linkResolver.hpp

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
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#ifndef SHARE_VM_INTERPRETER_LINKRESOLVER_HPP
#define SHARE_VM_INTERPRETER_LINKRESOLVER_HPP

#include "oops/method.hpp"
#include "utilities/top.hpp"

// All the necessary definitions for run-time link resolution.

// CallInfo provides all the information gathered for a particular
// linked call site after resolving it. A link is any reference
// made from within the bytecodes of a method to an object outside of
// that method. If the info is invalid, the link has not been resolved
// successfully.

class CallInfo VALUE_OBJ_CLASS_SPEC {
 public:
  // Ways that a method call might be selected (or not) based on receiver type.
  // Note that an invokevirtual instruction might be linked with no_dispatch,
  // and an invokeinterface instruction might be linked with any of the three options
  enum CallKind {
    direct_call,                        // jump into resolved_method (must be concrete)
    vtable_call,                        // select recv.klass.method_at_vtable(index)
    itable_call,                        // select recv.klass.method_at_itable(resolved_method.holder, index)
    unknown_kind = -1
  };
 private:
  KlassHandle  _resolved_klass;         // static receiver klass, resolved from a symbolic reference
  KlassHandle  _selected_klass;         // dynamic receiver class (same as static, or subklass)
  methodHandle _resolved_method;        // static target method
  methodHandle _selected_method;        // dynamic (actual) target method
  CallKind     _call_kind;              // kind of call (static(=bytecode static/special +
                                        //               others inferred), vtable, itable)
  int          _call_index;             // vtable or itable index of selected class method (if any)
  Handle       _resolved_appendix;      // extra argument in constant pool (if CPCE::has_appendix)
  Handle       _resolved_method_type;   // MethodType (for invokedynamic and invokehandle call sites)

  void         set_static(   KlassHandle resolved_klass,                             methodHandle resolved_method                                                       , TRAPS);
  void         set_interface(KlassHandle resolved_klass, KlassHandle selected_klass, methodHandle resolved_method, methodHandle selected_method, int itable_index       , TRAPS);
  void         set_virtual(  KlassHandle resolved_klass, KlassHandle selected_klass, methodHandle resolved_method, methodHandle selected_method, int vtable_index       , TRAPS);
  void         set_handle(                                                           methodHandle resolved_method, Handle resolved_appendix, Handle resolved_method_type, TRAPS);
  void         set_common(   KlassHandle resolved_klass, KlassHandle selected_klass, methodHandle resolved_method, methodHandle selected_method, CallKind kind, int index, TRAPS);

  friend class LinkResolver;

 public:
  CallInfo() {
#ifndef PRODUCT
    _call_kind  = CallInfo::unknown_kind;
    _call_index = Method::garbage_vtable_index;
#endif //PRODUCT
  }

  // utility to extract an effective CallInfo from a method and an optional receiver limit
  // does not queue the method for compilation
  CallInfo(Method* resolved_method, Klass* resolved_klass = NULL);

  KlassHandle  resolved_klass() const            { return _resolved_klass; }
  KlassHandle  selected_klass() const            { return _selected_klass; }
  methodHandle resolved_method() const           { return _resolved_method; }
  methodHandle selected_method() const           { return _selected_method; }
  Handle       resolved_appendix() const         { return _resolved_appendix; }
  Handle       resolved_method_type() const      { return _resolved_method_type; }

  BasicType    result_type() const               { return selected_method()->result_type(); }
  CallKind     call_kind() const                 { return _call_kind; }
  int          call_index() const                { return _call_index; }
  int          vtable_index() const {
    // Even for interface calls the vtable index could be non-negative.
    // See CallInfo::set_interface.
    assert(has_vtable_index() || is_statically_bound(), "");
    assert(call_kind() == vtable_call || call_kind() == direct_call, "");
    // The returned value is < 0 if the call is statically bound.
    // But, the returned value may be >= 0 even if the kind is direct_call.
    // It is up to the caller to decide which way to go.
    return _call_index;
  }
  int          itable_index() const {
    assert(call_kind() == itable_call, "");
    // The returned value is always >= 0, a valid itable index.
    return _call_index;
  }

  // debugging
#ifdef ASSERT
  bool         has_vtable_index() const          { return _call_index >= 0 && _call_kind != CallInfo::itable_call; }
  bool         is_statically_bound() const       { return _call_index == Method::nonvirtual_vtable_index; }
#endif //ASSERT
  void         verify() PRODUCT_RETURN;
  void         print()  PRODUCT_RETURN;
};

// Link information for getfield/putfield & getstatic/putstatic bytecodes
// is represented using a fieldDescriptor.

// The LinkResolver is used to resolve constant-pool references at run-time.
// It does all necessary link-time checks & throws exceptions if necessary.

class LinkResolver: AllStatic {
  friend class klassVtable;
  friend class klassItable;

 private:
  static void lookup_method_in_klasses          (methodHandle& result, KlassHandle klass, Symbol* name, Symbol* signature, bool checkpolymorphism, TRAPS);
  static void lookup_instance_method_in_klasses (methodHandle& result, KlassHandle klass, Symbol* name, Symbol* signature, TRAPS);
  static void lookup_method_in_interfaces       (methodHandle& result, KlassHandle klass, Symbol* name, Symbol* signature, TRAPS);
  static void lookup_polymorphic_method         (methodHandle& result, KlassHandle klass, Symbol* name, Symbol* signature,
                                                 KlassHandle current_klass, Handle *appendix_result_or_null, Handle *method_type_result, TRAPS);

  static void resolve_klass           (KlassHandle& result, constantPoolHandle  pool, int index, TRAPS);

  static void resolve_pool  (KlassHandle& resolved_klass, Symbol*& method_name, Symbol*& method_signature, KlassHandle& current_klass, constantPoolHandle pool, int index, TRAPS);

  static void resolve_interface_method(methodHandle& resolved_method, KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass, bool check_access, bool nostatics, TRAPS);
  static void resolve_method          (methodHandle& resolved_method, KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass, bool check_access, bool require_methodref, TRAPS);

  static void linktime_resolve_static_method    (methodHandle& resolved_method, KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass, bool check_access, TRAPS);
  static void linktime_resolve_special_method   (methodHandle& resolved_method, KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass, bool check_access, TRAPS);
  static void linktime_resolve_virtual_method   (methodHandle &resolved_method, KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature,KlassHandle current_klass, bool check_access, TRAPS);
  static void linktime_resolve_interface_method (methodHandle& resolved_method, KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass, bool check_access, TRAPS);

  static void runtime_resolve_special_method    (CallInfo& result, methodHandle resolved_method, KlassHandle resolved_klass, KlassHandle current_klass, bool check_access, TRAPS);
  static void runtime_resolve_virtual_method    (CallInfo& result, methodHandle resolved_method, KlassHandle resolved_klass, Handle recv, KlassHandle recv_klass, bool check_null_and_abstract, TRAPS);
  static void runtime_resolve_interface_method  (CallInfo& result, methodHandle resolved_method, KlassHandle resolved_klass, Handle recv, KlassHandle recv_klass, bool check_null_and_abstract, TRAPS);

  static void check_field_accessability   (KlassHandle ref_klass, KlassHandle resolved_klass, KlassHandle sel_klass, fieldDescriptor& fd, TRAPS);
  static void check_method_accessability  (KlassHandle ref_klass, KlassHandle resolved_klass, KlassHandle sel_klass, methodHandle sel_method, TRAPS);

 public:
  // constant pool resolving
  static void check_klass_accessability(KlassHandle ref_klass, KlassHandle sel_klass, TRAPS);

  // static resolving calls (will not run any Java code); used only from Bytecode_invoke::static_target
  static void resolve_method_statically(methodHandle& method_result, KlassHandle& klass_result,
                                        Bytecodes::Code code, constantPoolHandle pool, int index, TRAPS);

  // runtime/static resolving for fields
  static void resolve_field_access(fieldDescriptor& result, constantPoolHandle pool, int index, Bytecodes::Code byte, TRAPS);
  static void resolve_field(fieldDescriptor& result, KlassHandle resolved_klass, Symbol* field_name, Symbol* field_signature,
                            KlassHandle current_klass, Bytecodes::Code access_kind, bool check_access, bool initialize_class, TRAPS);

  // source of access_kind codes:
  static Bytecodes::Code field_access_kind(bool is_static, bool is_put) {
    return (is_static
            ? (is_put ? Bytecodes::_putstatic : Bytecodes::_getstatic)
            : (is_put ? Bytecodes::_putfield  : Bytecodes::_getfield ));
  }

  // runtime resolving:
  //   resolved_klass = specified class (i.e., static receiver class)
  //   current_klass  = sending method holder (i.e., class containing the method containing the call being resolved)
  static void resolve_static_call   (CallInfo& result,              KlassHandle& resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass, bool check_access, bool initialize_klass, TRAPS);
  static void resolve_special_call  (CallInfo& result,              KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass, bool check_access, TRAPS);
  static void resolve_virtual_call  (CallInfo& result, Handle recv, KlassHandle recv_klass, KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass, bool check_access, bool check_null_and_abstract, TRAPS);
  static void resolve_interface_call(CallInfo& result, Handle recv, KlassHandle recv_klass, KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass, bool check_access, bool check_null_and_abstract, TRAPS);
  static void resolve_handle_call   (CallInfo& result,                                      KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass, TRAPS);
  static void resolve_dynamic_call  (CallInfo& result,                                      Handle bootstrap_specifier, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass, TRAPS);

  // same as above for compile-time resolution; but returns null handle instead of throwing an exception on error
  // also, does not initialize klass (i.e., no side effects)
  static methodHandle resolve_virtual_call_or_null  (KlassHandle receiver_klass, KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass);
  static methodHandle resolve_interface_call_or_null(KlassHandle receiver_klass, KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass);
  static methodHandle resolve_static_call_or_null   (KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass);
  static methodHandle resolve_special_call_or_null  (KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass);
  static int vtable_index_of_interface_method(KlassHandle klass, methodHandle resolved_method);

  // same as above for compile-time resolution; returns vtable_index if current_klass if linked
  static int resolve_virtual_vtable_index  (KlassHandle receiver_klass, KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass);

  // static resolving for compiler (does not throw exceptions, returns null handle if unsuccessful)
  static methodHandle linktime_resolve_virtual_method_or_null  (KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass, bool check_access);
  static methodHandle linktime_resolve_interface_method_or_null(KlassHandle resolved_klass, Symbol* method_name, Symbol* method_signature, KlassHandle current_klass, bool check_access);

  // runtime resolving from constant pool
  static void resolve_invokestatic   (CallInfo& result,              constantPoolHandle pool, int index, TRAPS);
  static void resolve_invokespecial  (CallInfo& result,              constantPoolHandle pool, int index, TRAPS);
  static void resolve_invokevirtual  (CallInfo& result, Handle recv, constantPoolHandle pool, int index, TRAPS);
  static void resolve_invokeinterface(CallInfo& result, Handle recv, constantPoolHandle pool, int index, TRAPS);
  static void resolve_invokedynamic  (CallInfo& result,              constantPoolHandle pool, int index, TRAPS);
  static void resolve_invokehandle   (CallInfo& result,              constantPoolHandle pool, int index, TRAPS);

  static void resolve_invoke         (CallInfo& result, Handle recv, constantPoolHandle pool, int index, Bytecodes::Code byte, TRAPS);
};

#endif // SHARE_VM_INTERPRETER_LINKRESOLVER_HPP