/*

 * Copyright (c) 1997, 2009, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * 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,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "incls/_precompiled.incl"

#include "incls/_linkResolver.cpp.incl"

//------------------------------------------------------------------------------------------------------------------------

// Implementation of FieldAccessInfo

void FieldAccessInfo::set(KlassHandle klass, symbolHandle name, int field_index, int field_offset,

BasicType field_type, AccessFlags access_flags) {

  _klass        = klass;

  _name         = name;

  _field_index  = field_index;

  _field_offset = field_offset;

  _field_type   = field_type;

  _access_flags = access_flags;

}

//------------------------------------------------------------------------------------------------------------------------

// Implementation of CallInfo

void CallInfo::set_static(KlassHandle resolved_klass, methodHandle resolved_method, TRAPS) {

  int vtable_index = methodOopDesc::nonvirtual_vtable_index;

  set_common(resolved_klass, resolved_klass, resolved_method, resolved_method, vtable_index, CHECK);

}

void CallInfo::set_interface(KlassHandle resolved_klass, KlassHandle selected_klass, methodHandle resolved_method, methodHandle selected_method, TRAPS) {

  // This is only called for interface methods. If the resolved_method

  // comes from java/lang/Object, it can be the subject of a virtual call, so

  // we should pick the vtable index from the resolved method.

  // Other than that case, there is no valid vtable index to specify.

  int vtable_index = methodOopDesc::invalid_vtable_index;

  if (resolved_method->method_holder() == SystemDictionary::Object_klass()) {

    assert(resolved_method->vtable_index() == selected_method->vtable_index(), "sanity check");

    vtable_index = resolved_method->vtable_index();

  }

  set_common(resolved_klass, selected_klass, resolved_method, selected_method, vtable_index, CHECK);

}

void CallInfo::set_virtual(KlassHandle resolved_klass, KlassHandle selected_klass, methodHandle resolved_method, methodHandle selected_method, int vtable_index, TRAPS) {

  assert(vtable_index >= 0 || vtable_index == methodOopDesc::nonvirtual_vtable_index, "valid index");

  set_common(resolved_klass, selected_klass, resolved_method, selected_method, vtable_index, CHECK);

}

void CallInfo::set_common(KlassHandle resolved_klass, KlassHandle selected_klass, methodHandle resolved_method, methodHandle selected_method, int vtable_index, TRAPS) {

  assert(resolved_method->signature() == selected_method->signature(), "signatures must correspond");

  _resolved_klass  = resolved_klass;

  _selected_klass  = selected_klass;

  _resolved_method = resolved_method;

  _selected_method = selected_method;

  _vtable_index    = vtable_index;

  if (CompilationPolicy::mustBeCompiled(selected_method)) {

    // This path is unusual, mostly used by the '-Xcomp' stress test mode.

    // Note: with several active threads, the mustBeCompiled may be true

    //       while canBeCompiled is false; remove assert

    // assert(CompilationPolicy::canBeCompiled(selected_method), "cannot compile");

    if (THREAD->is_Compiler_thread()) {

      // don't force compilation, resolve was on behalf of compiler

      return;

    }

    if (instanceKlass::cast(selected_method->method_holder())->is_not_initialized()) {

      // 'is_not_initialized' means not only '!is_initialized', but also that

      // initialization has not been started yet ('!being_initialized')

      // Do not force compilation of methods in uninitialized classes.

      // Note that doing this would throw an assert later,

      // in CompileBroker::compile_method.

      // We sometimes use the link resolver to do reflective lookups

      // even before classes are initialized.

      return;

    }

    CompileBroker::compile_method(selected_method, InvocationEntryBci,

                                  methodHandle(), 0, "mustBeCompiled", CHECK);

  }

}

//------------------------------------------------------------------------------------------------------------------------

// Klass resolution

void LinkResolver::check_klass_accessability(KlassHandle ref_klass, KlassHandle sel_klass, TRAPS) {

  if (!Reflection::verify_class_access(ref_klass->as_klassOop(),

                                       sel_klass->as_klassOop(),

                                       true)) {

    ResourceMark rm(THREAD);

    Exceptions::fthrow(

      THREAD_AND_LOCATION,

      vmSymbolHandles::java_lang_IllegalAccessError(),

      "tried to access class %s from class %s",

      sel_klass->external_name(),

      ref_klass->external_name()

    );

    return;

  }

}

void LinkResolver::resolve_klass(KlassHandle& result, constantPoolHandle pool, int index, TRAPS) {

  klassOop result_oop = pool->klass_ref_at(index, CHECK);

  result = KlassHandle(THREAD, result_oop);

}

void LinkResolver::resolve_klass_no_update(KlassHandle& result, constantPoolHandle pool, int index, TRAPS) {

  klassOop result_oop =

         constantPoolOopDesc::klass_ref_at_if_loaded_check(pool, index, CHECK);

  result = KlassHandle(THREAD, result_oop);

}

//------------------------------------------------------------------------------------------------------------------------

// Method resolution

//

// According to JVM spec. $5.4.3c & $5.4.3d

void LinkResolver::lookup_method_in_klasses(methodHandle& result, KlassHandle klass, symbolHandle name, symbolHandle signature, TRAPS) {

  methodOop result_oop = klass->uncached_lookup_method(name(), signature());

  if (EnableMethodHandles && result_oop != NULL) {

    switch (result_oop->intrinsic_id()) {

    case vmIntrinsics::_invokeExact:

    case vmIntrinsics::_invokeGeneric:

    case vmIntrinsics::_invokeDynamic:

      // Do not link directly to these.  The VM must produce a synthetic one using lookup_implicit_method.

      return;

    }

  }

  result = methodHandle(THREAD, result_oop);

}

// returns first instance method

void LinkResolver::lookup_instance_method_in_klasses(methodHandle& result, KlassHandle klass, symbolHandle name, symbolHandle signature, TRAPS) {

  methodOop result_oop = klass->uncached_lookup_method(name(), signature());

  result = methodHandle(THREAD, result_oop);

  while (!result.is_null() && result->is_static()) {

    klass = KlassHandle(THREAD, Klass::cast(result->method_holder())->super());

    result = methodHandle(THREAD, klass->uncached_lookup_method(name(), signature()));

  }

}

int LinkResolver::vtable_index_of_miranda_method(KlassHandle klass, symbolHandle name, symbolHandle signature, TRAPS) {

  ResourceMark rm(THREAD);

  klassVtable *vt = instanceKlass::cast(klass())->vtable();

  return vt->index_of_miranda(name(), signature());

}

void LinkResolver::lookup_method_in_interfaces(methodHandle& result, KlassHandle klass, symbolHandle name, symbolHandle signature, TRAPS) {

  instanceKlass *ik = instanceKlass::cast(klass());

  result = methodHandle(THREAD, ik->lookup_method_in_all_interfaces(name(), signature()));

}

void LinkResolver::lookup_implicit_method(methodHandle& result,

                                          KlassHandle klass, symbolHandle name, symbolHandle signature,

                                          KlassHandle current_klass,

                                          TRAPS) {

      klass() == SystemDictionary::MethodHandle_klass() &&

      methodOopDesc::is_method_handle_invoke_name(name())) {

    methodOop result_oop = SystemDictionary::find_method_handle_invoke(name,

                                                                       signature,

                                                                       current_klass,

                                                                       CHECK);

    if (result_oop != NULL) {

      assert(result_oop->is_method_handle_invoke() && result_oop->signature() == signature(), "consistent");

      result = methodHandle(THREAD, result_oop);

    }

  }

}

void LinkResolver::check_method_accessability(KlassHandle ref_klass,

                                              KlassHandle resolved_klass,

                                              KlassHandle sel_klass,

                                              methodHandle sel_method,

                                              TRAPS) {

  AccessFlags flags = sel_method->access_flags();

  // Special case:  arrays always override "clone". JVMS 2.15.

  // If the resolved klass is an array class, and the declaring class

  // is java.lang.Object and the method is "clone", set the flags

  // to public.

  //

  // We'll check for the method name first, as that's most likely

  // to be false (so we'll short-circuit out of these tests).

  if (sel_method->name() == vmSymbols::clone_name() &&

      sel_klass() == SystemDictionary::Object_klass() &&

      resolved_klass->oop_is_array()) {

    // We need to change "protected" to "public".

    assert(flags.is_protected(), "clone not protected?");

    jint new_flags = flags.as_int();

    new_flags = new_flags & (~JVM_ACC_PROTECTED);

    new_flags = new_flags | JVM_ACC_PUBLIC;

    flags.set_flags(new_flags);

  }

  if (!Reflection::verify_field_access(ref_klass->as_klassOop(),

                                       resolved_klass->as_klassOop(),

                                       sel_klass->as_klassOop(),

                                       flags,

                                       true)) {

    ResourceMark rm(THREAD);

    Exceptions::fthrow(

      THREAD_AND_LOCATION,

      vmSymbolHandles::java_lang_IllegalAccessError(),

      "tried to access method %s.%s%s from class %s",

      sel_klass->external_name(),

      sel_method->name()->as_C_string(),

      sel_method->signature()->as_C_string(),

      ref_klass->external_name()

    );

    return;

  }

}

void LinkResolver::resolve_method(methodHandle& resolved_method, KlassHandle& resolved_klass,

                                  constantPoolHandle pool, int index, TRAPS) {

  // resolve klass

  resolve_klass(resolved_klass, pool, index, CHECK);

  symbolHandle method_name      (THREAD, pool->name_ref_at(index));

  symbolHandle method_signature (THREAD, pool->signature_ref_at(index));

  KlassHandle  current_klass(THREAD, pool->pool_holder());

  resolve_method(resolved_method, resolved_klass, method_name, method_signature, current_klass, true, CHECK);

}

void LinkResolver::resolve_dynamic_method(methodHandle& resolved_method, KlassHandle& resolved_klass, constantPoolHandle pool, int index, TRAPS) {

  // The class is java.dyn.MethodHandle

  resolved_klass = SystemDictionaryHandles::MethodHandle_klass();

  symbolHandle method_name = vmSymbolHandles::invokeExact_name();

  symbolHandle method_signature(THREAD, pool->signature_ref_at(index));

  KlassHandle  current_klass   (THREAD, pool->pool_holder());

  resolve_method(resolved_method, resolved_klass, method_name, method_signature, current_klass, true, CHECK);

}

void LinkResolver::resolve_interface_method(methodHandle& resolved_method, KlassHandle& resolved_klass, constantPoolHandle pool, int index, TRAPS) {

  // resolve klass

  resolve_klass(resolved_klass, pool, index, CHECK);

  symbolHandle method_name      (THREAD, pool->name_ref_at(index));

  symbolHandle method_signature (THREAD, pool->signature_ref_at(index));

  KlassHandle  current_klass(THREAD, pool->pool_holder());

  resolve_interface_method(resolved_method, resolved_klass, method_name, method_signature, current_klass, true, CHECK);

}

void LinkResolver::resolve_method(methodHandle& resolved_method, KlassHandle resolved_klass,

                                  symbolHandle method_name, symbolHandle method_signature,

                                  KlassHandle current_klass, bool check_access, TRAPS) {

  // 1. check if klass is not interface

  if (resolved_klass->is_interface()) {

    char buf[200];

    jio_snprintf(buf, sizeof(buf), "Found interface %s, but class was expected", Klass::cast(resolved_klass())->external_name());

    THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(), buf);

  }

  // 2. lookup method in resolved klass and its super klasses

  lookup_method_in_klasses(resolved_method, resolved_klass, method_name, method_signature, CHECK);

  if (resolved_method.is_null()) { // not found in the class hierarchy

    // 3. lookup method in all the interfaces implemented by the resolved klass

    lookup_method_in_interfaces(resolved_method, resolved_klass, method_name, method_signature, CHECK);

    if (resolved_method.is_null()) {

      // JSR 292:  see if this is an implicitly generated method MethodHandle.invoke(*...)

      lookup_implicit_method(resolved_method, resolved_klass, method_name, method_signature, current_klass, CHECK);

    }

    if (resolved_method.is_null()) {

      // 4. method lookup failed

      ResourceMark rm(THREAD);

      THROW_MSG(vmSymbols::java_lang_NoSuchMethodError(),

                methodOopDesc::name_and_sig_as_C_string(Klass::cast(resolved_klass()),

                                                        method_name(),

                                                        method_signature()));

    }

  }

  // 5. check if method is concrete

  if (resolved_method->is_abstract() && !resolved_klass->is_abstract()) {

    ResourceMark rm(THREAD);

    THROW_MSG(vmSymbols::java_lang_AbstractMethodError(),

              methodOopDesc::name_and_sig_as_C_string(Klass::cast(resolved_klass()),

                                                      method_name(),

                                                      method_signature()));

  }

  // 6. access checks, access checking may be turned off when calling from within the VM.

  if (check_access) {

    assert(current_klass.not_null() , "current_klass should not be null");

    // check if method can be accessed by the referring class

    check_method_accessability(current_klass,

                               resolved_klass,

                               KlassHandle(THREAD, resolved_method->method_holder()),

                               resolved_method,

                               CHECK);

    // check loader constraints

    Handle loader (THREAD, instanceKlass::cast(current_klass())->class_loader());

    Handle class_loader (THREAD, instanceKlass::cast(resolved_method->method_holder())->class_loader());

    {

      ResourceMark rm(THREAD);

      char* failed_type_name =

        SystemDictionary::check_signature_loaders(method_signature, loader,

                                                  class_loader, true, CHECK);

      if (failed_type_name != NULL) {

        const char* msg = "loader constraint violation: when resolving method"

          " \"%s\" the class loader (instance of %s) of the current class, %s,"

          " and the class loader (instance of %s) for resolved class, %s, have"

          " different Class objects for the type %s used in the signature";

        char* sig = methodOopDesc::name_and_sig_as_C_string(Klass::cast(resolved_klass()),method_name(),method_signature());

        const char* loader1 = SystemDictionary::loader_name(loader());

        char* current = instanceKlass::cast(current_klass())->name()->as_C_string();

        const char* loader2 = SystemDictionary::loader_name(class_loader());

        char* resolved = instanceKlass::cast(resolved_klass())->name()->as_C_string();

        size_t buflen = strlen(msg) + strlen(sig) + strlen(loader1) +

          strlen(current) + strlen(loader2) + strlen(resolved) +

          strlen(failed_type_name);

        char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);

        jio_snprintf(buf, buflen, msg, sig, loader1, current, loader2,

                     resolved, failed_type_name);

        THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);

      }

    }

  }

}

void LinkResolver::resolve_interface_method(methodHandle& resolved_method,

                                            KlassHandle resolved_klass,

                                            symbolHandle method_name,

                                            symbolHandle method_signature,

                                            KlassHandle current_klass,

                                            bool check_access, TRAPS) {

 // check if klass is interface

  if (!resolved_klass->is_interface()) {

    char buf[200];

    jio_snprintf(buf, sizeof(buf), "Found class %s, but interface was expected", Klass::cast(resolved_klass())->external_name());

    THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(), buf);

  }

  // lookup method in this interface or its super, java.lang.Object

  lookup_instance_method_in_klasses(resolved_method, resolved_klass, method_name, method_signature, CHECK);

  if (resolved_method.is_null()) {

    // lookup method in all the super-interfaces

    lookup_method_in_interfaces(resolved_method, resolved_klass, method_name, method_signature, CHECK);

    if (resolved_method.is_null()) {

      // no method found

      ResourceMark rm(THREAD);

      THROW_MSG(vmSymbols::java_lang_NoSuchMethodError(),

                methodOopDesc::name_and_sig_as_C_string(Klass::cast(resolved_klass()),

                                                        method_name(),

                                                        method_signature()));

    }

  }

  if (check_access) {

    HandleMark hm(THREAD);

    Handle loader (THREAD, instanceKlass::cast(current_klass())->class_loader());

    Handle class_loader (THREAD, instanceKlass::cast(resolved_method->method_holder())->class_loader());

    {

      ResourceMark rm(THREAD);

      char* failed_type_name =

        SystemDictionary::check_signature_loaders(method_signature, loader,

                                                  class_loader, true, CHECK);

      if (failed_type_name != NULL) {

        const char* msg = "loader constraint violation: when resolving "

          "interface method \"%s\" the class loader (instance of %s) of the "

          "current class, %s, and the class loader (instance of %s) for "

          "resolved class, %s, have different Class objects for the type %s "

          "used in the signature";

        char* sig = methodOopDesc::name_and_sig_as_C_string(Klass::cast(resolved_klass()),method_name(),method_signature());

        const char* loader1 = SystemDictionary::loader_name(loader());

        char* current = instanceKlass::cast(current_klass())->name()->as_C_string();

        const char* loader2 = SystemDictionary::loader_name(class_loader());

        char* resolved = instanceKlass::cast(resolved_klass())->name()->as_C_string();

        size_t buflen = strlen(msg) + strlen(sig) + strlen(loader1) +

          strlen(current) + strlen(loader2) + strlen(resolved) +

          strlen(failed_type_name);

        char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);

        jio_snprintf(buf, buflen, msg, sig, loader1, current, loader2,

                     resolved, failed_type_name);

        THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);

      }

    }

  }

}

//------------------------------------------------------------------------------------------------------------------------

// Field resolution

void LinkResolver::check_field_accessability(KlassHandle ref_klass,

                                             KlassHandle resolved_klass,

                                             KlassHandle sel_klass,

                                             fieldDescriptor& fd,

                                             TRAPS) {

  if (!Reflection::verify_field_access(ref_klass->as_klassOop(),

                                       resolved_klass->as_klassOop(),

                                       sel_klass->as_klassOop(),

                                       fd.access_flags(),

                                       true)) {

    ResourceMark rm(THREAD);

    Exceptions::fthrow(

      THREAD_AND_LOCATION,

      vmSymbolHandles::java_lang_IllegalAccessError(),

      "tried to access field %s.%s from class %s",

      sel_klass->external_name(),

      fd.name()->as_C_string(),

      ref_klass->external_name()

    );

    return;

  }

}

void LinkResolver::resolve_field(FieldAccessInfo& result, constantPoolHandle pool, int index, Bytecodes::Code byte, bool check_only, TRAPS) {

  resolve_field(result, pool, index, byte, check_only, true, CHECK);

}

void LinkResolver::resolve_field(FieldAccessInfo& result, constantPoolHandle pool, int index, Bytecodes::Code byte, bool check_only, bool update_pool, TRAPS) {

  assert(byte == Bytecodes::_getstatic || byte == Bytecodes::_putstatic ||

         byte == Bytecodes::_getfield  || byte == Bytecodes::_putfield, "bad bytecode");

  bool is_static = (byte == Bytecodes::_getstatic || byte == Bytecodes::_putstatic);

  bool is_put    = (byte == Bytecodes::_putfield  || byte == Bytecodes::_putstatic);

  // resolve specified klass

  KlassHandle resolved_klass;

  if (update_pool) {

    resolve_klass(resolved_klass, pool, index, CHECK);

  } else {

    resolve_klass_no_update(resolved_klass, pool, index, CHECK);

  }

  // Load these early in case the resolve of the containing klass fails

  symbolOop field = pool->name_ref_at(index);

  symbolHandle field_h (THREAD, field); // preserve in case we need the name

  symbolOop sig   = pool->signature_ref_at(index);

  // Check if there's a resolved klass containing the field

  if( resolved_klass.is_null() ) {

    ResourceMark rm(THREAD);

    THROW_MSG(vmSymbols::java_lang_NoSuchFieldError(), field->as_C_string());

  }

  // Resolve instance field

  fieldDescriptor fd; // find_field initializes fd if found

  KlassHandle sel_klass(THREAD, instanceKlass::cast(resolved_klass())->find_field(field, sig, &fd));

  // check if field exists; i.e., if a klass containing the field def has been selected

  if (sel_klass.is_null()){

    ResourceMark rm(THREAD);

    THROW_MSG(vmSymbols::java_lang_NoSuchFieldError(), field->as_C_string());

  }

  // check access

  KlassHandle ref_klass(THREAD, pool->pool_holder());

  check_field_accessability(ref_klass, resolved_klass, sel_klass, fd, CHECK);

  // check for errors

  if (is_static != fd.is_static()) {

    char msg[200];

    jio_snprintf(msg, sizeof(msg), "Expected %s field %s.%s", is_static ? "static" : "non-static", Klass::cast(resolved_klass())->external_name(), fd.name()->as_C_string());

    THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(), msg);

  }

  // Final fields can only be accessed from its own class.

  if (is_put && fd.access_flags().is_final() && sel_klass() != pool->pool_holder()) {

    THROW(vmSymbols::java_lang_IllegalAccessError());

  }

  // initialize resolved_klass if necessary

  // note 1: the klass which declared the field must be initialized (i.e, sel_klass)

  //         according to the newest JVM spec (5.5, p.170) - was bug (gri 7/28/99)