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

src/arm/code-stubs-arm.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_ARM
 
 #include "src/code-stubs.h"
 
 #include "src/api-arguments.h"
 #include "src/assembler-inl.h"
@@ skipping 2682 matching lines @@
 void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- r0                  : callee
   //  -- r4                  : call_data
   //  -- r2                  : holder
   //  -- r1                  : api_function_address
   //  -- cp                  : context
   //  --
   //  -- sp[0]               : last argument
   //  -- ...
-  //  -- sp[(argc - 1)* 4]   : first argument
+  //  -- sp[(argc - 1) * 4]  : first argument
   //  -- sp[argc * 4]        : receiver
+  //  -- sp[(argc + 1) * 4]  : accessor_holder
   // -----------------------------------
 
   Register callee = r0;
   Register call_data = r4;
   Register holder = r2;
   Register api_function_address = r1;
   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);
 
   // new target
   __ PushRoot(Heap::kUndefinedValueRootIndex);
 
   // context save
   __ push(context);
-  if (!is_lazy()) {
-    // load context from callee
-    __ ldr(context, FieldMemOperand(callee, JSFunction::kContextOffset));
-  }
 
   // callee
   __ push(callee);
 
   // call data
   __ push(call_data);
 
   Register scratch = call_data;
   __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
   // return value
   __ push(scratch);
   // return value default
   __ push(scratch);
   // isolate
   __ mov(scratch, Operand(ExternalReference::isolate_address(masm->isolate())));
   __ push(scratch);
   // holder
   __ push(holder);
 
+  // enter a new context
+  if (is_lazy()) {
+    // load context from accessor_holder
+    Register accessor_holder = context;
+    __ ldr(accessor_holder,
+           MemOperand(sp, (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.
   __ mov(scratch, sp);
 
   // Allocate the v8::Arguments structure in the arguments' space since
   // it's not controlled by GC.
   const int kApiStackSpace = 3;
 
   FrameScope frame_scope(masm, StackFrame::MANUAL);
   __ EnterExitFrame(false, kApiStackSpace);
 
@@ skipping 17 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(sp, 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;
 
   CallApiFunctionAndReturn(masm, api_function_address, thunk_ref, stack_space,
                            stack_space_operand, return_value_operand,
                            &context_restore_operand);
 }
 
 
 void CallApiGetterStub::Generate(MacroAssembler* masm) {
   // Build v8::PropertyCallbackInfo::args_ array on the stack and push property
   // name below the exit frame to make GC aware of them.
@@ skipping 54 matching lines @@
   CallApiFunctionAndReturn(masm, api_function_address, thunk_ref,
                            kStackUnwindSpace, NULL, return_value_operand, NULL);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM