runtime/mirror/emulated_stack_frame.cc - platform/art - Git at Google

 /*
  * 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 "emulated_stack_frame.h"

 #include "array-alloc-inl.h"
 #include "array-inl.h"
 #include "class-alloc-inl.h"
 #include "class_root.h"
 #include "jvalue-inl.h"
 #include "method_handles-inl.h"
 #include "method_handles.h"
 #include "object_array-alloc-inl.h"
 #include "object_array-inl.h"
 #include "reflection-inl.h"

 namespace art {
 namespace mirror {

 // Calculates the size of a stack frame based on the size of its argument
 // types and return types.
 static void CalculateFrameAndReferencesSize(ObjPtr<mirror::ObjectArray<mirror::Class>> p_types,
                                             ObjPtr<mirror::Class> r_type,
                                             size_t* frame_size_out,
                                             size_t* references_size_out)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   const size_t length = p_types->GetLength();
   size_t frame_size = 0;
   size_t references_size = 0;
   for (size_t i = 0; i < length; ++i) {
     ObjPtr<mirror::Class> type = p_types->GetWithoutChecks(i);
     const Primitive::Type primitive_type = type->GetPrimitiveType();
     if (primitive_type == Primitive::kPrimNot) {
       references_size++;
     } else if (Primitive::Is64BitType(primitive_type)) {
       frame_size += 8;
     } else {
       frame_size += 4;
     }
   }

   const Primitive::Type return_type = r_type->GetPrimitiveType();
   if (return_type == Primitive::kPrimNot) {
     references_size++;
   } else if (Primitive::Is64BitType(return_type)) {
     frame_size += 8;
   } else {
     frame_size += 4;
   }

   (*frame_size_out) = frame_size;
   (*references_size_out) = references_size;
 }

 // Allows for read or write access to an emulated stack frame. Each
 // accessor index has an associated index into the references / stack frame
 // arrays which is incremented on every read or write to the frame.
 //
 // This class is used in conjunction with PerformConversions, either as a setter
 // or as a getter.
 class EmulatedStackFrameAccessor {
  public:
   EmulatedStackFrameAccessor(Handle<mirror::ObjectArray<mirror::Object>> references,
                              Handle<mirror::ByteArray> stack_frame,
                              size_t stack_frame_size) :
     references_(references),
     stack_frame_(stack_frame),
     stack_frame_size_(stack_frame_size),
     reference_idx_(0u),
     stack_frame_idx_(0u) {
   }

   ALWAYS_INLINE void SetReference(ObjPtr<mirror::Object> reference)
       REQUIRES_SHARED(Locks::mutator_lock_) {
     references_->Set(reference_idx_++, reference);
   }

   ALWAYS_INLINE void Set(const uint32_t value) REQUIRES_SHARED(Locks::mutator_lock_) {
     int8_t* array = stack_frame_->GetData();

     CHECK_LE((stack_frame_idx_ + 4u), stack_frame_size_);
     memcpy(array + stack_frame_idx_, &value, sizeof(uint32_t));
     stack_frame_idx_ += 4u;
   }

   ALWAYS_INLINE void SetLong(const int64_t value) REQUIRES_SHARED(Locks::mutator_lock_) {
     int8_t* array = stack_frame_->GetData();

     CHECK_LE((stack_frame_idx_ + 8u), stack_frame_size_);
     memcpy(array + stack_frame_idx_, &value, sizeof(int64_t));
     stack_frame_idx_ += 8u;
   }

   ALWAYS_INLINE ObjPtr<mirror::Object> GetReference() REQUIRES_SHARED(Locks::mutator_lock_) {
     return ObjPtr<mirror::Object>(references_->Get(reference_idx_++));
   }

   ALWAYS_INLINE uint32_t Get() REQUIRES_SHARED(Locks::mutator_lock_) {
     const int8_t* array = stack_frame_->GetData();

     CHECK_LE((stack_frame_idx_ + 4u), stack_frame_size_);
     uint32_t val = 0;

     memcpy(&val, array + stack_frame_idx_, sizeof(uint32_t));
     stack_frame_idx_ += 4u;
     return val;
   }

   ALWAYS_INLINE int64_t GetLong() REQUIRES_SHARED(Locks::mutator_lock_) {
     const int8_t* array = stack_frame_->GetData();

     CHECK_LE((stack_frame_idx_ + 8u), stack_frame_size_);
     int64_t val = 0;

     memcpy(&val, array + stack_frame_idx_, sizeof(int64_t));
     stack_frame_idx_ += 8u;
     return val;
   }

  private:
   Handle<mirror::ObjectArray<mirror::Object>> references_;
   Handle<mirror::ByteArray> stack_frame_;
   const size_t stack_frame_size_;

   size_t reference_idx_;
   size_t stack_frame_idx_;

   DISALLOW_COPY_AND_ASSIGN(EmulatedStackFrameAccessor);
 };

 mirror::EmulatedStackFrame* EmulatedStackFrame::CreateFromShadowFrameAndArgs(
     Thread* self,
     Handle<mirror::MethodType> caller_type,
     Handle<mirror::MethodType> callee_type,
     const ShadowFrame& caller_frame,
     const InstructionOperands* const operands) {
   StackHandleScope<6> hs(self);

   // Step 1: We must throw a WrongMethodTypeException if there's a mismatch in the
   // number of arguments between the caller and the callsite.
   Handle<mirror::ObjectArray<mirror::Class>> from_types(hs.NewHandle(caller_type->GetPTypes()));
   Handle<mirror::ObjectArray<mirror::Class>> to_types(hs.NewHandle(callee_type->GetPTypes()));

   const int32_t num_method_params = from_types->GetLength();
   if (to_types->GetLength() != num_method_params) {
     ThrowWrongMethodTypeException(callee_type.Get(), caller_type.Get());
     return nullptr;
   }

   // Step 2: Calculate the size of the reference / byte arrays in the emulated
   // stack frame.
   size_t frame_size = 0;
   size_t refs_size = 0;
   Handle<mirror::Class> r_type(hs.NewHandle(callee_type->GetRType()));
   CalculateFrameAndReferencesSize(to_types.Get(), r_type.Get(), &frame_size, &refs_size);

   // Step 3 : Allocate the arrays.
   ObjPtr<mirror::Class> array_class(GetClassRoot<mirror::ObjectArray<mirror::Object>>());

   Handle<mirror::ObjectArray<mirror::Object>> references(hs.NewHandle(
       mirror::ObjectArray<mirror::Object>::Alloc(self, array_class, refs_size)));
   if (references == nullptr) {
     DCHECK(self->IsExceptionPending());
     return nullptr;
   }

   Handle<ByteArray> stack_frame(hs.NewHandle(ByteArray::Alloc(self, frame_size)));
   if (stack_frame == nullptr) {
     DCHECK(self->IsExceptionPending());
     return nullptr;
   }

   // Step 4 : Perform argument conversions (if required).
   ShadowFrameGetter getter(caller_frame, operands);
   EmulatedStackFrameAccessor setter(references, stack_frame, stack_frame->GetLength());
   if (!PerformConversions<ShadowFrameGetter, EmulatedStackFrameAccessor>(
           self, caller_type, callee_type, &getter, &setter, num_method_params)) {
     return nullptr;
   }

   // Step 5: Construct the EmulatedStackFrame object.
   Handle<EmulatedStackFrame> sf(hs.NewHandle(
       ObjPtr<EmulatedStackFrame>::DownCast(GetClassRoot<EmulatedStackFrame>()->AllocObject(self))));
   sf->SetFieldObject<false>(CallsiteTypeOffset(), caller_type.Get());
   sf->SetFieldObject<false>(TypeOffset(), callee_type.Get());
   sf->SetFieldObject<false>(ReferencesOffset(), references.Get());
   sf->SetFieldObject<false>(StackFrameOffset(), stack_frame.Get());

   return sf.Get();
 }

 bool EmulatedStackFrame::WriteToShadowFrame(Thread* self,
                                             Handle<mirror::MethodType> callee_type,
                                             const uint32_t first_dest_reg,
                                             ShadowFrame* callee_frame) {
   ObjPtr<mirror::ObjectArray<mirror::Class>> from_types(GetType()->GetPTypes());
   ObjPtr<mirror::ObjectArray<mirror::Class>> to_types(callee_type->GetPTypes());

   const int32_t num_method_params = from_types->GetLength();
   if (to_types->GetLength() != num_method_params) {
     ThrowWrongMethodTypeException(callee_type.Get(), GetType());
     return false;
   }

   StackHandleScope<3> hs(self);
   Handle<mirror::MethodType> frame_callsite_type(hs.NewHandle(GetType()));
   Handle<mirror::ObjectArray<mirror::Object>> references(hs.NewHandle(GetReferences()));
   Handle<ByteArray> stack_frame(hs.NewHandle(GetStackFrame()));

   EmulatedStackFrameAccessor getter(references, stack_frame, stack_frame->GetLength());
   ShadowFrameSetter setter(callee_frame, first_dest_reg);

   return PerformConversions<EmulatedStackFrameAccessor, ShadowFrameSetter>(
       self, frame_callsite_type, callee_type, &getter, &setter, num_method_params);
 }

 void EmulatedStackFrame::GetReturnValue(Thread* self, JValue* value) {
   StackHandleScope<2> hs(self);
   Handle<mirror::Class> r_type(hs.NewHandle(GetType()->GetRType()));

   const Primitive::Type type = r_type->GetPrimitiveType();
   if (type == Primitive::kPrimNot) {
     Handle<mirror::ObjectArray<mirror::Object>> references(hs.NewHandle(GetReferences()));
     value->SetL(references->GetWithoutChecks(references->GetLength() - 1));
   } else {
     Handle<ByteArray> stack_frame(hs.NewHandle(GetStackFrame()));
     const int8_t* array = stack_frame->GetData();
     const size_t length = stack_frame->GetLength();
     if (Primitive::Is64BitType(type)) {
       int64_t primitive = 0;
       memcpy(&primitive, array + length - sizeof(int64_t), sizeof(int64_t));
       value->SetJ(primitive);
     } else {
       uint32_t primitive = 0;
       memcpy(&primitive, array + length - sizeof(uint32_t), sizeof(uint32_t));
       value->SetI(primitive);
     }
   }
 }

 void EmulatedStackFrame::SetReturnValue(Thread* self, const JValue& value) {
   StackHandleScope<2> hs(self);
   Handle<mirror::Class> r_type(hs.NewHandle(GetType()->GetRType()));

   const Primitive::Type type = r_type->GetPrimitiveType();
   if (type == Primitive::kPrimNot) {
     Handle<mirror::ObjectArray<mirror::Object>> references(hs.NewHandle(GetReferences()));
     references->SetWithoutChecks<false>(references->GetLength() - 1, value.GetL());
   } else {
     Handle<ByteArray> stack_frame(hs.NewHandle(GetStackFrame()));
     int8_t* array = stack_frame->GetData();
     const size_t length = stack_frame->GetLength();
     if (Primitive::Is64BitType(type)) {
       const int64_t primitive = value.GetJ();
       memcpy(array + length - sizeof(int64_t), &primitive, sizeof(int64_t));
     } else {
       const uint32_t primitive = value.GetI();
       memcpy(array + length - sizeof(uint32_t), &primitive, sizeof(uint32_t));
     }
   }
 }

 }  // namespace mirror
 }  // namespace art
	/*
	* 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 "emulated_stack_frame.h"

	#include "array-alloc-inl.h"
	#include "array-inl.h"
	#include "class-alloc-inl.h"
	#include "class_root.h"
	#include "jvalue-inl.h"
	#include "method_handles-inl.h"
	#include "method_handles.h"
	#include "object_array-alloc-inl.h"
	#include "object_array-inl.h"
	#include "reflection-inl.h"

	namespace art {
	namespace mirror {

	// Calculates the size of a stack frame based on the size of its argument
	// types and return types.
	static void CalculateFrameAndReferencesSize(ObjPtr<mirror::ObjectArray<mirror::Class>> p_types,
	ObjPtr<mirror::Class> r_type,
	size_t* frame_size_out,
	size_t* references_size_out)
	REQUIRES_SHARED(Locks::mutator_lock_) {
	const size_t length = p_types->GetLength();
	size_t frame_size = 0;
	size_t references_size = 0;
	for (size_t i = 0; i < length; ++i) {
	ObjPtr<mirror::Class> type = p_types->GetWithoutChecks(i);
	const Primitive::Type primitive_type = type->GetPrimitiveType();
	if (primitive_type == Primitive::kPrimNot) {
	references_size++;
	} else if (Primitive::Is64BitType(primitive_type)) {
	frame_size += 8;
	} else {
	frame_size += 4;
	}
	}

	const Primitive::Type return_type = r_type->GetPrimitiveType();
	if (return_type == Primitive::kPrimNot) {
	references_size++;
	} else if (Primitive::Is64BitType(return_type)) {
	frame_size += 8;
	} else {
	frame_size += 4;
	}

	(*frame_size_out) = frame_size;
	(*references_size_out) = references_size;
	}

	// Allows for read or write access to an emulated stack frame. Each
	// accessor index has an associated index into the references / stack frame
	// arrays which is incremented on every read or write to the frame.
	//
	// This class is used in conjunction with PerformConversions, either as a setter
	// or as a getter.
	class EmulatedStackFrameAccessor {
	public:
	EmulatedStackFrameAccessor(Handle<mirror::ObjectArray<mirror::Object>> references,
	Handle<mirror::ByteArray> stack_frame,
	size_t stack_frame_size) :
	references_(references),
	stack_frame_(stack_frame),
	stack_frame_size_(stack_frame_size),
	reference_idx_(0u),
	stack_frame_idx_(0u) {
	}

	ALWAYS_INLINE void SetReference(ObjPtr<mirror::Object> reference)
	REQUIRES_SHARED(Locks::mutator_lock_) {
	references_->Set(reference_idx_++, reference);
	}

	ALWAYS_INLINE void Set(const uint32_t value) REQUIRES_SHARED(Locks::mutator_lock_) {
	int8_t* array = stack_frame_->GetData();

	CHECK_LE((stack_frame_idx_ + 4u), stack_frame_size_);
	memcpy(array + stack_frame_idx_, &value, sizeof(uint32_t));
	stack_frame_idx_ += 4u;
	}

	ALWAYS_INLINE void SetLong(const int64_t value) REQUIRES_SHARED(Locks::mutator_lock_) {
	int8_t* array = stack_frame_->GetData();

	CHECK_LE((stack_frame_idx_ + 8u), stack_frame_size_);
	memcpy(array + stack_frame_idx_, &value, sizeof(int64_t));
	stack_frame_idx_ += 8u;
	}

	ALWAYS_INLINE ObjPtr<mirror::Object> GetReference() REQUIRES_SHARED(Locks::mutator_lock_) {
	return ObjPtr<mirror::Object>(references_->Get(reference_idx_++));
	}

	ALWAYS_INLINE uint32_t Get() REQUIRES_SHARED(Locks::mutator_lock_) {
	const int8_t* array = stack_frame_->GetData();

	CHECK_LE((stack_frame_idx_ + 4u), stack_frame_size_);
	uint32_t val = 0;

	memcpy(&val, array + stack_frame_idx_, sizeof(uint32_t));
	stack_frame_idx_ += 4u;
	return val;
	}

	ALWAYS_INLINE int64_t GetLong() REQUIRES_SHARED(Locks::mutator_lock_) {
	const int8_t* array = stack_frame_->GetData();

	CHECK_LE((stack_frame_idx_ + 8u), stack_frame_size_);
	int64_t val = 0;

	memcpy(&val, array + stack_frame_idx_, sizeof(int64_t));
	stack_frame_idx_ += 8u;
	return val;
	}

	private:
	Handle<mirror::ObjectArray<mirror::Object>> references_;
	Handle<mirror::ByteArray> stack_frame_;
	const size_t stack_frame_size_;

	size_t reference_idx_;
	size_t stack_frame_idx_;

	DISALLOW_COPY_AND_ASSIGN(EmulatedStackFrameAccessor);
	};

	mirror::EmulatedStackFrame* EmulatedStackFrame::CreateFromShadowFrameAndArgs(
	Thread* self,
	Handle<mirror::MethodType> caller_type,
	Handle<mirror::MethodType> callee_type,
	const ShadowFrame& caller_frame,
	const InstructionOperands* const operands) {
	StackHandleScope<6> hs(self);

	// Step 1: We must throw a WrongMethodTypeException if there's a mismatch in the
	// number of arguments between the caller and the callsite.
	Handle<mirror::ObjectArray<mirror::Class>> from_types(hs.NewHandle(caller_type->GetPTypes()));
	Handle<mirror::ObjectArray<mirror::Class>> to_types(hs.NewHandle(callee_type->GetPTypes()));

	const int32_t num_method_params = from_types->GetLength();
	if (to_types->GetLength() != num_method_params) {
	ThrowWrongMethodTypeException(callee_type.Get(), caller_type.Get());
	return nullptr;
	}

	// Step 2: Calculate the size of the reference / byte arrays in the emulated
	// stack frame.
	size_t frame_size = 0;
	size_t refs_size = 0;
	Handle<mirror::Class> r_type(hs.NewHandle(callee_type->GetRType()));
	CalculateFrameAndReferencesSize(to_types.Get(), r_type.Get(), &frame_size, &refs_size);

	// Step 3 : Allocate the arrays.
	ObjPtr<mirror::Class> array_class(GetClassRoot<mirror::ObjectArray<mirror::Object>>());

	Handle<mirror::ObjectArray<mirror::Object>> references(hs.NewHandle(
	mirror::ObjectArray<mirror::Object>::Alloc(self, array_class, refs_size)));
	if (references == nullptr) {
	DCHECK(self->IsExceptionPending());
	return nullptr;
	}

	Handle<ByteArray> stack_frame(hs.NewHandle(ByteArray::Alloc(self, frame_size)));
	if (stack_frame == nullptr) {
	DCHECK(self->IsExceptionPending());
	return nullptr;
	}

	// Step 4 : Perform argument conversions (if required).
	ShadowFrameGetter getter(caller_frame, operands);
	EmulatedStackFrameAccessor setter(references, stack_frame, stack_frame->GetLength());
	if (!PerformConversions<ShadowFrameGetter, EmulatedStackFrameAccessor>(
	self, caller_type, callee_type, &getter, &setter, num_method_params)) {
	return nullptr;
	}

	// Step 5: Construct the EmulatedStackFrame object.
	Handle<EmulatedStackFrame> sf(hs.NewHandle(
	ObjPtr<EmulatedStackFrame>::DownCast(GetClassRoot<EmulatedStackFrame>()->AllocObject(self))));
	sf->SetFieldObject<false>(CallsiteTypeOffset(), caller_type.Get());
	sf->SetFieldObject<false>(TypeOffset(), callee_type.Get());
	sf->SetFieldObject<false>(ReferencesOffset(), references.Get());
	sf->SetFieldObject<false>(StackFrameOffset(), stack_frame.Get());

	return sf.Get();
	}

	bool EmulatedStackFrame::WriteToShadowFrame(Thread* self,
	Handle<mirror::MethodType> callee_type,
	const uint32_t first_dest_reg,
	ShadowFrame* callee_frame) {
	ObjPtr<mirror::ObjectArray<mirror::Class>> from_types(GetType()->GetPTypes());
	ObjPtr<mirror::ObjectArray<mirror::Class>> to_types(callee_type->GetPTypes());

	const int32_t num_method_params = from_types->GetLength();
	if (to_types->GetLength() != num_method_params) {
	ThrowWrongMethodTypeException(callee_type.Get(), GetType());
	return false;
	}

	StackHandleScope<3> hs(self);
	Handle<mirror::MethodType> frame_callsite_type(hs.NewHandle(GetType()));
	Handle<mirror::ObjectArray<mirror::Object>> references(hs.NewHandle(GetReferences()));
	Handle<ByteArray> stack_frame(hs.NewHandle(GetStackFrame()));

	EmulatedStackFrameAccessor getter(references, stack_frame, stack_frame->GetLength());
	ShadowFrameSetter setter(callee_frame, first_dest_reg);

	return PerformConversions<EmulatedStackFrameAccessor, ShadowFrameSetter>(
	self, frame_callsite_type, callee_type, &getter, &setter, num_method_params);
	}

	void EmulatedStackFrame::GetReturnValue(Thread* self, JValue* value) {
	StackHandleScope<2> hs(self);
	Handle<mirror::Class> r_type(hs.NewHandle(GetType()->GetRType()));

	const Primitive::Type type = r_type->GetPrimitiveType();
	if (type == Primitive::kPrimNot) {
	Handle<mirror::ObjectArray<mirror::Object>> references(hs.NewHandle(GetReferences()));
	value->SetL(references->GetWithoutChecks(references->GetLength() - 1));
	} else {
	Handle<ByteArray> stack_frame(hs.NewHandle(GetStackFrame()));
	const int8_t* array = stack_frame->GetData();
	const size_t length = stack_frame->GetLength();
	if (Primitive::Is64BitType(type)) {
	int64_t primitive = 0;
	memcpy(&primitive, array + length - sizeof(int64_t), sizeof(int64_t));
	value->SetJ(primitive);
	} else {
	uint32_t primitive = 0;
	memcpy(&primitive, array + length - sizeof(uint32_t), sizeof(uint32_t));
	value->SetI(primitive);
	}
	}
	}

	void EmulatedStackFrame::SetReturnValue(Thread* self, const JValue& value) {
	StackHandleScope<2> hs(self);
	Handle<mirror::Class> r_type(hs.NewHandle(GetType()->GetRType()));

	const Primitive::Type type = r_type->GetPrimitiveType();
	if (type == Primitive::kPrimNot) {
	Handle<mirror::ObjectArray<mirror::Object>> references(hs.NewHandle(GetReferences()));
	references->SetWithoutChecks<false>(references->GetLength() - 1, value.GetL());
	} else {
	Handle<ByteArray> stack_frame(hs.NewHandle(GetStackFrame()));
	int8_t* array = stack_frame->GetData();
	const size_t length = stack_frame->GetLength();
	if (Primitive::Is64BitType(type)) {
	const int64_t primitive = value.GetJ();
	memcpy(array + length - sizeof(int64_t), &primitive, sizeof(int64_t));
	} else {
	const uint32_t primitive = value.GetI();
	memcpy(array + length - sizeof(uint32_t), &primitive, sizeof(uint32_t));
	}
	}
	}

	} // namespace mirror
	} // namespace art