1 /*
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   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.
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   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
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  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.
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  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_handle(KlassHandle resolved_klass,
  73                   const methodHandle& resolved_method,
  74                   Handle resolved_appendix, Handle resolved_method_type, TRAPS);
  75   void set_common(KlassHandle resolved_klass, KlassHandle selected_klass,
  76                   const methodHandle& resolved_method,
  77                   const methodHandle& selected_method,
  78                   CallKind kind,
  79                   int index, TRAPS);
  80 
  81   friend class LinkResolver;
  82 
  83  public:
  84   CallInfo() {
  85 #ifndef PRODUCT
  86     _call_kind  = CallInfo::unknown_kind;
  87     _call_index = Method::garbage_vtable_index;
  88 #endif //PRODUCT
  89   }
  90 
  91   // utility to extract an effective CallInfo from a method and an optional receiver limit
  92   // does not queue the method for compilation
  93   CallInfo(Method* resolved_method, Klass* resolved_klass = NULL);
  94 
  95   KlassHandle  resolved_klass() const            { return _resolved_klass; }
  96   KlassHandle  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_type() const      { return _resolved_method_type; }
 101 
 102   BasicType    result_type() const               { return selected_method()->result_type(); }
 103   CallKind     call_kind() const                 { return _call_kind; }
 104   int          call_index() const                { return _call_index; }
 105   int          vtable_index() const {
 106     // Even for interface calls the vtable index could be non-negative.
 107     // See CallInfo::set_interface.
 108     assert(has_vtable_index() || is_statically_bound(), "");
 109     assert(call_kind() == vtable_call || call_kind() == direct_call, "");
 110     // The returned value is < 0 if the call is statically bound.
 111     // But, the returned value may be >= 0 even if the kind is direct_call.
 112     // It is up to the caller to decide which way to go.
 113     return _call_index;
 114   }
 115   int          itable_index() const {
 116     assert(call_kind() == itable_call, "");
 117     // The returned value is always >= 0, a valid itable index.
 118     return _call_index;
 119   }
 120 
 121   // debugging
 122 #ifdef ASSERT
 123   bool         has_vtable_index() const          { return _call_index >= 0 && _call_kind != CallInfo::itable_call; }
 124   bool         is_statically_bound() const       { return _call_index == Method::nonvirtual_vtable_index; }
 125 #endif //ASSERT
 126   void         verify() PRODUCT_RETURN;
 127   void         print()  PRODUCT_RETURN;
 128 };
 129 
 130 
 131 // Condensed information from constant pool to use to resolve the method or field.
 132 //   resolved_klass = specified class (i.e., static receiver class)
 133 //   current_klass  = sending method holder (i.e., class containing the method
 134 //                    containing the call being resolved)
 135 class LinkInfo : public StackObj {
 136   Symbol*     _name;            // extracted from JVM_CONSTANT_NameAndType
 137   Symbol*     _signature;
 138   KlassHandle _resolved_klass;  // class that the constant pool entry points to
 139   KlassHandle _current_klass;   // class that owns the constant pool
 140   bool        _check_access;
 141  public:
 142   LinkInfo(const constantPoolHandle& pool, int index, TRAPS);
 143   // Condensed information from other call sites within the vm.
 144   LinkInfo(KlassHandle resolved_klass, Symbol* name, Symbol* signature,
 145            KlassHandle current_klass, bool check_access = true) :
 146     _resolved_klass(resolved_klass),
 147     _name(name), _signature(signature), _current_klass(current_klass),
 148     _check_access(check_access) {}
 149 
 150   // accessors
 151   Symbol* name() const               { return _name; }
 152   Symbol* signature() const          { return _signature; }
 153   KlassHandle resolved_klass() const { return _resolved_klass; }
 154   KlassHandle current_klass() const  { return _current_klass; }
 155   bool check_access() const          { return _check_access; }
 156   char* method_string() const;
 157 
 158   void         print()  PRODUCT_RETURN;
 159 };
 160 
 161 // Link information for getfield/putfield & getstatic/putstatic bytecodes
 162 // is represented using a fieldDescriptor.
 163 
 164 // The LinkResolver is used to resolve constant-pool references at run-time.
 165 // It does all necessary link-time checks & throws exceptions if necessary.
 166 
 167 class LinkResolver: AllStatic {
 168   friend class klassVtable;
 169   friend class klassItable;
 170 
 171  private:
 172 
 173   static methodHandle lookup_method_in_klasses(const LinkInfo& link_info,
 174                                                bool checkpolymorphism,
 175                                                bool in_imethod_resolve, TRAPS);
 176   static methodHandle lookup_method_in_interfaces(const LinkInfo& link_info, TRAPS);
 177   static methodHandle lookup_polymorphic_method(const LinkInfo& link_info,
 178                                                 Handle *appendix_result_or_null,
 179                                                 Handle *method_type_result, TRAPS);
 180  JVMCI_ONLY(public:) // Needed for CompilerToVM.resolveMethod()
 181   // Not Linktime so doesn't take LinkInfo
 182   static methodHandle lookup_instance_method_in_klasses (
 183                                        KlassHandle klass, Symbol* name, Symbol* signature, TRAPS);
 184  JVMCI_ONLY(private:)
 185 
 186   // Similar loader constraint checking functions that throw
 187   // LinkageError with descriptive message.
 188   static void check_method_loader_constraints(const LinkInfo& link_info,
 189                                               const methodHandle& resolved_method,
 190                                               const char* method_type, TRAPS);
 191   static void check_field_loader_constraints(Symbol* field, Symbol* sig,
 192                                              KlassHandle current_klass,
 193                                              KlassHandle sel_klass, TRAPS);
 194 
 195   static methodHandle resolve_interface_method(const LinkInfo& link_info, bool nostatics, TRAPS);
 196   static methodHandle resolve_method          (const LinkInfo& link_info, bool require_methodref, TRAPS);
 197 
 198   static methodHandle linktime_resolve_static_method    (const LinkInfo& link_info, TRAPS);
 199   static methodHandle linktime_resolve_special_method   (const LinkInfo& link_info, TRAPS);
 200   static methodHandle linktime_resolve_virtual_method   (const LinkInfo& link_info, TRAPS);
 201   static methodHandle linktime_resolve_interface_method (const LinkInfo& link_info, TRAPS);
 202 
 203   static void runtime_resolve_special_method    (CallInfo& result,
 204                                                  const methodHandle& resolved_method,
 205                                                  KlassHandle resolved_klass,
 206                                                  KlassHandle current_klass,
 207                                                  bool check_access, TRAPS);
 208   static void runtime_resolve_virtual_method    (CallInfo& result,
 209                                                  const methodHandle& resolved_method,
 210                                                  KlassHandle resolved_klass,
 211                                                  Handle recv,
 212                                                  KlassHandle recv_klass,
 213                                                  bool check_null_and_abstract, TRAPS);
 214   static void runtime_resolve_interface_method  (CallInfo& result,
 215                                                  const methodHandle& resolved_method,
 216                                                  KlassHandle resolved_klass,
 217                                                  Handle recv,
 218                                                  KlassHandle recv_klass,
 219                                                  bool check_null_and_abstract, TRAPS);
 220 
 221   static void check_field_accessability(KlassHandle ref_klass,
 222                                         KlassHandle resolved_klass,
 223                                         KlassHandle sel_klass,
 224                                         const fieldDescriptor& fd, TRAPS);
 225   static void check_method_accessability(KlassHandle ref_klass,
 226                                          KlassHandle resolved_klass,
 227                                          KlassHandle sel_klass,
 228                                          const methodHandle& sel_method, TRAPS);
 229 
 230   // runtime resolving from constant pool
 231   static void resolve_invokestatic   (CallInfo& result,
 232                                       const constantPoolHandle& pool, int index, TRAPS);
 233   static void resolve_invokespecial  (CallInfo& result,
 234                                       const constantPoolHandle& pool, int index, TRAPS);
 235   static void resolve_invokevirtual  (CallInfo& result, Handle recv,
 236                                       const constantPoolHandle& pool, int index, TRAPS);
 237   static void resolve_invokeinterface(CallInfo& result, Handle recv,
 238                                       const constantPoolHandle& pool, int index, TRAPS);
 239   static void resolve_invokedynamic  (CallInfo& result,
 240                                       const constantPoolHandle& pool, int index, TRAPS);
 241   static void resolve_invokehandle   (CallInfo& result,
 242                                       const constantPoolHandle& pool, int index, TRAPS);
 243  public:
 244   // constant pool resolving
 245   static void check_klass_accessability(KlassHandle ref_klass, KlassHandle sel_klass, TRAPS);
 246 
 247   // static resolving calls (will not run any Java code);
 248   // used only from Bytecode_invoke::static_target
 249   static methodHandle resolve_method_statically(Bytecodes::Code code,
 250                                                 const constantPoolHandle& pool,
 251                                                 int index, TRAPS);
 252 
 253   static void resolve_field_access(fieldDescriptor& result,
 254                                    const constantPoolHandle& pool,
 255                                    int index, Bytecodes::Code byte, TRAPS);
 256   static void resolve_field(fieldDescriptor& result, const LinkInfo& link_info,
 257                             Bytecodes::Code access_kind,
 258                             bool initialize_class, TRAPS);
 259 
 260   static void resolve_static_call   (CallInfo& result,
 261                                      const LinkInfo& link_info,
 262                                      bool initialize_klass, TRAPS);
 263   static void resolve_special_call  (CallInfo& result,
 264                                      const LinkInfo& link_info,
 265                                      TRAPS);
 266   static void resolve_virtual_call  (CallInfo& result, Handle recv, KlassHandle recv_klass,
 267                                      const LinkInfo& link_info,
 268                                      bool check_null_and_abstract, TRAPS);
 269   static void resolve_interface_call(CallInfo& result, Handle recv, KlassHandle recv_klass,
 270                                      const LinkInfo& link_info,
 271                                      bool check_null_and_abstract, TRAPS);
 272   static void resolve_handle_call   (CallInfo& result,
 273                                      const LinkInfo& link_info, TRAPS);
 274   static void resolve_dynamic_call  (CallInfo& result, Handle bootstrap_specifier,
 275                                      Symbol* method_name, Symbol* method_signature,
 276                                      KlassHandle current_klass, TRAPS);
 277 
 278   // same as above for compile-time resolution; but returns null handle instead of throwing
 279   // an exception on error also, does not initialize klass (i.e., no side effects)
 280   static methodHandle resolve_virtual_call_or_null  (KlassHandle receiver_klass,
 281                                                      const LinkInfo& link_info);
 282   static methodHandle resolve_interface_call_or_null(KlassHandle receiver_klass,
 283                                                      const LinkInfo& link_info);
 284   static methodHandle resolve_static_call_or_null   (const LinkInfo& link_info);
 285   static methodHandle resolve_special_call_or_null  (const LinkInfo& link_info);
 286 
 287   static int vtable_index_of_interface_method(KlassHandle klass, const methodHandle& resolved_method);
 288 
 289   // same as above for compile-time resolution; returns vtable_index if current_klass if linked
 290   static int resolve_virtual_vtable_index  (KlassHandle receiver_klass,
 291                                             const LinkInfo& link_info);
 292 
 293   // static resolving for compiler (does not throw exceptions, returns null handle if unsuccessful)
 294   static methodHandle linktime_resolve_virtual_method_or_null  (const LinkInfo& link_info);
 295   static methodHandle linktime_resolve_interface_method_or_null(const LinkInfo& link_info);
 296 
 297   // runtime resolving from constant pool
 298   static void resolve_invoke(CallInfo& result, Handle recv,
 299                              const constantPoolHandle& pool, int index,
 300                              Bytecodes::Code byte, TRAPS);
 301 
 302   // runtime resolving from attached method
 303   static void resolve_invoke(CallInfo& result, Handle& recv,
 304                              const methodHandle& attached_method,
 305                              Bytecodes::Code byte, TRAPS);
 306 };
 307 #endif // SHARE_VM_INTERPRETER_LINKRESOLVER_HPP