Additional minor cleanup regarding CallWrapper: Use the null object pattern.

src/x64/macro-assembler-x64.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 737 matching lines @@
     const ExternalReference& ext, int result_size) {
   // Set the entry point and jump to the C entry runtime stub.
   LoadAddress(rbx, ext);
   CEntryStub ces(result_size);
   return TryTailCallStub(&ces);
 }
 
 
 void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id,
                                    InvokeFlag flag,
-                                   CallWrapper* call_wrapper) {
+                                   const CallWrapper& call_wrapper) {
   // Calls are not allowed in some stubs.
   ASSERT(flag == JUMP_FUNCTION || allow_stub_calls());
 
   // Rely on the assertion to check that the number of provided
   // arguments match the expected number of arguments. Fake a
   // parameter count to avoid emitting code to do the check.
   ParameterCount expected(0);
   GetBuiltinEntry(rdx, id);
   InvokeCode(rdx, expected, expected, flag, call_wrapper);
 }
@@ skipping 1280 matching lines @@
   CEntryStub ces(1);
   Call(ces.GetCode(), RelocInfo::DEBUG_BREAK);
 }
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 
 void MacroAssembler::InvokeCode(Register code,
                                 const ParameterCount& expected,
                                 const ParameterCount& actual,
                                 InvokeFlag flag,
-                                CallWrapper* call_wrapper) {
+                                const CallWrapper& call_wrapper) {
   NearLabel done;
   InvokePrologue(expected,
                  actual,
                  Handle<Code>::null(),
                  code,
                  &done,
                  flag,
                  call_wrapper);
   if (flag == CALL_FUNCTION) {
-    if (call_wrapper != NULL) call_wrapper->BeforeCall(CallSize(code));
+    call_wrapper.BeforeCall(CallSize(code));
     call(code);
-    if (call_wrapper != NULL) call_wrapper->AfterCall();
+    call_wrapper.AfterCall();
   } else {
     ASSERT(flag == JUMP_FUNCTION);
     jmp(code);
   }
   bind(&done);
 }
 
 
 void MacroAssembler::InvokeCode(Handle<Code> code,
                                 const ParameterCount& expected,
                                 const ParameterCount& actual,
                                 RelocInfo::Mode rmode,
                                 InvokeFlag flag,
-                                CallWrapper* call_wrapper) {
+                                const CallWrapper& call_wrapper) {
   NearLabel done;
   Register dummy = rax;
   InvokePrologue(expected,
                  actual,
                  code,
                  dummy,
                  &done,
                  flag,
                  call_wrapper);
   if (flag == CALL_FUNCTION) {
-    if (call_wrapper != NULL) call_wrapper->BeforeCall(CallSize(code));
+    call_wrapper.BeforeCall(CallSize(code));
     Call(code, rmode);
-    if (call_wrapper != NULL) call_wrapper->AfterCall();
+    call_wrapper.AfterCall();
   } else {
     ASSERT(flag == JUMP_FUNCTION);
     Jump(code, rmode);
   }
   bind(&done);
 }
 
 
 void MacroAssembler::InvokeFunction(Register function,
                                     const ParameterCount& actual,
                                     InvokeFlag flag,
-                                    CallWrapper* call_wrapper) {
+                                    const CallWrapper& call_wrapper) {
   ASSERT(function.is(rdi));
   movq(rdx, FieldOperand(function, JSFunction::kSharedFunctionInfoOffset));
   movq(rsi, FieldOperand(function, JSFunction::kContextOffset));
   movsxlq(rbx,
           FieldOperand(rdx, SharedFunctionInfo::kFormalParameterCountOffset));
   // Advances rdx to the end of the Code object header, to the start of
   // the executable code.
   movq(rdx, FieldOperand(rdi, JSFunction::kCodeEntryOffset));
 
   ParameterCount expected(rbx);
   InvokeCode(rdx, expected, actual, flag, call_wrapper);
 }
 
 
 void MacroAssembler::InvokeFunction(JSFunction* function,
                                     const ParameterCount& actual,
                                     InvokeFlag flag,
-                                    CallWrapper* call_wrapper) {
+                                    const CallWrapper& call_wrapper) {
   ASSERT(function->is_compiled());
   // Get the function and setup the context.
   Move(rdi, Handle<JSFunction>(function));
   movq(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
 
   if (V8::UseCrankshaft()) {
     // Since Crankshaft can recompile a function, we need to load
     // the Code object every time we call the function.
     movq(rdx, FieldOperand(rdi, JSFunction::kCodeEntryOffset));
     ParameterCount expected(function->shared()->formal_parameter_count());
@@ skipping 773 matching lines @@
   CPU::FlushICache(address_, size_);
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64