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

src/arm64/code-stubs-arm64.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_ARM64
 
 #include "src/api-arguments.h"
 #include "src/arm64/assembler-arm64-inl.h"
 #include "src/arm64/frames-arm64.h"
 #include "src/arm64/macro-assembler-arm64-inl.h"
@@ skipping 2923 matching lines @@
   //  -- x0                  : callee
   //  -- x4                  : call_data
   //  -- x2                  : holder
   //  -- x1                  : api_function_address
   //  -- cp                  : context
   //  --
   //  -- sp[0]               : last argument
   //  -- ...
   //  -- sp[(argc - 1) * 8]  : first argument
   //  -- sp[argc * 8]        : receiver
+  //  -- sp[(argc + 1) * 8]  : accessor_holder
   // -----------------------------------
 
   Register callee = x0;
   Register call_data = x4;
   Register holder = x2;
   Register api_function_address = x1;
   Register context = cp;
 
   typedef FunctionCallbackArguments FCA;
 
   STATIC_ASSERT(FCA::kContextSaveIndex == 6);
   STATIC_ASSERT(FCA::kCalleeIndex == 5);
   STATIC_ASSERT(FCA::kDataIndex == 4);
   STATIC_ASSERT(FCA::kReturnValueOffset == 3);
   STATIC_ASSERT(FCA::kReturnValueDefaultValueIndex == 2);
   STATIC_ASSERT(FCA::kIsolateIndex == 1);
   STATIC_ASSERT(FCA::kHolderIndex == 0);
   STATIC_ASSERT(FCA::kNewTargetIndex == 7);
   STATIC_ASSERT(FCA::kArgsLength == 8);
 
   // FunctionCallbackArguments
 
   // new target
   __ PushRoot(Heap::kUndefinedValueRootIndex);
 
   // context, callee and call data.
   __ Push(context, callee, call_data);
 
-  if (!is_lazy()) {
-    // Load context from callee
-    __ Ldr(context, FieldMemOperand(callee, JSFunction::kContextOffset));
-  }
-
-  __ LoadRoot(call_data, Heap::kUndefinedValueRootIndex);
+  Register scratch = call_data;
+  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
   Register isolate_reg = x5;
   __ Mov(isolate_reg, ExternalReference::isolate_address(masm->isolate()));
 
   // FunctionCallbackArguments:
   //    return value, return value default, isolate, holder.
-  __ Push(call_data, call_data, isolate_reg, holder);
+  __ Push(scratch, scratch, isolate_reg, holder);
+
+  // Enter a new context
+  if (is_lazy()) {
+    // Load context from accessor_holder
+    Register accessor_holder = context;
+    __ Ldr(accessor_holder,
+           MemOperand(__ StackPointer(),
+                      (FCA::kArgsLength + 1 + argc()) * kPointerSize));
+    __ Ldr(scratch, FieldMemOperand(accessor_holder, HeapObject::kMapOffset));
+    __ GetMapConstructor(scratch, scratch, context, callee);
+    __ Ldr(context, FieldMemOperand(scratch, JSFunction::kContextOffset));
+  } else {
+    // Load context from callee
+    __ Ldr(context, FieldMemOperand(callee, JSFunction::kContextOffset));
+  }
 
   // Prepare arguments.
   Register args = x6;
   __ Mov(args, masm->StackPointer());
 
   // Allocate the v8::Arguments structure in the arguments' space, since it's
   // not controlled by GC.
   const int kApiStackSpace = 3;
 
   // Allocate space for CallApiFunctionAndReturn can store some scratch
@@ skipping 21 matching lines @@
   MemOperand context_restore_operand(
       fp, (2 + FCA::kContextSaveIndex) * kPointerSize);
   // Stores return the first js argument
   int return_value_offset = 0;
   if (is_store()) {
     return_value_offset = 2 + FCA::kArgsLength;
   } else {
     return_value_offset = 2 + FCA::kReturnValueOffset;
   }
   MemOperand return_value_operand(fp, return_value_offset * kPointerSize);
-  int stack_space = 0;
-  MemOperand length_operand =
-      MemOperand(masm->StackPointer(), 3 * kPointerSize);
-  MemOperand* stack_space_operand = &length_operand;
-  stack_space = argc() + FCA::kArgsLength + 1;
-  stack_space_operand = NULL;
+  const int stack_space = argc() + FCA::kArgsLength + 2;
+  MemOperand* stack_space_operand = nullptr;
 
   const int spill_offset = 1 + kApiStackSpace;
   CallApiFunctionAndReturn(masm, api_function_address, thunk_ref, stack_space,
                            stack_space_operand, spill_offset,
                            return_value_operand, &context_restore_operand);
 }
 
 
 void CallApiGetterStub::Generate(MacroAssembler* masm) {
   // Build v8::PropertyCallbackInfo::args_ array on the stack and push property
@@ skipping 63 matching lines @@
                            kStackUnwindSpace, NULL, spill_offset,
                            return_value_operand, NULL);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM64