method_handles: Complete support for emulated stack frames.

Most of this change is a refactor that templatizes the code
that performs argument conversions. This allows us to copy arguments
between two shadow frames, or an emulated stack frame and a shadow
frame.

Test: make test-art-host
Bug: 30550796

Change-Id: I23e65735a2dbd28f3c7b7d1ccf9762e77e0cf1f1
diff --git a/runtime/mirror/emulated_stack_frame.cc b/runtime/mirror/emulated_stack_frame.cc
new file mode 100644
index 0000000..4ba71ea
--- /dev/null
+++ b/runtime/mirror/emulated_stack_frame.cc
@@ -0,0 +1,298 @@
+/*
+ * 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 "class-inl.h"
+#include "gc_root-inl.h"
+#include "jvalue-inl.h"
+#include "method_handles.h"
+#include "method_handles-inl.h"
+#include "reflection-inl.h"
+
+namespace art {
+namespace mirror {
+
+GcRoot<mirror::Class> EmulatedStackFrame::static_class_;
+
+// 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);
+};
+
+template <bool is_range>
+mirror::EmulatedStackFrame* EmulatedStackFrame::CreateFromShadowFrameAndArgs(
+    Thread* self,
+    Handle<mirror::MethodType> caller_type,
+    Handle<mirror::MethodType> callee_type,
+    const ShadowFrame& caller_frame,
+    const uint32_t first_src_reg,
+    const uint32_t (&arg)[Instruction::kMaxVarArgRegs]) {
+  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.
+  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
+  ObjPtr<mirror::Class> array_class(class_linker->GetClassRoot(ClassLinker::kObjectArrayClass));
+
+  Handle<mirror::ObjectArray<mirror::Object>> references(hs.NewHandle(
+      mirror::ObjectArray<mirror::Object>::Alloc(self, array_class, refs_size)));
+  Handle<ByteArray> stack_frame(hs.NewHandle(ByteArray::Alloc(self, frame_size)));
+
+  // Step 4 : Perform argument conversions (if required).
+  ShadowFrameGetter<is_range> getter(first_src_reg, arg, caller_frame);
+  EmulatedStackFrameAccessor setter(references, stack_frame, stack_frame->GetLength());
+  if (!PerformConversions<ShadowFrameGetter<is_range>, EmulatedStackFrameAccessor>(
+      self, from_types, to_types, &getter, &setter, num_method_params)) {
+    return nullptr;
+  }
+
+  // Step 5: Construct the EmulatedStackFrame object.
+  Handle<EmulatedStackFrame> sf(hs.NewHandle(
+      ObjPtr<EmulatedStackFrame>::DownCast(StaticClass()->AllocObject(self))));
+  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) {
+  StackHandleScope<4> hs(self);
+  Handle<mirror::ObjectArray<mirror::Class>> from_types(hs.NewHandle(GetType()->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(), GetType());
+    return false;
+  }
+
+  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, from_types, to_types, &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));
+    }
+  }
+}
+
+void EmulatedStackFrame::SetClass(Class* klass) {
+  CHECK(static_class_.IsNull()) << static_class_.Read() << " " << klass;
+  CHECK(klass != nullptr);
+  static_class_ = GcRoot<Class>(klass);
+}
+
+void EmulatedStackFrame::ResetClass() {
+  CHECK(!static_class_.IsNull());
+  static_class_ = GcRoot<Class>(nullptr);
+}
+
+void EmulatedStackFrame::VisitRoots(RootVisitor* visitor) {
+  static_class_.VisitRootIfNonNull(visitor, RootInfo(kRootStickyClass));
+}
+
+// Explicit DoInvokePolymorphic template function declarations.
+#define EXPLICIT_CREATE_FROM_SHADOW_FRAME_AND_ARGS_DECL(_is_range)                         \
+  template REQUIRES_SHARED(Locks::mutator_lock_)                                           \
+  mirror::EmulatedStackFrame* EmulatedStackFrame::CreateFromShadowFrameAndArgs<_is_range>( \
+    Thread* self,                                                                          \
+    Handle<mirror::MethodType> caller_type,                                                \
+    Handle<mirror::MethodType> callee_type,                                                \
+    const ShadowFrame& caller_frame,                                                       \
+    const uint32_t first_src_reg,                                                          \
+    const uint32_t (&arg)[Instruction::kMaxVarArgRegs])                                    \
+
+EXPLICIT_CREATE_FROM_SHADOW_FRAME_AND_ARGS_DECL(true);
+EXPLICIT_CREATE_FROM_SHADOW_FRAME_AND_ARGS_DECL(false);
+#undef EXPLICIT_CREATE_FROM_SHADOW_FRAME_AND_ARGS_DECL
+
+
+}  // namespace mirror
+}  // namespace art