1 /*
2 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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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).
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23 */
24
25 #ifndef SHARE_INTERPRETER_LINKRESOLVER_HPP
26 #define SHARE_INTERPRETER_LINKRESOLVER_HPP
27
28 #include "oops/method.hpp"
29
30 // All the necessary definitions for run-time link resolution.
31
32 // CallInfo provides all the information gathered for a particular
33 // linked call site after resolving it. A link is any reference
34 // made from within the bytecodes of a method to an object outside of
35 // that method. If the info is invalid, the link has not been resolved
36 // successfully.
37
38 class CallInfo : public StackObj {
39 public:
40 // Ways that a method call might be selected (or not) based on receiver type.
41 // Note that an invokevirtual instruction might be linked with no_dispatch,
42 // and an invokeinterface instruction might be linked with any of the three options
43 enum CallKind {
44 direct_call, // jump into resolved_method (must be concrete)
45 vtable_call, // select recv.klass.method_at_vtable(index)
46 itable_call, // select recv.klass.method_at_itable(resolved_method.holder, index)
47 unknown_kind = -1
48 };
49 private:
50 Klass* _resolved_klass; // static receiver klass, resolved from a symbolic reference
51 Klass* _selected_klass; // dynamic receiver class (same as static, or subklass)
52 methodHandle _resolved_method; // static target method
53 methodHandle _selected_method; // dynamic (actual) target method
54 CallKind _call_kind; // kind of call (static(=bytecode static/special +
55 // others inferred), vtable, itable)
56 int _call_index; // vtable or itable index of selected class method (if any)
57 Handle _resolved_appendix; // extra argument in constant pool (if CPCE::has_appendix)
58 Handle _resolved_method_name; // Object holding the ResolvedMethodName
59
60 void set_static(Klass* resolved_klass, const methodHandle& resolved_method, TRAPS);
61 void set_interface(Klass* resolved_klass, Klass* selected_klass,
62 const methodHandle& resolved_method,
63 const methodHandle& selected_method,
64 int itable_index, TRAPS);
65 void set_virtual(Klass* resolved_klass, Klass* selected_klass,
66 const methodHandle& resolved_method,
67 const methodHandle& selected_method,
68 int vtable_index, TRAPS);
69 void set_handle(const methodHandle& resolved_method,
70 Handle resolved_appendix, TRAPS);
71 void set_handle(Klass* resolved_klass,
72 const methodHandle& resolved_method,
73 Handle resolved_appendix, TRAPS);
74 void set_common(Klass* resolved_klass, Klass* selected_klass,
75 const methodHandle& resolved_method,
76 const methodHandle& selected_method,
77 CallKind kind,
78 int index, TRAPS);
79
80 friend class LinkResolver;
81
82 public:
83 CallInfo() {
84 #ifndef PRODUCT
85 _call_kind = CallInfo::unknown_kind;
86 _call_index = Method::garbage_vtable_index;
87 #endif //PRODUCT
88 }
89
90 // utility to extract an effective CallInfo from a method and an optional receiver limit
91 // does not queue the method for compilation. This also creates a ResolvedMethodName
92 // object for the resolved_method.
93 CallInfo(Method* resolved_method, Klass* resolved_klass, TRAPS);
94
95 Klass* resolved_klass() const { return _resolved_klass; }
96 Klass* selected_klass() const { return _selected_klass; }
97 methodHandle resolved_method() const { return _resolved_method; }
98 methodHandle selected_method() const { return _selected_method; }
99 Handle resolved_appendix() const { return _resolved_appendix; }
100 Handle resolved_method_name() const { return _resolved_method_name; }
101 // Materialize a java.lang.invoke.ResolvedMethodName for this resolved_method
102 void set_resolved_method_name(TRAPS);
103
104 BasicType result_type() const { return selected_method()->result_type(); }
105 CallKind call_kind() const { return _call_kind; }
106 int call_index() const { return _call_index; }
107 int vtable_index() const {
108 // Even for interface calls the vtable index could be non-negative.
109 // See CallInfo::set_interface.
110 assert(has_vtable_index() || is_statically_bound(), "");
111 assert(call_kind() == vtable_call || call_kind() == direct_call, "");
112 // The returned value is < 0 if the call is statically bound.
113 // But, the returned value may be >= 0 even if the kind is direct_call.
114 // It is up to the caller to decide which way to go.
115 return _call_index;
116 }
117 int itable_index() const {
118 assert(call_kind() == itable_call, "");
119 // The returned value is always >= 0, a valid itable index.
120 return _call_index;
121 }
122
123 // debugging
124 #ifdef ASSERT
125 bool has_vtable_index() const { return _call_index >= 0 && _call_kind != CallInfo::itable_call; }
126 bool is_statically_bound() const { return _call_index == Method::nonvirtual_vtable_index; }
127 #endif //ASSERT
128 void verify() PRODUCT_RETURN;
129 void print() PRODUCT_RETURN;
130 };
131
132
133 // Condensed information from constant pool to use to resolve the method or field.
134 // resolved_klass = specified class (i.e., static receiver class)
135 // current_klass = sending method holder (i.e., class containing the method
136 // containing the call being resolved)
137 // current_method = sending method (relevant for field resolution)
138 class LinkInfo : public StackObj {
139 Symbol* _name; // extracted from JVM_CONSTANT_NameAndType
140 Symbol* _signature;
141 Klass* _resolved_klass; // class that the constant pool entry points to
142 Klass* _current_klass; // class that owns the constant pool
143 methodHandle _current_method; // sending method
144 bool _check_access;
145 constantTag _tag;
146
147 public:
148 enum AccessCheck {
149 needs_access_check,
150 skip_access_check
151 };
152
153 LinkInfo(const constantPoolHandle& pool, int index, const methodHandle& current_method, TRAPS);
154 LinkInfo(const constantPoolHandle& pool, int index, TRAPS);
155
156 // Condensed information from other call sites within the vm.
157 LinkInfo(Klass* resolved_klass, Symbol* name, Symbol* signature, Klass* current_klass,
158 AccessCheck check_access = needs_access_check,
159 constantTag tag = JVM_CONSTANT_Invalid) :
160 _name(name),
161 _signature(signature), _resolved_klass(resolved_klass), _current_klass(current_klass), _current_method(methodHandle()),
162 _check_access(check_access == needs_access_check), _tag(tag) {}
163
164 LinkInfo(Klass* resolved_klass, Symbol* name, Symbol* signature, const methodHandle& current_method,
165 AccessCheck check_access = needs_access_check,
166 constantTag tag = JVM_CONSTANT_Invalid) :
167 _name(name),
168 _signature(signature), _resolved_klass(resolved_klass), _current_klass(current_method->method_holder()), _current_method(current_method),
169 _check_access(check_access == needs_access_check), _tag(tag) {}
170
171 // Case where we just find the method and don't check access against the current class
172 LinkInfo(Klass* resolved_klass, Symbol*name, Symbol* signature) :
173 _name(name),
174 _signature(signature), _resolved_klass(resolved_klass), _current_klass(NULL), _current_method(methodHandle()),
175 _check_access(false), _tag(JVM_CONSTANT_Invalid) {}
176
177 // accessors
178 Symbol* name() const { return _name; }
179 Symbol* signature() const { return _signature; }
180 Klass* resolved_klass() const { return _resolved_klass; }
181 Klass* current_klass() const { return _current_klass; }
182 methodHandle current_method() const { return _current_method; }
183 constantTag tag() const { return _tag; }
184 bool check_access() const { return _check_access; }
185 char* method_string() const;
186
187 void print() PRODUCT_RETURN;
188 };
189
190 // Link information for getfield/putfield & getstatic/putstatic bytecodes
191 // is represented using a fieldDescriptor.
192
193 // The LinkResolver is used to resolve constant-pool references at run-time.
194 // It does all necessary link-time checks & throws exceptions if necessary.
195
196 class LinkResolver: AllStatic {
197 friend class klassVtable;
198 friend class klassItable;
199
200 private:
201
202 static Method* lookup_method_in_klasses(const LinkInfo& link_info,
203 bool checkpolymorphism,
204 bool in_imethod_resolve);
205 static Method* lookup_method_in_interfaces(const LinkInfo& link_info);
206
207 static methodHandle lookup_polymorphic_method(const LinkInfo& link_info,
208 Handle *appendix_result_or_null, TRAPS);
209 JVMCI_ONLY(public:) // Needed for CompilerToVM.resolveMethod()
210 // Not Linktime so doesn't take LinkInfo
211 static methodHandle lookup_instance_method_in_klasses (Klass* klass, Symbol* name, Symbol* signature,
212 Klass::PrivateLookupMode private_mode, TRAPS);
213 JVMCI_ONLY(private:)
214
215 // Similar loader constraint checking functions that throw
216 // LinkageError with descriptive message.
217 static void check_method_loader_constraints(const LinkInfo& link_info,
218 const methodHandle& resolved_method,
219 const char* method_type, TRAPS);
220 static void check_field_loader_constraints(Symbol* field, Symbol* sig,
221 Klass* current_klass,
222 Klass* sel_klass, TRAPS);
223
224 static methodHandle resolve_interface_method(const LinkInfo& link_info, Bytecodes::Code code, TRAPS);
225 static methodHandle resolve_method (const LinkInfo& link_info, Bytecodes::Code code, TRAPS);
226
227 static methodHandle linktime_resolve_static_method (const LinkInfo& link_info, TRAPS);
228 static methodHandle linktime_resolve_special_method (const LinkInfo& link_info, TRAPS);
229 static methodHandle linktime_resolve_virtual_method (const LinkInfo& link_info, TRAPS);
230 static methodHandle linktime_resolve_interface_method (const LinkInfo& link_info, TRAPS);
231
232 static void runtime_resolve_special_method (CallInfo& result,
233 const LinkInfo& link_info,
234 const methodHandle& resolved_method,
235 Handle recv, TRAPS);
236
237 static void runtime_resolve_virtual_method (CallInfo& result,
238 const methodHandle& resolved_method,
239 Klass* resolved_klass,
240 Handle recv,
241 Klass* recv_klass,
242 bool check_null_and_abstract, TRAPS);
243 static void runtime_resolve_interface_method (CallInfo& result,
244 const methodHandle& resolved_method,
245 Klass* resolved_klass,
246 Handle recv,
247 Klass* recv_klass,
248 bool check_null_and_abstract, TRAPS);
249
250 static void check_field_accessability(Klass* ref_klass,
251 Klass* resolved_klass,
252 Klass* sel_klass,
253 const fieldDescriptor& fd, TRAPS);
254 static void check_method_accessability(Klass* ref_klass,
255 Klass* resolved_klass,
256 Klass* sel_klass,
257 const methodHandle& sel_method, TRAPS);
258
259 // runtime resolving from constant pool
260 static void resolve_invokestatic (CallInfo& result,
261 const constantPoolHandle& pool, int index, TRAPS);
262 static void resolve_invokespecial (CallInfo& result, Handle recv,
263 const constantPoolHandle& pool, int index, TRAPS);
264 static void resolve_invokevirtual (CallInfo& result, Handle recv,
265 const constantPoolHandle& pool, int index, TRAPS);
266 static void resolve_invokeinterface(CallInfo& result, Handle recv,
267 const constantPoolHandle& pool, int index, TRAPS);
268 static void resolve_invokedynamic (CallInfo& result,
269 const constantPoolHandle& pool, int index, TRAPS);
270 static void resolve_invokehandle (CallInfo& result,
271 const constantPoolHandle& pool, int index, TRAPS);
272 public:
273 // constant pool resolving
274 static void check_klass_accessability(Klass* ref_klass, Klass* sel_klass,
275 bool fold_type_to_class, TRAPS);
276 // The optional 'fold_type_to_class' means that a derived type (array)
277 // is first converted to the class it is derived from (element type).
278 // If this element type is not a class, then the check passes quietly.
279 // This is usually what is needed, but a few existing uses might break
280 // if this flag were always turned on. FIXME: See if it can be, always.
281 static void check_klass_accessability(Klass* ref_klass, Klass* sel_klass, TRAPS) {
282 return check_klass_accessability(ref_klass, sel_klass, false, THREAD);
283 }
284
285 // static resolving calls (will not run any Java code);
286 // used only from Bytecode_invoke::static_target
287 static methodHandle resolve_method_statically(Bytecodes::Code code,
288 const constantPoolHandle& pool,
289 int index, TRAPS);
290
291 static void resolve_field_access(fieldDescriptor& result,
292 const constantPoolHandle& pool,
293 int index,
294 const methodHandle& method,
295 Bytecodes::Code byte, TRAPS);
296 static void resolve_field(fieldDescriptor& result, const LinkInfo& link_info,
297 Bytecodes::Code access_kind,
298 bool initialize_class, TRAPS);
299
300 static void resolve_static_call (CallInfo& result,
301 const LinkInfo& link_info,
302 bool initialize_klass, TRAPS);
303 static void resolve_special_call (CallInfo& result,
304 Handle recv,
305 const LinkInfo& link_info,
306 TRAPS);
307 static void resolve_virtual_call (CallInfo& result, Handle recv, Klass* recv_klass,
308 const LinkInfo& link_info,
309 bool check_null_and_abstract, TRAPS);
310 static void resolve_interface_call(CallInfo& result, Handle recv, Klass* recv_klass,
311 const LinkInfo& link_info,
312 bool check_null_and_abstract, TRAPS);
313 static void resolve_handle_call (CallInfo& result,
314 const LinkInfo& link_info, TRAPS);
315 static void resolve_dynamic_call (CallInfo& result, int pool_index, Handle bootstrap_specifier,
316 Symbol* method_name, Symbol* method_signature,
317 Klass* current_klass, TRAPS);
318
319 // same as above for compile-time resolution; but returns null handle instead of throwing
320 // an exception on error also, does not initialize klass (i.e., no side effects)
321 static methodHandle resolve_virtual_call_or_null (Klass* receiver_klass,
322 const LinkInfo& link_info);
323 static methodHandle resolve_interface_call_or_null(Klass* receiver_klass,
324 const LinkInfo& link_info);
325 static methodHandle resolve_static_call_or_null (const LinkInfo& link_info);
326 static methodHandle resolve_special_call_or_null (const LinkInfo& link_info);
327
328 static int vtable_index_of_interface_method(Klass* klass, const methodHandle& resolved_method);
329
330 // same as above for compile-time resolution; returns vtable_index if current_klass if linked
331 static int resolve_virtual_vtable_index (Klass* receiver_klass,
332 const LinkInfo& link_info);
333
334 // static resolving for compiler (does not throw exceptions, returns null handle if unsuccessful)
335 static methodHandle linktime_resolve_virtual_method_or_null (const LinkInfo& link_info);
336 static methodHandle linktime_resolve_interface_method_or_null(const LinkInfo& link_info);
337
338 // runtime resolving from constant pool
339 static void resolve_invoke(CallInfo& result, Handle recv,
340 const constantPoolHandle& pool, int index,
341 Bytecodes::Code byte, TRAPS);
342
343 // runtime resolving from attached method
344 static void resolve_invoke(CallInfo& result, Handle& recv,
345 const methodHandle& attached_method,
346 Bytecodes::Code byte, TRAPS);
347
348 public:
349 // Only resolved method known.
350 static void throw_abstract_method_error(const methodHandle& resolved_method, TRAPS) {
351 throw_abstract_method_error(resolved_method, NULL, NULL, CHECK);
352 }
353 // Resolved method and receiver klass know.
354 static void throw_abstract_method_error(const methodHandle& resolved_method, Klass *recv_klass, TRAPS) {
355 throw_abstract_method_error(resolved_method, NULL, recv_klass, CHECK);
356 }
357 // Selected method is abstract.
358 static void throw_abstract_method_error(const methodHandle& resolved_method,
359 const methodHandle& selected_method,
360 Klass *recv_klass, TRAPS);
361 };
362 #endif // SHARE_INTERPRETER_LINKRESOLVER_HPP