Add native callbacks to FastAccessorAssembler.

src/compiler/fast-accessor-assembler.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/fast-accessor-assembler.h"
 
 #include "src/base/logging.h"
+#include "src/code-stubs.h"  // For CallApiFunctionStub.
 #include "src/compiler/graph.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/pipeline.h"
 #include "src/compiler/raw-machine-assembler.h"
 #include "src/compiler/schedule.h"
 #include "src/compiler/verifier.h"
 #include "src/handles-inl.h"
 #include "src/objects.h"  // For FAA::GetInternalField impl.
 
 namespace v8 {
@@ skipping 142 matching lines @@
                                                LabelId label_id) {
   CHECK_EQ(kBuilding, state_);
   RawMachineLabel pass;
   assembler_->Branch(
       assembler_->IntPtrEqual(FromId(value_id), assembler_->IntPtrConstant(0)),
       &pass, FromId(label_id));
   assembler_->Bind(&pass);
 }
 
 
+FastAccessorAssembler::ValueId FastAccessorAssembler::Call(
+    FunctionCallback callback_function, ValueId arg) {
+  CHECK_EQ(kBuilding, state_);
+
+  // Create API function stub.
+  CallApiFunctionStub stub(assembler_->isolate(), true);
+
+  // Wrap the FunctionCallback in an ExternalReference.
+  ApiFunction callback_api_function(FUNCTION_ADDR(callback_function));
+  ExternalReference callback(&callback_api_function,
+                             ExternalReference::DIRECT_API_CALL,
+                             assembler_->isolate());
+
+  // The stub has 5 parameters, and N (here: N = 1) parameters to pass through
+  // to the callback.
+  // See: ApiFunctionDescriptor::BuildCallInterfaceDescriptorFunctionType
+  Node* args[] = {
+      // Stub arguments:
+      assembler_->Parameter(0),               /* receiver (use accessor's) */
+      assembler_->UndefinedConstant(),        /* call_data (undefined) */
+      assembler_->NullConstant(),             /* holder (null) */
+      assembler_->ExternalConstant(callback), /* API callback function */
+      assembler_->IntPtrConstant(1),          /* # arguments */
+
+      // Callback arguments:
+      FromId(arg),
+      FromId(arg)

[vogelheim, 2016/01/25 17:10:33]

I'm not sure if I'm doing this right:

As I understand it, the stub itself has 5 params (described in the stub's
CallInterfaceDescriptor), the last being the # of additional params to pass to
the called function. So, logically, I have 6 parameters here. But as I read the
stub's code, it only expects five, and the rest on the stack (?). So I've added
a stack parameter (see below, 1 + stub.GetStackParameterCount() ), but now I
have to add this param twice to the args structure. That actually works, but it
looks wrong.

Honestly, I'm just guessing here... any comments?

+  };
+
+  Node* call = assembler_->CallN(
+      Linkage::GetStubCallDescriptor(
+          assembler_->isolate(), zone(), stub.GetCallInterfaceDescriptor(),
+          1 + stub.GetStackParameterCount(), CallDescriptor::kNoFlags),
+      assembler_->HeapConstant(stub.GetCode()), args);
+  return FromRaw(call);
+}
+
+
 MaybeHandle<Code> FastAccessorAssembler::Build() {
   CHECK_EQ(kBuilding, state_);
 
   // Cleanup: We no longer need this.
   nodes_.clear();
   labels_.clear();
 
   // Export the schedule and call the compiler.
   Schedule* schedule = assembler_->Export();
   MaybeHandle<Code> code = Pipeline::GenerateCodeForCodeStub(
@@ skipping 31 matching lines @@
 RawMachineLabel* FastAccessorAssembler::FromId(LabelId label) const {
   CHECK_LT(label.label_id, labels_.size());
   CHECK_NOT_NULL(labels_.at(label.label_id));
   return labels_.at(label.label_id);
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8