Set the current context to the function's context when entering to LAP.

src/ic/x64/handler-compiler-x64.cc

 // Copyright 2014 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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/ic/handler-compiler.h"
 
 #include "src/api-arguments.h"
 #include "src/field-type.h"
@@ skipping 91 matching lines @@
     __ Push(store_parameter);
   }
   __ PushReturnAddressFrom(scratch);
   // Stack now matches JSFunction abi.
 
   // Abi for CallApiCallbackStub.
   Register callee = rdi;
   Register data = rbx;
   Register holder = rcx;
   Register api_function_address = rdx;
-  scratch = no_reg;
+  Register context = rsi;
 
   // Put callee in place.
   __ LoadAccessor(callee, accessor_holder, accessor_index,
                   is_store ? ACCESSOR_SETTER : ACCESSOR_GETTER);
 
   // Put holder in place.
   CallOptimization::HolderLookup holder_lookup;
   optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup);
   switch (holder_lookup) {
     case CallOptimization::kHolderIsReceiver:
@@ skipping 25 matching lines @@
               FieldOperand(callee, FunctionTemplateInfo::kCallCodeOffset));
     }
     __ movp(data, FieldOperand(data, CallHandlerInfo::kDataOffset));
   }
 
   // Put api_function_address in place.
   Address function_address = v8::ToCData<Address>(api_call_info->callback());
   __ Move(api_function_address, function_address,
           RelocInfo::EXTERNAL_REFERENCE);
 
+  // Put context in place.
+  const bool is_lazy = !optimization.is_constant_call();
+  if (is_lazy) {
+    // load context from holder
+    __ movp(scratch, FieldOperand(holder, HeapObject::kMapOffset));
+    __ GetMapConstructor(scratch, scratch, context);
+    __ movp(context, FieldOperand(scratch, JSFunction::kContextOffset));
+  } else {
+    // load context from callee
+    __ movp(context, FieldOperand(callee, JSFunction::kContextOffset));
+  }
+
   // Jump to stub.
-  CallApiCallbackStub stub(isolate, is_store, !optimization.is_constant_call());
+  CallApiCallbackStub stub(isolate, is_store, is_lazy);
   __ TailCallStub(&stub);
 }
 
 
 void PropertyHandlerCompiler::GenerateCheckPropertyCell(
     MacroAssembler* masm, Handle<JSGlobalObject> global, Handle<Name> name,
     Register scratch, Label* miss) {
   Handle<PropertyCell> cell = JSGlobalObject::EnsureEmptyPropertyCell(
       global, name, PropertyCellType::kInvalidated);
   Isolate* isolate = masm->isolate();
@@ skipping 241 matching lines @@
 Register NamedStoreHandlerCompiler::value() {
   return StoreDescriptor::ValueRegister();
 }
 
 
 #undef __
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64