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

src/x64/code-stubs-x64.cc

 // Copyright 2013 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/api-arguments.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 2632 matching lines @@
   //  -- rbx                 : call_data
   //  -- rcx                 : holder
   //  -- rdx                 : api_function_address
   //  -- rsi                 : context
   //  -- rax                 : number of arguments if argc is a register
   //  -- rsp[0]              : return address
   //  -- rsp[8]              : last argument
   //  -- ...
   //  -- rsp[argc * 8]       : first argument
   //  -- rsp[(argc + 1) * 8] : receiver
+  //  -- rsp[(argc + 2) * 8] : accessor_holder
   // -----------------------------------
 
   Register callee = rdi;
   Register call_data = rbx;
   Register holder = rcx;
   Register api_function_address = rdx;
   Register context = rsi;
   Register return_address = r8;
 
   typedef FunctionCallbackArguments FCA;
@@ skipping 26 matching lines @@
   __ PushRoot(Heap::kUndefinedValueRootIndex);
   // return value default
   __ PushRoot(Heap::kUndefinedValueRootIndex);
   // isolate
   Register scratch = call_data;
   __ Move(scratch, ExternalReference::isolate_address(masm->isolate()));
   __ Push(scratch);
   // holder
   __ Push(holder);
 
+  // enter a new context
+  int argc = this->argc();
+  if (this->is_lazy()) {
+    // load context from accessor_holder
+    Register accessor_holder = context;
+    __ movp(accessor_holder,
+            MemOperand(rsp, (argc + FCA::kArgsLength + 1) * kPointerSize));
+    __ movp(scratch, FieldOperand(accessor_holder, HeapObject::kMapOffset));
+    __ GetMapConstructor(scratch, scratch, context);
+    __ movp(context, FieldOperand(scratch, JSFunction::kContextOffset));
+  } else {
+    // load context from callee
+    __ movp(context, FieldOperand(callee, JSFunction::kContextOffset));
+  }
+
   __ movp(scratch, rsp);
   // Push return address back on stack.
   __ PushReturnAddressFrom(return_address);
 
-  if (!this->is_lazy()) {
-    // load context from callee
-    __ movp(context, FieldOperand(callee, JSFunction::kContextOffset));
-  }
-
   // Allocate the v8::Arguments structure in the arguments' space since
   // it's not controlled by GC.
   const int kApiStackSpace = 3;
 
   PrepareCallApiFunction(masm, kApiStackSpace);
 
   // FunctionCallbackInfo::implicit_args_.
-  int argc = this->argc();
   __ movp(StackSpaceOperand(0), scratch);
   __ addp(scratch, Immediate((argc + FCA::kArgsLength - 1) * kPointerSize));
   // FunctionCallbackInfo::values_.
   __ movp(StackSpaceOperand(1), scratch);
   // FunctionCallbackInfo::length_.
   __ Set(StackSpaceOperand(2), argc);
 
 #if defined(__MINGW64__) || defined(_WIN64)
   Register arguments_arg = rcx;
   Register callback_arg = rdx;
@@ skipping 10 matching lines @@
   __ leap(arguments_arg, StackSpaceOperand(0));
 
   ExternalReference thunk_ref =
       ExternalReference::invoke_function_callback(masm->isolate());
 
   // Accessor for FunctionCallbackInfo and first js arg.
   StackArgumentsAccessor args_from_rbp(rbp, FCA::kArgsLength + 1,
                                        ARGUMENTS_DONT_CONTAIN_RECEIVER);
   Operand context_restore_operand = args_from_rbp.GetArgumentOperand(
       FCA::kArgsLength - FCA::kContextSaveIndex);
-  Operand length_operand = StackSpaceOperand(2);
   Operand return_value_operand = args_from_rbp.GetArgumentOperand(
       this->is_store() ? 0 : FCA::kArgsLength - FCA::kReturnValueOffset);
-  int stack_space = 0;
-  Operand* stack_space_operand = &length_operand;
-  stack_space = argc + FCA::kArgsLength + 1;
-  stack_space_operand = nullptr;
+  const int stack_space = argc + FCA::kArgsLength + 2;
+  Operand* stack_space_operand = nullptr;
   CallApiFunctionAndReturn(masm, api_function_address, thunk_ref, callback_arg,
                            stack_space, stack_space_operand,
                            return_value_operand, &context_restore_operand);
 }
 
 
 void CallApiGetterStub::Generate(MacroAssembler* masm) {
 #if defined(__MINGW64__) || defined(_WIN64)
   Register getter_arg = r8;
   Register accessor_info_arg = rdx;
@@ skipping 72 matching lines @@
                            kStackUnwindSpace, nullptr, return_value_operand,
                            NULL);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64