Eine aufbereitete Darstellung der Quelle

 
     
 
 
Anforderungen  |   Konzepte  |   Entwurf  |   Entwicklung  |   Qualitätssicherung  |   Lebenszyklus  |   Steuerung
 
 
 
 

Benutzer

Quelle  method_handles.cc

  Sprache: C
 

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


#include "method_handles-inl.h"

#include "android-base/macros.h"
#include "android-base/stringprintf.h"
#include "class_root-inl.h"
#include "common_dex_operations.h"
#include "common_throws.h"
#include "interpreter/shadow_frame-inl.h"
#include "interpreter/shadow_frame.h"
#include "jvalue-inl.h"
#include "mirror/class-inl.h"
#include "mirror/emulated_stack_frame-inl.h"
#include "mirror/emulated_stack_frame.h"
#include "mirror/method_handle_impl-inl.h"
#include "mirror/method_handle_impl.h"
#include "mirror/method_type-inl.h"
#include "mirror/var_handle.h"
#include "reflection-inl.h"
#include "reflection.h"
#include "thread.h"
#include "var_handles.h"
#include "well_known_classes.h"

namespace art HIDDEN {

using android::base::StringPrintf;

namespace {

#define PRIMITIVES_LIST(V) \
  V(Primitive::kPrimBoolean, Boolean, Boolean, Z) \
  V(Primitive::kPrimByte, Byte, Byte, B)          \
  V(Primitive::kPrimChar, Char, Character, C)     \
  V(Primitive::kPrimShort, ShortShort, S)       \
  V(Primitive::kPrimInt, Int, Integer, I)         \
  V(Primitive::kPrimLong, LongLong, J)          \
  V(Primitive::kPrimFloat, FloatFloat, F)       \
  V(Primitive::kPrimDouble, DoubleDouble, D)

// Assigns |type| to the primitive type associated with |klass|. Returns
// true iff. |klass| was a boxed type (Integer, Long etc.), false otherwise.
bool GetUnboxedPrimitiveType(ObjPtr<mirror::Class> klass, Primitive::Type* type)
    REQUIRES_SHARED(Locks::mutator_lock_) {
  ScopedAssertNoThreadSuspension ants(__FUNCTION__);
  std::string storage;
  const char* descriptor = klass->GetDescriptor(&storage);
  static const char kJavaLangPrefix[] = "Ljava/lang/";
  static const size_t kJavaLangPrefixSize = sizeof(kJavaLangPrefix) - 1;
  if (strncmp(descriptor, kJavaLangPrefix, kJavaLangPrefixSize) != 0) {
    return false;
  }

  descriptor += kJavaLangPrefixSize;
#define LOOKUP_PRIMITIVE(primitive, _, java_name, ___) \
  if (strcmp(descriptor, #java_name ";") == 0) {       \
    *type = primitive;                                 \
    return true;                                       \
  }

  PRIMITIVES_LIST(LOOKUP_PRIMITIVE);
#undef LOOKUP_PRIMITIVE
  return false;
}

ObjPtr<mirror::Class> GetBoxedPrimitiveClass(Primitive::Type type)
    REQUIRES_SHARED(Locks::mutator_lock_) {
  ScopedAssertNoThreadSuspension ants(__FUNCTION__);
  ArtMethod* m = nullptr;
  switch (type) {
#define CASE_PRIMITIVE(primitive, _, java_name, __)              \
    case primitive:                                              \
      m = WellKnownClasses::java_lang_ ## java_name ## _valueOf; \
      break;
    PRIMITIVES_LIST(CASE_PRIMITIVE);
#undef CASE_PRIMITIVE
    case Primitive::Type::kPrimNot:
    case Primitive::Type::kPrimVoid:
      return nullptr;
  }
  return m->GetDeclaringClass();
}

bool GetUnboxedTypeAndValue(ObjPtr<mirror::Object> o, Primitive::Type* type, JValue* value)
    REQUIRES_SHARED(Locks::mutator_lock_) {
  ScopedAssertNoThreadSuspension ants(__FUNCTION__);
  ObjPtr<mirror::Class> klass = o->GetClass();
#define CASE_PRIMITIVE(primitive, abbrev, java_name, shorthand)                 \
  if (klass == GetBoxedPrimitiveClass(primitive)) {                             \
    *type = primitive;                                                          \
    value->Set ## shorthand(                                                    \
        WellKnownClasses::java_lang_ ## java_name ## _value->Get ## abbrev(o)); \
    return true;                                                                \
  }
  PRIMITIVES_LIST(CASE_PRIMITIVE)
#undef CASE_PRIMITIVE
  return false;
}

inline bool IsReferenceType(Primitive::Type type) {
  return type == Primitive::kPrimNot;
}

inline bool IsPrimitiveType(Primitive::Type type) {
  return !IsReferenceType(type);
}

}  // namespace

bool IsParameterTypeConvertible(ObjPtr<mirror::Class> from, ObjPtr<mirror::Class> to)
    REQUIRES_SHARED(Locks::mutator_lock_) {
  // This function returns true if there's any conceivable conversion
  // between |from| and |to|. It's expected this method will be used
  // to determine if a WrongMethodTypeException should be raised. The
  // decision logic follows the documentation for MethodType.asType().
  if (from == to) {
    return true;
  }

  Primitive::Type from_primitive = from->GetPrimitiveType();
  Primitive::Type to_primitive = to->GetPrimitiveType();
  DCHECK(from_primitive != Primitive::Type::kPrimVoid);
  DCHECK(to_primitive != Primitive::Type::kPrimVoid);

  // If |to| and |from| are references.
  if (IsReferenceType(from_primitive) && IsReferenceType(to_primitive)) {
    // Assignability is determined during parameter conversion when
    // invoking the associated method handle.
    return true;
  }

  // If |to| and |from| are primitives and a widening conversion exists.
  if (Primitive::IsWidenable(from_primitive, to_primitive)) {
    return true;
  }

  // If |to| is a reference and |from| is a primitive, then boxing conversion.
  if (IsReferenceType(to_primitive) && IsPrimitiveType(from_primitive)) {
    return to->IsAssignableFrom(GetBoxedPrimitiveClass(from_primitive));
  }

  // If |from| is a reference and |to| is a primitive, then unboxing conversion.
  if (IsPrimitiveType(to_primitive) && IsReferenceType(from_primitive)) {
    if (from->DescriptorEquals("Ljava/lang/Object;")) {
      // Object might be converted into a primitive during unboxing.
      return true;
    }

    if (Primitive::IsNumericType(to_primitive) && from->DescriptorEquals("Ljava/lang/Number;")) {
      // Number might be unboxed into any of the number primitive types.
      return true;
    }

    Primitive::Type unboxed_type;
    if (GetUnboxedPrimitiveType(from, &unboxed_type)) {
      if (unboxed_type == to_primitive) {
        // Straightforward unboxing conversion such as Boolean => boolean.
        return true;
      }

      // Check if widening operations for numeric primitives would work,
      // such as Byte => byte => long.
      return Primitive::IsWidenable(unboxed_type, to_primitive);
    }
  }

  return false;
}

bool IsReturnTypeConvertible(ObjPtr<mirror::Class> from, ObjPtr<mirror::Class> to)
    REQUIRES_SHARED(Locks::mutator_lock_) {
  if (to->GetPrimitiveType() == Primitive::Type::kPrimVoid) {
    // Result will be ignored.
    return true;
  } else if (from->GetPrimitiveType() == Primitive::Type::kPrimVoid) {
    // Returned value will be 0 / null.
    return true;
  } else {
    // Otherwise apply usual parameter conversion rules.
    return IsParameterTypeConvertible(from, to);
  }
}

bool ConvertJValueCommon(
    const ThrowWrongMethodTypeFunction& throw_wmt,
    ObjPtr<mirror::Class> from,
    ObjPtr<mirror::Class> to,
    /*inout*/ JValue* value) {
  // The reader maybe concerned about the safety of the heap object
  // that may be in |value|. There is only one case where allocation
  // is obviously needed and that's for boxing. However, in the case
  // of boxing |value| contains a non-reference type.

  const Primitive::Type from_type = from->GetPrimitiveType();
  const Primitive::Type to_type = to->GetPrimitiveType();

  // Put incoming value into |src_value| and set return value to 0.
  // Errors and conversions from void require the return value to be 0.
  const JValue src_value(*value);
  value->SetJ(0);

  // Conversion from void set result to zero.
  if (from_type == Primitive::kPrimVoid) {
    return true;
  }

  // This method must be called only when the types don't match.
  DCHECK(from != to);

  if (IsPrimitiveType(from_type) && IsPrimitiveType(to_type)) {
    // The source and target types are both primitives.
    if (UNLIKELY(!ConvertPrimitiveValueNoThrow(from_type, to_type, src_value, value))) {
      throw_wmt();
      return false;
    }
    return true;
  } else if (IsReferenceType(from_type) && IsReferenceType(to_type)) {
    // They're both reference types. If "from" is null, we can pass it
    // through unchanged. If not, we must generate a cast exception if
    // |to| is not assignable from the dynamic type of |ref|.
    //
    // Playing it safe with StackHandleScope here, not expecting any allocation
    // in mirror::Class::IsAssignable().
    StackHandleScope<2> hs(Thread::Current());
    Handle<mirror::Class> h_to(hs.NewHandle(to));
    Handle<mirror::Object> h_obj(hs.NewHandle(src_value.GetL()));
    if (UNLIKELY(!h_obj.IsNull() && !to->IsAssignableFrom(h_obj->GetClass()))) {
      ThrowClassCastException(h_to.Get(), h_obj->GetClass());
      return false;
    }
    value->SetL(h_obj.Get());
    return true;
  } else if (IsReferenceType(to_type)) {
    DCHECK(IsPrimitiveType(from_type));
    // The source type is a primitive and the target type is a reference, so we must box.
    // The target type maybe a super class of the boxed source type, for example,
    // if the source type is int, it's boxed type is java.lang.Integer, and the target
    // type could be java.lang.Number.
    Primitive::Type type;
    if (!GetUnboxedPrimitiveType(to, &type)) {
      ObjPtr<mirror::Class> boxed_from_class = GetBoxedPrimitiveClass(from_type);
      if (LIKELY(boxed_from_class->IsSubClass(to))) {
        type = from_type;
      } else {
        throw_wmt();
        return false;
      }
    }

    if (UNLIKELY(from_type != type)) {
      throw_wmt();
      return false;
    }

    if (UNLIKELY(!ConvertPrimitiveValueNoThrow(from_type, type, src_value, value))) {
      throw_wmt();
      return false;
    }

    // Then perform the actual boxing, and then set the reference.
    ObjPtr<mirror::Object> boxed = BoxPrimitive(type, src_value);
    value->SetL(boxed);
    return true;
  } else {
    // The source type is a reference and the target type is a primitive, so we must unbox.
    DCHECK(IsReferenceType(from_type));
    DCHECK(IsPrimitiveType(to_type));

    ObjPtr<mirror::Object> from_obj(src_value.GetL());
    if (UNLIKELY(from_obj.IsNull())) {
      ThrowNullPointerException(
          StringPrintf("Expected to unbox a '%s' primitive type but was returned null",
                       from->PrettyDescriptor().c_str()).c_str());
      return false;
    }

    ObjPtr<mirror::Class> from_obj_type = from_obj->GetClass();
    Primitive::Type from_primitive_type;
    if (!GetUnboxedPrimitiveType(from_obj_type, &from_primitive_type)) {
      ThrowClassCastException(from, to);
      return false;
    }

    Primitive::Type unboxed_type;
    JValue unboxed_value;
    if (UNLIKELY(!GetUnboxedTypeAndValue(from_obj, &unboxed_type, &unboxed_value))) {
      throw_wmt();
      return false;
    }

    if (UNLIKELY(!ConvertPrimitiveValueNoThrow(unboxed_type, to_type, unboxed_value, value))) {
      if (from->IsAssignableFrom(GetBoxedPrimitiveClass(to_type))) {
        // CallSite may be Number, but the Number object is
        // incompatible, e.g. Number (Integer) for a short.
        ThrowClassCastException(from, to);
      } else {
        // CallSite is incompatible, e.g. Integer for a short.
        throw_wmt();
      }
      return false;
    }

    return true;
  }
}

namespace {

inline void CopyArgumentsFromCallerFrame(const ShadowFrame& caller_frame,
                                         ShadowFrame* callee_frame,
                                         const InstructionOperands* const operands,
                                         const size_t first_dst_reg)
    REQUIRES_SHARED(Locks::mutator_lock_) {
  for (size_t i = 0; i < operands->GetNumberOfOperands(); ++i) {
    size_t dst_reg = first_dst_reg + i;
    size_t src_reg = operands->GetOperand(i);
    // Uint required, so that sign extension does not make this wrong on 64-bit systems
    uint32_t src_value = caller_frame.GetVReg(src_reg);
    ObjPtr<mirror::Object> o = caller_frame.GetVRegReference<kVerifyNone>(src_reg);
    // If both register locations contains the same value, the register probably holds a reference.
    // Note: As an optimization, non-moving collectors leave a stale reference value
    // in the references array even after the original vreg was overwritten to a non-reference.
    if (src_value == reinterpret_cast<uintptr_t>(o.Ptr())) {
      callee_frame->SetVRegReference(dst_reg, o);
    } else {
      callee_frame->SetVReg(dst_reg, src_value);
    }
  }
}

// Calculate the number of ins for a proxy or native method, where we
// can't just look at the code item.
static inline size_t GetInsForProxyOrNativeMethod(ArtMethod* method)
    REQUIRES_SHARED(Locks::mutator_lock_) {
  DCHECK(method->IsNative() || method->IsProxyMethod());
  method = method->GetInterfaceMethodIfProxy(kRuntimePointerSize);
  uint32_t shorty_length = 0;
  const char* shorty = method->GetShorty(&shorty_length);

  // Static methods do not include the receiver. The receiver isn't included
  // in the shorty_length though the return value is.
  size_t num_ins = method->IsStatic() ? shorty_length - 1 : shorty_length;
  for (const char* c = shorty + 1; *c != '\0'; ++c) {
    if (*c == 'J' || *c == 'D') {
      ++num_ins;
    }
  }
  return num_ins;
}

static inline bool MethodHandleInvokeTransform(Thread* self,
                                               ShadowFrame& shadow_frame,
                                               Handle<mirror::MethodHandle> method_handle,
                                               Handle<mirror::MethodType> callsite_type,
                                               const InstructionOperands* const operands,
                                               JValue* result)
    REQUIRES_SHARED(Locks::mutator_lock_) {
  // This can be fixed to two, because the method we're calling here
  // (MethodHandle.transformInternal) doesn't have any locals and the signature
  // is known :
  //
  // private MethodHandle.transformInternal(EmulatedStackFrame sf);
  //
  // This means we need only two vregs :
  // - One for the method_handle object.
  // - One for the only method argument (an EmulatedStackFrame).
  static constexpr size_t kNumRegsForTransform = 2;

  ArtMethod* called_method = method_handle->GetTargetMethod();
  CodeItemDataAccessor accessor(called_method->DexInstructionData());
  DCHECK_EQ(kNumRegsForTransform, accessor.RegistersSize());
  DCHECK_EQ(kNumRegsForTransform, accessor.InsSize());

  StackHandleScope<2> hs(self);
  Handle<mirror::MethodType> callee_type(hs.NewHandle(method_handle->GetMethodType()));
  Handle<mirror::EmulatedStackFrame> sf(
      hs.NewHandle<mirror::EmulatedStackFrame>(
          mirror::EmulatedStackFrame::CreateFromShadowFrameAndArgs(
              self, callsite_type, callee_type, shadow_frame, operands)));
  if (sf == nullptr) {
    DCHECK(self->IsExceptionPending());
    return false;
  }

  const char* old_cause = self->StartAssertNoThreadSuspension("MethodHandleInvokeTransform");
  ShadowFrameAllocaUniquePtr shadow_frame_unique_ptr =
      CREATE_SHADOW_FRAME(kNumRegsForTransform, called_method, /* dex pc */ 0);
  ShadowFrame* new_shadow_frame = shadow_frame_unique_ptr.get();
  new_shadow_frame->SetVRegReference(0, method_handle.Get());
  new_shadow_frame->SetVRegReference(1, sf.Get());
  self->EndAssertNoThreadSuspension(old_cause);

  PerformCall(self,
              accessor,
              0 /* first destination register */,
              new_shadow_frame,
              result,
              interpreter::ShouldStayInSwitchInterpreter(called_method));
  if (self->IsExceptionPending()) {
    return false;
  }

  // If the called transformer method we called has returned a value, then we
  // need to copy it back to |result|.
  sf->GetReturnValue(self, result);
  return true;
}

inline static ObjPtr<mirror::Class> GetAndInitializeDeclaringClass(Thread* self, ArtField* field)
    REQUIRES_SHARED(Locks::mutator_lock_) {
  // Method handle invocations on static fields should ensure class is
  // initialized. This usually happens when an instance is constructed
  // or class members referenced, but this is not guaranteed when
  // looking up method handles.
  ObjPtr<mirror::Class> klass = field->GetDeclaringClass();
  if (UNLIKELY(!klass->IsInitialized())) {
    StackHandleScope<1> hs(self);
    HandleWrapperObjPtr<mirror::Class> h(hs.NewHandleWrapper(&klass));
    if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(self, h, truetrue)) {
      DCHECK(self->IsExceptionPending());
      return nullptr;
    }
  }
  return klass;
}

ArtMethod* RefineTargetMethod(Thread* self,
                              ShadowFrame& shadow_frame,
                              const mirror::MethodHandle::Kind& handle_kind,
                              ObjPtr<mirror::MethodType> handle_type,
                              const uint32_t receiver_reg,
                              ArtMethod* target_method) REQUIRES_SHARED(Locks::mutator_lock_) {
  if (handle_kind == mirror::MethodHandle::Kind::kInvokeVirtual ||
      handle_kind == mirror::MethodHandle::Kind::kInvokeInterface) {
    // For virtual and interface methods ensure target_method points to
    // the actual method to invoke.
    ObjPtr<mirror::Object> receiver(shadow_frame.GetVRegReference(receiver_reg));
    ObjPtr<mirror::Class> declaring_class(target_method->GetDeclaringClass());
    if (receiver == nullptr || receiver->GetClass() != declaring_class) {
      // Verify that _vRegC is an object reference and of the type expected by
      // the receiver.
      if (!VerifyObjectIsClass(receiver, declaring_class)) {
        DCHECK(self->IsExceptionPending());
        return nullptr;
      }
      return receiver->GetClass()->FindVirtualMethodForVirtualOrInterface(
          target_method, kRuntimePointerSize);
    }
  } else if (handle_kind == mirror::MethodHandle::Kind::kInvokeDirect) {
    // String constructors are replaced with static StringFactory methods when a MethodHandle
    // object is created.
    DCHECK(!target_method->IsStringConstructor());
    ObjPtr<mirror::Object> receiver(shadow_frame.GetVRegReference(receiver_reg));
    if (receiver == nullptr) {
      ThrowNullPointerException("null receiver");
      return nullptr;
    }
  } else if (handle_kind == mirror::MethodHandle::Kind::kInvokeSuper) {
    // Note that we're not dynamically dispatching on the type of the receiver
    // here. We use the static type of the "receiver" object that we've
    // recorded in the method handle's type, which will be the same as the
    // special caller that was specified at the point of lookup.
    ObjPtr<mirror::Class> referrer_class = handle_type->GetPTypes()->Get(0);
    ObjPtr<mirror::Class> declaring_class = target_method->GetDeclaringClass();
    if (referrer_class == declaring_class) {
      return target_method;
    }
    CHECK(!target_method->IsAbstract())
        << "invoke-super MethodHandle can't target abstract methods: "
        << target_method->PrettyMethod();
    if (!declaring_class->IsInterface()) {
      ObjPtr<mirror::Class> super_class = referrer_class->GetSuperClass();
      uint16_t vtable_index = target_method->GetMethodIndex();
      DCHECK(super_class != nullptr);
      DCHECK(super_class->HasVTable());
      // Note that super_class is a super of referrer_class and target_method
      // will always be declared by super_class (or one of its super classes).
      DCHECK_LT(vtable_index, super_class->GetVTableLength());
      return super_class->GetVTableEntry(vtable_index, kRuntimePointerSize);
    }
  }
  return target_method;
}

// Helper for getters in invoke-polymorphic.
inline static void MethodHandleFieldGet(Thread* self,
                                        const ShadowFrame& shadow_frame,
                                        ObjPtr<mirror::Object>& obj,
                                        ArtField* field,
                                        Primitive::Type field_type,
                                        JValue* result) REQUIRES_SHARED(Locks::mutator_lock_) {
  switch (field_type) {
    case Primitive::kPrimBoolean:
      DoFieldGetCommon<Primitive::kPrimBoolean>(self, shadow_frame, obj, field, result);
      break;
    case Primitive::kPrimByte:
      DoFieldGetCommon<Primitive::kPrimByte>(self, shadow_frame, obj, field, result);
      break;
    case Primitive::kPrimChar:
      DoFieldGetCommon<Primitive::kPrimChar>(self, shadow_frame, obj, field, result);
      break;
    case Primitive::kPrimShort:
      DoFieldGetCommon<Primitive::kPrimShort>(self, shadow_frame, obj, field, result);
      break;
    case Primitive::kPrimInt:
      DoFieldGetCommon<Primitive::kPrimInt>(self, shadow_frame, obj, field, result);
      break;
    case Primitive::kPrimLong:
      DoFieldGetCommon<Primitive::kPrimLong>(self, shadow_frame, obj, field, result);
      break;
    case Primitive::kPrimFloat:
      DoFieldGetCommon<Primitive::kPrimInt>(self, shadow_frame, obj, field, result);
      break;
    case Primitive::kPrimDouble:
      DoFieldGetCommon<Primitive::kPrimLong>(self, shadow_frame, obj, field, result);
      break;
    case Primitive::kPrimNot:
      DoFieldGetCommon<Primitive::kPrimNot>(self, shadow_frame, obj, field, result);
      break;
    case Primitive::kPrimVoid:
      LOG(FATAL) << "Unreachable: " << field_type;
      UNREACHABLE();
  }
}

// Helper for setters in invoke-polymorphic.
inline bool MethodHandleFieldPut(Thread* self,
                                 ShadowFrame& shadow_frame,
                                 ObjPtr<mirror::Object>& obj,
                                 ArtField* field,
                                 Primitive::Type field_type,
                                 JValue& value) REQUIRES_SHARED(Locks::mutator_lock_) {
  DCHECK(!Runtime::Current()->IsActiveTransaction());
  static const bool kTransaction = false;         // Not in a transaction.
  switch (field_type) {
    case Primitive::kPrimBoolean:
      return
          DoFieldPutCommon<Primitive::kPrimBoolean, kTransaction>(
              self, shadow_frame, obj, field, value);
    case Primitive::kPrimByte:
      return DoFieldPutCommon<Primitive::kPrimByte, kTransaction>(
          self, shadow_frame, obj, field, value);
    case Primitive::kPrimChar:
      return DoFieldPutCommon<Primitive::kPrimChar, kTransaction>(
          self, shadow_frame, obj, field, value);
    case Primitive::kPrimShort:
      return DoFieldPutCommon<Primitive::kPrimShort, kTransaction>(
          self, shadow_frame, obj, field, value);
    case Primitive::kPrimInt:
    case Primitive::kPrimFloat:
      return DoFieldPutCommon<Primitive::kPrimInt, kTransaction>(
          self, shadow_frame, obj, field, value);
    case Primitive::kPrimLong:
    case Primitive::kPrimDouble:
      return DoFieldPutCommon<Primitive::kPrimLong, kTransaction>(
          self, shadow_frame, obj, field, value);
    case Primitive::kPrimNot:
      return DoFieldPutCommon<Primitive::kPrimNot, kTransaction>(
          self, shadow_frame, obj, field, value);
    case Primitive::kPrimVoid:
      LOG(FATAL) << "Unreachable: " << field_type;
      UNREACHABLE();
  }
}

static JValue GetValueFromShadowFrame(const ShadowFrame& shadow_frame,
                                      Primitive::Type field_type,
                                      uint32_t vreg) REQUIRES_SHARED(Locks::mutator_lock_) {
  JValue field_value;
  switch (field_type) {
    case Primitive::kPrimBoolean:
      field_value.SetZ(static_cast<uint8_t>(shadow_frame.GetVReg(vreg)));
      break;
    case Primitive::kPrimByte:
      field_value.SetB(static_cast<int8_t>(shadow_frame.GetVReg(vreg)));
      break;
    case Primitive::kPrimChar:
      field_value.SetC(static_cast<uint16_t>(shadow_frame.GetVReg(vreg)));
      break;
    case Primitive::kPrimShort:
      field_value.SetS(static_cast<int16_t>(shadow_frame.GetVReg(vreg)));
      break;
    case Primitive::kPrimInt:
    case Primitive::kPrimFloat:
      field_value.SetI(shadow_frame.GetVReg(vreg));
      break;
    case Primitive::kPrimLong:
    case Primitive::kPrimDouble:
      field_value.SetJ(shadow_frame.GetVRegLong(vreg));
      break;
    case Primitive::kPrimNot:
      field_value.SetL(shadow_frame.GetVRegReference(vreg));
      break;
    case Primitive::kPrimVoid:
      LOG(FATAL) << "Unreachable: " << field_type;
      UNREACHABLE();
  }
  return field_value;
}

bool MethodHandleFieldAccess(Thread* self,
                             ShadowFrame& shadow_frame,
                             Handle<mirror::MethodHandle> method_handle,
                             Handle<mirror::MethodType> callsite_type,
                             const InstructionOperands* const operands,
                             JValue* result) REQUIRES_SHARED(Locks::mutator_lock_) {
  StackHandleScope<1> hs(self);
  const mirror::MethodHandle::Kind handle_kind = method_handle->GetHandleKind();
  ArtField* field = method_handle->GetTargetField();
  Primitive::Type field_type = field->GetTypeAsPrimitiveType();
  switch (handle_kind) {
    case mirror::MethodHandle::kInstanceGet: {
      size_t obj_reg = operands->GetOperand(0);
      ObjPtr<mirror::Object> obj = shadow_frame.GetVRegReference(obj_reg);
      if (obj == nullptr) {
        ThrowNullPointerException("Receiver is null");
        return false;
      }
      MethodHandleFieldGet(self, shadow_frame, obj, field, field_type, result);
      return true;
    }
    case mirror::MethodHandle::kStaticGet: {
      ObjPtr<mirror::Object> obj = GetAndInitializeDeclaringClass(self, field);
      if (obj == nullptr) {
        DCHECK(self->IsExceptionPending());
        return false;
      }
      MethodHandleFieldGet(self, shadow_frame, obj, field, field_type, result);
      return true;
    }
    case mirror::MethodHandle::kInstancePut: {
      size_t obj_reg = operands->GetOperand(0);
      size_t value_reg = operands->GetOperand(1);
      const size_t kPTypeIndex = 1;
      // Use ptypes instead of field type since we may be unboxing a reference for a primitive
      // field. The field type is incorrect for this case.
      JValue value = GetValueFromShadowFrame(
          shadow_frame,
          callsite_type->GetPTypes()->Get(kPTypeIndex)->GetPrimitiveType(),
          value_reg);
      ObjPtr<mirror::Object> obj = shadow_frame.GetVRegReference(obj_reg);
      if (obj == nullptr) {
        ThrowNullPointerException("Receiver is null");
        return false;
      }
      return MethodHandleFieldPut(self, shadow_frame, obj, field, field_type, value);
    }
    case mirror::MethodHandle::kStaticPut: {
      ObjPtr<mirror::Object> obj = GetAndInitializeDeclaringClass(self, field);
      if (obj == nullptr) {
        DCHECK(self->IsExceptionPending());
        return false;
      }
      size_t value_reg = operands->GetOperand(0);
      const size_t kPTypeIndex = 0;
      // Use ptypes instead of field type since we may be unboxing a reference for a primitive
      // field. The field type is incorrect for this case.
      JValue value = GetValueFromShadowFrame(
          shadow_frame,
          callsite_type->GetPTypes()->Get(kPTypeIndex)->GetPrimitiveType(),
          value_reg);
      return MethodHandleFieldPut(self, shadow_frame, obj, field, field_type, value);
    }
    default:
      LOG(FATAL) << "Unreachable: " << handle_kind;
      UNREACHABLE();
  }
}

bool DoVarHandleInvokeTranslation(Thread* self,
                                  ShadowFrame& shadow_frame,
                                  Handle<mirror::MethodHandle> method_handle,
                                  Handle<mirror::MethodType> callsite_type,
                                  const InstructionOperands* const operands,
                                  JValue* result) REQUIRES_SHARED(Locks::mutator_lock_) {
  //
  // Basic checks that apply in all cases.
  //
  StackHandleScope<6> hs(self);
  Handle<mirror::ObjectArray<mirror::Class>>
      callsite_ptypes(hs.NewHandle(callsite_type->GetPTypes()));
  Handle<mirror::ObjectArray<mirror::Class>>
         mh_ptypes(hs.NewHandle(method_handle->GetMethodType()->GetPTypes()));

  // Check that the first parameter is a VarHandle
  if (callsite_ptypes->GetLength() < 1 ||
      !mh_ptypes->Get(0)->IsAssignableFrom(callsite_ptypes->Get(0)) ||
      mh_ptypes->Get(0) != GetClassRoot<mirror::VarHandle>()) {
    ThrowWrongMethodTypeException(method_handle->GetMethodType(), callsite_type.Get());
    return false;
  }

  // Get the receiver
  ObjPtr<mirror::Object> receiver = shadow_frame.GetVRegReference(operands->GetOperand(0));
  if (receiver == nullptr) {
    ThrowNullPointerException("Expected argument 1 to be a non-null VarHandle");
    return false;
  }

  // Cast to VarHandle instance
  Handle<mirror::VarHandle> vh(hs.NewHandle(ObjPtr<mirror::VarHandle>::DownCast(receiver)));
  DCHECK(GetClassRoot<mirror::VarHandle>()->IsAssignableFrom(vh->GetClass()));

  // Determine the accessor kind to dispatch
  ArtMethod* target_method = method_handle->GetTargetMethod();
  mirror::VarHandle::AccessMode access_mode =
      mirror::VarHandle::GetAccessModeByIntrinsic(target_method->GetIntrinsic());
  Handle<mirror::MethodType> vh_type =
      hs.NewHandle(vh->GetMethodTypeForAccessMode(self, access_mode));
  Handle<mirror::MethodType> mh_invoke_type = hs.NewHandle(
      mirror::MethodType::CloneWithoutLeadingParameter(self, method_handle->GetMethodType()));
  if (method_handle->GetHandleKind() == mirror::MethodHandle::Kind::kInvokeVarHandleExact) {
    if (!mh_invoke_type->IsExactMatch(vh_type.Get())) {
      ThrowWrongMethodTypeException(vh_type.Get(), mh_invoke_type.Get());
      return false;
    }
  }

  Handle<mirror::MethodType> callsite_type_without_varhandle =
      hs.NewHandle(mirror::MethodType::CloneWithoutLeadingParameter(self, callsite_type.Get()));
  NoReceiverInstructionOperands varhandle_operands(operands);
  return VarHandleInvokeAccessor(self,
                                 shadow_frame,
                                 vh,
                                 callsite_type_without_varhandle,
                                 access_mode,
                                 &varhandle_operands,
                                 result);
}

static bool DoMethodHandleInvokeMethod(Thread* self,
                                       ShadowFrame& shadow_frame,
                                       Handle<mirror::MethodHandle> method_handle,
                                       const InstructionOperands* const operands,
                                       JValue* result) REQUIRES_SHARED(Locks::mutator_lock_) {
  ArtMethod* target_method = method_handle->GetTargetMethod();
  uint32_t receiver_reg = (operands->GetNumberOfOperands() > 0) ? operands->GetOperand(0) : 0u;
  ArtMethod* called_method = RefineTargetMethod(self,
                                                shadow_frame,
                                                method_handle->GetHandleKind(),
                                                method_handle->GetMethodType(),
                                                receiver_reg,
                                                target_method);
  if (called_method == nullptr) {
    DCHECK(self->IsExceptionPending());
    return false;
  }
  // Compute method information.
  CodeItemDataAccessor accessor(called_method->DexInstructionData());
  uint16_t num_regs;
  size_t first_dest_reg;
  if (LIKELY(accessor.HasCodeItem())) {
    num_regs = accessor.RegistersSize();
    first_dest_reg = num_regs - accessor.InsSize();
    // Parameter registers go at the end of the shadow frame.
    DCHECK_NE(first_dest_reg, (size_t)-1);
  } else if (called_method->IsNative() || called_method->IsProxyMethod()) {
    // No local regs for proxy and native methods.
    num_regs = GetInsForProxyOrNativeMethod(called_method);
    first_dest_reg = 0;
  } else {
    if (called_method->IsDefaultConflicting()) {
      ThrowIncompatibleClassChangeErrorForMethodConflict(called_method);
    } else {
      ThrowAbstractMethodError(called_method,
                               shadow_frame.GetVRegReference(operands->GetOperand(0)));
    }
    return false;
  }

  const char* old_cause = self->StartAssertNoThreadSuspension("DoMethodHandleInvokeMethod");
  ShadowFrameAllocaUniquePtr shadow_frame_unique_ptr =
      CREATE_SHADOW_FRAME(num_regs, called_method, /* dex pc */ 0);
  ShadowFrame* new_shadow_frame = shadow_frame_unique_ptr.get();
  // Restore the values of virtual registers if a virtual thread is unparking
  if (kIsVirtualThreadEnabled && UNLIKELY(self->IsVirtualThreadUnparking())) {
    interpreter::FillVirtualThreadFrame(self, new_shadow_frame);
  } else {
    CopyArgumentsFromCallerFrame(shadow_frame, new_shadow_frame, operands, first_dest_reg);
  }
  self->EndAssertNoThreadSuspension(old_cause);

  PerformCall(self,
              accessor,
              first_dest_reg,
              new_shadow_frame,
              result,
              interpreter::ShouldStayInSwitchInterpreter(called_method));
  if (self->IsExceptionPending()) {
    return false;
  }
  return true;
}

static bool MethodHandleInvokeExactInternal(Thread* self,
                                            ShadowFrame& shadow_frame,
                                            Handle<mirror::MethodHandle> method_handle,
                                            Handle<mirror::MethodType> callsite_type,
                                            const InstructionOperands* const operands,
                                            JValue* result) REQUIRES_SHARED(Locks::mutator_lock_) {
  if (!callsite_type->IsExactMatch(method_handle->GetMethodType())) {
    ThrowWrongMethodTypeException(method_handle->GetMethodType(), callsite_type.Get());
    return false;
  }

  switch (method_handle->GetHandleKind()) {
    case mirror::MethodHandle::Kind::kInvokeDirect:
    case mirror::MethodHandle::Kind::kInvokeInterface:
    case mirror::MethodHandle::Kind::kInvokeStatic:
    case mirror::MethodHandle::Kind::kInvokeSuper:
    case mirror::MethodHandle::Kind::kInvokeVirtual:
      return DoMethodHandleInvokeMethod(self, shadow_frame, method_handle, operands, result);
    case mirror::MethodHandle::Kind::kInstanceGet:
    case mirror::MethodHandle::Kind::kInstancePut:
    case mirror::MethodHandle::Kind::kStaticGet:
    case mirror::MethodHandle::Kind::kStaticPut:
      return MethodHandleFieldAccess(
          self, shadow_frame, method_handle, callsite_type, operands, result);
    case mirror::MethodHandle::Kind::kInvokeTransform:
      return MethodHandleInvokeTransform(
          self, shadow_frame, method_handle, callsite_type, operands, result);
    case mirror::MethodHandle::Kind::kInvokeVarHandle:
    case mirror::MethodHandle::Kind::kInvokeVarHandleExact:
      return DoVarHandleInvokeTranslation(
          self, shadow_frame, method_handle, callsite_type, operands, result);
  }
}

static bool MethodHandleInvokeInternal(Thread* self,
                                       ShadowFrame& shadow_frame,
                                       Handle<mirror::MethodHandle> method_handle,
                                       Handle<mirror::MethodType> callsite_type,
                                       const InstructionOperands* const operands,
                                       JValue* result) REQUIRES_SHARED(Locks::mutator_lock_) {
  StackHandleScope<2> hs(self);
  Handle<mirror::MethodType> method_handle_type(hs.NewHandle(method_handle->GetMethodType()));
  // Non-exact invoke behaves as calling mh.asType(newType). In ART, asType() is implemented
  // as a transformer and it is expensive to call so check first if it's really necessary.
  //
  // There are two cases where the asType() transformation can be skipped:
  //
  // 1) the call site and type of the MethodHandle match, ie code is calling invoke()
  //    unnecessarily.
  //
  // 2) when the call site can be trivially converted to the MethodHandle type due to how
  //    values are represented in the ShadowFrame, ie all registers in the shadow frame are
  //    32-bit, there is no byte, short, char, etc. So a call site with arguments of these
  //    kinds can be trivially converted to one with int arguments. Similarly if the reference
  //    types are assignable between the call site and MethodHandle type, then as asType()
  //    transformation isn't really doing any work.
  //
  // The following IsInPlaceConvertible check determines if either of these opportunities to
  // skip asType() are true.
  if (callsite_type->IsInPlaceConvertible(method_handle_type.Get())) {
    return MethodHandleInvokeExact(
        self, shadow_frame, method_handle, method_handle_type, operands, result);
  }

  // Use asType() variant of this MethodHandle to adapt callsite to the target.
  MutableHandle<mirror::MethodHandle> atc(hs.NewHandle(method_handle->GetAsTypeCache()));
  if (atc == nullptr || !callsite_type->IsExactMatch(atc->GetMethodType())) {
    // Cached asType adapter does not exist or is for another call site. Call
    // MethodHandle::asType() to get an appropriate adapter.
    ArtMethod* as_type = WellKnownClasses::java_lang_invoke_MethodHandle_asType;
    ObjPtr<mirror::MethodHandle> atc_method_handle = ObjPtr<mirror::MethodHandle>::DownCast(
        as_type->InvokeVirtual<'L''L'>(self, method_handle.Get(), callsite_type.Get()));
    if (atc_method_handle == nullptr) {
      DCHECK(self->IsExceptionPending());
      return false;
    }
    atc.Assign(atc_method_handle);
    DCHECK(!atc.IsNull());
  }

  return MethodHandleInvokeExact(self, shadow_frame, atc, callsite_type, operands, result);
}

}  // namespace

bool MethodHandleInvoke(Thread* self,
                        ShadowFrame& shadow_frame,
                        Handle<mirror::MethodHandle> method_handle,
                        Handle<mirror::MethodType> callsite_type,
                        const InstructionOperands* const operands,
                        JValue* result) REQUIRES_SHARED(Locks::mutator_lock_) {
    return MethodHandleInvokeInternal(
        self, shadow_frame, method_handle, callsite_type, operands, result);
}

bool MethodHandleInvokeExact(Thread* self,
                             ShadowFrame& shadow_frame,
                             Handle<mirror::MethodHandle> method_handle,
                             Handle<mirror::MethodType> callsite_type,
                             const InstructionOperands* const operands,
                             JValue* result) REQUIRES_SHARED(Locks::mutator_lock_) {
    return MethodHandleInvokeExactInternal(
        self, shadow_frame, method_handle, callsite_type, operands, result);
}

void MethodHandleInvokeExactWithFrame(Thread* self,
                                      Handle<mirror::MethodHandle> method_handle,
                                      Handle<mirror::EmulatedStackFrame> emulated_frame)
    REQUIRES_SHARED(Locks::mutator_lock_) {
  StackHandleScope<1> hs(self);
  Handle<mirror::MethodType> callsite_type = hs.NewHandle(emulated_frame->GetType());

  // Copy arguments from the EmalatedStackFrame to a ShadowFrame.
  const uint16_t num_vregs = callsite_type->NumberOfVRegs();

  const char* old_cause = self->StartAssertNoThreadSuspension("EmulatedStackFrame to ShadowFrame");
  ArtMethod* invoke_exact = WellKnownClasses::java_lang_invoke_MethodHandle_invokeExact;
  ShadowFrameAllocaUniquePtr shadow_frame =
      CREATE_SHADOW_FRAME(num_vregs, invoke_exact, /*dex_pc*/ 0);
  emulated_frame->WriteToShadowFrame(self, callsite_type, 0, shadow_frame.get());
  self->EndAssertNoThreadSuspension(old_cause);

  ManagedStack fragment;
  ScopedManagedStackFragment smsf(self, &fragment);
  ScopedShadowFrame pusher(self, shadow_frame.get());

  JValue result;
  RangeInstructionOperands operands(0, num_vregs);
  bool success = MethodHandleInvokeExact(self,
                                         *shadow_frame.get(),
                                         method_handle,
                                         callsite_type,
                                         &operands,
                                         &result);
  DCHECK_NE(success, self->IsExceptionPending());
  if (success) {
    emulated_frame->SetReturnValue(self, result);
  }
}

}  // namespace art

Messung V0.5 in Prozent
C=88 H=95 G=91

¤ Dauer der Verarbeitung: 0.3 Sekunden  (vorverarbeitet am  2026-06-29) ¤

*© Formatika GbR, Deutschland






Wurzel

Suchen

PVS Prover

Isabelle Prover

NIST Cobol Testsuite

Cephes Mathematical Library

Vienna Development Method

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung und die Messung sind noch experimentell.






                                                                                                                                                                                                                                                                                                                                                                                                     


Neuigkeiten

     Aktuelles
     Motto des Tages

Software

     Quellcodebibliothek
     Eigene Quellcodes
     Fremde Quellcodes
     Suchen

Aktivitäten

     Artikel über Sicherheit
     Anleitung zur Aktivierung von SSL

Muße

     Gedichte
     Musik
     Bilder

Jenseits des Üblichen ....
    

Besucherstatistik

Besucherstatistik