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

src/x87/code-stubs-x87.cc

 // Copyright 2012 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_X87
 
 #include "src/code-stubs.h"
 #include "src/api-arguments.h"
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
@@ skipping 3285 matching lines @@
   //  -- ebx                 : call_data
   //  -- ecx                 : holder
   //  -- edx                 : api_function_address
   //  -- esi                 : context
   //  --
   //  -- esp[0]              : return address
   //  -- esp[4]              : last argument
   //  -- ...
   //  -- esp[argc * 4]       : first argument
   //  -- esp[(argc + 1) * 4] : receiver
+  //  -- esp[(argc + 2) * 4] : accessor_holder
   // -----------------------------------
 
   Register callee = edi;
   Register call_data = ebx;
   Register holder = ecx;
   Register api_function_address = edx;
   Register context = esi;
   Register return_address = eax;
 
   typedef FunctionCallbackArguments FCA;
@@ skipping 32 matching lines @@
     // return value
     __ push(scratch);
     // return value default
     __ push(scratch);
   }
   // isolate
   __ push(Immediate(reinterpret_cast<int>(masm->isolate())));
   // holder
   __ push(holder);
 
+  // enter a new context
+  if (is_lazy()) {
+    // load context from accessor_holder
+    Register accessor_holder = context;
+    __ movp(accessor_holder,
+            MemOperand(esp, (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
+    __ mov(context, FieldOperand(callee, JSFunction::kContextOffset));
+  }
+
   __ mov(scratch, esp);
 
   // push return address
   __ push(return_address);
 
-  if (!is_lazy()) {
-    // load context from callee
-    __ mov(context, FieldOperand(callee, JSFunction::kContextOffset));
-  }
-
   // API function gets reference to the v8::Arguments. If CPU profiler
   // is enabled wrapper function will be called and we need to pass
   // address of the callback as additional parameter, always allocate
   // space for it.
   const int kApiArgc = 1 + 1;
 
   // Allocate the v8::Arguments structure in the arguments' space since
   // it's not controlled by GC.
   const int kApiStackSpace = 3;
 
@@ skipping 106 matching lines @@
                            kStackUnwindSpace, nullptr, return_value_operand,
                            NULL);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X87