Rework CallApi*Stubs.

src/compiler/fast-accessor-assembler.cc

Index: src/compiler/fast-accessor-assembler.cc
diff --git a/src/compiler/fast-accessor-assembler.cc b/src/compiler/fast-accessor-assembler.cc
index 518003b2eedb0d8885b27bd599dd6fb63e74ae71..1a97fd5337e6cc6aa9af729cb94a3bdb1f056b8e 100644
--- a/src/compiler/fast-accessor-assembler.cc
+++ b/src/compiler/fast-accessor-assembler.cc
@@ -5,7 +5,7 @@
 #include "src/compiler/fast-accessor-assembler.h"
 
 #include "src/base/logging.h"
-#include "src/code-stubs.h"  // For CallApiFunctionStub.
+#include "src/code-stubs.h"  // For CallApiCallbackStub.
 #include "src/compiler/graph.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/pipeline.h"
@@ -172,7 +172,8 @@ FastAccessorAssembler::ValueId FastAccessorAssembler::Call(
   CHECK_EQ(kBuilding, state_);
 
   // Create API function stub.
-  CallApiFunctionStub stub(assembler_->isolate(), true);
+  CallApiCallbackStub stub(assembler_->isolate(), 1, true);
+  DCHECK_EQ(1, stub.GetCallInterfaceDescriptor().GetStackParameterCount());
 
   // Wrap the FunctionCallback in an ExternalReference.
   ApiFunction callback_api_function(FUNCTION_ADDR(callback_function));
@@ -180,30 +181,27 @@ FastAccessorAssembler::ValueId FastAccessorAssembler::Call(
                              ExternalReference::DIRECT_API_CALL,
                              assembler_->isolate());
 
-  // The stub has 5 parameters, and kJSParam (here: 1) parameters to pass
-  // through to the callback.
-  // See: ApiFunctionDescriptor::BuildCallInterfaceDescriptorFunctionType
-  static const int kStackParam = 1;
+  // The stub has 6 parameters.
+  // See: ApiCallbackDescriptorBase::BuildCallInterfaceDescriptorFunctionType
   Node* args[] = {
       // Stub/register parameters:
-      assembler_->Parameter(0),                /* receiver (use accessor's) */
-      assembler_->UndefinedConstant(),         /* call_data (undefined) */
-      assembler_->NullConstant(),              /* holder (null) */
-      assembler_->ExternalConstant(callback),  /* API callback function */
-      assembler_->IntPtrConstant(kStackParam), /* # JS arguments */
+      assembler_->Parameter(0),               /* receiver (use accessor's) */
+      assembler_->UndefinedConstant(),        /* call_data (undefined) */
+      assembler_->NullConstant(),             /* holder (null) */
+      assembler_->ExternalConstant(callback), /* API callback function */
 
-      // kStackParam stack parameter(s):
+      // JS arguments, on stack:
       FromId(arg),
 
       // Context parameter. (See Linkage::GetStubCallDescriptor.)
       assembler_->UndefinedConstant()};

[danno, 2016/03/09 10:23:38]

It might be slightly more efficient to pass Smi(0) here.

[vogelheim, 2016/03/09 11:09:35]

Ack. But: The point of this CL is to enable moving FastAccessorAssembler out of
compiler/ and from CallN to CallStub. That will also give me the chance to fix
the Context properly - it shouldn't be 0 / Undefined anyhow - so this will be
removed anyhow in the follow-on CL.

-  CHECK_EQ(5 + kStackParam + 1, arraysize(args));
+  DCHECK_EQ(arraysize(args),
+            1 + stub.GetCallInterfaceDescriptor().GetParameterCount());
 
   Node* call = assembler_->CallN(
       Linkage::GetStubCallDescriptor(
           assembler_->isolate(), zone(), stub.GetCallInterfaceDescriptor(),
-          kStackParam + stub.GetStackParameterCount(),
-          CallDescriptor::kNoFlags),
+          stub.GetStackParameterCount(), CallDescriptor::kNoFlags),
       assembler_->HeapConstant(stub.GetCode()), args);
   return FromRaw(call);
 }