result, const LinkInfo& link_info, 254 Bytecodes::Code access_kind, 255 bool initialize_class, TRAPS); 256 257 static void resolve_static_call (CallInfo& result, 258 const LinkInfo& link_info, 259 bool initialize_klass, TRAPS); 260 static void resolve_special_call (CallInfo& result, 261 const LinkInfo& link_info, 262 TRAPS); 263 static void resolve_virtual_call (CallInfo& result, Handle recv, KlassHandle recv_klass, 264 const LinkInfo& link_info, 265 bool check_null_and_abstract, TRAPS); 266 static void resolve_interface_call(CallInfo& result, Handle recv, KlassHandle recv_klass, 267 const LinkInfo& link_info, 268 bool check_null_and_abstract, TRAPS); 269 static void resolve_handle_call (CallInfo& result, 270 const LinkInfo& link_info, TRAPS); 271 static void resolve_dynamic_call (CallInfo& result, Handle bootstrap_specifier, 272 Symbol* method_name, Symbol* method_signature, 273 KlassHandle current_klass, TRAPS); 274 275 // same as above for compile-time resolution; but returns null handle instead of throwing 276 // an exception on error also, does not initialize klass (i.e., no side effects) 277 static methodHandle resolve_virtual_call_or_null (KlassHandle receiver_klass, 278 const LinkInfo& link_info); 279 static methodHandle resolve_interface_call_or_null(KlassHandle receiver_klass, 280 const LinkInfo& link_info); 281 static methodHandle resolve_static_call_or_null (const LinkInfo& link_info); 282 static methodHandle resolve_special_call_or_null (const LinkInfo& link_info); 283 284 static int vtable_index_of_interface_method(KlassHandle klass, const methodHandle& resolved_method); 285 286 // same as above for compile-time resolution; returns vtable_index if current_klass if linked 287 static int resolve_virtual_vtable_index (KlassHandle receiver_klass, 288 const LinkInfo& link_info); 289 290 // static resolving for compiler (does not throw exceptions, returns null handle if unsuccessful) 291 static methodHandle linktime_resolve_virtual_method_or_null (const LinkInfo& link_info); 292 static methodHandle linktime_resolve_interface_method_or_null(const LinkInfo& link_info); 293 294 // runtime resolving from constant pool 295 static void resolve_invoke(CallInfo& result, Handle recv, 296 const constantPoolHandle& pool, int index, 297 Bytecodes::Code byte, TRAPS); 298 private: 299 static void trace_method_resolution(const char* prefix, KlassHandle klass, 300 KlassHandle resolved_klass, 301 const methodHandle& method) PRODUCT_RETURN; 302 }; 303 #endif // SHARE_VM_INTERPRETER_LINKRESOLVER_HPP