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 constantTag _tag; 139 public: 140 enum AccessCheck { 141 needs_access_check, 142 skip_access_check 143 }; 144 145 LinkInfo(const constantPoolHandle& pool, int index, TRAPS); 146 147 // Condensed information from other call sites within the vm. 148 LinkInfo(KlassHandle resolved_klass, Symbol* name, Symbol* signature, KlassHandle current_klass, 149 AccessCheck check_access = needs_access_check, 150 constantTag tag = JVM_CONSTANT_Invalid) : 151 _resolved_klass(resolved_klass), 152 _name(name), _signature(signature), _current_klass(current_klass), 153 _check_access(check_access == needs_access_check && current_klass.not_null()), _tag(tag) {} 154 155 // Case where we just find the method and don't check access against the current class 156 LinkInfo(KlassHandle resolved_klass, Symbol*name, Symbol* signature) : 157 _resolved_klass(resolved_klass), 158 _name(name), _signature(signature), _current_klass(NULL), 159 _check_access(false), _tag(JVM_CONSTANT_Invalid) {} 160 161 // accessors 162 Symbol* name() const { return _name; } 163 Symbol* signature() const { return _signature; } 164 KlassHandle resolved_klass() const { return _resolved_klass; } 165 KlassHandle current_klass() const { return _current_klass; } 166 constantTag tag() const { return _tag; } 167 bool check_access() const { return _check_access; } 168 char* method_string() const; 169 170 void print() PRODUCT_RETURN; 171 }; 172 173 // Link information for getfield/putfield & getstatic/putstatic bytecodes 174 // is represented using a fieldDescriptor. 175 176 // The LinkResolver is used to resolve constant-pool references at run-time. 177 // It does all necessary link-time checks & throws exceptions if necessary. 178 179 class LinkResolver: AllStatic { 180 friend class klassVtable; 181 friend class klassItable; 182 183 private: 184 185 static methodHandle lookup_method_in_klasses(const LinkInfo& link_info, 186 bool checkpolymorphism, 187 bool in_imethod_resolve, TRAPS); 188 static methodHandle lookup_method_in_interfaces(const LinkInfo& link_info, TRAPS); 189 static methodHandle lookup_polymorphic_method(const LinkInfo& link_info, 190 Handle *appendix_result_or_null, 191 Handle *method_type_result, TRAPS); 192 JVMCI_ONLY(public:) // Needed for CompilerToVM.resolveMethod() 193 // Not Linktime so doesn't take LinkInfo 194 static methodHandle lookup_instance_method_in_klasses ( 195 KlassHandle klass, Symbol* name, Symbol* signature, TRAPS); 196 JVMCI_ONLY(private:) 197 198 // Similar loader constraint checking functions that throw 199 // LinkageError with descriptive message. 200 static void check_method_loader_constraints(const LinkInfo& link_info, 201 const methodHandle& resolved_method, 202 const char* method_type, TRAPS); 203 static void check_field_loader_constraints(Symbol* field, Symbol* sig, 204 KlassHandle current_klass, 205 KlassHandle sel_klass, TRAPS); 206 207 static methodHandle resolve_interface_method(const LinkInfo& link_info, bool nostatics, TRAPS); 208 static methodHandle resolve_method (const LinkInfo& link_info, bool require_methodref, TRAPS); 209 210 static methodHandle linktime_resolve_static_method (const LinkInfo& link_info, TRAPS); 211 static methodHandle linktime_resolve_special_method (const LinkInfo& link_info, TRAPS); 212 static methodHandle linktime_resolve_virtual_method (const LinkInfo& link_info, TRAPS); 213 static methodHandle linktime_resolve_interface_method (const LinkInfo& link_info, TRAPS); 214 215 static void runtime_resolve_special_method (CallInfo& result, 216 const methodHandle& resolved_method, 217 KlassHandle resolved_klass, 218 KlassHandle current_klass, 219 bool check_access, TRAPS); 220 static void runtime_resolve_virtual_method (CallInfo& result, 221 const methodHandle& resolved_method, 222 KlassHandle resolved_klass, 223 Handle recv, 224 KlassHandle recv_klass, 225 bool check_null_and_abstract, TRAPS); 226 static void runtime_resolve_interface_method (CallInfo& result, 227 const methodHandle& resolved_method, 228 KlassHandle resolved_klass, 229 Handle recv, 230 KlassHandle recv_klass, 231 bool check_null_and_abstract, TRAPS); 232 233 static void check_field_accessability(KlassHandle ref_klass, 234 KlassHandle resolved_klass, 235 KlassHandle sel_klass, 236 const fieldDescriptor& fd, TRAPS); 237 static void check_method_accessability(KlassHandle ref_klass, 238 KlassHandle resolved_klass, 239 KlassHandle sel_klass, 240 const methodHandle& sel_method, TRAPS); 241 242 // runtime resolving from constant pool 243 static void resolve_invokestatic (CallInfo& result, 244 const constantPoolHandle& pool, int index, TRAPS); 245 static void resolve_invokespecial (CallInfo& result, 246 const constantPoolHandle& pool, int index, TRAPS); 247 static void resolve_invokevirtual (CallInfo& result, Handle recv, 248 const constantPoolHandle& pool, int index, TRAPS); 249 static void resolve_invokeinterface(CallInfo& result, Handle recv, 250 const constantPoolHandle& pool, int index, TRAPS); 251 static void resolve_invokedynamic (CallInfo& result, 252 const constantPoolHandle& pool, int index, TRAPS); 253 static void resolve_invokehandle (CallInfo& result, 254 const constantPoolHandle& pool, int index, TRAPS); 255 public: 256 // constant pool resolving 257 static void check_klass_accessability(KlassHandle ref_klass, KlassHandle sel_klass, TRAPS); 258 259 // static resolving calls (will not run any Java code); 260 // used only from Bytecode_invoke::static_target 261 static methodHandle resolve_method_statically(Bytecodes::Code code, 262 const constantPoolHandle& pool, 263 int index, TRAPS); 264 265 static void resolve_field_access(fieldDescriptor& result, 266 const constantPoolHandle& pool, 267 int index, Bytecodes::Code byte, TRAPS); 268 static void resolve_field(fieldDescriptor& result, const LinkInfo& link_info, 269 Bytecodes::Code access_kind, 270 bool initialize_class, TRAPS); 271 272 static void resolve_static_call (CallInfo& result, 273 const LinkInfo& link_info, 274 bool initialize_klass, TRAPS); 275 static void resolve_special_call (CallInfo& result, 276 const LinkInfo& link_info, 277 TRAPS); 278 static void resolve_virtual_call (CallInfo& result, Handle recv, KlassHandle recv_klass, 279 const LinkInfo& link_info, 280 bool check_null_and_abstract, TRAPS); 281 static void resolve_interface_call(CallInfo& result, Handle recv, KlassHandle recv_klass, 282 const LinkInfo& link_info, 283 bool check_null_and_abstract, TRAPS); 284 static void resolve_handle_call (CallInfo& result, 285 const LinkInfo& link_info, TRAPS); 286 static void resolve_dynamic_call (CallInfo& result, Handle bootstrap_specifier, 287 Symbol* method_name, Symbol* method_signature, 288 KlassHandle current_klass, TRAPS); 289 290 // same as above for compile-time resolution; but returns null handle instead of throwing 291 // an exception on error also, does not initialize klass (i.e., no side effects) 292 static methodHandle resolve_virtual_call_or_null (KlassHandle receiver_klass, 293 const LinkInfo& link_info); 294 static methodHandle resolve_interface_call_or_null(KlassHandle receiver_klass, 295 const LinkInfo& link_info); 296 static methodHandle resolve_static_call_or_null (const LinkInfo& link_info); 297 static methodHandle resolve_special_call_or_null (const LinkInfo& link_info); 298 299 static int vtable_index_of_interface_method(KlassHandle klass, const methodHandle& resolved_method); 300 301 // same as above for compile-time resolution; returns vtable_index if current_klass if linked 302 static int resolve_virtual_vtable_index (KlassHandle receiver_klass, 303 const LinkInfo& link_info); 304 305 // static resolving for compiler (does not throw exceptions, returns null handle if unsuccessful) 306 static methodHandle linktime_resolve_virtual_method_or_null (const LinkInfo& link_info); 307 static methodHandle linktime_resolve_interface_method_or_null(const LinkInfo& link_info); 308 309 // runtime resolving from constant pool 310 static void resolve_invoke(CallInfo& result, Handle recv, 311 const constantPoolHandle& pool, int index, 312 Bytecodes::Code byte, TRAPS); 313 private: 314 static void trace_method_resolution(const char* prefix, KlassHandle klass, 315 KlassHandle resolved_klass, 316 const methodHandle& method) PRODUCT_RETURN; 317 }; 318 #endif // SHARE_VM_INTERPRETER_LINKRESOLVER_HPP